Vibration of Hollow Core Concrete Elements Induced by Walking

Historically, traditional concrete floors have performed well with regard to vibration serviceability. This is much due to their heavy weight. However, the use of stronger concrete materials and prestressing has resulted in slender cross sections and the possibility to build long-span floor elements. The combination of long span and relatively light weight means that the floor element is more sensitive to vibrations. This thesis investigates vibration in hollow core concrete elements induced by human walking. One of the objectives of the thesis was to establish a maximum span with respect to vibration serviceability for the smallest HD elements in the series, HD/F 120/20. Another objective was to investigate how the dynamics of a floor structure is affected when different types of connections are used, when different spans are used, or when a concrete topping is cast. An experimental floor structure made of three hollow core elements was built in a laboratory. The floor was simply supported and the span of the floor was 8 m, which is within the recommended limits. Subjective tests were performed before and after a concrete topping was cast. The results from the subjective tests showed that a large majority of the test persons found the experimental floor structure unacceptable with regard to vibrations induced by another person walking. The results from the subjective tests indicated that a concrete topping improved the vibration performance slightly, but the vibrations were still classified as clearly perceptible or strongly perceptible. Accelerometers were used to measure the accelerations of the slab induced by a number of different persons walking, one at a time. For offices many researchers propose a single person walking to be the governing load case when checking the vibration serviceability of a floor structure. This is also the load case that was used in this study. A limitation of this master thesis is however that only one walking line was examined. From the measurements the dynamic properties of the test floor, such as damping and natural frequencies, could be determined. The improvement of the vibration performance of the experimental floor structure after a concrete topping was cast could also be seen in the measurements; in this case in the form of slightly reduced average values of overall weighted acceleration. The measured acceleration magnitudes were also evaluated according to the former ISO standard ISO 2631-2:1989 and a method proposed by Talja & Toratti. Both methods indicated the same as the subjective tests: the experimental floor structure is unacceptable with regard to vibrations. When the vibration signals were filtered and plotted in 1/3 octave bands it could be seen that the highest acceleration magnitudes were found in the frequency interval of maximum human sensitivity. A finite element model of the experimental floor structure was built in Abaqus. In order to decrease computational time and cost of each analysis the three-dimensional structure was replaced by a shell with the same stiffness properties and density as the hollow core elements. The results from the measurements were used to validate the FE-model of the floor, and then a number of simulations of different boundary conditions and different spans were performed. During the simulations it was found that the frequency content of the applied load function affected the resulting accelerations significantly. This sensitivity made it difficult to draw any clear conclusions about the maximum possible span, based on only the three different load functions that were used. However, it was concluded that supports with some rotational resistance, or a shorter span will improve the vibration performance. The calculations also showed that there is a probability of adverse comment in the case of simply supported slabs with spans of 6 or 7 m. In order to investigate if the problem with annoying vibrations in HD elements is widespread, a handful of interviews were performed with structural designers. Only one of the interviewed persons had come into contact with a case where people were complaining about annoying vibrations induced by human walking. However, one must keep in mind that only structural engineers were interviewed, and the picture might have been another if occupants of different office buildings had been interviewed

Decolonising the Rainbow Flag

The aim of the article is to explore the location and the meaning given to the rainbow flag in places outside the hegemonic center. Through three case studies in the global North and South, held together by a multi-ethnographic approach, as well as a certain theoretical tension between the rainbow flag as a boundary object and/or a floating signifier, we seek to study where the flag belongs, to whom it belongs, with particular focus on how. The three case studies, which are situated in a city in the Global South (Buenos Aires), in a conflict war zone in the Middle East (the West Bank) and in a racialised neighbourhood in the Global North (Sweden), share despite their diversity a peripheral location to hegemonic forms of knowledge production regimes. Central to our analysis is how the rainbow flag is given a multitude of original and radical different meanings that may challenge the colonial/Eurocentric notions which up to a certain extent are embedded in the rainbow flag

Häivähdys mustaa - yhdistelmävärjäyksen ja puretteiden vaikutus mustan luonnonvärin tuottamisessa

Tutkimuksen tavoitteena oli löytää menetelmä, jolla saisi luonnonvärisekoituksia ja puretteita käyttäen, mahdollisimman musta väri puuvillaan. Tutkimuksen hypoteesina oli, että sekoittamalla kolmea pääväriä, sinistä, keltaista ja punaista, saataisiin mustaa tekstiiliväriä. Tutkimuksessa toteutettiin kolme koesarjaa kattilavärjäysmenetelmällä. Koesarjojen välillä muuttujina käytettiin niin puretteita kuin väriliemien suhteita. Väriaineiksi valittiin granaattiomena, joka tuottaa keltaista väriä, kokenilli josta saadaan punaista väriä ja värimorsinko, joka antaa sinisen värin tekstiileille. Tutkimuksessa haluttiin hyödyntää sellaisia luonnonvärejä, joita jo nyt tuotetaan teollisesti, tai jotka tulevaisuudessa ovat mahdollisia käyttää teolliseen värjäykseen. Puretteina käytettiin yleisesti luonnonvärjäyksessä käytettyjä puretteita, kuten alunaa, rautavihtrilliä ja kalsinoitua soodaa. Koesarjat tuottivat eri värejä vihreästä, ruskeaan ja harmaaseen. Mustaa väriä ei saavutettu yhdessäkään koesarjassa, vaikka joissakin koesarjoissa näkyi viitteitä, että mustaa väriä olisi mahdollista tehdä tutkimukseen valituilla ainesosilla. Puretteista parhaiten toimi rautavihtrilli, joka oli olennainen osa harmaiden sävyjen värjäyksessä. Muut puretteet eivät auttaneet tuottamaan harmaita tai mustia sävyjä. Yleisesti voidaan todeta, että luonnonväreillä värjätessä muuttujien määrä on iso ja tutkimuksen optimoiminen on haastavaa ilman tarkempaa tuntemusta kemiasta. Toisaalta osa luonnonvärjäyksen viehätystä on se, että kattilasta paljastuva kangastilkku on aina yllätys

Non-pharmaceutical prevention of hip fractures – a cost-effectiveness analysis of a community-based elderly safety promotion program in Sweden

<p>Abstract</p> <p>Background</p> <p>Elderly injuries are a recognized public health concern and are due to two factors; osteoporosis and accidental falls. Several osteoporosis pharmaceuticals are considered cost-effective, but intervention programs aiming at preventing falls should also be subjected to economic evaluations. This study presents a cost-effectiveness analysis of a community-based elderly safety promotion program.</p> <p>Methods</p> <p>A five-year elderly safety promotion program combining environmental structural changes with individually based measures was implemented in a community in the metropolitan area of Stockholm, Sweden. The community had around 5,500 inhabitants aged 65+ years and a first hip fracture incidence of 10.7 per 1,000 in pre-intervention years 1990–1995. The intervention outcome was measured as avoided hip fractures, obtained from a register-based quasi-experimental longitudinal analysis with several control areas. The long-term consequences in societal costs and health effects due to the avoided hip fractures, conservatively assumed to be avoided for one year, were estimated with a Markov model based on Swedish data. The analysis holds the societal perspective and conforms to recommendations for pharmaceutical cost-effectiveness analyses.</p> <p>Results</p> <p>Total societal intervention costs amounted to 6.45 million SEK (in Swedish krona 2004; 1 Euro = 9.13 SEK). The number of avoided hip fractures during the six-year post-intervention period was estimated to 14 (0.44 per 1,000 person-years). The Markov model estimated a difference in societal costs between an individual that experiences a first year hip fracture and an individual that avoids a first year hip fracture ranging from 280,000 to 550,000 SEK, and between 1.1 and 3.2 QALYs (quality-adjusted life-years, discounted 3%), for males and females aged 65–79 years and 80+ years. The cost-effectiveness analysis resulted in zero net costs and a gain of 35 QALYs, and the do-nothing alternative was thus dominated.</p> <p>Conclusion</p> <p>The community-based elderly safety promotion program aiming at preventing accidental falls seems as cost-effective as osteoporosis pharmaceuticals.</p

Comparison of a high and a low intensity smoking cessation intervention in a dentistry setting in Sweden – a randomized trial

<p>Abstract</p> <p>Background</p> <p>Tobacco is still the number one life style risk factor for ill health and premature death and also one of the major contributors to oral problems and diseases. Dentistry may be a potential setting for several aspects of clinical public health interventions and there is a growing interest in several countries to develop tobacco cessation support in dentistry setting. The aim of the present study was to assess the relative effectiveness of a high intensity intervention compared with a low intensity intervention for smoking cessation support in a dental clinic setting.</p> <p>Methods</p> <p>300 smokers attending dental or general health care were randomly assigned to two arms and referred to the local dental clinic for smoking cessation support. One arm received support with low intensity treatment (LIT), whereas the other group was assigned to high intensity treatment (HIT) support. The main outcome measures included self-reported point prevalence and continuous abstinence (≥ 183 days) at the 12-month follow-up.</p> <p>Results</p> <p>Follow-up questionnaires were returned from 86% of the participants. People in the HIT-arm were twice as likely to report continuous abstinence compared with the LIT-arm (18% vs. 9%, p = 0.02). There was a difference (not significant) between the arms in point prevalence abstinence in favour of the HIT-protocol (23% vs. 16%). However, point prevalence cessation rates in the LIT-arm reporting additional support were relatively high (23%) compared with available data assessing abstinence in smokers trying to quit without professional support.</p> <p>Conclusion</p> <p>Screening for willingness to quit smoking within the health care system and offering smoking cessation support within dentistry may be an effective model for smoking cessation support in Sweden. The LIT approach is less expensive and time consuming and may be appropriate as a first treatment option, but should be integrated with other forms of available support in the community. The more extensive and expensive HIT-protocol should be offered to those who are unable to quit with the LIT approach in combination with other support.</p> <p>Trial Registration</p> <p>Trial registration number: NCT00670514</p

Complete genome sequence of Leuconostoc gelidum subsp. gasicomitatum KG16-1, isolated from vacuum-packaged vegetable sausages

Leuconostoc gelidum subsp. gasicomitatum is a predominant lactic acid bacterium (LAB) in spoilage microbial communities of different kinds of modified-atmosphere packaged (MAP) food products. So far, only one genome sequence of a poultry-originating type strain of this bacterium (LMG 18811T) has been available. In the current study, we present the completely sequenced and functionally annotated genome of strain KG16-1 isolated from a vegetable-based product. In addition, six other vegetable-associated strains were sequenced to study possible “niche” specificity suggested by recent multilocus sequence typing. The genome of strain KG16-1 consisted of one circular chromosome and three plasmids, which together contained 2,035 CDSs. The chromosome carried at least three prophage regions and one of the plasmids encoded a galactan degradation cluster, which might provide a survival advantage in plant-related environments. The genome comparison with LMG 18811T and six other vegetable strains suggests no major differences between the meat- and vegetable-associated strains that would explain their “niche” specificity. Finally, the comparison with the genomes of other leuconostocs highlights the distribution of functionally interesting genes across the L. gelidum strains and the genus Leuconostoc.Peer reviewe

Complete genome sequence of Leuconostoc gelidum subsp. gasicomitatum KG16-1, isolated from vacuum-packaged vegetable sausages

Leuconostoc gelidum subsp. gasicomitatum is a predominant lactic acid bacterium (LAB) in spoilage microbial communities of different kinds of modified-atmosphere packaged (MAP) food products. So far, only one genome sequence of a poultry-originating type strain of this bacterium (LMG 18811T) has been available. In the current study, we present the completely sequenced and functionally annotated genome of strain KG16-1 isolated from a vegetable-based product. In addition, six other vegetable-associated strains were sequenced to study possible “niche” specificity suggested by recent multilocus sequence typing. The genome of strain KG16-1 consisted of one circular chromosome and three plasmids, which together contained 2,035 CDSs. The chromosome carried at least three prophage regions and one of the plasmids encoded a galactan degradation cluster, which might provide a survival advantage in plant-related environments. The genome comparison with LMG 18811T and six other vegetable strains suggests no major differences between the meat- and vegetable-associated strains that would explain their “niche” specificity. Finally, the comparison with the genomes of other leuconostocs highlights the distribution of functionally interesting genes across the L. gelidum strains and the genus Leuconostoc.Peer reviewe

Dispensations of benzodiazepines, zhypnotics, and gabapentinoids to patients receiving opioid agonist therapy; a prospective cohort study in Norway from 2013 to 2017

Background Dispensations of benzodiazepines, z-hypnotics, and gabapentinoids to patients on opioid agonist therapy (OAT) are common and have pros and cons. The objectives of the current study are to define the dispensation rates of these potentially addictive drugs, and whether the number and the mean daily doses of dispensed OAT opioids and discontinuing OAT, are associated with being dispensed benzodiazepines, z-hypnotics and gabapentinoids among patients on OAT in Norway in the period 2013 to 2017. Methods Information about all dispensed opioids, benzodiazepines, z-hypnotics and gabapentinoids were recorded from the Norwegian Prescription Database (NorPD). A total of 10,371 OAT patients were included in the study period. The dispensation rates were defined as the number of patients who were dispensed at least one of the potentially addictive drugs divided among the number of patients who have dispensed an OAT opioid per calendar year. Mean daily doses were calculated, and for benzodiazepines and z-hypnotics, stated in diazepam equivalents. The association between dispensed potentially addictive drugs, and the number and the type of dispensed OAT opioids were calculated by using logistic regression models. Results Half of the OAT patients received at least one dispensation of a benzodiazepine or z-hypnotic, and 11% were dispensed at least a gabapentinoid in 2017. For dispensed benzodiazepines or z-hypnotics, the mean daily dose was reduced from 21 mg (95% confidence interval (CI): 20–23) diazepam equivalents in 2013 to 17 mg (95% CI: 16–17) in 2017. The mean daily dose of pregabalin increased from 365 mg (95% CI: 309–421) in 2013 to 386 mg (95% CI: 349–423) in 2017. Being dispensed a gabapentinoid (adjusted odds ratio (aOR) = 2.5, 95% CI: 2.1–3.0) or a non-OAT opioid (aOR = 3.0, 95% CI: 2.6–3.5) was associated with being dispensed a benzodiazepine or z-hypnotic. Discontinuing OAT did not affect the number of dispensations and the doses of potentially addictive drugs. Conclusion The dispensation rates of potentially addictive drugs are high in the OAT population. Treatment indications, as well as requirements for prescription authority, need to be debated and made explicit. Randomized controlled trials evaluating the benefits and risks of such co-prescription are required.publishedVersio

学会抄録

Genebank identifiers of the nucleotide sequences of atpA, pheS and rpoA genes, used for the phylogenetic analyses. Table S2. NCBI Refseq/Genbank assembly accession numbers for the comparative genomic analysis of Leuconostoc species (29.09.2015). Table S3. L. gelidum subsp. gasicomitatum draft genomes statistics. Figure S1. Phylogenetic tree showing the relationship of L. citreum 1300_LCIT, L. gelidum subsp. gasicomitatum 1301_LGAS and L. inhae LMG 22919 genomes to other Leuconostoc species. (PDF 406 kb