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PubMedDate not supplied

[Development of spatial orientation during pilot training].

The problem of spatial orientation of pilots flying high-altitude aircraft is in the focus of present-day aviation medicine because of a growing number of accidents in the air. One of the productive lines of research is to study spatial orientation in terms of active formation and maintenance of its imagery in a complex environment. However investigators usually emphasize the role of visual (instrumental) information in the image construction, almost ignoring the sensorimotor component of spatial orientation. The theoretical analysis of the process of spatial orientation has facilitated the development of the concept assuming that the pattern of space perception changes with growing professional experience. The concept is based on an active approach to the essence, emergence, formation and variation in the pattern of sensory perception of space in man's consciousness. This concept asserts that as pilot's professional expertise increases, the pattern of spatial orientation becomes geocentric because a new system of spatial perception evolves which is a result of the development of a new (instrumental) type of motor activity in space. This finds expression in the fact that perception of spatial position inflight occurs when man has to resolve a new motor task--movement along a complex trajectory in the three-dimensional space onboard a flying vehicle. The meaningful structure of this problem which is to be implemented through controlling movements of the pilot acts as a factor that forms this new system of perception. All this underlies the arrangement of meaningful collection of instrumental data and detection of noninstrumental signals in the comprehensive perception of changes in the spatial position of a flying vehicle.

Aerospace Medicine↗
PubMed1987

Development of the auditory orientation response in the albino rat (Rattus norvegicus).

The development of head orientation to auditory stimulation was examined in rat pups at Postnatal Days 8, 11, 14, 17, and 20. The animals were tested in a quiet environment with single bursts of 65 dB (SPL) broad-band noise. A reflexive head turn toward the sound was first seen on Postnatal Day 14 and subsequently on Days 17 and 20. This result demonstrates that the onset of directional auditory responses occurred between Day 11 and Day 14. The role of binaural cues in early sound orientation was examined in 17-day-old pups with monaural ligation of the external meatus. These animals were unable to localize a sound source and consistently turned toward the side of the unligated ear regardless of the position of the stimulus. Thus binaural cues were shown to be important for head orientation to sound in early development. In a separate study, head orientation to high and low frequency tone pips was examined. Directional responses were first seen on Day 12 for a 16-kHz tone and Day 14 for a 2-kHz tone. These results indicate an earlier onset for orientation to high frequency sounds in the rat.

Aging↗
PubMed1987

[Testing the scanning effect of a range of orientations by visual cortex neurons of the cat].

The preservation of the effect of dynamic scanning of a part of the orientation diapason during development of neuron responses in the primary visual cortex of cat was examined after equalization of their latencies and after estimation of only highly significant fragments of their reactions. It was found that this effect was preserved in 13 neurons out of 17 examined ones: it remained invariable in 7 units of this group and was modified due to a shift of the scanning beginning along the diapason of orientations, to an increase of scanning diapason or to a change of scanning direction. The stabilization of the orientational tuning occurred only in 4 cells after equalization of latencies. The obtained results confirm that the dynamic changes of orientation tuning in the majority of visual cortex neurons are connected with reorganization of the time pattern of the reaction, as suggested by the hypothesis of the spatial-temporal orientation coding in the visual system.

Animals↗
PubMed1986

Visual orientation to the human face in the premature and fullterm newborn.

Visual orientation to the human face was studied by the method of Brazelton in 15 fullterm newborns on the 4th-5th day of life and in 21 premature newborns (gestational age 27-37 weeks) tested weekly up to 40 weeks conceptional age. No evidence of visual orientation was found before 33 weeks. Performances on a par with those of fullterm newborns were not attained until 37-38 weeks on average, though in a few cases this was achieved at 35 weeks. The quality of orientation improved gradually from 32-33 weeks to 38 weeks, but with wide inter- and intra-individual variations. Noteworthy were the discontinuity and transient worsening of visual orientation of the extremely premature subjects (gestational age less than or equal to 31 weeks) in the weeks following birth. Neurological status at the time of the test, rather than pre-and perinatal risk factors, correlated positively with the quality of the visual responses. No statistically significant differences in orientation were found between premature newborns at term age and fullterm newborns.

Age Factors↗
PubMed1986

Orientation discrimination in amblyopia.

Using extended sinusoidal gratings to avoid potential problems of eccentric fixation, the authors have studied orientation discrimination in amblyopia. For all subjects, elevated orientation discrimination thresholds at high spatial frequencies were found. However, raised thresholds decrease with decreasing spatial frequency, and can be normal at low frequencies. Orientation discrimination thresholds for both amblyopic and non-amblyopic eyes are independent of contrast over most of the visible range. Therefore, amblyopic orientation discrimination thresholds cannot be mimicked in non-amblyopic eyes by reducing contrast. Control experiments show that the orientation discrimination deficits are not restricted to vertical stimuli and that they are not a result of exaggerated cyclotorsional eye movements.

Amblyopia↗
PubMed1985

Hyperthermia in radiofrequency-exposed rhesus monkeys: a comparison of frequency and orientation effects.

To compare the effects of exposure to a near-resonant frequency of microwaves at two orientations with a higher frequency exposure, five rhesus monkeys were exposed for 4 hr to 225 MHz, electric field oriented parallel to the long axis of the body (225 MHz-E), and to 225 MHz, magnetic field orientation (225 MHz-H), or to 1290 MHz, electric field orientation. On a separate occasion, the monkeys were exposed at night to 225 MHz-E. Exposures were conducted with the animal chair restrained in an anechoic chamber with rectal temperature continuously monitored. Blood samples were taken hourly during the 225-MHz-E exposures for cortisol analysis. The power densities used were 0, 1.2, 2.5, 5.0, 7.5, 10.0, and 15.0 mW/cm2 for 225 MHz-E (day), 0 and 5 mW/cm2 (225 MHz-E night and 225 MHz-H), and 0, 20, 28, and 38 mW/cm2 (1290 MHz). The monkeys were unable to tolerate exposure at power densities equal to or greater than 7.5 mW/cm2 (5.1 W/kg) at 225 MHz-E for longer than 90 min. The criterion for tolerance was that the rectal temperature would not exceed 41.5 degrees C. Average rectal temperature increases for day exposure to 225 MHz-E were 0.4 and 1.7 degrees C for 4-hr exposures to 2.5 and 5.0 mW/cm2 (1.7 and 3.4 W/kg). No changes in circulating cortisol levels occurred during any exposures to 5 mW/cm2 or less. Night exposures to 5 mW/cm2 (3.4 W/kg) at 225 MHz-E raised mean rectal temperature 2.1 degrees C. Exposure to 5 mW/cm2 (1.2 W/kg) at 225 MHz-H for 4 hr resulted in a 0.2 degree rise in mean rectal temperature. For 4 hr of 1290-MHz exposure to 20, 28, or 38 mW/cm2 (2.9, 4.0, and 5.4 W/kg), the mean body temperature increases were 0.4, 0.7, and 1.3 degrees C, respectively. The degree of hyperthermia caused by radiofrequency (rf) exposure was shown to be frequency and orientation dependent for equivalent power densities of exposure.

Animals↗
PubMed1983

[Orientational tuning of visual cortex neurons to different stimulus intensities in the cat].

The orientation tuning of field 17 neurons of the visual cortex was studied in immobilized and unanesthetized cats under different intensities of test light slits and constant light background. Orientation tuning of five neurons was invariant to stimulus intensity: their preferential orientation did not change. Thirteen cells were variable as during the change of the contrast they showed a statistically significant displacement of orientation tuning from 22 degrees to 90 degrees. Changes in other neurons were not significant. Invariant neurons differed from variable ones in several characteristics. The mechanisms of orientation tuning changes during contrast variations are discussed.

Adaptation, Physiological↗
PubMed1981

[Dynamics of orientational tuning of visual cortex neurons in the cat].

Orientational tuning of singly units in the primary visual cortex of a nonanesthetized paralyzed cat was studied by usual criteria (number of spikes and maximal frequency of the response) and by "time slices" method. A computer plotted graphs of orientational tuning for successive time intervals with a step of 10 or 20 ms (differential slices) or for prolonged intervals with same step (integral slices). In both cases it was revealed that in all the investigated units orientational tuning markedly changed in time, most often in wideness of characteristic and in 87% of cases in preferred orientation range was detected: preferred orientation systematically moved for 15-112 degrees in successive moments during some tens of ms of the first and the second burst of spikes. A possible functional significance of the data revealed and the neurophysiological mechanisms are discussed.

Animals↗
PubMed1980

Perceived orientation of dot patterns: influence of the number of dots and the overall form of the pattern.

Sixty subjects were tested to assign orientation to 10 dot patterns differing in their overall form and the number of dots in the pattern. The patterns were presented in four different positions in the visual field and two ways of estimation of the orientation were used. It was demonstrated that the assignment of orientation to the patterns did not depend on their position in the visual field, as well as on the method of estimation used. A quantitative measure for the elongation of a dot pattern has been proposed, which correlates with the degree of unambiguity in the estimation of the orientation of the pattern: the greater the elongation the smaller the standard deviation of the estimates given by the subjects. The same holds true for the dependence of the standard deviation on the dot number for dot patterns with equal elongations. The data obtained support the hypothesis that the assignment of orientation to dot patterns results from a process of optimization that takes place in the visual system.

Adult↗
PubMedDate not supplied

Medical risk report: improving patient management and record keeping through a problem-oriented approach.

The problem-oriented record satisfies the needs of the contemporary practitioner by addressing the transition from diagnosis to treatment. The technique organizes collected data, identifies all patient problems (medical and dental), defines solutions and/or management of those problems, and documents treatment rendered. Predictably, the problem-oriented record will avoid problems associated with malpractice litigation, conform to regulations of third-party payers, and facilitate practice analyses and quality assessment, i.e., through computer-assisted tracking of patient care based on problems and not just treatment rendered. As many practices today focus on a "patient-centered" approach to practice, the problem-oriented record clearly supports such a philosophy in its completeness of managing patient care information. The dentist, in consultation with other health care providers, can and should feel confident treating patients from the growing population of patients with medical risk. By integrating the problem-oriented approach into patient management and record keeping, dentists can more easily develop a plan for the complexities that accompany patients. Whether these complexities are of a medical, dental, or combined nature, the problem-oriented record helps the practitioner organize information, plan for treatment, and document patient care in a complete and concise manner.

Comorbidity↗
PubMed1999

Monastral bipolar spindles in meiosis II of male Trichosia pubescens (Sciaridae): early stages of spindle formation and chromosome orientation.

The metaphase spindle of male meiosis II in fungus gnats (Sciaridae) is one example of naturally occurring monastral bipolar spindles. To gain further insights into how the bipolar spindle is formed in the presence of only one polar center, prometaphase of male meiosis II was investigated in the sciarid Trichosia pubescens by means of anti-tubulin immunofluorescence, DAPI chromosome staining, and electron microscopy of ultrathin serial sections. The first step in spindle formation after interkinesis seems to be the organization of an astral half-spindle, probably by MTOC activity of the astral region. With the exception of the non-disjunctional X chromosome, which always lies close to the aster, the chromosomes are found to occupy various positions with respect to the astral region, revealing different orientations of their chromatid kinetochores. It was observed that some of the mal-oriented kinetochores are associated with microtubules that, due to their orientation perpendicular to the spindle axis, are unlikely to originate from the astral region. Therefore, these mal-oriented microtubules are taken as an indication of a dispersed MTOC activity near the chromosomes or at kinetochores. According to recent models of chromosome-induced spindle self-organization [e.g., Merdes et al., 1997: J. Cell Biol. 138:953-956], they could be responsible for the formation of the other (anastral) half-spindle and for amphitelic (bipolar) orientation of the chromosomes.

Animals↗
PubMedDate not supplied

Effect of antibody orientation on immunosorbent performance.

The impact of antibody orientation on immunosorbent efficiency was quantitatively assessed. A pH-dependent murine monoclonal antibody (Mab) against human protein C (hPC), recombinant hPC (rhPC) and two different immobilization chemistries and matrices were used as model systems. The lysyl groups of the rhPC were covalently modified with an acetic acid ester of N-hydroxysuccinimide and this modified rhPC was used as a Fab masking agent (FMA). The FMA was used to mask the antigen binding regions (Fab) of the Mab prior to and during covalent immobilization. Thereafter, the residual active sites of the support were inactivated and the FMA was removed. Mab was immobilizeed at low bead-averaged densities of about 0.4-1.1 mg Mab/mL matrix to minimize local density effects. Immunosorbents made using masked Mab (oriented coupling) gave antigen binding efficiencies (nAg) of 42-48% compared with 18-22% for those made by random coupling. The amount of (Fab)2 released from pepsin digestion of immunosorbents was about 3-4-fold higher for matrices having been made with FMA-masked Mab relative to unmasked Mab. Thus, the (Fab)2 accessibility to pepsin correlates well with higher functional efficiency (nAg) and serves as a measure of orientation. In summary, at low Mab density and a 2:1 molar rhPC to Mab binding stoichiometry, about 80% or more of the Mab randomly coupled through amino moieties was improperly oriented relative to oriented coupled Mab, which correlated with about 50% of lost Mab functionality upon immobilization.

Amines↗
PubMed1998

Raman linear intensity difference of membrane-bound peptides: indole ring orientations of tryptophans 11 and 13 in the gramicidin A transmembrane channel.

A Raman linear intensity difference (RLID) method has been developed to determine orientations of chromophores in membrane-bound peptides and proteins. The method involves orientation of the peptide or protein in lipid bilayer membranes and measurement of intensity differences between Raman spectra excited with two orthogonal laser polarizations. Analysis of the RLID spectrum is simplified when the chromophore exhibits a vibrational mode for which the Raman band is enhanced through resonance with a single molecular electronic transition. To examine the indole ring orientations of Trp residues in the gramicidin A transmembrane channel, we have prepared analogues of gramicidin A, in which one of four Trp residues is replaced by deuterated Trp (Trp-2,4,5,6,7-d5). Two vibrational Raman bands omega(d)3 and omega(d)2 of deuterated Trp have been shown to gain intensity predominantly through resonance with the Bb and La electronic transitions, respectively, when excited at 244 and 257 nm. By examining the RLID spectra of the omega(d)3 and omega(d)2 bands of gramicidin A channels oriented in phospholipid bilayer membranes, we have determined the inclination angles of the Bb and La transition moments with respect to the channel axis in the absence and presence of Na+. The orientations of the Trp-11 and Trp-13 indole rings in the gramicidin channel structure have been derived from the inclination angles of the transition moments. The indole rings of Trp-11 and Trp-13, which are known to shift along the channel axis upon binding of Na+, do not reorient during their positional shifts.

Binding Sites↗
PubMed1983

Preparing low-income hispanic, black, and white patients for psychotherapy: evaluation of a new orientation program.

Examined the effectiveness of a new orientation program designed to prepare low-income white and ethnic minority outpatients for psychotherapy. Sixty-two Hispanic, 51 black, and 60 white psychiatric outpatients in a large public psychiatric clinic participated prior to their first psychotherapy interview. Patients were presented with one of two experimental conditions; the oriented patients saw an audiovisual program that instructed them about psychotherapy, and the control patients saw a program that was neutral with regard to psychotherapy. The patients' knowledge and attitudes toward psychotherapy were assessed with two questionnaires. Results indicated that patients who were oriented were more knowledgeable about psychotherapy and more positive in their attitudes toward psychotherapy than were patients who had not been oriented. The role and utility of brief orientation programs for low-income and ethnic minority outpatients in public mental health facilities are discussed.

Adult↗
PubMed1984

Perception of theoretically derived counseling approaches as a function of preference for counseling orientation.

Examined the relationship between preference for major counseling orientations and perception of counselor behavior in theoretically derived counseling interviews. Seventy-seven undergraduate students viewed demonstration interviews by Rogers and Lazarus, rated the counselor behavior on the Counselor Rating Form, and were assessed in their endorsement of seven major counseling orientations. A regression analysis performed on the preference scores for seven counseling orientations (predictors) in response to the counselor perception scores on the Counselor Rating Form showed a significant relationship only between the client-centered orientation and Rogers. Lazarus was not predicted from any of the seven orientations. Additional analysis of the Counselor Rating Form data revealed that Lazarus was perceived as more expert, attractive, and trustworthy than Rogers. The results are discussed in relation to previous studies.

Adult↗
PubMed1981

The relationship between split-line orientation and in vivo bone strain in galago (G crassicaudatus) and macaque (Macaca mulatta and M. fascicularis) mandibles.

There is still disagreement concerning the functional significance of split-line patterns in bone. This study was undertaken to reexamine the mechanical forces hypothesis for split-line formation by comparing split-line patterns with in vivo mandibular bone strain patterns. The relationship between split-line orientation and in vivo stress and strain patterns on macaque and galago mandibles was examined during jaw opening and the power stroke of mastication and incision. An attempt was made to relate split-line orientation to the direction of tensile stress and strain along the primate mandible. In addition, we also investigated the alternative possibility that split-line orientation is related to the direction of low stresses (and strains) on the primate mandible. The results of this study showed that there was no consistent relationship between split-line orientation and the principal strains or stresses. Thus, split-lines did not run consistently in the direction of high or low stress and strain. Therefore, we have concluded that split-line orientation provides little useful information for inferring patterns of stress and strain in bone.

Animals↗
PubMed2004

Physicians don't ask, sometimes patients tell: disclosure of sexual orientation among women with breast carcinoma.

BACKGROUND: The disclosure of sexual orientation to physicians is uncertain and the reasons are poorly understood. The current study was undertaken to describe the disclosure of sexual orientation among sexual minority women with breast carcinoma. METHODS: Individual semi-structured interviews were conducted with a sample of 39 sexual minority women with a diagnosis of breast carcinoma who lived in New England. Transcribed interviews were analyzed using qualitative data analysis software. Through constant comparison methods, themes related to disclosure were identified from the narrative data. RESULTS: Sexual minority patient-provider relationships were marked by apprehension, and providers did not inquire about sexual orientation. The majority of women actively disclosed their sexual orientation, whereas 11 women passively refused disclosure. CONCLUSIONS: Providers should create opportunities for the disclosure of sexual orientation to provide more comprehensive care.

Adult↗
PubMed1994

Developmental changes in the number, size, and orientation of GFAP-positive cells in the CA1 region of rat hippocampus.

Changes in extracellular potassium concentration as measured with ion-selective microelectrodes revealed abnormally large accumulations in the hippocampus during postnatal development. While rises in [K+]o during stimulation of the Schaffer collaterals were limited to about 12 mM in adult animals, identical stimulations elicited rises to levels as large as 18 mM in juveniles. Since astrocytes are believed to play an important role in K+ homeostasis, we studied the postnatal development of astrocytes in the CA1 region of rat hippocampus in four age groups using a polyclonal antibody against glial fibrillary acidic protein (GFAP). The main proliferation of GFAP-positive cells (GFAPpc) occurred in all laminae between postnatal days 8 and 16. The number of GFAP-positive astrocytes per unit area was reached in stratum lacunosum-moleculare and stratum oriens at about 2 weeks and in stratum radiatum at about 3 weeks of age. During further development--at the age of 24 days--the orientation of individual astrocytes in stratum radiatum became polar with an orientation almost perpendicular to stratum pyramidale. This was revealed by an analysis based on determination of the quotients between the angular orientation of the processes of single individual GFAP-positive cells. When the crossing points of all glial processes over vertical and horizontal grid lines were determined and respective quotients evaluated, the same development towards a perpendicular orientation of astrocytes was noted in stratum radiatum. The same approach revealed a transient orientation parallel to the fissure in stratum lacunosum-moleculare around day 24. Camera lucida drawings of GFAPpc in stratum radiatum revealed that astrocytes became larger during the first three postnatal weeks, followed by a reduction of various parameters (e.g., cell extension, branching pattern) until adulthood. The observed developmental changes of astroglial cells may contribute to the known delayed maturation of potassium regulation in rat hippocampus.

Aging↗