24 research outputs found
"Mother-weights" and lost fathers: parents in South Asian American literature
That parent-child relationships should play a significant role within South Asian American literature is perhaps no surprise, since this is crucial material for any writer. But the particular forms they so often take – a dysfunctional mother-daughter dynamic, leading to the search for maternal surrogates; and the figure of the prematurely deceased father – are more perplexing. Why do families adhere to these patterns in so many South
Asian American texts and what does that tell us about this œuvre? More precisely, why are mothers subjected to a harsher critique than fathers and what purpose does this critique serve? How might we interpret the trope of the untimely paternal death? In this article I will seek to answer these questions – arguably key to an understanding of this growing body of writing – by considering works produced between the 1990s and the early twenty-first century by a range of South Asian American writers
Identification of a Positive Transcription Regulatory Element within the Coding Region of the nifLA Operon in Azotobacter vinelandii
Nitrogen fixation in Azotobacter vinelandii is regulated by the nifLA operon. NifA activates the transcription of nif genes, while NifL antagonizes the transcriptional activator NifA in response to fixed nitrogen and molecular oxygen levels. However, transcriptional regulation of the nifLA operon of A. vinelandii itself is not fully understood. Using the S1 nuclease assay, we mapped the transcription start site of the nifLA operon, showing it to be similar to the σ(54)-dependent promoters. We also identified a positive cis-acting regulatory element (+134 to +790) of the nifLA operon within the coding region of the nifL gene of A. vinelandii. Deletion of this element results in complete loss of promoter activity. Several protein factors bind to this region, and the specific binding sites have been mapped by DNase I foot printing. Two of these sites, namely dR1 (+134 to +204) and dR2 (+745 to +765), are involved in regulating the nifLA promoter activity. The absence of NtrC-like binding sites in the upstream region of the nifLA operon in A. vinelandii makes the identification of these downstream elements a highly significant finding. The interaction of the promoter with the proteins binding to the dR2 region spanning +745 to +765 appears to be dependent on the face of the helix as introduction of 4 bases just before this region completely disrupts promoter activity. Thus, the positive regulatory element present within the BglII-BglII fragment may play, in part; an important role in nifLA regulation in A. vinelandii
Positive regulation of prostate cancer cell growth by lipid droplet forming and processing enzymes DGAT1 and ABHD5
Abstract Background Neoplastic cells proliferate rapidly and obtain requisite building blocks by reprogramming metabolic pathways that favor growth. Previously, we observed that prostate cancer cells uptake and store lipids in the form of lipid droplets, providing building blocks for membrane synthesis, to facilitate proliferation and growth. Mechanisms of lipid uptake, lipid droplet dynamics and their contribution to cancer growth have yet to be defined. This work is focused on elucidating the prostate cancer-specific modifications in lipid storage pathways so that these modified gene products can be identified and therapeutically targeted. Methods To identify genes that promote lipid droplet formation and storage, the expression profiles of candidate genes were assessed and compared between peripheral blood mononuclear cells and prostate cancer cells. Subsequently, differentially expressed genes were inhibited and growth assays performed to elucidate their role in the growth of the cancer cells. Cell cycle, apoptosis and autophagy assays were performed to ascertain the mechanism of growth inhibition. Results Our results indicate that DGAT1, ABHD5, ACAT1 and ATGL are overexpressed in prostate cancer cells compared to PBMCs and of these overexpressed genes, DGAT1 and ABHD5 aid in the growth of the prostate cancer cells. Blocking the expression of both DGAT1 and ABHD5 results in inhibition of growth, cell cycle block and cell death. DGAT1 siRNA treatment inhibits lipid droplet formation and leads to autophagy where as ABHD5 siRNA treatment promotes accumulation of lipid droplets and leads to apoptosis. Both the siRNA treatments reduce AMPK phosphorylation, a key regulator of lipid metabolism. While DGAT1 siRNA reduces phosphorylation of ACC, the rate limiting enzyme in de novo fat synthesis and triggers phosphorylation of raptor and ULK-1 inducing autophagy and cell death, ABHD5 siRNA decreases P70S6 phosphorylation, leading to PARP cleavage, apoptosis and cell death. Interestingly, DGAT-1 is involved in the synthesis of triacylglycerol where as ABHD5 is a hydrolase and participates in the fatty acid oxidation process, yet inhibition of both enzymes similarly promotes prostate cancer cell death. Conclusion Inhibition of either DGAT1 or ABHD5 leads to prostate cancer cell death. Both DGAT1 and ABHD5 can be selectively targeted to block prostate cancer cell growth
Experimental investigation into indole production using passaging of E. coli and B. subtilis along with unstructured modeling and parameter estimation using dynamic optimization: An integrated framework
Greener process synthesis for drug production focuses on the replacement of chemical processes with biological processes. However, optimization of these processes remains challenging due to lack of experimental data, particularly for long term passaging and suitable parameter estimation techniques. In this context, we propose a mixed passaging scheme containing the co-culture of E. coli and B. subtilis that can be used to produce indole. The cell growth and product profiles obtained from fermenter corresponding to pure culture and individual culture obtained after passaging of E. coli and B. subtilis were used for unstructured model selection. Kinetic parameter estimation was performed using a hybrid technique combining classical and evolutionary algorithms. The dynamic interaction between the two organisms in long term passaging was captured by implementing optimal control for estimating time-varying parameters. The proposed unstructured model is capable of emulating the mixed culture effect on cell growth, product formation, and substrate depletion. This is the first instance where an integrated framework combining experimental and computational methodology is used to estimate and analyse model parameters in a mixed culture of E. coli and B. subtilis towards indole production. A similar framework can be used for optimizing the process parameters to improve the indole production
Feeling safe and content: A specific affect regulation system? Relationship to depression, anxiety, stress, and self-criticism.
Recent work in the neuroscience of positive affect has suggested that there may be two different types of positive affect. One is linked to a drive/seeking system (and may be dopaminergic mediated) and the other is a soothing-contentment system (and may be opiate/oxytocin mediated). This study sought to develop a self-report scale that could tap these positive affects in regard to characteristic feelings individuals may have. Results from 203 students suggested three (rather than two) underlying factors: activated positive affect, relaxed positive affect, and safe/content positive affect. It was the safe/content positive affect that had the highest negative correlations with depression, anxiety and stress, self-criticism, and insecure attachment. Hence, greater clarity on the different types and functions of positive affect may demystify the relationship between positive emotions and well-being.N/
Cultural differences in shame-focused attitudes towards mental health problems in Asian and Non-Asian student women.
This study explored differences in shame-focused attitudes to mental health problems in Asian and non-Asian students. The ‘Attitudes Towards Mental Health Problems’ (ATMHP) is a self-report scale designed for this study to measure: external shame (beliefs that others will look down on self if one has mental health problems); internal shame (related to negative self-evaluations); and reflected shame (believing that one can bring shame to family/community). A second questionnaire was designed to measure concerns with confidentiality. Results suggest that Asian students have higher external shame and reflected shame, but not internal shame beliefs. Asian students were also more concerned with confidentiality when it comes to talking about personal feeling/anxieties
An exploration of different types of positive affect in students and patients with bipolar disorder.
Objective: Depue and Morrone-Strupinsky (2005) distinguished between two different types of positive affect regulation system: 1. relates to activated positive affects such as excitement, joy and vitality; and 2. relates to positive affects associated with peacefulness, contentment and well-being, and is linked to the experience of attachment and social safeness. In addition, people can derive positive feelings from doing social things (e.g. enjoying being with friends), and non-social things (e.g. watching a sunset). The first aim of this study was to develop two scales to assess the enjoyment of social and non-social events and to explore how these relate to the two types of affect regulation. In addition, we explore how these two types of positive affect regulation system are related to measures of affective temperament linked to mood disorders. The second aim was to explore these dimensions in people who have a bipolar disorder. Method: Students (n=202) and patients with bipolar disorder (n=49) completed a set of self-report scales measuring: social and non-social positive affect; different types of positive affect; social rank; current affective temperament and mood. Results: Our data showed that, in both patient and student groups, non-social positive affect has few correlations with other types of positive affect and affective temperament. In contrast, the pleasures derived from social relationships are significantly related to other types of positive affect and mood linked affective temperaments. Conclusions: Social and non-social positive affect seem to operate quite differently. It is the positive affects that we receive from our social relationships that are most significantly linked to affective temperament and social rank variables. This finding may have implications for pharmacological, psychological and social therapies.Mental Health Research Unit Department of Healt
An exploration of different types of positive affect in students and patients with a bipolar disorder
Confocal imaging and k-means clustering of GABAB and mGluR mediated modulation of Ca2+ spiking in hippocampal neurons
Imaging cytosolic calcium in neurons is emerging as a new tool in neurological disease diagnosis, drug screening, and toxicity testing. Ca2+ oscillation signatures show a significant variation depending on GPCR targeting agonists. Quantification of Ca2+ spike trains in ligand induced Ca2+ oscillations remain challenging due to their inherent heterogeneity in primary culture. Moreover, there is no framework available for identification of optimal number of clusters and distance metric to cluster Ca2+ spike trains. Using quantitative confocal imaging and clustering analysis, we show the characterization of Ca2+ spiking in GPCR targeting drug-treated primary culture of hippocampal neurons. A systematic framework for selection of the clustering method instead of an intuition-based method was used to optimize the cluster number and distance metric. The results discern neurons with diverse Ca2+ response patterns, including higher amplitude fast spiking and lower spiking responses, and their relative percentage in a neuron population in absence and presence of GPCR-targeted drugs. This framework was employed to control clustering patterns of Ca2+ spiking using GABAB and mGluR targeting drugs. This approach can be used for unbiased measurement of neural activity and identification of spiking population with varying amplitude and frequencies, providing a platform for high-content drug screening