644 research outputs found
Resolving Disputes over Excess Frozen Embryos through the Confines of Property and Contract Law
This Article addresses the conflicts that arise due to the increased number of cryogenically frozen embryos produced during in vitro fertilization (IVF). Part I discusses the IVF process, in general. While it recognizes the man\u27s role in the process, it focuses primarily on the physical and emotional hardships that are placed on the woman. Part I also gives the backdrop of the case law in the area of embryo distribution. Part II introduces the idea that an embryo should be reduced to private property, through utilization of the labor and economic theories of property law. Additionally, an embryo\u27s use, rather than its waste, promotes a more efficient society. The role that the legislature should play in the appropriation of embryonic property is also addressed. The dominion of property law suggests that the enforcement of contracts is eminent to communal survival. Part II discusses the current regulations in place as well as the lack of direction given by these regulations when a dispute arises as to the distribution of embryos. Part IV discusses how contracts with IVF clinics meet the standard elements of enforceability in contract law. This article also addresses the current criticisms and possible defenses against such enforcement. Part V synthesizes the findings of the previous articles written on this topic
X-Raying the Dark Side of Venus - Scatter from Venus Magnetotail?
This work analyzes the X-ray, EUV and UV emission apparently coming from the
Earth-facing (dark) side of Venus as observed with Hinode/XRT and SDO/AIA
during a transit across the solar disk occurred in 2012. We have measured
significant X-Ray, EUV and UV flux from Venus dark side. As a check we have
also analyzed a Mercury transit across the solar disk, observed with Hinode/XRT
in 2006. We have used the latest version of the Hinode/XRT Point Spread
Function (PSF) to deconvolve Venus and Mercury X-ray images, in order to remove
possible instrumental scattering. Even after deconvolution, the flux from Venus
shadow remains significant while in the case of Mercury it becomes negligible.
Since stray-light contamination affects the XRT Ti-poly filter data from the
Venus transit in 2012, we performed the same analysis with XRT Al-mesh filter
data, which is not affected by the light leak. Even the Al-mesh filter data
show residual flux. We have also found significant EUV (304 A, 193 A, 335 A)
and UV (1700 A) flux in Venus shadow, as measured with SDO/AIA. The EUV
emission from Venus dark side is reduced when appropriate deconvolution methods
are applied; the emission remains significant, however. The light curves of the
average flux of the shadow in the X-ray, EUV, and UV bands appear different as
Venus crosses the solar disk, but in any of them the flux is, at any time,
approximately proportional to the average flux in a ring surrounding Venus, and
therefore proportional to the average flux of the solar regions around Venus
obscuring disk line of sight. The proportionality factor depends on the band.
This phenomenon has no clear origin; we suggest it may be due to scatter
occurring in the very long magnetotail of Venus.Comment: This paper has been accepted in The Astrophysical Journa
110GHz fT Silicon Bipolar Transistors Implemented using Fluorine Implantation for Boron Diffusion Suppression
This paper investigates how fluorine implantation can be used to suppress boron diffusion in the base of a double polysilicon silicon bipolar transistor and hence deliver a record fT of 110 GHz. Secondary Ion Mass Spectroscopy (SIMS) and transmission electron microscopy are used to characterize the effect of the fluorine implantation energy and dose, the anneal temperature and ambient and the germanium pre-amorphisation implant on the fluorine profiles. These results show that retention of fluorine in the silicon is maximised when a high-energy fluorine implant is combined with a low thermal budget inert anneal. TEM images show that a high-energy fluorine implant into germanium pre-amorphised silicon eliminates the end of range defects from the germanium implant and produces a band of dislocation loops deeper in the silicon at the range of the fluorine implant. Boron SIMS profiles show a suppression of boron diffusion for fluorine doses at and above 5?1014cm-2, but no suppression at lower fluorine doses. This suppression of boron diffusion correlates with the appearance on the SIMS profiles of a fluorine peak at a depth of approximately Rp/2, which is attributed to fluorine trapped in vacancy-fluorine clusters. The introduction of a fluorine implant at this critical fluorine dose into a bipolar transistor process flow leads to an increase in cut-off frequency from 46 to 60GHz. Further optimisation of the base-width and the collector profile leads to a further increase in cut-off frequency to 110GHz. Two factors are postulated to contribute to the suppression of boron diffusion by the fluorine implant. First, the elimination of the germanium end of range defects, and the associated interstitial population, by the fluorine implant, removes a source of transient enhanced diffusion. Second, any interstitials released by the dislocation loops at the range of the fluorine implant would be expected to recombine at the vacancy-fluorine clusters before reaching the boron profile
Activity of bacterial seed endophytes of landrace durum wheat for control of Fusarium foot rot
Five bacterial endophytic isolates obtained from durum wheat seeds (Iandrace "Timilia reste nere") and identified as belonging to Pantoea (isolates A1, F7, F15 and GI) and Paenibacillus (isolate B) genera on the basis of 16S rDNA gene sequences, were assayed in vitro and in vivo for their ability to inhibit Fusarium culmorum growth and the disease (Fusarium foot rot) it causes in durum wheat. All isolates significantly reduced in vitro growth of F. culmorum in comparison with the control. After 120 hours of incubation, isolates B and GI showed the greatest mycelial growth inhibition, i.e., respectively, 76 and 74%. When durum wheat "Simeto" seeds were treated with bacterial isolates singly or in combinations and then inoculated with F. culmorum, all treatments with endophytes showed increased, but not statistically significant, seed germination. Except for isolate Al, all bacterial isolates stimulated vegetative parameters of durum wheat seedlings. Mixture of isolates F7 + F15 was the most effective in improving shoot height (+94%), root length (+47%) and vigour index (+81%). Mixture of isolates A1 + B reduced Fusarium foot rot incidence (-21%) and severity (-30%), and isolate A1 reduced incidence (-15%) and severity (-16%) of the disease. These results indicate potential of bacterial seed endophytes, identified in this study, for control of Fusarium foot rot and suggest that bacterial seed endophytes may provide a new biocontrol agent for an environmentally sustainable durum wheat disease management programme
Measurement of the orientation of buffer-gas-cooled, electrostatically-guided ammonia molecules
AbstractThe extent to which the spatial orientation of internally and translationally cold ammonia molecules can be controlled as molecules pass out of a quadrupole guide and through different electric field regions is examined. Ammonia molecules are collisionally cooled in a buffer gas cell, and are subsequently guided by a three-bend electrostatic quadrupole into a detection chamber. The orientation of ammonia molecules is probed using (2+1) resonance-enhanced multiphoton ionisation (REMPI), with the laser polarisation axis aligned both parallel and perpendicular to the time-of-flight axis. Even with the presence of a near-zero field region, the ammonia REMPI spectra indicate some retention of orientation. Monte Carlo simulations propagating the time-dependent Schrödinger equation in a full basis set including the hyperfine interaction enable the orientation of ammonia molecules to be calculated – with respect to both the local field direction and a space-fixed axis – as the molecules pass through different electric field regions. The simulations indicate that the orientation of ∼95% of ammonia molecules in JK=11 could be achieved with the application of a small bias voltage (17V) to the mesh separating the quadrupole and detection regions. Following the recent combination of the buffer gas cell and quadrupole guide apparatus with a linear Paul ion trap, this result could enable one to examine the influence of molecular orientation on ion-molecule reaction dynamics and kinetics
Morphology of the Labial Gland System of the Mature Larva of the Black Carpenter Ant, Camponotus pennsylvanicus (DeGeer)
The morphology of the labial gland system of mature larvae of Camponotus pennsylvanicus is described. Regions of the labial gland system (gland tubes, reservoirs, thin and thick portions of the paired ducts, and common duct) were examined with electron microscopy, and a comparison of organelle and cell morphology was made. The gland tubes secrete silk which is stored in the reservoirs. The final water and/ or ion content of the secretion may be modified by the paired ducts and common duct
A systematic study of \ce{CO2} planetary atmospheres and their link to the stellar environment
The Milky Way Galaxy is literally teeming with exoplanets; thousands of
planets have been discovered, with thousands more planet candidates identified.
Terrestrial-like planets are quite common around other stars, and are expected
to be detected in large numbers in the future. Such planets are the primary
targets in the search for potentially habitable conditions outside the solar
system.
Determining the atmospheric composition of exoplanets is mandatory to
understand their origin and evolution, as atmospheric processes play crucial
roles in many aspects of planetary architecture. In this work we construct and
exploit a 1D radiative transfer model based on the discrete-ordinates method in
plane-parallel geometry. Radiative results are linked to a convective flux that
redistributes energy at any altitude producing atmospheric profiles in
radiative-convective equilibrium. The model has been applied to a large number
(6250) of closely dry synthetic \ce{CO2} atmospheres, and the resulting
pressure and thermal profiles have been interpreted in terms of parameter
variability. Although less accurate than 3D general circulation models, not
properly accounting for e.g., clouds and atmospheric and ocean dynamics, 1D
descriptions are computationally inexpensive and retain significant value by
allowing multidimensional parameter sweeps with relative ease.Comment: 12 pages, 9 figures, accepted for publication in MNRA
In-bore MRI targeted biopsy
Clinical suspicion of Prostate Cancer (PCa) is largely based on increased prostate specific antigen (PSA) level and/or abnormal digital rectal examination (DRE) and/or positive imaging and, up today, biopsy is mandatory to confirm the diagnosis. The old model consisted of Standard Biopsy (SBx), that is random sampling of the prostate gland under ultrasound guidance (TRUS), in subjects with clinical suspicion of PCa. This involves the risk of not diagnosing a high percentage of tumors (up to 30%) and of an incorrect risk stratification. Multiparametric Magnetic Resonance Imaging (mpMRI) has transformed the diagnostic pathway of PCa, not only as an imaging method for detecting suspicious lesions, but also as an intraprocedural guidance for Target Biopsy (MRI-TBx), thus bridging the diagnostic gap. Several single and multicenter randomized trials, such as PROMIS, MRI first, PRECISION and that reported by Van der Leest et al. have confirmed the superiority of the "MRI pathway", consisting of mpMRI and MRI-TBx of suspicious lesions, over the "standard pathway" of SBx in all patients with elevated PSA and/or positive DRE. MRI-TBx appears to be advantageous in reducing the overall number of biopsies performed, as well as in reducing the diagnosis of clinically insignificant disease while maintaining or improving the diagnosis of clinically significant PCa (cs-PCa). Moreover, it shows a reduction in the diagnosis of ins-PCa, and therefore, of overdiagnosis, when using MRI-TBx without sacrificing performance in the diagnosis of cs-PCa
Pentraxins coordinate excitatory synapse maturation and circuit integration of parvalbumin interneurons
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Circuit computation requires precision in the timing, extent, and synchrony of principal cell (PC) firing that is largely enforced by parvalbumin-expressing, fast-spiking interneurons (PVFSIs). To reliably coordinate network activity, PVFSIs exhibit specialized synaptic and membrane properties that promote efficient afferent recruitment such as expression of high-conductance, rapidly gating, GluA4-containing AMPA receptors (AMPARs). We found that PVFSIs upregulate GluA4 during the second postnatal week coincident with increases in the AMPAR clustering proteins NPTX2 and NPTXR. Moreover, GluA4 is dramatically reduced in NPTX2(-/-)/NPTXR(-/-) mice with consequent reductions in PVFSI AMPAR function. Early postnatal NPTX2(-/-)/NPTXR(-/-) mice exhibit delayed circuit maturation with a prolonged critical period permissive for giant depolarizing potentials. Juvenile NPTX2(-/-)/NPTXR(-/-) mice display reduced feedforward inhibition yielding a circuit deficient in rhythmogenesis and prone to epileptiform discharges. Our findings demonstrate an essential role for NPTXs in controlling network dynamics highlighting potential therapeutic targets for disorders with inhibition/excitation imbalances such as schizophrenia.Work supported by a PRAT fellowship to M.S.W., an NICHD intramural award to C.J.M., NIDCD intramural
research program funding to R.S.P., an NIMH intramural award to H.A.C., NIH grants (PAR-02-059, NS 039156)
to P.F.W., and an NIH grant (EY022730) to M.T.
Genetically altered AMPA-type glutamate receptor kinetics in interneurons disrupt long-range synchrony of gamma oscillation
Gamma oscillations synchronized between distant neuronal populations may be critical for binding together brain regions devoted to common processing tasks. Network modeling predicts that such synchrony depends in part on the fast time course of excitatory postsynaptic potentials (EPSPs) in interneurons, and that even moderate slowing of this time course will disrupt synchrony. We generated mice with slowed interneuron EPSPs by gene targeting, in which the gene encoding the 67-kDa form of glutamic acid decarboxylase (GAD67) was altered to drive expression of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptor subunit GluR-B. GluR-B is a determinant of the relatively slow EPSPs in excitatory neurons and is normally expressed at low levels in γ-aminobutyric acid (GABA)ergic interneurons, but at high levels in the GAD-GluR-B mice. In both wild-type and GAD-GluR-B mice, tetanic stimuli evoked gamma oscillations that were indistinguishable in local field potential recordings. Remarkably, however, oscillation synchrony between spatially separated sites was severely disrupted in the mutant, in association with changes in interneuron firing patterns. The congruence between mouse and model suggests that the rapid time course of AMPA receptor-mediated EPSPs in interneurons might serve to allow gamma oscillations to synchronize over distance
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