109 research outputs found
A BIM Template for Construction Site Planning
Building Information Modelling is gradually becoming the standard method for building design all over the world. Its rapid development is visible not only in the many researches carried on it but also in the several standards released in different countries. The spread of the method implied continuous software improvements with the aim to comply as much as possible different design needs. Nevertheless, an insufficiency of tools specifically developed for construction site planning is still detectable among BIM panorama. The principal aim of the presented research is then to develop BIM use for making more efficient construction site design. Having defined, in an early report, the structure and the contents of the postulated Construction Site Information Model, the research goes on by customizing the available tools in order to fit the needs of a construction site designer. One of these tools is a predetermined template, useful as a starting point for the design, as it is for other design disciplines. The aim is to have at disposal, since the beginning of the project, a model completed of a series of elements, parameters, visualization tools and many other issues able to satisfy the needs of construction site design in term of information contents, level of detail and model efficiency. A step-by-step procedure is also provided to assure the correct use and guarantee the completeness of the model. In particular the research steps has been the following: (i) analysis of some software to evaluate the chances of customizing templates; (ii) creation of the template according to the defined contents and aims of the Construction Site Model; (iii) test and improvement of the tool in a project simulator specifically created for the purpose; (iv) practice in real case study and evaluation about its operation. The case study permits to evaluate how this tool make more efficient site designer task in term of time spent and mistakes avoided
New horizons for a worker-effective training method in the AEC Sector
The training of site professionals is typically perceived as being monotonous, and ineffective in terms of information assimilation and retention. Furthermore, traditional training approaches such as lecture-based presentations, have been demonstrated to be unsuccessful at engaging site workers, resulting in decreased attention and motivation. This paper aims to develop the framework for gamified training, of site workers. It is intended to value the requirements that European H&S standards expect to be kept under surveillance. The outcome of this work is the definition of a new reward procedure focused on ongoing improvement via feedback to low-scoring individuals. Multiple screen boards are designed to facilitate key context interaction and possible reactions. This study outlines two theoretical applications of training, the first applicable transversally to many situations (i.e. Educational Construction Site Information Modeling) and the second as a site-specific solution based on its digital twin (i.e. Mockup Construction Site Information Modeling) intended to accurately foresee and train workers for dangerous operations
SAFETY AND HEALTH SITE INSPECTIONS FOR ON-FIELD RISK ANALYSIS AND TRAINING
The field of construction is always affected by a large number of accidents at work that
have many different causes and responsible. Therefore, it is of utmost importance to
focus on all these issues, in order to reduce all risk factors that can undermine
individuals’ safety on building sites. The objective of the research is then the
development of a method for quick on site analysis of all critical issues that can create
accidents and identification of the related causes in order to directly provide a correct
and focused training identified as the best method to act on the causes to reduce
accidents. The research was carried on during construction of the Universal Exhibition
of Milan – Expo 2015 – that counted almost 70 contemporary construction sites. To
reach the goals further research steps has been followed and in particular: (i)
inspections on building sites through all the Expo area; (ii) analysis of the main
identified problems; (iii) development of a methodology to quickly identify the cause
of problems; (iv) validation of the method through back office analysis of site
documents; (v) correct on-site training according to found problem. During the whole
construction site, the improvements in criticalities solving have been visible thanks to
the focused training. The developed method, carried on in a high-risk environment, is
applicable in any other building sites and environment as independent from the
boundary conditions of the place
THE ROLE OF PROJECT SUPERVISOR WITHIN THE BIM EXECUTION PLAN
In the AECO sector, the BIM approach is used to manage and exchange information between the different stakeholders involved in the development of a project. Central models, available on CDE, store the information that could be retrieved according to the role and to the specialism involved.
Drawing the right set of properties is crucial for successful workflows, hence cross-information is fundamental to achieve information exchange between disciplines, managed by each BIM coordinator.
According to ISO 19650 series the client specifies those requirements in the EIR, nevertheless, few cases show the implementation of Health and Safety measures in it. European Directive 89/391/EEC on health and safety (H&S) on workplaces and more specifically the directive 92/57/EEC addressing Project Supervisors can be both seen as a beacon in this field for their clear and neat list of compulsory and optional requirements. This work aims to create an integrated standard example to be used from the clients at the tender stage (pre-BEP) to verify and validate the completeness of H&S design outcome. Such integrations aim to facilitate the information flow mong the different specialists reducing the occurrence of onsite accidents
5D BIM FOR CONSTRUCTION SITE SURVEYNG
The scope of work presented in this paper is to provide a BIM-based workflow
supporting clients and contractors in construction site surveying. It is well known that
BIM technology offers many profitable issues that benefit owners, designers and
constructors, especially in terms of design efficiency and interoperability. Moreover, it
can become a powerful instrument for the client’s team and the General Contractor all
along the construction phase, starting from the construction site organization to answer
the bid requests. It can also support the supervision of work progress and amount, and
allow to periodically reconsider them in compliance with available resources. Starting
from these statements, the authors have developed some studies to obtain a systematic
and methodological approach for site surveying and optimization. Then, the research
focuses primarily on the definition of proper requirements to outline a 5D site
management throughout the whole construction process. After the definition of
different needs for the different actors of construction process, the research moved to
the possible BIM use for the satisfaction of these needs by the definition of
customized parameters dealing with site spaces and facilities, quantities, time and cost
management. The parameters have been identified to respond the needs of the on-field
case study concerning the realization of a school complex in Cernusco sul Naviglio
(Milan). Furthermore the field test proved efficiency and promptness to changes of the
developed method in particular concerning scheduling optimization. By further
inspections, this process is also supposed to become an instrument of dialog and
comparison with the Health & Safety team, to verify work items clashes against health
and safety on construction site
Human and animal integrated influenza surveillance: a novel sampling approach for an additional transmission way in the aquatic bird reservoir.
Background: infectious low pathogenic avian influenza viruses (LPAIVs) have been recently detected
on feathers of wild ducks. Laboratory trial results suggested that the preen oil gland secretion,
covering waterbirds\u2019 feathers, may attract and concentrate virus particles from AIV-contaminated
waters to birds\u2019 bodies. We evaluated whether ducks can become infected by the ingestion of preen
oil-associated viral particles, experimentally smeared on their plumage. In addition, we compared
virologic and serologic results obtained from mallards whose feathers were experimentally infected,
with those from wild mallards naturally carrying AIVs on feathers.
Methods: we experimentally coated 7 mallards (Anas plathyrynchos) using preen oil mixed with
a LPAIV (H10N7 subtype), and housed them for 45 days with a control, uncoated duck. Cloacal,
oropharyngeal and feather swabs were collected from all birds and examined for AIV molecular
detection and isolation. Blood samples were also taken to detect influenza specific antibodies. In
addition, sera from 10 wild mallards, carrying on feathers infectious LPAIV H10N7, were examined.
Results: virologic and serologic results indicated that through self- and allopreening all the birds
experimentally coated with the preen oil/AIV mix and the control duck ingested viruses covering
feathers and became infected. Virus isolation from feathers was up to 32 days post-coating treatment.
One out of 8 wild mallards showing antibodies against type A influenza virus was seropositive for H10
subtype too.
Conclusions: our experimental and field results show evidences suggesting that uninfected birds
carrying viruses on their feathers, including immune ones, might play an active role in spreading AIV
infection in nature. For this reason, routine AIV surveillance programs, aimed at detecting intestinal
and/or respiratory viruses, should include the collection of samples, such as feather swabs, enabling
the detection of viruses sticky to preened birds\u2019 bodies
Molecular analysis of avian H7 influenza viruses circulating in Eurasia in 1999-2005: detection of multiple reassortant virus genotypes.
Avian influenza infections by high and low pathogenicity H7 influenza viruses have caused several outbreaks in European poultry in recent years, also resulting in human infections. Although in some cases the source of H7 strains from domestic poultry was shown to be the viruses circulating in the wild bird reservoir, a thorough characterization of the entire genome of H7 viruses from both wild and domestic Eurasian birds, and their evolutionary relationships, has not been conducted. In our study, we have analysed low pathogenicity H7 influenza strains isolated from wild and domestic ducks in Italy and southern China and compared them with those from reared terrestrial poultry such as chicken and turkey. Phylogenetic analysis demonstrated that the H7 haemagglutinin genes were all closely related to each other, whereas the remaining genes could be divided into two or more phylogenetic groups. Almost each year different H7 reassortant viruses were identified and in at least two different years more than one H7 genotype co-circulated. A recent precursor in wild waterfowl was identified for most of the gene segments of terrestrial poultry viruses. Our data suggest that reassortment allows avian influenza viruses, in their natural reservoir, to increase their genetic diversity. In turn this might help avian influenza viruses colonize a wider range of hosts, including domestic poultry
Serologic evidence of occupational exposure to avian influenza viruses at the wildfowl/poultry/human interface
Ecological interactions between wild aquatic birds and outdoor-housed poultry can enhance spillover events of avian influenza viruses (AIVs) from wild reservoirs to domestic birds, thus increasing the related zoonotic risk to occupationally exposed workers. To assess serological evidence of AIV infection in workers operating in Northern Italy at the wildfowl/poultry interface or directly exposed to wildfowl, serum samples were collected between April 2005 and November 2006 from 57 bird-exposed workers (BEWs) and from 7 unexposed controls (Cs), planning three sample collec-tions from each individual. Concurrently, AIV surveillance of 3587 reared birds identified 4 AIVs belonging to H10N7, H4N6 and H2N2 subtypes while serological analysis by hemagglutination inhibition (HI) assay showed recent infections caused by H1, H2, H4, H6, H10, H11, H12, and H13 subtypes. Human sera were analyzed for specific antibodies against AIVs belonging to antigenic subtypes from H1 to H14 by using HI and virus microneutralization (MN) assays as a screening and a confirmatory test, respectively. Overall, antibodies specific to AIV-H3, AIV-H6, AIV-H8, and AIV-H9 were found in three poultry workers (PWs) and seropositivity to AIV-11, AIV-H13—still detectable in October 2017—in one wildlife professional (WP). Furthermore, seropositivity to AIV-H2, accounting for previous exposure to the “extinct” H2N2 human influenza viruses, was found in both BEWs and Cs groups. These data further emphasize the occupational risk posed by zoonotic AIV strains and show the possible occurrence of long-lived antibody-based immunity following AIV infections in humans
Development of machine learning models for fractional flow reserve prediction in angiographically intermediate coronary lesions
Background: Fractional flow reserve (FFR) represents the gold standard in guiding the decision to proceed or not with coronary revascularization of angiographically intermediate coronary lesion (AICL). Optical coherence tomography (OCT) allows to carefully characterize coronary plaque morphology and lumen dimensions. Objectives: We sought to develop machine learning (ML) models based on clinical, angiographic and OCT variables for predicting FFR. Methods: Data from a multicenter, international, pooled analysis of individual patient's level data from published studies assessing FFR and OCT on the same target AICL were collected through a dedicated database to train (n = 351) and validate (n = 151) six two‐class supervised ML models employing 25 clinical, angiographic and OCT variables. Results: A total of 502 coronary lesions in 489 patients were included. The AUC of the six ML models ranged from 0.71 to 0.78, whereas the measured F1 score was from 0.70 to 0.75. The ML algorithms showed moderate sensitivity (range: 0.68–0.77) and specificity (range: 0.59–0.69) in detecting patients with a positive or negative FFR. In the sensitivity analysis, using 0.75 as FFR cut‐off, we found a higher AUC (0.78–0.86) and a similar F1 score (range: 0.63–0.76). Specifically, the six ML models showed a higher specificity (0.71–0.84), with a similar sensitivity (0.58–0.80) with respect to 0.80 cut‐off. Conclusions: ML algorithms derived from clinical, angiographic, and OCT parameters can identify patients with a positive or negative FFR
A sensitive one-step real-time PCR for detection of avian influenza viruses using a MGB probe and an internal positive control
BACKGROUND: Avian influenza viruses (AIVs) are endemic in wild birds and their introduction and conversion to highly pathogenic avian influenza virus in domestic poultry is a cause of serious economic losses as well as a risk for potential transmission to humans. The ability to rapidly recognise AIVs in biological specimens is critical for limiting further spread of the disease in poultry. The advent of molecular methods such as real time polymerase chain reaction has allowed improvement of detection methods currently used in laboratories, although not all of these methods include an Internal Positive Control (IPC) to monitor for false negative results. Therefore we developed a one-step reverse transcription real time PCR (RRT-PCR) with a Minor Groove Binder (MGB) probe for the detection of different subtypes of AIVs. This technique also includes an IPC. METHODS: RRT-PCR was developed using an improved TaqMan technology with a MGB probe to detect AI from reference viruses. Primers and probe were designed based on the matrix gene sequences from most animal and human A influenza virus subtypes. The specificity of RRT-PCR was assessed by detecting influenza A virus isolates belonging to subtypes from H1–H13 isolated in avian, human, swine and equine hosts. The analytical sensitivity of the RRT-PCR assay was determined using serial dilutions of in vitro transcribed matrix gene RNA. The use of a rodent RNA as an IPC in order not to reduce the efficiency of the assay was adopted. RESULTS: The RRT-PCR assay is capable to detect all tested influenza A viruses. The detection limit of the assay was shown to be between 5 and 50 RNA copies per reaction and the standard curve demonstrated a linear range from 5 to 5 × 10(8 )copies as well as excellent reproducibility. The analytical sensitivity of the assay is 10–100 times higher than conventional RT-PCR. CONCLUSION: The high sensitivity, rapidity, reproducibility and specificity of the AIV RRT-PCR with the use of IPC to monitor for false negative results can make this method suitable for diagnosis and for the evaluation of viral load in field specimens
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