Showing papers by "University of Zagreb published in 2004"

The Second Data Release of the Sloan Digital Sky Survey

Abstract: The Sloan Digital Sky Survey (SDSS) has validated and made publicly available its Second Data Release. This data release consists of 3324 deg2 of five-band (ugriz) imaging data with photometry for over 88 million unique objects, 367,360 spectra of galaxies, quasars, stars, and calibrating blank sky patches selected over 2627 deg2 of this area, and tables of measured parameters from these data. The imaging data reach a depth of r ≈ 22.2 (95% completeness limit for point sources) and are photometrically and astrometrically calibrated to 2% rms and 100 mas rms per coordinate, respectively. The imaging data have all been processed through a new version of the SDSS imaging pipeline, in which the most important improvement since the last data release is fixing an error in the model fits to each object. The result is that model magnitudes are now a good proxy for point-spread function magnitudes for point sources, and Petrosian magnitudes for extended sources. The spectroscopy extends from 3800 to 9200 A at a resolution of 2000. The spectroscopic software now repairs a systematic error in the radial velocities of certain types of stars and has substantially improved spectrophotometry. All data included in the SDSS Early Data Release and First Data Release are reprocessed with the improved pipelines and included in the Second Data Release. Further characteristics of the data are described, as are the data products themselves and the tools for accessing them.

Reliability and factorial validity of squat and countermovement jump tests.

Abstract: The primary aim of this study was to determine reliability and factorial validity of squat (SJ) and countermovement jump (CMJ) tests. The secondary aim was to compare 3 popular methods for the estimation of vertical jumping height. Physical education students (n = 93) performed 7 explosive power tests: 5 different vertical jumps (Sargent jump, Abalakow's jump with arm swing and without arm swing, SJ, and CMJ) and 2 horizontal jumps (standing long jump and standing triple jump). The greatest reliability among all jumping tests (Cronbach's alpha = 0.97 and 0.98) had SJ and CMJ. The reliability alpha coefficients for other jumps were also high and varied between 0.93 and 0.96. Within-subject variation (CV) in jumping tests ranged between 2.4 and 4.6%, the values being lowest in both horizontal jumps and CMJ. Factor analysis resulted in the extraction of only 1 significant principal component, which explained 66.43% of the variance of all 7 jumping tests. Since all jumping tests had high correlation coefficients with the principal component (r = 0.76-0.87), it was interpreted as the explosive power factor. The CMJ test showed the highest relationship with the explosive power factor (r = 0.87), that is, the greatest factorial validity. Other jumping tests had lower but relatively homogeneous correlation with the explosive power factor extracted. Based on the results of this study, it can be concluded that CMJ and SJ, measured by means of contact mat and digital timer, are the most reliable and valid field tests for the estimation of explosive power of the lower limbs in physically active men.

Adhesion and aggregation ability of probiotic strain Lactobacillus acidophilus M92

Abstract: The ability of probiotic bacteria to adhere to the intestinal epithelium play an important role in colonization of the gastrointestinal tract, preventing their elimination by peristalsis and providing a competitive advantage in this ecosystem. To identify bacterial traits related to adhesion the probiotic strain L. acidophilus M92 was examined for autoaggregation ability and cell surface hydrophobicity L. acidophilus M92 exhibits a strong autoaggregation phenotype and also coaggregation with some pathogen microorganisms that may form a barrier that prevents their colonization. The examined probiotic strain manifests a good degree of hydrophobicity determined by microbial adhesion to hydrocarbons. Aggregation and hydrophobicity were abolished upon exposure of the cells to pronase, which suggests the possible role of cell surface layer (S-layer) proteins, approximated at 45 kDa, in a L. acidophilus M92. The relationship between autoaggregation and adhesion ability to intestinal tissue was investigated by observing the adhesivity of L. acidophilus M92 to porcine ileal epithelial cells. Removal of the S-layer proteins by extraction with 5 M LiCl reduced autaggregation and in vitro adhesion of this strain.

Mutant small heat-shock protein 27 causes axonal Charcot-Marie-Tooth disease and distal hereditary motor neuropathy

Abstract: Charcot-Marie-Tooth disease (CMT) is the most common inherited neuromuscular disease and is characterized by considerable clinical and genetic heterogeneity. We previously reported a Russian family with autosomal dominant axonal CMT and assigned the locus underlying the disease (CMT2F; OMIM 606595) to chromosome 7q11-q21 (ref. 2). Here we report a missense mutation in the gene encoding 27-kDa small heat-shock protein B1 (HSPB1, also called HSP27) that segregates in the family with CMT2F. Screening for mutations in HSPB1 in 301 individuals with CMT and 115 individuals with distal hereditary motor neuropathies (distal HMNs) confirmed the previously observed mutation and identified four additional missense mutations. We observed the additional HSPB1 mutations in four families with distal HMN and in one individual with CMT neuropathy. Four mutations are located in the Hsp20-alpha-crystallin domain, and one mutation is in the C-terminal part of the HSP27 protein. Neuronal cells transfected with mutated HSPB1 were less viable than cells expressing the wild-type protein. Cotransfection of neurofilament light chain (NEFL) and mutant HSPB1 resulted in altered neurofilament assembly in cells devoid of cytoplasmic intermediate filaments.

Particle-type dependence of azimuthal anisotropy and nuclear modification of particle production in Au plus Au collisions at root s(NN)=200 GeV

Abstract: We present STAR measurements of the azimuthal anisotropy parameter v{sub 2} and the binary-collision scaled centrality ratio R{sub CP} for kaons and lambdas ({Lambda} + {bar {Lambda}}) at mid-rapidity in Au+Au collisions at {radical}s{sub NN} = 200 GeV. In combination, the v{sub 2} and R{sub CP} particle-type dependencies contradict expectations from partonic energy loss followed by standard fragmentation in vacuum. We establish p{sub T} {approx} 5 GeV/c as the value where the centrality dependent baryon enhancement ends. The K{sub S}{sup 0} and {Lambda} + {bar {Lambda}} v{sub 2} values are consistent with expectations of constituent-quark-number scaling from models of hadron formation by parton coalescence or recombination.

A survey of biometric recognition methods

Abstract: Biometric recognition refers to an automatic recognition of individuals based on a feature vector (s) derived from their physiological and/or behavioral characteristic. Biometric recognition systems should provide a reliable personal recognition schemes to either confirm or determine the identity of an individual. Applications of such a system include computer systems security, secure electronic banking, mobile phones, credit cards, secure access to buildings, health and social services. By using biometrics a person could be identified based on "who she/he is" rather then "what she/he has" (card, token, key) or "what she/he knows" (password, PIN). In this paper, a brief overview of biometric methods, both unimodal and multimodal, and their advantages and disadvantages, will be presented.

Quantitative analysis of the flavonoids in raw propolis from northern Croatia

Abstract: Spectrometric analyses of flavonoids in twenty propolis samples collected from ten different geographic localities in northern Croatia using two complementary methods, are reported. Flavones and flavonols were determined using aluminum chloride and expressed as quercetine equivalent while flavanones were determined using 2,4-dinitrophenylhydrazine and expressed as naringenin. Contents of flavones and flavonols were similar for most samples and ranged from 2 to 2.3%, except for one sample with a concentration of 1.3% and one sample in which it was not possible to detect flavones and flavonols. The content of flavanones in propolis samples is very variable. 55% of samples contain flavanons between 15 and 24% and 45% of samples between 4 and 14%. Total levels of flavonoids in raw propolis samples ranged between 5 and 26%; for the majority of samples (75%), the total level of flavonoids ranged between 15 and 25.9%. The high variability of flavanone concentration will affect biological activity of propolis preparations.

Increasing renewable energy sources in island energy supply : case study Porto Santo

Abstract: While the energy supply of most islands depends mainly on expensive oil derivatives’ importation, the others are linked by usually a weak electricity grid connection to the mainland. Due to high energy costs the islands are proving to be excellent test beds for the introduction of new technologies, and some islands are trying to become so-called renewable islands, to satisfy their energy demand mainly or entirely from indigenous and renewable sources, thus increasing the security of supply, and employment opportunities, without necessarily increasing the costs. Islands that have energy sources, such as hydro or geothermal energy, can easily integrate them into the power system, but those with mainly intermittent renewable energy sources are confronted with the necessity of energy storage. The most promising technologies are reversible hydro where geography allows, and storing hydrogen where it does not. The stored hydrogen can later be used for electricity production, and also for transport. This paper describes the H2RES model for optimisation of integration of hydrogen usage with intermittent renewable energy sources on the example of an isolated island in the Madeira archipelago, Porto Santo. It shows that it is possible to significantly increase the penetration of renewable energy sources, albeit at a relatively high cost, with hydrogen storage technology. The H2RES model, which includes reversible hydro and batteries as storage technologies, can serve as a valuable tool for island energy planning.

S-adenosylhomocysteine hydrolase deficiency in a human: A genetic disorder of methionine metabolism

Abstract: We report studies of a Croatian boy, a proven case of human S-adenosylhomocysteine (AdoHcy) hydrolase deficiency. Psychomotor development was slow until his fifth month; thereafter, virtually absent until treatment was started. He had marked hypotonia with elevated serum creatine kinase and transaminases, prolonged prothrombin time and low albumin. Electron microscopy of muscle showed numerous abnormal myelin figures; liver biopsy showed mild hepatitis with sparse rough endoplasmic reticulum. Brain MRI at 12.7 months revealed white matter atrophy and abnormally slow myelination. Hypermethioninemia was present in the initial metabolic study at age 8 months, and persisted (up to 784 μM) without tyrosine elevation. Plasma total homocysteine was very slightly elevated for an infant to 14.5–15.9 μM. In plasma, S-adenosylmethionine was 30-fold and AdoHcy 150-fold elevated. Activity of AdoHcy hydrolase was ≈3% of control in liver and was 5–10% of the control values in red blood cells and cultured fibroblasts. We found no evidence of a soluble inhibitor of the enzyme in extracts of the patient's cultured fibroblasts. Additional pretreatment abnormalities in plasma included low concentrations of phosphatidylcholine and choline, with elevations of guanidinoacetate, betaine, dimethylglycine, and cystathionine. Leukocyte DNA was hypermethylated. Gene analysis revealed two mutations in exon 4: a maternally derived stop codon, and a paternally derived missense mutation. We discuss reasons for biochemical abnormalities and pathophysiological aspects of AdoHcy hydrolase deficiency.

Teaching research methodology in medical schools: students' attitudes towards and knowledge about science

Abstract: Objective To explore the relationship between teaching scientific methodology in Year 2 of the medical curriculum and student attitudes towards and knowledge about science and scientific methodology. Design Anonymous questionnaire survey developed for this purpose. Setting Zagreb University School of Medicine, Croatia. Participants A total of 932 students (response rate 58%) from all 6 years were invited to participate. Main outcome measures Score on attitude scale with 45 Likert-type statements and score on knowledge test consisting of 8 multiple choice questions. Results The average attitude score for all students was 166 ± 22 out of a maximum of 225, indicating a positive attitude towards science and scientific research. The students' average score on the knowledge test was 3.2 ± 1.7 on 8 questions. Students who had finished Year 2 had the highest mean attitude (173 ± 24) and knowledge (4.7 ± 1.7) scores compared with other year groups (P < 0.001, anova and Tukey posthoc test). For students who had attended a mandatory Year 2 course on the principles of scientific research in medicine (Years 3 to 6), multiple linear regression analysis showed that knowledge test score (B = 3.4; SE = 0.4; 95% confidence interval 2.5–4.2; P < 0.001) and average grades (B = 7.6; SE = 1.5; 95% CI 4.6–10.6; P < 0.001) were significant predictors of attitude towards science, but not sex or failure to pass a year (B = − 0.6; SE = 1.7; 95% CI − 3.9–2.6; P = 0.707; and B = − 3.1; SE = 1.9; 95% CI − 6.8–5.7; P = 0.097, respectively). Conclusion Medical students have generally positive attitudes towards science and scientific research in medicine. Attendance of a course on research methodology is related to a positive attitude towards science.

Azimuthal Anisotropy at the Relativistic Heavy Ion Collider: The First and Fourth Harmonics

Abstract: We report the first observations of the first harmonic (directed flow, v(1)) and the fourth harmonic (v(4)), in the azimuthal distribution of particles with respect to the reaction plane in Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). Both measurements were done taking advantage of the large elliptic flow (v(2)) generated at RHIC. From the correlation of v(2) with v(1) it is determined that v(2) is positive, or in-plane. The integrated v(4) is about a factor of 10 smaller than v(2). For the sixth (v(6)) and eighth (v(8)) harmonics upper limits on the magnitudes are reported.

Posterior dislocation of the shoulder

Abstract: ©2004 British Editorial Society of Bone and Joint Surgery doi:10.1302/0301-620X.86B3. 14985 $2.00 J Bone Joint Surg [Br] 2004;86-B:324-32. Posterior dislocation of the shoulder is a rare but clinically and radiologically well-defined entity. It accounts for less than 2% of all dislocations of the shoulder,1,2 but is of diagnostic and therapeutic interest because most are missed on the initial examination.3-6 In a series of 24 patients with posterior dislocation, 21 had not been recognised initially.7 There is confusion between posterior subluxation and dislocation. Posterior dislocation is an acute entity associated with trauma and with an impression defect of the humeral head. Its treatment is determined by the size of the defect and the duration of the dislocation. The term dislocation has been applied, but in fact this represents subluxation because some of the articular surface of the humeral head is in contact with the glenoid and some behind it. Recurrent posterior subluxation is a distinct and separate entity which is often not associated with trauma and requires completely different management such as non-operative treatment or posterior reconstruction of the shoulder.8 The patient complains of pain and instability with his arm in a provocative position usually including forward flexion, adduction and internal rotation.9 There is also confusion between posterior dislocation and fracture-dislocation. Posterior dislocation may be associated with fractures of the surgical neck of the humerus or fractures of the tuberosities. Fracture-dislocations have been classified by Neer10 as two-, threeor four-part posterior fracture-dislocations. They require a different approach and treatment such as osteosynthesis or shoulder arthroplasty. This report describes the diagnosis and treatment of posterior dislocation of the shoulder with an associated impression fracture of the articular surface of the humeral head. Chronic posterior dislocation of the shoulder has often been referred to as being either ‘old’, ‘missed’, ‘locked’ or ‘fixed’. The terms ‘locked’ or ‘fixed’ have also been used to describe irreducible acute dislocations associated with an impression defect of the humeral head.11 Chronic posterior dislocation of the shoulder is a missed acute posterior dislocation which has been unrecognised for more than three weeks and characteristically there is an impression fracture of the articular surface of the humeral head.

A multiwavelength study of solar flare waves. I. Observations and basic properties

Abstract: Propagating wave-like disturbances associated with solar flares - commonly observed in the chromosphere as Moreton waves - have been known for several decades. Recently, the phenomenon has come back into focus prompted by the observation of coronal waves with the SOHO/EIT instrument ("EIT waves"). It has been suggested that they represent the anticipated coronal counterpart to Moreton waves, but due to some pronounced differences, this interpretation is still being debated. We study 12 flare wave events in order to determine their physical nature, using Hα, EUV, He I 10 830 A SXR and radioheliographic data. The flare wave signatures in the various spectral bands are found to lie on closely associated kinematical curves, implying that they are signatures of the same physical disturbance. In all events, and at all wavelengths, the flare waves are decelerating, which explains the apparent "velocity discrepancy" between Moreton and EIT waves which has been reported by various authors. In this paper, the focus of the study is on the morphology, the spatial characteristics and the kinematics of the waves. The characteristics of the common perturbation which causes the wave signatures, as well as the associated type II radio bursts, will be studied in companion Paper II, and a consistent physical interpretation of flare waves will be given.

A multiwavelength study of solar flare waves II. Perturbation characteristics and physical interpretation

Abstract: The study of solar flare waves - globally propagating wave-like disturbances usually observed in Hα as Moreton waves - has recently come back into focus prompted by the observation of coronal waves in the EUV with the SOHO/EIT in- strument ("EIT waves"), and in several additional wavelength channels. We study 12 flare wave events in order to determine their physical nature, using Hα, EUV, helium I, SXR and radioheliographic data. In the companion Paper I, we have presented the observational data and have discussed the morphology, spatial characteristics and the kinematics of the different flare wave signatures. The wavefronts observed in the various spectral bands were found to follow kinematical curves that are closely associated, implying that they are signatures of the same physical disturbance. In the present paper, we continue the study with a close examination of the evolution of the common perturbation that causes the different wave signatures, and with a detailed analysis of the metric type II radio bursts that were associated with all flare wave events. The basic characteristics of the waves are deceleration, perturbation profile broadening, and perturbation amplitude decrease. This behavior can be interpreted in terms of a freely propagating fast-mode MHD shock formed from a large-amplitude simple wave. It is shown that this scenario can account for all observed properties of the flare waves in the various spectral bands, as well as for the associated metric type II radio bursts.

Authorship criteria and disclosure of contributions: comparison of 3 general medical journals with different author contribution forms.

Abstract: ContextA number of general medical journals and the International Committee of Medical Journal Editors (ICMJE) request authors to disclose their contributions. Little is known about the effect of journal policies on authors' disclosure of their contributions.ObjectiveTo determine the number of named authors who do not meet ICMJE criteria for authorship, according to their published contributions, in 3 medical journals with different contribution disclosure practices.DesignObservational study of authors' contributions in research articles published in 2002 in Annals of Internal Medicine (n = 72), BMJ (n = 107), and JAMA (n = 81). BMJ asks authors to describe research contributions in their own words; Annals asks authors to choose from a list of coded contributions; and JAMA uses a structured checklist with instructions on contributions that qualify for ICMJE authorship criteria. Honorary authorship was defined as the lack of contribution from the first ICMJE criterion (study conception and design, or acquisition of data, or analysis and interpretation of data) and/or second (drafting the article or critical revision for important intellectual content) ICMJE criterion.ResultsAccording to authors' published contributions, the number of honorary authors was highest in Annals (121/562 authors, 21.5%), followed by BMJ (46/482, 9.5%), and JAMA (3/641, 0.5%) (χ22 = 146.67, P<.001). The number of articles with honorary authors was 60% in Annals, 21% in BMJ, and 4% in JAMA. Honorary authors had fewer published contributions than authors who met ICMJE criteria and were positioned more toward the end of the byline. Honorary authors either lacked contributions for both ICMJE criteria (10% in Annals and 22% in BMJ) or contributions to the second ICMJE criterion (75% in Annals, 67% in BMJ, and 2 out of 3 in JAMA).ConclusionsGeneral medical journals differed in prevalence of honorary authors according to published research contributions of named authors. Different authorship/contributorship policies and procedures should be explored as a possible explanation for the differences in contributions disclosed by authors among these journals.

Behavioral pattern continuity from prenatal to postnatal life--a study by four-dimensional (4D) ultrasonography.

Abstract: AIM: To investigate whether the same behavioral patterns were present pre- and postnatally, and whether there were any differences in the frequency of movements observed in fetal and in early neonatal life. SUBJECTS AND METHODS: Ten out of 37 pregnant women in the third trimester of pregnancy (median gestational age 34 weeks, range 33 to 35 weeks) in the two-month period (from November 1st to December 31st, 2003) were enrolled in the investigation. Ten term, appropriate for gestational age newborns (seven born vaginally, three by elective SC, six girls, six first-born) and were enrolled in the study. All 4D examinations were performed on Voluson 730 (Kretztechnik, Zipt, Austria) and Acuvix (Medison, Korea) with transabdominal 5 MHz transducer. After standard assessment in 2D B-mode ultrasound, a 4D mode was switched on and live 3D image was reconstructed by selecting the ideal representative 2D image placed in the region of interest (ROI). The recordings of neonatal behavior were made on the Sony P-612 OHMPL videotape by video camera (Sony Camcoder CC DTRV 318 Hv8) and reviewed on the videocassette recorder (Sony VHS SLV-N 900). The median of newborns' age at the moment of recording was 49 hours (range 4 to 112). During the examination, newborns were lying in the bed, separated from other infants in the nursery, dressed, and lying on their backs in a supine position with unrestrained hands. The temperature in the room was 22 to 24 degrees C. The video recording was performed mainly while the children were actively awake or during alert inactivity. RESULTS: There were no movements observed in fetal life that were not present in neonatal life, while the Moro reflex was present only in neonates. The most frequent fetal and neonatal movements were scowling, eye and mouth opening, and hand to face, hand to eye and hand to head movements. Isolated blinking, mouth to eyelid movement, yawning, tongue expulsion and scowling were more frequent in neonates than in fetuses, although the difference was not statistically significant. Hand to mouth movements were more frequent in neonatal than in fetal life while all other hand movements were less frequent in neonates than in fetuses, although the differences did not reach statistical significance. Spearman rank order correlation reached statistical significance in smiling (R=0.71 ; t=2.91 ; P=0.02) and in hand to ear movement (R = 0.80 ; t= 3.86 ; P = 0.005), and was almost statistically significant in isolated eye blinking (R=0.61 ; t=2.17 ; P =0.06), while the correlations between the rest of the movements were not statistically significant. CONCLUSIONS: 4D ultrasonography is a powerful tool in the assessment of fetal behavior, and our study showed that there is a continuity from fetal to neonatal behavior, especially in terms of isolated eye blinking movements, mouth and eyelid opening, yawning, tongue expulsion, smiling, scowling and hand movements directed to other parts of the face.

Movement performance and body size: the relationship for different groups of tests

Abstract: It has been shown that inconsistently applied normalization for body size could be an important methodological problem in testing physical performance in areas such as sports, physical education, ergonomy, or physical medicine and rehabilitation. The aim of this study was to evaluate a part of the recently proposed classification of physical performance tests (Jaric 2003) based on the role of body size in the tested performance. Presuming a normalization method P n=P/S b based on an allometric relationship between the tested performance P and a selected index of body size S (P n performance normalized for body size; b allometric parameter), we specifically hypothesized that: (1) the tests of exertion of external force (e.g., lifting weight, pushing, pulling), (2) tests of rapid movements (jumping, sprinting, kicking) and (3) tests of supporting body weight (chin-ups, squats) would reveal the values of the allometric parameters b=0.67, b=0 and b=−0.33 when body size is expressed as body mass, or b=2, b=0 and b=−1 when body size is expressed as body height, respectively. Male physical education students (n=77) were tested on 18 standard physical performance tests belonging to the aforementioned three groups. The obtained values of the allometric parameters proved to be closely in line with the hypothesized ones. While the finding regarding the tests of exertion of external force (i.e., the tested force should be divided by m 0.67 in order to normalize the force for body size) have been already demonstrated by some authors, the findings related to the tests of rapid movements and, particularly, tests of supporting body weight are novel. Although the normalization methods discussed need further evaluation, a more accurate and consistently applied assessment of the body size-independent indices of the evaluated groups of standard tests could improve the methodology of physical performance testing in general.

Band-splitting of coronal and interplanetary type II bursts - III. Physical conditions in the upper corona and interplanetary space

Abstract: We analyse properties of 58 type II radio bursts recorded in the meter-to-kilometer wavelength range, focusing on episodes of band-split emission. The basic two parameters utilized are the frequency drift D f = df/dt and the relative band-split BDW = Δf/f of type II burst emission lanes. On average, in the meter-to-kilometer wavelength range D f increases with the emission frequency as D f f 1 . 8 3 , revealing that source velocities are smaller at larger heliocentric distances. The relative band-split shows a weak but statistically significant dependence on the emission frequency, BDW f - 0 . 0 6 , indicating an increase of BDW with the heliocentric distance. Combining the shock velocity estimated from the frequency drift, with the Mach number inferred from the band-split, the Alfven speed and the magnetic field in the ambient plasma can be estimated as a function of the heliocentric distance r. However, the outcome directly depends on the coronal/interplanetary density model used, which is poorly known in the upper corona and the near-Sun interplanetary space. So, we invert the problem: utilizing the results of the previous paper where it was shown that beyond the heliocentric distance of two solar radii (r/r O . = R > 2) the average magnetic field decreases approximately as B R - 2 , we infer the density n(R) in the upper corona and near-Sun interplanetary space. The obtained empirical dependence n(R) is presented in the analytical form as a four-degree polynomial of 1/R, and is compared with some theoretical n(R) models, considering also a deviation from the B 1/R 2 scaling used. The model matches the five-fold Saito density model (representing the active region corona) with the n R - 2 regime in the interplanetary space. Furthermore, it is shown that on average the magnetosonic speed attains a local minimum of v m s 400 km s - 1 around R = 3 and a broad local maximum of v m s 500 km s - 1 in the range R = 4-6, beyond which it gradually decreases to several tens km s - 1 at 1 a.u. The local minimum becomes even deeper if the super-radial expansion of the magnetic field is taken into account. The implications regarding the formation and evolution of shocks in the corona and upper corona are discussed in the framework of CME-piston and flare-blast scenarios. The inferred general decrease of type II burst source velocities and broadening of band-splits with distance is interpreted in terms of the deceleration of mass ejections driving the shocks in the decreasing v m s environment.

The prevalence of non-carious cervical lesions in permanent dentition

Abstract: A non-carious cervical lesion (NCCL) is the loss of hard dental tissue on the neck of the tooth, most frequently located on the vestibular plane. Causal agents are diverse and mutually interrelated. In the present study all vestibular NCCL were observed and recorded by the tooth wear index (TWI). The aim of the study was to determine the prevalence and severity of NCCL. For this purpose, 18555 teeth from the permanent dentition were examined in a population from the city of Rijeka, Croatia. Subjects were divided into six age groups. The teeth with most NCCL were the lower premolars, which also had the largest percentage of higher index levels, indicating the greater severity of the lesions. The most frequent index level was 1, and the prevalence and severity of the lesions increased with age.

Assessing the genetic diversity of Portuguese maize germplasm using microsatellite markers

Abstract: A collection of Portuguese maize accessions representing a valuable source of genes for introduction into modern cultivars is stored at the Portuguese Plant Germplasm Bank (Banco Portugues de Germoplasma Vegetal—BPGV). To assess genetic diversity among inbreds, microsatellite analysis was carried out for 54 inbred lines representing the diversity of Portuguese dent and flint maize germplasm. Fifty American and other European elite inbreds were also analysed for comparison. Fifteen microsatellite loci distributed throughout the maize genome were chosen based on their repeat unit and base composition. A total of 80 alleles were detected with an average allele number of 5.33 per locus. Polymorphism information content (PIC) values and observed genetic distances showed the existence of large variability among inbreds. Cluster analysis indicated that almost all of the inbreds could be distinguished from each other and Portuguese inbreds were present in all clusters formed. These associations were consistent with the known pedigree records of the inbreds, confirming a mixed origin of Portuguese materials. Comparative analysis of microsatellite diversity among groups was established according to important traits for both breeding and line identification. This revealed that, although most of the genetic diversity (>95%) was attributable to differences among inbreds of different groups, the existence of phenotypic differentiation in endosperm colour, kernel type and cob colour could be suggested for grouping. These findings support the joint use of molecular and morphological traits in management of the germplasm collection. In this study, SSR markers proved to be effective to characterise and identify maize inbred lines, and demonstrate associations among them.

Academic misconduct among medical students in a post-communist country.

Abstract: Aim To assess the prevalence of, attitudes towards and willingness to report different forms of academic dishonesty among medical students in a post-communist transitional country. Methods An anonymous, self-administered questionnaire was distributed to medical students in Years 2−6 at the Zagreb University School of Medicine; 827 (70%) valid questionnaires were returned and analysed. Results Most of the students (94%) admitted cheating at least once during their studies. The most frequent type of misconduct was ‘signing in an absent student on a class attendance list’ (89.1%), and the least frequent ‘paying for passing an examination’ (0.7%). The number of committed types of misconduct out of 11 listed types increased from Year 2 (median 2) to Year 6 (median 4). Cheating behaviours could be clustered into 4 groups based on self-reported cheating, perceived prevalence of cheating, attitude towards cheating, and willingness to report cheating. The clustered behaviours that most students admitted to were perceived as the most frequent, more approved of and less likely to be reported. The strongest predictors of dishonest behaviour were attitude, perception of peer group behaviour and study year. Almost half (44%) the students said they would never report any form of cheating. Conclusion Academic misconduct is widespread among medical students at the largest medical school in Croatia and its prevalence is greater than that reported for developed countries. This may be related to social and cultural factors specific to a country in the midst of a post-communist transition to a market economy, and calls for measures to be instigated at an institutional level to educate against and prevent such behaviour.

Genetic diversity of hexaploid wheat cultivars estimated by RAPD markers, morphological traits and coefficients of parentage

Abstract: Estimates of genetic diversity can be based on different types of data. The aim of this research were to study genetic diversity among Croatian wheat cultivars by random amplified polymorphic DNA (RAPD) markers, morphological traits and pedigree records; to analyse differences between wheat cultivars from two breeding centres; and to evaluate usability of RAPD markers for estimation of genetic diversity among wheat cultivars in comparison with morphological traits and pedigree record data. Studies were conducted on 14 wheat cultivars and breeding lines from two breeding centres in Croatia. For the RAPD analysis 36 primers were screened and the 14 most polymorphic ones yielded 341 polymorphic bands. Twelve morphological traits were used for morphological analysis. Pedigrees were composed of seven generations of ancestors. RAPD markers showed a high level of polymorphism among the cultivars examined and the breeding lines. No significant correlations were observed among the methods tested.

Evidence of genetic distinction and long‐term population decline in wolves (Canis lupus) in the Italian Apennines

Abstract: Historical information suggests the occurrence of an extensive human-caused contraction in the distribution range of wolves (Canis lupus) during the last few centuries in Europe. Wolves disappeared from the Alps in the 1920s, and thereafter continued to decline in peninsular Italy until the 1970s, when approximately 100 individuals survived, isolated in the central Apennines. In this study we performed a coalescent analysis of multilocus DNA markers to infer patterns and timing of historical population changes in wolves surviving in the Apennines. This population showed a unique mitochondrial DNA control-region haplotype, the absence of private alleles and lower heterozygosity at microsatellite loci, as compared to other wolf populations. Multivariate, clustering and Bayesian assignment procedures consistently assigned all the wolf genotypes sampled in Italy to a single group, supporting their genetic distinction. Bottleneck tests showed evidences of population decline in the Italian wolves, but not in other populations. Results of a Bayesian coalescent model indicate that wolves in Italy underwent a 100- to 1000-fold population contraction over the past 2000-10,000 years. The population decline was stronger and longer in peninsular Italy than elsewhere in Europe, suggesting that wolves have apparently been genetically isolated for thousands of generations south of the Alps. Ice caps covering the Alps at the Last Glacial Maximum (c. 18,000 years before present), and the wide expansion of the Po River, which cut the alluvial plains throughout the Holocene, might have provided effective geographical barriers to wolf dispersal. More recently, the admixture of Alpine and Apennine wolf populations could have been prevented by deforestation, which was already widespread in the fifteenth century in northern Italy. This study suggests that, despite the high potential rates of dispersal and gene flow, local wolf populations may not have mixed for long periods of time.