Air-borne infections. II. Detection methods of air-borne bacteria

Opisane su dvije jednostavne metode i aparati: rotor s krutom podlogom, odnosno modifikacija ispiraljke (bubblera) s tekućom podlogom, koji se mogu upotrebljavati i na terenu za kvantitativno ispitivanje zagađenja zraka bakterijama. Iako oba aparata, odnosno modifikacije prema izvršenim mjerenjima zaostaju za savršenijim aparatima, oni se mogu uspješno upotrebljavati na terenu.Two simple instruments and methods for quantitative measurement of air-borne bacteria are described. One is a new type of apparatus named »rotor for solid media« the other is a modification of the bubbler type instrument (Fig. 1-4) Both instruments have considerably lower efficiency than the slit-sampler which was used for comparing their efficiency in collecting air-borne bacteria. However, they can be used with advantage in field work if no electricity or piped water are available

Air-borne infections

Prikazano je značenje i važnost aerogenih infekcija u suvremenom životu, te iznesena dosadašnja postignuća na izučavanju putova infekcije i aerogenog prijenosa patogenih klica; zatim je iznesena metoda utvrđivanja aerogenih bakterija u zraku i načina njihova suzbijanja. Razmotren je problem aerogenih infekcija, njihova ispitivanja i suzbijanja u našim prilikama, pa je istaknuta potreba proučavanja ovog pitanja kod nas, i na kraju je dana opsežna literatura.A review of the present state and progress in the study of air-borne infections and their control with special reference to this problem in Yugoslavia

EKSPLOZIJA U KARTERU BRODSKOGA DIZELSKOG MOTORA

Svrha ovog rada je upozoriti na pojavu u radu brodskoga dizelskog motora koja, zbog nestručnog rukovanja, te nekada doista nesretnim razvojem okolnosti, često rezultira havarijom porivnog stroja, a u težim slučajevima i ozljedama i smrtnim stradanjima članova posade. Iz tog se razloga želi skrenuti više pozornosti na problematiku pojave ekspolozije u karteru brodskoga dizelskog motora. Pozornost se posvetila problemu nastanka eksplozije u karteru i načinu da se ona uspješno izbjegne kako bi se očuvao sam motor. Iz sigurnosnih razloga posebnu pozornost treba obratiti i sigurnosnoj opremi na karteru brodskog motora, a sve poradi smanjenja rizika stradavanja članova posade u strojarnici. Uz to, obrađen je i sustav za monitoring i detekciju uljnih para u karteru motora

Lost in Transition – The Island of Susak (1951–2001)

The isolated population of the Island of Susak was thoroughly studied by a multidisciplinary team of the Croatian Academy of Sciences and Arts in early 1950’s. Recently, a team of scientists revisited the island. This paper describes the main characteristics of the transition process during which a massive exodus occurred with 90% of the island’s population migrating to New Jersey, USA. We summarise the differences in lifestyle, economy, social structure and sense of identity between the historic (1950’s) and contemporary (2001) Susak population. We applied contemporary methods (analysis of microsatellite DNA polymorphisms) to investigate local myths about extreme levels of inbreeding and genetic homogeneity among the Susak islanders. Analysis of short-tandemrepeat (STR) loci showed that Susak displayed characteristics of a small homogeneous breeding isolate. The average heterozygosity was found to be low compared to outbred populations. The signature of a recent severe bottleneck could be detected. Analysis of 8 markers located on Xq13–21 in 71 individuals suggested extensive level of linkage disequilibrium (LD). A migrant study was designed to investigate the effects of large environmental changes (Susak vs. USA) and inbreeding (Susak vs. Croatian general population) on some biologically important quantitative traits, such as blood pressure and serum lipids. The results confirmed the positive correlation between inbreeding level and blood pressure that has been reported in the literature on several occasions. The last remnants of this traditional island community will soon be lost forever

Q - fever epidemic at Ogulin in 1952 and its occupational featur

Opisana je epidemija Q groznice, koja je izbila u mjesecu aprilu 1952. u Ogulinu. U toku epidemije bilo je 26 klinički manifestnih i sereloški dokazanih oboljenja. Opisana je klinička slika, serološke i epidemiološke osobine, koje osim tipičnih u literaturi navedenih karakteristika imaju neke svoje specifične značajke. Napose je istaknut i prikazan profesionalni karakter ove bolesti kod mesara i laboratorijskih radnika.Q-fever in Yugoslavia was first diagnosed and identified by Mihaljević in Zagreb (1) in 1948. Many sporadic clinical cases have been diagnosed since at Doboj (33), Gračanica (33). Banja Luka (33), Skoplje (34), Novi Pazar (35). Zagreb (2, 36), Beograd (37), Sarajevo (38), Travnik (39) and possibly Split (33). ln addition to sporadic cases five epidemics broke out so far with 5-35 cases each: at Pančevo (3) in 1949, at Kopar (40), Sokol (6, 41) and Gračanica (33) in 1950 and al Ogulin in 1952. It should be pointed out that serological analyses of iuhabitants of all republics, except Slovenia, imply a much wider contact with C. burneti (33) than shown by identified cases and epidemics. An outbreak of Q-fever in the town of Ogulin, which occurred in April 1952, is reported. That is the first epidemic of this disease known in Croatia. The authors describe shortly the progress of the knowledge about Q-fever and especially about the prevalence of the disease both in the world and Yugoslavia. The occupational character of the Q-fever epidemic at Ogulin is put forward. The first case was a butcher working at the town slaughterhouse. Later on also another butcher developed the disease. Other slaughterhouse workers showed positive C. F. tilers - 1 : 10 to 1 : 80. This is a proof of the high exposition of this profession to the infective agent. Moreover, a woman from the laboratory staff working on C. F. tests anti inoculating guinea-pigs for isolation of C. burneti from milk collected at Ogulin developed the disease as well. This implies that Q-·fever should be added to the list of occupational diseases, and that proper steps should he undertaken lo protect the workers exposed to this infection. Clinical features 26 serologically proved cases are listed in Table 1 and clinically analysed. According to clinical and epidemiological data there were some other cases as well but for various reasons the disease could not be proved serologically. In all 26 cases symptoms characteristic of U-fever, i. e. headache, especially in the frontal region, malaise, chilliness, high fever. pains in various parts of the body, sweating etc. were present. There were no definite symptoms of upper respiratory tract infection. In eight cases pneumonia was found by X-ray diascopy and only in some of them also by clinical examination. Pulmonary involvement was unilateral in six cases, and bilateral in two. All of them had all characteristics of primary atypical pneumonia. Because the patients with pneumonia had been in more intimate contact with animals it has been suggested that pneumonia might have resulted from more massive infection (dust). As to the gastrointestinal tract there was nothing significant, except diarrhoea in two cases and vomiting in one. Diarrhoea is rare in Q-fever and perhaps it occurs only in infection by ingestion. The spleen was enlarged in two cases only. B. S. R. was moderately increased both in cases with and those without pneumonia. The febrile period was between 4-14 days. The mean being 8 days both in cases without pneumonia and in those where the lungs were involved. There were no complications or fatal cases. Some patients late in convalescence complained of weakness, headache and sweating. Penicillin or sulfonamides treatment did not influence the course of the illness. Aureomycin and chloramphenicol were applied late so that it was not possible to assess their effectiveness. Serological findings were not especially discussed here and they were presented only lo prove the clinical diagnosis on men (see table 1). C. F. tests were carried out also on animals and men lo help epidemiological investigations. Eiridemiology An epidemic or Q-fever in the town or Ogulin with about 2000 inhabitants, broke out in the beginning of April. 1952. The Q-fever outbreak started on the peak of a respiratory disease clinically diagnosed as influenza and pneumonia, but no laboratory tests were made (sec Fig. 3.). There were 26 serologically proved cases mostly young males who had had a contact with domestic animals. Clinical and epidemiological observations gave evidence of more cases of Q-fever in this epidemic. The sudden outbreak of the epidemic and its short duration suggested a short exposition to the infection (see Graph 4). Later on it was realised that some sporadic cases of Q-fever occurred in May, July and November, and many healthy people (about 20%) showed a residual C. F. titer. This was proof of a permanent and widely spread infection in the area. In order to find out the source of infection we started testing cows with C. F. particularly those having some epidemiological connection with Q-fever cases. However, not one of them was found positive. The isolation of C. burneti by inoculation of guinea-pigs with milk taken from the town dairy center (collecting milk from this * The antigens were placed at the disposal of the Microbiological Department of the Medical Faculty-which carried out all serological est - by the World Health Organization. Division for Zoonoses (M. Kaplan, V. M. D.). area) yielded no positive results either. Then we proceeded to investigate sheep and found that those from the herds slaughtered at the town abattoir just prior to the epidemic had been positive. The butcher buying these sheep in the village and laughtering them in the town was first to develop the disease. However the way the infection spread was not clear at all. So we were forced to follow up all possible factors which might have played a role in spreading the infection. Water was the only common factor in all cases, but it was pure and clorinated. Milk was not considered as a cause of infection because only 50% of patients were drinking milk and all the cows were negative. No useful epidemiological data of major significance could be obtained from the examination of the patients\u27 living and working quarters. No history of a tick bite was heard from any patient: and no man to man transmission was observed. Four of the infected people were visiting the abattoir and handled in one way or another the meet of the sheep killed. A few were buying and eating the meet of those animals but many more had no contact with the animals or their products. The abattoir, its stable and refuse dump was close to each other and all were in the vicinity of the town square (used also as a market) of the hotel and of the Community Home (sec Fig. 5). All those that developed the disease used to pass often near by either for the purpose of marketing or going to the hotel or to meetings at the Community Home. As shown in Graph 4 about ten days before the first case developed the disease, and before the sheep from the infected herd were slaughtered, the temperature was well above zero Co. There was a north wind of considerable strength but there was no rainfall. Such conditions were bound lo promotre the formation of dust which the wind could easily carry to the objects concerned. The dust so created at the slaughterhouse. its stable and refuse dump may have contained at that time a considerable amount of the infective agent. It is obvious that passers-by could thus easily be infected. Six of our cases were attending the meeting in the Community Home and all developed the disease 20 to 22 days later. Only one was present at the meeting on the town square and he became ill after 20 days. Taking into consideration that the infective agent was widely spread al that period of the year when sheep have their young and are slaughtered, the infection could spread at the same time from many foci by different ways. Some clinical observation on the prevalence or pulmonary and intestinal involvement support it. It is very likely that the reservoir of Q-fever in the area of Ogulin are the tick invading the sheep particularly in spring. Of those ticks there are two (Hyaloma dromedarii and Rhipicephalus sanguincus) which have been proved to be the reservoir of Q-fever in nature. lt is worth noting that the epidemic broke out on the peak of the Lick invasion (see Fig. 6). The outbreak of Q-fever in men appeared at a time when sheep were highly invaded by licks transmitting the disease. Moreover, the sheep themselves were at that lime most infective precisely because they were breeding. This happened in the earl)\u27 spring when the disease, originally an epizootic was so prevalent among animals that it was easily transmitted to humans. The sporadic cases in men during the year prove permanent presence of the infection among animals. Those are the factors causing the endemo-epidemic pattern of Q-fever in the area of Ogulin, diagnosed recently hut obviously present for years

Lost in Transition – The Island of Susak (1951–2001)

The isolated population of the Island of Susak was thoroughly studied by a multidisciplinary team of the Croatian Academy of Sciences and Arts in early 1950’s. Recently, a team of scientists revisited the island. This paper describes the main characteristics of the transition process during which a massive exodus occurred with 90% of the island’s population migrating to New Jersey, USA. We summarise the differences in lifestyle, economy, social structure and sense of identity between the historic (1950’s) and contemporary (2001) Susak population. We applied contemporary methods (analysis of microsatellite DNA polymorphisms) to investigate local myths about extreme levels of inbreeding and genetic homogeneity among the Susak islanders. Analysis of short-tandemrepeat (STR) loci showed that Susak displayed characteristics of a small homogeneous breeding isolate. The average heterozygosity was found to be low compared to outbred populations. The signature of a recent severe bottleneck could be detected. Analysis of 8 markers located on Xq13–21 in 71 individuals suggested extensive level of linkage disequilibrium (LD). A migrant study was designed to investigate the effects of large environmental changes (Susak vs. USA) and inbreeding (Susak vs. Croatian general population) on some biologically important quantitative traits, such as blood pressure and serum lipids. The results confirmed the positive correlation between inbreeding level and blood pressure that has been reported in the literature on several occasions. The last remnants of this traditional island community will soon be lost forever

Disruptive Business Models: Sustainability of Tools

Od posljednjeg desetljeća tehnologija je dobila veliki utjecaj na razvoj poslovanja poduzeća. Među značajnim promjenama u ljudskom društvu je način na koji se provode komunikacijski i poslovni modeli. Cilj diplomskog rada je analizirati globalne trendova kao što su disruptivni poslovni modeli s naglaskom na turizam. Rezultati rada bi trebali pokazati veliku važnost digitalne transformacije kada je riječ o načinu poslovanja i to u cilju smanjenja operativnih troškova kako bi se postigla poslovna izvrsnost, povećanje prihoda i zadovoljstvo turista kao posljedica stvaranja novih temeljnih poslovnih vrijednosti na inovativnosti i prepoznatljivosti. Kroz pet poglavlja analizirat će se disruptivni poslovni modeli na primjerima Airbnb.com i Booking.com u turizmu. Pokazat će se važnost digitalne poslovne strategije u razvoju poslovanja, kao i potrebu promjene tradicionalnih poslovnih modela u nove disruptivne modele kako bi se stvorila održivost alata, konkurentnost i nova vrijednost temeljena na inovacijama.Since the last decade, technology has had a great influence on the development of business operations. Among the significant changes in human society is the way communication and business models are implemented. The aim of the thesis is to analyze global trends such as disruptive business models with an emphasis on tourism. The results of the work should show the great importance of digital transformation when it comes to the way of doing business, with the aim of reducing operational costs in order to achieve business excellence, increase income and tourist satisfaction as a result of creating new fundamental business values based on innovation and recognition. Through five chapters, disruptive business models will be analyzed using the examples of Airbnb.com and Booking.com in tourism. The importance of digital business strategy in business development will be shown, as well as the need to change traditional business models into new disruptive models in order to create tool sustainability, competitiveness and new value based on innovation

Theories of Consumer Motivation and Behavior in the Final Consumption Market

U radu je naglasak na analizi teorija motivacije i poticajima kao čimbenicima koji utječu na smjer ponašanja potrošača. Krajnji potrošači su osobe koje troše proizvode i koriste usluge koje nabavljaju. Oni kupuju te koriste proizvode i usluge široke potrošnje za vlastitu upotrebu ili upotrebu svojeg kućanstva. Teorije ponašanja potrošača prikazuju model po kojem se potrošač ponaša kako bi ostvario zadovoljstvo prilikom svih potrošačkih procesa. U radu je provedeno empirijsko istraživanje na uzorku od 150 ispitanika kako bi se ukazalo na dinamiku odabira vođenu pokretačima poput čimbenika koji definiraju potrošače i njihov odabir prilikom donošenja odluke o kupnji. Putem provedenog istraživanja važno je saznati koji to motivi najviše utječu na potrošača i njegov odabir proizvoda. Poslovanje sa krajnjim potrošačima je ponekad vrlo dinamično zbog čestih i naglih promjena u ukusu i preferencijama prema proizvodima i uslugama, to dovodi do konstantnog ispitivanja njihovih potreba i želja od strane poduzeća i poduzetnika. Marketinški stručnjaci ulažu velike napore kako bi potrošačima na tržištu ponudili što veći asortiman proizvoda ili usluga kojim će potrošači na što bolji način zadovoljiti svoje potrebe. Prije same kupovine potrošač mora proći kroz nekoliko faza. Najprije spoznaje probleme, odnosno potrebe koje treba zadovoljiti. Nakon što otkrije probleme, potrošač pronalazi karakteristike proizvoda te izabire najbolju alternativu. Nakon procjene dolazi do kupovine proizvoda. Svaka osoba je različita i troši novac na različite načine. Ponašanje potrošača motivirano je mislima, osjećajima te uvjerenjima. Takve motivacije mogu potaknuti osobu na kupnju određenih proizvoda.The paper emphasizes the analysis of motivation theories and incentives as factors influencing the direction of consumer behavior. End consumers are people who consume products and use the services they procure. They buy and use consumer products and services for their own use or the use of their household. Theories of consumer behavior show a model by which the consumer behaves in order to achieve satisfaction in all consumer processes. The paper conducted an empirical study on a sample of 150 respondents to indicate the dynamics of choice driven by drivers such as factors that define consumers and their choice when making a purchase decision. Through research, it is important to find out which motives most influence the consumer and his choice of product. Doing business with end consumers is sometimes very dynamic due to frequent and sudden changes in taste and preferences towards products and services, this leads to a constant examination of their needs and desires by businesses and entrepreneurs. Marketing experts make great efforts to offer consumers in the market as wide a range of products or services that consumers will best meet their needs. Before the purchase itself, the consumer must go through several stages. He first realizes the problems, that is, the needs that need to be met. After discovering the problems, the consumer finds the characteristics of the product and chooses the best alternative. After the assessment, the product is purchased. Every person is different and spends money in different ways. Consumer behavior is motivated by thoughts, feelings and beliefs. Such motivations can encourage a person to buy certain products