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PubMed2002

[The preliminary study on creating the differential templates of the skeletal profiles for Shanghainese with normal occlusion in early permanent dentition].

OBJECTIVE: To establish the differential templates of the skeletal profiles for Shanghainese with normal occlusion in early permanent dentition. METHODS: 71 lateral cephalometric radiographs of subjects with normal occlusion in early permanent dentition, aged from 11 - 15 years (37 females and 34 males) were traced. 23 skeletal landmarks were identified on the tracings, which afterwards were scanned on the computer. An x-y coordinate system was established: the tracing superimposed on sella rotated 7 degrees down from the sella-nasion line as the x axis and the vertical line through sella perpendicular to the x axis as the y axis. A special length/depth ratio was designed. The length/depth ratio of each graph were calculated. Steiner analysis was applied to check the difference between genders. RESULTS: There was no difference between genders. The tracings were divided into three categories: short face, normal face and long face according to the mean and standard deviation of the ratio. The three types of tracings were superimposed on the x axis with sella registered. Three templates were created. CONCLUSIONS: The differences were apparent when the three templates were superimposed.

Adolescent↗
PubMed2004

Loss of wild-type Trp53 protein in mouse fibroblasts leads to increased radioresistance with consequent decrease in repair of potentially lethal damage.

It has been reported that the loss of function of Trp53 protein is associated with a reduction in the expression of radiation-induced potentially lethal damage (PLD). These studies, however, were carried out using either transformed or transfected cell lines, and other factors may have existed that could interfere with PLD repair. In this study, we used isogenic fibroblasts derived from Trp53 knockout mice to study radiation sensitivity, PLD repair, and repair of DNA double-strand breaks (DSBs). Experiments were carried out using wild-type (Trp53(+/+)), heterozygous (Trp53(+/-)) and homozygous mutant (Trp53(-/-)) cells. This is an ideal system because the only difference in the three cell strains is the status of the Trp53 protein. DSB repair was measured by pulsed-field-gel electrophoresis (PFGE), while radiosensitivity and PLD repair were studied using the clonogenic survival assay. Cells were irradiated in plateau phase and then trypsinized and plated either immediately or 24 h later to allow for PLD repair. The results of Western blot analyses showed that Trp53(-/-) cells expressed a putative mutant form of Trp53 that was unable to transcriptionally activate Cdkn1a (p21) protein in response to irradiation. The Trp53(-/-) cells were significantly more radioresistant than the Trp53(+/+) cells, and this was associated with a moderate reduction in PLD repair. DNA repair experiments showed no difference in DSB rejoining capability between the two cell lines. In conclusion, our results show that loss of wild-type Trp53 leads to increased radioresistance with consequent reduction in PLD repair but with no effect on DNA DSB repair.

Animals↗
PubMed1987

Effect of recombinant tumor necrosis factor on HL-60 cells: cell-cycle specificity and synergism with actinomycin D.

The tumor necrosis factor (TNF) exhibits a multitude of activities depending on the type of target cells. We characterized the cytostatic and cytotoxic effects of recombinant TNF, alone and in combination with actinomycin D (AMD), on the human leukemic cell line HL-60. Because HL-60 cells, when triggered to monocytic differentiation by phorbol esters, are known to produce and secrete TNF, their sensitivity to the factor could indicate an autocrine function of TNF in this cell system. Indeed, HL-60 cells were affected by TNF; their doubling time was increased by about 50% and progression through the cell cycle was perturbed. Initially, (up to 8 h) TNF induced a temporary arrest in G2 while later (24-48 h) it delayed progression through the G1 phase. Also, a transient increase in RNA content peaking at 6-8 h was apparent. The cytotoxicity of TNF alone was low. Thus, TNF may be involved in the regulation of the cell cycle of HL-60 cells during early stages of their differentiation. The cytotoxicity of TNF was markedly potentiated in the presence of AMD; the effect was AMD but not TNF concentration-dependent. Whereas at 20 and 50 ng/ml of AMD alone nonviable cells did not exceed 20% during the first 24 h of treatment, their proportion increased to 80 and 90%, respectively, in the presence of TNF. The most sensitive were cells in the S phase of the cell cycle. The observed synergistic effect of TNF and AMD does not appear to be caused by the action of TNF increasing the permeability of the cell membrane to AMD. The results indicate that HL-60 cells, ordinarily resistant to the cytotoxic action of TNF, can be rendered sensitive by treatment with AMD. This implies that a combination of TNF and AMD may be considered in oncology for treatment of tumors otherwise nonresponding to TNF alone.

Cell Cycle↗
PubMed1998

Topographical relationship between neuronal nitric oxide synthase immunoreactivity and cyclic 3',5'-guanosine monophosphate accumulation in the brain of the adult Xenopus laevis.

Previous immunohistochemical staining procedures of the brain and pituitary in Xenopus laevis, using an antiserum against neuronal nitric oxide (NO) synthase (nNOS) and nicotinamide adenine dinucleotide phosphate-diaphorase histochemistry, have revealed NOS activity in neurons and fibers in a number of brain areas, as well as in fibers in the pituitary. In the present study we have localized the target structures of the NOergic system in the Xenopus brain by visualizing the sites of NO-sensitive cyclic 3',5'-guanosine monophosphate (cGMP) accumulation, according to a method for cGMP visualization in rat brain slices. Brain slices of unfixed Xenopus are incubated in the presence of the phosphodiesterase inhibitor isobutylmethylxanthine and the NO donor sodium nitroprusside, followed by fixation and cryosectioning. Sections were then processed for immunohistochemistry using rabbit and sheep antisera against cGMP and a sheep antiserum against nNOS. Visualization of single and double labeling of cGMP immunoreactive and/or nNOS immunoreactive structures was performed with combined CY3/fluorescein isothiocyanate fluorescence microscopy. Following this procedure, we provide immunohistochemical evidence for the distribution of cGMP-accumulating neurons in the brain of adult Xenopus. In most brain areas, the distribution of nNOS and cGMP immunoreactive structures (neuron somata and fibers) is distinct and separate, for instance in the dorsal pallium, the lateral thalamic nuclei, the optic tectum, the locus coeruleus and the reticular formation. However, nNOS and cGMP immunoreactive structures are often found in the vicinity of each other, and in the optic tectum even in adjacent neuron fibers and somata. The present observations are in line with the presence of an NO-dependent soluble guanylate cyclase in distinct brain areas of Xenopus laevis, corroborating similar data in the mammalian brain. Further, our observations may add to the understanding of the anatomical connectivity pattern and functional relevance of the NOergic system in the amphibian brain.

1-Methyl-3-isobutylxanthine↗
PubMed1988

Interactions between bladder tumor cells as tumor spheroids from the cell line J82 and human endothelial cells in vitro.

Multicellular tumor spheroids (MCTS) are a reliable model of nonvascularized tumor cell aggregates showing a well defined three-dimensional growth pattern and are comparable with small metastatic cancer cell complexes in blood circulation. In the present study we have established a co-culture system of multicellular bladder tumor spheroids with human endothelial cells on extracellular matrix (ECM) in order to investigate morphological and proliferative changes of endothelial and tumor cells within a defined time of cell-cell interaction. The MCTS--endothelial cell--extracellular matrix complex was observed within coculture periods from 1/2 to seven days. Morphological changes (light microscopy, scanning and electron microscopy) indicated that MCTS are not influenced by cocultured endothelial cells. The tumor cells invaded into the ECM after degradation of endothelial cells in the center of the contact zone. Endothelial cells, however, showed degenerative changes as well as a complex reaction in their proliferation activities. We could recognize an initial increase of proliferation of endothelial cells next to the MCTS. Later on, endothelial cells next to invading tumor cells showed changes in morphological polarity. The model system used has the advantage of using human tumor tissue. It distinguishes between basic cellular mechanisms like adherence, migration, DNA synthesis and proliferation in the study of the contact of tumor cells and vascular endothelial cells as an important event in hematogenous tumor spread.

Cell Communication↗
PubMed1998

Differential distribution, affinity and plasticity of dopamine D-1 and D-2 receptors in the target sites of the mesolimbic system in an animal model of ADHD.

The distribution of dopamine (DA) D-1 and D-2 receptors has been studied by autoradiography in the anterior forebrain of the pre-hypertensive spontaneously hypertensive rat (SHR) as an animal model of attention-deficit hyperactivity disorder (ADHD) in children. Juvenile male SHR and Wistar Kyoto (WKY) controls were given either vehicle or the DA re-uptake blocker methylphenidate (MP; 3 mg/kg, i.p.), daily during a 2-week period. A saturation analysis for the D-1 receptor subfamily was carried out with 0.1-5.0 nM of [3H]SCH23390 and two competition studies for the D-2 receptor subfamily with 4 nM of [3H]raclopride or 5 nM of [3H]quinpirole were carried out with unlabelled spiperone and 7-OH-DPAT as unlabelled displacers on cryostat coronal sections of the anterior forebrain. Quantitative receptor autoradiography and computer-assisted image analysis with reference to co-exposed 3H-microscale standards showed in vehicle-treated SHR higher density of DA D-1/D-5 receptor subtypes in the caudate-putamen (CPU), the nucleus accumbens (ACB) core and shell and the olfactory tubercle (OT), which was associated to a lower affinity. MP treatment normalised the DA D-1/D-5 receptors by decreasing the number of binding sites and increasing the affinity to control level. In addition, MP treatment 'down-regulated' DA D-2/D-4 subtypes in the CPU, ACB and OT, and 'up-regulated' mostly D-3 subtype in CPU, ACB, OT in both rat lines and in the globus pallidus, ventral pallidum and lateral septum in WKY rats only. In contrast, D-3 receptors were 'down-regulated' in the islands of Calleja in both rat lines. Moreover, regional cross-correlative analyses revealed a modulatory influence of DA receptors in the cross-talk within the anterior forebrain, which was altered in the SHR. Thus, the differential distribution and regulation of DA receptor subtypes following DA re-uptake blocker as well as the different regional cross-talk in the target sites of nigrostriatal and mesolimbic DA systems lend support to the DA hypothesis of ADHD in children.

Animals↗
PubMed1986

Sex determination of the human skull based upon line drawing from roentgen cephalograms.

The shape of the human skulls was studied with the aid of a personal computer to establish sex differences in quantitative anatomical terms. On the roentgen cephalograms from 50 adult males and 50 adult females, the lateral profile was transcribed onto an acetate sheet, on which the contour from the nasal apex to the forehead was digitized on a tablet digitizer into a series of dots which were input into the computer system. After this chain of dots was simulated by a spline function, the places most typically reflecting sex difference were determined in the profile based on the radius of curvature computed at each dot. The eminence of glabella and the nasal root, shown to be the places of skull apparently most characteristic of sex, were approximated to circular arcs with the least squares method, the radii of which were expected to serve for sexing. In both places, Student's t-test revealed a significant difference between the male and female groups (p less than 0.01). It was thus demonstrated that in male the eminence of glabella and the nasal concavity develop much more markedly than in female, presenting as a clear skeletal difference between both sexes.

Adolescent↗
PubMed1997

Architecture of the human jaw-closing and jaw-opening muscles.

BACKGROUND: The human jaw-closing and jaw-opening muscles produce forces leading to the development of three-dimensional bite and chewing forces and to three-dimensional movements of the jaw. The length of the sarcomeres is a major determinant for both force and velocity, and the maximal work, force, and shortening range each muscle is capable of producing are proportional to the architectural parameter volume, physiological cross-sectional area, and fiber length, respectively. In addition, the mechanical role the muscles play is strongly related to their three-dimensional position and orientation in the muscle-bone-joint system. The objective of this study was to compare relevant architectural characteristics for the jaw-closing and jaw-opening muscles and to provide a set of data that can be used in biomechanical modeling of the masticatory system. METHODS: In eight cadavers, sarcomere lengths, muscle masses, fiber lengths, pennation angles, and physiological cross-sectional areas were determined for the following muscles: superficial and deep masseter, anterior and posterior temporalis, anterior and posterior medial pterygoid, inferior and superior lateral pterygoid, posterior and anterior digastric, geniohyoid, posterior and anterior mylohyoid, and stylohyoid. To determine the spatial position of their action lines, the three-dimensional coordinates of the attachment sites were registered. RESULTS: Compared with the jaw openers, the jaw closers were characterized by shorter sarcomere lengths at the closed jaw, larger masses of contractile and tendinous tissue, larger physiological cross-sectional areas, larger pennation angles, shorter fiber lengths, shorter moment arms, and lower fiber-length-to-muscle-length ratios. In addition, architectural features differed across the muscles of the same functional group. Sarcomere length did not differ significantly among the regions of the same muscle. In contrast, in some muscles, significant intramuscular differences were found with respect to, e.g., physiological cross-sectional area, fiber length, pennation angle, and moment arm length. CONCLUSIONS: The results suggest that the jaw-closing muscles have architectural features that suit them for force production. Conversely, the jaw-opening muscles are better designed to produce velocity and displacement.

Aged↗
PubMed1987

Anatomic factors in the femoral implantation of the Ilizarov external fixator.

Ilizarov's method of external fixation with compression or distraction for lesions of the limbs demonstrates new possibilities in osteogenesis. Its performance with double horizontal pinning on several external rings calls for precautions to avoid lesions of the vessels, nerves and joints. This study, based on anatomic sections radiographed after opacification of the arterial system, makes it possible to propose rules for insertion of the pins. Insertion of the anteromedial pins of the thigh should be made 2 cm in front of the line of projection of the femoral artery, between the middle of the inguinal ligament and the posterior margin of the medial condyle. Insertion of the posterolateral thigh pins should be made 2 cm lateral to the line of projection of the sciatic nerve, between the center of the ischiotrochanteric interval, the apex of the popliteal fossa and the posterior aspect of the head of the fibula.

Bone Nails↗
PubMed2002

Overview of 321 patients with idiopathic thrombocytopenic purpura. Retrospective analysis of the clinical features and response to therapy.

In this retrospective study, we evaluated the clinical features and the effects of various treatment modalities on the clinical course in patients diagnosed with idiopathic thrombocytopenic purpura (ITP) at our center between 1984-2000. We retrospectively examined the medical records of 321 (229 females, 92 males) ITP patients. One hundred and seventy-one (53.3%) patients were lost to follow-up. When evaluating the clinical features, all 321 patients were included; however, when the response to treatment modalities was evaluated only 150 patients followed up regularly were considered. The median age of the patients on initial diagnosis was 34 years (range: 14-78). At initial diagnosis, 235 (73.2%) patients had signs of bleeding. Of patients diagnosed with ITP initially, six later turned out to have systemic lupus erythematosus (SLE) and two myelodysplastic syndrome (MDS). The median follow-up of 150 patients followed up regularly was 30 months (range: 4-396). One hundred and thirty-seven of these subjects had an indication for treatment and 94.2% of them were administered either standard or high-dose steroids as the first-line therapy. Complete remission (CR) was defined as any platelet count >100,000/mm(3) lasting for 3 months or longer without treatment. CR was achieved in 51.9% of the patients given steroids as the initial therapy. During a median follow-up of 33 months, relapse occurred in 58.2% of these patients, and after a median follow-up of 11 months the rest of them were still in remission. Ninety-eight patients followed up regularly were administered second-line therapies. CR was obtained in 44.4% of the patients who used steroids as second-line therapy. Within a median follow-up of 15 months, 20.8% of these patients relapsed. Splenectomy was performed in 76 patients and CR was obtained in 68.4% of the regularly followed up patients. Relapse occurred within a median of 96 months in 15.4% of the patients who had CR. Kaplan-Meier curves showed that the duration of CR obtained by splenectomy was significantly higher than that obtained by steroids (p<0.001). The 10-year disease-free survivals in patients who used steroids and who underwent splenectomy were, respectively, 13% and 58%. In our adult ITP patients, steroids induced nearly similar rates of CR both as first-and second-line therapies. Splenectomy seems to be effective in patients unresponsive to steroids. The duration of CR obtained by splenectomy is significantly longer when compared with the duration of CR obtained by steroid therapy.

Adolescent↗
PubMed1985

Analysis of the human fetal skeleton and organs with xeroradiography.

We have used xeroradiography to study normal and abnormal fetuses including some with anencephaly, hydrocephalus, spina bifida, osteogenesis imperfecta (type IV), Jeune syndrome, radial aplasia, thanatophoric dysplasia, and Pena-Shokeir syndrome. Xeroradiography images the lines of ossification and epiphyses in great detail, shows ossification, and reveals abnormalities that alter bone modeling as seen in Jeune syndrome, osteogenesis imperfecta (type IV), and thanatophoric dysplasia. This technique can be used successfully to examine soft tissues and organs. It can also be used in combination with contrast materials to identify the lateral ventricles, the cardiovascular, gastrointestinal, urinary, and respiratory systems, and the cavities (pleural and peritoneal) of the fetal body.

Abortion, Incomplete↗
PubMed1993

Azygos catheter placement as a cause of failure of dialysis.

Common complications of venous dialysis catheters include sepsis and accidental removal. Angiographic demonstration of dialysis lines is only rarely requested usually to confirm the presence of clot or stenosis as a cause for poor dialysis flow. Poor flow can also be due to inadvertent placement of the catheter in the azygos system. The use of dialysis catheters with a long venous limb which extends beyond the arterial port may predispose to such placement as their lumen is lateral to the central axis of the catheter. In those patients with poor venous access catheter placement under angiographic control may be helpful.

Aged↗
PubMed2002

Response of human pulps following acid conditioning and application of a bonding agent in deep cavities.

OBJECTIVES: The aim of this in vivo study was to evaluate the human dental pulp response when a one-bottle adhesive system was applied on etched or unetched deep dentine. METHODS: Eighteen class V deep cavity preparations were divided in three groups: group 1-total etching + two coats of single bond (SB) + composite resin (Z-100); group 2-enamel etching + two coats of SB + Z-100; group 3-cavity floor lined with a calcium hydroxide liner (Dycal) + acid-etching of enamel and lateral walls + two coats of SB + Z-100. Two teeth were used as intact control group. After 30 days the teeth were extracted and processed through H and E, Masson's trichrome and Brown and Brenn staining techniques. RESULTS: Moderate inflammatory response, disorganization of pulp tissue, as well as, deposition of thin layer of reactionary dentin were observed in group 1 teeth in which the remaining dentin thickness (RDT) was less than 300 microm. These histological findings appear to be related to long resin tags formation and bonding agent diffusion through dentinal tubules. In group 2, slight inflammatory response was observed only in one tooth in which the RDT was 162 microm. In group 3, all the teeth showed normal histological characteristics which were similar to the intact control group. Presence of bacteria was not correlated with the intensity of pulpal response. The patients reported no symptoms during the experiment. Radiographic evaluation showed no periapical pathology for any of the teeth. SIGNIFICANCE AND CONCLUSIONS: Acid-etched deep dentin (RDT less than 300 microm) lined with SB causes more intense pulpal response than unetched deep dentin. Based on the results observed in the present study and the conditions in which it was carried out, we recommend the application of a biocompatible liner before etching deep dentin and applying SB.

Acid Etching, Dental↗
PubMed2002

Inhibition of telomerase activity by a distamycin derivative: effects on cell proliferation and induction of apoptosis in human cancer cells.

In this study, we evaluated the potential of the distamycin derivative MEN 10716 as a telomerase inhibitor. Exposure of human melanoma cell extracts to MEN 10716 induced a dose-dependent inhibition of telomerase activity, with an IC50 of 24+/-3 microM. When intact JR8 melanoma cells were chronically exposed to the drug (200 microM every other day for 50 days), a marked inhibition (>80%) of the enzyme's catalytic activity was consistently observed starting from day 1. At later points in time, MEN 10716 inhibited melanoma cell proliferation and induced apoptosis. Cells surviving MEN 10716 exposure were characterised by a higher melanin content and a greater expression of p16(INK4A) protein than control cells. The effects of MEN 10716 were subsequently evaluated in different tumour cell systems. In particular, even in the H460 non-small cell lung cancer cell line, chronic exposure of the cells to the drug (100 microM every other day for 50 days) induced a consistent inhibition (>85%) of telomerase activity, a reduction of cell proliferation potential, and apoptosis. Conversely, MEN 10716 treatment did not appreciably inhibit cell proliferation in the U2-OS telomerase-negative human osteogenic sarcoma cell line. Interestingly, no variation in the mean telomere length was observed in MEN 10716-treated JR8 melanoma cells, whereas an appreciable increase in the mean telomere length was found in H460 lung cancer cells after drug exposure. Overall, the results of the study indicate that MEN 10716 is a possible telomerase inhibitor and suggest that abrogation of telomerase activity can affect cell proliferation even through pathways that are not dependent on telomere erosion.

Antineoplastic Agents↗
PubMed1999

Circadian rhythms in olfactory responses of Drosophila melanogaster.

The core mechanism of circadian timekeeping in arthropods and vertebrates consists of feedback loops involving several clock genes, including period (per) and timeless (tim). In the fruitfly Drosophila, circadian oscillations in per expression occur in chemosensory cells of the antennae, even when the antennae are excised and maintained in isolated organ culture. Here we demonstrate a robust circadian rhythm in Drosophila in electrophysiological responses to two classes of olfactory stimuli. These rhythms are observed in wild-type flies during light-dark cycles and in constant darkness, but are abolished in per or tim null-mutant flies (per01 and tim01) which lack rhythms in adult emergence and locomotor behaviour. Olfactory rhythms are also abolished in the per 7.2:2 transgenic line in which per expression is restricted to the lateral neurons of the optic lobe. Because per 7.2:2 flies do not express per in peripheral oscillators, our results provide evidence that peripheral circadian oscillators are necessary for circadian rhythms in olfactory responses. As olfaction is essential for food acquisition, social interactions and predator avoidance in many animals, circadian regulation of olfactory systems could have profound effects on the behaviour of organisms that rely on this sensory modality.

Animals↗
PubMed1999

Identification of intergranular phases in ceramic nanocomposites.

Analytical FEG-TEM was used for nanostructural and nanochemical characterization of Al2O3-TiN (composite I) and Si3N4-TiN (composite II) ceramic composite systems. The presence of vitreous intergranular phases in pockets at multiple grain junctions and in thin films ( approximately 0.8 nm thick) at grain boundaries was revealed by high resolution and Fresnel fringe imaging techniques. The existence of a Ti-rich thin intergranular film at alumina grain boundaries was revealed by EDS line-scanning across internal interfaces at the 1.5 nm lateral resolution level. Extracting interface specific information at subnanometre levels by means of quantitative spatial difference EELS allowed an identification of intergranular phases. Ti sub-oxide existed in thin films at Al2O3 and TiN grain boundaries, whereas a mixed Al-Ti-O-N glassy phase was observed in pockets at triple grain junctions in composite I. In composite II, residual siliceous oxide and oxynitride glass phases were identified in thin films at Si3N4 grain boundaries and multiple grain junctions, respectively. These observations indicated that the chemistry of the intergranular phase in thin grain boundary films is notably different from that in larger pockets at multiple grain junctions.

Journal Article↗
PubMed1997

Cadherins promote skeletal muscle differentiation in three-dimensional cultures.

The cell-cell adhesion molecule N-cadherin, with its associated catenins, is expressed by differentiating skeletal muscle and its precursors. Although N-cadherin's role in later events of skeletal myogenesis such as adhesion during myoblast fusion is well established, less is known about its role in earlier events such as commitment and differentiation. Using an in vitro model system, we have determined that N-cadherin- mediated adhesion enhances skeletal muscle differentiation in three-dimensional cell aggregates. We transfected the cadherin-negative BHK fibroblastlike cell line with N-cadherin. Expression of exogenous N-cadherin upregulated endogenous beta-catenin and induced strong cell-cell adhesion. When BHK cells were cultured as three-dimensional aggregates, N-cadherin enhanced withdrawal from the cell cycle and stimulated differentiation into skeletal muscle as measured by increased expression of sarcomeric myosin and the 12/101 antigen. In contrast, N-cadherin did not stimulate differentiation of BHK cells in monolayer cultures. The effect of N-cadherin was not unique since E-cadherin also increased the level of sarcomeric myosin in BHK aggregates. However, a nonfunctional mutant N-cadherin that increased the level of beta-catenin failed to promote skeletal muscle differentiation suggesting an adhesion-competent cadherin is required. Our results suggest that cadherin-mediated cell-cell interactions during embryogenesis can dramatically influence skeletal myogenesis.

Animals↗
PubMed2006

Stochastic re-calibration: contextual effects on perceived tilt.

The human visual system exaggerates the difference between the tilts of adjacent lines or grating patches. In addition to this tilt illusion, we found that oblique flanks reduced acuity for small changes of tilt in the centre of the visual field. However, no flanks--regardless of their tilts--decreased sensitivity to contrast. Thus, the foveal tilt illusion should not be attributed to orientation-selective lateral inhibition. Nor is it similar to conventional crowding, which typically does not impair letter recognition in the fovea. Our observers behaved as though the reference orientation (horizontal) had a small tilt in the direction of the flanks. We suggest that the extent of this re-calibration varies randomly over trials, and we demonstrate that this stochastic re-calibration can explain flank-induced acuity loss in the fovea.

Contrast Sensitivity↗