The role of extracellular structures in Clostridioides difficile biofilm formation.

C. difficile infection (CDI) is a costly and increasing burden on the healthcare systems of many developed countries due to the high rates of nosocomial infections. Despite the availability of several antibiotics with high response rates, effective treatment is hampered by recurrent infections. One potential mechanism for recurrence is the existence of C. difficile biofilms in the gut which persist through the course of antibiotics. In this review, we describe current developments in understanding the molecular mechanisms by which C. difficile biofilms form and are stabilized through extracellular biomolecular interactions.

Crowdsourcing: Global search and the twisted roles of consumers and producers.

Crowdsourcing spreads and morphs quickly, shaping areas as diverse as creating, organizing, and sharing knowledge; producing digital artifacts; providing services involving tangible assets; or monitoring and evaluating. Crowdsourcing as sourcing by means of 'global search' yields four types of values for sourcing actors: creative expertise, critical items, execution capacity, and bargaining power. It accesses cheap excess capacities at the work realm's margins, channeling them toward production. Provision and utilization of excess capacities rationalize society while intimately connecting to a broader societal trend twisting consumers' and producers' roles: leading toward 'working consumers' and 'consuming producers' and shifting power toward the latter. Similarly, marketers using crowdsourcing's look and feel to camouflage traditional approaches to bringing consumers under control preserve producer power.

Evaluation of digital fundus images as a diagnostic method for surveillance of diabetic retinopathy.

OBJECTIVE: The goal was to evaluate a digital imaging system for diagnosing and grading diabetic retinopathy (DR) and cystoid macular edema (CME). METHODS: A single 45 degrees, nonmydriatic, digital color photograph was taken of 231 eyes of 120 patients with diabetes mellitus. The images were graded for DR and CME by a remote ophthalmologist, and the results were compared with dilated ophthalmoscopy performed by a retina specialist. RESULTS: For DR, the level of agreement between digital image review and ophthalmoscopy was moderate (kappa = 0.44). The sensitivity and specificity of digital image review were 0.60 and 1.00, respectively. For CME, the level of agreement was moderate (kappa = 0.60). The sensitivity and specificity of digital image review were 0.60 and 0.99, respectively. CONCLUSION: A single 45 degrees, nonmydriatic, digital image is not reliable as the sole modality for DR screening. However, with modifications, it may be useful where access to an experienced ophthalmologist is limited.

Visual performance with night vision goggles after photorefractive keratectomy for myopia.

OBJECTIVE: To evaluate visual performance and resolution through night vision goggles (NVG) before and after photorefractive keratectomy (PRK). DESIGN: Nonrandomized, comparative (self-controlled) trial. PARTICIPANTS: Nineteen patients (38 eyes) of active-duty US Army Special Forces soldiers. INTERVENTION: PRK for myopia and astigmatism. MAIN OUTCOME MEASURES: Visual acuity with best optical correction was measured preoperatively and postoperatively (3 months) using acuity charts of various contrast (100%, 10%, 2.5%, 1.25%). Preoperative and postoperative (3 month) uncorrected and best-corrected visual resolutions through NVGs were assessed using a high contrast tribar chart presented at four light levels (3.44 x 10(-3), 1.08 x 10(-3), 1.04 x 10(-4), 1.09 x 10(-5) foot Lamberts) simulating a range of night sky conditions. Subjects were trained before testing. RESULTS: Uncorrected visual acuity at the 3-month postoperative assessment was greater than or equal to 20/20 in 33 of 38 (86.8%) eyes. No eyes lost 2 or more lines of best spectacle-corrected visual acuity. Preoperative and 3-month postoperative best-corrected low-contrast acuity measurements showed no significant differences at all levels of resolution. Preoperative visual resolution through NVGs decreased systematically with decreasing night sky condition. Visual acuities before PRK were reduced without optical correction. Postoperative visual performance with NVGs (without optical correction) equaled or exceeded performance preoperatively with best correction. CONCLUSIONS: This prospective case series provides data on the safety and efficacy of PRK with respect to visual performance under night sky conditions using NVGs. There was no significant loss of visual acuity across a range of contrast levels 3 months postoperatively. There was no change in best-corrected NVG visual resolution postoperatively, whereas uncorrected visual resolution was significantly enhanced compared with preoperative levels. This improvement may translate into better function for soldiers who are unable to or choose not to use optical correction in operational environments.