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There are many problems in physics, biology, and other natural sciences in which symbolic regression can provide valuable insights and discover new laws of nature. Widespread deep neural networks do not provide interpretable solutions. Meanwhile, symbolic expressions give us a clear relation between observations and the target variable. However, at the moment, there is no dominant solution for the symbolic regression task, and we aim to reduce this gap with our algorithm. In this work, we propose a novel deep learning framework for symbolic expression generation via variational autoencoder (VAE). We suggest using a VAE to generate mathematical expressions, and our training strategy forces generated formulas to fit a given dataset. Our framework allows encoding apriori knowledge of the formulas into fast-check predicates that speed up the optimization process. We compare our method to modern symbolic regression benchmarks and show that our method outperforms the competitors under noisy conditions. The recovery rate of SEGVAE is 65% on the Ngyuen dataset with a noise level of 10%, which is better than the previously reported SOTA by 20%. We demonstrate that this value depends on the dataset and can be even higher.
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Aggregation-induced quenching often restricts emissive performance of optically active solid materials with embedded fluorescent dyes. Delignified and nanoporous wood readily adsorbs organic dyes and is investigated as a host material for rhodamine 6G (R6G). High concentration of R6G (>35 mM) is achieved in delignified wood without any ground-state dye aggregation. To evaluate emissive performance, a solid-state random dye laser is prepared using the dye-doped wood substrates. The performance in terms of lasing threshold and efficiency was improved with increased dye content due to the ability of delignified wood to disperse R6G.
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An optical amplification-free deep reservoir computing (RC)-assisted high-baudrate intensity modulation direct detection (IM/DD) system is experimentally demonstrated using a 100G externally modulated laser operated in C-band. We transmit 112 Gbaud 4-level pulse amplitude modulation (PAM4) and 100 Gbaud 6-level PAM (PAM6) signals over a 200-m single-mode fiber (SMF) link without any optical amplification. The decision feedback equalizer (DFE), shallow RC, and deep RC are adopted in the IM/DD system to mitigate impairment and improve transmission performance. Both PAM transmissions over a 200-m SMF with bit error rate (BER) performance below 6.25% overhead hard-decision forward error correction (HD-FEC) threshold are achieved. In addition, the BER of the PAM4 signal is below the KP4-FEC limit after 200-m SMF transmission enabled by the RC schemes. Thanks to the use of a multiple-layer structure, the number of weights in deep RC has been reduced by approximately 50% compared with the shallow RC, whereas the performance is comparable. We believe that the optical amplification-free deep RC-assisted high-baudrate link has a promising application in intra-data center communications.
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High bitrate mid-infrared links using simple (NRZ) and multi-level (PAM-4) data coding schemes have been realized in the 8 µm to 14 µm atmospheric transparency window. The free space optics system is composed of unipolar quantum optoelectronic devices, namely a continuous wave quantum cascade laser, an external Stark-effect modulator and a quantum cascade detector, all operating at room-temperature. Pre- and post-processing are implemented to get enhanced bitrates, especially for PAM-4 where inter-symbol interference and noise are particularly detrimental to symbol demodulation. By exploiting these equalization procedures, our system, with a full frequency cutoff of 2 GHz, has reached transmission bitrates of 12 Gbit/s NRZ and 11 Gbit/s PAM-4 fulfilling the 6.25 % overhead hard-decision forward error correction threshold, limited only by the low signal-to-noise ratio of our detector.
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BACKGROUND: There are several approaches to the surgical treatment of the penile curvature conditionally divided into three large groups: tunica albuginea plication (TAP), corpus cavernosum rotation (CR), and transplantation of various materials. The study aims to compare the effectiveness of TAP and CR techniques in the treatment of penile curvature. There was a prospective randomized study of the effectiveness of surgical treatment of patients with an established diagnosis of the penile curvature from 2017 to 2020 in Irkutsk, Russian Federation. The final analysis of the results included 22 cases. RESULTS: The analysis of the comparative intergroup effectiveness of the treatment performed based on the criteria established in the study showed good treatment results in 8 (88.8%) patients in the CR group and 9 (69.2%) patients in the TAP group (p = 0.577). The other patients obtained satisfactory results. There were no negative outcomes. Simple logistic regression analysis showed that the preoperative flexion angle > 60 degrees (OR 2.7; 95% CI 0.12; 5.28; p = 0.040) was significant in predicting the complaints of penile shortening during TAP. Both methods are safe, effective, and bring minimal risk of complications. CONCLUSION: Thus, the effectiveness of both treatment methods is comparable. However, TAP surgery is not recommended for patients with an initial curvature of more than 60 degrees.
RéSUMé: CONTEXTE: Il existe plusieurs approches du traitement chirurgical de la courbure pénienne, divisées en trois grands groupes : plicature de la tunique albuginée (PTA), rotation du corps caverneux (RCC) et transplantation de divers matériaux. La présente étude vise à comparer l'efficacité des techniques PTA et RCC dans le traitement de la courbure du pénis. Il s'agit d'une étude prospective randomisée de l'efficacité du traitement chirurgical de patients ayant un diagnostic établi de courbure du pénis, de 2017 à 2020 à Irkoutsk, en Fédération de Russie. L'analyse finale des résultats comprend 22 cas. RéSULTATS: L'analyse de l'efficacité comparative intergroupe du traitement effectué sur la base des critères établis dans l'étude, a montré de bons résultats du traitement chez 8 (88,8%) patients du groupe RCC et 9 (69,2%) patients du groupe PTA (p = 0,577). Les autres patients ont obtenu des résultats satisfaisants. Il n'y a eu aucun résultat négatif. Une analyse de régression logistique simple a montré qu'un angle de flexion préopératoire > 60 degrés (OR 2,7 ; IC à 95 % 0,12 ; 5,28 ; p = 0,040) était significatif pour prédire les plaintes de raccourcissement du pénis avec l'approche de la PTA. Les deux méthodes sont sûres, efficaces et présentent un risque minimal de complications. CONCLUSIONS: Ainsi, l'efficacité des deux méthodes de traitement est comparable. Cependant, la chirurgie avec l'approche de la PTA n'est pas recommandée chez les patients ayant une courbure initiale de plus de 60 degrés.
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An approach for simultaneous modulation format identification (MFI) and optical signal-to-noise ratio (OSNR) monitoring in digital coherent optical communications is proposed based on optoelectronic reservoir computing (RC) and the signal's amplitude histograms (AHs) obtained after the adaptive post-equalization. The optoelectronic RC is implemented using a Mach-Zehnder modulator and optoelectronic delay feedback loop. We investigate the performance of the proposed model with the number of symbols, bins of AHs and the hyperparameters of optoelectronic RC. The results show that 100% MFI accuracy can be achieved simultaneously with accurate OSNR estimation for different modulation formats under study. The lowest achievable OSNR estimation mean absolute errors for the dual-polarization (DP)-quadrature phase-shift keying signal, the DP-16-ary quadrature amplitude modulation (16QAM) signal, and the DP-64QAM signal are 0.2 dB, 0.32 dB and 0.53 dB, respectively. The robustness of the proposed scheme is also evaluated when the optoelectronic RC is in presence of additive white Gaussian noises. Then, a proof of concept experiment is demonstrated to further verify our proposed method. The proposed approach offers a potential solution for next-generation intelligent optical performance monitoring in the physical layer.
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Photonic generation of Terahertz (THz) carriers displays high potential for THz communications with a large tunable range and high modulation bandwidth. While many photonics-based THz generations have recently been demonstrated with discrete bulky components, their practical applications are significantly hindered by the large footprint and high energy consumption. Herein, we present an injection-locked heterodyne source based on generic foundry-fabricated photonic integrated circuits (PIC) attached to a uni-traveling carrier photodiode generating high-purity THz carriers. The generated THz carrier is tunable within the range of 0-1.4 THz, determined by the wavelength spacing between the two monolithically integrated distributed feedback (DFB) lasers. This scheme generates and transmits a 131 Gbits-1 net rate signal over a 10.7-m distance with -24 dBm emitted power at 0.4 THz. This monolithic dual-DFB PIC-based THz generation approach is a significant step towards fully integrated, cost-effective, and energy-efficient THz transmitters.
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BACKGROUND: Historical reports on surgical renal denervation consistently describe renal plexus as a triangle or fan-like structure converging at the kidney gate. Following that anatomy, we developed a distal mode of radiofrequency renal denervation (RDN) mainly in segmental branches of the renal artery and confirmed its superior efficacy over the conventional main trunk procedure in a 6-months double-blind randomized controlled trial (NCT02667912). To assess the long-term effects of distal RDN we extended the follow-up of our study to three years. METHODS: BP, serum creatinine, eGFR were measured one and three years after randomization; major adverse renal events were assessed over the entire study period. The blinding was maintained over the entire three-year study period. FINDINGS: Of 55 randomized patients, 47 (23/24, distal/main trunk RDN, respectively) were assessed at one year and 39 (21/18) at three years post-procedure. Twenty-four-hour ambulatory systolic BP remained powerfully lowered after distal RDN both at one- and three-years assessments(mean change from baseline: -18.0, 95% CI -27.6 to -8.5; p<0.05 and -16·9, 95% CI -27·3 to -6·5; p<0·05, mmHg, respectively. This was accompanied by a moderate drop in eGFR at one year: -8·9 ml/min/m2, 95% CI -14·8 to -3·1; p<0·05, which, however, subsequently decreased in size at three years: -6·5, 95% CI -13·2 to 0·3; p>0·05. After main trunk RDN, the decrease of 24h systolic BP was quite moderate at one year: -12·1, 95% CI -19·2 to -5·0; p<0·05, and further weakened at three-year assessment: -8·5, 95% CI -19·7 to 2·2; p>0.05. eGFR was almost unchanged at one year: -1·3, 95% CI -6·6 to 4·0; p>0·05, but significantly decreased at three years: -5·0, 95% CI -9·6 to -0·3; p<0·05. INTERPRETATION: Our data demonstrate the durable strong BP-lowering efficacy and favorable long-term renal safety of distal RDN.
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Wood is an eco-friendly and abundant substrate and a candidate for functionalization by large-scale nanotechnologies. Infiltration of nanoparticles into wood, however, is hampered by the hierarchically structured and interconnected fibers in wood. In this work, delignified wood is impregnated with gold and silver salts, which are reduced in situ to plasmonic nanoparticles via microwave-assisted synthesis. Transparent biocomposites are produced from nanoparticle-containing wood in the form of load-bearing materials with structural color. The coloration stems from nanoparticle surface plasmons, which require low size dispersity and particle separation. Delignified wood functions as a green reducing agent and a reinforcing scaffold to which the nanoparticles attach, predesigning their distribution on the surface of fibrous "tubes". The nanoscale structure is investigated using scanning transmission electron microscopy (STEM), energy-dispersive spectroscopy (EDS), and Raman microscopy to determine particle size, particle distribution, and structure-property relationships. Optical properties, including response to polarized light, are of particular interest.
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INTRODUCTION: There are several options for vessel-sparing anastomotic procedures that allow one to avoid disturbances in the normal blood supply to the spongy body and successfully perform plastic surgery of distal urethral strictures. AIM: To perform a comparative analysis of the effectiveness of reconstructive surgical treatment of strictures of the bulbo-membranous urethra with anastomotic surgery with and without vessel-sparing. MATERIAL AND METHODS: A prospective study was carried out on 28 patients with a diagnosis of stricture of the bulbo-membranous urethra who underwent treatment in the period 2012-2018 in the conditions of a urological hospital of Irkutsk City Clinical Hospital No. 1. Anastomotic urethroplasty was performed using one of two methods: with full mobilization of the spongy body bulb and a vessel-sparing method when the spongy body does not intersect. RESULTS: The effectiveness of the classical method of anastomosing EPA-TWW ((excision and primary anastomosis urethroplasty (Turner-Warwick) and excision and Jordan's technique of vessel sparing excision and primary anastomosis)) was comparable with the method of anastomosing without crossing the (spongy body of EPA-J). Postoperative changes in the parameters of the functional status of patients based on the International Prostate Symptom Score (IPSS), International Index of Erectile Function, and Quality of Life were comparable in patients undergoing EPA-TWW and EPA-J. The final data indicate a statistically equivalent risk of developing complications such as urinary incontinence, shortening of the penis, and decreased erectile function. CONCLUSIONS: The study did not demonstrate a statistically significant difference in the effectiveness of the treatment and the risks of complications during anastomotic surgery with or without vessel-sparing. However, an unformalized assessment demonstrates the best state of erectile function in patients after vascular-preserving surgery.
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Transparent wood (TW)-based composites are of significant interest for smart window applications. In this research, we demonstrate a facile dual-stimuli-responsive chromic TW where optical properties are reversibly controlled in response to changes in temperature and UV-radiation. For this functionality, bleached wood was impregnated with solvent-free thiol and ene monomers containing chromic components, consisting of a mixture of thermo- and photoresponsive chromophores, and was then UV-polymerized. Independent optical properties of individual chromic components were retained in the compositional mixture. This allowed to enhance the absolute optical transmission to 4 times above the phase change temperature. At the same time, the transmission at 550 nm could be reduced 11-77%, on exposure to UV by changing the concentration of chromic components. Chromic components were localized inside the lumen of the wood structure, and durable reversible optical properties were demonstrated by multiple cycling testing. In addition, the chromic TW composites showed reversible energy absorption capabilities for heat storage applications and demonstrated an enhancement of 64% in the tensile modulus as compared to a native thiol-ene polymer. This study elucidates the polymerization process and effect of chromic components distribution and composition on the material's performance and perspectives toward the development of smart photoresponsive windows with energy storage capabilities.
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Twisted Laguerre-Gaussian Schell model (TLGSM) beams are a novel type of partially coherent beams, which carry the twist phase and the vortex phase simultaneously. In this paper, the self-reconstruction (SR) of the TLGSM beam partially blocked by an opaque obstacle and propagating through a thin lens focusing system is studied in detail. Implementing the pseudo-mode expansion method, we represent the TLGSM beam as a superposition of spatially coherent modes, which is applicable for calculating the cross spectral density (CSD) and spectral degree of coherence (SDOC) of such a beam using the Fourier transform. The numerical results reveal that the twist parameter, a measure of the strength of a twist phase, determines the characteristics of the SR. In the case of the topological charge of the vortex is positive, the SR capability of spectral density is significantly improved with the increase of the twist parameter. The physical mechanism behind these phenomena is analyzed in detail from the point view of mode expansion. Further, the dependence of the side ring intensity and SR capability of the SDOC on the twist parameter are also investigated. It is found that the SR capability and side ring intensity of the SDOC are simultaneously enhanced for a large twist parameter, providing an efficient way to determine the number of topological charge. Our study results may find application in communication and information recovery applications.
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INTRODUCTION: Urethral stricture is a partial or complete narrowing of the urethra, caused by damage to the urethral epithelium. This disease leads to a persistent urination dysfunction, the elimination of which is a difficult task. The aim of this study was to perform a comparative analysis of the immediate and long-term narrowing treatment results of the proximal part of the bulbar and membranous urethral parts using the developed magnifying and anastomotic methods. MATERIAL AND METHODS: A total of 102 patients with a confirmed diagnosis of stricture of the bulbomembranous urethral part of the urethra who underwent treatment in the urological hospital in Irkutsk City Clinical Hospital No. 1 during the period 2012-2018 participated in this prospective study. Urethroplasty operations were performed in two ways, using the anastomotic and intra-urethral substitution techniques. Through the assessment of preoperative parameters, statistical homogeneity of comparison groups was established. RESULTS: The final data analysis showed relapse for 4 patients from Group I and for 2 patients in Group II. The absence of relapse during the entire observation period was equal in both groups and after 2 years amounted to 83.0 ±7.9% in Group I and 92.5 ±5.1% in Group II. CONCLUSIONS: In both groups, the desired result was achieved - adequate independent urination was restored. The anastomotic method of urethroplasty should be used with caution in patients at risk groups, as well as with the presence of predictors of complications: previous transurethral surgeries on the urethra and prostate, anastomotic urethroplasty, radical prostatectomy. The developed minimally invasive substitution technique has a similar effectiveness with a lower risk of complications.
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Gold (Au) and silver (Ag) nanostructures have widespread utilization from biomedicine to materials science. Therefore, their synthesis with control of their morphology and surface chemistry have been among the hot topics over the last decades. Here, we introduce a new approach relying on sugar derivatives that work as reducing, stabilizing, and capping agents in the synthesis of Au and Ag nanostructures. These sugar derivatives are utilized alone and as mixture, resulting in spherical, spheroid, trigonal, polygonic, and star-like morphologies. The synthesis approach was further tested in the presence of acetate and dimethylamine as size- and shape-directing agents. With the use of transmission electron microscopy (TEM), selected area electron diffraction (SAED), x-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible (UV-vis) absorption spectroscopy techniques, the particle size, shape, assembly, aggregation, and film formation characteristics were evaluated. NPs' attributes were shown to be tunable by manipulating the sugar ligand selection and sugar ligand/metal-ion ratio. For instance, with an imine side group and changing the sugar moiety from cellobiose to lactose, the morphology of the Ag nanoparticles (NPs) transformed from well dispersed cubic to rough and aggregated. The introduction of acetate and dimethylamine further extended the growth pattern and morphological properties of these NPs. As examples, L5 AS, G5AS, and S5AS ligands formed spherical or sheet-like structures when used alone, which upon the use of these additives transformed into larger multicore and rough NPs, revealing their significant effect on the NP morphology. Selected samples were tested for their stability against protein corona formation and ionic strength, where a high chemical stability and resistance to protein coating were observed. The findings show a promising, benign approach for the synthesis of shape- and size-directed Au and Ag nanostructures, along with a selection of the chemistry of carbohydrate-derivatives that can open new windows for their applications.
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Refractive index (RI) determination for delignified wood templates is vital for transparent wood composite fabrication. Reported RIs in the literature are based on either single plant fibers or wood powder, measured by the immersion liquid method (ILM) combined with mathematical fitting. However, wood structure complexity and the physical background of the fitting were not considered. In this work, RIs of delignified wood templates were measured by the ILM combined with a light transmission model developed from the Fresnel reflection/refraction theory for composite materials. The RIs of delignified balsa wood are 1.536 ± 0.006 and 1.525 ± 0.008 at the wavelength of 589 nm for light propagating perpendicular and parallel to the wood fiber direction, respectively. For delignified birch wood, corresponding values are 1.537 ± 0.005 and 1.529 ± 0.006, respectively. The RI data for delignified wood scaffolds are important for tailoring optical properties of transparent wood biocomposites, and also vital in optical properties investigations by theoretical modelling of complex light propagation in transparent wood and related composites. The developed light transmission model in combination with the immersion liquid method can be used to determine the RI of complex porous or layered solid materials and composites.
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The genus Amphitetranychus Oudemans (Tetranychidae) consists of only three species, A. quercivorus (Ehara & Gotoh), A. savenkoae (Reck) and A. viennensis (Zacher). The original description of A. savenkoae was extremely simple and had no drawing of the aedeagus; however, a subsequent study described only the aedeagus. The present study investigated all three species in detail using a combination of morphological traits, crossbreeding experiments, esterase zymograms and the mitochondrial cytochrome c oxidase subunit I (COI) gene. Morphological differences in the peritremes and male aedeagi were observed among the three species. Complete reproductive isolation was confirmed in the reciprocal crosses between the morphologically similar A. savenkoae and A. quercivorus (no female offspring were produced). Esterase zymograms differed interspecifically, but not intraspecifically (among individuals in a given species). All three species formed clearly separate clades with 100% bootstrap values in the COI tree, and A. savenkoae was more closely related to A. quercivorus than to A. viennensis, which corresponded to the morphological similarity of their aedeagi and setal counts on tarsi IV. A key to Amphitetranychus species is provided.
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Tetranychidae/anatomia & histologia , Animais , DNA/genética , Código de Barras de DNA Taxonômico , Complexo IV da Cadeia de Transporte de Elétrons/genética , Esterases/metabolismo , Feminino , Hibridização Genética , Masculino , Fenótipo , Filogenia , Especificidade da Espécie , Tetranychidae/enzimologia , Tetranychidae/genéticaRESUMO
Transparent wood (TW) is an emerging optical material combining high optical transmittance and haze for structural applications. Unlike nonscattering absorbing media, the thickness dependence of light transmittance for TW is complicated because optical losses are also related to increased photon path length from multiple scattering. In the present study, starting from photon diffusion equation, it is found that the angle-integrated total light transmittance of TW has an exponentially decaying dependence on sample thickness. The expression reveals an attenuation coefficient which depends not only on the absorption coefficient but also on the diffusion coefficient. The total transmittance and thickness were measured for a range of TW samples, from both acetylated and nonacetylated balsa wood templates, and were fitted according to the derived relationship. The fitting gives a lower attenuation coefficient for the acetylated TW compared to the nonacetylated one. The lower attenuation coefficient for the acetylated TW is attributed to its lower scattering coefficient or correspondingly lower haze. The attenuation constant resulted from our model hence can serve as a singular material parameter that facilitates cross-comparison of different sample types, at even different thicknesses, when total optical transmittance is concerned. The model was verified with two other TWs (ash and birch) and is in general applicable to other scattering media.
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We report on the study of polarization properties of light propagating through transparent wood (TW), which is an anisotropically scattering medium, and consider two cases: completely polarized and totally unpolarized light. It was demonstrated that scattered light distribution is affected by the polarization state of incident light. Scattering is the most efficient for light polarized parallel to cellulose fibers. Furthermore, unpolarized light becomes partially polarized (with a polarization degree of 50%) after propagating through the TW. In the case of totally polarized incident light, however, the degree of polarization of transmitted light is decreased, in an extreme case to a few percent, and reveals an unusual angular dependence on the material orientation. The internal hierarchical complex structure of the material, in particular cellulose fibrils organized in lamellae, is believed to be responsible for the change of the light polarization degree. It was demonstrated that the depolarization properties are determined by the angle between the polarization of light and the wood fibers, emphasizing the impact of their internal structure, unique for different wood species.
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In this work, we demonstrate reconfigurable frequency manipulation of quantum states of light in the telecom C-band. Triggered single photons are encoded in a superposition state of three channels using sidebands up to 53 GHz created by an off-the-shelf phase modulator. The single photons are emitted by an InAs/GaAs quantum dot grown by metal-organic vapor-phase epitaxy within the transparency window of the backbone fiber optical network. A cross-correlation measurement of the sidebands demonstrates the preservation of the single photon nature; an important prerequisite for future quantum technology applications using the existing telecommunication fiber network.
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Two-spotted spider mite, Tetranychus urticae Koch (Tetranychidae: Acariformes), is one of the most important agricultural pests in the world. Their populations have a tendency of rapidly developing resistance to acaricides, making it necessary to have a variety of active ingredients for sustainable chemical control of this pest. We investigated acaricidal properties of a relatively new insecticide spirotetramat using its commercial formulation, Movento Energy. Spirotetramat applied at concentrations equivalent to the field rates of 78 and 90 g ai/ha had a strong negative effect on the survival of the treated T. urticae, with ca. 95% of females and ca. 65% of males dying after the treatment. Spirotetramat appeared to interfere with female reproductive system. Many of the dead treated females had eggs stuck in the oviduct and protruding from their bodies. Surviving treated females did not lay eggs. Furthermore, untreated females that mated with treated males did not produce female offspring and displayed the symptoms of spirotetramat poisoning. Toxic effects continued manifesting themselves after female mites were transferred from treated onto untreated plant culture. Contrary to previous studies, contact toxicity was also detected. None of the treated immature stages survived to adulthood. Based on these results, spirotetramat may be a good option for integrated pest management in crops that are simultaneously affected by sucking insects and spider mites and in pesticide rotation sequences that are a part of integrated resistance management programs.