Duration of Hydrogen Formation by Anabaena cylindrica B629 in Atmospheres of Argon, Air, and Nitrogen

The time course of hydrogen formation by Anabaena cylindrica was followed beneath an argon atmosphere alone and also beneath atmospheres of argon, nitrogen, and air in the presence of carbon monoxide (0.2%) and acetylene (5%). Hydrogen production beneath argon alone was comparable in rate and duration (7 to 12 days) to that which occurred beneath air in the presence of carbon monoxide (0.2%) and acetylene (5%). However, much greater longevity (16 to 26 days) and improved rates of hydrogen formation were obtained when algae were incubated beneath argon and particularly nitrogen, each supplemented with carbon monoxide and acetylene. The total hydrogen produced by these cultures was up to three times as much as that released by cultures incubated beneath argon alone. Hydrogen-oxygen ratios for argon cultures either with or without carbon monoxide and acetylene were initially 1:5 but approximated 1:2 when measured over the entire incubation period. In each case oxygen production and nitrogenase activity (acetylene reduction) continued at reduced rates after hydrogen evolution had ceased. The effects of methionine sulfoximine (2 μM), ammonium ions (0.5 mM), or both on oxygen production were generally negligible, while effects on hydrogen production were variable depending on the atmosphere used; in most cases, eventual destabilization of the system occurred. A brief comparison was made of the time courses of anaerobic and aerobic hydrogen formation by the marine cyanobacterium Calothrix membranacea. It was found that shaking of cultures was beneficial for hydrogen production but not strictly necessary. It is concluded that hydrogen production by A. cylindrica in air and particularly nitrogen in the presence of carbon monoxide and acetylene offers the best potential of the atmospheres considered on the basis of four criteria: rates and longevity of hydrogen formation, practicality of the atmosphere used, and tolerance of hydrogen evolution to slight changes in composition of the atmosphere.     

Comparative Study of Wastewater Lagoon with and without Water Hyacinth

A 3-year study was conducted on an existing, one-cell, facultative sewage lagoon having a total surface area of 3.6 ha and receiving a BOD₅ loading rate of 44 kglhald (40 Iblald). The comparative experimental periods ran from July through November for 3 consecutive years. During the first period, water hyacinths completely covered the lagoon. The water hyacinth coverage was reduced to 33% of the total surface area the second year. The lagoon, free of all vascular aquatic plants the third year, was monitored for comparative purposes. The most significant improvement overall in the effluent quality occurred when water hyacinths covered the entire lagoon. During this period the effluent BOD₅ and TSS were 23 and 6 mgll, respectively. Without water hyacinths, the effluent BOD₅ and TSS were 52 and 77 mgll, respectively. The effluent total organic carbon concentration with water hyacinths averaged 40 mgll, and without water hyacinths, 72 mgll. A discussion of the results from this 3-year study is presented in this paper along with associated problems that were observed when water hyacinths were introduced into the lagoon and altered its behavior from that of a normal facultative lagoon.     

The Chicago variant of clinical galactosemia

Summary A new variant of clinical galactosemia with two hitherto unidentified alleles on the transferase locus in one family is described. This new clinical variant of transferase has 25% of normal control activity in blood and in skin fibroblasts, and the patient accumulates galactose-1-phosphate in blood on an unrestricted galactose diet. Using starch gel electrophoresis on the hemolysate of the family members, a fast-moving transferase with mobility in between those of the normal control and of the Duarte variant is identified. This new allele is designated as (fast-moving Chicago variant). In addition, a second new allele was documented in this family by studying the instability of the transferase enzyme in hemolysates of family members at 50°C for various time intervals. This new allele is designated as (heat-labile Chicago variant). On the basis of the studies, the transferase genotype of this patients is thought to be a double heterozygote compound, /GALT^G.     

Mitogens for murine embryo cell lines

The growth-promoting activities of fetal bovine serum, cortisol, phorbol myristate acetate, prostaglandin F2α, insulin, epidermal growth factor, and fibroblast growth factor were evaluated on four murine embryo cell lines (Swiss 3T3, Balb 3T3, M2, and C3H10T1/2). Each cell had an unique response spectrum to this collection of reported mitogens. Phorbol myristate acetate and prostaglandin F2α were active only on selected cell lines; cortisol was inactive on all four lines. Serum, epidermal growth factor, and fibroblast growth factor were able to stimulate cell division in all four lines, albeit to varying degrees for the different target cells.     

Role of calcium in the initiation of fast axonal transport of protein: Effects of divalent cations

Fast axonal transport of [³H]protein has been examined in bullfrog primary afferent neurons incubated in media supplemented with divalent cations that can act as agonists or antagonists of calcium ions. Incubation in calcium-free medium (CFM) had no effect on the rate of transport, but reduced the amount of transported [³H]protein by 40–60% relative to transport in the contralateral preparation maintained in normal medium. Preparations incubated in CFM supplemented with 1.8 mM SrCl₂ (equimolar to the CaCl₂ concentration in normal medium) carried out transport at control levels. Incubation conditions in which primary afferent somata were exposed to the Sr²⁺-medium while nerve trunks were maintained in CFM also supported normal transport. By contrast, selective exposure of nerve trunks to Sr²⁺-medium, and somata to CFM resulted in a reduced level of transport similar to that observed when the whole preparation was incubated in CFM. The depression of transport resulting from incubation in CFM was shown to be reversible when preparations were transferred from CFM to either Sr²⁺-supplemented CFM or to normal medium. By contrast to the effects of Sr²⁺, Ba²⁺ (up to 18 mM) did not substitute for Ca²⁺ in the transport process. When normal medium was supplemented with calciumantagonist cations, the amount of transport was depressed (Co²⁺ > Mn²⁺ >> Mg²⁺), with no concomitant effect on the rate of transport. Results of studies with Co²⁺, as well as those with Sr²⁺, suggest that a major locus of action of these cations is within the neuronal soma at a step subsequent to protein synthesis, and prior to the onset of protein translocation via the transport system. Thus, it is inferred that these divalent cations affect a calcium-dependent step that occurs during the initiation phase of fast axonal transport.     

The activation of bovine Factor X by bovine Factor Xa

A steady-state kinetic analysis of the activation of bovine Factor X, by bovine Factor X_a, was undertaken. The activation was found to be dependent on the presence of divalent cations; Ca²⁺ showing the greatest stimulatory effect and Mn²⁺ exhibiting a lower degree of activity for this reaction. Although Sr²⁺ and Mg²⁺ were ineffective when present alone, each contributed synergistically to the activation rate at suboptimal levels of Ca²⁺. The effect of phospholipid (phosphatidylcholine:phosphatidylserine, 4:1, w:w) on the rate of activation and on the activation pathway was investigated. Phospholipid (PL) concentrations of up to 40 μm had no effect on the activation rate; whereas, concentrations of 40–180 μm were slightly inhibitory. In the absence of PL, the major product of the activation was Factor α-X_a, while in the presence of PL, lower-molecular-weight forms of Factor X (Factor β-X) and Factor X_a (Factor β-X_a were produced. At saturating levels of Ca²⁺, the K_{m app} for the activation, at pH 7.4 and 37 °C, in the absence of PL, was found to be 0.6 ± 0.1 μm and the V was 1.7 ± 0.3 mol Factor X cleaved min^?1 mol^?1 Factor X_a. The corresponding values, in the presence of 90 μm PL, were 1.4 ± 0.2 μm and 2.2 ± 0.2 mol Factor X cleaved min^?1 mol^?1 Factor X_a.     

Two distinct regulatory steps in cartilage differentiation

The effect of developmental stage on chondrogenic capacity in high-density cell cultures of chick embryonic wing bud mesenchyme is examined. Mesenchyme from stage 19 embryos forms aggregates of closely associated cells which do not form cartilage matrix, nor contain significant levels of type II collagen that are detectable by immunofluorescence, unless they are treated with dibutyryl cyclic AMP. Mesenchyme from stage 24 embryonic wing buds in high-density cell cultures will spontaneously form cartilage, as defined by electron microscopy and immunofluorescence with antibody to type II collagen. Cultures prepared from stage 26 wings form numerous aggregates which fail to accumulate an Alcian blue-staining matrix and which resemble mesenchyme cells morphologically. However, because these cells show considerable intracellular immunofluorescence for type II collagen, they are actually unexpressed cartilage cells. Several treatments, including exposure to dibutyryl cyclic AMP, ascorbic acid and an atmosphere of 5% oxygen, or mixture with small numbers of stage 24 wing mesenchyme cells, stimulate expression, as determined by the accumulation of an Alcian blue-staining matrix and an ultrastructurally recognizable cartilage matrix. Since the addition of similar numbers of differentiated cartilage cells does not stimulate expression of stage 26 cells, it is proposed that initial cartilage expression is dependent on a mesenchyme-specific influence which might be removed by cell dissociation. These studies demonstrate that there are at least two distinct transitions in cartilage differentiation: one involves the conversion of mesenchyme to unexpressed chondrocytes and the second involves mesenchyme-dependent expression of chondrogenic differentiation.     

Mitogenic property of the apical ectodermal ridge

While the apical ectodermal ridge (AER) is well known for its required role in the development of distal parts of the limb and for its ability to stimulate limb duplications, the mechanism of its action is unknown. In this study we use a culture system previously developed by M. Globus and S. Vethamany-Globus (1976, Differentiation6, 91–96) in which an AER grafted onto a high-density cell culture of limb mesenchyme stimulates the formation of an outgrowth. Time-lapse movies taken during the outgrowth period demonstrated no cellular activities other than cell division. Both the mitotic index and labeling index in the mesenchyme were significantly elevated under the AER as compared to that without AER, indicating that the AER provides a growth-promoting stimulus which increases the proportion of dividing cells. On the other hand, nonridge ectoderm had no detectable effect on the mitotic index. Treatment of cultures with cytosine arabinoside both inhibited DNA synthesis and prevented AER-induced outgrowth. These results demonstrate a mitogenic capacity of AER tissue and suggest that mesenchymal outgrowth requires this activity. The mitogenic property of the AER is considered in relation to limb outgrowth in situ.     

The Friesner Herbarium (BUT) of Butler University

The Friesner Herbarium (BUT) of Butler University is a collection of over 100,000 specimens built from the personal herbarium of Ray C. Friesner. He and other botanists at Butler amassed one of the largest and most complete collections of Indiana plants. Active exchange from the 1920’s through the 1940’s increased the holdings of plants from other states. Although the collection does not contain many type specimens, it is rich in vouchers from floristic and ecological studies conducted in the first half of the 20th century and published in the scientific journal,Butler University Botanical Studies.