A simple,inexpensive, liquid-tight swivel connection for use in chronic infusion systems

This note describes the fabrication of a simple, inexpensive, liquid-tight swivel joint for twist-free coupling of small, freely moving animals to infusion systems. The device uses a disposable hypodermic needle and syringe as the main components, and fabrication requires only readily available hand tools and minimal mechanical expertise.     

A tether system for psychophysiological studies in the dog

A system for monitoring blood pressure or other physiological variables in the unanesthetized and chronically instrumented dog is described. An indwelling catheter attaches to a pressure transducer affixed to the underside of a leather shield, which snaps onto a custom-fitted leather vest worn by the dog. The transducer cable ascends vertically through a hollow, flexible, stainless steel tether, which is attached at the lower end to the leather shield and at the upper end to a fluid and electrical swivel. The swivel is attached to an overhead counterbalanced boom assembly, which moves in concert with the dog, maintaining a constant minimal tension on the tether. The boom assembly is attached to a wall plate via a universal joint approximately 7 ft above floor level. Dogs can be maintained comfortably in this system 24 h/day over periods of months, with freedom of posture and movement, including rotational behavior. The system is economical to construct and provides versatile stimulation and record-ing capability and reliable long-term performance.     

A tether system for cardiovascular studies with the behaving micropig

A tether system has been developed for continuous monitoring of blood pressure in the micropig. The micropig is a suitable model for blood-pressure research because of the similarity of its cardiovascular system to that of humans and because of its sensitivity to high sodium intake. The system consists of a metal boom, attached via a universal joint to a wall 6 ft above floor level, that extends horizontally to the center of the enclosure. A fluid and electronic swivel affixed to the boom is connected to a flexible, hollow, metal tether that descends to a vest worn by the micropig. The vest contains a pressure transducer to which an indwelling arterial catheter is connected via a stopcock. The transducer cable and an infusion line ascend through the interior of the tether to the swivel. The system remains in equilibrium through a system of pulleys and counterweights. Continuous, 24-h recording shows a diurnal variation characterized by higher heart rate but lower blood pressure during the day than at night. The system has been found to be effective for continuous studies over intervals of a month or more.     

An inexpensive electro-fistular swivel for negative feedback control of self-stimulation

A swivel was developed for concurrent intraorganismic fluid injection and intracranial electrical stimulation of the unrestrained rat. Effects of various intragastric injections on bar-pressing maintained by electrical stimulation of the hypothalamus were studied. In some subjects, intragastric injections of either water or milk decreased the rate of responding. This decrease resulted from pauses in responding rather than from decreases in the local rates of responding. The decrement in responding occurred at a lower gastric volume during milk injection than during water injection. In other subjects, however, neither water, milk, nor 32% sucrose injections affected the rate of self-stimulation.     

Finger forces in fastball baseball pitching

Forces imparted by the fingers onto a baseball are the final, critical aspects for pitching, however these forces have not been quantified previously as no biomechanical technology was available. In this study, an instrumented baseball was developed for direct measurement of ball reaction force by individual fingers and used to provide fundamental information on the forces during a fastball pitch. A tri-axial force transducer with a cable having an easily-detachable connector were installed in an official baseball. Data were collected from 11 pitchers who placed the fingertip of their index, middle, ring, or thumb on the transducer, and threw four-seam fastballs to a target cage from a flat mound. For the index and middle fingers, resultant ball reaction force exhibited a bimodal pattern with initial and second peaks at 38–39 ms and 6–7 ms before ball release, and their amplitudes were around 97 N each. The ring finger and thumb produced single-peak forces of approximately 50 and 83 N, respectively. Shear forces for the index and middle fingers formed distinct peak at 4–5 ms before release, and the peaks summed to 102 N; a kinetic source for backspin on the ball. An additional experiment with submaximal pitching effort showed a linear relationship of peak forces with ball velocity. The peak ball reaction force for fastballs exceeded 80% of maximum finger strength measured, suggesting that strengthening of the distal muscles is important both for enhancing performance and for avoiding injuries.     

Instrumentation of a self-luminous fixation annulus

A simple and inexpensive way of constructing a fixation annulus is described. Such a device is important for experiments in which a fixation spot in the test field area is undesirable or when subjects’ experimental tasks preclude their manipulation of a fixation dot brightness control. A luminous compound is inserted into transparent plastic tubing which can be shaped and inserted into a groove milled to fit the tube’s diameter and shape. Annulus luminance is in the scotopic range. Repeated measurement showed that there was no brightness loss over time. Ways of further attenuating brightness are discussed.     

A cryogenic implant for producing reversible functional brain lesions

This paper describes a permanently implanted device for applying cold to localized parts of the brain surface in order to produce reversible functional lesions in behaving animals. It consists of an array of several independently controlled stainless steel tubing loops, each shaped to fit a separate brain area. Cooled alcohol is pumped through the tubing and temperatures are monitored with attached thermocouples. Implanted loops can be cooled to 0°C within 15 sec, and temperatures can be maintained at ±1°C of accuracy. Tissue tolerance is excellent: Implants have been demonstrated to last up to 1 year or more. Methods and materials for construction are discussed.     

The photo-lickerandum: A device for detecting the licking response,with capability for near-instantaneous programming of variable quantum reinforcement

A combined operandum-feeder is described that eliminates the necessity of passing an electrical sensing current through S while detecting and reinforcing tongue-licking responses. A glass nozzle for dispensing liquid reinforcers is situated just above a small separation in a loop of photo-conducting Sterite tubing; licks at a tiny area below the nozzle break a light beam and are detected via a photo-resistor and associated circuitry. Data are presented from a study in which rats worked at the operandum on a mult FR 40 ext schedule; performance and records are comparable to those obtained via conventional electronic sensing. Applications of the photo-lickerandum and an associated variable-quantum reinforcing system are suggested.     

A computer-controlled vapor-dilution olfactometer

A computer-controlled olfactometer with several innovations leading to closer control over the stimulus parameters and minimization of nonolfactory cues is presented. A microcomputer is used to control the stimulus duration and interstimulus interval. Electronic mass flow con-trollers are employed to maintain close control over the flow in the pure air line and the stimulus-bearing line. Both humidity and temperature are closely regulated. Using a nasal catheter, this stimulus delivery system coupled with velopharyngeal closure and oral breathing permits accurate specification of the quantity of stimulus material actually entering a subject’s nares. The design is such that the computer programming, patch panel interface, and threaded tubing allow versatility in the type of olfactometric study that can be conducted. This system is amenable for threshold, electrophysiological, and sensory adaptation studies of olfaction.     

An automated regional taste-testing system

A fully programmable and portable automated regional taste-testing system is described. This system utilizes a glass stimulator held to the surface of the tongue by a mild vacuum. Temporally and spatially discrete trains of stimuli, delivered from a bank of glass reservoirs through microprocessor-controlled Teflon solenoid valves and both glass and Tygon tubing, can be delivered to the lingual surface at millisecond durations. Rinses between stimuli are similarly programmed. The stimulus delivery is monitored at the surface of the tongue, using a capacitance sensor to alert the subject of stimulus delivery. An example of the application of this system is shown, in which we demonstrate that the detection threshold for NaCl is inversely related to stimulus duration by a power function.     

Spatial updating of virtual displays

In four experiments, we examined observers' ability to locate objects in virtual displays while rotating to new perspectives. In Experiment 1, participants updated the locations of previously seen landmarks in a display while rotating themselves to new views (viewer task) or while rotating the display itself (display task). Updating was faster and more accurate in the viewer task than in the display task. In Experiment 2, we compared updating performance during active and passive self-rotation. Participants rotated themselves in a swivel chair (active task) or were rotated in the chair by the experimenter (passive task). A minimal advantage was found for the active task. In the final experiments, we tested similar manipulations with an asymmetrical display. In Experiment 3, updating during the viewer task was again superior to updating during the display task. In Experiment 4, we found no difference in updating between active and passive self-movement. These results are discussed in terms of differences in sources of extraretinal information available in each movement condition.     

Nu-Way Snaps and Snap Leads: an Important Connection in the History of Behavior Analysis

Beginning in the early 1950s, the snap lead became an integral and ubiquitous component of the programming of electromechanical modules used in behavioral experiments. It was composed of a Nu-Way snap connector on either end of a colored electrical wire. Snap leads were used to connect the modules to one another, thereby creating the programs that controlled contingencies, arranged reinforcers, and recorded behavior in laboratory experiments. These snap leads populated operant conditioning laboratories from their inception until the turn of the twenty-first century. They allowed quick and flexible programming because of the ease with which they could be connected, stacked, and removed. Thus, the snap lead was integral to the research activity that constituted the experimental analysis of behavior for more than five decades. This review traces the history of the snap lead from the origins of the snap connector in Birmingham, England, in the late eighteenth century, through the use of snaps connected to wires during the Second World War, to its adoption in operant laboratories, and finally to its demise in the digital age.     

经皮肺活检对肺部病变的诊断价值

经皮肺活检技术应用已有100多年历史。随着影像技术的不断进步,目前已发展成为肺部疾病的重要诊断技术。本文综述了经皮肺活检对肺部病变的诊断价值。并探讨和比较了不同引导技术的特点,以及适应症、并发症及其处理。     

Mothers' facial expressions of pain and fear and infants' pain response during immunization

The goal of the current study was to examine the relationship between mothers' spontaneous facial expressions of pain and fear immediately preceding their infants' immunizations and infants' facial expressions of pain immediately following immunizations. Infants' observations of mothers' faces prior to immunization also were examined to explore whether these observations moderated the effect of mothers' facial expressions on infant pain. The final sample included 58 mothers and their infants. Video data were used to code maternal facial expressions, infants' observations, and infants' expressions of pain. Infants who observed their mothers' faces had mothers who expressed significantly more fear pre‐needle. Furthermore, mothers' facial expressions of mild fear pre‐needle were associated with lower levels of infants' pain expression post‐needle. A regression analysis confirmed maternal facial expressions of mild fear pre‐needle as the strongest predictor of infant pain post‐needle after controlling for infants' observations of mothers' faces. Mothers' subtle facial expressions of fear may indicate a relationship history of empathic caregiving that functions to support infants' abilities to regulate distress following painful procedures. Interventions aimed at improving caregiver sensitivity to infants' emotional cues may prove beneficial to infants in pain. Future directions in research are discussed.     

The flash-lag phenomenon: object motion and eye movements

An object flashed briefly in a given location, the moment another moving object arrives in the same location, is perceived by observers as lagging behind the moving object (flash-lag effect). Does the flash-lag effect occur if the retinal image of the moving object is rendered stationary by smooth pursuit of the moving object? Does the flash-lag effect occur if the retinal image of a stationary object is caused to move by smooth-pursuit eye movements? A disk was briefly flashed in the center of a moving ring such that the ring center was completely 'filled' by the disk. In this display, observers perceived the flashed disk to lag such that it appeared only to partially 'fill' the ring center. The 'unfilled' portion (perceived void) of the moving ring was seen in the color of the background. With smooth pursuit of the ring, the flash-lag effect was eliminated, and observers saw the flashed disk centered on the moving ring. A strong flash-lag effect was observed when observers smoothly pursued a moving point target past a continuously visible stationary ring. Once again, the flashed disk appeared to only partially fill the center of the continuously visible stationary ring, yielding a vivid 'perceived void'. These results are discussed in terms of neural delays and their compensation.     

The Ability to Render Something False

In this paper I try to explicate the idiom '(An agent) x is able to render (the proposition) p false', which plays a crucial role in van Inwagen's Consequence Argument and which has been extensively discussed in the literature on it. However, the explications offered so far fail to meet some intuitive desiderata which an analysis of the notion should fulfil, as for example the desiderata that (i) nobody can render necessary falsehoods false and that (ii) nobody can render historical falsities false. I propose a novel analysis which deviates from the foregoing in employing an explanatory notion, the connector 'because'.     

Preliminary evidence that the limbal ring influences facial attractiveness

The limbal ring of the eye appears as a dark annulus where the iris meets the sclera. Both width and opacity of the limbal ring are influenced by iris pigmentation and optical properties of the region. With age the limbal ring becomes less prominent, making it a probabilistic indicator of youth and health. This raises the question: Are judgments of facial attractiveness sensitive to this signal in a potentially adaptive way? Here we show that the answer is yes. For male and female observers, both male and female faces with a dark and distinct limbal ring are rated as more attractive than otherwise identical faces with no limbal ring. This result is observed not just for upright faces but also for inverted faces, suggesting that the limbal ring is processed primarily as a local feature rather than as a configural feature in the analysis of facial beauty. We also discuss directions for future research that can clarify the role of the limbal ring in the visual perception of facial attractiveness.     

Truth-Making without Truth-Makers

The article is primarily concerned with the notion of a truth-maker. An explication for this notion is offered, which relates it to other notions of making something such-and-such. In particular, it is shown that the notion of a truth-maker is a close relative of a concept employed by van Inwagen in the formulation of his Consequence Argument. This circumstance helps understanding the general mechanisms of the concepts involved. Thus, a schematic explication of a whole battery of related notions is offered. It is based on an explanatory notion, introduced by the sentential connector “because”, whose function is examined in some detail. Finally, on the basis of the explication proposed, an argument is developed to the effect that the objects usually regarded as truth-makers are not apt to play this role.