Ancient diversification in extreme environments: Exploring the historical biogeography of the Antarctic winged midge Parochlus steinenii (Diptera: Chironomidae)

The terrestrial fauna of Antarctica consists of a limited number of species, notably insects, small crustaceans and other micro-invertebrates. Over long periods of evolutionary isolation, these organisms have developed varying degrees of tolerance to multifaceted environmental stresses. Recent molecular biogeographical research highlights the enduring persistence of much of Antarctica's current terrestrial fauna, with estimates spanning from hundreds of thousands to millions of years. Parochlus steinenii, commonly known as the Antarctic winged midge, stands out as one of the only two insect species native to Antarctica. Distributed across three biogeographic regions, southern South America and the Falkland/Malvinas Islands, sub-Antarctic South Georgia and the Maritime Antarctic South Shetland Islands, this midge raises questions about the temporal isolation of its populations and their divergence. Employing mitochondrial and nuclear genetic markers, we conducted phylogeographic and demographic analyses on 151 individuals of P. steinenii obtained across the three main biogeographic regions including the Magellanic sub-Antarctic Ecoregion (MSE) of southern South America, the sub-Antarctic Island of South Georgia (SG) and the South Shetland Islands (SSI) within the Maritime Antarctic (MA). Our data support the diversification of P. steinenii during the mid-Pleistocene around 1.46 Mya. This period included a branching event between a clade containing only specimens from the MSE and a clade containing individuals from a broader range of locations including the SSI and SG. Based on intraspecific phylogeographic and demographic inferences, we detected strong evolutionary divergence between the three main biogeographic regions. We also detected a signal of population growth during the deglaciation process in SSI and SG, contrary to the pattern seen in the MSE. The different demographic and phylogeographic histories between the sampled biogeographic regions could result from the MA and SG experiencing a strong genetic bottleneck due to a reduction in population size during the Last Glacial Maximum, while the MSE maintained a significant effective population size. The high level of divergence detected between individuals from the MSE and the remaining biogeographic regions supports the hypothesis of a speciation process taking place in P. steinenii

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Using Weights In Abdominal Exercises: Electromyography Response Of The Rectus Abdominis And Rectus Femoris Muscles

Among persons who do regular exercises, many include abdominal exercises in their customary routine. For this, there are a growing variety of movements being created for strengthening the abdominal muscles. This work aims to know, through electromyography analysis, the action potencies of the supra and infra umbilical of the rectus abdominis and rectus femoris muscles during the execution of abdominal exercises with and without the addition of weights. Lying on the backside, seven flexing movements of the trunk - one without weight, three with 2 Kg on the neck, elbow and chest and three with 4 Kg on the same points - were executed. Nine female university students between 18 and 23 years old participated in the study. Surface electrodes were fixed to the supra and infra umbilical areas of the rectus abdominis and rectus femoris muscles. The results showed that the utilization of weights in the abdominal exercises did not appear to be effective for the rectus abdominis muscle since greater action potencies were only verified in the rectus femoris muscle. We concluded that the differences observed in the RMS were not relevant to the point of indicating the utilization of weights to improve abdominal exercises because greater action potencies were only observed in the rectus femoris muscle.438487496Axler, C.T., McGill, S.M., Low back loads over a variety of abdominal exercises: Searching for the safest abdominal challenge (1997) Medicine & Science in Sport & Exercise, pp. 804-811Bankoff, A.D.P., Furlani, J., Estudo eletromiográfico dos músculos Reto Abdominal e oblíquo externo em diversos exercícios na posição de decúbito dorsal (1986) Revista Brasileira de Ciências do Esporte, 7 (2), pp. 69-74Basmajian, J.V., (1976) Electrofisiologia de la Accion Muscular, , Buenos Aires: PanamericanaBeim, G.M., Giraldo, J.L., Pincivero, D.M., Borror, M.J., Fu, F.H., Abdominal strengthening exercises: A comparative EMG study (1997) Journal of Sport Rehabilitation, 6 (1), pp. 11-20Brooks, D., Brooks, C.C., (1994) Mitos do Exercício Abdominal, (71). , SprintFlint, M.M., Abdominal muscle involvement during the performance of various forms of sit-up exercises (1965) American Journal of Physical Medicine, 44 (5), pp. 224-233Floyd, W.F., Silver, P.H.S., Electromyographic study of patterns of activity of the anterior abdominal wall muscles in man (1950) Journal of Anatomy, 84, pp. 132-145Guimarães, A.C.S., The contribution of the rectus femoris in twelve selected abdominal exercise: An electromyographic study (1991) The Journal of Sports and Physical Fitness, 31 (2), pp. 222-230Hamill, J., Knutzen, K.M., (1999) Bases Biomecânicas do Movimento Humano, , São Paulo: ManoleJuker, D., McGill, S., Kropf, P., Steffen, T., Quantitative intramuscular myoelectric activity of lumbar portions of psoas and the abdominal wall during a wide variety of tasks (1998) Medicine Science in Sports and Exercise, 30, p. 301Kendall, F.P., Mc Creary, E.K., (1990) Músculos - Provas e Funçẽes. 3ed, pp. 205-271. , São Paulo: ManoleMoraes, A.C., Bankoff, A.D., Análise eletromiográfica dos músculos Reto Abdominal e Oblíquo Externo, em crianças na faixa etária de 8 a 10 anos. Campinas (1993), Dissertação - Faculdade de Educação Física, UNICAMPPellegrinotti, I.L., Moreira, Z.W., Galdi, E.H.G., Electromyography analysis of the rectus abdominis and external oblique muscles of children 8 to 10 years old (1995) Electromyography and Clinical Neurophysiology, 35 (7), pp. 425-430Rasch, P.J., Burke, R.K., (1977) Cinesiologia e Anatomia Aplicada: A Ciência do Movimento Humano. 5ed, , Rio de Janeiro: Guanabara KooganSheffield, F.J., Major, M.C., Electromyography study of the abdominal muscles in walking and other movements (1962) American Journal of Physical Medicine, 41, pp. 142-147Shirado, O., Ito, T., Kaneda, K., Strax, T.E., Electromyographic analysis of four techniques for isometric trunk muscle exercises (1995) Archives Physiology Medical Rehabilitation, (76)Tyson, A.D., (1997) Abdominal Anatomy and Strength Assessment. Part 1. Strength and Conditioning, 19 (2), pp. 38-41Walters, C.E., Partridge, M.J., Electromyographic study of the differential action of the abdominal muscles during exercise (1957) American Journal of Physical Medicine, 36, pp. 259-268Wardem, S., Waswelner, H., Bennell, K., Comparison of abshaper and conventionally performed abdominal exercises using surface electromyography (1999) Medicine Science Sports and Exercise, 31 (11), pp. 1656-1664Whiting, W.C., Rugg, S., Coleman, A., Vincent, W.J., Muscle activity during sit-ups using abodminal exercises devices (1999) The Journal of Strength and Conditioning Research, 13 (4), pp. 339-34

Experimental Investigation of the Effect of Subdicing on an Ultrasound Matrix Transducer

Over the past decades, real-time three-dimensional (3D) medical ultrasound has attracted much attention since it enables clinicians to diagnose more accurately. This calls for ultrasound matrix transducers with a large number of elements, which can be interfaced with an application-specific integrated circuit (ASIC) for data reduction. An important aspect of the design of such a transducer is the geometry of each element, since it affects the mode of vibration and, consequently, the efficiency of the transducer. In this paper, we experimentally investigate the effect of subdicing on a piezoelectric (PZT) transducer. We fabricate and acoustically characterize a prototype PZT matrix transducer built on top of ASICs. The prototype transducer contains subdiced and non-subdiced elements, whose performance can be directly compared under the same conditions. Measurement results show that subdiced elements have a better performance compared to non-subdiced ones. Subdicing increases the peak pressure by 25%, raises the bandwidth by 10% and reduces the ringing time by 25%.Accepted Author ManuscriptImPhys/Medical ImagingElectronic Instrumentatio

Automated Characterization of Matrix Transducer Arrays using the Verasonics Imaging System

Over the past decades, ultrasound imaging has made considerable progress based on the advancement of imaging systems as well as transducer technology. With the need for advanced transducer arrays with complex designs and technical requirements, there is also a need for suitable tools to characterize such transducers. However, despite the importance of acoustic characterization to assess the performance of novel transducer arrays, the characterization process of highly complex transducers might involve various manual steps, which are laborious, time-consuming, and subject to errors. These factors can hinder the full characterization of a prototype transducer, leading to an under-representation or inadequate evaluation. To come to an extensive, high-quality evaluation of a prototype transducer, the acoustic characterization of each transducer element is indispensable in both transmit and receive operations. In this paper, we propose a pipeline to automatically perform the acoustic characterization of a matrix transducer using a research imaging system. The performance of the pipeline is tested on a prototype matrix transducer consisting of 960 elements. The results show that the proposed pipeline is capable of performing the complete acoustic characterization of a high-element count transducer in a fast and convenient way. Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.ImPhys/Medical ImagingElectronic Instrumentatio

Design of an ultrasound transceiver asic with a switching-artifact reduction technique for 3D carotid artery imaging

This paper presents an ultrasound transceiver application-specific integrated circuit (ASIC) directly integrated with an array of 12 × 80 piezoelectric transducer elements to enable next-generation ultrasound probes for 3D carotid artery imaging. The ASIC, implemented in a 0.18 µm high-voltage Bipolar-CMOS-DMOS (HV BCD) process, adopted a programmable switch matrix that allowed selected transducer elements in each row to be connected to a transmit and receive channel of an imaging system. This made the probe operate like an electronically translatable linear array, allowing large-aperture matrix arrays to be interfaced with a manageable number of system channels. This paper presents a second-generation ASIC that employed an improved switch design to minimize clock feedthrough and charge-injection effects of high-voltage metal–oxide–semiconductor field-effect transistors (HV MOSFETs), which in the first-generation ASIC caused parasitic transmis-sions and associated imaging artifacts. The proposed switch controller, implemented with cascaded non-overlapping clock generators, generated control signals with improved timing to mitigate the effects of these non-idealities. Both simulation results and electrical measurements showed a 20 dB reduction of the switching artifacts. In addition, an acoustic pulse-echo measurement successfully demonstrated a 20 dB reduction of imaging artifacts.ImPhys/Medical ImagingElectronic Instrumentatio

An Ultrasound Matrix Transducer for High-Frame-Rate 3-D Intra-cardiac Echocardiography

Objective: Described here is the development of an ultrasound matrix transducer prototype for high-frame-rate 3-D intra-cardiac echocardiography. Methods: The matrix array consists of 16 × 18 lead zirconate titanate elements with a pitch of 160 µm × 160 µm built on top of an application-specific integrated circuit that generates transmission signals and digitizes the received signals. To reduce the number of cables in the catheter to a feasible number, we implement subarray beamforming and digitization in receive and use a combination of time-division multiplexing and pulse amplitude modulation data transmission, achieving an 18-fold reduction. The proposed imaging scheme employs seven fan-shaped diverging transmit beams operating at a pulse repetition frequency of 7.7 kHz to obtain a high frame rate. The performance of the prototype is characterized, and its functionality is fully verified. Results: The transducer exhibits a transmit efficiency of 28 Pa/V at 5 cm per element and a bandwidth of 60% in transmission. In receive, a dynamic range of 80 dB is measured with a minimum detectable pressure of 10 Pa per element. The element yield of the prototype is 98%, indicating the efficacy of the manufacturing process. The transducer is capable of imaging at a frame rate of up to 1000 volumes/s and is intended to cover a volume of 70° × 70° × 10 cm. Conclusion: These advanced imaging capabilities have the potential to support complex interventional procedures and enable full-volumetric flow, tissue, and electromechanical wave tracking in the heart.ImPhys/Verweij groupImPhys/Medical ImagingElectronic InstrumentationImPhys/De Jong grou

A Tiled Ultrasound Matrix Transducer for Volumetric Imaging of the Carotid Artery

High frame rate three-dimensional (3D) ultrasound imaging would offer excellent possibilities for the accurate assessment of carotid artery diseases. This calls for a matrix transducer with a large aperture and a vast number of elements. Such a matrix transducer should be interfaced with an application-specific integrated circuit (ASIC) for channel reduction. However, the fabrication of such a transducer integrated with one very large ASIC is very challenging and expensive. In this study, we develop a prototype matrix transducer mounted on top of multiple identical ASICs in a tiled configuration. The matrix was designed to have 7680 piezoelectric elements with a pitch of 300 μm × 150 μm integrated with an array of 8 × 1 tiled ASICs. The performance of the prototype is characterized by a series of measurements. The transducer exhibits a uniform behavior with the majority of the elements working within the −6 dB sensitivity range. In transmit, the individual elements show a center frequency of 7.5 MHz, a −6 dB bandwidth of 45%, and a transmit efficiency of 30 Pa/V at 200 mm. In receive, the dynamic range is 81 dB, and the minimum detectable pressure is 60 Pa per element. To demonstrate the imaging capabilities, we acquired 3D images using a commercial wire phantom.ImPhys/Verweij groupImPhys/Medical ImagingElectronic InstrumentationImPhys/De Jong grou