Algorithm to Estimate the Capacity Reserve of Existing Masonry Arch Railway Bridges

Most railway masonry arch bridges were designed according to codes that predate the 1950s; therefore, assessing their load-carrying capacity to comply with current codes is of the utmost importance. Nonetheless, acquiring the necessary information to conduct in-depth analyses is expensive and time consuming. In this article, we propose an expeditious procedure to conservatively assess the Load Rating Factor of masonry arch railway bridges based on a minimal set of information: the span, rise-to-span ratio, and design code. This method consists in applying the Static Theorem to determine the most conservative arch geometry compatible with the original design code; assuming this conservative geometrical configuration, the load rating factor, with respect to a different design load, is estimated. Using this algorithm, a parametric analysis was carried out to evaluate the Load Rating Factor of old arch bridges in respect of the modern freight load of the Trans-European Conventional Rail System, for different spans, rise-to-span ratios, and original design codes. The results are reported in easy-to-use charts, and summarized in simple, practical rules, which can help railway operators to rank their bridges based on capacity deficit.

A language of thought for the mental representation of geometric shapes

Why do geometric shapes such as lines, circles, zig-zags or spirals appear in all human cultures, but are never produced by other animals? Here, we formalize and test the hypothesis that all humans possess a compositional language of thought that can produce line drawings as recursive combinations of a minimal set of geometric primitives. We present a programming language, similar to Logo, that combines discrete numbers and continuous integration in higher-level structures based on repetition, concatenation and embedding, and show that the simplest programs in this language generate the fundamental geometric shapes observed in human cultures. On the perceptual side, we propose that shape perception in humans involves searching for the shortest program that correctly draws the image (program induction). A consequence of this framework is that the mental difficulty of remembering a shape should depend on its minimum description length (MDL) in the proposed language. In two experiments, we show that encoding and processing of geometric shapes is well predicted by MDL. Furthermore, our hypotheses predict additive laws for the psychological complexity of repeated, concatenated or embedded shapes, which are experimentally validated.

EXPRESS METHOD FOR CALCULATING THE SPECIFIC HEAT OF EXPLOSIVE TRANSFORMATION OF CHNO CONDENSED EXPLOSIVES

Разработан экспресс-метод расчета теплоты взрыва СаHbNcOdконденсированных взрывчатых веществ с различным кислородным балансом от резко отрицательного до положительного. Предложенный метод использует минимальный набор входных данных, состоящих из элементного состава, плотности энтальпий образований исходного взрывчатого вещества и его продуктов детонации. Расчет теплоты взрыва основывается на корреляционной связи между минимальной и максимальной теплотами взрыва с плотностью высокоэнергетического соединения. В статье подробно приведены реакции разложения взрывчатых веществ для случаев с минимальной и максимальными теплотами взрыва. Проведены расчеты теплоты взрыва по новому способу и методу Пепекина по представленной в статье базы взрывчатых веществ, а также приведены результаты сравнения, которые показали большую точность (в 2,3 раза) предложенного метода. An express method has been developed for calculating the explosion heat of cahbncod condensed explosives with different oxygen balance from sharply negative to positive. The proposed method uses a minimal set of input data consisting of the elemental composition, enthalpy density of the formations of the initial explosive and its detonation products. The calculation of the heat of explosion is based on the correlation between the minimum and maximum heat of explosion with the density of a high-energy compound. The article describes in detail the decomposition reactions of explosives for cases with minimum and maximum explosion heats. Calculations of the heat of explosion according to the new method and the pepekin method are carried out according to the explosives database presented in the article, and comparison results are also presented, which showed a better accuracy (2.3 times) of the proposed method.

Poisson algebra structure on the invariants of pairs of matrices of degree three

We provide a table of multiplication of the Poisson algebra on the minimal set of generators of the invariants of pairs of matrices of degree three.

On the dimension of $H^{*}((\mathbb Z_2)^{\times t}, \mathbb Z_2)$ as a module over Steenrod ring

We write $\mathbb P$ for the polynomial algebra in one variable over the finite field $\mathbb Z_2$ and $\mathbb P^{\otimes t} = \mathbb Z_2[x_1, \ldots, x_t]$ for its $t$-fold tensor product with itself. We grade $\mathbb P^{\otimes t}$ by assigning degree $1$ to each generator. We are interested in determining a minimal set of generators for the ring of invariants $(\mathbb P^{\otimes t})^{G_t}$ as a module over Steenrod ring, $\mathscr A_2.$ Here $G_t$ is a subgroup of the general linear group $GL(t, \mathbb Z_2).$ An equivalent problem is to find a monomial basis of the space of "unhit" elements, $\mathbb Z_2\otimes_{\mathscr A_2} (\mathbb P^{\otimes t})^{G_t}$ in each $t$ and degree $n\geq 0.$ The structure of this tensor product is proved surprisingly difficult and has been not yet known for $t\geq 5,$ even for the trivial subgroup $G_t = \{e\}.$ In the present paper, we consider the subgroup $G_t = \{e\}$ for $t \in \{5, 6\},$ and obtain some new results on $\mathscr A_2$-generators of $(\mathbb P^{\otimes t})^{G_t}$ in some degrees. At the same time, some of their applications have been proposed. We also provide an algorithm in MAGMA for verifying the results. This study can be understood as a continuation of our recent works in [23, 25].

Discordant diagnostic criteria for pneumonia in COPD trials: a review

Inhaled corticosteroids (ICS) have a class effect of increasing pneumonia risk in patients with COPD. However, pneumonia incidence varies widely across clinical trials of ICS use in COPD. This review clarifies methodological differences in defining and recording pneumonia events in these trials and discusses factors that could contribute to the varying pneumonia incidence. Literature searches and screening yielded 40 relevant references for inclusion. Methods used to capture pneumonia events in these studies included investigator-reported pneumonia adverse events, standardised list of signs or symptoms, radiographic confirmation of suspected cases and/or confirmation by an independent clinical end-point committee. In general, more stringent pneumonia diagnosis criteria led to lower reported pneumonia incidence rates. In addition, studies varied in design and population characteristics, including exacerbation history and lung function, factors that probably contribute to the varying pneumonia incidence. As such, cross-trial comparisons are problematic. A minimal set of standardised criteria for diagnosis and reporting of pneumonia should be used in COPD studies, as well as reporting of patients’ pneumonia history at baseline, to allow comparison of pneumonia rates between trials. Currently, within-trial comparison of ICS-containing versus non-ICS-containing treatments is the appropriate method to assess the influence of ICS on pneumonia incidence.

Min waves without MinC can pattern FtsA-FtsZ filaments on model membranes

Although the essential proteins that drive bacterial cytokinesis have been identified and reconstituted in vitro, the precise mechanisms by which they dynamically interact to enable symmetrical division are largely unknown. In Escherichia coli, cell division begins with the formation of a proto-ring composed of FtsZ and its membrane-tethering proteins FtsA and ZipA. In the broadly proposed molecular scenario for ring positioning, Min waves composed of MinD and MinE distribute the FtsZ-polymerization inhibitor MinC away from mid-cell, where the Z-ring can form. Therefore, MinC is believed to be an essential element connecting the Min and FtsZ systems. Here, by using cell-free gene expression on planar lipid membranes, we demonstrate that MinDE drive the formation of dynamic, antiphase patterns of FtsZ-FtsA co-filaments even in the absence of MinC. This behavior is also observed when the proteins are compartmentalized inside microdroplets. These results suggest that Z-ring positioning may be achieved with a more minimal set of proteins than previously envisaged, providing a fresh perspective about the role of MinC. Moreover, we propose that MinDE oscillations may constitute the minimal localization mechanism of an FtsA-FtsZ constricting ring in a prospective synthetic cell.

ETS Family Transcription Factor Fusions in Childhood AML: Distinct Expression Networks and Clinical Implications

The ETS family of genes encode transcription factors (TFs) containing the ETS DNA binding domain, which have roles in cellular growth and development, including embryonic hematopoiesis. Dysregulation of these genes is associated with malignant transformation and tumorigenesis. In childhood acute myeloid leukemia (AML), the MNX1-ETV6 t(7;12)(q36;p13) and FUS-ERG t(16;21)(p11;q22) fusions are associated with adverse outcome. However, the biological and clinical implications of other ETS oncofusions in pediatric AML remain unknown. We identified 62 ETS gene fusions in 1,473 primary diagnostic AML samples (4.2%) using whole transcriptome RNA-sequencing and karyotype data. Four ETS family genes were identified to be involved in fusions with various partner genes: ETV6, ERG, FEV, and FLI1. Fusions with ETV6 were the most abundant (58%, 36/62) while FEV and FLI1 were the least; 21 fusion partners were identified where many function as TFs and co-activators (Figure 1A). MNX1-ETV6 (N=16) is enriched in infants (87.5% < 3 years, p < 0.001, Figure 1B), consistent with previous reports. ETV6 fusions with various partners (ETV6-Other, N=20) were likewise enriched in infants (50% < 3 years) and were significantly younger than patients without ETS fusions (median age: 3.0 vs 9.6 years, p = 0.025). FUS-ERG (N=10), HNRNPH1-ERG (N=8), and ETS fusions with various partners (ETS-Other, N=8) were primarily identified in patients 5-18 years old. Outcomes for patients with ETS fusions was determined after censoring for stem cell transplantation. Patients with ETS fusions as a collective group had adverse outcome with an EFS of 17.7% vs 39.9% (p = 0.047, Figure 1C), similar to high-risk cases in the reference group (22%), suggesting that patients with any ETS fusion may be considered high risk. Evaluation of outcomes by individual fusion groups at 3 years from diagnosis demonstrated an EFS of 0% for HNRNPH1-ERG, 18.0% for FUS-ERG, 14.2% for ETV6-Other, 20.8% for ETS-Other, and 28.4% for those with MNX1-ETV6. Twenty-one patients (37.5%) with ETS family fusions received stem cell transplant (SCT) in first complete remission, including HNRNPH1-ERG (N=5), FUS-ERG (N=3), ETV6-Other (N=5), ETS-Other (N=2), and MNX1-ETV6 (N=6). For these SCT recipients, OS at 3 years after transplant was 60.2%. We investigated whether ETS family fusions might have similar transcriptome profiles. Unsupervised uniform manifold approximation and projection (UMAP) on RNA-seq gene expression data followed by Leiden clustering found that individual fusions clustered in the same 3D space. More importantly, ETS fusion groups clustered closely to one another, indicating a shared transcriptional profile (Figure 1D, circle). Next, ETS fusion groups were each independently compared to the reference cohort (N=1421) using differential expression (DE) analysis. Intersection of DE genes revealed 17 overexpressed genes common to ETS fusions and 9/17 (52%) were also dysregulated when contrasting ETS cohorts to healthy normal marrows' transcriptome (N=68, Figure 1E). The minimal set of dysregulated genes included an adhesion molecule EDIL3, a prostaglandin (PG) enzyme HPGD, and a tyrosine phosphatase PTP4A3, which is strongly associated with progression in lymphoblastic leukemia and multiple myeloma. EDIL3 was reported to be overexpressed in MNX1-ETV6 and we found this molecule is a common feature of ETS fusions and their cellular dysregulation. The minimal set of 9 genes were further investigated using protein interaction networks defined from Pathway Commons v11. FUS-ERG and HNRNPH1-ERG both had significantly (adj. p < 0.001) activated HPGD networks; PG-E synthase and > 10 PG metabolism genes were upregulated. PG metabolism has important roles in regulating hematopoietic stem and progenitor (HSPC) functions and PG-E2 was shown to increase HSPC survival. ETV6-MXN1, ETV6-Other, and FUS-ERG had activated PTP4A3 networks and its expression was associated with sensitivity to BET inhibitors (BETi) in myeloma. They also exhibited increased activity of an ERG network with the overexpression of upstream regulators CBFA2T3 and GATA, and downstream targets like VWF and ZBTB16. Overall, we show that ETS fusions are uniformly high risk and share dysregulated cell adhesion (EDIL3) and transcriptional networks for ERG, HPGD, and PTP4A3, which provide opportunities for further research into the metabolome and therapeutics (BETi) in these fusions. Figure 1 Figure 1. Disclosures Shaw: T-Cell and/or Gene Therapy for Cancer: Patents & Royalties.

Recognition of stimulus received by recurrent neural network

The study is concerned with the comparison of two methods for identification of stimulus received by artificial neural network using neural activity pattern that corresponds to the period of storing information about this stimulus in the working memory. We used simple recurrent neural networks learned to pass the delayed matching-to-sample test. Neural activity was detected at the period of pause between receiving stimuli. The analysis of neural excitation patterns showed that neural networks encoded variables that were relevant for the task during the delayed matching-to-sample test, and their activity patterns were dynamic. The method of centroids allowed identifying the type of the received stimuli with efficiency up to 75% while the method of neural network-based decoder showed 100% efficiency. In addition, this method was applied to determine the minimal set of neurons whose activity was the most significant for stimulus recognition.