Smooth bromegrass (Bromus inermis Leyss.) is an introduced, perennial, cool-season invasive grass that has invaded native rangelands in the Great Plains. Defoliation at specific growth stages may reduce the abundance of B. inermis but information is limited about when this should occur. Between 2018 and 2020 we assessed how defoliation at four different phenological stages influenced the amount of outgrowth on B. inermis tillers near Mandan, North Dakota, USA. In three replicated plots we evaluated axillary buds, tillers, and rhizome outgrowth. Each year, 10 tillers per plot were defoliated at a height of 5 cm at each of the following phenological stages: 1) once in the vegetative stage; 2) twice in the vegetative stage, 3) once in the elongation stage, 4) once in the reproductive stage, and an undefoliated control. Individual tillers were collected in the fall following defoliation and processed in the laboratory. The total number of crown positions were determined for each tiller and outgrowth (tillers and rhizomes) and number of axillary buds were counted on each tiller. A double staining technique was used to determine active, dead and dormant axillary buds. Tillers defoliated twice in the vegetative stage had less outgrowth per tiller than tillers defoliated once in the reproductive stage or the undefoliated controls (new outgrowth of 1.2, 2.2, and 1.8 per tiller for twice vegetatively, reproductive and control respectively). Results show that defoliating tillers in the elongation or reproductive stage resulted in nearly complete tiller mortality. Our data suggest managers who wish to reduce B. inermis abundance should focus on defoliating it twice in the vegetative stage and avoid defoliating B. inermis in the reproductive stage to limit outgrowth.

Drawing on examples and lessons learned from an array of the author’s collaborative exhibit projects, this essay offers a model for making exhibits that a novice can adopt and adapt in a variety of contexts.

The effect of a horizontal magnetic field on heat transport and flow structures in vertical liquid metal convection (Prandtl number $Pr \approx 0.03$) is investigated experimentally. The experiments are carried out for Rayleigh numbers in the range of $1.48 \times 10^6 \leqslant Ra \leqslant 3.54 \times 10^{7}$ and Chandrasekhar numbers in the range of $2 \times 10^2 \leqslant Q \leqslant 1.86 \times 10^6$, as well as for the non-magnetic case ($Q=0$). Measurements of the heat transport show a rise in the Nusselt number at low and moderate magnetic field strengths up to an optimum value of $Q$, before a further increase in the magnetic field leads to a decrease in the transport properties. By applying simultaneous velocity and temperature measurements, we are able to identify three different oscillatory flow regimes for $10^{-5}\lt Q/Ra \lt 0.5$ and assign them to the respective heat transfer characteristics. In the range $10^{-5}\gt Q/Ra\gt 10^{-3}$, first evidence of a transition to anisotropic flow structures caused by the magnetic field is visible. Two strongly oscillatory regimes are identified, where the energy is either distributed around a dominant frequency ($10^{-3}\gt Q/Ra\gt 10^{-2}$), or strongly concentrated on a single frequency ($10^{-2}\gt Q/Ra\gt 0.5$). The dominating frequency increases with the Rayleigh number according to $Ra^{0.71\pm 0.02}$. This flow structure based regime separation correspond to changes of both the heat transfer through the Nusselt number and mass transfer through the Reynolds number.

The classification of acacias has gone through recent upheaval. The latest phylogenies indicate that Acacia sensu stricto is only relatively distantly related to the species with which it was once grouped. Its sister group is the monospecific Paraserianthes. This study concerns P. lophantha subsp. lophantha, a species from SW Western Australia that is widely invasive. Both genera have seeds with physical dormancy (PY) and a lens-type water gap. Seed structure, particularly that of the lens, was assessed in Paraserianthes and compared with Acacia. Seed batch viability was almost 100%, all seeds had PY and average seed mass was 73 mg. The seed coat and the embryo made almost equal contributions to seed mass, indicating a substantial seed coat. Average testa (410 µm) and palisade layer (163 µm) thicknesses were greater than in most investigated Acacia species. Unpopped lenses were small (0.11 mm2, about 0.15% of the seed surface area). With a 1 min boiling water treatment, the lens detached from the seeds. The palisade cells of the lens were about 100% larger in area after detaching, which indicates that they previously were under considerable tension. With other PY-breaking treatments, the lens formed a mound or a slight change in colour occurred. The seeds of Paraserianthes lophantha had the same basic construction as most Acacia seeds, although they were relatively large and heavy, the testa made up a large proportion of the seed and the palisade cells were long. Different lens morphologies, associated with different dormancy-breaking treatments, have rarely been described.

Garnet and biotite are common minerals in and adjacent to metamorphosed massive sulphide deposits, but their trace element compositions are rarely used to explore for such ores. Both minerals are present in hydrothermal alteration zones metamorphosed to the amphibolite facies spatially related to semi-conformable massive sulphide horizons in the Paleoproterozoic Stollberg Zn-Pb-Ag-(Cu-Au) plus magnetite ore field, Bergslagen district, Sweden. The major-trace element chemistry of garnet in metamorphosed altered rocks, mafic dykes and sulphide mineralisation shows that garnet in garnet-biotite alteration (and high-grade sulphides) is Fe-rich (almandine ratio > 0.5) whereas garnet in skarn and garnet-pyroxene alteration contains significantly higher amounts of Ca and Mn and elevated concentrations of Co, Cr, Ga, Ge, Sc, Ti, V, Y, Zn and the heavy rare earth elements (HREEs). Chondrite-normalized REE patterns of garnet in all rock types are depleted in light REEs and enriched in heavy REEs. Garnet in sulphide-bearing altered rocks, including garnet-biotite and garnet-pyroxene alteration, shows a strong positive Eu anomaly and the highest concentrations of Ga, Ge, Mn, Pb and Zn. Rocks more distal to sulphide mineralisation typically contain garnet that exhibits no or negative Eu anomalies and lower mean concentrations of these elements and higher concentrations of Ti. Biotite shows variable Fe/(Fe+Mg) ratios with most centred around 0.5 and enrichments in Ga, Mn, Sn, Pb and Zn in and adjacent to sulphides. This suggests that garnet and biotite can be used as a vectoring tool to ore in the Stollberg ore field and potentially for metamorphosed massive sulphides elsewhere.

Magnetohydrodynamic turbulence with Hall effects is ubiquitous in heliophysics and plasma physics. Direct numerical simulations reveal that, when the forcing scale is comparable to the ion inertial scale, the Hall effects induce remarkable cross-helicity. It then suppresses the cascade efficiency, leading to the accumulation of large-scale magnetic energy and helicity. The process is accompanied by the disruption of current sheets through the entrainment by vortex tubes or the excitation of whistler waves. Using the solar wind data from the Parker Solar Probe, the numerical findings are separately confirmed. These findings provide new insights into the emergence of large-scale solar wind turbulence driven by helical fields and Hall effects.

Codebooks—documents that operationalize concepts and outline annotation procedures—are used almost universally by social scientists when coding political texts. To code these texts automatically, researchers are increasingly turning to generative large language models (LLMs). However, there is limited empirical evidence on whether “off-the-shelf” LLMs faithfully follow real-world codebook operationalizations and measure complex political constructs with sufficient accuracy. To address this, we gather and curate three real-world political science codebooks—covering protest events, political violence, and manifestos—along with their unstructured texts and human-coded labels. We also propose a five-stage framework for codebook-LLM measurement: Preparing a codebook for both humans and LLMs, testing LLMs’ basic capabilities on a codebook, evaluating zero-shot measurement accuracy (i.e., off-the-shelf performance), analyzing errors, and further (parameter-efficient) supervised training of LLMs. We provide an empirical demonstration of this framework using our three codebook datasets and several pre-trained 7–12 billion open-weight LLMs. We find current open-weight LLMs have limitations in following codebooks zero-shot, but that supervised instruction-tuning can substantially improve performance. Rather than suggesting the “best” LLM, our contribution lies in our codebook datasets, evaluation framework, and guidance for applied researchers who wish to implement their own codebook-LLM measurement projects.

This study explores the complexities of land formalization and the ongoing struggles for land justice among the Îgembe of the Kenyan Central Highlands. It begins by reviewing the prevailing argument that the formalization of land rights contributes to socio-economic growth and tenure security in the Global South. The study highlights the relational nature of rights in different contexts in African countries and discusses both the evidence and the scepticism surrounding land formalization. While the aim was to restore land rights to local people from colonial powers, the introduction of land registration in Kenya allowed political elites to appropriate land. The Îgembe people, having experienced land injustice in their local socio-historical context, have navigated the complexities of land disputes using indigenous institutions alongside state legal processes. I argue that success in land disputes often comes from a combination of personal courage and the use of both indigenous and formal legal frameworks.