PARP Inhibitors as Therapeutics: Beyond Modulation of PARylation

Poly (ADP-ribose) polymerase (PARP) 1 is an essential molecule in DNA damage response by sensing DNA damage and docking DNA repair proteins on the damaged DNA site through a type of posttranslational modification, poly (ADP-Ribosyl)ation (PARylation). PARP inhibitors, which inhibit PARylation through competitively binding to NAD+ binding site of PARP1 and PARP2, have improved clinical benefits for BRCA mutated tumors, leading to their accelerated clinical application. However, the antitumor activities of PARP inhibitors in clinical development are different, due to PARP trapping activity beyond blocking PARylation reactions. In this review, we comprehensively address the current state of knowledge regarding the mechanisms of action of PARP inhibitors. We will also discuss the different effects of PARP inhibitors in combination with cytotoxic chemotherapeutic agents regarding the mechanism of regulating PARylation.

Thermophoretic tweezers for single nanoparticle manipulation

We present the trapping and manipulation of a single nano-object in an aqueous medium by optically induced temporally varying temperature gradients. By real-time object tracking and control of the position of the heating laser focus, we can precisely employ thermophoretic drift to oppose the random diffusive motion. As a result, a nano-object is confined in a micrometer-sized trap. Numerical modeling gives a quantitative prediction of the effect. Traps can be dynamically created and relocated, which we demonstrate by the controlled independent manipulation of two nanoparticles.

Evaluation of Monitoring Traps and Lures for Drosophila suzukii (Diptera: Drosophilidae) in Berry Plantings in Florida

Drosophila suzukii (Diptera: Drosophilidae) is an invasive insect pest that was detected in Florida in August 2009 in Hillsborough County. Very limited information is available for berry growers to properly detect and monitor this serious pest in southern highbush blueberry (hybrids of Vaccinium corymbosum L. × V. darrowi Camp), rabbiteye blueberry (Vaccinium virgatum L.), and blackberry (Rubus fruticosus L.) production systems. We compared several D. suzukii traps and lures/baits at two sites in Florida. The traps evaluated included Trécé, Scentry, and a standard homemade cup trap. These traps were compared with various baits and lures, including Trécé lure, Scentry lure, yeast bait, and Suzukii trap, under Florida production systems. Early detection is important to develop an effective monitoring system so management action can be taken before economic damage occurs. Data were recorded as overall trends, as well as in 4–5 trapping periods from early to late season. Overall, the Scentry trap baited with Scentry lure, the Trécé trap baited with Trécé lure + yeast, and the Trécé trap baited with Scentry lure were the best performing traps. Yeast-based traps were also attractive to D. suzukii early in the season, but they did not provide consistent captures as the season progressed. The Scentry trap with yeast bait, the Scentry trap with Scentry lure, the Trécé trap with Trécé lure + yeast bait, and a cup trap with yeast bait caught most of the flies during the first trapping period in 2015 and 2016 in the rabbiteye blueberry. In the southern highbush blueberry, the population of D. suzukii was much lower than in the rabbiteye blueberry planting, and the Scentry trap with Scentry lure captured the highest number of flies during the first trapping period in 2016. In the blackberry, the Scentry trap with Scentry lure numerically had the highest captures during the first trapping period, but this was not significantly different from the cup trap with yeast bait, the Trécé trap baited with Suzukii trap, and the Trécé trap with Trécé lure. Overall, the Scentry trap with Scentry lure was the most consistent trap that captured D. suzukii flies throughout the season in the three production systems—rabbiteye blueberry, southern highbush blueberry, and blackberry. Growers in low pressure systems that are similar to Florida can use the Scentry trap with Scentry lure to monitor D. suzukii populations.

Comparison of Different Trap Designs for Capture of Noctuid Moths (Lepidoptera: Noctuidae) With Pheromone and Floral Odor Attractants

Six trap designs were assessed for capturing noctuid moths in field trials in the United Kingdom and Argentina. The traps were baited with either a sex pheromone for Autographa gamma in the UK trials and Helicoverpa gelotopoeon (Dyar) (Lepidoptera: Noctuidae) in Argentina, or a floral odor blend. In the UK trials the Universal Trap and a funnel sleeve trap were compared; in Argentina the funnel sleeve trap, a homemade bucket trap, and (L.) (Lepidoptera: Noctuidae) three sticky traps: LepTrap, wing trap, and delta trap were compared. Comparisons were made between the traps and attractants and captures of noctuid moths and nontarget insects. Traps baited with the floral attractant caught a lower number but a wider range of noctuid species including Helicoverpa, Spodoptera, Rachiplusia, Dargida, Mythimna, Chrysodeixis, Agrotis, and Autographa spp., and nontarget insects. In the UK trials, the funnel sleeve trap caught significantly more A. gamma than the Universal Trap. The addition of an insecticide to the Universal Trap marginally increased trap catches. In the Argentinian trials, the homemade bucket and the sleeve traps outperformed all sticky traps in most situations regardless of crop environment and attractant type. The homemade bucket and the funnel sleeve traps are also considerably cheaper than the other trap designs. Of the sticky traps the LepTrap caught more noctuids than the wing and delta traps. The results suggest that the bucket trap and the sleeve trap have a much greater maximum capacity and possibly a greater retention efficiency for noctuid moths compared to the sticky traps.

Dipteran Attraction to a Variety of Baits: Implications for Trapping Studies as a Tool for Establishing Seasonal Presence of Significant Species

Monitoring and collection of fly taxa (Diptera: Calliphoridae; Muscidae; Sarcophagidae) of medical, veterinary, and agricultural importance is often routine practice, providing data on target species presence, distribution and abundance. Collection practices currently involve baited trapping and while an inherent bias accompanying the choice of bait is acknowledged, there is little consistency in bait choice between studies and insufficient assessment of trapping success rates for bait types in current use. This study aimed to examine the effect of bait choice on trapping results for six commonly used bait types; a commercial bait (Envirosafe Fly Attractant, Envirosafe Products) and a combination of mixtures of liver, horse manure and 5% sodium sulfide (Na2S). Trapping success was compared under different seasonal conditions (Summer, Autumn, and Spring) to determine the most attractive bait for calliphorid species, with a secondary comparison of kangaroo versus ox liver occurring under summer conditions. Baits containing Na2S were the most successful in captures of all target taxa, with the addition of manure desirable, yielding increased diversity of taxa. Kangaroo liver baits attracted high numbers of Chrysomya spp. (Robineau-Desvoidy, Diptera: Calliphoridae), while Lucilia spp. (Robineau-Desvoidy, Diptera: Calliphoridae) were comparatively underrepresented in traps using liver alone. The use of a combined ox liver/manure/Na2S bait is recommended as the gold standard for generic screening of necrophagous flies. Where more specific target fly taxa are desired, such as Chrysomya spp. or Lucilia spp. only, alternate baits such as kangaroo or lamb may prove more attractive/successful.

Temperature-Induced Self-Compensating Defect Traps and Gain Thresholds in Colloidal Quantum Dots

Continuous-wave (CW) lasing was recently achieved in colloidal quantum dots (CQDs) by lowering the threshold through the introduction of biaxial strain. However, the CW laser threshold is still much higher than the femtosecond threshold. This must be addressed before electrically injected lasing can be realized. Here we investigate the relationship between threshold and temperature and find a subpicosecond recombination process that proceeds very efficiently at temperatures reached during CW excitation. We combine density functional theory and molecular dynamics simulations to explore potential candidates for such a process, and find that crystal defects having thermally vibrating energy levels can become electronic traps-i.e., they can protrude into the bandgap-when they are sufficiently distorted at higher temperatures. We find that biaxially strained CQDs, which have a lower femtosecond laser threshold than traditional CQDs, result in less heat for a given transparency/gain level and thus undergo this trapping to a lower extent. We also propose methods to tailor CQDs to avoid self-compensating defect traps.

Response to a Synthetic Pheromone Source by OX4319L, a Self-Limiting Diamondback Moth (Lepidoptera: Plutellidae) Strain, and Field Dispersal Characteristics of its Progenitor Strain

The diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), is a global pest that infests vegetable and field crops within the Brassica family. A genetically engineered strain of P. xylostella, OX4319L, carrying a 'self-limiting' gene, has shown potential for managing P. xylostella populations, using sustained releases of OX4319L male moths. In order for such a strain to provide control, the transgenic individuals must exhibit attraction to female P. xylostella sex pheromone and adequate dispersal in the field. In this study, we tested these key traits. First, we compared the responses of the OX4319L male moths to a synthetic female sex pheromone source in wind tunnel trials to those of males from three other strains. We found that OX4319L males responded comparably to strains of non-engineered males, with all males flying upwind towards the pheromone source. Second, we used mark-release-recapture studies of a wildtype P. xylostella strain, from which the OX4319L strain was originally developed, to assess dispersal under field conditions. Released males were recaptured using both pheromone-baited and passive traps within a 2.83 ha circular cabbage field, with a recapture rate of 7.93%. Males were recaptured up to the boundary of the field at 95 m from the central release point. The median dispersal of males was 14 m. These results showed the progenitor strain of OX4319L retained its ability to disperse within a host field. The results of these experiments are discussed in relation to the potential for the effective use of engineered male-selecting P. xylostella strains under field conditions.

Capture of Alouatta guariba clamitans for the surveillance of sylvatic yellow fever and zoonotic malaria: Which is the best strategy in the tropical Atlantic Forest?

Howler monkey capture is an arduous and expensive task requiring trained and specialized professionals. We compared strategies and methods to most efficiently capture Alouatta guariba clamitans in remnants of the Atlantic Forest in Rio de Janeiro and its bordering states of Minas Gerais and São Paulo. We tested whether or not the success of expeditions in the forest with anesthetic darts, nets, and baited traps differed with and without the support of an information network, a contact chain built with key institutions and inhabitants to continuously monitor howler monkey presence. The influence of forest conditions (vegetation type and fragment size) upon darting success was also evaluated. We captured 24 free-living A. guariba clamitans. No howler monkey was caught with traps, probably due to the predominantly folivore feeding to high local plant diversity providing a great variety of food options. Captures based on an information network were significantly more efficient in terms of numbers of caught monkeys than without it. Captures with darts were considerably more efficient when performed in semideciduous forests and small forest fragments as opposed to ombrophilous forests or large woods. Although we walked great distances within the forest searching for howler monkeys, all but one animal were captured at the forest fringes. Hindrances to search and the darting method in the Atlantic Forest, for example, the steep terrain, high tree canopies, hunt pressure, and low A. guariba clamitans population density, were mitigated with the use of the information network in this monkey capture. Moreover, the information network enhanced the surveillance of zoonotic diseases, which howler monkeys and other nonhuman primates are reservoirs in Brazil, such as malaria and yellow fever.

Screening Sticky Cards as a Simple Method for Improving Efficiency of Diaphorina citri (Hemiptera: Liviidae) Monitoring and Reducing Nontarget Organisms

Management of Diaphorina citri Kuwayama (Hemiptera: Liviidae) populations is one of the major strategies for reducing the spread and incidence of huanglongbing (HLB). HLB is putatively caused by Candidatus Liberibacter spp. (Rhizobiales: Phyllopbacteriaceae) that are transmitted to citrus by psyllid vectors. Diaphorina citri population monitoring is done to detect its presence and inform on management decisions. Various methods are used for detecting and estimating D. citri densities but trapping with yellow or lime-green sticky cards has proven to be the most effective method. These sticky cards rely on the color preference of adult D. citri, but many flying organisms are attracted to the same color spectrum as psyllids. Hence, in field situations, sticky traps are hampered by large numbers of bycatches of nontarget organisms and debris. Here, we described a method using a mesh laid on the surface of traps as a sift to catch mainly psyllids, while reducing bycatches. By filtering D. citri through this mesh, they can be counted more rapidly and accurately. Although mesh-covered traps captured 5-15% less D. citri relative to uncovered ACP traps, both types of traps statistically agreed on D. citri detection and population densities. The effectiveness of mesh-covered traps did not vary with season. In addition, mesh-covered traps eliminated >90% of nontarget organisms and allowed for quicker enumeration of D. citri. We expect this method will become an important component of redesigning integrated pest management programs in citrus groves by reducing unintended impacts of beneficial arthropods during large scale D. citri monitoring.

Measuring the Welfare Impact of Soft-Catch Leg-Hold Trapping for Feral Cats on Non-Target By-Catch

Simple Summary

Feral cats are linked to fauna extinctions and declines globally through predation, disease transmission, and hybridisation. Soft-catch leg-hold trapping, with or without olfactory lures, is used to capture feral cats; however, by-catch may occur, including species of conservation concern. Using data from 431 non-target animals trapped at six Western Australian sites over 18 years, we demonstrate that birds are at greatest risk of serious injury. Appropriate placement of traps, careful choice of lures depending on the non-target species known to be in the study area, adjustment of traps to minimize the chance of closing on small animals, and training of all personnel associated with trapping will minimize the risk to birds and other non-target fauna.

Abstract

To inform trapping protocols to reduce by-catch while trapping feral cats by-catch welfare costs should be quantified. During cat trapping programs at six Western Australian sites from 1997–2015, 431 non-target individuals, including 232 individuals from native species (132 mammals, 52 birds and 42 reptiles) were captured. Among the native fauna; birds were more likely to be severely injured (33%, compared to 12% in mammals and 21% in reptiles). Amongst other vertebrates, larger individuals were less likely to be injured. Olfactory lures used in these studies attracted reptiles, but repelled mammals. By-catch varied with climate and landscape. Trap injury to by-catch species poses ethical concerns, especially for threatened species that can least afford an additional threat. Future trapping should consider the timing of trapping, trap placement, trap settings (especially the treadle pressure needed to close the trap) and new innovations sending immediate capture alerts to minimise by-catch and potential injury associated with prolonged restraint. By-catch welfare data should be analysed to identify best practice and on-going improvement.

Time-resolved photoluminescence on double graded Cu(In,Ga)Se2 - Impact of front surface recombination and its temperature dependence

Time-resolved photoluminescence (TRPL) is applied to determine an effective lifetime of minority charge carriers in semiconductors. Such effective lifetimes include recombination channels in the bulk as well as at the surfaces and interfaces of the device. In the case of Cu(In,Ga)Se₂ absorbers used for solar cell applications, trapping of minority carriers has also been reported to impact the effective minority carrier lifetime. Trapping can be indicated by an increased temperature dependence of the experimentally determined photoluminescence decay time when compared to the temperature dependence of Shockley-Read-Hall (SRH) recombination alone and can lead to an overestimation of the minority carrier lifetime. Here, it is shown by technology computer-aided design (TCAD) simulations and by experiment that the intentional double-graded bandgap profile of high efficiency Cu(In,Ga)Se₂ absorbers causes a temperature dependence of the PL decay time similar to trapping in case of a recombinative front surface. It is demonstrated that a passivated front surface results in a temperature dependence of the decay time that can be explained without minority carrier trapping and thus enables the assessment of the absorber quality by means of the minority carrier lifetime. Comparison with the absolute PL yield and the quasi-Fermi-level splitting (QFLS) corroborate the conclusion that the measured decay time corresponds to the bulk minority carrier lifetime of 250 ns for the double-graded CIGS absorber under investigation.

Using Malaise traps for collecting Lepidoptera (Insecta), with notes on the preparation of Macrolepidoptera from ethanol

The present paper deals with the potential of employing Malaise traps for collecting butterflies and moths for morphological analysis and presents a protocol for preparing Macrolepidoptera from Malaise trap samples that were preserved in ethanol. About 80 specimens of Lepidoptera, including Nymphalidae, Geometridae, Hesperiidae, Erebidae, Noctuidae, Pyralidae and Tortricidae, were mounted, following the protocol. All specimens with robust wings and contrasting wing patterns were well suited for the study of external morphology, regardless of the family. The specimens used in this study were collected in highland forest areas of central Vietnam with a little known entomofauna, as part of the German-Vietnamese biodiversity project 'VIETBIO'. The study offers new methodological approaches in an attempt to make the most of the material that was obtained using Malaise traps.

Gating charge displacement in a monomeric voltage-gated proton (Hv1) channel

The voltage-gated proton (Hv1) channel, a voltage sensor and a conductive pore contained in one structural module, plays important roles in many physiological processes. Voltage sensor movements can be directly detected by measuring gating currents, and a detailed characterization of Hv1 charge displacements during channel activation can help to understand the function of this channel. We succeeded in detecting gating currents in the monomeric form of the Ciona-Hv1 channel. To decrease proton currents and better separate gating currents from ion currents, we used the low-conducting Hv1 mutant N264R. Isolated ON-gating currents decayed at increasing rates with increasing membrane depolarization, and the amount of gating charges displaced saturates at high voltages. These are two hallmarks of currents arising from the movement of charged elements within the boundaries of the cell membrane. The kinetic analysis of gating currents revealed a complex time course of the ON-gating current characterized by two peaks and a marked Cole-Moore effect. Both features argue that the voltage sensor undergoes several voltage-dependent conformational changes during activation. However, most of the charge is displaced in a single central transition. Upon voltage sensor activation, the charge is trapped, and only a fast component that carries a small percentage of the total charge is observed in the OFF. We hypothesize that trapping is due to the presence of the arginine side chain in position 264, which acts as a blocking ion. We conclude that the movement of the voltage sensor must proceed through at least five states to account for our experimental data satisfactorily.

Attraction of Moths of Two Noctuidae Species to Field Traps Baited With a Mixture of two to three Homologous Acetates in Poland

Field trials of a series of monounsaturated straight-chain acetates, including the (Z)-5-tetradecenyl acetate, (Z)-9-tetradecenyl acetate (pheromone blend A) and (Z)-5-decenyl acetate, (Z)-7-dodecenyl acetate, (Z)-9-tetradecenyl acetate (pheromone blend B), attracted the following species from the title family: Agrotis exclamationis (Linnaeus) and Agrotis segetum (Denis & Schiffermüller), respectively. Cutworms were monitored in the 2016-2017 season with the use of white Delta-type traps and different pheromone dispensers that contained above blends. The identified pheromone components at blend A elicited maximum trap captures when combined in a Z5-14:Ac/Z9-14:Ac-mixture ratio 100:16 at dose of 350 µg. The attractiveness of dispensers with pheromone blend B combined in a Z5-10:Ac/Z7-12:Ac/Z9-14:Ac-mixture ratio 1:1:1 at dose of 200 µg was the highest. Most kinds of the dispensers tested were similar or more active to the standard lures of the Csalomon company. Pheromone component of the A. exclamationis, (Z)-5-tetradecenyl acetate, was synthesized with a new, simple, and very efficient method in high summary yield and excellent isomeric purity.

Terminalia Larval Host Fruit Reduces the Response of Bactrocera dorsalis (Diptera: Tephritidae) Adults to the Male Lure Methyl Eugenol

Methyl eugenol (ME) is a powerful semiochemical attractant to males of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), and is the keystone of detection, control, and eradication programs against this polyphagous and highly invasive tephritid pest. Despite its status as a model lure against B. dorsalis, variation among individuals in their attraction is known, independent of the generally increasing attraction with age and decreases with previous exposure. Here we report that adult male B. dorsalis that fed on Terminalia catappa L. (Myrtales: Combretaceae) (tropical almond) fruit as larvae have a significantly lower behavioral response to ME compared with wild males from Psidium guajava L. (Myrtales: Myrtaceae) or colony-reared males raised on artificial larval diet. F1 males from the tropical almond stock reared on artificial larval diet did not show reduced attraction to ME, suggesting that the lowered response of parental males (sires) results from the host fruit itself, perhaps its relatively high amount of ME. Experiments with ME added to artificial diet lend some support to this interpretation. In addition to the results above, we report on quantities of ME in three different host fruits (T. catappa, P. guajava, and Carica papaya L. (Brassicales: Caricaceae)) of B. dorsalis. This study indicates the need for further research on the effect of host fruit on adult response to lures in economically important tephritids.

Monitoring and Biosurveillance Tools for the Brown Marmorated Stink Bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae)

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive pest of numerous agricultural crops with an increasing global distribution. Finding simple and reliable monitoring tools for H. halys agricultural and surveillance programs is imperative. In 2016, we compared standard pyramid traps to clear sticky cards attached atop wooden stakes and evaluated two commercially formulated lures (Trécé and AgBio) with low and high rates of the H. halys aggregation pheromone (PHER) and pheromone synergist (MDT) at 12 sites (low: 5 mg PHER + 50 mg MDT; high: 20 mg PHER + 200 mg MDT). In 2017, we reevaluated lure efficacy using only the clear sticky traps at six locations. Sites were classified as having low, moderate, or high relative population densities of H. halys in 2016, and as very low or low densities of H. halys in 2017. Although clear sticky traps captured fewer adults and nymphs than pyramid traps, their captures were generally correlated at all population levels indicating that clear sticky traps can reliably monitor H. halys presence and relative abundance regardless of relative population density. During both years, adult and nymphal captures were significantly greater in traps baited with Trécé lures than with AgBio lures. Captures were greater in traps baited with high loading rate lures for each lure type, and with the exception of traps baited with AgBio lures at high relative density sites in 2016, H. halys captures in traps with low and high loading rates of each lure type were correlated for both years. Comparison of yellow and clear sticky cards indicated they performed equally, but yellow cards captured more nontargets. In summary, clear sticky traps attached atop wooden posts and baited with H. halys pheromone and pheromone synergist lures are an effective option for this pest monitoring and detection.

Hydrodynamic Tweezers: Trapping and Transportation in Microscale Using Vortex Induced by Oscillation of a Single Piezoelectric Actuator

The demand for a harmless noncontact trapping and transportation method in manipulation and measurement of biological micro objects waits to be met. In this paper, a novel micromanipulation method named “Hydrodynamic Tweezers” using the vortex induced by oscillating a single piezoelectric actuator is introduced. The piezoelectric actuator is set between a micropipette and a copper beam. Oscillating the actuator at a certain frequency causes the resonance of the copper beam and extend 1D straight oscillation of the piezoelectric actuator to 2D circular oscillation of the micropipette, which induces a micro vortex after putting the micropipette into fluid. The induced vortex featuring low pressure in its core area can trap the object nearby. A robotic micromanipulator is utilized to transport the trapped objects together with the micropipette. Experiments of trapping and transportation microbeads are carried out to characterize the key parameters. The results show that the trapping force can be controlled by adjusting peak-peak voltage of the sinusoidal voltage input into the piezoelectric actuator.

Estimating mortality rates among passerines caught for ringing with mist nets using data from previously ringed birds

Mist netting is the most commonly used method for catching birds for scientific ringing, but despite decades of use, there have been few attempts to quantify the associated potential risks to the individuals caught. Any incidence of mortality through capture and handling, however low, is of potential ethical concern and may also introduce biases into the data. We estimate the mortality rate associated with capture of previously ringed (recaptured) passerines from the British and Irish Ringing Scheme (c. 1.5 million records) caught using mist nets. The importance of species, age, mass, month, time, previous captures, and an index of predator occurrence was tested using generalized linear mixed-effects models. The average mortality rate was 0.0011, most of which was reported to occur before the individuals had been extracted from the nets (c. 70% of incidents). Juveniles appeared to be at higher risk and the incidence of predation from mist nets was seasonal, with increased risk during the winter. Species differed in their reported mortality rates with the apparent risk being greatest for Chiffchaff Phylloscopus collybita (0.0029) and Bullfinch Pyrrhula pyrrhula (0.0027). To improve our understanding (and hence minimize risk in future), we recommend collecting more complete data on incidences of mortality, and also injuries; exercising increased care when the species we have identified as being at greater risk are likely to be captured, and ensuring there are robust procedures for the checking of nets (as most reported incidents of mortality occur before handling). We also recommend that all Ringing Schemes should collate and make available data on capture-related mortality. Overall rates of mortality associated with capture, although, were low and support the use of mist netting as a safe capture technique, without undue bias from mortality, when used by appropriately trained individuals.

Role of Hole Trap Sites in MoS2 for Inconsistency in Optical and Electrical Phenomena

Because of strong Coulomb interaction in two-dimensional van der Waals-layered materials, the trap charges at the interface strongly influence the scattering of the majority carriers and thus often degrade their electrical properties. However, the photogenerated minority carriers can be trapped at the interface, modulate the electron-hole recombination, and eventually influence the optical properties. In this study, we report the role of the hole trap sites on the inconsistency in the electrical and optical phenomena between two systems with different interfacial trap densities, which are monolayer MoS₂-based field-effect transistors (FETs) on hexagonal boron nitride (h-BN) and SiO₂ substrates. Electronic transport measurements indicate that the use of h-BN as a gate insulator can induce a higher n-doping concentration of the monolayer MoS₂ by suppressing the free-electron transfer from the intrinsically n-doped MoS₂ to the SiO₂ gate insulator. Nevertheless, optical measurements show that the electron concentration in MoS₂/SiO₂ is heavier than that in MoS₂/h-BN, manifested by the relative red shift of the A_1g Raman peak. The inconsistency in the evaluation of the electron concentration in MoS₂ by electrical and optical measurements is explained by the trapping of the photogenerated holes in the spatially modulated valence band edge of the monolayer MoS₂ caused by the local strain from the SiO₂/Si substrate. This photoinduced electron doping in MoS₂/SiO₂ is further confirmed by the development of the trion component in the power-dependent photoluminescence spectra and negative shift of the threshold voltage of the FET after illumination.

Field Evaluation of Commercial Attractants and Trap Placement for Monitoring Pine Sawyer Beetle, Monochamus alternatus (Coleoptera: Cerambycidae) in Guangdong, China

The pine sawyer beetle, Monochamus alternatus Hope (Coleoptera: Cerambycidae) is a serious insect pest of pine trees by vectoring the pine wood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle (Nematoda: Aphelenchoididae). Field studies were carried out during 2013-2015 in Guangdong (China) to evaluate the effectiveness of commercial attractants, effect of trap placement for monitoring M. alternatus, and temporal patterns of trap catch. Four commercial attractants, three trap placements (0, 1.5, and 3 m above ground) and different trapping distances (50, 200, 400, 600, and 900 m) from forest edge were evaluated for monitoring M. alternatus. Traps baited with a mixture of monochamol and plant volatiles captured significantly more beetles than traps baited with monochamol alone or plant volatiles alone. Traps set up at 1.5 m above the ground captured significantly more M. alternatus than those at 0 m and 3 m height. Based on 2,687 beetles trapped from two locations in 2013 and 2014, the female:male ratio was 2.9-4.1:1. The beetles' natural dispersal distance was approximately 100 m based on traps set at different distances from edge of the forest. Continuous monitoring over 38-wk period indicates the peak of adult M. alternatus emergence was between May and June within a year.

Enhanced Response of Halyomorpha halys (Hemiptera: Pentatomidae) to Its Aggregation Pheromone with Ethyl Decatrienoate

The invasive stink bug species, Halyomorpha halys (Stål) (Hemiptera; Pentatomidae), severely damages multiple agricultural commodities, resulting in the disruption of established IPM programs. Several semiochemicals have been identified to attract H. halys to traps and monitor their presence, abundance, and seasonal activity. In particular, the two-component aggregation pheromone of H. halys, (3S,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol and (3R,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol (PHER), in combination with the pheromone synergist, methyl (2E,4E,6Z)-decatrienoate (MDT), were found to be attractive. Here, we report that an analogous trienoate, ethyl (2E,4E,6Z)-decatrienoate (EDT), enhances H. halys captures when combined with PHER. In trials conducted in Eastern and Western regions of the United States, we observed that when traps were baited with the H. halys PHER + EDT, captures were significantly greater than when traps were baited with PHER alone. Traps baited with EDT alone were not attractive. Thus, the addition of EDT to lures for attracting H. halys to traps may further improve monitoring efficiency and management strategies for this invasive species.

Trapping Structural Coloration by a Bioinspired Gyroid Microstructure in Solid State

In theory, gyroid photonic crystals in butterfly wings exhibit advanced optical properties as a result of their highly interconnected microstructures. Because of the difficulties in synthesizing artificial gyroid materials having periodicity corresponding to visible wavelengths, human-made visible gyroid photonic crystals are still unachievable by self-assembly. In this study, we develop a physical approach-trapping of structural coloration (TOSC)-through which the visible structural coloration of an expanded gyroid lattice in a solvated state can be preserved in the solid state, thereby allowing the fabrication of visible-wavelength gyroid photonic crystals. Through control over the diffusivity and diffusive distance for solvent evaporation, the single-molecular-weight gyroid block copolymer photonic crystal can exhibit desired structural coloration in the solid state without the need to introduce any additives, namely, evapochromism. Also, greatly enhanced reflectivity is observed arising from the formation of porous gyroid nanochannels, similar to those in butterfly wings. As a result, TOSC facilitates the fabrication of the human-made solid gyroid photonic crystal featuring tunable and switchable structural coloration without the synthesis to alter the molecular weight. It appears to be applicable in the fields of optical communication, energy, light-emission, sensors, and displays.

Thrombosed Giant "True" Posterior Communicating Artery Aneurysm Treated by Trapping and Thrombectomy

Giant “true” posterior communicating artery (PCOM) aneurysms are rare and the best surgical treatment for them is unclear. We present a case of 85-year-old woman with this type of lesion, 35 mm in diameter, successfully treated by trapping and thrombectomy via pterional approach without complications. There were no perforating arteries originating from the aneurysmal wall. The patient had an uneventful postoperative course. The key for successful treatment for such lesions is preservation of perforators, as trapping may result in ischemic complications. However, our case indicates that trapping and thrombectomy might have relatively low risks for development of such complications, supposing that the thrombosis within the giant “true” PCOM aneurysm induced spontaneous obliteration of perforators, arising from the aneurysmal dome, and that collateral flow from the posterior cerebral artery already compensated the corresponding territories.

Success of capture of toads improved by manipulating acoustic characteristics of lures

BACKGROUND

Management of invasive vertebrates is a crucial component of conservation. Trapping reproductive adults is often effective for control, and modification of traps may greatly increase their attractiveness to such individuals. Cane toads (Rhinella marina) are invasive, and males use advertisement vocalisations to attract reproductive females. In amphibians, including toads, specific structural parameters of calls (e.g. dominant frequency and pulse rate) may be attractive to females. Some cane toad traps use an artificial advertisement vocalisation to attract toads. We determined whether variation of the call's parameters (volume, dominant frequency and pulse rate) could increase the capture rate of gravid females.

RESULTS

Overall, traps equipped with loud calls (80 dB at 1 m) caught significantly more toads, and proportionally more gravid females, than traps with quiet calls (60 dB at 1 m), and traps with low dominant frequency calls caught more gravid females than traps with median frequency calls. Traps with high pulse rate calls attracted more females than traps with low pulse rate calls. Approximately 91% of the females trapped using a low frequency and high pulse rate combination call were gravid, whereas in traps using a call with population median parameters only approximately 75% of captured females were gravid.

CONCLUSION

Calls that indicated large-bodied males (low frequency) with high energy reserves (high pulse rate) are often attractive to female anurans and were effective lures for female toads in our study. The design of future trapping regimes should account for behavioural preferences of the target sex. © 2017 Society of Chemical Industry.

Dose reduction and alternatives to the phenol pheromone in monitoring and management of the grass grub Costelytra zealandica

BACKGROUND

Endemic New Zealand grass grub Costelytra zealandica is a pest of introduced pasture that uses phenol as a sex pheromone. The pheromone could be used to monitor and manage grass grub populations, but the irritating properties and toxicity of phenol for human handlers, as well as the possible ecotoxicological effects, pose obstacles to the deployment of the pheromone. This study aimed to limit the use of phenol by dose-response studies and investigation into alternative attractants and synergists to phenol.

RESULTS

No difference in trap catch was seen across the range of 1-100 mg of phenol, while rates below this (0.001-0.1 mg) caused a large drop in catches. Our results indicated that 1 mg loading in lures was enough to indicate beetle presence over 1 week. 4-Hydroxybenzaldehyde and p-cresol proved unattractive in this study, both as single attractants and as synergists with phenol. Phenyl acetate, phenyl benzoate and diphenyl carbonate all formed phenol under hydrolytic conditions to act as successful propheromones, while phenyl acetate was found to be as attractive as phenol on its own.

CONCLUSION

This study described several ways to reduce or avoid the use of phenol in the field while maintaining lure effectiveness. © 2017 Society of Chemical Industry.