Fizička i kemijska svojstva gorskog bambusa (Yushania alpina) uzgojenoga u Etiopiji

Bamboo is the fastest growing plant currently known on earth, a property that enables it to be the best alternative as a future source of wood fi ber. This study investigated the effect of site and culm height on the physical and chemical properties of Yushania alpina culms grown in Ethiopia. Matured Yushania alpina 3 to 5-year-old samples were harvested from Hagere-Selam and Rebu-Gebeya sites. The culms were subdivided into three equal lengths (bottom, middle, and top), and the variations in physical and chemical properties between the two sites and the culm heights of Yushania alpina were investigated. The results showed that the average values of MC, basic density, tangential and longitudinal shrinkage of Yushania alpina culms for Hagere-Selam and Rebu-Gebeya sites were (91.78 and 80.32 %), (0.65 and 0.63 g/cm3), (6.63 and 5.84 %) and (0.63 and 0.56 %), respectively. The average values of cellulose, lignin, extractive and ash contents in the culms for Hagere-Selam and Rebu-Gebeya sites were (52.84 and 50.71 %), (26.55, and 26.04 %), (8.41 and 8.02 %) and (1.95 and 2.17 %), respectively. The results revealed that the site affected the MC, basic density, cellulose, lignin, extractive, and ash contents of Yushania alpina culms but not the tangential and longitudinal shrinkage. The culm height of Yushania alpina affected MC, basic density, tangential shrinkage, longitudinal shrinkage, cellulose, lignin, extractive, and ash contents. In the case of both sites, the highest percentages of MC, tangential and longitudinal shrinkage, and ash content were observed at the base and lowest at the top of the culms. On the contrary, both sites observed thehighest magnitude of basic density, cellulose and extractive at the top and lowest at the base of the culms. The variations in physical and chemical properties at different sites and culm heights infl uence the utilization of Yushania alpina culms for industries and end products.Bambus je trenutačno najbrže rastuća biljka u svijetu, što je čini najboljom alternativom za budući izvor drvnih vlakana. Ovom je studijom istraživan utjecaj staništa i visine bambusa Yushania alpina, uzgojenoga u Etiopiji, na fizička i kemijska svojstva njegove stabljike. Uzorci Yushania alpina stari tri do pet godina skupljeni su sa staništa Hagere-Selam i Rebu-Gebeya. Stabljike su podijeljene na tri jednake duljine (baza, sredina i vrh) na kojima su istraživane varijacije fizičkih i kemijskih svojstava stabljike s obzirom na dva staništa i visinu bambusa. Rezultati su pokazali da su prosječne vrijednosti sadržaja vode, gustoće te tangentnoga i uzdužnog utezanja stabljike Yushania alpina sa staništa Hagere-Selam i Rebu-Gebeya bile 91,78 i 80,32 %; 0,65 i 0,63 g/cm3; 6,63 i 5,84 % te 0,63 i 0,56 %, a prosječne vrijednosti sadržaja celuloze, lignina, ekstraktiva i pepela sa staništa Hagere-Selam i Rebu-Gebeya bile su 52,84 i 50,71 %; 26,55 i 26,04 %; 8,41 i 8,02 % te 1,95 i 2,17 %. Rezultati su pokazali da je stanište utjecalo na sadržaj vode, gustoću te sadržaj celuloze, lignina, ekstraktiva i pepela u stabljikama Yushania alpina, ali ne i na tangentno i uzdužno utezanje. Visina stabljike Yushania alpina utjecala je na sadržaj vode, gustoću, tangentno i uzdužno utezanje te na sadržaj celuloze, lignina, ekstraktiva i pepela. Za oba staništa utvrđen je najveći sadržaj vode, tangentno i uzdužno utezanje te sadržaj pepela u bazi stabljike, a najmanji u vrhu stabljike. Nadalje, u vrhu stabljike s oba staništa primijećena je najveća gustoća, sadržaj celuloze i ekstraktiva, a najmanje su vrijednosti izmjerene u bazi stabljike. Varijacije fizičkih i mehaničkih svojstava s obzirom na stanište i visinu stabljike utječu na upotrebu stabljike Yushania alpina u industriji i za završne proizvode

Density and Seasoning Characteristics of Pinus caribaea Lumber Grown at Suba Forest, Oromia, Ethiopia

Determination of the seasoning characteristics, physical and mechanical properties of lumber species is helpful in identifying the main factors affecting the quality, suitability and overall performance of wood and wood-based products. The Pinus caribaea has been considered as industrial lumber species and there is a little study conducted in identifying the physical characteristics which on turn affects the quality of product derived from the lumber. Therefore, this study aimed at evaluating the density and seasoning characteristics of P. caribaea lumber. Sample trees were harvested from Suba Forest Oromia, Ethiopia. The experiments were carried out using air and kiln seasoning methods. To measure the initial moisture content, seasoning rate, shrinkage, wood density, and seasoning defects, six replicates of samples from each tree portions were prepared when green and promptly weighed. Analysis of variance (ANOVA) has been employed in interpreting the experimental results. The obtained results have shown that the mean initial moisture content for air stacks was 78.2% while for the kiln seasoning stacks 82.9%. Seasoning time for sawn boards of 3 cm thick to reach 17% moisture continent (MC) required 61 days, while for kiln seasoning took 4.3 days to reach 14.62% MC. This showed that kiln seasoning was about 14 times faster than air seasoning. In air seasoning the MC (%) of the lumber from 78.2% to 16.9%; and, the obtained mean values of shrinkages were tangential (3.6%), radial (1.9%) and volumetric (5.4%). The initial moisture content (IMC) and green density (GD) of the lumber were significant difference along the tree height at a 95% probability level. The seasoning rate % and final MC (%) along the tree height were significant difference at 95% probability level, while the seasoning rate % and final MC were significant difference between seasoning methods at 99% probability level. Seasoning defects such as cup, bow, twist, and crook were observed on kiln seasoned. In addition, end checks and splits were observed on air seasoned boards. Therefore, the experimental factors should be monitored and optimized properly to obtain the lumber with good quality and utilize it for different purposes, including construction and industrial applications

The global burden of adolescent and young adult cancer in 2019 : a systematic analysis for the Global Burden of Disease Study 2019

Background In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15-39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15-39 years to define adolescents and young adults. Findings There were 1.19 million (95% UI 1.11-1.28) incident cancer cases and 396 000 (370 000-425 000) deaths due to cancer among people aged 15-39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59.6 [54.5-65.7] per 100 000 person-years) and high-middle SDI countries (53.2 [48.8-57.9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14.2 [12.9-15.6] per 100 000 person-years) and middle SDI (13.6 [12.6-14.8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23.5 million (21.9-25.2) DALYs to the global burden of disease, of which 2.7% (1.9-3.6) came from YLDs and 97.3% (96.4-98.1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe

Seasoning Characteristics and Potential uses of Eucalyptus pilularis, Eucalyptus viminalis and Trichilia dregeana lumber tree species

Technical information on lumber seasoning, moisture content (MC), density, mechanical, workability and chemical characteristics would strongly determine rational utilization of each lumber species. A study was conducted on home-grown two Eucalyptus species (Eucalyptus pilularis and Eucalyptus viminalis) and one indigenous (Trichilia dregeana) timbers with the main objective of determining some characteristics of lumber that will indicate quality and proper utilization. Study species were harvested from Shashemene, Asella and Arjo sites, respectively. The experimental design for seasoning and density was complete randomized design, a factorial experiment. The experiments were conducted using air and kiln seasoning methods. To determine initial moisture content oven drying method was used. The mean initial MC for the three timber species were 48.25%, 56.1% and 65.45%, respectively. The species were classified as very rapid seasoning rate during kiln seasoning. The mean shrinkage values were Tangential (6.31, 4.94 and 4.43%), radial (3.4, 4.02 and 2.10%) volumetric (9.46, 8.6 and 6.37%), when they seasoned from green to 12% MC, respectively. Seasoning defects such as cup, bow, crook, end split, surface and end-checks were observed, though the extent varies with species. The density of E. pilulalris, E. viminalis and T. dregeana at 12% MC was 780, 810 and 530 Kg/m3, respectively. The one-way analysis of variance indicated that there was significant difference (P>0.001) in initial MC, final MC, density values at different MC and shrinkage characteristics. They revealed good lumber characteristics and qualities, comparable with many indigenous and home-grown exotic timber species in density, seasoning rate and shrinkage. The tree species have to be well managed, properly harvested and sawn. Boards have to be properly stacked and seasoned to about 12% MC, with kiln and air seasoning methods that can help to minimize seasoning time, seasoning defects, shrinkage characteristics and increase quality

Seasoning technologies of Gmelina arborea Roxb. lumber species grown at Bonga, SNNP, Ethiopia

Quality and performance of wood and wood-based products have been seriously affected by the major factors, among which moisture content (MC), inappropriate drying (seasoning) and density are the preceding ones. A study was conducted on Gmelina arborea lumber with the main objective of determining some imperative seasoning and density characteristics of the lumber that will help determine its wood quality and decide proper utilization. Gmelina arborea logs were harvested from Bonga trial site of Central Ethiopian Environment and Forest Research Center (CEE-FRC). The experimental design for seasoning and density was complete randomized design. The experiments were conducted in air and kiln seasoning methods. Mean initial moisture content (IMC) of samples were determined using oven and MC for air seasoning stack was 143.80%, while for kiln seasoning was 120.19%. The final MC to reach to about 12% MC in air took 210 days, while kiln seasoning took 13.5 days. Kiln seasoning rate of Gmelina arborea lumber was 15 times faster than air seasoning. The species was classified as slow and fairly rapid air and kiln seasoning lumber species, respectively. When Gmelina arborea lumber seasoned from green to 12% MC, mean shrinkage (%) characteristic values: Tangential (3.63%), radial 1.58%), and volumetric (5.11 %). Mean density of Gmelina arborea lumber species at green (initial), basic and oven dried and at 12% MC was 940,400, 430 and 420 kg/m3, respectively. The density at 12% MC, (420 kg/m3) classified as light density lumber species. Gmelinaarboreashown good quality lumber characteristics, comparable with many indigenous and homegrown exotic lumber species in density, seasoning rate and shrinkage characteristics

The global burden of cancer attributable to risk factors, 2010-19: a systematic analysis for the Global Burden of Disease Study 2019

Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% 47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% 32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% 27.9-42.8] and 33.3% 25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license