Closed letter counters impair recognition.

An often-repeated piece of advice when choosing fonts for great legibility is to use fonts with large counters and apertures. To identify effects of open and closed apertures on the letters 'a', 'c', 'e', 'r', 's', 't' and 'f', we ran an experiment using the serif font Pyke as stimulus. The letters in focus were designed for this experiment with three variations of open apertures (Open, Medium and Closed). The experimental paradigm was to present a letter either with or without flankers in the parafovea at 2° eccentricity. The findings showed that participants had more trouble identifying the letter if it was set in a font variation with closed apertures.

Fonts of wider letter shapes improve letter recognition in parafovea and periphery.

Most text on modern electronic displays is set in fonts of regular letter width. Little is known about whether this is the optimal font width for letter recognition. We tested three variants of the font family Helvetica Neue (Condensed, Standard, and Extended). We ran two separate experiments at different distances and different retinal locations. In Experiment 1, the stimuli were presented in the parafovea at 2° eccentricity; in Experiment 2, the stimuli were presented in the periphery at 9° eccentricity. In both experiments, we employed a short-exposure single-report trigram paradigm in which a string of three letters was presented left or right off-centre. Participants were instructed to report the middle letter while maintaining fixation on the fixation cross. Wider fonts resulted in better recognition and fewer misreadings for neighbouring letters than narrower fonts, which demonstrated that wider letter shapes improve recognition at glance reading in the peripheral visual view. Practitioner summary: Most of the text is set in fonts of regular letter width. In two single-target trigram letter recognition experiments, we showed that wider letter shapes facilitate better recognition than narrower letter shapes. This indicates that when letter identification is a priority, it is beneficial to choose fonts of wider letter shapes.

High letter stroke contrast impairs letter recognition of bold fonts.

To make graphical user interfaces look more fashionable, designers often make use of high-stroke-contrast fonts. We are yet to understand how these fonts affect reading. We examined the effect of letter-stroke contrast on three bold fonts, one with extreme contrast between thick and thin strokes, one with no contrast, and one in between. The fonts were designed for this experiment to enable control of font variables. Participants identified the middle letter in a lowercase letter trigram in each trial, briefly presented in the parafovea (at 2° left and right of fixation) and at the foveal fixation point. There was evidence for letter recognition impairment for the font with high stroke contrast compared to the fonts with low and medium stroke contrast, while there was no significant difference in performance between the medium- and low-stroke-contrast fonts. The results suggest that bold fonts with high stroke contrast should not be considered for designs where letter recognition is a priority.

Smaller visual angles show greater benefit of letter boldness than larger visual angles.

Research has shown that fonts viewed at a smaller visual angle benefit from greater letter boldness. Since small and large visual angles operate on different spatial frequencies, we examined whether the effect was dependent on font size. By applying a paradigm of single-letter exposure across two experiments, we showed that fonts of thinner letter strokes and of extreme boldness decreased recognition for all tested font sizes, and that there was a positive effect of boldness at small visual angles which did not occur at large visual angles. The paper provides evidence that bolder fonts are less effective at improving recognition at larger visual angles, and that over a scale of font weights there is a drop-off at the lightest and the heaviest extremes at all tested font sizes.

How to demonstrate that eSET does not compromise the likelihood of having a baby?

BACKGROUND: In several randomized studies, elective single embryo transfer (eSET) has proven its effectiveness in reducing twin pregnancy rates while obtaining acceptable overall pregnancy rates. However, there is no outcome measurement consensus to evaluate the effectiveness of eSET versus double-embryo transfer (DET). METHODS: This study evaluated whether or not adopting an eSET strategy instead of a DET strategy lowers the probability of having at least one live-born infant in good prognosis couples. Seven hundred and twenty-six couples were divided into two groups. The retrospective arm of the study was undertaken on the first group of couples (n = 483, DET group) and the prospective arm performed on the second group of couples (n = 243, SET group). In these specific populations, the probability of a woman having at least one live-born infant and the probability that one embryo utilized leads to a child were the main outcome measures. RESULTS: The probability of a woman having at least one live-born infant was 60.5% in the DET group compared with 60.8% in the SET group. The probability of a live-born child per embryo utilized was not significantly different between the SET and the DET groups, 18.9% and 17.6%, respectively. In addition, the cumulative multiple live birth rate was significantly lower in the SET compared with the DET group. CONCLUSIONS: In this observational study, using appropriate cryopreservation techniques, the chance of delivering a live baby, per utilized embryo, in an elective SET strategy is as good as that for DET.

Fertilisation and pregnancy outcome after ICSI in globozoospermic patients without assisted oocyte activation.

The successful outcome of intracytoplasmic sperm injection (ICSI) with globozoospermic sperm and non-activated oocytes is reported. Three couples underwent ICSI treatment and two of the patients were siblings. Forty-four non-activated oocytes were injected, 26 oocytes fertilised normally and 17 good quality embryos were obtained. Six embryo transfers were carried out, three with fresh embryos and three with frozen-thawed embryos. Three pregnancies resulted from the fresh embryo transfers and additionally two pregnancies were obtained after the transfer of frozen-thawed embryos. Two healthy babies were born. One twin pregnancy is ongoing. Our case reports demonstrate that in some ICSI attempts undertaken with globozoospermic sperm cells from two of our patients, high fertilisation rates, pregnancies and live births can be achieved, without artificially activated oocytes. Our data also suggest that in some cases, round-headed spermatozoa lack the capacity to activate the oocyte. Therefore, it cannot be excluded that artificial oocyte activation could be of help in globozoospermic patients with complete fertilisation failure.

High frequency in esophageal cancers of p53 alterations inactivating the regulation of genes involved in cell cycle and apoptosis.

Somatic mutations of the tumor suppressor gene p53 have been frequently detected in esophagal cancers, but their biological significance remains to be established. The tumor suppressor activity of p53 results in part from its ability to transactivate genes involved in the cell cycle and apoptosis, such as p21, bax and PIG3, and some p53 mutations may have a differential effect on the transactivation of these target genes. We developed yeast strains in which the activation by wild-type p53 of reporter plasmids containing p53 binding sites present within these target genes induces a change in the color of the colonies (red/white). Using these strains, we analyzed 56 esophageal cancers from patients residing in Normandy, France, a high incidence geographic area. Forty-seven tumors (84%), scored as mutant with the p21, bax and PIG3 reporter strains and in most of the cases (76%), the percentage of red colonies suggested that both p53 alleles were inactivated. Sequencing analysis allowed the identification of a p53 mutation in each positive sample, and the spectrum of mutations was in agreement with the etiological role of tobacco and alcohol. These results confirm the high frequency of biallelic p53 mutations in esophageal carcinoma and strongly suggest that their biological consequence is the complete alteration of the transactivation of genes involved in the cell cycle and apoptosis, which indicates that p53 alteration is a key event in esophagus carcinogenesis.

Roux-en-Y limb motility after total or distal gastrectomy in symptomatic and asymptomatic patients.

BACKGROUND: The aims of this study were to compare Roux-en-Y limb motor patterns after total or distal gastrectomy, and to identify possible motor differences between symptomatic and asymptomatic patients. The usefulness of preoperative recording was also investigated. STUDY DESIGN: Sixteen patients were enrolled in the study, 10 patients after total gastrectomy (TG group) and 6 patients after distal gastrectomy (DG group). In 6 of 10 patients in the TG group, recordings were obtained before and after operation. Manometric recordings in the limb lasted 6 hours in all patients, 3 hours during fasting, and 3 hours after a 750-kcal meal. An intravenous injection of trimebutine (100-mg i.v.) was systematically administered at the end of each recording session. Motor results of the patients were compared with those obtained in the intact jejunum of 20 healthy controls. RESULTS: After operation, when patients were compared with controls, phase III (ie, regular activity of the migrating motor complex) was more frequent and more often incompletely propagated (5 of 16 patients versus 1 of 20 controls, unadjusted p < 0.05) and was significantly slower (p < 0.01 versus controls). Intravenous trimebutine induced phase III in 12 of 16 patients within a mean of 8.8 +/- 1 (SEM) minutes, longer than in controls (delay < 2 minutes). The fed pattern was shorter than in controls in both TG and DG groups, and the postprandial area under the curve during successive 30-minute periods was reduced in the DG group compared with controls (p < 0.01). In patients investigated before gastrectomy, motor parameters were not different from those of controls. Surgery resulted in an increased number of phase IIIs and a decreased migration velocity (p < 0.01) of phase III, a longer delay in response after trimebutine (p < 0.0001), and a reduced postprandial motor response (p < 0.01). After the operation, 4 of 10 patients in the TG group and 5 of 6 patients in the DG group were symptomatic. Symptomatic patients had slower and more often incompletely propagated (p < 0.01) phase III compared with asymptomatic patients. CONCLUSIONS: Roux-en-Y limb reconstruction mainly disturbs phase III propagation and the motor response to a meal. Motor changes are more marked after DG than after TG. Disturbed phase III propagation is the main difference between symptomatic and asymptomatic patients. Successful induction of phase III with trimebutine after gastrectomy and Roux-en-Y reconstruction indicates maintenance of encephalinergic mechanisms.

Nonlinear propagation of subpicosecond ultraviolet laser pulses in air.

We report filamentation of subpicosecond UV laser pulses with only millijoule energy in atmosphere. The results are in good agreement with a numerical simulation using a quasi-three-dimensional propagation code.

Postoperative management of stage II/III colon cancer: a decision analysis.

BACKGROUND & AIMS: Two separate decisions must be made for the management of patients with resected stage II/III colon cancer: whether to begin adjuvant chemotherapy and whether patients should be included in a follow-up protocol consisting of regular monitoring of carcinoembryonic antigen level and of colonoscopy and imaging. The standard management for these patients is adjuvant chemotherapy for stage III patients and follow-up for stage II/III patients with resected colon cancer. METHODS: Decision analysis was used to compare the effectiveness (5-year survival rate) and cost-effectiveness ratio of 7 strategies of treatment and follow-up. RESULTS: The most cost-effective strategies were adjuvant chemotherapy for all patients with stage II/III resected colon cancer, with either no follow-up or follow-up only for patients aged less than 75 years with a seric preoperative carcinoembryonic antigen level of >5 ng/mL (5-year survival, 62.3% or 62.7%; cost per surviving patient, $8254 or $8657, respectively). The order of efficacy of the strategies was insensitive to changes in the values of the studied variables. The method of follow-up does little to improve 5-year survival but adds substantial cost. CONCLUSIONS: The current standard strategy may not be the most cost-effective strategy for the management of patients with resected colon cancer.

Formation of a conducting channel in air by self-guided femtosecond laser pulses.

We report a drastic reduction of air resistivity following the passage of a self-guided femtosecond pulse from a Ti:sapphire laser system at 800 nm with energies per pulse between 1 and 14 mJ and a pulse duration of 120 fs. Connected plasma filaments with a length that can exceed 150 cm are created by these pulses. The presence of a conducting plasma channel results from multiphoton ionization of air molecules in the filament core.

Anomalous long-range propagation of femtosecond laser pulses through air: moving focus or pulse self-guiding?

Self-guided propagation of femtosecond laser pulses is studied for a converging-beam configuration. Channeling of the pulse energy through various gases is observed over distances well beyond the lens focal point, a fact that cannot be explained by the moving-focus model. The results are in good agreement with three-dimensional numerical simulations.

Brightness matching and flicker photometric data obtained over the full mesopic range.

Three normal observers made visual matches from 0.03 to 100 td on a 10 degree central field at 445, 560 and 630 nm, using two different methods: heterochromatic flicker photometry and direct comparison brightness matching. In a relative sensitivity vs illuminance plot, the brightness matches underwent smooth changes, while the flicker curve exhibited a step-like transition around 1 td, between two separate branches. A reverse Purkinje shift was found on the high mesopic branch at 630 nm, possibly due to cone-cone interactions, and on the low mesopic branch at 445 nm, with questionable origin. At 630 nm and 0.03 td, both methods yielded matches that were not truly scotopic but might not have addressed the same mechanisms.

[Study of spatial function using the contrast sensitivity function. Cases of presbyopic subjects fitted with progressive glasses]. / Exploration fonctionnelle spatiale par la fonction de sensibilité au contraste. Cas de sujets presbytes équipés de verres progressifs.

The spatial properties of the global visual system were measured on the basis of the contrast sensitivity function, in three presbyopic observers. Shape alterations of the contrast sensitivity curves were found depending on the experimental conditions: foveal vision, in far, intermediary and near vision, along central, 13 degrees nasal and 13 degrees temporal meridians (according to three parallels and three meridians), peripheral vision, in far and near vision, at 13 degrees and 26 degrees retinal eccentricities using the central or nasal part of the lens. The central meridian was found to be the most efficient part of the progressive lenses. These results strengthen the observations reported by ophthalmologists and progressive lens wearers.