INTER-FAMILY VARIATION IN FIBRE DIMENSIONS OF SIX TROPICAL HARDWOODS IN RELATION TO PULP AND PAPER PRODUCTION

Fibre characteristics determine utilizationpotentials of timbers. Fibre dimensions influencewood pulpability, durability and physico-mechanicalproperties. Fibre length, width, lumen width and wallthickness of six tropical timbers from three families(Meliaceae, Sterculiaceae and Ulmaceae) wereinvestigated from heartwood splinters (20×2×2mm)delignified in 1:1 glacial acetic acid and hydrogenperoxide [at 600C], teased out and stained. Fibrelengths range from 0.79mm for Holoptelea grandis(Ulmaceae) to 1.88mm for Khaya ivorensis(Meliaceae) similar to the mean (2mm) for tropicalhardwoods and pulpable length (0.65-1.2mm). TheMeliaceae has moderately long fibres (1.61mm) butmedium-sized for Ulmaceae (1.19mm) andSterculiaceae (1.59mm). Cedrella odorata(Meliaceae) has wide fibres (36.5μm) and lumina(27.6μm), Celtis milbraedii (Ulmaceae) has narrowfibres (17.49μm) and lumen (8.97μm), all withinpulpable range (i.e., 9-40μm). Fibre wall thicknessranges from 3.31μm (for H. grandis) to 5.49μm (forPterygota macrocarpa, Sterculiaceae) and is withinpulpable range (2.90-5.15μm). Fibre walls forMeliaceae and Sterculiaceae are thick (>4μm) butmedium (2-4μm) for Ulmaceae. Runkel ratio of 2.65(for C. odorata) to 3.9 (for C. milbraedii) is greaterthan stipulated for pulping (1.25). However,Flexibility Coefficients (within 75-50 category) andfibre dimensions for timbers from the three familiesindicate their pulping suitability. It is anticipated thewood and construction industries exploit their fibrecharacteristics for structural applications andengineering of fibre-based products

Levels of Soluble Endothelium Adhesion Molecules and Complications among Sickle Cell Disease Patients in Ghana

Background: Soluble adhesion molecules are involved in the gathering and joining of inflammatory cells to vascular endothelium. Therefore, they serve as potential markers of endothelial dysfunction in vascular diseases including sickle cell disease (SCD). In Ghana, there are scarcely any report on the levels of adhesion molecules among SCD patients. The current study aimed to determine plasma levels of ICAM-1, VCAM-1 and E-Selectin as markers of endothelial dysfunction in SCD patients in steady state, complications and controls. Methodology: This was a cross-sectional study involving 60 HbAA controls, 46 HbSS steady state, 57 HbSS VOC, 18 HbSC VOC, 21 HbSS with leg ulcer and 11 HbSS with priapism. Blood samples were collected from all the study subjects (n = 213) and processed into plasma. The plasma levels of VCAM-1, ICAM-1 and E-Selectin concentrations of SCD patients and controls were measured using a double sandwich ELISA technique. Demographic information was also collected from the study subjects. Results: Levels of all soluble proteins (ICAM-1, VCAM-1 and E-Selectin) were significantly higher in HbSS steady-state patients compared to non-SCD controls (p < 0.001). Generally, SCD patients with complications had relatively higher levels of the soluble proteins compared to those in the steady-state. Of the SCD patients with complications, those with vaso-occlusion crisis (HbSS VOC) had relatively higher levels of ICAM-1, VCAM-1 and E-Selectin at (62.42 ng/mL ± 26.09), (634.99 ng/mL ± 324.31) and (236.77 ng/mL ± 114.40) respectively; Conclusion: Although levels of adhesion molecules were high in all the SCD patients with complications, those with vaso-occlusive crisis had higher levels. This might reflect an ongoing endothelial dysfunction in these patients. SCD patients with vaso-occlusive crisis presents with a more severe pathophysiology condition

The Characteristics of Fibres within Coppiced and Non-Coppiced Rosewood (Pterocarpus erinaceus Poir.) and their Aptness for Wood - and Paper - Based Products

Rosewood (Pterocarpus erinaceus) is highly priced for furniture, flooring and cabinetry for its rich hue and durability. Its coppiced wood augments the timber for regular supply and sustainable utilization. Fibre morphology from macerated slivers within its coppiced and non-coppiced stems and their utilization potential were assessed. Derived ratios for the fibres were also calculated. The axial positions (butt, middle, crown) affected the fibre dimensions. Fibre length was greater for coppiced trees [i.e., 1663±11, 1488±5, 1511±10µm (for sapwood) and 1498±10, 1486±9, 1394±4µm (for heartwood)] than the non-coppiced [i.e., 1240±7, 1013±5, 1137±5µm (sapwood) and 1094±8, 1002±2, 1041±9µm (heartwood)]. In all, those for sapwoods were greater than heartwoods’. Significant differences (P˂0.05) existed between fibre lengths from the coppiced (1394±4-1663±11µm) and non-coppiced trees (1002±2-1240±7µm). Fibre diameters for coppiced sapwood and heartwood were 23±1, 20±1, 22±0.8µm and 21.5±0.3, 20.7±0.5, 21.3±2µm and noncoppiced recorded 21±0.6, 20.7±0.3, 20.6±0.1µm and 21±0, 21±0.4, 21±0.8µm respectively. Their respective double wall thicknesses were 8.4±0.2, 7.2±0.2, 9.4±1µm and 8.2±0.2, 9±0.3, 9.1±0.4µm for coppiced wood, and 9.1±1, 7.8±0.1, 8.1±0.3µm and 8.5±0.3, 8±0.4, 8±1 for non-coppiced. Thus, radial stem position also influenced fibre morphology. The fibre indices [i.e., Runkel Ratio, Slenderness Ratio and Flexibility Coefficient for coppiced wood (0.6±0.06-0.85±0.06, 68±4-77±6, 56±4-64±2 respectively) and non-coppiced (0.64±0.12-0.8±0, 49±1-58±4, 57±3-62±2 respectively)] indicate the timber’s aptness for pulp and paper. Besides, the Wood Industry could exploit the fibre characteristics of coppiced wood also for engineering of fibre-based products and structural applications

The Level of Utilization of Secondary Timber Species among Furniture Producers

Background and Purpose: Inadequate supply of wood raw material is one of the major obstacles for the global furniture industry’s growth. Several secondary timbers/Lesser-Utilized-Species (LUS) that could substitute the scarce traditional timbers for furniture production exist in tropical forests. However, the industry continuously faces persistent timber shortages. The extent to which manufacturers utilize LUS as alternatives is unclear, which this study sought to ascertain. Materials and Methods: Data were collected from 300 Timber Firms from Ghana primarily through questionnaires using the stratified random sampling technique. Results: Continuous decline and non-availability of preferred traditional timbers and competition from imported furniture were the main challenges confronting the furniture industry. Data obtained indicated that most manufacturers (85%) hardly use any LUS; 44% of these mentioned lack of information on their properties and prospective uses and 32% attributed it to non-availability on the domestic timber markets. However, 22% of these producers rely on traditionally ‘well-known’ timbers (e.g. mixed red wood, Guarea cedrata and Tectona grandis) owing to their strength properties, 20% due to their strength and durability and 14% because of their strength and aesthetic properties. Many LUS (with prospects for furniture-making) available in great quantities in many tropical forests could substitute the over-dependent timbers. However, information on their properties and uses are hardly available to local producers, which affects their popularity among timber suppliers and manufacturers. Conclusion: To improve on the level of utilization of secondary timbers, wood workers must be supplied with comprehensive information about their properties and economic values. This will contribute to reducing pressure on the primary timbers, ensuring consistent supply of timber and keeping the sector operational

Improving regeneration of mahogany: Techniques for vegetative propagation of four African mahogany species using leafy stem cuttings

Regeneration to ensure sustainable production and conservation of mahogany species globally is considered very important to foresters, investors in plantation, conservationists and timber industries worldwide. Natural regeneration of the mahoganies has been found to be far less than the rate of exploitation hence strong efforts are being made to develop other methods to regenerate mahogany seedlings to augment the low natural replacement and to ensure sustainability. This study was commissioned to investigate the effect of rooting media (river-sand, top soil and a mix of the two (50:50 v/v) on the rooting ability of four mahogany species (Khaya grandifoliola, K. ivorensis, Entandrophragma angolense and E. utile) using non-mist propagators. We investigated the effects of the source of stem cutting within a shoot (top, middle and basal position) on the rooting ability of stem cuttings from the four species in river-sand. Roots per cutting, longest root length and rooting percentage differed significantly among species in all three rooting media. Rooting ability was greatest in K. grandifoliola, which exhibited the highest average rooting percentage (73 %), longest average single root (9.9 mm) and the most roots per cutting (4.9). Rooting percentage was higher in the Khaya species than in the Entandrophragma species in all three rooting media. The mixed medium had the highest rooting percentage and the highest number of roots per rooted cutting in the two Khaya species, while the topsoil media had the best rooting percentage in the Entandrophragma species. Rooting of the two Khaya species can be maximized using a mixture of river-sand and topsoil. Cutting position within a shoot had significant impact on rooting in all four species with rooting percentage being best from middle positions in all four species. However, length of longest root and the number of roots per rooted cutting varied between the middle and basal portions. The study provides useful information for vegetative propagation of leafy stem cutting of the four African mahogany species, which could contribute to regeneration and conservation of these important timber species in the tropics. © 2014 Springer Science+Business Media Dordrecht

Serum sodium and potassium levels in preeclampsia: A case-control study in a large tertiary hospital in Ghana

Background: Preeclampsia remains a poorly understood complication of pregnancy affecting 5–14% pregnancies worldwide. Recent studies indicate that serum electrolytes may play a role in preeclampsia since it is a vascular endothelial disorder. Aim: To compare serum sodium and potassium levels between preeclamptics and normotensive pregnant women in a tertiary hospital in Ghana. Methods and materials: This was a case-control study consisting of 30 preeclamptics and 30 normotensive pregnant women recruited consecutively at their first third trimester pre-natal visit at Korle-Bu Teaching Hospital. Serum sodium and potassium were analysed using Sherwood Flame Photometer (Model 420 Sherwood Scientific Ltd, UK). Analysis was done using Statistical Package for Social Sciences (SPSS®) software version 20.0 and presented as means (standard deviation). A p-value of ≤0.05 was judged significant. Results: There was a significantly reduced (p < 0.001) serum sodium levels in preeclamptics (mean = 136.13; SD = 4.17 mmol/L) compared to normotensive pregnant women (mean = 142.17; SD = 5.66 mmol/L). There was a significantly reduced (p < 0.001) serum potassium levels in preeclamptics (mean = 3.45; SD = 0.54 mmol/L) compared to normotensive pregnant women (mean = 3.98; SD = 0.36 mmol/L). Conclusion: The reduced levels of serum sodium and potassium in preeclampsia as compared to normotensive pregnant women, suggests that changes in these electrolytes may be associated with preeclampsia

Correlation of lipid peroxidation and nitric oxide metabolites, trace elements, and antioxidant enzymes in patients with sickle cell disease.

Background: Lipid peroxidation plays a very important role in sickle cell pathophysiology. The formation of malondialdehyde (MDA) in patients with sickle cell disease (SCD) may lead to endothelial dysfunction. Nitric oxide (NO) is a known vasodilator which plays a role in endothelial function. The current study determined the association between MDA and NO metabolites (NOx), trace elements, and antioxidant enzymes (SOD and CAT) in patients with SCD. The ratio of MDA/NOx was also determined as an index of oxidative stress in the study groups. Methods: This was a cross-sectional study involving 90 patients with SCD and 50 “healthy” controls. Blood samples (n = 140) were collected from the study groups. The plasma, sera, and red cells were kept at −20°C for biochemical analyses. Hemoglobin (Hb) and NOx levels were determined in the plasma using Labsystem Multiskan MS and Griess reagent system, respectively. Super oxide dismutase (SOD) and catalase (CAT) levels were determined in the red cells using assay kits from Cayman chemicals. Lipid peroxidation biomarker MDA was determined in the sera using the TBARS assay. Levels of iron (Fe), copper (Cu), and zinc (Zn) were also determined in the sera using Variant 240FS. MDA and NOx ratio was computed for the study groups and compared. Results: Levels of Hb, NOx, SOD, CAT, and Zn were significantly lower in the patients with SCD (P <.001). MDA, Fe, and MDA/ NOx ratio were, however, significantly higher in the patients with SCD (P <.001). There was no significant correlation between MDA and NOx, SOD, CAT, Fe, and Zn in the study groups. MDA, however, correlated positively and significantly with Cu in the HbSS patients with vaso-occlusive crises (VOC). Gender did not affect the levels of oxidative stress markers. Conclusions: Findings from this study suggest a link between lipid peroxidation and Cu in HbSS patients with VOC. Increased MDA/NOx ratio may contribute to sickle cell pathophysiology by promoting oxidative stress

Oxidative Profile of Patients with Sickle Cell Disease.

Oxidative stress plays a very significant role in the pathophysiology of sickle cell disease (SCD) and associated complications. Oxidative stress, which is often experienced by SCD patients as a result of continuous production of reactive oxygen species (ROS), may lead to endothelial dysfunction and acute inflammation. Antioxidant enzymes, such as superoxide dismutase (SOD) and catalase (CAT), often play a protective role. The current study aimed at determining the oxidative profile of persons with SCD at a tertiary hospital in Ghana. This was a case-control study involving 90 patients with SCD (34 HbSS patients at steady state, 30 HbSC at steady state, 15 HbSS with vaso-occlusive crisis, 11 HbSC with vaso-occlusive crisis), and 50 HbAA control group. Whole blood samples were collected from the study participants and analyzed for full blood counts. The blood samples were assayed for SOD and CAT as a measure of antioxidant defense, while lipid peroxidation was quantified as malondialdehyde (MDA). The results showed that the levels of SOD and CAT were significantly lower in SCD patients as compared to the control group. Patients with HbSS vaso-occlusive crisis had the lowest levels of SOD and CAT. The difference in SOD levels between HbSS at steady state and HbSC with vaso-occlusive crisis was, however, not significant (p = 0.228). The MDA level was significantly higher in SCD patients compared to the control group. This study concludes that the levels of various antioxidant enzymes (erythrocyte SOD and erythrocyte CAT) and oxidative marker (MDA) and are altered in SCD patients