Insulin, a key regulator of hormone responsive milk protein synthesis during lactogenesis in murine mammary explants

Murine milk protein gene expression requires insulin, hydrocortisone, and prolactin; however, the role of insulin is not well understood. This study, therefore, examined the requirement of insulin for milk protein synthesis. Mammary explants were cultured in various combinations of the lactogenic hormones and global changes in gene expression analysed using Affymetrix microarray. The expression of 164 genes was responsive to insulin, and 18 were involved in protein synthesis at the level of transcription and posttranscription, as well as amino acid uptake and metabolism. The folate receptor gene was increased by fivefold, highlighting a potentially important role for the hormone in folate metabolism, a process that is emerging to be central for protein synthesis. Interestingly, gene expression of two milk protein transcription factors, Stat5a and Elf5, previously identified as key components of prolactin signalling, both showed an essential requirement for insulin. Subsequent experiments in HCll cells confirmed that Stat5a and Elf5 gene expression could be induced in the absence of prolactin but in the presence of insulin. Whereas prolactin plays an essential role in phosphorylating and activating Stat5a, gene expression is only induced when insulin is present. This indicates insulin plays a crucial role in the transcription of the milk protein genes.

Effect of thermo-mechanical processing on precipitate formation in next generation HSLA steel

Development of advanced high strength steels (AHSS) using a conventional rolling setup is one of the biggest challenges to steel industry. It has been found that fine precipitation in a soft matrix, formed after hot rolling, can markedly improve the mechanical properties. In this work, three dimensional atom probe tomography (3D-APT) has been used to study the formation of precipitates in thermomechanically simulated steel. 3D-APT data reveals co-existence of numerous nano clusters with precipitates. Also, quantitative analysis of the nano clusters and precipitates shows clusters are as small as mm in size. Precipitates are found to be disc shaped with the composition of equilibrium precipitates (TiMo)C. Thus, 3D-APT is seen as an ideal technique to complement TEM to understand the nanoscale features in thermomechanically processed steel for further improvements in the mechanical properties of AHSS.

Formulation of vanillin cross-linked chitosan nanoparticles and its characterization.

Chitosan nanoparticles were successfully prepared by chemical cross-linking with vanillin. The nanoparticles were spherical in shape with smooth surface, and the average particle size of chitosan nanoparticles was 141 nm. The formulation of chitosan nanoparticles is based on Shiff reaction between aldehyde group of vanillin and amino group of chitosan. Chitosan nanoparticles prepared by crosslinking with vanillin are promising vehicle for the drug delivery of various anticancer drugs in the chemotherapy of cancers.

Chronic stress alters the density and morphology of microglia in a subset of stress-responsive brain regions

The current study, in parallel experiments, evaluated the impact of chronic psychological stress on physiological and behavioural measures, and on the activation status of microglia in 15 stress-responsive brain regions. Rats were subjected, for 14 days, to two 30 min sessions of restraint per day, applied at random times each day. In one experiment the effects of stress on sucrose preference, weight gain, core body temperature, and struggling behaviour during restraint, were determined. In the second experiment we used immunohistochemistry to investigate stress-induced changes in ionized calcium-binding adaptor molecule-1 (Iba1), a marker constitutively expressed by microglia, and major histocompatibility complex-II (MHC-II), a marker often expressed on activated microglia, in a total of 15 stress-responsive nuclei. We also investigated cellular proliferation in these regions using Ki67 immunolabelling, to check for the possibility of microglial proliferation. Collectively, the results we obtained showed that chronic stress induced a significant increase in anhedonia, a decrease in weight gain across the entire observation period, a significant elevation in core body temperature during restraint, and a progressive decrease in struggling behaviour within and over sessions. With regard to microglial activation, chronic stress induced a significant increase in the density of Iba1 immunolabelling (nine of 15 regions) and the number of Iba1-positive cells (eight of 15 regions). Within the regions that exhibited an increased number of Iba1-positive cells after chronic stress, we found no evidence of a between group difference in the number of MHC-II or Ki67 positive cells. In summary, these results clearly demonstrate that chronic stress selectively increases the number of microglia in certain stress-sensitive brain regions, and also causes a marked transition of microglia from a ramified-resting state to a non-resting state. These findings are consistent with the view that microglial activation could play an important role in controlling and/or adapting to stress.

Efficient cross-validation of the complete two stages in KFD classifier formulation

This paper presents an efficient evaluation algorithm for cross-validating the two-stage approach of KFD classifiers. The proposed algorithm is of the same complexity level as the existing indirect efficient cross-validation methods but it is more reliable since it is direct and constitutes exact cross-validation for the KFD classifier formulation. Simulations demonstrate that the proposed algorithm is almost as fast as the existing fast indirect evaluation algorithm and the twostage cross-validation selects better models on most of the thirteen benchmark data sets.

Industry self regulation of television food advertising : responsible or responsive?

Introduction. This study evaluated the impact of the Australian Food and Grocery Council (AFGC) self-regulatory initiative on unhealthy food marketing to children, introduced in January 2009. The study compared patterns of food advertising by AFGC and non-AFGC signatory companies in 2009, 2007 and 2006 on three Sydney commercial free-to-air television channels.

Methods. Data were collected across seven days in May 2006 and 2007, and four days in May 2009. Advertised foods were coded as core, non-core and miscellaneous. Regression for counts analyses was used to examine change in rates of advertisements across the sampled periods and differential change between AFGC-signatory or non-signatory companies between 2007 and 2009.

Results. Of 36 food companies that advertised during the 2009 sample period, 14 were AFGC signatories. The average number of food advertisements decreased significantly from 7.0 per hour in 2007 to 5.9 in 2009. There was a significant reduction in non-core food advertising from 2007 to 2009 by AFGC signatories compared with non-signatory companies overall and during peak times, when the largest numbers of children were viewing. There was no reduction in the rate of non-core food advertisements by all companies, and these advertisements continue to comprise the majority during peak viewing times.

Discussion. While some companies have responded to pressures to reduce unhealthy food advertising on television, the impact of the self-regulatory code is limited by the extent of uptake by food companies. The continued advertising of unhealthy foods indicates that this self-regulatory code does not adequately protect children.