TANNINS AND NON-TANNINS OF THE BARKS OF SOME EASTERN CANADIAN CONIFERS, PARTICULARLY WHITE SPRUCE

1938 ◽  
Vol 16b (10) ◽  
pp. 369-379
Author(s):  
W. E. Graham ◽  
A. Rose
Keyword(s):  
Chemical Reactions ◽  
White Spruce ◽  
Group Comparison ◽  
Intensive Study ◽  
Tannin Content ◽  
Standard Methods ◽  
Titration Curves ◽  
Spruce Bark

The tannin content of the barks of several Eastern Canadian conifers has been determined by standard methods in an attempt to assess their value as sources of tanning extracts.A more intensive study has been made of the extractable materials of white spruce bark. The chemical reactions of the extract from this bark show that the tannins therein are typical examples of the catechol or condensed group. Comparison of the ratio of tannin to non-tannins and the buffer index of this extract with the corresponding values for several commercial extracts indicates that the spruce extract would probably be fairly astringent. The titration curves of various fractions of the extract show some indications of the character of the non-tannin constituents.

Did the 1976–77 switch in the Pacific Decadal Oscillation make white spruce in the southwest Yukon more susceptible to spruce bark beetle?

2012 ◽  
Vol 88 (05) ◽  
pp. 513-518 ◽  
Author(s):  
Raphaël D. Chavardès ◽  
Lori D. Daniels ◽  
Patrick O. Waeber ◽  
John L. Innes ◽  
Craig R. Nitschke
Keyword(s):  
Bark Beetle ◽  
Pacific Decadal Oscillation ◽  
White Spruce ◽  
Climatic Changes ◽  
Climate Projections ◽  
Local Climate ◽  
Spruce Bark Beetle ◽  
Temperature And Precipitation ◽  
Spruce Bark ◽  
The Pacific

We applied dendrochronology to quantify the effects of climatic variation on white spruce radial growth in southwest Yukon, Canada. Local climate is cold and dry, thus tree growth was primarily limited by moisture, rather than temperature, although the mechanisms varied through time. Regionally, both temperature and precipitation increased in recent decades, in part due to the shift from the negative to positive phase of the Pacific Decadal Oscillation. Climate projections for this region include further increases in temperature and precipitation. Such changes may benefit white spruce growth and disturbance agents like the spruce bark beetle; however, specific impacts will depend on the seasonality and magnitude of climatic changes.

Treatment and Detoxification of Aqueous Spruce Bark Extracts by Aspergillus niger

1991 ◽  
Vol 24 (3-4) ◽  
pp. 127-137 ◽  
Author(s):  
J. A. Field ◽  
G. Lettinga
Keyword(s):  
Aspergillus Niger ◽  
Biological Treatment ◽  
Test Organism ◽  
Methanogenic Bacteria ◽  
Toxic Waste ◽  
Gel Chromatography ◽  
Tannin Content ◽  
Waste Streams ◽  
Citrate Buffer ◽  
Spruce Bark

Debarking effluents of the forest industry are severely toxic waste streams due to their high tannin content. The objectives of this study were to evaluate the treatment and detoxification of debarking wastewater with tannin tolerant fungi. For this purpose, Aspergillus niger was cultivated on aqueous bark extracts and the toxicity was assayed utilizing methanogenic bacteria as the test organism. Sterilized aqueous extracts of spruce bark were diluted to 5.2 g COD L−1 (containing 2.7 g tannin COD L−1) in either citrate or tartrate buffer and inoculated with A. niger spores. During four day aerobic fermentations with citrate buffer, the elimination of unfiltered and soluble COD was 28 and 63%, respectively. The apparent yield of biomass averaged 34% of the extract COD; however, 12% of the extract COD was tannins adsorbed on the fungal biomass. The decrease in the tannin concentratio was 50%. According to gel chromatography results, the original oligomeric tannins that resisted biodegradation were those of the highest MW. The toxicity was consequently only partially reduced by the fermentation. During the tartrate buffered fermentations, the pH rose due to the metabolism of the organic acid in the buffer. The rise in pH beyond 6 promoted autoxidative reactions that caused extensive polymerization of the tannins which resisted biodegradation. This resulted not only in an enhanced elimination of the tannins but also in a complete detoxification of the extracts. Similar levels of detoxification could be obtained in sterile un-inoculated extracts by autoxidation alone (raising the pH and aerating the extracts). Likewise, extracts fermented in citrate buffer could be completely detoxified by a subsequent autoxidation treatment. The exclusion peak of the gel chromatograms (MW > 30,000 g mole−1) obtained from the highly autoxidized samples accounted for 53% of the UV absorbance, whereas no exclusion peak was present in the unoxidized extracts. For the biological treatment and detoxification of debarking wastewaters, we recommend the cultivation of tannin tolerant fungi followed by short autoxidation treatments that polymerize the oligomeric tannin fraction resisting biodegradation to non-toxic high molecular weight polymers.

scholarly journals A Bark Thickness Model for White Spruce in Alaska Northern Forests

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Thomas Malone ◽  
Jingjing Liang
Keyword(s):  
Linear Model ◽  
Geographic Variation ◽  
White Spruce ◽  
Geographic Area ◽  
Bark Thickness ◽  
Future Studies ◽  
Spruce Bark ◽  
Southcentral Alaska ◽  
Northern Forests ◽  
Forest Managers

Here we developed a simple linear model to estimate white spruce bark thickness in the northern forests of Alaska. Data were collected from six areas throughout interior and southcentral Alaska. Geographic variation of bark thickness was tested between the Alaska statewide model and for each geographic area. The results show that the Alaska statewide model is accurate, simple, and robust, and has no practical geographic variation over the six areas. The model provides accurate estimates of the bark thickness for white spruce trees in Alaska for a wide array of future studies, and it is in demand by landowners and forest managers to support their management decisions.

3-D reconstruction of molecular shape from microcrystal thin sections

1983 ◽  
Vol 41 ◽  
pp. 748-749
Author(s):  
S. Cusack ◽  
J.-C. Jésior
Keyword(s):  
Three Dimensional ◽  
Molecular Shape ◽  
Biological Molecules ◽  
Fourier Space ◽  
Single Particles ◽  
Thin Sections ◽  
Standard Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dimensional Reconstruction

Three-dimensional reconstruction techniques using electron microscopy have been principally developed for application to 2-D arrays (i.e. monolayers) of biological molecules and symmetrical single particles (e.g. helical viruses). However many biological molecules that crystallise form multilayered microcrystals which are unsuitable for study by either the standard methods of 3-D reconstruction or, because of their size, by X-ray crystallography. The grid sectioning technique enables a number of different projections of such microcrystals to be obtained in well defined directions (e.g. parallel to crystal axes) and poses the problem of how best these projections can be used to reconstruct the packing and shape of the molecules forming the microcrystal.Given sufficient projections there may be enough information to do a crystallographic reconstruction in Fourier space. We however have considered the situation where only a limited number of projections are available, as for example in the case of catalase platelets where three orthogonal and two diagonal projections have been obtained (Fig. 1).

Ultrastructural Localization of Phycocyanin in the Acidophilic, Thermophilic Alga, Cyanidium Caldarium

1973 ◽  
Vol 31 ◽  
pp. 462-463
Author(s):  
M. R. Edwards ◽  
J. D. Mainwaring
Keyword(s):  
Yellowstone National Park ◽  
National Park ◽  
Ultrastructural Localization ◽  
Review Of Literature ◽  
Cyanidium Caldarium ◽  
Taxonomic Rank ◽  
Thin Sections ◽  
Standard Methods ◽  
Laboratory Cultures

Although the general ultrastructure of Cyanidium caldarium, an acidophilic, thermophilic alga of questionable taxonomic rank, has been extensively studied (see review of literature in reference 1), some peculiar ultrastructural features of the chloroplast of this alga have not been noted by other investigators.Cells were collected and prepared for thin sections at the Yellowstone National Park and were also grown in laboratory cultures (45-52°C; pH 2-5). Fixation (glutaraldehyde-osmium), dehydration (ethanol), and embedding (Epon 812) were accomplished by standard methods. Replicas of frozenfracture d- etched cells were obtained in a Balzers apparatus. In addition, cells were examined after disruption in a French Press.

Otoconia formation in the chick embryo

1983 ◽  
Vol 41 ◽  
pp. 572-573
Author(s):  
C.D. Fermin ◽  
M. Igarashi
Keyword(s):  
Chick Embryo ◽  
Inner Ear ◽  
Gallus Domesticus ◽  
The Body ◽  
Abnormal Behavior ◽  
Intensive Study ◽  
Basic Fuchsin ◽  
Gestational Period ◽  
Sensory Epithelia ◽  
Transmission Electron

Otoconia are microscopic geometric structures that cover the sensory epithelia of the utricle and saccule (gravitational receptors) of mammals, and the lagena macula of birds. The importance of otoconia for maintanance of the body balance is evidenced by the abnormal behavior of species with genetic defects of otolith. Although a few reports have dealt with otoconia formation, some basic questions remain unanswered. The chick embryo is desirable for studying otoconial formation because its inner ear structures are easily accessible, and its gestational period is short (21 days of incubation).The results described here are part of an intensive study intended to examine the morphogenesis of the otoconia in the chick embryo (Gallus- domesticus) inner ear. We used chick embryos from the 4th day of incubation until hatching, and examined the specimens with light (LM) and transmission electron microscopy (TEM). The embryos were decapitated, and fixed by immersion with 3% cold glutaraldehyde. The ears and their parts were dissected out under the microscope; no decalcification was used. For LM, the ears were embedded in JB-4 plastic, cut serially at 5 micra and stained with 0.2% toluidine blue and 0.1% basic fuchsin in 25% alcohol.

A Device for Magnification Measurement

1972 ◽  
Vol 30 ◽  
pp. 622-623
Author(s):  
J.A. Eades ◽  
A. van Dun
Keyword(s):  
Electron Microscope ◽  
Small Displacement ◽  
Private Communication ◽  
Piezoelectric Crystal ◽  
Double Exposure ◽  
Standard Methods ◽  
Elegant Method ◽  
The Right ◽  
Piezo Electric

The measurement of magnification in the electron microscope is always troublesome especially when a goniometer stage is in use, since there can be wide variations from calibrated values. One elegant method (L.M.Brown, private communication) of avoiding the difficulties of standard methods would be to fit a device which displaces the specimen a small but known distance and recording the displacement by a double exposure. Such a device would obviate the need for changing the specimen and guarantee that the magnification was measured under precisely the conditions used.Such a small displacement could be produced by any suitable transducer mounted in one of the specimen translation mechanisms. In the present case a piezoelectric crystal was used. Modern synthetic piezo electric ceramics readily give reproducible displacements in the right range for quite modest voltages (for example: Joyce and Wilson, 1969).

Surface reactions observed by photoemission electron microscopy (PEEM)

1992 ◽  
Vol 50 (1) ◽  
pp. 286-287
Author(s):  
H.H. Rotermund
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Work Function ◽  
Chemical Reactions ◽  
Reaction Diffusion ◽  
Dynamic Processes ◽  
Clean Surface ◽  
Crystal Surfaces ◽  
Single Crystal Surfaces ◽  
Photoemission Electron

Chemical reactions at a surface will in most cases show a measurable influence on the work function of the clean surface. This change of the work function δφ can be used to image the local distributions of the investigated reaction,.if one of the reacting partners is adsorbed at the surface in form of islands of sufficient size (Δ>0.2μm). These can than be visualized via a photoemission electron microscope (PEEM). Changes of φ as low as 2 meV give already a change in the total intensity of a PEEM picture. To achieve reasonable contrast for an image several 10 meV of δφ are needed. Dynamic processes as surface diffusion of CO or O on single crystal surfaces as well as reaction / diffusion fronts have been observed in real time and space.

Microwaves: Application in Electron Microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 140-141
Author(s):  
Anthony S-Y Leong ◽  
David W Gove
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Chemical Reactions ◽  
Electromagnetic Waves ◽  
Tissue Fixation ◽  
Primary Method ◽  
Dipolar Molecules ◽  
Wide Range ◽  
Time Required ◽  
Cryostat Sections

Microwaves (MW) are electromagnetic waves which are commonly generated at a frequency of 2.45 GHz. When dipolar molecules such as water, the polar side chains of proteins and other molecules with an uneven distribution of electrical charge are exposed to such non-ionizing radiation, they oscillate through 180° at a rate of 2,450 million cycles/s. This rapid kinetic movement results in accelerated chemical reactions and produces instantaneous heat. MWs have recently been applied to a wide range of procedures for light microscopy. MWs generated by domestic ovens have been used as a primary method of tissue fixation, it has been applied to the various stages of tissue processing as well as to a wide variety of staining procedures. This use of MWs has not only resulted in drastic reductions in the time required for tissue fixation, processing and staining, but have also produced better cytologic images in cryostat sections, and more importantly, have resulted in better preservation of cellular antigens.

Fine structure and properties of defects in naturally occurring silicates and oxides

1990 ◽  
Vol 48 (4) ◽  
pp. 460-461
Author(s):  
David R. Veblen
Keyword(s):  
Chemical Reactions ◽  
High Resolution Electron Microscopy ◽  
Extended Defects ◽  
Single Chain ◽  
Naturally Occurring ◽  
Resolution Electron ◽  
Fine Structures ◽  
Image Simulations ◽  
Similar Crystal Structure

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.

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