Post Fire Behavior of Structural Reinforced Concrete Member (Slab) Repairing with Various Materials

One of the most significant building materials used to build a variety of infrastructure, military, and civil structures is concrete. It can effectively withstand fire mishaps for a long period of time. This study employs a finite element simulation approach in Three steps: the first involves applying mechanical loading, the second involves applying mechanical and thermal loading; and the third involves strengthening the damaged model. Two different strengthening procedures were used to evaluate the performance of the fire-damaged slab. Two types of strengthening techniques—carbon-fiber-reinforced polymer (CFRP) sheet and slurry-infiltrated fibrous concrete (SIFCON) jacketing—were used. Studying the performance of SIFCON and CFRP together and in two different thicknesses of each for repairing both normal and high-strength concretes after fire exposure is considered limited. An investigation of their behavior can provide insights into how effective the restoration of strength is. The study aims to assess how well various repair materials perform in restoring the durability and strength of reinforced concrete members after being exposed to fire. This will assist in determining the best materials for concrete repair after a fire. Results show that the enhancements by SIFCON with a thickness of 30 mm significantly improved many indices, including load displacement behavior, ductility, and absorption energy of the slab. Doi: 10.28991/CEJ-2023-09-08-013 Full Text: PD

Blunt force homicides in Denmark 1992–2016

Blunt force trauma is a common homicide method, inflicted in three different ways: bodily force, assault with blunt objects of various types and falls from height. The objective of this study is to provide thorough information on blunt force homicides with data on the victims, the offenders, the surrounding circumstances, the injury methods, the extent of injuries, and survival time, which will help inform the inexperienced as well as the seasoned forensic pathologist in their daily work with death investigation and as expert witnesses in court. We have analyzed autopsy reports and available case files of 311 blunt force homicides, making up 21.9% of all homicides in Denmark during 1992–2016. Most victims and offenders were male. Altercation in the setting of nightlife and intoxication was common in male victims, while most female victims were killed in a domestic setting. Bodily force was the most common primary homicide method, followed by assault with a blunt object and fall from height. The head was the region that most often had external injuries, with no noteworthy difference between cases with bodily force and blunt objects. Two out of three victims had one or more lacerations, most often located on the head and more often on the front. Brain injury was the primary cause of death in at least 72.0% victims. Compared to bodily force victims of blunt object assault were especially prone to skull and brain injuries, had a higher trauma score, and more died at the crime scene and had a shorter survival time.</p

Performance of reinforced concrete elements strengthened with carbon fiber CFRP at elevated temperatures

The importance of the research topic is established by the problems that occur in structural buildings when exposed to fire accidents, where the concrete loses much part of its mechanical properties and therefore becomes out of service. Because reconstruction of damaged buildings has a high financial cost, it is necessary to focus on the restoration of damaged concrete members with performant techniques and proven efficiency in terms of increasing the strength of concrete and its resistance to high temperatures. The authors conduct a numerical investigation on the use of carbon fiber-reinforced polymer sheeting CFRP to restore various structural concrete elements such as beams, columns, and slabs damaged in fire accidents for two types of normal and high-strength concrete, in addition to studying the behavior of concrete after strengthening it with CFRP sheets. The results by showed that load capacity, stiffness index, and absorption energy index have been improve

Current strategies for mobilome research

Mobile genetic elements (MGE) are pivotal for bacterial evolution and adaptation, allowing shuffling of genes even between distantly related bacterial species. The study of MGEs is biologically interesting as the mode of genetic propagation is kaleidoscopic and important, as MGEs are the main vehicles of the increasing bacterial antibiotic resistance that causes thousands of human deaths each year. The study of MGEs has previously focused on plasmids from individual isolates, but the revolution in sequencing technology has allowed the study of mobile genomic elements of entire communities using metagenomic approaches. The problem in using metagenomic sequencing for the study of MGEs is that plasmids and other mobile elements only comprise a small fraction of the total genetic content that are difficult to separate from chromosomal DNA based on sequence alone. Several different approaches have been proposed that specifically enrich plasmid DNA from community samples. Here, we review recent approaches used to study entire plasmid pools from complex environments, and point out possible future developments for and pitfalls of these approaches. Further, we discuss the use of the PacBio long-read sequencing technology for MGE discovery

Plasmids, viruses, and other circular elements in rat gut

Circular DNA such as plasmids and some viruses is the major source of genetic variation in bacteria and thus has the same important evolutionary function as sexual reproduction in eukaryotic species: It allows dissemination of advantageous traits through bacterial populations. Here, we present the largest collection of novel complete extrachromosomal genetic elements to date, and compare the diversity, distribution, and content of circular sequences from 12 rat cecum samples from the pristine Falkland Islands and Danish hospital sewers, two environments with contrasting anthropogenic impact. Using a validated pipeline, we find 1,869 complete, circular, non-redundant sequences, of which only 114 are previously described. While sequences of similar size from the two environments share general features, the size distribution of the elements between environments differs significantly, with hospital sewer samples hosting larger circular elements than Falkland Island samples, a possible consequence of the massive anthropogenic influence in the hospital sewer environment. Several antibiotic resistance genes have been identified with a notably larger diversity in hospital sewer samples than in Falkland Islands samples in concordance with expectations. Our findings suggest that even though sequences of similar length carry similar traits, the mobilome of rat gut bacteria are affected by human activities in that sewer rats have larger elements and more diverse large elements than pristine island rats. More than 1000 small, novel and not classified small sequences was identified and hint the existence of a biological unit not previously described on a community level.</jats:p

Homicide drop in seven European countries: General or specific across countries and crime types?

This study examines homicide trends in seven European countries – Denmark, Estonia, Finland, the Netherlands, Scotland, Sweden and Switzerland – all of which manifested a substantial drop in homicide mortality between 1990 and 2016. By using data from the European Homicide Monitor, a coding scheme created to enable cross-country comparisons, combined with the national cause-of-death statistics, we explore generality versus specificity of the homicide drop. We examine changes in the demographic structure of victims and offenders and disaggregate homicides by different subtypes of lethal incidents, such as family-related homicides referring to conflicts between family members, and criminal milieu homicides occurring in the context of robberies, gang-related conflicts or organised crime. Results point to the generality of the drop: in most of the countries studied, the declining trend included all homicide types. The overall decline in homicide mortality was driven mostly by the decline in male victimisation and offending. In most of the countries, the gender distribution of victims and offenders changed only slightly during the study period, whereas the development of the distribution of homicide types manifested greater diversity. Our findings illustrate the benefits of disaggregated analyses in comparative homicide research

Extinction intensity during Ordovician and Cenozoic glaciations explained by cooling and palaeogeography

A striking feature of the marine fossil record is the variable intensity of extinction during superficially similar climate transitions. Here we combine climate models and species trait simulations to explore the degree to which differing paleogeographic boundary conditions and differing magnitudes of cooling and glaciation can explain the relative intensity of marine extinction during greenhouse-icehouse transitions in the Late Ordovician and the Cenozoic. Simulations modelled the response of virtual species to cooling climate using a spatially explicit cellular automaton algorithm. We find that paleogeography alone may be a minor contributing factor, as identical changes in meridional sea surface temperature gradients caused greater extinction in Late Ordovician simulations than in Cenozoic simulations. Differences in extinction from paleogeography are significant but by themselves insufficient to explain observed differences in extinction intensity. However, when simulations included inferred changes in continental flooding and interval-specific models of sea surface temperature, predicted differences in relative extinction intensity were more consistent with observations from the fossil record. Our results support the hypothesis that intense extinction in the Late Ordovician is partially attributable to exceptionally rapid and severe cooling compared to Cenozoic events

Neutrophil-mediated degradation of type III collagen is elevated in inflammatory bowel disease and DSS-induced colitis reflecting early mucosal damage

Inflammatory Bowel Disease (IBD) is characterized by mucosal injury in the gastrointestinal (GI) tract. During an abnormal immune response in the GI tract, excessive secretion of immune-cell proteases occurs. Neutrophils are the first responders, infiltrating into the inflamed interstitial matrix, where type III collagen accumulates. We aimed to develop a biomarker that reflects early inflammation before clinical symptoms arise; allowing us to intervene and prevent cumulative damage. A competitive enzyme-linked immunosorbent assay targeting a human neutrophil elastase degraded neo-epitope fragment of type III collagen (C3-HNE) was developed and assessed in serum samples from DSS-treated rats and a clinical cohort (n = 91, UC and CD). Moreover, C3M, an MMP- mediated type III collagen degradation marker, was tested for comparison. The DSS-treated rats had elevated C3-HNE levels on day 4, while C3M increased on days 10 and 14, compared to the non-DSS treated group. Percentage change analysis showed that C3-HNE rapidly peaked (day 1), while C3M displayed a sustained elevation over time. Serum C3-HNE concentrations increased in patients with IBD, including those in remission, compared to healthy donors, possibly indicating subclinical inflammation. This biomarker may reflect initial mucosal injury and could provide early detection of inflammation for patients in remission, monitoring flare episodes.</p

Evaluating a tobacco-free university policy: A repeated crosssectional survey of faculty and staff in Lebanon

INTRODUCTION A growing body of research has evaluated the effect of university tobacco-free policies on faculty and staff, however, none of these studies has been carried out in the Eastern Mediterranean Region. This study evaluates changes in faculty and staff attitudes, perceptions and smoking behavior, at 1 year post adoption of a tobacco-free policy in a medium-sized university in Lebanon and the region. METHODS Two cross-sectional surveys were conducted in 2017 and 2018: Baseline and at 1 year post policy implementation. A random sample of 625 and 624 participants took part in the 2017 and 2018 studies, respectively. RESULTS Faculty and staff had a positive attitude towards the policy at the two time points. The belief that there should be exceptions to the policy significantly decreased from 79% to 59% (p=0.002) among all smokers, particularly those with lower educational attainment (81% to 57%, p=0.007). Perception of compliance among peer smokers increased from 73% to 87% (p=0.009). The proportion of smokers did not significantly change at 1 year post policy implementation, however, 44% of smokers with lower educational attainment, compared to only 7% of those with higher educational attainment (p<0.001), reported a decrease in their smoking behavior outside campus. CONCLUSIONS The policy had a positive effect on the attitude, behavior and perception of policy benefits among smokers with lower educational attainment, who constitute the majority of smokers. Findings from this study inform and support future efforts to develop university and workplace tobacco-free policies. © 2021 Farran D. et al