3,172 research outputs found
The Effect of Visible Light on Carotenogenesis of Arthrosporulating Trichophyton Mentagrophytes
Some comments on reconstructing the historical climate of California, USA
This paper describes some examples of historical climate reconstruction pertaining to California, USA, focusing mostly on winter climate given the expected strongest teleconnection signals for this season. Climatic data consist of early instrumental data from the US Army Surgeon General at military forts, observers of the Smithsonian Institution, the Signal Service, and some private observers.
Documentary (non-instrumental) data were also used in assessing extreme events. Original daily records of these data were carefully assessed for discontinuities from examining diurnal temperature ranges and daily precipitation amounts. The climatic reconstructions conducted were as follows: 1) winter precipitation time series for selected locations since 1850, particularly for Sacramento and San Francisco, 2) winter temperature time series for selected locations since 1850, and 3) analyses of an extreme flooding event in January 1862 and a landfalling tropical cyclone of September 1939. Results indicate distinctive wetter winters for central and northern California in the late nineteenth century, and some of these wetter years correspond to well-known very strong El Ni˜no events. Connections to weaker El Ni˜no and La Ni˜na events, however, are not clearly evident. The flood of January 1862 is considered unprecedented when compared to other floods of the last 130 years. The reconstruction of a landfalling tropical cyclone for September 1939 near Los Angeles suggests its intensity at just below hurricane strength
Functions of pets for young children
Includes bibliographical references (pages [57]-61.).August, 1971.The role or function that dogs and cats fulfill as pets in families with preschool-age children was examined in terms of pet prevalence, their relationship to animal fears, and their association with imaginary companions. The sample consisted of 37 children, three years nine months to five years nine months of age, in the Colorado State University Preschool Laboratory and their mothers. Mothers' data was collected by means of a questionnaire and an interview was conducted with the children. Measures used to determine the level of significance were the single-variable chi-square test, and the chi ... square contingency table. The first hypothesis, that there would be no difference between the prevalence of dogs and cats and any other pet in the preschooler's family, was rejected on the basis of the single variable application of the chi-square test. Dogs were revealed to be the preferred pet. Hypothesis two, relating mothers' fear and children's fear of dogs and cats, showed no statistical significance, therefore the null hypothesis was not rejected. However, statistically significant findings indicated that children who had an experience with a pet were less fearful of dogs and cats. The third hypothesis, which examined selection of pets and non-pets as imaginary companions was rejected. Statistical analysis revealed that children chose non-pets as imaginary companions more often than they did pets. Conclusions based on the study may be applicable to similar samples. There is a high incidence of pet possession among preschool children. Children can and do assimilate realistic aspects of their pets, and relate positively to types of pets that are similar to the ones they have presently or previously owned. Those children who have an experience with a pet are less likely to be fearful of dogs and cats, though the effects of their mothers' fear of dogs and cats were negligible. Data on the role of the pet as an imaginary companion suggested that the pet experience needs to be of a concrete tangible nature to be meaningful to young children, rather than an imaginary one. Pets in families are more likely to play the role of family pets rather than the role of pets to any single family member
SB 2404, Conservation Lands (Beaches at Haena, Kauai) - Statement for Senate Committee on Economic Development Public Hearing - February 20, 1986
Alternating-Current Equipment for the Measurement of Fluctuations of Air Speed in Turbulent Flow
Recent electrical and mechanical improvements have been made in the equipment developed at the National Bureau of Standards for measurement of fluctuations of air speed in turbulent flow. Data useful in the design of similar equipment are presented. The design of rectified alternating-current power supplies for such apparatus is treated briefly, and the effect of the power supplies on the performance of the equipment is discussed
Hysterectomy in the rural tropics
A clinical study on hysterectomy in the rural tropics of Ghana and the challenges faced by rural health care providers to render effective and meaningful medical assistance to rural patients due to the scarcity of medical equipment and medical drugs in such neglected outlying areas..A retrospective study of hysterectomy at a rural hospital in Ghana revealed a high incidence of emergency cases. Uterine fibroids were the commonest indication for elective hysterectomy, followed by surgery for suspected cervical carcinoma. Most emergency hysterectomies were performed because of uterine rupture. The difficulties of managing these problems against the background of the diagnostic and therapeutic facilities available are discussed
A method to detect oxidative stress by monitoring changes in the extracellular antioxidant capacity in plant suspension cells
Detection of H2O2 in the supernatant of plant suspension cells is often used to indicate the time and extent of the oxidative burst during interactions with either bacteria or pathogen-related elicitors. We have found that suspensions of plant cells, depending on conditions, may produce considerable levels of extracellular phenolics that can function as antioxidants and prevent or suppress the detection of H2O2. These compounds can be used as substrates by extracellular peroxidases to scavenge stoichiometric amounts of H2O2. When this occurs during plant/pathogen interactions it can mask both the timing and extent of the oxidative burst if detection of free H2O2 is the only technique used. We have developed a chemiluminescent technique that will account for the H2O2 scavenged by these extracellular metabolites. A known quantity of H2O2 is added to samples and allowed to react with the extracellular antioxidants. The amount of H2O2 that remains is then determined by adding luminol to the sample and measuring luminol-dependent-chemiluminescence. The difference between treated and control samples represents the amount of H2O2 that has been produced by the cells in response to the treatment. We have found that this technique provides a better estimate of both the magnitude and timing of the oxidative burst in bacterial/suspension cell systems
Stimulus-dependent dynamics of p53 in single cells
Many biological networks respond to various inputs through a common signaling molecule that triggers distinct cellular outcomes. One potential mechanism for achieving specific input-output relationships is to trigger distinct dynamical patterns in response to different stimuli. Here we focused on the dynamics of p53, a tumor suppressor activated in response to cellular stress. We quantified the dynamics of p53 in individual cells in response to UV and observed a single pulse that increases in amplitude and duration in proportion to the UV dose. This graded response contrasts with the previously described series of fixed pulses in response to γ-radiation. We further found that while γ-triggered p53 pulses are excitable, the p53 response to UV is not excitable and depends on continuous signaling from the input-sensing kinases. Using mathematical modeling and experiments, we identified feedback loops that contribute to specific features of the stimulus-dependent dynamics of p53, including excitability and input-duration dependency. Our study shows that different stresses elicit different temporal profiles of p53, suggesting that modulation of p53 dynamics might be used to achieve specificity in this network
Improved Apparatus for the Measurement of Fluctuations of Air Speed in Turbulent Flow
This report describes recent improvements in the design of the equipment associated with the hot-wire anemometer for the measurement of fluctuating air speeds in turbulent air flow, and presents the results of some experimental investigations dealing with the response of the hot wire to speed fluctuations of various frequencies. Attempts at measuring the frequency of the fluctuations encountered in the Bureau of Standards' 54-inch wind tunnel are also reported. In addition, the difficulties encountered in the use of such apparatus and the precautions found helpful in avoiding them are discussed
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