Tal Conditions Research Articles

Effect of Accelerated Ageing on Ballistic Textiles Modified By Plasma-Assisted Chemical Vapour Deposition (PACVD)

The functionalisation of textile products and materials using the low temperature plasma technique is increasingly used in industrial practice, mainly because of the many benefits, often unattainable with the use of other techniques. The study focused on the modification of the composite textile materials - sheets of Ultra High Molecular Weight Polyethylene (UHMWPE) fibres (Dyneema ® SB51) by applying the surface deposition of silicone-like polymer in an environment of low temperature plasma. The aim of this study was to evaluate changes in the mechanical and physical properties of modified ballistic textiles un der simulated storage conditions in accelerated time. Based on experiences in planning the research on accelerated aging, a test programme was developed for the assessment of changes during the aging process in ballistic fibrous materials under various environmen tal conditions. The process of low temperature plasma modification affected the mechani cal properties of the ballistic composite textile materials during the accelerated ageing using temperature or temperature and humidity. The effect of the modification varied with the mechanical properties investigated.

Trace elements in the statoliths of jumbo flying squid off the Exclusive Economic Zones of Chile and Peru

Ontogenetic variation in 4 trace element ( 88 Sr, 137 Ba, 24 Mg, 23 Na) concentrations and their ratios to Ca were measured in statoliths of the jumbo flying squid Dosidicus gigas off the Exclu- sive Economic Zone of Chilean and Peruvian waters using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The element compositions of statoliths showed no significant differ- ences between females and males. All of the elements in different growth zones showed significant variations, except for Mg. Sr:Ca and Mg:Ca were good indicators for distinguishing squid from autumn and winter spawning seasons. Sr:Ca and Ba:Ca distribution patterns in statoliths confirmed that paralarvae and juvenile squid inhabit surface waters, while subadult squid migrate into deeper waters. An increasing Sr:Ca ratio of subadult squid could be explained by declining temperature gra- dients from northern to southern sampling locations, although no significant Sr:Ca differences were observed (p > 0.05). Mg:Ca ratios decreased progressively from the nucleus to the peripheral zone, which might be correlated with statolith growth rates. Na:Ca ratios slightly declined from paralarvae to the subadult phase. Quantitative relationships between statolith trace elements and environmen- tal conditions under different growth stages are needed to improve our understanding of life history of D. gigas.

Long-term growth rates of four Mediterranean cold-water coral species maintained in aquaria

Growth rates of the cold-water corals (CWC) Madrepora oculata, Lophelia pertusa, Desmophyllum dianthus and Dendrophyllia cornigera were measured over 8 mo under controlled conditions (12°C in the dark, fed 5 times a week) by means of the buoyant weight technique. Addi- tionally, linear growth rates were measured in M. oculata and L. pertusa for 2 and 1 yr, respectively. The weight measurements revealed growth rates, expressed as percent growth per day (mean ± SD), of 0.11 ± 0.04 for M. oculata, 0.02 ± 0.01 for L. pertusa, 0.06 ± 0.03 for D. dianthus and 0.04 ± 0.02 % d -1 for D. cornigera. Growth in M. oculata was significantly higher (p < 0.0001) than in the other 3 CWC species. For M. oculata and L. pertusa, also linear growth was recorded. These values (mean ± SD) were 0.014 ± 0.007 and 0.024 ± 0.018 mm d -1 for M. oculata and L. pertusa, respectively. This is the first study that compares the growth rates of 4 different CWC species under the same experimen- tal conditions of water flow, temperature, salinity and food supply. These corals have different growth rates, both in terms of total weight increase and linear increase, and these growth rates can be related to interspecific physiological differences. Data on growth rates are essential to understand the popu- lation dynamics of CWC as well as the recovery capacity of these communities after disturbance.

Diet and prey preference of juvenile lemon sharks Negaprion brevirostris

Sharks are often regarded as opportunistic asynchronous predators that feed on the most abundant prey. In the present study, 2 populations of juvenile lemon sharks Negaprion brevi- rostris were investigated from Bimini, Bahamas, with well-defined home ranges facilitating the esti- mation of prey preference. Stomach contents were quantitatively analysed from 396 lemon sharks with data on prey species and abundance obtained from quantitative sampling of mangrove and sea- grass faunal communities to elucidate preferences with respect to prey type, prey size and location. Yellowfin mojarra Gerres cinereus dominated the diet of juvenile lemon sharks (>50% by weight and percentage index of relative importance, %IRI), even when present in lower abundances in the environment. Preference was determined and compared using abundance, %IRI values and original weight of prey, with the latter preferred due to their close relationship with energetic intake. Juve- nile lemon sharks do not feed indiscriminately, but exhibit prey preference and size selection. Juve- nile lemon sharks at Bimini demonstrated a hierarchy of prey preference: parrotfish (Scaridae) > mojarra (Gerreidae) > toadfish (Batrachoididae) > filefish (Balistidae) > grunts (Haemulidae) > bar- racuda (Sphyraenidae). High overlap between shark diet and mangrove communities revealed the importance of mangroves to lemon sharks and their prey. Lemon sharks fed disproportionately on intermediate sized teleosts and crustaceans, with maximum prey size of nursery-bound sharks pri- marily limited by availability in the environment. We conclude that sharks can be highly plastic for- agers, capable of selective feeding, but will switch to more opportunistic foraging when environmen- tal conditions deteriorate.

Spatially variable larval histories may shape recruitment rates of a temperate reef fish

Several long-standing hypotheses purport variation in recruitment to be positively cor- related with pelagic environmental conditions that enhance larval growth, survival, and/or delivery to recruitment sites. However, the relationship between recruitment intensity and larval environmen- tal conditions (or more directly, larval condition) is difficult to evaluate and poorly known for most species. We evaluate this relationship for the reef fish Forsterygion lapillum that commonly inhabits rocky reefs throughout New Zealand. We quantified variation in recruitment of F. lapillum using a nested sampling design, and found that the largest source of variation was between 2 nearby regions (a semi-enclosed harbour and an adjacent open coast system). We estimated 'settler condition' as the composite of residual body mass and 2 measurements of larval growth (reconstructed from otolith microstructure) and found that recruitment intensity was positively correlated with settler condition for sites within the harbour, but negatively correlated with settler condition for sites on the open coast. Mean pelagic larval duration of recruits to the harbour was ~3 d shorter than recruits to the open coast. These results suggest that larval experience and relationships between recruitment and settler condition are spatially variable. We speculate that (1) larval retention within a productive embayment facilitates a positive relationship between recruitment and settler condition while (2) dis- persal through a less productive environment drives a negative relationship for replenishment on the open coast. These putative differences may have important implications for patterns of recruitment, the strength of post-settlement density-dependent interactions, and dynamics of local populations.

Effects of abiotic stressors on infaunal burrowing and associated sediment characteristics

Infauna play key roles in nutrient cycling and bioturbation by facilitating exchange across the sediment-water interface, but the effects of environmental stressors on the behavior of infauna are poorly studied compared to epifauna. Here we used laboratory experiments to examine the effects of temperature (15, 21, and 32°C), salinity (16, 22, 28, and 34), and food availability (low, moderate, high) on the burrowing activity of the opportunistic deposit-feeding polychaete Capitella sp. 1. We also used pH and O2 fluorosensors to investigate the effects of burrowing on marine sedi- ment chemistry. Worms buried significantly deeper at 21 than at 15°C, and they died at 32°C. Salin- ity only marginally affected the area of burrowing activity, with greater area at 35 than at 22. Burrows in highly enriched treatments were significantly more shallow than those in moderate and low food treatments. The fluorosensors showed that the exchange of solutes between the sediment and over- lying water was associated with burrowing activity. These results show that changes in environmen- tal conditions affect infaunal burrowing activity, which in turn affects sediment characteristics. We discuss the need to consider infaunal responses to abiotic stress in order to understand community and ecosystem responses to environmental changes associated with climate change, pollution, and eutrophication.

Role of H-bond formation in the photoreactivity of curcumin

Curcumin is the main constituent of curry. In its ground state it shows chemo-preventive, chemo-therapeutic and anti-inflammatory effects. For its immunostimulating action it has been considered for the development of drugs suitable for treating AIDS and cystic fibrosis. Further biological action is induced in curcumin by photoactivation: in suitable environmen- tal conditions electronically excited curcumin can act as a singlet oxygen generator. Moreover, cytotoxicity is enhanced by light exposure and antibacterial effects are photosensitized. This work is aimed to understand the photobiological action of curcumin by elucidating the deactivation mechanisms of its first excited singlet state. In particular we find evidence of the role of tautomerization in the excited state by measuring fluorescence lifetimes and quantum yields for such compound dissolved in solvents of different polarity and H-bonding capability. Degradation quantum yield and singlet oxygen generation efficiency were also measured in acetonitrile and methanol. The results emphasize the strong dependence of the deactivation processes from the environment. The deactivation phenomenology can be fully explained by postulating intramolecular proton transfer in the cis enol conformer to be the leading non-radiative deactivation pathway.

Stress protein (HSP70 family) expression in intertidal benthic organisms: the example of &lt;i&gt;Anthopleura elegantissima&lt;/i&gt; (Cnidaria: Anthozoa)

Both the physiology and distribution of intertidal organisms are strongly influenced by different kinds of physical stress. Temperature, UV radiation and desiccation in low tide conditions are usually considered the most important physical stresses. These factors impact cell metabolism, and the organism's ability to rapidly adapt to altering environmen- tal conditions sets its tidal distribution limits. The role of the HSP70 protein (stress protein) family in thermal stress respons- es has been widely demonstrated. Although it has been shown that stress protein expression is a useful tool to quantify part of this physical stress, few studies have been made with different in situ intertidal organisms. To test differences in HSP70 expression under natural conditions in the intertidal environment, we chose a common cnidarian of the eastern Pacific Ocean: the anemone Anthopleura elegantissima. Polyp HSP70 expression depends on the degree of emersion and the extent of physical stress (0.1-3.6 ± 1.5 ng HSP70 µg Protein-1 were registered between fully immersed and fully emersed polyps of the same clone). The time of immersion is reflected in the recovery of polyp HSP70 levels from the high tidal exposure (reaching again as shallower clones express more HSP70 (2.5 ng HSP70 µg P-1), than deeper ones (0.1 ng HSP70 µg P-1). Also sunny and foggy environmental situations influence the stress response. Anemone clones exposed to the sunny high intertidal zone express more than three times HSP70 (2.2 ng HSP70 µg P-1) than those on a foggy high intertidal day (0.6 ng HSP70 µg P -1 ). For A. elegantissima, shrinking of polyps, mucus secretion, sand covering, UV absorbing molecules, and a tight patch structure work concurrently with HSP70 expression to alleviate the effects of physical stress in low tidal emer- sion.

Understory vegetation in northern Ontario jack pine and black spruce plantations: 20-year successional changes

The 20-year successional development of understory vegetation was investigated in jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana (Mill.) BSP) plantations in northern Ontario, in relation to stand species composition, species diversity, and the rate of change in stands of different post-disturbance ages. Detrended correspondence analysis (DCA) ordination of plantation stands using species composition data from 1978 and 1998 indicated variation among stands in directions and rates of change in species composition over time. Rank correlations of environmental variables with the DCA axes suggested a light–moisture gradient along the first axis, driven by soil texture and overstory species, and a gradient representing time since disturbance and stand development along the second axis. Although overall beta diversity among stands remained constant over time, some convergence was found among a smaller group of stands, and divergence was noted between spruce and pine stands. Species composition also became more highly correlated with environmental variables through time. From 1978 to 1998, species richness increased in young, dry pine stands; decreased in older, dry pine stands; and decreased in young spruce stands. The understory vegetation in stands on mesic sites was more diverse than that on dry, sandy sites at both times. The rate of change in understory species composition slowed with time after disturbance, indicating an increasing stability in micro en vi ron men tal conditions as the influence of harvesting disturbance became weaker with time.

Worldwide fluctuations in dengue fever cases related to climate variability

Dengue fever is the most significant mosquito-borne viral disease of humans and is a leading cause of childhood deaths and hospitalizations in many countries. Variations in environmen- tal conditions, especially climatic parameters, affect the dengue viruses and their principal mosquito vector, Aedes aegypti, but few studies have attempted to quantify these relationships at the global scale. Here we use a numerical model to simulate the response of Ae. aegypti to observed climatic variations from 1958 to 1995 and to examine how modelled Ae. aegypti populations may be related to dengue and DHF cases worldwide. We find that variations in climate can induce large variations in modelled Ae. aegypti populations at the global scale. Furthermore, these climate-induced varia- tions in modelled Ae. aegypti populations are strongly correlated to reported historical dengue/DHF cases, especially in Central America and Southeast Asia. These results suggest that potential dengue caseloads could be anticipated using seasonal climate forecasts to drive the mosquito model, thus providing a useful tool in public health management.

Sub-grid-scale differences between individuals influence simulated phytoplankton production and biomass in a shelf-sea system

In reality, individuals differ from one another. Some of this can be attributed to genetic differences, but much is due to environmental effects. Even neighbouring cells will have differing histories and may be in differing physiological condition in consequence. Many of the processes governing cell-growth are non-linear functions of the cell's physiological state. This, together with the possibility that each cell will be in a unique physiological state, implies that it is not possible reliably to infer the population-level growth rate from the product of population abundance and an individual growth-rate derived on the basis of the average physiological characteristics of the local population. Unfortunately, this is precisely the assumption that is implicit in the vast majority of phytoplankton models —which take no account of local-scale physiological structure in the phyto- plankton population. Here, we present an individual-based population model of phytoplankton dynamics. This model utilises the Lagrangian Ensemble method to take account of local-scale physio- logical structure in the population. We make comparisons of the predictions of this model when run as a truly individual-based model or in a manner mimicking a model having no representation of local-scale population physiological structure. The results suggest that, under realistic environmen- tal conditions, individuals in close proximity to one another can indeed be in substantially different physiological condition. More importantly, failure to take proper account of this variability results in differences of more than 30% between the predictions of standing crop and productivity made by the structured-model descriptions of the same underlying biology.

Growth rate variability and lipofuscin accumulation rates in the blue crab Callinectes sapidus

To better understand growth and age-pigment (lipofuscin) accumulation rates of the blue crab Callinectes sapidus under natural conditions, juveniles (33 to 94 mm carapace width) were reared in outdoor ponds for over 1 yr. Growth rates, measured by carapace width, during summer and fall exceeded all those reported in the literature; the initial carapace width of 59 ± 14 mm (mean ± SD) increased to 164 ± 15 mm within a 3 mo period. No growth occurred during winter months (Novem- ber to April) at low water temperatures. Growth rates of crabs in ponds were substantially higher (von Bertalanffy growth parameter K = 1.09) than those of crabs held in laboratory environments, and than rate estimates for natural populations of mid-Atlantic blue crabs. Model comparisons indicated that seasonalized von Bertalanffy growth models (r 2 > 0.9) provide a better fit than the non-seasonalized model (r 2 = 0.74) for pond-reared crabs and, by implication, are more appropriate for field popula- tions. Despite growth rates that varied strongly with season, lipofuscin (normalized to protein con- centration) accumulation rate was nearly constant throughout the year. Although the lipofuscin level in pond-reared crabs was significantly correlated with size (carapace width), it was more closely cor- related with chronological age. Lipofuscin accumulation rates were also similar to those observed for laboratory-reared crabs, despite very large differences in growth rates and temperature regimes. The constancy of normalized-lipofuscin accumulation rates of blue crabs across seasons and environmen- tal conditions suggests that lipofuscin concentration can be a more robust indicator of age than cara- pace width alone.

Timing Effect on Performance of RH0345, Merit 75WP, Tempo 2, and Dursban Pro for Management of Black Cutworm of Creeping Bentgrass, 1996

Abstract Treatment plots were 6X10 ft, arranged in a RCB design and replicated 4 times at Uni versity Park, PA. Liquid formulations were applied by using a CO2 compressed air sprayer with 4 8002VS TeeJet nozzles mounted on a 6 ft boom, operating at 28 psi, and applied in 208 ml of water/60 ft2 or delivering 0.92 gal/1,000 ft2. At the 1st treatment on 23 Aug, the following soil and environmen tal conditions existed: air temperature, 66°F; soil temperature at 1 inch depth, 62°F; soil temperature at 2 inch depth, 64°F; RH, 97%; amount of thatch 0.125-0.25 inch; soil textural class, sandy loam; soil particle size analysis: 58.2% sand, 33.9% silt, 7.9% clay; soil moisture (oven dry weight), 18.6%; or ganic matter, 2.7%; water pH, 7.0; soil pH, 6.8%; time of application, early morning; and clear skies. A total of 0.8 inch of rain fell between late evening on 23 Aug through early morning on 24 Aug. At the 2nd treatment on 6 Sep, the following soil and environmental conditions existed: air temperature 67°F; soil temperature at 1 inch depth, 65°F; soil temperature at 2 inch depth, 65°F; RH, 87%; amount of thatch, 0.125-0.25 inch; soil textural class, sand) loam; soil particle size analysis: 58.2% sand, 33.9% silt, 7.9% clay; soil moisture (oven dry weight), 26.9%; organic matter, 2.8%; water pH, 7.0; soil pH 6.4; time of application, early morning; and overcast skies. A total of 2.7 inches of rainfall was recorded over a 72-h interval following the second treat ment on 6 Sep; however, the area did have 8 h drying time prior to the latter rainfall. Evaluation was done on 9 Sep and 12 Sep by counting the number o: black cutworm larvae flushed to the surface within a 1.0 yd2 wood frame sampling area using a soap irritant drench of 30 ml Lemon Joy™ dishwashing detergent in 2 gal of water. An average of 16/yd2 cutworm larvae was recorded on 4 Sep following infestation of the experimental area with 2nd and 3rt instar black cutworms. The entire experimental area was covered with bird netting until posttreatment counts were recorded on 9 Sep.

Chemical durability of some lead borate glasses in different aqueous solutions

The effect of hydrochloric acid and sodium hydroxide solutions on some lead borate glasses con­ taining high proportions of lead oxide was investigated to study the chemical durability of these glas­ ses in different aqueous media. Different factors were studied such as the glass composition, con­ centration of the aqueous solution, temperature, and time of immersion. The change in the value of the mass loss (<5/(g cm-2)) with the change in the glass composition was found to be due to the change in the corrosion rate. In the case of increasing the concentration of the immersion solution, the in­ crease in the mass loss can be attributed to the pH value. The results obtained from the immersion condition were also explained. Glass is distinguished, besides other properties, by its great resistance with respect to most chemi­ cals at usual temperatures. Without this property, the wide range of the glass applications would be unthinkable. The term chemical durability has been used conventionally to express the resistance offered by a glass towards the attack by aqueous solutions and atmospheric agents. There is no absolute or explicit measure of the chemical durability and the different glasses are usually graded relative to one another after subjecting them to similar experimen­ tal conditions. The interactions between a glass and different aque­

Elderly Admissions to a State Psychiatric Hospital

Admissions to the Geriatric Unit of a 270-bed state psychiatric hospital in western Virginia during a twelvemonth peri- od of time were followed until discharge, but no longer than one year from the day of admission to the hospital, to: describe the admission cohort characteristics; determine their aftercare service needs; and examine the associations between patient characteristics, after-care needs, and discharge destinations Lo either institutional- or cornmu- nity-based care settings. The results describe a service-needy popu- lation in which trans-institutional transfers are a prevalent discharge destination However. the significant findings are not atypical of reporls of other long-term care populations whose physical and men- tal conditions warrant institutional placement decisions.

Morphological Assortment and the Assembly of Communities of Introduced Passeriforms on Oceanic Islands: Tahiti Versus Oahu

We conducted an ecomorphological analysis on the introduced passeriforms of Ta- hiti and tested for community patterns reported for the introduced passeriforms of Oahu, Hawaii. Although the island of Tahiti is similar to Oahu in size, distance from the equator, and number of passeriform introductions, the two islands differ greatly in rates of introduction success: on Oahu 27 of 43 (63%) introductions have been successful, whereas on Tahiti only 7 of 41 (17%) have been successful. Possible explanations for this difference include unfavorable environmen- tal conditions, differences in the timing of the introductions, differences in the taxonomic diver- sity of the sets of introduced species, and differences in habitat diversity between the islands. Despite the difference in rates of introduction success, the same pattern of morphological over- dispersion seen on Oahu also occurs on Tahiti. The pattern of morphological overdispersion is consistent with the hypothesis that interspecific competition has influenced the assembly of this community.

Annual Cycles of Soil Moisture and Temperature as Related to Grass Development in the Steppe of Eastern Washington

The annual cycle of soil moisture use and recharge was followed in eight climax steppe communities by making gravimetric analyses to a depth of 1 m. Soil temperatures were measured at depths of 50 to 100 cm. The data were related to the phenologies of the dominant grasses. Differences in soil moisture and temperature seem to contribute more toward explaining the distributions of these steppe communities than do chemical content of the soils of their profile characters.

The Accumulation of 36 Cl Ring-Labeled DDT in a Freshwater Marsh

An enclosed 4-acre marsh at the southwestern edge of Lake Erie was treated by helicopter with 3.9 millicuries of chlorine-36 ring-labeled DDT at a rate of 0.2 lb technical DDT per acre. Radiolabeled DDT residues were traced until 15 months after the application. Whole body residues were of major concern, although tissues were assayed from vertebrates too large to assay entire. DDT residues were detected in sago pondweed (Potamogeton pectinatus), duckweed (Lemna minor), bladderwort (Utricularia vulgaris), crayfish (Orconectes immunis), tadpoles (Rana pipiens), and carp (Cyprinus carpio) when first assayed 4 hours after the application. The alga Cladophora averaged 96 ppm DDT, or 3,125 times the environmental level, 3 days after the application. A northern water snake (Natrix sipedon) accumulated 36 ppm 13 months after the application. The maximum level in carp was 19 ppm in the soft palate, also after 13 months. Plants and most invertebrates accumulated their highest residues during the first week; vertebrates required longer periods. Algae, the pondweeds (Potamogeton spp.), duckweed, crayfish, and small carp should make good indicator species of environmental DDT residues. This study was initiated to increase our knowledge of natural DDT accumulation in wetland organisms. Serious doubts have been raised when the results of laboratory toxicity studies are projected to the field (Stickel et al. 1965). Although a single large insecticide dose is often administered to an organism in the laboratory, small frequent doses are ingested in the field through the food web. Since the amount of an ingested toxicant that is assimilated by an organism varies with the rate and form of intake, long-term toxicity studies must be conducted under near environmen1 Financed by U. S. Atomic Energy Commission Grant AT (11-1)-1358 and the Winous Point Research Committee in cooperation with the North American Wildlife Foundation and the Ohio Cooperative Wildlife Research Unit. 2 Present address: 3500 Lattimore Road, Port Clinton, Ohio. tal conditions to obtain accurate information. Such studies cannot be soundly designed until more is known about natural insecticide accumulation in food-chain organisms. The main concern of the project was with food-chain aspects of DDT accumulation. The total quantity of DDT was usually determined irrespective of its actual location within or on individual species. However, organs and tissues from vertebrates were also analyzed at intervals to supplement the whole body assay data or to obtain information on animals too large to assay whole. No attempt was made to determine the effect of the DDT on animal populations. Our current use of persistent chemicals to control nuisance and vector insects poses a threat to this country's wetland environments that cannot be fully assessed with our existing knowledge of wetland-insectiThis content downloaded from 157.55.39.92 on Wed, 22 Jun 2016 06:56:54 UTC All use subject to http://about.jstor.org/terms ACCUMULATION OF DDT IN A FRESHWATER MARSH Meeks 377 cide dynamics. As many as 2.5 million acres are treated annually for mosquito control at an average rate of 1 lb of chemical per acre (Hall 1962). Some wetlands are sprayed a dozen or more times a year (Springer 1956). These same lands maintain diverse endemic wildlife populations, exceeding all other land types in wildlife productivity (DeVos and Mosby 1963:87). I thank Dr. Tony J. Peterle, John M. Anderson, Charles W. Kellenbarger, Robert Orr, and David Guest for special services they freely offered. Achem Corporation, Ambler, Pennsylvania, supplied the granular applicator, and the Minerals and Chemicals Corporation of America, Menlo Park, New Jersey, furnished the granules.

Analysis of Mixed Drugs by Mass Spectrometry, X. Pesticide Analysis (2), Analysis of Pesticide from their Preparations

As a Preliminary study of pesticide analysis by mass spectrometry, we examined the experimen tal conditions for obtaining spectra of several organic phosphorus compounds. (1) Identification of Pesticide from the various commercial Preparations: Commercially available dichlorodiphenyl trichloroethane emulsion (DDT) and hexachlorobenzene powder(γ-BHC)contain various surfactants and diluents, but these preparations give the spectra of respective pure compouds by direct measurement. (2) Temperature Dependene: Although low temperature measurements are expected to be suitable for good reproducibility, almost no change of spectra was observed for the temperature range of 100-200°C. (3) Effect of Time: The intensities of the molecular peak and fragment peaks weres table for 60 minutes. These results indicate that the quantitative analyses of pesticides by mass spectrometric deter mination seem to be very attractive.