Effects of mist acidity and ambient ozone removal on montane red spruce.

Recent forest studies have established that high-elevation (> 900 m) populations of red spruce (Picea rubens Sarg.) in the northeastern USA are declining. Because it has been suggested that changes in air quality are responsible for the decline, we examined the effects of acidic mists and ozone on several biochemical and growth parameters in mature montane red spruce. We used branch-sized environmental chambers to introduce mists of controlled composition and exclude ambient clouds and ozone from individual branches within a tree. Mists consisting of distilled water increased the end-of-season pigment concentration and shoot length of enclosed branches relative to ambient or artificial mists. Needle and twig weights and starch concentrations were not significantly altered by the acidic mist treatments. Removal of ambient ozone had no apparent effect on the variables measured.

Rapid reporting of cancer incidence in a population-based study of breast cancer: one constructive use of a central cancer registry.

To support a study of genetic risk factors for breast cancer, the North Carolina Central Cancer Registry has implemented a rapid reporting procedure for hospitals in the study area. This system permits the identification of newly diagnosed breast cancer cases within a very short time period (less than one month). The procedures are straightforward, cost-effective, and greatly benefit the objectives of tissue collection and interviews with the cases. This article describes the rapid reporting procedures and their potential impact for population-based research. For the objective of making generalizable risk statements, the necessity of population-based research is stressed; participation with central cancer registries is endorsed for this and other molecular epidemiologic applications.

Effect of elevated temperatures on carbon dioxide exchange in Picea rubens.

We examined some of the physiological reasons that may underlie past and expected future migrations of red spruce (Picea rubens Sarg.) by evaluating the effects of high temperatures on photosynthesis and respiration of trees growing on Whiteface Mountain, NY. At temperatures of 35-40 degrees C, the trees exhibited a zero or negative carbon balance. Higher temperatures resulted in cellular disorganization and death. Temperatures around 30 degrees C resulted in reduced CO(2) uptake, a condition that could decrease future reproductive output and competitive stature. We conclude that thermal intolerance explains, at least in part, the absence of red spruce at low elevations and latitudes where temperatures of >/= 30 degrees C occur. We suggest that the thermosensitivity of this species is important with respect to global climate trends and migration patterns.

Midwinter needle temperature and winter injury of montane red spruce.

To assess the role of solar warming and associated temperature fluctuations in the winter injury of sun-exposed red spruce foliage, we used fine wire thermocouples to monitor midwinter needle temperature in the upper canopy of mature red spruce trees over two winters. In 1989-1990, 15-min mean temperatures were recorded for six needles in a single tree. In 1990-1991, 10-min mean temperatures of six needles in one tree, and 1-min mean temperatures of seven needles in a second tree were recorded during rapid temperature changes. Warming was more frequent and greatest on terminal shoots of branches with a south to southwest aspect. The maximum rise above ambient air temperature exceeded 20 degrees C, and the maximum one minute decrease in temperature was 9 degrees C, with maximum rates of 0.8 and 0.6 degrees C min(-1) sustained over 10- and 15-min intervals, respectively. These data demonstrate that red spruce is subject to rapid temperature fluctuations similar to those known to produce visible injury in American aborvitae, a much hardier species. We concluded that solar warming to temperatures above the freezing point was unlikely to result in dehardening and subsequent freezing injury, because warming was infrequent, of short duration, and did not always raise needle temperature above the freezing point. Parts of branches and some individual shoots were frequently covered by snow or rime that may have prevented injury by reducing the frequency or intensity of needle temperature fluctuations. Radiation load on exposed shoots may have been increased by reflection of short wave radiation from snow and rime deposits on surrounding surfaces, which would exacerbate temperature fluctuations.

Monoclonal antibody-based enzyme-linked immunoassays for the measurement of palytoxin in biological samples.

Mouse monoclonal and rabbit polyclonal antibodies were produced against conjugates of keyhole limpet hemocyanin and chemically defined palytoxin haptens. Palytoxin haptens were produced by derivatization of the primary amino group with sulfosuccinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate or succinimidyl 3-(2-pyridyldithio)propionate. Selected antibodies were used to develop five palytoxin-specific enzyme-linked immunoassay formats for the quantitation of palytoxin in biological matrices, including crude extracts of Palythoa tuberculosa. The formats developed include an indirect competitive inhibition enzyme-linked immunoassay, two types of direct competitive inhibition enzyme-linked immunoassays, and both indirect and direct sandwich enzyme-linked immunosorbent assays. The sandwich enzyme-linked immunosorbent assays are capable of detecting as little as 10 pg palytoxin per test, but may be subject to matrix interference. The direct competitive inhibition enzyme-linked immunoassays detect as little as 30 pg palytoxin per test with a total assay time of only 4 hr. The enzyme-linked immunoassays do not cross-react with the other marine toxins tested, but do cross-react with certain non-toxic, treated preparations of palytoxin. The enzyme-linked immunoassays were used to quantitate palytoxin in P. tuberculosa extracts and to monitor toxin isolation. These enzyme-linked immunoassay systems can substitute for the mouse bioassay of palytoxin, providing a rapid, sensitive, and accurate means of toxin detection.

A monoclonal antibody-based immunoassay for detecting tetrodotoxin in biological samples.

Spleen cells from mice hyperimmunized with a keyhole limpet hemocyanin-tetrodotoxin-formaldehyde conjugate were fused with murine P3X63Ag8.653 myeloma cells. A single hybridoma clone was identified that secretes an IgG1,k monoclonal antibody (MAb), designated T20G10, against tetrodotoxin (TTX), with an estimated affinity of 1.2 x 10(8) L/M. Competitive inhibition enzyme immunoassays (CIEIAs) for detecting TTX were developed using this MAb. A direct CIEIA using alkaline phosphatase-labeled MAb detected TTX with sensitivities at IC50 and IC20 of 6-7 ng/ml and 2-3 ng/ml, respectively. The accuracy of the direct CIEIA was comparable with the high-performance liquid chromatography (HPLC) and the mouse bioassay systems, but the direct CIEIA exhibited greater sensitivity. The direct CIEIA was also more cost effective, as it required less sample preparation, a shorter assay time, and reduced investment in equipment than either of the other assay systems.

In situ experimental freezing produces symptoms of winter injury in red spruce foliage.

Two mechanisms have been proposed to explain winter injury to needles of red spruce (Picea rubens Sarg.): (1) desiccation, which is characterized by net loss of foliar water from the needle to the environment, with cell injury resulting from dehydration; and (2) freezing, which is characterized by direct injury to cells resulting from intracellular or extracellular ice formation during exposure to low temperature. To compare the separate and combined effects of freezing and desiccation, branches of a mature red spruce at 1160 m were (a) experimentally frozen in situ to -50 degrees C; (b) cut and tied in their original orientation and allowed to desiccate passively; or (c) both frozen in situ and cut and tied in their original orientation. Needle water content, electrolyte leakage (an index of cell injury), and needle color were monitored for 60 days after treatment. Freezing resulted in immediate increases in electrolyte leakage, rapid water loss, and reddening necrosis of needles similar to that of naturally injured needles. Cutting resulted in more gradual water loss, no significant changes in electrolyte loss until severe desiccation had occurred, and a change in the color of the needles to a dull green. Because freezing produced reddening necrosis, a key symptom of winter injury, whereas desiccation did not, we conclude that freezing is probably the primary cause of winter injury in red spruce, and that desiccation is a secondary effect.

Parental perceptions of behaviors in preschool children.

A comparison of parental descriptions revealed that mothers of developmentally delayed children listed fewer deviant behaviors than did mothers of behaviorally disturbed children, but significantly more than mothers of non-clinic children. The Washington Symptom Checklist, used in this research, proved a useful clinical tool.