Polymorphism and solid−gas/solid−solid reactions of isonicotinic acid, isonicotinamide, and nicotinamide copper chloride compounds

The crystal structures of eight new copper chloride coordination complexes with substituted pyridines have been determined through a combination of single crystal X-ray diffraction and ab initio structure solution from X-ray powder diffraction data. The polymeric compounds [CuCl₂(INAc)₂]n (1), [CuCl₂(INAm)₂]n (2), and [CuCl₂(NAm)₂]n (3) (INAc = isonicotinic acid; INAm = isonicotinamide; NAm = nicotinamide) consist of chains of CuCl4 edge-sharing rhombi decorated by the pyridine-based ligands. All three compounds display similar hydrogen bonding interactions but differ in the arrangement of the polymeric chains. 1, 2, and 3 react reversibly with hydrochloric acid in solution/vapor form to produce the corresponding tetrachlorocuprate salts [CuCl₄](H-INAc)₂(H₂O) (4a), [CuCl₄](H-INAc)₂ (4b), [CuCl₄](H-INAm)₂ (form I/form II 5a/5b), and [CuCl₄](H-NAm)₂ (form I/form II 6a/6b). 4a exhibits discrete square planar [CuCl4]₂– ions, whereas the Cu in 4b, 5a, and 5b is in a 4 + 2 coordination. All four compounds display hydrogen bonding arrangements similar to those found in 1 and 2. 6a and 6b differ substantially from these compounds in both the hydrogen bonding contacts and the coordination geometry of the cuprate ion (flattened tetrahedral), though they differ from each other only in the orientation of the amide groups and packing arrangements. The formation of 6a/6b depends on the configuration of nicotinamide in the starting material

Crystal structure of 4-carbamoylpyridinium chloride

The hydro­chloride salt of isonicotinamide, C6H7N2O+·Cl-, has been synthesized from a dilute solution of hydro­chloric acid in aceto­nitrile. The compound displays monoclinic symmetry (space group C2/c) at 150 K, similar to the related hydro­chloride salt of nicotinamide. The asymmetric unit contains one protonated isonicotinamide mol­ecule and a chloride anion. An array of hydrogen-bonding inter­actions, including a peculiar bifurcated pyridinium-chloride inter­action, results in linear chains running almost perpendicularly in the [150] and [1-50] directions within the structure. A description of the hydrogen-bonding network and comparison with similar compounds are presented

Are spherulitic lacustrine carbonates an expression of large-scale mineral carbonation? : A case study from the East Kirkton Limestone, Scotland

BP Exploration Co. is thanked for funding, and particularly the Carbonate Team for supporting this research and for fruitful discussions. West Lothian Council and Scottish Natural Heritage are thanked for allowing access and permission for sampling the site. The Core Store Team at BGS Keyworth is particularly acknowledged for their assistance. Mark Anderson, Tony Sinclair (University of Hull), and Bouk Lacet (VU University Amsterdam) are thanked for technical support. Anne Kelly (SUERC) for carrying out the Strontium Isotope analyses. Mark Tyrer is thanked for his advice on PHREEQC modelling.Peer reviewedPostprin

Precision digital mapping of endogenous and induced genomic DNA breaks by INDUCE-seq

Understanding how breaks form and are repaired in the genome depends on the accurate measurement of the frequency and position of DNA double strand breaks (DSBs). This is crucial for identification of a chemical’s DNA damage potential and for safe development of therapies, including genome editing technologies. Current DSB sequencing methods suffer from high background levels, the inability to accurately measure low frequency endogenous breaks and high sequencing costs. Here we describe INDUCE-seq, which overcomes these problems, detecting simultaneously the presence of low-level endogenous DSBs caused by physiological processes, and higher-level recurrent breaks induced by restriction enzymes or CRISPR-Cas nucleases. INDUCE-seq exploits an innovative NGS flow cell enrichment method, permitting the digital detection of breaks. It can therefore be used to determine the mechanism of DSB repair and to facilitate safe development of therapeutic genome editing. We further discuss how the method can be adapted to detect other genomic features

Midwives Understanding of Physical Activity Guidelines During Pregnancy

Objective to examine the current level of understanding held by midwives regarding the NICE physical activity guidelines in the UK, and to investigate the physical activity guidance given to women during pregnancy. Design an 11 question online survey comprising of a mixture of closed and open ended questions. Setting data reflects participants sampled across the United Kingdom. Participants fifty-nine midwives completed the online survey Measurements and findings an electronic survey was used to explore the midwives understanding of physical activity guidelines during pregnancy, and the advice they offered to women in their care. Qualitative content analysis was used to gain a more in-depth understanding of midwife knowledge. Two per cent of midwives correctly identified the physical activity guidelines, with 44 giving partially correct responses, 25 giving incorrect responses and 29 unsure of what the guidelines are. Despite the low level of correct responses, 59 of respondents reported they were confident or very confident in answering questions regarding physical activity. Only 4 of respondents reported having access to continual professional development (CPD) in the area of PA guidance. Key conclusions there appears to be a misplaced confidence amongst midwives in their knowledge of the NICE PA guidelines for pregnancy. Implications for practice as physical inactivity can be detrimental for the health of both mother and baby, there is a clear need for better dissemination of the current and future NICE physical activity guidelines in primary health care settings. The current study determined a substantial lack of CPD in the area of PA guidance, which may be a contributing factor to the lack of knowledge of the guidelines. As such, increasing CPD may in turn improve the accuracy of the advice given to pregnant women and consequently benefit the health of both mother and baby. © 2018 Elsevier Lt

Inverse Compton X-ray Emission from Supernovae with Compact Progenitors: Application to SN2011fe

We present a generalized analytic formalism for the inverse Compton X-ray emission from hydrogen-poor supernovae and apply this framework to SN2011fe using Swift-XRT, UVOT and Chandra observations. We characterize the optical properties of SN2011fe in the Swift bands and find them to be broadly consistent with a "normal" SN Ia, however, no X-ray source is detected by either XRT or Chandra. We constrain the progenitor system mass loss rate to be lower than 2x10^-9 M_sun/yr (3sigma c.l.) for wind velocity v_w=100 km/s. Our result rules out symbiotic binary progenitors for SN2011fe and argues against Roche-lobe overflowing subgiants and main sequence secondary stars if >1% of the transferred mass is lost at the Lagrangian points. Regardless of the density profile, the X-ray non-detections are suggestive of a clean environment (particle density < 150 cm-3) for (2x10^15<R<5x10^16) cm around the progenitor site. This is either consistent with the bulk of material being confined within the binary system or with a significant delay between mass loss and supernova explosion. We furthermore combine X-ray and radio limits from Chomiuk et al. 2012 to constrain the post shock energy density in magnetic fields. Finally, we searched for the shock breakout pulse using gamma-ray observations from the Interplanetary Network and find no compelling evidence for a supernova-associated burst. Based on the compact radius of the progenitor star we estimate that the shock break out pulse was likely not detectable by current satellites.Comment: Submitted to Ap

People Efficiently Explore the Solution Space of the Computationally Intractable Traveling Salesman Problem to Find Near-Optimal Tours

Humans need to solve computationally intractable problems such as visual search, categorization, and simultaneous learning and acting, yet an increasing body of evidence suggests that their solutions to instantiations of these problems are near optimal. Computational complexity advances an explanation to this apparent paradox: (1) only a small portion of instances of such problems are actually hard, and (2) successful heuristics exploit structural properties of the typical instance to selectively improve parts that are likely to be sub-optimal. We hypothesize that these two ideas largely account for the good performance of humans on computationally hard problems. We tested part of this hypothesis by studying the solutions of 28 participants to 28 instances of the Euclidean Traveling Salesman Problem (TSP). Participants were provided feedback on the cost of their solutions and were allowed unlimited solution attempts (trials). We found a significant improvement between the first and last trials and that solutions are significantly different from random tours that follow the convex hull and do not have self-crossings. More importantly, we found that participants modified their current better solutions in such a way that edges belonging to the optimal solution (“good” edges) were significantly more likely to stay than other edges (“bad” edges), a hallmark of structural exploitation. We found, however, that more trials harmed the participants' ability to tell good from bad edges, suggesting that after too many trials the participants “ran out of ideas.” In sum, we provide the first demonstration of significant performance improvement on the TSP under repetition and feedback and evidence that human problem-solving may exploit the structure of hard problems paralleling behavior of state-of-the-art heuristics

Do guidelines influence breathlessness management in advanced lung diseases? A multinational survey of respiratory medicine and palliative care physicians

Background Respiratory medicine (RM) and palliative care (PC) physicians’ management of chronic breathlessness in advanced chronic obstructive pulmonary disease (COPD), fibrotic interstitial lung disease (fILD) and lung cancer (LC), and the influence of practice guidelines was explored via an online survey. Methods A voluntary, online survey was distributed to RM and PC physicians via society newsletter mailing lists. Results 450 evaluable questionnaires (348 (77%) RM and 102 (23%) PC) were analysed. Significantly more PC physicians indicated routine use (often/always) of opioids across conditions (COPD: 92% vs. 39%, fILD: 83% vs. 36%, LC: 95% vs. 76%; all p < 0.001) and significantly more PC physicians indicated routine use of benzodiazepines for COPD (33% vs. 10%) and fILD (25% vs. 12%) (both p < 0.001). Significantly more RM physicians reported routine use of a breathlessness score (62% vs. 13%, p < 0.001) and prioritised exercise training/rehabilitation for COPD (49% vs. 7%) and fILD (30% vs. 18%) (both p < 0.001). Overall, 40% of all respondents reported reading non-cancer palliative care guidelines (either carefully or looked at them briefly). Respondents who reported reading these guidelines were more likely to: routinely use a breathlessness score (χ2 = 13.8; p < 0.001), use opioids (χ2 = 12.58, p < 0.001) and refer to pulmonary rehabilitation (χ2 = 6.41, p = 0.011) in COPD; use antidepressants (χ2 = 6.25; p = 0.044) and refer to PC (χ2 = 5.83; p = 0.016) in fILD; and use a handheld fan in COPD (χ2 = 8.75, p = 0.003), fILD (χ2 = 4.85, p = 0.028) and LC (χ2 = 5.63; p = 0.018). Conclusions These findings suggest a need for improved dissemination and uptake of jointly developed breathlessness management guidelines in order to encourage appropriate use of existing, evidence-based therapies. The lack of opioid use by RM, and continued benzodiazepine use in PC, suggest that a wider range of acceptable therapies need to be developed and trialled

The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements

The top-shaped morphology characteristic of asteroid (101955) Bennu, often found among fast-spinning asteroids and binary asteroid primaries, may have contributed substantially to binary asteroid formation. Yet a detailed geophysical analysis of this morphology for a fast-spinning asteroid has not been possible prior to the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission. Combining the measured Bennu mass and shape obtained during the Preliminary Survey phase of the OSIRIS-REx mission, we find a notable transition in Bennu’s surface slopes within its rotational Roche lobe, defined as the region where material is energetically trapped to the surface. As the intersection of the rotational Roche lobe with Bennu’s surface has been most recently migrating towards its equator (given Bennu’s increasing spin rate), we infer that Bennu’s surface slopes have been changing across its surface within the last million years. We also find evidence for substantial density heterogeneity within this body, suggesting that its interior is a mixture of voids and boulders. The presence of such heterogeneity and Bennu’s top shape are consistent with spin-induced failure at some point in its past, although the manner of its failure cannot yet be determined. Future measurements by the OSIRIS-REx spacecraft will provide insight into and may resolve questions regarding the formation and evolution of Bennu’s top-shape morphology and its link to the formation of binary asteroids

Evidence for widespread hydrated minerals on asteroid (101955) Bennu

Early spectral data from the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid (101955) Bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spectral features that are most similar to those of aqueously altered CM-type carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of metres observed to date. In the visible and near-infrared (0.4 to 2.4 µm) Bennu’s spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth