Showing papers by "University of Zagreb published in 2001"

HUman MicroNucleus Project: International database comparison for results with the cytokinesis-block micronucleus assay in human lymphocytes: I. Effect of laboratory protocol, scoring criteria, and host factors on the frequency of micronuclei

Abstract: Micronucleus (MN) expression in peripheral blood lymphocytes is well established as a standard method for monitoring chromosome damage in human populations. The first results of an analysis of pooled data from laboratories using the cytokinesis-block micronucleus (CBMN) assay and participating in the HUMN (HUman MicroNucleus project) international collaborative study are presented. The effects of laboratory protocol, scoring criteria, and host factors on baseline micronucleated binucleate cell (MNC) frequency are evaluated, and a reference range of "normal" values against which future studies may be compared is provided. Primary data from historical records were submitted by 25 laboratories distributed in 16 countries. This resulted in a database of nearly 7000 subjects. Potentially significant differences were present in the methods used by participating laboratories, such as in the type of culture medium, the concentration of cytochalasin-B, the percentage of fetal calf serum, and in the culture method. Differences in criteria for scoring micronuclei were also evident. The overall median MNC frequency in nonexposed (i.e., normal) subjects was 6.5 per thousand and the interquartile range was between 3 and 12 per thousand. An increase in MNC frequency with age was evident in all but two laboratories. The effect of gender, although not so evident in all databases, was also present, with females having a 19% higher level of MNC frequency (95% confidence interval: 14-24%). Statistical analyses were performed using random-effects models for correlated data. Our best model, which included exposure to genotoxic factors, host factors, methods, and scoring criteria, explained 75% of the total variance, with the largest contribution attributable to laboratory methods.

Degree of conversion and temperature rise during polymerization of composite resin samples with blue diodes.

Abstract: To ensure an adequate clinical composite filling light source for photopolymerization is of great importance. In everyday clinical conditions commonly used unit for polymerization of composite material is halogen curing unit. The development of new blue superbright light emitting diodes (LED) of 470 nm wavelengths comes as an alternative to standard halogen curing unit of 450-470 nm wavelengths. The purpose of this study was to compare the degree of conversion (DC) and temperature rise of four hybrid composite materials: Tetric Ceram, Pertac II, Valux Plus and Degufill Mineral during 40 s illumination with standard halogen curing unit Heliolux GTE of 600 mW cm(-2) intensity, Elipar Highlight soft-start curing unit of 100 mW cm(-2) (10 s) and 700 mW cm(-2) (30 s) intensity and 16 blue superbright LED of minimal intensity of 12 mW cm(-2) on the surface and 1 mm depth. The results revealed only a little bit higher DC values in case of polymerization with even 66 times stronger halogen curing units which showed twice higher temperature than blue diodes. Temperature and DC obtained are higher on the surface than on 1 mm depth regardless on the light source used.

Performance analysis of image compression using wavelets

Abstract: The aim of this paper is to examine a set of wavelet functions (wavelets) for implementation in a still image compression system and to highlight the benefit of this transform relating to today's methods. The paper discusses important features of wavelet transform in compression of still images, including the extent to which the quality of image is degraded by the process of wavelet compression and decompression. Image quality is measured objectively, using peak signal-to-noise ratio or picture quality scale, and subjectively, using perceived image quality. The effects of different wavelet functions, image contents and compression ratios are assessed. A comparison with a discrete-cosine-transform-based compression system is given. Our results provide a good reference for application developers to choose a good wavelet compression system for their application.

The mutational spectrum of human malignant autosomal recessive osteopetrosis

Abstract: Human malignant infantile osteopetrosis (arOP; MIM 259700) is a genetically heterogenous autosomal recessive disorder of bone metabolism, which, if untreated, has a fatal outcome. Our group, as well as others, have recently identified mutations in the ATP6i (TCIRG1) gene, encoding the a3 subunit of the vacuolar proton pump, which mediates the acidification of the bone/osteoclast interface, are responsible for a subset of this condition. By sequencing the ATP6i gene in arOP patients from 44 unrelated families with a worldwide distribution we have now established that ATP6i mutations are responsible for similar to 50% of patients affected by this disease. The vast majority of these mutations (40 out of 42 alleles, including seven deletions, two insertions, 10 nonsense substitutions and 21 mutations in splice sites) are predicted to cause severe abnormalities in the protein product and are likely to represent null alleles. In addition, we have also analysed nine unrelated arOP patients from Costa Rica, where this disease is apparently much more frequent than elsewhere. All nine Costa Rican patients bore either or both of two missense mutations (G405R and R444L) in amino acid residues which are evolutionarily conserved from yeast to humans. The identification of ATP6i gene mutations in two families allowed us for the first time to perform prenatal diagnosis: both fetuses were predicted not to be affected and two healthy babies were born. This study contributes to the determination of genetic heterogeneity of arOP and allows further delineation of the other genetic defects causing this severe condition. (Less)

Assessment of endometrial receptivity by transvaginal color Doppler and three-dimensional power Doppler ultrasonography in patients undergoing in vitro fertilization procedures.

Abstract: The objective of this study was to investigate the usefulness of transvaginal color Doppler and three-dimensional power Doppler ultrasonography for the assessment of endometrial receptivity. A total of 89 patients undergoing in vitro fertilization procedures were evaluated for endometrial thickness and volume, endometrial morphology, and subendometrial perfusion on the day of embryo transfer. Neither the volume nor the thickness of the endometrium on the day of embryo transfer had a predictive value for conception during in vitro fertilization cycles (P > .05). Patients who became pregnant were characterized by a significantly lower resistance index, obtained from subendometrial vessels by transvaginal color Doppler ultrasonography (resistance index = 0.53 +/- 0.04 versus 0.64 +/- 0.04, pregnant versus not pregnant, respectively; P < .05), and a significantly higher flow index (13.2 +/- 2.2 versus 11.9 +/- 2.4; P < .05), as measured by a three-dimensional power Doppler histogram. No difference was found in the predictive value of scoring systems analyzing endometrial thickness and volume, endometrial morphology, and subendometrial perfusion by color Doppler and three-dimensional power Doppler ultrasonography. The high degree of endometrial perfusion shown by color Doppler ultrasonography and on three-dimensional power Doppler histograms on the day of embryo transfer can indicate a more favorable endometrial milieu for successful in vitro fertilization.

High-transport critical current density above 30 K in pure Fe-clad MgB2 tape

Abstract: Fe-clad MgB 2 long tapes have been fabricated using a powder-in-tube technique. An Mg+2B mixture was used as the central conductor core and reacted in situ to form MgB 2 . The tapes were sintered in pure Ar at 800°C for 1 h at ambient pressure. SEM shows a highly dense core with a large grain size of 100 μm. The Fe-clad tape shows a sharp transition with transition width of ΔT c of 0.2 K and a T c0 of 37.5 K. We have achieved the highest transport critical current reported so far at 1.7×10 4 A/cm 2 for both 29.5 K in 1 T and 33 K in zero applied field. Resistivity temperature dependence and transport critical current were also measured in magnetic fields applied perpendicular and parallel to the tape plane. Not only is the use of an Fe sheath necessary for the successful processing of in situ reacted powder-in-tube MgB 2 , it confers on the finished wire the additional benefit of magnetic screening.

Bis(Amino Acid) Oxalyl Amides as Ambidextrous Gelators of Water and Organic Solvents. Supramolecular Gels With Temperature Dependent Assembly-Dissolution Equilibrium

Abstract: Bis(LeuOH) (1a), bis-(ValOH) (2a) and bis(PhgOH) (5a) (Phg denotes (R)-phenylglycine) oxalyl amides are efficient low molecular weight organic gelators of various organic solvents and their mixtures as well as water, water/DMSO, and water/DMF mixtures. The organisational motifs in aqueous gels are dominated primarily by lipophilic interactions while those in organic solvents are formed by intermolecular hydrogen bonding. Most of the gels are thermoreversible and stable for many months. However, 2a forms unstable gels with organic solvents which upon ageing transform into variety of crystalline shapes. For some 1a/alcohol gels, a linear correlation between alcohol dielectric constants (epsilon) and gel melting temperatures (Tg) was found. The 1H NMR and FTIR spectroscopic investigations of selected gels reveal the existence of temperature dependent network assembly/dissolution equilibrium. In the 1H NMR spectra of gels only the molecules dissolved in entrapped solvent could be observed. By using an internal standard, the concentration of dissolved gelator molecules could be determined. In FTIR spectra, the bands corresponding to network assembled and dissolved gelator molecules are simultaneously present. This enabled determination of the Kgel values by using both methods. From the plots of InKgel versus 1/T, the deltaHgel values of selected gels have been determined (-deltaHgel in 10-36 kJ mol(-1) range) and found to be strongly solvent dependent. The deltaHgel values determined by 1H NMR and FTIR spectroscopy are in excellent agreement. Crystal structures of 2a and rac-5a show the presence of organisational motifs and intermolecular interactions in agreement with those in gel fibres elucidated by spectroscopic methods.

Dirac cohomology, unitary representations and a proof of a conjecture of Vogan

Abstract: U radu je dokazana slutnja D. Vogana, koja odredjuje infinitesimalni karakter ireducibilnog (g, K)-modula koji ima Diracovu kohomologiju razlicitu od nula. Infinitesimalni karakter je dan kao rho-translat najvece tezine K-tipa u Diracovoj kohomologiji. Diracova kohomologija se definira kao ker D / (im D \cap ker D), gdje D oznacava Diracov operator na zadanom (g, K)-modulu tenzoriranom sa spin modulom.

Mucoadhesive chitosan-coated liposomes: characteristics and stability.

Abstract: Lecithin liposomes, empty or containing FITC-dextran, were prepared by the ethanol injection method. Three different types of chitosans with different molecular weight and degrees of deacetylation were used (Seacure 113, 210 and 311). Chitosan coating was carried out by mixing the liposomal suspension with the chitosan solution followed by incubation. The size of liposomes was measured before and after polymer coating by an image analysis technique. The mean diameter of liposomes containing FITC-dextran was in the size range 250-280 nm, whereas the size after coating was 300-330 nm, regardless of chitosan type. All chitosan-coated liposomes were of spherical shape and no morphological differences between uncoated and coated liposomes were observed. Liposomes with FITC-dextran, originally entrapping 50% of the marker substance taken in the preparation and coated in the presence of unentrapped marker substance, contained 60-65% of the marker substance. The highest entrapment was found for liposomes coated with medium molecular weight chitosan. The stability of chitosan-coated liposomes in simulated gastric fluid was significantly higher as compared to uncoated liposomes. One can conclude that chitosan is stabilizing the original liposomal structure and protecting liposomally entrapped drug.

Band-splitting of coronal and interplanetary type II bursts - I. Basic properties

Abstract: Patterns analogous to the band-splitting of metric type II bursts are found in a number of type II bursts observed in the dekameter-kilometer wavelength range. A similarity of morphological and frequency-time characteristics of two emission components are indicative of a common source. Relative frequency splits span in the range f=f =0 :05 0:6. At radial distances between 2 and 4 R only small splits around 0.1 can be found. In the interplanetary space the relative split on average increases with the radial distance, whereas the inferred shock velocity decreases. In three events extrapolations of the split components point to the base and the peak of the jump in the local plasma frequency caused by the associated shock passage at 1 AU. This is suggestive of the plasma radiation from the regions upstream and downstream of the shock. Adopting this interpretation, one nds that the drop of f=f at 2{4 R is congruent with the Alfv en velocity maximum expected there. The split increase and the velocity decrease at larger distances can be explained as a consequence of declining Alfv en speed in the interplanetary space.

Variability of 5-HT2C receptor cys23ser polymorphism among European populations and vulnerability to affective disorder.

Abstract: Substantial evidence supports a role for dysfunction of brain serotonergic (5-HT) systems in the pathogenesis of major affective disorder, both unipolar (recurrent major depression) and bipolar.(1) Modification of serotonergic neurotransmission is pivotally implicated in the mechanism of action of antidepressant drugs(2) and also in the action of mood stabilizing agents, particularly lithium carbonate.(3) Accordingly, genes that code for the multiple subtypes of serotonin receptors that have been cloned and are expressed in brain,(4) are strong candidates for a role in the genetic etiology of affective illness. We examined a structural variant of the serotonin 2C (5-HT2C) receptor gene (HTR2C) that gives rise to a cysteine to serine substitution in the N terminal extracellular domain of the receptor protein (cys23ser),(5) in 513 patients with recurrent major depression (MDD-R), 649 patients with bipolar (BP) affective disorder and 901 normal controls. The subjects were drawn from nine European countries participating in the European Collaborative Project on Affective Disorders. There was significant variation in the frequency of the HT2CR ser23 allele among the 10 population groups included in the sample (from 24.6% in Greek control subjects to 9.2% in Scots, chi(2) = 20.9, df 9, P = 0.01). Logistic regression analysis demonstrated that over and above this inter-population variability, there was a significant excess of HT2CR ser23 allele carriers in patients compared to normal controls that was demonstrable for both the MDD (chi(2) = 7.34, df 1, P = 0.006) and BP (chi(2) = 5.45, df 1, P = 0.02) patients. These findings support a possible role for genetically based structural variation in 5-HT2C receptors in the pathogenesis of major affective disorder.

Detection of DNA damage in haemocytes of zebra mussel using comet assay.

Abstract: The aim of the study was to use the comet assay on haemocytes of freshwater mussel, Dreissena polymorpha Pallas, for detection of possible DNA damage after exposure to pentachlorophenol (PCP) and to evaluate the potential application of the comet assay on mussel haemocytes for genotoxicity monitoring of freshwater environment. Zebra mussels were exposed for seven days to different concentrations (10, 80, 100, 150 μg/l) of PCP and in the river Sava downstream from Zagreb municipal wastewater outlet. Significant increase in DNA damage was observed after exposure to PCP at doses of 80 μg/l and higher and after in situ exposure in the river Sava as well. This study confirmed that the comet assay applied on zebra mussel haemocytes may be a useful tool in determining the potential genotoxicity of water pollutants.

Inhibitory mechanism of low-carbon steel corrosion by mimosa tannin in sulphuric acid solutions

Abstract: Mimosa tannin was investigated as inhibitor of low-carbon steel sulphuric acid corrosion in concentrations from 10−5 to 10−1 mol L−1, at the temperature of 298 K in the solutions of pH 1, 2 and 3. The inhibitor effectiveness increases with increase in concentration. The adsorptive behaviour of mimosa tannin in solutions of pH 1 and 2 may be approximated, both by Temkin and Frumkin type isotherms, probably due to the chemisorption of tannin molecules on the metal surface. The free energies of adsorption are in the range from −35.1 to −39.5 kJ mol−1. At pH 3, a Freundlich type isotherm is obeyed, probably due to the physisorption of ferric-tannate that forms at this pH, both on the metal surface and in the bulk electrolyte. The free energy of adsorption at pH 3 is −11.8 kJ mol−1. The activation energy of the iron dissolution process at pH 1 was found to be 51.4 kJ mol−1 and decreased to 48.0 kJ mol−1 on the addition of 1.25 × 10−2 mol L−1 mimosa tannin. The addition of the same amount of mimosa tannin into solutions of pH 2 and 3, increased the activation energy of iron dissolution from 15.6 to 34.3 kJ mol−1 and from 12.0 to 19.2 kJ mol−1, respectively.

Neogene-Quaternary structures in the border zone between Alps, Dinarides and Pannonian Basin (Hrvatsko zagorje and Karlovac Basins, Croatia)

Abstract: Analysis of Neogene–Quaternary structures from seismic lines, surface measurements and geological-mapping is presented from the border zone between the Alps, Dinarides and Pannonian Basin. First, Early Miocene extension was possibly characterised by ENE directed extension. It was partly synchronous with NW–SE shortening. Second, Middle Miocene extension was possibly characterised by NW–SE to WNW–ESE directed extension. Again, this event was followed by a new generation of thrusts related to end-Sarmatian shortening. The last, Late Miocene E–W to WNW–ESE directed extension was followed by a final shortening that created major, map-scale folds, basement pop-ups and inverted former basins. Geometry, onlap and thickness patterns of the youngest syn-tectonic basin fill indicate that this last, N–S to NW–SE directed shortening started in Late Pontian and continued up to the present time. When taking into account the wider surrounding area, it seems that the structures related to this latest shortening are arranged in often perpendicular directions, centred at the eastern end of the Periadriatic lineament. To explain this fan-like pattern of synchronous shortenings a kinematic model is proposed combining counter-clockwise rotation with north- or northwestward shift of the Dinaridic block with respect to the more stable Alpine buttress.

Data warehouse design from XML sources

Abstract: A large amount of data needed in decision-making processes is stored in the XML data format, which is widely used for e-commerce and Internet-based information exchange. Thus, as more organizations view the web as an integral part of their communication and business, the importance of integrating XML data in data warehousing environments is becoming increasingly high. In this paper we show how the design of a data mart can be carried out starting directly from an XML source. Two main issues arise: on the one hand, since XML models semi-structured data, not all the information needed for design can be safely derived; on the other, different approaches for representing relationships in XML DTDs and Schemas are possible, each with different expressive power. After discussing these issues, we propose a semi-automatic approach for building the conceptual schema for a data mart starting from the XML sources.

Influence of high intensity training on menstrual cycle disorders in athletes.

Abstract: AIM To estimate the influence of intensive training on menstrual cycles in female athletes. METHOD The questionnaire was used to determine the time of menarche, and the prevalence of primary and secondary amenorrhea and dysmenorrhea in 72 active female athletes from Zagreb (10 volleyball players, 18 basketball players, 10 ballet dancers, and 34 runners) aged between 15 and 21. The control group comprised 96 girls of the same age not engaged in any sports activity. RESULTS The prevalence of secondary amenorrhea was three times higher in athletes than in the control group (p=0.037). The prevalence of primary amenorrhea was substantially higher in athletes than in the control group (6/72 vs. 0/96, p=0.014), whereas the prevalence of dysmenorrhea was twofold lower in athletes than in the control group (p<0.001). The highest prevalence of secondary amenorrhea was recorded in runners (14/31), particularly long-distance runners (11/17), whereas there was only one case of secondary amenorrhea among basketball players. Menarche was significantly delayed in the athletes who started physical activities before the onset of menstruation (13.8+1.4 vs. 12.6+1.0 years, p<0.001). CONCLUSION High-intensity training before menarche postpones its onset. Type of training may be related to a significantly higher prevalence of secondary amenorrhea in runners than in basketball players.

Clinical implications of sonographic detection of uterine anomalies for reproductive outcome.

Abstract: The purpose of this review article was to analyze the literature on the prevalence, diagnosis and treatment of the congenital uterine anomalies and to discuss current dilemmas on their influence on reproductive outcome. Congenital uterine anomalies are commonly associated with repeated pregnancy failure, in particular an increased risk of first- and second-trimester miscarriages and preterm delivery. Recent reports on two-dimensional and three-dimensional transvaginal ultrasound and saline contrast sonohysterography appear promising for diagnosis and classification of congenital uterine anomalies. The ability to visualize both the uterine cavity and the fundal uterine contour on a three-dimensional scan facilitates the diagnosis of uterine anomalies and enables differentiation between septate and bicornuate uteri. Color Doppler ultrasound allows visualization of intraseptal vascularity and may help in distinguishing the avascular from the vascular septum. Less connective tissue in the septum may result in poor decidualization and placentation, while an increased amount of muscle tissue in the septum can cause miscarriage by the production of local uncoordinated myometrial contractility. Hysteroscopic septum excision is an effective procedure which improves live-birth rates. Because of its simplicity, minimal invasiveness, low morbidity and low cost, a more liberal approach to the treatment of uterine anomalies is being advocated.

Regeneration of articular cartilage chondral defects by osteogenic protein-1 (bone morphogenetic protein-7) in sheep.

Abstract: The efficacy of osteogenic protein-1 (OP-1; BMP-7) in regeneration of articular cartilage was examined by creating knee chondral defects in sheep. With a specially designed instrument in both knees, two 10 mm (diameter) chondral defects were created: one in the trochlea and the other on the femoral condyle. The recombinant BMP was delivered via an extra-articulary positioned mini-osmotic pump, which was fixed to the femoral diaphysis above the knee joint, and connected by a polyethylene tubing to the articular space. Prior to use, the compatibility of OP-1 with mini-osmotic pumps was tested in vitro by measuring aggregation/precipitation and modification of the released protein by size exclusion and reversed phase HPLC. The average amount of aggregation was 15% and about 5% of OP-1 was modified. However, the biological activity of OP-1 released from pumps over a period of 2 weeks at 37°C was equal to ROS cell assay OP-1 standard. Following surgery, a total of 55 μg (low dose) or 170 μg (high dose) OP-1 in...

A case study of bora-driven flow and density changes on the adriatic shelf (January 1987)

Abstract: A numerical modelling study of the response of the Adriatic shelf waters and the Po River plume to a bora wind event has been undertaken using the Princeton Ocean Model (POM). After a bora episode from 16 to 20 January 1987, Advanced Very High Resolution Radiometer (AVHRR) satellite image revealed a cold filament protruding from the Italian coastal area toward the open sea. To understand and numerically simulate the offshore spreading of cold water from the western coastal area, the effects of three external forcings have been examined: wind stress, heat flux and river discharge. Wind stress and surface heat flux, calculated by bulk method from the winds, air temperatures and humidities obtained by Mesoscale Model 5 (MM5) with space and time resolution of 9 km and 1 h, respectively, were used to force the oceanographic model. River discharge was introduced in the oceanographic model as a source term in the continuity equation. Moreover, it was assumed that river water had zero salinity and a 5°C lower temperature than the surrounding sea water, following some climatological estimations. The results of numerous numerical experiments revealed that the filament observed in the AVHRR satellite image was formed by the joint action of three external forcings mentioned, and that none of them could be neglected while considering the observed pattern. Although the bora is, due to its NE direction, downwelling favourable wind for the western Adriatic coast, its alongshore variability induces offshore spreading of cold and less saline Po-influenced water. The effects of air stability and wind wave field are important for the wind stress estimation. The role of the Po River is to reduce sea surface salinity and to prevent cold water from sinking; it is introduced in the oceanographic model mainly through the initial salinity field. The combined effects of the basin topography and surface heat flux create an extra amount of cold water in the western coastal strip, which is then advected by bora wind action toward the open sea. High horizontal resolution of the numerical experiments is important in resolving the alongshore variability of the bora wind field and to correctly simulate the narrow filament observed in the AVHRR image.

Incomplete lupus erythematosus: results of a multicentre study under the supervision of the EULAR Standing Committee on International Clinical Studies Including Therapeutic Trials (ESCISIT)

Abstract: textOBJECTIVE: Patients characterized with antinuclear antibodies (ANA) and disease symptoms related to one organ system can be described as having incomplete systemic lupus erythematosus (SLE). The aim of this multicentre study was to describe the outcome of these so-called incomplete SLE patients. Two aspects of the outcome were studied: (i) the disease course, defined by the presence or absence of clinical symptoms; and (ii) the number of patients that eventually developed full SLE. METHODS: Outcome parameters were the ACR criteria, the SLE disease Activity Index (SLEDAI), the European Consensus Lupus Activity Measure (ECLAM) and the requirement for treatment. In 10 European rheumatology centres, patients who had been evaluated in the last 3 months of 1994 and had been diagnosed as having incomplete SLE on clinical grounds for at least 1 yr were included in the study. All 122 patients who were included in the study were evaluated annually during 3 yr of follow-up. RESULTS: Our results are confined to a patient cohort defined by disease duration of at least 1 yr, being under clinical care at the different centres in Europe. These patients showed disease activity that was related mostly to symptoms of the skin and the musculoskeletal system, and leucocytopenia. During the follow-up, low doses of prednisolone were still being prescribed in 43% of the patients. On recruitment to the study, 22 of the 122 incomplete SLE patients already fulfilled the ACR criteria for the diagnosis of SLE. In the 3 yr of follow-up only three patients developed SLE. CONCLUSIONS: A high proportion of patients in our cohort defined on clinical grounds as having incomplete SLE eventually showed disease activity defined by the SLEDAI as well as ECLAM. However, only three cases developed to SLE during the follow-up. This suggests that incomplete SLE forms a subgroup of SLE that has a good prognosis.

Aggressive behavior in combat veterans with post-traumatic stress disorder.

Abstract: The incidence of aggression and violent behavior in combat veterans varies and can be observed with regard to the presence or absence of post-traumatic stress disorder (PTSD). Significantly greater occurrence of aggression was observed in combat veterans with PTSD compared with those without PTSD. There are various types of aggressive behavior that frequently are combined. Autoaggressive (suicidal) and heteroaggressive (interpersonal violence) behaviors predominate, with dominating verbal aggression and impulsive somatic reactions. Impulsive reactions are more frequently directed toward unknown persons, whereas verbal aggression is mostly aimed at known people. In the occurrence of aggressive behavior in combat veterans with PTSD, important roles are played by education level, low socioeconomic status, maltreatment in childhood, and previous types of violent behavior (before participation in war events).