406 research outputs found
Il grano, la falce, la "rivoluzione". Antropologia storica di un eccidio nel Mezzogiorno d'Italia di inizio Novecento
Analisi storica e antropologica di un eccidio di inizio Novecento, con particolare attenzione alle dimensioni rituali e simboliche
Rediscovery of the nucleolinus, a dynamic RNA-rich organelle associated with the nucleolus, spindle, and centrosomes
Author Posting. © The Authors, 2010. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 107 (2010): 13718-13723, doi:10.1073/pnas.1008469107.The nucleolinus is an RNA-rich compartment, closely apposed to or embedded within
the nucleolus. Discovered over 150 years ago, fewer than two dozen articles have been
published on the nucleolinus, probably because complex histochemical stains are required
for its visualization in the great majority of cells. The nucleolinus has been reported in
invertebrate oocytes, mammalian and amphibian epithelial cells, neurons, and several
transformed cell lines. A prominent nucleolinus, clearly visible with transmitted light
microscopes at 10x magnification, is present in each oocyte of the surf clam, Spisula
solidissima. We observed a consistent relationship between the nucleolinus and the
developing meiotic apparatus following Spisula oocyte activation. Through sonication
and sucrose gradient fractionation of purified oocyte nuclei, we isolated nucleolini,
extracted their RNA, and prepared an in situ riboprobe (NLi-1) that is associated
specifically with the nucleolinus, confirming its unique composition. Other in situ
observations revealed a NLi-1 and nucleolinar association with the developing spindle and
centrosomes. Laser microsurgery that targeted the nucleolinus resulted in failed meiotic
cell division in parthenogenetically activated oocytes and failed mitosis in fertilized
oocytes. Although the nucleolinus may be a forgotten organelle, its demonstrated role in
spindle formation suggests it deserves renewed attention.This work was supported by grants from
the NIH (GM088503) and NSF (MCB0843092) to MCA. J.H. acknowledges support
from the National Science Foundation (IOB 05-16799) and the Directors of the MBL
Embryology Cours
Perceived stress, caregiver burden, and emotional distress in caregivers of head and neck cancer and lung cancer
2019 Fall.Includes bibliographical references.Caregiving research focuses highly on the impact burden of care has on the mental health of caregivers (Nightingale et al., 2014; Northouse et al., 2012; Perz et al., 2011). However, little research focuses on how stress, as an independent construct contributes to the emotional distress caregivers of Head and Neck and Lung Cancer patients experience (Luchesia et al., 2016). This project aims to investigate the relationship between caregiver burden, perceived stress, and emotional distress (depression and anxiety) of caregivers of HNC and LC patients. Results revealed positive and significant relationships between predictor variables (perceived stress and caregiver burden) and emotional distress. Results further revealed higher perceived stress is indicative of higher caregiver burden. Additionally, preliminary results suggested the relationship between caregiver burden and emotional distress is moderated by the caregiver's level of perceived stress. Explanations and implications of all investigated relationships are discussed. This study highlights that in fact, perceived stress as a construct is important to explore when understanding the mental health needs of caregivers of Head and Neck and Lung Cancer patients
Existential concerns and risky behavior in college students
2021 Spring.Includes bibliographical references.Substance use and sexual behavior are highly prevalent on college campuses (Arria et al., 2017; American College Health Association, 2018; Schulenberg et al., 2017). Substance misuse and risky sex can lead to adverse consequences (Furman & Collibee, 2014; Patrick & Terry-McElrath, 2016; Read, Haas. Radomski, Wickham, & Borish, 2016). There is high comorbidity between anxiety, substance use, and substance use disorders (Wolitzky et al., 2018). Existential anxiety may be a form of anxiety that is relevant to the college experience because college aged emerging adults are coping with existential issues, e.g., freedom, isolation, meaninglessness, and death, often for the first time. In a sample of undergraduate students, existential concerns predicted higher reports of binge drinking behavior. Existential concerns did not predict cannabis use or unprotected vaginal sex. Moderation analyses indicated that variables such as coping, and mindfulness are variables of interest that require further research to understand their influence on risky behavior as they relate to existential anxiety. Supplemental analyses revealed that a focus on construct validity and continued measurement development for assessing existential concerns is critical. Various existential themes (i.e., isolation, meaning, freedom) were found to be more strongly associated with risky behavior. This study demonstrates the importance of considering the role existential anxiety plays in engagement of high-risk behaviors among college students
Composition and dynamics of the nucleolinus, a link between the nucleolus and cell division apparatus in surf clam (Spisula) oocytes
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of American Society for Biochemistry and Molecular Biology for personal use, not for redistribution. The definitive version was published in Journal of Biological Chemistry 287 (2012): 6702-6713, doi:10.1074/jbc.M111.288506.The nucleolinus is a little-known
cellular structure, discovered over 150
years ago (1) and thought by some
investigators in the late 19th to mid-20th
century to function in the formation of the
centrosomes or spindle. A role for the
nucleolinus in formation of the cell division
apparatus has recently been confirmed in
oocytes of the surf clam, Spisula solidissima
(2). However, we know so little about the
composition and dynamics of this
compartment, it is difficult to construct
mechanistic hypotheses or even to be sure
that prior reports were describing
analogous structures in the cells of mammals, amphibians, plants, and other
organisms where it was observed. Surf
clam oocytes are an attractive model to
approach this problem because the
nucleolinus is easily visible by light
microscopy, making it accessible by laser
microsurgery as well as isolation by
common cell fractionation techniques. In
this report we analyze the macromolecular
composition of isolated Spisula nucleolini
and examine the relationship of this
structure to the nucleolus and cell division
apparatus. Analysis of nucleolinar RNA
and protein revealed a set of molecules that
overlaps with, but is nevertheless distinct
from the nucleolus. The proteins identified
were primarily ones involved in nucleic acid
metabolism and cell cycle regulation.
Monoclonal antibodies generated against
isolated nucleolini revealed centrosomal
forerunners in the oocyte cytoplasm.
Finally, induction of damage to the
nucleolinus by laser microsurgery altered
the trafficking of α- and γ-tubulin after
fertilization. These observations strongly
support a role for the nucleolinus in cell
division and represent our first clues
regarding mechanism.This work was supported by a grant from the NIH (GM088503) to M.C.A
The karyomastigont as an evolutionary seme
Author Posting. © University of Chicago Press, 2012. This article is posted here by permission of University of Chicago Press for personal use, not for redistribution. The definitive version was published in Quarterly Review of Biology 87 (2012): 315-324, doi:10.1086/668165.The problem of eukaryogenesis—the evolutionary mechanism whereby eukaryotic cells evolved from prokaryotes—remains one of the great unsolved mysteries of cell biology, possibly due to the reductionist tendency of most scientists to work only within their subdisciplines. Communication between biologists who conduct research on the nucleus and those working on the cytoskeleton or endomembrane system are sometimes wanting, and yet, all of these quintessentially eukaryotic elements of the cell are interdependent, and are physically associated in many protists as the karyomastigont organellar system: nucleus, one or more basal bodies and flagella, nuclear connector, and Golgi apparatus. Here we suggest a more holistic view of the karyomastigont as not simply an organellar system, but an evolutionary seme, the archaic state of the eukaryotic cell. We also present a scheme whereby the karyomastigont may have dissociated, giving rise in more derived cells to one or more free nuclei and discrete flagellar apparati (akaryomastigonts).Mark C. Alliegro is supported by grants from the
National Institutes of Health (NIGMS) and National
Science Foundation.2013-12-0
Self-Supervision for 3D Real-World Challenges
We consider several possible scenarios involving synthetic and real-world point clouds where supervised learning fails due to data scarcity and large domain gaps. We propose to enrich standard feature representations by leveraging self-supervision through a multi-task model that can solve a 3D puzzle while learning the main task of shape classification or part segmentation
Joint supervised and self-supervised learning for 3D real world challenges
Point cloud processing and 3D shape understanding are challenging tasks for which deep learning techniques have demonstrated great potentials. Still further progresses are essential to allow artificial intelligent agents to interact with the real world. In many practical conditions the amount of annotated data may be limited and integrating new sources of knowledge becomes crucial to support autonomous learning. Here we consider several scenarios involving synthetic and real world point clouds where supervised learning fails due to data scarcity and large domain gaps. We propose to enrich standard feature representations by leveraging self-supervision through a multi-task model that can solve a 3D puzzle while learning the main task of shape classification or part segmentation. An extensive analysis investigating few-shot, transfer learning and cross-domain settings shows the effectiveness of our approach with state-of-the-art results
Joint Supervised and Self-Supervised Learning for 3D Real-World Challenges
Point cloud processing and 3D shape understanding are very challenging tasks
for which deep learning techniques have demonstrated great potentials. Still
further progresses are essential to allow artificial intelligent agents to
interact with the real world, where the amount of annotated data may be limited
and integrating new sources of knowledge becomes crucial to support autonomous
learning. Here we consider several possible scenarios involving synthetic and
real-world point clouds where supervised learning fails due to data scarcity
and large domain gaps. We propose to enrich standard feature representations by
leveraging self-supervision through a multi-task model that can solve a 3D
puzzle while learning the main task of shape classification or part
segmentation. An extensive analysis investigating few-shot, transfer learning
and cross-domain settings shows the effectiveness of our approach with
state-of-the-art results for 3D shape classification and part segmentation
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