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Copyright of International Forestry Review is the property of Commonwealth Forestry Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding harvesting impacts on non-industrial private forestlands is important, since they represent 75% of all commercial forestlands in the State of Pennsylvania, as well as a large percentage of most of the eastern United States. This study measured species composition, richness, and diversity of herb- and shrub-layer plant communities on a total of 40 non-industrial private forest stands in northeastern Pennsylvania. These northern hardwood and oak-hickory stands had been recently harvested at different intensities. Remaining basal areawas used as an indicator of harvest intensity. Species richness and diversity were not significantly related to basal area for summer or vernal herb understory plant communities for either forest type, although there was some evidence of a weak negative relationship between plant species richness and remaining basal area on more intensively harvested northern hardwood stands. Summer plant-species richness and diversity were related to percent litter cover and percent slope on northern hardwood stands, and percent Vaccinium cover and percent slope on oak-hickory stands. Ground- and shrub-layer cover significantly increased with increasing harvest intensity. Species composition of vernal herb communities did not vary in stands with differing amounts of basal area. Species composition of summer forest-floor communitiesdiffered with amount of basal area remaining, but only for northern hardwood stands. Shade-intolerant ruderal species dominated northern hardwood stands with low basal area, while more shade-tolerant plantsdominated northern hardwood stands with high basal area. Summer plant understories of northern hardwood stands were generally dominated by fern and/or Rubus spp. (blackberry and raspberry), while oak-hickory stands were dominated by Vaccinium (blueberry) species. Litter cover, Vaccinium cover, fern cover, total ground cover, and forest type were significant variables related to species composition of vernal herb [ABSTRACT FROM AUTHOR]

Exposure to stress alters the behavioral and neurochemical effects of drugs of abuse. However, it is unknown if chronic stress can affect the serotonergic depletions induced by the psychostimulant drug 3,4-methylenedioxymethamphetamine (MDMA). Rats were exposed to 10 days of chronic unpredictable stress (CUS) which resulted in the predicted elevation of basal plasma corticosterone concentrations. On the 11th day, rats received four challenge doses of MDMA (5 mg/kg every 2 h, i.p.) or saline. Five days later, rats were killed and serotonin (5-HT) and dopamine content were measured in the striatum, hippocampus, and frontal cortex. MDMA produced greater depletions of 5-HT in all three brain regions of rats pre-exposed to CUS compared to rats not exposed to CUS. CUS-exposed rats also had an augmented acute hyperthermic response but a similar increase in plasma corticosterone after challenge injections of MDMA compared with non-stressed rats similarly challenged with MDMA. Moreover, CUS-exposed rats exhibited an MDMA-induced depletion of striatal dopamine that was absent in non-stressed rats that received MDMA. To investigate the role of corticosterone in these effects, the corticosterone synthesis inhibitor, metyrapone (50 mg/kg i.p.), was administered prior to each stressor on each of the 10 days of CUS. Metyrapone blocked the chronic stress-induced elevation in basal plasma corticosterone, prevented the enhancement of MDMA-induced hyperthermia, and blocked the enhanced depletions of 5-HT and dopamine in CUS-exposed rats, but had no effect on the acute MDMA-induced increases in plasma corticosterone. These findings suggest that CUS alone can increase the basal level of corticosterone that in turn, plays an important role in enhancing the sensitivity of both 5-HT and dopamine terminals to the hyperthermic and monoamine depleting effects of MDMA without altering the acute corticosterone response to an MDMA challenge.

Cisplatin is a potent anti-cancer agent which has been shown to activate Kupffer cells. These activated macrophages demonstrate an increase in extensions, lysosomes, and peroxisomes increasing their anti-tumor activity. Wistar rats were treated with cisplatin (9 mg/kg) and sections of liver were excised for light and electron microscopic analysis at 1, 6, 15, and thirty days post treatment. Non-specific esterase staining was used to differentiate Kupffer cells using light microscopy, morphologic criteria were used for TEM analysis. Liver sections taken 6 days post treatment showed the greatest number of activated macrophages, with the highest degree of activation. Interaction between natural killer cells and Kupffer cells was only seen 6 days post treatment. These results show that cisplatin's ability to enhance the immune system requires several days post treatment to reach maximum potency.

A device was developed that uses microfabricated fluidic channels, heaters, temperature sensors, and fluorescence detectors to analyze nanoliter-size DNA samples. The device is capable of measuring aqueous reagent and DNA-containing solutions, mixing the solutions together, amplifying or digesting the DNA to form discrete products, and separating and detecting those products. No external lenses, heaters, or mechanical pumps are necessary for complete sample processing and analysis. Because all of the components are made using conventional photolithographic production techniques, they operate as a single closed system. The components have the potential for assembly into complex, low-power, integrated analysis systems at low unit cost. The availability of portable, reliable instruments may facilitate the use of DNA analysis in applications such as rapid medical diagnostics and point-of-use agricultural testing.

Isotachophoretic separations of the herbicides paraquat and diquat are performed in a glass microchip etched channel and monitored on-chip by normal Raman spectroscopy. The 40-micron-wide and 75-micron-deep separation channels are chemically etched in a serpentine design to 21-cm total length. A 120-micron-thick glass cover slip is used to seal the channels. Separation field strengths up to 380 V/cm are used. The microchip is directly coupled to a Raman microprobe. No interfacing is required. Raman spectra are generated with a 2-W, 532-nm NdY-VO4 laser and collected at 8-cm-1 resolution with a holographic transmissive spectrograph and a cryogenically cooled CCD. Data acquisition is at 2-5 spectra/s. Raman isotachopherograms of the pesticides at starting concentrations as low as 2.3 x 10(-7) M (60 ppb paraquat/80 ppb diquat) are presented.

This study compared the classic discontinuous Taylor et al. (1955) protocol to a continuous version of the same protocol to evaluate maximal physiological responses, and the quantitative values and incidence of achievement of the various maximal oxygen uptake (VO2max) criteria in 10 males (24.1 +/- 2.5 yr). Criteria were a plateau in VO2 (change < 2.1 ml.kg-1.min-1), HR = age adjusted maximal, PER > or = 1.15, and lactate > 8 mmol.l-1. Values for VO2max (56.8 +/- 4.7 vs 55.8 +/- 4.2 ml.kg-1.min-1), ventilation (150.7 +/- 16 vs 149.5 +/- 17.5 l.min-1 BTPS), and HR (186.3 +/- 7.7 beats.min-1 vs 191.7 +/- 6.7 beats.min-1) were similar (P < 0.05) between the discontinuous protocol (DT) and the continuous protocol (CT), respectively. Values for RER (1.28 +/- 0.05 vs 1.22 +/- 0.05) and lactate (14.3 +/- 2.7 vs 11.9 +/- 2.7 mmol.l-1) were greater (P < 0.05) on the DT than the CT. Criteria achievement were the following: 40% (CT) and 10% (DT) for HR; 50% (CT) and 60% (DT) for a VO2 plateau; and, 90% (CT) and 100% (DT) for RER and lactate. It is concluded that a VO2 plateau is not a prerequisite for defining VO2max and is of limited use as the primary objective criterion for evaluating the quality of a graded exercise test. Therefore, the achievement of secondary objective criteria, specifically RER and lactate in combination, increases the likelihood that the highest VO2 value achieved is VO2max.