Palladium Allylic Complexes with enantiopure bis(diamidophosphite) ligands bearing a cyclohexane-1,2-diamine skeleton as catalysts in the allylic substitution reaction

A series of cationic allyl palladium complexes [Pd(η3-CH3-C3H5)(P-P)]X (X = PF6, 2a-c, 2e; and X = BPh4, 3a, 3b, 3d, 3e) and [Pd(η3-1,3-Ph2-C3H3)(P-P)]X (X = PF6, 6b; and X = BPh4, 7a) have been prepared. The bis(diamidophosphite) ligands (P-P) contain a diazaphospholidine terminal fragment derived from (R,R)- and (S,S)-N,N'-dibenzyl- and (R,R)-N,N'-dimethyl-cyclohexane-1,2-diamines and dialcoxy bridging fragment derived from (R,R)- and (S,S)-butanediol, (R,R)-cyclohexanediol, (4R,5R)- and (4S,5S)-4,5-di(hydroxymethyl)-2,2-dimethyl-1,3-dioxolane and (R)- and (S)-binaphthol. Complexes [Pd(η3-CH3-C3H5l)P2]X (X = PF6, 4f, 4g; and X = BPh4, 5f), where P are monodentate diamidophosphite ligands with diazaphospholidine heterocyclic backbone obtained from (R,R)- and (S,S)-N,N'-dibenzylcyclohexane-1,2-diamine and alcoxy groups coming from (R)-phenyl-ethanol and (S)-borneol have been also prepared. Neutral palladium complexes [PdCl2(P-P)] (1a, 1c) were synthesized to prove the C2 symmetry of the P-P ligand. The new compounds were fully characterized in solution by NMR spectroscopy. The X-ray crystal structure determination for 2e-(R,R,Ral,Ral;R,R) and 1a-(S,S;Sal,Sal;S,S) has been achieved. The new allyl-palladium complexes were applied in the asymmetric allylic substitution reaction of the benchmark substrate rac-3-acetoxy-1,3-diphenyl-1-propene with dimethyl malonate and benzylamine as nucleophiles in order to test their catalytic potential. The best results were obtained with the 3a-(R,R;Ral,Ral;R,R) precursor (up to 84% ee) while complexes with the e ligand derived from the (R,R)-N,N'-dimethylcyclohexane-1,2-diamine terminal fragment resulted inactive in the process. The influence of the nature and the absolute configuration of both the bridging and the terminal fragments of the bis(diamidophosphite) ligand on the asymmetric induction is discussed. A preliminary study of the anion effect (PF6− vs. BPh4-) on the activity and the enantioselectivity of the Pd-catalysed allylic substitution has also been performed

Cross-linguistic adaptations of The Comprehensive Aphasia Test: Challenges and solutions

Comparative research on aphasia and aphasia rehabilitation is challenged by the lack of comparable assessment tools across different languages. In English, a large array of tools is available, while in most other languages, the selection is more limited. Importantly, assessment tools are often simple translations and do not take into consideration specific linguistic and psycholinguistic parameters of the target languages. As a first step in meeting the needs for comparable assessment tools, the Comprehensive Aphasia Test is currently being adapted into a number of languages spoken in Europe. In this article, some key challenges encountered in the adaptation process and the solutions to ensure that the resulting assessment tools are linguistically and culturally equivalent, are proposed. Specifically, we focus on challenges and solutions related to the use of imageability, frequency, word length, spelling-to-sound regularity and sentence length and complexity as underlying properties in the selection of the testing material

Imageability ratings across languages

Imageability is a psycholinguistic variable that indicates how well a word gives rise to a mental image or sensory experience. Imageability ratings are used extensively in psycholinguistic, neuropsychological, and aphasiological studies. However, little formal knowledge exists about whether and how these ratings are associated between and within languages. Fifteen imageability databases were cross-correlated using nonparametric statistics. Some of these corresponded to unpublished data collected within a European research network-the Collaboration of Aphasia Trialists (COST IS1208). All but four of the correlations were significant. The average strength of the correlations (rho = .68) and the variance explained (R (2) = 46%) were moderate. This implies that factors other than imageability may explain 54% of the results. Imageability ratings often correlate across languages. Different possibly interacting factors may explain the moderate strength and variance explained in the correlations: (1) linguistic and cultural factors; (2) intrinsic differences between the databases; (3) range effects; (4) small numbers of words in each database, equivalent words, and participants; and (5) mean age of the participants. The results suggest that imageability ratings may be used cross-linguistically. However, further understanding of the factors explaining the variance in the correlations will be needed before research and practical recommendations can be made

The governmentally supported book Högspänning : A case study of value-creating library actors

The aim of this thesis is to study the valuation process of a work of fiction by actors within or linked to the library system in Sweden, to identify who these library actors are as well as the value regimes that they express. The theory of value was devised by Barbara Herrstein Smith (1988) and states that a work of literature, through encounters with different actors within the field of literature, acquires several different values. This theory was concretized and put into practice by Ohlsson, et al. (2013) and Forslid et al. (2015) who discovered values within five categories as well as two value regimes. Högspänning, written by Henrik Bromander, is a work of fiction that received state supported distribution from Kulturrådet in year 2019. This means that the book was distributed to more than 280 public libraries in Sweden. This thesis follows Högspänning and its value negotiation process through encounters with different library actors, from publication in January 2019 to November 2020. Actors within or linked to the library system were identified by the collection of public digital documents containing value judgements through searching for them online. The results of the thesis show that Högspänning meets 16 different library actors who express different values and who perform various acts of value creation. The finding that is of most interest is the fact that librarians, with both professional and personal knowledge of literature, can be found in the intermediate range between the two value regimes.

The impact of masking noise on the learning ability of visual information : the effect of masking noise in open-plan offices

Denna experimentella studie undersökte om maskerande brusljud på ovidkommande tal påverkar inlärning av visuell information. Experimentet genomfördes i ett laboratorium med 32 försöksdeltagare. Visuella ord presenterades för försöksdeltagarna samtidigt som auditivt tal från samma semantiska kategori, med eller utan maskerande brusljud, presenterades. De visuella orden skulle återges i valfri ordning. Resultatet av studien visar att ett maskerande brusljud på ovidkommande tal har positiv effekt på inlärningsförmågan. Detta visades av att försökspersonerna mindes fler visuellt presenterade ord samt att de lyckades ignorera det ovidkommande talet bättre då talet maskerades av ett brusljud jämfört med om talet inte maskerades av ett brusljud. Resultaten av studien kan med fördel tillämpas i öppna kontorslandskap. Detta då medarbetare i öppna kontorslandskap ofta utför kognitivt krävande uppgifter i en bullrig miljö innehållande bland annat bakgrundstal. Ett maskerande brusljud kan minska störningen av ovidkommande kontorsljud och ovidkommande tal och på så sätt positivt påverka arbetsprestationen.This study examined if a masking white noise on irrelevant speech affects the encoding of visual information. An experiment was carried out in a laboratory with 32 participants. The participants were presented to a series of written words and were prompted to recall these words in any order. While the participants studied the written words, irrelevant speech from the same semantic category was presented with or without a masking noise. The participants were told to ignore the irrelevant speech. The results of this study showed that the number of intrusions from the irrelevant speech decreases and the number of recalled written words increases when the irrelevant speech is masked by a white noise compared to irrelevant speech without a masking noise. The findings of this study could be applied in the acoustic design of open-plan offices where cognitive tasks, such as reading comprehension and proofreading, are performed in a noisy environment. A white noise can reduce the intelligibility of office noise and irrelevant speech, which have positive effect on work performance. 

Hållbar utveckling i ett socialt sammanhang i skolan : Hur vill du att andra skall vara mot dig?

Syftet med denna undersökning är att via en kvalitativ forskningsmetod med hjälp av semistrukturerade intervjuer belysa hållbar utveckling i ett socialt sammanhang i skolan. Hur resonerar lärare och elever om den sociala miljön och språket i skolan? Lärarna har skilda uppfattningar om hur det sociala klimatet är och eleverna använder ett fult språk till varandra men tar det oftast inte på allvar. Flera elever uttryckte att de vill ha ordning och reda samt lugn och ro i skolan. Vår slutsats är att både lärarna och eleverna kan ha blivit "hemmablinda" och därför inte tycker att den sociala miljön i skolan är så hård som vi upplever. Det kan också vara så att den naturliga språkutvecklingen har bidragit till att de fula och kränkande orden har kommit in i vardagen. Det är enligt oss viktigt att alla i skolans värld arbetar för en hållbar utveckling i ett socialt sammanhang och att det genomsyrar läraren själv samt undervisningen

Efficient Band Gap Prediction for Solids

An efficient method for the prediction of fundamental band gaps in solids using density functional theory (DFT) is proposed. Generalizing the Delta self-consistent-field (ΔSCF [delta SCF]) method to infinite solids, the Δ-sol [delta-sol] method is based on total-energy differences and derived from dielectric screening properties of electrons. Using local and semilocal exchange-correlation functionals (local density and generalized gradient approximations), we demonstrate a 70% reduction of mean absolute errors compared to Kohn-Sham gaps on over 100 compounds with experimental gaps of 0.5–4 eV, at computational costs similar to typical DFT calculations.Eni S.p.A. (Firm)Eni-MIT Solar Frontiers CenterChesonis Family Foundatio

Prediction of semiconductor band edge positions in aqueous environments from first principles

The ability to predict a semiconductor's band edge positions in solution is important for the design of water-splitting photocatalyst materials. In this paper, we introduce a first-principles method to compute the conduction-band minima of semiconductors relative to the water H2O/H2 [H subscript 2 O / H subscript 2] level using density functional theory with semilocal functionals and classical molecular dynamics. We test the method on six well known photocatalyst materials: TiO2 [Ti O subscript 2], WO3 [W O subscript 3], CdS, ZnSe, GaAs, and GaP. The predicted band edge positions are within 0.34 eV of the experimental data, with a mean absolute error of 0.19 eV.Eni S.p.A. (Firm)Eni-MIT Solar Frontiers CenterChesonis Family FoundationMIT Solar Revolution ProjectNational Science Foundation (U. S.) (Grant no. TG-DMR970008S

Intrinsic stoichiometry and oxygen-induced p-type conductivity of pyrite FeS2

The stoichiometry and ubiquitous observation of p-type conductivity of synthetic pyrite FeS[subscript 2] thin films are investigated via first-principles computations of native (vacancies, interstitials, antisites) and extrinsic (O[subscript S], O[subscript i]) point defects. Native defects have high formation energies and are predicted to occur in low concentrations within the Fe- and S-rich limits, showing that pyrite should be intrinsically stoichiometric. Under sufficiently oxidizing conditions, O[subscript S] becomes the most dominant defect type and induces p-type conductivity. At the experimental oxygen impurity concentration, the hole concentration is predicted to be O(10[superscript 19]) cm[superscript −3], in agreement with Hall measurements reported in the literature. Therefore, we attribute the unintentional p-type conductivity of pyrite to oxygen impurities and propose that improvements in device performance may be achieved under more reducing conditions.National Science Foundation (U.S.) (Grant No. TG-DMR970008S

IDENTIFYING KNOWLEDGE GAPS AND PROPOSE CHEMICAL CANDIDATES FOR FUTURE SCREENING

From a gross list of chemical substances, most of them considered as highly relevant for environmental screening, a selection filter was developed with the aim of scientifically transparently selecting substances for environmental screening in Sweden. The gross list itself was compiled by combining high quality scientifically annotated lists of chemical substances with either confirmed or highly SVHC properties, with normalised exposure index data for chemical substances (as such and in mixtures imported to or manufactured in Sweden), and data of tonnage used as well as data of environmental monitoring in Sweden 1900-2017. The application of the filter on the gross list (all lists above mentioned combined) resulted in 16 substances merited for screening. One of the substances (a "high scorer") was disqualified for being used solemnly as intermediate (Anthracene oil, Anthracenelow") and another two substances ("Pitch, coal tar, high-temp." and "Anthracene oil", both "high-scorers" in the selection filter) were considered less suitable for screening since they are quite complex UVCB substances (substances with a less defined composition) containing a variety of polycyclic hydrocarbons (PAHs). The resulting 13 substances spans a variety of chemical functionalities, usages and tonnages in the EU (see Table 1). Purposely omitted from the selection process were metals, metal salts and organo-metallic compounds. A rationale for this discriminatory treatment is provided within the report. The gross filter and the corresponding data lists do not take chemical substances in articles into consideration due to lack of information. For the selected substances, some information on their use in articles has been compiled together with some relevant phys-chem data on the substances, primarily from the lead registrants REACH-registration. Based on phys-chem data and recipients of highest predicted exposed from an exposure-tool provided by the Swedish Chemical agency (KemI), a list of suggested environmental matrices for sampling, has been compiled for the selected substances. One drawback with the selection process and the filter tool is that it takes only chemical substances as such, as well as in chemical products into consideration. Chemical substances imported to Sweden in articles are not taken into consideration. Also chemical substances mainly being used as pharmaceuticals, cosmetics, as biocides or pesticides will not automatically be considered. Possibly contradicting the overall purpose of the developed selection tool, screening candidate selection with minimal preconceptional bias, the project group has also taken the advantage to propose a couple of "wild card" alternatives (Table 2). These are substances that may have trajected "under the radar" and hence do not score high points in the selection tool, or does not even occur on any list. Among the "wild card" substances there are one substitute substance for PFOA, often referred to as "GenX" (Ammonium perfluoro(2-methyl-3-oxahexanoate) and two substitute substances for PFOS; "F-53B" and the cyclic PFHCES (see Table 2). Based on scientific literature, all these three PFAS-homologs may very well enter in to the EU in chemical products and in articles. Environmental monitoring efforts especially in China has shown that the new PFAS-homologs are frequently detected in environmental matrices as well as in human plasma. Another suggested group to include in the screening selection is cyclic siloxanes (see Table 2). The group has been suspected to be used as replacement tensides class B fire- fighting foams as well as in other hitherto, PFAS-tainted product groups. Cyclic siloxanes were included in a national screening program in Sweden in 2005 (screening conducted by IVL), but 14 years later the uses of this group of chemicals may have changed considerably in Sweden. In annex 2 of the report, more specific information on the suggested screening candidates has been compiled such as molecular structure, type of substance, uses, tonnages etc. The data in annex 2 stems mainly from ECHAs registered substance database, reflecting key information from the lead registrant’s REACH registration.Ett selektionsverktyg har utvecklats för att välja ut kemiska ämnen, vetenskapligt transparent, för screening i enlighet med Naturvårdsverkets program för miljöövervakning i Sverige. I verktyget kombineras data från vetenskapligt granskade och recenserade listor innehållandes kemiska ämnen med fastställda eller högst sannolika så kallade SVHC-egenskaper (substances of very high concern) med uppskattad exponering från Kemikalieinspektionens framtagna verktyg Exponeringsindex, samt med tonnageuppgifter avseende ämnena (som sådana och i kemiska produkter), och all samlad miljöövervakning i Sverige (1900 – 2017). Selektionsverktyget inkluderande listor med ämnenas egenskaper, i kombination med exponeringsindex, använda volymer och tidigare förekommande miljöövervakning för kemiska ämnen i Sverige, medför möjligheten att filtrera fram de mest lämpade ämnena att screena. I det föreslagna, fram-filtrerade screeningförslaget som tagits fram inom ramen för uppdraget föreligger 16 ämnen. Vid en mer detaljerad genomgång av dessa 16 ämnen kunde konstateras att tre (3) av dem var mindre lämpliga för screening (även om dom i filterverktyget genererade mycket höga poäng). En av de föreslagna screeningkandidaterna (Anthracene Oil, AnthracenLow) har endast en registrerad användning inom EU såsom intermediär. De övriga två ämnena ("Pitch, coal tar, high-temp" och "Anthracene Oil") är s k UVCB-ämnen (enligt definitionen i REACH EG nr 1907/2006) där ämnets kemiska sammansättning är komplex och ämnesidentiteten definieras utifrån syntesråvaran vid tillverkning. Alla tre ämnena har dessutom PAH:er som dominerande komponenter i sammansättningsprofilen. PAH:er förekommer redan i ett flertal miljöövervakningsprogram varför det ej kan anses som befogat att inkludera dem i det föreslagna screeningprogrammet. En annan ämnesgrupp som avsiktligt utelämnats från hela selektionsprocessen är metaller, metallsalter och metallorganiska föreningar. Metaller är redan frekvent förekommande i de miljöövervakningsprogram som redan pågår och då bestäms de som totalhalter av en given metall. En annan svårighet med att inkludera specifika metalspecies, en metallorganisk förening eller ett metallsalt, är att i miljön kommer de flesta metallorganiska ämnen sönderdelas och inte heller metallsalterna kommer att föreligga som just salter som filtrerats fram ifrån verktyget. Dock finns det skäl att överväga en bättre specificering förekomsten av vissa metallorganiska föreningar i miljön, t ex tennorganiska ämnen, vissa bly- och nickelkomplex. Förslagsvis görs en metallscreening var 5:e eller var 10:e år för att då specialstudera förekomst av vissa metallorganiska ämnen. De resulterande 13 ämnena som filtrerats fram med hjälp av selektionsverktyget har listats i "Table 1" (se den engelska sammanfattningen på föregående sida) tillsammans med sina summerade poäng i verktyget. Viktigt att poängtera är att verktyget och filterinställningar mm, endast beaktar kemiska ämnen som sådana, samt kemiska ämnen i kemiska produkter. Kemiska ämnen i varor har ej kunnat beaktas i selektionen då information om dessa är bristfällig och svår-aggregerad. Inte heller kommer kemiska ämnen som främst förekommer som aktiva läkemedelssubstanser, som beståndsdelar i kosmetika, samt biocider och pesticider, att vara föremål för de regulatoriska triggers, t ex inklusion i REACH Kandidatlista, som gör att de inkluderas i den bruttolista varifrån screeningkandidater filtrerats fram ifrån.  För de framselekterade 13 ämnena har viss information om förekomst i varor inom EU, samt ämnenas molekylstrukturer och förslag på relevanta matriser i miljön, att mäta dem i, sammanställts på basis av offentliga delar av förekommande REACH-registrering samt utdrag ur Exponeringsindex. Möjligen i motsägelse till uppdragets övervägande syfte, att utveckla en metod för bias-fri selektion av screeningkandidater, har ett antal ämnen (ca 5 st) föreslagits som screeningkandidater trots att de inte meriterar sig för screening baserat på aggregerade poäng. Vissa av ämnena förekommer inte ens i den genererade bruttofilen om ca 1 200 ämnen (se t ex "F-53B och PFHCES i "Table 2") men bedöms av projektgruppen ändå som relevanta att föreslå för nationell screening i Sverige. Dessa ämnen får betraktas som "wild cards" i selektionsförslaget. Bland dessa "wild cards" återfinns bl a s k perfluorerade eller högfluorerade substitutionsämnen för PFOS och PFOA. Utifrån genomförda litteratursökningar i vetenskaplig litteratur förefaller t ex GenX i mycket stor utsträckning ersätta PFOA vid tillverkning av polytetrafluoreten (PTFE). Vidare kan konstateras att "F-53B" och den cykliska PFAS-homologen PFHCES numera anses substituera PFOS i många applikationer. Screeningundersökningar i Kina har redovisat att dessa tre PFAS-homologer detekteras frekvent i många matriser i miljön men även i humanplasma. Ytterligare en begränsad ämnesgrupp som föreslås att övervägas för screening är cykliska siloxaner. Dessa antas i allt högre utsträckning substituera PFAS i släckskum klass B. Cykliska siloxaner var föremål för nationell screening i Sverige 2005 (genomförd av IVL) men det kan finnas skäl att ånyo screena dem då ämnesgruppens användning kan ha förändrats en hel del de senaste 14 åren