Outer Crown Research Articles

CHANGES IN SOIL PROPERTIES AND NUTRIENT ACCUMULATION IN NEEM UNDER THE CANOPY OFACACIA TORTILIS

ABSTRACT Investigations were made on the growth of young neem (Azadirachta indica A. Juss) seedlings, planted among mature Acacia tortilis trees, and associated soil properties, to determine whether seedlings could be successfully introduced among old tree stands in the arid environment. Size measures of 52 mo-old neem seedlings planted along the mature and unlopped trees of Acacia tortilis (mean height 8.3 m, crown diameter 12.6 m and diameter at breast height 24.7 cm), indicated that A. tortilis significantly affected the growth of neem seedlings planted under the canopy. Maximum size reduction was observed in the plants found under the inner crown (IC) compared to the plants in the outer crown (OC) and outside crown (OS) zone. Soil parameters (0 to 75 cm depth) of pH, electrical conductivity, and P, Ca and Mg concentrations, were higher in the soil of the OC (6 to 9 m) zone of A. tortilis compared to the IC zone (1 to 4 m) and OS zone (15 to 24 m). The concentration of K, NH4-N and NO3-N were highest u...

Foliar plasticity of hybrid spruce in relation to crown position and stand age

This study examined the foliar response of putative hybrid Engelmann × white × Sitka spruce (Picea engelmannii Parry × Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carr) needles in relation to crown position and across three stages of development (15, 55, and 145 years). We focused on the morphological and anatomical response, and used physiological measures (photosynthesis and stomatal conductance) to emphasize the important relationship between structure and function. We found that needles from the upper outer crown position were adaptated to reduce stress from evapotranspiration. Trees from the 15- and 55-year-old stands generally responded the most, and trees from the 145-year-old stand responded the least. As they mature, these spruce trees may have reduced ability to adapt to their environment. Some of our results contradict what the literature considers "typical" for sun-shade dimorphism in temperate forests. For example, in all stands, sun needles were broader than shade needles and, in t...

Effects of solar ultraviolet radiation on the potential efficiency of photosystem II in leaves of tropical plants

The effects of solar ultraviolet (UV)-B and UV-A radiation on the potential efficiency of photosystem II (PSII) in leaves of tropical plants were investigated in Panama (9 degrees N). Shade-grown tree seedlings or detached sun leaves from the outer crown of mature trees were exposed for short periods (up to 75 min) to direct sunlight filtered through plastic or glass filters that absorbed either UV-B or UV-A+B radiation, or transmitted the complete solar spectrum. Persistent changes in potential PSII efficiency were monitored by means of the dark-adapted ratio of variable to maximum chlorophyll a fluorescence. In leaves of shade-grown tree seedlings, exposure to the complete solar spectrum resulted in a strong decrease in potential PSII efficiency, probably involving protein damage. A substantially smaller decline in the dark-adapted ratio of variable to maximum chlorophyll a fluorescence was observed when UV-B irradiation was excluded. The loss in PSII efficiency was further reduced by excluding both UV-B and UV-A light. The photoinactivation of PSII was reversible under shade conditions, but restoration of nearly full activity required at least 10 d. Repeated exposure to direct sunlight induced an increase in the pool size of xanthophyll cycle pigments and in the content of UV-absorbing vacuolar compounds. In sun leaves of mature trees, which contained high levels of UV-absorbing compounds, effects of UV-B on PSII efficiency were observed in several cases and varied with developmental age and acclimation state of the leaves. The results show that natural UV-B and UV-A radiation in the tropics may significantly contribute to photoinhibition of PSII during sun exposure in situ, particularly in shade leaves exposed to full sunlight.

Foliage biomass distribution of loblolly pine as affected by tree dominance, crown size, and stand characteristics

Horizontal and vertical distributions of foliage biomass of loblolly pine (Pinus taeda L.) were analyzed for 30 trees in a plantation that had developed 12 years after several site-preparation treatments in the Georgia Piedmont, U.S.A. Regression analyses indicated that foliage biomass of individual branches increased with branch diameter and with branch relative height. Weibull models were used to characterize foliage biomass distributions and analyses revealed that branch foliage biomass distribution varied with branch-level, tree-level, and stand-level variables. Results indicate that the proportion of foliage biomass occurring within the inner crown increased with branch diameter and relative height. For trees of greater dominance, branch foliage biomass was more evenly distributed across the branch length. With increasing crown ratio of a tree, branch foliage biomass shifted from the inner to the outer crown. For trees of greater dominance, the vertical distribution of crown foliage biomass was more even, whereas less dominant trees shifted their foliage to the top of the crown. For trees of similar dominance, crown foliage tended to shift upward as stand leaf area index increased.

Plumage Redness and Pigment Symmetry in the House Finch

The redness of carotenoid pigmentation has been shown to be an indicator of individual condition. I tested whether the asymmetry of carotenoid pigmentation of male House Finches Carpodacus mexicanus, an indicator of developmental stability, decreases with plumage redness. Consistent with predictions, I found a significant relationship between the symmetry of carotenoid-based crown pigmentation and the redness of body plumage redder plumage was more symmetrical. There was no significant relationship between the symmetry of the outer rectrices and either crown symmetry or plumage redness. The energetic cost of having asymmetrical carotenoid pigmentation is no greater for males with elaborate ornamentation (red plumage) than for males with less elaborate ornamentation (orange or yellow plumage). These observations are consistent with the idea that the magnitude of fluctuating asymmetry of an ornamental trait reflects the phenotypic or genotypic condition of the individual.

A new telescopic crown system using a soldered horizontal pin for removable partial dentures

Clinical and laboratory procedures used in a new telescopic system for removable partial dentures are discussed. This system uses 2-degree tapered inner and outer crowns with a horizontal pin soldered into the outer crown. The pin is easily adjusted to monitor the level of retention for the telescopic crown after long-term use of dentures.

コーヌスクローネの外冠に関する研究 脚部荷重時の外冠のひずみと前装陶材破折

Recently, the metal fused porcelain work has been utilized to outer crown for conical telescopic dentures. However, it has the problem of porcelain fracture, caused by the deformation of the outer crown for lower premolar which is worked as a retainer of the free-end saddle denture. Three kinds of skeleton, 15×6×1.2mm in dimension (Standard), reinforced with beam (Beam), and increased thickness to double (Double), were cast with an outer crown. Two kinds of dental casting alloy, Au-Pt alloy and Co-Cr alloy containing Ti, were used. Conical angle was 6°, and retentive force was adjusted to 750±50g on the metal model. The deformation of outer crown were measured under loading at the free-end skeleton. Measurement was carried out at mesial, buccal (lingual), and distal parts of outer crowns, and then the fracture of metal fused porcelain's outer crowns was investigated.Deformation of all test pieces increased at every additional stress. This tendency was more drastic in Au-Pt alloy than that of Co-Cr alloy containing Ti, due to different physical properties. Deformation of the Beam and the Double was more remarkably decreased than that of the Standard. The Beam exhibited the least fracture of metal fused porcelain's outer crown when compard with the other two types, due to the stress relieving function of the reinforced beams.

コーヌス冠の維持力に関する基礎的研究 第１報 内冠の形態が維持力に及ぼす影響

In using the conic telescope crown for anterior teeth, it is necessary for the inner crown to have a larger taper and chamfered margin on the labial surface in order to keep sufficient space for facing material. Although there are a lot of reports on the relationship between the retention of the outer crown and the taper of the inner crown, the effect of the chamfer depth on the retention has been unknown. In this study, the retention of the outer crown was examined in relation to the chamfer depth or knife-edge diameter of the inner crown.The results were as follows:1. The retention of the outer crown was significantly larger with the chamfer type inner crown than with the knife-edge type.2. The retention increased with increase in the chamfer depth.

コーヌス・テレスコープ義歯撤去用具（コーヌス・リムーバー）の試作

The conical telescopic system (Konuskronen) developed by Körber, as ridged support retainers for removable partial dentures, has rapidly increased popularity in Japanese dentistry because of its many clinical advantages.In spite of these advantages, this system still poses some problem in its clinical application. One of them is the necessity of highly skilled technique in adjusting the outer crown to the inner one to control the retentive force. Patients often complain that they can not remove the denture by themselves. On the contrary, some dentures are easily drifted in the oral cavity. Every prostheses should stay in place tightly during function, and should be able to be removed easily in need. If the patient has an effective means to remove the prosthesis, a very rigidly supported denture can be provided.For this purpose, a specific denture remover has been developed introducing the impact force mechanism which is very effective to separate these telescopic systems. As the remover is designed very compact, it is easy to carry with the patient.From the fundamental experiment and clinical trials, this new denture remover has been found to be a very useful apparatus.

チタン含有コバルトクロム合金のコーヌス・クローネ内外冠への応用

The chrome cobalt alloys containing titanium (Dentitan) has excellent porcelain-to-metal bond strength. Therefore, it is used as outer telescope crown alloys of cone telescope denture in actual clinic. The purpose of this study is to investigate the fitness and the change of metal before or after porcelain firing of chrome-cobalt alloys containing titanium. The results of this investigation indicate that (1) chrome-cobalt alloys containing titanium can be used as metal for inner crown because it showed the same degree of fitness compared with precious metal, and (2) the optimal water/powder ratio of the outer telescope crown was 28 ml; 2 ml, or 27 ml; 3 ml, and (3) although the full porcelain veneer-coverage was greater vertical distortion than the partial-veneer-coverage, either metal can be applied to outer crown by adjusting of the retention.

Densitometry, Image Analysis, and Interpretation of Aerial Color Infrared Photographs of Citrus

Abstract Spectral densitometry measurements of aerial color infrared (ACIR) photographs of citrus trees made from outer crown and tree center correlated well with visual grading of the photographs. Measurements made from 400 to 700 nm identified two intensity peaks at 480 to 490 nm (I1) and another between 610 to 620 nm (I2). Spectral ratios (SR) (I1/I2) <0.69 were associated with healthy trees visual grade 0 (VG 0, 0% stress), ratios >0.86 were associated with moderate and severely stressed trees (VG 1, 2, 3; 25%, 50%, and 75% stress, respectively), and ratios >1.28 were found only in dead trees (VG 4, 100% stress). A formula whereby the absolute difference between wavelengths of the two peaks (DSR) was divided by the SR improved the accuracy of analysis of the densitometric measurements, making the separation of stressed trees more distinct. Image analysis of color infrared transparencies of groves indicated positive correlations between: 1) transmitted light brightness and dark class 1, 2) dark classes 1 and 2, and 3) gray levels 2 and 3. These results suggest that densitometric measurements were equal or better than visual grading and could be used in an automated system to count and separate stressed from healthy trees.

Observations on the Foraging Ecology and Social Behavior of the Bridled White-Eye

I studied the foraging ecology and social behavior of the Bridled White-eye (Zosterops conspicillatus) on Saipan and Tinian, Mariana Islands. On Saipan, birds foraged in flocks of 10-40, and dominance relationships existed within flocks. The white-eye appeared socially subordinate to the other insectivorous passerines. Bridled White-eyes foraged principally on the outer crown of trees and shrubs, where they perched on relatively slender branches to glean invertebrates from leaf surfaces. They foraged similarly in two habitats, but they used a wider range of perch sizes in limestone forest than in tangantangan (Leucaena leucocephala) thickets. Hence, absolute vegetation height was of little importance to this species. Bridled White-eyes were versatile in their foraging, which included every microenvironment from the ground to treetops. They used gleaning, probing, hovering, and sallying to feed on invertebrates, nectar, fruits, and seeds.

The displacement of abutments, changing angles, heights and shapes of Konus-telescope inner crowns

It is clinically well known that the secondary splinting is as effective as the primary splinting, using the konus-telescope crown. The purpose of this study is to investigate and to evaluate the displacement of the konus-telescope outer crown under the lateral loads of them, changing angles, heights and shapes of konus-telescope inner crowns.The results were as follows:1. The horizontal and vertical displacement of the outer crown were influenced by not so much the angle as the height of inner crown.2. As for inner crown shape, the displacement of c.s.c. type outer crown was larger than that of konus-type.

Clinical study of two luting cements used on student-treated patients: final report.

Abstract A long-term test was started in 1979 to evaluate the clinical serviceability of a zinc-phosphate and a polycarboxylate cement. After 54 months observation both cements had served equally well. One crown had come loose in either group, but that was due to loosening of separately cemented posts and not to loosening of the outer crown. The results of the PAI scores indicated a possible difference in pulpal compatibility between the 2 cements, polycarboxylate cement giving the lowest scores.

Effectiveness of Foliar Systemic Insecticides for Controlling Scales on Forest and Ornamental Hemlock, 1976, 1977

Abstract A row of 40 ornamental Eastern hemlock, Tsugacanadensis (12 m tall), and an adjacent hemlock forest (trees to 18 m tall), heavily infested with Fioriniaexterna, located in Westport, CT, were sprayed in mid-June during peak activity of crawlers to evaluate the effectiveness of two foliar systemic insecticides. Treatments were applied to the point of runoff using either a John Bean Hydraulic Sprayer (Hereafter HS) operating at 200 psi or a mistsprayer attachment for a leaf-blower (U.S. Pat. No. 3,776,459, hereafter MS). A conscientious effort was made to cover the foliage completely and to direct the spray to the lower surface of the foliage, the feeding sites of F. externa. For ornamentals a minimum of 10 trees was used for each treatment; for forest trees all hemlocks within the 10-acre forest were sprayed. For each of five randomly selected ornamentals in each treatment four branches were sampled from the inner and outer crown at two heights 1 wk prior to and 3 and 7 wk following treatment. The numbers of living and dead scales occurring on 100 needles of current year growth were determined for each branch. Five randomly selected, mature forest hemlocks were sampled 3 wk following treatment. Four branches were taken from each of three vertical levels of the crown and scale mortality was determined as previously discussed. Data were subjected to an analysis of variance.

The Relation of the Water Content of Loquat Trees to Various Weather in Early Spring

Since it is said that evergreen fruit trees, the water absorption of which is very much reduced at low temperature, often suffer more from the dryness of winter wind than from its coldness, the water content of the Tanaka loquat tree was investigated in the cold season. The water content of the leaves was measured with the impedance bridge which had special measuring terminal plates, and that of the trunk was measured with a hundredth millimeter dial guage and indicated in terms of radius fluctuation. The results of the investigation was summarized below.1. The daily water content of the leaves reached the minimum at 4 p.m. and the maximum at 2 a.m., the range of fluctuation being 2.5 percent. That of the trunk showed much the same change.2. In the daytime, the water content of the leaves of the outer crown was larger than that of the inner crown and reached the minimum at noon. The water content of the leaves of the inner crown reached the minimum 6 hours later, and so did that of the trunk 2 hours later than that of the leaves of the outer crown. The similar type of fluctuation was observed in the water content of those three.3. The water content of the leaves was largest on rainy day and smallest on windy day, the difference being about 4 percent at the largest. The water content of the leaves on fine day was about 1 percent larger than on windy day. It may be said that the loquat leaves have so numerous hairs that they can keep transpiration down a little. It may be for this reason that the water in the leaves did not show great change in amount. It is suggested, therefore, that the loquat trees do not suffer very much from dry winter wind in warm regions.