SM Medium Research Articles

Exploring Predictors of Social Media Use for Health and Wellness during COVID-19 among Adults in the US: A Social Cognitive Theory Application.

During COVID-19, SM media was relied upon for health-related information-seeking and activity support. This study uses the social cognitive theory (SCT) and a representative dataset of the population in the US to explore the factors influencing patients' perceptions of SM for health-related activities. As per SCT, consolidated factors comprised personal factors (sociodemographic, health perception, self-efficacy) and environmental factors (social isolation, purpose in life). Multivariate logistic regression analysis was conducted. Among the 6252 respondents, 95.15% rarely use SM to share personal health-related information, and 90.44% rarely use it to share general health-related information. Older individuals and Whites are less likely to consider SM for healthcare decisions. Education levels influence SM's perceived reliability. Those with positive health perceptions find SM more suitable for healthcare discussions. Socially-isolated individuals are less likely to use SM for healthcare. Those with a strong sense of purpose are less inclined to trust it for health decisions and may question its accuracy. SM-based interventions should address sociodemographic differences. Our findings contribute to the literature by SCT relevance validation in identifying the antecedents of SM use in healthcare. Our results also help to understand the challenges to its adoption. This can help enhance SM-based communication strategies and interventions.

Human Adipose-Derived Mesenchymal Stromal Cells Exhibit High HLA-DR Levels and Altered Cellular Characteristics under a Xeno-free and Serum-free Condition

BackgroundWe have observed an increased expression of negative markers in some clinical-grade, xeno- and serum-free cultured adipose-derived mesenchymal stem/stromal cell (ADMSC) samples. It gave rise to concern that xeno- and serum-free conditions might have unexpected effects on human ADMSCs. This study aims to test this hypothesis for two xeno- and serum-free media, PowerStem MSC1 media (PS) and StemMACS MSC Expansion Media (SM), that support the in vitro expansion of ADMSCs.MethodsWe investigated the expression of negative markers in 42 clinical-grade ADMSC samples expanded in PS. Next, we cultured ADMSCs from seven donors in PS and SM and examined their growth and colony-forming ability, surface marker expression, differentiation, cell cycle and senescence, as well as genetic stability of two passages representing an early and late passage for therapeutic MSCs.Results15 of 42 clinical-grade PS-expanded ADMSC samples showed an increased expression of negative markers ranging from 2.73% to 34.24%, which positively correlated with the age of donors. This rise of negative markers was related to an upregulation of Human Leukocyte Antigen – DR (HLA-DR). In addition, the PS-cultured cells presented decreased growth ability, lower frequencies of cells in S/G2/M phases, and increased ß-galactosidase activity in passage 7 suggesting their senescent feature compared to those grown in SM. Although MSCs of both PS and SM cultures were capable of multilineage differentiation, the PS-cultured cells demonstrated chromosomal abnormalities in passage 7 compared to the normal karyotype of their SM counterparts.ConclusionsThese findings suggest that the SM media is more suitable for the expansion of therapeutic ADMSCs than PS. The study also hints a change of ADMSC features at more advanced passages and with increased donor’s age. Thus, it emphasizes the necessity to cover these aspects in the quality control of therapeutic MSC products.Graphical abstract

Molecular Genetic Analysis of Drought Stress Response Traits in Brachypodium spp.

The root is the organ responsible for the uptake of water and therefore has a very important role in drought tolerance. The aims of the present work were to characterize nine traits of the root system architecture (RSA) and the shoot dry weight (W) of twelve genotypes of Brachypodium spp. under water stress and to establish the relationship between RSA phenotyping traits and SSRs. Two culture media, one standard (SM) and one (PEG) to induced water stress have been used. In SM medium, B. stacei had the highest values of W and all the RSA traits, except the mean diameter of the seminal roots, followed by B. hybridum and B. distachyon. In the PEG medium, root length increased in B. distachyon, decreased in B. hybridum and remained the same in B. stacei. A two-way hierarchical cluster analysis from 117 polymorphic SSRs and the traits of the RSA of the Brachypodium spp. genotypes, was performed. Brachypodium genotypes were separated into three groups corresponding to each species. In the second way of the hierarchical clustering association were observed between five RSA variables and SSR markers, which could be useful in the search for genes or QTLs related to RSA characters.

Characterization and population dynamics of germ cells in adult macaque testicular cultures.

BackgroundFrom a biological and clinical perspective, it is imperative to establish primate spermatogonial cultures. Due to limited availability of human testicular tissues, the macaque (Macaca fascicularis) was employed as non-human primate model. The aim of this study was to characterize the expression of somatic as well as germ cell markers in testicular tissues and to establish macaque testicular primary cell cultures.Materials and methodsCharacterization of macaque testicular cell population was performed by immunohistochemical analyses for somatic cell markers (SOX9, VIM, SMA) as well as for germ cell markers (UTF1, MAGEA4, VASA). Testicular cells from adult macaque testes (n = 4) were isolated and cultured for 21 days using three stem cell culture media (SSC, PS and SM). An extended marker gene panel (SOX9, VIM, ACTA2; UTF1, FGFR3, MAGEA4, BOLL, DDX4) was then employed to assess the changes in gene expression levels and throughout the in vitro culture period. Dynamics of the spermatogonial population was further investigated by quantitative analysis of immunofluorescence-labeled MAGEA4-positive cells (n = 3).ResultsRNA expression analyses of cell cultures revealed that parallel to decreasing SOX9-expressing Sertoli cells, maintenance of VIM and ACTA2-expressing somatic cells was observed. Expression levels of germ cell marker genes UTF1, FGFR3 and MAGEA4 were maintained until day 14 in SSC and SM media. Findings from MAGEA4 immunofluorescence staining corroborate mRNA expression profiling and substantiate the overall maintenance of MAGEA4-positive pre- and early meiotic germ cells until day 14.ConclusionsOur findings demonstrate maintenance of macaque germ cell subpopulations in vitro. This study provides novel perspective and proof that macaques could be used as a research model for establishing in vitro germ cell-somatic cell cultures, to identify ideal culture conditions for long-term maintenance of primate germ cell subpopulation in vitro.

A Study on the Effect of used Floor Area Ratio on the Price of Small & Medium Sized Building

In this study, the hedonic price model was used to analyze the factors affecting the price of small and medium sized buildings. In addition, it studied how the over floor area ratio reflected in the wake of the changes in the legal affects the price of small and medium sized buildings. According to the analysis results, the factors affecting the increase in the price per unit area of sm all and medium sized buildings were corners status, publicly notified individual land price, parking lots, rent, loan amount and over floor area ratio. On the other hand, the factors affecting the decrease in the price per unit area of sm all and medium sized buildings were distance from subway stations, land area, elapsed years, bank of korea base rate and unused floor area ratio. The over floor area ratio, which we have seen closely in this study, has a positive effect on the unit price of small and medium sized buildings. These results are as follows. First, the larger the over floor area ratio, the larger the rentable area, and thus the rent revenue increases and the price of small and medium size buildings increases. Second, more land area is needed to acquire the same gross area as the small and medium sized building that has the over floor ratio under the current legislation in the same use area, the building with the over floor area ratio acts as a premium for the increased floor space can be. In contrast, small and medium sized buildings with unused floor area ratio have low prices because they have the potential to increase the floor area in the future, but have a smaller leased area now. Furthermore, in order to realize unused floor area ratio, it also has to bear both the cost and time of the construction and the risks of development.

In Saccharomyces cerevisiae grown in synthetic minimal medium supplemented with non-fermentable carbon sources glutamate is synthesized within mitochondria

In Saccharomyces cerevisiae the export of 2-oxoglutarate from the mitochondria, catalyzed by Yhm2p, Odc1p and Odc2p or by at least one of these transporters, has recently been shown to be essential for glutamate biosynthesis in glucose-supplemented minimal synthetic (SM) medium without glutamate, because the triple mutant yhm2∆odc1∆odc2∆ displays a growth defect under these conditions. Surprisingly, in this study it was found that yhm2∆odc1∆odc2∆ cells grow like wild-type (WT) cells in the same medium supplemented with non-fermentable carbon sources. Direct transport assays of 2-oxoglutarate/2-oxoglutarate homoexchange activity in mitochondria from WT and yhm2∆odc1∆odc2∆ cells (solubilized and reconstituted into liposomes) showed that the mitochondrial extract from yhm2∆odc1∆odc2∆ was completely inactive at variance with that from WT cells, showing that S. cerevisiae mitochondria do not contain additional proteins capable of catalyzing 2-oxoglutarate transport efficiently besides Yhm2p, Odc1p and Odc2p. Furthermore, quantitative real-time PCR experiments showed that in both WT and yhm2∆odc1∆odc2∆ cells the expression of GDH1 is low on lactate and high on glucose and, vice versa, the expression of GDH3 is high on lactate and low on glucose. These results may be interpreted to indicate that in S. cerevisiae, grown in glucose-supplemented SM medium, glutamate is synthesized by Gdh1p in the cytosol, whereas in lactate-supplemented SM medium glutamate is synthesized by Gdh3p in the mitochondria; therefore, the pathway of ammonia assimilation under fermentative conditions requires export of 2-oxoglutarate from the mitochondria, whereas the alternative pathway under respiratory conditions does not.

Inhibitory effect of quercetin on the biofilm formation of Streptococcus mutans

To observe the inhibitory effect of quercetin on the biofilm formation of Streptococcus mutans(Sm), to preliminarily reveal the possible underlying mechanisms, and to evaluate the cytotoxicity of quercetion to human dental pulp cells so as to provide the theoretical basis for the application of quercetin in oral biomaterials. Quercetin storage solution was diluted to 0, 3.125, 6.25, 12.5, 25, 50, 100, 200, 400 and 800 mg/L, and added into Sm medium for 4 h and 24 h, crystal violet staining was used to evaluate the biofilm volume. In subsequent detections, three groups were set: control(0 mg/L), 200 mg/L quercetin and 400 mg/L quercetin. Confocal laser scanning microscopy was used to observe the morphology of the biofilm; qPCR for gtfB, gtfC, comD, comE, and luxS were assessed to preliminarily investigate the mechanisms. Finally, the methyl thiazolyl tetrazolium(MTT)test using human dental pulp cells was used to investigate cytotoxicity. Quercetin could significantly inhibit up to(86.16±0.45)% of the biofilm formation of Sm(Compared with the control group P=0.00)and effectively removed(43.04±0.53)% of the mature biofilm(Compared with the control group P=0.00). Confocal laser scanning microscopy photographs showed that after co-incubated for 24 h, the dense biofilm structures of the experimental group were destroyed by quercetin both at 200 mg/L and 400 mg/L. Quercetin suppressedover 50% of the expression of gtfB, gtfC, comD, comE(compared with the control group P<0.05)and promoted the expression of luxS up to 2.18 ± 0.24 and 2.84 ± 0.26 after 4 h and 24 h, respectively(compared with the control group P<0.05). Quercetin also exhibited acceptable compatibility for human dental pulp cells. Quercetin could effectively reduce the biofilm formation of Sm by inhibiting the expression of the related genes, and exhibited no cytotoxicity for human dental pulp cells. Quercetin has good potential to be applied in oral biological materials.

Biological role of Trichoderma harzianum-derived platelet-activating factor acetylhydrolase (PAF-AH) on stress response and antagonism.

We investigated the properties of platelet-activating factor acetylhydrolase (PAF-AH) derived from Trichoderma harzianum. The enzyme, comprised of 572 amino acids, shares high homology with PAF-AH proteins from T. koningii and other microbial species. The optimum enzymatic activity of PAF-AH occurred at pH 6 in the absence of Ca2+ and it localized in the cytoplasm, and we observed the upregulation of PAF-AH expression in response to carbon starvation and strong heat shock. Furthermore, PAF-AH knockout transformant growth occurred more slowly than wild type cells and over-expression strains grown in SM medium at 37°C and 42°C. In addition, PAF-AH expression significantly increased under a series of maize root induction assay. Eicosanoic acid and ergosterol levels decreased in the PAF-AH knockouts compared to wild type cells, as revealed by GC/MS analysis. We also determined stress responses mediated by PAF-AH were related to proteins HEX1, Cu/Zn superoxide dismutase, and cytochrome c. Finally, PAF-AH exhibited antagonistic activity against Rhizoctonia solani in plate confrontation assays. Our results indicate PAF-AH may play an important role in T. harzianum stress response and antagonism under diverse environmental conditions.

Improved sperm cryosurvival in diluents containing amides versus glycerol in the Przewalski’s horse (Equus ferus przewalskii)

Two studies were conducted to understand sperm cryosensitivity in an endangered equid, the Przewalski’s horse (Equus ferus przewalski), while testing the cryoprotectant ability of formamides. The first assessed the toxicity of permeating cryoprotectants (glycerol, methylformamide [MF] and dimethylformamide [DMF]) to Przewalski’s horse spermatozoa during liquid storage at 4°C. The second examined the comparative influence of three diluents (with or without formamides) on cryosurvival of sperm from the Przewalski’s versus domestic horse. When Przewalski’s horse spermatozoa were incubated at 4°C in INRA 96 with differing concentrations of glycerol, MF or DMF or a combination of these amides, cells tolerated all but the highest concentration (10% v/v) of MF alone or in combination with DMF, both of which decreased (P<0.05) motility traits. There was no effect of cryoprotectants on sperm acrosomal integrity. In the cryosurvival study, average sperm motility and proportion of cells with intact acrosomes in fresh ejaculates were similar (P>0.05) between the Przewalski’s (67%, 84%, respectively) and domestic (66%, 76%) horse donors. Sperm from both species were diluted in lactose–EDTA–glycerol (EQ), Botu-Crio (BOTU; a proprietary product containing glycerol and MF) or SM (INRA 96 plus 2% [v/v] egg yolk and 2.5% [v/v] MF and DMF) and then frozen over liquid nitrogen vapor. After thawing, the highest values recovered for total and progressive sperm motility, acrosomal integrity and mitochondrial membrane potential were 42.4%, 21.8%, 88.7% and 25.4CN (CN=mean JC-1 fluorescence intensity/cell on a channel number scale), respectively, in the Przewalski’s and 49.3%, 24.6%, 88.9% and 25.8CN, respectively, in the domestic horse. Although sperm progressive motility and acrosome integrity did not differ (P>0.05) among treatments across species, mitochondrial membrane potential was higher (P<0.05) in both species using EQ compared to BOTU or SM media. Additionally, Przewalski’s stallion sperm expressed higher (P<0.05) post-thaw total motility in BOTU and SM compared to EQ, whereas there were no differences among freezing diluents in the domestic horse. In summary, Przewalski’s stallion sperm benefit from exposure to either MF or DMF as an alternative cryoprotectant to glycerol. Overt sperm quality appears similar between the Przewalski’s and domestic horse, although the total motility of cells from the former appears more sensitive to certain freezing diluents. Nonetheless, post-thaw motility and acrosomal integrity values for Przewalski’s horse spermatozoa mimic findings in the domestic horse in the presence of INRA 96 supplemented with 2% (v/v) egg yolk and a combined 2.5% concentration of MF and DMF.

Effect of Salvia miltiorrhiza on retinopathy

ObjectiveTo explore the effect of Salvia miltiorrhiza on diabetic retinopathy (DR). MethodsDiabetic mice of natural incidence type with monogenic inheritance were selected. Alloxan was injected into the caudal vein of mice once to induce DR. The structural changes of retina tissue in normal mice, DR mice and mice with high, medium and low dose of Salvia miltiorrhiza injection were observed under microscope. Then the blood glucose concentration and malonaldehyde (MDA) content were detected. ResultsThere were some microaneurysms in retina of DR group, number of gangliocyte was decreased significantly, and cells were sparse and in disorder. After modeling, the blood glucose level of high-dose Salvia miltiorrhiza group (SM III group) was significantly different from DR group (P<0.01). Till the tenth week, the blood glucose level of all SM groups was decreased significantly compared with DR group (P<0.01). The effective rates of three SM groups were 93.8%, 76.4% and 50.3%, respectively. After ten weeks, MDA content of DR group was significantly higher than those of the normal control group and SM group (P<0.01), and medium and low dose SM groups had significantly higher MDA than that of normal control group (P<0.01). ConclusionsSalvia miltiorrhiza had certain protective effect on DR mice through the blood-ocular barrier.

Effect of Dose-Response of Zinc and Manganese on Siderophores Production

Problem statement: This study was conducted to find and determine whether the siderophores of the four environmental Pseudomonas spp. isolates possess a sequestering activity towards essential transition metals (Zn and Mn) other than iron. Approach: Four fluorescent Pseudomonads isolated from various environments, were characterized analytically (Isoelectric focusing), biologically (pyoverdine-mediated uptake) and genetically (16S rDNA sequencing). By means of spectrophotometric measurements, it was possible to establish and compare the levels of pyoverdine production, in two different nutrient-poor media. Results: The strains were assigned, by sequencing, to P. fluorescens, P. aeruginosa, P. putida and P. mosselii isolated, respectively from soil, compost, sea water and waste water treatment plant. These bacterial strains were recognized as producing diver’s yellow-green siderophores types, when grown under conditions of iron starvation. The highest metabolite concentration was obtained with PsC132 and PsTp171 strains isolated respectively from compost and waste water treatment plant, in CAA medium. Strains grown in CAA medium exhibit a higher PVD level compared to SM medium. Mn (II) was found to promote pyoverdine biosynthesis, but rather, Zn (II) had no significant effect on siderophore production when compared to control medium. For both strains PsS29 and PsC132, the increase of iron concentration quenched siderophore production especially above 20 μM. Pyoverdine level declined with the high concentration of zinc but increased with Manganese concentration ranging up to 70 μM (in case of PsC132) and 300 μM (in case of PsS29). Conclusion/Recommendations: The ability of fluorescent Pseudomonas, isolated from wastewater treatment plant and from compost, to sequester zinc, point to a unique advantage of these species for divers bioremediation applications.

An Efficient Intergeneric Conjugation of DNA from Escherichia coli to Mycelia of the Lincomycin-Producer Streptomyces lincolnensis

Streptomyces lincolnensis is a producer of lincomycin, which is a lincosamide antibiotic for the treatment of infective diseases caused by Gram-positive bacteria. S. lincolnensis is refractory to introducing plasmid DNA into cells because of resistance of foreign DNAs and poor sporulation. In this study, a simple and efficient method of transferring plasmids into S. lincolnensis through the intergeneric Escherichia coli-mycelia conjugation was established and optimized for the first time. The recipient mycelia of S. lincolnensis were prepared in liquid SM medium containing 10.3% sucrose for three days. The dispersed mycelia were conjugated with competent E. coli donor cells. The exconjugants were regenerated efficiently on solid mannitol soya flour (MS) medium containing 20 mM MgCl2. The average conjugation frequency was observed at 1.1 × 10−4 per input donor cell and validated functionally by transferring two types of vectors containing lincomycin resistance genes lmrA, lmrB and lmrC into S. lincolnensis mycelia. The data of fermentation in shaking flasks showed the lincomycin yield of the exconjugants increased by 52.9% for the multiple copy vector and 38.3% for the integrative one, compared with the parental strain. The efficient and convenient method of intergeneric E. coli-mycelia conjugation in this study provides a promising procedure to introduce plasmid DNA into other refractory streptomycetes.

Initial crystallization in a nanostructured Al–Sm rare earth alloy

The transformation kinetics and microstructural evolution during initial crystallization in highly driven Al 90Sm 10 were investigated using transmission electron microscopy (TEM), conventional Cu K α and high-energy synchrotron X-ray diffraction (HEXRD) and differential scanning calorimetry (DSC). The highest cooling rate obtained in this study yielded a high number density of fcc-Al nanocrystals, with sizes on the order of 2–5 nm, embedded in a disordered matrix rich in an Al–Sm medium range order (MRO) structure. Isothermal in-situ HEXRD results indicated a single crystallization of a large primitive cubic phase from the disordered state. Further analysis using DSC showed two crystallization events; a small peak overlapping the peak from the main crystallization event. TEM analysis performed at different stages of crystallization resolved pre-existing fcc-Al crystals, further crystallization of fcc-Al, (corresponding to the first small peak) and evolution of the cubic phase, corresponding to the main crystallization event. Fcc-Al nanocrystals showed a restricted growth and stayed at an average size of 16 nm after full crystallization was established. Transformation kinetics was described using Johnson–Mehl–Avrami approach after deconvolution of the overlapping crystallization peaks using a Gaussian approximation.

Strategic Approach To Produce Low-Cost, Efficient, and Stable Competitive Internal Controls for Detection of RNA Viruses by Use of Reverse Transcription-PCR

Molecular diagnostics based on reverse transcription (RT)-PCR are routinely complicated by the lack of stable internal controls, leading to falsely negative results. We describe a strategy to produce a stable competitive internal control (CIC) based on a Qbeta phage derivative (recombinant Qbeta [rQbeta]) bearing primers KY78 and KY80, which are widely used in the detection of hepatitis C virus (HCV). rQbeta was RNase resistant and stable at 4 degrees C for 452 days in SM medium (0.1 M NaCl, 8 mM MgSO(4).7H(2)O, 50 mM Tris HCl [pH 7.5], 2% gelatin) and for 125 days after lyophilization and reconstitution. rQbeta performance as a CIC was evaluated. rQbeta was added to HCV-positive samples, followed by RNA extraction and a CIC-HCV RT-PCR assay. This method combines RT-PCR, liquid hybridization with nonradioactive probes, and enzyme immunoanalysis. No influence of the CIC on qualitative HCV detection was observed independently of viral load, and results had high concordance with those of commercial kits. In conclusion, we describe a versatile, low-cost alternative strategy to armored RNA technology that can be adapted for detection or real-time applications of any RNA target. Moreover, the CIC reported here is an essential reagent for HCV screening in blood banks in resource-limited settings.

Enhanced iturin A production by Bacillus subtilis and its effect on suppression of the plant pathogen Rhizoctonia solani

Enhanced production of the antibiotic iturin A by Bacillus subtilis RB14-CS reached 4.4 g L(-1) in SM medium containing soybean meal and maltose, which was 16-fold and 2.2-fold higher than that in original and modified number 3S media, respectively. When various volumes of RB14-CS cultures grown in SM medium were applied to pot tests of tomato damping-off caused by Rhizoctonia solani, damping-off was dose-dependently suppressed by the cultures. Suppression by SM-grown cultures was significantly more effective than that by cultures grown in original or modified number 3S media. The iturin A concentrations in soil decreased to undetectable levels after 17 days of cultivation in pot tests, indicating that iturin A has a low persistence in soil.

Occurrence ofStreptococcus macedonicusin Italian cheeses

A new approach for the detection and enumeration of Streptococcus macedonicus in cheese was developed. The method which is based on a first screening of cheeses by a PCR assay specific for S. macedonicus followed by plating positive samples on a differential medium (SM medium) was applied to 51 samples derived from PDO and traditional Italian cheeses. Streptococcus macedonicus was found in 16 of the 51 samples examined in the present work. With the exclusion of an Asiago cheese sample in which very high numbers of S. macedonicus (7.13 log CFU g(-1)) were found, the counts of S. macedonicus in SM medium ranged from 2.48 to 4.70 log CFU g(-1). In the same cheeses, total streptococci enumerated onto M17 agar were found at higher concentrations with values up to 7.88 log CFU g(-1). The system developed was particularly useful for the differential count of S. macedonicus in cheese and allowed to evaluate the occurrence of this species within the complex microbial lactic acid bacteria (LAB) population, which is typical of traditional cheeses. Results showed that in the examined cheeses S. macedonicus cannot be considered as a dominant LAB species.

Analysis of the thermal behavior of photoluminescent optical memory based on CaS:Eu,Sm media

The temperature dependence of the photoluminescence (PL) and infrared stimulated luminescence (ISL) exhibited by CaS doped with both europium (Eu) and samarium (Sm) ions is reported for temperatures in the range between 100 and 700 K. Behavior indicative of strong electron-phonon coupling is observed in the PL emission of the ${\mathrm{Eu}}^{2+}$ ion and two processes with activation energies $(\ensuremath{\Delta}{E}_{1},\ensuremath{\Delta}{E}_{2})$ are recognized in the quenching of the PL intensity. The smaller of these $(\ensuremath{\Delta}{E}_{2}=0.056\phantom{\rule{0.3em}{0ex}}\mathrm{eV})$ is identified as the energy separation between ${\mathrm{Eu}}^{2+}$ excited states and the conduction band of CaS while $\ensuremath{\Delta}{E}_{1}$, which has a value of 0.55 eV, is attributed to some intervening quenching state. On the other hand, analysis of the integrated ISL intensity as a function of temperature prompts the conclusion that the separation $(\ensuremath{\Delta}\ensuremath{\epsilon})$ between the lowest excited energy levels of ${\mathrm{Eu}}^{2+}$ ions and that of ${\mathrm{Sm}}^{2+}$ ions is approximately 28 meV at low temperature. When it is considered for an optical memory medium, recording experiments performed at different temperatures show the writing process to be more efficient when conducted at higher temperatures rather than lower ones. Moreover, two different time constants, that are themselves linear functions of temperature, are observed to govern the readout process in which electrons trapped at the Sm ions are depleted under continuous (IR) irradiation. Finally, studies of the ISL intensity versus storage time at different temperatures show the reading output to be lowered for longer storage times due to a thermally assisted decay route facilitating the release of electrons trapped at ${\mathrm{Sm}}^{2+}$ ions back to ${\mathrm{Eu}}^{2+}$ ions.

田子の浦底泥焼結物の植物育成培地としての利用可能性に関する研究 （２） バラ養液栽培の実験結果

Two kinds of plant growth media were made by sintering the sludge dredged from Tagonoura Bay (SM medium) and the mixing materials of the sludge and glass powder (GM medium). Rose plants were hydroponically grown with the sintered materials for 21 months. Trace elements in the media, elutions and rose leaves, and gas concentration in the media were analyzed. Temperature of the media and pH and EC in the solution were also measured. Rose flower stalks were harvested 7 times (about 30 stalks in each harvest) during the experimental period.The length and quality of the flower stalks were comparable in the SM medium with the Rockwool medium, but lower in the GM medium. Trace element analysis of the elutions of the sintered materials showed that the concentrations of the elements were lower than the toxic levels reported before. The nutrient solutions passing through the GM medium had a lower pH (about 5) on days 468-593 during the experimental period. The EC, medium temperature and gas concentration do not seem to have any significant effect on rose growth.From this experiment, it became clear that the SM medium is suitable for the rose culture. The rose growth anomalies in the GM medium might be related to a decrease in PH in the nutrient solution passed through the medium but the cause could not be clarified.

A new technique for storage of meristem-tip cultures of ‘Cavendish’ banana

Meristem-tip tissues of ‘Cavendish’ banana were incubated at 17°C under light on cheesecloth over cotton saturated with 3% solution of various kinds of sugars. All the sugars tested were found to be capable of extending the survival time of banana tissues and ribose was the best followed by sucrose, glucose, fructose and lactose. After 21 months, 33% of banana tissues incubated with ribose solution remained viable and resumed growth within two weeks after being transferred to fresh SM medium. About 99% of plantlets developed from these tissues were normal. In a separate experiment, 67% of banana tissues incubated with 3% ribose solution remained viable after 24 months. Ribose solutions at 0.3% and 0.03% were not as effective and over saturation of cotton with 3% ribose solution was not beneficial. The new technique may be useful for storage of tissue cultures of other species and cultivars.

New culture medium for maintenance of tsetse tissues and growth of trypanosomatids.

SYNOPSIS. A new culture medium (SM), based on the amino‐acid composition of tsetse hemolymph and containing fetal bovine serum, was designed for the maintenance of tsetse organs and the cultivation of various trypanosomatids. For optimum growth 20% (v/v) serum was required. The medium supported prolonged peristalsis of the alimentary tract and salivary glands of pre‐emerged Glossina morsitans morsitans. In established cultures, derived from bloodstream forms of pleomorphic Trypanosoma brucei brucei and Trypanosoma brucei rhodesiense strains, inocula of ∼ 106 procyclics/ml yielded 4–5 × 107 organisms/ml after 4 or 5 days of incubation at 28 C. Bloodstream forms of a cloned monomorphic T. b. brucei strain were also able to transform into procyclics, which, however, multiplied at a lower rate, with maximum yields of ∼ 2 × 107 after 5 days. Cultures of Trypanosoma congolense and of a nearly monomorphic Trypanosoma brucei gambiense strains could be established in SM medium only in the presence of tsetse alimentary tract. The procyclic trypomastigotes of these species, adapted to SM medium and able to grow in it without Glossina organs, gave maximum populations of ∼ 4.5 × 107 cells/ml.Promastigotes of Leishmania donovani, cultivated routinely in a diphasic Table's medium, multiplied actively upon being transferred into SM medium, producing yields of ∼ 4 × 107 cells/ml.