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The fast and forceful kicking strike of the secretary bird
The study of animal locomotion has uncovered principles that can be applied to bio-inspired robotics, prosthetics and rehabilitation medicine, while also providing insight into musculoskeletal form and function [1, 2, 3, 4]. In particular, study of extreme behaviors can reveal mechanical constraints and trade-offs that have influenced evolution of limb form and function [1, 2]. Secretary birds (Sagittarius serpentarius; Figure 1A) are large terrestrial birds of prey endemic to sub-Saharan Africa, which feed on snakes, lizards and small mammals [5]. They frequently kick and stamp on the prey’s head until it is killed or incapacitated, particularly when dispatching larger lizards and venomous snakes [5]. The consequences of a missed strike when hunting venomous snakes can be deadly [5], so the kicking strikes of secretary birds require fast yet accurate neural control. Delivery of fast, forceful and accurate foot strikes that are sufficient to stun and kill prey requires precision targeting, demanding a high level of coordination between the visual and neuromuscular systems
GRASSP: a spectrograph for the study of transient luminous events
We present the main parameters, design features, and optical characterization of the Granada Sprite Spectrograph and Polarimeter (GRASSP), a ground- based spectrographic system intended for the analysis of the spectroscopic signature of transient luminous events (TLEs) occurring in the mesosphere of the Earth. It has been designed to measure the spectra of the light emitted from TLEs with a mean spectral resolution of 0.235 nm and 0.07 nm/px dispersion in the wavelength range between 700 and 800 nm. (C) 2016 Optical Society of AmericaSpanish Ministry of Science and Innovation, Ministerio de Economia y Competitividad (MINECO) (ESP2013-48032-C5-5-R, ESP2015-69909-C5-2-R, FIS2014-61774-EXP); European Union FEDER Program; Ramon y Cajal Contract (RYC-2011-07801).Peer reviewe
Wearable HD-DOT for investigating functional connectivity in the adult brain: A single subject, multi-session study
We applied a wearable 24-module high-density diffuse optical tomography (HD-DOT) system in a resting state (RS) paradigm repeatedly in one subject. Seed-based correlation maps show large field-of-view RS functional connectivity
Group-level cortical functional connectivity patterns using fNIRS: assessing the effect of bilingualism in young infants
Epub 2021 Jun 12.Significance: Early monolingual versus bilingual experience induces adaptations in the development
of linguistic and cognitive processes, and it modulates functional activation patterns during
the first months of life. Resting-state functional connectivity (RSFC) is a convenient approach to
study the functional organization of the infant brain. RSFC can be measured in infants during
natural sleep, and it allows to simultaneously investigate various functional systems. Adaptations
have been observed in RSFC due to a lifelong bilingual experience. Investigating whether bilingualism-
induced adaptations in RSFC begin to emerge early in development has important
implications for our understanding of how the infant brain’s organization can be shaped by early
environmental factors.
Aims: We attempt to describe RSFC using functional near-infrared spectroscopy (fNIRS) and to
examine whether it adapts to early monolingual versus bilingual environments. We also present
an fNIRS data preprocessing and analysis pipeline that can be used to reliably characterize RSFC
in development and to reduce false positives and flawed results interpretations.
Methods: We measured spontaneous hemodynamic brain activity in a large cohort (N ¼ 99) of
4-month-old monolingual and bilingual infants using fNIRS. We implemented group-level
approaches based on independent component analysis to examine RSFC, while providing proper
control for physiological confounds and multiple comparisons.
Results: At the group level, we describe the functional organization of the 4-month-old infant
brain in large-scale cortical networks. Unbiased group-level comparisons revealed no differences
in RSFC between monolingual and bilingual infants at this age.
Conclusions: High-quality fNIRS data provide a means to reliably describe RSFC patterns in
the infant brain. The proposed group-level RSFC analyses allow to assess differences in RSFC
across experimental conditions. An effect of early bilingual experience in RSFC was not
observed, suggesting that adaptations might only emerge during explicit linguistic tasks, or at
a later point in development.The authors would like to thank all the parents and infants who generously participate in our
studies. The authors also would like to thank Elena Aguirrebengoa for her assistance on recruiting
and testing participants and Enrico Amico for discussion regarding the connICA approach.
This work was supported by the Basque Government (Nos. PRE_2018_2_0154, PIBA_2019_
104, and BERC 2018-2021); the Spanish Ministry of Economy and Competitiveness (Nos.
RYC-2017-21845, PID2019-105520GB-100, and PSI2014-5452-P); the Natural Sciences and
Engineering Research Council of Canada (Nos. 506948 and 506993); and the Engineering and
Physical Sciences Research Council (Nos. EP/N025946/1 and EP/509577/1)
Geología y metalogenia del depósito celesto-barítico Llao Llao (Paleógeno?), provincia del Neuquén
Fil: Del Blanco, Miguel Angel. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales; ArgentinaFil: de Barrio, Raúl Ernesto. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales; ArgentinaFil: Hernández, Clemente Recio. Universidad de Salamanca. Servicio General de Isótopos Estables; EspañaFil: Zuazo, Jerónimo J.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales; Argentin
Ontogeny of sex-related differences in foetal developmental features, lipid availability and fatty acid composition
Sex-related differences in lipid availability and fatty acid composition during swine foetal development were investigated. Plasma cholesterol and triglyceride concentrations in the mother were strongly related to the adequacy or inadequacy of foetal development and concomitant activation of protective growth in some organs (brain, heart, liver and spleen). Cholesterol and triglyceride availability was similar in male and female offspring, but female foetuses showed evidence of higher placental transfer of essential fatty acids and synthesis of non-essential fatty acids in muscle and liver. These sex-related differences affected primarily the neutral lipid fraction (triglycerides), which may lead to sex-related postnatal differences in energy partitioning. These results illustrate the strong influence of the maternal lipid profile on foetal development and homeorhesis, and they confirm and extend previous reports that female offspring show better adaptive responses to maternal malnutrition than male offspring. These findings may help guide dietary interventions to ensure adequate fatty acid availability for postnatal development
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
DNA Methylation-Independent Reversion of Gemcitabine Resistance by Hydralazine in Cervical Cancer Cells
BACKGROUND: Down regulation of genes coding for nucleoside transporters and drug metabolism responsible for uptake and metabolic activation of the nucleoside gemcitabine is related with acquired tumor resistance against this agent. Hydralazine has been shown to reverse doxorubicin resistance in a model of breast cancer. Here we wanted to investigate whether epigenetic mechanisms are responsible for acquiring resistance to gemcitabine and if hydralazine could restore gemcitabine sensitivity in cervical cancer cells. METHODOLOGY/PRINCIPAL FINDINGS: The cervical cancer cell line CaLo cell line was cultured in the presence of increasing concentrations of gemcitabine. Down-regulation of hENT1 & dCK genes was observed in the resistant cells (CaLoGR) which was not associated with promoter methylation. Treatment with hydralazine reversed gemcitabine resistance and led to hENT1 and dCK gene reactivation in a DNA promoter methylation-independent manner. No changes in HDAC total activity nor in H3 and H4 acetylation at these promoters were observed. ChIP analysis showed H3K9m2 at hENT1 and dCK gene promoters which correlated with hyper-expression of G9A histone methyltransferase at RNA and protein level in the resistant cells. Hydralazine inhibited G9A methyltransferase activity in vitro and depletion of the G9A gene by iRNA restored gemcitabine sensitivity. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that acquired gemcitabine resistance is associated with DNA promoter methylation-independent hENT1 and dCK gene down-regulation and hyper-expression of G9A methyltransferase. Hydralazine reverts gemcitabine resistance in cervical cancer cells via inhibition of G9A histone methyltransferase
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