Morphogenesis of Chloroplasts during the Illumination in Etiolated Cotyledons of a C4 Plant Amaranthus

To investigate the development of plastids in various leaf tissues of a NAD-MEtype C4 plant, Amaranthus patulus Bertoloni, structural changes of etioplasts undercontinuous illumination were observed by means of an electron microscope. Before theillumination, all etioplasts in epidermal cells including guard cells, mesophyll cells, bundlesheath cells, and vascular parenchymatous cells were small and spherical in shape, andcontained prolamellar bodies with extending single-thylakoids. After the illumination, theplastids elongated, and the disorganization of prolamellar bodies and the formation ofprimary grana occurred at first in epidermal plastids, secondary in mesophyll plastids,then in bundle sheath plastids, and finally in vascular parenchymatous plastids. Thisdifference of start for plastid morphogenesis among leaf tissues may be reflected simply bythose anatomical arrangement for light exposure. The function of peripheral reticulumfound in mesophyll and bundle sheath chloroplasts and the crystalline iclusion in epidermalplastids was also discussed

Support for UNRWA's survival

The United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA) provides life-saving humanitarian aid for 5·4 million Palestine refugees now entering their eighth decade of statelessness and conflict. About a third of Palestine refugees still live in 58 recognised camps. UNRWA operates 702 schools and 144 health centres, some of which are affected by the ongoing humanitarian disasters in Syria and the Gaza Strip. It has dramatically reduced the prevalence of infectious diseases, mortality, and illiteracy. Its social services include rebuilding infrastructure and homes that have been destroyed by conflict and providing cash assistance and micro-finance loans for Palestinians whose rights are curtailed and who are denied the right of return to their homeland

Syntheses and Molecular Structures of Monomeric and Hydrogen-Bonded Dimeric Dawson-Type Trialuminum-Substituted Polyoxotungstates Derived under Acidic and Basic Conditions

The syntheses and molecular structures of the two types of α-Dawson-type trialuminum-substituted polyoxometalates, [B-α-H₃P₂W₁₅O₅₉{Al­(OH₂)}₃]^6– (<b>1</b>) and [B-α-H₃P₂W₁₅O₅₉{Al­(OH)}₂{Al­(OH₂)}]₂^16– (<b>2</b>), are described herein. The potassium and cesium salts of <b>1</b>, K₆[B-α-H₃P₂W₁₅O₅₉{Al­(OH₂)}₃]·14H₂O (<b>K-1</b>), and Cs₆[B-α-H₃P₂W₁₅O₅₉{Al­(OH₂)}₃]·13H₂O (<b>Cs-1</b>) were formed by a stoichiometric reaction in water of trilacunary α-Dawson polyoxotungstate with aluminum nitrate under acidic conditions (pH ∼3). The potassium/sodium and tetramethylammonium/sodium salts of <b>2</b>, K₁₄Na₂[B-α-H₃P₂W₁₅O₅₉{Al­(OH)}₂{Al­(OH₂)}]₂·30H₂O (<b>KNa-2</b>) and [(CH₃)₄N]₁₄Na₂[B-α-H₃P₂W₁₅O₅₉{Al­(OH)}₂{Al­(OH₂)}]₂·39H₂O (<b>TMANa-2</b>) were obtained under basic conditions (pH ∼9). These compounds were characterized by X-ray structure analyses, elemental analyses, thermogravimetric/differential thermal analyses, Fourier transform infrared, and solution ³¹P, ²⁷Al, and ¹⁸³W NMR spectroscopy. The polyoxoanion <b>1</b> is a monomeric, α-Dawson-type structure, resulting in an overall <i>C</i>_3<i>v</i> symmetry, while the polyoxoanion <b>2</b> is a hydrogen-bonded dimeric structure, resulting in an overall <i>S</i>₃ symmetry in the solid state. The pH dependence of polyoxoanions <b>1</b> and <b>2</b> in aqueous solution was also investigated by ³¹P NMR spectroscopy