Development of heartwood,sapwood,bark,pith and specific gravity of teak(Tectona grandis)in fast-growing plantations in Costa Rica

To elucidate the development of heartwood,bark,sapwood,pith and specific gravity of wood in fastgrowing teak(Tectona grandis)plantations in Costa Rica,we sampled three trees in each of 55 plantations and modelled each variable with age,site and different tree heights.Age and stand density of plantations were significant correlated with stem diameter at breast height and total height of the tree.Formation of heartwood was initiated at the age of 4-year-old and increased in direct proportion with age.The age of plantation had a significant relationship with stem diameter at breast height,heartwood percentage,sapwood thickness,sapwood percentage,percentage of bark,pith diameter and percentage,and specify gravity.The model for these tree parameters was model with these parameters as dependent variable and in relation to age as independent variable.

Effect of Changes in Body Weight,Body Condition and Back Fat During Last Month of Pregnancy on the Reproductive Efficiency of Bos indicus Cows in the Tropics of Costa Rica

With the aim of evaluating how changes in the metabolic status in the last month of pregnancy affects reproductive efficiency, forty six Bos indicus multiparous cows (5.5 ± 2.4 parturitions), were used. Measurements of body weight (BW), body condition score (BCS) and dorsal back fat (BF) were taken in the last month of pregnancy, postpartum period previous to synchronization (average 50 d) and at breeding by natural mating following synchronization with a progestin (average 70 d). Average postpartum days to resumption to ovarian activity were 79.96 ± 16.5 d, and average postpartum days to conception was 88.5 ± 14 d. Days postpartum to resumption of the ovarian activity was positively correlated (0.51, P 0.01) with days postpartum to conception, also, days postpartum to conception was positively correlated with prepartum back fat (14 d before parturition) (0.44, P 0.05). It was observed that BF at calving which is an objective measurement had a low correlation with other productive variables such as BCS and BW (always less than 0.39). Body fat might be a more reliable indicator of the current metabolic status of the animal particularly in the last month of pregnancy when the indicators of BCS are somehow more difficult to interpret and subjective.

CLT Fabricated with Gmelina arborea and Tectona grandis Wood from Fast-Growth Forest Plantations: Physical and Mechanical Properties

Fabrication and use of Cross Laminated Timber(CLT)using tropical woods is still limited at present.Therefore objective of the present study aims to determine the possibility of using CLT panels of 3 and 5 layers,fabricated withTectona grandis and Gmelina arborea wood using adhesive of isocyanate polymer emulsion system catalyzed with polymeric isocyanate.Delamination,water absorption,density,flexure test,compression and glue-line shear were evaluated using ANSI/APA PRG320-2012 ASTM D198 and ASTM D4761 standard.The results showed that CLT panels of T.grandis presented higher values of density,less water absorption and lower delamination,with no evident differences between the CLT of 3 and 5 layers.The high density of T.grandis resulted in higher values of the mechanical properties.The flatwise and edgewise flexure tests in 5-layer CLT panels of both species pre-sented higher values of bending stiffness compared to those of 3-layer CLT panels.Further the bending stress values in 3-layer CLT panels were higher than for 5-layer CLT panels.As for shear stress in bending flatwise,in both species,3-layer CLT surpassed 5-layer CLT panels,but in the edgewise test no differences were observed.The MOE and Fc in the compression test were superior in relation to the edgewise test.MOE and Fc in compres-sion flatwise in 3-layer CLT was greater than in 5-layer CLT in both species,but edgewise these values were higher in 5-layer CLT panels.The most common failures were stress and delamination in the flexure test,whereas in the compression test these were:shearing,splitting and crushing.In the glue-line shear test no differences were observed between CLT panels of 3 and 5 layers for both species.

Occurrence and ecological risk assessment of pharmaceutical products in the Kadicha river in Lebanon

Contamination of aquatic systems with pharmaceutical products represents a rising concern.The Kadicha river in Northern Lebanon is an illustrative example of a small Mediterranean river affected by rapid urbanization and population growth.This paper reports the first study on occurrence and ecological risk assessments on selected pharmaceuticals and their metabolites within the Kadicha river.For this purpose,surface water samples were collected over two sampling campaigns from twelve sites impacted by urban,rural,and mixed land uses(residential and agricultural zones)within the Kadicha river basin.Among the studied pharmaceuticals,six compounds(carbamazepine,diclofenac,acetaminophen,sulfamethoxazole,ofloxacin,and atenolol)were detected with detection frequencies and concentrations that vary according to the sampling sites.Carbamazepine was the most frequently detected compound and showed the highest concentrations(not detected-290 ng/L).The presence of pharmaceuticals carbamazepine,ofloxacin(not detected-190 ng/L),and atenolol(not detected-93 ng/L)was related to raw wastewater inputs in the water body,while the presence of sulfamethoxazole(not detected-23 ng/L)was associated with its usage in specific sites with livestock activity.Besides,the presence of acetaminophen(not detected-242 ng/L)and diclofenac(not detected-1055 ng/L)can be affected by their degradation properties in river waters.The highest concentrations were observed in the urbanized downstream area,while the lowest concentrations were within the rural upstream area.Thus,the urbanized downstream area presents the highest potential risks for aquatic species.Moreover,ofloxacin may pose high ecotoxicological risks in this watershed.The levels of contamination with pharmaceuticals do not exceed the concentrations reported in the literature.Furthermore,the levels of carbamazepine,diclofenac,and acetaminophen were more similar to sites receiving raw wastewaters,while the concentration levels of sulfamethoxazole,ofloxacin,and atenolol were more similar to sites receiving treated wastewaters.This paper highlights the need to collect and treat wastewater in this watershed to improve the situation for health and the environment.Monitoring programs on pharmaceutical compounds in Lebanese river waters are needed to better understand the pollution situation and make future public policies on water quality in Lebanon.