Unreflective use of old data sources produced echo chambers in the water-electricity nexus

This meta-analysis of over 2,400 papers tracks the influence of older publications that have 'echoed' through the decades, cited in countless publications and creating a potentially false confirmation bias. Echo chambers in science describe the amplification and repetition of information within closed networks. Frequently used data sources can cause echo chambers as scientists keep reading similar outputs from different sources, creating false perceptions of certainty and variety of data sources. We show this effect by studying the scientific and grey literature on water use by electricity systems. The power sector is the largest contributor to anthropogenic carbon emissions and the second largest water consumer. We have assessed the scope and references of 2,426 papers and created a citation network to trace original data sources. Most data sources used for the last 30 years originate from a few old US publications, recently also Chinese, that echo through publications. This echo effect, also reflected in recent scientific publications, creates a confirmation bias, also facilitating double counting of the water intensities of electricity generation. This example from sustainability science warns of the risk of echo chambers in other scientific disciplines

Factors Associated with Complications in Older Adults with Isolated Blunt Chest Trauma

Objective: To determine the prevalence of adverse events in elderly trauma patients with isolated blunt thoracic trauma, and to identify variables associated with these adverse events.Methods: We performed a chart review of 160 trauma patients age 65 and older with significant blunt thoracic trauma, drawn from an American College of Surgeons Level I Trauma Center registry. Patients with serious injury to other body areas were excluded to prevent confounding the cause of adverse events. Adverse events were defined as acute respiratory distress syndrome or pneumonia, unanticipated intubation, transfer to the intensive care unit for hypoxemia, or death. Data collected included history, physical examination, radiographic findings, length of hospital stay, and clinical outcomes.Results: Ninety-nine patients had isolated chest injury, while 61 others had other organ systems injured and were excluded. Sixteen patients developed adverse events [16.2% 95% confidence interval (CI) 9.5-24.9%], including two deaths. Adverse events were experienced by 19.2%, 6.1%, and 28.6% of those patients 65-74, 75-84, and >85 years old, respectively. The mean length of stay was 14.6 days in patients with an adverse event and 5.8 days in patients without. Post hoc analysis revealed that all 16 patients with an adverse event had one or more of the following: age ≥85, initial systolic blood pressure <90 mmHg, hemothorax, pneumothorax, three or more unilateral rib fractures, or pulmonary contusion (sensitivity 100%, CI 79.4-100%; specificity 38.6%, CI 28.1-49.9%).Conclusion: Adverse events from isolated thoracic trauma in elderly patients complicate 16% of our sample. These criteria were 100% sensitive and 38.5% specific for these adverse events. This study is a first step to identifying variables that might aid in identifying patients at high risk for serious adverse events. [WestJEM. 2009;10:79-84.

The pressure-volume-temperature relationship of cellulose

Pressure–volume–temperature (PVT) mea- surements of a-cellulose with different water contents, were performed at temperatures from 25 to 180 °C and pressures from 19.6 to 196 MPa. PVT measurements allowed observation of the combined effects of pressure and temperature on the specific volume during cellulose thermo-compression. All isobars showed a decrease in cellulose specific volume with temperature. This densification is associated with a transition process of the cellulose, occurring at a temperature defined by the inflection point Tt of the isobar curve. Tt decreases from 110 to 40 °C with pressure and is lower as moisture content increases. For isobars obtained at high pressures and high moisture contents, after attaining a minimum, an increase in volume is observed with temperature that may be related to free water evaporation. PVT a-cellulose experimental data was compared with predicted values from a regression analysis of the Tait equations of state, usually applied to synthetic polymers. Good correla- tions were observed at low temperatures and low pressures. The densification observed from the PVT experimental data, at a temperature that decreases with pressure, could result from a sintering phenomenon, but more research is needed to actually understand the cohesion mechanism under these conditions

Recording 2-D Nutation NQR Spectra by Random Sampling Method

The method of random sampling was introduced for the first time in the nutation nuclear quadrupole resonance (NQR) spectroscopy where the nutation spectra show characteristic singularities in the form of shoulders. The analytic formulae for complex two-dimensional (2-D) nutation NQR spectra (I = 3/2) were obtained and the condition for resolving the spectral singularities for small values of an asymmetry parameter η was determined. Our results show that the method of random sampling of a nutation interferogram allows significant reduction of time required to perform a 2-D nutation experiment and does not worsen the spectral resolution

Structural and functional analysis of APOA5 mutations identified in patients with severe hypertriglyceridemia

During the diagnosis of three unrelated patients with severe hypertriglyceridemia, three APOA5 mutations [p.(Ser232_Leu235)del, p.Leu253Pro, and p.Asp332ValfsX4] were found without evidence of concomitant LPL, APOC2, or GPIHBP1 mutations. The molecular mechanisms by which APOA5 mutations result in severe hypertriglyceridemia remain poorly understood, and the functional impairment/s induced by these specific mutations was not obvious. Therefore, we performed a thorough structural and functional analysis that included follow-up of patients and their closest relatives, measurement of apoA-V serum concentrations, and sequencing of the APOA5 gene in 200 nonhyperlipidemic controls. Further, we cloned, overexpressed, and purified both wild-type and mutant apoA-V variants and characterized their capacity to activate LPL. The interactions of recombinant wild-type and mutated apoA-V variants with liposomes of different composition, heparin, LRP1, sortilin, and SorLA/LR11 were also analyzed. Finally, to explore the possible structural consequences of these mutations, we developed a three-dimensional model of full-length, lipid-free human apoA-V. A complex, wide array of impairments was found in each of the three mutants, suggesting that the specific residues affected are critical structural determinants for apoA-V function in lipoprotein metabolism and, therefore, that these APOA5 mutations are a direct cause of hypertriglyceridemia.</p

Effect of weight loss on HDL-apoA-II kinetics in the metabolic syndrome

Reduced HDL (high-density lipoprotein) concentration in the MetS (metabolic syndrome) is associated with increased risk of cardiovascular disease and is related to defects in HDL-apoA-II (apolipoprotein A-II) kinetics. Dietary restriction is the most commonly used weight loss strategy. In the present study, we examined the effect of weight loss on HDL-apoA-II kinetics in men with the MetS at the start and end of a 16-week intervention trial of a hypocaloric low-fat diet (n=20) compared with a weight maintenance diet (n=15), using a stable isotope technique and compartmental modelling. The low-fat diet achieved a significant reduction (P<0.01) in BMI (body mass index), abdominal fat compartments and HOMA (homoeostasis model assessment) score compared with weight maintenance. Weight loss also significantly (P<0.05) decreased both the production rate (−23%) and FCR (fractional catabolic rate) (−12%) of HDL-apoA-II, accounting for a net decrease in apoA-II concentration (−9%). Reductions in the HDL-apoA-II production rate were significantly associated with changes in body weight (r=0.683, P<0.01), plasma triacylglycerols (triglycerides) (r=0.607, P<0.01) and, to a lesser extent, plasma insulin (r=0.440, P=0.059) and HOMA-IR (HOMA of insulin resistance) (r=0.425, P=0.069). Changes in the apoA-II FCR were also significantly associated with reductions in visceral adipose tissue mass (r=0.561, P=0.010). In conclusion, in obese men with the MetS, short-term weight loss with a low-fat low-caloric diet lowers plasma apoA-II concentrations by decreasing both the production and catabolism of HDL-apoA-II. The cardiometabolic significance of this effect on HDL metabolism remains to be investigated further

Analysis of age-related left ventricular collagen remodeling in living donors: Implications in arrhythmogenesis

Age-related fibrosis in the left ventricle (LV) has been mainly studied in animals by assessing collagen content. Using second-harmonic generation microscopy and image processing, we evaluated amount, aggregation and spatial distribution of LV collagen in young to old pigs, and middle-age and elder living donors. All collagen features increased when comparing adult and old pigs with young ones, but not when comparing adult with old pigs or middle-age with elder individuals. Remarkably, all collagen parameters strongly correlated with lipofuscin, a biological age marker, in humans. By building patient-specific models of human ventricular tissue electrophysiology, we confirmed that amount and organization of fibrosis modulated arrhythmia vulnerability, and that distribution should be accounted for arrhythmia risk assessment. In conclusion, we characterize the age-associated changes in LV collagen and its potential implications for ventricular arrhythmia development. Consistency between pig and human results substantiate the pig as a relevant model of age-related LV collagen dynamics. © 2022 The Author(s

Cytochrome P450 1A2 (CYP1A2) activity, mammographic density, and oxidative stress: a cross-sectional study

INTRODUCTION: Mammographically dense breast tissue is a strong predictor of breast cancer risk, and is influenced by both mitogens and mutagens. One enzyme that is able to affect both the mitogenic and mutagenic characteristics of estrogens is cytochrome P450 1A2 (CYP1A2), which is principally responsible for the metabolism of 17β-estradiol. METHODS: In a cross-sectional study of 146 premenopausal and 149 postmenopausal women, we examined the relationships between CYP1A2 activity, malondialdehyde (MDA) levels, and mammographic density. In vivo CYP1A2 activity was assessed by measuring caffeine metabolites in urine. Levels of serum and urinary MDA, and MDA–deoxyguanosine adducts in DNA were measured. Mammograms were digitized and measured using a computer-assisted method. RESULTS: CYP1A2 activity in postmenopausal women, but not in premenopausal women, was positively associated with mammographic density, suggesting that increased CYP1A2 activity after the menopause is a risk factor for breast cancer. In premenopausal women, but not in postmenopausal women, CYP1A2 activity was positively associated with serum and urinary MDA levels; there was also some evidence that CYP1A2 activity was more positively associated with percentage breast density when MDA levels were high, and more negatively associated with percentage breast density when MDA levels were low. CONCLUSION: These findings provide further evidence that variation in the activity level of enzymes involved in estrogen metabolism is related to levels of mammographic density and potentially to breast cancer risk