Monotone Circuit Lower Bounds from Robust Sunflowers.

Robust sunflowers are a generalization of combinatorial sunflowers that have applications in monotone circuit complexity Rossman (SIAM J. Comput. 43:256-279, 2014), DNF sparsification Gopalan et al. (Comput. Complex. 22:275-310 2013), randomness extractors Li et al. (In: APPROX-RANDOM, LIPIcs 116:51:1-13, 2018), and recent advances on the Erdos-Rado sunflower conjecture Alweiss et al. (In: Proceedings of the 52nd Annual ACM SIGACT Symposium on Theory of Computing, STOC. Association for Computing Machinery, New York, NY, USA, 2020) Lovett et al. (From dnf compression to sunflower theorems via regularity, 2019) Rao (Discrete Anal. 8,2020). The recent breakthrough of Alweiss, Lovett, Wu and Zhang Alweiss et al. (In: Proceedings of the 52nd Annual ACM SIGACT Symposium on Theory of Computing, STOC. Association for Computing Machinery, New York, NY, USA, 2020) gives an improved bound on the maximum size of a w-set system that excludes a robust sunflower. In this paper, we use this result to obtain an exp ( n 1 / 2 - o ( 1 ) ) lower bound on the monotone circuit size of an explicit n-variate monotone function, improving the previous best known exp ( n 1 / 3 - o ( 1 ) ) due to Andreev (Algebra and Logic, 26:1-18, 1987) and Harnik and Raz (In: Proceedings of the Thirty-Second Annual ACM Symposium on Theory of Computing, ACM, New York, 2000). We also show an exp ( Ω ( n ) ) lower bound on the monotone arithmetic circuit size of a related polynomial via a very simple proof. Finally, we introduce a notion of robust clique-sunflowers and use this to prove an n Ω ( k ) lower bound on the monotone circuit size of the CLIQUE function for all k ⩽ n 1 / 3 - o ( 1 ) , strengthening the bound of Alon and Boppana (Combinatorica, 7:1-22, 1987).

Hematological toxicities associated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

INTRODUCTION: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been found to prolong survival in selected patients with peritoneal disease, but the extent of cytoreduction and chemoperfusion can result in systemic toxicities. We evaluate the incidence of perioperative hematological complications and its associated risk factors. METHODS: Retrospective analysis of a prospectively collected database of CRS-HIPEC cases between April 2001 and October 2016 was performed. Patients were stratified based on the clinicopathological characteristics, perioperative incidence, grade, and duration of leukopenia (white blood cells < 4000/mm3 ), neutropenia (absolute neutrophils < 2000/mm3 ), and thrombocytopenia (platelets < 140 000/mm3 ). RESULTS: Two hundred and thirty-five CRS-HIPEC were performed in 220 patients with peritoneal metastasis of colorectal, ovarian, primary peritoneal, appendiceal, or mesothelioma origins. The incidences of leukopenia, neutropenia, and thrombocytopenia were 15.3%, 3.8%, and 37.9%, respectively. Median time to onset was 1 day (0-16 days), 0 day (0-2 days), and 1 day (1-2 days), respectively, after operation. Median duration of leukopenia, neutropenia, and thrombocytopenia was 1 day (1-3 days), 1 day (1-2days), and 3 days (range 0-16 days), respectively. Age > 60 (odds ratio [OR] 0.229 [95% CI: 0.105-0.502], P < .001) and the use of prior chemotherapy (OR 2.46 [95% CI: 1.24, 4.83], P = .010) were independent risk factors for thrombocytopenia on multivariable logistic regression. CONCLUSION: Hematological toxicities are common after hyperthermic intraperitoneal chemotherapy with thrombocytopenia being most common. Patients with age > 60, and who have undergone chemotherapy, are at risk of these toxicities and should be closely monitored post CRS-HIPEC.

Morbidity and mortality of elderly patients following cytoreductive surgery and Hyperthermic Intraperitoneal Chemotherapy (HIPEC).

AIM: Cytoreductive surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) is known to improve survival in selected patients with peritoneal metastasis. However, there is limited data supporting the role of CRS and HIPEC in elderly patients (≥65 years old). METHODS: A retrospective review of a prospectively maintained database of patients who underwent CRS-HIPEC between April 2001 and July 2015 from a single institution was performed. Patients were divided into two groups non-elderly (<65 years old), and elderly (≥65 years old). Clinico- pathological parameters, morbidity and overall (OS) and disease-free survival (DFS) of the patients were compared. RESULTS: A total of 177 patients (median age 52, range 9-74) underwent CRS-HIPEC with curative intent. There were 159 non-elderly patients and 18 elderly patients. Median PCI scores were 12 (0-39) for the non- elderly patients and 11 (1-29) for the elderly patients (p=0.77). High-grade complications occurred in 39 non-elderly patients (24.5%) and 8 elderly patients (44.4%) (p=0.79), while 58 non-elderly patients (38.7%) and 7 elderly patients (41.2%) stayed in ICU for more than 1 day (p=0.69). There was no difference in the 30-day mortality between the two groups (0% vs. 0%, p=1). After a median follow-up of 16 months for all patients, there was no difference in 5-years OS (51.0% vs. 59.6%, p=0.88) and 5-years DFS (23.3% vs. 53.3%, p=0.60) between non-elderly and elderly patients. CONCLUSIONS: Surgical outcomes after CRS-HIPEC do not differ significantly between non-elderly and elderly patients. Hence, age should not be a contraindication in selecting patients for CRS and HIPEC.

Computational Approaches Toward Integrating Quantified Self Sensing and Social Media.

The growing amount of data collected by quantified self tools and social media hold great potential for applications in personalized medicine. Whereas the first includes health-related physiological signals, the latter provides insights into a user's behavior. However, the two sources of data have largely been studied in isolation. We analyze public data from users who have chosen to connect their MyFitnessPal and Twitter accounts. We show that a user's diet compliance success, measured via their self-logged food diaries, can be predicted using features derived from social media: linguistic, activity, and social capital. We find that users with more positive affect and a larger social network are more successful in succeeding in their dietary goals. Using a Granger causality methodology, we also show that social media can help predict daily changes in diet compliance success or failure with an accuracy of 77%, that improves over baseline techniques by 17%. We discuss the implications of our work in the design of improved health interventions for behavior change.

201 consecutive cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) procedures in a single Asian tertiary centre.

INTRODUCTION: Peritoneal carcinomatosis (PC) is increasingly being treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). We provide a review of a high-volume Asian institute's experience and survival outcomes with this procedure. METHODS: Data were prospectively collected from 201 consecutive CRS and HIPEC procedures performed in a single institution between April 2001 and November 2015. Our primary endpoints were overall survival (OS) and disease-free survival (DFS), and secondary endpoints were morbidity and mortality. RESULTS: 77% of patients were Chinese, 9% were Malay, 6% were Indian and 8% were other ethnicities. Primary tumours were colorectal (30%), ovarian (32%), appendiceal (20%), primary peritoneal (6.5%), mesothelioma (4.5%) and others (5%). The median peritoneal cancer index (PCI) was 12, and 92% of patients achieved a completeness of cytoreduction score (CC) of 0. High-grade morbidity occurred in 25.8% of cases, and there were no 30-day mortalities. At 5-years, the OS was 55.1% and DFS was 20.3%. Factors associated with improved OS on multivariate analysis were PCI <15 (p < 0.001) and a CC 0 (p = 0.016). CONCLUSIONS: The combined treatment of CRS and HIPEC is beneficial and is associated with reasonable morbidity and mortality in Asian patients with PC from colorectal, ovarian, appendiceal, primary peritoneal and mesothelioma primaries. Complete cytoreduction and extent of disease are the most important prognostic factors for survival.

Surgical Management of Metastatic Colorectal Cancer: A Single-Centre Experience on Oncological Outcomes of Pulmonary Resection vs Cytoreductive Surgery and HIPEC.

PURPOSE: Metastasectomy is accepted as standard of care for selected patients with colorectal pulmonary metastases (CLM); however, the role of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal peritoneal metastases (CPM) is not universally accepted. We aim to compare oncological outcomes of patients with CLM and CPM after pulmonary resection and CRS-HIPEC, respectively, by comparing overall survival (OS) and disease-free survival (DFS). METHODS: A retrospective review of 49 CLM patients who underwent pulmonary resection, and 52 CPM patients who underwent CRS-HIPEC in a single institution from January 2003 to March 2015, was performed. RESULTS: The 5-year OS for CLM patients and CPM patients were 59.6 and 40.5%, respectively (p = 0.100), while the 5-year DFS were 24.0 and 14.2%, respectively (p = 0.173). CPM patients had longer median operative time (8.38 vs. 1.75 h, p < 0.001), median hospital stay (13 vs. 5 days, p < 0.001), a higher rate of intensive care unit (ICU) admissions (67.3 vs. 8.2%, p < 0.001), and a higher rate of high-grade complications (17.3 vs. 4.1%, p < 0.001). Multivariate analysis demonstrated that recurrent lung metastasis after metastasectomy was an independent prognostic factor for OS of CLM patients (OR = 0.045, 95%, CL 0.003-0.622, p = 0.021). There were no independent prognostic factors for OS in CPM patients by multivariate analysis. There were no independent prognostic factors for DFS in CLM patients by multivariate analysis, but peritoneal cancer index score, bladder involvement, and higher nodal stage at presentation of the initial malignancy were independent prognostic factors for DFS in CPM patients. CONCLUSIONS: OS and DFS for CPM patients after CRS and HIPEC are comparable to CLM patients after lung resection, although morbidity appears higher. The prognostic factors affecting survival after surgery are different between CPM and CLM patients and must be considered when selecting patients for metastasectomy.

Is multivisceral resection in locally advanced gastrointestinal stromal tumours an acceptable strategy?

BACKGROUND: Gastrointestinal stromal tumours (GISTs) represent the most common mesenchymal tumour of the gastrointestinal tract. Although the efficacy of targeted therapy cannot be over-emphasized, surgery remains the only curative primary treatment for patients with localized disease. The median size of GIST at diagnosis is approximately 5-7 cm; however, it is not uncommon for tumours to be as large as 30-40 cm and involving multiple viscera. METHODS: Data were retrospectively collected from patients with GISTs treated at the Singapore General Hospital and the National Cancer Centre Singapore over a 15-year period. Standard resection of GIST without any additional organ removal was termed as a single organ resection (SOR). If the tumour was adjacent to another organ, necessitating the removal of more than one organ, the procedure was defined as a multivisceral resection (MVR). We aim to evaluate the role of MVR in the management of large GISTs. RESULTS: A total of 187 patients underwent curative surgery for GIST between January 2000 and January 2014. Of the 187 patients, 40 (21%) underwent MVR whereas 147 (79%) had SOR. Patients in the MVR group had significantly larger tumour sizes (P < 0.001) yet R0 and R1 resection was achieved in all patients, and no intra-peritoneal rupture was reported. On comparison of MVR versus SOR groups, there was no significant difference in in-hospital morbidity and mortality. CONCLUSION: MVR may be required to achieve negative margins in patients with large GISTs, and can be performed with acceptable morbidity and mortality.

Discovering Shifts to Suicidal Ideation from Mental Health Content in Social Media.

History of mental illness is a major factor behind suicide risk and ideation. However research efforts toward characterizing and forecasting this risk is limited due to the paucity of information regarding suicide ideation, exacerbated by the stigma of mental illness. This paper fills gaps in the literature by developing a statistical methodology to infer which individuals could undergo transitions from mental health discourse to suicidal ideation. We utilize semi-anonymous support communities on Reddit as unobtrusive data sources to infer the likelihood of these shifts. We develop language and interactional measures for this purpose, as well as a propensity score matching based statistical approach. Our approach allows us to derive distinct markers of shifts to suicidal ideation. These markers can be modeled in a prediction framework to identify individuals likely to engage in suicidal ideation in the future. We discuss societal and ethical implications of this research.

Detecting Changes in Suicide Content Manifested in Social Media Following Celebrity Suicides.

The Werther effect describes the increased rate of completed or attempted suicides following the depiction of an individual's suicide in the media, typically a celebrity. We present findings on the prevalence of this effect in an online platform: r/SuicideWatch on Reddit. We examine both the posting activity and post content after the death of ten high-profile suicides. Posting activity increases following reports of celebrity suicides, and post content exhibits considerable changes that indicate increased suicidal ideation. Specifically, we observe that post-celebrity suicide content is more likely to be inward focused, manifest decreased social concerns, and laden with greater anxiety, anger, and negative emotion. Topic model analysis further reveals content in this period to switch to a more derogatory tone that bears evidence of self-harm and suicidal tendencies. We discuss the implications of our findings in enabling better community support to psychologically vulnerable populations, and the potential of building suicide prevention interventions following high-profile suicides.

Lactic acid fermentation by cells immobilised on various porous cellulosic materials and their alginate/poly-lactic acid composites.

Porous delignified cellulose (or tubular cellulose, abbr. TC) from Indian Mango (Mangifera indica) and Sal (Shorea robusta) wood and Rice husk, and TC/Ca-alginate/polylactic acid composites, were used as Lactobacillus bulgaricus immobilisation carriers leading to improvements in lactic acid fermentation of cheese whey and synthetic lactose media, compared to free cells. Specifically, shorter fermentation rates, higher lactic acid yields (g/g sugar utilised) and productivities (g/Ld), and higher amounts of volatile by-products were achieved, while no significant differences were observed on the performance of the different immobilised biocatalysts. The proposed biocatalysts are of food grade purity, cheap and easy to prepare, and they are attractive for bioprocess development based on immobilised cells. Such composite biocatalysts may be used for the co-immobilisation of different microorganisms or enzymes (in separate layers of the biocatalyst), to efficiently conduct different types of fermentations in the same bioreactor, avoiding inhibition problems of chemical or biological (competition) nature.