•Non-pharmaceutical interventions (NPIs) were enacted in COVID-19 pandemic.•We examine effect of NPIs on total disease burden of a non-target respiratory disease.•To do this, we mathematically ...analyse and simulate four models of varying complexity.•We show that NPIs over about a year have a negative effect on total disease burden.•The negative effect increased in magnitude with the rate at which immunity is lost.
The recent global COVID-19 pandemic resulted in governments enacting non-pharmaceutical interventions (NPIs) targeted at reducing transmission of SARS-CoV-2. But the NPIs also affected the transmission of viruses causing non-target seasonal respiratory diseases, including influenza and respiratory syncytial virus (RSV). In many countries, the NPIs were found to reduce cases of such seasonal respiratory diseases, but there is also evidence that subsequent relaxation of NPIs led to outbreaks of these diseases that were larger than pre-pandemic ones, due to the accumulation of susceptible individuals prior to relaxation. Therefore, the net long-term effects of NPIs on the total disease burden of non-target diseases remain unclear. Knowledge of this is important for infectious disease management and maintenance of public health. In this study, we shed light on this issue for the simplified scenario of a set of NPIs that prevent or reduce transmission of a seasonal respiratory disease for about a year and are then removed, using mathematical analyses and numerical simulations of a suite of four epidemiological models with varying complexity and generality. The model parameters were estimated using empirical data pertaining to seasonal respiratory diseases and covered a wide range. Our results showed that NPIs reduced the total disease burden of a non-target seasonal respiratory disease in the long-term. Expressed as a percentage of population size, the reduction was greater for larger values of the basic reproduction number and the immunity loss rate, reflecting larger outbreaks and hence more infections averted by imposition of NPIs. Our study provides a foundation for exploring the effects of NPIs on total disease burden in more-complex scenarios.
Both cones or sleeves have been developed to address metaphyseal bone loss in revision total knee arthroplasty (TKA), but few studies have directly compared the outcomes. The purpose of this study ...was to compare the survivorship and aseptic revision rates between metaphyseal cones and sleeves at intermediate follow-up.
We reviewed a consecutive series of 1,172 revision TKA patients between 2009 and 2018 with a minimum two-year follow-up on all patients. We compared demographics, surgical indication, stem fixation, constraint, rates of rerevision, and Short-Form-12 scores between patients with cones and sleeves. A multivariate analysis was performed to identify the effect of cones and sleeves on aseptic rerevision. Kaplan-Meier curves were generated to compare aseptic survivorship of cones and sleeves.
There were 194 tibial cones (17%), 107 tibial sleeves (9%), 31 femoral cones (3%), and 135 femoral sleeves (12%) with a mean follow-up of 6.5 years (range: 2-12 years). There was no difference in demographics, indication, stem fixation, or constraint (P > .05). Although overall aseptic failure rates may be lower for tibial sleeves, there were no significant differences in survivorship over a one-year, two-year, and five-year follow-up when both tibial and femoral sleeves were directly compared to cones.
Both tibial and femoral sleeves and cones perform well at an intermediate-term follow-up. Further investigation of these two are required to better understand their survivorship relative to each other.
The Stroke Preclinical Assessment Network (SPAN) is a multicenter preclinical trial platform using rodent models of transient focal cerebral ischemia to address translational failure in experimental ...stroke. In addition to centralized randomization and blinding and large samples, SPAN aimed to introduce heterogeneity to simulate the heterogeneity embodied in clinical trials for robust conclusions. Here, we report the heterogeneity introduced by allowing the 6 SPAN laboratories to vary most of the biological and experimental model variables and the impact of this heterogeneity on middle cerebral artery occlusion (MCAo) performance. We included the modified intention-to-treat population of the control mouse cohort of the first SPAN trial (n=421) and examined the biological and procedural independent variables and their covariance. We then determined their impact on the dependent variables cerebral blood flow drop during MCAo, time to achieve MCAo, and total anesthesia duration using multivariable analyses. We found heterogeneity in biological and procedural independent variables introduced mainly by the site. Consequently, all dependent variables also showed heterogeneity among the sites. Multivariable analyses with the site as a random effect variable revealed filament choice as an independent predictor of cerebral blood flow drop after MCAo. Comorbidity, sex, use of laser Doppler flow to monitor cerebral blood flow, days after trial onset, and maintaining anesthesia throughout the MCAo emerged as independent predictors of time to MCAo. Total anesthesia duration was predicted by most independent variables. We present with high granularity the heterogeneity introduced by the biological and model selections by the testing sites in the first trial of cerebroprotection in rodent transient filament MCAo by SPAN. Rather than trying to homogenize all variables across all sites, we embraced the heterogeneity to better approximate clinical trials. Awareness of the heterogeneity, its sources, and how it impacts the study performance may further improve the study design and statistical modeling for future multicenter preclinical trials.
This paper describes the homology of various simplicial complexes associated to set families from combinatorial number theory, including primitive sets, pairwise coprime sets, product-free sets, and ...coprime-free sets. We present a condition on a set family that results in easy computation of the homology groups, and show that the first three examples, among many others, admit such a structure. We then extend our techniques to address the complexes associated to coprime-free sets and a generalization of primitive sets.
Background
Many chest wall reconstruction algorithms have been proposed, but there is still no general consensus. The purpose of this study is to review our single institutional experience in chest ...wall reconstruction and identify a working algorithm based on our retrospective analysis.
Methods
This is a retrospective analysis of 54 patients who underwent chest wall reconstruction in our department from 1996 to 2011.
Results
The mean follow-up was 38 months. Central chest wall defects were the most common, while infection and tumour resection were the two most common indications. The pedicled latissimus dorsi flap was a versatile flap, used as a single or combination flap for anterolateral, lateral and posterior defects. The pectoralis major flap was suitable for central and anterolateral defects and the rectus abdominis flap for lower central defects. Omentum flaps were useful in radiation-damage skin or in patients with recurrent infection.
Conclusions
Locoregional flaps are the mainstay of chest wall reconstruction. Most skeletal reconstruction, when required, is safely accomplished with the use of prosthetic materials. Free flaps are usually only indicated for large defects or when regional flaps are unavailable.
Level of Evidence: Level IV, therapeutic study.
This paper concerns the lattice \(L_n\) of subsets of \(\{1,\ldots,n\}\) that are arithmetic progressions, under the inclusion order. For \(n\geq 4\), this poset is not graded and thus not ...semimodular. We give three independent proofs of the fact that for \(n\geq 2\), \(\mu_n(L_n) = \mu(n-1)\), where \(\mu_n\) is the M\"obius function of \(L_n\) and \(\mu\) is the classical (number-theoretic) M\"obius function. We also show that \(L_n\) is comodernistic, which implies that \(L_n\) is EL-labelable. Comodernism is then used to prove that the order complex \(\Delta_n\) of the lattice is either contractible or homotopy equivalent to a sphere.
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