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Biomedical subjects

I Rabino

Publications and source records attributed to I Rabino.

10 recordsLinked to original sources

Societal and commercial issues affecting the future of biotechnology in the United States: a survey of researchers' perceptions.

A 1995 survey of 1,257 U.S. recombinant DNA researchers assessed how they view outside factors affecting their work, including public and media attention; regulation; funding; international competition; commercialization of research and university/ industry collaboration; health care reform efforts; and patenting laws and policies. Generally, respondents view public attention as-having had positive effects on biotechnology progress, but they are concerned about the decrease in R&D funding, especially from government; the loss of scientific openness and basic-research quality caused by academic/industrial collaboration; international competition, particularly from Japan and Germany; overly stringent regulations that control R&D processes rather than products; inefficient regulatory agencies focused on irrelevant criteria; and threats to basic biomedical research from the short-term cost focus of managed-care companies.

Attitude↗

Ethical debates in genetic engineering: U.S. scientists' attitudes on patenting, germ-line research, food labeling, and agri-biotech issues.

A 1995 survey of 1,257 scientists working in the field of recombinant DNA research indicates wide areas of agreement as well as some noteworthy divisions when it comes to such thorny questions as patenting, germ-line research, food labeling, and biodiversity. In general, the scientists surveyed approve of patenting living organisms that result from rDNA research, but vary significantly on what should be patentable. They advocate human germ-line therapy, yet have reservations about using it for any but serious diseases. They oppose mandatory labeling of biologically engineered food products, but understand that the public has a right to know and advocate openness. Finally, they favor development of threats to biodiversity and maintain that publicly funded researchers should be legally obligated to consider the potential environmental effects of their research. Some clear differences arise between scientists working in industry and those in academia and between men and women.

Access to Information↗

Light, temperature, and anthocyanin production.

Temperature affects the total amount, the time course, and the red/far-red effectiveness ratio of light-dependent anthocyanin production in Brassica oleracea L. seedlings. Some of the effects of temperature on anthocyanin production in cabbage are in agreement with the predictions of a model proposed by JK Wall and CB Johnson (1983 Planta 159: 387-397) for the effects of temperature on the state of phytochrome and on the expression of phytochrome-mediated high irradiance responses, but others are not. The lack of a complete agreement between experimental results and model predictions might be due to factors related to the experimental system used or to limitations of the model or both.

Journal Article↗

Effectiveness of intermittent light treatments on anthocyanin synthesis in dark-grown and light-pretreated seedlings.

Differences in the extent of anthocyanin production between intermittent light treatments with short and long dark intervals between successive irradiations are more pronounced in dark-grown than in light-pretreated cabbage seedlings. This observation is consistent with the hypothesis, based on destruction kinetics data, that there might be two pools of phytochrome, a labile one and a stable one, present in different proportions in dark-grown and light-pretreated seedlings, and suggests that light-dependent changes of the stable to labile phytochrome ratio might be physiologically significant in the photoregulation of photomorphogenic responses.

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Photocontrol of Anthocyanin Synthesis: VI. Spectral Sensitivity, Irradiance Dependence, and Reciprocity Relationships.

The spectral sensitivity and the irradiance dependence of anthocyanin synthesis, a "high irradiance response," in cabbage (Brassica oleracea, cv. Red Acre) and tomato (Lycopersicon esculentum, cv. Beefsteak) seedlings exposed to continuous irradiation depend upon the length of the exposure. In cabbage, blue and red are more effective than far red when the irradiations are shorter than 12 hours and less effective than far red when the irradiations are longer than 12 hours. The irradiance dependence is negligible under red and becomes evident under blue and far red red only for exposures longer than 12 hours. Anthocyanin synthesis under intermittent light treatments, of efficiency comparable to that of continuous treatments, obeys the Bunsen-Roscoe reciprocity law and is a function of the dose (irradiance x time), rather than of the irradiance alone. The validity of the reciprocity relationships suggests that only one photoreceptor is responsible for the photocontrol of the response in the blue, red, and far red spectral regions. The characteristics of the response suggest that the photoreceptor is phytochrome, at least in cabbage.

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Photocontrol of Anthocyanin Synthesis: V. Further Evidence against the Involvement of Photosynthesis in High Irradiance Reaction Anthocyanin Synthesis of Young Seedlings.

Streptomycin and chloramphenicol inhibit the development of the photosynthetic apparatus and enhance anthocyanin synthesis in tomato (Lycopersican esculentum, cv. Beefsteak) and red cabbage (Brassica oleracea, cv. Red Acre) seedlings. The two antibiotics do not affect the basic features of light-dependent anthocyanin formation: the relative effectiveness of different irradiance levels and of different spectral regions and the red-far red reversibility of the response are essentially the same in seedlings grown in water or in solution of the two antibiotics. The action of the two antibiotics on anthocyanin synthesis is probably independent of the action of light. The results provide further evidence that the role played by photosynthesis in high irradiance reaction anthocyanin synthesis of young seedlings is only a minor one, if at all.

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Photocontrol of Anthocyanin Synthesis: III. The Action of Streptomycin on the Synthesis of Chlorophyll and Anthocyanin.

Streptomycin enhances the synthesis of anthocyanins and inhibits the synthesis of chlorophylls and the development of chloroplasts in dark-grown seedlings of cabbage (Brassica oleracea), mustard (Sinapis alba), tomato (Lycopersicon esculentum), and turnip (Brassica rapa) exposed to prolonged periods of irradiation in various spectral regions. These results suggest that the contribution of photosynthesis to light-dependent high irradiance reaction anthocyanin synthesis in seedlings of cabbage, mustard, tomato, and turnip is minimal, if any at all. So far, phytochrome is the only photoreceptor whose action in the control of light-dependent anthocyanin synthesis in seedlings of cabbage, mustard, tomato, and turnip has been satisfactorily demonstrated.

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Photocontrol of Anthocyanin Synthesis: IV. Dose Dependence and Reciprocity Relationships in Anthocyanin Synthesis.

Under continuous far red light, anthocyanin synthesis in young, dark-grown cabbage seedlings (Brassica oleracea cv. Red Acre) is irradiance-dependent and fails to follow the reciprocity (irradiance x time = constant) relationships. Under intermittent far red treatments extended over a prolonged period of time, anthocyanin synthesis becomes dose dependent, and reciprocity relationships are valid. Intermittent far red treatments with short dark intervals between successive irradiations are as effective as continuous treatments, if the total radiation doses applied with the two types of treatments are equal and are applied over equally long periods of time. The high effectiveness of inter-mittent treatments, the dose dependence, and the validity of the reciprocity relationships suggest that cycling between red-absorbing form of phytochrome and far red-absorbing form of phytochrome and the formation of electronically excited far red-absorbing form of phytochrome, or the involvement of a second photoreactive system, besides phytochrome, may play only a minor role in high irradiance reaction anthocyanin synthesis brought about by prolonged exposures to far red irradiation.

Journal Article↗