Development of detection system of extraterrestrial microorganisms]

A noble method for the exploration of terrestrial and extraterrestrial soil microorganisms, especially targeted for Mars, has been developed. The method is based on the microscopic observation using fluorescence techniques. Microorganisms could be fluorescent by adsorption, enzymatic cleavage of extrinsic fluorescence chromophores such as acridine orange, ANS and SFDA, and also by intrinsic chromophores. The characteristic points of our fluorescence method are shown below. 1. The present method detected all the culturable cells tested (about 200 species from bacteria to eukaryofic cells). 2. Microorganisms in soil were much brighter than background fluorescence of soil. Cell shapes and location were clearly observed. 3. An esterase substatum SFDA, discriminated vital (reproductive) cells from dead. On the other hand, a membrane probe, ANS, detected both vital and dead cells. 3. Pre-treatment of cells with bleaching reagents improved the detection efficiency. Especially, this pretreatment was effecfive in Fungi with black chromophores. 4. Some anaerobic microorganisms such as methanogenic bacteria with intrinsic chromophores can be detected without stain. 5. Application of the technique to terrestrial soil revealed that more than 100 times larger cell density was obtained compared to the value obtained by the classic plate counting technique. Vertical distribution of microorganism of soil microorganisms from Mt. Shigayama showed that, at surface, cell density was small and maximum was shown below 15 cm from surface. 6. Some pre-biotic cell (cell like aggregates composed of amino acids) could be detected by SFDA or ANS. It can be concluded that the fluorescence technique is one of the most promising method for the exploration of extraterrestrial microorganisms.     

Extrasolar terrestrial planets and possibility of extraterrestrial life]

Recent development of research on extrasolar planets are reviewed. About 120 extrasolar Jupiter-mass planets have been discovered through the observation of Doppler shift in the light of their host stars that is caused by acceleration due to planet orbital motions. Although the extrasolar planets so far observed may be limited to gas giant planets and their orbits differ from those of giant planets in our Solar system (Jupiter and Saturn), the theoretically predicted probability of existence of extrasolar terrestrial planets that can have liquid water ocean on their surface is comparable to that of detectable gas giant planets. Based on the number of extrasolar gas giants detected so far, about 100 life-sustainable planets may exist within a range of 200 light years. Indirect observation of extrasolar terrestrial planets would be done with space telescopes within several years and direct one may be done within 20 years. The latter can detect biomarkers on these planets as well.     

A close encounter with DNA

Atomic force microscopy, associated with surface science, has the potential to resolve the secondary structure of DNA in liquid form with unusually high resolution and with unprecedented accuracy.     

An encounter between a pelagic shark and giant cephalopod

An oceanic whitetip shark (Carcharhinus longimanus) was observed off the coast of Kona, Hawaii, with scars caused by the tentacles of a large cephalopod. While the exact species could not be confirmed, candidate species include the giant squid (Architeuthis dux) or species from the genera Thysanoteuthis (flying squids) and Megalocranchia (glass squids). Telemetry shows C. longimanus will dive within the mesopelagic zone and may interact with or even forage for large cephalopods.     

Planetary systems and extraterrestrial life

The paper revies the present status of the problem of the existence of other planetary systems in the Galaxy. Observational data and theoretical results are presented to show that the occurrence of planetary systems is, most probably, not a universal phenomenon. Study of the stability of planetary orbits in the vicinity of double stars indicates that, in general, planetary systems can not survive around them over long periods. Therefore, we should rule out the possibility of the existence of planetary systems similar to our own in the neighborhood of double stars. In the solar neighborhood, at least 60% of the stars are known to be members of double systems. The nature of the dark companions is discussed and it is concluded that they are stellar objects and not planets. Recent work on the absence of a perturbation in the motion of Barnard's star is discussed. Comments are made on the existence of extraterrestrial life in the solar system and around other stars in the Galaxy.     

A 20-year encounter with the imposter syndrome

Both in their formative years and later careers, some scientists suffer from something more than occasional self-doubts. There is a more severe affliction that strikes many more than was once realized. Here I reflect on my encounter, in the hope that sharing it can be of some value.

A landmark study 42 years ago presented the results of a survey of 150 highly successful women professionals as regards their self-assessment of confidence. The results were stunning. Many subjects gave responses revealing moderate to intense emotional stress and anxiety as to their qualifications. To characterize this revealed broad experience, the authors coined the term “the imposter syndrome” (Clance and Imes, 1978). It was apt indeed, the first word conveying the haunting sense of being an intruder in the guild, unqualified, and in the game only by some fluke; the second term meaning that the condition was encountered as a constellation of effects, from heart to mind to gut, with fear the signal transduction onto all those centers. This study was a turning point, inter alia, in the broadening field of scholarship examining the barriers to women in the workplace.At the time of the Clance and Imes publication it was not known if this same affliction occurs in men and, if so, with what prevalence, or whether it occurs in some professions more than others. In at least the sciences, it now appears that both females and males encounter it, both as students and as young trainees, although the prevalence is less well known for males. I have no expertise in this field beyond my one experience, which I share here in the hope that it may have some nugget of value for all those who doubt their talent.Science was not my first love academically. I had no butterfly collection, nor did I conduct explosion-seeking chemistry experiments in the cellar. My favorite subject in high school was Latin, my least favorite was biology. I remember a lecture on vitamins in the latter course, where we had to memorize what happens when each one is missing or limiting in the diet. We asked the teacher for an explanation for pellagra, scurvy, and so forth (meaning: what do these vitamins do?). He replied, “They are essential.” QED. (But in fairness, this teacher could be better sometimes—for example, he told us why the mouthwash “Listerine” was so named.)After studying English and Latin in college, I came to biology for a second try and it felt better. I applied to medical school but declined my acceptances and went for a Ph.D. During this time, I do not recall feeling particularly anxious about my abilities, although I had not yet really done anything to reveal their presence or absence. I do recall a few times when I was nervous, but that is not uncommon for graduate students. But one day, I got the first sensation of perhaps something more. It was my Ph.D. qualifying exam in the Department of Zoology at Syracuse University, in 1961. One part was a four-hour written exam in one’s field, the other was a free-for-all with the whole faculty asking about anything under the sun in biology. At one point I was asked to derive the Nernst equation (describing a cell’s membrane resting potential). I replied “OK, but from what?” The faculty member thought I was being evasive, but I was just looking for a little guidance (as when the Scripps–Howard Spelling Bee contestant asks the moderator: “Can you please use that in a sentence?”) I knew one cannot get the Nernst equation from f = ma, there is an electrical component (duly named for Michael Faraday). I managed to get through this question and all the others, but it was then I began to wonder if I was playing some charade. Maybe I had been clever but not really grounded. That I had gotten through the oral exam didn’t quiet my sense that I might have “pulled something off” and maybe hadn’t deserved to have passed. That was the moment when a visitor first arrived in my consciousness. It whispered, “You know, Thoru, it’s just possible that you might be a phony.”During my postdoc this nagging feeling got stronger. I had moved from a very good zoology program at Syracuse to an elite department of cell biology at the Albert Einstein College of Medicine. My work was going well, but all the people around me seemed so much smarter and their research seemed more significant. On one side of the lab I was in, Phillip Coffino, an M.D./Ph.D. student, was measuring the somatic mutation rate of immunoglobulin genes with Matthew Scharff, and on the other side, Ellie Ehrenfeld was isolating the poliovirus RNA replicase in the laboratory of Donald Summers. These were pioneering projects and I was in awe of both them and their science. By the time I left Einstein my case of the imposter syndrome had reached the point where I felt lucky to get an independent position.Today, I reflect on all this. First, and as conveyed in the original study, was the certitude in my assessment of myself. At the time this affliction had me in its maw, no one could have convinced me otherwise. As other victims of this condition have attested, the sense that it is totally true is overwhelming. The second feature of the imposter syndrome, as was also revealed in the study, was that the day was just around the corner when I would be found out. This evokes a pattern of paranoia where, on each and every day, one is just waiting for “the truth” to come out.But then, when I was 40, I got over this thing. It was quite sudden. I was on my way to Caltech to give a seminar and looked out the window over Kansas at the puffed popcorn of white clouds and got a simple idea, a question that should always be asked by any scientist. What if I were wrong? What if I were misinterpreting the data? For the first time, looking out that airplane window, it came to me that the obsession that I was totally incompetent was not supported by the facts, and that a hypothesis that I was at least competent in a “guild-average” sense seemed to be at hand.How the imposter syndrome affects females vs. males is still being studied. I do think that when it hits males, we compensate in ways that are different from females. One of the most compelling books in this field describes an intrepid group of women who provided powerful anchors for each other (Daniell, 2008). They were not all suffering from the imposter syndrome, but rather receiving the totality of slings and arrows that professional women face on many fronts. This landscape of inquiry and scholarship is worthy of further investigation as we seek to understand the degrees to which gender differentially influences the aspirations of all those coming up, and to which the imposter syndrome is an infection that may have no host restriction as to gender or ethnicity. The key question now, more than four decades after the landmark study, is whether the imposter syndrome has afflicted all genders and ethnicities to similar or differing degrees, and not only in America and not just in the sciences. This is the total perspective in which this career-inhibitory/destructive phenomenon must be understood, to elevate our ability to mentor, and if possible “vaccinate,” all students and emerging young professionals who suffer from it. Only when we all understand the roots of the phenomenon’s existence in the first place can we do our best to stamp it out.     

Determination of optical activity of the growth medium as a method for detection of extraterrestrial life]

Determination of optical activity of the cultural medium can be used for detection of extraterrestrial life. The composition of the growth medium depends on the duration of the experiment. Automatic biological stations are sent to planets for a short time, and the best components of the growth medium are D-glucose and D-maltose; optical activity of the cultural broth disappears upon assimilation of these compounds. Tartaric acid is less suitable since the duration of the experiment increases several times and desert soils do not always contain microorganisms assimilating tartaric acid.     

Preface: Genetics and the human encounter with alcohol

Abstract

In this paper, we calculate a base line of statistical data on the frequency of sexual activity at various ages of Taiwanese women. A cross‐sectional study using questionnaires administered during personal interviews was conducted on more than seventeen thousand women who attended family planning clinics in the Taipei metropolitan area in 1991 and 1992. Of the women surveyed, 2.8 per cent were sexually inactive in the previous month, 83.67 per cent had intercourse one to nine times in the previous month, and 13.56 per cent had intercourse ten times or more. The mean frequency of sexual activity was 6.8 times a month. Age‐specific mean coital frequencies for the age groups of less than 25 years, of 25–34 years, and of 35–44 years were 10.3, 7.3, and 6.6 times per month, respectively. Increased sexual frequency was associated with the following factors: young age, unmarried, lower educational level, fewer years of marriage and being on the pill. When logistic regression was used to control for confounding variables, we found that a woman's age is the most significant factor in predicting her sexual frequency.