666 research outputs found
Hominid butchers and biting crocodiles in the African Plio-Pleistocene.
Zooarchaeologists have long relied on linear traces and pits found on the surfaces of ancient bones to infer ancient hominid behaviors such as slicing, chopping, and percussive actions during butchery of mammal carcasses. However, such claims about Plio-Pleistocene hominids rely mostly on very small assemblages of bony remains. Furthermore, recent experiments on trampling animals and biting crocodiles have shown each to be capable of producing mimics of such marks. This equifinality-the creation of similar products by different processes-makes deciphering early archaeological bone assemblages difficult. Bone modifications among Ethiopian Plio-Pleistocene hominid and faunal remains at Asa Issie, Maka, Hadar, and Bouri were reassessed in light of these findings. The results show that crocodiles were important modifiers of these bone assemblages. The relative roles of hominids, mammalian carnivores, and crocodiles in the formation of Oldowan zooarchaeological assemblages will only be accurately revealed by better bounding equifinality. Critical analysis within a consilience-based approach is identified as the pathway forward. More experimental studies and increased archaeological fieldwork aimed at generating adequate samples are now required
Stochastic Step-wise Feature Selection for Exponential Random Graph Models (ERGMs)
Statistical analysis of social networks provides valuable insights into
complex network interactions across various scientific disciplines. However,
accurate modeling of networks remains challenging due to the heavy
computational burden and the need to account for observed network dependencies.
Exponential Random Graph Models (ERGMs) have emerged as a promising technique
used in social network modeling to capture network dependencies by
incorporating endogenous variables. Nevertheless, using ERGMs poses multiple
challenges, including the occurrence of ERGM degeneracy, which generates
unrealistic and meaningless network structures. To address these challenges and
enhance the modeling of collaboration networks, we propose and test a novel
approach that focuses on endogenous variable selection within ERGMs. Our method
aims to overcome the computational burden and improve the accommodation of
observed network dependencies, thereby facilitating more accurate and
meaningful interpretations of network phenomena in various scientific fields.
We conduct empirical testing and rigorous analysis to contribute to the
advancement of statistical techniques and offer practical insights for network
analysis.Comment: 23 pages, 6 tables and 18 figure
CCR2 mediates Helicobacter pyloriâ induced immune tolerance and contributes to mucosal homeostasis
BackgroundWe previously demonstrated that H. pylori infection leads to increased induction of regulatory T cells in local and systemic immune compartments. Here, we investigate the role of CCR2 in the tolerogenic programing of dendritic cells in a mouse model of H. pylori infection.Materials and MethodsCCR2 deficient (CCR2KO) mice and wildâ type (Wt) mice infected with H. pylori SS1 strain were analyzed by qPCR and FACS analysis. In vitro, bone marrowâ derived DC on day 6 from CCR2KO and Wt mice cocultured with or without H. pylori were examined to determine the impact of CCR2 signaling on dendritic cells function by qPCR, ELISA, and FACS analyses.ResultsAcute H. pylori infection was associated with a threefold increase in CCR2 mRNA expression in the gastric mucosa. H. pyloriâ infected CCR2KO mice exhibited a higher degree of mucosal inflammation, that is, increased gastritis scores and proâ inflammatory cytokine mRNA levels, but lower degree of H. pylori gastric colonization compared to infected Wt mice. Peripheral H. pyloriâ specific immune response measured in the CCR2KO spleen was characterized by a higher Th17 response and a lower Treg response. In vitro, CCR2KO bone marrowâ derived DC was less mature and shown a lower Treg/Th17 ratio. Moreover, blockade of CCR2 signaling by MCPâ 1 neutralizing antibody inhibited H. pyloriâ stimulated bone marrowâ derived DC maturation.ConclusionsOur results indicate that CCR2 plays an essential role in H. pyloriâ induced immune tolerance and shed light on a novel mechanism of CCR2â dependent DC Treg induction, which appears to be important in maintaining mucosal homeostasis during H. pylori infection.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136416/1/hel12366.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136416/2/hel12366_am.pd
Muscularity and attractiveness as predictors of human egalitarianism
This is the post-print version of the final paper published in Personality and Individual Differences. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2010 Elsevier B.V.In ancestral human environments, muscularity and height (in males) and physical attractiveness (in both sexes) would theoretically have correlated positively with oneâs social status, and thus with oneâs ability to benefit from social inequality. We therefore hypothesized that individuals who are more characterized by these traits would be less egalitarian (i.e., less likely to believe that resources should be distributed equally in social groups). We used a white-light 3D body scanner to extract anthropometric measurements from 118 participants, and our four egalitarianism measures included social dominance orientation and social value orientation. We found that as hypothesized, muscularity and waistâchest ratio in males, and self-perceived attractiveness in both sexes, tended to associate significantly in the predicted directions with the four egalitarianism measures; most of these correlations were of medium size. Neither height, nor two anthropometrically-assessed attractiveness measures (volume height index and waistâhip ratio), associated significantly with any egalitarianism measure in either sex. Egalitarianism has crucial social repercussions (e.g., taxes, welfare and civil rights), and results from the current study shed light on its origins
Pomegranate Juice Prevents the Formation of Lung Nodules Secondary to Chronic Cigarette Smoke Exposure in an Animal Model
Background. Cigarette smoke (CS) induces an oxidative stress, DNA damage, and lung cancer. Pomegranate juice (PJ) possess potent antioxidant activity attributed to its polyphenols. We investigated whether PJ supplementation would prevent the formation of lung nodules, attenuate mitotic activity, and reduce hypoxia-inducible factor-1Îą (HIF-1Îą) expression secondary to CS exposure in an animal model. Methods. Mice were divided into: Control group, CS group, CSâ+âPJ group, and PJ-only group. CS and CSâ+âPJ were exposed to CS, 5 days per week, for a total of 5 months. Animals were then housed for additional four months. CSâ+âPJ and PJ groups received PJ throughout the experiment period while others received placebo. At the end of the experiment, the incidence of lung nodules was assessed by (1) histological analysis, (2) mitotic activity [measurement of PHH3 antibodies], and (3) measurement of HIF-1Îą expression. Results. The incidence of lung nodules was significantly increased in CS. CS exposure significantly increased PHH3 and HIF-1Îą expression. PJ supplementation attenuated the formation of lung nodules and reduced PHH3 and HIF-1Îą expression. Conclusion. PJ supplementation significantly decreased the incidence of lung cancer, secondary to CS, prevented the formation of lung nodules, and reduced mitotic activity and HIF-1Îą expression in an animal model
Beyond Erasure and Profiling: Cultivating Strong and Vibrant Arab American Communities in Chicagoland
This report captures the conditions and experiences of Arab Americans in the Chicagoland area. The report uses demographic research, surveys, focus group data, as well as expert commentaries by organizers and academics to analyze how systemic inequities and anti-Arab/anti-Muslim racism affect the lives of Arab Americans in employment, education, health care, housing, and policing. The report engages with the diversity of experiences among Arab American communities and their common challenge in navigating being at once hypervisible as a result of commonplace stereotypes as well as invisible due to being classified as white by government agencies and due to the general lack of knowledge about Arab Americans in our society
A Machine Learning based Expert System for Optimizing CFD Solver Parameters
Computational Fluid Dynamics is a viable tool in the field of aerodynamics enabling to reduce time, effort and budget required for experimental testing. Although powerful and established for various years, it remains a complex tool calling for experienced users to ensure consistent high-quality results. This complexity primarily stems from the underlying model, namely the Navier-Stokes equations typically combined with a set of equations resolving the effects of turbulence. Additionally, to obtain accurate high-fidelity result appropriate meshes are required. As a consequence, a substantial number of parameters needs to be selected carefully and the quality of a result often highly depends on individual knowledge and experience of a user. Hence, a strong desire exists to reduce the number of input parameters without causing a loss of accuracy and efficiency. Such reduction of parameters might be viewed as a prerequisite to CFD as a tool in process chains for multidisciplinary applications where typically no user interaction is possible. In this article we propose a machine-learned Expert System for CFD to provide guidance for users in selecting optimal or at least near optimal parameter combinations. The proposed Expert System is divided into two macro steps, the surrogate model and a genetic algorithm to determine from the surrogate model the parameters. Numerical examples are presented to demonstrate the approach
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