H2-Uptake Activity, Spectra, Reduction Potentials, and Kinetics of Iron Release on the Surface of Iron Core from Azotobacter vinelandii Bacterial Ferritin

Bacterial ferritin from Azotobacter vinelandii (AvBF_o has a function in H₂ uptake. The Fe³⁺ reduction on the surface of the iron core from AvBF_o is accompanied simultaneously by H₂ uptake, with a maximum activity of H₂ uptake of 450 H₂/AvBF_o. A reduction potential of –402 mV for iron reduction on the surface of the core is found. A shift to the red the protein absorbance peaks ranging from 280 to 290 nm is observed between pH5 and 9 under 100% H₂ reduction. The reduction potential for iron release becomes negative at a rate of 0.025 mV/Fe²⁺ released. The kinetics of iron release on the surface of the core is a first-order reaction.     

Scientific and clinical biofeedback in the USSR

This paper describes the history of biofeedback research and application in the USSR. The approach of USSR scientists to the study of basic mechanisms of biofeedback and the status of clinical applications of biofeedback in the Soviet Union are described. Trends in the publication of biofeedback-related papers in Russian are presented, and the present state of the art described. Promising prospects for biofeedback research and application are discussed.     

Prolongation of Postembryonic Development in Experimental and Natural Cladoceran Populations

One of the methods for determining the duration of postembryonic development is the calculation method suggested by Gras and Saint-Jean (1978) for populations with continuous reproduction and stable age distribution. After inserting time-weighted means for instantaneous birth rates into the formula, it is possible to calculate the growth rates of the juveniles during each interval between obersvations for a non-stationary population. Estimated values were in a good agreement with those obtained from computer-constructed populations and determined directly from a natural cladoceran population. The duration of postembryonic development in cladoceran populations increases significantly during periods of food depletion caused by filtering activity of herbivorous zooplankton. This physiological response together with the decrease in age-specific fecundity permits effective regulation of population abundance through the birth rate.     

Is the Working Definition of Applied Psychophysiology Proposed by Schwartz Too Narrow/Restrictive?

This paper raises issues in further refining the working definition of applied psychophysiology proposed by Schwartz (1999). Issues to be addressed include defining what the word psycho means within the definition of applied psychophysiology and the implications of this word in practice. Other issues discussed include the meaning of the word applied, and how incorporating the acquisition of self-regulatory skills or behaviors as one aspect of the definition of applied psychophysiology would help differentiate applied psychophysiology from other specialty areas. Finally, a revised definition is proposed to stimulate further discussion.     

Self-regulation of Slow Cortical Potentials in Children with Migraine: An Exploratory Study

Migraine patients are characterized by increased amplitudes of slow cortical potentials (SCPs), representing pronounced excitability of cortical networks. The present study investigated the efficiency of biofeedback training of SCPs in young migraineurs. Ten children suffering from migraine without aura participated in 10 feedback sessions. They were compared with 10 healthy children for regulation abilities of cortical negativity and with 10 migraineurs from the waiting list for clinical efficacy. During the first two sessions, the migraine children were characterised by lacking ability to control cortical negativity, especially during transfer trials, compared with healthy controls. However, there was no difference following 10 sessions of training. Feedback training was accompanied by significant reduction of cortical excitability. This was probably responsible for the clinical efficacy of the training; a significant reduction of days with migraine and other headache parameters was observed. It is suggested that normalization of the threshold regulation of cortical excitability during feedback training may result in clinical improvement.     

Applied Psychophysiology: Beyond the Boundaries of Biofeedback (Mending a Wall, a Brief History of Our Field, and Applications to Control of the Muscles and Cardiorespiratory Systems)

The field of applied psychophysiology overlaps a number of others, from behavioral and psychosomatic medicine to Eastern disciplines and complementary medicine. Although the proliferation of societies and professional identities across these fields emphasizes this diversity, it also may hinder growth. The history of our field is one of innovation, often at odds with conventional wisdom and practice. It is important that this innovativeness not be sacrificed in a justified quest for professional respectability. This paper reviews the earliest research in biofeedback and applied psychophysiology, and modern applications and interpretations in the areas of muscular and autonomic control, including progressive relaxation and heart rate variability biofeedback, and draws parallels to disciplines of Yoga, QiGong, and Zen practices and their psychophysiological effects.     

Behavioral Psychophysiological Intervention in a Mentally Retarded Epileptic Patient with Brain Lesion

Behavioral psychophysiological treatment entailing Slow Cortical Potential (SCP) biofeed-back training and behavioral self-control training was conducted with a 27-year-old male epileptic patient (seizures for 23 years) with Wechsler IQ 64 who underwent callosotomy. The patient had 12/week secondary generalized tonic-clonic seizures. The treatment, consisting of 43 SCP training sessions and 22 behavioral control sessions, yielded a highly significant reduction of seizure frequency to about 7.5/week; such a decrease had never been observed after administration of new anticonvulsant drugs, nor after the callosotomy. During SCP feedback training, the patient was able to produce highly-significant cortical differentiation of SCPs of about 4 µV. In addition, he developed several new behaviors indicating growing ability of self-perception and self-regulation. These findings suggest that a combination of SCP biofeedback with behavioral treatment of epilepsy can be used even in mentally retarded patients with organic brain disorders.     

Biobehavioral treatment of essential hypertension: A group outcome study

In a group outcome and follow-up study of 77 patients with essential hypertension, significant reductions were seen in systolic and diastolic blood pressure (BP) and in hypotensive medication requirement. A multimodality biobehavioral treatment was used which included biofeedback-assisted training techniques aimed at teaching self-regulation of vasodilation in the hands and feet. Of the 54 medicated patients, 58% were able to eliminate hypotensive medication while at the same time reducing BP an average of 15/10 mm Hg. An additional 19 (35%) of the medicated patients were able to cut their medications approximately in half while reducing BP by 18/10 mm Hg. The remaining 4 (7%) medicated patients showed no improvement in either BP or medication requirement. Similar reductions in BP were seen in initially unmedicated patients. Seventy percent of the 23 unmedicated patients achieved average pressures below 140/90 mm Hg, with an additional 22% of these patients making clinically significant reductions in pressure without becoming normotensive, and with 8% unsuccessful at lowering pressures to a clinically significant extent. Follow-up data available on 61 patients over an average of 33 months indicated little regression in these results with 51% of the total patient sample remaining well-controlled off medication, an additional 41% partially controlled, and 8% unsuccessful in lowering either medications and/or blood pressures to a clinically significant extent.This research was partially supported by grant HL-32136. The Authors wish to thank Sarah Bremer for her assistance in preparing this article.     

Non-random interactions within and across guilds shape the potential to coexist in multi-trophic ecological communities

Theory posits that the persistence of species in ecological communities is shaped by their interactions within and across trophic guilds. However, we lack empirical evaluations of how the structure, strength and sign of biotic interactions drive the potential to coexist in diverse multi-trophic communities. Here, we model community feasibility domains, a theoretically informed measure of multi-species coexistence probability, from grassland communities comprising more than 45 species on average from three trophic guilds (plants, pollinators and herbivores). Contrary to our hypothesis, increasing community complexity, measured either as the number of guilds or community richness, did not decrease community feasibility. Rather, we observed that high degrees of species self-regulation and niche partitioning allow for maintaining larger levels of community feasibility and higher species persistence in more diverse communities. Our results show that biotic interactions within and across guilds are not random in nature and both structures significantly contribute to maintaining multi-trophic diversity.     

Thermal and EMG Biofeedback Learning in Nonhuman Primates

Four monkeys were found able to learn to raise and lower hand temperature and to reduce muscle tension to low levels using feedback from the target physiological system. The establishment of this model of biofeedback learning in monkeys enables work on mechanisms mediating the modes of biofeedback most used in clinical practice. Results suggest that biofeedback learning does not need to be mediated by the type of human-specific cognitive strategies employed by humans.