High-acuity vision from retinal image motion.

A mathematical model and a possible neural mechanism are proposed to account for how fixational drift motion in the retina confers a benefit for the discrimination of high-acuity targets. We show that by simultaneously estimating object shape and eye motion, neurons in visual cortex can compute a higher quality representation of an object by averaging out non-uniformities in the retinal sampling lattice. The model proposes that this is accomplished by two separate populations of cortical neurons - one providing a representation of object shape and another representing eye position or motion - which are coupled through specific multiplicative connections. Combined with recent experimental findings, our model suggests that the visual system may utilize principles not unlike those used in computational imaging for achieving "super-resolution" via camera motion.

A qualitative study of parental preferences for postcircumcision care education.

INTRODUCTIONR/BACKGROUND: Although uncommon, complications associated with newborn male circumcision may require costly and emotionally upsetting surgical revisions. Improvements in parental education regarding postcircumcision care may reduce preventable complications; however, little is known about parents' preferences for education of this type. OBJECTIVE: The authors sought to describe parents' preferences regarding the content and delivery of education on postcircumcision care as a first step toward improving parental education and ultimately reducing the need for surgical revisions. STUDY DESIGN: The authors conducted a qualitative, descriptive study, collecting data from 14 parents during two separate focus group discussions. The authors applied thematic analysis techniques to analyze the transcribed content of both groups. RESULTS: Parents indicated that postcircumcision care instructions should be detailed and include clear images and/or an actual demonstration of care processes. Despite being aware of the low likelihood of complications, parents expressed a preference for providers who took education seriously rather than those approaching it with a 'cavalier attitude.' There was widespread support for delivering education at a time that met each family's unique circumstances and needs. DISCUSSION: Consistent with prior research, parents in this study identified gaps in understanding postprocedure care instructions. However, this study adds to the literature in highlighting the specific concerns and preferences of parents with regard to the content and delivery of postcircumcision care education. Based on these findings, the authors conclude that healthcare teams should ensure that parents have access to detailed instructions for postcircumcision care. Education of parents should occur at times when they are able to pay attention and should be supplemented with materials that they can easily access from home. Pediatric urologists can play a leading role in the development and dissemination of high-quality, family-centered educational materials to both parents and providers in other specialty areas that perform high volumes of newborn circumcision. Future research would benefit from larger, more diverse samples. In addition, future studies investigating the effect of parental education on potentially avoidable complications are needed to maximize clinical impact. CONCLUSION: Parents readily provided detailed input into what they perceived as much-needed improvements in postcircumcision care education. Future research is needed to determine what effect, if any, such changes would have on the incidence of preventable complications, particularly those requiring surgical intervention.

The Hemodynamic Effects of Intracavernosal Phenylephrine for the Treatment of Ischemic Priapism.

AIM: We sought to evaluate whether the administration of phenylephrine (PE) at concentrations higher than those described in guidelines resulted in any significant changes in vital signs or impacted outcomes. METHODS: After receiving institutional review board approval, we retrospectively reviewed the charts of patients presenting to our emergency department between May 1, 2014, and August 15, 2016, using International Classification of Diseases, Ninth Edition and Internation Classification of Disease, Tenth Edition diagnosis codes for priapism. Treatment was reviewed, including corporal aspiration/irrigation, injection of PE, and shunt procedures. Vital signs were compared before and after treatment with PE. Baseline variables were explored with categorical data analysis (chi-squared tests, t-tests, and Mann-Whitney nonparametric tests). Where feasible, linear regression was used to evaluate outcomes. MAIN OUTCOME MEASURE: Detumescence and changes in blood pressure and heart rate. RESULTS: We identified 74 different patient encounters of acute priapism. The median age was 36.5 years (interquartile range [IQR] = 27-47), and the median time to presentation was 5.4 hours (IQR = 4.0-9.6). 62 percent of cases were due to drug-induced priapism. In 58 (74%) encounters, patients received PE. The median dose of PE given was 1000 µg (IQR 500-2,000). Univariate regression found no association between PE dose and change in patient heart rate or blood pressure. A statistically significant decrease in heart rate (HR) (-4.2 BPM), systolic blood pressure (BP) (-1.8 mm Hg), and diastolic BP (-5.4 mm Hg) was noted. Fifty-three of 58 (91%) patients receiving PE experienced detumescence at the bedside, 2 required shunting in operating room, and 3 refused treatment and left against medical advice. No adverse events occurred. CONCLUSION: We frequently treat patients with high doses of PE and seldom notice adverse effects, typically resulting in resolution of priapism without any additional procedures. Careful administration of high doses of intracavernosal PE in patients presenting with priapism does not appear to significantly affect heart rate or blood pressure and may help prevent further ischemic damage and achieve detumescence effectively and efficiently. Sidhu AS, Wayne GF, Kim BJ, et al. The hemodynamic effects of intracavernosal phenylephrine for the treatment of ischemic priapism. J Sex Med 2018;15:990-996.

Expanding the diversity of mycobacteriophages: insights into genome architecture and evolution.

Mycobacteriophages are viruses that infect mycobacterial hosts such as Mycobacterium smegmatis and Mycobacterium tuberculosis. All mycobacteriophages characterized to date are dsDNA tailed phages, and have either siphoviral or myoviral morphotypes. However, their genetic diversity is considerable, and although sixty-two genomes have been sequenced and comparatively analyzed, these likely represent only a small portion of the diversity of the mycobacteriophage population at large. Here we report the isolation, sequencing and comparative genomic analysis of 18 new mycobacteriophages isolated from geographically distinct locations within the United States. Although no clear correlation between location and genome type can be discerned, these genomes expand our knowledge of mycobacteriophage diversity and enhance our understanding of the roles of mobile elements in viral evolution. Expansion of the number of mycobacteriophages grouped within Cluster A provides insights into the basis of immune specificity in these temperate phages, and we also describe a novel example of apparent immunity theft. The isolation and genomic analysis of bacteriophages by freshman college students provides an example of an authentic research experience for novice scientists.