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When ecosystems are under severe pressure or environments change, trophic position and intraspecific niche width may decrease or narrow, signalling that conservation action is required. In New Zealand, alpine and subalpine ecosystems have been extensively modified through farming since 19th-century European settlement, with consequences for indigenous species such as the kea Nestor notabilis. We investigated feather stable isotope values in the kea and predicted a lower trophic position in modern kea populations, to reflect reduced lowland habitat and a mixed diet with more plant material. We predicted that size and sex would influence trophic values in this sexually dimorphic species, with larger birds more likely to have a high protein diet. We examined potential dietary changes in 68 museum collected kea from 1880s to 2000s, first recording accession details including provenance and sex and measuring culmen length. We used bulk carbon and nitrogen stable isotope analyses (BSIAs) of feathers and a further feather subset using compound-specific stable isotope analyses of amino acids (CSIA-AA) to obtain isotopic values and estimate trophic position. BSIA showed δ

The site-selective modification of peptides and proteins facilitates the preparation of targeted therapeutic agents and tools to interrogate fundamental biochemistry. Among the numerous bioconjugation techniques developed to install groups of interest, those that generate C(sp3)-C(sp3) bonds are significantly underrepresented despite affording proteolytically stable, biogenic linkages. Herein we describe a visible-light-mediated reaction that enables the site-selective modification of peptides and proteins via desulfurative C(sp3)-C(sp3) bond formation. The reaction is rapid and high yielding in peptide systems, with comparable translation to proteins. Using this chemistry, we demonstrate the installation of a range of moieties into model systems and successfully integrate an effective PTM-mimic into a recombinantly expressed histone.

Species distribution models (SDMs) are widely used to predict range shifts but could be unreliable under climate change scenarios because they do not account for evolution. The thermal physiology of a species is a key determinant of its range and thus incorporating thermal trait evolution into SDMs might be expected to alter projected ranges. We identified a genetic basis for physiological and behavioural traits that evolve in response to temperature change in natural populations of threespine stickleback (Gasterosteus aculeatus). Using these data, we created geographical range projections using a mechanistic niche area approach under two climate change scenarios. Under both scenarios, trait data were either static ("no evolution" models), allowed to evolve at observed evolutionary rates ("evolution" models) or allowed to evolve at a rate of evolution scaled by the trait variance that is explained by quantitative trait loci (QTL; "scaled evolution" models). We show that incorporating these traits and their evolution substantially altered the projected ranges for a widespread panmictic marine population, with over 7-fold increases in area under climate change projections when traits are allowed to evolve. Evolution-informed SDMs should improve the precision of forecasting range dynamics under climate change, and aid in their application to management and the protection of biodiversity.

The biodiversity and climate crises are critical challenges of this century. Wildflower meadows in urban areas could provide important nature‐based solutions, addressing the biodiversity and climate crises jointly and benefitting society in the process. King's College Cambridge (England, UK) established a wildflower meadow over a portion of its iconic Back Lawn in 2019, replacing a fine lawn first laid in 1772. We used biodiversity surveys, Wilcoxon signed rank and ANOVA models to compare species richness, abundance and composition of plants, spiders, bugs, bats and nematodes supported by the meadow, and remaining lawn, over 3 years. We estimated the climate change impact of meadow vs lawn from maintenance emissions, soil carbon sequestration and reflectance effect. We surveyed members of the university to quantify the societal benefits of, and attitudes towards, increased meadow planting on the collegiate university estate. In spite of its small size (0.36 ha), the meadow supported approximately three times more plant species, three times more spider and bug species and individuals, and bats were recorded three times more often over the meadow than the remaining lawn. Terrestrial invertebrate biomass was 25 times higher in the meadow compared with the lawn. Fourteen species with conservation designations were recorded on the meadow (six for lawn), alongside meadow specialist species. Reduced maintenance and fertilising associated with meadow reduced emissions by an estimated 1.36 Mg CO2‐e per hectare per year compared with lawn. Relative reflectance increased by 25%–34% for meadow relative to lawn. Soil carbon stocks did not differ between meadow and lawn. Respondents thought meadows provided greater aesthetic, educational and mental wellbeing services than lawns. In open responses, lawns were associated with undesirable elitism and social exclusion (most colleges in Cambridge restrict lawn access to senior members of college), and respondents proved overwhelmingly in favour of meadow planting in place of lawn on the collegiate university estate. This study demonstrates the substantial benefits of small urban meadows for local biodiversity, cultural ecosystem services and climate change mitigation, supplied at lower cost than maintaining conventional lawn.

Sarcopenia, or the age‐related loss of skeletal muscle mass and function, is an increasingly prevalent condition that contributes to reduced quality of life, morbidity, and mortality in older adults. Older adults display blunted anabolic responses to otherwise anabolic stimuli—a phenomenon that has been termed anabolic resistance (AR)—which is likely a casual factor in sarcopenia development. AR is multifaceted, but historically much of the mechanistic focus has been on signalling impairments, and less focus has been placed on the role of the vasculature in postprandial protein kinetics. The vascular endothelium plays an indispensable role in regulating vascular tone and blood flow, and age‐related impairments in vascular health may impede nutrient‐stimulated vasodilation and subsequently the ability to deliver nutrients (e.g. amino acids) to skeletal muscle. Although the majority of data has been obtained studying younger adults, the relatively limited data on the effect of blood flow on protein kinetics in older adults suggest that vasodilatory function, especially of the microvasculature, strongly influences the muscle protein synthetic response to amino acid feedings. In this narrative review, we examine evidence of AR in older adults following amino acid and mixed meal consumption, examine the evidence linking vascular dysfunction and insulin resistance to age‐related AR, review the influence of nitric oxide and endothelin‐1 on age‐related vascular dysfunction as it relates to AR, briefly review the potential causal role of arterial stiffness in promoting skeletal muscle microvascular dysfunction and AR, and provide a brief overview and future considerations for research examining age‐related AR.

This work probes the slurry architecture of a high silicon content electrode slurry with and without low molecular weight polymeric dispersants as a function of shear rate to mimic electrode casting conditions for poly(acrylic acid) (PAA) and lithium neutralized poly(acrylic acid) (LiPAA) based electrodes. Rheology coupled ultra-small angle neutron scattering (rheo-USANS) was used to examine the aggregation and agglomeration behavior of each slurry as well as the overall shape of the aggregates. The addition of dispersant has opposing effects on slurries made with PAA or LiPAA binder. With a dispersant, there are fewer aggregates and agglomerates in the PAA based silicon slurries, while LiPAA based silicon slurries become orders of magnitude more aggregated and agglomerated at all shear rates. The reorganization of the PAA and LiPAA binder in the presence of dispersant leads to a more homogeneous slurry and a more heterogeneous slurry, respectively. This reorganization ripples through to the cast electrode architecture and is reflected in the electrochemical cycling of these electrodes.

Severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) has caused substantially more infections, deaths, and economic disruptions than the 2002‐2003 SARS‐CoV. The key to understanding SARS‐CoV‐2's higher infectivity lies partly in its host receptor recognition mechanism. Experiments show that the human angiotensin converting enzyme 2 (ACE2) protein, which serves as the primary receptor for both CoVs, binds to the receptor binding domain (RBD) of CoV‐2's spike protein stronger than SARS‐CoV's spike RBD. The molecular basis for this difference in binding affinity, however, remains unexplained from X‐ray structures. To go beyond insights gained from X‐ray structures and investigate the role of thermal fluctuations in structure, we employ all‐atom molecular dynamics simulations. Microseconds‐long simulations reveal that while CoV and CoV‐2 spike‐ACE2 interfaces have similar conformational binding modes, CoV‐2 spike interacts with ACE2 via a larger combinatorics of polar contacts, and on average, makes 45% more polar contacts. Correlation analysis and thermodynamic calculations indicate that these differences in the density and dynamics of polar contacts arise from differences in spatial arrangements of interfacial residues, and dynamical coupling between interfacial and non‐interfacial residues. These results recommend that ongoing efforts to design spike‐ACE2 peptide blockers will benefit from incorporating dynamical information as well as allosteric coupling effects.

Advances in video technology enable new strategies for stream fish research. We compared juvenile (age-0) and adult (age-1 and older) Brook Trout Salvelinus fontinalis abundance estimates from underwater video with those from backpack electrofishing and dive count methods across a series of stream pools in Shenandoah National Park, Virginia (n = 41). Video methods estimated greater mean abundance of adult trout than did one-pass electrofishing, but video estimates of adult abundance were not different than estimates from three-pass electrofishing or dive count methods. In contrast, videos underestimated the abundance of juvenile trout; we suggest that this is because predator avoidance behaviors by juvenile trout limit their use of microhabitat locations visible to cameras. Integrated abundance estimates from two cameras increased correspondence to comparison methods relative to estimates from single cameras, demonstrating the importance of an expanded field of view for video sampling in streams. Geomorphic features helped to explain methodwise differences: more adult Brook Trout were estimated with video than with three-pass electrofishing as riffle crest depth and boulder composition increased, indicating habitat associations with trout escapement from electrofishing. Our results demonstrated that video techniques can provide a robust alternative or supplement to traditional methods for estimating adult trout abundance in stream pools. U.S. Geological Survey's Ecosystems Mission Area; Chesapeake Bay studies; Natural Resource Preservation Program We thank the following individuals for assistance with this study: S. Faulkner, T. O'Connell, A. Ostroff, S. Phillips, K. Hyer, E. Rodway, S. Brown, J. Dehnert, K. Kessler, Z. Kelly, K. Krause, and C. Muhlfeld (U.S. Geological Survey); C. Krause, C. Roghair, K. Schaefer, and K. Thornhill (USFS); and J. Cummings, J. Schaberl, D. Demarest, and E. Childress (National Park Service). Funding was provided by the U.S. Geological Survey's Ecosystems Mission Area, Chesapeake Bay studies, and Natural Resource Preservation Program. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. There is no conflict of interest declared in this article. Public domain – authored by a U.S. government employee

BACKGROUND: Tracheal intubation is a common procedure performed to secure the airway in adults undergoing surgery or those who are critically ill. Intubation is sometimes associated with difficulties and complications that may result in patient harm. While it is traditionally achieved by performing direct laryngoscopy, the past three decades have seen the advent of rigid indirect videolaryngoscopes (VLs). A mounting body of evidence comparing the two approaches to tracheal intubation has been acquired over this period of time. This is an update of a Cochrane Review first published in 2016. OBJECTIVES: To assess whether use of different designs of VLs in adults requiring tracheal intubation reduces the failure rate compared with direct laryngoscopy, and assess the benefits and risks of these devices in selected population groups, users and settings. SEARCH METHODS: We searched MEDLINE, Embase, CENTRAL and Web of Science on 27 February 2021. We also searched clinical trials databases, conference proceedings and conducted forward and backward citation searches. SELECTION CRITERIA: We included randomized controlled trials (RCTs) and quasi‐RCTs with adults undergoing laryngoscopy performed with either a VL or a Macintosh direct laryngoscope (DL) in any clinical setting. We included parallel and cross‐over study designs. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. We collected data for the following outcomes: failed intubation, hypoxaemia, successful first attempt at tracheal intubation, oesophageal intubation, dental trauma, Cormack‐Lehane grade, and time for tracheal intubation. MAIN RESULTS: We included 222 studies (219 RCTs, three quasi‐RCTs) with 26,149 participants undergoing tracheal intubation. Most studies recruited adults undergoing elective surgery requiring tracheal intubation. Twenty‐one studies recruited participants with a known or predicted difficult airway, and an additional 25 studies simulated a difficult airway. Twenty‐one studies were conducted outside the operating theatre environment; of these, six were in the prehospital setting, seven in the emergency department and eight in the intensive care unit. We report here the findings of the three main comparisons according to videolaryngoscopy device type. We downgraded the certainty of the outcomes for imprecision, study limitations (e.g. high or unclear risks of bias), inconsistency when we noted substantial levels of statistical heterogeneity and publication bias. Macintosh‐style videolaryngoscopy versus direct laryngoscopy (61 studies, 9883 participants) We found moderate‐certainty evidence that a Macintosh‐style VL probably reduces rates of failed intubation (risk ratio (RR) 0.41, 95% confidence interval (CI) 0.26 to 0.65; 41 studies, 4615 participants) and hypoxaemia (RR 0.72, 95% CI 0.52 to 0.99; 16 studies, 2127 participants). These devices may also increase rates of success on the first intubation attempt (RR 1.05, 95% CI 1.02 to 1.09; 42 studies, 7311 participants; low‐certainty evidence) and probably improve glottic view when assessed as Cormack‐Lehane grade 3 and 4 (RR 0.38, 95% CI 0.29 to 0.48; 38 studies, 4368 participants; moderate‐certainty evidence). We found little or no clear difference in rates of oesophageal intubation (RR 0.51, 95% CI 0.22 to 1.21; 14 studies, 2404 participants) but this finding was supported by low‐certainty evidence. We were unsure of the findings for dental trauma because the certainty of this evidence was very low (RR 0.68, 95% CI 0.16 to 2.89; 18 studies, 2297 participants). We were not able to pool data for time required for tracheal intubation owing to considerable heterogeneity (I(2) = 96%). Hyperangulated videolaryngoscopy versus direct laryngoscopy (96 studies, 11,438 participants) We found moderate‐certainty evidence that hyperangulated VLs probably reduce rates of failed intubation (RR 0.51, 95% CI 0.34 to 0.76; 63 studies, 7146 participants) and oesophageal intubation (RR 0.39, 95% CI 0.18 to 0.81; 14 studies, 1968 participants). In subgroup analysis, we noted that hyperangulated VLs were more likely to reduce failed intubation when used on known or predicted difficult airways (RR 0.29, 95% CI 0.17 to 0.48; P = 0.03 for subgroup differences; 15 studies, 1520 participants). We also found that these devices may increase rates of success on the first intubation attempt (RR 1.03, 95% CI 1.00 to 1.05; 66 studies, 8086 participants; low‐certainty evidence) and the glottic view is probably also improved (RR 0.15, 95% CI 0.10 to 0.24; 54 studies, 6058 participants; data for Cormack‐Lehane grade 3/4 views; moderate‐certainty evidence). However, we found low‐certainty evidence of little or no clear difference in rates of hypoxaemia (RR 0.49, 95% CI 0.22 to 1.11; 15 studies, 1691 participants), and the findings for dental trauma were unclear because the certainty of this evidence was very low (RR 0.51, 95% CI 0.16 to 1.59; 30 studies, 3497 participants). We were not able to pool data for time required for tracheal intubation owing to considerable heterogeneity (I(2) = 99%). Channelled videolaryngoscopy versus direct laryngoscopy (73 studies, 7165 participants) We found moderate‐certainty evidence that channelled VLs probably reduce rates of failed intubation (RR 0.43, 95% CI 0.30 to 0.61; 53 studies, 5367 participants) and hypoxaemia (RR 0.25, 95% CI 0.12 to 0.50; 15 studies, 1966 participants). They may also increase rates of success on the first intubation attempt (RR 1.10, 95% CI 1.05 to 1.15; 47 studies, 5210 participants; very low‐certainty evidence) and probably improve glottic view (RR 0.14, 95% CI 0.09 to 0.21; 40 studies, 3955 participants; data for Cormack‐Lehane grade 3/4 views; moderate‐certainty evidence). We found little or no clear difference in rates of oesophageal intubation (RR 0.54, 95% CI 0.17 to 1.75; 16 studies, 1756 participants) but this was supported by low‐certainty evidence. We were unsure of the findings for dental trauma because the certainty of the evidence was very low (RR 0.52, 95% CI 0.13 to 2.12; 29 studies, 2375 participants). We were not able to pool data for time required for tracheal intubation owing to considerable heterogeneity (I(2) = 98%). AUTHORS' CONCLUSIONS: VLs of all designs likely reduce rates of failed intubation and result in higher rates of successful intubation on the first attempt with improved glottic views. Macintosh‐style and channelled VLs likely reduce rates of hypoxaemic events, while hyperangulated VLs probably reduce rates of oesophageal intubation. We conclude that videolaryngoscopy likely provides a safer risk profile compared to direct laryngoscopy for all adults undergoing tracheal intubation.

To help inform global guidelines on infant feeding, this systematic review synthesizes evidence related to the presence of the Ebola virus (EBOV) in breast milk and its potential risk of viral transmission to the infant when breastfeeding. We relied on a comprehensive search strategy to identify studies including women with suspected, probable, or confirmed EBOV infection, intending to breastfeed or give breast milk to an infant. Our search identified 10,454 records, and after deduplication and screening, we assessed 148 full texts. We included eight studies reporting on 10 breastfeeding mothers and their children (one mother with twins), who provided breast milk samples for assessment. EBOV was detected via RT‐PCR or viral culture in seven out of ten breast milk samples. Four out of the five‐breastfed infants with EBOV‐positive breast milk were found positive for EBOV infection, and all of these EBOV‐positive infants died. Since previous reports have detected EBOV in tears, saliva, sweat, and contaminated surfaces, with the current evidence, it is not possible to conclude with certainty that breast milk was the main route of EBOV transmission., Understanding maternal‐to‐child transmission routes is key to lowering, and ultimately preventing, the exposure of Ebola virus (EBOV) in pediatric populations. We undertook a systematic review of the available scientific literature to determine whether EBOV can be transmitted through breast milk and to describe the outcomes of the infants that ingested EBOV laboratory‐confirmed breast milk.

Interaction networks among native and invasive species in a community can inform both invasion impacts and applied management of invasive species. The intensity of aggressive interactions may be related to the overlap in species’ ecological niche and functional traits, especially in cavity-breeding species, that often compete for limited nesting sites. Australia is home to over 100 native and introduced cavity-nesting species, including several invasive species that are widespread globally, such as the common myna Acridotheres tristis. Here, we aimed to test the extent to which shared functional traits inform the intensity of aggression between cavity-nesting birds. We quantified the outcomes of aggressive interactions between birds in large hollow-bearing trees in SE Queensland, Australia. We examined whether more similarly sized birds interacted more frequently, whether larger species won aggressive interactions more often, and whether cavity-breeding species with similar preferences for nesting sites (breeding-niche space) interacted more frequently. We recorded a total of 410 aggressive interactions and 48 interacting bird species around tree hollows, including 20 cavity-nesting bird species. These interactions were dominated by the invasive common myna, the native noisy miner (a non-cavity-breeder) and the native rainbow lorikeet Trichoglossus moluccanus, but the common myna won the largest total number of interspecific interactions. On average, larger birds won aggressive interactions more frequently, yet there were some important exceptions to this finding; the common myna (113 ± 30 g) won 26 of the 29 interactions against the larger native rainbow lorikeet (126 ± 44 g). Importantly, species with more similar nest-site preferences were observed aggressively interacting more frequently. Synthesis and applications. The impact of the invasive common myna was higher-site preferences. Control efforts for the myna should focus on birds that nest in natural tree hollows. An analysis of shared traits by managers could be used to help identify how many local species would benefit from common myna control in a given area and test if further behavioural studies of common myna are warranted.

Daily consumption of iron-containing supplements is recommended for all pregnant women but there is no approved global standard indicator for assessing supplementation coverage. Furthermore, the validity of commonly used coverage indicators for iron-containing supplement consumption is questionable. The WHO-UNICEF Technical Expert Advisory Group on Nutrition Monitoring, and partners, have systematically worked to identify a feasible and valid indicator of iron-containing supplement coverage for reporting by countries. In 2019, we conducted key informant interviews with respondents in eight countries, fielded an online survey (in three languages using SurveyMonkey) to which 142 nutrition professionals from 52 countries responded, and used Demographic and Health Surveys (DHS) data from four countries to assess determinants of the quality of iron-containing supplement coverage data. Less than half (45%) of online survey respondents were satisfied with the current methods for collecting iron-containing supplement coverage data in their context. Recommended changes by study respondents include recall period5 years, adding questions about counselling, including other beneficiary groups, and assessing supply chain functionality. The DHS analysis suggested an association between time since pregnancy and data quality. Data heaping on multiples of 30 was observed in 40%-75% of data. There is a clear demand for a revised indicator and measurement guidance for coverage of iron-containing supplementation during pregnancy. Future research should continue the development and validation of a global indicator, to more precisely validate the quality of recall data, including the distinction between distribution and consumption using various question formulations.

Transcription activator‐like effector (TALE) proteins have been used extensively for targeted binding of fusion proteins to loci of interest in (epi)genome engineering. Such approaches typically utilize four canonical TALE repeat variable diresidue (RVD) types, corresponding to the identities of two key amino acids, to target each nucleotide. Alternate RVDs with improved specificity are desired. Here, we focused on seven noncanonical RVDs that have been suggested to have improved specificity for their target nucleotides. We used custom protein binding microarrays to characterize the DNA‐binding activity of 65 TALEs containing these alternate or corresponding canonical RVDs at multiple positions to ~5,000 unique DNA sequences per protein. We found that none of the noncanonical thymine‐targeting RVDs displayed stronger preference for thymine than did the canonical RVD. Of the noncanonical RVDs with putatively improved specificity for guanine, only EN and NH showed greater discrimination of guanine over adenine. This improved specificity, however, comes at a cost: more substitutions of a noncanonical RVD for a canonical RVD generally decreased the protein's DNA‐binding activity. Our results highlight the need to investigate RVD‐nucleotide specificities in multiple protein contexts and suggest that a balance between canonical and noncanonical RVDs is needed to build TALEs with improved specificity.

Fire is a primary disturbance in boreal forests and generates both positive and negative climate forcings. The influence of fire on surface albedo is a predominantly negative forcing in boreal forests, and one of the strongest overall, due to increased snow exposure in the winter and spring months. Albedo forcings are spatially and temporally heterogeneous and depend on a variety of factors related to soils, topography, climate, land cover/vegetation type, successional dynamics, time since fire, season, and fire severity. However, how these variables interact to influence albedo is not well understood, and quantifying these relationships and predicting postfire albedo becomes increasingly important as the climate changes and management frameworks evolve to consider climate impacts. Here we developed a MODIS-derived ‘blue sky’ albedo product and a novel machine learning modeling framework to predict fire-driven changes in albedo under historical and future climate scenarios across boreal North America. Converted to radiative forcing (RF), we estimated that fires generate an annual mean cooling of −1.77 ± 1.35 W/m 2 from albedo under historical climate conditions (1971–2000) integrated over 70 years postfire. Increasing postfire albedo along a south–north climatic gradient was offset by a nearly opposite gradient in solar insolation, such that large-scale spatial patterns in RF were minimal. Our models suggest that climate change will lead to decreases in mean annual postfire albedo, and hence a decreasing strength of the negative RF, a trend dominated by decreased snow cover in spring months. Considering the range of future climate scenarios and model uncertainties, we estimate that for fires burning in the current era (2016) the cooling effect from long-term postfire albedo will be reduced by 15%–28% due to climate change.

Climate change‐driven droughts and insect outbreaks are becoming more frequent and widespread, increasing forest vulnerability to mortality. By addressing the impacts of climate and insects on tree growth preceding death, we can better understand tree mortality risk under a changing climate. Here, we used tree stature and interannual growth (basal area increment; BAI) to assess processes leading to trembling aspen (Populus tremuloides) survival or mortality during an unprecedented leaf miner (Phyllocnistis populiella) outbreak in boreal North America. We identified eight sites (22 plots) in the longest running forest monitoring network in Alaska, spanning ~350 km of latitude, that experienced ≥0.25 Mg·ha−1·yr−1 aspen mortality during the outbreak. We compared the size and canopy position, growth patterns, and sensitivity to climate and leaf mining of aspen that survived (living; n = 84) vs. died (dying; n = 76) and linked the normalized difference vegetation index (NDVI) to plot‐level aspen growth and stand biomass recruitment, growth, and mortality. Dying aspen were in the subcanopy, smaller in diameter, and after a drought in 1957 had lower growth than living aspen until death. Before the outbreak, growth of all trees was positively influenced by moisture and negatively by temperature, but only living trees maintained this climate response during the outbreak. Leaf mining reduced growth of both groups, exerting at least a twofold greater impact than climate. The NDVI captured plot‐level tree growth and stand biomass growth and mortality, yet it was nearly two times more strongly associated with living than dying tree growth and 12 times more strongly associated with biomass growth than mortality. These differences suggest that NDVI may inadequately detect insect‐driven dieback and dispersed mortality of aspen across the boreal biome. Our findings reveal that a historic drought triggered a multi‐decadal growth decline that predisposed aspen to mortality during the leaf miner outbreak and that while aspen growth is influenced by moisture and temperature, it is more strongly affected by P. populiella. We conclude that as the climate warms and insect outbreaks increase in frequency and magnitude at high latitudes, we should expect to see persistent and greater declines in aspen growth and increases in mortality.

Mesenchymal stromal cells (MSCs) have emerged as candidate cells with therapeutic potential to treat different pathologies. The underlying mechanism is paracrine signaling. The cells secrete proteins that can impact inflammation, apoptosis, angiogenesis, and cell proliferation. All are important in wound healing and tissue regeneration. Although the bone marrow has been the most widely used source of MSCs, umbilical cord tissue (CT) presents a source that is just starting to be used in the clinic, yet can be obtained with more ease and easily stored. Here, we characterize CT-MSCs obtained from multiple donors by analyzing cell surface proteins, differentiation capacity, and proteome profile. Analysis of low, medium, and high passage cells indicates that the morphology and proliferation rate stay constant and with the exception of cluster of differentiation (CD) 105 at late passage, there are no changes in the cell surface protein characteristics, indicating the population does not change with passage. TNF-stimulated gene 6 protein was measured in a subset of samples and variable expression was observed, but this did not impact the ability of the cells to enhance skin regeneration. In conclusion, CT-MSC represents a consistent, easily accessible source of cells for cell therapy. Stem Cells Translational Medicine 2019;8:1041–1054

Acute kidney injury (AKI) initiates a complex pathophysiological cascade leading to epithelial cell death. Recent studies identify autophagy, a key intracellular process that degrades cytoplasmic constituents, as protective against AKI. We have previously reported that the protein thrombospondin-1 and its receptor CD47 are induced in AKI; however, the mechanism underlying their regulation of injury is unknown. Here, we investigated whether CD47 signaling affects autophagy to regulate AKI. Wild-type (WT) and CD47-/- mice were challenged with renal ischemia-reperfusion injury. All animals underwent analysis of renal function and biomolecular phenotyping. CD47-/- mice were resistant to AKI, with decreased serum creatinine and ameliorated histologic changes compared with WT animals. These mice also displayed increased abundance of key autophagy genes, including autophagy-related gene (Atg)5, Atg7, beclin-1, and microtubule-associated proteins 1A/1B light chain 3 (LC3) at baseline and post-AKI, which were significantly reduced in WT mice. Changes in protein expression correlated with increased autophagosome and autolysosome formation in renal tubular epithelial cells (RTECs). In mouse kidney transplantation, treatment with a CD47-blocking antibody that improved function was associated with increased autophagy compared with control mice. Primary isolated RTECs from CD47-/- mice demonstrated increased basal expression of several autophagy components that was preserved under hypoxic stress. These data suggest that activated CD47 promotes AKI through inhibition of autophagy and point to CD47 as a target to preserve renal function following injury.-El-Rashid, M., Ghimire, K., Sanganeria, B., Lu, B., Rogers, N. M. CD47 limits autophagy to promote acute kidney injury.

RATIONALE Isotope reference materials are essential to enable reliable and comparable isotope data across multiple laboratories. Although many reference materials already exist, the best reference materials should mimic the unknown samples, so new reference materials continue to evolve with the development of isotope research in new product areas. METHODS Two defatted beef reference materials, CAAS-1801 and CAAS-1802, with substantially different δ13 C values (due to difference in dietary intake), have been prepared as reference materials for stable C and N isotope analysis of meat tissue. Homogeneity, and short- and long-term stability tests of these reference materials have been performed. The δ13 C and δ15 N values of both materials were measured for two-point isotopic normalization against international reference materials by elemental analyzer/isotope ratio mass spectrometry (EA/IRMS). A total of nine international laboratories were selected for the joint evaluation. Cochran statistical analysis yielded the values reported here. RESULTS The defatted beef reference material CAAS-1801 from Heilongjiang province has a δ13 C value of -13.58 ± 0.56‰ relative to VPDB and a δ15 N value of 4.23 ± 0.56‰ relative to N2 in air. The defatted beef reference material CAAS-1802 from Sichuan province has a δ13 C value of -25.03 ± 0.45‰ and a δ15 N value of 4.36 ± 0.69‰. CONCLUSIONS The two defatted beef reference materials were found to be isotopically stable across a range of ambient temperatures, and to have low volatility and toxicity, which enables them to be useful as stable isotope reference materials in the field of authentication and traceability of meat.

Rationale Deliberate and fraudulent origin mislabeling of Chinese green tea motivated by large price differences often brings significant food safety risks and damages consumer trust. Currently, there is no reliable method to verify the origin of green tea produced in China. Stable isotope and multi-element analyses combined with statistical models are widely acknowledged as useful traceability techniques for many agro-products, and could be developed to confirm the geographical origin of Chinese green tea and, more importantly, combat illegal green tea mislabeling and fraud. Methods An analytical strategy combining elemental analyzer/isotope ratio mass spectrometry (EA/IRMS) and inductively plasma coupled mass spectrometry (ICP-MS) with chemometrics tools was used to confirm the origin of green tea grown in the main tea production provinces around China. Stable C, N, H, O isotope ratios and twenty elements were measured to build mathematical discriminant models using unsupervised principal component analysis (PCA) and supervised linear discriminant analysis (LDA). Two main problems: (i) tracing the origin of Chinese green tea from different tea growing provinces (Zhejiang, Shandong, and other provinces); (ii) authentication of high-value Westlake Longjing tea from the Westlake region and surrounding areas in Zhejiang province, were investigated and assessed. Results The results demonstrated that PCA and follow-up LDA based on stable isotope and multi-element signatures can verify the geographical origin of Chinese green tea from different provinces, and even localized zones in the same province could be distinguishable, with discrimination accuracies higher than 92.3% and 87.8%, respectively. Conclusions Geochemical fingerprinting techniques coupled with chemometric tools offer an accurate and effective verification method for the geographical origin of Chinese green tea, providing a promising tool to combat fraudulent mislabeling of high-value green tea.

The pandemic of coronavirus disease 2019 (COVID‐19) is caused by infection with a novel coronavirus strain, the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). At present, there is limited information on potential transmission of the infection from mother to child, particularly through breast milk and breastfeeding. Here, we provide a living systematic review to capture information that might necessitate changes in the guidance on breast milk and breastfeeding given the uncertainty in this area. Our search retrieved 19,414 total records; 605 were considered for full‐text eligibility and no ongoing trials were identified. Our review includes 340 records, 37 with breast milk samples and 303 without. The 37 articles with analyzed breast milk samples reported on 77 mothers who were breastfeeding their children; among them, 19 of 77 children were confirmed COVID‐19 cases based on RT‐PCR assays, including 14 neonates and five older infants. Nine of the 68 analyzed breast milk samples from mothers with COVID‐19 were positive for SARS‐CoV‐2 RNA; of the exposed infants, four were positive and two were negative for COVID‐19. Currently, there is no evidence of SARS‐CoV‐2 transmission through breast milk. Studies are needed with longer follow‐up periods that collect data on infant feeding practices and on viral presence in breast milk., The objective of this review is to assess available evidence related to the possible transmission of SARS‐ CoV‐2 through breast milk and through breastfeeding (i.e., related bodily fluids, such as blood, sweat, and respiratory droplets) or droplet transmission due to close contact with the infant or young child via skin‐to‐skin exposure or airborne transmission. The review aims to support policymakers in making evidence‐informed global, regional, and national guidelines on infant feeding in the context of the ongoing pandemic.

Life history theory provides a framework to understand environmental change based on species traits that capitalize on stable, predictable, or stochastic environmental conditions. We evaluated life history strategies and temporal trends in abundance from 1975 to 2017 for 28 fish species within the Potomac River of eastern North America. Multivariate analysis identified life history strategies defined by small‐bodied species with extended spawning seasons and early maturation (opportunistic strategists), large‐bodied species with delayed maturation and long lifespans (periodic strategists), and intermediate‐sized species exhibiting parental care (equilibrium strategists). Linear mixed models detected temporal trends in abundance for 13 species (46%), of which nine increased and four decreased over time. Increasing species were characterized by opportunistic life history strategies (e.g., banded killifish, Fundulus diaphanous; mosquito fish, Gambusia holbrooki), whereas decreasing species were characterized by periodic or equilibrium strategies (e.g., smallmouth bass, Micropterus dolomieu; river chub, Nocomis micropogon). Recent introductions can account for temporal increases in some cases, but most increasing species are native to the study area. Observed increases in opportunistic native species and decreases in periodic and equilibrium species indicate that environmental conditions have become less stable and less predictable over time, consistent with observed increases in spring peak flows in the study area. Our study indicates the importance of environmental stochasticity for fish community responses to land use and climate change and demonstrates the utility of life history theory in this regard.