Practical Methods for the Control of Hydrogenion Concentration in Staining Procedures—The Use of “Buffers”

Data are given for the simple preparation of dry chemical mixtures to be used in the easy preparation of buffer solutions for use in the control of stain procedures. Two of these mixtures of special value in practical staining operations are the following: 4.539 g. KH₂PO₄, 5.940 g. Na₂.HPO₄.2H₂O. (pH=6.8); 7.262 g. KH₂PO₄, 2.376 g Na₂HPO₄.2H₂O (pH = 7.4). Hydrogen-ion control has been found to be essential to consistent results with the compound blood and tissue stains such as Wright's and Giemsa preparations. The more general use of a pre-determined pH in staining procedures is indicated; several possible methods of application are suggested.     

Detection of Radio-Elements in Histological Slides by Coating with Stripping Emulsion—The “Strip-Coating” Technic

The “strip-coating” technic offers some improvement of the published methods for the autographic detection of Tadio-elements in sections by stripping films. Reproducible results are easily obtained with Ilford Half Tone Stripping Plate Emulsion. The method does not lend itself readily to the preparation of the large number of slides usually required for biological research.     

“Autoreduction”—An unusual property of pure spinach cytochrome ƒ

Pure spinach cytochrome ƒ exhibits the anomalous property of autoreduction at physiological pH. After complete oxidation followed by removal of oxidant, about 80% of the cytochrome ƒ content appeared in reduced form without addition of exogenous reductant. The phenomenon was observed with two different buffers, two different oxidants, and three different methods of removing the oxidant.     

“Advanced Voice Function Assessment”—Goals and activities of COST Action 2103

The COST Action 2103 “Advanced Voice Function Assessment” is a joint initiative of speech processing teams (engineers and physicists) and the European Laryngological Research Group (ELRG) (laryngologists/phoniatricians). The Action officially started in December 2006, and is running till the end of 2010. 17 European countries are involved. A main objective is a better understanding of the relationship between biomechanical changes at the level of the vocal folds – as induced by pathology and tissue reaction to strain – and alterations of the acoustical voice signal. This needs to result in developing accurate, objective and clinically useful methods of investigation of voice quality in patients, and of strategies for preventing occupational voice disorders in professional speakers. Modelling is an essential tool in this process.     

Molybdenum EXAFS of the desulfovibrio gigas MO(2Fe-2S) protein—structural similarity to “desulfo” xanthine dehydrogenase

The molybdenum EXAFS of the Mo(2Fe-2S) protein from Desulfovibrio gigas has been examined using fluorescence detection and synchrotron radiation. In the oxidized form the molybdenum environment is found to contain two terminal oxo groups and two long (2.47 Å) Mo-S bonds. Evidence was also found for an oxygen or nitrogen donor ligand a 1.90 Å. Addition of dithionite to the oxidized enzyme results in loss of a terminal oxo group, perhaps due to protonation. In addition, a 0.1 Å contraction in the Mo-S bond lengths is observed. The behavior of both oxidized and dithionite-treated forms is similar to that observed previously with “desulfo” xanthine oxidase.     

“The smallest grain in the balance”

Darwin viewed evolution as a continuous force perfectly sensitive to variation. The nearly‐neutral theory of evolution says something quite different. Both may be right.