Onset Of 20th Century Research Articles

Evolution of staining methods in neuroanatomy: Impetus for emanation of neuron doctrine during the turn of 20th century.

The nervous system is distinctive as compared to other tissue systems in human body owing to intricate structural organization. Histological studies played a key role in unveiling complex details of nervous tissue. However, the process of developing suitable staining method for nerve cells was arduous and spanned across almost half a century. The present study explored details of the journey involving quest for propitious staining method in neuroanatomy culminating in promulgation of neuron doctrine at the onset of 20th century. Initial efforts involving hematoxylin (including its diverse modifications) and subsequent adoption of analogous dye-based stains (like Nissl's method) had limited success in visualization of different parts of a nerve cell and structural details of nervous tissue. This was due to inability of dye-based stains to penetrate the connective tissue sheath of nervous tissue. Eventually, advent of metallic stains in form of silver impregnation method (Golgi stain), reduced silver impregnation method with gold stain (Cajal's stain) and silver carbonate staining method of Río-Hortega unraveled the structure of nervous tissue. The evolution of staining methods catalyzed the refinement of theories pertinent to constitution of nervous tissue. Golgi's staining led to emergence of reticular theory (neurons exist as a network) and Nissl's staining was the basis of the concept of Nervösen Grau (nerve cells and glial cells are embedded in mass of gray matter). Finally, Cajal's staining method successfully elucidated the complex anatomy of nerve terminals and resulted in emanation of neuron doctrine (neurons exists as individual units with adjacent connections).

An Experiment on Incorporation of Bentonite Clay in Mortar

Mortar refers to a binding paste which is workable in nature and consistency, used as a binder in construction activities such as stone bonding in stone masonry, brick bonding in brick masonry and as well as in concrete works. Mortar is often used as a means for decorative works attaining to its workable nature, which in this project I have intended to enhance. Mortar is further used as a sealant in order to fill cracks and gaps within the structure. The term mortar is taken from the Latin term “mortarium” which means crushed. Mortar is often prepared by mixing a suitable binder, fine aggregate or in simpler terms sand and water by a fixed proportion by mass or volume. The ratio of the constituents depends on the quality and magnitude of the work being done. Mortar gains its strength due to the various chemical reactions that occur while the mortar is being cured in water, gaining 99% strength in 28 days. The most used binder in modern times is Portland cement, which was used at the onset of 20th century. A common binder prevailing in the past was lime and the associated mortar mix was called lime mortar. A major part of this project lies in the use of clay as a substitute for sand in mortar. Clay refers to a fine-grained soil deriving its origin from naturally occurring rocks that have undergone chemical weathering. Clay mineral can be classified into three types i.e. Kaolinite, montmorillonite and illite. The type of clay that has been used in this experiment is Bentonite which is a volcanic in origin and has montmorillonite as a major constituent. Clay has water entrapped within its structure and the amount of water depends on the type of clay mineral being dealt with. One of the major properties of clay that I have tried to exploit in this project is its plastic nature i.e. the ability of the soil to gain resistance against shear failure by sliding as they get into a dry state as opposed to possessing very little or no resistance to the same when they absorb water. Attaining help of various properties of clay, in this project I will try to evaluate the various properties of a mortar cube by mixing a fixed proportion by mass of clay in the same and present my observations

A 400-year record of black carbon flux in the Xisha archipelago, South China Sea and its implication

We reconstructed the first long-term (∼400years) records of black carbon (BC) deposition flux from three ornithogenic sediment profiles, which were collected from three remote, isolated islets of the Xisha archipelago, South China Sea. The significant correlations between black carbon, organic matter and excess 210Pb suggested that black carbon was mainly derived from atmospheric deposition, and further enriched by plant-derived organic matter in sediments. During the past 400years, the BC flux remained relatively low before the onset of 20th century; it started to increase from approximately 1900 AD, and peaked around the 1970s. In the recent 30years, the BC flux seemed to display decreasing trend, very likely due to the change of energy structure and development of pollution control techniques. In comparison with marginal sea regions that are greatly impacted by anthropogenic activities, these pristine Xisha islands were not significantly influenced by black carbon of anthropogenic origin.

De Einstein a Gómez de la Serna. La Teoría de la Relatividad y el secreto del arte moderno

Albert Einstein’s visit to Spain in 1923 was a major scientific, social and mass media event. Apart from the major impact of his conferences for the Spanish scientific community, the theory of relativity had a relevant influence in Spanish avant-garde narrative. The philosophical interpretation of Einstein’s relativity by Henri Bergson and Jose Ortega y Gasset had its echoes in Spanish prose through Ramon Gomez de la Serna, and favoured a change in aesthetic that had timidly began few years before. This work examines the underlying role of Einstein’s relativity on Gomez de la Serna’s work El novelista (1923), and the implications of the concept of relativity on the development of the Spanish modern narrative at the onset of 20th century.