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The typical marine animal has increased in biovolume by more than two orders of magnitude since the beginning of the Cambrian, but the causes of this trend remain unknown. We test the hypothesis that the efficiency of intra-organism oxygen delivery is a major constraint on body-size evolution in marine animals. To test this hypothesis, we compiled a dataset comprising 13,723 marine animal genera spanning the Phanerozoic. We coded each genus according to its respiratory medium, circulatory anatomy, and feeding mode. In extant genera, we find that respiratory medium and circulatory anatomy explain more of the difference in size than feeding modes. Likewise, we find that most of the Phanerozoic increase in mean biovolume is accounted for by size increase in taxa that accomplish oxygen delivery through closed circulatory systems. During the Cambrian, water-breathing animals with closed circulatory systems were smaller, on average, than contemporaries with open circulatory systems. However, genera with closed circulatory systems superseded in size genera with open circulatory systems by the Middle Ordovician, as part of their Phanerozoic-long trend of increasing size. In a regression analysis, respiratory and circulatory anatomy explain far more size variation in the living fauna than do feeding modes, even after accounting for taxonomic affinity at the class level. These findings suggest that ecological and environmental drivers of the Phanerozoic increase in the mean size of marine animals operated within strong, anatomically determined constraints.
Hospital environmental surfaces are frequently contaminated by microorganisms. However, the causal mechanism of bacterial contamination of the environment as a source of transmission is still debated. This prospective study was performed to characterize the nature of multidrug-resistant organism (MDRO) transmission between the environment and patients using standard microbiological and molecular techniques.
Prospective cohort study at 2 academic medical centers.
A prospective multicenter study to characterize the nature of bacterial transfer events between patients and environmental surfaces in rooms that previously housed patients with 1 of 4 ‘marker’ MDROs: methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Clostridium difficile, and MDR Acinetobacter baumannii. Environmental and patient microbiological samples were obtained on admission into a freshly disinfected inpatient room. Repeat samples from room surfaces and patients were taken on days 3 and 7 and each week the patient stayed in the same room. The bacterial identity, antibiotic susceptibility, and molecular sequences were compared between organisms found in the environment samples and patient sources.
We enrolled 80 patient–room admissions; 9 of these patients (11.3%) were asymptomatically colonized with MDROs at study entry. Hospital room surfaces were contaminated with MDROs despite terminal disinfection in 44 cases (55%). Microbiological Bacterial Transfer events either to the patient, the environment, or both occurred in 12 patient encounters (18.5%) from the microbiologically evaluable cohort.
Microbiological Bacterial Transfer events between patients and the environment were observed in 18.5% of patient encounters and occurred early in the admission. This study suggests that research on prevention methods beyond the standard practice of room disinfection at the end of a patient’s stay is needed to better prevent acquisition of MDROs through the environment.
Improvements in computational resources over the last decade are enabling a new era of computational prediction and design of novel materials. The resulting resources are databases such as the Materials Project (www.materialsproject.org), which is harnessing the power of supercomputing together with state-of-the-art quantum mechanical theory to compute the properties of all known inorganic materials, to design novel materials, and to make the data available for free to the community, together with online analysis and design algorithms. The current release contains data derived from quantum mechanical calculations for more than 70,000 materials and millions of associated materials properties. The software infrastructure carries out thousands of calculations per week, enabling screening and predictions for both novel solids as well as molecular species with targeted properties. As the rapid growth of accessible computed materials properties continues, the next frontier is harnessing that information for automated learning and accelerated discovery. In this article, we highlight some of the emerging and exciting efforts, and successes, as well as current challenges using descriptor-based and machine-learning methods for data-accelerated materials design.
To investigate the predictive ability of the previously established global cerebrovascular disease (CeVD) burden scale on long-term clinical outcomes in a longitudinal study of Asian elderly participants across the spectrum of cognitive impairment.
A case-control study was conducted over a 2-year period involving participants with no cognitive impairment, cognitive impairment-no dementia (CIND), and Alzheimer's disease (AD). Annually, cognitive function was assessed with a comprehensive neuropsychological battery and the clinical dementia rating (CDR) scale was used to stage disease severity.
Of 314 participants, 102 had none/very mild CeVD, 31 mild CeVD, 94 moderate CeVD, and 87 severe CeVD at baseline. There was a 1.14 and 1.42 units decline per year on global cognitive z-scores in moderate and severe CeVD groups, respectively, compared to none/very mild CeVD. Moderate-severe CeVD predicted significant functional deterioration at year 2 (HR = 2.0, 95% CI = 1.2–3.4), and conversion to AD (HR = 6.3, 95% CI = 1.7–22.5), independent of medial temporal atrophy.
The global CeVD burden scale predicts poor long-term clinical outcome independent of neurodegenerative markers. Furthermore, CeVD severity affects the rate of cognitive and functional deterioration. Hence, cerebrovascular burden, which is potentially preventable, is a strong prognostic indicator, both at preclinical and clinical stages of AD, independent of neurodegenerative processes.
We explore the status of state-of-the-art upconverter materials in the context of improving solar cell performance. We focus on semiconductor upconversion nanostructures that can harvest two separate bands of the solar spectrum and offer a promising path to rational engineering of improved performance and thus improved overall solar energy harvesting.
Photon upconversion is a process in which two low-energy photons are sequentially absorbed and one high-energy photon is emitted. Photon upconversion in both inorganic and organic material platforms has been used to improve solar cell efficiency. Lanthanide-doped salts (inorganic) and triplet–triplet annihilation molecules (organic) have achieved 33% and 60% internal upconversion quantum efficiency, respectively, leading to current density increases of 17 mA/cm2 and 0.86 mA/cm2. However, their performance is limited by their narrow absorption bandwidth (AB) and limited tunability, especially at low photon fluxes. Recently, colloidal semiconductor nanostructures have emerged as a promising material platform for upconversion. The optical absorption in these low-dimensional heterostructures involves both quantum-confined and continuum band states, enabling a much larger AB. Moreover, the techniques of semiconductor heterostructure engineering can be used to optimize performance and to tailor absorption and emission wavelengths. We review the performance and potential impact on solar energy harvesting of upconversion materials, focusing on semiconductor upconverters. We discuss computational models that suggest that semiconductor upconverter nanostructures could have outstanding performance for photovoltaic. We then discuss the current state of the art in semiconductor upconversion morphologies and compositions and provide an outlook on the ways in which nanostructures can be tailored to improve performance for applications.
Despite recent interest in community-based screening programs to detect undiagnosed cognitive disorder, little is known about whether screening leads to further diagnostic evaluation, or the effects of such programs in terms of actual changes in patient or caregiver behavior. This study followed up informants of older adults (i.e. caregivers of patients who completed informant-based screening regarding the patient) following participation in a study screening for undiagnosed memory problems, to explore uptake of further diagnostic evaluation or treatment, advance planning or preparations, lifestyle changes, medication adherence, and use of support services.
A total of 140 informants of older adult patients were surveyed four to fifteen months following participation in a cognitive screening study. The informants were interviewed with a study-specific survey about cognitive assessment, advance planning, lifestyle changes, and use of support services and general medication adherence.
A minority of patients and informants had engaged in advance planning or made relevant lifestyle changes following cognitive screening. Those assessed as being at higher risk of memory problems were more likely to have attended a full diagnostic evaluation, engaged in support services and experienced medication adherence difficulties.
Only a small proportion of patients participating in cognitive screening subsequently engaged in diagnostic evaluation, advance planning, or lifestyle changes. However, those with higher risk of cognitive impairment were generally more likely to take some action following cognitive screening. Those at higher risk were also more vulnerable due to greater difficulties with medication adherence.
Severe longitudinally extensive transverse myelitis (LETM) can cause quadriplegia, marked sensory dysfunction, and respiratory failure. Some patients are unresponsive to conventional immune therapy. We report two cases of severe immune-mediated LETM requiring intensive care admission that failed to respond to high-dose corticosteroids, plasma exchange, intravenous immunoglobulin, and rituximab. Disease cessation and significant recovery was achieved after cyclophosphamide induction. In patients with severe acute immune-mediated LETM who fail to respond to corticosteroids and plasma exchange, cyclophosphamide induction should be considered. This agent and regimen provides a robust immunosuppressive response and can be induced rapidly. Cyclophosphamide effects and supportive evidence are discussed.
It is unclear which of four popular contemporary diet patterns is best for weight maintenance among postmenopausal women. Four dietary patterns were characterised among postmenopausal women aged 49–81 years (mean 63·6 (sd 7·4) years) from the Women’s Health Initiative Observational Study: (1) a low-fat diet; (2) a reduced-carbohydrate diet; (3) a Mediterranean-style (Med) diet; and (4) a diet consistent with the US Department of Agriculture’s Dietary Guidelines for Americans (DGA). Discrete-time hazards models were used to compare the risk of weight gain (≥10 %) among high adherers of each diet pattern. In adjusted models, the reduced-carbohydrate diet was inversely related to weight gain (OR 0·71; 95 % CI 0·66, 0·76), whereas the low-fat (OR 1·43; 95 % CI 1·33, 1·54) and DGA (OR 1·24; 95 % CI 1·15, 1·33) diets were associated with increased risk of weight gain. By baseline weight status, the reduced-carbohydrate diet was inversely related to weight gain among women who were normal weight (OR 0·72; 95 % CI 0·63, 0·81), overweight (OR 0·67; 95 % CI 0·59, 0·76) or obese class I (OR 0·63; 95 % CI 0·53, 0·76) at baseline. The low-fat diet was associated with increased risk of weight gain in women who were normal weight (OR 1·28; 95 % CI 1·13, 1·46), overweight (OR 1·60; 95 % CI 1·40, 1·83), obese class I (OR 1·73; 95 % CI 1·43, 2·09) or obese class II (OR 1·44; 95 % CI 1·08, 1·92) at baseline. These findings suggest that a low-fat diet may promote weight gain, whereas a reduced-carbohydrate diet may decrease risk of postmenopausal weight gain.
Metsulfuron is used for POST control of spotted spurge in many warm-season
turfgrasses. A suspected resistant (R) biotype of spotted spurge was
collected from turfgrass in Georgia with a history of exclusive metsulfuron
use. Research was conducted to evaluate the resistance level of this biotype
to metsulfuron, efficacy of other mechanisms of action for control, and the
molecular basis for resistance. Compared with a susceptible (S) biotype, the
R biotype required >90 and >135 times greater metsulfuron rates to
reach 50% injury and reduce biomass 50% from the nontreated, respectively.
The R biotype was also resistant to trifloxysulfuron but was injured
equivalent to the S biotype from dicamba, glyphosate, and triclopyr. Gene
sequencing of the R biotype revealed a Trp574 to Leu substitution
that has conferred resistance to acetolactate synthase (ALS) inhibitors in
previous research. This is the first report of ALS resistance in spotted
spurge. More importantly, this is the first report of a herbicide-resistant
broadleaf weed from a turfgrass system in the United States.
Increased temporal and frontal slow-wave delta (1–4 Hz) and theta (4–7
Hz) activities are the most consistent resting-state neural abnormalities
reported in schizophrenia. The frontal lobe is associated with negative
symptoms and cognitive abilities such as attention, with negative
symptoms and impaired attention associated with poor functional
To establish whether frontal dysfunction, as indexed by slowing, would be
associated with functional impairments.
Eyes-closed magnetoencephalography data were collected in 41 participants
with schizophrenia and 37 healthy controls, and frequency-domain source
imaging localised delta and theta activity.
Elevated delta and theta activity in right frontal and right
temporoparietal regions was observed in the schizophrenia
v. control group. In schizophrenia, right-frontal
delta activity was uniquely associated with negative but not positive
symptoms. In the full sample, increased right-frontal delta activity
predicted poorer attention and functional capacity.
Our findings suggest that treatment-associated decreases in slow-wave
activity could be accompanied by improved functional outcome and thus