Evaluation of Alkaline Compounds Used for Deacidification and Simultaneous Lining of Extremely Degraded Manuscripts

Iron gall ink’s natural acidity promotes the degradation of manuscripts. This process mostly affects the areas containing ink, causing fragility of the paper carrier that limits its manipulation. The cellulosic material is modified by two chemical reactions, acidic hydrolysis and oxidation, both depending on the pH of the paper. This article explores the distribution of acidity in manuscripts and its link to iron gall ink corrosion and cellulose degradation. Subsequently, different treatment methods of deacidification, specifically designed for extremely degraded paper documents and sheets bound in volumes were tested. Documents were deacidified and at the same time mechanically supported, using an alkaline compound for deacidification that increases the pH to a range at which iron ion oxidation is decreased. Three alkaline compounds at different concentrations were evaluated: (1) calcium carbonate microparticles, (2) calcium hydroxide nanoparticles and (3) calcium propionate solution. The immediate and long-term effects after ten months of storage of these compounds on the increase of the pH of manuscripts are described in this study. All tested compounds were able to increase the pH and maintain it in the course of the observed period. Moreover, a lining with thin tissue and a mixture of 3 % gelatine dissolved in 60 % water and 40 % alcohol provides the consolidation required for manipulation of the manuscripts.

Contrasting effects of anthropogenic and natural acidity in streams: a meta-analysis

Large-scale human activities including the extensive combustion of fossil fuels have caused acidification of freshwater systems on a continental scale, resulting in reduced species diversity and, in some instances, impaired ecological functioning. In regions where acidity is natural, however, species diversity and functioning seem to be less affected. This contrasting response is likely to have more than one explanation including the possibility of adaptation in organisms exposed to natural acidity over evolutionary time scales and differential toxicity due to dissimilarities in water chemistry other than pH. However, empirical evidence supporting these hypotheses is equivocal. Partly, this is because previous research has mainly been conducted at relatively small geographical scales, and information on ecological functioning in this context is generally scarce. Our goal was to test whether anthropogenic acidity has stronger negative effects on species diversity and ecological functioning than natural acidity. Using a meta-analytic approach based on 60 datasets, we show that macroinvertebrate species richness and the decomposition of leaf litter—an important process in small streams—tend to decrease with increasing acidity across regions and across both the acidity categories. Macroinvertebrate species richness, however, declines three times more rapidly with increasing acidity where it is anthropogenic than where it is natural, in agreement with the adaptation hypothesis and the hypothesis of differences in water chemistry. By contrast, the loss in ecological functioning differs little between the categories, probably because increases in the biomass of taxa remaining at low pH compensate for losses in functionality that would otherwise accompany losses of taxa from acidic systems. This example from freshwater acidification illustrates how natural and anthropogenic stressors can differ markedly in their effects on species diversity and one aspect of ecological functioning.

Growth of Cypripedium Orchids in Soilless Media Containing Anaerobic Digestion-derived Biosolids

Lady slipper orchids have great potential as a perennial bedding plant in temperate-zone climates Unfortunately, many gardeners fear these species because of their high cost and perceived difficulties associated with growing plants outdoors. The former factor can be addressed by improving the production of plants at the wholesale level. Growers contest that sphagnum peat and coconut coir are poor organic addenda for these species due to their natural acidity. Anaerobic digestion-derived biosolids (ADB) are not acidic like sphagnum peat or coconut coir, and may be the perfect organic addendum for the culture of ladyslipper orchids. Hence, 3-year-old plants of showy (Cypripedium reginae) and yellow ladyslipper (Cypripedium parviflorum var. pubescens) orchids were grown in soilless potting mixes containing vermiculite and perlite plus various concentrations and combinations of ADB and coconut coir. Plants were grown in the greenhouse at 70 ± 10 °F and received normal light and photoperiod during Summer 2005. Growth, as assessed by the dry weight of dormant stem tissue, of showy ladyslipper potted in media containing ADB was three- to four-times greater than those grown in media containing coconut coir. Growth was similar among yellow ladyslippers grown in media containing ADB or coconut coir due to the fact that these plants had produced all their stem growth for the season before the experiment was initiated. ADB has great potential as an organic addendum to horticultural growing media used for the culture of Cypripedium species. Use of anaerobic digester-derived biosolids in horticultural growing media is a protected intellectual property and available for license through the WiSys Technology Foundation.

Influences of natural acidity and introduced fish on faunal assemblages in California alpine lakes

In an alpine area of the Sierra Nevada of California, naturally acidic waters and introduced fishes both strongly affect the distributions of native amphibians, zooplankton, and macroinvertebrates. The study area in Kings Canyon National Park contains 104 lakes with pH values between 5.0 and 9.3, including 10 lakes with pH < 6.0 (defined here as acidic lakes) and 18 lakes with introduced trout. We surveyed 33 of these lakes (8 acidic, 7 non-acidic with trout, 18 non-acidic without trout) for water chemistry and faunal assemblages. Yellow-legged frog tadpoles (Rana muscosa), common microcrustaceans (Daphnia, Hesperodiaptomus, Diaptomus), and larvae of a caddisfly (Hesperophylax) were rare or absent in acidic lakes but common in non-acidic lakes, and microcrustacean and macroinvertebrate species richness decreased with decreasing pH. Large and (or) mobile, conspicuous taxa, including tadpoles, large-bodied microcrustaceans (Hesperodiaptomus, Daphnia middendorffiana), and many epibenthic or limnetic macroinvertebrates (baetid and siphlonurid mayfly nymphs, notonectids, corixids, limnephilid caddis larvae, and dytiscid beetles), were rare or absent in trout lakes but were relatively common in lakes lacking trout, and the taxon richness of macroinvertebrates was reduced by trout.

Factors controlling the expressed activity of histidine ammonia-lyase in the epidermis and the resulting accumulation of urocanic acid

The synthesis of urocanic acid by histidine ammonia-lyase in guinea-pig epidermis was investigated in various ways. 1. In epidermal homogenates the enzyme obeys Michaelis-Menten kinetics and shows marked dependence of its activity of pH, such that below pH 6 it is inactive. 2. Part-thickness skin samples cultured with radioactive histidine do not accumulate detectable radioactive urocanic acid during 3 days in culture. 3. Very little histidine ammonia-lyase activity can be detected in the living cells of the epidermis. The enzyme is almost completely restricted to the dead cells of the stratum corneum. 4. Radioactive histidine injected into living animals does not result immediately in the accumulation of radioactive urocanic acid. By 3 days after the injection, however, both radioactive urocanic acid and histidine appear, apparently at the expense of radioactive proteins, 5. In isolated stratum corneum, the residual histidine can be converted into urocanic acid by the histidine ammonia-lyase in the tissue only if the natural acidity of the tissue is neutralized. It is concluded from these observations that the biosynthesis of urocanic acid occurs naturally only in the stratum corneum, which contains only dead cells. The amount of urocanic acid accumulated is limited by the availability of free histidine produced by proteolysis of residual protein in these cells and by the penetration into the stratum corneum of the ‘acid mantle’ of the skin.