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1.
Proc Natl Acad Sci U S A ; 119(46): e2211283119, 2022 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-36343251

RESUMEN

Springtails (Collembola) have been traditionally portrayed as explosive jumpers with incipient directional takeoff and uncontrolled landing. However, for these collembolans that live near the water, such skills are crucial for evading a host of voracious aquatic and terrestrial predators. We discover that semiaquatic springtails, Isotomurus retardatus, can perform directional jumps, rapid aerial righting, and near-perfect landing on the water surface. They achieve these locomotive controls by adjusting their body attitude and impulse during takeoff, deforming their body in midair, and exploiting the hydrophilicity of their ventral tube, known as the collophore. Experiments and mathematical modeling indicate that directional-impulse control during takeoff is driven by the collophore's adhesion force, the body angle, and the stroke duration produced by their jumping organ, the furcula. In midair, springtails curve their bodies to form a U-shape pose, which leverages aerodynamic forces to right themselves in less than ~20 ms, the fastest ever measured in animals. A stable equilibrium is facilitated by the water adhered to the collophore. Aerial righting was confirmed by placing springtails in a vertical wind tunnel and through physical models. Due to these aerial responses, springtails land on their ventral side ~85% of the time while anchoring via the collophore on the water surface to avoid bouncing. We validated the springtail biophysical principles in a bioinspired jumping robot that reduces in-flight rotation and lands upright ~75% of the time. Thus, contrary to common belief, these wingless hexapods can jump, skydive, and land with outstanding control that can be fundamental for survival.


Asunto(s)
Artrópodos , Animales , Artrópodos/fisiología , Rotación , Agua , Fenómenos Biomecánicos
2.
Omega (Westport) ; : 302228231190240, 2023 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-37470363

RESUMEN

There is limited knowledge regarding Colombian patients with advanced cancer preferences regarding their final moments, place of death, and post-death wishes. To better understand these preferences, we conducted 23 in-depth interviews with patients between the ages of 28 and 78 receiving treatment at two academic hospitals and the National Cancer Institute. While many participants desired a peaceful death, few were comfortable discussing the topic of death directly. Some younger participants expressed an interest in euthanasia but had not received any guidance or support. While several participants preferred a home death, some expressed a desire to die in a hospital due to better symptom control. Additionally, when discussing post-death wishes, some participants expressed frustration about being unable to have these conversations with their loved ones and their preferences for funeral arrangements. Socioeconomic and geographical factors significantly impacted the wishes and preferences expressed, with many individuals hesitant to initiate difficult conversations.

3.
J Exp Biol ; 225(7)2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-35217876

RESUMEN

Rapid turning and swimming contribute to ecologically important behaviors in fishes such as predator avoidance, prey capture, mating and the navigation of complex environments. For riverine species, such as knifefishes, turning behaviors may also be important for navigating locomotive perturbations caused by turbulent flows. Most research on fish maneuvering focuses on fish with traditional fin and body morphologies, which primarily use body bending and the pectoral fins during turning. However, it is uncertain how fishes with uncommon morphologies are able to achieve sudden and controllable turns. Here, we studied the turning performance and the turning hydrodynamics of the black ghost knifefish (Apteronotus albifrons, N=6) which has an atypical elongated ribbon fin. Fish were filmed while swimming forward at ∼2 body lengths s-1 and feeding from a fixed feeder (control) and an oscillating feeder (75 Hz) at two different amplitudes. 3D kinematic analysis of the body revealed the highest pitch angles and lowest body bending coefficients during steady swimming. Low pitch angle, high maximum yaw angles and large body bending coefficients were characteristic of small and large turns. Asynchrony in pectoral fin use was low during turning; however, ribbon fin wavelength, frequency and wave speed were greatest during large turns. Digital particle image velocimetry (DPIV) showed larger counter-rotating vortex pairs produced during turning by the ribbon fin in comparison to vortices rotating in the same direction during steady swimming. Our results highlight the ribbon fin's role in controlled rapid turning through modulation of wavelength, frequency and wave speed.


Asunto(s)
Gymnotiformes , Natación , Aletas de Animales , Animales , Fenómenos Biomecánicos , Hidrodinámica , Reología
4.
J Sci Food Agric ; 102(14): 6340-6348, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35527679

RESUMEN

BACKGROUND: Local leafy vegetables are gaining attention as affordable sources of micronutrients, including vitamins, pro-vitamin carotenoids and other bioactive compounds. Stinging nettles (Urtica spp.) are used as source of fibers, herbal medicine and food. However, despite the relatively wide geographical spread of Urtica leptophylla on the American continent, little is known about its content of vitamin E congeners and carotenoids. We therefore investigated the particular nutritional potential of different plant structures of wild Costa Rican U. leptophylla by focusing on their vitamin E and carotenoid profiles. RESULTS: Young, mature and herbivore-damaged leaves, flowers, stems and petioles were collected and freeze-dried. Vitamin E and carotenoids were determined by high-performance liquid chromatography after liquid/liquid extraction with hexane. α-Tocopherol was the major vitamin E congener in all structures. Flowers had a high content of γ-tocopherol. Herbivore-damaged leaves had higher contents of vitamin E than undamaged leaves. Lutein was the major and ß-carotene the second most abundant carotenoid in U. leptophylla. No differences in carotenoid profiles were observed between damaged and undamaged leaves. CONCLUSION: The leaves of U. leptophylla had the highest nutritional value of all analyzed structures; therefore, they might represent a potential source of α-tocopherol, lutein and ß-carotene. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Asunto(s)
Urtica dioica , Vitamina E , Carotenoides/análisis , Costa Rica , Flores/química , Hexanos , Luteína/análisis , Vitamina E/análisis , Vitaminas/análisis , alfa-Tocoferol/análisis , beta Caroteno/análisis , gamma-Tocoferol/análisis
5.
Compr Rev Food Sci Food Saf ; 21(5): 4002-4017, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35876644

RESUMEN

Pulses, dry grains of the Fabaceae family used for food and feed, are particularly important agricultural products with increasing commercial and nutritional relevance. Similar to other plant commodities, pulses can be affected by fungi in the field and during postharvest. Some of these fungi produce mycotoxins, which can seriously threaten human and animal health by causing acute poisoning and chronic effects. In this review, information referring to the analysis and occurrence of these compounds in pulses is summarized. An overview of the aims pursued, and of the methodologies employed for mycotoxin analysis in the different reports is presented, followed by a comprehensive review of relevant articles on mycotoxins in pulses, categorized according to the geographical region, among other considerations. Moreover, special attention was given to the effect of climatic conditions on microorganism infestation and mycotoxin accumulation. Furthermore, the limited literature available was considered to look for possible correlations between the degree of fungal infection and the mycotoxin incidence in pulses. In addition, the potential effect of certain phenolic compounds on reducing fungi infestation and mycotoxin accumulation was reviewed with examples on beans. Emphasis was also given to a specific group of mycotoxins, the phomopsins, that mainly impact lupin. Finally, the negative consequences of mycotoxin accumulation on the physiology and development of contaminated seeds and seedlings are presented, focusing on the few reports available on pulses. Given the agricultural and nutritional potential that pulses offer for human well-being, their promotion should be accompanied by attention to food safety issues, and mycotoxins might be among the most serious threats. Practical Application: According to the manuscript template available in the website, this section is for "JFS original research manuscripts ONLY; optional". Since we are publishing in CRFSFS this requirement will not be done.


Asunto(s)
Micotoxinas , Animales , Contaminación de Alimentos/análisis , Hongos , Humanos , Micotoxinas/análisis
6.
J Pharmacol Exp Ther ; 377(1): 29-38, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33431611

RESUMEN

Opioid use disorder affects over 2 million Americans with an increasing number of deaths due to overdose from the synthetic opioid fentanyl and its analogs. The Food and Drug Administration-approved opioid receptor antagonist naloxone (e.g., Narcan) is used currently to treat overdose; however, a short duration of action limits its clinical utility. Methocinnamox (MCAM) is a long-lasting opioid receptor antagonist that may reverse and prevent the ventilatory-depressant effects of fentanyl. This study compared the ability of naloxone (0.0001-10 mg/kg) and MCAM (0.0001-10 mg/kg) to reverse and prevent ventilatory depression by fentanyl and compared the duration of action of MCAM intravenously and subcutaneously in two procedures: ventilation and warm-water tail withdrawal. In male Sprague-Dawley rats (N = 8), fentanyl (0.0032-0.178 mg/kg, i.v.) decreased minute volume in a dose- and time-dependent manner with a dose of 0.178 mg/kg decreasing VE to less than 40% of control. MCAM and naloxone reversed the ventilatory-depressant effects of 0.178 mg/kg fentanyl in a dose-related manner. The day after antagonist administration, MCAM but not naloxone attenuated the ventilatory-depressant effects of fentanyl. The duration of action of MCAM lasted up to 3 days and at least 2 weeks after intravenous and subcutaneous administration, respectively. MCAM attenuated the antinociceptive effects of fentanyl, with antagonism lasting up to 5 days and more than 2 weeks after intravenous and subcutaneous administration, respectively. Reversal and prolonged antagonism by MCAM might provide an effective treatment option for the opioid crisis, particularly toxicity from fentanyl and related highly potent analogs. SIGNIFICANCE STATEMENT: This study demonstrates that like naloxone, methocinnamox (MCAM) reverses the ventilatory-depressant effects of fentanyl in a time- and dose-related manner. However, unlike naloxone, the duration of action of MCAM was greater than 2 weeks when administered subcutaneously and up to 5 days when administered intravenously. These data suggest that MCAM might be particularly useful for rescuing individuals from opioid overdose, including fentanyl overdose, as well as protecting against the reemergence of ventilatory depression (renarconization).


Asunto(s)
Cinamatos/uso terapéutico , Derivados de la Morfina/uso terapéutico , Antagonistas de Narcóticos/uso terapéutico , Insuficiencia Respiratoria/tratamiento farmacológico , Animales , Cinamatos/administración & dosificación , Fentanilo/toxicidad , Inyecciones Intravenosas , Masculino , Derivados de la Morfina/administración & dosificación , Antagonistas de Narcóticos/administración & dosificación , Narcóticos/toxicidad , Ratas , Ratas Sprague-Dawley , Insuficiencia Respiratoria/etiología , Insuficiencia Respiratoria/prevención & control
7.
J Exp Biol ; 224(10)2021 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-33795417

RESUMEN

Neotropical freshwater fishes such as knifefishes are commonly faced with navigating intense and highly unsteady streams. However, our knowledge on locomotion in apteronotids comes from laminar flows, where the ribbon fin dominates over the pectoral fins or body bending. Here, we studied the 3D kinematics and swimming control of seven black ghost knifefish (Apteronotus albifrons) moving in laminar flows (flow speed U∞≈1-5 BL s-1) and in periodic vortex streets (U∞≈2-4 BL s-1). Two different cylinders (∼2 and ∼3 cm diameter) were used to generate the latter. Additionally, fish were exposed to an irregular wake produced by a free oscillating cylinder (∼2 cm diameter; U∞≈2 BL s-1). In laminar flows, knifefish mainly used their ribbon fin, with wave frequency, speed and acceleration increasing with U∞. In contrast, knifefish swimming behind a fixed cylinder increased the use of pectoral fins, which resulted in changes in body orientation that mimicked steady backward swimming. Meanwhile, individuals behind the oscillating cylinder presented a combination of body bending and ribbon and pectoral fin movements that counteract the out-of-phase yaw oscillations induced by the irregular shedding of vortices. We corroborated passive out-of-phase oscillations by placing a printed knifefish model just downstream of the moving cylinder, but when placed one cylinder diameter downstream, the model oscillated in phase. Thus, the wake left behind an oscillating body is more challenging than a periodic vortex shedding for an animal located downstream, which may have consequences on inter- and intra-specific interactions.


Asunto(s)
Gymnotiformes , Natación , Animales , Fenómenos Biomecánicos , Marcha
8.
Muscle Nerve ; 60(1): 90-95, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30994189

RESUMEN

INTRODUCTION: Myotonic dystrophy type 1 (DM1) is a multisystemic disorder characterized mainly by skeletal muscle alterations. Although oropharyngeal dysphagia is a prominent clinical feature of DM1, it remains poorly studied in its early disease stages. METHODS: Dysphagia was investigated in 11 presymptomatic DM1 carriers, 14 patients with DM1 and 12 age-matched healthy controls, by using fiberoptic endoscopic evaluation of swallowing (FEES) and clinical scores. RESULTS: Scores for the FEES variables, delayed pharyngeal reflex, posterior pooling, and postswallow residue were significantly greater in patients with DM1 and in presymptomatic DM1 carriers than in healthy controls (P < 0.05); oropharyngeal dysfunction was more severe in patients than in presymptomatic carriers. Penetration/aspiration was found altered exclusively in patients with DM1 (P < 0.05). DISCUSSION: Swallowing dysfunction occurs in presymptomatic DM1 carriers. Timely diagnosis of dysphagia in preclinical stages of the disease will aid in the timely management of presymptomatic carriers, potentially preventing medical complications. Muscle Nerve, 2019.


Asunto(s)
Enfermedades Asintomáticas , Trastornos de Deglución/fisiopatología , Distrofia Miotónica/fisiopatología , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Trastornos de Deglución/etiología , Endoscopía del Sistema Digestivo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Distrofia Miotónica/complicaciones , Distrofia Miotónica/genética , Proteína Quinasa de Distrofia Miotónica/genética , Adulto Joven
9.
Proc Biol Sci ; 281(1783): 20140180, 2014 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-24671978

RESUMEN

Animal fliers frequently move through a variety of perturbed flows during their daily aerial routines. However, the extent to which these perturbations influence flight control and energetic expenditure is essentially unknown. Here, we evaluate the kinematic and metabolic consequences of flight within variably sized vortex shedding flows using five Anna's hummingbirds feeding from an artificial flower in steady control flow and within vortex wakes produced behind vertical cylinders. Tests were conducted at three horizontal airspeeds (3, 6 and 9 m s(-1)) and using three different wake-generating cylinders (with diameters equal to 38, 77 and 173% of birds' wing length). Only minimal effects on wing and body kinematics were demonstrated for flight behind the smallest cylinder, whereas flight behind the medium-sized cylinder resulted in significant increases in the variances of wingbeat frequency, and variances of body orientation, especially at higher airspeeds. Metabolic rate was, however, unchanged relative to that of unperturbed flight. Hummingbirds flying within the vortex street behind the largest cylinder exhibited highest increases in variances of wingbeat frequency, and of body roll, pitch and yaw amplitudes at all measured airspeeds. Impressively, metabolic rate under this last condition increased by up to 25% compared with control flights. Cylinder wakes sufficiently large to interact with both wings can thus strongly affect stability in flight, eliciting compensatory kinematic changes with a consequent increase in flight metabolic costs. Our findings suggest that vortical flows frequently encountered by aerial taxa in diverse environments may impose substantial energetic costs.


Asunto(s)
Movimientos del Aire , Aves/fisiología , Metabolismo Energético , Vuelo Animal , Animales , Fenómenos Biomecánicos , Masculino
10.
Planta ; 240(5): 1037-50, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25023631

RESUMEN

MAIN CONCLUSION: High levels of ß-carotene, lycopene, and the rare γ-carotene occur predominantly lipid-dissolved in the chromoplasts of peach palm fruits. First proof of their absorption from these fruits is reported. The structural diversity, the physical deposition state in planta, and the human bioavailability of carotenoids from the edible fruits of diverse orange and yellow-colored peach palm (Bactris gasipaes Kunth) varieties were investigated. HPLC-PDA-MS(n) revealed a broad range of carotenes, reaching total carotenoid levels from 0.7 to 13.9 mg/100 g FW. Besides the predominant (all-E)-ß-carotene (0.4-5.4 mg/100 g FW), two (Z)-isomers of γ-carotene (0.1-3.9 mg/100 g FW), and one (Z)-lycopene isomer (0.04-0.83 mg/100 g FW) prevailed. Approximately 89-94 % of total carotenoid content pertained to provitamin A carotenoids with retinol activity equivalents ranging from 37 to 609 µg/100 g FW. The physical deposition state of these carotenoids in planta was investigated using light, transmission electron, and scanning electron microscopy. The plastids found in both orange and yellow-colored fruit mesocarps were amylo-chromoplasts of the globular type, containing carotenoids predominantly in a lipid-dissolved form. The hypothesis of lipid-dissolved carotenoids was supported by simple solubility estimations based on carotenoid and lipid contents of the fruit mesocarp. In our study, we report first results on the human bioavailability of γ-carotene, ß-carotene, and lycopene from peach palm fruit, particularly proving the post-prandial absorption of the rarely occurring γ-carotene. Since the physical state of carotenoid deposition has been shown to be decisive for carotenoid bioavailability, lipid-dissolved carotenoids in peach palm fruits are expected to be highly bioavailable, however, further studies are required.


Asunto(s)
Arecaceae/química , Carotenoides/análisis , Frutas/química , Plastidios/química , beta Caroteno/análisis , Adulto , Arecaceae/ultraestructura , Disponibilidad Biológica , Carotenoides/química , Carotenoides/farmacocinética , Cromatografía Líquida de Alta Presión , Color , Femenino , Humanos , Lípidos/química , Licopeno , Masculino , Espectrometría de Masas , Microscopía Electrónica de Transmisión , Plastidios/ultraestructura , Solubilidad , beta Caroteno/química , beta Caroteno/farmacocinética
11.
J Microbiol Methods ; 219: 106892, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38311183

RESUMEN

Gracilibacillus halotolerans, a new and relatively unstudied extremophile, extracted from the Great Salt Lake USA, survives in an extreme saline environment. Uncovering optimal laboratory growth conditions can be useful to improve treatment strategies against antibiotic resistance and biofilm formation. In the current study, G. halotolerans growth optimization was tested to determine the ideal saline concentration. In addition, a variety of G. halotolerans'-derived survival strategies were reviewed. The major findings of the current study includes the optimal laboratory growth condition for G. halotolerans that requires the supplement of 5% NaCl. In addition, optimal growth was observed up to 72 h in Luria Bertani (LB) broth. Identifying the optimal laboratory growth conditions for G. halotolerans will standardize growth methods, reduce laboratory cost, and can improve future investigations of extremophile bacteria as model organisms to combat antibiotic resistance, biofilm, and other persister cell characteristics that negatively affect research and clinical settings.


Asunto(s)
Bacillaceae , Composición de Base , ADN Bacteriano , Bacillaceae/genética , Lagos
12.
Int Immunopharmacol ; 130: 111753, 2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38401463

RESUMEN

A decade of clinical research has indicated psilocybin's effectiveness in treating various neuropsychiatric disorders, such as depression and substance abuse. The correlation between increased pro-inflammatory cytokines and the severity of neuropsychiatric symptoms, along with the known anti-inflammatory potential of some psychedelics, suggests an immunomodulatory role for psilocybin. This study aims to understand the mechanism of action of psilocybin by investigating the cytotoxic and immunomodulatory effects of psilocybin and psilocin on both resting and LPS-activated RAW 264.7 murine macrophages. The study evaluated the cytotoxicity of psilocybin and psilocin using an LDH assay across various doses and assessed their impact on cytokine production in RAW 264.7 cells, measuring cytokine expression via ELISA. Different doses, including those above and below the LC50, were used in both pre-treatment and post-treatment approaches. The LDH assay revealed that psilocybin is almost twice as cytotoxic as psilocin, with an LC50 of 12 ng/ml and 28 ng/ml, respectively. In resting macrophages, both psilocybin and psilocin triggered significant release of TNF- α after 4 h, with the lowest doses inducing higher levels of the cytokine than the highest doses. IL-10 expression in resting cells was only triggered by the highest dose of psilocin in the 4-hour incubation group. In LPS-stimulated cells, psilocin reduced TNF- α levels more than psilocybin in pre-treatment and post-treatment, with no significant effects on IL-10 in pre-treatment. Psilocin, but not psilocybin, induced a significant increase of IL-10 in post-treatment, leading to the conclusion that psilocin, but not psilocybin, exerts anti-inflammatory effects on classically activated macrophages.


Asunto(s)
Interleucina-10 , Psilocibina , Ratones , Animales , Psilocibina/farmacología , Psilocibina/uso terapéutico , Psilocibina/análisis , Lipopolisacáridos , Citocinas , Factor de Necrosis Tumoral alfa , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico
13.
bioRxiv ; 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38915562

RESUMEN

Entomopathogenic nematodes (EPNs) exhibit a bending-elastic instability, or kink, before becoming airborne, a feature hypothesized but not proven to enhance jumping performance. Here, we provide the evidence that this kink is crucial for improving launch performance. We demonstrate that EPNs actively modulate their aspect ratio, forming a liquid-latched closed loop over a slow timescale O (1 s), then rapidly open it O (10 µs), achieving heights of 20 body lengths (BL) and generating ∼ 10 4 W/Kg of power. Using jumping nematodes, a bio-inspired Soft Jumping Model (SoftJM), and computational simulations, we explore the mechanisms and implications of this kink. EPNs control their takeoff direction by adjusting their head position and center of mass, a mechanism verified through phase maps of jump directions in simulations and SoftJM experiments. Our findings reveal that the reversible kink instability at the point of highest curvature on the ventral side enhances energy storage using the nematode's limited muscular force. We investigated the impact of aspect ratio on kink instability and jumping performance using SoftJM, and quantified EPN cuticle stiffness with AFM, comparing it with C. elegans . This led to a stiffness-modified SoftJM design with a carbon fiber backbone, achieving jumps of ∼25 BL. Our study reveals how harnessing kink instabilities, a typical failure mode, enables bidirectional jumps in soft robots on complex substrates like sand, offering a novel approach for designing limbless robots for controlled jumping, locomotion, and even planetary exploration.

14.
Food Chem ; 416: 135601, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-36907011

RESUMEN

Anthocyanins in red cabbage, sweet potato, and Tradescantia pallida leaves were characterised. A total of 18 non-, mono-, and diacylated cyanidins was identified in red cabbage by high performance liquid chromatography-diode array detection coupled to high-resolution and multi-stage mass spectrometry. Sweet potato leaves contained 16 different cyanidin- and peonidin glycosides being predominantly mono- and diacylated. In T. pallida leaves, the tetra-acylated anthocyanin tradescantin prevailed. The large proportion of acylated anthocyanins resulted in a superior thermal stability during heating of aqueous model solutions (pH 3.0) coloured with red cabbage and purple sweet potato extracts as compared to that of a commercial Hibiscus-based food dye. However, their stability was still outperformed by that of the most stable Tradescantia extract. Comparing vis spectra from pH 1-10, the latter had an additional, uncommon absorption maximum at approx. 585 nm at slightly acidic to neutral pH values, yielding intensely red to purple colours.


Asunto(s)
Brassica , Colorantes de Alimentos , Ipomoea batatas , Tradescantia , Antocianinas/análisis , Espectrometría de Masas en Tándem , Ipomoea batatas/química , Cromatografía Líquida de Alta Presión/métodos , Extractos Vegetales/química
15.
Trends Parasitol ; 39(10): 806-807, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37573176

RESUMEN

Ticks are blood-feeding parasites with limited locomotion, known for transmitting multiple pathogens to vertebrates. England et al. suggest that ticks can be easily pulled, via electrostatic induction, toward charged hosts with fluffy coats that are prone to accumulate higher electrostatic potentials. Thus, static electricity may influence ticks' ecology and management.


Asunto(s)
Garrapatas , Animales , Vertebrados , Ecología
16.
Bioinspir Biomim ; 18(5)2023 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-37552773

RESUMEN

Recent observations of wingless animals, including jumping nematodes, springtails, insects, and wingless vertebrates like geckos, snakes, and salamanders, have shown that their adaptations and body morphing are essential for rapid self-righting and controlled landing. These skills can reduce the risk of physical damage during collision, minimize recoil during landing, and allow for a quick escape response to minimize predation risk. The size, mass distribution, and speed of an animal determine its self-righting method, with larger animals depending on the conservation of angular momentum and smaller animals primarily using aerodynamic forces. Many animals falling through the air, from nematodes to salamanders, adopt a skydiving posture while descending. Similarly, plant seeds such as dandelions and samaras are able to turn upright in mid-air using aerodynamic forces and produce high decelerations. These aerial capabilities allow for a wide dispersal range, low-impact collisions, and effective landing and settling. Recently, small robots that can right themselves for controlled landings have been designed based on principles of aerial maneuvering in animals. Further research into the effects of unsteady flows on self-righting and landing in small arthropods, particularly those exhibiting explosive catapulting, could reveal how morphological features, flow dynamics, and physical mechanisms contribute to effective mid-air control. More broadly, studying apterygote (wingless insects) landing could also provide insight into the origin of insect flight. These research efforts have the potential to lead to the bio-inspired design of aerial micro-vehicles, sports projectiles, parachutes, and impulsive robots that can land upright in unsteady flow conditions.


Asunto(s)
Robótica , Animales , Vuelo Animal/fisiología , Insectos , Gravitación , Semillas , Fenómenos Biomecánicos
17.
Front Plant Sci ; 13: 995307, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36247585

RESUMEN

In this work, we report a successful protocol to obtain in vitro peach palm (Bactris gasipaes Kunth) "Diamantes 10" plants through somatic embryogenesis from transverse thin cell layer (TCL) explants, dissected from three sections (basal, medial, and apical) of lateral offshoots of adult plants cultured on different concentrations of 4-amino-3,5,6-trichloropicolonic acid (picloram). After swelling and development of primary callus in all treatments, without any strong effect of explant origin or picloram concentration, it was possible to observe the formation of embryogenic structures and the exact point from where they developed. Browning was also observed and correlated to the induction treatments, although it was not an impairment for the production of embryogenic structures. Subsequent maturation and conversion of somatic embryos into plantlets allowed their acclimatization 17 months after culture initiation (ACI), which was quicker than previous reports with juvenile tissues (from embryos or seed-germinated plantlets). To the best of our knowledge, this is the first report on peach palm regeneration through somatic embryogenesis from TCL explants from adult plants and could constitute, after fine-tuning the acclimatization stage, a tool for mass clonal propagation of elite genotypes of this open-pollinated crop, as well as for the establishment of conservation strategies of in situ gene bank plant accessions endangered due to aging and other threats.

18.
Micromachines (Basel) ; 13(4)2022 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-35457930

RESUMEN

The agile and power-efficient locomotion of a water strider has inspired many water-walking devices. These bioinspired water strider robots generally adopt a DC motor to create a sculling trajectory of the driving leg. These robots are, thus, inevitably heavy with many supporting legs decreasing the velocity of the robots. There have only been a few attempts to employ smart materials despite their advantages of being lightweight and having high power densities. This paper proposes an artificial muscle-based water-walking robot capable of moving forward and turning with four degrees of freedom. A compliant amplified shape memory alloy actuator (CASA) used to amplify the strain of a shape memory alloy wire enables a wide sculling motion of the actuation leg with only four supporting legs to support the entire weight of the robot. Design parameters to increase the actuation strain of the actuator and to achieve a desired swing angle (80°) are analyzed. Finally, experiments to measure the forward speed and angular velocities of the robot are carried out to compare with other robots. The robot weighs only 0.236 g and has a maximum and average speed of 1.56, 0.31 body length per second and a maximum and average angular velocity of 145.05°/s and 14.72°/s.

19.
Nat Genet ; 54(5): 715-724, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35551309

RESUMEN

Transgenic papaya is widely publicized for controlling papaya ringspot virus. However, the impact of particle bombardment on the genome remains unknown. The transgenic SunUp and its progenitor Sunset genomes were assembled into 351.5 and 350.3 Mb in nine chromosomes, respectively. We identified a 1.64 Mb insertion containing three transgenic insertions in SunUp chromosome 5, consisting of 52 nuclear-plastid, 21 nuclear-mitochondrial and 1 nuclear genomic fragments. A 591.9 kb fragment in chromosome 5 was translocated into the 1.64 Mb insertion. We assembled a gapless 9.8 Mb hermaphrodite-specific region of the Yh chromosome and its 6.0 Mb X counterpart. Resequencing 86 genomes revealed three distinct groups, validating their geographic origin and breeding history. We identified 147 selective sweeps and defined the essential role of zeta-carotene desaturase in carotenoid accumulation during domestication. Our findings elucidated the impact of particle bombardment and improved our understanding of sex chromosomes and domestication to expedite papaya improvement.


Asunto(s)
Carica , Carica/genética , Cromosomas de las Plantas/genética , Domesticación , Fitomejoramiento , Cromosomas Sexuales
20.
Sci Rep ; 10(1): 18698, 2020 10 29.
Artículo en Inglés | MEDLINE | ID: mdl-33122715

RESUMEN

We discovered that knifefish (Apteronotus albifrons) during suction feeding can produce millimeter-sized cavitation bubbles and flow accelerations up to ~ 450 times the acceleration of gravity. Knifefish may use this powerful suction-induced cavitation to cause physical damage on prey hiding in narrow refuges, therefore facilitating capture.

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