Development of large-scale microalgae production in the Middle East.

Microalgae in the Middle East can theoretically address food security without competing for arable land, but concerns exist around scalability and durability of production systems under the extreme heat. Large-scale Chlorella sorokiniana production was developed in outdoor raceway ponds in Oman and monitored for 2 years to gather data for commercial production. Biological and technical challenges included construction, indoor/outdoor preculturing, upscaling, relating productivity to water temperature and meteorological conditions, harvesting, drying, and quality control. Small cultivation systems required cooling for initial scale-up, but, despite maximum temperatures of 49.7 °C, water temperatures were at acceptable levels by evaporative cooling in larger raceway ponds. Contamination with Vampirovibrio chlorellavorus was identified by 16S rDNA amplicon sequencing and addressed by culture replacement. Productivities ranged from 8 to 30 g-dry weight m-2d-1, with estimated annual productivity of 16 g-dry weight m-2d-1 as functions of solar intensity and water temperature, confirming that the region is suitable for commercial microalgae production.

Soft-diet feeding inhibits adult neurogenesis in hippocampus of mice.

Our previous study showed that mice fed on a soft diet after weaning had reduced levels of brain-derived neurotrophic factor (BDNF) protein in the hippocampus after 3 months of age compared with mice fed on a hard diet. BDNF is one of the most effective promoters of neurogenesis in the hippocampus, and enhancement of BDNF production has been shown to enhance neural precursor cell proliferation in the dentate gyrus. We hypothesized that soft-diet feeding during development would reduce the proliferation rate of precursor cells, resulting in lower production of new neurons in the hippocampus. Male C57BL/6 mice pups were fed either a solid (hard-diet group) or powdered (soft-diet group) diet starting at weaning. Three and six months after birth, mice of each group received intraperitoneal injections of bromodeoxyuridine (BrdU, 50 mg/kg body weight), twice a day for 3 consecutive days. After survival time of 1 day, 1 week, or 4 weeks, the mice were anesthetized and perfused transcardially. Newborn cells in the dentate gyrus were examined by immunohistochemistry using anti-BrdU antibody. In addition, phenotypically neuronal cells among the newborn cells were detected by immunofluorescent double labeling for BrdU and mature neuron-specific nuclear protein (NeuN) using anti-BrdU and anti-NeuN antibodies. Total number of BrdU-positive cells in the dentate gyrus was fewer in the 6-month-old mice than in the 3-month-old mice at any survival time investigated, and fewer in the soft-diet group than in the hard-diet group at 3 and 6 months of age. Neither soft-diet feeding nor aging affected ratio of phenotypically neuronal cells among newborn cells. These results indicate that insufficient mastication activity during development as well as aging restrains hippocampal neurogenesis in adulthood.

Fine structure and mineral components of primary calculi in some human prostates.

The fine structure of prostatic calculi has not been elucidated yet, although the chemical components were reported in detail. We studied the primary or endogenous calculi removed from eight human prostates by secondary scanning electron microscopy, backscattered electron imaging, energy-dispersive X-ray microanalysis and X-ray diffraction. The primary calculi containing Mg, Zn and S, besides Ca and P were basically classified into four stone groups (I-IV) by fine structure and mineral components. Stone I had the core deposits of calcospherites showing concentric rings and the laminated deposits concentrically around the core. Their deposits were identified as apatite. Stone II was occupied with the calcospherite deposits of apatite although the stone growth showed a rough concentric formation. Stone III contained the core of calcospherites and concentric laminated structures, similar to a smaller type of group I, whereas the wider peripheral region was deposited with needle-like structures, identified as calcium oxalates. Stone IV had the core deposits containing small hexahedral structures, identified as whitlockite, which were surrounded with several incompletely concentric laminated bands of apatite. Whitlockite crystals were also found between the fused large calculi. The initial and formative calculi were basically observed as the deposition of mineralizing spherical structures suggesting variously sized corpora amylaceous bodies. Thus, the primary prostatic calculi of stones I-III will begin from the mineralization of amylaceous bodies as a core, while the organic substances, which form stone IV, might be derived from the simple precipitation of prostatic secretion.

Effects of soft-diet feeding on BDNF expression in hippocampus of mice.

Our previous study showed that mice fed a soft diet after weaning had reduced synaptic connections in the hippocampal formation and impaired spatial learning ability after 3 months of age. We hypothesized that soft-diet feeding during development reduced levels of brain-derived neurotrophic factor (BDNF) protein in the hippocampus, resulting in lower synaptic densities in this region. Male pups of C57BL/6 mice were fed either a solid (hard-diet group) or powdered diet (soft-diet group), starting at weaning. Expression of BDNF protein in the hippocampus and cerebral cortex was evaluated quantitatively with enzyme-linked immunosorbent assay (ELISA) at 1, 3 and 6 months of age. Reduction in BDNF protein levels due to soft diet was detected markedly in the hippocampus of 3- and 6-month-old mice. On the other hand, a soft diet showed no significant effect on BDNF content in the cerebral cortex throughout the ages investigated. Immunohistochemistry of hippocampal formation in 3-month-old mice revealed that intensities of BDNF immunoreactivity in the dentate gyrus granule cell layer and CA1 and CA3 pyramidal cell layers appeared diminished in mice fed the soft diet compared with mice fed the hard diet. These results indicate that insufficient mastication activity during development reduces BDNF protein levels in the hippocampus and influences synaptic plasticity in this region.

Specific timing of taurine supplementation affects learning ability in mice.

The effects of taurine supplementation on visual discrimination in mice were examined. Taurine, 2-aminoethane-sulphonic acid, found in high concentrations in the central nervous system of mammals and in human milk, has been shown to be essential for development. Male mice were divided into four groups according to taurine supplementation periods. 1) Lifelong: taurine (400 mg/kg/day) was dissolved in distilled water and provided as drinking water. In the prenatal period, taurine was given via the mother. After weaning mice were administered taurine in drinking water. 2) Pre-weaning: mice were exposed to taurine prior to weaning, 3) Post-weaning: mice were exposed to taurine after weaning. 4) CONTROL: no supplementation of taurine. It was shown that the Lifelong group required a longer period of time to acquire visual discrimination than the CONTROL group. Conversely, in the Post-weaning group, mice learned the task faster than CONTROLs. Visual discrimination learning time in the Pre-weaning group showed no significant difference compared with that in the CONTROL group. From these results, we suggest that the perinatal to early postnatal period is a "sensitive period" where taurine supplementation can result in retardation of learning in later life. At the same time, taurine supplementation after weaning improved visual discrimination learning. Thus, timing of taurine supplementation affected learning.

Histological and physicochemical studies of hypercalcified primear lines in the laminar bone of young calves.

There are many reports on laminar bone in various young animals during their growth periods. One of the concentric laminar bone units around the long-bone marrow periphery consists of three components: bright line, woven bone, and lamellar bone in the long-bone cortex of young calves and pigs. However, the fine structure, especially the uniform bright line or 'hypercalcified line' present in the unit-center, has not been elucidated as yet. The laminar bone of young calves was found to be initially formed from the hypercalcified lines; that is, 'hypercalcified primear' reported previously by the other authors. Such primear lines containing collagen fibrils scattered deposits of rod-like structures containing fine non-collagenous fibrils and globular structures showing no fibrils and some remnants. Osteocytes occasionally existed in the lines as well as adjacent to the lines, although no cells have been reported in the line. The cell lacunae were larger than those of woven bone and lamellar bone. The hypercalcified primear lines contained higher Ca and P content, and the molar ratio (1.78) was similar to 1.75 in the woven bone and lamellar bone. However, the physical and chemical resistances were significantly lower than that of the surrounding bone. Therefore, the hypercalcified primear lines are strongly suggested to show a lower crystallization. Further, fine structural observations of the primear-line forming cells and histochemical and immuno-histochemical investigations of the primear lines will be necessary.

Fine structure and mineral components of fibrous stonelike masses obtained from the human mesenteries.

We investigated the fine structure and mineral components of 29 stonelike masses obtained from the mesenteries of four adult cadavers, using optical microscopy, backscattered electron imaging, scanning electron microscopy, energy-dispersive X-ray microanalysis, and X-ray diffraction. Although the overall appearance of the stonelike masses measuring about 5-20 mm in diameter and 0.06-3.1 g in dry weight was roughly grouped into smooth bulb- and uneven bulk-shaped types, all the calcified masses basically consisted of core and mantle regions. The smooth bulb-shaped masses had a broad mantle with many concentric rings, whereas the uneven bulk-shaped masses contained a large core. In their core regions, spherulitic and short bundle-shaped deposits composed of needle-shaped apatite crystals were mainly found among loose collagen fibers. Their mantle regions, on the other hand, showed the concentric structures of dense collagen fibers in the intra- and/or extrafibrous calcification with fine sandy grain-shaped deposits. The mineral elements were mainly Ca and P, and the major crystals were hydroxyapatite. Hexahedral whitlockite containing Mg was a minor component. The fiber-rich mantle regions showed lower calcification and lesser crystallization than the fiber-poor core region. When necrotic or some tumor adipose tissues and necrotic lymphoid tissues that might have been caused by some digestive diseases are recognized as foreign matter, their tissues occasionally will be calcified and grow into stonelike masses. These stonelike masses tend to occur more often in women than in men.