The effect of the electric trapping field on state-selective loading of molecules into rf ion traps

Trapped molecular ions in pure rovibronic states are desirable in experiments ranging from cold chemistry to searches for physics beyond the Standard Model. Resonance-enhanced multiphoton ionisation (REMPI) can be used to prepare molecular ions in specific internal states with high fidelities. However, in the presence of electric fields, ionisation spectra exhibit frequency shifts and the ionisation thresholds are broadened. For this reason, REMPI studies are normally conducted in low and highly homogeneous electric fields, whereas the operating principle of rf ion traps requires electric fields that vary in space and time. In order to investigate the impact of this on the state-selectivity of REMPI in ion traps, we have simulated the expected broadening of the ionisation threshold under various operating conditions of a typical linear Paul trap. In many cases, the width of the ionisation threshold exceeds the separation between rotational energy levels, preventing state-selective ionisation. Careful choice of the trapping and laser parameters during loading can reduce this broadening, enabling state-selective ionisation in some instances. Where this strategy is not sufficient, the broadening can be reduced further by rapidly switching the trapping voltages off and on again during loading. This has been demonstrated experimentally for a Coulomb crystal of $$^{40}\hbox {Ca}^+$$ 40 Ca + ions without descrystallising it.

Non-volant mammal inventory of western Mongolian-Manchurian Grassland Ecoregion: a biogeographic crossroad worth preserving

The extensive Mongolian grasslands hosts a high variety of micro-habitats which wildlife uses as corridors that enable species to expand their range. Between May 2017 and March 2018, we conducted an intensive survey in the Mongolian-Manchurian Grassland Ecoregion using camera trapping, field transects, live trapping and opportunistic observations, in mountain outcrops, grass steppe and sand dune habitats across seasons. Our aim was to compile the first satisfactory inventory of mammals based on scientific methods for a diverse landscape in the Mongolian provinces of Tov and Dundgovi. Furthermore, our research seeks to fill in knowledge gaps on species distribution and range expansions in the endangered west Mongolian-Manchurian Grassland ecoregion and identify biodiversity hotspot areas encompassed in this biogeographic crossroad. We recorded 31 species of non-volant mammals, including a globally Endangered species and two Near Threatened species, according to the IUCN Red List, and three species listed in Appendix II of CITES.

Please come again: attractive bait augments recapture rates of capture-naïve snowshoe hares

ContextCapture–recapture sampling is one of the most commonly used methods for monitoring population demographics and is needed in a wide variety of studies where repeat sampling of individuals is desired. Although studies employing capture–recapture methods often assume unbiased sampling, it is well established that inherent capture biases can occur with these methods, including those related to baits. Reducing sources of sampling bias and augmenting recapture reliability is necessary for capture-dependent studies. However, few studies have examined the efficacy of baits on individuals with variable capture experience. AimsTo investigate the use of an attractant-augmented bait in enhancing capture–recapture probabilities for snowshoe hares (Lepus americanus). MethodsTo examine the efficacy of different attractant-augmented bait types, a variety of baits were created, with bait preference tested on a captive hare. Because a strawberry jam-based bait was preferentially consumed (in comparison with other tested baits), the effectiveness of this attractant in enhancing capture–recapture rates was subsequently examined in wild hares, using paired live-trapping field trials (n=6 trials). ResultsLive-trapping trials showed that although overall hare capture rates were not affected by the use of a jam-based bait, recaptures were 33.1% higher in capture-naïve individuals exposed to our attractant. This was not the case for hares with prior capture experience; such hares had an equal likelihood of being recaptured regardless of the bait type used. ConclusionsThe tested attractant improved recapture rates of capture-naïve hares. ImplicationsStudies relying on high recapture rates should use methods that maximise recapture rates wherever possible, including the use of baits that may augment recaptures in capture-naïve animals.

Gap analysis and implications for seasonal management on a local scale

Background Identifying biodiversity hotspots on a local scale, using multiple data sources, and ecological niche modeling, has the potential to contribute to more effective nature reserve management. Methods In this study, we used infrared-triggered camera trapping, field surveys, and interviews to create a dataset on the distribution of species (mammals and birds) in Hebei Wulingshan Nature Reserve (Hebei Province, China). Results We identified 101 species (14 orders, 38 families), 64 of which (2,142 effective records) were selected for environmental niche modeling. All results were reclassified into three groups: “priority areas” (areas including the potential distributions of over 80% of species), “important areas” (those with 50% of species), and “normal areas” (all other areas). Our results show that priority areas (1.31–1.82 km2) and important areas (7.73–21.44 km2) for conservation were mainly covered by the core and experimental zones of the reserve; additionally, a kilometer-wide margin around the outside of the nature reserve seems to be important to maintaining biodiversity. Discussion We close by suggesting some actions for enhancing conservation of biodiversity in the reserve, including monitoring, strengthen law enforcements, introducing popular science, and co-operating with local people.

Seasonal Patterns of Protoschinia scutosa (Lepidoptera: Noctuidae) Migration Across China’s Bohai Strait

The spotted clover moth, Protoschinia scutosa (Denis & Schiffermüller) (Lepidoptera: Noctuidae), is an important polyphagous pest that is widely distributed in the world. P. scutosa overwinters as pupae in agricultural soils in Northern China. Yet, it is unclear whether P. scutosa also engages in seasonal migration over mid- to long-range distances. In this study, we employ light trapping, field surveys, and ovarian dissection of captured adults over a 2003–2015 time period to assess P. scutosa migration in Northern China. Our work shows that P. scutosa migrates across the Bohai Strait seasonally; the mean duration of its windborne migration period was 121.6 d, and the mean trapping number was 1053.6 moths. Nightly catches of P. scutosa were significantly different between months, but the differences between years were not significant. During 2009–2011 and 2013, the monthly proportion of migrating females (65.5%) was significantly higher than that of males and showed no difference between months. In May to June, the majority of females (May: 63.0%; June: 61.1%) were mated individuals with relatively high level of ovarian development; however, in August and September, most females were unmated. The mean proportion of mated females was significantly different across months but did not differ between years. The results of long-term searchlight trapping and ovarian dissection indicate that P. scutosa exhibits a seasonal characteristic of typical population dynamics and reproductive development of migratory insects. Our work sheds light upon key facets of P. scutosa ecology and facilitates the future development of pest forecasting systems and pest management schemes.

Условия финитности движения иона в электростатической ловушке с разделением переменных в параболических координатах

Refined conditions for the confinement of ion motion in the trapping field admitting separation of variables in parabolic coordinates are formulated. The simplicity of equations allows some results to be obtained in an elementary form, which makes it possible to consider the issue of particle confinement in these systems in detail.