Regulation Of Protein Synthesis By Leucine And Amino Acid Balance.

The effects of a physiologically balanced mixture of amino acids on the synthesis of proteins has been investigated. The roles of leucine and tryptophan, both implicated in the regulation of protein synthesis, were also studied. The balance of amino acids is important under specific rate-limiting conditions; the physiological balance protects the protein synthesizing system from the stressed condition of leucine limitation. Leucine is an important regulator of protein synthesis and the tryptophan effect on translation is dependent on the concentration of leucine. Thus tryptophan is a secondary regulator. The relative concentration of amino acids, described as balance, alterned the synthesis of protein in cell-free and intact cell culture experiments, when leucine was limiting. Both qualitative and quantitative differences were observed. The effect of the amino acid mixture decreased when the concentration of leucine was physiological. Two different components were sensitive to added leucine. This sensitivity was indicated by different kinetics; one component showed low Km and Vmax values while the other showed high Km and Vmax values. The initial rate of protein synthesis was first order with respect to leucine when it was limiting and mixed order when it was physiological. The effect of tryptophan on stimulation of protein synthesis was small in comparison to the effect of leucine, and was dependent on the ooncentration of leucine. The incorporation of leucine into protein was changed as the tryptophan concentration changed when leucine was limiting; synthesis of albumin was slightly stimulated. The ribosome distribution did not change as indicated by polysome analysis. The incorporation of leucine into protein did not change when· leucine was physiological and tryptophan was. varied. However, the ribosome distribution was altered. A low molecular weight inhibitor of protein synthesis was found in cell extracts which acted independently of amino acid or leucine concentrations. It could be partially removed by treatment with G-25 Sephadex, but has not been purified. Several nucleotide effects independent of amino acid concentration were also observed. ATP, at increasing concentrations, significantly depressed levels of synthesis and concentrations greater than 4 mM caused 100% inhibition of the protein synthesizing system. The phosphodiesterase inhibitor, theophyllin~ enhanced synthesis of albumin, although the cyclic nucleotide, cAMP, did not itself alter synthesis of protein. Finally, the concentrations of amino acids in plasma of C3HeB/FeJ mice were determined. The two amino acids examined in the protein synthesis experiments, tryptophan and leucine, were found to remain relatively constant, regardless of the fed or fasted condition of the animals, but showed changes with the age of the animals

TUCK YOUR BOOTS IN

This thesis discusses my labor experiences and the acquired skills that have been an influential part of my art making process. Developing my own technique and ways of working are very important to me. By nature, I am driven to acquire as many skills as possible. Skills are valuable. It is the desire of still wanting more that has led me to make art

High resolution record of the Last Glacial Maximum in eastern Australia

A continuous, high resolution (average ca. 22 year) record encompassing the Last Glacial Maximum (LGM) has been developed using multiple proxies (aeolian sediment flux, grain size, pollen and charcoal) in lake sediment from Tortoise Lagoon (TOR), North Stradbroke Island, Queensland, Australia. The presence of Asteraceae tubilifloreae and spineless Asteraceae (common indicators of glacial conditions in Australia) at TOR indicates significantly cooler temperatures (mean annual temperature up to 6oC lower than today). In addition to the palaeoclimatic reconstruction, a record of palaeodust transport pathways for eastern Australia was developed using ICP-MS trace element analysis and geochemical “fingerprinting” of TOR aeolian sediment to continental dust source areas. Vectors between dominant dust source areas and North Stradbroke Island allowed the reconstruction of the position and intensity of LGM dust transport pathways. Furthermore, changes in likely synpotic scale conditions can be postulated based on the position of the dust transport corridors. Similarities between the vegetation at TOR during the LGM and that at temperate sites e.g. Caledonia Fen, Victoria (Kershaw et al. 2007), Redhead Lagoon, New South Wales (Williams et al. 2006) and Barrington Tops, New South Wales (Sweller and Martin 2001) suggests that this record reflects regional conditions across southeastern Australia. The TOR record also correlates well with that from nearby Native Companion Lagoon which suggests that the LGM was actually an extended period of ca. 8 – 10 kyr, characterised by 2 periods of increased aridity (ca. 30 – 26.5 kyr and 21 – 19.5 kyr) (Petherick et al. 2008). A growing number of records from across the Southern Hemisphere e.g. New Zealand (Suggate and Almond 2003; Alloway et al. 2007; Newnham et al. 2007), Chile (Denton et al. 1999), Antarctica (Röthlisberger et al. 2002; EPICA 2006) and Australia (Smith 2009) also show evidence that the LGM encompassed a longer period of time than traditionally accepted, and was not uniformly cool and dry

β-diketonate versus β-ketoiminate:the importance of a ferrocenyl moiety on improving the anticancer potency

Herein we present a library of fully characterized beta-diketonate and beta-ketoiminate compounds that are functionalized with a ferrocenyl moiety. Their cytotoxic potential has been determined by screening against human breast adenocarcinomas (MCF-7 and MDA-MB-231), human colorectal carcinoma p53 wild type (HCT116 p53(+/+)) and normal human prostate (PNT2) cell lines. The ferrocenyl beta-diketonate compounds are more than 18 times more cytotoxic than the ferrocenyl beta-ketoiminate analogues. Against MCF-7, compounds functionalized at the meta position are up to nine times more cytotoxic than when functionalized at the para position. The ferrocenyl beta-diketonate compounds have increased selectivity towards MCF-7 and MDA-MB-231, with several complexes having selectivity index (SI) values that are more than nine times (MCF-7) and more than six times (MDA-MB-231) that of carboplatin. The stability of these compounds in dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) has been assessed by NMR spectroscopy and mass spectrometry studies, and the compounds show no oxidation of the iron center from Fe-II to Fe-III. Cytotoxicity screening was performed in both DMSO and DMF, with no significant differences observedin their potency

Maternal Predator Odor Exposure in Mice Programs Adult Offspring Social Behavior and Increases Stress-Induced Behaviors in Semi-Naturalistic and Commonly-Used Laboratory Tasks

Maternal stress has a profound impact on the long-term behavioral phenotype of offspring, including behavioral responses to stressful and social situations. In this study, we examined the effects of maternal exposure to predator odor, an ethologically relevant psychogenic stressor, on stress-induced behaviors in both semi-naturalistic and laboratory-based situations. Adult C57BL/6 mice offspring of dams exposed to predator odor during the last half of pregnancy showed increased anti-predatory behavior, more cautious foraging behavior and, in the elevated plus maze, avoidance of elevated open areas and elevated open areas following restraint stress challenge. These offspring also exhibited alterations in social behavior including reduced free interaction and increased initial investigation despite normal social recognition. These changes in behavior were associated with increased transcript abundance of corticotropin-releasing factor, mineralocorticoid receptor and oxytocin (Oxt) in the periventricular nucleus of the hypothalamus. Taken together, the findings are consistent with a long-term increase in ethologically-relevant behavioral and neural responses to stress in male and female offspring as a function of maternal predator odor exposure

Simulasi Routing Protokol Berbasis Distance Vector Menggunakan Gns3 Versi 0.8.

Measurement of routing protocol performance in a network can be done with the help of simulation. The writers are trying to simulate package delivery data over Virtual Private Network (VPN) with the use of Graphical Network Simulator version 0.8.6 (GNS3). The topology used in the delivery of data packets is a ring topology which consists of 6 routers based on distance vector routing protocol. The results of simulation that the writers get are the throughput of the wireless and wireline on the server and client were averaging 1Mbit/s. The packet loss values generated for both wireless and wireline were 0 %. The measurement delay of the wireless and wireline for server and client side were averaging 7 ms.Pengukuran performansi routing protocol dalam suatu network dapat dilakukan dengan bantuan simulasi. Penulis mencoba mensimulasikan pengiriman paket data melalui Virtual Private Network (VPN) menggunakan simulator Graphical Network Simulator versi 0.8.6 (GNS3). Topologi yang penulis gunakan dalam pengiriman data paket menggunakan topologi ring yang terdiri dari 6 router, dengan salah satu routing protokol yang berbasis distance vector. Hasil simulasi yang penulis dapatkan nilai throughput dari wireless maupun wireline pada sisi server dan client rata-rata 1Mbit/sec. Sedangkan untuk nilai packet loss dihasilkan 0% baik itu wireless dan wireline dari posisi server ataupun client. Pengukuran pada delay wireless maupun wireline pada sisi server dan client rata-rata 7ms