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Assis Neto, A. C., F. T. Verechia, C. E. Ambrosio, M. L. V. Alberto, F. V. Meirelles, J. M. Garcia, J. M. Santos, and M. A. Miglino. "119 EARLY BOVINE GESTATIONAL DEVELOPMENT: MANIPULATED (IVF) AND NOT MANIPULATED IN LABORATORY." Reproduction, Fertility and Development 18, no. 2 (2006): 168. http://dx.doi.org/10.1071/rdv18n2ab119.
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High embryonic and fetal death rates in manipulated embryos in laboratory suggest that the process of early placentation can be inefficient. This investigation aimed to evaluate the development of placenta, and organogenesis of Nelore bovine embryos, and fetuses by natural stud and in vitro fertilization (IVF) over the period from 15 to 70 days of pregnancy. Fifty-nine embryos (15 to 50 days of gestation), 9 fetuses in initial period (60 to 70 days of gestation), and 10 embryos originated by IVF technique (35 to 46 days of gestation) were used. The same semen was used for all IVF, except the embryos originated by natural stud. The embryos were prepared by serial sections and the fetal membranes were fixed in 4% paraformaldehyde for light and scanning electron microscopy (SEM) and 2.5% glutaraldehyde for transmission electron microscopy (TEM). All material was routinely processed and stained. The embryos and fetuses originating from natural stud showed an increase in growth based on the weight of the gestational sac, and related with cranio-caudal and dorso-ventral length of the chorioallantois and amniotic membrane in periods from 20 to 30 and from 50 to 60 days of the pregnancy. The gross appearance of the first cotyledons in development (9.39 � 0.73 cm) was quantified at 30 to 40 days of pregnancy. The IVF embryos on days 35 to 46 of gestation showed discreet cotyledons presenting a functional decrease of development related to embryo derived naturally. Ultrastructurally, the trophoblast showed binucleate trophoblast giant cells with a cytoplasm rich in electrodense vesicles and few mitochondria located in the apical poles suggesting lower cell activity. The yolk sacs of IVF embryos were shorter (1.07 � 0.55 cm) when compared with the natural group (5.53 � 3.14 cm) over 30 to 40 days of pregnancy. In both groups, the epithelium of the yolk sac presented cells with round nuclei, hemangioblast cells, and blood islands with a great number of primitive mononuclear cells. Embryos by natural stud (10% of analyzed ones) showed malformations in cephalic and frontal curvature, encephalocele, gastroschisis, and hepatomegaly. In conclusion, these results indicate occurrence of alteration in the organogenesis in bovine embryos originated by natural stud and retardation of fetal membrane development in bovine embryos by IVF. This work was supported by FAPESP and CAPES.
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Pruitt, Dean. "Field Experiments on Social Conflict." International Negotiation 10, no. 1 (2005): 33–50. http://dx.doi.org/10.1163/1571806054741173.
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AbstractField experiments, in which the researcher manipulates one or more variables in a naturally occurring setting, have sometimes been used in studies of social conflict and should probably be used more often. They are more useful than observational studies for assessing the impact of novel conditions, establishing cause and effect, and reducing confounding. And they are more useful than laboratory experiments for examining long-term effects and those that involve strong passions, and for establishing external validity. However field experiments also have their limitations. Some variables cannot be practically or ethically manipulated and require the use of observational methods, which are also more useful for looking at the relationships among a large number of variables and for estimating the strength of association between variables. Furthermore, laboratory experiments allow more control of conditions and greater flexibility in designing manipulations. What this suggests is that all three methods have their value.
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Whitelock, Victoria, and Eric Robinson. "Remembered Meal Satisfaction, Satiety, and Later Snack Food Intake: A Laboratory Study." Nutrients 10, no. 12 (December 3, 2018): 1883. http://dx.doi.org/10.3390/nu10121883.
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It is well established that the satiety providing effects of food can influence meal size and a disparate area of research suggests that memory regarding recent eating informs food intake. Here we examined whether remembered meal satisfaction (encompassing memory for meal liking and satiety) can be manipulated in the laboratory and whether this influences later food intake. Participants (N = 128, body mass index mean = 23.46kg/m2, standard deviation = 4.70) consumed a fixed lunch and then rehearsed the satisfying or dissatisfying aspects of the meal, or a neutral experience (control), in order to manipulate memory for meal satisfaction. Three hours later participants completed a bogus taste-test to measure food intake and meal memory measures. There was no evidence that memory for general satisfaction with the meal was affected by the rehearsal condition. However, in the dissatisfying rehearsal condition, participants remembered being less satisfied with the satiety-providing effects of the lunch meal than in the satisfying and neutral rehearsal conditions. Snack food consumption did not differ across conditions and there was a small negative correlation between how satiating participants remembered their earlier meal to be and later snack food intake (r = −0.16, p = 0.07). The present study did not produce evidence that memory relating to meal satiety affects later food intake but further research is warranted.
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Du, Weiguo, Jonathan K. Webb, and Richard Shine. "Heat, sight and scent: multiple cues influence foraging site selection by an ambush-foraging snake Hoplocephalus bungaroides (Elapidae)." Current Zoology 55, no. 4 (August 1, 2009): 266–71. http://dx.doi.org/10.1093/czoolo/55.4.266.
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Abstract Most mobile organisms respond to multiple cues when selecting habitat types, and laboratory experiments that manipulate only single cues may fail to reveal the true complexity of habitat-selection behaviour. In south- eastern Australia, broad headed snakes Hoplocephalus bungaroides (Elapidae) lie in wait under sun-warmed rocks to ambush velvet geckos Oedura leseuerii (Gekkonidae). Previous laboratory work has shown that both the geckos and the snakes actively select hotter rather than colder rocks, and that the snakes actively select rocks scented by geckos. We manipulated rock temperature and the presence of two types of cues from geckos (chemical and visual information) to clarify the causal basis for foraging site selection by the juveniles of this snake. When given a choice between cold lizard-scented rocks and hot unscented rocks, our captive snakes gave a higher priority to lizard scent than to temperature. The snakes also selected shelter-sites that provided visual as well as scent cues from lizards, rather than shelter-sites with scent cues alone. Thus, although broad-headed snakes show a direct preference for hotter rather than colder rocks in the laboratory, their choice of foraging site in the field may also be influenced by the presence of scent cues from prey. Our laboratory results suggest that habitat selection by broad-headed snakes may be more complex than has been suggested by previous single-factor laboratory trials.
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Homann, Peter S., and David F. Grigal. "Molecular Weight Distribution of Soluble Organics from Laboratory-Manipulated Surface Soils." Soil Science Society of America Journal 56, no. 4 (July 1992): 1305–10. http://dx.doi.org/10.2136/sssaj1992.03615995005600040049x.
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Dunbar, Maureen E., and John J. Wysolmerski. "Mammary ductal and alveolar development: Lesson learned from genetically manipulated mice." Microscopy Research and Technique 52, no. 2 (2001): 163–70. http://dx.doi.org/10.1002/1097-0029(20010115)52:2<163::aid-jemt1002>3.0.co;2-r.
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Oberst, Sebastian, Michael Lenz, Joseph C. S. Lai, and Theodore A. Evans. "Termites manipulate moisture content of wood to maximize foraging resources." Biology Letters 15, no. 7 (July 2019): 20190365. http://dx.doi.org/10.1098/rsbl.2019.0365.
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Animals use cues to find their food, in microhabitats within their physiological tolerances. Termites build and modify their microhabitat, to transform hostile environments into benign ones, which raises questions about the relative importance of cues. Termites are desiccation intolerant and foraging termites are attracted to water, so most research has considered moisture to be a cue. However, termites can also transport water to food, and so moisture may play other roles than previously considered. To examine the role of moisture, we compared Coptotermes acinaciformis termite foraging decisions in laboratory experiments when they were offered dry and moist wood, with and without load. Without load, termites preferred moist wood and ate it without any building, whereas they moistened dry wood after wrapping it in a layer of clay. For the ‘With load’ units, termites substituted some of the wood for load-bearing clay walls, and kept the wood drier than on the unloaded units. As drier wood has higher compressive strength and higher rigidity, it allows more of the wood to be consumed. These results suggest that moisture plays a more important role in termite ecology than previously thought. Termites manipulate the moisture content according to the situational context and use it for multiple purposes: increased moisture levels soften the fibre, which facilitates foraging, yet keeping the wood dry provides higher structural stability against buckling which is especially important when foraging on wood under load.
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Andersen, David J., and Tessa Ditonto. "Information and its Presentation: Treatment Effects in Low-Information vs. High-Information Experiments." Political Analysis 26, no. 4 (August 3, 2018): 379–98. http://dx.doi.org/10.1017/pan.2018.21.
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This article examines how the presentation of information during a laboratory experiment can alter a study’s findings. We compare four possible ways to present information about hypothetical candidates in a laboratory experiment. First, we manipulate whether subjects experience a low-information or a high-information campaign. Second, we manipulate whether the information is presented statically or dynamically. We find that the design of a study can produce very different conclusions. Using candidate’s gender as our manipulation, we find significant effects on a variety of candidate evaluation measures in low-information conditions, but almost no significant effects in high-information conditions. We also find that subjects in high-information settings tend to seek out more information in dynamic environments than static, though their ultimate candidate evaluations do not differ. Implications and recommendations for future avenues of study are discussed.
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Pittenger, David J. "Perception Laboratory: A Computer Program to Demonstrate Perceptual Phenomena." Teaching of Psychology 23, no. 1 (February 1996): 46–48. http://dx.doi.org/10.1207/s15328023top2301_12.
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I developed an interactive computer program that allows one to demonstrate and experiment with various phenomena in visual perception using IBM-compatible computers. The program contains modules for demonstrating the color afterimage, the cafe illusion, additive color mixing and the opponent-process theory of color vision, the glowing axes illusion, the Hermann grid, the McCollough effect, the motion aftereffect, the neon illusion, and simultaneous contrast. The user has considerable control over the stimuli making up the image and can manipulate the variables that contribute to the perception of the effect. The program can be used far classroom demonstrations and student laboratory projects.
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Simmons, Mike, Sharon Daniel, and Mark Temple. "How to manipulate friends and influence practice: Application of complexity science leads to quality improvement in laboratory sample submissions." Journal of Infection Prevention 20, no. 2 (March 2019): 91–98. http://dx.doi.org/10.1177/1757177419831348.
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Background: We sought to reduce healthcare-associated infections (HCAIs) through the application of complexity science. Objective: To confirm incidental findings that altering the structure of microbiology reports with targeted education led to better utilisation of laboratory resources, while participating in efforts to reduce HCAI. Methods: We adopted a different approach to laboratory result authorisation, using narrative to engage the clinicians and induce behavioural change. Subsequent educational opportunities emphasised key messages. Findings/Results: Positive urine means calculated by the analysis tool numbered 2179/month throughout the study period. Negative urines started at 5576/month, reduced to 5134/month in November 2014 and to 4602/month in April 2016, coinciding with our changes. Opportunity costs were saved. Discussion: The changes in both policy and reporting were contemporaneous with a decline in negative samples. There were no significant changes in the number of positive specimens. The efficiency and effectiveness of the laboratory was improved and resources released: £145,000 ($182,000) for a resident population of 384,000. This suggests an annual release of about £25 million ($31 million) may be possible in the UK and £122 million ($155 million) in the USA.
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Al-Ubaydli, Omar, and John A. List. "Do Natural Field Experiments Afford Researchers More or Less Control than Laboratory Experiments?" American Economic Review 105, no. 5 (May 1, 2015): 462–66. http://dx.doi.org/10.1257/aer.p20151013.
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A commonly held view is that laboratory experiments provide researchers with more “control” than natural field experiments. This paper explores how natural field experiments can provide researchers with more control than laboratory experiments. While laboratory experiments provide researchers with a high degree of control in the environment which participants agree to be experimental subjects, when participants systematically opt out of laboratory experiments, the researcher's ability to manipulate certain variables is limited. In contrast, natural field experiments bypass the participation decision altogether due to their covertness, and they allow for a potentially more diverse participant pool within the market of interest.
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Hermawan, Yulius Deddy. "Design of Flow Control System with A Kickback Flow as A Manipulated Variable." Eksergi 14, no. 2 (December 31, 2017): 23. http://dx.doi.org/10.31315/e.v14i2.2089.
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The open loop experiment of water flow dynamic in pipe has been done in laboratory. Pump was used to flow water in pipe. Part of liquid from discard of pump was recycled back to the suction of pump (kickback) and adjusted to control the liquid flow to the next process. The open loop laboratory experiment produced the steady state parameters; they were discard flowrate =16.6 [L/min], kickback flowrate =5.8 [L/min], and liquid flowrate to the next process =10.8 [L/min]. These steady state parameters were then used as the initial value for closed loop simulation with computer programming. This study has proposed the liquid flow control configuration by manipulating the kickback flow. Proportional Integral (PI) was proposed to control the flow and Routh-Hurwitz (RH) stability criterion was chosen to predict the range of the controller gain (Kc) that gives stable response. The closed loop model was solved analytically with Laplace method for both servo and regulatory problems. The set point change of flow and disturbance were made based on step function. The scilab software was used to do closed loop simulation. Based on RH stability criterion, the controller gain should be negative in order to give stable response. The closed loop simulation showed that by using controller gain Kc=–0.5 and integral time constant tI=0.3 [min], stable and fast response with Integral Absolute Error (IAE) near to zero (0,0022) could be achieved.
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Esposito, Raffaela, Ilaria Lusini, Kristýna Večeřová, Petra Holišová, Emanuele Pallozzi, Gabriele Guidolotti, Otmar Urban, and Carlo Calfapietra. "Shoot-level terpenoids emission in Norway spruce ( Picea abies ) under natural field and manipulated laboratory conditions." Plant Physiology and Biochemistry 108 (November 2016): 530–38. http://dx.doi.org/10.1016/j.plaphy.2016.08.019.
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Coutteau, Peter, Luc Brendonck, Patrick Lavens, and Patrick Sorgeloos. "The use of manipulated baker's yeast as an algal substitute for the laboratory culture of Anostraca." Hydrobiologia 234, no. 1 (May 1992): 25–32. http://dx.doi.org/10.1007/bf00010776.
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Hui, Chun, Dennis W. Organ, and Karen Crooker. "Time Pressure, Type a Syndrome, and Organizational Citizenship Behavior: A Laboratory Experiment." Psychological Reports 75, no. 1 (August 1994): 199–208. http://dx.doi.org/10.2466/pr0.1994.75.1.199.
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Time pressure was manipulated in a laboratory task for 77 undergraduate subjects, who also responded to a measure of Type A syndrome. Afterwards, an occasion for organizational citizenship behavior was presented in the form of participation in a survey. Type A scores were unrelated to those on any measure of organizational citizenship behavior; time pressure acted to depress especially the quality of organizational citizenship behavior.
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Porta, Angela R., and Edward Enners. "Determining Annealing Temperatures for Polymerase Chain Reaction." American Biology Teacher 74, no. 4 (April 1, 2012): 256–60. http://dx.doi.org/10.1525/abt.2012.74.4.9.
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The polymerase chain reaction (PCR) is a common technique used in high school and undergraduate science teaching. Students often do not fully comprehend the underlying principles of the technique and how optimization of the protocol affects the outcome and analysis. In this molecular biology laboratory, students learn the steps of PCR with an emphasis on primer composition and annealing temperature, which they manipulate to test the effect on successful DNA amplification. Students design experiments to test their hypotheses, promoting a discovery-based approach to laboratory teaching and development of critical-thinking and reasoning skills.
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Llerena Cano, Guillermo. "Retrospectiva de la tecnología de laboratorio en reproducción asistida." Revista Peruana de Ginecología y Obstetricia 57, no. 1 (April 19, 2015): 8–12. http://dx.doi.org/10.31403/rpgo.v57i198.
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Se revisa la secuencia evolutiva de la tecnología de laboratorio en reproducción asistida. Desde los primeros intentos de manipular embriones preimplantacionales recuperados de oviductos animales, en 1912, las transferencias directas o con breves periodos de incubación a madres receptoras, el complejo proceso bioquímico de preparación y suplementación de los medios de cultivo a partir de soluciones salinas químicamente definidas, la etapa de transición de esta tecnología a los humanos en la que se trabajo básicamente la maduración de ovocitos y la selección de espermatozoides motiles in vitro, hasta los procedimientos que culminaron con la primera aplicación clínica descrita en 1980.
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Schlagintweit, Hera E., Robin N. Perry, Christine Darredeau, and Sean P. Barrett. "Non-pharmacological Considerations in Human Research of Nicotine and Tobacco Effects: A Review." Nicotine & Tobacco Research 22, no. 8 (May 6, 2019): 1260–66. http://dx.doi.org/10.1093/ntr/ntz064.
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Abstract Human research of nicotine and tobacco effects demonstrates that non-pharmacological factors may systematically affect responses to administered substances and inert placebos. Failure to measure or manipulate these factors may compromise study reliability and validity. This is especially relevant for double-blind placebo-controlled research of nicotine, tobacco, and related substances. In this article, we review laboratory-based human research of the impact of non-pharmacological factors on responses to tobacco and nicotine administration. Results suggest that varying beliefs about drug content and effects, perceptions about drug use opportunities, and intentions to cease drug use systematically alter subjective, behavioral, and physiological responses to nicotine, tobacco, and placebo administration. These non-pharmacological factors should be considered when designing and interpreting the findings of human research of nicotine and tobacco effects, particularly when a double-blind placebo-controlled design is used. The clinical implications of these findings are discussed, and we propose methodological strategies to enhance the reliability and validity of future research. Implications Growing research demonstrates that non-pharmacological factors systematically alter responses to acute nicotine, tobacco, and placebo administration. Indeed, varying beliefs about nicotine and/or tobacco administration and effects, differing perceptions about nicotine and/or tobacco use opportunities, and inconsistent motivation to quit smoking have been found to exert important influences on subjective, physiological, and behavioral responses. These variables are infrequently measured or manipulated in nicotine and tobacco research, which compromises the validity of study findings. Incorporating methodological strategies to better account for these non-pharmacological factors has the potential to improve the quality of addiction research and treatment.
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ANUKUL, PREEYANUCH, SOMWANG KHANTAYANUWONG, and PHICHIT SOMBOON. "Development of laboratory wet creping method to evaluate and control pulp quality for tissue." May 2015 14, no. 5 (June 1, 2015): 339–45. http://dx.doi.org/10.32964/tj14.5.339.
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The required properties of tissue paper including softness and liquid absorption are predominantly manipulated by the creping process, which cannot be simply produced in the laboratory. This causes problems in controlling the stock quality prepared using the various types of industrial pulps and consequently affects the creping operation and tissue quality. Our objectives were to develop a laboratory creping method and to apply it for the evaluation and control of the quality of pulp raw materials used in industrial tissue production. The experiment consisted of the development of a laboratory wet creping method and the study of the creping devices and the creping conditions, including basis weight of the base paper, sheet dryness, and degrees of pulp refining. The results showed that the method could produce crepes on laboratory sheets and the structures of the creped sheets could be engineered to improve their softness and liquid absorption. The tested pulps were found to produce significantly different responses to the laboratory wet creping, depending on their morphology and the mechanical treatments. The examination of industrial pulps found that eucalypt, bagasse, bamboo, and deinking pulps needed to be manipulated using different refining levels and required optimization among their softness, liquid absorption, and strength properties.
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Pang, Raina D., Mariel S. Bello, Madalyn M. Liautaud, Andrea H. Weinberger, and Adam M. Leventhal. "Gender Differences in Negative Affect During Acute Tobacco Abstinence Differ Between African American and White Adult Cigarette Smokers." Nicotine & Tobacco Research 21, no. 8 (June 15, 2018): 1072–78. http://dx.doi.org/10.1093/ntr/nty122.
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Abstract Introduction Prior studies have found heightened negative affect following tobacco abstinence in women compared to men. However, experimental work addressing whether these findings generalize across racial groups is scarce. This study investigated whether race (non-Hispanic White vs. non-Hispanic African American) moderated gender differences in abstinence-induced negative affect and smoking behavior. Methods Data were collected from 2010 to 2017 from two separate laboratory studies investigating experimentally manipulated tobacco abstinence. Following a baseline session, adult daily smokers (≥10 cigarettes/day; women: n = 297, 83.8% non-Hispanic African American; men: n = 492, 86.2% non-Hispanic African American) attended two counterbalanced lab sessions (16 hours abstinent vs. non-abstinent) and completed self-report measures of negative affect followed by a laboratory analogue smoking reinstatement task. Results We found a gender × race interaction for several negative affect states and composite negative affect (βs = −.12 to −.16, Ps < .05). Analyses stratified by race showed that non-Hispanic White women compared to non-Hispanic White men exhibited greater abstinence-induced increases in anger, anxiety, and composite negative affect (βs = −.20 to −.29, Ps < .05). No significant gender differences in abstinence-induced negative affect were found for non-Hispanic African American smokers (βs = .00 to − .04, Ps > .05). Conclusion These findings suggest that negative affect during acute tobacco abstinence may be a clinically important and intervenable factor that can inform cessation interventions specifically for non-Hispanic White women smokers. Further empirical exploration of mechanisms underlying interactions of gender and race in tobacco addiction may benefit smoking cessation efforts in non-Hispanic African American women smokers. Implications This study contributes to a scant body of research examining the intersectional influence of race and gender on abstinence-induced negative affect—a central, motivationally prepotent feature of tobacco withdrawal. Using a laboratory-based design to experimentally manipulate abstinence, we provide evidence of a gender × race interaction on negative affect–related withdrawal. Our findings suggest that gender differences in abstinence-induced negative affect observed among non-Hispanic White smokers may not generalize to non-Hispanic African American smokers, highlighting the need for future work to address potential mechanisms underlying the racially discrepant impact of gender on affective tobacco withdrawal.
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Nittérus, Karolina, Åsa Gunnarsson, and Bengt Gunnarsson. "Manipulated structural variability affects the habitat choice of two ground-living beetle species in a laboratory experiment." Entomologica Fennica 19, no. 2 (June 1, 2008): 122–28. http://dx.doi.org/10.33338/ef.84423.
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The habitat choice of two ground-living carabid beetle species (Pterostichus oblongopunctatus (Fabricius) and Carabus hortensis Linneaus) was investigated in a laboratory experiment. Beetles were released in test arenas with two options of manipulated structural variability on the ground, i.e.; bare ground spots versus spots with logging residue (slash). Beetles were studied for 600 seconds and the total time spent on bare ground versus in slash was measured. The results revealed a preference for slash covered ground amongst the investigated beetles. Regardless of species or type of release spot (in the middle of the bare ground or in slash), the carabids resided significantly longer in slash compared with the bare ground. The results support recent studies emphasizing the importance of microhabitat variability for the abundance distribution of arthropods inmanaged systems.
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Seppala, Maisa, Finn Geoghegan, Guilherme Xavier, and Martyn T. Cobourne. "Using the mouse to understand the molecular basis of human craniofacial disorders." Faculty Dental Journal 2, no. 4 (October 2011): 196–202. http://dx.doi.org/10.1308/204268511x13154691747210.
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At first glance the humble mouse might seem an odd choice as a model for studying complex human craniofacial disorders. However, similarities in embryonic development and genome organisation, and our ability to manipulate its genes have made this species the model of choice for investigating human development. Here we describe some examples from our own laboratory of mouse models that are providing insight into the mechanisms underlying two human craniofacial syndromes.
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DI CICCA, GAETANO MARIA, GAETANO IUSO, PIER GIORGIO SPAZZINI, and MICHELE ONORATO. "Particle image velocimetry investigation of a turbulent boundary layer manipulated by spanwise wall oscillations." Journal of Fluid Mechanics 467 (September 24, 2002): 41–56. http://dx.doi.org/10.1017/s002211200200157x.
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Particle image velocimetry has been applied to the study of a canonical turbulent boundary layer and to a turbulent boundary layer forced by transversal wall oscillations. This work is part of the research programme at the Politecnico di Torino aerodynamic laboratory with the objective of investigating the response of near-wall turbulence to external perturbations. Results are presented for the optimum oscillation period of 100 viscous time units and for an oscillation amplitude of 320 viscous units. As expected, turbulent velocity fluctuations are considerably reduced by the wall oscillations. Particle image velocimetry has allowed comparisons between the canonical and forced flows in an attempt to find the physical mechanisms by which the wall oscillation influences the near-wall organized motions.
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Meisel, David D., Kenneth F. Kinsey, and Charles H. Recchia. "Microcomputers in an Introductory College Astronomy Laboratory: A Software Development Project." International Astronomical Union Colloquium 105 (1990): 175–76. http://dx.doi.org/10.1017/s0252921100086656.
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We have developed software for the Apple IIe series of microcomputers for use in labs in an introductory astronomy course. This software emphasizes a toolkit approach to data analysis; it has been class tested with over 170 students and was a resounding success as a replacement for previously used graphical approximations. A unique feature of this software is the incorporation of image-processing techniques into a course designed for non-science majors.The five software packages are:(a)Datasheet - A six-column spreadsheet with columnwise operations, statistical functions, and double-high-resolution graphics.(b)Image-Processor Program - Allows 37 × 27 pixel × 8 bit video captured images to be manipulated using standard image-processing techniques such as low pass/high pass filtering and histogram equalization.(c)Picture-Processor Program - Allows 256 × 192 bilevel pictures to be manipulated and measured with functions that include calipers, odometer, planimeter, and protractor.(d)Orrery Program - Simulates planet configurations along the ecliptic. A movable cursor allows selection of specific configurations. Since both relative times and angular positions are given, students can deduce the scale of the solar system using simple trigonometry.(e)Plot Program - Allows orbital positions as observed from above the pole to be plotted on the screen. By entering trial values of elliptical orbit parameters, students obtain and the program plots the best fitting ellipse to the data. The sum of the squares of the residuals in the radial coordinate is given after each trial so that students can discover convergence more easily than by simple visual examination of a plot comparing the trial theoretical points with the raw data points.
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Giusti, Giovanni, and Roberto Dopeso-Fernández. "Incentive magnitude and reference point shifting: a laboratory experiment." International Journal of Manpower 41, no. 8 (June 26, 2020): 1157–77. http://dx.doi.org/10.1108/ijm-09-2019-0428.
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PurposeThis paper analyzes how different dynamics of changes in piece-rate incentives affect individuals' exerted effort.Design/methodology/approachThe authors constructed an across-subjects three-period laboratory setting where, for each period, they exogenously manipulate the amount of piece-rate incentive paid for correct answer. The same experimental conditions were separately applied to two different laboratory tasks, one boring and the other entertaining.FindingsIt was found that performance contingent incentives affect participants' effort provision, while the effect is task dependent and it is much stronger for the boring task. Moreover, a unique increase in the amount of piece rate between periods leads to an increase in performance only for the boring task. A decrease in piece rate incentive between periods negatively affects subjects' performance on both tasks, but only provided that the decrease follows a previous increase.Originality/valueThe paper is the first to study the effect of a sequence of changes in the amount of piece rate incentives on individual effort provided. Our main result highlights the relevance of the order in which the sequence of changes in piece-rate incentive occurs. Results could be useful for the designing of performance rewards in organizations.
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Easton, D. M. "Simple, inexpensive suction electrode system for the student physiology laboratory." Advances in Physiology Education 265, no. 6 (December 1993): S35. http://dx.doi.org/10.1152/advances.1993.265.6.s35.
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A versatile, inexpensive, easily constructed suction electrode system is described that can be used for routine exercises by the student on, or for demonstrations of, the electrophysiology of frog sciatic nerve and gastrocnemius and sartorius muscles. A disposable plastic syringe and a disposable pipette with Ag-AgCl wire comprise the suction electrode. Six readily manipulable electrodes are installed in the walls of the Plexiglas preparation bath, and an arbitrary number of additional "free" electrodes can be placed where desired. An optional small chamber, formed from a disposable plastic culture dish and Gootch rubber tubing, provides for "barrier" recording within the larger chamber. Interpretations are given of the electrical responses of nerve and muscle in terms of longitudinal currents along the preparation within the suction electrode tubes.
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Criscuolo, F., S. Smith, S. Zahn, B. J. Heidinger, and M. F. Haussmann. "Experimental manipulation of telomere length: does it reveal a corner-stone role for telomerase in the natural variability of individual fitness?" Philosophical Transactions of the Royal Society B: Biological Sciences 373, no. 1741 (January 15, 2018): 20160440. http://dx.doi.org/10.1098/rstb.2016.0440.
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Telomeres, the non-coding ends of linear chromosomes, are thought to be an important mechanism of individual variability in performance. Research suggests that longer telomeres are indicative of better health and increased fitness; however, many of these data are correlational and whether these effects are causal are poorly understood. Experimental tests are emerging in medical and laboratory-based studies, but these types of experiments are rare in natural populations, which precludes conclusions at an evolutionary level. At the crossroads between telomere length and fitness is telomerase, an enzyme that can lengthen telomeres. Experimental modulation of telomerase activity is a powerful tool to manipulate telomere length, and to look at the covariation of telomerase, telomeres and individual life-history traits. Here, we review studies that manipulate telomerase activity in laboratory conditions and emphasize the associated physiological and fitness consequences. We then discuss how telomerase's impact on ageing may go beyond telomere maintenance. Based on this overview, we then propose several research avenues for future studies to explore how individual variability in health, reproduction and survival may have coevolved with different patterns of telomerase activity and expression. Such knowledge is of prime importance to fully understand the role that telomere dynamics play in the evolution of animal ageing. This article is part of the theme issue ‘Understanding diversity in telomere dynamics’.
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Riascos, Roy, Diego Aldana, Miguel Ruiz, and Francisco Villa. "Técnicas histológicas aplicadas a la docencia en morfología." Revista Repertorio de Medicina y Cirugía 10, no. 1 (April 1, 2001): 23–26. http://dx.doi.org/10.31260/repertmedcir.v10.n1.2001.241.
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Se presenta la descripción de una técnica utilizada en histología como lo es la parafinización, aplicada a conservación de piezas de morfología macroscópica. Esta técnica utiliza materiales que se encuentran en cualquier laboratorio de histología, obteniendo como resultado piezas que se pueden manipular sin guantes y sin las desventajas del formol.
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Vaughn, Charlotte, and Tyler Kendall. "Stylistically coherent variants: Cognitive representation of social meaning / Variantes estilisticamente coerentes: representação cognitiva de significados sociais." REVISTA DE ESTUDOS DA LINGUAGEM 27, no. 4 (October 11, 2019): 1787. http://dx.doi.org/10.17851/2237-2083.0.0.1787-1830.
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Abstract: The perception of social meanings and styles is dependent upon the contributions of a constellation of multiple covarying sociolinguistic variants. This suggests that listeners maintain associations between stylistically coherent variants and their social meanings in mental representation. The present paper expands upon this notion, aiming to gain converging evidence from production as a way to explore the cognitive representations of variants and their social meanings more deeply. To do this, four American English speakers were asked to produce sentences containing (ING) words (as in talking vs. talkin’), in their –in and –ing variants, in a laboratory setting. Productions were acoustically analyzed to evaluate whether the speakers also manipulated other stylistically-linked variables, even though prompted only to manipulate (ING). The variant –in has been shown to index a range of social meanings in American English, including Southern and casual. Results demonstrate that speakers indeed modulated other variables beyond (ING) in ways that align with the Southern and casual social meanings of –in. That producing one variant (–in) could lead to stylistically congruent realizations of other variables suggests that speakers not only hold indexical linkages between variants and styles in mental representation, but that variants are also linked to variants of other variables through associations with those styles. A better understanding of social meaning in cognition provides an important base upon which to advance research on sociolinguistic perception.Keywords: covariation; social meaning; cognitive representation; style.Resumo: A percepção de significados sociais e de estilos depende das constribuições de uma constelação de múltiplas variantes sociolinguísticas em covariação. Isto sugere que os falantes mantêm associações entre variantes estilisticamente coerentes e seus significados sociais numa representação mental. O presente trabalho expande essa noção, com o objetivo de ganhar evidências advindas da produção como meio de explorar mais profundamente as representações cognitivas de variantes e de seus significados sociais. Para isso, quatro falantes de inglês norte-americano foram convidados a produzir sentenças que contêm variantes de (ING) (como em talking vs. talkin’ ‘falando’), em contexto de laboratório. As produções foram acusticamente analisadas no sentido de avaliar se os falantes também manipularam estilisticamente outras variáveis, ainda que houvessem sido instruídos a manipular apenas (ING). Trabalhos anteriores já mostraram que a variante –in indicia uma grande extensão de significados sociais em inglês norte-americano, incluindo sotaque sulista e casualidade. Os resultados mostram que os falantes de fato modulam outras variáveis além de (ING) que se alinham a esses significados sociais de –in. O fato de que a produção de uma variante pode conduzir a realizações estilisticamente congruentes de variantes de outras variáveis sugere que os falantes não apenas detêm associações indiciais entre variantes e estilos em sua representação mental, mas também que variantes de diferentes variáveis estão ligadas entre si na sua associação a tais estilos. Entender melhor a significação social de múltiplas variáveis na cognição oferece uma base importante na qual deve avançar a pesquisa sobre percepção sociolinguística.Palavras-chave: covariação; significado social; representação cognitiva; estilo.
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Kinzler, PhD, Eric R., Carmela Pantaleon, BS, Matthew Iverson, MPH, and Stefan Aigner, MD. "In vitro evaluation of a novel immediate-release formulation of oxycodone (RoxyBond™) for the potential for abuse via injection." Journal of Opioid Management 16, no. 5 (September 1, 2020): 383–90. http://dx.doi.org/10.5055/jom.2020.0593.
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Objective: Immediate-release (IR) oxycodone formulations may be manipulated for nonoral routes of administration. Oxycodone abuse-resistant immediate-release (ARIR) is a novel abuse-deterrent formulation (ADF) of IR oxycodone. This study aimed to assess the intravenous (IV) abuse potential of Oxycodone ARIR relative to commercially available IR oxycodone tablets using in vitro laboratory studies.Design: Intact or manipulated tablets were incubated in 5 or 10 mL of room temperature water for increasing amounts of time. For each timepoint, syringeability, defined as the ability to draw up water-immersed intact or manipulated tablets into a syringe, was assessed on a scale of 1 (very easy) to 10 (impossible). If the prepared sample could be drawn into a syringe, the proportion of syringeable oxycodone was measured analytically.Results: In all conditions, it was nearly impossible to draw any liquid into a syringe from samples containing manipulated Oxycodone ARIR tablets (N = 5/ group), and most samples released very low concentrations (10%) of their total oxycodone content, regardless of sample volume. In contrast, samples containing crushed IR oxycodone (N = 5/group) in small volumes of fluid were easily drawn into a syringe through the smallest needle, and more than 90% of the oxycodone content was released from relatively small sample volumes (5 mL).Conclusion: The difficulty required to prepare an injectable solution from Oxycodone ARIR when manipulated suggests that Oxycodone ARIR has abuse-deterrent properties that may deter IV abuse.
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Wang, Shih-Hao, Chung-Lin Tsai, and Han-Chao Chang. "Laboratory Environmental Conditions Influence Patent Inventors’ Creative Self-efficacy." International Business Research 11, no. 5 (April 23, 2018): 159. http://dx.doi.org/10.5539/ibr.v11n5p159.
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A comfortable experimental environment usually enables stress relief among inventors, allowing them to focus on inventing. However, to facilitate smooth and continuous experimental procedures, the public spaces and computing environments of conventional laboratories are usually replete with heavy instruments and interconnected wires; consequently, inventors have limited space to conduct complex experiments. These public spaces and computing environments negatively affect the creative self-efficacy (CSE) of inventors. Based on CSE theory and modified information layout complexity theory, in this study, 100 inventors who had obtained patents were recruited. The results indicated that a wireless cloud public space and computing environment positively moderated and enhanced the relationship between low layout complexity and inventor CSE; conventional public spaces and computing environments featuring cables negatively moderated and weakened the relationship between high layout complexity and inventor CSE. More than 40% of participants highly supported using one electronic tablet to manipulate multiple instruments. The results also revealed that approximately 64% of participants did not think they were essential in promoting critical mass in the laboratory. This finding was significantly different from the degree centrality of creativity perspective. Critical indicators of inventor CSE were found to be inventors’ decision-making capabilities regarding innovative research directions and their communication skills with supervisors.
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Anderson, R. A. "Fertility preservation techniques: laboratory and clinical progress and current issues." REPRODUCTION 136, no. 6 (December 2008): 667–69. http://dx.doi.org/10.1530/rep-08-0270.
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Human fertility is dependent on maturation of germ cells through meiosis and their association with supporting cells, which in the female are also the source of sex steroids. These processes are sensitive to both chemotherapy and radiotherapy thus can be damaged by anti-cancer treatments. The uterus is also sensitive to radiotherapy. Our understanding of and the ability to manipulate fertility has increased together with survival rates from many cancers, particularly those affecting children, younger men, and women. The growth of interest in fertility preservation for cancer patients is a natural union of these two fields. Sperm banking has been available for many years, and is a recognized and evidence-based option for men that should be available to all. Options for women and pre-pubertal boys and girls are, however, more experimental, other than for women of committing oocytes to fertilization and cryopreservation as embryos. This Focus Issue of Reproduction aims to address the current status of some of the clinical and laboratory aspects of this burgeoning subspecialty to highlight not only areas of progress but also areas of uncertainty where future developments are required to allow the provision of accurate information, and safe and effective treatments.
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Miller, R. J., and J. T. Addison. "Trapping interactions of crabs and American lobster in laboratory tanks." Canadian Journal of Fisheries and Aquatic Sciences 52, no. 2 (February 1, 1995): 315–24. http://dx.doi.org/10.1139/f95-032.
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The relationship between trap catches of decapods and their abundance is not well established. Because it is difficult to manipulate density in the field, laboratory tanks were used to examine 10 hypotheses about the intra- and interspecific interactions of rock crab (Cancer irroratus), green crab (Carcinus maenas), and American lobster (Homarus americanus). The proportion of rock crabs captured did not differ among high, medium, and low densities, but the proportion captured was reduced at high densities for both green crabs and lobsters. Additional experiments demonstrated that large green and rock crabs in the tanks reduced the catch of small green and rock crabs and that the presence of lobsters reduced the catch of both crab species considerably. However, small rock crabs did not reduce the catch of large rock crabs, and neither green nor rock crabs reduced the catch of each other. Reductions in the catch of a target species caused by interactions in the field can perhaps be lessened by removing the catch from the trap at intervals of less than 24 h. Then the catches would be summed over 24 h for an index of abundance.
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Grinbaum, Renato Satovschi, Thaís Guimarães, Elisa Kusano, Nair Hosino, Helio Sader, and Rosangela Ferraz Cereda. "A Pseudo-Outbreak of Vancomycin-ResistantEnterococcus faecium." Infection Control & Hospital Epidemiology 24, no. 6 (June 2003): 461–64. http://dx.doi.org/10.1086/502235.
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AbstractFive VRE isolates were reported from sterile samples. No infections were diagnosed among the patients, who were on different wards. PFGE showed that all five isolates were clonal. All samples were manipulated by the same worker, but the source could not be found. Contamination was probably related to manipulation of a source specimen in the laboratory.
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Haney, Justin M., Mary Owczarczak, Clive D’Souza, Monica L. H. Jones, and Matthew P. Reed. "A Pilot Study of the Effects of Pulley Location and Design Parameters on Hand Movements during Pulley Threading Operations." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 60, no. 1 (September 2016): 908–12. http://dx.doi.org/10.1177/1541931213601208.
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Three healthy individuals participated in a laboratory experiment that required routing a thin continuous thread through a series of pulleys mounted on a vertical work surface. Task precision demand was manipulated by altering pulley outer diameter (38 mm, 76 mm, and 152 mm) and groove width (3 mm, 6 mm, and 9 mm). The target location of each destination pulley relative to the origin at the mid-sagittal plane was also manipulated. These factors were hypothesized to influence hand motion trajectories, peak speed, and task completion time. Smaller pulley diameters and larger groove widths, representing lower precision demands, were associated with smoother trajectories and a faster task completion time. These preliminary findings suggest a systematic influence of task precision demands on movement kinematics and task performance.
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Houston, Stephanie. "Arkaitz Carracedo: If the scientific question is good, the result will be interesting." Journal of Experimental Medicine 216, no. 11 (October 15, 2019): 2449–50. http://dx.doi.org/10.1084/jem.20191880.
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Arkaitz Carracedo is a principal investigator at the Association for Cooperative Research in Biosciences (CIC bioGUNE) in Spain; his laboratory focuses on signaling and metabolic alterations in cancer. Arkaitz has investigated the regulation of fatty acid oxidation in cancer cells and how these changes could be manipulated therapeutically. We chatted with Arkaitz to find out about his career in science so far.
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Wogalter, Michael S., Nancy A. McKenna, and Scott T. Allison. "Warning Compliance: Behavioral Effects of Cost and Consensus." Proceedings of the Human Factors Society Annual Meeting 32, no. 15 (October 1988): 901–4. http://dx.doi.org/10.1518/107118188786761785.
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Two laboratory experiments were conducted to examine the behavioral effects of cost and consensus on warning compliance. Subjects performed a chemistry demonstration task using a set of instructions that contained a warning directing them to wear a safety mask and gloves. In Experiment 1, cost was manipulated by locating the masks and gloves in either an accessible location (low cost) or a less accessible location (high cost). In Experiment 2, consensus was manipulated by the additional presence of a confederate subject who either did or did not comply with the warning. The results showed reduced compliance to the warning when the cost was high, and that the compliance rate was biased up or down depending on the behavior of the confederate. Implications of this research for facilitating warning effectiveness and safety are discussed.
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Arteaga Averos, Lenin, and Marcelo Ortíz Suárez. "Bioseguridad para el personal y laboratorio, asociado al manejo de muestras de casos para coronavirus (covid-19)." Pro Sciences: Revista de Producción, Ciencias e Investigación 4, no. 32 (March 31, 2020): 34–46. http://dx.doi.org/10.29018/issn.2588-1000vol4iss32.2020pp34-46.
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El propósito de este documento es proporcionar orientación en bioseguridad para laboratorios (análisis clínico) y para el personal que manipula las muestras provenientes de personas con posible infección de coronavirus (COVID-19), de tal manera que facilite la información de consulta para la acreditación (opcional) con el SAE y obtención del permiso de funcionamiento (obligatorio) con el ACESS para el Laboratorio de Biología Molecular y Bioquímica de la Universidad Regional Amazónica Ikiam, como un laboratorio de ensayo clínico de dichas muestras, en apoyo al MSP por la emergencia sanitaria que cursa el Ecuador.
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Ikhsan, Jaslin, Kristian Handoyo Sugiyarto, and Tiwi Nur Astuti. "Fostering Student’s Critical Thinking through a Virtual Reality Laboratory." International Journal of Interactive Mobile Technologies (iJIM) 14, no. 08 (May 20, 2020): 183. http://dx.doi.org/10.3991/ijim.v14i08.13069.
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Virtual reality (VR) laboratory is great potential for education. It is recognized as a technological advance that can facilitate a learning process through the development of highly realistic 3D visualization. Using VR laboratory in teaching and learning makes it possible to manipulate objects in the virtual scene in a manner similar to the real world. Virtual reality laboratory was developed to enhance the students’ critical thinking skills. A Research and Development (R & D) method with a post-test design was used in the research. The subjects included the students who were enrolled at Senior High School in Yogyakarta, Indonesia with a total of 96 grade 10<sup>th</sup> students. The samples divided into three classes, namely EC-1 with virtual reality laboratory, EC-2 with virtual reality and real laboratory, and CC with real laboratory while the quality VR was applied to chemistry teachers. The findings of this research reveal that the quality of VR laboratory integrated hybrid learning was in a very good category. The results of students' critical thinking skills were analyzed using ANOVA test and it was found that there is a significant difference on students’ critical thinking skills of the three classes. Students who took part in learning using VR laboratory both in the EC-1 and EC-2 classes had better critical thinking skills compared to the CC class. Thus, the VR laboratory is potentially used for further teaching-learning process.
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Wogalter, Michael S., Scott T. Allison, and Nancy A. Mckenna. "Effects of Cost and Social Influence on Warning Compliance." Human Factors: The Journal of the Human Factors and Ergonomics Society 31, no. 2 (April 1989): 133–40. http://dx.doi.org/10.1177/001872088903100202.
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The behavioral effects of cost and social influence on warning compliance were examined. Participants in several studies performed a chemistry laboratory task using a set of instructions that contained a warning directing them to wear a safety mask and gloves. Cost was manipulated by locating the masks and gloves in either an accessible location (low cost) or a less accessible location (high cost); social influence was manipulated by the presence of a confederate who either did or did not comply with the warning. The results showed reduced compliance with the warning when the cost was high and that the compliance rate was biased up or down depending on the behavior of the confederate. The results from a field study confirmed the social influence effect. Implications of this research for facilitating warning effectiveness and safety are discussed.
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Chaplin, Susan B. "GUIDED DEVELOPMENT OF INDEPENDENT INQUIRY IN AN ANATOMY/PHYSIOLOGY LABORATORY." Advances in Physiology Education 27, no. 4 (December 2003): 230–40. http://dx.doi.org/10.1152/advan.00002.2003.
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Student-originated projects are increasingly utilized in the biology laboratory as a means of engaging students and revitalizing the laboratory experience by allowing them one to two weeks to collect data on a manipulated variable of their choice by use of an introduced technique. Such experiments fail as good models of investigative learning when they place more emphasis on novel ideas than on hypothesis testing, experimental design, statistical rigor, or use of the primary literature. In addition, students get used to the routine and tend to design the same type of simplistic experiments in each course unless challenged. Laboratories in a Comparative Anatomy and Physiology course at the University of St. Thomas were reorganized to encourage the development of investigative skills in a stepwise fashion throughout the semester. Initial labs concentrated on experimental design and statistical analysis, then use of the primary literature in interpretation of the data was emphasized, and finally, students were asked to design their experiments and analyze their data on the basis of models from the primary literature.
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Hafer, Nina, and Manfred Milinski. "Inter- and intraspecific conflicts between parasites over host manipulation." Proceedings of the Royal Society B: Biological Sciences 283, no. 1824 (February 10, 2016): 20152870. http://dx.doi.org/10.1098/rspb.2015.2870.
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Host manipulation is a common strategy by which parasites alter the behaviour of their host to enhance their own fitness. In nature, hosts are usually infected by multiple parasites. This can result in a conflict over host manipulation. Studies of such a conflict in experimentally infected hosts are rare. The cestode Schistocephalus solidus (S) and the nematode Camallanus lacustris (C) use copepods as their first intermediate host. They need to grow for some time inside this host before they are infective and ready to be trophically transmitted to their subsequent fish host. Accordingly, not yet infective parasites manipulate to suppress predation. Infective ones manipulate to enhance predation. We experimentally infected laboratory-bred copepods in a manner that resulted in copepods harbouring (i) an infective C plus a not yet infective C or S, or (ii) an infective S plus a not yet infective C. An infective C completely sabotaged host manipulation by any not yet infective parasite. An infective S partially reduced host manipulation by a not yet infective C. We hence show experimentally that a parasite can reduce or even sabotage host manipulation exerted by a parasite from a different species.
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Leary, Mark R., Jean M. Twenge, and Erin Quinlivan. "Interpersonal Rejection as a Determinant of Anger and Aggression." Personality and Social Psychology Review 10, no. 2 (May 2006): 111–32. http://dx.doi.org/10.1207/s15327957pspr1002_2.
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This article reviews the literature on the relationship between interpersonal rejection and aggression. Four bodies of research are summarized: laboratory experiments that manipulate rejection, rejection among adults in everyday life, rejection in childhood, and individual differences that may moderate the relationship. The theoretical mechanisms behind the effect are then explored. Possible explanations for why rejection leads to anger and aggression include: rejection as a source of pain, rejection as a source of frustration, rejection as a threat to self-esteem, mood improvementfollowing aggression, aggression as social influence, aggression as a means of reestablishing control, retribution, disinhibition, and loss of self-control.
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Ardi, Dennise Tanoko, Yue Gang Li, Kelvin Hau Kong Chan, Liam Blunt, and M. R. Bache. "The Role of Surface Topography on Fatigue Behaviour of Nickel Based Superalloys." Advanced Materials Research 891-892 (March 2014): 48–53. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.48.
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Advanced areal (three-dimensional) characterisation of surface topography was applied to laboratory scale fatigue test specimens manufactured from the nickel based superalloy Alloy720Li. Finishing was deliberately manipulated to offer four distinct grades of topography. Subsequent low cycle fatigue performance was then correlated to a range of parameters selected to represent the surface topography. The aim of the ongoing study is to predict fatigue performance and aid to establish correlations between topographic parameters and fatigue life.
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Montagnini, F., B. L. Haines, W. T. Swank, and J. B. Waide. "Nitrification in undisturbed mixed hardwoods and manipulated forests in the southern Appalachian Mountains of North Carolina, U.S.A." Canadian Journal of Forest Research 19, no. 10 (October 1, 1989): 1226–34. http://dx.doi.org/10.1139/x89-187.
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This paper summarizes data on nitrification at the Coweeta Hydrologic Laboratory, in the southern Appalachian Mountains of North Carolina, U.S.A., focusing on effects of watershed treatment and vegetation type. At Coweeta, as at other United States sites, oak–hickory forests gave the lowest nitrification potentials. Nitrification potentials and nitrifier numbers were lower in oak–hickory forests of undisturbed watersheds than in disturbed watersheds. Nitrification potentials were also low in a white pine plantation, although higher than in other pine forests in the United States. In a regenerating clear-cut and in a 17-year-old successional forest at Coweeta, nitrification potential was higher in dense stands of black locust (Robiniapseudoacacia L.) than in areas where black locust was absent. In the undisturbed forests at Coweeta, low nutrient availability probably limits the size of nitrifier populations; the influence of soil pH on nitrification was unclear. In the disturbed forests, nitrification is apparently controlled by the availability of ammonium nitrogen and other nutrients.
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Yunda, Leonardo, Steve Rodriguez G., Luis Fernando Gómez, Oscar Jairo Maya, and Oscar Arnulfo Barrera. "Sistema de microscopía robotizada para diagnóstico y confirmación de diagnóstico a distancia." Ingenium 5, no. 10 (December 31, 2011): 39. http://dx.doi.org/10.21774/ing.v5i10.48.
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El tratamiento de la malaria requiere del análisis de gota gruesa, un procedimiento de diagnóstico en laboratorio clínico que utiliza el microscopio para observar y caracterizar el tipo de parásito de malaria que afecta al paciente para formular los medicamentos específicos para combatirlo. La malaria está presente en el pacífico colombiano, una zona con baja infraestructura de salud, que debe recurrir a los servicios de telemedicina para apoyar los procedimientos de laboratorio clínico y obtener resultados oportunos y de calidad. El Laboratorio de Telemedicina e Ingeniería Biomédica de la USC implementó un sistema de microscopía robotizada por control remoto, que le permite al especialista o bacteriólogo presente en el centro de referencia, un laboratorio clínico en el área metropolitana, manipular a control remoto un microscopio ubicado en la entidad remisora, a kilómetros de distancia, apoyado en una aplicación Web que le permite controlar su movimiento y magnificación, y observar así, en tiempo real, la muestra de sangre del paciente.
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Habibi, Saeid, Richard Burton, and Eric Sampson. "High Precision Hydrostatic Actuation Systems for Micro- and Nanomanipulation of Heavy Loads." Journal of Dynamic Systems, Measurement, and Control 128, no. 4 (September 22, 2005): 778–87. http://dx.doi.org/10.1115/1.2229259.
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In this paper reports on an important finding, that is, hydrostatic actuation systems are able to manipulate heavy loads with submicron precision and a large stroke. In this relation, the design of a high-precision hydrostatic actuation system referred to as the ElectroHydraulic Actuator (EHA) is presented. A laboratory prototype of this system has achieved an unprecedented level of performance by being able to move a large load of 20Kg with a precision of 100nm and a stroke of 12cm. This level of performance places the hydrostatic actuation concept in competition with piezoelectric platforms in terms of positional accuracy. Experimental results from this prototype are reported and analyzed.
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Bibb, Mervyn J. "Understanding and manipulating antibiotic production in actinomycetes." Biochemical Society Transactions 41, no. 6 (November 20, 2013): 1355–64. http://dx.doi.org/10.1042/bst20130214.
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Actinomycetes are prolific producers of natural products with a wide range of biological activities. Many of the compounds that they make (and derivatives thereof) are used extensively in medicine, most notably as clinically important antibiotics, and in agriculture. Moreover, these organisms remain a source of novel and potentially useful molecules, but maximizing their biosynthetic potential requires a better understanding of natural product biosynthesis. Recent developments in genome sequencing have greatly facilitated the identification of natural product biosynthetic gene clusters. In the present article, I summarize the recent contributions of our laboratory in applying genomic technologies to better understand and manipulate natural product biosynthesis in a range of different actinomycetes.
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Lynch, Gordon S., and René Koopman. "Overcoming nature’s paradox in skeletal muscle to optimise animal production." Animal Production Science 59, no. 11 (2019): 1957. http://dx.doi.org/10.1071/an19361.
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Nature’s paradox in skeletal muscle describes the seemingly mutually exclusive relationship between muscle fibre size and oxidative capacity. In mammals, there is a constraint on the size at which mitochondria-rich, high O2-dependent oxidative fibres can attain before they become anoxic or adapt to a glycolytic phenotype, being less reliant on O2. This implies that a muscle fibre can hypertrophy at the expense of its endurance capacity. Adaptations to activity (exercise) generally obey this relationship, with optimal muscle endurance generally being linked to an enhanced proportion of small, slow oxidative fibres and muscle strength (force and/or power) being linked to an enhanced proportion of large, fast glycolytic fibres. This relationship generally constrains not only the physiological limits of performance (e.g. speed and endurance), but also the capacity to manipulate muscle attributes such as fibre size and composition, with important relevance to the livestock and aquaculture industries for producing specific muscle traits such as (flesh) quality, texture and taste. Highly glycolytic (white) muscles have different traits than do highly oxidative (red) muscles and so the ability to manipulate muscle attributes to produce flesh with specific traits has important implications for optimising meat production and quality. Understanding the biological regulation of muscle size, and phenotype and the capacity to manipulate signalling pathways to produce specific attributes, has important implications for promoting ethically sustainable and profitable commercial livestock and aquaculture practices and for developing alternative food sources, including ‘laboratory meat’ or ‘clean meat’. This review describes the exciting potential of manipulating muscle attributes relevant to animal production, through traditional nutritional and pharmacological approaches and through viral-mediated strategies that could theoretically push the limits of muscle fibre growth, adaptation and plasticity.
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Dennehy, John J., Nicholas A. Friedenberg, Yul W. Yang, and Paul E. Turner. "Bacteriophage Migration via Nematode Vectors: Host-Parasite-Consumer Interactions in Laboratory Microcosms." Applied and Environmental Microbiology 72, no. 3 (March 2006): 1974–79. http://dx.doi.org/10.1128/aem.72.3.1974-1979.2006.
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ABSTRACT Pathogens vectored by nematodes pose serious agricultural, economic, and health threats; however, little is known of the ecological and evolutionary aspects of pathogen transmission by nematodes. Here we describe a novel model system with two trophic levels, bacteriophages and nematodes, each of which competes for bacteria. We demonstrate for the first time that nematodes are capable of transmitting phages between spatially distinct patches of bacteria. This model system has considerable advantages, including the ease of maintenance and manipulation at the laboratory bench, the ability to observe many generations in short periods, and the capacity to freeze evolved strains for later comparison to their ancestors. More generally, experimental studies of complex multispecies interactions, host-pathogen coevolution, disease dynamics, and the evolution of virulence may benefit from this model system because current models (e.g., chickens, mosquitoes, and malaria parasites) are costly to maintain, are difficult to manipulate, and require considerable space. Our initial explorations centered on independently assessing the impacts of nematode, bacterium, and phage population densities on virus migration between host patches. Our results indicated that virus transmission increases with worm density and host bacterial abundance; however, transmission decreases with initial phage abundance, perhaps because viruses eliminate available hosts before migration can occur. We discuss the microbial growth dynamics that underlie these results, suggest mechanistic explanations for nematode transmission of phages, and propose intriguing possibilities for future research.