855 research outputs found
Examination of the Mental Health and Family Dynamics in Caribbean Immigrants using the National Survey of American Life
Previous studies have documented an association between mental illness rates and US-nativity, younger age at immigration, and recent immigration status among Caribbean immigrants to the US. This analysis examines these associations with the addition of important demographic controls and two indices of family support and conflict in Caribbean immigrants represented in the National Survey of American Life (n = 1623). The results indicate that previous correlates disappear when the index of family conflict is taken into account. Future efforts should focus on culturally appropriate identification and treatment methods addressing family dynamics in Caribbean immigrants. INDEX WORDS: immigrant mental health, family dynamics, National Survey of American Life
Paleoecological Reconstructions of the South African Plio-Pleistocene Based on Low-Magnification Dental Microwear of Fossil Primates.
Cercopithecines are common in hominid producing deposits and are a useful proxy for determining the ecological context of the early hominids. For this study, dental microwear is examined through low-magnification stereomicroscopy and used to reconstruct the diets of sampled primates. Those from the earliest sites, predominantly Parapapio, are primarily frugivorous while the incidence of gramnivory increases in the later Dinopithecus, Gorgopithecus, and Papio individuals denoting a general cooling and drying trend over the South African Plio-Pleistocene with a distinct pulse between 1.9-1.8 million years ago (mya). Australopithecus is reconstructed as a primary gramnivore which indicates that hominids adapted early in their evolution to expanding grasslands
Epigenetic aging signatures in mice livers are slowed by dwarfism, calorie restriction and rapamycin treatment
Background: Global but predictable changes impact the DNA methylome as we age, acting as a type of molecular
clock. This clock can be hastened by conditions that decrease lifespan, raising the question of whether it can also
be slowed, for example, by conditions that increase lifespan. Mice are particularly appealing organisms for studies of
mammalian aging; however, epigenetic clocks have thus far been formulated only in humans.
Results: We first examined whether mice and humans experience similar patterns of change in the methylome with
age. We found moderate conservation of CpG sites for which methylation is altered with age, with both species
showing an increase in methylome disorder during aging. Based on this analysis, we formulated an epigenetic-aging
model in mice using the liver methylomes of 107 mice from 0.2 to 26.0 months old. To examine whether epigenetic
aging signatures are slowed by longevity-promoting interventions, we analyzed 28 additional methylomes from mice
subjected to lifespan-extending conditions, including Prop1df/df dwarfism, calorie restriction or dietary rapamycin. We
found that mice treated with these lifespan-extending interventions were significantly younger in epigenetic age than
their untreated, wild-type age-matched controls.
Conclusions: This study shows that lifespan-extending conditions can slow molecular changes associated with an
epigenetic clock in mice livers
The HIV-1 late domain-2 S40A polymorphism in antiretroviral (or ART)-exposed individuals influences protease inhibitor susceptibility.
BackgroundThe p6 region of the HIV-1 structural precursor polyprotein, Gag, contains two motifs, P7TAP11 and L35YPLXSL41, designated as late (L) domain-1 and -2, respectively. These motifs bind the ESCRT-I factor Tsg101 and the ESCRT adaptor Alix, respectively, and are critical for efficient budding of virus particles from the plasma membrane. L domain-2 is thought to be functionally redundant to PTAP. To identify possible other functions of L domain-2, we examined this motif in dominant viruses that emerged in a group of 14 women who had detectable levels of HIV-1 in both plasma and genital tract despite a history of current or previous antiretroviral therapy.ResultsRemarkably, variants possessing mutations or rare polymorphisms in the highly conserved L domain-2 were identified in seven of these women. A mutation in a conserved residue (S40A) that does not reduce Gag interaction with Alix and therefore did not reduce budding efficiency was further investigated. This mutation causes a simultaneous change in the Pol reading frame but exhibits little deficiency in Gag processing and virion maturation. Whether introduced into the HIV-1 NL4-3 strain genome or a model protease (PR) precursor, S40A reduced production of mature PR. This same mutation also led to high level detection of two extended forms of PR that were fairly stable compared to the WT in the presence of IDV at various concentrations; one of the extended forms was effective in trans processing even at micromolar IDV.ConclusionsOur results indicate that L domain-2, considered redundant in vitro, can undergo mutations in vivo that significantly alter PR function. These may contribute fitness benefits in both the absence and presence of PR inhibitor
To Vax or Not to Vax: Predictors of Anti-Vax Attitudes and COVID-19 Vaccine Hesitancy Prior to Widespread Vaccine Availability
The novel coronavirus (COVID-19) is a highly contagious disease responsible for millions of deaths worldwide. Effective vaccines against COVID-19 are now available, however, an extreme form of vaccine hesitancy known as anti-vax attitudes challenge vaccine acceptance and distribution efforts. To understand these anti-vax attitudes and their associated psychological characteristics, we examined several predictors of vaccine hesitancy for COVID-19 and anti-vax attitudes generally. We surveyed 1004 adults (M = 47.0 years, SD = 17.1 years, range 18–98 years) in September-October 2020 across the United States (51% female, 49% male; 76.5% White, 23.5% non-White), prior to widespread availability of the COVID-19 vaccines. Attitudes toward vaccinations were influenced by a variety of factors, especially political attitudes. We should therefore anticipate and attempt to mitigate these challenges to achieving widespread vaccination to reduce the spread of COVID-19 and other communicable diseases
Electrolysis Propulsion for Spacecraft Applications
Electrolysis propulsion has been recognized over the last several decades as a viable option to meet many satellite and spacecraft propulsion requirements. This technology, however, was never used for in-space missions. In the same time frame, water based fuel cells have flown in a number of missions. These systems have many components similar to electrolysis propulsion systems. Recent advances in component technology include: lightweight tankage, water vapor feed electrolysis, fuel cell technology, and thrust chamber materials for propulsion. Taken together, these developments make propulsion and/or power using electrolysis/fuel cell technology very attractive as separate or integrated systems. A water electrolysis propulsion testbed was constructed and tested in a joint NASA/Hamilton Standard/Lawrence Livermore National Laboratories program to demonstrate these technology developments for propulsion. The results from these testbed experiments using a I-N thruster are presented. A concept to integrate a propulsion system and a fuel cell system into a unitized spacecraft propulsion and power system is outlined
Killing Tensors and Conformal Killing Tensors from Conformal Killing Vectors
Koutras has proposed some methods to construct reducible proper conformal
Killing tensors and Killing tensors (which are, in general, irreducible) when a
pair of orthogonal conformal Killing vectors exist in a given space. We give
the completely general result demonstrating that this severe restriction of
orthogonality is unnecessary. In addition we correct and extend some results
concerning Killing tensors constructed from a single conformal Killing vector.
A number of examples demonstrate how it is possible to construct a much larger
class of reducible proper conformal Killing tensors and Killing tensors than
permitted by the Koutras algorithms. In particular, by showing that all
conformal Killing tensors are reducible in conformally flat spaces, we have a
method of constructing all conformal Killing tensors (including all the Killing
tensors which will in general be irreducible) of conformally flat spaces using
their conformal Killing vectors.Comment: 18 pages References added. Comments and reference to 2-dim case.
Typos correcte
Feasibility of Implementing a School Nutrition Intervention That Addresses Policies, Systems, and Environment
We conducted a process evaluation of the Shaping Healthy Choices Program, a multicomponent school-based nutrition program, when implemented in partnership with University of California (UC) CalFresh and UC Cooperative Extension (UCCE). There were positive impacts on participating students, but results varied across counties, possibly due to variation in fidelity to the curriculum and implementation of program components. Our evaluation identified the strength of UCCE in delivering nutrition education and a need for additional support and training for building capacity to effect change in school policies, systems, and environment. Because educators throughout Extension are working to integrate programs addressing policies, systems, and environment, our results may have applicability in other Extension programs
Human severe sepsis cytokine mixture increases β2-integrin-dependent polymorphonuclear leukocyte adhesion to cerebral microvascular endothelial cells in vitro.
INTRODUCTION: Sepsis-associated encephalopathy (SAE) is a state of acute brain dysfunction in response to a systemic infection. We propose that systemic inflammation during sepsis causes increased adhesion of leukocytes to the brain microvasculature, resulting in blood-brain barrier dysfunction. Thus, our objectives were to measure inflammatory analytes in plasma of severe sepsis patients to create an experimental cytokine mixture (CM), and to use this CM to investigate the activation and interactions of polymorphonuclear leukocytes (PMN) and human cerebrovascular endothelial cells (hCMEC/D3) in vitro.
METHODS: The concentrations of 41 inflammatory analytes were quantified in plasma obtained from 20 severe sepsis patients and 20 age- and sex-matched healthy controls employing an antibody microarray. Two CMs were prepared to mimic severe sepsis (SSCM) and control (CCM), and these CMs were then used for PMN and hCMEC/D3 stimulation in vitro. PMN adhesion to hCMEC/D3 was assessed under conditions of flow (shear stress 0.7 dyn/cm(2)).
RESULTS: Eight inflammatory analytes elevated in plasma obtained from severe sepsis patients were used to prepare SSCM and CCM. Stimulation of PMN with SSCM led to a marked increase in PMN adhesion to hCMEC/D3, as compared to CCM. PMN adhesion was abolished with neutralizing antibodies to either β2 (CD18), αL/β2 (CD11α/CD18; LFA-1) or αM/β2 (CD11β/CD18; Mac-1) integrins. In addition, immune-neutralization of the endothelial (hCMEC/D3) cell adhesion molecule, ICAM-1 (CD54) also suppressed PMN adhesion.
CONCLUSIONS: Human SSCM up-regulates PMN pro-adhesive phenotype and promotes PMN adhesion to cerebrovascular endothelial cells through a β2-integrin-ICAM-1-dependent mechanism. PMN adhesion to the brain microvasculature may contribute to SAE
Human severe sepsis cytokine mixture increases beta 2-integrin-dependent polymorphonuclear leukocyte adhesion to cerebral microvascular endothelial cells in vitro
Introduction: Sepsis-associated encephalopathy (SAE) is a state of acute brain dysfunction in response to a systemic infection. We propose that systemic inflammation during sepsis causes increased adhesion of leukocytes to the brain microvasculature, resulting in blood-brain barrier dysfunction. Thus, our objectives were to measure inflammatory analytes in plasma of severe sepsis patients to create an experimental cytokine mixture (CM), and to use this CM to investigate the activation and interactions of polymorphonuclear leukocytes (PMN) and human cerebrovascular endothelial cells (hCMEC/D3) in vitro. Methods: The concentrations of 41 inflammatory analytes were quantified in plasma obtained from 20 severe sepsis patients and 20 age- and sex-matched healthy controls employing an antibody microarray. Two CMs were prepared to mimic severe sepsis (SSCM) and control (CCM), and these CMs were then used for PMN and hCMEC/D3 stimulation in vitro. PMN adhesion to hCMEC/D3 was assessed under conditions of flow (shear stress 0.7 dyn/cm(2)). Results: Eight inflammatory analytes elevated in plasma obtained from severe sepsis patients were used to prepare SSCM and CCM. Stimulation of PMN with SSCM led to a marked increase in PMN adhesion to hCMEC/D3, as compared to CCM. PMN adhesion was abolished with neutralizing antibodies to either beta 2 (CD18), alpha(L)/beta(2) (CD11 alpha/CD18; LFA-1) or alpha(M)/beta(2) (CD11 beta/CD18; Mac-1) integrins. In addition, immune-neutralization of the endothelial (hCMEC/D3) cell adhesion molecule, ICAM-1 (CD54) also suppressed PMN adhesion. Conclusions: Human SSCM up-regulates PMN pro-adhesive phenotype and promotes PMN adhesion to cerebrovascular endothelial cells through a beta 2-integrin-ICAM-1-dependent mechanism. PMN adhesion to the brain microvasculature may contribute to SAE
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