Factors influencing the success of capturing European brown bears with foot snares

Management of free-ranging wildlife may include the capture of animals, with the implication that the capture process is optimized, both logistically and economically and in a way that avoids animal suffering, injury or accidental mortality. Studies targeting the optimization of trapping techniques are scarce, especially when focusing on large European mammals. Therefore, to fill this knowledge gap, we aimed to evaluate key factors that help determine brown bear capture success. This was done by analysing a complete data set from 23 years of capturing free-living Eurasian brown bears in Croatia by using Aldrich-type foot snares. Results showed significantly higher capture efficiency when traps were located at permanent feeding sites when compared to temporary feeding sites. Also, the use of a trail trap design was significantly more efficient in capturing bears than using a cubby set. Finally, results showed that trapping was more efficient when we bait the traps more frequently and when we implemented longer trap-sessions, with at least 14 days.

Continuous Flow Labeling and In-Line Magnetic Separation of Cells

There is an identified need for point-of-care diagnostic systems for detecting and counting specific rare types of circulating cells in blood. By adequately labeling such cells with immunomagnetic beads and quantum dots, they can be efficiently collected magnetically for quantification using fluorescence methods. Automation of this process requires adequate mixing of the labeling materials with blood samples. A static mixing device can be employed to improve cell labeling efficiency and eliminate error-prone laboratory operations. Computational fluid dynamics (CFD) were utilized to simulate the flow of a labeling-materials/blood mixture through a 20-stage in-line static mixer of the interfacial-surface-generator type. Optimal fluid mixing conditions were identified and tested in a magnetic bead/tumor cell model, and it was found that labeled cells could be produced at 1.0 mL/min flow rate and fed directly into an in-line magnetic trap. The trap design consists of a dual flow channel with three bends and a permanent magnet positioned at the outer curve of each bend. The capture of labeled cells in the device was simulated using CFD, finite-element analysis and magnetophoretic mobility distributions of labeled cells. Testing with cultured CRL14777 human melanoma cells labeled with anti-CD146 1.5 μm diameter beads indicated that 90 ± 10% are captured at the first stage, and these cells can be captured when present in whole blood. Both in-line devices were demonstrated to function separately and together as predicted.

Generation of scalable cancer models by combining AAV-intron-trap, CRISPR/Cas9, and inducible Cre-recombinase

Scalable isogenic models of cancer-associated mutations are critical to studying dysregulated gene function. Nonsynonymous mutations of splicing factors, which typically affect one allele, are common in many cancers, but paradoxically confer growth disadvantage to cell lines, making their generation and expansion challenging. Here, we combine AAV-intron trap, CRISPR/Cas9, and inducible Cre-recombinase systems to achieve >90% efficiency to introduce the oncogenic K700E mutation in SF3B1, a splicing factor commonly mutated in multiple cancers. The intron-trap design of AAV vector limits editing to one allele. CRISPR/Cas9-induced double stranded DNA breaks direct homologous recombination to the desired genomic locus. Inducible Cre-recombinase allows for the expansion of cells prior to loxp excision and expression of the mutant allele. Importantly, AAV or CRISPR/Cas9 alone results in much lower editing efficiency and the edited cells do not expand due to toxicity of SF3B1-K700E. Our approach can be readily adapted to generate scalable isogenic systems where mutant oncogenes confer a growth disadvantage.

Detection and monitoring of Drosophila suzukii in raspberry and cherry orchards with volatile organic compounds in the USA and Europe

Spotted wing drosophila (SWD) causes significant economic loss in fruit crops to growers worldwide. There is immediate need for efficacious and selective monitoring tools that can detect infestations early. Previously, volatile organic compounds derived from apple were studied and a quinary chemical component blend (QB) was identified as the key SWD attractant in a blueberry orchard in the United States. This study’s aim was to determine whether previously observed QB efficacy, selectivity, and early detection levels could be attained within raspberry and cherry fields in the USA and Europe. Results demonstrated that sticky trap baited QB dispenser provided earlier SWD detection potential than the usually adopted apple cider vinegar (ACV) trap. The number of SWD captured/trap by QB baited trapping systems was significantly lower than that of the ACV trap. However, percent SWD/trap of QB baited traps was same within cherry. Lower non-target capture will save farmer/grower’s labor and time allocated to traps installation and drosophila species identification. Within the USA, SWD selectivity of QB baited liquid traps was consistently greater than sticky trap in raspberry field, suggesting that the QB dispenser can be an alternative to the standard ACV lure and that trap design could improve selectivity further.

Liquid Baits with Oenococcus oeni Increase Captures of Drosophila suzukii

The spotted-wing drosophila (SWD), Drosophila suzukii Matsumura (Diptera: Drosophilidae), native to Eastern Asia, is an invasive alien species in Europe and the Americas, where it is a severe pest of horticultural crops, including soft fruits and wine grapes. The conventional approach to controlling infestations of SWD involves the use of insecticides, but the frequency of application for population management is undesirable. Consequently, alternative strategies are urgently needed. Effective and improved trapping is important as an early risk detection tool. This study aimed to improve Droskidrink® (DD), a commercially available attractant for SWD. We focused on the chemical and behavioral effects of adding the bacterium Oenococcus oeni (Garvie) to DD and used a new trap design to enhance the effects of attractive lures. We demonstrate that microbial volatile compounds produced by O. oeni are responsible for the increase in the attractiveness of the bait and could be later utilized for the development of a better trapping system. Our results showed that the attractiveness of DD was increased up to two-fold by the addition of commercially available O. oeni when combined with an innovative trap design. The new trap-bait combination increased the number of male and especially female catches at low population densities.

Non-resonant power-efficient directional Nd:YAG ceramic laser using a scattering cavity

Non-resonant lasers exhibit the potential for stable and consistent narrowband light sources. Furthermore, non-resonant lasers do not require well-defined optics, and thus has considerably diversified the available types of laser gain materials including powders, films, and turbid ceramics. Despite these intrinsic advantages, the practical applications of non-resonant lasers have been limited so far, mainly because of their low power efficiency and omnidirectional emission. To overcome these limitations, here we propose a light trap design for non-resonant lasers based on a spherical scattering cavity with a small entrance. Using a porous Nd3+:YAG ceramic, directional laser emission could be observed with significant enhancements in the slope efficiency and linewidth (down to 32 pm). A theoretical model is also developed to describe and predict the operation characteristics of proposed non-resonant laser.

A Review of Terrestrial and Canopy Malaise Traps

Malaise traps are important tools for the large-scale collection of arthropod taxa. Here, an extensive review of the history and literature concerning Malaise and canopy traps is given. This review highlights how trap design and placement can affect trap catch, which will help researchers to make more informed choices when planning research endeavors. Additionally, terrestrial and canopy-style Malaise traps are compared to each other and other types of arthropod traps.

Which Pitfall Traps and Sampling Effort to Choose to Evaluate Cropping System Effects on Spider and Carabid Assemblages?

In arable agroecosystems, arthropod communities often have a reduced abundance and diversity, which represents a challenge for sampling techniques needed to detect small differences among these simplified communities. We evaluated the suitability of pitfall traps for comparing the effects of cropping systems on arthropod communities. In a field experiment, we compared the effects of two pitfall trap diameters, the type of preserving fluid and the sampling effort on three metrics (activity density, taxonomic richness, and community weighted mean [CWM] of body size) for carabids and spiders. Trap size affected the observed composition of communities, with large traps yielding a higher proportion of spiders, and a higher richness and CWM body size for both taxa. The type of preserving fluid had a weaker effect. Simulations with various sampling efforts showed that only very different communities could be distinguished with less than 10 traps per field or less than 30 field replicates. Fewer traps were required to find differences between cropping systems for body size than for other metrics. Carabid activity density and body size, and spider genus richness, were the variables better distinguishing between cropping systems with the smallest sampling effort. A high sampling effort was required for comparing activity density and richness across cropping systems. Selection of the most appropriate trap design, metrics, and crops are the main factors for optimizing the trade-off between sampling effort and the ability to detect arthropod community responses to habitat management.