RESUMEN
Despite the importance of bumble bees (genus Bombus Latreille) for their services to natural and agricultural environments, we know little about the relationship between grassland management practices and bumble bee conservation. Prescribed fire is a common grassland maintenance tool, including in areas where endangered and threatened bumble bees are present. Thus, knowledge of the effects of prescribed fire on bumble bees is essential for designing management schemes that protect and bolster their populations. Using nonlethal surveys to record bumble bee species richness, abundance, and community composition, we evaluated the effects of spring controlled burns on summer bumble bee gynes and workers across five sites in southern Wisconsin. In addition, we explored the effects of fire on floral resources by measuring floral genus richness, abundance, ground cover, and proportion of transects containing blooming flowers in adjacent burned and unburned parcels. Prescribed fire had no measurable effects on bumble bee gyne or worker community composition, species richness, or abundance. However, consistent with previous studies prescribed fire increased floral genus richness and ground cover. The disconnect between bumble bee and floral responses to fire highlights some opportunities for improving our understanding of fire's effects on bumble bee diapause, nest site choice, and foraging.
Asunto(s)
Abejas , Incendios , Flores , Agricultura , Animales , WisconsinRESUMEN
The Concentration of nitric oxide can be monitored by a new device in which the Zeeman effect is used to shift an absorption line of nitric oxide into coincidence with a laser line of carbon monoxide. The absorption is modulated by a small, oscillating magnetic field. This device is specific for nitric oxide and is not subject to interference from other gases.
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Contaminación del Aire/análisis , Rayos Láser , Óxido Nítrico/análisis , Monóxido de Carbono , Rayos Infrarrojos , Métodos , Análisis EspectralRESUMEN
Isotope-selective photodissociation of the volatile complex uranyl hexafluoroacetylacetonate . tetrahydrofuran [UO(2)(hfacac)(2) . THF] has been achieved with both a continuous-wave and a pulsed carbon dioxide laser. The photodissociation was carried out in a low-density molecular beam under collisionless conditions. Transitions of the laser are in resonance with the asymmetric O-U-O stretch of the uranyl moiety, a vibrational mode whose frequency is sensitive to the masses of the uranium and oxygen isotopes. Unimolecular dissociation is observed mass spectrometrically at an extremely low energy fluence, with no evidence of an energy fluence or intensity threshold. The dissociation yield increases nearly linearly with increasing energy fluence. At constant fluence the dissociation yield is independent of contact time between the radiation field and the molecule, indicating that the decomposition is driven by laser energy fluence and not laser intensity. The oxygen and uranium isotope selectivities measured in these experiments are nearly those predicted by the ratio of the linear absorption cross sections for the respective isotopes. Thus, essentially complete selectivity is observed for oxygen isotopes, while a selectivity of only about 1.25 is measured for the uranium isotopes. A model presented to describe these results is based on rapid intramolecular vibrational energy flow from the pumped mode into a limited number of closely coupled modes.
RESUMEN
Delayed and sometimes total lack of communications, lower standards of medical care, low physician: population ratio, absence of monitoring systems affect all phases of drug consumption in developing countries--from procedures for introducing a new drug to its marketing on a broad scale, and ultimate decline. The number of prescriptions and the choice of drug are determined only partly by physicians. Such other factors as medicaments furnished by the government either free or at a small charge, the type of health service, accessibility to paramedical and nonmedical advice, as well as hard-sell marketing practices, often through the mass media, tend to set the pattern of drug usage. The practice of drug storming in "home pharmacies", a phenomenon surveyed by the author, is described and the reasons for it analyzed. In general, the categories of drugs (e.g., antibiotics, cardiovascular, analgesics) consumed are the same in the rest of Europe, the United States, and Latin America. Among the minor tranquilizers, the consumption of meprobamate has risen by about a third, chlordiazepoxide markedly, while phenobarbital consumption has remained about the same from 1969 to 1973. This is said to illustrate the pattern of an upward curve in consumption of a new drug, and the displacement of an old one. The overall rise of these drugs during this period was 72.1% in Hungary. Similar surveys are reported for oral hypoglycemic and antiarrhythmic drugs. Of hypotensive drugs, rauwolfia usage has declined and methyldopa has increased by over 200%.
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Países en Desarrollo , Utilización de Medicamentos , Antiarrítmicos/uso terapéutico , Antihipertensivos/uso terapéutico , Prescripciones de Medicamentos , Humanos , Hungría , Hipoglucemiantes/uso terapéutico , Automedicación , SuicidioRESUMEN
In Hungary, the actual drug evaluation and registration system reflects international standards and national traditions. The compulsory drug registration system that was established in 1933 was among the first in Europe. Laboratory control (since 1927), clinical trials (since 1951) and human clinical pharmaceutical experiments (since 1967) are prerequisites for new-drug approval. Applications should be sent to the National Institute of Pharmacy, which has the overall responsibility for the registration of pharmaceutical products. Applications are assessed on the basis of the drug's quality, safety, and efficacy. The procedure follows several steps: evaluation of chemical and pharmaceutical data by the staff of the National Institute of Pharmacy; evaluation of toxicologic and pharmacologic documentation with the help of the Committee on Drug Administration; after consultation with the Committee on Medical Research Ethics (mandatory in cases of original new drugs), authorized clinical pharmacologic investigations are conducted in the units of the Clinical Pharmacological Network, which are supervised by the National Center for Clinical Pharmacology; clinical trials; application for registration (scientific evaluation); and finally, application to the Ministry of Health for a marketing authorization. The process may be facilitated appreciably for preparations already registered in another country. Moreover, Hungary is an active member in the World Health Organization (WHO), Pharmaceutical Inspection Convention of the European Free Trade Association (EFTA PIC), the Council of Mutual Economic Assistance (COMECON), and other international pharmaceutical and clinical pharmaceutical collaborations.
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Evaluación de Medicamentos , Legislación de Medicamentos , Hungría , Sistema de RegistrosRESUMEN
PIP: The authors examined the effect of 3 oral contraceptives (OCs) (Bisecurin, Ovidon, and Rigevidon) on serum lipids, gamma glutamyl transpeptidase, and D-glutaric acid elimination. After 3-9 months of this medical contraception the two with the highest hormonal content significantly increased the serum cholesterol and the BLP levels. Neither one influenced the level of serum triglycerides. All significantly increased the serum level of gamma-glutamyl transpeptidase. The elimination of D-glutaric acid was also augmented. They did not find any correlation between the parameters of enzyme induration and lipid metabolism due to the taking of OCs.^ieng