170 research outputs found
Eastward Ho: Issues and Options in Regional Development for the Metropolitan Boston Region
Conventional wisdom suggests that the basic job of public policy studies (and public institutions, for that matter) is to deal in a timely and practical fashion with pressing public issues of the day. The focus typically is on \u27ripe\u27 topics, \u27hot\u27 political problems. If a study can be ahead of the curve, in John Kingdon\u27s apt phrase an idea whose time has come, so much the better. But unlike more traditional academic research, where the focus is timeless — i.e., an explanation of previously inexplicable phenomena, timeliness is a prime reason for initiating a policy study.
In this context, analyzing the prospects for regional governance in Massachusetts and New England and suggesting the creation of any new arrangement for metropolitan regions for the Commonwealth seems premature or, at best, wishful thinking. But these are not conventional times. Wrenching changes in welfare, education, and health care are accelerating in a nation being demographically transformed.
Three important forces are at work which suggest that regional goverment may be a timely topic after all. First, as we will describe, the academic community is giving some priority to the subject after two generations of neglect. Second, in a time of budgetary constraints, the economic development strategies of metropolitan communities increasingly require a global perspective that emphasizes the interdependence of central city and surrounding suburbs in achieving and maintaining an international competitive advantage. Especially in Massachusetts, given the effects of Proposition 2 1/2 and pressures on the costs of land and home ownership, the need to develop and articulate a common metropolitan economic strategy grows. Third, political forces speak increasingly to the ineffectiveness of local governments in coping with the critical issues of the day. In the midst of the Big Dig and a long-term inability to site a new convention center and a stadium within the metropolitan Boston region, how to plan and provide key metropolitan infrastructure is definitely a \u27hot\u27 political issue
Checklist for anesthesiological process: analysis of risks
Several methods are reported in the literature to analyze medically undesirable events during hospital care. Each method has several limitations, so no one has been defined as the standard tool to be able to detect failure during a medical process. The aim of this study was to compare an anesthesiological perioperative checklist with traditional Regional Incident Reporting (RIR) form in detecting and describing failures
Expression of functional inhibitory neurotransmitter transporters GlyT1, GAT-1, and GAT-3 by astrocytes of inferior colliculus and hippocampus.
Neuronal inhibition is mediated by glycine and/or GABA. Inferior colliculus (IC) neurons receive glycinergic and GABAergic inputs, whereas inhibition in hippocampus (HC) predominantly relies on GABA. Astrocytes heterogeneously express neurotransmitter transporters and are expected to adapt to the local requirements regarding neurotransmitter homeostasis. Here we analyzed the expression of inhibitory neurotransmitter transporters in IC and HC astrocytes using whole-cell patch-clamp and single-cell reverse transcription-PCR. We show that most astrocytes in both regions expressed functional glycine transporters (GlyTs). Activation of these transporters resulted in an inward current (IGly) that was sensitive to the competitive GlyT1 agonist sarcosine. Astrocytes exhibited transcripts for GlyT1 but not for GlyT2. Glycine did not alter the membrane resistance (RM) arguing for the absence of functional glycine receptors (GlyRs). Thus, IGly was mainly mediated by GlyT1. Similarly, we found expression of functional GABA transporters (GATs) in all IC astrocytes and about half of the HC astrocytes. These transporters mediated an inward current (IGABA) that was sensitive to the competitive GAT-1 and GAT-3 antagonists NO711 and SNAP5114, respectively. Accordingly, transcripts for GAT-1 and GAT-3 were found but not for GAT-2 and BGT-1. Only in hippocampal astrocytes, GABA transiently reduced RM demonstrating the presence of GABAA receptors (GABAARs). However, IGABA was mainly not contaminated by GABAAR-mediated currents as RM changes vanished shortly after GABA application. In both regions, IGABA was stronger than IGly. Furthermore, in HC the IGABA/IGly ratio was larger compared to IC. Taken together, our results demonstrate that astrocytes are heterogeneous across and within distinct brain areas. Furthermore, we could show that the capacity for glycine and GABA uptake varies between both brain regions
The role of preclinical models in creatine transporter deficiency: Neurobiological mechanisms, biomarkers and therapeutic development
Creatine (Cr) Transporter Deficiency (CTD) is an X-linked metabolic disorder, mostly caused by missense mutations in the SLC6A8 gene and presenting with intellectual disability, autistic behavior, and epilepsy. There is no effective treatment for CTD and patients need lifelong assistance. Thus, the research of novel intervention strategies is a major scientific challenge. Animal models are an excellent tool to dissect the disease pathogenetic mechanisms and drive the preclinical development of therapeutics. This review illustrates the current knowledge about Cr metabolism and CTD clinical aspects, with a focus on mainstay diagnostic and therapeutic options. Then, we discuss the rodent models of CTD characterized in the last decade, comparing the phenotypes expressed within clinically relevant domains and the timeline of symptom development. This analysis highlights that animals with the ubiquitous deletion/mutation of SLC6A8 genes well recapitulate the early onset and the complex pathological phenotype of the human condition. Thus, they should represent the preferred model for preclinical efficacy studies. On the other hand, brain-and cell-specific conditional mutants are ideal for understanding the basis of CTD at a cellular and molecular level. Finally, we explain how CTD models might provide novel insight about the pathogenesis of other disorders, including cancer
Ultrafast optical control of nonlinear dielectric nanoantennas
Efficient ultrafast reconfiguration of the second-harmonic generation of AlGaAs nonlinear nanoantennas operating at 1550 nm telecom wavelength, is achieved by ultrafast interband photoexcitation with femtosecond visible pulses. The combination of broadband transient transmittivity, time-revolved second harmonic generation, and nonlinear optics nanoscale modeling, allows to track the ultrafast modulation of the second harmonic signal, into the nanoscale charge carrier dynamics at the base of a giant permittivity change at the semiconducting band edg
Enhanced nonlinear emission from single multilayered metal–dielectric nanocavities resonating in the near-infrared
Harmonic generation mechanisms are of great interest in nanoscience and nanotechnology, since they allow generating visible light by using near-infrared radiation, which is particularly suitable for its countless applications in bionanophotonics and optoelectronics. In this context, multilayer metal–dielectric nanocavities are widely used for light confinement and waveguiding at the nanoscale. They exhibit intense and localized resonances that can be conveniently tuned in the near-infrared and are therefore ideal for enhancing nonlinear effects in this spectral range. In this work, we experimentally investigate the nonlinear emission properties of multilayer metal–dielectric nanocavities. By engineering their absorption efficiency and exploiting their intrinsic interface-induced symmetry breaking, we achieve an almost 2 orders of magnitude higher second-harmonic generation efficiency compared to gold nanostructures featuring the same geometry and optical resonant behavior. In particular, while both the third-order nonlinear susceptibility and conversion efficiency are comparable with those of the Au nanoresonators, we estimate a second-order nonlinear susceptibility of the order of 1 pm/V, which is comparable with that of typical nonlinear crystals. We envision that our system, which combines the advantages of both plasmonic and dielectric materials, might enable the realization of composite and multifunctional nanosystems for the efficient manipulation of nonlinear optical processes at the nanoscale
The distribution of dark matter and gas spanning six megaparsecs around the post-merger galaxy cluster MS0451-03
Using the largest mosaic of Hubble Space Telescope images around a galaxy cluster, we map the distribution of dark matter throughout an ∼6 × 6 Mpc2 area centred on the cluster MS 0451−03 (z = 0.54, M200=1.65×1015M⊙). Our joint strong- and weak-lensing analysis shows three possible filaments extending from the cluster, encompassing six group-scale substructures. The dark matter distribution in the cluster core is elongated, consists of two distinct components, and is characterized by a concentration parameter of c200 = 3.79 ± 0.36. By contrast, XMM–Newton observations show the gas distribution to be more spherical, with excess entropy near the core, and a lower concentration of c200=2.35+0.89−0.70 (assuming hydrostatic equilibrium). Such a configuration is predicted in simulations of major mergers 2–7 Gyr after the first core passage, when the two dark matter haloes approach second turnaround, and before their gas has relaxed. This post-merger scenario finds further support in optical spectroscopy of the cluster’s member galaxies, which shows that star formation was abruptly quenched 5 Gyr ago. MS 0451−03 will be an ideal target for future studies of the growth of structure along filaments, star formation processes after a major merger, and the late-stage evolution of cluster collisions
Impacts of exhaust gas cleaning systems (EGCS) discharge waters on planktonic biological indicators
Exhaust Gas Cleaning Systems (EGCS), operating in open-loop mode, continuously release acidic effluents (scrubber waters) to marine waters. Furthermore, scrubber waters contain high concentrations of metals, polycyclic aromatic hydrocarbons (PAHs), and alkylated PAHs, potentially affecting the plankton in the receiving waters. Toxicity tests evidenced significant impairments in planktonic indicators after acute, early-life stage, and long-term exposures to scrubber water produced by a vessel operating with high sulphur fuel. Acute effects on bacterial bioluminescence (Aliivibrio fischeri), algal growth (Phaeodactylum tricornutum, Dunaliella tertiolecta), and copepod survival (Acartia tonsa) were evident at 10 % and 20 % scrubber water, while larval development in mussels (Mytilus galloprovincialis) showed a 50 % reduction at ∼5 % scrubber water. Conversely, larval development and reproductive success of A. tonsa were severely affected at scrubber water concentrations ≤1.1 %, indicating the risk of severe impacts on copepod populations which in turn may result in impairment of the whole food web
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