Brown Type Research Articles

Crossing Experiments and the Behavioral Study of Two Types of the Mulberry Pyralid, Glyphodes pyloalis WALKER (Lepidoptera : Pyralidae)

A type of mulberry pyralid, Glyphodes pyloalis WALKER whose larval head-capsule is brownish, was found; the standard type is whitish. Its reproductive biology was studied in comparison with the white type. The hybrid progenies of the brown type were repeatedly fertile with the white type. The wing-color morph of the brown type always corresponded to the larval phenotype, and the brown type was segregated even in the F1 generation. Except for the homogamic cross, the segregation ratio of the brown type was always lower than that of white type in successive generations. There were almost no significant differences in emergence, calling or mating time between the two types. They mated at random with each other in the laboratory, and both females showed high cross-attractiveness to males of the two types in a field cage. The brown type showed a high deformity and mortality at the pupal stage. Therefore, the brown type appears to be a recessive mutant or a race of the mulberry pyralid which occurs with a small populatino in limited localities.

Factors affecting snowmelt streamwater chemistry in the black forest (West Germany)

Site conditions such as parent material, soils, but also vegetation cover and elevation explain the varying snowmelt streamwater chemistry in the Black Forest. The results are derived from multiple statistical analysis of a regional survey of 104 small mountain streams in the first phase of snowmelt in spring 1984. Cluster analysis classifies the snowmelt streams into three groups which are clearly linked to bedrock geology. Factor analysis finds podsolization, weathering and mineralization processes in the soils of the catchments to have most impact even under snowmelt conditions. There is no evidence that acidic atmospheric deposition directly affects the acidity of the investigated streams. However, the deposition rates are low compared to certain other regions in Central Europe. In areas with podsolic soils the organic soil layer plays a key role in the acidity and mobilization of Al and heavy metals. This is shown in the high correlations between pH, DOC, UV-extinction, color and metal concentrations. Because the concentrations of DOC are low (<10 mg.L−1) and an anion deficit cannot be found, it is assumed that water acidity is not caused by dissolved humic acids, but by cations exchanged in the organic layer of acidic soils. Streamwater chemistry in areas with brown earth soil types is mainly affected by leaching of basic cations in the mineral soil horizons and mineral weathering.

Impact of clearcutting and slash burning on ectomycorrhizal associations of Douglas-fir seedlings

The effect of clear-cutting, with and without slash burning, on ectomycorrhizal formation of Douglas-fir seedlings (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) was studied in field and greenhouse bioassays. Twelve ectomycorrhizal types were found in three western Cascade Mountain sites on seedlings planted in soils exchanged among burned and unburned portions of clear-cuts and undisturbed forest. Rhizopogon sp. and an unidentified brown type consistently formed at least two-thirds of the ectomycorrhizal root tips. Regardless of soil origin, more ectomycorrhizae formed in clear-cuts than in undisturbed forest (primarily due to more brown mycorrhizae). Soil origin did not affect total numbers of ectomycorrhizae; however, more different types formed in undisturbed forest soils than in clear-cut soils, irrespective of aboveground environment. More nonmycorrhizal tips occurred in clear-cut soils. Seedlings grown in the same soils formed the same proportions of Rhizopogon and brown types in field and greenhouse, but not the same proportions of less common ectomycorrhizal types. Soil pasteurization increased root-tip numbers. Inoculated soils (1 part nonpasteurized: 9 parts pasteurized) produced as many ectomycorrhizae as nonpasteurized field soils and generally fewer tips than pasteurized soils. Formation of major (but not minor) ectomycorrhizal types on all sites was influenced more by aboveground changes that accompany clear-cutting and site preparation than by alterations in soil chemistry or biology.

Examination of low‐pathogenicity isolates of Armillaria mellea from natural stands of Picea abies in Middle‐Europe

AbstractIn certain indigenous Picea abies Karst. stands in the Thuringian Forest (Middle‐Europe), the incidence of butt rot and die‐back of saplings caused by Armillaria mellea (Vahl ex Fr.) Karst. is conspicuously low in spite of a general spread of this fungus on stumps of clear‐fellings. The majority of 43 isolates of A. mellea recovered from 13 highland infection centres were unable to form the brown type of rhizo‐morphs (BR) in soil but could form the white type rhizomorphs (WR) on sterile substrates. In contrast, 17 isolates from lowland hardwood stands of average disease incidence produced both types of rhizo‐morphs on both substrates. Results of inoculation of excised stem and root sections of Picea abies and Fagus sylvatica L. and saplings of P. abies associated with soils of different fertility levels indicated that the low disease index of certain P. abies stands is caused by the dominance of low‐pathogenicity strains of A. mellea which lack the ability to form BR and penetrate non‐injured bark of roots. Moreover, the poor podzolic highland soil types may contribute more to increase the survival rate and resistance of transplanted P. abies saplings than to reduce the spread of A. mellea.

Nonenzymatic Browning via the Maillard Reaction in Foods

Nonenzymatic glycosylation of human hemoglobin has recently received increased attention because of its relevance to diabetes mellitus. The reaction of carbohydrates and protein, often called the Maillard reaction, is well known in the food industry. The Maillard reaction is actually a complex scheme of many reactions and is the primary type of nonenzymatic browning that can occur in dehydrated or semimoist foods during storage. This reaction results from reducing compounds, primarily sugars, reacting with proteins, peptides, amino acids, or free amine groups and results in changes in the aesthetic, functional, and nutritional properties of the food in which the reaction occurs. In the present review, no attempt is made to cover all the literature. Rather, attention is given to the various chemical and physical factors that can affect the Maillard reaction in foods. Chemical factors include the type and amount of initial reactant species, pH, water content or water activity, and the presence of substances such as liquid humectants and bisulfite. In addition physical factors such as processing and storage temperature, atmospheric oxygen, and packaging during storage can affect the Maillard reaction in foods.

Weathering of a soil glauconite in Southern England

The weathering of glauconite in a soil from southern England has been examined by optical and chemical methods. Glauconite in the parent material is shown to consist of ca. 80% iron-rich illite-like layers randomly interstratified with ca. 20% smectite layers, and to contain < 1% Fe-II (as oxide). During weathering the glauconite changes from darkgreen, smooth lustrous grains through a pale green, less smooth and lustrous phase to a completely brown type of grain. The change is accompanied by loss of K and Mg, increase in Al, formation of ferrunginous illite—smectite and considerable grain disaggregation. In relation to the probable age of the landscape (Late Weichselian) the glauconite in this soil is relatively little altered en masse. The very low ferrous iron content results in relatively little lattice strain and the stability of the glauconite in the weathering sense is attributed to this.

Ectomycorrhizae Associated With Jarrah

Three major morphological types of ectomycorrhizae have been distinguished on roots of Eucalyptus marginara (jarrah). These were broadly classified as white, brown and black types. The variation in type of ectornycorrhizae and number of infected tips with season and depth in the soil were monitored at three forest sites. The sites had been burnt 1 , 6 and 45 years before sampling. Formation of ectomycorrhizae occurred in winter and spring. The black type was found predominantly in the soil whilst the white and brown types were associated with litter. The mean number of ectomycorrhizal root tips was highest in the 45 year unburnt and least in the 1 year unburnt site, suggesting that burning history influences their abundance.

The mycelial status and reversibility inHistoplasma capsulatum

The highly variable mycelial phase cultures of Histoplasma capsulatum are generally described as brown to albino colonies with the albino type overtaking the brown in a unidirectional and mainly irreversible process. In this study it was found that cultures could be reversed from albino to brown type by manipulation of substrates. As the cultural morphology and stability were shown to be essentially substrate-dependent, the mycelial status of this organism was reassessed. It is proposed that albino and intermediate variants are usually artificially induced by conventional refined carbohydrate media, while crude guano substrates tend to promote cultures of a brown wild type.

Factors affecting perithecial production in Gibberella (Fusarium) tricincta

Three pigmentation types (brown, red, and white) of Fusarium tricinctum (Corda) Sacc. were observed when an isolated mass culture from leaf spots on English ivy (Hedera helix L.) was single spored. Perithecia of the heterothallic fungus Gibberella tricincta El-Gholl were produced at 20 and 27 °C on stem pieces of Cynodon dactylan Pers. resting on water agar, under 12-h alternating light and dark when certain pigmentation types were paired. Pairing of red and brown pigmentation types yielded significantly (P &lt; 0.05) more perithecia than red and white pairings at 20 and 27 °C. Perithecia were formed only in combinations of red with brown or white pigmentation types. In both sets of pairings, significantly (P &lt; 0.05) more perithecia were produced at 27 than at 20 °C. No perithecia were formed in constant darkness. Occasionally, the red pigmentation type became white after subsequent transfers and never reverted to the red pigmentation on various media and failed to produce perithecia with any pigmentation type. Continuous darkness slightly favored red pigment formation over continuous light as detected by the Munsell color codes. Increasing temperatures from 20 to 32 °C decreased the colony growth diameter of the red-pigmented cultural type. At 32 °C a change in hue was noted with corresponding changes in color codes. Red mycelial pigmentation was intensified by the addition of copper, iron, manganese, and zinc to a basal medium. The addition of 0.1% yeast extract favored mycelial development and caused a more pronounced red mycelial pigmentation in the presence of heavy metals.

Effect of Date of Pruning, Timing, Number and Composition of Oil Emulsion Sprays on Harvest Pruned Sultana

During four seasons of harvest pruning from 1972 to 1975 Sultana canes were cut in early, mid or late March. The bunches were sprayed either once (on the same day, or three days later) or twice (on the day of pruning and again four days later, or three and seven days after pruning) with 0.7, 1.2, or 1.7% potassium carbonate oil-in-water emulsion (oil spray). Rate of fruit drying was increased by: pruning in early instead of mid or late March, using two instead of one oil spray, using 1.7% potassium carbonate instead of 1.2 or 0.7% in the oil sprays, and applying the first spray on the day of pruning instead of three days later. There was no consistent effect of date of pruning on fruit grade, yield or vine growth. The early March pruning produced light type fruit (unless rain occurred) and the mid and late March prunings had brown type fruit. There were no consistent differences in fruit grade and yield between one or two oil sprays, 1.7, 1.2 or 0.7% potassium carbonate, and first oil spray applied on the same day as pruning or three days later. Harvest pruning produced fruit that was almost free of grit.

A low power magnetometer for vehicle detection

A miniature, low power two-axis Brown type ring. core magnetometer is described which can be used for motor vehicle detection. For relatively little power (<1mw), the sensor functions over a large dynamic range ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\pm.8\times10^{-4}</tex> Tesla) with a sensitivity of 7μv/nT (both orthogonal axes) and a self noise at zero field less than 3nT <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p_p</inf> (.03 to 3 Hz). A low power digital feedback loop has been developed to null the magnetometer signal and compensate for temperature induced offset variations. The sensor is also suitable for a stationary short baseline gradiometer.

The physical aspects with respect to water and non-enzymatic browning.

Non-enzymatic browning is one of the major probles that occurs during the processing and storage of dehydrated and semi-moist foods. One type of browning is the Maillard reaction between reducing sugars and proteins or free amines. This leads to a darkening of color, protein insolubility with subsequent possible nutrition loss and a bitter off-flavor. The reaction has been extensively researched since the early 1940's. From a storage standpoint, browning rate increases as water activity (aw) increases up to a maximum where reactant dilution causes a subsequent decrease in rate. Use of liquid humectants in high moisture foods increase phase volume and viscosity, thereby lowering the aw of the rate maximum. These humectants thus act as inhibitors at high aw. Sorbitol also decreases the rate by a viscosity effect. Kinetic studies at normal storage conditions show browning to occur by a zero order reaction although the sugar and amine initial reaction occurs by first order. Studies with Tetrahymena show that the initial Schiff's base and reaction products may be partially biologically available although chemical assays show up to 50% loss of protein value. For dehydrated foods the zero order kinetics can be used to predict shelf life under a variable time-temperature-humidity condition.

Effects of continuous light and total darkness on cultures of Histoplasma capsulatum.

A (albino) and B (brown) type mycelium of 6 human and soil isolates of Histoplasma capsulatum grown at 26°C on modified Sabouraud agar in the dark or in continuous fluorescent light, show marked morphological and physiological differences. Under continuous illumination both types have flat, restricted, subsurface growth with few or no conidia. In total darkness B type mycelium is not overgrown by A type, produces abundant brown pigment, profuse aerial mycelium and tuberculate macroconidia. Cleistothecia are not formed in continuous light. Long exposures to light have a lethal effect on conversion of yeast to mycelium. Yeasts grown at 36°C on brain heart infusion agar or in trypticase soy broth show no microscopic or growth curve differences. Both A and B mycelium convert more rapidly, profusely and completely to the yeast phase in total darkness regardless of the presence or absence of CO2.

Comparative pathogenicity of albino and brown types of Histoplasma capsulatum for mice.

Albino (A) and brown (B) types of three strains of Histoplasma capsulatum (G-184, G-186, and G-217) were compared for their pathogenicity in mice. Mice were inoculated intravenously with dosages of 0.5-16 x 106 yeast cells of H. capsulatum, and the clinical picture, body weight and mortality 30 days after infection were recorded. Type B was more pathogenic than type A in all three strains tested. Both A and B types were isolated from organs of the mice inoculated with either type, but the type used to infect the mice remained the predominant form. This suggests in-vivo conversion of one morphologic type into the other.

Variability of Thielaviopsis basicola in culture

The fungus Thielaviopsis basicola (Berk. &amp; Br.) Ferraris exhibited considerable variability when grown on potato dextrose and V8 juice agars. Variants were frequently obtained from single chlamydospore cells. In general, many different cultural variants were obtained from the grey wild biotype. These arose from single chlamydospore cell isolations, from sector and patch variants, and from colonies which initially were of single spore origin. The variants differed from their respective parents and from each other in macroscopic and microscopic characteristics including colony appearance, color, zonation, growth rate, production of spores, and shape and number of cells in the chlamydospores. Some variants were less pathogenic than the parents from which they arose; in others pathogenicity was not significantly changed, and others exhibited higher pathogenicity.Contrary to earlier reports, it was found that the typical brown type can be derived in culture from the grey wild biotype. This brown type is similar to the brown wild biotype in cultural behavior and in relative pathogenicity to red clover.

Pyridone–pyridol tautomerism in 2-hydroxypyridines with [5,6]-annelated rings and oxygen at the [6]-position: 2,3-dihydro-6-hydroxy-4-methylfuro[2,3-b]pyridine and 3,4-dihydro-7-hydroxy-5-methylpyrano-[2,3-b]pyridine

U.v. spectra in a range of solvents, i.r. and 1H n.m.r. spectra, and ionization constants in water have been determined for the title compounds (I) to (IV) and their O- and N-methylated derivatives (V) to (VIII). Replacement of the annelated five-membered ring by a six-membered one (a) reduces the ratio [pyridol]/[pyridone](KT) by a factor of ca. 15–30; (b) raises the base strength of the 2-methoxypyridine; (c) scarcely changes the base strength of the 2-pyridone; (d) lowers the acid strength of the 2-pyridone. The greater part of the ring-size effect on the tautomeric equilibrium is attributable to a Mills–Nixon–Brown type of ring strain, which is present in the five-membered ring in (II) but absent from the six-membered one in (IV); this strain is relieved by conversion into the pyridol (I), and by ionization; in part the ring-size effect is due to electron-withdrawal by the (strained) five-membered ring. In cation formation by the 2-pyridone (II) this electron-withdrawal and relief of ring strain oppose and almost cancel one another. 2-Hydroxy-6-methoxypyridine is intermediate between [(I). (II)] and [(III). (IV)] in both tautomeric equilibrium constants and ionization constants, but when allowance is made for the effect that a 4- and 5-alkyl group is expected to have in the first-named compound it is found that the properties of the pyrano-compound are quite similar to those of the ‘open-chain’ counterpart, whereas those of the furocompound are normally different. In the solid state all three above compounds exist in the pyridone form. Differences in zwitterionic character between the furopyridones and the pyranopyridones are shown not to be significant.In an Appendix attention is drawn to the relatively large errors in KT values derived by some common pK–KT relations.

Pyridone–pyridol tautomerism in 2-hydroxypyridines with [5,6]-annelated rings and carbon atoms at positions [5] and [6] : 1,3-dihydro-5-hydroxyfuro[3,4-b]pyridine, 1,3-dihydro-5-hydroxythieno[3,4-b]pyridine, and 1,3-dihydro-5-hydroxythieno[3,4-b]pyridine S,S-dioxide

U.v. spectra, in a range of solvents, i.r. spectra, and ionization constants in water have been determined for the title compounds (I) to (VI), their O- and N-methylated derivatives (VII) to (XII), counterparts that correspond to O- and S-ring fission products (XIII) to (XVI), and their methylated derivatives (XVII) to (XIX). All the the title compounds exist to an appreciable extent in the pyridol form in solution in dioxan. By a comparison of the cyclic sulphide with, on the one hand the cyclic sulphone, and on the other the cyclic ether, the effects of electron withdrawal and of ring strain have been assessed almost independently of one another. Replacement of the sulphide ring by the (smaller) ether ring (a) increases the ratio [pyridol]/[pyridone](KT) in dioxan by a factor of 2·7, (b) lowers the base strength of the 2-methoxypyridine, (c) lowers the base strength of the 2-pyridone, but by a much smaller amount, (d) raises the acid strength of the 2-pyridone. Replacement of the sulphide by the sulphone ring (a) produces a 2·8-fold increase in KT in dioxan, and (b), (c), and (d) reduces the base strengths and raises the acid strength, all by much greater amounts than in the above comparison. Analysis shows that no more than a third of the difference in KT between the cyclic ether and the cyclic sulphide is attributable to greater electron withdrawal (inherent plus ring-strain-induced) by the oxygen ring; about two thirds of it is due to a Mills–Nixon–Brown type of ring strain in the pyridone (II), which is relieved by conversion into the pyridol (I) or by ionization. The effects of ‘ring closure’ of the di-(methyl ether) to the cyclic ether, e.g. of [(XIII), (XIV)] to the [(I), (II)], show clear evidence of ring strain in the latter, whereas the effects of ‘ring closure’ of the dimethylthio-compounds to the cyclic sulphides indicate only a small amount of ring strain in the last-named. All the 2-hydroxypyridines listed are in the pyridone form in the solid state.

Fungal deterioration of second-growth Douglas-fir logs in coastal British Columbia

Fungal deterioration of second-growth Douglas-fir logs, felled each month from August 1961 to May 1962, was studied 2, 4, and 6 years after felling. Decay increased from 10% of log volumes after 2 years to 47% after 6 years. The rate of decay, particularly for the brown cubical type, was greater for autumn- and winter-felled logs than for those felled in the spring and late summer, and closely paralleled the seasonal pattern of ambrosia beetle attack.Decay rates increased with decreasing log size, increasing percentage of sapwood, and increasing height of log above ground. For the same diameter of log, base logs decayed less rapidly than second logs, possibly because of their lower proportion of sapwood in relation to heartwood.Decay expressed as a percentage of total log volume (Y) may be estimated (R2 = 0.71) with the following equation: Y = 13.2 + 10.7X1 − 3.2X2, where X1 = years elapsed and X2 = d.i.b. (diameter inside bark) top of log.Of 30 wood-decay fungi isolated, Naematoloma sp. (N. capnoides or N. fasciculare), which causes a white rot, was associated with the most decay. Fomes pinicola was mainly responsible for brown cubical sap rot, while Poria monticola and P. carbonica caused a brown cubical heart rot at the ends of logs.The significance of variations in deterioration rate and fungal associates is discussed in relation to log durability and salvability.

Primary subcultures ofHistoplasma capsulatum

The colonial and micromorphology of 36 primary subcultures of H. capsulatum from various sources have been studied in depth. Most strains separate into 2 main types on the basis of colony appearance. The A or albino type with white aerial mycelium and smooth macroconidia and the B or brown type consisting almost solely of masses of tuberculate macroeonidia. The implications of this in identification and epidemiology are discussed. Several new or improved cytological observations are reported including racket hyphae, nuclei and nucleoli, gelatinous wall sculptures and perforate septa. Although much is being written (Ajello, 1967; Campbell, 1967; Nielsen, 1967) about the medical, serological, diagnostic and epidemiologic aspects of histoplasmosis and its etiological agent, Histoplasma capsulatum, little has been done systematically to characterize the morphology and cytology of the many strains which different investigators use. This often makes comparisons of results meaningless. It was therefore decided to study in depth as many primary isolates from as many sites and geographic areas as were available to me in a year period. Observations recorded here relate only to the macromorphology and cytology of the mycelial phase. Studies on the physiology, morphology and pathogenicity of the yeast phase are in progress and will be reported later. Only strains for which a complete history was available were used. They were received as isolated, in the plates or tubes of media planted usually with livers and spleens of mice inoculated with specimens from patients and nature, and only occasionally with specimens directly from the patient. As especially requested they were not subcultured before shipping. This seemed to be the only logical approach to the study of an organism as seemingly exasperating in its morphological and physiological variation as H. capsulatum if meaningful correlations were to be established among source, morphology, pathogenicity, antigenic properties and conversion ability.

The Browning Problem in Wines II. Ion Exchange Effects

The effects of Na⁺ exchange, H⁺ exchange, and H⁺ exchange followed by OH^- exchange on browning of four dry white wines were compared in the presence and in the absence of oxygen, Wines browned more when oxygenated than when stripped with N₂, and ion-exchanged wines browned less than the untreated controls. H⁺ exchange was more effective than Na⁺ exchange in inhibiting the browning of all wines. H⁺ exchange, followed by OH^- exchange practically eliminated browning, but wines so treated were water-white and retained little wine character. This pattern was similar for samples stored at ambient temperatures for 18 months as at 110°F for 24 days. Varietal effect remains an important factor in determining the extent of browning to be expected in white wine. Evidence is presented which indicates that two distinct types of browning may occur simultaneously in wine, oxidative and non-oxidative, and that the varieties differ in their capacities for each. This work indicates that Palomino wine browning is essentially oxidative, but that French Colombard wine is capable of considerable browning both in the absence of oxygen and in its presence. Even at 140°F the Palomino browned little without 0₂, but drastically when O₂ was introduced. Added brown wine did not affect browning rate or extent in any of the wines tested, and it is concluded that there is no autocatalytic effect.