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Abstract Background Makers are a growing community of STEM-minded people who bridge technical and non-technical backgrounds to imagine, build and fabricate engineering systems. Some have engineering training, some do not. This paper presents a study to explore the educational pathways of adult Makers and how they intersect with engineering. This research is guided by the following research questions: (1) What can we learn about the educational pathways of adult Makers through the lens of constructivist grounded theory? and (2) How do the educational pathways of Makers intersect with engineering? This study relied on qualitative interviews, using artifact elicitation interviews and constructivist critical incident technique interviews, of 42 adult Makers. Results Through inductive analysis of a collection of interviews with Makers, a theme emerged where Makers from different educational backgrounds and with different careers (e.g., art, STEM, business) were making artifacts that had similar purposes. We present two cases of parallel pathways, (1) musical artifacts and (2) large-scale interactive artifacts, to demonstrate the multiple, parallel life pathways that Makers take to making their artifacts and the contextual events and activities that are critical to the direction of these pathways. Conclusions The stories and life pathways of adult learners engaged in Making can offer valuable insight into how we might identify practices that promote the access and success of a larger and more diverse population of students for engineering. Makers are engaged in activities that embody the Engineer of 2020 (e.g., lifelong learning, creativity, and practical ingenuity). By studying Makers, we can consider the multiplicity of pathways into engineering majors and careers.

The article presents a reprint of the article "The West Indian Diaspora to the United States: Remittances and Development of the Homeland," by Aubrey W. Bonnett, which appeared in the Summer 2007 edition of "Forum on Public Policy Online." It focuses on the socio-economic condition of the Afro-West Indian diaspora in the U.S. based on "remittances sent home." The author also explores the influence of these immigrants on the economic and political landscapes of their homeland.

The mechanisms by which immunotherapy (IT) modulates allergic airway response are not entirely clear. Exhaled nitric oxide (eNO) is a sensitive marker of airway inflammation in allergic respiratory disorders. We hypothesize that eNO may serve as a barometer of the immunomodulatory changes occurring during IT. We aimed to characterize the pattern of eNO levels in children undergoing traditional IT (TradIT) and rush IT (RushIT). Off-line measurements of eNO were obtained in children electing to undergo RushIT or TradIT at a University-based Allergy/Asthma Clinic. The eNO was measured before IT (pre-IT, week 0) was initiated, and at 2, 4, 6, 8, and 12 weeks after starting IT. Nine children received TradIT and 10 children received RushIT. Pre-IT eNO in the RushIT group averaged 12.6 parts per billion (ppb). This was followed by a rise to 17.7 ppb at week 2. The elevated eNO levels persisted till week 8, and then dramatically dropped below the pre-IT values to 8.9 ppb at week 12 (p = 0.038). Similar changes in eNO were not seen in the TradIT group. The difference in eNO levels between the two groups was most marked at 4 weeks (p = 0.014). Initiation of IT produces significant immunomodulatory changes such as a rise in eNO levels. Temporally, the changes appear to be accelerated in the RushIT group compared with the TradIT group, with return to baseline as maintenance IT levels are achieved. [ABSTRACT FROM AUTHOR]

The active, far-red light absorbing, form of phytochrome was found to inhibit growth and phytochrome levels in the mesocotyl and coleoptile of 4- to 5.5-day-old seedlings of Zea mays L. Short, low-irradiance red or far-red light treatments were used to produce different proportions of active phytochrome at the end of high-irradiance white-light periods, which left different levels of total phytochrome in the plants. After light treatments which left relatively high levels of spectrophotometrically assayable phytochrome in the seedlings, apparent phytochrome synthesis in the subsequent dark period was low regardless of the proportions of each form of the pigment present at the beginning of the dark period. In light treatments producing relatively low levels of assayable phytochrome, levels of apparent phytochrome synthesis in both red and far-red treatments and differences between apparent synthesis in red and far-red treatments were maximal. No simple correlation was found between growth and apparent phytochrome synthesis. However, growth and total phytochrome levels were positively correlated in both organs. Using a subtractive method of correlation, in which only phytochrome effects were plotted, strong linear relationships between phytochrome levels or longitudinal growth and Pfr levels were found in those light treatments leaving greater than 8% of dark control levels of phytochrome in the tissues. Using this technique non-linear, inverse relationships between Pfr and apparent phytochrome synthesis was found, indicating that modes of phytochrome control over phytochrome synthesis and growth differ. Our results are consistent with the view that in vivo assays of "bulk" phytochrome reflect- levels and states of the physiologically active phytochrome fraction under our experimental conditions in maize. [ABSTRACT FROM AUTHOR]

Evidence for involvement of two non-photosynthetic pigments in photoinduction of anthocyanin biosynthesis in the roots and mesocotyls of Zea mays L. seedlings is presented. Short (5 min), low energy (4.5 × 10³ J.m-2) fluences of red light neither induced anthocyanin synthesis nor enhanced phenylalanine ammonia-lyase activity in dark-grown maize seedlings. Little anthocyanin synthesis and no enhancement of phenylalanine ammonia-lyase activity was induced by continuous far-red light. Continuous white or blue light induced both anthocyanin synthesis and enhanced phenylalanine ammonia-lyase activity. These results show that phytochrome alone cannot induce anthocyanin synthesis in maize seedlings. However, a strong phytochrome mediation of white light induced pigment synthesis was demonstrated. This effect was not demonstrable with white light enhanced phenylalanine ammonia-lyase activity, indicating that phytochrome controls another step in anthocyanin biosynthesis. [ABSTRACT FROM AUTHOR]

The effects of light and water stress upon chilling injury of chloroplasts have been assessed by electron microscopy in seedlings of three species known to differ in their chilling susceptibility. Chilling injury to chloroplasts was first manifested by distortion and swelling of thylakoids, reduction in starch granule size, and the formation of small vesicles of the envelope, called the peripheral reticulum. More prolonged treatment produced accumulations of lipid droplets, increased staining of the stroma, disintegration of the envelope, and mixing with cytoplasmic contents. Cotton, a notably chilling-sensitive plant and bush bean, a somewhat less sensitive plant, showed damage within 6 h when exposed to both light and water stress at chilling temperatures (5°C). Even collard, a chilling-resistant species, exhibited signs of chilling injury to chloroplasts after 6 h when exposed to both light and water stress but the plastids remained intact throughout the 48 h of treatment. Comparable chilling injury does not occur in cotton until around 72 h if the plants are exposed to water stress or light separately. Bush bean was affected less by separate treatments of light and water stress. The least chilling injury occurred in all three species when they were kept in the dark at a high humidity. [ABSTRACT FROM AUTHOR]

Seedlings of loblolly pine were grown in sand culture at two concentrations of nitrogen 110 and 75 ppm N) and calcium (0 and 200 ppm Cal for a four month period in order to determine which form of nitrogen was used most readily and to learn if there was an effect of calcium on nitrogen metabolism. Three sources of nitrogen were employed: nitrate. ammonium, and urea. A number of indicators of growth were followed, and chemical analyses were made of foliage and roots. The results are summarized as follows: 1.Urea, when supplied at 75 ppm of N, resulted in production of the greatest height. diameter, fresh weight. dry weight. and the lowest root/ shoot ratio of any of the treatments. 2.A number of seedlings died when ammoniinn nitrogen was supplied in the presence of calcium. but not in its absence. .3. Use of urea was associated with the highest total nitrogen content of foliage and nitrate with the least. Nitrogen source, however, did not have a major influence on the total nitrogen content of roots. 4.The soluble nitrogen content of foliage and roots was greatest with urea, and least with nitrate. when nitrogen was supplied at 75 ppm and calcium at 200 ppm. 5.Total and individual free amino acids, especially arginine, glutamine. asparagine. and praline. varied greatly with the nitrogen source. Seedlings supplied with ammonium had the largest amount of free amino acids. while those receiving nitrate had the smallest reserves. Nitrogen deficiency symptoms were produced in all 10 ppm nitrogen treatments. There was very little difference in the appearance of the plants in any of the 10 ppm series. 7. Calcium deficiency symptoms were not produced at 0 ppm calcium. However. 200 ppm calcium in the nutrient solution resulted in slight increases in almost all indices of growth that were used. 8. The foliage total nitrogen content in most treatment sequences was influenced positively by the presence of calcium in the nutrient solution, whereas the root nitrogen content was generally influenced negatively when calcium was supplied. O. The calcium content of the foliage was influenced not only by calcium level, but also by the nitrogen source. Nitrate was associated with the greatest foliage calcium content at each level of nitrogen supplied. [ABSTRACT FROM AUTHOR]

1. 3-Amino-1,2,4-triazole (ATA) was found to have very little effect upon the metabolism by bean plants of NaHC14O3, succinate-2,3-C14, and glucose-U-C14. 2. The effect of ATA upon the metabolism of glycine-1-C14, glycine-2-C14, glycine-U-C14, and serine-U-C14 was quite striking. In the presence of a high percentage of radioactivity from these labeled compounds entered an unidentified compound previously reported to be a metabolic product of ATA. 3. The unidentified compound, compound "1", does not appear to be an iron chelate or a sugar adduct. It may possibly be 3-amino-1,2,4-triazolylalanine but this, too, appears unlikely. 4. It is postulated that the phytotoxicity of ATA may result in part from interference in the normal metabolism of glycine and serine. [ABSTRACT FROM AUTHOR]

1. Isolated roots of pond pine (Pinus serotina Michx.) were grown in sterile culture with γ-aminobutyric acid, arginine, aspartic acid, citrulline, glutamic acid, ornithine, proline and urea as sole nitrogen sources. 2. The most effective organic nitrogen sources supporting, growth were found to be citrulline and γ-aminobutyric acid, both at concentrations of 10-3 M. Growth in length with these amino acids in the medium was almost as rapid as when nitrate was used. 3. Citrulline and γ-aminobutyric acid (10-3 M) also bad morphogenetic effects in that they stimulated formation of short dicholomous branches .strongly resembling mycorrhizae. 4. Arginine, ornithine, urea and aspartic acid were found to be moderately good to poor sole sources of nitrogen. Although they did cause some change in branching habit of the roots, they did not produce as strong morphogenetic effects as γ-aminobutyric acid and citrulline. 5. Glutamic acid and proline were not effective as nitrogen sources or in promoting dichotomous branching of pond pine roots. [ABSTRACT FROM AUTHOR]

Demonstrates the ability of mitochondria from higher plants to catalyze the incorporation of orthophosphate into adenosine triphosphate during the oxidation of acids of the citric acid cycle. Differences in properties of mitochondria from various plant tissues; Details concerning the sequence of events involved in oxidative phosphorylation by plant mitochondria; Investigation of succinate oxidation by particulate enzymes from plant tissue.

Products from the metabolism of uniformly labeled glutamic-C14 acid by green and etiolated Sacramento barley leaves have been analyzed chromato-graphically after time intervals of 1/2 to 3 hours under four different experimental conditions of light or dark, with atmospheres of air or nitrogen. 1. The rate of glutamic acid metabolism was faster in light than in darkness. 2. Glutamine, malate, citrate, aspartate, and γ-aminobutyric acid were associated with aerobic metabolism in the light. Therefore it appears that light did not interfere with the functioning of the Krebs cycle. 3. Glutamic acid was decarboxylated anaerobically in vivo to γ-amino-butyric acid; about 80 per cent of the metabolized amino acid appeared in this amine. 4. In etiolated seedlings in air and light, γ-aminobutyric acid appeared at first as rapidly, or more rapidly, from glutamic acid as did glutamine. After a short period during which γ-aminobutyric acid accumulated, it subsequently decreased to a small equilibrium amount by the time the etiolated leaf had been in the light 2 1/2 hours. 5. γ-Aminobutyric acid was the only product in vitro from the action of glutamic acid decarboxylase on glutamic-C14 acid as shown by paper chromatography and autoradiography. 6. In vivo, and especially anaerobically, the carbon label appeared in several compounds as yet unidentified. High Rf values of some of the compounds suggest ring configurations. [ABSTRACT FROM AUTHOR]

A survey was made of the terminal respiratory enzymes in Rumex virus tumor tissue grown in culture. The oxygen uptake of slices of Rumex virus tumors was inhibited about 45 per cent by 0.001 M cyanide. This inhibition suggested the presence of a heavy-metal mediated oxidase system. Cytochrome oxidase. DPNH-linked cytochrome c reductase, and succinic dehydrogenase were found to be present. Catalase and peroxidase activities were also demonstrated. The copper-protein oxidases - polyphenol oxidase, laccase, and ascorbic acid oxidase, were absent in this tissue. Although a residual cyanide respiration suggested the presence of a flavin oxidase, attempts to show glycolic acid dehydrogcnase activity were unsuccessful. [ABSTRACT FROM AUTHOR]

1. Attempts have been made to grow isolated roots of three varieties of pea — World's Record, Telephone, and Perfection — in culture for six or more weeks. 2. Neither Bonner's nor White's medium supported maximum growth of these varieties. Perfection pea roots made the most growth, World's Record was next, and Telephone pea grew least of all. With mass populations of roots of all three varieties, however, decline in growth was continuous with time. 3. The amount of sucrose in the nutrient markedly influenced growth of the roots. Perfection pea roots grew most rapidly with 6 and 8% sucrose in the medium; Telephone pea roots grew most vigorously with 4%: but results with World's Record roots were not decisive. 4. Dextrose and levulose separately and in combination did not prove to be satisfactory sources of carbon for growth of isolated roots of any one of the three varieties tested. 5. Casein hydrolysate together with L-cysteine and L-tryptophane (each at 6.67 mg. per 100 mg. casein) was found to be an excellent supplement to Bonner's solution when added at the rate of 200 and 400 p.p.m. Perfection pea roots grew very well at these concentrations but at concentrations above this, 800 and 1600 p.p.m., growth was no greater than the controls. World's Record pea roots were grown satisfactorily for the first time, concentrations of 100, 200 and 400 p.p.m. proving most effective in sustaining growth at a uniform level. Roots of Telephone pea still could not be maintained satisfactorily. 6. L-Cysteine and L-tryptophane in combination supported growth of Perfection and World's Record pea roots at a level above the controls, but growth of roots of Telephone pea was not sustained. 7. With casein hydrolysate added to the basal medium some factor or factors became limiting in the growth of Perfection pea roots within 12 days. This made it necessary to transfer the roots to fresh medium each week. 8. Indoleacetic acid added to the basal medium was very effective, in a narrow range, in promoting uniform and high growth rates of Perfection pea roots. Although indoleacetic acid at 10-4 gm./I. was toxic, concentrations of 10-7 and 10-8 were insufficient to stimulate growth significantly. Greatest promotive activity was induced by indoleacetic acid at 10-6 gm./liter. 9. Coconut milk and banana fruit diffusate both proved ineffective in stimulating growth of Perfection pea roots. Both caused marked inhibition at all concentrations employed. [ABSTRACT FROM AUTHOR]