A Wiener--Hopf Monte Carlo simulation technique for L\'{e}vy processes

We develop a completely new and straightforward method for simulating the joint law of the position and running maximum at a fixed time of a general L\'{e}vy process with a view to application in insurance and financial mathematics. Although different, our method takes lessons from Carr's so-called "Canadization" technique as well as Doney's method of stochastic bounds for L\'{e}vy processes; see Carr [Rev. Fin. Studies 11 (1998) 597--626] and Doney [Ann. Probab. 32 (2004) 1545-1552]. We rely fundamentally on the Wiener-Hopf decomposition for L\'{e}vy processes as well as taking advantage of recent developments in factorization techniques of the latter theory due to Vigon [Simplifiez vos L\'{e}vy en titillant la factorization de Wiener-Hopf (2002) Laboratoire de Math\'{e}matiques de L'INSA de Rouen] and Kuznetsov [Ann. Appl. Probab. 20 (2010) 1801--1830]. We illustrate our Wiener--Hopf Monte Carlo method on a number of different processes, including a new family of L\'{e}vy processes called hypergeometric L\'{e}vy processes. Moreover, we illustrate the robustness of working with a Wiener--Hopf decomposition with two extensions. The first extension shows that if one can successfully simulate for a given L\'{e}vy processes then one can successfully simulate for any independent sum of the latter process and a compound Poisson process. The second extension illustrates how one may produce a straightforward approximation for simulating the two-sided exit problem.Comment: Published in at http://dx.doi.org/10.1214/10-AAP746 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

Total Endovascular Repair of the Aortic Arch:Initial Experience in the Netherlands

Background. We report procedural and early results in the Netherlands of the Relay Branch device (Terumo Aortic, Sunrise, FL) for total endovascular repair of the aortic arch. Methods. Between 2014 and 2018, all consecutive patients who received the Aortic Relay double-branched stent graft in the Netherlands were included in a multicenter, retrospective registry. Results. The Relay Branch device was used in 11 patients to treat saccular (n = 4), fusiform (n = 5), or false aneurysms (n = 2) in the aortic arch. Patients were deemed unfit or extreme high-risk for open (redo) surgery. The brachiocephalic trunk and left common carotid artery were branched using a retrograde approach in all cases. Additional surgical left subclavian artery revascularization was performed in 8 patients. The main device and the branches were successfully introduced, positioned, and deployed with complete exclusion of the aortic pathology in all patients (100% technical success). There was no retrograde type A dissection or conversion to open surgery. Two procedure-related deaths occurred, both caused by perioperative or postoperative strokes. There were 2 minor strokes with full recovery. One patient recovered from transient paraplegia after spinal fluid drainage. No permanent paraplegia was observed. Follow-up imaging showed persistent adequate exclusion of aortic arch pathology. Mean follow-up was 17 months (range, 3-42 months). Conclusions. Total endovascular aortic arch repair using the Relay Branch device is technically feasible and effective in excluding aortic arch pathology. The observed stroke rate in the initial experience, however, was considerable. Although appealing, this new less-invasive technique should be carefully introduced and its progress thoroughly evaluated. (C) 2020 by The Society of Thoracic Surgeon

Noise reduction strategies in metagenomic chromosome confirmation capture to link antibiotic resistance genes to microbial hosts

The gut microbiota is a reservoir for antimicrobial resistance genes (ARGs). With current sequencing methods, it is difficult to assign ARGs to their microbial hosts, particularly if these ARGs are located on plasmids. Metagenomic chromosome conformation capture approaches (meta3C and Hi-C) have recently been developed to link bacterial genes to phylogenetic markers, thus potentially allowing the assignment of ARGs to their hosts on a microbiome-wide scale. Here, we generated a meta3C dataset of a human stool sample and used previously published meta3C and Hi-C datasets to investigate bacterial hosts of ARGs in the human gut microbiome. Sequence reads mapping to repetitive elements were found to cause problematic noise in, and may importantly skew interpretation of, meta3C and Hi-C data. We provide a strategy to improve the signal-to-noise ratio by discarding reads that map to insertion sequence elements and to the end of contigs. We also show the importance of using spike-in controls to quantify whether the cross-linking step in meta3C and Hi-C protocols has been successful. After filtering to remove artefactual links, 87 ARGs were assigned to their bacterial hosts across all datasets, including 27 ARGs in the meta3C dataset we generated. We show that commensal gut bacteria are an important reservoir for ARGs, with genes coding for aminoglycoside and tetracycline resistance being widespread in anaerobic commensals of the human gut

Mapping orangutan habitat and agricultural areas using Landsat OLI imagery augmented with unmanned aircraft system aerial photography

Conservation of the Sumatran orangutans’ (Pongo abelii) habitat is threatened by change in land use/land cover (LULCC), due to the logging of its native primary forest habitat, and the primary forest conversion to oil palm, rubber tree, and coffee plantations. Frequent LULCC monitoring is vital to rapid conservation interventions. Due to the costs of high-resolution satellite imagery, researchers are forced to rely on cost-free sources (e.g. Landsat), those, however, provide images at a moderate-to-low resolution (e.g. 15–250 m), permitting identification only general LULC classes, and limit the detection of small-scale deforestation or degradation. Here, we combine Landsat imagery with very high-resolution imagery obtained from an unmanned aircraft system (UAS). ​The UAS imagery was used as ‘drone truthing’ data to train image classification algorithms. Our results show that UAS data can successfully be used to help discriminate similar land-cover/use classes (oil palm plantation vs. reforestation vs. logged forest) with consistently high identification of over 75% on the generated thematic map, where the oil palm detection rate was as high as 89%. Because UAS is employed increasingly in conservation projects, this approach can be used in a large variety of them to improve land-cover classification or aid-specific mapping needs

Outcome of Colonic Surgery in Elderly Patients with Colon Cancer

Introduction. Colonic cancer is one of the most commonly diagnosed malignancies and most often occurs in patients aged 65 years or older. Aim. To evaluate the outcome of colonic surgery in the elderly in our hospital and to compare five-year survival rates between the younger and elderly patients. Methods. 207 consecutive patients underwent surgery for colon cancer. Patients were separated in patients younger than 75 and older than 75 years. Results. Elderly patients presented significantly more (P < .05) as a surgical emergency, had a longer duration of admission and were more often admitted to the ICU (P < .01). Also, elderly patients had significant more co-morbidities, especially cardiovascular pathology (P < .01). Post-operative complications were seen more often in the elderly, although no significant difference was seen in anastomotic leakage. The five-year survival rate in the younger group was 62% compared with 36% in the elderly (P < .05). DFS was 61% in the younger patients compared with 32% in the elderly (P < .05). Conclusion. Curative resection of colonic carcinoma in the elderly is well tolerated and age alone should not be an indication for less aggressive therapy. However, the type and number of co-morbidities influence post-operative mortality and morbidity

Glycoprotein Nonmetastatic Melanoma Protein B as Potential Imaging Marker in Posttherapeutic Metastatic Head and Neck Cancer

OBJECTIVE: To evaluate expression of potential molecular imaging targets epidermal growth factor receptor (EGFR), glycoprotein nonmetastatic melanoma protein B (GPNMB), and vascular endothelial growth factor (VEGF) in lymph nodes (LNs) with or without head and neck squamous cell carcinoma (HNSCC) metastases after (chemo)radiation. STUDY DESIGN: Retrospective study comparing receptor expression in paired lymph nodes after initial treatment. SETTING: A tertiary referral hospital. SUBJECTS AND METHODS: Salvage neck dissection specimens of 40 patients treated with (chemo)radiation were selected. LNs that contained viable tumor, reactive changes after initial treatment, and normal LNs were analyzed using immunohistochemically determined H-scores and by calculating sensitivity and specificity rates and positive/negative predictive values (PPVs/NPVs). RESULTS: EGFR expression was found in 86% and GPNMB expression in 100% of the LNs with viable tumor. VEGF expression was present in all lymph node types. For EGFR, the sensitivity rate was 86%, and specificity rate was 81%. For GPNMB, these were 100% and 75%, respectively. PPV of EGFR was 61.8% and NPV was 98.2%. These were 56.4% and 100% for GPNMB, respectively. CONCLUSION: In residual or recurrent HNSCC lymph node metastases, both EGFR and GPNMB show tumor-specific expression in immunohistochemistry, which may prove useful in future molecular imaging in salvage neck dissections. Immunohistochemically detected VEGF expression indicates that this target is not feasible for imaging purposes in salvage surgery. Therefore, GPNMB could be a new potential imaging target showing comparable results to EGFR in immunohistochemistry

Effectiveness of supported self-help in recurrent depression: a randomized controlled trial in primary care

Background: The burden and economic consequences of depression are high, mostly due to its recurrent nature. Due to current budget and time restraints, a preventive, low-cost, accessible minimal intervention is much needed. In this study, we evaluated the effectiveness of a supported self-help preventive cognitive therapy (S-PCT) added to treatment as usual (TAU) in primary care, compared to TAU alone. Methods: We conducted a randomized controlled trial among 248 patients with a history of depression, currently in full or partial remission or recovery. Participants were randomized to TAU augmented with S-PCT (n = 124) or TAU alone (n = 124). S-PCT consisted of an 8-week self-help intervention, supported by weekly telephone guidance by a counselor. The intervention included a self-help book that could be read at home. The primary outcome was the incidence of relapse or recurrence and was assessed over the telephone by the Structured Clinical Interview for DSM-IV axis 1 disorders. Participants were observed for 12 months. Secondary outcomes were depressive symptoms, quality of life (EQ-5D and SF-12), comorbid psychopathology, and self-efficacy. These secondary outcomes were assessed by digital questionnaires. Results: In the S-PCT group, 44 participants (35.5) experienced a relapse or recurrence, compared to 62 participants (50.0) in the TAU group (incidence rate ratio = 0.71, 95 CI 0.52-0.97; risk difference = 14, 95 CI 2-24, number needed to treat = 7). Compared to the TAU group, the S-PCT group showed a significant reduction in depressive symptoms over 12 months (mean difference-2.18; 95 CI-3.09 to-1.27) and a significant increase in quality of life (EQ-5D) (mean difference 0.04; 95 CI 0.004-0.08). S-PCT had no effect on comorbid psychopathology, self-efficacy, and quality of life based on the SF-12. Conclusions: A supported self-help preventive cognitive therapy, guided by a counselor in primary care, proved to be effective in reducing the burden of recurrent depression

A supported self-help for recurrent depression in primary care; an economic evaluation alongside a multi-center randomised controlled trial

Background Major depression is a prevalent mental disorder with a high risk of relapse or recurrence. Only few studies have focused on the cost-effectiveness of interventions aimed at the prevention of relapse or recurrence of depression in primary care. Aim To evaluate the cost-effectiveness of a supported Self-help Preventive Cognitive Therapy (S-PCT) added to treatment-as-usual (TAU) compared with TAU alone for patients with a history of depression, currently in remission. Methods An economic evaluation alongside a multi-center randomised controlled trial was performed (n = 248) over a 12-month follow-up. Outcomes included relapse or recurrence of depression and quality-adjusted-life-years (QALYs) based on the EuroQol-5D. Analyses were performed from both a societal and healthcare perspective. Missing data were imputed using multiple imputations. Uncertainty was estimated using bootstrapping and presented using the cost-effectiveness plane and the Cost- Effectiveness Acceptability Curve (CEAC). Cost estimates were adjusted for baseline costs. Results S-PCT statistically significantly decreased relapse or recurrence by15% (95%CI 3;28) compared to TAU. Mean total societal costs were €2,114 higher (95%CI -112;4261). From a societal perspective, the ICER for recurrence of depression was 13,515. At a Willingness To Pay (WTP) of 22,000 €/recurrence prevented, the probability that S-PCT is cost-effective, in comparison with TAU, is 80%. From a healthcare perspective, the WTP at a probability of 80% should be 11,500 €/recurrence prevented. The ICER for QALYs was 63,051. The CEA curve indicated that at a WTP of 30,000 €/QALY gained, the probability that S-PCT is cost-effective compared to TAU is 21%. From a healthcare perspective, at a WTP of 30,000 €/QALY gained, the probability that S-PCT is cost-effective compared to TAU is 46%. Conclusions Though ultimately depending on the WTP of decision makers, we expect that for both relapse or recurrence and QALYs, S-PCT cannot be considered cost-effective compared to TAU