The effect of isoelectric amino acids on the pH(+) of a phosphate buffer solution - A contribution in support of the "Zwitter Ion" hypothesis

The relative merits of the classical conception and of the Zwitter Ion conception of the dissociation of amphoteric electrolytes are discussed, and the following data are presented which confirm the Zwitter Ion hypothesis of Bjerrum, and which are not in accord with the classical view. 1. Amino acids in the isoelectric form resemble strong electrolytes in that they contribute to the ionic strength of the solution. 2. The dielectric constants of aqueous solutions of amino acids, like those of solutions of strong electrolytes greater than 0.02 normal, are considerably greater than that of pure water. 3. The magnitude of the dissociation constants of substituted acetic acids and of glycine, are more easily accounted for with the Zwitter Ion than with the classical conception

Mathematicians take a stand

We survey the reasons for the ongoing boycott of the publisher Elsevier. We examine Elsevier's pricing and bundling policies, restrictions on dissemination by authors, and lapses in ethics and peer review, and we conclude with thoughts about the future of mathematical publishing.Comment: 5 page

The substrate in peptic synthesis of protein

Experiments are described in which it was observed that the yield of protein that can be synthesized by pepsin from a given peptic digest is highest when the hydrolyzing action of the pepsin is stopped as soon as all the protein has disappeared from the solution; and that the longer the digest is permitted to contain active enzyme the more the yield diminishes. 2. Exposure of the digest to a hydrogen ion concentration of pH 1.6 in the absence of active enzyme, does not cause a diminution in the amount of protein which can be synthesized from that digest. 3. Synthesis can be effected also in concentrated solutions of isolated fractions of a peptic digest, i.e. of proteose and of peptone. The yields are approximately the same as in similar concentrations of the whole digest, though the proteins so synthesized differ in some respects from those obtained from the whole digest. 4. The cessation of synthesis in any one digest is due to the attainment of equilibrium and not to the complete utilization of available synthesizeable material. The amount of the equilibrium yield, on the other hand, is dependent on the amount of synthesizeable material in the digest. 5. These observations are taken to show that the synthesizeability of a given mixture of protein cleavage products by pepsin depends upon its possession of a special complex in these products. This complex appears as a result of the primary hydrolysis of the protein molecule by pepsin and is decomposed in the slow secondary hydrolysis which ensues as digestion is prolonged

Radiation chemistry of aqueous chloroform solutions

Saturated aqueous chloroform solutions have been irradiated with gamma rays from a cobalt-60 source. G values for the formation of HCl in oxygenated and deaerated solutions have been determined. Preliminary work involving the determination of hydrogen gas from the irradiated solutions is reported

Evapotranspiration in a catchment dominated by eucalypt forest and woodland

There is on-going need for reliable estimates of evapotranspiration (ET) at catchment scales to support objective decision-making for managing water supplies, and enhancing understanding of processes and modelling. Without reliable estimates of ET, water supply and catchment management agencies are exposed to significant economic, social and even environmental risks. This thesis focuses on identifying possible methodologies for estimating ET in a catchment dominated by eucalypt forest and woodland. More specifically, this thesis tests the hypothesis that different methods of deriving daily, catchment ET for a headwater in Australia meet underlying assumptions and yield similar results. The hypothesis was tested by using three approaches to estimate catchment ET: soil moisture changes (point scale), satellite imagery of leaf area index (MODIS, hillslope scale), and discharge (streamflow) and the storage-discharge relationship (catchment scale). Data from Corin Catchment, an unregulated catchment vital to the Australian Capital Territory and the surrounding region, is the basis of this study. After the General Introduction (Chapter 1), methods for estimating ET in eucalypt communities throughout Australia at various temporal and spatial scales are systematically reviewed (Chapter 2). Of the 1614 original research papers investigated, 52 were included for further investigation. A clear outcome is that transpiration by the overstorey, measured using sap flow, is the most frequently measured component of ET, and that physiological studies dominate estimates of ET. Very few studies were conducted at the catchment scale. Further, scaling ET from tree to catchment scales was rarely attempted, and the effect of scaling for water resource management is mostly unquantified and requires attention. The first method used to calculate catchment ET is based on up-scaling of soil moisture changes on the basis of a digital soil map (Chapter 4). The data presented here rejects the hypothesis that ET (derived from soil moisture) and overstorey transpiration (derived from sap flow) are well correlated. Instead, the data suggest that soil moisture-derived ET and overstorey transpiration obtained water from different sources. The key findings of this chapter are that this approach is not suitable for estimating ET at catchment scales because it is restricted to drier periods, and because trees did not solely rely on the defined root-zone for water supply. The second method to calculate catchment scale ET (Chapter 5) tests if hillslope-scale satellite imagery (MODIS leaf area index) can be up-scaled to estimate catchment ET. An outcome of this work is that caution is needed when using MODIS leaf area index for water resource planning in evergreen forests across the globe, particularly for forests with significant understorey and a relatively open overstorey canopy at some periods of the year. This method is deemed not suitable for estimating ET over the study area. The third method to calculate catchment scale ET (Chapter 6) is based on integrating discharge using a single non-linear equation to characterise the study area. This method yielded catchment ET far greater (18 times larger) than the largest observed measure of potential ET. As with the method based on soil moisture changes, it was restricted to drier periods. This method was clearly unsuitable for estimating ET over the study area due to relatively quick recession, large range in hourly discharge and significant scattered recession at low discharge. Overall, this thesis rejects the hypothesis that different methods of deriving daily, catchment ET for a headwater in Australia meet underlying assumptions and yield similar results. An important limitation identified through this research is the ability to determine a ‘correct’ estimate of catchment ET. Further research should focus on enhancing understanding of scaling ET within and beyond Australia, generating more daily catchment ET from up-scaled soil moisture changes, further evaluating ET from up-scaled satellite imagery, and identifying catchment characteristics to allow ET to be derived from discharge. Water resource managers must be diligent when selecting and applying a method to estimate catchment ET

The geography of industry in the U.S.S.R.

Thesis (M.A.)--Boston UniversityThe "Geography of Industry in the U.S.S.R." deals with the geographic distribution, the present structure and productive capacity, and the future potential of Soviet heavy industry. Each industry is treated separately, and a regional approach is used. The factors which affect the geography of specific industries are discussed, such as raw material needs, power requirements, etc. Attention is also given to the current industrial problems being faced by the Soviets, and the means by which they are trying to overcome these problems. The first group of industries discussed in the thesis are the fuel industries; coal, oil, lumber, and electric power. In all of these industries a general introductory statement precedes the regional information. The chapter on the coal industry contains information on coal reserves and mining throughout the U.S.S.R. Emphasis is given to the major coal fields and mining areas, such as the Donets Basin, Kuznets Basin, and Karaganda. The petroleum industry chapter, besides having general and regional information, has data on the productive capacities of most of the Soviet oil refineries. A great deal of attention is also given to the transport of oil within the country. The natural gas and oil-shale branches of the industry are included in this chapter. The lumber industry chapter follows the same general line as the other chapters already mentioned. The basic lumber industry, the plywood industry, and the wood-chemical industry are studied, but such items as paper production and furniture-making are omitted (belonging more properly to a work dealing with light industries in the U.S.S.R.). Electric power production in the Soviet Union is handled completely, with all the various sources of power being treated. The importance of hydroelectric power is stressed, and recent developments (such as the construction of new dams) appear in the chapter. The second group of industries taken up are the ferrous metallurgical, the tool and machine, and the transport machinery industries. The iron and steel industry is considered in great detail, since it is the most important one in the Soviet Union. Each region is investigated as to the raw material sources available for the industry, and iron ore deposits are in particular discussed fully. The structures of the individual iron and steel works are taken up, and the metallurgical equipment and productive capacities related to each are mentioned. Facts on the planned expansion of iron and steel production to new areas also appear in the chapter. Following the chapter on iron and steel two chapters are found which deal with tool and machine output in the U.S.S.R. The geography of all sorts of tool and machine production is studied (such as agricultural, metallurgical, and transport machine-building). A separate chapter is devoted to transport machinery, and the motor vehicle, railroad machinery, and shipbuilding branches are taken up regionally. Reference in this chapter is also made to the general transportation situation in the Soviet Union. A third section of the thesis is concerned with the production of metals (non-ferrous) within the U.S.S.R. Individual metals are treated separately, and chapters appear on the production of copper, lead and zinc, aluminum, nickel, manganese, gold,and tin. The geographic factors which affect the distribution of each metallic industry are mentioned, so as to clarify the reasons for their distribution as it exists in the U.S.S.R. Special problems of production (where applicable) are mentioned, such as those related to low grade ores, transport problems, and inadequate fuel supplies. The importance of the Kazakh S.S.R. and the Ural Mountains in metallic production is stressed in most cases. The last portion of the thesis discusses various industries which do not fall under any of the categories previously mentioned. The chemical industry of the U.S.S.R. is covered extensively in an important chapter on the subject. In the introductory statement which precedes the regional breakdown, the various raw materials needed by the chemical industry are taken up, so as to show to what use each is put. Raw materials used in fertilizer, synthetic rubber, and plastics production are mentioned, and the methods of converting them into the finished product are explained in a general manner. The natural rubber industry is briefly included in this chapter so as to keep rubber production (both synthetic and natural) together, and the Soviet sources of natural rubber are discussed along with the chemical industry raw material sources. In the section which follows the introduction the production of chemicals, fertilizers, plastics, rubber, and drugs in each region of the U.S.S.R. is investigated. Raw material deposits used by the industry in each area appear here also. The construction materials industry follows the chapter on the chemical industry, and such items as construction material sources, cement production, and mill capacities are treated. The relation between this industry and Soviet industrial development is drawn in the discussion. A chapter on the defense industries of the Soviet Union attempts to relate armament production to the non-defense industries, as well as discussing those which are currently turning out war goods. For example, a relation is made to tank and locomotive production in the U.S.S.R. The aircraft industry, normally being almost completely military in nature, is included within this chapter. Chemical plants which manufacture explosives are also found under the defense industry category. Because of a general scarcity of information on the subject of Soviet armament production, the information given in the chapter is of a general nature in most cases. The Soviet atomic energy industry, the geography of which was not available in any sources, is treated mainly with respect to its supplies of radioactive ores. The location of Soviet uranium ore deposits is studied, as well as the role played by satellite mining areas. No attempt is made to guess at the distribution of atomic energy plants. In the summary of the thesis the weaknesses, strengths, and probable future developments, of heavy industry in the U.S.S.R. are discussed

It\u27s About Time: Length of Incarceration, Gang Membership, and Recidivism among Illinois Prison Releasees

This study explored the effect of time spent incarcerated on recidivism among a sample of individuals released from IDOC facilities from 2011 to 2014 (N = 72,716). Gang members were compared to non-gang members in order to evaluate the potentially heterogeneous nature of the effect of length of stay on recidivism within the competing frameworks of deterrence theory and social learning theory. The samples were further split into separate analyses based on the current felony class, and length of stay was operationalized as incarceration in months and split into quartiles based on the distribution of each felony class sample. The results indicate that the effect of length of incarceration on recidivism is dependent not only on gang affiliation but also on felony class. Ultimately, these findings indicate that the effect of length of incarceration on recidivism is too heterogeneous to draw any universal conclusions that can reliably inform sentencing policy