This paper develops and deploys a theoretical framework for assessing the prospects of a cluster of technologies driving what is often called the digital transformation. There is considerable ...uncertainty regarding this transformation’s future trajectory, and to understand and bound that uncertainty, we build on Schumpeter’s macro-level theory of economy-wide, technological revolutions and on the work of several scholars who have extended that theory. In this perspective, such revolutions’ trajectories are shaped primarily by the interaction of changes within and between three spheres—technology, organization, and public policy. We enrich this account by identifying the critical problems and the collective choices among competing solutions to those problems that together shape the trajectory of each revolution. We argue that the digital transformation represents a new phase in the wider arc of the information and communication technology revolution—a phase promising much wider deployment—and that the trajectory of this deployment depends on collective choices to be made in the organization and public policy spheres. Combining in a 2 × 2 matrix the two main alternative solutions on offer in each of these two spheres, we identify four scenarios for the future trajectory of the digital transformation: digital authoritarianism, digital oligarchy, digital localism, and digital democracy. We discuss how these scenarios can help us trace and understand the future trajectory of the digital transformation.
Transition metal oxides with mobile electrons and oxygen ions (mixed conductors) constitute a broad class of materials that include selective oxidation catalysts, high-temperature electrocatalysts, ...and ion-transport membrane materials. Although the thermodynamic and transport properties of mixed conductors are generally understood, a consensus has not yet emerged regarding the mechanisms and rate laws governing exchange of oxygen with the bulk at the gas-exposed surface. To aid interpretation of existing kinetic data, and generate testable hypotheses for further research, this paper outlines a framework for predicting O
2 reduction rate laws based on specific reaction mechanisms. Based on nonequilibrium thermodynamics and transition state theory, this framework yields rate laws that are rigorously consistent with thermodynamics, yet allow rates of individual steps to be developed in terms of simple mass action laws, where appropriate. This framework is used to reexamine equilibrium oxygen-exchange kinetics reported for electron-rich perovskite mixed conductors La
1−
x
Sr
x
CoO
3−
δ
(LSC) and La
1−
x
Sr
x
FeO
3−
δ
(LSF), which have a metallic and a semiconducting band structure, respectively. Our analysis suggests that metallic band structure may play an important role in catalysis by stabilizing physisorbed O
2 on the surface. We also show that equilibrium surface exchange rates (as measured by
18O/
16O isotopes, concentration steps, impedance, etc.) are generally only weak indicators of mechanism, and emphasize the need for kinetic data involving moderate to large displacements from equilibrium.
Abstract
Background
Plastic is everywhere. It is used in food packaging, storage containers, electronics, furniture, clothing, and common single-use disposable items. Microplastic and nanoplastic ...particulates are formed from bulk fragmentation and disintegration of plastic pollution. Plastic particulates have recently been detected in indoor air and remote atmospheric fallout. Due to their small size, microplastic and nanoplastic particulate in the atmosphere can be inhaled and may pose a risk for human health, specifically in susceptible populations. When inhaled, nanosized particles have been shown to translocate across pulmonary cell barriers to secondary organs, including the placenta. However, the potential for maternal-to-fetal translocation of nanosized-plastic particles and the impact of nanoplastic deposition or accumulation on fetal health remain unknown. In this study we investigated whether nanopolystyrene particles can cross the placental barrier and deposit in fetal tissues after maternal pulmonary exposure.
Results
Pregnant Sprague Dawley rats were exposed to 20 nm rhodamine-labeled nanopolystyrene beads (2.64 × 10
14
particles) via intratracheal instillation on gestational day (GD) 19. Twenty-four hours later on GD 20, maternal and fetal tissues were evaluated using fluorescent optical imaging. Fetal tissues were fixed for particle visualization with hyperspectral microscopy. Using isolated placental perfusion, a known concentration of nanopolystyrene was injected into the uterine artery. Maternal and fetal effluents were collected for 180 min and assessed for polystyrene particle concentration. Twenty-four hours after maternal exposure, fetal and placental weights were significantly lower (7 and 8%, respectively) compared with controls. Nanopolystyrene particles were detected in the maternal lung, heart, and spleen. Polystyrene nanoparticles were also observed in the placenta, fetal liver, lungs, heart, kidney, and brain suggesting maternal lung-to-fetal tissue nanoparticle translocation in late stage pregnancy.
Conclusion
These studies confirm that maternal pulmonary exposure to nanopolystyrene results in the translocation of plastic particles to placental and fetal tissues and renders the fetoplacental unit vulnerable to adverse effects. These data are vital to the understanding of plastic particulate toxicology and the developmental origins of health and disease.
Although patients with cardiovascular disease face excess risks of severe illness with coronavirus disease-2019 (COVID-19), there may be indirect consequences of the pandemic on this high-risk ...patient segment.
This study sought to examine longitudinal trends in hospitalizations for acute cardiovascular conditions across a tertiary care health system.
Acute cardiovascular hospitalizations were tracked between January 1, 2019, and March 31, 2020. Daily hospitalization rates were estimated using negative binomial models. Temporal trends in hospitalization rates were compared across the first 3 months of 2020, with the first 3 months of 2019 as a reference.
From January 1, 2019, to March 31, 2020, 6,083 patients experienced 7,187 hospitalizations for primary acute cardiovascular reasons. There were 43.4% (95% confidence interval CI: 27.4% to 56.0%) fewer estimated daily hospitalizations in March 2020 compared with March 2019 (p < 0.001). The daily rate of hospitalizations did not change throughout 2019 (–0.01% per day 95% CI: –0.04% to +0.02%; p = 0.50), January 2020 (–0.5% per day 95% CI: –1.6% to +0.5%; p = 0.31), or February 2020 (+0.7% per day 95% CI: –0.6% to +2.0%; p = 0.27). There was significant daily decline in hospitalizations in March 2020 (–5.9% per day 95% CI: –7.6% to –4.3%; p < 0.001). Length of stay was shorter (4.8 days 25th to 75th percentiles: 2.4 to 8.3 days vs. 6.0 days 25th to 75th percentiles: 3.1 to 9.6 days; p = 0.003) and in-hospital mortality was not significantly different (6.2% vs. 4.4%; p = 0.30) in March 2020 compared with March 2019.
During the first phase of the COVID-19 pandemic, there was a marked decline in acute cardiovascular hospitalizations, and patients who were admitted had shorter lengths of stay. These data substantiate concerns that acute care of cardiovascular conditions may be delayed, deferred, or abbreviated during the COVID-19 pandemic.
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A second-generation capsule endoscopy system, using the PillCam Colon 2, was developed to increase sensitivity for colorectal polyp detection compared with the first-generation system. The ...performance of this new system is reported.
In a five-center feasibility study, second-generation capsule endoscopy was prospectively compared with conventional colonoscopy as gold standard for the detection of colorectal polyps and other colonic disease, in a cohort of patients scheduled for colonoscopy and having known or suspected colonic disease. Colonoscopy was independently performed within 10 hours after capsule ingestion. Capsule-positive but colonoscopy-negative cases were counted as false-positive.
104 patients (mean age 49.8 years) were enrolled; data from 98 were analyzed. Patient rate for polyps of any size was 44 %, 53 % of these patients having adenomas. No adverse events related to either procedure were reported. The capsule sensitivity for the detection of patients with polyps >or= 6 mm was 89 % (95 % confidence interval CI 70 - 97) and for those with polyps >or= 10 mm it was 88 % (95 %CI 56 - 98), with specificities of 76 % (95 %CI 72 - 78) and 89 % (95 %CI 86 - 90), respectively. Both polyps missed by colonoscopy and mismatch in polyp size by study definition lowered specificity. Overall colon cleanliness for capsule endoscopy was adequate in 78 % of patients (95 %CI 68 - 86).
The new second-generation colon capsule endoscopy is a safe and effective method for visualizing the colon and detecting colonic lesions. Sensitivity and specificity for detecting colorectal polyps appear to be very good, suggesting a potential for improved accuracy compared with the first-generation system. Further prospective and comparative studies are needed.
Recent research has shown that management control systems (MCS) can improve performance in contexts characterized by high levels of task uncertainty. This seems to conflict with a second stream of ...research, which argues that MCSs risk undermining the intrinsic motivation needed for effective performance in such settings. To solve this puzzle, we build on theories of perceived locus of causality and self-construal and develop an integrative model summarized in 15 propositions. To explicate our proposed solution and to show its robustness, we focus on the class of activities we call
large-scale collaborative creativity (LSCC) – contexts where individuals face a dual challenge of demonstrating creativity and embracing the formal controls that coordinate their creative activities with others’. We argue that LSCC requires the simultaneous activation of intrinsic and identified forms of motivation, and simultaneously independent and interdependent self-construals. Against some scholarship that argues or assumes that such simultaneous combinations are infeasible, we argue that they can be fostered through appropriate attraction–selection–attrition policies and management control systems design. We also show how our propositions can enrich our understanding of motivation in other settings, where creativity and/or coordination demands are less pressing.
Many organisms face challenges in avoiding predation while searching for mates. For plants, emitting floral fragrances to advertise reproductive structures could increase the attraction of ...detrimental insects along with pollinators. Very few studies have experimentally evaluated the costs and benefits of fragrance emission with explicit consideration of how plant fitness is affected by both pollinators and florivores. To determine the reproductive consequences of increasing the apparency of reproductive parts, we manipulated fragrance, pollination, and florivores in the wild Texas gourd, Cucurbita pepo var. texana. With enhanced fragrance we found an increase in the attraction of florivores, rather than pollinators, and a decrease in seed production. This study is the first to demonstrate that enhanced floral fragrance can increase the attraction of detrimental florivores and decrease plant reproduction, suggesting that florivory as well as pollination has shaped the evolution of floral scent.
Population-based screening for colorectal cancer is widely recommended, with conventional colonoscopy considered to be the preferred diagnostic modality. However, compliance with screening ...colonoscopy is low and manpower capacity is limited. Capsule endoscopy might therefore represent a desirable alternative strategy.
The PillCam Colon capsule endoscope was prospectively tested in a multicenter setting. The indications for endoscopy in the enrolled patients included colorectal cancer screening (43 %), postpolypectomy surveillance (26 %), and lower gastrointestinal signs and symptoms (31 %). Study subjects underwent colon preparation and then ingested the capsule on the morning of the examination, with conventional colonoscopy being performed the same day. The PillCam Colon capsule findings were reviewed by three experts in capsule endoscopy who were blinded to the conventional colonoscopy findings.
A total of 91 subjects were enrolled in three Israeli centers (55 men, 36 women; mean age 57), and the results were evaluable in 84 cases. The capsule was excreted within 10 hours in 74 % of the patients and reached the rectosigmoid colon in the other 16 %. Of the 84 evaluable patients, 20 (24 %) had significant findings, defined as at least one polyp of 6 mm or more in size or three or more polyps of any size: 14/20 (70 %) were identified with the capsule and 16/20 (80 %) were identified by conventional colonoscopy. Polyps of any size were found in 45 patients, 34/45 (76 %) found by the capsule and 36/45 (80 %) by conventional colonoscopy. In comparison with conventional colonoscopy, false-positive findings on PillCam Colon capsule examination were recorded in 15/45 cases (33 %). There were no adverse events related to the capsule endoscopy.
PillCam Colon capsule endoscopy appears to be a promising new modality for colonic evaluation. Further improvements in the procedure will probably increase capsule examination completion and polyp detection rates. Additional studies are needed to evaluate the accuracy of PillCam Colon endoscopy in other patient populations with different prevalence levels of colonic disease.
Several floral microbes are known to be pathogenic to plants or floral visitors such as pollinators. Despite the ecological and economic importance of pathogens deposited in flowers, we often lack a ...basic understanding of how floral traits influence disease transmission. Here, we provide the first systematic review regarding how floral traits attract vectors (for plant pathogens) or hosts (for animal pathogens), mediate disease establishment and evolve under complex interactions with plant mutualists that can be vectors for microbial antagonists. Attraction of floral visitors is influenced by numerous phenological, morphological and chemical traits, and several plant pathogens manipulate floral traits to attract vectors. There is rapidly growing interest in how floral secondary compounds and antimicrobial enzymes influence disease establishment in plant hosts. Similarly, new research suggests that consumption of floral secondary compounds can reduce pathogen loads in animal pollinators. Given recent concerns about pollinator declines caused in part by pathogens, the role of floral traits in mediating pathogen transmission is a key area for further research. We conclude by discussing important implications of floral transmission of pathogens for agriculture, conservation and human health, suggesting promising avenues for future research in both basic and applied biology.
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