928 research outputs found

    Market Allocations under Ambiguity: A Survey

    Get PDF
    We review some of the (theoretical) economic implications of David Schmeidler's models of decision under uncertainty (Choquet expected utility and maxmin expected utility) in competitive market settings. We start with the portfolio inertia result of Dow and Werlang (1992), show how it does or does not generalize in an equilibrium setting. We further explore the equilibrium implications (indeterminacies, non revelation of information) of these decision models. A section is then devoted to the studies of Pareto optimal arrangements under these models. We conclude with a discussion of experimental evidence for these models that relate, in particular, to the implications for market behaviour discussed in the preceding sections

    Alu-miRNA interactions modulate transcript isoform diversity in stress response and reveal signatures of positive selection

    Get PDF
    Primate-specific Alus harbor different regulatory features, including miRNA targets. In this study, we provide evidence for miRNA-mediated modulation of transcript isoform levels during heat-shock response through exaptation of Alu-miRNA sites in mature mRNA. We performed genome-wide expression profiling coupled with functional validation of miRNA target sites within exonized Alus, and analyzed conservation of these targets across primates. We observed that two miRNAs (miR-15a-3p and miR-302d-3p) elevated in stress response, target RAD1, GTSE1, NR2C1, FKBP9 and UBE2I exclusively within Alu. These genes map onto the p53 regulatory network. Ectopic overexpression of miR-15a-3p downregulates GTSE1 and RAD1 at the protein level and enhances cell survival. This Alu-mediated fine-tuning seems to be unique to humans as evident from the absence of orthologous sites in other primate lineages. We further analyzed signatures of selection on Alu-miRNA targets in the genome, using 1000 Genomes Phase-I data. We found that 198 out of 3177 Alu-exonized genes exhibit signatures of selection within Alu-miRNA sites, with 60 of them containing SNPs supported by multiple evidences (global-FST > 0.3, pair-wise-FST > 0.5, Fay-Wu's H  2.0, high ΔDAF) and implicated in p53 network. We propose that by affecting multiple genes, Alu-miRNA interactions have the potential to facilitate population-level adaptations in response to environmental challenges

    Subcutaneous Delivery of Nanoconjugated Doxorubicin and Cisplatin for Locally Advanced Breast Cancer Demonstrates Improved Efficacy and Decreased Toxicity at Lower Doses Than Standard Systemic Combination Therapy In Vivo

    Get PDF
    Background—Combination cytotoxic agents in breast cancer carry dose-limiting toxicities. We hypothesize that nanocarrier-conjugated doxorubicin and cisplatin will have improved tumor efficacy with decreased systemic toxicity over standard drugs, even at lower doses. Methods—Female Nu/Nu mice were injected in the breast with human MDA-MB-468LN cells and treated with either standard or nanocarrier-conjugated combination therapy (doxorubicin +cisplatin) at 50% or 75% MTD, and monitored for efficacy and toxicity over 12-weeks. Results—Efficacy results for mice treated with HA-conjugated doxorubicin/cisplatin at 50% MTD include:[complete responses(CR)=5, partial responses(PR)=2, and stable disease(SD)=1]and for HA-conjugated dox/cis at 75% MTD:[CR=7,PR=1; all CR’s confirmed histologically]. In comparison, mice given standard dox/cis(50% MTD)demonstrated:[progressive disease(PD)=6, SD=1, and PR=1] and for standard dox/cis(75% MTD):[PD=5,SD=3; p<0.0001 on multivariate ANOVA]. At 75% MTD, standard drug-treated mice had significant weight loss compared to nanocarrier drug-treated mice(p<0.001). Conclusion—Subcutaneous nanocarrier-delivery of doxorubicin and cisplatin demonstrated significantly improved efficacy with decreased toxicity compared to standard agent combination therapy at all doses tested achieving complete pathologic tumor response

    Exploring Manifestations of TB-Related Stigma Experienced by Women in Kolkata, India

    Get PDF
    Background: Stigma associated with tuberculosis (TB) is still common in many societies, contributing to delays in treatment seeking and treatment non-compliance. India has the highest burden of TB in the world with female TB patients bearing a considerable burden of TB-related stigma. Objectives: This study aimed to explore the manifestations and consequences of stigma experienced by female TB patients in an urban setting in India and their strategies to cope with the social stigma of TB. Methods: Twenty qualitative interviews were conducted with female TB patients who were either currently on treatment or had undergone treatment at a TB clinic in Kolkata, India. Data were coded and analyzed with the NVivo qualitative software using a thematic approach. Results: Our results indicated that TB stigma mainly manifested through social isolation and avoidance due to fear of contagion, gossip and verbal abuse, failed marriage prospects, and neglect from family. Consequences of stigma described by the women included non-disclosure, feelings of guilt, and mental health issues including suicidal ideation. Positive coping strategies used by women to cope with the experiences of stigma included positive reframing, prayer, talking to other patients, focusing on school work, and relaxation activities. Negative coping activities included self-imposed social isolation and anger. In some cases, non-disclosure due to stigma had an impact on TB transmission and control behaviors. Conclusions: Stigma-reduction strategies, such as community awareness programs and formation of social support groups to dispel the myths and misconceptions associated with TB, may improve TB treatment seeking and adherence. Acknowledgement: Our deepest thanks to the Reverend, St. James’ Church, Dr. Ali Akbar Chowdhury (Medical Officer), staff and participants at the Calcutta Diocesan Tuberculosis Relief Trust, without whom this study would not be possible. We also thank Sushmita Mukherjee for help with translations. Lastly, we thank the Sparkman Center for Global Health at the University of Alabama at Birmingham for providing travel funds for this study

    The Neural Basis of Social Cognition in Typically Developing Children and Its Relationship to Social Functioning

    Get PDF
    Theory of mind (ToM), the ability to think about the perspectives, beliefs, and feelings of another, develops throughout childhood and adolescence and is an important skill for social interactions. This study examines neural activity in typically developing children during a novel ToM task – the Movie Mentalizing Task– and tests its relations to ToM behavioral performance and social functioning. In this fMRI task, children ages 8–13years (N=25) watched a brief movie clip and were asked to predict a character’s mental state after a social interaction. Engaging in the Movie Mentalizing Task activated the ToM neural network. Moreover, greater neural activity in the ToM network, including the superior temporal gyrus and inferior frontal gyrus, was associated with better behavioral performance on independent ToM tasks and was related to better social functioning, though these results do not survive correction for multiple comparisons. Results offer a new affective theory of mind task for children in the scanner that robustly recruits activity in theory of mind regions

    Molecular analysis of autosomal dominant hereditary ataxias in the Indian population: high frequency of SCA2 and evidence for a common founder mutation

    Get PDF
    Expansion of CTG/CAG trinucleotide repeats has been shown to cause a number of autosomal dominant cerebellar ataxias (ADCA) such as SCA1, SCA2, SCA3/MJD, SCA6, SCA7, SCA8 and DRPLA. There is a wide variation in the clinical phenotype and prevalence of these ataxias in different populations. An analysis of ataxias in 42 Indian families indicates that SCA2 is the most frequent amongst all the ADCAs we have studied. In the SCA2 families, together with an intergenerational increase in repeat size, a horizontal increase with the birth order of the offspring was also observed, indicating an important role for parental age in repeat instability. This was strengthened by the detection of a pair of dizygotic twins with expanded alleles showing the same repeat number. Haplotype analysis indicates the presence of a common founder chromosome for the expanded allele in the Indian population. Polymorphism of CAG repeats in 135 normal individuals at the SCA loci studied showed similarity to the Caucasian population but was significantly different from the Japanese population

    Nociceptin/Orphanin FQ receptor expression in clinical pain disorders and functional effects in cultured neurons

    Get PDF
    The Nociceptin/Orphanin FQ peptide receptor (NOP), activated by its endogenous peptide ligand Nociceptin/Orphanin FQ (N/OFQ), exerts several effects including modulation of pain signalling. We have examined, for the first time, the tissue distribution of the NOP receptor in clinical visceral and somatic pain disorders by immunohistochemistry, and assessed functional effects of NOP and [micro] opioid receptor activation in cultured human and rat dorsal root ganglion (DRG) neurons. Quantification of NOP-positive nerve fibres within the bladder sub-urothelium revealed a remarkable several-fold increase in Detrusor Overactivity (p<0.0001) and Painful Bladder Syndrome patient specimens (p=0.0014), compared to controls. In post-mortem control human DRGs, 75-80% of small/medium neurons (<=50 [micro]m diameter) in the lumbar (somatic) and sacral (visceral) DRG were positive for NOP, and fewer large neurons; avulsion-injured cervical human DRG neurons showed similar numbers. NOP-immunoreactivity was significantly decreased in injured peripheral nerves (p=0.0004), and also in painful neuromas (p=0.025). Calcium imaging studies in cultured rat DRG neurons demonstrated dose-dependent inhibition of capsaicin responses in the presence of N/OFQ, with an IC50 of 8.6 pM. In cultured human DRG neurons, 32% inhibition of capsaicin responses was observed in the presence of 1 pM N/OFQ (p<0.001). The maximum inhibition of capsaicin responses was greater with N/OFQ than [mu]-opioid receptor agonist DAMGO. Our findings highlight the potential of NOP agonists, particularly in urinary bladder overactivity and pain syndromes. The regulation of NOP expression in visceral and somatic sensory neurons by target-derived neurotrophic factors deserves further study, and the efficacy of NOP selective agonists in clinical trials

    Novel C-Terminal Hsp90 Inhibitor for Head and Neck Squamous Cell Cancer (HNSCC) with in vivo Efficacy and Improved Toxicity Profiles Compared with Standard Agents

    Get PDF
    The final publication is available at Springer via http://dx.doi.org/10.1245/s10434-011-1971-1.Background - Current therapies for HNSCC, especially platinum agents, are limited by their toxicities and drug resistance. This study evaluates a novel C-terminal Hsp90 inhibitor (CT-Hsp90-I) for efficacy and toxicity in vitro and in vivo in an orthotopic HNSCC model. Our hypothesis is that C-terminal inhibitors exhibit improved toxicity/efficacy profiles over standard therapies and may represent a novel group of anticancer agents. Methods - MDA-1986 HNSCC cells were treated with doses of 17-AAG or KU363 (a CT-Hsp90-I) and compared for antiproliferation by GLO-Titer and trypan blue exclusion and for apoptosis by PARP cleavage and caspase-3 inactivation by Western analysis. In vivo studies in Nu/Nu mice examined an orthotopic model of MDA-1986 cells followed by drug dosing intraperitoneally for a 21-day period (mg/kg/dose: cisplatin = 3.5, low-dose KU363 = 5, high-dose KU363 = 25, 17-AAG = 175). Tumor size, weight, and toxicity (body score) were measured 3×/week. Results - The IC50 levels for KU363 = 1.2–2 ÎŒM in MDA-1986. KU363 induces apoptosis at 1 ÎŒM with cleavage of PARP and inactivation of caspase-3 levels after 24 h. Client proteins Akt and Raf-1 were also downregulated at 1–3 ÎŒM of drug. In vivo, 100% of controls had progressive disease, while 100% of cisplatin animals showed some response, all with significant systemic toxicity. High-dose KU363 showed 88% of animals responding and low-dose KU363 showed 75% responding. KU363 animals showed significantly less toxicity (P < 0.01) than cisplatin or 17-AAG. Conclusion - This novel CT-Hsp90-I KU363 manifests potent anticancer activity against HNSCC, showing excellent in vivo efficacy and reduced toxicity compared with standard agents justifying future translational evaluation

    Hierarchical model for the scale-dependent velocity of seismic waves

    Get PDF
    Elastic waves of short wavelength propagating through the upper layer of the Earth appear to move faster at large separations of source and receiver than at short separations. This scale dependent velocity is a manifestation of Fermat's principle of least time in a medium with random velocity fluctuations. Existing perturbation theories predict a linear increase of the velocity shift with increasing separation, and cannot describe the saturation of the velocity shift at large separations that is seen in computer simulations. Here we show that this long-standing problem in seismology can be solved using a model developed originally in the context of polymer physics. We find that the saturation velocity scales with the four-third power of the root-mean-square amplitude of the velocity fluctuations, in good agreement with the computer simulations.Comment: 7 pages including 3 figure
    • 

    corecore