It has recently been argued that a sensitivity theory of knowledge cannot account for intuitively appealing instances of higher-order knowledge. In this paper, we argue that it can once careful attention is paid to the methods or processes by which we typically form higher-order beliefs. We base our argument on what we take to be a well-motivated and commonsensical view on how higher-order knowledge is typically acquired, and we show how higher-order knowledge is possible in a sensitivity theory once this view is adopted.

Lithium was added to the hypereutectic Mg–Ni alloy to investigate the effect of volatilization of Li on the hydrogen storage characteristics of the eutectic Mg–Ni alloy at 300 °C. After fully activated at 300 °C, Li was almost completely volatilized and the structure of Li-containing Mg82Ni18 alloy was converted to the structure of Li-free Mg82Ni18 alloy, but hydrogen absorption capacity significantly decreased. This is because volatilization of Li weakened the bonding between eutectic Mg and Mg2Ni, lowering the catalytic effect of Mg2Ni on Mg. The decrease in hydrogen absorption capacity was more obvious with increasing Li content. In addition, experimental alloy in powder form could increase surface area, causing Li to volatilize at 300 °C.

Field trials were conducted at Pontotoc, Mississippi, Chase, Louisiana, and Clinton, North Carolina in 2017 and 2018 to determine the effect of pendimethalin rate and timing on sweetpotato crop tolerance, yield, and storage root quality. Treatments consisted of five pendimethalin rates (266, 532, 1065, 1597, and 2130 g ai ha-1) by two application timings (0 to 1 or 10 to 14 d after transplanting). Additionally, a nontreated check was included for comparison. Crop injury (stunting) was minimal (< 4%) through 6 wk after transplanting (WAP) and no injury was observed from 8 to 14 WAP, regardless of application timing or rate. The nontreated check yielded 6.6, 17.6, 5.5, and 32.1 × 103 kg ha-1 of canner, no.1, jumbo, and total grades, respectively. Neither pendimethalin application timing nor rate influenced jumbo, no.1, marketable or total sweetpotato yield. Overall, these results indicate that pendimethalin will be a valuable addition to the toolkit of sweetpotato growers.

Compound-specific radiocarbon (14C) dating often requires working with small samples of < 100 µg carbon (µgC). This makes the radiocarbon dates of biomarker compounds very sensitive to biases caused by extraneous carbon of unknown composition, a procedural blank, which is introduced to the samples during the steps necessary to prepare a sample for radiocarbon analysis by accelerator mass spectrometry (i.e., isolating single compounds from a heterogeneous mixture, combustion, gas purification and graphitization). Reporting accurate radiocarbon dates thus requires a correction for the procedural blank. We present our approach to assess the fraction modern carbon (F14C) and the mass of the procedural blanks introduced during the preparation procedures of lipid biomarkers (i.e. n-alkanoic acids) and lignin phenols. We isolated differently sized aliquots (6–151 µgC) of n-alkanoic acids and lignin phenols obtained from standard materials with known F14C values. Each compound class was extracted from two standard materials (one fossil, one modern) and purified using the same procedures as for natural samples of unknown F14C. There is an inverse linear relationship between the measured F14C values of the processed aliquots and their mass, which suggests constant contamination during processing of individual samples. We use Bayesian methods to fit linear regression lines between F14C and 1/mass for the fossil and modern standards. The intersection points of these lines are used to infer F14Cblank and mblank and their associated uncertainties. We estimate 4.88 ± 0.69 μgC of procedural blank with F14C of 0.714 ± 0.077 for n-alkanoic acids, and 0.90 ± 0.23 μgC of procedural blank with F14C of 0.813 ± 0.155 for lignin phenols. These F14Cblank and mblank can be used to correct AMS results of lipid and lignin samples by isotopic mass balance. This method may serve as a standardized procedure for blank assessment in small-scale radiocarbon analysis.

Bog bodies are among the best-known archaeological finds worldwide. Much of the work on these often extremely well-preserved human remains has focused on forensics, whereas the environmental setting of the finds has been largely overlooked. This applies to both the ‘physical’ and ‘cultural’ landscape and constitutes a significant problem since the vast spatial and temporal scales over which the practice appeared demonstrate that contextual assessments are of the utmost importance for our explanatory frameworks. In this article we develop best practice guidelines for the contextual analysis of bog bodies, after assessing the current state of research and presenting the results of three recent case studies including the well-known finds of Lindow Man in the United Kingdom, Bjældskovdal (Tollund Man and Elling Woman) in Denmark, and Yde Girl in the Netherlands. Three spatial and chronological scales are distinguished and linked to specific research questions and methods. This provides a basis for further discussion and a starting point for developing approaches to bog body finds and future discoveries, while facilitating and optimizing the re-analysis of previous studies, making it possible to compare deposition sites across time and space.

Field studies were conducted in 2016 and 2017 at Clinton, NC, to quantify the effects of season-long interference of large crabgrass [Digitaria sanguinalis (L.) Scop.] and Palmer amaranth (Amaranthus palmeri S. Watson) on ‘AG6536’ soybean [Glycine max (L.) Merr.]. Weed density treatments consisted of 0, 1, 2, 4, and 8 plants m−2 for A. palmeri and 0, 1, 2, 4, and 16 plants m−2 for D. sanguinalis with (interspecific interference) and without (intraspecific interference) soybean to determine the impacts on weed biomass, soybean biomass, and seed yield. Biomass per square meter increased with increasing weed density for both weed species with and without soybean present. Biomass per square meter of D. sanguinalis was 617% and 37% greater when grown without soybean than with soybean, for 1 and 16 plants m−2 respectively. Biomass per square meter of A. palmeri was 272% and 115% greater when grown without soybean than with soybean for 1 and 8 plants m−2, respectively. Biomass per plant for D. sanguinalis and A. palmeri grown without soybean was greatest at the 1 plant m−2 density. Biomass per plant of D. sanguinalis plants across measured densities was 33% to 83% greater when grown without soybean compared with biomass per plant when soybean was present for 1 and 16 plants m−2, respectively. Similarly, biomass per plant for A. palmeri was 56% to 74% greater when grown without soybean for 1 and 8 plants m−2, respectively. Biomass per plant of either weed species was not affected by weed density when grown with soybean due to interspecific competition with soybean. Yield loss for soybean grown with A. palmeri ranged from 14% to 37% for densities of 1 to 8 plants m−2, respectively, with a maximum yield loss estimate of 49%. Similarly, predicted loss for soybean grown with D. sanguinalis was 0 % to 37% for densities of 1 to 16 m−2 with a maximum yield loss estimate of 50%. Soybean biomass was not affected by weed species or density. Results from these studies indicate that A. palmeri is more competitive than D. sanguinalis at lower densities, but that similar yield loss can occur when densities greater than 4 plants m−2 of either weed are present.

In the 2015 review paper ‘Petawatt Class Lasers Worldwide’ a comprehensive overview of the current status of high-power facilities of ${>}200~\text{TW}$ was presented. This was largely based on facility specifications, with some description of their uses, for instance in fundamental ultra-high-intensity interactions, secondary source generation, and inertial confinement fusion (ICF). With the 2018 Nobel Prize in Physics being awarded to Professors Donna Strickland and Gerard Mourou for the development of the technique of chirped pulse amplification (CPA), which made these lasers possible, we celebrate by providing a comprehensive update of the current status of ultra-high-power lasers and demonstrate how the technology has developed. We are now in the era of multi-petawatt facilities coming online, with 100 PW lasers being proposed and even under construction. In addition to this there is a pull towards development of industrial and multi-disciplinary applications, which demands much higher repetition rates, delivering high-average powers with higher efficiencies and the use of alternative wavelengths: mid-IR facilities. So apart from a comprehensive update of the current global status, we want to look at what technologies are to be deployed to get to these new regimes, and some of the critical issues facing their development.

De Dreu and Gross argue that only asymmetric games allow the motives underlying defense and attack to be disentangled. However, the Prisoner's Dilemma Game Alt matrix (PDG-Alt matrix), a modified symmetric PDG, also allows these motives to be disentangled. Studies using the PDG-Alt matrix produced findings contradicting a central claim of De Dreu and Gross.

The Critically Endangered blue-eyed black lemur Eulemur flavifrons of north-western Madagascar is one of the most threatened primates. The majority of research and conservation efforts for the species have been restricted to the Sahamalaza Peninsula but there are unstudied and unprotected populations farther inland. The dearth of information regarding the transition between E. flavifrons and its parapatric sister species, the Vulnerable black lemur Eulemur macaco, and the possibility of a hybrid population complicates conservation planning for both species. We surveyed 29 forest fragments across both species’ ranges to investigate the boundary between the taxa, whether hybrids persist, and the threats to lemurs in the region. We found E. flavifrons in six fragments and E. macaco in 17. We never observed E. flavifrons and E. macaco in the same location and we found no conclusive evidence of hybrids. Three fragments in which E. flavifrons was present were north of the Andranomalaza River, which had previously been considered the barrier between the two species. Based on these observations and a literature review, we provide updated ranges, increasing the extent of occurrence (EOO) of E. flavifrons by 28.7% and reducing the EOO of E. macaco by 44.5%. We also evaluate the capacity of protected areas to conserve these lemurs. We recommend additional surveys and the implementation of an education programme in this region to help conserve both species.