Review Article: Recent Research On the Military in Society

The Social Psychology of Military Service; Sage Research Progress Series on War, Revolution, and Peacekeeping; Vol. VI, Young Men and Military Service; Vol. V, Youth in Transition, and The Soldier and Social Change; Comparative Studies in the History and Sociology of the Militar

Structural elements of metal selectivity in metal sensor proteins

Staphylococcus aureus CzrA and Mycobacterium tuberculosis NmtR are homologous zinc/cobalt-responsive and nickel/cobalt-responsive transcriptional repressors in vivo, respectively, and members of the ArsR/SmtB superfamily of prokaryotic metal sensor proteins. We show here that Zn(II) is the most potent negative allosteric regulator of czr operator/promoter binding in vitro with the trend Zn(II)>Co(II)≫Ni(II), whereas the opposite holds for the binding of NmtR to the nmt operator/promoter, Ni(II)>Co(II)>Zn(II). Characterization of the metal coordination complexes of CzrA and NmtR by UV/visible and x-ray absorption spectroscopies reveals that metals that form four-coordinate tetrahedral complexes with CzrA [Zn(II) and Co(II)] are potent regulators of DNA binding, whereas metals that form five- or six-coordinate complexes with NmtR [Ni(II) and Co(II)] are the strongest allosteric regulators in this system. Strikingly, the Zn(II) coordination complexes of CzrA and NmtR cannot be distinguished from one another by x-ray absorption spectroscopy, with the best fit a His-3-carboxylate complex in both cases. Inspection of the primary structures of CzrA and NmtR, coupled with previous functional data, suggests that three conserved His and one Asp from the C-terminal α5 helix donate ligands to create a four-coordinate complex in both CzrA and NmtR, with NmtR uniquely capable of expanding its coordination number in the Ni(II) and Co(II) complexes by recruiting additional His ligands from a C-terminal extension of the α5 helix

Relative amounts of antagonistic splicing factors, hnRNP A1 and ASF/SF2, change during neoplastic lung growth: implications for pre-mRNA processing

Pre-mRNA processing is an important mechanism for globally modifying cellular protein composition during tumorigenesis. To understand this process during lung cancer, expression of two key pre-mRNA alternative splicing factors was compared in a mouse model of early lung carcinogenesis and during regenerative growth following reversible lung injury. Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 and alternative splicing factor/splicing factor 2 (ASF/SF2) act antagonistically to modulate splice site selection. Both hnRNP A1 and ASF/SF2 contents rose in adenomas and during injury-induced hyperplasia compared to control lungs, as measured by immunoblotting. While both proteins increased similarly during compensatory hyperplasia, hnRNP A1 increased to a much greater extent than ASF/SF2 in tumors, resulting in a 6-fold increase of the hnRNP A1 to ASF/SF2 ratio. Immunohistochemical analysis showed that hnRNP A1 localized exclusively within tumor nuclei, while ASF/SF2 appeared in cytoplasm and/or nuclei, depending on the growth pattern of the tumor cells. We also demonstrated cancer-associated changes in the pre-mRNA alternative splicing of CD44, a membrane glycoprotein involved in cell-cell and cell-extracellular matrix interactions. hnRNP A1 and ASF/SF2 expression is thus differentially altered in neoplastic lung cells by mechanisms that do not strictly arise from increased cell division. These changes are influenced by tumor histology and may be associated with production of variant CD44 mRNA isoforms

A combined computational and experimental investigation of the [2Fe–2S] cluster in biotin synthase

Biotin synthase was the first example of what is now regarded as a distinctive enzyme class within the radical S-adenosylmethionine superfamily, the members of which use Fe/S clusters as the sulphur source in radical sulphur insertion reactions. The crystal structure showed that this enzyme contains a [2Fe–2S] cluster with a highly unusual arginine ligand, besides three normal cysteine ligands. However, the crystal structure is at such a low resolution that neither the exact coordination mode nor the role of this exceptional ligand has been elucidated yet, although it has been shown that it is not essential for enzyme activity. We have used quantum refinement of the crystal structure and combined quantum mechanical and molecular mechanical calculations to explore possible coordination modes and their influences on cluster properties. The investigations show that the protonation state of the arginine ligand has little influence on cluster geometry, so even a positively charged guanidinium moiety would be in close proximity to the iron atom. Nevertheless, the crystallised enzyme most probably contains a deprotonated (neutral) arginine coordinating via the NH group. Furthermore, the Fe···Fe distance seems to be independent of the coordination mode and is in perfect agreement with distances in other structurally characterised [2Fe–2S] clusters. The exceptionally large Fe···Fe distance found in the crystal structure could not be reproduced

Sexual dimorphism in cancer.

The incidence of many types of cancer arising in organs with non-reproductive functions is significantly higher in male populations than in female populations, with associated differences in survival. Occupational and/or behavioural factors are well-known underlying determinants. However, cellular and molecular differences between the two sexes are also likely to be important. In this Opinion article, we focus on the complex interplay that sex hormones and sex chromosomes can have in intrinsic control of cancer-initiating cell populations, the tumour microenvironment and systemic determinants of cancer development, such as the immune system and metabolism. A better appreciation of these differences between the two sexes could be of substantial value for cancer prevention as well as treatment

Moisture Relationships in 39 Year Old Rotation Plots on an Irrigated Chestnut Soil

A series of crop rotations experiments were initiated in 1912 and continued until 1951 at the Scotts Bluff Field Station in Nebraska. The purpose of these rotation experiments was to compare the influence on crop yields resulting from the various cropping and manorial systems. The influence of the various systems was determined by comparing: (i) crop yields of 2-, 3-, 4-, and 6-year rotations with those of continuous cropping, (ii) crop yields from rotations which included alfalfa with those from similar rotations without alfalfa, and (iii) crop yields from rotations which included applications of manure with those from similar rotations without manure. Soil moisture is an important factor in the production of plants. Water infiltration rates were determined on all plots. The data obtained for the infiltration of water into the soil suggests that an optimum level of organic matter, supplied as manure, may exist for maximum water infiltration. From the results obtained on these experimental plots a beneficial effect from alfalfa on the infiltration of water into the soil did not occur until the alfalfa had been growing for two years. Advisor: Andrew P. Mazurak

The Influence of Tillage Systems on Corn Yields and Soil Loss in Ohio, Indiana, Illinois and Iowa

Excerpts from the paper: Planning efforts underway to improve water quality of the nation's rivers and streams are a result of the Water Pollution Control Act of 1972. Section 208 of that act requires implementation of techniques and procedures recognized as having the ability to control nonpoint pollutants from agricultural lands. The pollutants identified include sediment from soil erosion, plant nutrients and pesticides. Controlled studies of crop management systems have demonstrated the success of various tillage systems to control one pollutant, sediment, from entering the nation's waterways. By volume, sediment is the single largest source of pollution of all waters of the nation. It is the by-product of soil erosion from all land, from streambanks and from drainage channels. Soil losses from agricultural lands have continued to accelerate in recent years because of more intensive crop management systems such as the monoculture. These management systems encourage additional tillage and agitation of the soil which furthers soil erosion. In order to provide the basis for a more systematic assessment of crop yields that can be expected from various conservation cropping practices, a survey was made of results obtained from recent site specific research studies. The survey was limited to the four Corn Belt states of Ohio, Indiana, Illinois and Iowa mainly because this section of the United States represents one of the most intensively tilled areas in the country. In addition to crop yields from the various conservation cropping practices a summary of the physical variables associated with each study was made and included soil loss whenever the information was available

Influence of Supplemental Run-off Water and Fertilizer on Production and Chemical Composition of Native Forage

This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202