A NEW RESIDENT OF BELGRADE (SERBIA), THE MEDITERRANEAN SPIDER ZOROPSIS SPINIMANA (DUFOUR, 1820)

A Mediterranean synanthropic spider species, Zoropsis spinimana (Dufour, 1820), was recently found in Belgrade and recorded as a new member of Serbian fauna. Several individuals of both sexes and juveniles were caught or observed. Pregnant females and their cocoons were also observed. According to our findings, this spider has established a small population in the city. Considering that this species has been recognized as a successful colonizer and could be identified by the general public, the first “Citizen Science” approach in Serbia was applied. An invitation to participate was made via social media. The manuscript includes photos contributed from other parts of the country. This confirmed our suspicion that Z. spinimana is to be found in more than one place in Serbia, which requires further investigation. This paper aims to report this species as a new member of the national and synanthropic fauna and to present the benefit of using “Citizen Science” data

Sustainability assessment of recycled aggregate concrete structures: A critical view on the current state-of-knowledge and practice

The environmental impacts of activities such as raw material extraction, construction of infrastructure, and demolition, place construction as one of the sectors that exert the highest pressures on the environment, society, and economy. Some of the major environmental impacts for which the construction industry is responsible are mineral resource depletion, greenhouse gas emissions, and waste generation. Among the different strategies that exist to decrease such impacts, recycling demolition waste into recycled concrete aggregates has been considered a promising alternative. As such, at present, the literature dealing with the impact assessment of recycled aggregate concrete structures is very extensive. Therefore, the objective of this article is to present a critical view of the state-of-the-art in terms of sustainability assessment of recycled aggregate concrete structures, taking a holistic perspective by considering environmental, social, and economic impacts

Discussion of the article 'Prediction of creep of recycled aggregate concrete using back-propagation neural network and support vector machine'

In a recent study, Rong et al.1 investigate the prediction of recycled aggregate concrete (RAC) creep using back-propagation neural network and support vector machine. For this purpose, the authors compiled a database of experimental results on the creep of RAC on which they first tested five analytical RAC creep prediction models2-6 and concluded that the performance of all five models is inadequate, thereby justifying the use of a back-propagation neural network and a support vector machine. The main argument for declaring the performance of the five analytical models inadequate is the analysis of “performance indices” of the correlation coefficient (R), mean absolute error (MAE), mean square error (MSE), and integral absolute error (IAE). The found ranges of values were 0.45–0.55 for R, 0.41–0.64 for MAE, 0.33–0.70 for MSE, and 0.33–0.53 for IAE. Nonetheless, there are errors and uncertainties regarding the study that are pointed out herein, some methodological and some formal.Postprint (published version

Parametric study of long-term deflections of reinforced recycled aggregate concrete members according to the fib model code 2010

In this study, a parametric analysis of the deflection calculations of reinforced RAC members is presented. Within the parametric analysis, member support conditions, ambient conditions (influencing shrinkage and creep), reinforcement ratios, and quasi-permanent–to–design load ratios are varied. Through the analysis, the change in deflections is observed against RCA percentage (from NAC to RAC with 100% of coarse RCA) and span-to-effective depth ratio. The results of the analysis enable a clear overview of the variability of the deflections of RAC members relative to NAC.This work was supported by the Ministry for Education, Science and Technology, Republic of Serbia [grant number TR36017] and the SAES project [BIA2016-78742-C2-1-R] of the Spanish Ministerio de Economía, Industria y Competitividad. This support is gratefully acknowledged.Postprint (published version

Model Code 2010 creep and shrinkage models extension to recycled aggregate concrete

Recycled aggregate concrete (RAC) produced with recycled concrete aggregate (RCA) is one of the most promising ways of eliminating concrete waste and saving natural resources. However, shrinkage and creep behaviour of RAC, important for serviceability design of reinforced and prestressed concrete structures, are still insufficiently studied and guidelines for RAC serviceability design are still not incorporated into design codes and standards. This study aims to systematize the knowledge gained on RAC shrinkage and creep behaviour thus far and to offer analytic expressions for predicting RAC shrinkage strain and creep coefficient. For this purpose, databases of previously published results on RAC shrinkage and creep were compiled and the results on RAC were analysed relative to companion natural aggregate concrete (NAC). The results showed a systematically higher shrinkage and creep of RAC relative to NAC. Finally, analytic expressions for correction coefficients, dependent on RAC compressive strength and RCA replacement ratio, were formulated for predicting RAC shrinkage strain and creep coefficient using the fib Model Code 2010.This work was supported by the Ministry for Education, Science and Technology, Republic of Serbia under grant number TR 36017 and Spansh Ministerio de Economía, Industra y Competividad under the SAES project BIA2016-78742-C2-1-R. This support is gratefully acknowledgedPostprint (published version

Sustainability assessment of recycled aggregate concrete structures: a critical view on the current state-of-knowledge and practice

The environmental impacts of activities such as raw material extraction, construction of infrastructure, and demolition, place construction as one of the sectors that exert the highest pressures on the environment, society, and economy. Some of the major environmental impacts for which the construction industry is responsible are mineral resource depletion, greenhouse gas emissions, and waste generation. Among the different strategies that exist to decrease such impacts, recycling demolition waste into recycled concrete aggregates has been considered a promising alternative. As such, at present, the literature dealing with the impact assessment of recycled aggregate concrete structures is very extensive. Therefore, the objective of this article is to present a critical view of the state-of-the-art in terms of sustainability assessment of recycled aggregate concrete structures, taking a holistic perspective by considering environmental, social, and economic impacts.Peer ReviewedPostprint (published version

Retrospective evaluation of the incidental finding of 403 papillary thyroid microcarcinomas in 2466 patients undergoing thyroid surgery for presumed benign thyroid disease

This research was aimed to describe the effectiveness of discovery learning model to increase student’s fluency thinking skills on chemical equilibrium subject matter.  The method of the research was quasi-experimental with  Non Equivalent Control Group Design.  The population of this research was all students in XI science class of MA Negeri 1 Metro whose sit in odd semester of academic year 2013-2014.  The sample were taken by purposive sampling technique then obtained XI IPA2 dan XI IPA3 class as sample of the research.  The effectiveness of discovery learning model was showed by the significant difference of n-Gain between control and experiment class.The result of research showed that the average n-Gain score for experiment class was  0,32 and the average n-Gain score for control class was 0,21.  Proving the hypothesis showed that discovery learning model is effective to increase student’s fluency thinking skills on chemical equilibrium subject matter. Tujuan penelitian ini adalah untuk mendiskripsikan efektivitas model discovery learning dalam meningkatkan keterampilan berpikir lancar siswa pada materi kesetimbangan kimia.  Metode dalam penelitian ini adalah kuasi eksperimen.  Populasi dalam peneliian ini adalah semua siswa kelas XI IPA MA Negeri 1 Metro semester ganjil Tahun Pelajaran 2013-2014.  Sampel diambil dengan tehnik purposive sampling sehingga diperoleh kelas XI IPA2 dan XI IPA3 sebagai sampel penelitian.  Efektivitas model discovery learning ditunjukan berdasarkan perbedaan nilai n-Gain yang signifikan antara kelas eksperimen dan kelas kontrol. Hasil penelitian menunjukan rata-rata nilai n-Gain untuk kelas eksperimen adalah 0,32 dan rata-rata nilai n-Gain  untuk kelas kontrol adalah 0,21.  Pengujian hipotesis menunjukan bahwa model discovery learning efektif dalam meningkatkan keterampilan berpikir lancar siswa pada materi kesetimbangan kimia. Kata kunci : kesetimbangan kimia, keterampilan berpikir lancar, model discovery learnin

ECO2 framework assessment of limestone powder concrete slabs and columns

Producing limestone powder requires comparably far less energy than the production of ordinary Portland cement (OPC), making it a promising sustainable solution for partial replacement of OPC in concrete. Lower production energy could be translated into lower environmental impact and lower cost, which are two pillars of the sustainability of the resulting concrete. However, the question remains if replacing OPC with larger percentages of limestone powder would compromise the performance of the resulting concrete to a level that surpasses the environmental and economic gains. In order to assess the collective impact of these concretes, a performance-based multi-criteria decision analysis framework, ECO2, is used. For that purpose, 26 experimentally verified, concrete mixtures with and without limestone powder were evaluated through potential application in two types of reinforced concrete (RC) structural elements (slabs and columns) under identical environmental condition. The main results of the research showed a clear environmental advantage of concrete with a reduced OPC content, but the relatively higher superplasticizer amount in some cases could affect the final sustainability performance of the resulting mix. In the case of RC slabs, the best ECO2 score was obtained for concrete containing limestone powder. Mixtures with 200–250 kg of cement per unit volume of concrete had the highest ECO2 score for all the considered criteria. In the second case, due to the nature of the structural performance requirements in columns, the crucial influence of the concrete compressive strength is clear. The obtained results have shown approximately equal sustainability potential of OPC and limestone concretes in vertical elements such as columns. However, it seems that a certain improvement in the design of concrete mixtures with a high limestone powder content could make these competitive in all fields.This work was supported by the Ministry for Education, Science and Technology, Republic of Serbia [grant number TR36017].Peer ReviewedPostprint (published version

The assessment of health-related quality of life in relation to the body mass index value in the urban population of Belgrade

<p>Abstract</p> <p>Background</p> <p>The association between excess body weight, impairment of health and different co-morbidities is well recognized; however, little is known on how excess body weight may affect the quality of life in the general population. Our study investigates the relationship between perceived health-related quality of life (HRQL) and body mass index (BMI) in the urban population of Belgrade.</p> <p>Methods</p> <p>The research was conducted during 2005 on a sample of 5,000 subjects, with a response of 63.38%. The study sample was randomly selected and included men and women over 18 years of age, who resided at the same address over a period of 10 years. Data were collected by means of a questionnaire and nutritional status was categorized using the WHO classification. HRQL was measured using the SF-36 generic score. Logistic regression analysis was used to compare HRQL between subjects with normal weight and those with different BMI values; we monitored subject characteristics and potential co-morbidity.</p> <p>Results</p> <p>The prevalence of overweight males and females was 46.6% and 22.1%, respectively. The prevalence of obesity was 7.5% in males and 8.5% in females.</p> <p>All aspects of health, except mental, were impaired in males who were obese. The physical and mental wellbeing of overweight males was not significantly affected; all score values were similar to those in subjects with normal weight.</p> <p>By contrast, obese and overweight females had lower HRQL in all aspects of physical functioning, as well as in vitality, social functioning and role-emotional.</p> <p>Conclusion</p> <p>The results of our study show that, in the urban population of Belgrade, increased BMI has a much greater impact on physical rather than on mental health, irrespective of subject gender; the effects were particularly pronounced in obese individuals.</p

Serbia within the European context: An analysis of premature mortality

<p>Abstract</p> <p>Background</p> <p>Based on the global predictions majority of deaths will be collectively caused by cancer, cardiovascular diseases, and traffic accidents over the coming 25 years. In planning future national health policy actions, inter – regional assessments play an important role. The purpose of the study was to analyze similarities and differences in premature mortality between Serbia, EURO A, EURO B, and EURO C regions in 2000.</p> <p>Methods</p> <p>Mortality and premature mortality patterns were analysed according to cause of death, by gender and seven age intervals. The study results are presented in relative (%) and absolute terms (age-specific and age-standardized death rates per 100,000 population, and age-standardized rates of years of life lost – YLL per 1,000). Direct standardization of rates was undertaken using the standard population of Europe. The inter-regional comparison was based on a calculation of differences in YLL structures and with a ratio of age-standardized YLL rates per 1,000. A multivariate generalized linear model was used to explore mortality of Serbia and Europe sub-regions with <it>ln </it>age-specific death rates. The dissimilarity was achieved with a p ≤ 0.05.</p> <p>Results</p> <p>According to the mortality pattern, Serbia was similar to EURO B, but with a lower average YLL per death case. YLL patterns indicated similarities between Serbia and EURO A, while SRR YLL had similarities between Serbia and EURO B. Compared to all Europe sub-regions, Serbia had a major excess of premature mortality in neoplasms and diabetes mellitus. Serbia had lost more years of life than EURO A due to cardiovascular, genitourinary diseases, and intentional injuries. Yet, Serbia was not as burdened with communicable diseases and injuries as were EURO B and EURO C.</p> <p>Conclusion</p> <p>With a premature mortality pattern, Serbia is placed in the middle position of the Europe triangle. The main excess of YLL in Serbia was due to cardiovascular, malignant diseases, and diabetes mellitus. The results may be used for assessment of unacceptable social risks resulting from health inequalities. Within intentions to reduce an unfavourable premature mortality gap, it is necessary to reconsider certain local polices and practices as well as financial and human resources incorporated in the prevention of disease and injury burden.</p