We measured the forces required to slide sessile drops over surfaces. The forces were measured by means of a vertical deflectable capillary stuck in the drop. The drop adhesion force instrument ...(DAFI) allowed the investigation of the dynamic lateral adhesion force of water drops of 0.1 to 2 μL volume at defined velocities. On flat PDMS surfaces, the dynamic lateral adhesion force increases linearly with the diameter of the contact area of the solid–liquid interface and linearly with the sliding velocity. The movement of the drop relative to the surfaces enabled us to resolve the pinning of the three-phase contact line to individual defects. We further investigated a 3D superhydrophobic pillar array. The depinning of the receding part of the rim of the drop occurred almost simultaneously from four to five pillars, giving rise to peaks in the lateral adhesion force.
Transcriptional codes initiated during brain development are ultimately realized in adulthood as distinct cell types performing specialized roles in behavior. Focusing on the mouse external globus ...pallidus (GPe), we demonstrate that the potential contributions of two GABAergic GPe cell types to voluntary action are fated from early life to be distinct. Prototypic GPe neurons derive from the medial ganglionic eminence of the embryonic subpallium and express the transcription factor Nkx21. These neurons fire at high rates during alert rest, and encode movements through heterogeneous firing rate changes, with many neurons decreasing their activity. In contrast, arkypallidal GPe neurons originate from lateral/caudal ganglionic eminences, express the transcription factor FoxP2, fire at low rates during rest, and encode movements with robust increases in firing. We conclude that developmental diversity positions prototypic and arkypallidal neurons to fulfil distinct roles in behavior via their disparate regulation of GABA release onto different basal ganglia targets.
Inhibitory GABAergic interneurons of the mouse neocortex are a highly heterogeneous population of neurons that originate from the ventral telencephalon and migrate tangentially up into the developing ...cortical plate. The majority of cortical interneurons arise from a transient embryonic structure known as the medial ganglionic eminence (MGE), but how the remarkable diversity is specified in this region is not known. We have taken a genetic fate mapping strategy to elucidate the temporal origins of cortical interneuron subtypes within the MGE. We used an inducible form of Cre under the regulation of Olig2, a basic helix-loop-helix transcription factor highly expressed in neural progenitors of the MGE. We observe that the physiological subtypes of cortical interneurons are, to a large degree, unique to their time point of generation.
By combining an inducible genetic fate mapping strategy with electrophysiological analysis, we have systematically characterized the populations of cortical GABAergic interneurons that originate from ...the caudal ganglionic eminence (CGE). Interestingly, compared with medial ganglionic eminence (MGE)-derived cortical interneuron populations, the initiation embryonic day 12.5 (E12.5) and peak production (E16.5) of interneurons from this embryonic structure occurs 3 d later in development. Moreover, unlike either pyramidal cells or MGE-derived cortical interneurons, CGE-derived interneurons do not integrate into the cortex in an inside-out manner but preferentially (75%) occupy superficial cortical layers independent of birthdate. In contrast to previous estimates, CGE-derived interneurons are both considerably greater in number (approximately 30% of all cortical interneurons) and diversity (comprised by at least nine distinct subtypes). Furthermore, we found that a large proportion of CGE-derived interneurons, including the neurogliaform subtype, express the glycoprotein Reelin. In fact, most CGE-derived cortical interneurons express either Reelin or vasoactive intestinal polypeptide. Thus, in conjunction with previous studies, we have now determined the spatial and temporal origins of the vast majority of cortical interneuron subtypes.
The neuronal networks that generate vertebrate movements such as walking and swimming are embedded in the spinal cord. These networks, which are referred to as central pattern generators (CPGs), are ...ideal systems for determining how ensembles of neurons generate simple behavioural outputs. In spite of efforts to address the organization of the locomotor CPG in walking animals, little is known about the identity and function of the spinal interneuron cell types that contribute to these locomotor networks. Here we use four complementary genetic approaches to directly address the function of mouse V1 neurons, a class of local circuit inhibitory interneurons that selectively express the transcription factor Engrailed1. Our results show that V1 neurons shape motor outputs during locomotion and are required for generating ‘fast’ motor bursting. These findings outline an important role for inhibition in regulating the frequency of the locomotor CPG rhythm, and also suggest that V1 neurons may have an evolutionarily conserved role in controlling the speed of vertebrate locomotor movements.
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Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We report experimental observation of a normal incidence phononic band gap in one-dimensional periodic (SiO2/poly(methyl methacrylate)) multilayer film at gigahertz frequencies using Brillouin ...spectroscopy. The band gap to midgap ratio of 0.30 occurs for elastic wave propagation along the periodicity direction, whereas for inplane propagation the system displays an effective medium behavior. The phononic properties are well captured by numerical simulations. The porosity in the silica layers presents a structural scaffold for the introduction of secondary active media for potential coupling between phonons and other excitations, such as photons and electrons.
Obesity is a major risk factor for breast cancer. This study examines whether bariatric surgery affects breast cancer incidence in women with obesity compared to BMI-matched controls.
EMBASE, ...MEDLINE, Web of Science, and CINAHL were searched. Primary studies on female breast cancer incidence after bariatric surgery were eligible.
11 studies were included (n = 1,106,939). The rate of cancer diagnosis was lower in the surgical group (0.54%) compared to control (0.84%; risk ratio (RR) 0.50, 95%CI 0.37–0.67, I2 = 88%). The results were robust to sensitivity analyses for patient age and study size. Bariatric surgery was associated with increased risk of stage I cancer (RR 1.23, 95%CI 1.06–1.44) and reduced risk of stage III or IV cancer (RR 0.50, 95%CI 0.28–0.88). Hormone receptor characteristics were not affected.
Bariatric surgery is associated with reduced incidence and earlier stage at diagnosis of breast cancer in women with obesity compared to BMI-matched controls.
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•Bariatric surgery in women with obesity may result in lower risk of breast cancer.•Bariatric surgery in women with obesity does not appear to affect hormone receptors.•Bariatric surgery in women with obesity may result in earlier stage at diagnosis.
GABAergic activity is thought to influence developing neocortical sensory circuits. Yet the late postnatal maturation of local layer (L)4 circuits suggests alternate sources of GABAergic control in ...nascent thalamocortical networks. We show that a population of L5b, somatostatin (SST)-positive interneuron receives early thalamic synaptic input and, using laser-scanning photostimulation, identify an early transient circuit between these cells and L4 spiny stellates (SSNs) that disappears by the end of the L4 critical period. Sensory perturbation disrupts the transition to a local GABAergic circuit, suggesting a link between translaminar and local control of SSNs. Conditional silencing of SST+ interneurons or conversely biasing the circuit toward local inhibition by overexpression of neuregulin-1 type 1 results in an absence of early L5b GABAergic input in mutants and delayed thalamic innervation of SSNs. These data identify a role for L5b SST+ interneurons in the control of SSNs in the early postnatal neocortex.
•Early postnatal thalamic synaptic input onto L5b somatostatin interneurons•Transient reciprocal connectivity between L5b INs and L4 spiny stellate cells•Sensory activity is required for the transition to a local L4 GABAergic circuit•Molecular bias toward early local IN synapses delays thalamic innervation of SSNs
Marques-Smith et al. identify a transient, early postnatal GABAergic interneuron circuit involved in thalamocortical integration in primary somatosensory cortex. Perturbation of sensory and molecular cues alters the temporal dynamics of this circuit and thereby maturation of thalamocortical afferent input.
Aerosols, both natural and anthropogenic, are an important but complex component of the Earth’s climate system. Their net impact on climate is about equal in magnitude to that of greenhouse gases but ...can vary significantly by region and type. Understanding and quantifying these aerosol effects is critical for accurate climate modeling and for developing strategies to mitigate climate change. In this paper, we utilize AERONET (Aerosol Robotic NETwork) data from 10 stations situated in the dust belt region to characterize aerosol properties essential for climate change assessment. Aerosol optical depth (AOD) data at 500 nm and Ångström exponent (α) data at the pair of wavelengths of 440 and 870 nm (α440-870) in the study region are analyzed to discriminate among different types of aerosols. The annual and monthly variabilities in AODs are analyzed to see the aerosols trend in the study region. In addition, the AOD and α440-870 data are utilized in order to determine different aerosol types during the period of study. Furthermore, the correlation coefficient between AODs and various meteorological parameters (temperature, wind speed, wind direction, relative humidity, and visibility) is analyzed. The results of the study indicate that Tamanrasset (2.49%), KAUST (1.29%), Solar Village (1.67%), and Dalanzadgad (0.64%) indicate an increasing trend, while Cairo (−0.38%), Masdar (−2.31%), Dushanbe (−1.18%), and Lahore (−0.10%) indicate a decreasing trend in AODs during the study period. Similarly, the results of characterizing aerosol types show that the highest percentage of desert dust aerosols (68%), mixed aerosols (86%), and biomass burning aerosols (15%) are found over Tamanrasset, Lahore, and Dalanzadgad AERONET stations. The study revealed a strong correlation between AODs and visibility, a moderate correlation with temperature, and a low correlation with other meteorological parameters (wind speed, wind direction, and relative humidity) in the study region. The results of the study are very encouraging and enhance our confidence in using historical AERONET data to improve our understanding of atmospheric aerosols’ characteristics.
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