Laboratory Environment (laboratory + environment)

Distribution by Scientific Domains


Selected Abstracts


Laboratory environments are not conducive for allopatric speciation

JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 1 2002
A.-B. Florin
We review published records of laboratory experiments on peripatric and vicariance allopatric speciation to address the following three questions: (1) What was the true effect size of reproductive isolation? (2) Was the reproductive isolation persistent? (3) What influenced the development of isolation? Contrary to popular belief, laboratory evidence for allopatric speciation is quite weak. Assortative mating was only found among derived populations in vicariance experiments. Reproductive isolation against control populations was only intermittent, so there is reason to doubt if some cases showing significant reproductive isolation really should be attributed to speciation. The method of testing was at least as important as the speciation model. Experimental populations tested against each other were the most likely to demonstrate reproductive isolation. This study suggests that allopatric speciation experiments are more likely to yield conclusive results under divergent selection than under drift, and points to the benefits of large populations and many generations. [source]


Interactive Web-based package for computer-aided learning of structural behavior

COMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 3 2002
X. F. Yuan
Abstract This paper presents an innovative Web-based package named CALSB for computer-aided learning of structural behavior. The package was designed to be widely accessible through the Internet, user-friendly by the automation of many input functions and the extensive use of cursor movements, and dynamically interactive by linking all input and output data to a single graphical display on the screen. The package includes an analysis engine based on the matrix stiffness method, so the response of any two-dimensional skeletal structure can be predicted and graphically displayed. The package thus provides a virtual laboratory environment in which the user can "build and test" two-dimensional skeletal structures of unlimited choices to enhance his understanding of structural behavior. In addition, the package includes two other innovative features, structural games and paradoxes. The structural games in the package represent perhaps the first attempt at intentionally combining the learning of structural behavior with joy and excitement, while the structural paradoxes provide a stimulating environment conducive for the development of creative problem solving skills of the user. © 2002 Wiley Periodicals, Inc. Comput Appl Eng Educ 10: 121,136, 2002; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.10020 [source]


Facilitating process control teaching and learning in a virtual laboratory environment

COMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 2 2002
T. Murphy
Abstract The rapid pace of technological developments and the high cost of engineering equipment, pose several challenges to traditional modes of engineering education. Innovations in education are desirable. In particular, education on practical aspects of engineering and personnel training can be enhanced through the use of virtual laboratories. Such educative experiences allow a student to better understand the theoretical aspects of the discipline in addition to its integration with practical knowledge. In this work, the development, set-up and application of a virtual twin heat exchanger plant is described. The philosophy and methodology of our approach is described, including the implementation details and our experience in using it. The effectiveness of the platform in educating students and in training industrial personnel is described. © 2002 Wiley Periodicals, Inc. Comput Appl Eng Educ 10: 79,87, 2002; Published online in Wiley InterScience (www.interscience.wiley.com.); DOI 10.1002/cae.10011 [source]


Behavioral economic analysis of cue-elicited craving for alcohol

ADDICTION, Issue 9 2010
James MacKillop
ABSTRACT Aims Craving as a motivational determinant of drug use remains controversial because of ambiguous empirical findings. A behavioral economic approach may clarify the nature of craving, theorizing that subjective craving functionally reflects an acute increase in a drug's value. The current study tested this hypothesis via a multidimensional assessment of alcohol demand over the course of an alcohol cue reactivity procedure. Design One-way within-subjects design. Setting Human laboratory environment. Participants Heavy drinkers (n = 92) underwent exposures to neutral (water) cues followed by personalized alcohol cues. Assessments Participants were assessed for craving, alcohol demand, affect, and salivation following each exposure. Findings Alcohol versus neutral cues significantly increased craving and multiple behavioral economic measures of the relative value of alcohol, including alcohol consumption under conditions of zero cost (intensity), maximum expenditure on alcohol (Omax), persistence in drinking to higher prices (breakpoint) and proportionate price insensitivity (normalized Pmax). Craving was significantly correlated with demand measures at levels ranging from 0.21,0.43. Conclusions These findings support the potential utility of a behavioral economic approach to understanding the role of environmental stimuli in alcohol-related decision making. Specifically, they suggest that the behavioral economic indices of demand may provide complementary motivational information that is related to though not entirely redundant with measures of subjective craving. [source]


The fig wax scale Ceroplastes rusci (Linnaeus) (Homoptera: Coccidae) in south-east Vietnam: Pest status, life history and biocontrol trials with Eublemma amabilis Moore (Lepidoptera: Noctuidae)

ENTOMOLOGICAL RESEARCH, Issue 4 2006
Nga Thi VU
Abstract The fig wax scale Ceroplastes rusci (Linnaeus) is a serious pest of fruit trees in many countries. In the present study we investigated the extent of C. rusci infestation and the range of host species, particularly in fruit orchards, in south-east Vietnam. Captive populations of C. rusci were established to record life history parameters and to investigate the efficacy of an endemic predacious moth, Eublemma amabilis Moore, as a potential biocontrol agent. Heavy infestation of C. rusci (up to 100%) was recorded in soursop and other fruit orchards, and the culturally important Hoa Mai flower was also affected. Captive breeding trials found E. amabilis to be an efficient predator of C. rusci, but an unusual hyperactive trait in early instars of E. amabilis resulted in lower than expected survival rates. The implications of this trait in terms of the laboratory environment, augmentative release protocols and as a survival strategy are discussed. [source]


Postexposure feeding depression: A new toxicity endpoint for use in laboratory studies with Daphnia magna

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2002
Ruth A. McWilliam
Abstract In situ bioassays with daphnids currently employ lethality as an endpoint, and although sublethal responses (reproduction and feeding rate) can be measured in the field, such endpoints pose major practical challenges. Previous studies have indicated that Daphnia magna exposed to toxic substances can exhibit delayed recovery in feeding behavior (postexposure feeding depression). This simple, robust response has the potential to be an ecologically relevant and potentially diagnostic endpoint. This study developed and tested the use of postexposure feeding depression as a toxicity endpoint in the laboratory environment. First, replicate numbers were manipulated to produce statistically reliable results. Second, postexposure feeding depression in D. magna was studied under laboratory conditions, by employing toxic substances with differing modes of action. Although most substances caused feeding inhibition during direct exposure, not all substances produced postexposure feeding depression. However, the use of lethality as a supplementary endpoint provided an alternative measure when no feeding depression was apparent after exposure. In combination, these endpoints offer a potentially more sensitive, ecologically relevant alternative to the use of lethality alone for in situ bioassay studies. [source]


Dose-dependent growth inhibition and bioaccumulation of hexavalent chromium in land snail Helix aspersa aspersa

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2000
Michaël C, urdassier
Abstract The toxicity of Cr6+ was determined in a laboratory environment in the snail Helix aspersa aspersa. The effects on growth were evaluated on animals reared in controlled conditions at the age of one month that had been exposed for 28 d to increasing doses of Cr6+ mixed in with their food. Two experimental groups were set up with concentrations of chromium in the feed of 250 to 1,250 ,g/g (test 1) and 100 to 800 ,g/g (test 2). Growth inhibition was dose dependent, and the mean EC50 calculated at four weeks for tests 1 and 2 were, respectively, 354.7 and 298.8 ,g/g and for the EC10 195.3 and 160.9 ,g/g. The levels of Cr6+ bioaccumulated in the foot and the viscera of the snails were dose dependent in both types of tissues. The highest concentrations occurred in the viscera, the levels being 0.79 ,g/g in the controls and reaching 3,067 ,g/g in the animals exposed to the maximum contamination (1,250 ,g/g). These high levels of bioaccumulation in addition to the lower concentrations of Cr6+ excreted in the feces than those present in the food suggest that chromium is not physiologically regulated by Helix aspersa. The results provide added support for the use of snails as a model to determine the toxicity of substances in laboratory biotests by measuring the effects on growth and by assessing bioaccumulation. [source]


DO FEMALE SPIDERS SELECT HEAVIER MALES FOR THE GENES FOR BEHAVIORAL AGGRESSIVENESS THEY OFFER THEIR OFFSPRING?

EVOLUTION, Issue 6 2003
S. E. RIECHERT
Abstract., We explore the hypothesis that females choose to mate with heavier males for the genes for behavioral aggressiveness they offer their offspring in the desert spider, Agelenopsis aperta. Behavioral aggressiveness is important to competition for limited resources in the field and is thus correlated with the mass spiders achieve. We established four crosses based on the body mass relationships of parents subjected to selection in their natural environment (female mass/male mass: HI/HI, HI/LO, LO/HI, and LO/LO) and reared the F1 offspring in a noncompetitive laboratory environment. Offspring size and mass at maturity were measured, life history parameters recorded, and behavioral aggressiveness scored in a series of tests. Significant familial effects were detected in all of these measures, but pertinent cross effects were observed only in the assays measuring behavioral aggressiveness. The results were summarized in terms of the fitness costs to HI females of mating with LO males (fewer female offspring of the more aggressive phenotypes) and the benefits to LO females of mating with HI males (fewer fearful offspring of both sexes). [source]


Common variations in the pretest environment influence genotypic comparisons in models of anxiety

GENES, BRAIN AND BEHAVIOR, Issue 7 2005
G. S. Izídio
The behavioral characterization of rodent strains in different studies and laboratories can provide unreplicable results even when genotypes are kept constant and environmental control is maximized. In the present study, the influence of common laboratory environmental variables and their interaction with genotype on the results of behavioral tests of anxiety/emotionality were investigated. To this end, the inbred rat strains Lewis (LEW) and spontaneously hypertensive rats (SHR), which are known to differ for numerous emotionality-related behaviors, were tested in the open field (OF), elevated plus maze (EPM) and black/white box (BWB), while three environmental factors were systematically controlled and analyzed: (1) the experimenter handling the animal (familiar or unfamiliar); (2) the position of the home cage (top or bottom shelf of the rack) and (3) the behavioral state of the animal immediately before the test (arousal or rest). Experimenter familiarity did not alter the behavior of rats in the OF. Cage position, on the other hand, influenced the behavior in the OF and BWB, with rats housed in top cages appearing less anxious like than those housed in the bottom. In the BWB (but not in the OF), these effects were genotype dependent. Finally, the behavioral state of the animals prior to testing altered the results of the EPM in a strain-dependent manner, with some anxiety-related genotypic differences being found only among rats that were aroused in their home cages. This study showed that common variations in the laboratory environment interact with genotype in behavioral tests of anxiety/emotionality. Recognizing and understanding such variations can help in the design of more effective experiments. [source]


Vision system for on-line characterization of paper slurry ,

INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 4 2000
Hamed Sari-Sarraf
This paper presents a detailed description of a vision system that detects and localizes the nonuniformities that appear on the paper slurry (wood fiber and water mixture) at the wet end of a paper machine. Specifically, the system monitors the paper slurry as it exits the headbox and alerts the operators of any event (e.g., streaks) that disrupts the otherwise homogeneous background. These events affect crucial product properties such as formation. A poor formation results in thick and thin spots on the sheet and impacts its strength and printability. This paper describes the vision system in terms of its hardware modules, as well as the image processing algorithms that it utilizes to perform its function. The system acquires intensity and topographic information from the scene. It uses texture-based features for the detection and facet-based descriptors for the localization of the nonuniformities. In addition to being tested in a laboratory environment, a prototype of this system was constructed and deployed to a paper mill, where its performance was evaluated under realistic conditions. Installed on a fourdrinier paper machine, running at 480 m/min and producing linerboard material, the vision system monitored about a 1 m wide area and successfully detected and localized slurry streaks. Published 2001 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 11, 231,242, 2000 [source]


A focusing Laue diffractometer for the investigation of bulk crystals

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2008
Matthias Stockmeier
A focusing Laue diffractometer for high-energy X-rays of up to 300,keV in a laboratory environment is presented. The long attenuation length for X-ray energies above 50,keV allows for the non-destructive investigation of structural issues and bulk properties of single crystals. Furthermore, massive sample environments such as high-temperature furnaces can be used more easily. With an area detector, anisotropic mosaicities or crystallite structure become visible without any rocking movement of the sample. [source]


Predicting % of crystallinity in FCC catalysts by FT-MIR and PLS

JOURNAL OF CHEMOMETRICS, Issue 11-12 2008
Angel Dago
Abstract This paper describes an analytical procedure for prediction of percent of crystallinity of fluidized catalytic cracking catalysts (FCC) using Fourier transform mid infrared spectroscopy (FT-MIR) and partial least-squares (PLS) multivariate calibration technique. In order to make a robust regression model, multiplicative scatter correction (MSC) and smoothed second derivative pre-processing methods were tested. Root mean squared error of prediction (RMSEP) of an independent test set was used to measure the performance of the models. The comparison shows that reasonable values of RMSEP and RMSECV were obtained for PLS-MSC model (RMSEP,=,0.8% and RMSECV,=,1.3%). The accuracy of the results obtained by the PLS-MSC regression model is in accordance with the uncertainty of the XRPD reference method. The developed method can be implemented in a refinery laboratory environment with ease. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Phenotypic and genetic variation in emergence and development time of a trimorphic damselfly

JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 6 2005
J. ABBOTT
Abstract Although colour polymorphisms in adult organisms of many taxa are often adaptive in the context of sexual selection or predation, genetic correlations between colour and other phenotypic traits expressed early in ontogeny could also play an important role in polymorphic systems. We studied phenotypic and genetic variation in development time among female colour morphs in the polymorphic damselfly Ischnura elegans in the field and by raising larvae in a common laboratory environment. In the field, the three different female morphs emerged at different times. Among laboratory-raised families, we found evidence of a significant correlation between maternal morph and larval development time in both sexes. This suggests that the phenotypic correlation between morph and emergence time in the field has a parallel in a genetic correlation between maternal colour and offspring development time. Maternal colour morph frequencies could thus potentially change as correlated responses to selection on larval emergence dates. The similar genetic correlation in male offspring suggests that sex-limitation in this system is incomplete, which may lead to an ontogenetic sexual conflict between selection for early male emergence (protandry) and emergence times associated with maternal morph. [source]


Adaptation to the laboratory environment in Drosophila subobscura

JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 1 2000
Matos
Adaptation to a novel environment is expected to have a number of features. Among these is a temporal increase in fitness and some or all of its components. It is also expected that additive genetic variances for these fitness characters will fall. Finally, it is expected that at least some additive genetic correlations will decrease, from positive toward negative values. In a study of several life-history variables in a Drosophila subobscura population sampled from the wild and then cultured in the laboratory, we did not find any such longitudinal trends over the first 29 generations. However, a temporal comparison (over 14 generations) of the later generations of this laboratory-adapted population with a new population, derived from a more recent wild-caught sample, indicated clearly that laboratory adaptation was nonetheless occurring. This study suggests the need for extensive replication and control in studies of the features of adaptation to a novel environment. [source]


The role of predation in variation in body shape in guppies Poecilia reticulata: a comparison of field and common garden phenotypes

JOURNAL OF FISH BIOLOGY, Issue 6 2009
J. G. Burns
The body shapes of both wild-caught and laboratory-reared male and female Trinidadian guppies Poecilia reticulata from two low-predation and two high-predation populations were studied, but predation regime did not seem to be the most important factor affecting body shape. Instead, complicated patterns of plasticity in body shape among populations and the sexes were found. In particular, populations differed in the depth of the caudal peduncle, which is the muscular region just anterior to the tail fin rays and from which most swimming power is generated. Strikingly, the direction of population differences in caudal peduncle depth observed in wild-caught individuals was reversed when P. reticulata were raised in a common laboratory environment. [source]


Chemical understanding and graphing skills in an honors case-based computerized chemistry laboratory environment: The value of bidirectional visual and textual representations,

JOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 2 2008
Yehudit J. Dori
Abstract The case-based computerized laboratory (CCL) is a chemistry learning environment that integrates computerized experiments with emphasis on scientific inquiry and comprehension of case studies. The research objective was to investigate chemical understanding and graphing skills of high school honors students via bidirectional visual and textual representations in the CCL learning environment. The research population of our 3-year study consisted of 857 chemistry 12th grade honors students from a variety of high schools in Israel. Pre- and postcase-based questionnaires were used to assess students' graphing and chemical understanding,retention skills. We found that students in the CCL learning environment significantly improved their graphing skills and chemical understanding,retention in the post- with respect to the prequestionnaires. Comparing the experimental students to their non-CCL control peers has shown that CCL students had an advantage in graphing skills. The CCL contribution was most noticeable for experimental students of relatively low academic level who benefit the most from the combination of visual and textual representations. Our findings emphasize the educational value of combining the case-based method with computerized laboratories for enhancing students' chemistry understanding and graphing skills, and for developing their ability to bidirectionally transfer between textual and visual representations. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 219,250, 2008. [source]


The effect of genetic and environmental variation on metabolic gene expression

MOLECULAR ECOLOGY, Issue 13 2009
CINDA P. SCOTT
Abstract What is the relationship between genetic or environmental variation and the variation in messenger RNA (mRNA) expression? To address this, microarrays were used to examine the effect of genetic and environmental variation on cardiac mRNA expression for metabolic genes in three groups of Fundulus heteroclitus: (i) individuals sampled in the field (field), (ii) field individuals acclimated for 6 months to laboratory conditions (acclimated), or (iii) individuals bred for 10 successive generations in a laboratory environment (G10). The G10 individuals have significantly less genetic variation than individuals obtained in the field and had a significantly lower variation in mRNA expression across all genes in comparison to the other two groups (P = 0.001). When examining the gene specific variation, 22 genes had variation in expression that was significantly different among groups with lower variation in G10 individuals than in acclimated individuals. Additionally, there were fewer genes with significant differences in expression among G10 individuals vs. either acclimated or field individuals: 66 genes have statistically different levels of expression vs. 107 or 97 for acclimated or field groups. Based on the permutation of the data, these differences in the number of genes with significant differences among individuals within a group are unlikely to occur by chance (P < 0.01). Surprisingly, variation in mRNA expression in field individuals is lower than in acclimated individuals. Relative to the variation among individual within a group, few genes have significant differences in expression among groups (seven, 2.3%) and none of these are different between acclimated and field individuals. The results support the concept that genetic variation affects variation in mRNA expression and also suggests that temporal environmental variation associated with estuarine environments does not increase the variation among individuals or add to the differences among groups. [source]


Female multiple mating in wild and laboratory populations of the two-spot ladybird, Adalia bipunctata

MOLECULAR ECOLOGY, Issue 13 2008
PENELOPE R. HADDRILL
Abstract Female mating rate is an important variable for understanding the role of females in the evolution of mating systems. Polyandry influences patterns of sexual selection and has implications for sexual conflict over mating, as well as for wider issues such as patterns of gene flow and levels of genetic diversity. Despite this, remarkably few studies of insects have provided detailed estimates of polyandry in the wild. Here we combine behavioural and molecular genetic data to assess female mating frequency in wild populations of the two-spot ladybird, Adalia bipunctata (Coleoptera: Coccinellidae). We also explore patterns of sperm use in a controlled laboratory environment to examine how sperm from multiple males is used over time by females, to link mating with fertilization. We confirm that females are highly polyandrous in the wild, both in terms of population mating rates (~20% of the population found in copula at any given time) and the number of males siring offspring in a single clutch (three to four males, on average). These patterns are consistent across two study populations. Patterns of sperm use in the laboratory show that the number of mates does not exceed the number of fathers, suggesting that females have little postcopulatory influence on paternity. Instead, longer copulations result in higher paternity for males, probably due to the transfer of larger numbers of sperm in multiple spermatophores. Our results emphasize the importance of combining field and laboratory data to explore mating rates in the wild. [source]


Analysis of von Willebrand factor structure by multimer analysis,

AMERICAN JOURNAL OF HEMATOLOGY, Issue 7 2010
Marlies R. Ledford-Kraemer
Analysis of von Willebrand factor (VWF) structure is achieved by performing a highly specialized procedure, VWF multimer analysis. The test is reserved for the reference or specialized laboratory environment. The assay is qualitative (though under some circumstances multimers may be quantified) in that it assesses the overall size distribution of VWF multimers as well as their individual internal structure. The test is used predominantly to type or subtype von Willebrand disease. The analysis of VWF multimers generally consists of four steps: (1) electrophoresis of plasma in an agarose gel, (2) either gel fixation or transfer of the electrophoretic protein product to a membrane, (3) immunodetection of the protein, and (4) evaluation of the protein in the gel or membrane. The assay is complex, time consuming, requires specialized equipment and technical expertise, and is not standardized. Am. J. Hematol., 2010. © 2010 Wiley-Liss, Inc. [source]


Feedback withdrawal and changing compliance during manual hyperinflation

PHYSIOTHERAPY RESEARCH INTERNATIONAL, Issue 2 2002
Julie Hila
Abstract Background and Purpose The performance of manual hyperinflation by physiotherapists can be improved by the availability of a pressure manometer. The present study aimed to test whether these benefits could be maintained when the manometer is withdrawn and whether the availability of a manometer affects the pressures delivered under changing respiratory compliances. Method Manual hyperinflation breaths were delivered to a test lung by student physiotherapists, with a target peak airway pressure of 30 cm H2O under control, feedback and feedback-withdrawal conditions. The breaths were delivered for three trials under each testing condition at each of three respiratory compliance settings. Results The availability of augmented feedback increased the accuracy and reduced the variability of performance; however, these improvements were not maintained when feedback was withdrawn. Changing respiratory compliance significantly affected the accuracy and variability during the control and withdrawal conditions, but the availability of a manometer negated these differences. Conclusions The availability of a pressure manometer negates the influence of respiratory compliance on the achievement of target peak airway pressures during manual hyperinflation in the laboratory environment, however these benefits are not retained when feedback is withdrawn. Therefore, it is recommended that a pressure manometer should be routinely available during manual hyperinflation in clinical practice to optimize treatment safety and effectiveness. Copyright © 2002 Whurr Publishers Ltd. [source]


Do Strong Group Identities Fuel Intolerance?

POLITICAL PSYCHOLOGY, Issue 5 2006
Evidence From the South African Case
One conventional explanation of intergroup conflict is Social Identity Theory. That theory asserts that strong ingroup sympathies can give rise to outgroup antipathies which in turn fuel intolerance and conflict. While embraced by both macro- and microlevel analysts, this theory actually has not been widely investigated outside a laboratory environment. In this article, I test hypotheses linking group identities with intolerance, based on a 2001 survey in South Africa, a country where group identities have long been politicized. My empirical findings indicate that group identities are not useful predictors of South African intolerance. Indeed, for neither the black majority nor the white minority do ingroup identities activate very much outgroup intolerance. Moreover, group identities are positively, not negatively, correlated with holding a South African national identity. These findings, based on unusually broad indicators of both identity and tolerance, suggest that the causes of group conflict lie elsewhere than in group attachments. [source]


Porous polymer monolith for surface-enhanced laser desorption/ionization time-of-flight mass spectrometry of small molecules

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 13 2004
Dominic S. Peterson
Porous poly(butyl methacrylate- co -ethylene dimethacrylate), poly(benzyl methacrylate- co -ethylene dimethacrylate), and poly(styrene- co -divinylbenzene) monoliths have been prepared on the top of standard sample plates used for matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and the modified plates were used for laser desorption/ionization mass spectrometry (LDI-MS). The hydrophobic porous surface of these monoliths enables the transfer of sufficient energy to the analyte to induce desorption and ionization prior to TOFMS analysis. Both UV and thermally initiated polymerization using a mask or circular openings in a thin gasket have been used to define spot locations matching those of the MALDI plates. The desorption/ionization ability of the monolithic materials depends on the applied laser power, the solvent used for sample preparation, and the pore size of the monoliths. The monolithic matrices are very stable and can be used even after long storage times in a typical laboratory environment without observing any deterioration of their properties. The performance of the monolithic material is demonstrated with the mass analysis of several small molecules including drugs, explosives, and acid labile compounds. The macroporous spots also enable the archiving of samples. Copyright © 2004 John Wiley & Sons, Ltd. [source]


Habituation and desensitization as methods for reducing fearful behavior in singly housed rhesus macaques

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 1 2009
Andrea W. Clay
Abstract Operant conditioning using positive reinforcement techniques has been used extensively in the management of nonhuman primates in both zoological and laboratory settings. This research project was intended to test the usefulness of counter-conditioning techniques in reducing the fear-responses of singly housed male rhesus macaques living in the laboratory environment. A total of 18 male rhesus macaques (Macaca mulatta) were selected for this project and randomly assigned to one of three groups: a desensitization training group, a husbandry training group, or a control group. Behavioral data were collected before and after a 6 weeks training and/or habituation period during which the first two groups received a total of 125,min of positive reinforcement training (and also were assumed to undergo habituation to the environment) and the control group experienced only simple habituation to the environment. Based on a Wilcoxon Matched-Pairs Sign Test, we found that a significant proportion of animals exposed to desensitization training showed a reduction in the rate at which they engaged in cringing toward humans (exact significance=0.016, one-tailed, N,ties=6), cringing in general (exact significance=0.016, one-tailed, N,ties=6), and in stress-related behaviors (exact significance=0.016, one-tailed, N,ties=6). This was not the case for animals exposed to basic husbandry training or animals in the control group. A significant proportion of desensitization-exposed animals also showed a reduction in the duration of time spent cringing toward humans (exact significance=0.016, one-tailed, N,ties=6), but not in cringing behaviors in general or in stress-related behaviors. There were not a significant proportion of animals in either the husbandry training group or the control group that showed a decrease in duration of these behaviors. Results of this study could enhance both laboratory animal welfare and laboratory animal research, and could be a first step in developing techniques for reducing fearful behavior in rhesus monkeys in the laboratory environment. Am. J. Primatol. 71:30,39, 2009. © 2008 Wiley-Liss, Inc. [source]


A review of the effects of catch-and-release angling on black bass, Micropterus spp.: implications for conservation and management of populations

FISHERIES MANAGEMENT & ECOLOGY, Issue 2 2007
M. J. SIEPKER
Abstract, This paper summarises recent peer-reviewed literature addressing the effects of catch-and-release angling on black bass, Micropterus spp., to facilitate management and conservation of these fish. Traditionally, the effects of catch and release have been evaluated by measuring mortality. Many recent studies have measured sublethal effects on physiology and behaviour. There is also greater emphasis on adding more realism to sublethal catch-and-release experiments through angler involvement in research activities and by conducting studies in the field rather than in laboratory environments. Owing to these advances, there have been a number of recent findings, which are summarised here, related to air exposure, gear (e.g. circle hooks) and the weigh-in procedure that are particularly relevant to black bass anglers, tournament organisers and fishery managers. Additional research is particularly needed for: (1) population-level effects of angling for nesting fish; (2) population-level effects of tournament-associated mortality; (3) effectiveness of livewell additives for enhancing survival; (4) consequences of fish displacement in competitive events; (5) effects of weigh-in procedures and other organisational issues on fish condition and survival; and (6) reducing barotrauma. [source]