Cryopreservation of Sperm of Spotted Seatrout (Cynoscion nebulosus)

Cryopreservation of fish sperm has applications in preserving genetic resources from stocks of endangered fishes, replenishing fisheries, reducing the number of males needed in hatchery situations, and allowing repeated spawning of specific males. As part of a larger study on artificial breeding of sciaenid fishes, we developed procedures for collection, handling, refrigerated storage, and cryopreservation of spotted seatrout sperm. Hanks\u27 balanced salt solution (HBSS) was used as an extender for collection and storage of sperm. Sperm motility in relation to graded concentrations of HBSS was used to determine the osmolality at which sperm were activated. Based on these findings, HBSS was prepared at 201 mOsm/kg as an extender for sperm storage. To determine if ions present in HBSS were involved in sperm activation, separate activating solutions were prepared by the addition of NaCl, CaCl2, KCl, Na2HPO4, or MgSO4 to aliquots of a stock glucose solution (185 mOsm/kg). The chemicals were added at the concentration of each found in 1-x HBSS. Only the glucose solution containing 8 g/l NaCl(424 mOsm/kg) produced activation of sperm. We also evaluated four chemicals as cyroprotectants: methanol, glycerol, dimethyl sulfoxide (DMSO), and n,n-dimethyl acetamide. Two freezing rates were evaluated by placing samples at either of two heights within a nitrogen vapor shipping dewar. The highest post-thaw motilities were in 10% DMSO with an average retention of 60% of initial motility at the lower position in the dewar, and 37% at the upper position. A third freezing rate was produced using a computer-controlled freezer programmed for a rate of -45ºC/min, yielding a retention of initial motility of 31%. Our freezing and transport of cryopreserved sperm in shipping dewars demonstrate the utility of this procedure for field applications

Cryopreservation of Sperm of Spotted Seatrout (Cynoscion nebulosus)

Cryopreservation of fish sperm has applications in preserving genetic resources from stocks of endangered fishes, replenishing fisheries, reducing the number of males needed in hatchery situations, and allowing repeated spawning of specific males. As part of a larger study on artificial breeding of sciaenid fishes, we developed procedures for collection, handling, refrigerated storage, and cryopreservation of spotted seatrout sperm. Hanks\u27 balanced salt solution (HBSS) was used as an extender for collection and storage of sperm. Sperm motility in relation to graded concentrations of HBSS was used to determine the osmolality at which sperm were activated. Based on these findings, HBSS was prepared at 201 mOsm/kg as an extender for sperm storage. To determine if ions present in HBSS were involved in sperm activation, separate activating solutions were prepared by the addition of NaCl, CaCl2, KCl, Na2HPO4, or MgSO4 to aliquots of a stock glucose solution (185 mOsm/kg). The chemicals were added at the concentration of each found in 1-x HBSS. Only the glucose solution containing 8 g/l NaCl(424 mOsm/kg) produced activation of sperm. We also evaluated four chemicals as cyroprotectants: methanol, glycerol, dimethyl sulfoxide (DMSO), and n,n-dimethyl acetamide. Two freezing rates were evaluated by placing samples at either of two heights within a nitrogen vapor shipping dewar. The highest post-thaw motilities were in 10% DMSO with an average retention of 60% of initial motility at the lower position in the dewar, and 37% at the upper position. A third freezing rate was produced using a computer-controlled freezer programmed for a rate of -45ºC/min, yielding a retention of initial motility of 31%. Our freezing and transport of cryopreserved sperm in shipping dewars demonstrate the utility of this procedure for field applications

Coupled Analysis of an Inlet and Fan for a Quiet Supersonic Jet

A computational analysis of a Gulfstream isentropic external compression supersonic inlet coupled to a Rolls-Royce fan has been completed. The inlet was designed for a small, low sonic boom supersonic vehicle with a design cruise condition of M = 1.6 at 45,000 ft. The inlet design included an annular bypass duct that routed flow subsonically around an engine-mounted gearbox and diverted flow with high shock losses away from the fan tip. Two Reynolds-averaged Navier-Stokes codes were used for the analysis: an axisymmetric code called AVCS for the inlet and a three dimensional (3-D) code called SWIFT for the fan. The codes were coupled at a mixing plane boundary using a separate code for data exchange. The codes were used to determine the performance of the inlet/fan system at the design point and to predict the performance and operability of the system over the flight profile. At the design point the core inlet had a recovery of 96 percent, and the fan operated near its peak efficiency and pressure ratio. A large hub radial distortion generated in the inlet was not eliminated by the fan and could pose a challenge for subsequent booster stages. The system operated stably at all points along the flight profile. Reduced stall margin was seen at low altitude and Mach number where flow separated on the interior lips of the cowl and bypass ducts. The coupled analysis gave consistent solutions at all points on the flight profile that would be difficult or impossible to predict by analysis of isolated components

Coupled Analysis of an Inlet and Fan for a Quiet Supersonic Aircraft

A computational analysis of a Gulfstream isentropic external compression supersonic inlet coupled to a Rolls-Royce fan was completed. The inlet was designed for a small, low sonic boom supersonic vehicle with a design cruise condition of M = 1.6 at 45,000 feet. The inlet design included an annular bypass duct that routed flow subsonically around an engine-mounted gearbox and diverted flow with high shock losses away from the fan tip. Two Reynolds-averaged Navier-Stokes codes were used for the analysis: an axisymmetric code called AVCS for the inlet and a 3-D code called SWIFT for the fan. The codes were coupled at a mixing plane boundary using a separate code for data exchange. The codes were used to determine the performance of the inlet/fan system at the design point and to predict the performance and operability of the system over the flight profile. At the design point the core inlet had a recovery of 96 percent, and the fan operated near its peak efficiency and pressure ratio. A large hub radial distortion generated in the inlet was not eliminated by the fan and could pose a challenge for subsequent booster stages. The system operated stably at all points along the flight profile. Reduced stall margin was seen at low altitude and Mach number where flow separated on the interior lips of the cowl and bypass ducts. The coupled analysis gave consistent solutions at all points on the flight profile that would be difficult or impossible to predict by analysis of isolated components

Size Control in the Colloidal Synthesis of Plasmonic Magnesium Nanoparticles.

Nanoparticles of plasmonic materials can sustain oscillations of their free electron density, called localized surface plasmon resonances (LSPRs), giving them a broad range of potential applications. Mg is an earth-abundant plasmonic material attracting growing attention owing to its ability to sustain LSPRs across the ultraviolet, visible, and near-infrared wavelength range. Tuning the LSPR frequency of plasmonic nanoparticles requires precise control over their size and shape; for Mg, this control has previously been achieved using top-down fabrication or gas-phase methods, but these are slow and expensive. Here, we systematically probe the effects of reaction parameters on the nucleation and growth of Mg nanoparticles using a facile and inexpensive colloidal synthesis. Small NPs of 80 nm were synthesized using a low reaction time of 1 min and ∼100 nm NPs were synthesized by decreasing the overall reaction concentration, replacing the naphthalene electron carrier with biphenyl or using metal salt additives of FeCl3 or NiCl2 at longer reaction times of 17 h. Intermediate sizes up to 400 nm were further selected via the overall reaction concentration or using other metal salt additives with different reduction potentials. Significantly larger particles of over a micrometer were produced by reducing the reaction temperature and, thus, the nucleation rate. We showed that increasing the solvent coordination reduced Mg NP sizes, while scaling up the reaction reduced the mixing efficiency and produced larger NPs. Surprisingly, varying the relative amounts of Mg precursor and electron carrier had little impact on the final NP sizes. These results pave the way for the large-scale use of Mg as a low-cost and sustainable plasmonic material.Support for this project was provided by the EU Framework Programme for Research and Innovation Horizon 2020 (ERC Starting Grant SPECs 804523). E.R.H. is thankful for funding from the EPSRC NanoDTC Cambridge (EP/L015978/1). J.A. acknowledges financial support from Natural Sciences and Engineering Research Council of Canada and Fonds de Recherche du Québec–Nature et Technologies postdoctoral fellowships (BP and B3X programs). C.B. is thankful for funding from the Engineering and Physical Sciences Research Council (Standard Research Studentship (DTP) EP/R513180/1). B.P. and L.T.M. acknowledge support from UK Engineering and Physical Science and Research Council (grant number EP/L020443/2). Thanks to Giulio I. Lampronti for helpful discussions and support

Experimental Sonic Boom Measurements on a Mach 1.6 Cruise Low-Boom Configuration

A wind tunnel test has been conducted by Gulfstream Aerospace Corporation (GAC) to measure the sonic boom pressure signature of a low boom Mach 1.6 cruise business jet in the Langley Unitary Plan Wind Tunnel at Mach numbers 1.60 and 1.80. Through a cooperative agreement between GAC and the National Aeronautics and Space Administration (NASA), GAC provided NASA access to some of the experimental data and NASA is publishing these data for the sonic boom research community. On-track and off-track near field sonic boom pressure signatures were acquired at three separation distances (0.5, 1.2, and 1.7 reference body lengths) and three angles of attack (-0.26deg, 0.26deg, and 0.68deg). The model was blade mounted to minimize the sting effects on the sonic boom signatures. Although no extensive data analysis is provided, selected data are plotted to illustrate salient features of the data. All of the experimental sonic boom pressure data are tabulated. Schlieren images of the configuration are also included

miR-132/212 knockout mice reveal roles for these miRNAs in regulating cortical synaptic transmission and plasticity

miR-132 and miR-212 are two closely related miRNAs encoded in the same intron of a small non-coding gene, which have been suggested to play roles in both immune and neuronal function. We describe here the generation and initial characterisation of a miR-132/212 double knockout mouse. These mice were viable and fertile with no overt adverse phenotype. Analysis of innate immune responses, including TLR-induced cytokine production and IFNβ induction in response to viral infection of primary fibroblasts did not reveal any phenotype in the knockouts. In contrast, the loss of miR-132 and miR-212, while not overtly affecting neuronal morphology, did affect synaptic function. In both hippocampal and neocortical slices miR-132/212 knockout reduced basal synaptic transmission, without affecting paired-pulse facilitation. Hippocampal long-term potentiation (LTP) induced by tetanic stimulation was not affected by miR-132/212 deletion, whilst theta burst LTP was enhanced. In contrast, neocortical theta burst-induced LTP was inhibited by loss of miR-132/212. Together these results indicate that miR-132 and/or miR-212 play a significant role in synaptic function, possibly by regulating the number of postsynaptic AMPA receptors under basal conditions and during activity-dependent synaptic plasticity

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

Synaptic Wnt signaling—a contributor to major psychiatric disorders?

Wnt signaling is a key pathway that helps organize development of the nervous system. It influences cell proliferation, cell fate, and cell migration in the developing nervous system, as well as axon guidance, dendrite development, and synapse formation. Given this wide range of roles, dysregulation of Wnt signaling could have any number of deleterious effects on neural development and thereby contribute in many different ways to the pathogenesis of neurodevelopmental disorders. Some major psychiatric disorders, including schizophrenia, bipolar disorder, and autism spectrum disorders, are coming to be understood as subtle dysregulations of nervous system development, particularly of synapse formation and maintenance. This review will therefore touch on the importance of Wnt signaling to neurodevelopment generally, while focusing on accumulating evidence for a synaptic role of Wnt signaling. These observations will be discussed in the context of current understanding of the neurodevelopmental bases of major psychiatric diseases, spotlighting schizophrenia, bipolar disorder, and autism spectrum disorder. In short, this review will focus on the potential role of synapse formation and maintenance in major psychiatric disorders and summarize evidence that defective Wnt signaling could contribute to their pathogenesis via effects on these late neural differentiation processes