bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Investigation of Thermal Dispersion in Saturated Soils with One‐Dimensional Water Flow
Authors: Lu Xinrui , Ren Tusheng , Gong Yuanshi
Published: October 2009

Microscopic differences in soil pore water velocity cause hydrodynamic dispersion of solute transport. By analogy, thermal dispersion should be considered in soils where water and heat flow occur simultaneously. Few published data are available regarding thermal dispersion in soils. In this study, we investigated thermal dispersion influences on heat transport in saturated soils with one‐dimensional water flow. A new soil container was developed to eliminate wall flow influences on saturated water flow. An inverse model was applied to obtain the thermal dispersion coefficient (λd) by fitting the conduction–convection–dispersion (CCD) model to soil temperature change as a function of time from heat‐pulse measurements. Thermal dispersion became significant when the water flux was higher than a threshold value. In the studied water flux range, the maximum contribution of hydrodynamic dispersion to effective heat conduction [λd/(λd + λ0), where λ0 is the bulk thermal conductivity] was 6, 9, and 12% in a sand, a silt loam, and a sandy clay loam, respectively. A power function relationship was established between λd and the soil water flux density (Jw): λd = kJw0.9, where k is a coefficient related to soil texture. Experimental evaluation indicated that, compared with the conduction–convection model, the CCD model performed better in describing the temperature change vs. time data from heat‐pulse measurements.
Extracting Topsoil Information from EM38DD Sensor Data using a Neural Network Approach
Authors: Cockx L. , Van Meirvenne M. , Vitharana U. W. A. , Verbeke L. P. C. , Simpson D. , Saey T. , Van Coillie F. M. B.
Published: October 2009

Electromagnetic induction soil sensors are an increasingly important source of secondary information to predict soil texture. In a 10.5‐ha polder field, an EM38DD survey was performed with a resolution of 2 by 2 m and 78 soil samples were analyzed for sub‐ and topsoil texture. Due to the presence of former water channels in the subsoil, the coefficient of variation of the subsoil clay content (45%) was much larger compared with the topsoil (13%). The horizontal (ECa–H) and vertical (ECa–V) electrical conductivity measurements displayed a similar pattern, indicating a dominant influence of the subsoil features on both signals. To extract topsoil textural information from the depth‐weighted EM38DD signals we turned to artificial neural networks (ANNs). We evaluated the effect of different input layers on the ability to predict the topsoil clay content. To identify the response of the topsoil, both EM38DD orientations were used. To examine the influence of the local neighborhood, contextual ECainformation by means of a window around each soil sample was added to the input. The best ANN model used both ECa–H and ECa–V data but no contextual information: a mean squared estimation error of 2.83%2was achieved, explaining 65.5% of the topsoil clay variability with a variance of 0.052%2So, with the help of ANNs, the prediction of the topsoil clay content was optimized through an integrated use of the two EM38DD signals.
Geochemical Resilience of a Ferralsol Subjected to Anoxia and Organic Matter Amendment
Authors: Lahlah Jasmina , Renault Pierre , Cazevieille Patrick , Buzet Aurélie , Hazemann Jean-Louis , Womes Manfred , Cambier Philippe
Published: October 2009

The spreading of vinasse on soils may favor not only anoxia but also mineral alterations and metal mobilization. Our aims were to record the geochemical changes occurring in a ferralsol subjected to vinasse input and anaerobiosis, and to check for soil resilience after a return to aerobic conditions. Soil slurries were therefore incubated under successive 7 d of aerobic, 0 to 28 d of anaerobic, and 28 d of aerobic conditions, vinasse being supplied at one of three levels when anaerobiosis began. At several dates, the slurry solution was characterized (pH and organic and mineral compounds) and Mn and Fe oxidation states in solids were assessed. Before incubations, about 20% of the Fe in solids was already reduced, whereas almost all Mn was found as Mn(IV). During the first aerobic period, mobilized metals included Pb, Zn, Ni, Cu, and Cr. After vinasse input during the first 14 d of anaerobiosis, the principal biotransformations were fermentation and true acetogenesis; Fe and Mn were mobilized during this period (up to 4.05 and 6.2 mmol L−1, respectively), and most Mn and an unknown but small fraction of Fe in solids were reduced. During the subsequent 14 d of anaerobiosis, only acetoclastic methanogenesis was observed. The return to aerobic conditions led to rapid oxidative immobilization of Fe, desorption of exchangeable Fe(II), and the partial immobilization of other metals (Ca, Mg, K, Na, Mn, Pb, and Ni). Manganese was not oxidized, and there was no return to the initial conditions for Fe and Mn in solids.
Improving Rietveld‐Based Clay Mineralogic Quantification of Oxisols Using Siroquant
Authors: Alves M. E. , Omotoso O.
Published: October 2009

Although mineralogic quantitative phase analysis (QPA) of the soil clay fraction can provide useful information for the improvement of soil management practices, QPA often requires a combination of several analytical techniques, which can be expensive and time consuming. One alternative that involves a single analysis to give accurate QPA of soils is the use of the Rietveld method to analyze powder x‐ray diffraction (XRD) data. In this study, we evaluated the accuracy of the XRD–Rietveld approach for mineralogic quantitative analyses of Oxisol clays when observed structure factors [F(hkl)] of pedogenic minerals (i.e., kaolinite, hematite, and goethite) are used in the Rietveld analyses performed using Siroquant software. The results showed that although the structures of disordered clay minerals are especially difficult to incorporate in standard Rietveld refinement, which relies on ordered three‐dimensional structure models, Mineralogic quantification can be accurately done for complex matrices having a large number of phases and various degrees of structural and compositional disorders when observedF(hkl) values are used. It is also possible to develop observedF(hkl) values for Al‐hematite and Al‐goethite from impure samples of such oxides to use as starting structure models for Rietveld analysis. We believe that this approach can be successfully extended to other geologic materials.
Prediction Soil Fertilization Maps Using Logistic Modeling and a Geographical Information System
Authors: Elprince Adel M.
Published: October 2009

Multivariable fertilizer recommendation (MVFR) models allowed for variable rate fertilizer applications and precision agriculture. The objectives of this study were (i) to use binary logistic modeling to assess the importance of site variables in farms' decisions for implementing optimal N and K fertilization, and (ii) to combine multivariable logistic models in a geographic information system for the prediction of N and K fertilization class maps. These were based on experimental optimal N and K fertilization data at 67 sites and survey data for 22 site variables in an arid date palm (Phoenix dactyliferaL.) region (20,000 ha). Only nine of the 22 site variables were found to be statistically significant in influencing the probability of N and K responses: surface Fe, Mn, and Cu; profile residual NO3–N; surface organic matter (OM), sand, and clay; surface extract soil salinity (ECes), and quantity of irrigation water (Qiw). The probability of response (Y= 1 means success andY= 0 indicates failure) to the levels of minor, major, and excessive N application were expressed by the logistic models: logit[Pr(Y= 1|N = 0.25,0.5,1|X)] = 0.574 − 0.015Qiw+ 0.768ECes+ 0.455Fe − 1.336 Cu, logit[Pr(Y= 1|N = 0.5,1|X)] = 3.274 − 0.011Qiw− 0.307Mn, and logit[Pr(Y= 1|N = 1|X)] = 4.394 + 1.463ECes− 0.826NO3–N, respectively. The corresponding models for K were: logit[Pr(Y= 1|K = 0.25,0.5,1|X)] = 4.424 − 0.104OM − 0.108NO3–N, logit[Pr(Y= 1|K = 0.5,1|X)] = −1.189 + 0.015Qiw, and logit[Pr(Y= 1|K = 1|X)] = 37.582 − 0.560Mn − 0.036Sand − 0.046Clay. These logistic models were cross‐validated and combined in a geographic information system to derive N and K fertilization class maps using kriged‐interpolated data sets of the significant site variables. Logistic modeling could utilize low‐cost data for MVFR model calibration and validation and the production of soil fertilization maps with larger scales.
Timing of Broadcast Phosphorus Fertilization for No‐Till Corn and Soybean
Authors: Mallarino A. P. , Barcos S. R. , Prater J. R. , Wittry D. J.
Published: October 2009

Iowa research has shown a small and inconsistent grain yield response to P fertilizer placement methods for no‐till corn (Zea mays L.) and soybean [Glycine max (L.) Merr.]. One reason for this result might be that P was broadcast in the fall (before snow and 4–5 mo before planting crops) with sufficient time to reach soil and active roots. We evaluated fall and spring broadcast P application for no‐till corn and soybean by conducting 20 single‐year trials during 3 yr in Iowa soils with 6 to 29 mg P kg−1 (Bray‐P1, 15‐cm depth). Triple superphosphate was broadcast at 0, 10, 20, 30, 40, and 50 kg P ha−1 in the fall (November or December) or in spring before planting crops. We measured early plant growth (dry weight, DW), early plant P concentration and uptake (V5–V6 growth stage), and grain yield. Crop responses to P (P < 0.1) were observed at five corn sites and seven soybean sites for yield, three corn sites and three soybean sites for early DW, and six corn sites and five soybean sites for early P uptake. Yield responses occurred in soils with ≤21 mg P kg−1 The timing of P application did not affect yield or early DW, and there were inconsistent differences for early P uptake at two sites. We concluded that the time of application did not affect the efficacy of P broadcast for no‐till crops in this study, but results should not be directly extrapolated to regions with different soils and climate.
The Nature of Organic Matter and Sorption of Phosalone in Soil
Authors: Popova Inna E. , Deng Shiping , Nofziger David L. , Eastman Margaret A.
Published: October 2009

The nature and quantity of soil organic matter play dominant roles controlling the fate of pesticide in the environment. We hypothesized that land use such as cultivation has profound impacts to the nature and quantity of soil organic carbon (SOC), and thus affects the mechanisms as well as magnitude of pesticide sorption in soil. Twenty‐one soils with a wide range of properties under various land uses were examined in this study. The specific objectives were to evaluate the nature of SOC using solid state nuclear magnetic resonance (NMR), and to determine sorption behavior of a nonionic pesticide, phosalone (S‐6‐chloro‐2,3‐dihydro‐2‐oxobenzoxazol‐3‐ylmethyl O,O‐diethyl phosphorodithioate) in these soils, and to elucidate the relationships between SOC fractions and sorption parameters in cultivated and uncultivated soils. As revealed by NMR spectra and principal component analysis (PCA) of tested variables, the quantity and composition of SOC differed considerably between cultivated and uncultivated soils. The decline of O‐alkyl carbon fraction of SOC is proportional to the increase in fractions of aryl carbon, O‐aryl carbon, and ketones/aldehydes carbon with the correlation coefficients of 0.78***, 0.66***, and 0.82***, respectively (n = 21). This change in the SOC composition and quantity led to changes in the sorption behavior of phosalone in soil. Uncultivated soils exhibited a linear increase of pesticide binding strength to SOC (organic carbon [OC] partition coefficients) with the increase of the reciprocal OC content (r = 0.95***, n = 9), while this relationship was not observed in cultivated soils. The obtained results suggested that mechanisms of pesticide sorption were different in cultivated and uncultivated soils.
Wettability and Hysteresis Effects on Water Sorption in Relatively Dry Soil
Authors: Davis Dedrick D. , Horton Robert , Heitman Joshua L. , Ren Tusheng
Published: October 2009

The soil water retention curve (SWRC) is a key tool for understanding the fundamental relationship between soil moisture content and its associated energy. The objective of this study was to measure soil water retention including hysteresis at the dry end of the SWRC and to examine the effect of wettability on the SWRCs of two wettable soils and their hydrophobized counterparts. Two conditions, wettable and hydrophobic, were measured for each soil. The method used to measure the SWRCs was vapor equilibration over salt solutions of known osmotic potentials. Free water in the form of individual droplets was found to be present at the surface of the unwashed hydrophobic soils due to decreases in the osmotic potential during the hydrophobizing process. Water droplets did not form on the hydrophilic and washed hydrophobic soils. Soil wettability was found to affect soil water retention in relatively dry soil. The hydrophilic soils used in this study exhibited significant hysteresis in the water potential range of −2.3 to −19.2 MPa. Soil wettability and hysteresis should be considered when studying water sorption and desorption in relatively dry soil.
Process‐Based Assessment of Phosphorus Availability in a Low Phosphorus Sorbing Forest Soil using Isotopic Dilution Methods
Authors: Achat David L. , Bakker Mark R. , Morel Christian
Published: October 2009

Our objective was to evaluate the relative contribution of physicochemical (diffusion) and biological (mineralization) processes to the supply of ionic P (iP) in solution and potential P availability to plants in a low P sorbing forest soil. To this end, we quantified the gross amount of diffusive iP (ionic P species that can be transferred from the solid phase to the soil solution due to a gradient of concentration, FDIFF), P remineralization (gross mineralization of microbial P, FREM), and gross mineralization of P in dead soil organic matter (FMDSOM) using isotopic dilution techniques during a long‐term (154 d) incubation experiment. Initial pools of P in dead soil organic matter and of microbial P represented high proportions (77 and 17%, respectively) of total P (31 μg g−1). The FMDSOM value (1.0 μg g−1) was lower than the FDIFF value (1.2 μg g−1) during the 154‐d period of incubation. The FMDSOM and FDIFF values were quantitatively very low compared with FREM (13.7 μg g−1). The FREM value contributed largely to the total pool of isotopically exchangeable iP (89%), suggesting that microorganisms play a crucial role in P availability and cycling. Net organic P mineralization (FMDSOM + FREM – P immobilization by microorganisms) caused a large increase (340%) in readily available P (iP in solution). Extrapolated to longer time scales (1 yr or more), FMDSOM appeared to be higher than FDIFF since FDIFF rapidly reaches its theoretical maximum value. We conclude that, in our low P sorbing sandy forest soil, inorganic P sorbed to the solid phase represented a small but rapidly available pool, and P in dead soil organic matter a larger but slowly available pool. Our work showed that the relative contribution of physicochemical or biological processes to plant available P depends on the length of the observation period. Limits of the isotopic dilution approaches to quantify gross or net organic P mineralization are discussed.
Making Soil Oxidation–Reduction Potential Measurements using Multimeters
Authors: Rabenhorst M. C.
Published: October 2009

Researchers studying the chemistry of soil systems may be interested in documenting the oxidation–reduction potential (Eh) for a variety of purposes, and this is often accomplished by measuring the Eh using platinum (Pt) electrodes in conjunction with a reference electrode and a voltmeter. It has been shown that Eh values obtained when using high resistance research grade instruments often are much different from values measured using standard multimeters. This difference appears to be a function of the input resistance, with the low resistance multimeters allowing a higher current to flow during measurement which alters the electrochemical environment causing the voltage to drift. The objectives of this paper are (i) to report on a device which when attached to a low resistance multimeter facilitates the accurate measurement of soil redox potential, and (ii) to better understand the nature of the drift observed when measurements are made using a standard multimeter. Redox potentials were measured with Pt and calomel electrodes in soil mesocosms using a research grade voltmeter and a standard multimeter, with and without an inexpensive device that effectively increased the input resistance of the multimeter to 1 Tohm. The device was constructed using a TL082 wide bandwidth dual JFET input operational amplifier which effectively raised the input resistance from 10 Mohm to approximately 1 Tohm. When a small correction factor was applied to account for the internal offset error from the amplifier, the Eh data recorded using the modified multimeter were essentially identical to those collected using higher end, research grade instruments (n = 162; Y = 0.9996X– 0.09; r2 = 1.0000). Depending on the pH of the system and the type of reference electrode used, and the redox couple of interest, Eh data collected using standard multimeters could lead to erroneous conclusions regarding whether a soil is oxidized or reduced.
Contemporary Evidence of Soil Carbon Loss in the U.S. Corn Belt
Authors: Senthilkumar S. , Basso B. , Kravchenko A. N. , Robertson G. P.
Published: October 2009

Temporal changes in soil C content vary as a result of complex interactions among different factors including climate, baseline soil C levels, soil texture, and agricultural management practices. The study objectives were: to estimate the changes in soil total C contents that occurred in the past 18 to 21 yr in soils under agricultural management and in never‐tilled grassland in southwest Michigan; to explore the relationships between these changes and soil properties, such as baseline C levels and soil texture; and to simulate C changes using a system approach model (SALUS). The data were collected from two long‐term experiments established in 1986 and 1988. Georeferenced samples were collected from both experiments before establishment and then were resampled in 2006 and 2007. The studied agricultural treatments included the conventional chisel‐plow and no‐till management systems with and without N fertilization and the organic chisel‐plow management with cover crops. Total C was either lost in the conventional chisel‐plowed systems or was only maintained at the 1980s levels by the conservation management systems. The largest loss in the agricultural treatments was 4.5 Mg ha−1total C observed in the chisel‐plow system without N fertilization. A loss of 17.3 Mg ha−1occurred in the virgin grassland soil. Changes in C content tended to be negatively related to baseline C levels. Under no‐till, changes in C were positively related to silt + clay contents. The SALUS predictions of soil C changes were in excellent agreement with the observed data for most of the agricultural treatments and for the virgin soil.
Separation of Coarse Organic Particles from Bulk Surface Soil Samples by Electrostatic Attraction
Authors: Kaiser M. , Ellerbrock R. H. , Sommer M.
Published: October 2009

Different separation procedures are suggested for studying the stability and functionality of soil organic matter (OM). Density fractionation procedures using high‐molarity, water‐based salt solutions to separate organic particles may cause losses or transfers of C between particle and soluble OM fractions during separation, which may be a result of solution processes. The objective of this study was to separate coarse organic particles (>0.315 mm) from air‐dried surface soil samples to avoid such solution processes as far as possible. Air‐dried surface soil samples (<2 mm) from nine adjacent arable and forest sites were sieved into five soil particle size fractions (2–1.25, 1.25–0.8, 0.8–0.5, 0.5–0.4, and 0.4–0.315 mm). Coarse organic particles were separated from each of these fractions using electrostatic attraction by a charged glass surface. The sum of the total dry matter content of the electrostatically separated coarse organic particles ranged from 0.05 to 140 g kg−1 Scanning electron microscopy images and organic C (OC) analyses indicated, however, that the coarse organic particle fractions were also composed of 20 to 76% mineral particles (i.e., 200–760 g mineral kg−1 fraction). The repeatability of the electrostatic attraction procedure falls within a range similar to that of accepted density fractionation methods using high‐molarity salt solutions. Based on the similarity in repeatability, we suggest that the electrostatic attraction procedure will successfully remove coarse organic particles (>0.315 mm) from air‐dried surface soil samples. Because aqueous solutions are not used, the electrostatic attraction procedure to separate coarse organic particles avoids C losses and transfers associated with solution‐dependent techniques. Therefore, this method can be used as a pretreatment for subsequent density‐ or solubility‐based soil OM fractionation procedures.
An Improved Model of Nitrogen Release for Surface‐applied Controlled‐release Fertilizer
Authors: Fujinuma Ryosuke , Balster Nick J. , Norman John M.
Published: October 2009

Empirical temperature models are commonly used to estimate N release from polymer‐coated controlled‐release fertilizers (CRFs) under field conditions where the influence of soil moisture is negligible. For surface‐applied CRF in bare‐root nurseries, the effect of soil moisture may be important. To quantify the effect of soil moisture on N release from surface‐applied CRF, two experiments were conducted in a sandy‐textured soil: (i) a laboratory experiment to develop two semiempirical models that characterized the effect of soil temperature (T model) and moisture (MT model) on N release, and (ii) a field experiment to evaluate the precision of these models. In the laboratory experiment, the N release from CRF (urea, 41–0–0, ∼2‐mo release) was measured under 16 combinations of four soil temperatures (5, 10, 23, and 35°C) and four soil moisture contents (0.002, 0.04, 0.11, 0.22 kg kg−1). The calculated time constants for each abiotic combination showed that both soil temperature and soil moisture content controlled the cumulative N release (CNR). The difference between model estimates and field measurements of CNR indicated that the T model significantly underestimated CNR by as much as 18% (P< 0.01). In contrast, this difference was reduced to 8% using the MT model; the slope of the least‐square fit for the MT model was not significantly different from unity at the 1% level and just significant at 5% (P= 0.052). Therefore, we argue that a model parameterized by both soil temperature and soil moisture will improve estimates of CNR from surface‐applied CRF in irrigated tree nurseries.
Proton Charge and Adsorption of Humic Acid and Phosphate on Goethite
Authors: Shuai Xiufu , Zinati Gladis
Published: October 2009

Little information is available about the changes of the proton charge of goethite in the presence of phosphate (P) and humic acid (HA). The objectives of this study were to systematically measure the proton charge of the ternary mixture and adsorption of HA and P on goethite. The potentiometric titration method was used to measure proton charges in single, binary, and ternary mixtures of goethite, HA, and P as a function of pH and ionic strengths. Results showed that proton charge in the ternary mixture became more negative with increasing pH and the loadings of HA and P. The point of zero charge (PZC) decreased linearly with the initial concentrations of HA and P. At low to intermediate pH, little variation was observed in adsorption of P on goethite in the presence of HA. A small reduction in the adsorption of P in the presence of HA was observed when compared with the control (without HA loading) at high pH. In 2008, Weng et al. developed a model describing the electrostatic interaction between HA and P at the 1‐plane of the compact part of the electrical double layer (EDL). In this study, Weng et al.'s model was used to interpret the effect of adsorbed HA on the adsorption of P on goethite as well as the nonsignificant interaction of PZC between HA and P.
The Stakes in the Google Book Search Settlement
Authors: Courant Paul N
Published: October 2009

Google has scanned millions of works from the world's great libraries, but will we be able to read them on-line, asks Paul N. Courant?
The investigation of ultrasound efficacy in cleaning the surface of new endodontic instruments
Authors: Popovic Jelena , Gasic Jovanka , Radicevic Goran
Published: October 2009

Introduction. Active parts and tips of various new stainless steel and nickel-titanium endodontic instruments can be coated with fragments or metal residues, which can become detached during endodontic treatment. These fragments may obstruct the root canals or even reach the periapical tissue during biomechanical preparation and should be removed before clinical use. Objective. The aim of this study was to evaluate the presence of metal residues on both new stainless steel and nickel-titanium endodontic instruments, and to determine the cleaning efficacy of ultrasound using distilled water or disinfectant solution for removing these residues. Methods. Forty-eight stainless steel and nickel-titanium instruments were carefully removed from their original packages with dental tweezers, in order to avoid any contact with the cutting flutes and tips. The instruments were evaluated in term of metal debris presence, using scanning electron microscopy (SEM) and x-ray energy-dispersive spectroscopy (EDS). The instruments were then removed from the electron microscopy analysis stubs and placed in an ultrasonic bath for 15 minutes at a frequency of 28 kHz, using distilled water or disinfectant solution. The surfaces of the instruments were re-evaluated after cleaning. Results. Before ultrasound cleaning, a larger amount of metal debris was observed on the nickel-titanium endodontic instruments when compared to those made of stainless steel. The presence of metal particles on the instruments was evaluated by using EDS analysis. The use of ultrasound was effective in removing the metal residues from both types of endodontic instrument surfaces. Conclusion. The use of ultrasound proved to be an efficient method for the removal of metal particles from the surface of new stainless steel and nickel-titanium endodontic instruments.
The influence of continuous magnetic field on periodontal tissues under overdentures
Authors: Brkovic-Popovic Snezana , Stamenkovic Dragoslav , Stanisic-Sinobad Darinka , Rakocevic Zoran , Zelic Obrad
Published: October 2009

Introduction. Last remained teeth with reduced alveolar support do not have long-term prognosis, which is the reason for prolonging the life and thus providing a stable support of overdenture. The data from literature point out that static magnetic field has certain possibilities in resolving such problems. Objective. Having in mind the pathogenetic factors which cause the reduction of the alveolar ridge and periodontal problems in our population, as well as osteoblastic and antiinflamatory activity, the aim of this investigation was to assess the effect of static magnetic field on periodontal tissue under the overdenture. Methods. The investigation involved 38 partially edentulous patients, of both sexes and similar oral status who were bearers of a lower complete overdenture and upper classic complete denture as antagonist restoration. In the base of the lower overdenture the micromagnets were installed in the region of the remained teeth, which had static concentrated field of 60-80 mT power. The evaluation was done after 3, 6 and 12 months using the method of light densitometry. Periodontologic analysis was performed by standard and modified periodontologic tests. Results. In patients with overdentures, after exposure to a magnetic field, the density of bone was not significantly changed, but the use of ANOVA disclosed changes in the observed interval. The tendency of increased density of the alveolar part of the observed region was noted. The region of the corresponding tooth of the contralateral side without magnetic influence showed decreased density of this region in the observed intervals. Plaque index and gingival index were improved under the influence of the magnetic field, while after 6 and 12 months following the magnet insertion statistically significant changes were confirmed. The magnetic devices did not show any influence on the level of the gingival margin and junction epithelium. Conclusion. Static magnetic field is to be considered as a noninvasive procedure which is recommended to patients with reduced number of teeth and alveolar support.
The significance of amlodipine on autonomic nervous system adjustment (ANSA method): A new approach in the treatment of hypertension
Authors: Milovanovic Branislav , Trifunovic Danijela , Milicevic Nebojsa , Vasic Karin , Krotin Mirjana
Published: October 2009

Introduction. Cardiovascular autonomic modulation is altered in patients with essential hypertension. Objective To evaluate acute and long-term effects of amlodipine on cardiovascular autonomic function and haemodynamic status in patients with mild essential hypertension. Methods. Ninety patients (43 male, mean age 52.12 ?10.7) years with mild hypertension were tested before, 30 minutes after the first 5 mg oral dose of amlodipine and three weeks after monotherapy with amlodipine. A comprehensive study protocol was done including finger blood pressure variability (BPV) and heart rate variability (HRV) beat-to-beat analysis with impedance cardiography, ECG with software short-term HRV and nonlinear analysis, 24-hour Holter ECG monitoring with QT and HRV analysis, 24-hour blood pressure (BP) monitoring with systolic and diastolic BPV analysis, cardiovascular autonomic reflex tests, cold pressure test, mental stress test. The patients were also divided into sympathetic and parasympathetic groups, depending on predominance in short time spectral analysis of sympathovagal balance according to low frequency and high frequency values. Results. We confirmed a significant systolic and diastolic BP reduction, and a reduction of pulse pressure during day, night and early morning hours. The reduction of supraventricular and ventricular ectopic beats during the night was also achieved with therapy, but without statistical significance. The increment of sympathetic activity in early phase of amlodipine therapy was without statistical significance and persistence of sympathetic predominance after a few weeks of therapy detected based on the results of short-term spectral HRV analysis. All time domain parameters of long-term HRV analysis were decreased and low frequency amongst spectral parameters. Amlodipne reduced baroreflex sensitivity after three weeks of therapy, but increased it immediately after the administration of the first dose. Conclusion. The results of the study showed that amlodipine affected autonomic modulation as a shift to sympathetic hyperactivity, but without statistical significance. In the selected group of patients with vagal predominance in sympathovagal balance, amlodipine increased sympathetic and decreases vagal activity. Therefore we conclude that amlodipine mostly exerts impact on autonomic function modulation in patients with vagal predominance in resting state.
Incidence of penile curvature in various forms of hypospadias
Authors: Djordjevic Miroslav , Stojanovic Borko , Stojsavljevic Miodrag , Ducic Sinisa , Bizic Marta , Majstorovic Marko
Published: October 2009

Introduction. Hypospadias is a congenital anomaly of the penis, characterised by ectopically positioned urethral meatus and associated anomalies (cryptorchidism, inguinal hernia, penile curvature). Proximal forms of hypospadias, as severe cases, are particularly accompanied by penile curvature (chordee). Distal types are considered to be mild degrees. Objective. To determine the incidence of congenital curvature within various forms of hypospadias in order to signify preoperative and intraoperative diagnosis of chordee as a part of hypospadias repair. Methods. The total of 454 patients with hypospadias were treated surgically in a five-year period (2001-2006.) at the University Children's Hospital of Belgrade. The patients were divided into two groups according to the surgeon who had treated them. Only the first group of patients was tested for chordee as a part of standard procedure and complete treatment. In both groups we analyzed the number of patients treated for penile curvature within various types of hypospadias. We also compared scores in the two groups using Fisher test and ?2-test. Results. Scanning retrospective, 104 cases (22.9%) of diagnosed and surgically corrected chordee were determined. In 31.6% of patients from the first group and 11.6% of patients from the second group we diagnosed and corrected some form of penile curvature was. Chordee was significantly more frequent in the first group, regarding hypospadias in general (p<0.01), as well as distal (p<0.05) and mid shaft forms (p<0.01). Conclusion. Penile curvature is not uncommon in hypospadias. In this study we report a significantly higher frequency as related to the patients in the second group who were not tested for curvature during hypospadias treatment. This is why standard techniques in hypospadias repair should definitely include the diagnosis and surgical correction of penile curvature.
Bone mineral density in patients with juvenile idiopathic arthritis
Authors: Susic Gordana , Pilipovic Nada , Stojanovic Roksanda
Published: October 2009

Introduction. It is well known that juvenile idiopathic arthritis (JIA) as a chronic inflammatory disease with onset during the childhood, beside other complication, can lead to bone metabolism disturbance and osteoporosis. Objective. To assess bone mineral density (BMD) in children with JIA and to identify factors playing role in bone mineral disturbance. Methods. Seventy-five patients (26 male and 49 female) average disease duration 7.2 (2.4-16.8) years, and 73 age matched healthy control subjects (29 male and 44 female) participated in the study. Mean age of the groups was about 14.5 years. BMD was determined by dual x-ray absorptiometry (DEXA) of the lumbar spine (L2-L4). For further analysis we used the absolute value of BMD, expressed as g/cm2, Z score expressed as SD (relative value as standard deviation decline of normal BMD values of referent Italian population with identical age and gender), bone mineral content (BMC) as g/cm, and corrected BMD - BMDv as g/cm3. Results. Z score in the group of patients was significantly lower (-1.02?1.6) in comparison to the control group (-0.09?1.4; p<0.001). BMD, BMDv and BMC were also statistically lower in patients with JIA. The lowest Z score was found in patients with systemic onset (-2.63 SD). Z score showed a statistically significant positive correlation with arthritis course (polyarticular course had lower Z score), body mass index and standard deviation score for height and weight. Statistically significant negative correlation was detected in regard to Z score and glucocorticoid (GC) treatment duration, GC cumulative dose, number of joints with limited range of motion, radiological stage and functional class. Conclusion. The results showed a decreased BMD in patients with JIA in comparison to the control group. Systemic onset, polyarthritis, longer treatment with GC and higher cumulative dosage, as well as higher damage level (functional status and radiological stage) are factors playing negative role in bone metabolism in children with JIA.
Pacemaker optimization guided by echocardiography in cardiac resynchronization therapy
Authors: Trifunovic Danijela , Petrovic Milan , Milasinovic Goran , Vujisic-Tesic Bosiljka , Boricic Marija , Nedeljkovic Ivana , Jelic Vera , Zivkovic Mirjana , Jovanovic Velibor , Petrovic Olga , Banovic Marko , Nikcevic Gabrijala , Ostojic Miodrag
Published: October 2009

Introduction. Cardiac resynchronization therapy (CRT) or biventricular pacing is a contemporary treatment in the management of advanced heart failure. Echocardiography plays an evolving and important role in patient selection for CRT, follow-up of acute and chronic CRT effects and optimization of device settings after biventricular pacemaker implantation. In this paper we illustrate usefulness of echocardiography for successful AV and VV timing optimization in patients with CRT. A review of up-to-date literature concerning rationale for AV and VV delay optimization, echocardiographic protocols and current recommendations for AV and VV optimization after CRT are also presented. Outline of Cases. The first case is of successful AV delay optimization guided by echocardiography in a patient with dilated cardiomyopathy treated with CRT is presented. Pulsed blood flow Doppler was used to detect mitral inflow while programming different duration of AV delay. The AV delay with optimal transmittal flow was established. The optimal mitral flow was the one with clearly defined E and A waves and maximal velocity time integral (VTI) of the mitral flow. Improvement in clinical status and reverse left ventricle remodelling with improvement of ejection fraction was registered in our patient after a month. The second case presents a patient with heart failure caused by dilated cardiomyopathy; six months after CRT implantation the patient was still NYHA class III and with a significantly depressed left ventricular ejection fraction. Optimization of VV interval guided by echocardiography was undertaken measuring VTI of the left ventricular outflow tract (LVOT) during programming of different VV intervals. The optimal VV interval was determined using a maximal LVOT VTI. A month after VV optimization our patient showed improvement in LV ejection fraction. Conclusion. Optimal management of patients treated with CRT integrate both clinical and echocardiographic follow-up with, if needed, echocardiographically guided optimization of AV and VV delays, which offers the possibility of additional clinical improvement in such patients.
Recurrent Fournier's gangrene in a diabetic patient
Authors: Terzic Milan , Micic Jelena , Maricic Sanja , Arsenovic Nebojsa
Published: October 2009

Introduction. Fournier's gangrene (FG) is a fulminant form of infective necrotizing fascitis of the perineal, genital, or perianal regions caused by anorectal or urogenital and perineal trauma, more common in patients with diabetes mellitus and alcohol misuse. Despite contemporary management, mortality is still high and averages 20-30%. Case Outline. A 53-year-old extremely obese diabetic postmenopausal woman with the history of poorly regulated insulin-dependent diabetes mellitus lasting for 20 years, and gangrene followed by autoamputation of minor labia a year ago, was admitted due to severe suprapubic pain and septic fever. Gynaecological examination revealed suprapubic abscess spontaneously perforated few hours prior to admission. Contraincision was performed and purulent green-yellowish discharge appeared. Microbial evaluation of the obtained specimen identified Peptostreptoccocus, Enterococcus and E.coli. Antibiotics were administered according to the sensitivity test and suprapubic tumour formation was irrigated and drained. The procedure lasted seven days and resulted in the healing of the pathological process. Conclusion. FG is still a life-threatening condition; so, diagnosis should be prompt with early surgical intervention, along with antibiotics and good supportive care. Proactive management of the diabetic patient with perineal infections is of extreme importance, in order to prevent the development of FG, the entity associated with very high mortality. According to the literature data available, this is the first reported case of FG relapse.
Did we forget tetanus?
Authors: Alempijevic Djordje , Baralic Ivanka , Kiurski Milosav , Jecmenica Dragan , Pavlekic Snezana , Zivkovic Vladimir , Savic Slobodan
Published: October 2009

Introduction. Currently, in our country (Republic of Serbia) tetanus is a rarely occurring disease, mainly affecting people older than 65 years of age. A small number of reported cases is mainly due to appropriate immunization. Therefore, each case of tetanus may be considered as failure of health care system to provide adequate immunization. Case outline. A 71-year-old woman was injured in her garden. She sustained laceration in the left coccygeal region. The next day the wound was treated by a surgeon, but tetanus postexposure prophylaxis was not administrated. On the fifth day following the incident, the symptoms and signs of tetanus became apparent, and the patient died two days later. Postmortem examination revealed the wound that was not adequately treated, since there was a foreign body and a dressing inserted in the wound. Signs of acute (aerobic) infection were also present. Conclusion. Tetanus is a severe, potentially lethal disease that is absolutely preventable. Mistakes in immunization and surgical treatment of the wound can be considered as medical malpractice.
Developmental hip dysplasia in adolescence
Authors: Vukasinovic Zoran , Zivkovic Zorica , Vucetic Cedomir
Published: October 2009

The authors define adolescence and developmental dysplasia of the hip (DDH). Special attention is paid to pathological findings characteristic of DDH in adolescence (unrecognized and untreated DDH; treated DDH, but non-terminated treatment; DDH diagnosed with delay, inadequately treated, with complications). The authors emphasise that DDH treatment has to be successfully terminated well before the adolescence; possibilities are explained on management modes at the time of adolescence, and possible persons guilty for the persistence of later hip problems are indicated. Based on the authors' experience and having in mind all surgical possibilities for the treatment (pelvic osteotomies, femoral osteotomies, trochanteroplasties, leg length equalization procedures) the authors propose treatment protocols. The intention is to provide better treatment results and to prevent secondary hip arthrosis. Furthermore, how to improve the struggle against DDH is suggested.
L'image du mauvais moine: Les remnuoths et les sarabaïtes de Jérôme et de Cassien
Authors: Caseau Béatrice
Published: October 2009

Two Latin authors of the 4th and 5th century offer a typology of good and bad monks. Both of them describe the lifestyles of monks in Egypt. Their aim was to condemn the lifestyle of monks living in the West, but the main point was to condemn domestic monasticism and to replace it with the coenobitic one.
Once again on the fragment of a fresco in Vatopedi
Authors: Miljkovic Bojan
Published: October 2009

As an iconographic theme, the representation of the embraced apostles Peter and Paul appears even in Early Byzantine art and symbolizes the universal Christian ideas of communion, concord and love. Based on its stylistic features, the fragment from Vatopedi can be dated to the very end of the 12th century and most probably belonged to the earliest preserved fresco paintings in the main church.
L'État et l'Église en Serbie au XIIIe siècle
Authors: Kalic Jovanka
Published: October 2009

(francuski) Ce texte reprend l'introduction d'une communication pr?sent?e lors de la Conf?rence international organis?e a Belgrad en 2008, sous l'intitule 'La r?ciprocit? serbo-bulgare dans le monde byzantin du XIIIe si?cle'. L'auteur de cette communication observe les rapports entre l'Etat et l'Eglise au sein de la Serbie dans le cadre plus large de la sc?ne internationale au lendemain de la prise de Constantinople (1204) lors de la IVe croisade et durant la longue ?clipse de l'Empire grec byzantin qui se solda par une profonde modification de l'espace des Balkans. Sans avoir jou? un r?le significatif dans l'av?nement m?me de cette politique ? leurs fronti?res, la Serbie et la Bulgarie ont ?t? contraintes de s'y adapter. C'est alors que ces Etats ?tablissent d'intenses relations avec le monde occidental. L'un comme l'autre acc?dent au rang de monarchie gr?ce aux couronnes royales respectivement envoy?es par le pape Innocent III pour la Bulgarie, et Honorius III pour la Serbie (1217). Selon des conceptions de l'?poque, un tel acte ?quivalait ? une reconnaissance politique internationale. S'agissant de la Serbie l'auteur montre toutefois que l'?tablissement de relations soutenues avec le monde occidental, et ce avant tout avec les pays d'Europe centrale (Hongrie, Moravie, Allemagne, Pologne) ?tait d?j? ant?rieur ? 1204. Puis, il en vient a l'observation des rapports entre l'Etat et l'Eglise dans les terres serbes sur les bases des listes recensant les ?v?ch?s de Eglise orthodoxe serbe. Une place importante revient ici aux Notitiae episcopatuum du XIIIe si?cle. Datant de l'?poque de Saint Sava, la plus ancienne liste est conserv?e dans la Collection des actes juridiques du monast?re de Krusedol, alors que la seconde remonte ? l'?poque du roi Stefan Milutin et de l'?v?que Nikodim, soit au debut du XIVe si?cle. Ces listes des ?v?ch?s montrent que l'organisation de l'Eglise suivait le d?veloppement de l'Etat.
V'tresnopoliticeskoto razvitie na v'zobnovenoto B'lgarsko carstvo (kraja na XII - kraja na XIII v): Faktori i problemi
Authors: Nikolov Georgi
Published: October 2009

(bugarski) Posoceni sa osnovnite faktori, koito harakterizirat v'tresnopoliticeskoto razvitie na v'zobnovenoto B'lgarsko carstvo ot kraja na XII i prez XIII v. d'rzavnoto ustrojstvo, separatizma, roljata na kumanite, kakto i borbata za carskija prestol v T'rnovo i prevratite v perioda 1185-1300 g.
The data on Serbian history of the 13th century in the chronicle of Ephraim from Ainos
Authors: Nikolic Maja , Radic Radivoj
Published: October 2009

Ephraim from Ainos wrote a chronicle (Chronik? Istoria), in the twelve-syllable verse, which covered the history of the Old and New Rome from the 1st century A.D. to 1261, i.e. the period covering twelve centuries. While writing this chronicle, he predominantly relied on the world chronicle by John Zonaras and the historical works by Niketas Choniates and George Akropolites. In regard to Serbian 13th century history, it should be pointed out that Ephraim mentioned three pieces of information. Chronologically speaking, the two of them, the first and the third, are well known from other sources as well. The first one was the information that Eudokia, daughter of the Byzantine emperor Alexios III Angelos, had been married to Stefan, son of Nemanja, and the third one was about the well-known and well-documented event, the Serbian invasion into the European territories of the Empire of Nicaea, in the vicinity of towns Kicevo and Prilep, in 1257. The second news in order, and controversial to certain degree, spoke about the alleged occupation of the part of Serbian territories by the ruler of Epiros Theodore I Angelos during the first years of his rule. The contemporary historian George Akropolites, who was much closer to these events, did not list the Serbian territories among those conquered by the ruler of Epiros.
Reinterpretacija na krilatata zmija (drakon) v hristijanskata tradicija: Po povod ukrasata na Divosevoto evangelie
Authors: Dzurova Aksinija
Published: October 2009

(bugarski) V statijata se razglezda edin ot motivite v ukrasata na Divosevoto evangelie ot XIV v. - tozi na krilatija drakon (na mesta s kozja glava) i podobnata na nego ukrasa v sr'bski, gr'cki i ruski r'kopisi, povlijani v svojata dekoracija ot romanskoto izkustvo, koeto ot svoja strana interpretira rannohristijanski motivi, vlezli v r'kopisnija repertoar na gr'ckite kodeksi osce prez X-XI v. i otnovo pojavili se v k'snovizantijskata tradicija.