bluuebunny/crossref_metadata_2025 huggingface dataset:
The temporal dynamics of resource use by frugivorous birds: a network approach
Authors: Carnicer Jofre , Jordano Pedro , Melián Carlos J.
Published: July 2009

Ecological network patterns are influenced by diverse processes that operate at different temporal rates. Here we analyzed whether the coupled effect of local abundance variation, seasonally phenotypic plastic responses, and species evolutionary adaptations might act in concert to shape network patterns. We studied the temporal variation in three interaction properties of bird species (number of interactions per species, interaction strength, and interaction asymmetry) in a temporal sequence of 28 plant–frugivore interaction networks spanning two years in a Mediterranean shrubland community. Three main hypotheses dealing with the temporal variation of network properties were tested, examining the effects of abundance, switching behavior between alternative food resources, and morphological traits in determining consumer interaction patterns. Our results demonstrate that temporal variation in consumer interaction patterns is explained by short‐term variation in resource and bird abundances and seasonal dietary switches between alternative resources (fleshy fruits and insects). Moreover, differences in beak morphology are associated with differences in switching behavior between resources, suggesting an important role of foraging adaptations in determining network patterns. We argue that beak shape adaptations might determine generalist and specialist feeding behaviors and thus the positions of consumer species within the network. Finally, we provide a preliminary framework to interpret phylogenetic signal in plant–animal networks. Indeed, we show that the strength of the phylogenetic signal in networks depends on the relative importance of abundance, behavioral, and morphological variables. We show that these variables strongly differ in their phylogenetic signal. Consequently, we suggest that moderate and significant phylogenetic effects should be commonly observed in networks of species interactions.
Life‐history divergence facilitates regional coexistence of competing Ficedula flycatchers
Authors: Qvarnström Anna , Wiley Chris , Svedin Nina , Vallin Niclas
Published: July 2009

Regional coexistence of ecologically similar species is facilitated when fluctuations in environmental conditions favor different species at different times or places. However, why species with similar ecology should vary in their response to environmental change is unclear. In this study, we explore the role of a life‐history divergence in causing changes in relative fitness across environmental conditions experienced by populations of two closely related Ficedula flycatchers on the Baltic island of Öland, Sweden. We compared patterns of nestling survival between Pied (Ficedula hypoleuca) and Collared (F. albicollis) Flycatchers in relation to two factors known to influence the environment experienced by nestlings: natural variation in their parents' onset of breeding and artificial manipulation of the brood size. Possible differences in the location of the nests (i.e., microhabitat differences) or in habitat use (i.e., feeding patterns) by the adult birds were controlled for by partial cross‐fostering of young between the two species. We found that nestling mortality was relatively higher among Collared Flycatchers and that this difference increased with later breeding. Mass gain, which predicted survival probability, of nestling Collared Flycatchers did not respond to the seasonal decline in environmental conditions when they were raised in nests with reduced brood size (i.e., where sibling competition was experimentally reduced). This latter result suggests that the smaller clutch size of Collared Flycatchers reflects an adaptive adjustment to their offspring's higher sensitivity to environmental change. We discuss the possibility that the divergence in life‐history traits between the two species represents adaptation to different environments experienced during their recent evolutionary history. We conclude that the survival of nestling Collared Flycatchers is more sensitive to harsh environment and that this is likely to limit where and when the more aggressive Collared Flycatchers are able to displace Pied Flycatchers. Our results provide support for models of species coexistence that emphasize the importance of spatial or temporal heterogeneity in relative fitness or life‐history divergence. More precisely, our results demonstrate that variation in life‐history adaptations may result in changes in relative fitness of species across environments despite their use of similar resources.
Species interaction mechanisms maintain grassland plant species diversity
Authors: Isbell Forest I. , Polley H. Wayne , Wilsey Brian J.
Published: July 2009

Development of theory has outpaced experimental tests for most maintenance of diversity mechanisms. Here we demonstrate how data from biodiversity–ecosystem functioning experiments can be used to determine the mechanisms that maintain plant species diversity. We hypothesized that grassland plant diversity is maintained by two classes of mechanisms: (1) equalizing mechanisms, which reduce asymmetric competition by reducing differences in monoculture biomass production among species in mixture, and (2) species interaction mechanisms, which increase overyielding by increasing niche partitioning and facilitation among species in mixture. Specifically, equalizing mechanisms reduce the coefficient of variation in monoculture biomass production among species in mixture. Species interaction mechanisms increase species overyielding in mixture, especially for low‐biomass species. We tested these predictions with a seven‐year data set from an experiment that varied grassland plant species evenness and richness. We used path analysis to model effects of these mechanisms on annual and multiyear changes in diversity. We found that diversity was frequently maintained by species interaction mechanisms and was infrequently maintained by equalizing mechanisms. Species interaction mechanisms maintained diversity by allowing the species that produced the least biomass in monoculture to benefit the most from species interactions in mixture. Equalizing mechanisms infrequently maintained diversity because asymmetric competition infrequently resulted in competitive exclusion. We propose that this mechanistic framework be used to better understand the specific processes that influence diversity.
Species–area curves, neutral models, and long‐distance dispersal
Authors: Rosindell James , Cornell Stephen J.
Published: July 2009

We simulate species–area curves (SACs) using a spatially explicit neutral model. These display three distinct phases with the central phase being well approximated by a “power law” where species richness (S) is related to area (A) by S = cAz. If seeds are normally distributed in space about their parent, the power law phase of the SAC is unrealistically narrow, and implausibly large speciation rates are required to fit empirical data. However, if dispersal follows a more realistic “fat‐tailed” distribution (where long‐distance dispersal events are more likely) the SACs fit the empirical data better, have a power law that holds for a much broader range of areas, and require a dramatically smaller speciation rate than when dispersal is normally distributed. Neutral models with biologically plausible dispersal parameters and speciation rates lead to empirically realistic SACs.
Is the growth of temperate forest trees enhanced along an ambient nitrogen deposition gradient?
Authors: Bedison James E. , McNeil Brenden E.
Published: July 2009

The extent to which atmospheric N deposition is enhancing primary production and CO2 sequestration along the ambient N deposition gradients found within many regional temperate forest ecosystems remains unknown. We used tree diameter measurements from 1984 and 2004, allometric equations, and estimates of wet N deposition from 32 permanent plots located along an ambient N deposition gradient in the Adirondack Park, New York, USA, to determine the effects of N deposition on the basal area and woody biomass increments (BAI and WBI, respectively) of individual stems from all the major tree species. Nitrogen deposition had either a neutral or positive effect on BAI and WBI, with the positive effects especially apparent within the smaller size classes of several species. The nature of these growth responses suggests that other co‐varying factors (e.g., temperature, tropospheric ozone, soil acidification) may be partially counteracting the species‐dependent fertilization effect of N deposition that was suggested by recent foliar N data across this gradient. Nevertheless, in documenting a fertilization effect from chronic, low‐level, ambient rates of N deposition, this study underscores the need for more research on how N deposition is affecting rates of primary production, CO2 sequestration, and even vegetation dynamics in many forests worldwide.
Chemical diversity in Brassica oleracea affects biodiversity of insect herbivores
Authors: Poelman Erik H. , Dam Nicole Mvan , Loon Joop J. Avan , Vet Louise E. M. , Dicke Marcel
Published: July 2009

Intraspecific variation in plants plays a major role in the composition and diversity of the associated insect community. Resistance traits of plants are likely candidates mediating community composition. However, it is debated whether total concentrations of chemical compounds or specific compounds determine herbivore resistance, and how chemical diversity among plant genotypes in turn affects the composition of the associated herbivore community.

To study the role of specific chemical compounds in affecting the herbivore community, we used cultivated Brassica oleracea. The cultivars differ qualitatively in glucosinolate profile, i.e., foliar composition of different glucosinolate compounds, and only a little in total concentration of glucosinolates, the secondary metabolites specific for the Brassicaceae family. In field and laboratory experiments, we tested whether individual compounds explained differences in herbivore community composition, and whether herbivores with a similar degree of host plant specialization responded in a similar way to variation in glucosinolate profiles.

In the field B. oleracea cultivars differed widely in species richness and composition of the herbivore community, as well as in the density of insects they harbored. Plants with high concentrations of the short side chain alkenyl glucosinolate, glucoiberin, harbored low herbivore diversity. Higher biodiversity was found when plants had glucosinolate profiles containing high concentrations of glucosinolates with elongated side chains, which are biosynthetically linked to glucoiberin. Although glucosinolates are known to have differential effects on generalist and specialist herbivores, all herbivore species exhibited similar responses to the intraspecific variation in foliar glucosinolate profiles of the B. oleracea cultivars. This observation is supported by the correspondence between oviposition preferences of the specialist herbivore Pieris rapae and the generalist Mamestra brassicae in the field and the laboratory, using the same cultivars, and may be due to the relatively low concentrations of glucosinolates in cultivars. Our results show that variation in the concentration of short side‐chain glucosinolates affects the composition of the herbivore community associated with brassicaceous plants.
Contrasting patterns of transgenerational plasticity in ecologically distinct congeners
Authors: Sultan Sonia E. , Barton Kasey , Wilczek Amity M.
Published: July 2009

Stressful parental environments can influence offspring size and development either adaptively or maladaptively, yet little is known about species' differences in this complex aspect of phenotypic plasticity. We performed a reciprocal split‐brood experiment to compare transgenerational plasticity in response to drought stress in two closely related annual plant species. We raised inbred replicate parent plants of eight genotypes per species in dry vs. moist soil to generate offspring of each genetic line that differed only in parental environment, then monitored seedling development in both dry and moist conditions. Individuals of the two species expressed contrasting patterns of transgenerational plasticity for traits important to seedling drought tolerance. InPolygonum persicaria, a weedy generalist found in moist, dry, and variably dry sites, drought‐stressed plants produced offspring with longer and more rapidly extending root systems and greater biomass when growing in dry soil. In contrast, inP. hydropiper, a non‐weedy congener restricted to moist habitats, the offspring of drought‐stressed parents had reduced root system development and seedling biomass in dry soil. InP. persicaria, transgenerational and immediate adaptive plasticity combined to produce drought‐adapted seedling phenotypes. These results make clear that characteristic patterns of transgenerational plasticity can contribute to ecological diversity among species.
Pests vs. drought as determinants of plant distribution along a tropical rainfall gradient
Authors: Brenes-Arguedas Tania , Coley Phyllis D. , Kursar Thomas A.
Published: July 2009

Understanding the mechanisms that shape the distribution of organisms can help explain patterns of local and regional biodiversity and predict the susceptibility of communities to environmental change. In the species‐rich tropics, a gradient in rainfall between wet evergreen and dry seasonal forests correlates with turnover of plant species. The strength of the dry season has previously been shown to correlate with species composition. Herbivores and pathogens (pests) have also been hypothesized to be important drivers of plant distribution, although empirical evidence is lacking. In this study we experimentally tested the existence of a gradient in pest pressure across a rainfall gradient in the Isthmus of Panama and measured the influence of pests relative to drought on species turnover. We established two common gardens on the dry and wet sides of the Isthmus using seedlings from 24 plant species with contrasting distributions along the Isthmus. By experimentally manipulating water availability and insect herbivore access, we showed that pests are not as strong a determinant of plant distributions as is seasonal drought. Seasonal drought in the dry site excluded wet‐distribution species by significantly increasing their seedling mortality. Pathogen mortality and insect herbivore damage were both higher in the wet site, supporting the existence of a gradient in pest pressure. However, contrary to predictions, we found little evidence that dry‐distribution species suffered significantly more pest attack than wet‐distribution species. Instead, we hypothesize that dry‐distribution species are limited from colonizing wetter forests by their inherently slower growth rates imposed by drought adaptations. We conclude that mechanisms limiting the recruitment of dry‐distribution species in wet forests are not nearly as strong as those limiting wet‐distribution species from dry forests.
Partial thermoregulatory compensation by a rapidly evolving invasive species along a latitudinal cline
Authors: Huey Raymond B. , Pascual Marta
Published: July 2009

In fewer than two decades after invading the Americas, the European fly Drosophila subobscura evolved latitudinal clines in several traits. Moreover, its chromosomal inversion frequencies at given localities have shifted with climate warming. Temperature may have driven the evolution of both geographic clines and within‐site shifts. Nevertheless, whether body temperature (Tb) of active flies actually varies geographically and temporally is unknown: if these flies are effective behavioral thermoregulators, they might maintain relatively constant Tb when active, independent of season and latitude. To evaluate these possibilities, we monitored activity and estimated Tb of active flies in all seasons and at five sites (37–49° N) in western North America. Latitudinal and seasonal shifts in activity are conspicuous. Flies have longer activity seasons (and are much more active) at higher latitudes. Flies are generally active only at midday in cool seasons, and only early and late in the day (if active at all) in warm seasons. Despite these behavioral shifts active flies have much lower Tb in cooler seasons and at higher latitudes. The observed pattern is consistent with the hypothesis that geographic shifts in Tb may be an evolutionary driver of latitudinal clines in this invading species.
Fluid Flow in a Fractured Reservoir Using a Geomechanically Constrained Fault-Zone-Damage Model for Reservoir Simulation
Authors: Paul Pijush , Zoback Mark , Hennings Peter
Published: July 2009

Secondary fractures and faults associated with reservoir-scale faults affect both permeability and permeability anisotropy and hence play an important role in controlling the production behavior of a faulted reservoir. It is well known from geologic studies that there is a concentration of secondary fractures and faults in damage zones adjacent to large faults. Because there are usually inadequate data to fully incorporate damage-zone fractures and faults into reservoir-simulation models, this study uses the principles of dynamic rupture propagation from earthquake seismology to predict the nature of fractured/damage zones associated with reservoir-scale faults. We include geomechanical constraints in our reservoir model and propose a generalized workflow to incorporate damage zones into reservoir-simulation models more routinely.

The model we propose calculates the extent of the damage zone along the fault plane by estimating the volume of rock brought to failure by the stress perturbation associated with dynamic-rupture propagation. We apply this method to a real reservoir using both field- and well-scale observations. At the rupture front, damage intensity gradually decreases as we move away from the rupture front or fault plane. In the studied reservoir, the secondary-failure planes in the damage zone are high-angle normal faults striking subparallel to the parent fault, which may affect the permeability of the reservoir in both horizontal and vertical directions. We calibrate our modeling with both outcrop and well observations from a number of studies. We show that dynamic-rupture propagation gives a reasonable first-order approximation of damage zones in terms of permeability and permeability anisotropy in order to be incorporated into reservoir simulators.
Undeserved Loss: The Spread of Legitimacy Loss to Innocent Organizations in Response to Reported Corporate Deviance
Authors: Jonsson Stefan , Greve Henrich R. , Fujiwara-Greve Takako
Published: July 2009

This paper theorizes about why discoveries of corporate deviance that damage the legitimacy of the responsible organization may also have consequences for other organizations. We propose that audiences generalize from deviance by one organization to others that are similar. The result is a withdrawal from transactions even from non-culpable organizations as audiences seek to avoid organizations that they associate with a deviant act. We show that two scandals involving Skandia AB, a Swedish insurance firm that had a subsidiary offering mutual funds, affected mutual fund providers owned by other insurance firms in 2000–2004, as well as mutual fund subsidiaries of other firms with similar characteristics. The effect was greatest for firms more similar to Skandia and firms owning real estate, which was the context for one of the scandals. Thus audience members' categorization rules lead to spread of legitimacy loss in response to an isolated act of organizational deviance.
The Rationalization of Charity: The Influences of Professionalism in the Nonprofit Sector
Authors: Hwang Hokyu , Powell Walter W.
Published: July 2009

This paper analyzes how professional values and practices influence the character of nonprofit organizations, with data from a random sample of 501 (c)(3) operating charities in the San Francisco Bay Area collected between 2003 and 2004. Expanded professionalism in the nonprofit world involves not only paid, full-time careers and credentialed expertise but also the integration of professional ideals into the everyday world of charitable work. We develop key indicators of professionalism and measure organizational rationalization as expressed in the use of strategic planning, independent financial audits, quantitative program evaluation, and consultants. As hypothesized, charities operated by paid personnel and full-time management show higher levels of rationalization. While traditional professionals (doctors, lawyers, and the clergy) do not differ significantly from executives with no credentialed background in eschewing business-like practices, managerial professionals champion such efforts actively, as do semi-professionals, albeit more modestly. Management training is also an important spur to rationalization. We assess what is gained and lost and the tension that can arise when nonprofits become professionalized and adopt more methodical, bureaucratic procedures.
The Two Faces of Control: Network Closure and Individual Performance among Knowledge Workers
Authors: Gargiulo Martin , Ertug Gokhan , Galunic Charles
Published: July 2009

This paper argues that the effect of dense social ties, or network closure, on a knowledge worker's performance depends on the predominant role this worker plays with his or her exchange partners in the relationships affected by that closure. Using data on informal exchanges among investment bankers in the equities division of a large financial services firm operating in Europe, Asia-Pacific, Africa, and the Americas in 2001, we find that network closure in relationships in which the banker acts as an acquirer of information increases his or her performance, whereas closure in relationships in which the banker acts as a provider of information decreases it. We also find that these effects are moderated by the bankers' ability to employ alternative means (such as formal authority) to induce the cooperation of exchange partners in their acquirer role, as well as by the extent to which the bankers can benefit from being free from the control of exchange partners in their provider role. Our findings highlight the two sides of the normative control associated with network closure: control benefits people when they need to induce exchange partners to behave according to their preferences, but it hurts them when it forces them to behave according to the preferences of those partners.
Temperature Regulation via PI High-Order Sliding-Mode Controller Design: Application to a Class of Chemical Reactor
Authors: Aguilar-López Ricardo , Martínez-Guerra Rafael , Maya-Yescas Rafael
Published: July 2009

The main issue of this paper is the synthesis of a robust control law for regulation purposes, which is applied to a class of chemical reactor which exhibits highly nonlinear and oscillatory behavior. The considered methodology employs the typical structure of Proportional-Integral controllers, where the corresponding integral term is now proposed as an integral high order sliding-mode compensator, which deals with the intrinsic nonlinearities of the system to be regulated. A theoretical frame is provided to demonstrate that the proposed controller produces semi-global practical stability; performance of the proposed methodology is assessed via comparison with other controllers.
Predictive Modeling of Salmonella Species Inactivation in Ground Pork and Turkey during Cooking
Authors: Takhar Pawan S , Head Kari L , Hendrix Kathleen M. , Smith Denise M
Published: July 2009

The objective of this study was to evaluate the ability of the Weibull distribution to predict the inactivation of Salmonella in three meat products cooked under isothermal and non-isothermal conditions. Ground turkey thigh (5.09% fat, pH 6.45), turkey breast (0.47% fat, pH 6.04) and pork (17.04% fat, pH 6.36) were inoculated with an 8 strain Salmonella cocktail. The meat was cooked isothermally at 50, 54, 58, 62 and 66ºC, and non-isothermally at two heating rates (5 or 10 ºC/min) to 54, 60 and 66 ºC. Surviving Salmonella were enumerated at intervals during the cooking process. Isothermal survival curves were described by the Weibull distribution, log S (t) = -b (T) tn(T), and its simplified form as a linear equation (n=1). Nonlinearity was observed in Salmonella survival curves. The Weibull distribution described pathogen inactivation better than its simplified linear form for all isothermal trials. The b and n parameters from isothermal data were used to predict the non-isothermal survival curves. Piecewise cubic hermite interpolating polynomial was used to estimate b and n in the non-isothermal program. At 54 and 66 ºC, the Weibull model well predicted the non-isothermal Salmonella survival curves for all meats. The model over-predicted the destruction of Salmonella in three meats at 60 ºC for both heating rates. The accurate prediction of Salmonella destruction at 66 ºC was at a higher temperature than the range of validity reported in the literature.
The structural characteristics of world trade and the merchandise exports of Serbia
Authors: Kovacevic Radovan
Published: July 2009

This paper analyses the world merchandise trade structure and the structure of Serbian merchandise exports. The analysis shows that the prominent characteristic of post-World War II world trade is more dynamic growth in the volume of manufactured goods as compared to agricultural goods. Due to the lessening share of agricultural products world merchandise trade has decreased and rapid industrialization has been fostered in developing countries. An increased share for developing countries followed the developed countries' decreasing share in world manufacturing trade. The developing countries' increased share was strongest in telecom and office equipment exports. These sectors are characterized by production fragmentation, which is being realized by transnational companies. Serbia, like the other South East European countries, has not yet managed to significantly integrate into international production networks. Serbia's most important exports are manufactured products with a low level of added value . In addition, Serbia still has a high share of primary products in its exports. A higher share of exports of goods and services in the gross domestic products (GDP) cannot be achieved without increasing imports of new technologies and equipment, i.e. without a higher investment share of the GDP. The main conclusion of this article is that the creation of a favorable investment climate and an increase in Serbia's international credit rating are the preconditions for stronger foreign direct investment (FDI), which would be the main channel for restructuring in the real sector. Creation of new small and medium enterprises (SMEs) through greenfield investment and their integration into the international production networks is the starting point for the restructuring of Serbian industrial production and merchandise export, i.e. the way of increasing the share of merchandise exports in the GDP.
Epidemiological characteristics of road traffic injuries in AP Vojvodina
Authors: Djuric Predrag , Miladinov-Mikov Marica
Published: July 2009

Introduction. Traffic accidents are one of the leading epidemiological problems in developed countries as well as in developing ones. It is estimated that every day in the world 1308 person die in car accidents. Causes of traffic accidents are factors of road, vehicle and human factors, the latter one being the cause of more than 90% car accidents, isolated or linked with other factors. Material and methods .Data from the Ministry of Internal Affairs - Department in Novi Sad were collected for the period 1992 - 2001 and analyzed. All road traffic accidents were divided into those with and without injured persons. All injured were divided in three categories: slightly injured, severely injured and killed. Categorisation was done by the Ministry of Internal Affairs (police). Results. Avarage number of road traffic accidents in AP Vojvodina is 13,191, and 3502 with injured persons per year. Avarage incidence is 174 accidents per 100,000 population, and 301 injured per 100 000 population. Mortality rate is 30.6 per 100 000 population. Number of killed in road traffic accidents per 10,000 vehicles is 6.91. Discussion. During the 1992-2001 period, morbidity and mortality rates of traffic accidents in AP Vojvodina were high. Participating of bicycle drivers, car passengers and pedestrians is higher than in developed countries. Injured persons are mostly 20-29 y.o., but rates of killed persons are the same in all age groups older than 19. Men are more in danger than women. Majority of accidents happen during the early autumn months, on Fridays and Saturdays, in early evening hours. Most persons have been injured or killed in city accidents,along Subotica-Belgrade highway. Conclusion. AP Vojvodina had the highest mortality rate of road traffic injuries per ten thousand vehicles in Europe - 6.91. Effective preventive meausres are needed to decrease rates of road traffic accidents.
The first case of endoscopic submucosal dissection of cecal adenoma in Serbia
Authors: Ivanov Dejan , Toyonaga Takaski
Published: July 2009

Endoscopic submucosal dissection is a therapeutic procedure for the removal of early stage gastrointestinal cancer. In 2006, we performed a colonic ESD in Serbia. ESD had never been performed until then in Serbia, nor do we have a written report, so this article is a document of the first performed procedure of this kind. On the 21st of October 2006, the patient was admitted to the General Hospital MC in Novi Sad for the performance of ESD of the cecal lesion. A flat-elevated type of lesion on the upper lip of ileocecal valve with a size of 8 mm was found on the colonoscopy. The adenoma was removed en bloc and prepared for further histopathological examination. Histopathological examination showed that the tumor was a 'flat adenoma' of the colon mucosa with a low grade dysplasia. The procedure lasted for 30 minutes and went without complications. The first case of ESD in Serbia was performed in 2006, only four years after it was developed in Japan. To have more ESD cases in our country a screening program for detection of early cancers is needed as well as education of endoscopists in performing ESD.
Experimental vaccines for sexually transmitted infections
Authors: Jovanovic Marina , Karadaglic Djordjije , Golusin Zoran , Brkic Silvija , Poljacki Mirjana
Published: July 2009

Introduction. Sexually transmitted infections (STIs) are major global public health problems. Present strategies for prevention have limitations. Vaccines are an attractive addition to the current prevention armamentarium because they provide durable protection and do not require repetitive adherence to be effective. Challenges for vaccination include induction and long-term maintaince of mucosal immune responses in the female genital tract. Vaccines: a realistic goal?. For the time being, US Centers for Disease Control and Prevention have recommended only hepatitis and HPV immunization to be routinely offered. Final, III stage trials are underway on other prophylactic vaccines for human papillomavirus and genital herpes. Though vaccines against Chlamydia trachomatis and Neisseria gonorrhoeae are in early stages of development they do offer the hope of preventing pelvic inflammations. The high incidence of HIV-infection for which a vaccine would not be readily available, 'cries out' for an effective vaccine. Vaccines for HPV infections. According to a recent meta-analysis of worldwide prevalence data, vaccinating with HPV-16/18 VLP against HPV-16 and HPV-18 could prevent over 70% of invasive cervical cancer worldwide. The latest release of data from the phase III trial of a quadrivalent recombinant non-infectious vaccine HPV-6/11/ 16/18 L1 VLP, including HPV types 6,11,16,18 have given complete protection against HPV-16/18-related cervical intraepithelial neoplasias 1, 2/3, and adenocarcinoma in situ and cancer through 2 years of post-vaccination follow up. Conclusion. Despite the fact that the development of vaccines for STI prevention was rather slow in the past, the ideal vaccine would decrease transmission of the infection between partners and would prevent complications of disease. Moreover, in future decades, increasingly successful universal vaccination of newborns and children will substantially reduce the need for vaccination of persons with specific risk factors, including sexual risk.
Deficiency of the natural anticoagulant proteins in women with pregnancy related venous thromboembolism
Authors: Mitic Gorana , Povazan Ljubica , Lazic Radmila , Spasic Dragan , Maticki-Sekulic Milana
Published: July 2009

Inherited thrombophilia can be defined as a predisposition to thrombosis caused by heritable defects, such as mutations in genes encoding the natural anticoagulants or clotting factors. Pregnancy related risk of VTE is sixfold increased comparing to non pregnant age matched women. Pregnancy is an independent risk factor for the development of venous thromboembolism and this risk is further increased by the presence of thrombophilia. Aim of the study: The aim of the study was to evaluate the association between deficiency of natural anticoagulants: antithrombin, protein C and protein S and pregnancy related thromboembolism. We have determined the activities of antithrombin, proten C and protein S in 74 women with pregnancy related thrombosis and in 45 healthy women who had at least two uncomplicated pregnancies. Among the women with the history of venous thromboembolism antithrombin deficiency was found in 4 (5.4%), protein C deficiency in 2 (2.7%) and protein S deficiency in 5 (6.76%). The total of 11 (14.6%) women was found to be deficient. Not a single woman in the control group was found to be deficient in natural anticoagulants. Deficiencies of coagulation inhibitors are associated with an increased risk of venous thrombosis during pregnancy and puerperium (p= 0.006). Antithrombin, protein C and protein S deficient women are at higher risk of developing venous thromboembolism during antepartal period (p= 0.0097). Prophylactic treatment with heparin should be recommended from the very beginning of the following pregnancy in women with antithrombin, protein C or protein S deficiency.
The influence of overweight on the quality of life of health workers
Authors: Rancic Natasa , Nikolic Maja , Deljanin Zorana , Petrovic Branislav , Kocic Biljana , Ilic Mirko
Published: July 2009

Introduction. The number of people who are considered to be either overweight or obese continues to increase, worldwide. The aim of the paper was to determine the influence of overweight on the quality of life of health workers. Material and methods. The study of prevalence was used. We observed 108 health workers both men and women from the Institute for Public Health in the City of Nis. The questionnaire Obesity Related Well-Being 97 (ORWELL97) was applied in all health workers. Results. A hundred and five health workers filled in the ORWELL97 questionnaire. There were 40% of men and 60% of women; 72% of them were married and 28% of them were single; 68% were from the urban area and 32% were from the rural area. The average age was 29.5 (SD=3.2) and the average value of BMI was 25.4 (SD=4,0). There were 54 (48.6%) health workers having normal weight and there were 51(5.4%) who were considered overweight. No one was obese among them. The difference between the average sum of scores in the group of health workers who had normal weight and the group of health workers who were overweight was not statistically significant (t=1.1 i p<0.05). Nor was the difference statistically significant for the average sum of scores of subquestion O (t=3.6 and p<0.05), and subquestion R (t=2.9 and p<0.05). BMI showed a weak positive correlation with both occurrence and relevance of symptoms. A weak positive correlation of BMI was found with average sum of scores in the first, second and third groups of questions in ORWELL 97 questionnaire. Conclusion. According to the presented results, health workers who were overweight did not have lower quality of life than health workers who had normal weight.
Late stent thrombosis
Authors: Petrovic Milovan , Bikicki Miroslav , Panic Gordana , Canji Tibor , Srdanovic Ilija , Ivanovic Vladimir
Published: July 2009

Introduction. Late stent thrombosis is a serious complication after stent Implantation and it can lead to the development of acute myocardial infarction or death. A case report. A 43-year-old patient was admitted to our clinic to coronary care unit. He was diagnosed with acute ST elevation myocardial reinfarction of inferoposterior localisation and with right ventricular myocardial infarction. Eighteen months ago, he had acute myocardial infarction of the same localisation, and at the same time, PCI (Percutaneous Coronary Intervention) was performed in acute phase, and two bare metal stents were implanted. Now, the patient had chest discomfort two hours before admittance, and PCI was performed once again in acute phase. The diagnostic coronarography resulted in occlusion of the right coronary artery, on the spot of the previously implanted stents. After the passage of guidewire, the artery was recanalized, and defects of artery opacification, which might have been thrombs, were noticed. The thrombs were seen on the spots of earlier implanted stents and in the posterior inteventricular and posterolateral branches of the right coronary artery. PTCA was performed and the patient received the GP IIb/IIIa antagonist therapy after which the control coronarography showed minimal defects of artery opacification, with good anterograde flow. After complete treatment the patient was in good condition. Conclusion. Late stent thrombosis, although not very often, is a very serious complication and can lead to death or acute myocardial infarction. To prevent it, it is necessary that the patient receives dual antiplatelet therapy, and that PCI procedure is performed technically correctly (suitable stent dimensions and proper stent expansion).
Physical activity as an important determinant in developing childhood obesity
Authors: Bukara-Radujkovic Gordana , Zdravkovic Dragan
Published: July 2009

The correlation between physical activity and sedentary life style was investigated as a determinant of the body mass index in children and adolescents in Banjaluka region. The study involved 1204 children and adolescents, 6-17 years old, 578 boys, 626 girls. BMI was calculated from their height and weight using standard formula. Each child, together with their parents answered the questions considering their level of involvement in physical versus sedentary activities. Physical activity was defined as involvement in sports activities, while sedentary life style was defined as time spent on computer, games, video, and TV. The prevalence of overweight and obesity were 12.2% and 6.1% in our study group. Increased physical activity showed strong positive correlation with normal, lower BMI in boys (p<0,05), and girls (p<0.001). Sedentary lifestyle, prolonged TV watching was strongly associated with increased BMI only in girls (p<0.05). However, computer use for 2 hours/day was strongly associated with increased BMI (p<0.05) only in boys, although computer use for more than 3 hours/day was associated with lower BMI in boys. Physical activity and sedentary lifestyle are significant determinants of BMI and risk factors in developing overweight and obesity in childhood, as shown in our study.
Reaction time of drivers who caused road traffic accidents
Authors: Djuric Predrag , Filipovic Danka
Published: July 2009

Introduction. Human factor is the single cause of road traffic injuries in 57%, and together with other factors in more than 90% of all road traffic accidents. Human factor includes many aspects, where reaction time is very important. Material and methods. Thirty healthy drivers 28-40 y.o. with 50-500 km passed per week, having caused at least one road traffic accident in the last ten years were selected, provided they were not under the influence of alcohol and drugs during traffic accident. The same number of control were selected. Both cases and controls were tested to reaction time. Results. We found statistically significant difference between car drivers who caused car accidents and those who did not in both simple and choice reaction times. Discussion. Car drivers who caused road traffic accidents have longer reaction time (both simple and choice reaction time), but as the tasks were more complex, that difference was less visible. Since drivers involved in this study had introductory phase before measuring their reaction times, they faced with unpleasant sound when they made mistake, which forced them to be aware not to make a mistake in further tasks, so they showed longer reaction times. Conclusion. Measuring of reaction time seems to be important, and as we have showed they are different in drivers who have caused road traffic accidents and those who have do not.
The neutral zone and vertical dimension of occlusion
Authors: Aleksov Ljiljana , Stankovic Sasa , Ajdukovic Zorica
Published: July 2009

Introduction. More recent research points out to the existence of a new concept of the technique for locating the neutral zone. The objective of the study was to determine the effect of changing vertical dimension of occlusion, as well as that of the alveolar ridge type, on the neutral zone dimensions. Material and methods. The neutral zone was investigated in two groups of patients, with prominent (the control group) and flat alveolar ridges and it was determined for each patient at 3 heights (the correct, the increased and the decreased vertical dimension of occlusion). It was studied both vertically and horizontally. The width of the neutral zone was measured in different regions. Results. The width of the neutral zone was minimal at the level of the occlusal plane, and it increased gradually as the occlusal plane went down and up, towards the anterior region. Conclusion. No statistically significant difference was found in the width of the neutral zone, between the group of patients with prominent alveolar ridges (the control group), and that with the flat ones. There was, also, no difference at all, at any level of the vertical dimension of occlusion, that could possibly bear statistical significance.
Efficacy of antiviral therapy in patients with hemophilia and hepatitis C virus infection
Authors: Kostic Velimir , Djordjevic Marina , Popovic Lidija , Kostic Emina , Djordjevic Jovana , Govedarevic Nenad
Published: July 2009

Introduction. HCV infection was common cause of morbidity and mortality in patients with hemophilia before 1986. We wanted to investigate the effect of treatment with combination therapy in HCV positive patients with hemophilia. Material and methods. The research included totally 13 persons afflicted with hemophilia and HCV infection out of 21 tested. The patients were submitted to laboratory and clinical tests as well as genotypization, whereby a different hepatitis C virus genetic adherence was observed. Parallel with this subcategory the other one was put into comparison, consisting of 12 patients afflicted with chronic C hepatitis, marked as non-hemophilics. The both subcategories were treated with combination antiviral therapy (peginterferon a-2a and ribavirin) during 48 weeks for genotype 1 and 4, in reference to 24 weeks for genotype 2 and 3. Within the treatment, clinical and laboratory side-effects were noticed, which did not require therapy interruption. A more frequent hemorrhage during the therapy was found within the hemophilics, rather than before initiliazing it. Results. After the statistical processing of the results (Students' t-test), statistically significant difference among these two subcategories was noticed as values for ALT (***p<0.0001) after 24 weeks of therapy, red blood cells (*p<0.05), haemoglobin and haematocrite (***p<0.0001) 24 weeks after therapy completing. By PCR examination of the patients, 6 months after the end of treatment, a sustained viral response (SVR) of the same percentage was registrated within both subcategories, which is even greater than what the other authors have described. Discussion. Main results were without important difference between two subgroups, except for higher number of spontanuous bleeding in group with hemophilia, which was somewhat expected. Most importantly, we didn't find any difference in SVR rates between groups. Conclusion. HCV positive patients with hemophilia could be successfully treated with combination therapy of peginterferon alfa-2a and ribavirin.
Problems of psychiatrization, medicalization and related social phenomena
Authors: Opalic Petar
Published: July 2009

The introduction contains definitions of the terms psychiatrization, medicalization, psychotherapeutization and psychologization of the society, i.e. social problems. Different aspects of the above phenomena are analyzed, their origin, relation with the professions they originate from, and, finally, their social significance, i.e. social function. In conclusion, the article points to different possibilities to prevent the above phenomena, undesirable both for the society and the objectives and activities of the professions they originate from.
Inulin: Potential prebiotic
Authors: Sokic Zdenka , Knezevic Jasmina , Vrvic Miroslav
Published: July 2009

Introduction. Prebiotic factor, such as inulin, is able to stimulate the growth of bifidobacteria selectively at the expense of more putrefactive bacteria. Chemical structure - Inulin has been defined as carbohydrate material consisting of ? (2-1) fructosyl-fructose links. Physical and chemical properties - Chicory inulin is available as white, odourless powders. The taste is neutral or slightly sweet. Caloric value - The value of 1.5 kcal/g is generally used. Improvement of lipid metabolism - The consumption of fructans reduces serum triglycerides and sometimes also cholesterol in healthy volunteers who were hyperlipidemic. Modulation of gut microflora - Inulin induces effects on gut function, such as a reduction of intestinal pH, relief of constipation, increased stool weight and frequency. Intestinal acceptability - Osmotic effect leads to an increased presence of water in the colon. The second effect is caused by the fermentation products. Suitability for diabetics - Inulin has been shown to reduce postprandial glycemia and insulinemia. Reduction of cancer risk - The production of toxic metabolites may be reduced by increasing the proportion of healthier colonic micro flora, which competes with pathogenic bacteria to reduce the levels of toxin and carcinogenic-producing enzymes. Increase in mineral absorption. The increase in calcium absorption did not negatively alter the absorption of other minerals. Food applications - Inulin improves organoleptic quality and a better-balanced nutritional composition. Perspectives - Fundamental mechanisms governing the nutritional benefits of inulin need to be further investigated. Conclusion. Inulin represents a key ingredient that offers new opportunities to food industry, which is constantly seeking well balanced, yet better tasting.