Contemporary distribution of high-grade prostate cancer in the circumstances of opportunistic testing

© 2020, University of Kragujevac, Faculty of Science. All rights reserved. Screening has dramatically changed the distribution of the mean age, stage and grade of prostate cancer (PCa) at diagnosis. However, regional-level data that characterize contemporary PCa patients are limited. The aim of the study was to ascertain main clinical and pathological characteristics of PCa at the present time in the circumstances of opportunistic testing. High-grade PCa according to age, serum prostate specific antigen (PSA), volume prostate, PSA density (PSAD), digital rectal examination (DRE) number of positive cores biopsies and the average percentage of cancer in biopsy at diagnosis has been retrospectively evaluated in 100 men with biopsy-proven PCa, at Clinical Centre Kragujevac, from September 2016 until September 2017. PCa were stratified according to Gleason score (GS) into low/intermediate-grade (GS ≤ 7) and high-grade (GS ≥ 8). To identify the determinants as-sociated with high-grade PCa, we performed univariate and multivariate logistic regression. The most prevalent PCa were the low/intermediate-grade (65%), followed by high-grade (35%). The mean age of the patients was 71.5 (range: 56–88) years and median PSA was 14.6 (range: 1.4–935) ng/ml. There were significant dif-ferences in age, PSA, PSAD, DRE, number of positive biopsy and average percentage of cancer in biopsy between patients with or without high-grade GS. Logistic analysis demon-strated the PSAD and age have strong prognostic value of high-grade PCa. In conclusion, our study has shown the worrying frequen-cy of high-grade PCa in the circumstances of opportunistic testing. Older men and higher level of PSAD had a much higher probability of high-grade PCa

Assortment structure in beech coppice stands in Boljevac region

Assortment structure in beech coppice stands was studied in the area of Boljevac. Assortment structure was evaluated according to the articles of the valid standard (JUS). The assortments represented in the assortment structure, based on the stemwood quality are: Logs for matches, sawlogs I II and III classes, mine timber, technical roundwood, pulpwood, wood for excelsior and fuelwood, I and II classes. The results of the analyses show that the value assortment structure (sum of the values of assortments produced from one tree) grows significantly with the increase of tree diameter and this dependence is presented by a degree function. The value percentage of logs for matches, sawlogs of the I and II classes, technical roundwood, mine timber, fuelwood and pulpwood, grows with the increase of the tree diameter. The occurrence of better quality logs (sawlogs) in these stands, in contrast to the beech coppice stand in the area of Crni Vrh results from the more favourable diameter structure. There are no statistically significant differences between the value assortment structure on the established sample plot series within the same locality, consequently the data ere united. Because of the differences in stand age, the data are not unified for the localities, although there are no statistically significant differences between value assortment structure for diameter degrees represented in them. False heart (red heart) is one of very significant defects of beech wood, and its incidence, inter alia, depends on tree age. The low effect of this defect of wood resulted in a significant percentage of logs for matches. Along with the value assortment structure this paper also presents the percentage of assortments depending on tree diameter

Regression models of volume increment percentage in the Most represented stands of coniferous tree species in Serbia

Considering the great significance of volume increment in forestry, it is understandable that there are numerous methods of its assessment. However, all these methods have some disadvantages, either the accuracy of the obtained results, too large scope of works of forest inventory (economicity), or the restriction only to stands of certain silvicultural type. To make the method of stand volume increment more economic and simplified, we defined regression models for volume increment percentage assessment in fir, spruce, Austrian pine and Scots pine stands in Serbia. Empirical data were fitted by four regression models for each tree species. The criteria for the final selection of models for the determination of volume increment percentage were the relevant statistic parameters of regression and correlation analysis, and the degree of concordance of "real" and fitted ("table") values of volume increment percentage. The selected models for the above tree species are Fir Spruce Austrian pine Scots pine In the practical work of the assessment of current volume increment in the stand, in regular forest inventories, the method of volume increment percentage should be implemented with correction factors for the fitting of "table" (obtained by this method) values of volume increment and "real" values (obtained by the method of diameter increment), on at least 10 % of the stands of the same or similar stand class (same or similar tree species and stand form). In this way, the costs of forest inventory would be reduced, and the obtained results would range within the limits of the required accuracy

Form of turkey oak tree stems in coppice forests of Fruška Gora

The study of tree stem form-form factors and form quotients, and their dependence, and the relation with other volume elements is a necessary precondition for the construction of volume tables by indirect methods, which are increasingly applied. After determining the magnitudes of the above indicators of tree stem form, this paper studies the correlation between normal form quotients and normal form factor, then the correlation between normal form factor and tree diameter and height, as well as the correlation of normal and artificial form factor

A comparative analysis of directed and spontaneous development of mixed forests of fir, spruce and beech on Mt. Tara

The data of periodic complete measurements of permanent sample plots and compartments in which they were located in the period 1955/60-2005/2010 served as the basis for this research. Two sets of data from a 50-year time span enabled a comparative analysis of a number of structural and numerical elements of regularly managed selection forests of fir, spruce and beech that more or less spontaneously developed in the sample plots. The number of trees in low-diameter categories decreased in the regularly managed compartments, but it was partly compensated by regeneration and ingrowth, which amounted to 7.9 trees per year. In forests with spontaneous development, the ingrowth is either missing or minimal, and it amounts to 2.7 trees per year. From the aspect of preserving the natural composition of these forests and thus their biological stability, a significant decline in the number of beech trees is worrying, above all in the lowest-diameter categories. The accumulation of large-dimension trees is more pronounced in the sample plots in relation on the compartments with regular management. This trend resulted in high basal area values (max. was observed in compartment 131 and at the end of the analyzed period, it amounted to 37.8 m2•ha-1, and in SP-2 to 55.7 m2•ha-1) and volume (max. 605.4 m3•ha-1 was achieved in compartment 66, with a 79% share of fir, i.e. 898 m3•ha-1 in SP-2 in which the share of fir is 71%). Increase of volume in diameter catagories above 50 cm amounts to on average 120% in compartments, and in stands with spontaneous development to as much as 230%. Current volume increment is high and at the end of the period it amounted to on average 12.9 m3•ha-1 in the compartments, and 14.9 m3•ha-1 in the sample plots. In both these values the share of fir is 80%. However, increment percentage, as a more reliable indicator of vitality and good living and stand conditions decreased from 2.54% to 2.32% in the observed compartments and from 2.31% to 1.91% in the sample plots, under the conditions of spontaneous development. On the basis of the above, certain disturbances and negative trends can be identified, both in regularly managed forests and stands with spontaneous development, while they are significantly more pronounced in the latter case. This is reflected in the unfavorable spatial relationships and light regime, and consequently difficult regeneration and ingrowth (especially of beech) as well as the slowing dynamics of these forests, which finally disrupts their structure and functional value. In regularly managed forests, the reason for that is the rigid understanding of the felling ripeness diamater and lower intensity cutting of large-dimension inventory, which slowed down the dynamics and made regeneration and ingrowth difficult. More intensive operations in this part of the inventory would provide a better spatial distribution of trees (horizontal and vertical) and a a better light regime, while the development of these forests would be accelerated. This is confirmed by the fact that forests with self-regulation processes (spontaneous development) become gradually depleted in low and medium storey trees and turn into a one-layer structure with a horizontal canopy which was observed in the investigated sample plots. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 37008: Sustainable Management of Total Forest Potentials in the Republic of Serbia

Opportunities for the application of linear program­ming in forest management planning

In situations where it is necessary to consider a variety of options when making decisions in forestry (and in general), with the choice influenced by hardly comparable criteria and a number of conflicting interests, a possible solution is to use multiple criteria methods. One of these methods, which can be applied in forestry, is mathematical programming (in particular, linear programming). Linear programming has a long tradition of being used in the U.S. and European forestry, whereas in the forestry of Serbia it still represents a theoretically and practically unknown tool. Therefore, in this paper we analyze the possibility of applying the methods of linear programming in developing a plan of regeneration cutting in the poplar plantations of FMU "Topolik" managed by PE "Vojvodinašume." Using the aimed function (linear programming) and the corresponding software package the maximum yield that can be achieved by cutting the plantation was obtained. The planned management period was from 2012 to 2021 and its volume was 155 852 m3. The preset condition that the yield in half-periods remains equal was fulfilled (half-period I 77,925 m3, half-period II 77,927 m3). The maximum yield obtained with this methodology was by 4,040 m3 lower than the theoretically possible yield that would be obtained if all stands were cut down at the end of the second half-period, i.e. higher by 8,430 m3 than the yield that would be obtained if cutting of the stands were performed at the start of the management period. The results obtained and foreign experience in this area clearly indicate that linear programming can successfully be used to solve this problem and even more complex problems (than the one presented in this paper) in our local forest practice (multidimensional planning with a series of constraints). [Projekat Ministarstva nauke Republike Srbije, br. 37008: Održivo gazdovanje ukupnim potencijalima šuma u Republici Srbiji