Evolution of Soil Carbon Storage and Morphometric Properties of Afforested Soils in the U.S. Great Plains

The objective of this project was to use detailed soil profi le descriptions and soil carbon analyses to determine the soil C sequestration potential of tree planting across climatic gradients in the U.S. Great Plains. Tree windbreak age ranged from 19 to 70 years and age of cultivation from 22 to ~110 years. At each site, soil pits were prepared within the tree planting, the adjacent crop fi elds, and nearby undisturbed grassland. Windbreak soils had consistently thicker soil organic carbon (SOC)- enriched A or A+AB horizons when compared to the crop fi elds. The thickness of A or A+AB horizons in the windbreak soils were comparable to the undisturbed grassland soils. A linear relationship was detected between the difference in A+AB thickness of soils beneath windbreaks and undisturbed grasslands and a climate index (hydrothermal coeffi cient, HTC). These results indicate that tree windbreaks with more cool and moist climate conditions are more favorable for SOC accumulation in the surface soil. The relationship between SOC accumulation and climate factors enables the estimation of soil carbon stocks in existing windbreaks and the prediction of potential carbon sequestration of future plantings

The Searsville Lake Site (California, USA) as a candidate Global Boundary Stratotype Section and Point for the Anthropocene Series

Cores from Searsville Lake within Stanford University’s Jasper Ridge Biological Preserve, California, USA, are examined to identify a potential GSSP for the Anthropocene: core JRBP2018-VC01B (944.5 cm-long) and tightly correlated JRBP2018-VC01A (852.5 cm-long). Spanning from 1900 CE ± 3 years to 2018 CE, a secure chronology resolved to the sub-annual level allows detailed exploration of the Holocene-Anthropocene transition. We identify the primary GSSP marker as first appearance of 239,240Pu (372–374 cm) in JRBP2018-VC01B and designate the GSSP depth as the distinct boundary between wet and dry season at 366 cm (6 cm above the first sample containing 239,240Pu) and corresponding to October-December 1948 CE. This is consistent with a lag of 1–2 years between ejection of 239,240Pu into the atmosphere and deposition. Auxiliary markers include: first appearance of 137Cs in 1958; late 20th-century decreases in δ15N; late 20th-century elevation in SCPs, Hg, Pb, and other heavy metals; and changes in abundance and presence of ostracod, algae, rotifer, and protozoan microfossils. Fossil pollen document anthropogenic landscape changes related to logging and agriculture. As part of a major university, the Searsville site has long been used for research and education, serves users locally to internationally, and is protected yet accessible for future studies and communication about the Anthropocene. PLAIN WORD SUMMARY: The Global Boundary Stratotype Section and Point (GSSP) for the proposed Anthropocene Series/Epoch is suggested to lie in sediments accumulated over the last ~120 years in Searsville Lake, Woodside, California, USA. The site fulfills all of the ideal criteria for defining and placing a GSSP. In addition, the Searsville site is particularly appropriate to mark the onset of the Anthropocene, because it was anthropogenic activities–the damming of a watershed–that created a geologic record that now preserves the very signals that can be used to recognize the Anthropocene worldwide

Hawk Eyes I: Diurnal Raptors Differ in Visual Fields and Degree of Eye Movement

BACKGROUND: Different strategies to search and detect prey may place specific demands on sensory modalities. We studied visual field configuration, degree of eye movement, and orbit orientation in three diurnal raptors belonging to the Accipitridae and Falconidae families. METHODOLOGY/PRINCIPAL FINDINGS: We used an ophthalmoscopic reflex technique and an integrated 3D digitizer system. We found inter-specific variation in visual field configuration and degree of eye movement, but not in orbit orientation. Red-tailed Hawks have relatively small binocular areas (∼33°) and wide blind areas (∼82°), but intermediate degree of eye movement (∼5°), which underscores the importance of lateral vision rather than binocular vision to scan for distant prey in open areas. Cooper's Hawks' have relatively wide binocular fields (∼36°), small blind areas (∼60°), and high degree of eye movement (∼8°), which may increase visual coverage and enhance prey detection in closed habitats. Additionally, we found that Cooper's Hawks can visually inspect the items held in the tip of the bill, which may facilitate food handling. American Kestrels have intermediate-sized binocular and lateral areas that may be used in prey detection at different distances through stereopsis and motion parallax; whereas the low degree eye movement (∼1°) may help stabilize the image when hovering above prey before an attack. CONCLUSIONS: We conclude that: (a) there are between-species differences in visual field configuration in these diurnal raptors; (b) these differences are consistent with prey searching strategies and degree of visual obstruction in the environment (e.g., open and closed habitats); (c) variations in the degree of eye movement between species appear associated with foraging strategies; and (d) the size of the binocular and blind areas in hawks can vary substantially due to eye movements. Inter-specific variation in visual fields and eye movements can influence behavioral strategies to visually search for and track prey while perching

Motivational Interviewing as Evidence-Based Practice? An Example from Sexual Risk Reduction Interventions Targeting Adolescents and Young Adults

This paper critically examines sexual risk reduction interventions, more specifically how they are evaluated and the implications that this has for sexual health policy. The focus is on motivational interviewing (MI) interventions which aim to promote protective behaviors related to sexual risk on the part of young people. MI has become increasingly popular, largely due to it being a highly flexible counseling approach that may, with adequate staff training, and fidelity in implementation, be tailored to many different settings (e.g., health care, schools and in community work). Following a scoping review that comprised 34 papers, of which 29 were unique studies, the range and type of existing research were examined. The results show a wide range of study designs and evaluation procedures, MI conceptualizations, modes of MI delivery, and the particular sub-populations of youth and sexual risk behaviors targeted. While this makes it difficult to draw any generalized conclusions about “what works” in prevention, it provides important insights about the complexity of sexual risk behavior as well as complex behavioral treatment approaches like MI. We therefore problematize the political drive to implement evidence-based methods without adequate resource allocation and contextual adaptation

Organs-on-Chips as Bridges for Predictive Toxicology

The next generation of chemical toxicity testing will use organs-on-chips (OoCs)—3D cultures of heterotypic cells with appropriate extracellular matrices to better approximate the in vivo cellular microenvironment. Researchers are already working to validate whether OoCs are predictive of toxicity in humans. Here, we review two other key aspects of how OoCs may advance predictive toxicology—each taking advantage of OoCs as systems of intermediate complexity that remain experimentally accessible. First, the intermediate complexity of OoCs will help elucidate the scale(s) of organismal complexity that currently confound computational predictions of in vivo toxicity from in vitro data sets. Identifying the strongest confounding factors will help researchers improve the computational models underlying such predictions. Second, the experimental accessibility of OoCs will allow researchers to analyze chemical-exposure responses in OoCs using an array of high-content readouts—from fluorescent biosensors that report dynamic changes in specific cell signaling pathways to unbiased searches over broader biochemical space using technologies like ion mobility-mass spectrometry. Such high-content information on OoC responses will help determine the details of adverse outcome pathways. We note these possible uses of OoCs so that researchers and engineers can consider them in the design of next-generation OoC control, perfusion, and analysis platforms