Advancement of Photospheric Radius Expansion and Clocked Type-I X-Ray Burst Models with the New ^{22}Mg(α,p)^{25}Al Reaction Rate Determined at the Gamow Energy

We report the first (in)elastic scattering measurement of ^{25}Al+p with the capability to select and measure in a broad energy range the proton resonances in ^{26}Si contributing to the ^{22}Mg(α,p) reaction at type I x-ray burst energies. We measured spin-parities of four resonances above the α threshold of ^{26}Si that are found to strongly impact the ^{22}Mg(α,p) rate. The new rate advances a state-of-the-art model to remarkably reproduce light curves of the GS 1826-24 clocked burster with mean deviation <9% and permits us to discover a strong correlation between the He abundance in the accreting envelope of the photospheric radius expansion burster and the dominance of ^{22}Mg(α,p) branch.

Following in Jakobson and Lévi-Strauss' footsteps: A neurocognitive poetics investigation of eye movements during the reading of Baudelaire's 'Les Chats'

Following Jakobson and Levi-Strauss [1] famous analysis of Baudelaire's poem 'Les Chats' ('The Cats'), in the present study we investigated the reading of French poetry from a Neurocognitive Poetics perspective. Our study is exploratory and a first attempt in French, most previous work having been done in either German or English (e.g. [2] [3] [4] [5] [6]). We varied the presentation mode of the poem Les Chats (verse vs. prose form) and measured the eye movements of our readers to test the hypothesis of an interaction between presentation mode and reading behavior. We specifically focussed on rhyme scheme effects on standard eye movement parameters. Our results replicate those from previous English poetry studies in that there is a specific pattern in poetry reading with longer gaze durations and more rereading in the verse than in the prose format. Moreover, presentation mode also matters for making salient the rhyme scheme. This first study generates interesting hypotheses for further research applying quantitative narrative analysis to French poetry and developing the Neurocognitive Poetics Model of literary reading [NCPM; 2] into a cross-linguistic model of poetry reading.

Context matters: Anterior and posterior cortical midline responses to sad movie scenes

Narrative movies can create powerful emotional responses. While recent research has advanced the understanding of neural networks involved in immersive movie viewing, their modulation within a movie's dynamic context remains inconclusive. In this study, 24 healthy participants passively watched sad scene climaxes taken from 24 romantic comedies, while brain activity was measured using functional magnetic resonance (fMRI). To study effects of context, the sad scene climaxes were presented with either coherent scene context, replaced non-coherent context or without context. In a second viewing, the same clips were rated continuously for sadness. The ratings varied over time with peaks of experienced sadness within the assumed climax intervals. Activations in anterior and posterior cortical midline regions increased if presented with both coherent and replaced context, while activation in the temporal gyri decreased. This difference was more pronounced for the coherent context condition. Psycho-Physiological interactions (PPI) analyses showed a context-dependent coupling of midline regions with occipital visual and sub-cortical reward regions. Our results demonstrate the pivotal role of midline structures and their interaction with perceptual and reward areas in processing contextually embedded socio-emotional information in movies.

The neural bases of the pseudohomophone effect: Phonological constraints on lexico-semantic access in reading

We investigated phonological processing in normal readers to answer the question to what extent phonological recoding is active during silent reading and if or how it guides lexico-semantic access. We addressed this issue by looking at pseudohomophone and baseword frequency effects in lexical decisions with event-related functional magnetic resonance imaging (fMRI). The results revealed greater activation in response to pseudohomophones than for well-controlled pseudowords in the left inferior/superior frontal and middle temporal cortex, left insula, and left superior parietal lobule. Furthermore, we observed a baseword frequency effect for pseudohomophones (e.g., FEAL) but not for pseudowords (e.g., FEEP). This baseword frequency effect was qualified by activation differences in bilateral angular and left supramarginal, and bilateral middle temporal gyri for pseudohomophones with low- compared to high-frequency basewords. We propose that lexical decisions to pseudohomophones involves phonology-driven lexico-semantic activation of their basewords and that this is converging neuroimaging evidence for automatically activated phonological representations during silent reading in experienced readers.

Identical words are read differently in different languages

It is hypothesized that written languages differ in the preferred grain size of units that emerge during reading acquisition. Smaller units (graphemes, phonemes) are thought to play a dominant role in relatively consistent orthographies (e.g., German), whereas larger units (bodies, rhymes) are thought to be more important in relatively inconsistent orthographies (e.g., English). This hypothesis was tested by having native English and German speakers read identical words and nonwords in their respective languages (zoo-Zoo, sand-Sand, etc.). Although the English participants exhibited stronger body-rhyme effects, the German participants exhibited a stronger length effect for words and nonwords. Thus, identical items were processed differently in different orthographies. These results suggest that orthographic consistency determines not only the relative contribution of orthographic versus phonological codes within a given orthography; but also the preferred grain size of units that are likely to be functional during reading.

Pseudohomophone effects in lexical decision: still a challenge for current word recognition models

Computational models that implement a serial mechanism of phonological assembly predict interactions between the size of the pseudohomophone (PsH) effect and stimulus length. Models with frequency-sensitive word representations predict baseword frequency effects. These predictions were tested in a lexical-decision task. The results showed constant PsH effects across different word lengths (in favor of parallel phonological activation) and baseword frequency effects (in favor of frequency-sensitive representations). However, the baseword frequency effect was opposite of what the models predicted. This result is most easily accommodated by models that assume an orthographic verification mechanism. The plausibility of such a mechanism was further supported by the results of 2 additional experiments investigating the effects of response speed and spelling probability (feedback consistency) on the size of the PsH effect.

Visual and phonological codes in letter and word recognition: evidence from incremental priming

Critical issues in letter and word priming were investigated using the novel incremental priming technique. This technique adds a parametric manipulation of prime duration (or prime intensity) to the traditional design of a fast masked priming study. By doing so, additional information on the time course and nature of priming effects can be obtained. In Experiment 1, cross-case letter priming (a-A) was investigated in both alphabetic decision (letter/non-letter classification) and letter naming. In Experiment 2, cross-case word priming was investigated in lexical decision and naming. Whereas letter priming in alphabetic decision was most strongly determined by visual overlap between prime and target, word priming in lexical decision was facilitated by both orthographic and phonological information. Orthographic activation was stronger and occurred earlier than phonological activation. In letter and word naming, in contrast, priming effects were most strongly determined by phonological/articulatory information. Differences and similarities between letter and word recognition are discussed in the light of the incremental priming data.

Graphemes are perceptual reading units

Graphemes are commonly defined as the written representation of phonemes. For example, the word 'BREAD' is composed of the four phonemes /b/, /r/, /e/ and /d/, and consequently, of the four graphemes 'B', 'R', 'EA', and 'D'. Graphemes can thus be considered the minimal 'functional bridges' in the mapping between orthography and phonology. In the present study, we investigated the hypothesis that graphemes are processed as perceptual units by the reading system. If the reading system processes graphemes as units, then detecting a letter in a word should be harder when this letter is embedded in a multi-letter grapheme than when it corresponds to a single-letter grapheme. In Experiment 1A, done in English, participants were slower to detect a target letter in a word when the target letter was embedded in multi-letter grapheme (i.e. 'A' in 'BEACH') than when it corresponded to a single-letter grapheme (i.e. 'A' in 'PLACE'). In Experiment 1B, this effect was replicated in French. In Experiment 2, done in English, this grapheme effect remained when phonemic similarity between the target letter alone and the target letter inside the word was controlled. Together, the results are consistent with the assumption that graphemes are processed as perceptual reading units in alphabetic writing systems such as English or French.

Foot-ulcer prevention in the elderly diabetic patient

Diabetic foot ulceration is frequently the result of repetitive trauma, foot deformity, malfunction, or ill-fitting footwear. The failure of such ulcers to heal is most often a consequence of the failure to provide protection from continuing trauma. Risk evaluation of the diabetic patient, with appropriate correction or accommodation of deformity or mechanical pressure, can be expected to reduce the incidence of serious infection secondary to ulceration.

A phoneme effect in visual word recognition

In alphabetic writing systems like English or French, many words are composed of more letters than phonemes (e.g. BEACH is composed of five letters and three phonemes, i.e./biJ/). This is due to the presence of higher order graphemes, that is, groups of letters that map into a single phoneme (e.g. EA and CH in BEACH map into the single phonemes /i/ and /J/, respectively). The present study investigated the potential role of these subsyllabic components for the visual recognition of words in a perceptual identification task. In Experiment 1, we manipulated the number of phonemes in monosyllabic, low frequency, five-letter, English words, and found that identification times were longer for words with a small number of phonemes than for words with a large number of phonemes. In Experiment 2, this 'phoneme effect' was replicated in French for low frequency, but not for high frequency, monosyllabic words. These results suggest that subsyllabic components, also referred to as functional orthographic units, play a crucial role as elementary building blocks of visual word recognition.

Letter legibility and visual word recognition

Word recognition performance varies systematically as a function of where the eyes fixate in the word. Performance is maximal with the eye slightly left of the center of the word and decreases drastically to both sides of this optimal viewing position. While manipulations of lexical factors have only marginal effects on this phenomenon, previous studies have pointed to a relation between the viewing position effect (VPE) and letter legibility: When letter legibility drops, the VPE becomes more exaggerated. To further investigate this phenomenon, we improved letter legibility by magnifying letter size in a way that was proportional to the distance from fixation (e.g., TABLE). Contrary to what would be expected if the VPE were due to limits of acuity, improving the legibility of letters has only a restricted influence on performance. In particular, for long words, a strong VPE remains even when letter legibility is equalized across eccentricities. The failure to neutralize the VPE is interpreted in terms of perceptual learning: Since normally, because of acuity limitations, the only information available in parafoveal vision concerns low-resolution features of letters; even when magnification provides better information, readers are unable to make use of it.

Simulating individual word identification thresholds and errors in the fragmentation task

This article presents a large-scale study that collected word identification thresholds and errors in the fragmentation task for all four-letter French words. In the first part of this article, we identify some of the variables (e.g., word frequency, neighborhood size, letter confusability) that affect performance in the fragmentation task. In the second part, we analyze individual response performance and identify different response strategies. We demonstrate that the interactive activation model can account for individual response strategies by adapting two of its original parameters: word-letter feedback and letter-word inhibition. In the third part, we demonstrate that the adaptation of the interactive activation model to the fragmentation task makes it possible to successfully simulate a facilitatory frequency effect on identification thresholds, an inhibitory neighborhood size effect on error rates, and an inhibitory letter confusability effect on identification thresholds. When the task-specific processes of the fragmentation task are specified and individual response strategies are considered, the interactive activation model provides a parsimonious architecture for modeling the task-independent processes involved in word perception.

Ankle arthrodesis following avascular necrosis of the talus in a patient with lupus

Avascular necrosis of bone is a common manifestation of systemic lupus erythematosus, particularly in those patients receiving corticosteroids. The authors review the pathogenesis and diagnosis of avascular necrosis and describe an ankle arthrodesis in a patient with systemic lupus erythematosus who developed avascular necrosis of the talus.

Phonology can help or hurt the perception of print

Phonological manipulations affect performance in a letter search task that requires only a shallow level of processing. In Experiment 1, phonology reduced accuracy in the letter search task when a pseudohomophone (GAIM) contained a target letter ("i") that was missing in the spelling of its (nonpresented) sound-alike base word (GAME). In Experiment 2, phonology increased accuracy in the letter search task when the target letter was present in both the spelling of the pseudohomophone and the spelling of its sound-alike base word ("m" in GAIM and GAME). In Experiment 3, we showed that the phonology-hurts effect of Experiment 1 is not peculiar to nonword letter strings but generalizes to familiar words. In Experiment 4, we obtained a phonology-hurts effect on correct response times when stimuli were visible until participants responded (stimuli were not masked).

Phonology can help or hurt the perception of print

Phonological manipulations affect performance in a letter search task that requires only a shallow level of processing. In Experiment 1, phonology reduced accuracy in the letter search task when a pseudohomophone (GAIM) contained a target letter ("i") that was missing in the spelling of its (nonpresented) sound-alike base word (GAME). In Experiment 2, phonology increased accuracy in the letter search task when the target letter was present in both the spelling of the pseudohomophone and the spelling of its sound-alike base word ("m" in GAIM and GAME). In Experiment 3, we showed that the phonology-hurts effect of Experiment 1 is not peculiar to nonword letter strings but generalizes to familiar words. In Experiment 4, we obtained a phonology-hurts effect on correct response times when stimuli were visible until participants responded (stimuli were not masked).

Considerations of prescription medications for the pregnant podiatric patient

Prescription medications are thought to cause less than 1% of all congenital abnormalities. However, prescribing a medication to treat the foot disorder of a pregnant patient can be a source of anxiety for the physician. The authors review some of the medications commonly prescribed in podiatric medical practice and evaluate their use and safety during pregnancy.

Orthographic processing in visual word recognition: a multiple read-out model

A model of orthographic processing is described that postulates read-out from different information dimensions, determined by variable response criteria set on these dimensions. Performance in a perceptual identification task is simulated as the percentage of trials on which a noisy criterion set on the dimension of single word detector activity is reached. Two additional criteria set on the dimensions of total lexical activity and time from stimulus onset are hypothesized to be operational in the lexical decision task. These additional criteria flexibly adjust to changes in stimulus material and task demands, thus accounting for strategic influences on performance in this task. The model unifies results obtained in response-limited and data-limited paradigms and helps resolve a number of inconsistencies in the experimental literature that cannot be accommodated by other current models of visual word recognition.

The incremental priming technique: a method for determining within-condition priming effects

A novel priming technique is applied in two experiments using an alphabetic decision and a lexical decision task to study effects of repetition, and form-related priming on letter and word recognition. The incremental priming technique consists of a gradual increase of the prime's informational value (operationalized as prime intensity). The minimum prime-intensity level serves as a within-condition baseline for each priming condition. Thus, we can define any priming effect with respect to two baseline conditions: one is the minimum-intensity condition of the particular priming condition (within-condition baseline), and the other is a different priming condition (across-condition baseline). This double-baseline approach makes measuring of priming effects more reliable and imposes stronger constraints on our interpretations of these effects.

Masked partial-word priming in visual word recognition: effects of positional letter frequency

In 4 primed lexical decision experiments, it was found that the positional frequencies of letters shared by the prime and target relative to the overall positional letter frequency of the target determined the magnitude of priming effects. The lower the positional frequency of shared letters, the stronger the facilitatory effect observed. Both an interactive and noninteractive semistochastic version of the interactive activation model captured the principal trends in the data. It is argued that masked partial-word priming arises from a tradeoff between the facilitation generated by prime-target letter overlap and the inhibition generated from all lexical representations activated by letters in the prime that receive further support on target presentation.

Masked partial-word priming in visual word recognition: effects of positional letter frequency

In 4 primed lexical decision experiments, it was found that the positional frequencies of letters shared by the prime and target relative to the overall positional letter frequency of the target determined the magnitude of priming effects. The lower the positional frequency of shared letters, the stronger the facilitatory effect observed. Both an interactive and noninteractive semistochastic version of the interactive activation model captured the principal trends in the data. It is argued that masked partial-word priming arises from a tradeoff between the facilitation generated by prime-target letter overlap and the inhibition generated from all lexical representations activated by letters in the prime that receive further support on target presentation.

Diabetes mellitus

Diabetes mellitus occurs commonly in the older patient and is frequently undiagnosed. In many cases, the initial manifestations of diabetes mellitus are lower extremity complications with which this disease is known to be associated. Unfortunately, these complications are similar to other age-related degenerative processes; therefore, vigilance for the detection of undiagnosed diabetes mellitus is essential in the evaluation and treatment of lower extremity pathologic conditions.

An alternative approach to the mandatory year of clinical residency training

The author takes the position that a mandatory fifth postgraduate year to serve as a uniform period of clinical education for podiatric medical graduates is unnecessary. A need exists to define primary podiatric medicine as the entry level podiatric medical field of practice. The colleges of podiatric medicine are urged to deemphasize podiatric surgery while placing greater emphasis on primary podiatric care. The author believes that the colleges are responsible for preparing primary podiatric medical practitioners. Residency programs should focus on specialty training in podiatric surgery and podiatric orthopedics.

Testing a semistochastic variant of the interactive activation model in different word recognition experiments

A semistochastic variant of the interactive activation (IA) model of context effects in letter perception (McClelland & Rumelhart, 1981) was used to simulate response time distributions and means in different experiments investigating the effects of word frequency, neighborhood size and frequency, and orthographic priming in visual word recognition. The results provide evidence in favor of the connectivity assumption underlying the model but question the necessity of the interactivity assumption for simulating latencies in word recognition tasks. Together with those of a recent study by McClelland (1991), the present results suggest that 10 years after its appearance, the IA model's potential for testing hypotheses about the structure and dynamics of basic phenomena of human information processing in a variety of perceptual and cognitive tasks is not yet fully exploited.

Opioid receptor affinity for agonist-antagonist analgesics

Analgesic medications are distributed to a variety of receptors within the central nervous system. Activity at these receptors (mu 1, mu, sigma, delta, kappa) results in both the beneficial pain-relieving effects of analgesics as well as undesirable side effects. The mixed agonist-antagonist class of analgesics offers the potential benefit of greater receptor site selectivity while diminishing the incidence of adverse sequelae, such as respiratory depression. Traditionally, it has been suggested that mixed agonist-antagonist medications may be associated with decreased analgesic effectiveness. However, newer agents of this mixed class may result in effective analgesia while diminishing the incidence of side effects.

Home healthcare nursing: a clinical specialty in need of graduate education

Home healthcare nursing administrators in Southern California affirm the need for clinical nurse specialists prepared at the graduate level, and registered nurses express interest in a Master's degree program with home healthcare as the clinical specialty.

Testing a semistochastic variant of the interactive activation model in different word recognition experiments

A semistochastic variant of the interactive activation (IA) model of context effects in letter perception (McClelland & Rumelhart, 1981) was used to simulate response time distributions and means in different experiments investigating the effects of word frequency, neighborhood size and frequency, and orthographic priming in visual word recognition. The results provide evidence in favor of the connectivity assumption underlying the model but question the necessity of the interactivity assumption for simulating latencies in word recognition tasks. Together with those of a recent study by McClelland (1991), the present results suggest that 10 years after its appearance, the IA model's potential for testing hypotheses about the structure and dynamics of basic phenomena of human information processing in a variety of perceptual and cognitive tasks is not yet fully exploited.

Neighborhood frequency effects and letter visibility in visual word recognition

Two experiments are described that measured lexical decision latencies and errors to five-letter French words with a single higher frequency orthographic neighbor and control words with no higher frequency neighbors. The higher frequency neighbor differed from the stimulus word by either the second letter (e.g., ASTRE-AUTRE) or the fourth letter (CHOPE-CHOSE). Neighborhood frequency effects were found to interact with this factor, and significant interference was observed only to CHOPE-type words. The effects of neighborhood frequency were also found to interact with the position of initial fixation in the stimulus word (either the second letter or the fourth letter). Interference was greatly reduced when the initial fixation was on the critical disambiguating letter (i.e., the letter P in CHOPE). Moreover, word recognition was improved when subjects initially fixated the second letter relative to when they initially fixated the fourth letter of a five-letter word, but this second-letter advantage practically disappeared when the stimulus differed from a more frequent word by its fourth letter. The results are interpreted in terms of the interaction between visual and lexical factors in visual work recognition.

Synovectomy-arthroplasty as an alternative to triple arthrodesis in the management of subtalar joint pain

Subtalar joint synovectomy-arthroplasty represents an intermediate intervention between more traditional conservative and surgical techniques. Localization of pathology to the structures of the subtalar joint is essential. The likelihood of operative success is predicted by a prolonged remission of symptoms following the injection of steroid and local anesthesia within the subtalar joint. The procedure reduces pain and swelling while increasing ambulatory capacity. No appreciable increase in subtalar joint motion occurs.

Posterior calcaneal osteotomy. Effect, technique, and indications

Posterior calcaneal osteotomy is a technically simple procedure that may be used to correct frontal, transverse, or sagittal plane displacement of the calcaneus associated with flatfoot deformity. In selected individuals, subluxation about the oblique axis of the midtarsal joint may be stabilized. Forefoot supinatus may be expected to reduce secondary to the reduction of heel valgus obtained, although with deformity chronicity, adaptive midtarsal joint changes may necessitate medial column stabilization. Posterior calcaneal osteotomy increases rotational stability of the subtalar joint in a supinatory direction. In addition, displacement of the posterior calcaneal fragment effects a dynamic correction force by translocation of the Achilles tendon and its posterior relation to the axis of the subtalar joint.

Epidural morphine as an adjuvant to the treatment of pain in a patient with acute inflammatory polyradiculopathy secondary to Guillain-Barré syndrome

The authors discuss a case of acute inflammatory polyradiculopathy in a patient with Guillain-Barré syndrome. Consultation with podiatry was requested in an effort to remit the severe lower extremity symptoms. Treatment using epidural morphine with subsequent results is discussed. It is the authors' opinion that Guillain-Barré syndrome is the most common acutely or subacutely evolving inflammatory, demyelinating, neuropathy in the United States.

The search operating characteristic as a tool for analyzing performance in dynamic visual search tasks

A standard data plot for the analysis of eye movement behavior in visual search and related tasks, a Search Operating Characteristic (SOC), is proposed. The SOC plots mean fixation duration (in ms) vs. search span (in items/fixation) for different difficulty levels. It is well specified by a reciprocal power function and this function can be explained with the help of Piéron's law.

Automatic letter priming in an alphabetic decision task

An alphabetic decision task was used to study effects of form priming on letter recognition at very short prime durations (20 to 80 msec). The task required subjects to decide whether a stimulus was a letter or a nonletter. Experiment 1 showed clear facilitatory effects of primes being either physically or nominally identical to the targets, with a stable advantage for the former. Experiment 2 demonstrated that uppercase letters are classified more rapidly as letters (vs. non-letters) when they are preceded by a briefly exposed, forward- and backward-masked, visually similar uppercase letter than when they are preceded by a visually dissimilar uppercase letter. Finally, Experiment 3 demonstrated that nominally identical and visually similar primes facilitate processing more than do nominally identical, visually dissimilar primes. The alphabetic decision task proved to produce sensitive and stable priming effects at the feature, letter, and response-choice level. The present results on letter-letter priming thus constitute a solid data base against which to evaluate other priming effects, such as word-letter priming. The results are discussed in light of current activation models of letter and word recognition and are compared with data simulated by the interactive activation model (McClelland & Rumelhart, 1981).

The effects of target discriminability and retinal eccentricity on saccade latencies: an analysis in terms of variable-criterion theory

Two experiments are reported that studied changes in saccade latencies (SLs) in a target-identification task as a function of target discriminability and eccentricity. SLs were found to be longer when target discriminability was low and eccentricity was large, both factors showing a significant interaction. Variable-criterion theory (Grice, 1968) was used to derive a working model of the perceptual and decisional processes influencing SLs in the present task. Application of the measurement operations of the theory provided a good quantitative description of individual SL distributions. The analyses in terms of variable-criterion theory suggest that the perceptual process influencing SLs starts earlier and operates at a faster rate when the saccade target can be discriminated on the basis of global-visual features (e.g., size) than when local features (e.g., gaps) have to be extracted.

Use of antibiotic-loaded bone cement in the management of common infections of the foot and ankle

Antibiotic-loaded bone cement is a useful adjunct in the management of chronic osteomyelitis and in the prevention of recurrent osteomyelitis after an initial attack. Additionally, antibiotic-loaded bone cement stimulated the formation of granulation tissue in excess of that which would normally be expected. Our experience has been consistent with others' experience, which suggests that the use of antibiotic-loaded bone cement is an effective means of reducing the length of hospitalization and the cost usually associated with traditional methods in the management of bone and soft-tissue infections.

Local antibiotic treatment of soft tissue and bone infections of the foot

Twenty-seven pedal soft tissue and bone infections in 26 patients were treated with surgical necrectomy of infected tissues and implantation of antibiotic-loaded polymethyl methacrylate bone cement beads on chains. The definitive diagnosis of the infected tissues was obtained by culture and histologic examination in all of the cases. A wide variety of foot infections was successfully treated in this manner. The success rate without recurrence of osteomyelitis or soft tissue infection was 95% in this study at an average of 16 months after surgery.

Development and application of antibiotic-loaded bone cement beads

The authors presented an overview of the development of antibiotic-loaded bone cement beads and their indications for usage, method of application, advantages, disadvantages, and causes of failure. This method of treatment for bone and soft tissue infections of the foot is not a panacea and should be used only in selected cases. The vascular status and the physiologic ability of the patient to heal a peripheral wound or infection are the basis for the success of this method of therapy. European literature makes little mention of adjunctive systemic antibiotic therapy with local antibiotic-loaded bone cement bead use. It is the authors' opinion that clinical judgment should be used to determine the necessity for such therapy.

Eye movement control during reading: II. Frequency of refixating a word

An analysis of over 40,000 eye fixations made by college students during reading indicates that the frequency of immediately refixating a word following an initial eye fixation on it varies with the location of that fixation. The refixation frequency is lowest near the center of the word, positively accelerating with distance from the center. The data are well fit by a parabolic function. Assuming that refixation frequency is related to the frequency of successful word identification, the observed curvilinear relation results naturally from models that postulate a linear decrease in visual information with retinal eccentricity. A single letter difference in fixation location in a word can make a sizeable difference in the likelihood of refixating that word. The effects of word length and cultural frequency on the frequency of refixating are also examined.

Basal cell carcinoma: an infrequent pedal reality

The authors intend to present a more detailed look at the basal cell carcinoma, both clinically and histologically. An in-depth treatment approach, case presentation, and literature review is provided in order to aid the practicing physician to better understand and treat this cutaneous malignancy. Through describing the variety of appearances of the basal cell carcinoma, the practitioner, hopefully, will be made more aware of the very real possibility of carcinoma in the differential diagnosis of dermatologic lesions.

Thermographic evaluation of the autonomic effects of nerve blocks in the foot

The authors evaluated regional skin temperatures of the foot following the administration of a variety of local anesthetic nerve blocks with either Xylocaine (lidocaine hydrochloride) or Sensorcaine (bupivacaine hydrochloride). The study was carried out on ten randomized parallel groups of five subjects, each group being tested with one drug and one regional nerve block. The results indicated that both Xylocaine and Sensorcaine, when administered as a posterior tibial block, result in a significantly increased blood flow to the foot. Nerve blockade of the remaining nerves of the foot did not significantly increase the sympatholytic effect obtained by posterior tibial nerve block alone.

On the role of competing word units in visual word recognition: the neighborhood frequency effect

Current models of word recognition generally assume that word units orthographically similar to a stimulus word are involved in the visual recognition of this word. We refer to this set of orthographically similar words as an orthographic neighborhood. Two experiments are presented that investigate the ways in which the composition of this neighborhood can affect word recognition. The data indicate that the presence in the neighborhood of at least one unit of higher frequency than the stimulus word itself results in interference in stimulus word processing. Lexical decision latencies (Experiment 1) and gaze durations (Experiment 2) to words with one neighbor of higher frequency were significantly longer than to words without a more frequent neighbor. This neighborhood frequency effect is discussed in terms of the different types of candidate selection process postulated by contemporary models of visual word recognition.

Sensory factors are insufficient to define the ocular saccade goal in complex visual fields

In most normal visual search situations, the environment is filled with a variety of stimuli, and selection among possible saccade targets is necessary. Current theories of visuomotor mechanisms must take into account not only the classical 'retinal error' input signal, but also perceptual and decisional factors as well as task-specific strategies adopted by the subjects. Experiments are reported in which eye movements are recorded in tasks requiring ocular saccades to be made onto target letters indicated by a peripherally visible mark or embedded within lines of homogeneous background letters. The results show how nonsensory factors interact with visual determinants in the preparation of the exploratory saccades. Expectations concerning the visibility of the sought-for target influence the spatial and temporal parameters of the eye movement which will be executed.

A negative selection scheme for tobacco protoplast-derived cells expressing the T-DNA gene 2

The amido hydrolase encoded by the T-DNA gene 2 catalyzes the conversion of indole-acetamide, α-naphthalene acetamide, and other substrate analogues into the corresponding auxins. As a result, only gene 2-expressing protoplast-derived tobacco cells can grow in medium containing low concentrations (0.2-1 μM) of α-naphthalene acetamide as auxin precursor. However, in a mixture of SR1 and SR1, gene 2 (+) protoplast-derived cells, cross-feeding occurs and consequently no positive selection for gene 2 is obtained. A 100-times higher concentration of α-naphthalene acetamide (between 30 and 300 μM) provides a negative selection scheme. Only the tobacco cells expressing gene 2 are sensitive to the high naphthalene acetamide concentration and cannot grow to colonies, while cells lacking the gene 2 product regenerate calli even in mixed gene 2 (+) and gene 2 (-) cell populations. Thus, gene 2 might provide a unique biochemically defined marker to investigate mutations and gene inactivation.

Magnetic resonance imaging of the foot and ankle

Magnetic resonance imaging enhances the inherent differences in the density of tissues to allow the diagnosis of pedal disorders not readily observed by other diagnostic means. The technique is particularly useful for the evaluation of the nature and extent of soft tissue pathology. In addition, certain osseous and joint disorders, such as osteomyelitis and Sudeck's atrophy, may be detected in their incipient stages.

Complications of subtalar arthroereisis

Arthroereisis procedures involving the subtalar joint in the pediatric flatfoot have had great success in limiting/preventing abnormal or destructive pronating forces transmitted into the foot. This report presents actual and potential complications of these procedures.