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Certain hypotheses cannot be directly confirmed for theoretical, practical, or moral reasons. For some of these hypotheses, however, there might be a workaround: confirmation based on analogical reasoning. In this paper we take up Dardashti, Hartmann, Thébault, and Winsberg’s (2019) idea of analyzing confirmation based on analogical inference Bayesian style. We identify three types of confirmation by analogy and show that Dardashti et al.’s approach can cover two of them. We then highlight possible problems with their model as a general approach to analogical inference and argue that these problems can be avoided by supplementing Bayesian update with Jeffrey conditionalization.
An antimicrobial screen was applied to the cell phones of 26 resident physicians to determine its effects on the phone microbiome and its potential to serve as a selective agent for antibiotic or silver resistance genes. No increase of these genes was observed now was there a shift in the overall microbial community.
High-resolution Chirp sub-bottom data were obtained offshore from the Northern Channel Islands (NCI), California, to image submerged paleoshorelines and assess local uplift rates. Although modern bathymetry is often used for modeling paleoshorelines, Chirp data image paleoshorelines buried beneath sediment that obscures their seafloor expression. The NCI were a unified landmass during the last glacial maximum (LGM; ~20 ka), when eustatic sea level was ~120 m lower than present. We identified seven paleoshorelines, ranging from ~28 to 104 m in depth, across this now-submerged LGM platform. Paleoshoreline depths were compared to local sea-level curves to estimate ages, which suggest that some were reoccupied over multiple sea-level cycles. Additionally, previous studies determined conflicting uplift rates for the NCI, ranging from 0.16 to 1.5 m/ka. Our results suggest that a rate on the lower end of this range better fits the observed submerged paleoshorelines. Using the uplift rate of ~0.16 m/ka, we estimate that paleoshorelines formed during Marine Oxygen Isotope Stage 3, the LGM, and the Younger Dryas stade are preserved on the NCI platform. These results help clarify uplift rates for the NCI and illustrate the importance of sub-bottom data for mapping submerged paleoshorelines.
Positive symptoms are a useful predictor of aggression in schizophrenia. Although a similar pattern of abnormal brain structures related to both positive symptoms and aggression has been reported, this observation has not yet been confirmed in a single sample.
To study the association between positive symptoms and aggression in schizophrenia on a neurobiological level, a prospective meta-analytic approach was employed to analyze harmonized structural neuroimaging data from 10 research centers worldwide. We analyzed brain MRI scans from 902 individuals with a primary diagnosis of schizophrenia and 952 healthy controls.
The result identified a widespread cortical thickness reduction in schizophrenia compared to their controls. Two separate meta-regression analyses revealed that a common pattern of reduced cortical gray matter thickness within the left lateral temporal lobe and right midcingulate cortex was significantly associated with both positive symptoms and aggression.
These findings suggested that positive symptoms such as formal thought disorder and auditory misperception, combined with cognitive impairments reflecting difficulties in deploying an adaptive control toward perceived threats, could escalate the likelihood of aggression in schizophrenia.
We sampled individual growth rings from three ancient remnant bald cypress (Taxodium distichum) trees from a massive buried deposit at the mouth of the Altamaha River on the Georgia Coast to determine the best technique for radiocarbon (14C) dating pretreatment. The results of our comparison of traditional ABA pretreatment and holocellulose and α-cellulose fractions show no significant differences among the pretreatments (<1 sigma) thereby suggesting that ABA pretreatment will prove sufficient for the development of a high-resolution 14C tree-ring chronology based on these ancient bald cypresses which will indicate whether the U.S. Southeast is subject to a regional radiocarbon offset.
Sintered tape-cast yttria-stabilized zirconia (YSZ) was evaluated for its elemental composition, crystal structure, and imaged with atomic force microscopy (AFM) and scanning electron microscopy (SEM). Human bone marrow stem cells (hBMSC) were cultured on the ceramic and differentiated into the osteoblast lineage; alkaline phosphatase (ALP) activity was tracked as a differentiation marker. The YSZ was composed of purely tetragonal grains with a median equivalent circular diameter of 283 nm. Zirconium, yttrium, oxygen, and adventitious carbon was detected on the substrate with no other elements in significant quantities detected. YSZ samples had an RMS roughness value of 27 nm, elastic modulus of 206 ± 14 GPa, and hardness of 14 ± 2 GPa. hBMSC were observed to attach and proliferate on the YSZ surfaces and had significantly increased ALP versus the undifferentiated control cultured on glass. This method for producing a YSZ ceramic yields a typical material of this type and supports attachment and differentiation of hBMSC; thus, making it useful as a bone implant material.
Social anxiety lies on a continuum, and young adults with elevated symptoms are at risk for developing a range of psychiatric disorders. Yet relatively little is known about the factors that govern the hour-by-hour experience and expression of social anxiety in the real world.
Here we used smartphone-based ecological momentary assessment (EMA) to intensively sample emotional experience across different social contexts in the daily lives of 228 young adults selectively recruited to represent a broad spectrum of social anxiety symptoms.
Leveraging data from over 11 000 real-world assessments, our results highlight the central role of close friends, family members, and romantic partners. The presence of such close companions was associated with enhanced mood, yet socially anxious individuals had fewer confidants and spent less time with the close companions that they do have. Although higher levels of social anxiety were associated with a general worsening of mood, socially anxious individuals appear to derive larger benefits – lower levels of negative affect, anxiety, and depression – from their close companions. In contrast, variation in social anxiety was unrelated to the amount of time spent with strangers, co-workers, and acquaintances; and we uncovered no evidence of emotional hypersensitivity to these less-familiar individuals.
These findings provide a framework for understanding the deleterious consequences of social anxiety in emerging adulthood and set the stage for developing improved intervention strategies.
The effects of roughness on the frictional drag and pressure drop in laminar channel flow are investigated numerically. The inflow is fully developed smooth wall flow, and square rib roughness, aligned normal to the bulk flow direction, is introduced as a step change. The roughness height and spacing are systematically varied, and the flow is examined as it develops over the rough wall and becomes fully developed. The length of the development region depends primarily on the roughness height, although the effects of spacing become more important as the height decreases. In the fully developed rough wall regime, the friction coefficients always increase with roughness when compared to the smooth wall case, but the increase depends crucially on the roughness height and to a lesser extent on the spacing. Using the constricted diameter in the definition of the friction factor collapses the data on the smooth wall value to within 10 % for all roughnesses studied here, with the remaining deviation increasing linearly with roughness spacing. The friction factors scale with the inverse of the Reynolds number, as seen elsewhere. The scaling of the development length and the friction coefficient can be explained by the relative contributions made by the pressure drop on each element and the skin friction acting over the surface area. These observations are examined in terms of the flow patterns in the vicinity of the roughness elements, which leads us to propose a definition for fully rough laminar flow.
First-degree relatives of patients with psychotic disorder have higher levels of polygenic risk (PRS) for schizophrenia and higher levels of intermediate phenotypes.
We conducted, using two different samples for discovery (n = 336 controls and 649 siblings of patients with psychotic disorder) and replication (n = 1208 controls and 1106 siblings), an analysis of association between PRS on the one hand and psychopathological and cognitive intermediate phenotypes of schizophrenia on the other in a sample at average genetic risk (healthy controls) and a sample at higher than average risk (healthy siblings of patients). Two subthreshold psychosis phenotypes, as well as a standardised measure of cognitive ability, based on a short version of the WAIS-III short form, were used. In addition, a measure of jumping to conclusion bias (replication sample only) was tested for association with PRS.
In both discovery and replication sample, evidence for an association between PRS and subthreshold psychosis phenotypes was observed in the relatives of patients, whereas in the controls no association was observed. Jumping to conclusion bias was similarly only associated with PRS in the sibling group. Cognitive ability was weakly negatively and non-significantly associated with PRS in both the sibling and the control group.
The degree of endophenotypic expression of schizophrenia polygenic risk depends on having a sibling with psychotic disorder, suggestive of underlying gene–environment interaction. Cognitive biases may better index genetic risk of disorder than traditional measures of neurocognition, which instead may reflect the population distribution of cognitive ability impacting the prognosis of psychotic disorder.
In recent years, the discovery of massive quasars at
has provided a striking challenge to our understanding of the origin and growth of supermassive black holes in the early Universe. Mounting observational and theoretical evidence indicates the viability of massive seeds, formed by the collapse of supermassive stars, as a progenitor model for such early, massive accreting black holes. Although considerable progress has been made in our theoretical understanding, many questions remain regarding how (and how often) such objects may form, how they live and die, and how next generation observatories may yield new insight into the origin of these primordial titans. This review focusses on our present understanding of this remarkable formation scenario, based on the discussions held at the Monash Prato Centre from November 20 to 24, 2017, during the workshop ‘Titans of the Early Universe: The Origin of the First Supermassive Black Holes’.
This is a copy of the slides presented at the meeting but not formally written up for the volume.
Research into new concepts for oxide-electronic devices has been enriched by the emerging field of functional interfaces. A high control of the materials down to the atomic level enables the improvement of existing oxide devices, like magnetic tunnel junctions, but also the formation of new artificial interface phases. Previous work revealed the existence of a metallic electron gas at the interface between the two band-insulators, LaAlO3 and SrTiO3, for a certain atomic arrangement [1,2]. Several studies on single epitaxial connections between LaAlO3 and SrTiO3 have revealed them to be either high-mobility electron conductors or insulating, depending on the atomic stacking sequences. An important point to take into account is the formation of oxygen vacancies for low deposition pressures (<10-5 mbar). For this growth regime the transport properties are fully dominated by the presence of the oxygen vacancies. In this talk we will show a detailed investigation of the controllable electronic properties of coupled interfaces in SrTiO3-LaAlO3-SrTiO3 heterostructures. Recently we reported a critical separation distance of 6 perovskite unit cell layers (~23 Å) for the electronic coupling of closely-spaced complementary interfaces in SrTiO3/LaAlO3 multilayer structures . We showed that a decrease of the interface conductivity and carrier density occurs when the LaO:TiO2 and AlO2:SrO interfaces are brought closer together. Interestingly, the high carrier mobilities characterizing the separate conducting interfaces were found to be maintained in such coupled structures down to sub-nanometer interface spacing. Here, we will explain in more detail the electronic properties of the closely spaced LaO:TiO2 and AlO2:SrO interfaces below the critical separation distance. The carrier density at room temperature for dLAO5 is similar to a single LaO:TiO2 interface and has a value of ~1.5X1014 cm-2, corresponding to ~0.23 electrons per unit cell area on the LaO:TiO2 interface. In this, the contribution by the AlO2:SrO interface to the sheet carrier density is neglected, due to its much lower conductivity. When both interfaces are brought closer to each other the electronic coupling between them is increased and the charge density at room temperature is reduced to 0.15, 0.11 and 0.07 electrons per unit cell area for a spacing of respectively 3, 2 and 1 unit cells. However, for lower temperatures the sheet carrier density decreases and becomes constant for all coupled heterostructures at temperatures below 10 K. This constant low temperature carrier density has a value of 2.0×1013 cm-2 and corresponds to 0.003 electrons per unit cell area. These results show the ability to control the electronic properties in SrTiO3 heterostructures and to vary the carrier density homogeneously over the interface.
Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total score correlations and the diagnostic accuracy to detect major depression of the PHQ-8 and PHQ-9.
We conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy.
16 742 participants (2097 major depression cases) from 54 studies were included. The correlation between PHQ-8 and PHQ-9 scores was 0.996 (95% confidence interval 0.996 to 0.996). The standard cutoff score of 10 for the PHQ-9 maximized sensitivity + specificity for the PHQ-8 among studies that used a semi-structured diagnostic interview reference standard (N = 27). At cutoff 10, the PHQ-8 was less sensitive by 0.02 (−0.06 to 0.00) and more specific by 0.01 (0.00 to 0.01) among those studies (N = 27), with similar results for studies that used other types of interviews (N = 27). For all 54 primary studies combined, across all cutoffs, the PHQ-8 was less sensitive than the PHQ-9 by 0.00 to 0.05 (0.03 at cutoff 10), and specificity was within 0.01 for all cutoffs (0.00 to 0.01).
PHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.