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PubMed1994

Tumors and surgery of the parapharyngeal space.

The parapharyngeal space, an area of complex anatomic relationships, is involved in a wide variety of benign and malignant neoplasms. Because primary parapharyngeal space tumors are rare, it is difficult to obtain surgical experience in this region. This paper reviews the anatomy, presentation, evaluation, surgical approaches, and pathologic features and complications reported in managing patients with parapharyngeal space neoplasms. Two surgical procedures have been used by the author to treat 44 tumors in the parapharyngeal space. The cervical-parotid approach was used in 35 patients, and the cervical-parotid approach with midline mandibulotomy was used in 9 patients. Of the 44 tumors, 32 were benign lesions and 12 were malignant neoplasms. Forty tumors were primary parapharyngeal space tumors, and 4 cases represented isolated metastases to parapharyngeal nodes. Recurrent tumors accounted for 12 of the 44 cases. Discussion of the indications, surgical technique, and select points pertinent to using these two operative procedures is based on the operative experience gained from these 44 patients. The use of these two operations resulted in low morbidity and provided a safe, efficacious approach to the management of all parapharyngeal space neoplasms encountered.

Adolescent↗
PubMed1978

A general zone theory of color and brightness vision. II. The space-time field.

The elements of vision are brightness and color varying in time and space, constituting a vector space-time function: the visual sensation field. The sensory-field generated from the light-field variations on the retina is analyzed here in terms of elemental space-time responses (Green's functions). Both chromaticity and intensity variations in either time or space are included in a unified theory, to bridge the existing gap between color theory and analyses of spatial and temporal brightness. Sensory Green's functions are here related to standard color models and to familiar responses for special stimuli, and are shown to be advantageous for nonhomogeneous and/or nonstationary visual conditions. The theory is first applied for intensity space-time variations, to elucidate existing intensity-contrast analyses. Then the general theory including chromatic contrast is illustrated by deriving color vision generalizations of the Bloch and Ricco laws and a general space-time reciprocity law, by analyses of wavelength-pulse and color-flicker experiments, and by derivation of Abney's law of luminance additivity for heterochromoatic flicker and minimally distinct borders.

Color↗
PubMed2006

Performance of a color-difference formula based on OSA-UCS space using small-medium color differences.

An investigation of the color metrics and the complexity of the CIEDE2000 formula shows that CIELAB space is inadequate to represent small-medium color differences. The OSA-UCS (Uniform Color Space) Committee has shown that no space with uniform scale for large color differences exists. Therefore the practical way for color-difference specification is a color-difference formula in a nonuniform space. First, the BFD (Bradford University) ellipses are considered in the OSA-UCS space, and their very high regularity suggests a new and very simple color-difference formula at constant luminance. Then the COM (combined) data set used for the development of the CIEDE2000 formula is considered in the OSA-UCS space, and the color-difference formula is extended to sample pairs with a different luminance factor. The value of the performance factor PF/3 for the proposed OSA-UCS-based formula shows that the formula performs like the more complex CIEDE2000 formula for small-medium color differences.

Algorithms↗
PubMed1985

Influence of lung and chest wall compliances on transmission of airway pressure to the pleural space in critically ill patients.

Nineteen patients with acute respiratory failure were divided into three groups according to their total compliance (CT). Transmission of airway pressure to the pleural space was then evaluated by measurement of esophageal pressure at both end-expiration and end-inspiration, and at three levels of PEEP. Chest wall (CW) and lung complicance (CL) were also calculated from simultaneous measurements of lung volume changes induced by tidal delivery. In group 1 (CT greater than 45 ml/cmH2O), 37 percent of airway pressure was transmitted to pleural space. In group 2 (CT between 45 and 30 ml/cmH2O), 32 percent of airway pressure was transmitted to the pleural space. In group 3 (CT less than 30 ml/cmH2O), only 24 percent of airway pressure was transmitted to the pleural space. These differences are statistically significant (p less than 0.001) and illustrate the influence of a progressive increase in lung stiffness (CL = 100.3 +/- 17.2 ml/cmH2O in group 1, CL = 45.0 +/- 6.3 ml/cmH2O in group 2, and CL = 28.6 +/- 8.9 ml/cmH2O in group 3) on transmission of airway pressure to the pleural space. Despite lesser transmission of airway pressure to the pleural space in the most damaged lungs, no significant difference was found between groups with regard to transmural venous pressure changes throughout the study.

Acute Disease↗
PubMed2004

Simulations of action of DNA topoisomerases to investigate boundaries and shapes of spaces of knots.

The configuration space available to randomly cyclized polymers is divided into subspaces accessible to individual knot types. A phantom chain utilized in numerical simulations of polymers can explore all subspaces, whereas a real closed chain forming a figure-of-eight knot, for example, is confined to a subspace corresponding to this knot type only. One can conceptually compare the assembly of configuration spaces of various knot types to a complex foam where individual cells delimit the configuration space available to a given knot type. Neighboring cells in the foam harbor knots that can be converted into each other by just one intersegmental passage. Such a segment-segment passage occurring at the level of knotted configurations corresponds to a passage through the interface between neighboring cells in the foamy knot space. Using a DNA topoisomerase-inspired simulation approach we characterize here the effective interface area between neighboring knot spaces as well as the surface-to-volume ratio of individual knot spaces. These results provide a reference system required for better understanding mechanisms of action of various DNA topoisomerases.

Bacteriophage T4↗
PubMed2004

Amino acid composition of parturient plasma, the intervillous space of the placenta and the umbilical vein of term newborn infants.

The objective of the present study was to determine the levels of amino acids in maternal plasma, placental intervillous space and fetal umbilical vein in order to identify the similarities and differences in amino acid levels in these compartments of 15 term newborns from normal pregnancies and deliveries. All amino acids, except tryptophan, were present in at least 186% higher concentrations in the intervillous space than in maternal venous blood, with the difference being statistically significant. This result contradicted the initial hypothesis of the study that the plasma amino acid levels in the placental intervillous space should be similar to those of maternal plasma. When the maternal venous compartment was compared with the umbilical vein, we observed values 103% higher on the fetal side which is compatible with currently accepted mechanisms of active amino acid transport. Amino acid levels of the placental intervillous space were similar to the values of the umbilical vein except for proline, glycine and aspartic acid, whose levels were significantly higher than fetal umbilical vein levels (average 107% higher). The elevated levels of the intervillous space are compatible with syncytiotrophoblast activity, which maintain high concentrations of free amino acids inside syncytiotrophoblast cells, permitting asymmetric efflux or active transport from the trophoblast cells to the blood in the intervillous space. The plasma amino acid levels in the umbilical vein of term newborns probably may be used as a standard of local normality for clinical studies of amino acid profiles.

Amino Acids↗
PubMed2005

Three-dimensional reconstruction of glomeruli by electron microscopy reveals a distinct restrictive urinary subpodocyte space.

For more than 150 years, the only urinary space that has been recognized in the glomerulus conducting primary filtrate to the proximal convoluted tubule has been Bowman's space (BS) (1). Here it is shown that ultrastructural reconstructions of the podocyte and the glomerulus reveal BS to be formed from three distinct urinary spaces through which filtrate must pass before reaching the proximal convoluted tubule. The most restricted region, the subpodocyte space (SPS; first described by Gautier in 1950), was found to cover 58 to 65% of the glomerular filtration barrier. It is morphologically distinct from the rest of BS and has a highly significant restriction to flow based on morphometric measurements. This SPS was altered during increased renal perfusion pressure, consistent with the podocyte dynamically reacting to the increase in filtration. A second anastomosing branching region draining the glomerular center, which has been termed the interpodocyte space, has fewer restrictions to flow into the final region--the shell-like peripheral urinary space. The physiologic role of the restrictive SPS is yet to be determined but likely possibilities include regulation of glomerular filtration and cleaning of the glomerular filtration barrier.

Animals↗
PubMed1999

Radiographic evaluation of the position of implants in the medial malleolus in relation to the ankle joint space: anteroposterior compared with mortise radiographs.

BACKGROUND: Displaced transverse fractures of the medial malleolus are commonly treated with open reduction and internal fixation with two screws or wires. A mortise radiograph is often used to verify the position of the implants relative to the joint space. However, because the medial and lateral talomalleolar spaces are normally not parallel, the mortise projection (which is colinear with the lateral space) does not provide an accurate radiograph of the medial joint space. METHODS: In ten cadaveric ankles, two wires were inserted into the medial malleolus, as is done for fixation of a fracture, and the distance of the wires from the joint space was measured on an anteroposterior radiograph, on mortise radiographs made with the foot in 15 and 30 degrees of internal rotation, and on anatomical cross section. RESULTS: The measurement on the anteroposterior radiograph exceeded the anatomical measurement in only two specimens, and the discrepancy was 0.5 millimeter in both instances. Measurement of the osseous thickness between the joint surface and the posterior wire on the mortise radiographs always revealed a lower value than the measurements on the anteroposterior radiograph and the anatomical cross section of the same specimen. There was a false appearance of intra-articular placement of the posterior wire on the 15-degree mortise radiographs of four specimens and on the 30-degree mortise radiographs of eight specimens. CONCLUSIONS: These findings demonstrate that the mortise projection provides an oblique radiograph of the medial joint space that can inaccurately reflect the true position of fixation implants in the medial malleolus. Because an anteroposterior radiograph is made with the articular surface of the medial malleolus tangential to the beam, it provides a more accurate representation of implants in the medial malleolus.

Ankle Injuries↗
PubMed1995

Relationship between key space and user performance on reduced keyboards.

Small computers are much in demand for mobile computing. However, keyboard size is an obstacle to further size reduction. Reducing the space occupied by keys would affect the usability of the keyboard. On the other hand, if the keys were closer together, the fingers would reach them faster. This could improve typing performance. An experiment was therefore conducted to investigate the relationship between users' performance and the center-to-center key space of reduced-size keyboards. Eighteen touch-typists were asked to do a word typing task on five different keyboards. A standard keyboard with a key space of 19.05 mm and smaller keyboards with key spaces of 16.7, 16.0, 15.6, and 15.0 mm were used in this study. No performance degradation was found on keyboards with a key space of 16.7 mm for faster typists (those capable of about 40 wpm), including those with large fingers (97.5 percentile of Japanese adult males). For faster typists with narrow fingers, there was no performance degradation on keyboards with a key space of 15.0 mm.

Adult↗
PubMed1988

Brain MR: pathologic correlation with gross and histopathology. 1. Lacunar infarction and Virchow-Robin spaces.

MR imaging was performed on 36 formalin-fixed brain specimens. For three of these specimens, in vivo MR studies had also been performed before death. Changes that take place in the MR appearance of the brain after fixation are discussed. Gross and microscopic pathology revealed 14 lacunar infarctions in seven cases and enlarged Virchow-Robin spaces (état criblé) in four. Both types of lesion were seen in specimens from predominantly elderly, hypertensive patients. Eight lacunae were in the deep gray-matter nuclei (four in the putamen with variable involvement of the internal capsule and caudate nuclei, two in the thalami, and two in the dentate nuclei), five were in the supratentorial white matter, and one was in the brainstem. Enlarged Virchow-Robin spaces were identified in the basal ganglia. All lesions were detected on MR. CT failed to disclose the brainstem and dentate lacunae and the enlarged Virchow-Robin spaces. On MR, all lacunae were slitlike or ovoid, except one that was round. They were less than 1 cm in greatest diameter in all but two cases. The lacunae were hyperintense relative to brain parenchyma on both long TR sequences (short and long TEs) in all cases except that of a chronic infarct that underwent cystic change and was isointense relative to CSF on all pulse sequences. In contrast, dilated Virchow-Robin spaces were isointense relative to CSF in vivo or to fluid in the subarachnoid space in the postmortem state on all pulse sequences in all four cases. They were round or linear, and in general were smaller than the lacunae, although some overlap in size did occur. They were seen at the level immediately above the bifurcation of the internal carotid into the middle and anterior cerebral arteries and were seen on successive axial sections in the putamen (most prominent along its lateral margin) and in the internal capsule. MR studies of gross and microscopic pathology of lacunae and dilated Virchow-Robin spaces are useful in correlating MR and pathologic findings. However, changes resulting from the fixation process must be considered when postmortem and in vivo MR findings are correlated.

Adult↗
PubMed1991

Differential diagnosis of head and neck lesions based on their space of origin. 2. The infrahyoid portion of the neck.

The infrahyoid portion of the neck can be considered as a series of contiguous fascial planes and intervening spaces that lend themselves well to axial imaging. These spaces can serve as a basis on which to formulate differential diagnoses for diseases in this region. This pictorial essay describes the fascia and fascial spaces of the infrahyoid portion of the neck. The contents of each space, the common abnormalities affecting the space, and the characteristic displacements produced by disease in each space are reviewed.

Diagnosis, Differential↗
PubMed1991

Relations among mental capacity, Short-term Storage Space, and operational efficiency.

According to R. Case, a subject's Total Processing Space is the sum of his Short-term Storage Space (STSS) and Operating Space (OS). Case has hypothesized a trade-off between the two, that is, an increase in operational efficiency leads to a decrease in operating space, and consequently more short-term space is available for information processing. To test Case's hypothesis 52 freshman students were tested to estimate operational efficiency (time taken to finish the Figural Intersection Test, when administered with a time limit), Pascual-Leone's Structural M-capacity, Ms (i.e., STSS), and Functional M-capacity, Mf. A zero correlation was obtained between operational efficiency and Ms/STSS, which suggests that subjects find it difficult to distribute attentional load from one reserve (OS) to another (STSS). This study supports Pascual-Leone's construct of Ms and Mf. It is concluded that subjects with high operational efficiency seem to be operating with the field-independent cognitive style rather than using a strategy of decreasing operating space.

Adolescent↗
PubMed2001

A guilt gradient in the illegal use of parking spaces reserved for people with disabilities: field observations over five years.

Three parking spaces clearly designated as reserved for people with disabilities were observed from 8:00 AM until 9:00 PM on Monday through Saturday of the second or third week in November for five consecutive years. During the seven weeks of observation, 962 drivers parked illegally in those three reserved spaces. Informal observations and previous research suggested that illegal parkers would be more likely to park in the least conspicuous parking spaces, and, as predicted, a significant monotonic relationship was found. Thus, the data generally agree with the prediction that illegal parkers in spaces reserved for people with disabilities are less likely to park in the more conspicuous parking spaces and are more likely to park in the least conspicuous parking spaces, suggesting a guilt gradient in this illegal parking.

Attitude↗
PubMed1993

Effects of dietary lysine levels on performance and immune response of weanling pigs housed at two floor space allowances.

Three 35-d trials involving 288 crossbred weanling pigs (initial weight, 7.1 kg; age, 28 d) were used to determine the separate and interactive effects of two floor space allowances (.28 and .14 m2/pig) and three dietary lysine levels (NRC recommended, NRC+ .1% crystalline lysine-HCl, and NRC+ .2% crystalline lysine-HCl) on growth performance and several factors that measure variation within pens. Each trial was conducted as a 2 x 3 factorial arrangement of treatments in a randomized complete block design. There were four pens (four pigs per pen) for each of the six treatment combinations in each trial. The lysine x floor space allowance interaction was not significant (P = .25) for daily gain, daily feed intake, or gain/feed. Restriction of the floor space allowance decreased (P < .001) daily gain and daily feed intake, but gain/feed was not affected. The humoral immune response, as measured by the level of antibodies produced after two injections of ovalbumin, was not affected by floor space allowance. Addition of .1 and .2% crystalline lysine-HCl improved daily gain (P < .07), gain/feed (P < .10), and humoral immune response (P < .05) and was without effect (P = .28) on feed intake. Natural logarithms of variance, coefficients of variation, and range of daily gain and body weights were not changed by floor space allowance or dietary lysine level. Pigs on adequate and restricted floor space allowances responded similarly to dietary lysine levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1996

Response of pigs to space allocation and diets varying in nutrient density.

Three experiments were conducted to determine the main and interacting effects on growth performance of floor space allowance and dietary lysine and energy concentrations for growing-finishing pigs. In each experiment, space allocations of .56 or .78 m2/pig were achieved with 14 or 10 pigs per pen, respectively. In Exp. 1, diets investigated were National Research Council (NRC) recommended nutrient densities, NRC plus 5% added fat (F), NRC plus .15% added L-lysine. HCl (L), and NRC plus fat plus lysine (FL) in a 4 x 2 x 2 factorial arrangement of diets with space and season (winter vs summer). In Exp. 2 and 3, a 2 x 3 factorial treatment arrangement was used to investigate space and diet effects. Diets investigated contained 0, 2.5, or 5% added fat (choice white grease [Exp. 2]; tallow [Exp. 3]) with L-lysine.HCl added to maintain a constant lysine:ME ratio. In Exp.1, pigs given .56 m2/pig vs .78 m2/pig ate less feed (P < .001) and grew slower (P < .001) with no difference in gain:feed ratio or carcass lean percentage. Feed intake was decreased (P < .005) and gain:feed ratio increased (P < .001) for the FL vs L diet. In Exp. 2, pigs given .56 m2/pig vs .78 m2/pig grew slower (P < .001) with a poorer gain:feed ratio (P < .05) and a slower rate of lean gain (P < .05). In Exp. 3, pigs given .56 m2/pig vs .78 m2/pig grew slower (P < .05) with no difference in gain:feed ratio and a slower rate of lean gain (P < .005). There was a linear improvement in ADG (P < .01, Exp. 2; P = .011, Exp. 3) and gain:feed ratio (P < .001, Exp. 2 and 3) with increasing amounts of fat in the diet. The lack of space x diet interactions in these experiments suggests that the reduction in ADG associated with the reduction in ADFI for pigs given less space is independent of dietary lysine and energy concentrations.

Animal Nutritional Physiological Phenomena↗
PubMed2002

Effects of feeder-trough space and variation in body weight within a pen of pigs on performance in a wean-to-finish production system.

Two studies were carried out with the same group of pigs within a wean-to-finish system. In Study 1 (weaning to wk 8 postweaning), the effect of feeder-trough space in pens that were double-stocked on pig growth was evaluated. In Study 2 (end of wk 8 to 112 +/- 1.5 kg BW), the effect of variation in pig BW within a pen on growth was investigated. In Study 1, a randomized block design was used to compare two feeder-trough space treatments (Double [4 cm/pig] vs Control [2 cm/pig]). Pigs (n = 1,728) were randomly allocated at weaning (5.4 +/- 0.01 kg BW; 16 d of age) to mixed-sex pens (8 pens/treatment) of 108 pigs/pen on the basis of BW. Floor-space (0.30 m2/pig) and drinker allocation (13 pigs/drinker) were the same for both treatments. Two six-place (35 cm/place) feeders were positioned together in the center of each pen and were accessible from both sides. For the Double treatment, both feeders contained feed, whereas for the Control only one feeder contained feed. In Study 2, a randomized block design was used to compare three BW/variation in BW treatments: 1) Heavy BW/Low variation, 2) Light BW/Low variation, and 3) Mixed BW/Normal variation. The double-stocked pens of pigs from within previous feeder-trough space treatment were split into two groups of 54 pigs (equal sex ratio) having either high or low BW variation within pen. Pigs had free access to feed and water throughout the studies. In Study 1, doubling feeder-trough space did not affect (P > 0.05) pig growth from weaning to the end of wk 6. From wk 6 to 8, pigs on the Double treatment compared to the Control treatment had higher (P < 0.05) ADG and were heavier (P < 0.05), but had similar (P > 0.05) ADFI and gain:feed ratio. In Study 2, pen-BW treatment did not impact (P > 0.05) ADG or gain:feed ratio; however, Heavy/Low had greater (P < 0.01) ADFI than Light/Low with Mixed/Normal being intermediate for ADFI. At 112 kg BW, CV of BW within a pen was similar (P > 0.05) across treatments; however, days to market BW was greater (P < 0.001) for Light/Low than Heavy/ Low with Mixed/Normal being intermediate. In summary, increasing feeder-trough space from 2 to 4 cm per pig increased daily gain after wk 6 postweaning in double-stocked pens of pigs; however, sorting pigs on the basis of BW when splitting pens did not impact growth rate or variation in BW within a pen at market BW.

Animal Husbandry↗
PubMed2004

The effect of space allocation on barrow and gilt performance.

Two experiments were conducted to determine the variation in response to space allocation between barrows and gilts and to examine an alternative allocation regimen for barrows and gilts. Experimental space allocations in both experiments were achieved by varying the number of pigs per pen in a fully slatted facility. In Exp. 1, barrows were given 0.58 and 0.65 m2/pig (nine and eight pigs per pen, respectively) and gilts were given 0.65 and 0.74 m2/pig (eight and seven pigs per pen, respectively). In addition, barrows at 0.58 m2/pig were fed diets formulated for barrows or diets formulated for gilts. Barrows grew 4.8% slower (P = 0.031) and ate 3.1% less feed daily (P = 0.062) at 0.58 vs. 0.65 m2/pig from 22 to 115 kg BW, with no difference in feed conversion, daily lean gain, carcass lean percent, or variation in weight within the pen at time of first pig removal to slaughter. There was no improvement in daily gain, feed intake, feed efficiency, lean gain, or carcass lean percent when gilts were given 0.74 vs. 0.65 m2/pig from 22 to 115 kg BW. There was no difference in performance between the population that consisted of barrows and gilts at 0.65 m2/pig vs. the population of barrows at 0.58 m2/pig and gilts at 0.74 m2/pig. There was no difference in performance by barrows at 0.58 m2/pig when fed either barrow or gilt diets, except for a slight increase (P = 0.078) in within-pen weight variation when the first pig was removed for slaughter for the barrows fed gilt diets. In Exp. 2, barrows and gilts were given 0.58 m2/pig or 0.74 m2/pig (18 vs. 14 pigs per pen) from weaning (mean age 17 d) to slaughter on d 168 postweaning. There were no interactions between space allocation and gender. Daily gain and feed intake were decreased by 2.8% (P = 0.037) and 2.9% (P = 0.084), respectively, with no effect on feed conversion or standardized fat-free lean daily gain for the 0.58 vs. the 0.74 m2/pig treatment, whereas total live weight gain per pen was increased 20.8% (P < 0.001). Results of Exp. 1 suggest that space allocation can be used to achieve similar growth rates between barrows and gilts, and results of Exp. 2 suggest that the response to space allocation is similar for barrows and gilts. The difference in magnitude of response to space allocation between experiments may be due in part to when the social group was formed, with a smaller difference in performance in Exp. 2 associated with a stable social group from weaning to slaughter.

Age Factors↗
PubMed2004

Obesity related measurements and joint space width in patients with knee osteoarthritis.

BACKGROUND: The aim of this study is to analyze the relationship between body mass index and obesity related measurements and tibiofemoral joint space which have been the principal method of radiographic evaluation in progression and therapeutic trials of knee osteoarthritis. METHODS: Fifty-five female patients with the diagnosis of osteoarthritis in knees according to the criteria of American College of Rheumatology in knees were included in the study. The mean age of patients was 57,42+/-8,60(SD) years with a range of 42-77. Medial and lateral compartment joint space widths were measured on antero-posterior knee radiography. Body mass index, triceps, biceps, subscapular and suprailiac skinfold thickness, waist and hip circumference were measured. Body composition was determined by dual energy X-ray absorpsiometry (DEXA) (Norland XR 46) and total lean mass (g), total fat mass (g), trunk lean mass, trunk fat mass, abdomen lean mass, abdomen fat mass measurements were recorded. RESULTS: Patients with body mass index>30 were accepted as obese patients. According to these criteria 33 of the 55 patients were obese. Tibial medial compartment and tibial lateral compartment measurements of obese patients were significantly lower than nonobese patients (p=0,000, p=0,003 respectively). Body mass index was correlated with total lean mass, total fat mass, trunk fat mass, abdominal fat mass, leg fat mass. Tibial medial compartment and tibial lateral compartment space measurements were negatively correlated with body mass index. CONCLUSION: Our results revealed significant difference in both medial and lateral joint spaces of obese and nonobese patients with knee osteoarthritis. Medial and lateral joint spaces of obese patients were narrower than nonobese osteoarthritis patients. The more body mass index had the patients the narrower joint space they had displayed. However body composition analysis and obesity related measurements did not show additional correlation with tibial compartment measurement.

Adult↗