Publications by authors named "Pragya Shah"

We possess a remarkably acute ability to detect even small misalignments between extended line segments. This "vernier acuity" significantly exceeds our "resolution acuity"-the ability to resolve closely separated stimuli-and is generally considered a "hyperacuity," since the detectable misalignments are markedly finer than the diameter of single retinal cones. Vernier acuity has, thus, often been proposed to reflect spatial organization and multi-unit cortical processing, rendering it an important index of visual function.

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In his 1872 monograph, Charles Darwin posited that "… the habit of expressing our feelings by certain movements, though now rendered innate, had been in some manner gradually acquired." Nearly 150 years later, researchers are still teasing apart innate versus experience-dependent contributions to expression recognition. Indeed, studies have shown that face detection is surprisingly resilient to early visual deprivation, pointing to plasticity that extends beyond dogmatic critical periods.

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Human visual memory capacity has a rapid developmental progression. Here we examine whether image semantics modulate this progression. We assessed the performance of children (6-14 years) and young adults (19-36 years) on a visual memory task using real-world (or meaningful) as well as abstract image sets, which were matched in low-level image attributes.

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Human visual recognition is remarkably robust to chromatic changes. In this work, we provide a potential account of the roots of this resilience based on observations with 10 congenitally blind children who gained sight late in life. Several months or years following their sight-restoring surgeries, the removal of color cues markedly reduced their recognition performance, whereas age-matched normally sighted children showed no such decrement.

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While organ-confined prostate cancer (PCa) is mostly therapeutically manageable, metastatic progression of PCa remains an unmet clinical challenge. Resistance to anoikis, a form of cell death initiated by cell detachment from the surrounding extracellular matrix, is one of the cellular processes critical for PCa progression towards aggressive disease. Therefore, further understanding of anoikis regulation in PCa might provide therapeutic opportunities.

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Article Synopsis
  • Aberrations in nuclear size and shape can indicate cancer, but it's unclear if these changes directly cause cancer or are a side effect of tumor development.
  • The study finds that invasive breast cancer cells often have lower levels of lamin A/C, a nuclear envelope protein, driven by Akt signaling, which makes their nuclei more deformable and enhances their ability to migrate, similar to conditions during metastasis.
  • In human breast tumors, lower lamin A levels were linked to increased Akt activity and worse survival rates, suggesting that the reduction of lamin A/C may enhance both the physical and biochemical properties of cancer cells to promote metastasis.
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The long-standing nativist vs. empiricist debate asks a foundational question in epistemology - does our knowledge arise through experience or is it available innately? Studies that probe the sensitivity of newborns and patients recovering from congenital blindness are central in informing this dialogue. One of the most robust sensitivities our visual system possesses is to 'biological motion' - the movement patterns of humans and other vertebrates.

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Ataxia-telangiectasia mutated (ATM) is one of the three main apical kinases at the crux of DNA damage response and repair in mammalian cells. ATM activates a cascade of downstream effector proteins to regulate DNA repair and cell cycle checkpoints in response to DNA double-strand breaks. While ATM is predominantly known for its role in DNA damage response and repair, new roles of ATM have recently begun to emerge, such as in regulating oxidative stress or metabolic pathways.

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It is unknown whether visual memory capacity can develop if onset of pattern vision is delayed for several years following birth. We had an opportunity to address this question through our work with an unusual population of 12 congenitally blind individuals ranging in age from 8 to 22 years. After providing them with sight surgery, we longitudinally evaluated their visual memory capacity using an image-memorization task.

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Judgments of facial attractiveness invariably accompany our perception of faces. Even neonates appear to be capable of making such judgments in a manner consistent with adults. This suggests that the processes supporting facial attractiveness require little, if any, visual experience to manifest.

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Early visual deprivation is known to have profound consequences on the subsequent development of spatial visual processing. However, its impact on temporal processing is not well characterized. We have examined spatial and temporal contrast sensitivity functions following treatment for early and extended bilateral visual deprivation in fifteen children born with congenital cataracts in rural India.

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Cancer metastasis, i.e., the spreading of tumor cells from the primary tumor to distant organs, is responsible for the vast majority of cancer deaths.

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While ductal carcinoma in situ (DCIS) is known as a precursor lesion to most invasive breast carcinomas, the mechanisms underlying this transition remain enigmatic. DCIS is typically diagnosed by the mammographic detection of microcalcifications (MC). MCs consisting of non-stoichiometric hydroxyapatite (HA) mineral are frequently associated with malignant disease, yet it is unclear whether HA can actively promote malignancy.

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Chromosomal instability is a hallmark of cancer that results from ongoing errors in chromosome segregation during mitosis. Although chromosomal instability is a major driver of tumour evolution, its role in metastasis has not been established. Here we show that chromosomal instability promotes metastasis by sustaining a tumour cell-autonomous response to cytosolic DNA.

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Background: Penetration of the mammary gland basement membrane by cancer cells is a crucial first step in tumor invasion. Using a mouse model of ductal carcinoma in situ, we previously found that inhibition of peptidylarginine deiminase 2 (PAD2, aka PADI2) activity appears to maintain basement membrane integrity in xenograft tumors. The goal of this investigation was to gain insight into the mechanisms by which PAD2 mediates this process.

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The nuclear envelope safeguards the genetic material inside the nucleus by separating it from the cytoplasm. Until recently, it was assumed that nuclear envelope (NE) breakdown occurs only in a highly controlled fashion during mitosis when the chromatin is condensed and divided between the daughter cells. However, recent studies have demonstrated that adherent and migrating cells exhibit transient NE rupture during interphase caused by compression from cytoskeletal or external forces.

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