A tribute to Hemming Virgin (1918–2005), a Swedish pioneer in plant photobiology

We present here a tribute to Hemming Ivar Virgin (October 19, 1918–October 19, 2005), a pioneer in Swedish plant photobiology, developer of a University, and an outstanding educator.     

Atsushi Komamine (1929–2011): a tribute

Atsushi Komamine was one of the pioneers of plant tissue culture in Japan and a researcher with many friends throughout the world. His objective was to determine the potential capacities of plant cells, and he contributed considerably to plant tissue cultivation research by establishing several unique culture systems that controlled cell division and differentiation. He emphasized that the uniformity of cultured cells and the synchrony of the plant cell response at a high frequency were necessary to study the functions of plant cells using biochemical and molecular biological methods. He trained over 300 people, and many outstanding individuals in academia and industry emerged under his tutelage. He was an outstanding mentor: with his accommodating attitude, he was loved dearly by students and foreign researchers alike. He set up the Asia Pacific Association of Plant Tissue Culture and Agribiotechnology in 2000, and he established the international journal Plant Biotechnology Reports with Jang R. Liu in 2006, thereby contributing to Asian plant sciences. In addition to describing his achievements and activities, this article aims to paint a portrait of the man himself.     

Margareta Ryberg (1946–2012): a personal tribute

We pay tribute to the life and work of Margareta Ryberg (1946-2012). She was an expert on the different forms of protochlorophyll(ide), their protein partners, and their transformations in angiosperms; on the structural aspects, and the nature of prolamellar bodies, as well as on the localization of light-dependent NADPH:protochlorophyllide oxido-reductase. She was a great teacher, who also loved gardening and handicraft. But above all, she was a beloved wife, mother, grandmother, and friend who will be deeply missed.     

Purinergic signalling in the cardiovascular system—a tribute to Geoffrey Burnstock

Purinergic Signalling - Geoffrey Burnstock made groundbreaking discoveries on the physiological roles of purinergic receptors and led on P2 purinergic receptor classification. His knowledge, vision...     

A tribute to Robert John Porra (august 7, 1931–may 16, 2019)

Photosynthesis Research - Robert John Porra (7.8.1931–16.5.2019) is probably best known for his substantial practical contributions to plant physiology and photosynthesis by addressing the...     

Philip R. White (1901–1968)—a tribute

The groundbreaking research carried out by Philip R. White in the 1930s and 1940s played a critical early role in the development of modern plant biotechnology and the production of biotech crops. He gained instant fame and became a historical figure early in his career by becoming the first person to attain unlimited growth of cultured plant tissues. White was one of the best known and most influential figures of his generation in plant cell culture research. His tireless and lifelong efforts to promote the use of plant cell culture systems inspired a generation of scientists and stimulated much scientific activity. White was not only a brilliant and visionary scientist but also a highly principled man who spoke courageously about the great moral and political issues of his day. He was admired as much for his science as for his humanity. His belief that plant cell culture research was not well represented at national and international meetings, and his deeply held conviction that science had to be international and without borders in order to be of service to humankind led to the founding of the International Association for Plant Biotechnology in 1963, currently the largest forum for the international plant biotechnology community. This tribute honors and celebrates Philip R. White for his inspiring science, for his kind and generous mentoring of young scientists, for his advocacy of plant cell culture research and its applications, for his promotion of international scientific exchange and cooperation, and for his leadership in the founding of the International Association for Plant Biotechnology.     

Floristic diversity in the transition from traditional to modern land-use in southern Sweden a.d. 1800–2008

We aim to provide a long-term ecological analysis of land-use and floristic diversity in the transition from traditional to modern land-use management in the time a.d. 1800–2008 in southern Sweden. We use the Regional Estimates of Vegetation Abundance from Large Sites (REVEALS) model to quantify land-cover changes on a regional scale at 20-year intervals, based on the fossil pollen record. Floristic richness and evenness are estimated using palynological richness and the Shannon index applied to the REVEALS output, respectively. We identified a transition period of 60?years between 1880 and 1940 when the total tree cover increased and the tree composition changed from deciduous to coniferous dominance. Within the shrinking area of open land, arable land taxa expanded, while the number and coverage of herbs in the remaining grasslands decreased. The succession from open grasslands to more tree-covered habitats initially favoured palynological richness, which reached its highest values during the first 40?years of the transition period. The highest REVEALS-based evenness was recorded in the time of traditional land-use and at the beginning of the transition period, reflecting higher habitat diversity at these time intervals. Our results support a more dynamic ecosystem management that changes between traditional land-use and phases of succession (<40?years) to promote floristic diversity. We have developed and applied a palaeoecological methodology that contributes realistic estimates to be used in ecosystem management.     

Functional role of water in membranes updated: A tribute to Träuble

The classical view of a cell membrane is as a hydrophobic slab in which only nonpolar solutes can dissolve and permeate. However, water-soluble non-electrolytes such as glycerol, erythritol, urea and others can permeate lipid membranes in the liquid crystalline state. Moreover, recently polar amino acid's penetration has been explained by means of molecular dynamics in which appearance of water pockets is postulated. According to Träuble (1971), water diffuses across the lipid membranes by occupying holes formed in the lipid matrix due to fluctuations of the acyl chain trans–gauche isomers. These holes, named “kinks” have the molecular dimension of CH₂ vacancies. The condensation of kinks may form aqueous spaces into which molecular species of the size of low molecular weight can dissolve. This molecular view can explain permeability properties considering that water may be distributed along the hydrocarbon chains in the lipid matrix. The purpose of this review is to consolidate the mechanism anticipated by Träuble by discussing recent data in literature that directly correlates the molecular state of methylene groups of the lipids with the state of water in each of them. In addition, the structural properties of water near the lipid residues can be related with the water activity triggering kink formation by changes in the head group conformation that induces the propagation along the acyl chains and hence to the diffusion of water.     

Airborne bacteria in Kuwait (1986–1988)

Totally 341 outdoors air samples were taken by Casella Airborne Sampler at a height of 7 m in the Allergy Centre of Kuwait between 1986 and 1988. Bacillus was detected in 85.3% of the samples. Micrococcus (71.3%), Staphylococcus albus (65.4%). Gram-positive rods (53.4%) were more prevalent than gram-negative rods (23.7%). Higher counts were seen in 1986 (500 CFU m^?3) compared to 1987 (407 CFU m^?3) and 1988 (369 CFU m^?3). Relatively higher counts were seen in August and September and a smaller peak was found in February and March. The correlation between the various types was always positive and was frequently highly significant. High counts were seen with strong winds. Among the meteorological factors, wind speed was the only significant factor. High average of bacteria counts were found when winds were blowing from the land (574 CFU m^?3) compared with the sea (346.5 CFU m^?3). Higher average counts were observed in the days with sand storms (1769 CFU m^?3), with rising sand (534.8 CFU m^?3) and the other days with dust phenomena, compared with clear weather (317 CFU m^?3).