trap door
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Author(s):  
Anthony R. Martin

AbstractThe deployment of cage traps rather than kill traps can greatly reduce non-target mortality in an invasive species control/eradication operation, but their use is normally constrained by the need for them to be checked frequently on animal welfare grounds. This paper examines the reliability of electronic monitoring devices that use cellular (mobile phone) networks to alert the operator when a trap door closes, and also discusses the management network that is needed to convert an alarm into a timely trap visit without fail. The two monitoring systems tested were 100% reliable in notifying the operator when a trap door closed, and their use reduced the burden of trap visits by 98% compared to the standard protocol of daily checks. As such, these systems can be of great value to campaigns operating large numbers of traps, especially when capture rates are low.


2021 ◽  
Vol 11 (9) ◽  
pp. 4152
Author(s):  
Hongbo Zhang ◽  
Mingpeng Liu ◽  
Pengfei Zhou ◽  
Zhizhong Zhao ◽  
Xiaoliang Li ◽  
...  

Parts of the retaining wall might produce displacement under different load conditions. The moveable wall could impact the adjacent fixed wall, mainly reflecting on the variation of earth pressure and formation of the soil arching effect. This paper conducted the horizontal trap-door test to explore the variation of active earth pressure caused by partial displacement of the retaining wall. Different trap-door width and three displacement modes were addressed as the influence factors. The results indicated that the horizontal soil arching effect was generated after the active displacement of the trap-door and the soil pressure was redistributed. The distribution of lateral soil pressure was approximately an “inverted bell” curve. For trap-door widths of 20 cm, 30 cm, and 40 cm, a secondary soil arching effect appeared in the test. The relationship between lateral earth pressure and displacement was different with the traditional limited theory due to the influence of the soil arching effect. The variation curve of earth pressure corresponding to displacement could be divided into three stages. In addition, the distribution of earth pressure along the trap-door height was non-linear. Trap-door width can significantly influence the maximum earth pressure on the fixed wall and the range where pressure changes. Finally, the effect of load sharing was explored and found to be related with displacement and width of trap-door as well as the displacement mode.


2021 ◽  
Vol 120 (2) ◽  
pp. 343-361
Author(s):  
Jake Pyne

The desire for transgender futures has grown exponentially in recent years, but many of these futures are traps, concealing a demand to assume normative and neoliberal priorities in exchange for citizenship and belonging. This article argues that some of these traps might be undone through autistic disruption. Dwelling with the life writing and memoir of individuals both autistic and trans, it suggests that, by choice or by circumstance, autistic-trans narratives defy the chrononormative mandate of the able-minded future. By claiming autism and gender nonconformity as mutually inclusive, foregrounding alternative sensorealities, and interrupting the incitement to get better, this article argues that cripping trans time through autistic disruption offers what Gossett, Stanley, and Burton call a “trap door”: a route of escape from the normate trans future and a way for autistic life to insist on its own continuation and survivance.


Children ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 229
Author(s):  
Giuseppe Martucciello ◽  
Federica Fati ◽  
Stefano Avanzini ◽  
Filippo Maria Senes ◽  
Irene Paraboschi

Cervicothoracic neuroblastomas (NBs) pose unique surgical challenges due to the complexity of the neurovascular structures located in the thoracic inlet. To date, two main techniques have been reported to completely remove these tumours in children: the trans-manubrial and the trap-door approaches. Herein, the authors propose a third new surgical approach that allows a complete exposure of the posterior costovertebral space starting from the retro-clavicular space: Cervico-Parasternal Thoracotomy (CPT). The incision is made along the anterior margin of the sternocleidomastoid muscle until its sternal insertion, and then the incision proceeds vertically following the ipsilateral parasternal line. The major pectoralis muscle is detached, and the clavicle and the ribs are disarticulated from their sternal insertions. Following an accurate isolation of the major subclavian blood vessels and the brachial plexus roots, the tumour is then completely exposed and resected by switching from a frontal to a lateral view of the costo-vertebral space. By adopting this technique, five cervicothoracic NBs were completely resected in a median operative time of 370 min (range: 230–480 min). By proceeding in safety with the heart apart, neither vascular injuries nor nerve damages occurred, and all patients were safely discharged in a median postoperative time of 11 days (range: 7–14 days). At the last follow-up visit (median: 16 months, range: 13–21 months), all patients were alive and disease-free.


2021 ◽  
Vol 28 (3) ◽  
pp. 866-881
Author(s):  
Xue-yan Liu ◽  
Hong-yuan Fang ◽  
Fu-ming Wang ◽  
Da-jun Yuan

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhenyao Luo ◽  
Jacqueline R. Morey ◽  
Evelyne Deplazes ◽  
Alina Motygullina ◽  
Aimee Tan ◽  
...  

ABSTRACT Zinc is an essential element in all domains of life. Nonetheless, how prokaryotes achieve selective acquisition of zinc from the extracellular environment remains poorly understood. Here, we elucidate a novel mechanism for zinc-binding in AdcA, a solute-binding protein of Streptococcus pneumoniae. Crystal structure analyses reveal the two-domain organization of the protein and show that only the N-terminal domain (AdcAN) is necessary for zinc import. Zinc binding induces only minor changes in the global protein conformation of AdcA and stabilizes a highly mobile loop within the AdcAN domain. This loop region, which is conserved in zinc-specific solute-binding proteins, facilitates closure of the AdcAN binding site and is crucial for zinc acquisition. Collectively, these findings elucidate the structural and functional basis of selective zinc uptake in prokaryotes. IMPORTANCE Zinc is an essential nutrient for the virulence of bacterial pathogens such as Streptococcus pneumoniae. Many Gram-positive bacteria use a two-domain lipoprotein for zinc acquisition, but how this class of metal-recruiting proteins acquire zinc and interact with the uptake machinery has remained poorly defined. We report the first structure of a two-domain lipoprotein, AdcA from S. pneumoniae, and use computational, spectroscopic, and microbiological approaches to provide new insights into the functional basis of zinc recruitment. Our findings reveal that AdcA employs a novel mechanism for zinc binding that we have termed the “trap-door” mechanism, and we show how the static metal-binding site of the protein, which confers its selectivity for zinc ions, is combined with a dynamic surface element to facilitate zinc recruitment and import into the bacterium. Together, these findings expand our understanding of how bacteria acquire zinc from the environment and provide a foundation for inhibiting this process, through antimicrobial targeting of the dynamic structural elements to block bacterial zinc scavenging.


2021 ◽  
Vol 27 (1) ◽  
pp. 3-12
Author(s):  
Bjoern Raupers ◽  
Hana Medhat ◽  
Juergen Grotemeyer ◽  
Frank Gunzer

Ion traps like the Orbitrap are well known mass analyzers with very high resolving power. This resolving power is achieved with help of ions orbiting around an inner electrode for long time, in general up to a few seconds, since the mass signal is obtained by calculating the Fourier Transform of the induced signal caused by the ion motion. A similar principle is applied in the Cassinian Ion Trap of second order, where the ions move in a periodic pattern in-between two inner electrodes. The Cassinian ion trap has the potential to offer mass resolving power comparable to the Orbitrap with advantages regarding the experimental implementation. In this paper we have investigated the details of the ion motion analyzing experimental data and the results of different numerical methods, with focus on increasing the resolving power by increasing the oscillation frequency for ions in a high field ion trap. In this context the influence of the trap door, a tunnel through which the ions are injected into the trap, on the ion velocity becomes especially important.


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