Amino acid sequence of the chymotryptic protease II from the larvae of the hornet, Vespa crabro

AbstractThe covalent structure of the chymotrypsin II from the larvae of the hornet, Vespa crabro, has been determined. The sequence has been deduced from 3 sets of overlapping peptides generated by trypsin after modification of the lysine or arginine residues and by chymotrypsin. The enzyme is a serine endopeptidase and contains 218 residues in a single polypeptide chain cross-linked by 3 disulfide bonds. Alignment of the sequence of this insect protease with those of chymotrypsin, elastase and trypsin shows about 35% identity with each and a homologous relationship is evident

Influence of hydrogen bonds on glass transition and dielectric relaxations of cellulose

The molecular dynamics in hydrated cellulose has been investigated by a combination of thermal analyses and dielectric spectroscopy. Differential scanning calorimetry shows the dependence upon hydration of the glass transition temperature Tg. A physical ageing phenomenon has been observed. At the molecular scale, bound water is hydrogen bonded to polar sites of cellulose macromolecules. At the macroscopic scale, water molecules play the role of a plasticizer for cellulose lowering its Tg. Dynamic dielectric spectroscopy combined with thermostimulated currents have allowed us to follow more localized molecular mobility. The β relaxation mode is characterized by activation entropies that vanish for higher water contents indicating molecular mobility localization. It is plasticized by water like the glass transition. This analogy is explained by a common origin of both mechanisms: the mobility of the cellulose backbone. The evolution of the γ mode upon hydration follows an anti-compensation law. Water acts as an anti-plasticizer in a hydrogen bonded network

Electroactive influence of ferroelectric nanofillers on polyamide 11 matrix properties

Barium titanate ceramic powders have been incorporated in polyamide 11 to form homogeneous dispersion of particles in the matrix. Barium titanate/polyamide 11 nanocomposites have been synthesized using a solvent casting method with ultrasonic stirring to homogeneously disperse inclusions in the matrix. Composites with volume fraction of barium titanate / ranging from 0.01 to 0.4 were elaborated. Films were fabricated using a hot press method. Only the inclusions were poled in the matrix to form a ferroelectric particles/ unpoled matrix composite. Interactions between the particles and the matrix, pyroelectric and piezoelectric response were studied as a function of / by dynamic dielectric spectroscopy. Composites show interesting pyro-piezoelectric activity. Pyroelectric merit factor increases linearly and it reaches a limit value of 0.3 for a volume fraction / = 0.1

Coming Home: The Bruderhof Returns to Germany

The Bruderhof Community, founded by Eberhard Arnold in Germany shortly after World War I, envisions communal life according to the principles of early Anabaptism, Christian Socialism, and the German Youth Movement. Persecuted by the National Socialists in the 1930s, the group migrated to America. Despite harassment and expulsion from Germany, it has attempted to reunite with its geographic birthplace. Reasons for continued efforts to reconnect to the German homeland can be found in the movement’s historical development as a free church with a global awareness and outreach. Analyzing the Bruderhof’s experience with persecution, its distinct theology, and perseverance as a communal order, I explore the motivations that led to the community’s resettlement in Germany and the consequences of that endeavor

Quantifying colors at micrometer scale by colorimetric microscopy (C-Microscopy) approach

The color is the primal property of the objects around us and is direct manifestation of light-matter interactions. The color information is used in many different fields of science, technology and industry to investigate material properties or for identification of concentrations of substances. Usually the color information is used as a global parameter in a macro scale. To quantitatively measure color information in micro scale one needs to use dedicated microscope spectrophotometers or specialized micro-reflectance setups. Here, the Colorimetric Microscopy (C-Microscopy) approach based on digital optical microscopy and a free software is presented. The C-Microscopy approach uses color calibrated image and colorimetric calculations to obtain physically meaningful quantities i.e., dominant wavelength and excitation purity maps at micro level scale. This allows for the discovery of the local color details of samples surfaces. Later, to fully characterize the optical properties, the hyperspectral reflectance data at micro scale (reflectance as a function of wavelength for a each point) are colorimetrically recovered. The C-Microscopy approach was successfully applied to various types of samples i.e., two metamorphic rocks unakite and lapis lazuli, which are mixtures of different minerals; and to the surface of gold 99.999 % pellet, which exhibits different types of surface features. The C-Microscopy approach could be used to quantify the local optical properties changes of various materials at microscale in an accessible way. The approach is freely available as a set of python jupyter notebooks

Coming Home: The Bruderhof Returns to Germany

The Bruderhof Community, founded by Eberhard Arnold in Germany shortly after World War I, envisions communal life according to the principles of early Anabaptism, Christian Socialism, and the German Youth Movement. Persecuted by the National Socialists in the 1930s, the group migrated to America. Despite harassment and expulsion from Germany, it has attempted to reunite with its geographic birthplace. Reasons for continued efforts to reconnect to the German homeland can be found in the movement’s historical development as a free church with a global awareness and outreach. Analyzing the Bruderhof’s experience with persecution, its distinct theology, and perseverance as a communal order, I explore the motivations that led to the community’s resettlement in Germany and the consequences of that endeavor