Trap Construction Research Articles

Are phlebotomine sand flies (Diptera: Psychodidae) really attracted to UV-light sources?

Phlebotomine sand flies are the sole confirmed vector of leishmaniosis, a group of endemic and re-emerging diseases in southern European countries such as Spain. Light traps are the major surveillance method currently being employed. Nevertheless, color light attraction by sand flies remains mostly unknown. Following prior research, the effect of UV-LED light sources, and its synergic effect with different color lights has been evaluated employing a modified Flebocollect (FC) light trap model. Results suggest that female Phlebotomus perniciosus sand flies are more attracted to a FC trap lured with the combination of blue and UV LED light sources than commercial CDC (Center for Disease Control and prevention) traps (Bonferroni post-hoc test; p < 0.08; blue/UV mean = 0.50; CDC mean = 0.13), while the combination of red and UV modified-traps excel in capturing Sergentomyia minuta sand flies (Bonferroni post-hoc test; p < 0.04; blue/UV mean = 1.19; CDC mean = 0.66). However, based on our prior studies, incorporating UV light sources into sand fly traps does not seem to enhance their attractiveness, as it has not resulted in higher capture rates. These findings contribute to understanding how sand flies’ vision and light color detection is. Further research is recommended to standardize trap construction procedures and explore variations in different endemic regions according to different sand fly species.

Revamping Triboelectric Output by Deep Trap Construction.

High output performance is critical for building triboelectric nanogenerators (TENGs) for future multifunctional applications. Unfortunately, the high triboelectric charge dissipation rate has a significant negativeimpact on its electrical output performance. Herein, a newtribolayer is designed through introducing self-assembled molecules with large energy gaps on commercial PET fibric toform carrier deep traps, which improve charge retention while decreasing dissipation rates. The deep trap density of the PET increases by two orders of magnitude, resulting in an 86% reduction in the rate of charge dissipation and a significant increase in the charge density that can be accumulated on tribolayer during physical contact. The key explanation is that increasing the density of deep traps improves the dielectric's ability to store charges, making it more difficult for the triboelectric charges trapped by the tribolayer to escape from the deep traps, lowering the rate of charge dissipation. This TENG has a 1300% increase in output power density as a result of altering the deep trap density, demonstrating a significant improvement. This work describes a simple yetefficient method for building TENGs withultra-high electrical output and promotes their practical implementation in the sphere of the Internet of Things.

EVALUATING POTENTIAL BIODEGRADABLE TWINE FOR USE IN THE BLUE SWIMMING CRAB COLLAPSIBLE POTS

This study addresses the global issue of lost fishing gear, specifically traps and pots, which rank second regarding gear lost in marine environments. These traps often contain synthetic fibers that decompose slowly, producing long-lasting ghost fishing. To mitigate this problem, the study explores using biodegradable materials in trap construction. The research focuses on assessing biodegradable materials' physical and mechanical properties and how immersion affects them. Field surveys and sample immersion were conducted at Kejawanan Fishing Port Cirebon, with subsequent testing at IPB University. The study compared three natural materials: cotton, agel, and hemp twines. The cotton twine stood out with its soft texture compared to the rougher agel and hemp twines. Regarding elongation, cotton 20.76% outperformed agel 13.70% and hemp 4.42%. Sequential breaking strength tests revealed cotton's superior strength at 9.84 kgf over agel at 3.61 kgf and hemp at 2.72 kgf, even after immersion. These findings indicate that cotton twine is a viable biodegradable alternative to synthetic twines in blue swimming crab pot fishing. By adopting such materials, fishermen can reduce the environmental impact of lost gear and contribute to more sustainable fishing practices.

Wind impairs pit trap construction and hunting success in a pit‐building predator

AbstractAnimals require a set of abiotic conditions to survive and reproduce. When one of these requirements is not met, the animal's performance is impaired. The most often studied abiotic factor is temperature but less is known on other such factors. We examined, here, the effect of wind on the hunting performance of pit‐building predators, insect larvae that dig pit traps in loose soil to hunt arthropod prey. We used wormlions (Diptera: Vermileonidae) as a case study. Pit‐building predators depend on their immediate environment for efficient pit construction and maintenance. For example, they require dry suitable substrate (loose soil) comprised of particles of a specific size range. Because wind blows loose soil and impairs pit construction and maintenance, we expected strong negative effects of wind on pit design and hunting success. Wind destroyed both artificial pit traps and wormlion‐dug pits by moving sand into the pits and reducing their slopes—an important parameter of pits in terms of prey capture. Wormlions also attempted less frequently to attack the prey when the wind was blowing compared to the control and, among the wormlions responding, such response took place later, allowing the prey to escape. We expected wormlions to relocate away when exposed to the wind, but this did not hold true. This result is in line with the generally low relocation rate in wormlions. We suggest that wind has strong negative effects on the performance of pit builders in nature. Sites that provide at least partial protection from wind should be preferred for pit establishment.

Targeted disruption of Rab1a causes early embryonic lethality.

Guanosine nucleotide diphosphate (GDP) dissociation inhibitor 2 (GDI2) regulates the GDP/guanosine triphosphate (GTP) exchange reaction of Rab proteins by inhibiting the dissociation of GDP and the subsequent binding of GTP. The present study aimed to determine the function of Rab1a in vivo, and thus generated mice with a trapped Rab1a gene. It was demonstrated that Rab1a is essential for embryonic development. It was also found that one functional Rab1a allele was sufficient for development in a heterozygous murine embryo, whereas a double mutant led to embryonic lethality. The dissection of uteri on embryonic day (E)10.5-14.5 yielded no homozygous embryos, indicating that homozygotes die between E10.5 to E11.5. The gene trap construct contains a β-galactosidase/neomycin reporter gene, allowing for heterozygotes to be stained for β-galactosidase to determine the tissue-specific expression of Rab1a. Rab1a was found to be highly expressed in the small intestine of both adult mice and embryos, although its expression levels were low in the brains of embryos. Moreover, there was no significant change in cytokine production and survival in wild-type and heterozygous Rab1a+/− mice following a challenge with lipopolysaccharide. On the whole, the present study demonstrates that the disruption of the Rab1a gene causes embryonic lethality and homozygotes die between E10.5 and E11.5, suggesting that Rab1a is essential for the early development of mouse embryos.

A novel gene trap line for visualization and manipulation of erbb3b+ neural crest and glial cells in zebrafish

Glia are a diverse and essential cell type in the vertebrate nervous system. Transgenic tools and fluorescent reporter lines are critical resources to investigate how glial subtypes develop and function. However, despite the many lines available in zebrafish, the community still lacks the ability to label all unique stages of glial development and specific subpopulations of cells. To address this issue, we screened zebrafish gene and enhancer trap lines to find a novel reporter for peripheral glial subtypes. From these, we generated the gSAIzGFFD37A transgenic line that expresses GFP in neural crest cells and central and peripheral glia. We found that the gene trap construct is located within an intron of erbb3b, a gene essential for glial development. Additionally, we confirmed that GFP+ ​cells express erbb3b along with sox10, a known glial marker. From our screen, we have identified the gSAIzGFFD37A line as a novel and powerful tool for studying glia in the developing zebrafish, as well as a new resource to manipulate erbb3b+ ​cells.

Past thermal conditions affect hunting behaviour in larval antlions.

Some sit-and-wait predators, such as antlion larvae, construct traps to capture passing prey. The location of these traps depends on many abiotic and biotic factors, including temperature and the presence of conspecifics, which probably stimulate behaviours that minimize the costs and maximize the benefits of trap building. Here, we exposed second instar antlion larvae to elevated temperatures of 25°C (mild treatment) or 31°C (harsh treatment) for one month and then transferred them to common conditions (20°C) to examine the effects of previous thermal treatment on aggregation tendency and trap size. We predicted that antlions that experienced harsh conditions would subsequently increase the neighbouring distance and trap diameter to reduce competition with conspecifics and improve prey capture success, compensating for past conditions. In contrast with these predictions, antlions exposed to harsh conditions displayed a trend in the opposite direction, towards the decreased neighbouring distance. Furthermore, some of these antlions also built smaller traps. We discuss possible reasons for our results. The effects of previous thermal exposure have rarely been considered in terms of trap construction in antlions. Described effects may possibly apply to other sit-and-wait predators and are significant considering that many of these predators are long-lived.

Plasticity in extended phenotypes: how the antlion Myrmeleon crudelis adjusts the pit traps depending on biotic and abiotic conditions

Abstract The physical structures built by animals are considered extended phenotypes that reflect how organisms make decisions and deal with changes in their biotic and abiotic environment. We summarize the results of several studies on Myrmeleon crudelis, a neuropteran larva that digs pit-traps in the soil to capture small arthropods (mostly ants) in the tropical dry forests of Costa Rica. Specifically, we showed how this species responds to varying biotic and abiotic conditions with changes in the design and/or location of its pit traps. Several experiments and field comparisons indicate that: 1) antlions adjust the pit design according to the abundance and type of prey. When prey is scarce, antlions increased trap diameter, an architectural adjustment that enhances the probability of prey encounter. Antlions that experienced high prey abundance, but the prey easily escaped, then increased pit depth, an adjustment that increases the chance of prey retention; 2) soil compaction strongly reduced pit-trap size and abundance; 3) antlions preferred soils with high proportion of fine-particle size to build pits. In fine-grained soil, pit-traps are larger and more efficient to capture prey than traps in coarse-grained soils; and 4) pit-traps may also be affected through indirect effects of soil structure and vegetation cover. Areas with fine-soil presented less plant cover, and plant cover could be beneficial for antlions because it acts as a shelter against direct sunlight and rainfall, or it may represent a cost because it is a source of leaflitter falling in the pits. The works summarized here how trap-building predators can exhibit considerable flexibility in trap construction in response to various biotic and abiotic factors, emphasizing how the study of extended phenotypes can be a useful approach to better understand the flexibility of foraging behaviors.

Wild boar behaviour during live-trap capture in a corral-style trap: implications for animal welfare

BackgroundWildlife traps are used in many countries without evaluation of their effect on animal welfare. Trap-capture of wild animals should minimise negative effects on animal welfare, irrespective of whether the animals are trapped for hunting, research, or management purposes. Live-trap capture of wild boar (Sus scrofa) followed by killing inside the trap by gunshot is a recently introduced but disputed hunting method in Sweden. Approval of trap constructions is based on gross necropsy findings of 20 trapped and shot wild boars. For improved animal welfare evaluation, our aim was to study wild boar behaviour during live-trapping in a 16 m2 square corral-style trap. Behavioural assessments were conducted after filming 12 capture events of in total 38 wild boars (five adults, 20 subadults, 13 piglets). Selected behavioural traits were compared with pathological changes (trap-related lesions) found at necropsy of the 20 subadults, to determine if these variables were useful proxies of capture-induced stress in wild boar.ResultsThe wild boars spent less time resting in the evening than in the night and morning. Using Friedman’s ANOVA, there was an overall difference in the time spent foraging. However, we only found a difference between the evening and morning in the Wilcoxon matched pairs test after the Sequential Bonferroni correction, where the wild boars spent more time foraging in the evening than in the morning. Single captured individuals showed more escape behaviours and reacted more strongly to external stimuli than individuals captured in a group. It was more common for animals to charge against the mesh walls of the trap upon human approach compared to upon initial capture when the trap door closed. Trap-related pathological findings due to trauma were documented in 13 of the 20 subadults that were necropsied. Behavioural alterations indicative of capture-induced stress (e.g. charging into the trap walls) were documented in trapped wild boars with no or minor physical injuries (e.g. skin abrasions, subcutaneous haemorrhage).ConclusionsBehavioural assessment provided valuable information for determination of capture-induced stress in wild boar when evaluating live-trapping in a corral-style trap, whereas pathological evaluation through necropsy did not fully reflect the animal welfare aspects of live-trapping. We emphasize the inclusion of species-specific behavioural data assessment for evaluation of capture-related stress during live-trapping and for testing of new trap constructions before approval.

Trapping Fruit Flies: A Guided-Inquiry Lab Approach to Teaching Biology to Nonmajors

Current trends in education include offering students authentic experiences that generate broad interest, develop their cognitive flexibility, and prepare them to be scientifically literate members of society. We present a three-part guided-inquiry lab that gives students practice applying the scientific method to control fruit fly outbreaks and reinforces concepts related to behavioral and sensory biology. This activity was designed and tested at a four-year university but can be modified for high school courses. Students are “employed” by the fictional Fruit Fly Trap Company to design a device to maximize capture of female fruit flies using environmentally friendly lures. During this lab, students collaborate to conduct literature searches, ask research questions, develop hypotheses, design experiments, collect and analyze data, and present findings in a short oral presentation. In our implementation of this module in a biology class for nonmajors in fall 2017, over 50% of students reported that the literature research, scent experiments, trap construction, trap testing, and PowerPoint presentation were extremely effective in teaching science process and biological problem-solving skills. Over 70% of our students rated the practical, hands-on elements of the activity as enjoyable. Overall, students generally enjoyed the lab and reported positive impacts on their learning.

Oncostatin M Is a Novel Niche Factor That Restrains Hematopoietic Stem Cell Mobilization in Response to G-CSF and CXCR4 Antagonist Plerixafor

Granulocyte colony-stimulating factor (G-CSF) and the CXCR4 chemokine receptor antagonist Plerixafor are used to mobilize hematopoietic stem and progenitor cells (HSPC). However, in the autologous setting, prior chemotherapy and radiotherapy impair HSPC mobilizing response to G-CSF and Plerixafor thereby precluding autologous HSC transplantation. We now demonstrate in mice that oncostatin M (OSM) production in the bone marrow (BM) is dramatically increased in response to G-CSF and that OSM counteracts the mobilizing effect of G-CSF and Plerixafor indirectly through the BM stroma. Indeed, by immunohistochemistry, a 4-day G-CSF treatment strongly increased OSM protein expression in cell clusters containing F4/80+ macrophages in the endosteal and central region of the mobilized BM. OSM concentration was 7-fold higher in BM fluids of G-CSF mobilized mice compared to control mice as measured by ELISA. To investigate OSM effects on HSPC mobilization, C57BL/6 mice (WT) and mice lacking the OSM receptor gene (OSMR-/-) were treated with 125 μg/kg human G-CSF bidaily for 2-6 days and/or Plerixafor (10 mg/kg) one hour before harvest. Absence of OSMR increased HSPC mobilization with a 4-fold increase in colony forming cells (CFC), phenotypic Lin-Kit+Sca1+ HSPC (LKS+ cells) and LKS+Flt3-CD48-CD150+ HSC into the blood at days 2 and 4 of G-CSF treatment and increased accumulation of HSPC and HSC in the spleen of OSMR-/- mice at day 6 of G-CSF treatment. In a competitive repopulation assay with serial dilutions of mobilized blood, deletion of OSMR gene enhanced ≈4-fold mobilization of functional reconstituting HSC in response to G-CSF as shown by Poisson's distribution analysis. HSPC mobilization in response to Plerixafor was also significantly enhanced with a doubling of CFC, HSPC and HSC into the blood of OSMR-/- mice compared to WT. OSMR gene deletion also significantly enhanced HSPC mobilization (3-fold) in response to G-CSF plus Plerixafor combination, the most effective mobilization regimen currently approved. To further demonstrate that endogenous OSM restrains HSPC mobilization in response to G-CSF, we produced a recombinant mouse OSM-trap, a dimeric protein chimera made of the extracellular domain of mouse OSMR and mouse gp130 fused with a mutant Fc fragment of mouse IgG2a. Co-administration of this OSM-trap together with G-CSF also increased HSPC and HSC mobilization into the blood in response to G-CSF compared to mice treated with G-CSF and control trap construct. This negative effect of endogenous OSM on HSPC mobilization was indirectly mediated by BM stromal cells. qRT-PCR on BM myeloid and stromal cells sorted from steady-state or mobilized mice showed that Osm mRNA is mostly expressed by CD11b+F4/80+CD169+VCAM1+ macrophages and CD11b+F4/80-Ly6G+ neutrophils. In sharp contrast, Osmr mRNA was undetectable in any sorted BM leukocyte population, but abundantly expressed by CD45-Lin-CD31+Sca1+CD105+ endothelial and CD45-Lin-CD31-CD51+PDGFRα+/-Sca-1+/- mesenchymal progenitor cells. OSMR protein was expressed by vascular beds in the BM as detected by IHC. Confirming the indirect effect of OSM, we found that recombinant OSM had no effect on HSPC chemotaxis in response to CXCL12, or HSPC adhesion to immobilized VCAM-1 or selectins in vitro. However, HSPC freshly isolated from the BM of OSMR-/- mice had enhanced chemotaxis in response to CXCL12 compared to HSPC isolated from WT mice. In conclusion, G-CSF increases OSM expression in the BM, and this appears to restrain HSPC mobilization in response to G-CSF via OSMR-expressing endothelial and mesenchymal cells that decreases HSPC responsiveness to CXCL12 gradient. Disclosures Winkler: GlycoMimetics: Patents &amp; Royalties. Levesque:GlycoMimetics: Equity Ownership.

A Long‐Term Analysis of Channel Morphology and Stream Substrates before and after Sediment Trap Construction in Michigan Trout Streams

AbstractSediment traps are commonly used to remove excess sand bedload from coldwater streams and to improve channel morphology and substrate conditions for salmonids in the Midwestern United States. However, few scientific evaluations of the rate and spatial extent of channel changes associated with sediment trapping efforts have occurred. We used a series of stream channel morphology measurements taken over a 10‐year period in five Michigan streams to show that excavation of sediment traps had only small effects on mean channel bank‐full depth, bank‐full cross‐sectional area, and bank‐full width as well as substrate composition in the streams studied. When they did occur, changes in each of these metrics occurred both upstream and downstream of—and often in close proximity to—the sediment traps. While few positive effects of sediment traps were noted, there were also no negative effects to report. The construction of sediment traps did not lead to broad‐scale widening of stream channels, and no excessive channel incision was observed in any of the study streams. Thus, concerns about typical sediment trap operations upsetting the stream‐sediment equilibrium and creating excessive down‐cutting appear to be unfounded for Michigan's low‐gradient, naturally sandy stream channels. We conclude that sediment traps are unlikely to have any large‐scale channel morphology or substrate effects that would be beneficial to stream salmonids when used as a stand‐alone habitat treatment.

An Anopheles stephensi Promoter-Trap: Augmenting Genome Annotation and Functional Genomics.

The piggyBac transposon was modified to generate gene trap constructs, which were then incorporated into the genome of the Asian malaria vector, Anopheles stephensi and remobilized through genetic crosses using a piggyBac transposase expressing line. A total of 620 remobilization events were documented, and 73 were further characterized at the DNA level to identify patterns in insertion site preferences, remobilization frequencies, and remobilization patterns. Overall, the use of the tetameric AmCyan reporter as the fusion peptide displayed a preference for insertion into the 5′-end of transcripts. Notably 183 – 44882 bp upstream of the An. stephensi v1.0 ab initio gene models, which demonstrated that the promoter regions for the genes of An. stephensi are further upstream of the 5′-proximal regions of the genes in the ab inito models than may be otherwise predicted. RNA-Seq transcript coverage supported the insertion of the splice acceptor gene trap element into 5′-UTR introns for nearly half of all insertions identified. The use of a gene trap element that prefers insertion into the 5′-end of genes supports the use of this technology for the random generation of knock-out mutants, as well as the experimental confirmation of 5′-UTR introns in An. stephensi.

Wormlions prefer both fine and deep sand but only deep sand leads to better performance.

Wormlions are small fly larvae that dig pits in loose soil to trap their prey. Similar to other trap-building predators, like spiders and antlions, they depend on the habitat structure for successful trap construction and prey catch. We examined whether sites at which wormlions are present differ in sand depth and particle size from nearby sites, at which wormlions are absent. Next, in the laboratory we manipulated both sand depth and type (fine vs. coarse) to determine their joint effect on microhabitat preference, the size of the constructed pit, wormlion movement, and their latency to respond to prey. We expected better performance by wormlions in fine and deep sand, and the sand in wormlions’ natural sites to be finer and deeper. However, in only partial agreement with our expectations, wormlion sites featured finer sand but not deeper sand. In the laboratory, wormlions preferred both fine and deep sand, and moved more in shallow and coarse sand, which we interpret as an attempt to relocate away from unfavorable conditions. However, only deep sand led to larger pits being constructed and to a faster response to prey. The preference for fine sand could, therefore, be related to other benefits that sand provides. Finally, body mass was a dominant factor, interacting with the preference for both deep and fine sand: deep over shallow sand was more favored by large wormlions and fine over coarse sand by smaller ones. Our results suggest that several factors should be incorporated when studying microhabitat selection.

Building Double-decker Traps for Early Detection of Emerald Ash Borer.

Emerald ash borer (EAB) (Agrilus planipennis Fairmaire), the most destructive forest insect to have invaded North America, has killed hundreds of millions of forest and landscape ash (Fraxinus spp.) trees. Several artificial trap designs to attract and capture EAB beetles have been developed to detect, delineate, and monitor infestations. Double-decker (DD) traps consist of two corrugated plastic prisms, one green and one purple, attached to a 3 m tall polyvinyl chloride (PVC) pipe supported by a t-post. The green prism at the top of the PVC pipe is baited with cis-3-hexenol, a compound produced by ash foliage. Surfaces of both prisms are coated with sticky insect glue to capture adult EAB beetles. Double-decker traps should be placed near ash trees but in open areas, exposed to sun. Double-decker trap construction and placement are presented here, along with a summary of field experiments demonstrating the efficacy of DD traps in capturing EAB beetles. In a recent study in sites with relatively low EAB densities, double-decker traps captured significantly more EAB than green or purple prism traps or green funnel traps, all of which are designed to be suspended from a branch in the canopy of ash trees. A greater percentage of double decker traps were positive, i.e., captured at least one EAB, than the prism traps or funnel traps that were hung in ash tree canopies.

Pitfall trap construction affects the efficacy of ground beetle counts

Ground beetles were sampled in a broadleaved deciduous forest in Kaluga Province in April–October 1995 using 90 traps grouped in 18 experimental plots. Three types of pitfall traps were used: glass jars, white plastic cups, and cylindrical containers made of transparent plastic bottles. Two types of cover put above the traps were tested: transparent and black. Altogether, 72 carabid species were found, of which only 10 species were shared by all the experimental plots: Leistus terminatus, Carabus hortensis, C. glabratus, Cychrus caraboides, Pterostichus niger, P. oblongopunctatus, P. strenuus, P. melanarius, Calathus micropterus, and Badister lacertosus. The Jaccard binary similarity index between the experimental plots amounted to 37–68% while the Bray-Curtis similarity index was 66–89%. Both the trap type and the cover color significantly affected the similarity of the species structure and species composition of the samples. Plastic cups provided the highest catches of beetles, but this was due to the most abundant species, P. oblongopunctatus. Containers provided the highest catches of C. glabratus. The total abundance was higher for the traps with transparent covers than for those with black covers. Traps with transparent covers provided significantly higher catches of L. terminatus, P. oblongopunctatus, Asaphidion flavipes, and Harpalus rufipes. An adequate assessment of the species composition of a particular habitat requires at least 30 pitfall traps.

Trap Design and Construction for High-Power Multinuclear Magnetic Resonance Experiments.

Performing multinuclear experiments requires one or more radiofrequency (RF) coils operating at both the proton and second-nucleus frequencies; however, inductive coupling between coils must be mitigated to retain proton sensitivity and coil tuning stability. The inclusion of trap circuits simplifies placement of multinuclear RF coils while maintaining inter-element isolation. Of the commonly investigated non-proton nuclei, perhaps the most technically demanding is carbon-13, particularly when applying a proton decoupling scheme to improve the resulting spectra. This work presents experimental data for trap circuits withstanding high-power broadband proton decoupling of carbon-13 at 7 T. The advantages and challenges of building trap circuits with various inductor and capacitor components are discussed. Multiple trap designs are evaluated on the bench and utilized on an RF coil at 7 T to detect broadband proton-decoupled carbon-13 spectra from a lipid phantom. A particular trap design, built from a coaxial stub inductor and high-voltage ceramic chip capacitors, is highlighted owing to both its performance and adaptability for planar array coil elements with diverse spatial orientations.

The effect of previous experience on trap construction and movement distance in a pit-building predator

Wormlion larvae are sit-and-wait predators that construct cone-shaped pits in sandy patches to capture prey. Wormlions select microhabitats that feature favorable conditions for pit construction, in a similar way to other trap-building predators, like spiders and antlions. We investigated whether wormlions exhibit an experience-based behavioral plasticity in their pit construction behavior. In a laboratory experiment, pit sizes and relocation distances were compared between larvae that experienced either a period of unfavorable conditions, i.e., surface obstacles, shallow or coarse sand, or a period of favorable conditions, i.e., clear, deep, and fine sand and were able to construct pits undisturbed. We expected that wormlions experiencing improving conditions would build larger pits than those experiencing deteriorating conditions. In addition, we expected that larvae experiencing unfavorable conditions would be less choosy in their new microhabitat and move over shorter distances. We observed a certain effect of recent experience on the trap-building behavior; however, it was not consistent among treatments. Additionally, we detected a correlation between larval body mass, relocation distance, and pit area. These findings might suggest that past experience does not influence wormlion foraging behavior in a simple manner but that different types of experience induce different behavioral responses.

THE INFLUENCE ANALYSIS OF DIFFERRENTLY CONSTRUCTED FOLDED TRAPS AND TYPES OF BAITS TO CATCH CRABS [Portunus pelagicus, (Linnaeus,1758)] IN REMBANG SEA WATERS

Blue Swimming Crab [Portunus pelagicus (Linnaeus,1758)] is one of the fishery commodities which is prospective to be exported, highly nutritious, commercial, and wholly valuable. In Kabongan lor village, Rembang, Central Java, Indonesia the fishing gear used to catch crabs is folded trap. Kabongan lor village has a small scale of captured marine resources, so it needs to be utilized further. Because of its large potency, a research need to be conducted to improve the haul. Different trap construction and type of baits is one important factor to improve it. This study was aimed to analyze the influence of the dome-folded traps construction and box-folded traps (control), and the influence of fermented mackerel, fresh mackerel, and puffer fish’s head as baits over the crabs in Rembang waters. The method applied is field experiment with six repetitions and two variables in a treatment. The data was analyzed using normality test, homogeneity test, and ANOVA test using SPSS program ver 20.00. The results showed that dome-folded traps gained more crabs compared to box-folded traps (control). Dome-folded traps gained 3 230 g of crabs, while box-folded traps gained 1 620 g. Meanwhile, the use of fresh mackerel as baits gained better crabs than fermented mackerel and puffer fish’s head (control). According to this research known that the captured crabs in which consume; fresh mackerel baits got 1 890 g of crabs, fermented mackerel got 1 500 g and 1 460 g for puffer fish’s head. The results of ANOVA test show the differences of folded traps construction with F sig value as much as 0.022 shows that Ho is accepted; while that with F sig value as much as 0.686 shows that the Ho is denied. Based on these results known that the different folded traps construction does affect to the amount of captured crabs while the differences of baits type do not.

Biomechanical evaluation of finger trap suture variants for securing catheters.

To biomechanically evaluate various finger trap patterns and suture materials for securing 5F polyvinylchloride and polypropylene catheters. In vitro prospective study. 132 finger trap constructs. Each group of constructs comprised 6 to 10 replicates each of 3 finger trap patterns tied with 2-0 glycolide-lactide copolymer (GLC), braided nylon, and monofilament polypropylene suture on 5F polypropylene and polyvinylchloride catheters. The 3 finger trap variants were of similar lengths but differed in the number of surgeon's throws included in the pattern. Constructs were tested with a universal materials testing machine to the point of failure or a maximum of 100 mm of distraction. Force and distraction data were evaluated for significance with a competing risks model. There was no difference in performance (as measured by the proportion of test failures, median distraction distance, or median force at failure or end of testing) attributable to the finger trap pattern variants. Sixteen of 66 constructs with polyvinylchloride catheter material failed at ≤ 100 mm distraction, whereas all polypropylene constructs failed during testing. For polypropylene catheters, braided nylon or GLC suture withstood greater distraction distance and force, respectively. For polyvinylchloride catheters, differences among suture types were nonsignificant. Data suggested that, for the material combinations evaluated, a finger trap suture pattern with fewer knots may provide catheter security similar to that for patterns tied with a more traditional pattern. These results should not be extrapolated to catheters of different diameters or materials, patterns tied with different suture sizes, or clinical performance in vivo without further testing.