1,3,4,6-Tetramethyl-1,4-dihydro-1,2,4,5-tetrazine, C_6H_(12)N_4

M_r =140∙19, monoclinic, P2_1/n, a = 10∙612(3), b=6∙820(1), c= 10∙975 (2) Å, β=95∙31(2)°, V=790.9(5) Å^3, Z=4, D_m=1.13(5) (flotation), D_x = 1∙177 g cm^(-3), Mo Kα, λ = 0.71073 Å, μ= 0.848 cm^(-1), F(000) = 304, T= 295 K, R = 0∙077 for 704 observed reflections. This potentially antiaromatic or homoaromatic ring system has a flattened boat conformation with both N-methyls in equatorial positions. Bond angles and distances (excluding H's) predicted to be symmetry equivalent exhibit variations of 0.002-0.014 Å and 0.0-2.0°. Substantial delocalization of the electron lone pairs of N(1) and N(4) is found

SPP and the Way Forward for North American Integration

During the past year, relations among the NAFTA partners took on an increasingly two-tier structure. More visible were a widening array of disagreements over issues including BMD, Iraq, US demands on passports, the Senate’s vote to keep the border shut to Canadian cattle, alleged American gun trafficking and, above all, Washington’s efforts to evade the NAFTA ruling on softwood lumber. Yet, despite this mix of genuine grievances and political posturing, we saw substantial movement toward a more efficient North American economic system. Reports from the Security and Prosperity Partnership Working Groups set up after the Bush-Fox-Martin meeting in Waco, Texas, illustrated a wide array of activities under the politico-journalistic radar. Perhaps more important are the myriad of business- and community-driven initiatives underway to expand and improve cross-border links. How much of all of this will actually lead to concrete results is unclear. But several conclusions are evident. One is that this movement is driven by deepening interdependence. The second is that the current two-tier process in which national leaders kick each other in the shins while businesses and bureaucrats in federal, state, and municipal governments and community groups squirrel away to repair problems in the North American system will not work. Third is that integration-by-stealth is also unacceptable. The time has come to examine carefully what is happening in North America, to explore what our interests are in this emerging continental system, and to open a dialogue about different, even competing, visions of North America. The dialogue should involve perspectives from different regions, different economic and social sectors, and those who oppose as well as support integration. The process must get outside of the beltways—it must give voice to community and economic leaders who are most deeply involved in this new system

Staying Alive: North American Competitiveness and the Challenge of Asia

While analyses of North American integration after NAFTA continue to stress outdated notions of country-to-country trade and the exchange of finished products across national borders, our paper starts from the premise that what we have now is a single, integrated regional economic system whose expansion has followed the pace and contours of business strategies emphasizing continentally-integrated supply chains, but whose management via regulatory and policy coordination has lagged dangerously behind. Most dangerous of all has been the massive gap between our region\u27s infrastructure needs – ports, transportation, and borders – and what has been coordinated and facilitated by the public sector. In this paper we investigate this current impasse from the point of view of reframing the competition with Asia\u27s export giants – in particular China – as an impetus to enhance the competitive edge not of our national economies but rather of the regional economic system as a whole. We highlight the potential for synergy between the dynamism of cross-border regions such as the Pacific Northwest and their gateway strategies of coping with booming trade with Asia, on the one hand, and the aim of enhancing North American regional competitiveness via a more rationalized and effective continental transportation and infrastructure strategy. For example, British Columbia\u27s plans to expand the Prince Rupert port facility, or the West Coast Corridor Coalition\u27s plans for transportation links from B.C. [British Columbia] to B.C. [Baja California] would do well to explore their potential to connect with developing transportation networks and trade corridors in the center of the continent, as well as emerging export centers on the Eastern seaboard (Halifax/Atlantica), and on Mexico\u27s Pacific coast. In keeping with North America\u27s unique integration pattern – decentralized and business-driven – this focus on cross-border regions and public-private partnerships could bridge the infrastructure gap, linking local concerns with greater continental prosperity

The association between preoperative cardiopulmonary exercise test variables and short-term morbidity following oesophagectomy: A hospital-based cohort study

Background: Postoperative complications after esophagectomy are thought to be associated with reduced fitness. This observational study explored the associations between aerobic fitness, as determined objectively by preoperative cardiopulmonary exercise testing (CPEX), and 30-day morbidity after esophagectomy. Methods: We retrospectively identified 254 consecutive patients who underwent esophagectomy at a single academic teaching hospital between September 2011 and March 2017. Postoperative complication data were measured using the Esophageal Complications Consensus Group definitions and graded using the Clavien-Dindo classification system of severity (blinded to cardiopulmonary exercise testing values). Associations between preoperative cardiopulmonary exercise testing variables and postoperative outcomes were estimated using logistic regression. Results: A total of 206 patients (77% male) were included in the analyses, with a mean age of 67 years (SD 9). The mean values for the maximal oxygen consumed at the peak of exercise (VO 2peak) and the anaerobic threshold were 21.1 mL/kg/min (SD 4.5) and 12.4 mL/kg/min (SD 2.8), respectively. The vast majority of patients (98.5%) had malignant disease—predominantly adenocarcinoma (84.5%), for which most received neoadjuvant chemotherapy (79%) and underwent minimally invasive Ivor Lewis esophagectomy (53%). Complications at postoperative day 30 occurred in 111 patients (54%), the majority of which were cardiopulmonary (72%). No associations were found between preoperative cardiopulmonary exercise testing variables and morbidity for either VO 2peak (OR 1.00, 95% CI 0.94–1.07) or anaerobic threshold (OR 0.98, 95% CI 0.89–1.09). Conclusion: Preoperative cardiopulmonary exercise testing variables were not associated with 30-day complications after esophagectomy. The findings do not support the use of cardiopulmonary exercise testing as an isolated preoperative screening tool to predict short-term morbidity after esophagectomy. This modestly sized observational work highlights the need for larger studies examining associations between preoperative cardiopulmonary exercise testing and outcomes after esophagectomy to look for consistency in our findings

Fundamental approach for optoelectronic and microfluidic integration for miniaturizing spectroscopic devices

We have described an approach for miniaturizing spectroscopic devices by using the advantages presented by elastomeric based microfluidics and semiconductor detectors/emitters. Elastomers allow for both absorption and fluorescent spectroscopy in the visible range to be conducted on small volumes of solution and allow for easy integration with existing detectors such as CMOS imagers, CCD imagers, and silicon photodiodes. Results of some basic experiments are presented to demonstrate the effectiveness of the system. In addition, several ideas for emission sources are also discussed with their relevance yet to be determined

HST/NICMOS Observations of Fast Infrared Flickering in the Microquasar GRS 1915+105

We report infrared observations of the microquasar GRS 1915+105 using the NICMOS instrument of the Hubble Space Telescope during 9 visits in April-June 2003. During epochs of high X-ray/radio activity near the beginning and end of this period, we find that the $1.87$\um infrared flux is generally low ($\sim 2$ mJy) and relatively steady. However, during the X-ray/radio ``plateau'' state between these epochs, we find that the infrared flux is significantly higher ($\sim 4-6$ mJy), and strongly variable. In particular, we find events with amplitudes $\sim 20-30$% occurring on timescales of $\sim 10-20$s (e-folding timescales of $\sim 30$s). These flickering timescales are several times faster than any previously-observed infrared variability in GRS 1915+105 and the IR variations exceed corresponding X-ray variations at the same ($\sim 8s$) timescale. These results suggest an entirely new type of infrared variability from this object. Based on the properties of this flickering, we conclude that it arises in the plateau-state jet outflow itself, at a distance $<2.5$ AU from the accretion disk. We discuss the implications of this work and the potential of further flickering observations for understanding jet formation around black holes.Comment: 19 pages, incl. 4 figures; accepted for publication in Ap

Band gaps of crystalline solids from Wannier-localization based optimal tuning of a screened range-separated hybrid functional

Accurate prediction of fundamental band gaps of crystalline solid state systems entirely within density functional theory is a long standing challenge. Here, we present a simple and inexpensive method that achieves this by means of non-empirical optimal tuning of the parameters of a screened range-separated hybrid functional. The tuning involves the enforcement of an ansatz that generalizes the ionization potential theorem to the removal of an electron in an occupied state described by a localized Wannier function in a modestly sized supercell calculation. The method is benchmarked against experiment for a set of systems ranging from narrow band gap semiconductors to large band gap insulators, spanning a range of fundamental band gaps from 0.2 to 14.2 eV and is found to yield quantitative accuracy across the board, with a mean absolute error of $\sim$0.1 eV and a maximal error of $\sim$0.2 eV.Comment: 10 pages, 2 figure

Grounding Hypnosis in Science: The 'New' APA Division 30 definition of hypnosis as a step backwards.

Every decade or so, the Division 30 of the American Psychological Association (APA) has seen fit to redefine hypnosis (Elkins, Barabasz, Council, & Spiegel, 2015; Green, Barabasz, Barrett, & Montgomery, 2005; Kirsch, 1994). In the latest attempt, the Hypnosis Definition Committee (HDC) defined hypnosis as a 'state of consciousness involving focused attention and reduced peripheral awareness characterized by an enhanced capacity for response to suggestion' (Elkins et al., 2015, p. 6). One might justifiably wonder whether important discoveries or scientific breakthroughs or novel theoretical insights motivated the impetus to update the previous definition. In fact, the recently adopted definition is neither based on any apparent empirical foundation, noris it 'new.' Moreover, it has the potential to sow the seeds of conceptual and pragmatic confusion to an area sorely in need of greater clarification

A study of long-term potentiation in transgenic mice over-expressing mutant forms of both amyloid precursor protein and presenilin-1

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract Synaptic transmission and long-term potentiation (LTP) in the CA1 region of hippocampal slices have been studied during ageing of a double transgenic mouse strain relevant to early-onset familial Alzheimer's disease (AD). This strain, which over-expresses both the 695 amino acid isoform of human amyloid precursor protein (APP) with K670N and M671L mutations and presenilin 1 with the A246E mutation, has accelerated amyloidosis and plaque formation. There was a decrease in synaptic transmission in both wildtype and transgenic mice between 2 and 9 months of age. However, preparing slices from 14 month old animals in kynurenic acid (1 mM) counteracted this age-related deficit. Basal transmission and paired-pulse facilitation was similar between the two groups at all ages (2, 6, 9 and 14 months) tested. Similarly, at all ages LTP, induced either by theta burst stimulation or by multiple tetani, was normal. These data show that a prolonged, substantially elevated level of A&#946; are not sufficient to cause deficits in the induction or expression of LTP in the CA1 hippocampal region.Published versio