Dilatant hardening is one proposed mechanism that causes slow earthquakes along faults. Previous experiments and models show that dilatant hardening can stabilize fault rupture and slip in several ...lithologies. However, few studies have systematically measured the mechanical behavior across the transition from dynamic to slow rupture or considered how the associated damage varies. To constrain the processes and scales of dilatant hardening, we conducted triaxial compression experiments on cores of Crab Orchard sandstone and structural analyses using micro‐computed tomography imaging and petrographic analysis. Experiments were conducted at an effective confining pressure of ∼10 MPa, while varying confining pressure (10–130 MPa) and pore fluid pressure (1–120 MPa). Above 15 MPa pore fluid pressure, dilatant hardening slows the rate of fault rupture and slip and deformation becomes more distributed amongst multiple faults as microfracturing increases. The resulting increase in fracture energy has the potential to control fault slip behavior.
Plain Language Summary
When rocks are breaking, the pore spaces and developing fractures dilate, resulting in a decrease in pore fluid pressures. This decrease can strengthen the rock from ongoing deformation in a process known as dilatant hardening. We conducted experiments to better understand how this strengthening effect works, in particular looking at the ratio of pore fluid pressure to the external confining pressure (simulating rocks buried at depth), and also analyzed how the fractures that develop can vary from dilatant hardening. We found a threshold pressure at which the strengthening peaked, and increasing pore fluid pressure did not change how strong the rocks got from continuing deformation. We also observed a drastic increase in how damage was distributed due to this hardening effect at both a large (visible to the naked eye) and small scale (only visible in a high‐magnification microscope). These results indicate that dilatant hardening can increase how much energy must be expended to break the rock and to cause faults to slip when pore fluid pressures are high enough, and likely plays a role in stabilizing fault slip, causing earthquakes to slow down and be less dynamic.
Key Points
We measured the transition between dynamic and stable rupture as a result of dilatant hardening
We observed differences in microstructural development tied to the shift in rupture style
We developed a model of fracture nucleation and propagation at different pore fluid pressures
Cancer incidence and mortality estimates for 19 cancers (among solid tumors) are presented for France between 1980 and 2012.
Incidence data were collected from 21 local registries and correspond to ...invasive cancers diagnosed between 1975 and 2009. Mortality data for the same period were provided by the Institut national de la santé et de la recherche médicale. The national incidence estimates were based on the use of mortality as a correlate of incidence. The observed incidence and mortality data were modeled using an age-period-cohort model. The numbers of incident cases and deaths for 2010-2012 are the result of short-term projections.
In 2012, the study estimated that 355,000 new cases of cancer (excluding non-melanoma skin cancer) and 148,000 deaths from cancer occurred in France. The incidence trend was not linear over the study period. After a constant increase from 1980 onwards, the incidence of cancer in men declined between 2005 and 2012. This recent decrease is largely related to the reduction in the incidence of prostate cancer. In women, the rates stabilized, mainly due to a change in breast cancer incidence. Mortality from most cancer types declined over the study period. A combined analysis of incidence and mortality by cancer site distinguished cancers with declining incidence and mortality (e.g., stomach) and cancers with increasing incidence and mortality (e.g., lung cancer in women). Some other cancers had rising incidence but declining mortality (e.g., thyroid).
This study reveals recent changes in cancer incidence trends, particularly regarding breast and prostate cancers.
There are many homeostatic mechanisms for coping with stress conditions in cells, including autophagy. In many studies autophagy, as an intracellular pathway which degrades misfolded and damaged ...protein, and Mallory-Denk Body (MDB) formation have been shown to be protective mechanisms against stress such as alcoholic hepatitis. Alcohol has a significant role in alteration of lipid homeostasis, sterol regulatory element-binding proteins (SREBPs) and peroxidase proliferator-activated receptors through AMP-activated protein kinase (AMPK)-dependent mechanism. AMPK is one of the kinases that regulate autophagy through the dephosphorylation of ATG1. Activation of ATG1 (ULK kinases family) activates ATG6. These two activated proteins relocate to the site of initial autophagosome and activate the other downstream components of autophagocytosis. Many other proteins regulate autophagocytosis at the gene level. CHOP (C/EBP homologous protein) is one of the most important parts of stress-inducible transcription that encodes a ubiquitous transcription factor. In this report we measure the upregulation of the gene that are involved in autophagocytosis in liver biopsies of alcoholic hepatitis and NASH. Electron microscopy was used to document the presence of autophagosomes in the liver cells. Expression of AMPK1, ATG1, ATG6 and CHOP in ASH were significantly (p value<0.05) upregulated in comparison to control. Electron microscopy findings of ASH confirmed the presence of autophagosomes, one of which contained a MDB, heretofore undescribed. Significant upregulations of AMPK-1, ATG-1, ATG-6, and CHOP, and uptrending of ATG-4, ATG-5, ATG-9, ATR, and ATM in ASH compared to normal control livers indicate active autophagocytosis in alcoholic hepatitis.
IL-8 (C-X-L motif chemokine ligase 8) and CXCR2 (C-X-C-motif chemokine receptor 2) are up regulated in alcoholic hepatitis (AH) liver biopsies. One of the consequences is the attraction and ...chemotactic neutrophilic infiltrate seen at the AH stage of alcoholic liver disease.
Human formalin-fixed, paraffin-embedded (FFPE) liver biopsies from patients who have AH were studied by (2.1) RNA sequencing, (2.2) PCR and (2.3) semi quantitation of specific proteins in biopsy sections using immunohistochemical measurements of antibody fluorescent intensity with morphometric technology.
Immunohistochemistry of IL-8 showed that the expression was increased in the cytoplasm of the hepatocytes in AH liver biopsies compared to the controls. IL-8 and ubiquitin were co-localized in the MDBs. Numerous neutrophils were found throughout and satellitosis of neutrophils around MDBs was present. This suggested that IL-8 may be involved in MDB pathogenesis. RNA seq analysis revealed activation by IL-8 which included neutrophil chemotaxis by LIM domain kinase 2 (LIMK2) (17.5 fold increase) and G protein subunit alpha 15 (GNA15) (27.8 fold increase).
The formation of MDBs by liver cells showed colocalization of ubiquitin and IL-8 in the MDBs. This suggested that IL-8 in these hepatocytes attracted the neutrophils to form satellitosis. This correlated with up regulation of the proteins downstream from the IL-8 pathways including LIMK2, GNG2 (guanine nucleotide binding proteins) and PIK3CB (phosphatidyl isitol-4, 5-biophosphate-3-kinase, catalytic subunit beta).
To examine demographic, behavioral and dietary correlates of frequency of fast food restaurant use in a community-based sample of 891 adult women.
A survey was administered at baseline and 3 y later ...as part of a randomized, prospective intervention trial on weight gain prevention.
Women (n = 891) aged 20-45 y who enrolled in the Pound of Prevention study.
Frequency of fast food restaurant use, dietary intake, demographic and behavioral measures were self-reported. Dietary intake was measured using the 60-item Block Food Frequency Questionnaire. Body weight and height were directly measured.
Twenty-one percent of the sample reported eating > or = 3 fast food meals per week. Frequency of fast food restaurant use was associated with higher total energy intake, higher percentage fat energy, more frequent consumption of hamburgers, French fries and soft drinks, and less frequent consumption of fiber and fruit. Frequency of fast food restaurant use was higher among younger women, those with lower income, non-White ethnicity, greater body weight, lower dietary restraint, fewer low-fat eating behaviors, and greater television viewing. Over 3 y, increases in frequency of fast food restaurant use were associated with increases in body weight, total energy intake, percentage fat intake, intake of hamburgers, French fries and soft drinks, and with decreases in physical activity, dietary restraint and low-fat eating behaviors. Intake of several other foods, including fruits and vegetables, did not differ by frequency of fast food restaurant use.
Frequency of fast food restaurant use is associated with higher energy and fat intake and greater body weight, and could be an important risk factor for excess weight gain in the population.
Background
Visual data are particularly amenable for machine learning techniques. With clinical photography established for skin surveillance and documentation purposes as well as progress checks, ...dermatology is an ideal field for the development and application of emerging machine learning health care applications (ML‐HCAs). To date, several ML‐HCAs have detected malignant skin lesions on par with experts or found overlooked visual patterns that correlate with certain dermatological diseases. However, it is well established that ML‐HCAs come with ethical and social implications.
Objectives
Currently, there is a lack of research that establishes model design, training, usage and regulation of such technologies sufficient to ensure ethically and socially responsible development and clinical translation, specifically within the field of dermatology. With this paper, we aim to give an overview of currently discussed ethical issues relating to dermatological ML‐HCAs.
Methods
On the basis of a thematic, keyword‐based literature search, we performed an ethical analysis against established frameworks of biomedical ethics. We combined our results with current, relevant normative machine learning ethics literature to identify the status quo of the ethics of ML‐HCAs in dermatology. We describe the benefits and risks of dermatological ML‐HCAs that are currently being developed for clinical purposes.
Results
The potential benefits range from better patient outcomes to better knowledge accessibility to decreasing health care disparities, that is, standards of care between different population groups. The risks associated with ML‐HCAs range from confidentiality issues to individual patient outcomes as well as the exacerbation of prevalent health care disparities. We discuss the practical implications for all stages of dermatological ML‐HCA development.
Conclusion
We found that ML‐HCAs present stakeholder‐specific risks for patients, health care professionals and society, which need to be considered separately. The discipline lacks sufficient biomedical ethics research that could standardize the approach to ML‐HCA model design, training, use and regulation of such technologies.
Obesity has increased dramatically over the past two decades and currently about 50% of US adults and 25% of US children are overweight. The current epidemic of obesity is caused largely by an ...environment that promotes excessive food intake and discourages physical activity. This chapter reviews what is known about environmental influences on physical activity and eating behaviors. Recent trends in food supply, eating out, physical activity, and inactivity are reviewed, as are the effects of advertising, promotion, and pricing on eating and physical activity. Public health interventions, opportunities, and potential strategies to combat the obesity epidemic by promoting an environment that supports healthy eating and physical activity are discussed.
The monochromatic illumination system is constructed to carry out in situ measurements of the response function of the mosaicked CCD imager used in the Sloan Digital Sky Survey (SDSS). The system is ...outlined and the results of the measurements, mostly during the first six years of the SDSS, are described. We present the reference response functions for the five color passbands derived from these measurements, and discuss column-to-column variations and variations in time, and also their effects on photometry. We also discuss the effect arising from various, slightly different response functions of the associated detector systems that were used to give SDSS photometry. We show that the calibration procedures of SDSS remove these variations reasonably well with the resulting final errors from variant response functions being unlikely to be larger than 0.01 mag for g, r, i, and z bands over the entire duration of the survey. The considerable aging effect is uncovered in the u band, the response function showing a 30% decrease in the throughput in the short wavelength side during the survey years, which potentially causes a systematic error in photometry. The aging effect is consistent with variation of the instrumental sensitivity in the u band, which is calibrated out. The expected color variation is consistent with measured color variation in the catalog of repeated photometry. The color variation is Delta *D(u -- g) ~ 0.01 for most stars, and at most Delta *D(u -- g) ~ 0.02 mag for those with extreme colors. We verified in the final catalog that no systematic variations in excess of 0.01 mag are detected in the photometry which can be ascribed to aging and/or seasonal effects except for the secular u -- g color variation for stars with extreme colors.
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