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Contaminated fomites can lead to hepatitis A virus (HAV) and human norovirus (HuNoV) disease outbreaks. Improved decontamination methods that are user-friendly, cost-effective, and waterless are being researched for sustainability. Traditional ultraviolet light (UV-C) technologies though effective for surface decontamination have drawbacks, using mercury lamps, that pose user-safety risk and environmental hazards. Therefore, UV-C light emitting diode (LED) systems are being designed for delivering required antiviral doses. The objective of this research was to determine the ability of UV-C LED (279 nm) systems to inactivate HuNoV surrogates, feline calicivirus (FCV-F9) and Tulane virus (TV), and HAV on Formica coupons in comparison to UV-C (254 nm) systems. FCV-F9 (∼6 log PFU/mL), TV (∼7 log PFU/mL), or HAV (∼6 log PFU/mL) at 100 µL were surface-spread on sterile Formica coupons (3 × 3 cm2), air-dried, and treated for up to 2.5 min with both systems. Each experiment was replicated thrice. Recovered infectious plaque counts were statistically analyzed using mixed model analysis of variance. FCV-F9, TV, and HAV showed D10 values of 23.37 ± 0.91 mJ/cm2, 16.32 ± 3.6 mJ/cm2, and 12.39 ± 0.70 mJ/cm2 using 279 nm UV-C LED, respectively and D10 values of 9.97 ± 2.44 mJ/cm2, 6.83 ± 1.13 mJ/cm2 and 12.40 ± 1.15 mJ/cm2, respectively with 254 nm UV-C. Higher 279 nm UV-C LED doses were required to cause HuNoV surrogate reduction than 254 nm UV-C, except similar doses with both systems were needed for HAV inactivation on Formica surfaces. It remains critical to measure UV intensity of optical sources and optimize exposure times for desired log reduction on surfaces.

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Membrane capacitance and membrane conductance values are reported for insulin secreting cells (primary -cells and INS-1 insulinoma cells), determined using the methods of dielectrophoresis and electrorotation. The membrane capacitance value of 12.57 (+/-1.46) mFm(-2), obtained for -cells, and the values from 9.96 (+/-1.89) mFm(-2) to 10.65 (+/-2.1) mFm(-2), obtained for INS-1 cells, fall within the range expected for mammalian cells. The electrorotation results for the INS-1 cells lead to a value of 36 (+/-22) Sm(-2) for the membrane conductance associated with ion channels, if values in the range 2-3 nS are assumed for the membrane surface conductance. This membrane conductance value falls within the range reported for INS cells obtained using the whole-cell patch-clamp technique. However, the total 'effective' membrane conductance value of 601 (+/-182) Sm(-2) obtained for the INS-1 cells by dielectrophoresis is significantly larger (by a factor of around three) than the values obtained by electrorotation. This could result from an increased membrane surface conductance, or increased passive conduction of ions through membrane pores, induced by the larger electric field stresses experienced by cells in the dielectrophoresis experiments.

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Experiments on naturally occurring hyperkinetic and violent dogs and cats demonstrated the usefulness of low dosages of amphetamine (0,2-1,0 mg/kg per os) in inhibiting these nonadaptive forms of behavior, permitting the development of discriminated Pavlovian and operant conditional responses. When amphetamine therapy was combined systematically with conditioning experiments and psychosocial therapy, for long enough periods of time (many weeks), the beneficial effects of this drug persisted in the nodrug state, i.e. the learning was not state-dependent. Amphetamine also ameliorated significantly conditional emotional visceral responses in dogs with low adaptation to psychologically stressful situations. The same low dosage of amphetamine which improved the behavior and learning of hyperkinetic and violent dogs disrupted the behavior and produced disorientation in normal dogs with previously stable conditional responses.

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Activ. nerv. sup. (Praha) 28, 2, 1986. Utilizing a combination of idiographic and nomothetic research designs with repeated measures in several breeds of dogs, we discovered stable constitutional differences in psychophysiologic reactions to repeated exposure to psychologically stressful situations. Some dogs showed high psychophysiologic adaptation (HA dogs). Other dogs developed persistent psychophysiologic reactions to the psychologically aversive environment: tachycardia, polypnea, profuse salivation, high energy metabolism and muscle tension, and high urinary vasopressin and catecholamines (low adaptation or LA dogs). Retrospective analysis of the development and extinction of cardiac and respiratory orienting reflexes (OR) in these two types of dogs revealed that the LA dogs exhibit higher frequency and more intense, persistent and highly fluctuating (poorly modulated) cardiac and respiratory OR than the HA dogs, which show rapid OR habituation and good modulation. Insofar as one may extrapolate these data to human subjects, recording dynamics of development and habituation and degree of modulation of visceral OR may facilitate early detection of individuals at risk for cardiorespiratory and other psychovisceral disorders.

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We previously described stable constitutional differences in psychophysiologic reactions of dogs exposed repeatedly to psychologically stressful situations induced by Pavlovian conditioning techniques with electrocutaneous reinforcement. Some dogs (e.g., most beagles and other hounds, and some mongrels) showed high psychophysiologic adaptation (HA dogs). Other dogs (e.g., many wirehair fox terriers, border collies, German shepherds, cocker spaniels, and some mongrels) developed persistent, almost inextinguishable psychophysiologic reactions to the entire Pavlovian aversive room complex: tachycardia, polypnea, profuse salivation, vasopressin release, high energy metabolism, and high urinary catecholamines (low adaptation or LA dogs). Analysis of the development and extinction of cardiac and respiratory orienting reflexes (O.R.) in these two types of dogs indicates that the LA dogs exhibit higher frequency and more intensive, persistent, and highly fluctuating (poorly modulated) cardiac and respiratory O.R.s than those exhibited by the HA dogs, which show rapid O.R. habituation and good modulation. Insofar as one may extrapolate these data to human subjects, recording of the dynamics of the development and habituation and the degree of modulation of visceral orienting reflexes may facilitate the early detection of individuals at risk for cardio-respiratory and other psychovisceral disorders.

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Selye refers to stress as 'the nonspecific response of the body to any demand made upon it'. Our experimental data indicate that: (1) there are significant constitutional differences in the types of stress reactions exhibited by different breeds of dogs; (2) inability to achieve an adaptive consummatory response or to develop a sense of control over stressful situations may lead in susceptible individuals (low adaptation dogs) to the development of maladaptive distress reactions, evidenced by persistent psychovisceral turmoil; (3) such maladaptive distress reactions represent a physiologic substrate of anxiety and frustration; (4) exposure of the low adaptation dogs to similar stressors but under conditions where the animals can develop avoidance responses, inhibited the psychovisceral disturbances, suggesting that it is the inability to develop control over psychosocially aversive situations that is primarily responsible for psychophysiologic disorders.

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