STATE ORGANIZATION STRUCTURE BASED ON DUTIES AND POSITIONS OF TANJUNGBALAI CITY DPRD

The 1945 Constitution besides being a basic law in the field of politics, also became the basic law for social, economic and cultural life. This is different from the tradition of writing the constitution of Western European countries and America which only contains political material in its constitution. This difference is due to the influence of socialist constitution writing patterns on the 1945 Constitution. The position and role of the State Law Law in Indonesian development can be seen from various contexts of the development of science, education and the structure of social life.Keywords : Organizational Structure, Tasks and Position, Tanjung Balai                    City DPR

RANCANG BANGUN ALAT UJI LAJU DAN WAKTU PEMBAKARAN PLASTIK PADA ARAH HORIZONTAL

Penggunaan material plastik dan komposit polimer semakin massif di berbagai aplikasi khususnya  industri otomotif. Berbagai rekayasa dan penelitian telah mampu menghasilkan karakteristik mekanis dan fisis material plastik yang mampu menggantikan material logam. Namun demikian, penggunan plastik pada aplikasi dengan resiko kebakaran perlu melalui pengujian hambat bakar. Pengujian tersebut menghasilkan tingkat kemampuan material menghambat laju pembakaran serta penundaan waktu penyalaan api. Metode pengujian tersebut salah satunya diatur di dalam standar UL 94 AVH. Untuk mendapatkan hasil yang akurat serta memberikan kemudahan dalam mengoperasikan, maka perlu dibuat sebuah alat uji laju dan waktu pembakaran plastik pada arah horizontal. Artikel ini membahas proses hingga unjuk kerja alat dengan tetap berdasar pada  standar yang diacu. Proses manufaktur alat uji dimulai dengan observasi, pembuatan desain alat dan skematik pemantik otomatis, machining komponen, wiring kelistrikan, perpipaan dukungan gas, assembly, dan finishing. Hasil pengujian menunjukkan bahwa alat uji laju pembakaran ini dapat digunakan secara akurat dan menunjukkan perbedaan laju pembakaran setiap specimen uji dengan material dasar yang berbeda

Gene expression and metabolite profiling of Populus euphratica growing in the Negev desert

BACKGROUND: Plants growing in their natural habitat represent a valuable resource for elucidating mechanisms of acclimation to environmental constraints. Populus euphratica is a salt-tolerant tree species growing in saline semi-arid areas. To identify genes involved in abiotic stress responses under natural conditions we constructed several normalized and subtracted cDNA libraries from control, stress-exposed and desert-grown P. euphratica trees. In addition, we identified several metabolites in desert-grown P. euphratica trees. RESULTS: About 14,000 expressed sequence tag (EST) sequences were obtained with a good representation of genes putatively involved in resistance and tolerance to salt and other abiotic stresses. A P. euphratica DNA microarray with a uni-gene set of ESTs representing approximately 6,340 different genes was constructed. The microarray was used to study gene expression in adult P. euphratica trees growing in the desert canyon of Ein Avdat in Israel. In parallel, 22 selected metabolites were profiled in the same trees. CONCLUSION: Of the obtained ESTs, 98% were found in the sequenced P. trichocarpa genome and 74% in other Populus EST collections. This implies that the P. euphratica genome does not contain different genes per se, but that regulation of gene expression might be different and that P. euphratica expresses a different set of genes that contribute to adaptation to saline growth conditions. Also, all of the five measured amino acids show increased levels in trees growing in the more saline soil

Cellulose and lignin biosynthesis is altered by ozone in wood of hybrid poplar (Populus tremula×alba)

Wood formation in trees is a dynamic process that is strongly affected by environmental factors. However, the impact of ozone on wood is poorly documented. The objective of this study was to assess the effects of ozone on wood formation by focusing on the two major wood components, cellulose and lignin, and analysing any anatomical modifications. Young hybrid poplars (Populus tremula×alba) were cultivated under different ozone concentrations (50, 100, 200, and 300 nl l−1). As upright poplars usually develop tension wood in a non-set pattern, the trees were bent in order to induce tension wood formation on the upper side of the stem and normal or opposite wood on the lower side. Biosynthesis of cellulose and lignin (enzymes and RNA levels), together with cambial growth, decreased in response to ozone exposure. The cellulose to lignin ratio was reduced, suggesting that cellulose biosynthesis was more affected than that of lignin. Tension wood was generally more altered than opposite wood, especially at the anatomical level. Tension wood may be more susceptible to reduced carbon allocation to the stems under ozone exposure. These results suggested a coordinated regulation of cellulose and lignin deposition to sustain mechanical strength under ozone. The modifications of the cellulose to lignin ratio and wood anatomy could allow the tree to maintain radial growth while minimizing carbon cost

Cell wall rearrangement in wood of poplars subjected to abiotic stresses

International audienc

Light quality (red:far-red ratio): does it affect photosynthetic activity, net CO2 assimilation, and morphology of young white clover leaves?

International audienceWe assessed the effects of red:far-red (R:FR) ratio on net CO2 assimilation, photosynthetic activity, and morphology of young white clover leaves developed under a simulated canopy light environment. Isolated cuttings of Trifolium repens L. were grown in controlled conditions under two irradiances in combination with two R:FR ratios. We used far-red light emitting diodes to reduce the R:FR ratio on leaves that were successively developing on the main stolon and were subject to strong competition for light within a sward. A leaf that developed under a low R:FR ratio had a lower chlorophyll content than the controls. However, this change had no consequences on the net CO2 assimilation rate and on the biomass allocated to shoots. The low R:FR ratio modified the leaf morphology by increasing the leaf area. A leaf that developed in lower irradiance had a lower net CO2 assimilation rate and a greater leaf area and petiole length than leaves that developed in higher irradiance. Therefore, irradiance was the main factor limiting the leaf CO2 assimilation under a canopy. Capture of light by clover leaves was improved by FR light only via modifications of leaf morphology, because there were no significant effects of FR light on photosynthesis.Nous avons étudié les effets de modifications du rapport des radiations rouge clair et rouge sombre (RC:RS) sur l'assimilation nette de CO2, l'activité photosynthétique et la morphologie de jeunes feuilles de trèfle blanc dans des conditions simulant l'environnement lumineux d'un couvert. Nous avons appliqué deux niveaux d'éclairement en combinaison avec deux rapports RC:RS sur des boutures isolées de Trifolium repens L. Des diodes monochromatiques RS ont permis de réduire le rapport RC:RS sur des feuilles se développant successivement sur le stolon. Une feuille développée sous un faible rapport RC:RS se caractérise par une plus faible teneur en chlorophylles que le traitement témoin. Cette modification est sans conséquence sur l'assimilation nette de CO2 par unité de surface et sur l'accumulation de biomasse dans les parties aériennes. La réponse des feuilles à un faible rapport RC:RS est essentiellement morphologique par l'augmentation de la surface foliaire. Un faible éclairement réduit l'assimilation nette de CO2. Cette diminution pourrait être partiellement compensée par une augmentation de la surface foliaire et de la longueur des pétioles. L'éclairement est le principal facteur limitant la fixation du carbone dans un couvert. La capture de la lumière par les feuilles de trèfle est améliorée par un faible rapport RC:RS via des modifications morphologiques, puisqu'il n'y a pas d'effets significatifs des éclairements RS sur la photosynthèse

Carbon fixation in Pinus halepensis submitted to ozone. Opposite response of ribulose-1,5-bisphosphate carboxylase/oxygenase and phosphoenolpyruvate carboxylase

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Carbon metabolism enzyme activities and carbon partitioning in Pinus halepensis Mill. exposed to mild drought and ozone

International audienceSince several years, accelerated decline of Aleppo pine (Pinus halepensis) forests has been observed in mediterranean areas. In fact, the combination of various environmental factors (photochemical oxidants, drought, high light,...) was suspected to cause this decline. In this study, three year-old Aleppo pines were exposed during 3 months to ozone fumigation (100 ppb) combined or not with mild drought to study the effects of these combined factors on some sequences linked to carbon partitioning and primary carbon metabolism within the tree. After a cumulative ozone exposure of 132 ppm . h, ozone induced a significant decrease in specific activity of the whole-plant (-38%) combined with a disequilibrium of the carbon transfer between root and shoot in favour of the shoots (non significant). Moreover, while the same cumulative dose of ozone had no effect on total Rubisco activity in one year-old needles, mitochondrial NAD malic enzyme activity increased significantly (+32%). By combining ozone with mild drought, the ozone-induced responses of all the parameters were significantly amplified and Rubisco activity was significantly decreased (by 44%). These results allowed us to conclude that at 132 ppm . h, ozone alone led to an increase in dark respiration. Moreover, by the combination of ozone and mild drought, a decrease carbon fixation capacity was associated to a decrease of the carbon transfered to the roots, leading to a reduced root growth. Thus, there are indications that high levels of ozone during the summer months may impair the ability of Pinus halepensis to withstand severe water stress in its natural environment

Deciphering the ozone-induced changes in cellular processes: a prerequisite for ozone risk assessment at the tree and forest levels

International audienceOzone, one of the major atmospheric pollutants, alters tree growth, mainly by decreasing carbon assimilation and allocation to stems and roots. To date, the mechanisms of O-3 impact at the cellular level have been investigated mainly on young trees grown in controlled or semi-controlled conditions. In the context of climate change, it is necessary to introduce a valuable defence parameter in the models that currently predict O-3 impact on mature trees and the carbon sequestration capacity of forest ecosystems.Air pollution is an important factor that affects negatively forest ecosystems. Among oxidative air pollutants, ozone is considered as the most toxic in terms of impact on vegetation.This paper focuses on the negative impacts of ozone on trees in controlled conditions or in their natural environment. The current knowledge of the responses at cell level is presented and ways to improve their use for ozone risk assessment of forest stands are discussed.Information was collected from original papers or reviews, providing an overview of the research conducted over the last 60 years.The negative effects of ozone on carbon assimilation and tree biomass production were reviewed and discussed, with a focus on effects on cell processes implied in cell defence, including stomatal regulation, detoxification, signalling, and biosynthesis of wood compound.In the context of increasing significance of O-3 flux approach, this review intends to shed light into the black box of defence processes, which are playing a crucial part within the effective O-3 dose modelling. Today, it is recognized that tropospheric ozone inhibits tree growth and its role on the future carbon sink of the forest ecosystem is discussed along with the combination of other environmental factors like elevated temperature, water, and nitrogen supply, likely to be modified in the context of climate change