Predicting crystal structure has always been a challenging problem for physical sciences. Recently, computational methods have been built to predict crystal structure with success but have been ...limited in scope and computational time. In this paper, we review computational methods such as density functional theory and machine learning methods used to predict crystal structure. We also explored the breadth versus accuracy of building a model to predict across any crystal structure using machine learning. We extracted 24 913 unique chemical formulas existing between 290 and 310 K from the Pearson Crystal Database. Of these 24 913 formulas, there exists 10 711 unique crystal structures referred to as entry prototypes. Common entries might have hundreds of chemical compositions, while the vast majority of entry prototypes is represented by fewer than ten unique compositions. To include all data in our predictions, entry prototypes that lacked a minimum number of representatives were relabeled as “Other”. By selecting the minimum numbers to be 150, 100, 70, 40, 20, and 10, we explored how limiting class sizes affected performance. Using each minimum number to reorganize the data, we looked at the classification performance metrics: accuracy, precision, and recall. Accuracy ranged from 97 ± 2 to 85 ± 2%; average precision ranged from 86 ± 2 to 79 ± 2%, while average recall ranged from 73 ± 2 to 54 ± 2% for minimum-class representatives from 150 to 10, respectively.
Recurrent hepatic encephalopathy (HE) is a leading cause of readmission despite standard of care (SOC) associated with microbial dysbiosis. Fecal microbiota transplantation (FMT) may improve ...dysbiosis; however, it has not been studied in HE. We aimed to define whether FMT using a rationally derived stool donor is safe in recurrent HE compared to SOC alone. An open‐label, randomized clinical trial with a 5‐month follow‐up in outpatient men with cirrhosis with recurrent HE on SOC was conducted with 1:1 randomization. FMT‐randomized patients received 5 days of broad‐spectrum antibiotic pretreatment, then a single FMT enema from the same donor with the optimal microbiota deficient in HE. Follow‐up occurred on days 5, 6, 12, 35, and 150 postrandomization. The primary outcome was safety of FMT compared to SOC using FMT‐related serious adverse events (SAEs). Secondary outcomes were adverse events, cognition, microbiota, and metabolomic changes. Participants in both arms were similar on all baseline criteria and were followed until study end. FMT with antibiotic pretreatment was well tolerated. Eight (80%) SOC participants had a total of 11 SAEs compared to 2 (20%) FMT participants with SAEs (both FMT unrelated; P = 0.02). Five SOC and no FMT participants developed further HE (P = 0.03). Cognition improved in the FMT, but not the SOC, group. Model for End‐Stage Liver Disease (MELD) score transiently worsened postantibiotics, but reverted to baseline post‐FMT. Postantibiotics, beneficial taxa, and microbial diversity reduction occurred with Proteobacteria expansion. However, FMT increased diversity and beneficial taxa. SOC microbiota and MELD score remained similar throughout. Conclusion: FMT from a rationally selected donor reduced hospitalizations, improved cognition, and dysbiosis in cirrhosis with recurrent HE. (Hepatology 2017;66:1727–1738)
This meta-analysis reviewed 82 school-based, universal social and emotional learning (SEL) interventions involving 97,406 kindergarten to high school students (Mage = 11.09 years; mean percent low ...socioeconomic status = 41.1; mean percent students of color = 45.9). Thirty-eight interventions took place outside the United States. Follow-up outcomes (collected 6 months to 18 years postintervention) demonstrate SEL's enhancement of positive youth development. Participants fared significantly better than controls in social-emotional skills, attitudes, and indicators of well-being. Benefits were similar regardless of students' race, socioeconomic background, or school location. Postintervention social-emotional skill development was the strongest predictor of well-being at follow-up. Infrequently assessed but notable outcomes (e.g., graduation and safe sexual behaviors) illustrate SEL's improvement of critical aspects of students' developmental trajectories.
Amino acids play an important role in ecology as essential nutrients for animals and as currencies in symbiotic associations. Here we present a new approach to tracing the origins of amino acids by ...identifying unique patterns of carbon isotope signatures generated by amino acid synthesis in plants, fungi, and bacteria ("¹³C fingerprints"). We measured amino acid δ¹³C from 10 C₃ plants, 13 fungi, and 10 bacteria collected and isolated from a boreal forest in interior Alaska, USA, using gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Microorganisms were cultured under amino-acid-free conditions and identified based on DNA sequences. Bacteria, fungi, and plants generated consistent, unique ¹³C fingerprints based on the more complex amino acids (five or more biosynthetic steps) that are classified as essential for animals. Linear discriminant analysis classified all samples correctly with >99% certainty and correctly classified nearly all insect samples from a previous study by diet. Our results suggest that ¹³C fingerprints of amino acids could provide a powerful in situ assay of the biosynthetic sources of amino acids and a potential new tool for understanding nutritional linkages in food webs.
Mycoplankton have so far been a neglected component of pelagic marine ecosystems, having been poorly studied relative to other plankton groups. Currently, there is a lack of understanding of how ...mycoplankton diversity changes through time, and the identity of controlling environmental drivers. Using Fungi-specific high-throughput sequencing and quantitative PCR analysis of plankton DNA samples collected over 6 years from the coastal biodiversity time series site Station L4 situated off Plymouth (UK), we have assessed changes in the temporal variability of mycoplankton diversity and abundance in relation to co-occurring environmental variables. Mycoplankton diversity at Station L4 was dominated by Ascomycota, Basidiomycota and Chytridiomycota, with several orders within these phyla frequently abundant and dominant in multiple years. Repeating interannual mycoplankton blooms were linked to potential controlling environmental drivers, including nitrogen availability and temperature. Specific relationships between mycoplankton and other plankton groups were also identified, with seasonal chytrid blooms matching diatom blooms in consecutive years. Mycoplankton α-diversity was greatest during periods of reduced salinity at Station L4, indicative of riverine input to the ecosystem. Mycoplankton abundance also increased during periods of reduced salinity, and when potential substrate availability was increased, including particulate organic matter. This study has identified possible controlling environmental drivers of mycoplankton diversity and abundance in a coastal sea ecosystem, and therefore sheds new light on the biology and ecology of an enigmatic marine plankton group. Mycoplankton have several potential functional roles, including saprotrophs and parasites, that should now be considered within the consensus view of pelagic ecosystem functioning and services.
•Roadway visibility has been a transportation topic of interest for over 100 years.•Traditional visibility techniques include: overhead lighting, glass beads in paint, raised markers, and embedded ...LED’s.•The very long lasting phosphor SrAl2O4:Eu2+,Dy3+ shows promise as an alternative lighting technique.•Phosphorescent paint must be optimized for paint stability and to protect it from hydrolysis.
Roadway marking visibility has made substantial improvements since the beginning of the 20th century. The most common solution for increasing the visibility of road markings is the use of retroreflective beads, which suffer from decreased performance under wet conditions. To remedy this, alternative road marking visibility techniques such as luminescent paint have been investigated. A promising new technology involves the use of phosphors such as strontium aluminate doped with europium and dysprosium ions (SrAl2O4:Eu2+,Dy3+). This technology shows potential to be seen throughout the night. The two hurdles blocking the path for the use of phosphors in road marking paint are the need to stabilize the particles in the paint matrix, and the tendency of the phosphor to hydrolyze. In this review, an explanation of the science behind stabilization is set forth alongside several methods that show potential for mitigating hydrolysis.
Fungal species have numerous important environmental functions. Where these functions occur will depend on how fungi are spatially distributed, but the spatial structures of fungal communities are ...largely unknown, especially in understudied hyperdiverse tropical tree canopy systems. Here we explore fungal communities in a Costa Rican tropical rainforest canopy, with a focus on local‐scale spatial structure and substrate specificity of fungi. Samples of ~1 cm3 were collected from 135 points along five adjacent tree branches, with intersample distances from 1 to 800 cm, and dissected into four substrates: outer host tree bark, inner bark, dead bryophytes and living bryophytes. We sequenced the ITS2 region to characterize total fungal communities. Fungal community composition and diversity varied among substrate types, even when multiple substrates were in direct contact. Fungi were most diverse in living bryophytes, with 39% of all operational taxonomic units (OTUs) found exclusively in this substrate, and the least diverse in inner bark. Fungal communities had significant positive spatial autocorrelation and distance decay of similarity only at distances less than 1 m. Similarity among samples declined by half in less than 10 cm, and even at these short distances, similarities were low with few OTUs shared among samples. These results indicate that community turnover is high and occurs at very small spatial scales, with any two locations sharing very few fungi in common. High heterogeneity of fungal communities in space and among substrates may have implications for the distributions, population dynamics and diversity of other tree canopy organisms, including epiphytic plants.
Carrier transport characteristics in high-efficiency single-walled carbon nanotubes (SWNTs)/silicon (Si) hybrid solar cells are presented. The solar cells were fabricated by depositing intrinsic ...p-type SWNT thin-films on n-type Si wafers without involving any high-temperature process for p–n junction formation. The optimized cells showed a device ideality factor close to unity and a record-high power-conversion-efficiency of >11%. By investigating the dark forward current density characteristics with varying temperature, we have identified that the temperature-dependent current rectification originates from the thermally activated band-to-band transition of carriers in Si, and the role of the SWNT thin films is to establish a built-in potential for carrier separation/collection. We have also established that the dominant carrier transport mechanism is diffusion, with minimal interface recombination. This is further supported by the observation of a long minority carrier lifetime of ∼34 μs, determined by the transient recovery method. This study suggests that these hybrid solar cells operate in the same manner as single crystalline p–n homojunction Si solar cells.
While it is now well established that fungal community composition varies spatially at a variety of scales, temporal turnover of fungi is less well understood. Here we studied inter-annual community ...compositional changes of fungi in a rainforest tree canopy environment. We tracked fungal community shifts over 3 years in three substrate types (live bryophytes, dead bryophytes, and host tree bark) and compared these changes to amounts of community turnover seen at small spatial scales in the same system. The effect of substrate type on fungal community composition was stronger than that of sampling year, which was very small but significant. Although levels of temporal turnover varied among substrates, with greater turnover in live bryophytes than other substrates, the amount of turnover from year to year was comparable to what is seen at spatial distances between 5 and 9 cm for the same substrate. Stability of communities was largely driven by a few fungi with high relative abundances. A majority of fungal occurrences were at low relative abundances (≤ 0.1%). These fungi tended to be short lived and persisted to following years ≤ 50% of the time, depending on substrate. Their presence and persistence are likely impacted by stochastic processes like dispersal limitation and disturbance. Most samples contained only one or a few fungi at high relative abundance (≥ 10%) that persisted half or more of the time. These more abundant and persistent fungi are expected to have sustained functional interactions within the canopy ecosystem.
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