Structural revelations of photosynthesis' membrane protein complexes

Photosynthetic organisms appeared early in evolution and their photosynthetic apparatus has evolved along. The first bacteria carried out only anoxygenic photosynthesis catalyzed by one type of reaction center, type I or II, which somehow came together in cyanobacteria, and evolved into photosystems I and II. This was an evolutionary step that enabled cyanobacteria to carry out oxygenic photosynthesis. The photosystems have the unique capacity to perform and fix energy in a process where water splitting and oxygen evolution takes place, providing planet Earth with an essential molecule for development of life, i.e. Oxygen. Throughout evolution, primordial organisms became more complex upon colonizing diverse environments resulting into the current day sophisticated systems. Nevertheless, the photosystems have preserved their vital mechanisms of sunlight conversion with PSI at almost 100% efficiency, and PSII’s unique water splitting property. Important about photosynthesis systems are the high-energy conversion efficiency and oxygen evolution besides hydrogen generation by some organisms like cyanobacteria. These features are precious global demands for efficient sun utilizing devices, environmental concerns and current economics of alternative energy source to fossil fuel depletion. The diversity of the photosynthesis proteins due to evolution upon adaptation and exploitability is intriguing for researchers from all fields of science to understand aspects of structural diversity, function and dynamics. This work is highly complementary and has been carried out in multidisciplinary collaborations to get more impact for understanding the photosynthesis systems that evolved early or later. The results of which can be integrated into applied technology.

Application of continuous monitoring of honeybee colonies

International audienceMonitoring physical variables associated with honeybee colonies, including weight, temperature, humidity, respiratory gases, vibration, sound, and forager traffic, in a continuous manner is becoming feasible for most researchers as the cost and size of electronic sensors decrease while their precision and capacity increase. Researchers have taken different approaches to collecting and analyzing the resulting datasets, with a view toward extracting information on colony behavior and phenology. The objective of this review is to examine critically the different kinds of data and data analyses, providing researchers with better-informed options for obtaining information on colony phenology in the field without disturbing the hive, and for combining information from different kinds of sensors to obtain a more complete picture of colony status. Wireless sensor networks and powering sensors are briefly discussed

Distribution and sampling of Prostephanus truncatus (Coleoptera: Bostrichidae) and Sitophilus zeamais (Coleoptera: Curculionidae) in maize stores in Benin

The distribution among and within grain stores of 2 grain store pests, Prostephanus Truncatus (Horn) and Sitophilus zeamais Motschulsky were examined over time using different maize cultivars. Incidence in stores was variable between seasons for both species. The b coefficient of Taylor's power law did not differ among maize cultivars. Within-store distribution among cobs could be approximated by the negative binomial and an overall k parameter was estimated for both species. These data were used to develop sampling plans to estimate sample size needed to determine insect density for both pest species over different densities given a desired precision. Sequential sampling stop lines were calculated to determine pest status given action and no-action threshold densities. The possibility of applying the sampling plans as an integrated pest management tool is discussed