Showing papers by "Mississippi State University published in 1996"

Distinguishing the Effects of Functional and Dysfunctional Conflict on Strategic Decision Making: Resolving a Paradox for Top Management Teams

Abstract: Top management teams make strategic decisions, and the products of their decision making influence organizational performance. However, a subtle paradox is embedded in this relationship. This study focuses on conflict as the crux of this paradox and provides evidence from two different samples of conflict's consistent yet contradictory effects on decision quality, consensus, and affective acceptance.

A high-performance, portable implementation of the MPI message passing interface standard

Abstract: MPI (Message Passing Interface) is a specification for a standard library for message passing that was defined by the MPI Forum, a broadly based group of parallel computer vendors, library writers, and applications specialists. Multiple implementations of MPI have been developed. In this paper, we describe MPICH, unique among existing implementations in its design goal of combining portability with high performance. We document its portability and performance and describe the architecture by which these features are simultaneously achieved. We also discuss the set of tools that accompany the free distribution of MPICH, which constitute the beginnings of a portable parallel programming environment. A project of this scope inevitably imparts lessons about parallel computing, the specification being followed, the current hardware and software environment for parallel computing, and project management; we describe those we have learned. Finally, we discuss future developments for MPICH, including those necessary to accommodate extensions to the MPI Standard now being contemplated by the MPI Forum.

Image-guided streamline placement

Abstract: Accurate control of streamline density is key to producing several effective forms of visualization of two-dimensional vector fields. We introduce a technique that uses an energy function to guide the placement of streamlines at a specified density. This energy function uses a low-pass filtered version of the image to measure the difference between the current image and the desired visual density. We reduce the energy (and thereby improve the placement of streamlines) by (1) changing the positions and lengths of streamlines, (2) joining streamlines that nearly abut, and (3) creating new streamlines to fill sufficiently large gaps. The entire process is iterated to produce streamlines that are neither too crowded nor too sparse. The resulting streamlines manifest a more hand-placed appearance than do regularlyor randomly-placed streamlines. Arrows can be added to the streamlines to disambiguate flow direction, and flow magnitude can be represented by the thickness, density, or intensity of the lines. CR Categories: I.3.3 [Computer Graphics]: Picture/Image generation; I.4.3 [Image Processing]: Enhancement. Additional

A Comparison of Multivariate Control Charts for Individual Observations

Abstract: For multivariate statistical process control with individual observations the usually recommended procedure in the retrospective phase is the Hotelling's T2 control chart. All the observations are pooled to estimate the mean vector and covariance matrix..

Social psychological models of interpersonal communication

Abstract: states or predispositions. Any particular behavioral episode can be characterized in a variety of ways at different levels of abstraction: "A Models of Interpersonal Communication page 32 punches B," or "A hurts B," or "A dislikes B." The most abstract way to characterize a behavior would be as evidence of a predisposition: "A is aggressive." Maass et al. found that negatively valent behaviors of outgroup members tend to be characterized at relatively high levels of abstraction, and those of in-group members are characterized more concretely, but for positively valent behaviors the pattern is reversed. Positively valent behaviors of out-group members are characterized as specific episodes, while those of in-group members are characterized abstractly. Maass et al. call this the "linguistic intergroup bias" (see also Hamilton, Gibbons, Stroessner, & Sherman, 1992; Maass & Arcuri, 1992). One consequence of the linguistic intergroup bias is to help make stereotypes resistant to disconfirmation, since behaviors that are congruent with the negative out-group stereotype will tend to be characterized as general properties ("Smith is lazy"), while behaviors that are inconsistent with the stereotype will tend to be characterized in quite specific terms ("Smith painted his house"). Although examining the causal implications of language has yielded fascinating results, there are reasons to be cautious about generalizing these findings to language use. Edwards and Potter (1993) have pointed out that simple, out of context subject-verb-object sentences of the kind typically used in studies of implicit causality are rarely encountered in discourse. Consequently, the judgments subjects make from them may have little to do with the way language normally is processed in communication. Seen in isolation, "Alan desires Jane" may be understood as consequence of Jane's desirability, but in the context of a narrative that depicts Alan as a compulsive womanizer, his desire for Jane may be attributed less as to her desirability than it is to his proclivity. Models of Interpersonal Communication page 33 Is implicit causality really a matter of encoding and decoding? Or, to put it another way, is an interpersonal verb's causal implications part of its linguistic meaning, or is it an inference an addressee will draw in a particular context of usage about what the speaker intended? Semin and Marsman (in press) argue that interpersonal verbs invite inferences about a variety of properties (e.g., the perceived temporal duration of the action or state, how enduring a quality they imply, affective consistency, etc.), causal agency being only one of them. Researchers have assumed that interpersonal verbs automatically trigger inferences about causal agency, but Semin and Marsman suggest that such inferences are themselves a consequence of contextual factors (e.g., the question the subject is asked). Much of the work on implicit causality has approached the phenomenon in linguistic terms, but it may be more readily understood as part of the addressee's attempt to infer an intended meaning. The general question of how addressee's extract intended meanings from messages is discussed in Section 3. 2.3 Issues and Limitations Two features of the Encoder/Decoder model should be highlighted. One is implicit in the very notion of a code, and is illustrated in the early color codability studies. It is that the meaning of a message is fully specified by its elements—i.e., that meaning is encoded, and that decoding the message is equivalent to specifying its meaning. The other feature is that communication consists of two autonomous processes—encoding and decoding. We have tried to illustrate the Encoder/Decoder schematically in Figure 1. Despite the fact that language can in certain respects be regarded as a code, and the fact that both encoding and encoding processes are involved in communication, encoding and decoding do not adequately Models of Interpersonal Communication page 34 describe what occurs in communication, as will be discussed in the next three sections. Here we will just briefly point to some areas where the approach falls short. In the first place, it is often the case that the same message can (correctly) be understood to mean different things in different circumstances. For example, some messages are understood to mean something other than their literal meaning. While there is not universal agreement on the value of the literal vs. nonliteral distinction (Dascal, 1989; Gibbs, 1982, 1984; Katz, 1981; Keysar, 1989; Searle, 1978), it is abundantly clear that the most commonplace utterance (e.g., "You're leaving") can be understood differently in different contexts (e.g., as an observation of a state of affairs, as a prediction of a future state of affairs, etc.). Without making the relevant context part of the code, a model that conceptualizes communication as simply encoding and decoding will have difficulty explaining how the same message can be understood to mean different things at different times. Moreover, even when context is held constant, the same message can mean different things to different addressees. And there is considerable evidence to indicate that speakers design messages with their eventual destinations in mind (Bell, 1980; Clark & Murphy, 1982; Fussell & Krauss, 1989a; Graumann, 1989; Krauss & Fussell, 1991). Similarly, there is growing evidence that nonverbal behaviors are not simply signs that encode internal state in a straightforward way. A facial expression may be related to a person's internal state, but comprehending its significance can require considerably more than simply identifying the expression as a smile, a frown, an expression of disgust, etc. For example, smiles are understood to encode a affectively positive internal state, but they hardly do this in a reflexive fashion. In a series of ingenious field Models of Interpersonal Communication page 35 experiments, Kraut (1979) found smiling to be far more dependent on whether or not the individual was interacting with another person than it was on the affective quality of the precipitating event, and Fridlund (1991) has shown that even for people who were alone, the belief that another person was engaged in the same task (albeit in another room) was sufficient to potentiate smiling. In dyadic conversations, the facial expressions of the listener (i.e., the person not holding the conversational floor at a given moment) may change rapidly. Some of these changes (e.g., smiles) may represent back-channel signals (Brunner, 1979; Chen, 1990), while others (e.g., wincing at the other's pain) may serve to signal the listener's concern (Bavelas, Black, Chovil, Lemery, & Mullet, 1988; Bavelas, Black, Lemery, & Mullet, 1986). Even aspects of voice quality cannot be straightforwardly interpreted. For example, a speaker's vocal pitch range is a consequence of the architecture of the vocal tract. However, social factors can influence how a given speaker places his or her voice within that range. Men seem to place their voices in the lower part of their vocal range, and women do not, which, incidentally helps explain why a man's size can more accurately be predicted from his voice than a woman's (Gradol & Swann, 1983). In addition, a speaker's pitch and amplitude will be influenced by the pitch and amplitude of the conversational partner (Gregory, 1986, 1990; Lieberman, 1967; Natale, 1975). In a similar fashion, a speaker's internal state can induce changes in voice quality, but the relationship is hardly one-to-one. For example, stress profoundly affects voice fundamental frequency, but in any specific instance the effect can vary considerably depending on the conversational partner (Streeter et al., 1983). So, while encoding and decoding may characterize the role of nonverbal behavior is Models of Interpersonal Communication page 36 some communication situations, the applicability of the model is far from universal. 3. INTENTIONALIST MODELS

The feeding value of soybeans fed to rats, chickens, catfish and dairy cattle is not altered by genetic incorporation of glyphosate tolerance.

Abstract: Animal feeding studies were conducted with rats, broiler chickens, catfish and dairy cows as part of a safety assessment program for a soybean variety genetically modified to tolerate in-season application of glyphosate. These studies were designed to compare the feeding value (wholesomeness) of two lines of glyphosate-tolerant soybeans (GTS) to the feeding value of the parental cultivar from which they were derived. Processed GTS meal was incorporated into the diets at the same concentrations as used commercially; diary cows were fed 10 g/100 g cracked soybeans in the diet, a level that is on the high end of what is normally fed commercially. In a separate study, laboratory rats were fed 5 and 10 g unprocessed soybean meal 100 g diet. The study durations were 4 wk (rats and dairy cows), 6 wk (broilers) and 10 wk (catfish). Growth, feed conversion (rats, catfish, broilers), fillet composition (catfish), and breast muscle and fat pad weights (broilers) were compared for animals fed the parental and GTS lines. Milk production, milk composition, rumen fermentation and nitrogen digestibility were also compared for dairy cows. In all studies, measured variables were similar for animals fed both GTS lines and the parental line, indicating that the feeding value of the two GTS lines is comparable to that of the parental line. These studies support detailed compositional analysis of the GTS seeds, which showed no meaningful differences between the parental and GTS lines in the concentrations of important nutrients and antinutrients. They also confirmed the results of other studies that demonstrated the safety of the introduced protein, a bacterial 5-enolpyruvyl-shikimate-3-phosphate synthase from Agrobacterium sp. strain CP4.

Use of Microbial Phytase in Channel Catfish Ictalurus punctatus Diets to Improve Utilization of Phytate Phosphorus

Abstract: A 10-wk feeding trial was conducted in the laboratory during which channel catfish Ictalurus punctatus (average initial weight: 6.5 g/fish) were fed five practical diets containing either 0, 500, 1,000, 2,000, or 4,000 units of microbial phytase/kg diet. Fish fed diets containing 500 or more units of microbial phytase/kg consumed more feed and gained more weight than fish fed the basal diet without supplemental phytase. Feed conversion ratios (FCR) did not differ among treatments except the FCR for fish fed 1,000 units of microbial phytase/kg diet was lower than that of fish fed no supplemental phytase. Fish survival was not different among treatments. Contrast analysis showed that weight gain, feed consumption, bone ash, and bone phosphorus were higher and feed conversion ratio was lower for fish fed diets supplemented with phytase as compared to fish fed no supplemental phytase. The concentration of fecal phosphorus decreased linearly as phytase supplementation increased. Results from this study demonstrate that microbial phytase is effective in improving bioavailability of phytate phosphorus to channel catfish, which may eventually lead to a reduction in the amount of supplemental phosphorus added to commercial channel catfish feeds.

Increasing learning rates by increasing student response rates: A summary of research.

Abstract: Summary of Teacher-Led Procedures Wait-times, choral responding, and response cards increase the number of studentsresponding to task stimuli following teacher questions. Consequently, these proce-dures can increase the number and the rate of complete learning trials duringrecitation. However , each of thes e procedure s has uniqu e strength s and shortcomings .Increasing wait times may increase the number of students responding; but, becausethese cognitive responses are unobservable, teachers can not monitor or evaluateresponses. Respons e cards occasio n observable written responses which teachers canmonitor. After asking a question, the teacher can determine who is responding andevaluate the accuracy of those responses. This can allow teachers to encourageresponding from all students and provide corrective feedback to students who aremaking errors . However, writin g response s take s time . Therefore, response card s maybe less efficient (lower learning trial rates) than longer wait times and calling on onestudent to respond aloud when questions require long responses .Choral responding is overt and efficient. However, teachers have difficultydetermining which students are responding and evaluating response accuracy(Narayan et al., 1990). Therefore, when students have obtained some degree ofaccuracy, choral responding may prove to be useful for increasing fluency becauseit allow s for a larg e numbe r of response s in a brie f perio d of time . Chora l respondingmay also be useful when the goal response is verbal. For example, you could notuse response cards for sight-word responding. When teachers are presenting taskstimuli and providing feedback they can control the pace of instruction. ReducingITIs and increasing wait times may improve the quality and possibly the quantityof learning trials in a fixed period of time. Teachers can also control the form andtiming of responses . Choral responding and response card research reviewed showhow altering the form (written as opposed to subvocal) or timing (unison or one ata time) of responses can increase rates of responding and learning rates in groupsof students.

MPI-2: Extending the Message-Passing Interface

Abstract: This paper describes current activities of the MPI-2 Forum The MPI-2 Forum is a group of parallel computer vendors, library writers, and application specialists working together to define a set of extensions to MPI (Message Passing Interface) MPI was defined by the same process and now has many implementations, both vendor-proprietary and publicly available, for a wide variety of parallel computing environments In this paper we present the salient aspects of the evolving MPI-2 document as it now stands We discuss proposed extensions and enhancements to MPI in the areas of dynamic process management, one-sided operations, collective operations, new language binding, real-time computing, external interfaces, and miscellaneous topics

Development and Characterization of a Binge Drinking Model in Mice for Evaluation of the Immunological Effects of Ethanol

Abstract: This study describes the development and characterization of a binge drinking model in which a single dose of ethanol (EtOH) is administered by gavage to B6C3F1 mice. Blood EtOH levels were monitored over time after administration of EtOH at doses of 3.0-7.0 g/kg. Peak levels were in the range of 0.2-0.5%, and clearance was complete within 2-12 hr. Substantial increases in blood corticosterone levels were noted. Behavioral changes in EtOH-treated mice aged 8 weeks ranged from no effect (3-4 g/kg) to severe ataxia (6-7 g/kg). In mice aged 16 weeks, a dosage of 7 g/kg caused less of the righting reflex in some animals and severe ataxia in most of the others. Clinical chemistry results did not indicate biologically important changes in general physiological/homeostatic systems in EtOH-treated mice, but there were indications of minor liver damage at the 7 g/kg dosage. Thus, administration of EtOH to B6C3F1 mice by gavage produces behavioral changes, changes in blood EtOH levels, and probably glucocorticoid levels representative of at least some human binge drinkers. The model was used to evaluate the effects of binge drinking on antibody responses, and the results indicate the model will be useful for such studies.

Survival and Antibody Response of Channel Catfish, Blue Catfish, and Channel Catfish Female × Blue Catfish Male Hybrids after Exposure to Edwardsiella ictaluri

Abstract: Juvenile Norris strain channel catfish Ictalurus punctatus, blue catfish I. furcatus, and Norris strain channel catfish female × blue catfish male hybrids were challenged with Edwardsiella ictaluri by bath immersion or intraperitoneal injection (high or low dose) in aquaria. Survival (%) after bath immersion was highest for blue catfish (89.5 ± 2.8), intermediate for hybrids (73.8 ± 6.7), and lowest for channel catfish (62.0 ± 4.2). Prechallenge antibody levels to E. ictaluri, measured by enzyme-linked immunosorbent assay, were negative (mean ± SE optical density [OD] = 0.010 ± 0.003). Postchallenge antibody response for blue catfish (OD = 0.132 ± 0.045) was significantly lower than that of channel catfish (OD = 0.350 ± 0.045), whereas the response of the channel × blue catfish F1 hybrids (OD = 0.263 ± 0.051) was intermediate and not significantly different from either parental species. Intraperitoneal injections of E. ictaluri resulted in significant mortality only in channel catfish (88.3 ± 2.6...

A new test of classic strain theory

Abstract: The central variable in classic strain theory is the individual's level of dissatisfaction or frustration with his or her monetary status. This variable, however, has been ignored in virtually all tests of the theory. Most often, strain is measured indirectly in terms of the disjunction between aspirations and expectations. This paper directly measures dissatisfaction with monetary status, and draws on classic strain theory to explore the determinants and effects of such dissatisfaction. Data from a sample of adults in Cincinnati indicate that dissatisfaction is highest among objectively deprived individuals and those who desire a lot of money, have low expectations for making a lot of money, and feel relatively deprived. Further, dissatisfaction has a positive effect on both income-generating crime and drug use. This effect is strongest among those who have criminal friends and beliefs conductive to crime. Unlike the findings in much previous research, these data provide qualified support for classic str...

Applying Herrnstein's Matching Law to Influence Students' Choice to Complete Difficult Academic Tasks

Abstract: In an extension of choice research and Herrnstein's matching law to a more ecologically valid setting, college students were asked to work on a control mathematics assignment containing 16 three-digit by two-digit multiplication (3 × 2) problems and an experimental assignment that contained 16 equivalent 3 × 2 problems plus six interspersed 1 × 1 problems. Afterwards, they rated the experimental assignment as less difficult and time-consuming and requiring less effort than the control assignment. Performance on 3 × 2 problems was equivalent across the control and experimental assignments. Furthermore, when given the opportunity to choose a new control-format or experimental-format assignment (each containing similar, but different, problems as the initial assignments), significantly more students chose the latter format Because these results could be explained by the novelty of the problems interspersed in the experimental assignment, another experiment that interspersed division problems was con...

Independent and Interdependent Group Contingencies: Smoothing the Rough Waters

Abstract: Independent and interdependent group contingencies have many applied advantages for influencing behaviors in school settings. However, there are negative side effects associated with these group oriented contingencies. A scenario is presented that illustrates some negative side effects of independent and interdependent group oriented contingencies. Specific recommendations for altering group oriented contingencies to reduce these negative side effects and increase the probability that teachers will use these contingencies to increase students' academic performance and prosocial behaviors follows the scenario.

Evaluation of genetic variances, heritabilities and correlations for yield and fiber traits among cotton F(2) hybrid populations

Abstract: F2 hybrid cultivars continue to occupy a small portion of the cotton (Gossypium hirsutum L) production are in the United States, but occupy a larger proportion of the production area in some other countries Sixty-four F2 hybrids resulting from crosses of four commercial cultivars and 16 pest-resistant germplasm lines were evaluated for five fiber and four yield traits in four environments at Mississippi State, MS An additive-dominance genetic model was employed for these traits The minimum norm quadratic unbiased estimation (MINQUE) method was used with a mixed model approach for estimating genetic variance and covariance components and for predicting genetic correlations This study investigated genetic variances, heritabilities, and genetic and phenotypic correlations between agronomic and fiber traits among these 64 F2 hybrid populations and discussed the usefulness of these populations for use as hybrids or for selections for pure lines

Religion, social bonds, and delinquency

Abstract: Although criminologists have generally been indifferent or even hostile to the idea that religion inhibits criminal deviance, evidence of a consistent inverse relationship between religion and deviance—including crime and delinquency—has steadily accumulated over the last three decades. Yet controversy abounds concerning the extent to which this relationship is shaped by offense type, group affiliation, and other religious and social contexts. Some researchers have also claimed that, in fully specified models with controls for secular bonds, religion has no direct impact on delinquency. Using comprehensive measures of religion, secular social bonds, and delinquency, the present study seeks to resolve questions concerning the relative efficacy of religion as an inhibitor of delinquency. Unlike prior research, our models also include measures of three separate dimensions of religiosity (religious activities, salience, and “hellfire") and peer religiosity. In our most fully specified models, we find that gen...

Phased logic: supporting the synchronous design paradigm with delay-insensitive circuitry

Abstract: Phased logic is proposed as a solution to the increasing problem of timing complexity in digital design. It is a delay-insensitive design methodology that seeks to restore the separation between logical and physical design by eliminating the need to distribute low-skew clock signals and carefully balance propagation delays. However, unlike other methodologies that avoid clocks, phased logic supports the cyclic, deterministic behavior of the synchronous design paradigm. This permits the designer to rely chiefly on current experience and CAD tools to create phased logic systems. Marked graph theory is used as a framework for governing the interaction of phased logic gates that operate directly on Level-Encoded two-phase Dual-Rail (LEDR) signals. A synthesis algorithm is developed for converting clocked systems to phased logic systems and is applied to benchmark examples. Performance results indicate that phased logic tends to be tolerant of logic delay imbalances and has predictable worst-case timing behavior. Although phased logic requires additional circuitry, it has the potential to shorten the design cycle by reducing timing complexities.

Nitrogen nutrition and photosynthesis in leaves of Pima cotton

Abstract: The influence of nitrogen (N) on dry matter accumulation and yield in cotton is well documented, but its effects on carbon (C) assimilation and transpiration are less clear. The objectives of this study were to characterize leaf photosynthetic and stomatal responses of Pima cotton (Gossypium barbadense L., cv. S‐6) plants, grown under different N nutritional regimes. Pima cotton was grown in pots under natural environmental conditions. Varying N regimes were imposed on 20‐day‐old plants by fertilizing with nutrient solutions containing 0, 0.5, 1.5, and 6 mM of nitrate (NO3) concentrations. Net carbon dioxide (CO2) assimilation rates, stomatal conductance, internal CO2 partial pressures, transpiration rates, leaf carbohydrate status, ribulose 1,5‐bisphosphate carboxylase/oxygenase (Rubisco) activities, and leaf N concentrations were determined in the youngest fully expanded leaves. Net photosynthetic rates, stomatal conductance and transpiration were positively correlated with leaf N concentration...

Hispanic and Anglo Interviewer and Respondent Ethnicity and Gender: The Impact on Survey Response Quality:

Abstract: The author applies a hierarchical regression model to analyze the simultaneous effects of Hispanic and Anglo interviewer and respondent ethnicity and gender on response quality in survey research. ...

Multi-frequency noise for LIC

Abstract: We present a way to visualize a flow field using Line Integral Convolution (LIC) with a multi frequency noise texture. A broad range of feature sizes can enhance a user's perception of the magnitudes and direction of the flow. In addition, the multiple scales of feature size help a user clarify the motion of the flow in an animation.

Heat-Shock Response in Heat-Tolerant and Nontolerant Variants of Agrostis palustris Huds

Abstract: The heat-shock response in heat-tolerant variants (SB) and non-tolerant variants (NSB) of creeping bentgrass (Agrostis palustris Huds.) was investigated. Both variants were derived from callus initiated from a single seed of the cultivar Penncross. SB and NSB synthesized heat-shock proteins (HSPs) of 97, 83, 70, 40, 25, and 18 kD. There were no major differences between SB and NSB in the time or temperature required to induce the heat-shock response. When the HSPs synthesized by SB and NSB were analyzed by two-dimensional gel electrophoresis, it was apparent that SB synthesized two to three additional members of the HSP27 family, which were smaller (25 kD) and more basic than those synthesized by NSB. Analysis of F1 progeny of NSB x SB indicated that 7 of the 20 progeny did not synthesize the additional HSP25 polypeptides. These progeny were significantly less heat tolerant than progeny that did synthesize the additional HSP25 polypeptides. The X2 test of independence (X2 = 22.45, P

Tillage systems for cotton on silty upland soils

Abstract: No-tillage systems for cotton (Gossypium hirsutum L.) production on sloping, upland sites have not been widely adopted in the Mid-South of the USA, even though conventional cotton production creates a serious erosion hazard. A field study was established following sod on a site with loess soils to evaluate tillage system effect on cotton yield and earliness. The sod was tilled prior to establishment of treatments, which included conventional (chisel, disk, bed, cultivate), ridge till (remove ridge tops at planting, cultivate postemergence to rebuild ridges), no-tillage [wheat (Triticum aestivum L.) cover seeded following cotton harvest, killed prior to planting], and minimum tillage (one pass with a mulch finisher prior to planting, cultivate postemergence). During the first year of the study, no-tillage cotton yields were lower and maturity delayed compared with conventional tillage. During Years 3 to 5, no-tillage crop yields were is to 42% greater and crop maturity was 6 to 10 d earlier than conventional tillage. Minimum tillage yields were similar to conventional tillage while ridge tillage was lower in two of the last 3 yr of the study. Results of this study indicate viable no-tillage production systems for cotton can be developed for highly erosive loess soils in the Mid-South.

2,4,6-Trinitrotoluene detection by laser-photofragmentation–laser-induced fluorescence

Abstract: Photofragmentation (PF) and subsequent nitric oxide (NO) laser-induced fluorescence (LIF) is being developed to measure the concentration of energetic materials (EM's) in soil and other media. Laser radiation near 226 nm photodissociates gas-phase EM to NO(2), which predissociates into NO that gives an intense luminescence. The EM concentration is inferred from the intensity of the NO fluorescence. We have studied the factors that affect the PF-LIF signal intensity, including the effect of buffer gas on the LIF spectrum of pure NO, the effect of 2,4,6-trinitrotoluene (TNT) pressure on the PF-LIF spectrum, the effect of buffer-gas pressure on the PF-LIF signal intensity of pure TNT, and the effect of temperature on the PF-LIF spectra of pure TNT and of TNT in simulated soil. Heating of the TNT sample above 343 K was found to increase the magnitude of the PF-LIF signal intensity significantly, but also was found to cause physical and chemical changes in the TNT sample. The effects of heating and evacuating on the TNT sample were investigated. TNT concentration calibration curves were obtained for TNT in simulated soil mixtures. The limit of detection of TNT in soil was estimated to be 40 parts in 10(9).