High Fat Diet Prevents Over-Crowding Induced Decrease of Sex Ratio in Mice

Adaptive theory predicts that mothers would be advantaged by adjusting the sex ratio of their offspring in relation to their offspring's future reproductive success. In the present study, we tested the effect of housing mice under crowded condition on the sex ratio and whether the fat content of the diet has any influence on the outcome of pregnancies. Three-week-old mice were placed on the control diet (NFD) for 3 weeks. Thereafter the mice were allotted randomly to two groups of 7 cages each with 4, 6, 8, 10, 12, 14, and 16 mice in every cage to create increasing crowding gradient and fed either NFD or high fat diet (HFD). After 4 weeks, dams were bred and outcomes of pregnancy were analyzed. The average dam body weight (DBW) at conception, litter size (LS) and SR were significantly higher in HFD fed dams. Further, male biased litters declined with increasing crowding in NFD group but not in HFD. The LS and SR in NFD declined significantly with increasing crowding, whereas only LS was reduced in HFD group. We conclude that female mice housed under overcrowding conditions shift offspring SR in favor of daughters in consistent with the TW hypothesis and high fat diet reduces this influence of overcrowding

Subanesthetic ketamine treatment promotes abnormal interactions between neural subsystems and alters the properties of functional brain networks

Acute treatment with subanesthetic ketamine, a non-competitive N-methyl-D-aspartic acid (NMDA) receptor antagonist, is widely utilized as a translational model for schizophrenia. However, how acute NMDA receptor blockade impacts on brain functioning at a systems level, to elicit translationally relevant symptomatology and behavioral deficits, has not yet been determined. Here, for the first time, we apply established and recently validated topological measures from network science to brain imaging data gained from ketamine-treated mice to elucidate how acute NMDA receptor blockade impacts on the properties of functional brain networks. We show that the effects of acute ketamine treatment on the global properties of these networks are divergent from those widely reported in schizophrenia. Where acute NMDA receptor blockade promotes hyperconnectivity in functional brain networks, pronounced dysconnectivity is found in schizophrenia. We also show that acute ketamine treatment increases the connectivity and importance of prefrontal and thalamic brain regions in brain networks, a finding also divergent to alterations seen in schizophrenia. In addition, we characterize how ketamine impacts on bipartite functional interactions between neural subsystems. A key feature includes the enhancement of prefrontal cortex (PFC)-neuromodulatory subsystem connectivity in ketamine-treated animals, a finding consistent with the known effects of ketamine on PFC neurotransmitter levels. Overall, our data suggest that, at a systems level, acute ketamine-induced alterations in brain network connectivity do not parallel those seen in chronic schizophrenia. Hence, the mechanisms through which acute ketamine treatment induces translationally relevant symptomatology may differ from those in chronic schizophrenia. Future effort should therefore be dedicated to resolve the conflicting observations between this putative translational model and schizophrenia

Model studies of dense water overflows in the Faroese Channels Topical Collection on the 5th International Workshop on Modelling the Ocean (IWMO) in Bergen, Norway 17-20 June 2013

The overflow of dense water from the Nordic Seas through the Faroese Channel system was investigated through combined laboratory experiments and numerical simulations using the Massachusetts Institute of Technology General Circulation Model. In the experimental study, a scaled, topographic representation of the Faroe-Shetland Channel, Wyville-Thomson Basin and Ridge and Faroe Bank Channel seabed bathymetry was constructed and mounted in a rotating tank. A series of parametric experiments was conducted using dye-tracing and drogue-tracking techniques to investigate deep-water overflow pathways and circulation patterns within the modelled region. In addition, the structure of the outflowing dense bottom water was investigated through density profiling along three cross-channel transects located in the Wyville-Thomson Basin and the converging, up-sloping approach to the Faroe Bank Channel. Results from the dye-tracing studies demonstrate a range of parametric conditions under which dense water overflow across the Wyville-Thomson Ridge is shown to occur, as defined by the Burger number, a non-dimensional length ratio and a dimensionless dense water volume flux parameter specified at the Faroe-Shetland Channel inlet boundary. Drogue-tracking measurements reveal the complex nature of flow paths and circulations generated in the modelled topography, particularly the development of a large anti-cyclonic gyre in the Wyville-Thompson Basin and up-sloping approach to the Faroe Bank Channel, which diverts the dense water outflow from the Faroese shelf towards the Wyville-Thomson Ridge, potentially promoting dense water spillage across the ridge itself. The presence of this circulation is also indicated by associated undulations in density isopycnals across the Wyville-Thomson Basin. Numerical simulations of parametric test cases for the main outflow pathways and density structure in a similarly-scaled Faroese Channels model domain indicate excellent qualitative agreement with the experimental observations and measurements. In addition, the comparisons show that strong temporal variability in the predicted outflow pathways and circulations have a strong influence in regulating the Faroe Bank Channel and Wyville-Thomson Ridge overflows, as well as in determining the overall response in the Faroese Channels to changes in the Faroe-Shetland Channel inlet boundary conditions. © 2014 Springer-Verlag Berlin Heidelberg

Multi-photon ionisation spectroscopy for rotational state preparation of N+2

In this paper we investigate the 2 + 1′ resonance enhanced multi-photon ionisation (REMPI) of molecular nitrogen via the a1Πg(v = 6) intermediate state and analyse its feasibility to generate molecular nitrogen ions in a well defined ro-vibrational state. This is an important tool for high precision experiments based on trapped molecular ions, and is crucial for studying the time variation of the fundamental constant mp/me using N+2. The transition is not reported in the literature and detailed spectral analysis has been conducted to extract the molecular constants of the intermediate state. By carefully choosing the intermediate ro-vibrational state, the ionisation laser wavelength and controlling the excitation laser pulse energy, unwanted formation of rotationally excited molecular ions can be suppressed and ro-vibrational ground state ions can be generated with high purity

Nanoparticles as multimodal photon transducers of ionizing radiation

In biomedical imaging, nanoparticles combined with radionuclides that generate Cerenkov luminescence are used in diagnostic imaging, photon-induced therapies, and as activatable probes. In these applications, the nanoparticle is often viewed as a carrier inert to ionizing radiation from the radionuclide. However, certain phenomena such as enhanced nanoparticle luminescence and generation of reactive oxygen species cannot be explained by only Cerenkov luminescence interactions with nanoparticles. Herein, we report methods to examine the mechanisms of nanoparticle excitation by radionuclides, including interactions with Cerenkov luminescence, β particles, and γ radiation. We demonstrate that β scintillation contributes appreciably to excitation and reactivity in certain nanoparticle systems and that excitation of nanoparticles composed of large atomic number atoms by radionuclides generates X-rays, enabling multiplexed imaging through single photon emission computed tomography. These findings demonstrate practical optical imaging and therapy using radionuclides with emission energies below the Cerenkov threshold, thereby expanding the list of applicable radionuclides

Ulnar-sided wrist pain. Part I: anatomy and physical examination

Ulnar-sided wrist pain is a common complaint, and it presents a diagnostic challenge for hand surgeons and radiologists. The complex anatomy of this region, combined with the small size of structures and subtle imaging findings, compound this problem. A thorough understanding of ulnar-sided wrist anatomy and a systematic clinical examination of this region are essential in arriving at an accurate diagnosis. In part I of this review, ulnar-sided wrist anatomy and clinical examination are discussed for a more comprehensive understanding of ulnar-sided wrist pain

Origin of reduced magnetization and domain formation in small magnetite nanoparticles

The structural, chemical, and magnetic properties of magnetite nanoparticles are compared. Aberration corrected scanning transmission electron microscopy reveals the prevalence of antiphase boundaries in nanoparticles that have significantly reduced magnetization, relative to the bulk. Atomistic magnetic modelling of nanoparticles with and without these defects reveals the origin of the reduced moment. Strong antiferromagnetic interactions across antiphase boundaries support multiple magnetic domains even in particles as small as 12–14 nm

Differentiation of neurons from neural precursors generated in floating spheres from embryonic stem cells

<p>Abstract</p> <p>Background</p> <p>Neural differentiation of embryonic stem (ES) cells is usually achieved by induction of ectoderm in embryoid bodies followed by the enrichment of neuronal progenitors using a variety of factors. Obtaining reproducible percentages of neural cells is difficult and the methods are time consuming.</p> <p>Results</p> <p>Neural progenitors were produced from murine ES cells by a combination of nonadherent conditions and serum starvation. Conversion to neural progenitors was accompanied by downregulation of <it>Oct4 </it>and <it>NANOG </it>and increased expression of <it>nestin</it>. ES cells containing a GFP gene under the control of the <it>Sox1 </it>regulatory regions became fluorescent upon differentiation to neural progenitors, and ES cells with a tau-GFP fusion protein became fluorescent upon further differentiation to neurons. Neurons produced from these cells upregulated mature neuronal markers, or differentiated to glial and oligodendrocyte fates. The neurons gave rise to action potentials that could be recorded after application of fixed currents.</p> <p>Conclusion</p> <p>Neural progenitors were produced from murine ES cells by a novel method that induced neuroectoderm cells by a combination of nonadherent conditions and serum starvation, in contrast to the embryoid body method in which neuroectoderm cells must be selected after formation of all three germ layers.</p

Angiogenesis gene expression in murine endothelial cells during post-pneumonectomy lung growth

Although blood vessel growth occurs readily in the systemic bronchial circulation, angiogenesis in the pulmonary circulation is rare. Compensatory lung growth after pneumonectomy is an experimental model with presumed alveolar capillary angiogenesis. To investigate the genes participating in murine neoalveolarization, we studied the expression of angiogenesis genes in lung endothelial cells. After left pneumonectomy, the remaining right lung was examined on days 3, 6, 14 and 21days after surgery and compared to both no surgery and sham thoracotomy controls. The lungs were enzymatically digested and CD31+ endothelial cells were isolated using flow cytometry cell sorting. The transcriptional profile of the CD31+ endothelial cells was assessed using quantitative real-time polymerase chain reaction (PCR) arrays. Focusing on 84 angiogenesis-associated genes, we identified 22 genes with greater than 4-fold regulation and significantly enhanced transcription (p <.05) within 21 days of pneumonectomy. Cluster analysis of the 22 genes indicated that changes in gene expression did not occur in a single phase, but in at least four waves of gene expression: a wave demonstrating decreased gene expression more than 3 days after pneumonectomy and 3 sequential waves of increased expression on days 6, 14, and 21 after pneumonectomy. These findings indicate that a network of gene interactions contributes to angiogenesis during compensatory lung growth

Epstein-Barr virus-encoded microRNA BART1 induces tumour metastasis by regulating PTEN-dependent pathways in nasopharyngeal carcinoma.

Epstein-Barr virus (EBV), aetiologically linked to nasopharyngeal carcinoma (NPC), is the first human virus found to encode many miRNAs. However, how these viral miRNAs precisely regulate the tumour metastasis in NPC remains obscure. Here we report that EBV-miR-BART1 is highly expressed in NPC and closely associated with pathological and advanced clinical stages of NPC. Alteration of EBV-miR-BART1 expression results in an increase in migration and invasion of NPC cells in vitro and causes tumour metastasis in vivo. Mechanistically, EBV-miR-BART1 directly targets the cellular tumour suppressor PTEN. Reduction of PTEN dosage by EBV-miR-BART1 activates PTEN-dependent pathways including PI3K-Akt, FAK-p130(Cas) and Shc-MAPK/ERK1/2 signalling, drives EMT, and consequently increases migration, invasion and metastasis of NPC cells. Reconstitution of PTEN rescues all phenotypes generated by EBV-miR-BART1, highlighting the role of PTEN in EBV-miR-BART-driven metastasis in NPC. Our findings provide new insights into the metastasis of NPC regulated by EBV and advocate for developing clinical intervention strategies against NPC