Wooded Plots Research Articles

Specific heat of amorphous Ce xRu 100−x alloys

We have measured the specific heat on sputtered amorphous (a-) Ce x Ru 100− x alloys for 15⩽ x⩽80 from 5 to 300 K. The C p/T nicely follows a function of γ+ BT 2 above 8 K in each Ce concentration. In the Ce-rich side ( x⩾67), the electronic specific coefficient γ shows a very large value ( γ=180 mJ/mol K 2 at x=80), suggesting formation of the heavy fermion (dense Kondo) state at low temperature. However, the γ decreases rapidly with decreasing the Ce concentration. In the Ru-rich side ( x<39), the γ becomes less than 10 mJ/mol K 2 and the superconductivity occurs. This γ-value is almost the same as for a-Ce 20− y La y Ru 80 in each La concentration, where the superconductivity occurs at the same superconducting temperature T c. We made the Kadowaki–Woods plot from the coefficient A of the T 2 term in resistivity and γ in the Ce-rich side. The value of A/ γ 2 for present alloys shows about 3.5×10 −6 μ Ω cm(mol K 2/mJ) 2.

Y substitution effect to the dense Kondo behavior of amorphous Ce–Mn alloys

We have measured the specific heat and the resistivity on sputtered amorphous (a-) Ce 80− x Y x Mn 20 alloys ( x = 10 , 20, 30, 50 and 70), substituted by Y for dense Kondo a-Ce–Mn alloy. The electronic specific heat coefficient γ shows the large value ( γ = 133 mJ / mol K 2 ) at x = 10 and decreases with increase of the Y concentration linearly. The resistivity at low temperature shows the T 2 dependence and the large coefficient A at x = 10 , 20. However, the T 2 dependence was not observed for x⩾30. Thus, a-Ce 80− x Y x Mn 20 for x⩽20 is also the dense Kondo system. We made Kadowaki–Woods plot from A and γ of a-Ce–Mn and a-Ce-Y-Mn alloys. The ratio of A/ γ 2 for a-Ce-Y-Mn is much larger than the value of a-Ce–Mn alloy.

Superconductivity and normal state properties of non-centrosymmetric CePt3Si: a status report

Ternary CePt3Si crystallizes in the tetragonal P4mm structure which lacks a center of inversion. Antiferromagnetic order sets in at TN≈2.2 K followed by superconductivity (SC) below Tc≈0.75 K. Large values of Hc2′≈−8.5 T/K and Hc2(0)≈5 T were derived, referring to Cooper pairs formed out of heavy quasiparticles. The mass enhancement originates from Kondo interactions with a characteristic temperature TK≈8 K. CePt3Si follows the general features of correlated electron systems and can be arranged within the Kadowaki–Woods plot next to the unconventional SC UPt3. NMR and μSR results show that both magnetic order and SC coexist on a microscopic scale without having spatial segregation of both phenomena. The absence of an inversion symmetry gives rise to a lifting of the degeneracy of electronic bands by spin-orbit coupling. As a consequence, the SC order parameter may have uncommon features as indicated from a very unique NMR relaxation rate 1/T1 and a linear temperature dependence of the penetration depth λ.

Non-generality of the Kadowaki–Woods Ratio in Correlated Oxides

An explicit expression for the Kadowaki–Woods ratio in correlated metals is derived by invoking saturation of the (high-frequency) Fermi-liquid scattering rate at the Mott–Ioffe–Regel limit. Significant deviations observed in a number of oxides are quantitatively explained due to variations in carrier density, dimensionality, unit cell volume and the number of individual sheets in the Brillouin zone. A generic re-scaling of the original Kadowaki–Woods plot is also presented.

Kadowaki–Woods plot of exchange-enhanced Pauli paramagnetic Laves phase quasi-binary compoundsLu(Co1−xMx)2

The electrical resistivity and low-temperature specific heat ofexchange-enhanced Pauli paramagnetic Laves phase quasi-binary compoundsLu(Co1−xMx)2 (M = Al, Ga and Si) have been investigated in order to discuss the spinfluctuation characteristics and the Kadowaki–Woods plot. In these threekinds of quasi-binary system, both the electrical resistivity coefficientA and the specificheat coefficient γtot at low temperatures decrease at first and then significantly increase with increasingx. The concentration dependence of magnetic susceptibility at 0 K,χ(0), is also similarto that of A and γtot. The Wilson ratio becomes very large because of the enhancement of magnetic susceptibility. TheKadowaki–Woods plot is fitted to the same universal line of heavy-fermion compounds, A15-typeNb3Sn and V3Si compounds because of significant spin fluctuations in the present quasi-binary compoundsystems.

Effectiveness of gypsy moth mating disruption from aerial applications of plastic laminate flakes with and without a sticking agent

Summary1 The plastic laminate flake formulation, Disparlure II, is currently the only gypsy moth mating disruption product available for aerial application. The elimination of a sticking agent from the formulation would reduce costs, simplify application, and make it possible to apply the product without specialized equipment.2 A test was conducted in wooded plots in Virginia during 1997 and 1998 to determine whether a sticking agent is necessary. Treatment effectiveness was assessed from the rates of male moth capture in pheromone‐baited traps and mating success of both laboratory‐reared and wild females.3 Male moth capture was reduced 75.6 and 92.9% in plots treated with flakes without and with a sticking agent, respectively. The percentage of mated females that produced egg masses with more than 5% fertile eggs was reduced by 86.3 and 99.5% in plots treated with flakes without and with a sticking agent, respectively.4 Moth capture and mating success of laboratory‐reared females did not differ significantly between plots treated with flakes with and without a sticking agent. However, the consistently greater reduction in mating success in both years provides strong evidence that mating disruption is less effective when flakes are applied without a sticking agent. The proportion of wild egg masses collected in 1998 with more than 5% fertile eggs was significantly higher under the no‐sticking agent treatment.5 In special situations where the use of a sticking agent may be problematic, such as in residential areas, the data indicate that a high level of mating disruption is likely to occur even without the use of a sticking agent.

Forest birds in forest fragments: are fragmentation effects independent of season?

The aim of this study was to examine whether effects of habitat fragmentation on forest birds persist across seasons. W e noted the presence or absence of 18 bird species in 16 wood plots on 12 occasions (six in winter and six in spring). Woodland area ranged between 0.5 and 200 ha. All patches consisted of mature deciduous woodland. Degree of fragmentation for each woodland patch was indexed by the factor scores on the first two axes resulting fvom a principal component analysis, performed on a number of area and isolation variables. Both in winter and in spring, species richness correlated negatively with degree of fragmentation. The number of species observed was higher in winter than in spring for most patches, but the difference was unrelated to the degree of fragmentation. On a species level, little evidence was found for an effect of interaction between season and degree of fragmentation on the frequency of occurrence. The effects of fragmentation seem to depend on season in the Great Spotted Woodpecker Dendrocopos major and the Treecreeper Certhia brachydactyla, but not in the other species considered. Fragmentation has a negative effect on the frequency of occurrence of the Nuthatch Sitta europaea, Goldcrest Regulus regulus, Treecreeper, Great Spotted Woodpecker and the Starling Sturnus vulgaris, and a positive effect for the Chaffinch Fringilla coelebs and, possibly, the Lesser Spotted Woodpecker Dendrocopos minor. Seasonal changes in frequency of occurrence were noted in four of the species considered.

Low temperature properties ofY 3 Ni

The electrical resistivity (ρ) in the temperature range from 20mK up to 1000K and the low temperature specific heat ofY3Ni have been studied. Neithera magnetic order nor a superconducting transition have been found. An enhanced spin fluctuation contributution to the temperature dependence of the resistivity is concluded from the low temperatureT2 behaviour and the pronounced negative curvature at elevated temperatures in ρ vs. T. However, the large A/γ2Y3Ni (5.6×10−5 is beyond the spin fluctuation regime in the Kadowaki—Woods plot) does not enable us to classify this compound as a typical spin fluctuation system.

Structural Stability Status as Affected by Long-Term Continuous Maize and Bluegrass Sod Treatments

ABSTRACT The effect of long-term continuous fertilized and unfertilized corn and bluegrass crops on the structural stability status of a clay loam soil was studied. Water-stable aggregates were measured with and without an ethanol pretreatment and before and after the extraction of unbound lipids and after hydrophobic lipids were extracted with chloroform. Compared to corn, sod and wooded plots had three to four times more stable aggregates associated with the dispersive and dissolution action of water and two to three times more stable aggregates associated with slaking forces. The data also indicate that the stability of aggregates associated with bound organic materials was affected by cropping history rather than fertilization. Although the unbound lipids varied significantly between treatments, the unbound lipids were responsible for a similar amount of stable aggregates when compared against dispersive and dissolution action of water and slaking forces. The results indicate that the mono- and dieste...

SEDIMENT, NITRATE, AND AMMONIUM IN SURFACE RUNOFF FROM TWO TAHOE BASIN SOIL TYPES 1

ABSTRACT: Few studies have addressed the natural pollution potential of pristine subalpine forested watersheds on a site‐specific basis. Consequently, specific source and amounts of nutrient discharge to tributaries of the Tahoe Basin are difficult to identify. The sediment content and nitrate and ammonium levels in surface runoff from two soil types (Meeks and Umpa), four plot conditions (wooded natural and disturbed, open natural and disturbed), and three slopes (gentle, moderate, and steep) were studied using rainfall simulation that applied a 9 cm h1, 1‐h event. A significant (P ≤ 0.005) two‐way interaction between soil type and plot condition affected runoff nitrate concentration. Runoff from natural or disturbed open plots contained significantly (P = 0.05) greater nitrate than wooded plots. Peak concentrations of nitrate commonly occurred during early runoff, suggesting that peak nitrate discharge to Lake Tahoe tributaries can be expected during early runoff from snowmelt and summer precipitation events. The highest nitrate runoff concentration and 1‐h cumulative loading from the 0.46 m2 plots were 6.7 mg L‐1 (Umpa, open natural, 15–30 percent slope), and 0.7 mg (Umpa, open natural, ≥ 30 percent slope), respectively. Ammonium in surface runoff was generally below detection limits (≤ 0.05 μg L−1). No statistical relationship between runoff nitrate and sediment discharge was detected.

Sticky Barrier Bands Affect Density of Gypsy Moth (Lepidoptera: Lymantriidae) and Damage in Oak Canopies

Sticky barrier bands made of duct tape and Tanglefoot were applied to only oak (Quercus spp.) trees in four wooded plots (0.14-0.25ha) in 1990 and to all trees in five wooded plots (0.25 ha) in 1991. All plots with banded trees were paired with plots of equal size with no banded trees to test the effect of bands on population density of the gypsy moth, Lymantria dispar (L.), and damage to oak foliage. Late-instar population densities in the oak canopies of banded plots were 28% lower than those in unbanded plots. Defoliation, pupal numbers under burlap refugia, and the ratio of post-/pretreatment egg mass density were not significantly affected by banding. The number of egg masses deposited in the banded plots after the 1990 test was significantly higher than the number deposited in the unbanded plots. The inconsistent effect of barrier bands on defoliation indicates that these devices should not be relied upon to protect oak foliage from gypsy moths.

Use of synthetic peptides to map the antigenic determinants of glycoprotein D of herpes simplex virus

The predictive algorithm Surfaceplot (J.M.R. Parker, D. Guo, and R.S. Hodges, Biochemistry 25:5425-5432, 1986) was used to examine glycoprotein D of herpes simplex virus type 1 (HSV-1) for amino acid residues with a high probability of being exposed on the molecular surface. Based on these data, 11 different peptides corresponding to 10-residue segments in the primary sequence of glycoprotein D and one 20-residue segment were synthesized, conjugated to carrier proteins, and used to generate specific antisera in rabbits. Two synthetic peptides predicted not to be on the surface of glycoprotein D were included as negative controls. The polyclonal antisera against individual synthetic peptide conjugates were in turn evaluated for their ability to recognize both isolated glycoprotein D and intact HSV-1 virions in an enzyme-linked immunosorbent assay. Based on Surfaceplot predictions, eight linear antigenic sites on glycoprotein D were thereby defined from the 12 antipeptide antisera prepared. Four of these sites contained epitopes to which complement-independent neutralizing antibodies could be generated. The latter sites corresponded to sequences 12 to 21, 267 to 276, 288 to 297, and 314 to 323 of the mature protein. An additional peptide sequence, 2 to 21, was found to generate antisera which had potent virus-neutralizing capacity in the presence of complement. Identification of a neutralizing epitope in the sequence 314 to 323 makes it likely that the membrane-spanning region of glycoprotein D is within the subsequent sequence, 323 to 339. Antipeptide antisera prepared in this study from 12 synthetic peptides contained 13 surface sites predicted by Surfaceplot, of which 7 were not predicted by the parameters of Hopp and Woods (Proc. Natl. Acad. Sci. USA 78:3824-3828, 1981). Of these seven sites not predicted by the Hopp and Woods plot, all generated antipeptide antibodies that bound to HSV-1 virions and three of these seven sites generated neutralizing antibodies. In total, 8 of 12 synthetic peptides containing surface regions produced antipeptide antibodies that bound to HSV-1 virions and 5 of these generated neutralizing antibodies. These results suggest the advantages of Surfaceplot in mapping antigenic determinants in proteins.

Agricultural impact on the horizontal distribution of oribatid mites (acari: oribatida)

Abstract The long-term effect of intensive agricultural practices on oribatid mite distribution and diversity was examined. Soil cores were taken in agricultural areas which were subdivided into three adjacent strip plots: cultivated, grassy, and woods. Diversity of collected oribatids was noted. Statistical interpretations revealed that oribatid heterogeneity, at the generic level, was significantly reduced in the total cultivated plots as compared to the total wood plot sections. The average number of soil mite genera encountered in the grassy plots (−x = 3.67) was more than that encountered in the cultivated plots (−x = 2.92) but less than the wood plots (−x = 5.58) and not significantly different from the cultivated plots. The possible use of oribatids as environmental “indicators” was noted.

How Do Great Tit (Parus Major) Pair Mates Cooperate in Brood Defence?

Using economic theory CHASE (1980) predicted that a member of a group should contribute to the group's common interest, i. e. cooperate, as a function of the other members' contributions. In a group of two, e.g., a pair of parents caring for offspring, there are three possible stable equilibria of genuine cooperation: 1) Solely the male invests; 2) Solely the female invests; 3) Male and female invest into their common interest. It was examined in which of these ways members of great tit (Parus major) pairs cooperate while defending their nestlings and themselves against predatory danger of two sorts (owl (Glaucidium perlatum) + mixed mobbing chorus; the latter only). Employing multiway contingency analysis and information theoretic analysis it was also examined whether pair mates coordinate their defence among themselves. The experiments comprised of 1st and 2nd broods over five seasons in Lower Saxon wood plots. The following results were found: 1. Pair mates cooperate by confronting the danger jointly in 77.2 % of all cases tested (n = 158 pairs). In pairs with only one mate cooperating it is more often the male (15.2%) than the female (3.2%) that contributes to defence. In only 4.4% of all pairs both pair mates display noncooperative behaviour. There is no difference among broods of a season and the stimuli employed. 2. During a defence episode, mates of 1st brood pairs repeatedly approach the owl in succession jointly and withdraw from it likewise rather than alternate direction among each other's successive moves. The spatio-temporal dynamics implied in this synergism cannot be due to pair-specific environmental commonalities (brood, nest environs, etc.) at the time of the test, as is possible for the gross cooperation mentioned (1.); rather pair mates appear to gear their risk-taking to one another. From 5 to 29% of the variance of all moves' directions is thus explained by an influence of the mate's move. Another significant influence lies in a bird's own moves in that, on average, homing in on the danger and retreating from it, tend to alternate. The diminution of synergism between broods in both mates may be due to their becoming more familiar with their nest environs, as indicated both by comparison within the 1st brood and by a sexual difference in the strength of synergism. 3. In moving synergistically (see 2.), the male exerts a stronger facilitatory influence on the female than vice versa. This sex-specific effect abates between broods. The facilitatory effect on the mate tends to disappear after 15 to 30 s, i. e. tends to affect but the mate's next move in time. 4. Coordination of defence is also borne out by both mates homing in on the predatory danger more closely once both are present, as measured by their within-trial average distance from danger. This suggests for the first time that, apart from the accepted determinants of altruism, that the degree of altruism exhibited by a group member feeds back positively on that of another. A short term self-protection hypothesis for this type of synergism is rejected. Like the synergism of moving jointly (2.), this type of synergism is due to mutual positive feedback among the pair mates. 5. Between 1st and 2nd broods, the female's within-trial average distance from danger tends to relax both in the presence and in the absence of the male whereas the male's does not. This sex difference may be due to the male's greater interest in the pair's home range. Pestering a raptor with perseverence at an average distance tends to move it on. By contrast, the 2nd brood male's riskier, yet shorter-term minimum distance in the female's presence has relaxed, thus supporting a female-investment explanation for this measure.

Ultralow-volume mists of chlorpyrifos from a tractor-mounted blower for area control of the lone star tick (Acari: Ixodidae).

A conventional tractor-mounted mist blower was modified for ultralow-volume (ULV) application of nonaqueous formulations of chlorpyrifos for area control of the lone star tick, Amblyomma americanum (L.), in wooded plots (0.20–0.36 hal and high-use recreational areas (0.98–5.10 ha) in Oklahoma during 1981 to 1983. The construction of the mist blower for ULV application is described. Mist deposits of a red fluorescent dye indicated that uniformity of coverage over 15-m swaths with the prototype ULV mist blower was equal to that obtained with another mist blower used for low-volume (LV) application of aqueous formulations. Field assays with a dose of 0.28 kg chlorpyrifos/ha showed that ULV mists (volumes of 0.39–1.17 liters/ha) were equal to LV mists (47 liters/hal in effectiveness against ticks. The overall levels of control of ticks with ULV mists were 85% (larvae), 94% (nymphs), 90% (adult males), and 86% (adult females) for posttreatment intervals of 1 to 6 weeks (nymphs and adults) and one day to 3 weeks (larvae). Relative densities of ticks were determined by a dry ice method (nymphs and adults) and a cloth drag method (larvae).

Aerial application of diazinon granules for area control of the lone star tick (Acari: Ixodidae).

Field assays of 14% diazinon granules against free-living lone star ticks, Amblyomma americanum (L.), in wooded plots in Oklahoma from 1981 to 1983 indicated that an aerial application method was equal in efficiency to concurrent ground applications of equivalent doses (0.9 to 1.2 kg [AI]/ha) of the same formulation of acaricide. Aerial (and ground) applications of granules were 18 and 33% less effective against nymphs and adults, respectively, when applied in mid-April versus mid-May. Furthermore, these applications provided higher levels of control of nymphs (81% in April and 97% in May) than of adults (57% in April and 85% in May). The mean level of control from both types of application of diazinon granules against early season larvae of the lone star tick was 93%.

Toponymie et société. Contribution à l'étude de l'espace communautaire en Basse-Provence

Toponymy and Society. A Contribution to the Study of Community and Space in Basse-Provence. The system of named places is not to be considered only as a symbolical transposition of land-use patterns ; it stands also as the «language» of agricultural, pastoral and wooded plots. The object of the research which was carried out in a rural community of Basse-Provence was to define general features of toponymie organization. It is the produce of a logical classification process which arranges land properties in categories and enables village people to mark the difference between places and others. This process reveals the objective criteria in the representation of territory as a reality and as a symbol. Thus the network of named places takes place as an indicator of Mediterranean peasant community organization.

Metallic minerals, thermal histories and parent bodies of some xenolithic, ordinary chondrite meteorites

We have studied metal grains in the hosts and lithic fragments of widely differing petrologic types in four xenolithic chondrftes, using reflected-light microscopy and electron-probe analysis. In Weston and Fayetteville, which both contain solar-flare tracks and solar-wind gases, kamacite, taenite and tetrataenite (ordered FeNi) and troilite show a variety of textures. On a Wood plot of central Ni content vs dimension, taenite analyses scatter as if metal grains cooled at rates of 10–1000 and 1–100 K/Myr respectively through 700 K, although metal in an H6 clast in Fayetteville plots coherently with a cooling rate of 50 K/Myr. We propose that metal grains cooled at these rates in chondritic clasts at different locations before host and clasts were compacted, and were not subsequently heated above 650 K. We predict a similar history for all gas-rich ordinary chondrites. By contrast, metallic minerals throughout Bhola and Mezö-Madaras show more uniform textures and plot coherently giving cooling rates in the range 750 to ~600 K of 0.1 and 1 K/Myr, respectively. We conclude that host and xenoliths in both chondrites were slowly cooled after compaction. Thus clasts in these chondrites experienced peak metamorphic temperatures and slow cooling through 700 K in different environments. According to the conventional onion-shell model for H, L or LL chondrite parent bodies, material of petrologic types 3–5 was arranged in successive shells around a type 6 core prior to catastrophic collisions which mixed all types intimately. But if peak metamorphic temperatures were reached during, not after accretion, as seems plausible, maximum metamorphism may have occurred in planetesimals <10 km in radius. Cooling through 700 K may then have occurred in larger bodies that accreted from these planetesimals. Iron meteorites, mesosiderites and some achondrites may also have experienced melting in planetesimals and slow cooling in larger bodies.

Area control of chigger mites with granules and concentrated sprays of chlorpyrifos.

Chlorpyrifos was applied as an undiluted concentrate (Dursban® 2E) and as 0.5 and 10% granules for area control of the so-called common chigger mite, Eutrombicula alfreddugesi (Oudemans), in 0.05-ha wooded plots. Estimated effective doses for 90% control through 4 wk were 1.1, 1.3, and 1.6 kg AI/ha for the 0.5% granules, 10%granules, and 22.4% spray, respectively.

Amblyomma americanum: area control with granules or concentrated sprays of diazinon, propoxur, and chlorpyrifos.

Natural infestations of lone star ticks in wooded plots at Camp Lejeune, NC, were treated with granules or concentrated sprays of diazinon, propoxur, and chlorpyrifos. Then the effects of the treatments were measured for 6 wk post-treatment. Probit analysis of the 6-wk dose-control data indicated that 90% effective doses ED90 for 10.25% chlorpyrifos sprays, 1% chlorpyrifos granules, 12.8% propoxur sprays, and 14% diazinon granules were 0.31, 0.54, 0.69, and 2.2 kg AI/ha, respectively.