3,687 research outputs found
Cytogenetic and immunohistochemical characterization of Mammary Analogue Secretory Carcinoma of salivary glands
Objectives: Mammary analogue secretory carcinoma (MASC), initially considered a sub-set of acinic cell carcinoma (ACC) harbours an ETV6 translocation [t(12:15)(p13:25q)] and is now regarded as a distinct entity. Several putative markers to differentiate MASC from ACC have been reported however, the immunohistochemical profile is still being explored and updated. The purpose of this study was to further explore the cytogenetic and immunohistochemical profile of MASC. Study design: Cases were analysed for ETV6 translocation using fluorescent in situ hybridisation(FISH) and stained for CK8, amylase, mammaglobin, GCDFP 15, MUC1, MUC4, STAT5a, Ki 67 (n=37), CK7, Cam5.2, CK14, SMA, p63, S100, vimentin and DOG- 1 (n=42). Histochemical stains for mucins were also performed and data collected for age, gender and site. Results: FISH showed nine cases with ETV6 rearrangement and two with increased ETV6 copies. These eleven cases showed absence of PAS-D resistant granules with 10/11 showing strong S100, mammaglobin and Stat5a staining. All ACCs showed diffuse DOG-1 staining whereas 8/11 MASCs were negative and three showed only focal DOG1 staining. Conclusion: DOG-1 can be used in conjunction with PAS-D, S100 and mammaglobin to identify MASCs. Cases with increased ETV6 copies are a novel finding with a similar immunostaining profile and should be considered as MASCs
Production and Reproductive Performance of Bhadawari Buffaloes in Uttar Pradesh, India
Bhadawari is one of the recognized buffalo breeds of India and is famous for high fat content in their milk. Data on production and reproductive traits were collected under Network Project on Bhadawari buffaloes, at Indian Grassland and Fodder Research Institute, Jhansi, Uttar Pradesh, India. The overall least squares means (±SE) for peak yield, days to attain peak yield, lactation milk yield, lactation length, 305 days milk yield, milk yield per day of lactation, service period, calving interval and dry period were 6.96±0.10 kg, 52.8±4.1 days, 1250.5±24.6 kg, 291.4±4.9 days, 1213.5±21.6 kg, 4.30±0.06 kg, 172.4±7.7 days, 522.1±12.1 days and 241.80±11.3 days, respectively. Period of calving had a significant (p<0.05) to highly significant (p<0.01) effect on all the traits studied except service period and dry period, where it was not significant. Season of calving had a significant (p<0.05) effect or lactation length and highly significant (p<0.01) effect on lactation milk yield, 305 days milk yield and all the reproductive traits under study. The lowest calving interval, service period and dry period were observed in rainy season calvers and they differed significantly (p<0.01) with winter and summer calvers. Parity had a significant effect (p<0.05) on lactation milk yield, 305 days milk yield and milk yield per day of lactation. Pair-wise comparison revealed that lactation milk yield was highest in the 2nd lactation followed by 3rd and 4th lactation. Large coefficient of variation observed for different traits under study indicates that there is enough scope for improvement in the production and reproduction traits. Better breeding management and selection for increased performance is needed for genetic improvement of these traits
Silent synapses generate sparse and orthogonal action potential firing in adult-born hippocampal granule cells.
In adult neurogenesis young neurons connect to the existing network via formation of thousands of new synapses. At early developmental stages, glutamatergic synapses are sparse, immature and functionally 'silent', expressing mainly NMDA receptors. Here we show in 2- to 3-week-old young neurons of adult mice, that brief-burst activity in glutamatergic fibers is sufficient to induce postsynaptic AP firing in the absence of AMPA receptors. The enhanced excitability of the young neurons lead to efficient temporal summation of small NMDA currents, dynamic unblocking of silent synapses and NMDA-receptor-dependent AP firing. Therefore, early synaptic inputs are powerfully converted into reliable spiking output. Furthermore, due to high synaptic gain, small dendritic trees and sparse connectivity, neighboring young neurons are activated by different distinct subsets of afferent fibers with minimal overlap. Taken together, synaptic recruitment of young neurons generates sparse and orthogonal AP firing, which may support sparse coding during hippocampal information processing
Marketing Percolation
A percolation model is presented, with computer simulations for
illustrations, to show how the sales of a new product may penetrate the
consumer market. We review the traditional approach in the marketing
literature, which is based on differential or difference equations similar to
the logistic equation (Bass 1969). This mean field approach is contrasted with
the discrete percolation on a lattice, with simulations of "social percolation"
(Solomon et al 2000) in two to five dimensions giving power laws instead of
exponential growth, and strong fluctuations right at the percolation threshold.Comment: to appear in Physica
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The vertical cloud structure of the West African monsoon: a 4 year climatology using CloudSat and CALIPSO
The West African summer monsoon (WAM) is an important driver of the global climate and locally provides most of the annual rainfall. A solid climatological knowledge of the complex vertical cloud structure is invaluable to forecasters and modelers to improve the understanding of the WAM. In this paper, 4 years of data from the CloudSat profiling radar and CALIPSO are used to create a composite zonal mean vertical cloud and precipitation structure for the WAM. For the first time, the near-coincident vertical radar and lidar profiles allow for the identification of individual cloud types from optically thin cirrus and shallow cumulus to congestus and deep convection. A clear diurnal signal in zonal mean cloud structure is observed for the WAM, with deep convective activity enhanced at night producing extensive anvil and cirrus, while daytime observations show more shallow cloud and congestus. A layer of altocumulus is frequently observed over the Sahara at night and day, extending southward to the coastline, and the majority of this cloud is shown to contain supercooled liquid in the top. The occurrence of deep convective systems and congestus in relation to the position of the African easterly jet is studied, but only the daytime cumulonimbus distribution indicates some influence of the jet position
Influence of Surfactant-Mediated Interparticle Contacts on the Mechanical Stability of Supraparticles
[Image: see text] Colloidal supraparticles are micron-scale spherical assemblies of uniform primary particles, which exhibit emergent properties of a colloidal crystal, yet exist as a dispersible powder. A prerequisite to utilize these emergent functionalities is that the supraparticles maintain their mechanical integrity upon the mechanical impacts that are likely to occur during processing. Understanding how the internal structure relates to the resultant mechanical properties of a supraparticle is therefore of general interest. Here, we take the example of supraparticles templated from water/fluorinated oil emulsions in droplet-based microfluidics and explore the effect of surfactants on their mechanical properties. Stable emulsions can be generated by nonionic block copolymers consisting of a hydrophilic and fluorophilic block and anionic fluorosurfactants widely available under the brand name Krytox. The supraparticles formed in the presence of both types of surfactants appear structurally similar, but differ greatly in their mechanical properties. While the nonionic surfactant induces superior mechanical stability and ductile fracture behavior, the anionic Krytox surfactant leads to weak supraparticles with brittle fracture. We complement this macroscopic picture with Brillouin light spectroscopy that is very sensitive to the interparticle contacts for subnanometer-thick adsorbed layers atop of the nanoparticle. While the anionic Krytox does not significantly affect the interparticle bonds, the amphiphilic nonionic surfactant drastically strengthens these bonds to the point that individual particle vibrations are not resolved in the experimental spectrum. Our results demonstrate that seemingly subtle changes in the physicochemical properties of supraparticles can drastically impact the resultant mechanical properties
Synaptic Integration of Adult-Born Hippocampal Neurons Is Locally Controlled by Astrocytes.
Adult neurogenesis is regulated by the neurogenic niche, through mechanisms that remain poorly defined. Here, we investigated whether niche-constituting astrocytes influence the maturation of adult-born hippocampal neurons using two independent transgenic approaches to block vesicular release from astrocytes. In these models, adult-born neurons but not mature neurons showed reduced glutamatergic synaptic input and dendritic spine density that was accompanied with lower functional integration and cell survival. By taking advantage of the mosaic expression of transgenes in astrocytes, we found that spine density was reduced exclusively in segments intersecting blocked astrocytes, revealing an extrinsic, local control of spine formation. Defects in NMDA receptor (NMDAR)-mediated synaptic transmission and dendrite maturation were partially restored by exogenous D-serine, whose extracellular level was decreased in transgenic models. Together, these results reveal a critical role for adult astrocytes in local dendritic spine maturation, which is necessary for the NMDAR-dependent functional integration of newborn neurons
Pregnancy complications and adverse birth outcomes among women with celiac disease: a population-based study from England
OBJECTIVES: Evidence-based information about adverse birth outcomes and pregnancy complications is crucial when counseling women with celiac disease (CD); however, limited population-based data on such risks exist. We estimated these for pregnant women with CD diagnosed before and after delivery.
METHODS: We included all singleton pregnancies between 1997 and 2012 using linked primary care data from the Clinical Practice Research Datalink and secondary care Hospital Episode Statistics data. Risks of pregnancy complications (antepartum and postpartum hemorrhage, pre-eclampsia, and mode of delivery) and adverse birth outcomes (preterm birth, stillbirth, and low birth weight) were compared between pregnancies of women with and without CD using logistic/multinomial regression. Risks were stratified on the basis of whether women were diagnosed or yet undiagnosed before delivery.
RESULTS: Of 363,930 pregnancies resulting in a live birth or stillbirth, 892 (0.25%) were among women with CD. Diagnosed CD was not associated with an increased risk of pregnancy complications or adverse birth outcomes compared with women without CD. However, the risk of postpartum hemorrhage and assisted delivery was slightly higher among pregnant women with diagnosed CD (adjusted odds ratio (aOR)=1.34). We found no increased risk of any pregnancy complication among those with undiagnosed CD. We only observed a 1% absolute excess risk of preterm birth and low birth weight among undiagnosed CD mothers corresponding to aOR=1.24 (95% confidence interval (CI)=0.82–1.87) and aOR=1.36 (95% CI=0.83–2.24), respectively.
CONCLUSIONS: Whether diagnosed or undiagnosed during pregnancy, CD is not associated with a major increased risk of pregnancy complications and adverse birth outcomes. These findings are reassuring to both women and clinicians
Neurogenesis Drives Stimulus Decorrelation in a Model of the Olfactory Bulb
The reshaping and decorrelation of similar activity patterns by neuronal
networks can enhance their discriminability, storage, and retrieval. How can
such networks learn to decorrelate new complex patterns, as they arise in the
olfactory system? Using a computational network model for the dominant neural
populations of the olfactory bulb we show that fundamental aspects of the adult
neurogenesis observed in the olfactory bulb -- the persistent addition of new
inhibitory granule cells to the network, their activity-dependent survival, and
the reciprocal character of their synapses with the principal mitral cells --
are sufficient to restructure the network and to alter its encoding of odor
stimuli adaptively so as to reduce the correlations between the bulbar
representations of similar stimuli. The decorrelation is quite robust with
respect to various types of perturbations of the reciprocity. The model
parsimoniously captures the experimentally observed role of neurogenesis in
perceptual learning and the enhanced response of young granule cells to novel
stimuli. Moreover, it makes specific predictions for the type of odor
enrichment that should be effective in enhancing the ability of animals to
discriminate similar odor mixtures
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