Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Linear-time Algorithms for the 2-connected Steiner Subgraph Problem On Special Classes of Graphs

The 2-connected Steiner subgraph problem is that of finding a minimum-weight 2-connected subgraph that spans a subset of distinguished vertices. This paper presents linear-time algorithms for solving the 2-connected Steiner subgraph problem on two special classes of graphs, W4-free graphs and Halin graphs. Although different in detail, the algorithms adopt a common strategy exploiting known decompositions. As a special case, the algorithms also solve the Traveling Salesman Problem on W4-free graphs and Halin graphs

Midurethral sling incision: indications and outcomes

INTRODUCTION AND HYPOTHESIS: Controversy continues over the effectiveness of sling incision, which is the most common operative approach to treating complications following suburethral sling insertion. This retrospective analysis assessed the indications for sling incision and patient outcomes regarding resolution of complications and stress urinary incontinence. METHODS: A review was conducted of the medical records of women who underwent sling incision between 2003 and 2010. Data such as surgical indications, ultrasound findings and medical outcomes were extracted from 198 records, and descriptive and inferential statistical methods of analysis were used. RESULTS: In the 198 patients eligible for study inclusion, the primary reasons for sling incision were overactive bladder (68 %), voiding dysfunction (61 %), and recurrent urinary tract infections (53 %). Additional complications included dyspareunia (18 %), chronic pelvic pain (17 %), and sling exposure (15 %). Sling incision led to immediate postoperative cure of voiding dysfunction in 97 % of patients. Cure rates for overactive bladder and dyspareunia were 60 % and 94 % respectively. Chronic pelvic pain was resolved in 82 % of cases and all cases of sling exposure were cured. Eighty-five (61 %) of the 140 patients who were continent before sling incision developed recurrent stress urinary incontinence (SUI) postoperatively. CONCLUSIONS: These findings indicate that sling incision can be highly successful in improving voiding dysfunction and dyspareunia, and moderately successful in curing overactive bladder and chronic pain. However, SUI may recur in more than 60 % of the patients undergoing sling incision. Consequently, patients being considered for a sling incision procedure should be informed about this possible complication