1,641 research outputs found

    My Way or the Highway: a More Naturalistic Model of Altruism Tested in an Iterative Prisoners' Dilemma

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    There are three prominent solutions to the Darwinian problem of altruism, kin selection, reciprocal altruism, and trait group selection. Only one, reciprocal altruism, most commonly implemented in game theory as a TIT FOR TAT strategy, is not based on the principle of conditional association. On the contrary, TIT FOR TAT implements conditional altruism in the context of unconditionally determined associates. Simulations based on Axelrod\'s famous tournament have led many to conclude that conditional altruism among unconditional partners lies at the core of much human and animal social behavior. But the results that have been used to support this conclusion are largely artifacts of the structure of the Axelrod tournament, which explicitly disallowed conditional association as a strategy. In this study, we modify the rules of the tournament to permit competition between conditional associates and conditional altruists. We provide evidence that when unconditional altruism is paired with conditional association, a strategy we called MOTH, it can out compete TIT FOR TAT under a wide range of conditions.Game Theory; Altruism; Prisoners' Dilemma; TIT FOR TAT; MOTH; Docking; Netlogo

    Post-Traumatic Stress and Academic Performance Among Entry-Level Doctoral Physical Therapy Students in a Human Anatomy Cadaver Dissection Course

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    Background: Dissection of human cadavers can be a stressful experience for students. Purpose: The purposes of this study were twofold: 1) to determine if physical therapy students develop or experience a worsening of post-traumatic stress disorder (PTSD) symptoms during exposure to and dissection of human cadavers; and 2) to determine if these symptoms are related to academic performance. Methods: Previous history of a diagnosis of anxiety or post-traumatic stress disorder and level of prior exposure to cadavers were recorded among 26 entry-level first semester doctoral students in physical therapy (DPT) taking gross human anatomy. Their level of anxiety about working with cadavers before and after the course was recorded. The Life Events Checklist (LEC-5) for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) was used as a self-report measure to record potentially traumatic events in a subject’s life prior to the study and during the course. Subjects also completed the Post-Traumatic Stress Disorder Checklist (PCL-5) at the beginning and end of the course to assess for symptoms of post-traumatic stress disorder. Student performance was assessed using written and practical examination grades. Results: Overall, the PCL-5 score for the group decreased significantly over the semester (p = 0.01). However, 3 subjects’ PCL-5 scores increased. Risk factors present among these subjects included previous diagnosis of post-traumatic stress disorder or anxiety, combat exposure, history of physical or sexual abuse, lack of previous exposure to cadavers, and coinciding traumatic events. Written examination performance was not significantly related to either change in PCL-5 (p = 0.84) or post-PCL-5 (p = 0.69) scores. Practical examination performance was not significantly related to either change in PCL-5 (p = 0.28) or post-PCL-5 (p = 0.51) scores. However, consistent with previous research, students with a history of post-traumatic stress disorder and/or anxiety did have statistically significant lower written examination scores. Conclusions: Physical therapy students neither developed nor experienced a worsening of, but rather a reduction in, PTSD symptoms during exposure to and dissection of human cadavers. Overall, symptoms of PTSD did not seem to be related to academic performance

    Self-assembling nanoparticles containing dexamethasone as a novel therapy in allergic airways inflammation.

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    Nanocarriers can deliver a wide variety of drugs, target them to sites of interest, and protect them from degradation and inactivation by the body. They have the capacity to improve drug action and decrease undesirable systemic effects. We have previously developed a well-defined non-toxic PEG-dendritic block telodendrimer for successful delivery of chemotherapeutics agents and, in these studies, we apply this technology for therapeutic development in asthma. In these proof-of-concept experiments, we hypothesized that dexamethasone contained in self-assembling nanoparticles (Dex-NP) and delivered systemically would target the lung and decrease allergic lung inflammation and airways hyper-responsiveness to a greater degree than equivalent doses of dexamethasone (Dex) alone. We found that ovalbumin (Ova)-exposed mice treated with Dex-NP had significantly fewer total cells (2.78 ± 0.44 × 10(5) (n = 18) vs. 5.98 ± 1.3 × 10(5) (n = 13), P<0.05) and eosinophils (1.09 ± 0.28 × 10(5) (n = 18) vs. 2.94 ± 0.6 × 10(5) (n = 12), p<0.05) in the lung lavage than Ova-exposed mice alone. Also, lower levels of the inflammatory cytokines IL-4 (3.43 ± 1.2 (n = 11) vs. 8.56 ± 2.1 (n = 8) pg/ml, p<0.05) and MCP-1 (13.1 ± 3.6 (n = 8) vs. 28.8 ± 8.7 (n = 10) pg/ml, p<0.05) were found in lungs of the Dex-NP compared to control, and they were not lower in the Dex alone group. In addition, respiratory system resistance was lower in the Dex-NP compared to the other Ova-exposed groups suggesting a better therapeutic effect on airways hyperresponsiveness. Taken together, these findings from early-stage drug development studies suggest that the encapsulation and protection of anti-inflammatory agents such as corticosteroids in nanoparticle formulations can improve efficacy. Further development of novel drugs in nanoparticles is warranted to explore potential treatments for chronic inflammatory diseases such as asthma

    Assessment of the genetic basis of rosacea by genome-wide association study.

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    Rosacea is a common, chronic skin disease that is currently incurable. Although environmental factors influence rosacea, the genetic basis of rosacea is not established. In this genome-wide association study, a discovery group of 22,952 individuals (2,618 rosacea cases and 20,334 controls) was analyzed, leading to identification of two significant single-nucleotide polymorphisms (SNPs) associated with rosacea, one of which replicated in a new group of 29,481 individuals (3,205 rosacea cases and 26,262 controls). The confirmed SNP, rs763035 (P=8.0 × 10(-11) discovery group; P=0.00031 replication group), is intergenic between HLA-DRA and BTNL2. Exploratory immunohistochemical analysis of HLA-DRA and BTNL2 expression in papulopustular rosacea lesions from six individuals, including one with the rs763035 variant, revealed staining in the perifollicular inflammatory infiltrate of rosacea for both proteins. In addition, three HLA alleles, all MHC class II proteins, were significantly associated with rosacea in the discovery group and confirmed in the replication group: HLA-DRB1*03:01 (P=1.0 × 10(-8) discovery group; P=4.4 × 10(-6) replication group), HLA-DQB1*02:01 (P=1.3 × 10(-8) discovery group; P=7.2 × 10(-6) replication group), and HLA-DQA1*05:01 (P=1.4 × 10(-8) discovery group; P=7.6 × 10(-6) replication group). Collectively, the gene variants identified in this study support the concept of a genetic component for rosacea, and provide candidate targets for future studies to better understand and treat rosacea

    Semi-supervised Classification of Malware Families Under Extreme Class Imbalance via Hierarchical Non-Negative Matrix Factorization with Automatic Model Selection

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    Identification of the family to which a malware specimen belongs is essential in understanding the behavior of the malware and developing mitigation strategies. Solutions proposed by prior work, however, are often not practicable due to the lack of realistic evaluation factors. These factors include learning under class imbalance, the ability to identify new malware, and the cost of production-quality labeled data. In practice, deployed models face prominent, rare, and new malware families. At the same time, obtaining a large quantity of up-to-date labeled malware for training a model can be expensive. In this paper, we address these problems and propose a novel hierarchical semi-supervised algorithm, which we call the HNMFk Classifier, that can be used in the early stages of the malware family labeling process. Our method is based on non-negative matrix factorization with automatic model selection, that is, with an estimation of the number of clusters. With HNMFk Classifier, we exploit the hierarchical structure of the malware data together with a semi-supervised setup, which enables us to classify malware families under conditions of extreme class imbalance. Our solution can perform abstaining predictions, or rejection option, which yields promising results in the identification of novel malware families and helps with maintaining the performance of the model when a low quantity of labeled data is used. We perform bulk classification of nearly 2,900 both rare and prominent malware families, through static analysis, using nearly 388,000 samples from the EMBER-2018 corpus. In our experiments, we surpass both supervised and semi-supervised baseline models with an F1 score of 0.80.Comment: Accepted at ACM TOP

    Ipatasertib plus paclitaxel for PIK3CA/AKT1/PTEN-altered hormone receptor-positive HER2-negative advanced breast cancer: primary results from cohort B of the IPATunity130 randomized phase 3 trial

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    HER2 negative; Ipatasertib; PI3K/AKTHER2 negativo; Ipatasertib; PI3K/AKTHER2 negatiu; Ipatasertib; PI3K/AKTPurpose PI3K/AKT pathway alterations are frequent in hormone receptor-positive (HR+) breast cancers. IPATunity130 Cohort B investigated ipatasertib–paclitaxel in PI3K pathway-mutant HR+ unresectable locally advanced/metastatic breast cancer (aBC). Methods Cohort B of the randomized, double-blind, placebo-controlled, phase 3 IPATunity130 trial enrolled patients with HR+ HER2-negative PIK3CA/AKT1/PTEN-altered measurable aBC who were considered inappropriate for endocrine-based therapy (demonstrated insensitivity to endocrine therapy or visceral crisis) and were candidates for taxane monotherapy. Patients with prior chemotherapy for aBC or relapse < 1 year since (neo)adjuvant chemotherapy were ineligible. Patients were randomized 2:1 to ipatasertib (400 mg, days 1–21) or placebo, plus paclitaxel (80 mg/m2, days 1, 8, 15), every 28 days until disease progression or unacceptable toxicity. The primary endpoint was investigator-assessed progression-free survival (PFS). Results Overall, 146 patients were randomized to ipatasertib–paclitaxel and 76 to placebo–paclitaxel. In both arms, median investigator-assessed PFS was 9.3 months (hazard ratio, 1.00, 95% CI 0.71–1.40) and the objective response rate was 47%. Median paclitaxel duration was 6.9 versus 8.8 months in the ipatasertib–paclitaxel versus placebo–paclitaxel arms, respectively; median ipatasertib/placebo duration was 8.0 versus 9.1 months, respectively. The most common grade ≄ 3 adverse events were diarrhea (12% with ipatasertib–paclitaxel vs 1% with placebo–paclitaxel), neutrophil count decreased (9% vs 7%), neutropenia (8% vs 9%), peripheral neuropathy (7% vs 3%), peripheral sensory neuropathy (3% vs 5%) and hypertension (1% vs 5%). Conclusion Adding ipatasertib to paclitaxel did not improve efficacy in PIK3CA/AKT1/PTEN-altered HR+ HER2-negative aBC. The ipatasertib–paclitaxel safety profile was consistent with each agent’s known adverse effects.This work was supported by Genentech/Roche. Medical writing assistance was provided by Jennifer Kelly, MA (Medi-Kelsey Ltd), funded by F. Hoffmann-La Roche Ltd, Basel, Switzerland

    Preoperative statin treatment is associated with reduced postoperative mortality and morbidity in patients undergoing cardiac surgery: An 8-year retrospective cohort study

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    BackgroundCardiac surgical procedures can be associated with significant morbidity and mortality. Recently, it has been recognized that statins might induce multiple biologic effects independent of lipid lowering that could potentially ameliorate adverse surgical outcomes. Accordingly, this study tested the central hypothesis that pretreatment with statins before cardiac surgery would reduce adverse postoperative surgical outcomes.MethodsDemographic and outcomes data were collected retrospectively for 3829 patients admitted for planned cardiac surgery between February 1994 and December 2002. Statin pretreatment occurred in 1044 patients who were comparable with non–statin-pretreated (n = 2785) patients with regard to sex, race, and age. Primary outcomes examined included postoperative mortality (30-day) and a composite morbidity variable.ResultsThe odds of experiencing 30-day mortality and morbidity were significantly less in the statin-pretreated group, with unadjusted odds ratios of 0.43 (95% confidence interval [CI], 0.28-0.66) and 0.72 (95% CI, 0.61-0.86), respectively. Risk-adjusted odds ratios for mortality and morbidity were 0.55 (95% CI, 0.32-0.93) and 0.76 (95% CI, 0.62-0.94), respectively, by using a logistic regression model and 0.51 (95% CI, 0.27-0.94) and 0.71 (95% CI, 0.55-0.92), respectively, in the propensity-matched model, demonstrating significant reductions in 30-day morbidity and mortality. In a subsample of patients undergoing valve-only surgery (n = 716), fewer valve-only patients treated with statins experienced mortality, although these results were not statistically significant (1.96% vs 7.5%).ConclusionsThese findings indicate that statin pretreatment before cardiac surgery confers a protective effect with respect to postoperative outcomes

    Treatment Outcomes for Rheumatoid Arthritis-Associated Interstitial Lung Disease: A Real-World, Multisite Study of the Impact of Immunosuppression on Pulmonary Function Trajectory

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    BACKGROUND: Rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) is common in patients with RA and leads to significant morbidity and mortality. No randomized, placebo-controlled data are available that support the role of immunosuppression to treat RA-associated ILD, despite being widely used in clinical practice. RESEARCH QUESTION: How does immunosuppression impact pulmonary function trajectory in a multisite retrospective cohort of patients with RA-associated ILD? STUDY DESIGN AND METHODS: Patients with RA who started treatment for ILD with mycophenolate, azathioprine, or rituximab were identified retrospectively from five ILD centers. Change in lung function before and after treatment was analyzed using a linear spline mixed-effect model with random intercept. Prespecified secondary analyses examined the impact of radiologic pattern of ILD (ie, usual interstitial pneumonia [UIP] vs non-UIP) on treatment trajectory. RESULTS: Two hundred twelve patients were included in the analysis: 92 patients (43.4%) were treated with azathioprine, 77 patients (36.3%) were treated with mycophenolate mofetil, and 43 patients (20.3%) were treated with rituximab. In the combined analysis of all three agents, an improvement in FVC % predicted was found after 12 months of treatment compared with the potential 12-month response without treatment (+3.90%; P ≀ .001; 95% CI, 1.95-5.84). Diffusing capacity of the lungs for carbon monoxide (Dlco) % predicted also improved at 12 months (+4.53%; P ≀ .001; 95% CI, 2.12-6.94). Neither the UIP pattern of ILD nor choice of immunosuppressive agent significantly impacted the pulmonary function trajectory on immunosuppression. INTERPRETATION: Immunosuppression was associated with an improved trajectory in FVC and Dlco compared with the pretreatment pulmonary function trajectory. Prospective, randomized trials are required to validate these findings

    Protocol for Improving Care by FAster risk-STratification through use of high sensitivity point-of-care troponin in patients presenting with possible acute coronary syndrome in the EmeRgency department (ICare-FASTER):a stepped-wedge cluster randomised quality improvement initiative

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    Introduction Clinical assessment in emergency departments (EDs) for possible acute myocardial infarction (AMI) requires at least one cardiac troponin (cTn) blood test. The turn-around time from blood draw to posting results in the clinical portal for central laboratory analysers is ~1–2 hours. New generation, high-sensitivity, point-of-care cardiac troponin I (POC-cTnI) assays use whole blood on a bedside (or near bedside) analyser that provides a rapid (8 min) result. This may expedite clinical decision-making and reduce length of stay. Our purpose is to determine if utilisation of a POC-cTnI testing reduces ED length of stay. We also aim to establish an optimised implementation process for the amended clinical pathway.Methods and analysis This quality improvement initiative has a pragmatic multihospital stepped-wedge cross-sectional cluster randomised design. Consecutive patients presenting to the ED with symptoms suggestive of possible AMI and having a cTn test will be included. Clusters (comprising one or two hospitals each) will change from their usual-care pathway to an amended pathway using POC-cTnI—the ‘intervention’. The dates of change will be randomised. Changes occur at 1 month intervals, with a minimum 2 month ‘run-in’ period. The intervention pathway will use a POC-cTnI measurement as an alternate to the laboratory-based cTn measurement. Clinical decision-making steps and logic will otherwise remain unchanged. The POC-cTnI is the Siemens (Erlangen Germany) Atellica VTLi high-sensitivity cTnI assay. The primary outcome is ED length of stay. The safety outcome is cardiac death or AMI within 30 days for patients discharged directly from the ED.Ethics and dissemination Ethics approval has been granted by the New Zealand Southern Health and Disability Ethics Committee, reference 21/STH/9. Results will be published in a peer-reviewed journal. Lay and academic presentations will be made. Māori-specific results will be disseminated to Māori stakeholders.Trial registration number ACTRN12619001189112
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