Spiropyran-Based Hyperbranched Star Copolymer: Synthesis, Phototropy, FRET, and Bioapplication

Photo- and pH-responsive amphiphilic hyperbranched star copolymers, poly(6-O-methacryloyl-1,2;3,4-di-O-isopropylidene-d-galactopyranose)[poly(2-(N,N-dimethylaminoethyl) methacrylate)-co-poly(1'-(2-methacryloxyethyl)-3',3'-dimethyl-6-nitro-spiro(2H-1-benzo-pyran-2,2'-indoline))](n)s [HPMAlpGP(PDMAEMA-co-PSPMA)(n)], were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization of the DMAEMA and the SPMA using hyperbranched PMAlpGP as a macro RAFT agent. In aqueous solution, the copolymers self-assembled to form core-shell micelles with HPMAlpGP core and PDMAEMA-co-PSPMA shell. The hydrophobic fluorescent dye nitrobenzoxadiazolyl derivative (NBD) was loaded into the spiropyran-containing micelles. The obtained micelles not only have the photochromic properties, but also modulate the fluorescence of NBD through fluorescence resonance energy transfer (FRET), which was also observed in living cells. Slight fluorescence intensity decrease of the spiropyran in merocyanine (ME) form was observed after five UV-visible light irradiation cycles. The cytotoxicity of the HPMAlpGP(PDMAEMA-co-PSPMA)(n) micelles was lower than that of 25k PEI. All the results revealed that these photoresponsive nanoparticles are a good candidate for cell imaging and may find broad applications in biological areas such as biological diagnosis, imaging, and detection.     

Star Wars: About Anthropology,Culture and Globalisation1

This paper explores the connection between debates within anthropology and larger political processes affecting the universities frequently relating to contemporary globalisation. Such connection is important in order to evaluate some directions in critical reflection within the discipline. It is claimed that anthropological positions concerning ‘fieldwork’ and ‘culture’, often devalued in the climate of current discourse, are significant epistemologically for the discipline and important for its radical potential as offering a continual challenge to the hegemony of metropolitan thought. This kind of challenge may be lost in certain redirections in anthropological approaches that often seem to be more dictated by the managerial revolution in universities than otherwise realised.     

广东肇庆星湖浮游甲壳类的生态调查

1996年4月至1997年8月对广东肇庆星湖的两个重要子湖（里湖和中心湖）的浮游甲壳类进行6次调查,共观察到枝角类17种,桡足类11种。两个湖泊浮游甲壳类的种类组成差异不显著,但数量及生物量差异十分显著,这与两湖泊的水质不同特征有密切关系。     

广东肇庆星湖浮游甲壳类的生态调查

1996年4月至1997年8月对广东肇庆星湖的两个重要子湖(里湖和中心湖)的浮游甲壳类进行6次调查.共观察到枝角类17种,桡足类11种.两个湖泊浮游甲壳类的种类组成差异不显著,但数量及生物量差异十分显著,这与两湖泊的水质不同特征有密切关系.     

Star Gods of the Maya: Astronomy in Art, Folklore, and Calendars

Star Gods of the Maya: Astronomy in Art, Folklore, and Calendars. Susan Milbrath. Austin: University of Texas Press, 2000. 382 pp.     

Description of a Novel Symbiotic Bacterium from the Brittle Star, Amphipholis squamata

A gram-negative, marine, facultatively anaerobic bacterial isolate designated strain AS-1 was isolated from the subcuticular space of the brittle star, Amphipholis squamata. Its sensitivity to O/129 and novobiocin, overall morphology, and biochemical characteristics and the moles percent guanine-plus-cytosine composition of its DNA (42.9 to 44.4) suggest that this isolate should be placed in the genus Vibrio. Strain AS-1 was not isolated from ambient seawater and is distinct from described Vibrio species. This symbiotic bacterium may assist its host as one of several mechanisms of nutrient acquisition during the brooding of developing embryos.     

Function of the Drosophila TGF-alpha homolog Spitz is controlled by Star and interacts directly with Star

Drosophila Spitz is a homolog of transforming growth factor alpha (TGF-alpha) and is an activating ligand for the EGF receptor (Egfr). It has been shown that Star is required for Spitz activity. Here we show that Star is quantitatively limiting for Spitz production during eye development. We also show that Star and Spitz proteins colocalize in Spitz sending cells and that this association is not coincident with the site of translation--consistent with a function for Star in Spitz processing or transmission. Finally, we have defined minimal sequences within both Spitz and Star that mediate a direct interaction and show that this binding can occur in vivo.     

Star Trek replicators and diatom nanotechnology

Diatoms are single celled algae, the 10(5)-10(6) species of which create a wide variety of three-dimensional amorphous silica shells. If we could get them to produce useful structures, perhaps by compustat selection experiments (i.e. forced evolution of development or evodevo), their exponential growth in suspension cultures could compete with the lithography techniques of present day nanotechnology, which have limited 3D capabilities. Alternatively, their fine detail could be used for templates for MEMS (micro electro mechanical systems), or their silica deposition systems isolated for guiding silica deposition. A recent paper has demonstrated that silica can be replaced atom for atom without change of shape--a step towards the Star Trek replicator.     

Decreased Temperature Facilitates Short-Term Sea Star Wasting Disease Survival in the Keystone Intertidal Sea Star Pisaster ochraceus

An extensive 2013 mass mortality event along the West Coast of North America due to Sea Star Wasting Disease (SSWD) has affected at least 20 species of sea stars. Among environmental factors potentially contributing to the timing of the current outbreak, increased coastal water temperatures are hypothesized to have contributed to previous and current outbreaks of SSWD. With a laboratory experiment, we tested whether cooler temperatures, similar to average winter temperatures, compared to average summer temperatures could slow the progression of morbidity or prevent SSWD mortality entirely in Pisaster ochraceus. Sea stars housed in cooler water progressed through SSWD states more slowly than sea stars housed at summer temperatures. However, the cooler temperature did not prevent SSWD mortality, and all stars died of the disease. Our data are consistent with experimental studies and field observations during previous and current outbreaks, and support the hypothesis that changes in coastal water temperatures have influenced one of the largest disease related mass mortality events in our oceans.     

Evaluating Potential Spectral Impacts of Various Artificial Lights on Melatonin Suppression,Photosynthesis, and Star Visibility

Artificial light at night can be harmful to the environment, and interferes with fauna and flora, star visibility, and human health. To estimate the relative impact of a lighting device, its radiant power, angular photometry and detailed spectral power distribution have to be considered. In this paper we focus on the spectral power distribution. While specific spectral characteristics can be considered harmful during the night, they can be considered advantageous during the day. As an example, while blue-rich Metal Halide lamps can be problematic for human health, star visibility and vegetation photosynthesis during the night, they can be highly appropriate during the day for plant growth and light therapy. In this paper we propose three new indices to characterize lamp spectra. These indices have been designed to allow a quick estimation of the potential impact of a lamp spectrum on melatonin suppression, photosynthesis, and star visibility. We used these new indices to compare various lighting technologies objectively. We also considered the transformation of such indices according to the propagation of light into the atmosphere as a function of distance to the observer. Among other results, we found that low pressure sodium, phosphor-converted amber light emitting diodes (LED) and LED 2700 K lamps filtered with the new Ledtech’s Equilib filter showed a lower or equivalent potential impact on melatonin suppression and star visibility in comparison to high pressure sodium lamps. Low pressure sodium, LED 5000 K-filtered and LED 2700 K-filtered lamps had a lower impact on photosynthesis than did high pressure sodium lamps. Finally, we propose these indices as new standards for the lighting industry to be used in characterizing their lighting technologies. We hope that their use will favor the design of new environmentally and health-friendly lighting technologies.     

Diversity of Rickettsiales in the Microbiome of the Lone Star Tick,Amblyomma americanum

Ticks are important vectors for many emerging pathogens. However, they are also infected with many symbionts and commensals, often competing for the same niches. In this paper, we characterize the microbiome of Amblyomma americanum (Acari: Ixodidae), the lone star tick, in order to better understand the evolutionary relationships between pathogens and nonpathogens. Multitag pyrosequencing of prokaryotic 16S rRNA genes (16S rRNA) was performed on 20 lone star ticks (including males, females, and nymphs). Pyrosequencing of the rickettsial sca0 gene (also known as ompA or rompA) was performed on six ticks. Female ticks had less diverse microbiomes than males and nymphs, with greater population densities of Rickettsiales. The most common members of Rickettsiales were “Candidatus Rickettsia amblyommii” and “Candidatus Midichloria mitochondrii.” “Ca. Rickettsia amblyommii” was 2.6-fold more common in females than males, and there was no sequence diversity in the sca0 gene. These results are consistent with a predominantly vertical transmission pattern for “Ca. Rickettsia amblyommii.”     

甜杨桃鲜果的化学成分研究

为了解甜杨桃(Averrhoa carambola L.)中的化学成分,采用乙醇提取、乙酸乙酯和正丁醇分别萃取及色谱分离方法,从其鲜果中分离得到8个化合物。通过波谱数据分析鉴定,它们的结构分别为苄基芸香糖苷(1)、苯乙基芸香糖苷(2)、腺苷(3)、乙基β-D-果糖苷(4)、正丁基β-D-果糖苷(5)、姜糖脂A(6)、姜糖脂C(7)和4-羟甲基-5-羟基-2H-吡喃-2-酮(8)。上述化合物均为首次从该植物中获得。