1,519 research outputs found
Influence of lithophysal geometry on the uniaxial compression of tuff-like rock
The purpose of this report is to summarize the work and present conclusions of Project Activity Task ORD-FY04-013 conducted under Cooperative Agreement No. DEFC28- 04RW12232 between the U.S. Department of Energy and the Nevada System of Higher Education (NSHE). This document describes results of laboratory testing on analog lithophysal tuff (Hydro-StoneTB®) conducted in the Department of Civil and Environmental Engineering of the University of Nevada at Las Vegas (UNLV) from 2004 to 2006
Circulation and Chemotaxis of Fetal Hematopoietic Stem Cells
The major site of hematopoiesis transitions from the fetal liver to the spleen and bone marrow late in fetal development. To date, experiments have not been performed to evaluate functionally the migration and seeding of hematopoietic stem cells (HSCs) during this period in ontogeny. It has been proposed that developmentally timed waves of HSCs enter the bloodstream only during distinct windows to seed the newly forming hematopoietic organs. Using competitive reconstitution assays to measure HSC activity, we determined the localization of HSCs in the mid-to-late gestation fetus. We found that multilineage reconstituting HSCs are present at low numbers in the blood at all timepoints measured. Seeding of fetal bone marrow and spleen occurred over several days, possibly while stem cell niches formed. In addition, using dual-chamber migration assays, we determined that like bone marrow HSCs, fetal liver HSCs migrate in response to stromal cell-derived factor-1α (SDF-1α); however, unlike bone marrow HSCs, the migratory response of fetal liver HSCs to SDF-1α is greatly increased in the presence of Steel factor (SLF), suggesting an important role for SLF in HSC homing to and seeding of the fetal hematopoietic tissues. Together, these data demonstrate that seeding of fetal organs by fetal liver HSCs does not require large fluxes of HSCs entering the fetal bloodstream, and that HSCs constitutively circulate at low levels during the gestational period from 12 to 17 days postconception. Newly forming hematopoietic tissues are seeded gradually by HSCs, suggesting initial seeding is occurring as hematopoietic niches in the spleen and bone marrow form and become capable of supporting HSC self-renewal. We demonstrate that fetal and adult HSCs exhibit specific differences in chemotactic behavior. While both migrate in response to SDF-1α, fetal HSCs also respond significantly to the cytokine SLF. In addition, the combination of SDF-1α and SLF results in substantially enhanced migration of fetal HSCs, leading to migration of nearly all fetal HSCs in this assay. This finding indicates the importance of the combined effects of SLF and SDF-1α in the migration of fetal HSCs, and is, to our knowledge, the first demonstration of a synergistic effect of two chemoattractive agents on HSCs
Meek Mill’s Trauma: Brutal Policing as an Adverse Childhood Experience
Meek Mill’s life and career have been punctuated by trauma, from his childhood lived on the streets of Philadelphia, through his rise to fame and eventual arrival as one of hip hop’s household names. his 2018 track Trauma, Meek Mill describes, in revealing prose, just how the traumatic experiences he endured personally impacted and harmed him. He also embodies a role as narrator in describing the same traumas and harms that impact the daily lives of countless similarly situated young Black people in the United States. As a child, Mill’s lived experience was one of pervasive poverty and fear, as the world surrounding him consisted of large-scale poverty, addiction, crime, violence, and death. As a young man—at just 19 years of age—he was beaten by police, wrongfully arrested and incarcerated, and ultimately convicted of crimes that he did not commit, becoming another statistic as a young Black man swallowed by the American criminal justice system. Meek’s story, lyrics and contributions to hip hop illuminate the Black experience with law enforcement. His personal involvements provide a powerful narrative for exactly how a racially biased criminal justice system perpetrates a trauma that extends far greater than the law has traditionally recognized. This article highlights this narrative through the lens that Meek Mill provides because of his current prominence in hip hop and the importance of his narrative claims. Despite his success in achieving the status of a true hip hop icon, Meek Mill suffered the kind of childhood adversity and trauma that emerging health care research indicates leads to debilitating health outcomes in adulthood.
Powerful health studies conducted over the past two decades have uncovered the startling impact of Adverse Childhood Experiences (“ACEs”). ACEs are traumatic events that occur in childhood, ranging from abuse and neglect to other traumatic experiences derived from household and community dysfunction. Today, ACEs are generally placed by health researchers into seven to ten categories of childhood adversities ranging from sexual, physical and emotional abuse to the incarceration of a family member, living with someone who abuses alcohol or drugs and poverty, community violence and homelessness. These identified categories of trauma, although not fully understood or grasped as late as the 1990s, were known to occur in the lives of children all over the United States; however, the overall impact of childhood trauma on an individual’s long term health outcomes was only first measured in the now famous CDC-Kaiser Permanente ACE study. The findings of this study shook the health care world, forever altering the understanding of the link between childhood trauma and adult health outcomes. These links pushed researchers to look more deeply into the ultimate impact of traumatic childhood experiences on overall adult health. The groundbreaking study concluded that the more trauma a child experiences, the fewer years that child would live as an adult. In fact, in a 2009 study, CDC researchers determined that exposure to childhood trauma literally shortens an individual’s lifespan. On average, a person with six or more ACEs died twenty years earlier than a person that had experienced no Adverse Childhood Experiences.
This reality, that traumatic childhood experiences are directly and inextricably linked to negative health outcomes, is now widely recognized in the public health and clinical literature. Dr. Robert Block, former President of the American Academy of Pediatrics, has warned that “[a]dverse childhood experiences are the single greatest unaddressed public health threat facing our nation today.” More recently, this literature has begun to explore the connection between trauma and race, outlining how structural violence and historical trauma—particularly violence and discrimination experienced by Black, indigenous, and persons of color—is often experienced both at the individual and community levels. Such work has focused on improving economic opportunities for trauma- stricken communities, improving the physical/built environment, and supporting the development of healthy social-cultural environments. The prevailing framework for addressing the ACEs crisis has been a medical model focused on interventions for individual survivors and communities rather than addressing the glaring systemic issues that directly contribute to the vast majority of the trauma suffered by those communities and the individuals and families that inhabit them. Largely and undeniably absent from the body of work on childhood trauma, and the proposed solutions to confronting and rectifying its deadly impact, is the exploration of how the American legal and justice systems, from municipal law enforcement to the appellate courts, stands at the epicenter of the current crisis.
Each of the recognized categories of ACEs listed in medical screening instruments used by physicians to identity trauma have a direct nexus to the justice system. If we as a society are committed to treating ACEs as the public health crisis that they are, it is incumbent upon us to examine where and how our legal system is complicit in perpetuating trauma upon minority children. In addition, we need to consider how it can intervene—both at the individual and structural levels—to eliminate practices that contribute to multi-generational cycles of trauma and work to equip those with justice-system involvement to succeed and build the resilience necessary to heal minority individuals and communities who have been stricken by trauma and its life-long negative consequences. Indeed it is the responsibility of our justice system, as a major contributor to so-called “social determinants of health.”
Meek Mill, in his intimate autobiographical tracks of Trauma, Oodles O’Noodles Babies, and Otherside of America, describes experiencing not just several instances of childhood trauma as identified by the CDC-Kaiser Permanente study, but as a teenager, he suffered additional cruel trauma at the hands of U.S. police and a criminal justice system that wrongly imprisoned and unfairly positioned him in a revolving door between probation and prison. The data tells us that the trauma Meek experienced as a child and teenager statistically predicts a poorer life expectancy for him than those individuals that experienced no trauma or little trauma as a child and youth. Because of the anti-Black culture of policing in America, and because of the deep systemic racism that permeates the criminal justice system, simple exposure to U.S. policing and its courts should qualify as an Adverse Childhood Experience for Black and minority children—one that contributes to harmful adult outcomes, including a shortened life expectancy. Mill’s personal childhood trauma as described in his music carefully extrapolates the ways that American policing and the criminal justice system literally traumatized and endangered his young Black life, as it does so many Black children.
This article begins in Section I by providing an in-depth examination of ACEs research, including how the groundbreaking original ACE study discovered the direct link between high ACE scores and poor health outcomes and the prevalence of ACEs in the Black community. It then turns, in Section II, to a brief discussion of the broad ACE category of social disadvantage, and how a child growing up in an environment built on a foundation of poverty and violence will inevitably have more trauma, more ACEs, and be harmed through his or her experience of toxic stress. Section III will provide an overview of anti-Black policing and how law enforcement, as currently constituted, traumatizes minority communities and youth. Section IV explains how criminal charging, jailing, and sentencing traditions have disproportionately targeted Black men, contributing to the trauma that their children and families experience with the loss of a loved one to death or incarceration. The article next argues that minority youth exposure to U.S. law enforcement agents and the justice system at large functions as an ACE for youth of color in a way that is simply not present for non-minority youth and, as such, should be added to the list of ACEs that are formally recognized by public health officials. Finally, the article concludes with how Meek Mill himself is seeking to reform a system rife with debilitating trauma. Throughout each section, Meek Mill, and the raw lyrics from some of his most personal tracks, will serve as an illustration, and example, of how social disadvantage, police misconduct and brutality, and the American criminal justice system at large, cause harmful and lifelong trauma for Black Americans
Altered patterns of gene duplication and differential gene gain and loss in fungal pathogens
<p>Abstract</p> <p>Background</p> <p>Duplication, followed by fixation or random loss of novel genes, contributes to genome evolution. Particular outcomes of duplication events are possibly associated with pathogenic life histories in fungi. To date, differential gene gain and loss have not been studied at genomic scales in fungal pathogens, despite this phenomenon's known importance in virulence in bacteria and viruses.</p> <p>Results</p> <p>To determine if patterns of gene duplication differed between pathogens and non-pathogens, we identified gene families across nine euascomycete and two basidiomycete species. Gene family size distributions were fit to power laws to compare gene duplication trends in pathogens <it>versus </it>non-pathogens. Fungal phytopathogens showed globally altered patterns of gene duplication, as indicated by differences in gene family size distribution. We also identified sixteen examples of gene family expansion and five instances of gene family contraction in pathogenic lineages. Expanded gene families included those predicted to be important in melanin biosynthesis, host cell wall degradation and transport functions. Contracted families included those encoding genes involved in toxin production, genes with oxidoreductase activity, as well as subunits of the vacuolar ATPase complex. Surveys of the functional distribution of gene duplicates indicated that pathogens show enrichment for gene duplicates associated with receptor and hydrolase activities, while euascomycete pathogens appeared to have not only these differences, but also significantly more duplicates associated with regulatory and carbohydrate binding functions.</p> <p>Conclusion</p> <p>Differences in the overall levels of gene duplication in phytopathogenic species <it>versus </it>non-pathogenic relatives implicate gene inventory flux as an important virulence-associated process in fungi. We hypothesize that the observed patterns of gene duplicate enrichment, gene family expansion and contraction reflect adaptation within pathogenic life histories. These adaptations were likely shaped by ancient, as well as contemporary, intimate associations with monocot hosts.</p
Trauma-Informed Policing: The Impact of Adult and Childhood Trauma on Law Enforcement Officers
Pilot Testing Behavior Therapy for Chronic Tic Disorders in Neurology and Developmental Pediatrics Clinics
Comprehensive Behavioral Intervention for Tics (CBIT) is an efficacious treatment with limited regional availability. As neurology and pediatric clinics are often the first point of therapeutic contact for individuals with tics, the present study assessed preliminary treatment response, acceptability, and feasibility of an abbreviated version, modified for child neurology and developmental pediatrics clinics. Fourteen youth (9-17) with Tourette disorder across 2 child neurology clinics and one developmental pediatrics clinic participated in a small case series. Clinician-rated tic severity (Yale Global Tic Severity Scale) decreased from pre- to posttreatment, z = –2.0, P \u3c .05, r = –.48, as did tic-related impairment, z = –2.4, P \u3c .05, r = –.57. Five of the 9 completers (56%) were classified as treatment responders. Satisfaction ratings were high, and therapeutic alliance ratings were moderately high. Results provide guidance for refinement of this modified CBIT protocol
A systematic review of the role of heat therapy for patients with intermittent claudication due to peripheral artery disease
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