16,753 research outputs found
Catalytic formation of C(sp(3))-F bonds via heterogeneous photocatalysis
Due to their chemical, physical, and biological properties, fluorinated compounds are widely employed throughout society. Yet, despite their critical importance, current methods of introducing fluorine into compounds suffer from severe drawbacks. For example, several methods are noncatalytic and employ stoichiometric equivalents of heavy metals. Existing catalytic methods, on the other hand, exhibit poor activity, generality, selectivity and/or have not been achieved by heterogeneous catalysis, despite the many advantages such an approach would provide. Here, we demonstrate how selective C(sp3)–F bond synthesis can be achieved via heterogeneous photocatalysis. Employing TiO2 as photocatalyst and Selectfluor as mild fluorine donor, effective decarboxylative fluorination of a variety of carboxylic acids can be achieved in very short reaction times. In addition to displaying the highest turnover frequencies of any reported fluorination catalyst to date (up to 1050 h–1), TiO2 also demonstrates excellent levels of durability, and the system is catalytic in the number of photons required; i.e., a photon efficiency greater than 1 is observed. These factors, coupled with the generality and mild nature of the reaction system, represent a breakthrough toward the sustainable synthesis of fluorinated compounds
Uncle Curro : J.R.R. Tolkien\u27s Spanish Connection (2018) by José Manuel Ferrández Bru
Book review, by Wayne G. Hammond and Christina Scull, of Uncle Curro: J.R.R. Tolkien\u27s Spanish Connection (2018) by José Manuel Ferrández Br
Opacity of hot, highly compressed hydrogen Final report
Ballistic piston compressor used to study opacity of hot highly compressed hydroge
Computed tomography and magnetic resonance diagnosis of variations in the anatomical location of the major salivary glands in 1680 dogs and 187 cats
During assessment of routine clinical magnetic resonance imaging (MRI) of the heads of dogs, variations in the location of mandibular and zygomatic salivary glands (SGs) were observed incidentally. The aims of this retrospective study were to describe anatomical variations of the major SGs found on MRI and computed tomography (CT) studies of the head in dogs and cats and to investigate possible clinical relevancy.
No anatomical variation of the SGs was seen in cats, but in dogs, although variation of the parotid SG was not identified, that of the mandibular SG was found in 33/1680 animals (2%), either unilaterally (6/33 right-sided, 13/33 left-sided) or bilaterally (14/33). The Border terrier breed (19/33, 58%) was over-represented. Each atypically located mandibular SG was positioned medial to the digastric muscle and rostral to the retropharyngeal lymph node. The sublingual glands were difficult to delineate from the mandibular glands. Anatomical variation of one zygomatic gland (3/4 left-sided) was identified in four small-breed dogs (0.2%). Each atypically located zygomatic gland was tilted at the ventrorostral aspect of the masseter muscle underneath the skin surface. MRI and CT characteristics were not different between typically and atypically located SGs. None of the dogs had clinical signs related with SG disease. It was concluded that, with suspected breed predispositions, incidental unilateral or bilateral anatomical variations of mandibular and zygomatic SGs can be encountered in dogs and an awareness of these possible variations may be important in pre-surgical planning
Sustainable Prosperity and Democracy: A Research Agenda
As environmental crises, most notably climate change, become ever more severe, voices are reappearing that call for authoritarian solutions: Democracy, so the argument goes, has proven to be too slow to respond to urgent threats, and so a stronger, authoritarian hand is needed to push through the necessary socio-political changes. In this paper, we respond to this charge by revisiting the role of democracy within a transition to sustainable prosperity. We argue it is not democracy as such that is the problem, but rather democracy in its current form is itself constrained by structural and discursive forces including the almost hegemonic status of capitalist politico-economic discourses and tendencies towards shorttermism in political decision-making. Thus, instead of advocating further constraints on democracy, we explore new institutional and societal spaces that can revitalise democracy, ameliorating existing constraints and infusing sustainability politics with new ways of thinking. In particular we highlight the potential promise of participatory and deliberative innovations, prefigurative politics, reform of established structures and institutions, and deliberative systems and cultural change. The paper acts as an introduction to some of the political theory and political science aspects of the research programme of the Centre for the Understanding of Sustainable Prosperity (CUSP)
Effects of Enamel Paint on the Behavior and Survival of the Periodical Cicada, \u3ci\u3eMagicicada Septendecim\u3c/i\u3e (Homoptera) and the Lesser Migratory Grasshopper, \u3ci\u3eMelanoplus Sanguinipes (Orthoptera).
We present information compiled from several studies on the effects of methods for marking individual arthropods on their longevity and behavior. Results from our own research on effects of enamel paint marking on two in- sect species, the periodical cicada, Magicicada septendecim, and the lesser migratory grasshopper, Melanoplus sanguinipes, are also presented. Neither species showed any adverse survivorship or behavioral effects from marking
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Precision placement of fertiliser for optimising the early nutrition of vegetable crops : a review of the implications for the yield and quality of crops, and their nutrient use efficiency
The research outlined in this paper highlights the importance of the early nutrition of vegetable crops, and its long-term effects on their subsequent growth and development. Results are also presented to demonstrate how the nutrient supply during the establishment stages of young seedlings and transplants can be enhanced by targeting fertiliser to a zone close to their developing roots. Three different precision fertiliser placement techniques are compared for this purpose: starter, band or side-injected fertiliser. The use of each of these methods consistently produced the same (or greater) yields at lower application rates than those from conventional broadcast applications, increasing the apparent recovery of N, P and K, and the overall efficiency of nutrient use, while reducing the levels of residual nutrients in the soil. Starter fertilisers also advanced the maturity of some crops, and enhanced produce quality by increasing the proportions of the larger and/or more desirable marketable grades. The benefits of the different placement techniques are illustrated with selected examples from research at Warwick HRI using different vegetable crops, including lettuce, onion and carrot
Radiographic measurements of the trachea in domestic short haired and Persian cats
Tracheal diameter can be assessed from a thoracic radiograph, with assessment of tracheal diameter in dogs based on ratios between tracheal diameter and a skeletal measurement – however reference ranges are not available for the cat. Tracheal narrowing may cause significant clinical problems, although tracheal hypoplasia in dogs may be clinically silent, and is rarely reported in cats (both mesati- and brachycephalic). The tracheal diameter and trachea:thoracic inlet and trachea:rib ratios were calculated for populations of Domestic Short Haired (DSH) (n=68) and Persian (n=40) cats. This gave reference ranges for radiographic tracheal measurements in these breeds. It is proposed that the tracheal diameter in a normal DSH cat should be 18% of the diameter of the thoracic inlet, and compared to 20% in Persian cats
Cupid\u27s Wings
One sunny day as Cupid lay, In rosy dreams asleep I stole his fairy wings away, And biding him a fond adieu, I quickly donned the pennons gay, That I might fly to you One sunny day as Cupid lay, In rosy dreams asleep, I stole his fairy wings away, That I might fly. That I might fly. to you
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