Algal populations in Bottle Hollow Reservoir, Duchesne County, Utah

Bottle Hollow Reservoir contains a diverse algal flora. A total of 289 taxa was observed, 227 of which were diatoms. Both littoral and planktonic communities had high diatom diversity. During summer months filamentous Chlorophvta were diverse and high in biomass in the littoral zone. Phytoplankton collections in Bottle Hollow Reservoir were dominated by four species: Asterionella formosa, Cyclotella comta, Dinobryon divergens, and Fragilaria crotonensis. Plankton samples contained mostly small diatoms in early spring, with larger algae succeeding these as the summer progressed. No blue - green algae were important in this succession. Two peak production periods were observed, one in the fall and one in the spring. Bottle Hollow Reservoir appears to be a healthy mesotrophic system based on the evidences of moderately high algal diversity, insignificance of blue-green algae, and the presence of a suite of diatom species indicative of mesotrophic conditions.     

β-Chitin/Chitosan Obtained from Loligo and Humboldt Squids Effectiveness as Wound Dressing Material

A number of materials are utilized to develop wound care dressing materials with metallic treatments such as ionic silver and zinc. Metallic ions if used for a prolonged time may lead to toxicity. Alternatively chitin,a natural polysaccharide found in nature, is utilized. It is found in fungi, crabs, mushrooms,squids, octopus, and many other living organisms. Chitin has similar structure to cellulose but its deacetylated derivate chitosan has amine groups that provide potential antibacterial properties along with a number of other advantages. Chitin in its natural form is found in three different structural forms,namely α,β,and γ.The β-chitin and chitosan are mostly found in the exoskeleton of squids. Loligo and Humboldt squids were studied. It is anticipated that Humboldt chitin is more effective in serving as antibacterial material and can be utilized for wound care. Differences in steriochemical structure were observed among β-chitin structures obtained and amine group’s presences were found along with ability of materials to swell.     

Palaeontology: spider-web silk from the Early Cretaceous

The use of viscid silk in aerial webs as a means to capture prey was a key innovation of araneoid spiders and has contributed largely to their ecological success. Here I describe a single silk thread from a spider's web that bears glue droplets and has been preserved in Lebanese amber from the Early Cretaceous period for about 130 million years. This specimen not only demonstrates the antiquity of viscid silk and of the spider superfamily Araneoidea, but is also some 90 million years older than the oldest viscid spider thread previously reported in Baltic amber from the Eocene epoch.     

Nucleation and growth of fibres and gel formation in sickle cell haemoglobin

Deoxygenated sickle haemoglobin polymerizes into long 210-A diameter fibres that distort and decrease the deformability of red blood cells, and cause sickle cell disease. The fibres consist of seven intertwined double strands. They can form birefringent nematic liquid crystals (tactoids) and spherulites. Rheologically, the system behaves as a gel. The equilibria show a phase separation and a solubility. The reaction kinetics show a delay time, are then roughly exponential and are highly dependent on concentration and temperature, and accord with the double nucleation model. But these conclusions are derived from macroscopic data, without direct observation of individual fibres. We have now used non-invasive video-enhanced differential interference contrast (DIC) and dark-field microscopy to observe nucleation, growth and interaction of sickle deoxyhaemoglobin fibres in real time. The fibres originate both from centres that produce many radially distributed fibres and on the surface of pre-existing fibres, from which they then branch. The resulting network is cross-linked and dynamic in that it is flexible and continues to grow and cross-link. Our results support most aspects of the double nucleation model.     

云及其他颠覆性技术趋势对商业经济领域的影响

 技术革命带动社会变革,人类社会发展经历的3次浪潮--从农业革命到工业革命再到信息革命,无一不是当时的“颠覆性技术”带来的巨大变革。如今,从云计算到大数据,到人工智能等,这些颠覆性技术每年都给世界经济甚至世界格局带来巨大影响。世界主要国家对技术预见能力都高度重视,颠覆性技术发展核心技术能力成为各国战略布局的重点。本文阐述了颠覆性技术的8个趋势、2个环境和7层技术模型,并介绍了云计算、人工智能对数字化经济的重要变革作用。     

Tetraspanin-enriched microdomains regulate digitation junctions

Tetraspanins co-emerged with multi-cellular organisms during evolution are typically localized at the cell–cell interface, and form tetraspanin-enriched microdomains (TEMs) by associating with each other and other membrane molecules. Tetraspanins affect various biological functions, but how tetraspanins engage in multi-faceted functions at the cellular level is largely unknown. When cells interact, the membrane microextrusions at the cell–cell interfaces form dynamic, digit-like structures between cells, which we term digitation junctions (DJs). We found that (1) tetraspanins CD9, CD81, and CD82 and (2) TEM-associated molecules integrin α3β1, CD44, EWI2/PGRL, and PI-4P are present in DJs of epithelial, endothelial, and cancer cells. Tetraspanins and their associated molecules also regulate the formation and development of DJs. Moreover, (1) actin cytoskeleton, RhoA, and actomyosin activities and (2) growth factor receptor-Src-MAP kinase signaling, but not PI-3 kinase, regulate DJs. Finally, we showed that DJs consist of various forms in different cells. Thus, DJs are common, interactive structures between cells, and likely affect cell adhesion, migration, and communication. TEMs probably modulate various cell functions through DJs. Our findings highlight that DJ morphogenesis reflects the transition between cell–matrix adhesion and cell–cell adhesion and involves both cell–cell and cell–matrix adhesion molecules.     

Mutations in TMPRSS6 cause iron-refractory iron deficiency anemia (IRIDA)

Iron deficiency is usually attributed to chronic blood loss or inadequate dietary intake. Here, we show that iron deficiency anemia refractory to oral iron therapy can be caused by germline mutations in TMPRSS6, which encodes a type II transmembrane serine protease produced by the liver that regulates the expression of the systemic iron regulatory hormone hepcidin. These findings demonstrate that TMPRSS6 is essential for normal systemic iron homeostasis in humans.     

Life extension through neurofibromin mitochondrial regulation and antioxidant therapy for neurofibromatosis-1 in Drosophila melanogaster

We investigated the pathophysiology of neurofibromatosis-1 (NF1) in Drosophila melanogaster by inactivation or overexpression of the NF1 gene. NF1 gene mutants had shortened life spans and increased vulnerability to heat and oxidative stress in association with reduced mitochondrial respiration and elevated reactive oxygen species (ROS) production. Flies overexpressing NF1 had increased life spans, improved reproductive fitness, increased resistance to oxidative and heat stress in association with increased mitochondrial respiration and a 60% reduction in ROS production. These phenotypic effects proved to be modulated by the adenylyl cyclase/cyclic AMP (cAMP)/protein kinase A pathway, not the Ras/Raf pathway. Treatment of wild-type D. melanogaster with cAMP analogs increased their life span, and treatment of NF1 mutants with metalloporphyrin catalytic antioxidant compounds restored their life span. Thus, neurofibromin regulates longevity and stress resistance through cAMP regulation of mitochondrial respiration and ROS production, and NF1 may be treatable using catalytic antioxidants.     

Genome sequence and comparative analysis of the model rodent malaria parasite Plasmodium yoelii yoelii

Species of malaria parasite that infect rodents have long been used as models for malaria disease research. Here we report the whole-genome shotgun sequence of one species, Plasmodium yoelii yoelii, and comparative studies with the genome of the human malaria parasite Plasmodium falciparum clone 3D7. A synteny map of 2,212 P. y. yoelii contiguous DNA sequences (contigs) aligned to 14 P. falciparum chromosomes reveals marked conservation of gene synteny within the body of each chromosome. Of about 5,300 P. falciparum genes, more than 3,300 P. y. yoelii orthologues of predominantly metabolic function were identified. Over 800 copies of a variant antigen gene located in subtelomeric regions were found. This is the first genome sequence of a model eukaryotic parasite, and it provides insight into the use of such systems in the modelling of Plasmodium biology and disease.