On the acquisition of the german plural markings

In the following, we will discuss the acquisition of plural forms in German from the unified perspective of the two, in our opinion compatible, approaches, on the basis of a longitudinal data sample of eight children. There are at least six recordings of each child, all of whom are girls. Together, the data cover the acquisition period from 1;11 to 2;10. One may thus anticipate that the data sample under investigation reflects the transition from purely lexical memorization to the acquisition of regularities or patterns

Investigations of Synthetic Models of Mononuclear Nonheme Iron Dioxygenases

Ring cleaving dioxygenases, such as o-aminophenol dioxygenase (APDO) and extradiol catechol dioxygenases (CatD), play an important role in human metabolism and the degradation of aromatic pollutants, yet questions still remain concerning the enzymatic mechanisms. One area of the catalytic cycle that remains controversial is the geometric and electronic structure of the intermediate formed after O2 binding to the Fe(II) centers. Synthetic model systems can be useful for studying enzyme active sites, as they are easier to modify and characterize than the enzymes themselves. However, synthetic models of APDOs have been relatively rare thus far. We prepared several monoiron(II) complexes that faithfully model the enzyme-substrate intermediates of o-aminophenol dioxygenases (APDO) and catechol dioxygenases. The complexes use either the Ph2Tp (Ph2Tp = hydrotris(3,5-diphenylpyrazol-1-yl)borate) or Ph2TIP (Ph2TIP = tris(4,5-diphenyl-1-methylimidazole)phosphine) supporting ligands and one of three bidentate, redox-active ligands: 4-tert-butylcatecholate, 4,6-di-tert-butyl-2-aminophenolate, or 4-tert-butyl-1,2-phenylenediamine. These complexes have been extensively characterized with crystallographic, spectroscopic, and electrochemical techniques, in conjunction with computational methods (e.g, density functional theory). Each complex is reactive towards O2, and the geometric and electronic structures of the resulting species were examined with various methods to determine whether the oxidation is iron-based, ligand-based, or a combination of both. Treatment of the Ph2Tp Ph2TIP monoiron(II) aminophenolate complex with a phenoxyl radical results in formation of a complex containing an iron(II) center coordinated to an iminobenzosemiquinonate radical, that to the best of our knowledge has no synthetic precedence. Further oxidation leads to a complex best described as a ferric center bound to the iminiobenzosemiquinate radical. The electronic structures of these complexes were determined with the aid of spectroscopic and computational methods. Several monoiron(II) complexes were also prepared to model the active-site structure of β-diketone dioxygenase (Dke1). For this purpose, we employed the Ph2Tp supporting ligand and acacX substrate ligands, where acacX represents the anion of dialkyl malonate. Upon exposure to O2 in toluene it was found that the complexes exhibited reactivity similar to Dke1, although at a much slower rate than the native enzyme

The Missing Link: Democratic Citizenship in Service Learning A Case Study of Undergraduate Course Offerings at a Large Urban University

The purpose of this study was to explore a discrete set of service-learning courses to determine. (1) were they of the type conducive to fostering democratic citizens. and (2) did the coordinating center that supported service-learning advocate it for democratic Citizenship. Sixteen university instructors and two administrative staff members from a coordinating center were interviewed, and documents describing the courses and coordinating center were reviewed. Drawing from the literature. a list of ten criteria for democratic citizenship was assembled, and two sets of questions-one for the instructors and another for the administrative staff-were devised to prompt the response of the participants. It was determined that: (1) the coordinating center exhibited nearly twice as many characteristics of democratic citizenship as did the instructors\u27 courses; (2) the coordinating center and the instructors had considerable room for improvement if democratic citizenship was a motivation and a goal for the students; (3) curricular interests were the primary reason for engaging in service learning; and (4) more support needs to be provided by the coordinating center if instructors are to gain confidence, and effectively develop service 1eaming for democratic citizenship

A Synthetic Model of the Putative Fe(II)-Iminobenzosemiquinonate Intermediate in the Catalytic Cycle of \u3cem\u3eo\u3c/em\u3e-Aminophenol Dioxygenases

The oxidative ring cleavage of aromatic substrates by nonheme Fe dioxygenases is thought to involve formation of a ferrous–(substrate radical) intermediate. Here we describe the synthesis of the trigonal-bipyramdial complex Fe(Ph2Tp)(ISQtBu) (2), the first synthetic example of an iron(II) center bound to an iminobenzosemiquinonate (ISQ) radical. The unique electronic structure of this S = 3/2 complex and its one-electron oxidized derivative ([3]+) have been established on the basis of crystallographic, spectroscopic, and computational analyses. These findings further demonstrate the viability of Fe2+–ISQ intermediates in the catalytic cycles of o-aminophenol dioxygenases

Comparison between economic growth and satellite-based measurements of NO2 pollution over northern Italy

The aim of this study is to investigate to what extent spatiotemporal fluctuations in the tropospheric NO2 column concentration can map variations in economic output. To do so satellite based tropospheric NO2 column measurements obtained from the ERS-2, ENVISAT, MetOp-A, and MetOp-B satellite missions covering the period from 1996 to 2017 over the Po valley in northern Italy is analyzed. A harmonic analysis is carried out in order to exclude influences such as the annual or semi-annual cycle. Afterwards the residues of the tropospheric NO2 time series are further investigated by means of a wavelet analysis method. The result is a spectrogram which implies the NO2 variability for the study area between 1996 and 2017. Therefore, the gross domestic product (GDP) is used as an indicator for economic performance and thus, as an approximation, of anthropogenically induced NO2 pollution. Clear conspicuous signatures occurred almost simultaneously both within the temporal development of the GDP growth rate and the spectral characteristic of the NO2 variability during the studied period. The comparison of the temporal course of the GDP shows that the period of systematically reduced spectral intensity in NO2 coincides strikingly well with the period of the global financial crisis in 2008 which was then followed by a second crisis in 2014. The economic growth decreased by 7.9% between 2007 and 2009 and by 5.2% between 2011 and 2014 in comparison to the same quarter of the previous year. It is found that during the crises (2007–2013) the variability of NO2 is reduced by about 80%

Dioxygen Reactivity of Biomimetic Fe(II) Complexes with Noninnocent Catecholate, \u3cem\u3eo\u3c/em\u3e-Aminophenolate, and \u3cem\u3eo\u3c/em\u3e-Phenylenediamine Ligands

This study describes the O2 reactivity of a series of high-spin mononuclear Fe(II) complexes each containing the facially coordinating tris(4,5-diphenyl-1-methylimidazol-2-yl)phosphine (Ph2TIP) ligand and one of the following bidentate, redox-active ligands: 4-tert-butylcatecholate (tBuCatH–), 4,6-di-tert-butyl-2-aminophenolate (tBu2APH–), or 4-tert-butyl-1,2-phenylenediamine (tBuPDA). The preparation and X-ray structural characterization of [Fe2+(Ph2TIP)(tBuCatH)]OTf, [3]OTf and [Fe2+(Ph2TIP)(tBuPDA)](OTf)2, [4](OTf)2 are described here, whereas [Fe2+(Ph2TIP)(tBu2APH)]OTf, [2]OTf was reported in our previous paper [Bittner et al., Chem.—Eur. J. 2013, 19, 9686–9698]. These complexes mimic the substrate-bound active sites of nonheme iron dioxygenases, which catalyze the oxidative ring-cleavage of aromatic substrates like catechols and aminophenols. Each complex is oxidized in the presence of O2, and the geometric and electronic structures of the resulting complexes were examined with spectroscopic (absorption, EPR, Mössbauer, resonance Raman) and density functional theory (DFT) methods. Complex [3]OTf reacts rapidly with O2 to yield the ferric-catecholate species [Fe3+(Ph2TIP)(tBuCat)]+ (3ox), which undergoes further oxidation to generate an extradiol cleavage product. In contrast, complex [4]2+ experiences a two-electron (2e–), ligand-based oxidation to give [Fe2+(Ph2TIP)(tBuDIBQ)]2+ (4ox), where DIBQ is o-diiminobenzoquinone. The reaction of [2]+ with O2 is also a 2e– process, yet in this case both the Fe center and tBu2AP ligand are oxidized; the resulting complex (2ox) is best described as [Fe3+(Ph2TIP)(tBu2ISQ)]+, where ISQ is o-iminobenzosemiquinone. Thus, the oxidized complexes display a remarkable continuum of electronic structures ranging from [Fe3+(L2–)]+ (3ox) to [Fe3+(L•–)]2+ (2ox) to [Fe2+(L0)]2+ (4ox). Notably, the O2 reaction rates vary by a factor of 105 across the series, following the order [3]+ \u3e [2]+ \u3e [4]2+, even though the complexes have similar structures and Fe3+/2+ redox potentials. To account for the kinetic data, we examined the relative abilities of the title complexes to bind O2 and participate in H-atom transfer reactions. We conclude that the trend in O2 reactivity can be rationalized by accounting for the role of proton transfer(s) in the overall reaction

Chemicals having estrogenic activity can be released from some bisphenol a-free, hard and clear, thermoplastic resins

Background: Chemicals that have estrogenic activity (EA) can potentially cause adverse health effects in mammals including humans, sometimes at low doses in fetal through juvenile stages with effects detected in adults. Polycarbonate (PC) thermoplastic resins made from bisphenol A (BPA), a chemical that has EA, are now often avoided in products used by babies. Other BPA-free thermoplastic resins, some hypothesized or advertised to be EA-free, are replacing PC resins used to make reusable hard and clear thermoplastic products such as baby bottles. Methods: We used two very sensitive and accurate in vitro assays (MCF-7 and BG1Luc human cell lines) to quantify the EA of chemicals leached into ethanol or water/saline extracts of fourteen unstressed or stressed (autoclaving, microwaving, UV radiation) thermoplastic resins. Estrogen receptor (ER)-dependent agonist responses were confirmed by their inhibition with the ER antagonist ICI 182,780. Results: Our data showed that some (4/14) unstressed and stressed BPA-free thermoplastic resins leached chemicals having significant levels of EA, including one polystyrene (PS), and three Tritan™ resins, the latter reportedly EA-free. Exposure to UV radiation in natural sunlight resulted in an increased release of EA from Tritan™ resins. Triphenyl-phosphate (TPP), an additive used to manufacture some thermoplastic resins such as Tritan™, exhibited EA in both MCF-7 and BG1Luc assays. Ten unstressed or stressed glycol-modified polyethylene terephthalate (PETG), cyclic olefin polymer (COP) or copolymer (COC) thermoplastic resins did not release chemicals with detectable EA under any test condition. Conclusions: This hazard survey study assessed the release of chemicals exhibiting EA as detected by two sensitive, widely used and accepted, human cell line in vitro assays. Four PC replacement resins (Tritan™ and PS) released chemicals having EA. However, ten other PC-replacement resins did not leach chemicals having EA (EA-free-resins). These results indicate that PC-replacement plastic products could be made from EA-free resins (if appropriate EA-free additives are chosen) that maintain advantages of re-usable plastic items (price, weight, shatter resistance) without releasing chemicals having EA that potentially produce adverse health effects on current or future generations.This work was supported by the following NIH/NIEHS grants: R44 ES011469, 01–03 (CZY); 1R43/44 ES014806, 01–03 (CZY); subcontract (CZY, PI) on an NIH Grant 01–03 43/44ES018083-01. This work was also supported by NIH grants to MSD (P42 ES004699), and DJK and SIY (1R43ES018083-01-03, NIEHS 1R44ES019442-01-03 and NIEHS 2R44ES016964-01-03).Neuroscienc

Synthetic, Spectroscopic and DFT Studies of Iron Complexes with Iminobenzo(semi)quinone Ligands: Implications for o-Aminophenol Dioxygenases

The oxidative CC bond cleavage of o-aminophenols by nonheme Fe dioxygenases is a critical step in both human metabolism (the kynurenine pathway) and the microbial degradation of nitroaromatic pollutants. The catalytic cycle of o-aminophenol dioxygenases (APDOs) has been proposed to involve formation of an FeII/O2/iminobenzosemiquinone complex, although the presence of a substrate radical has been called into question by studies of related ring-cleaving dioxygenases. Recently, we reported the first synthesis of an iron(II) complex coordinated to an iminobenzosemiquinone (ISQ) ligand, namely, [Fe(Tp)(tBuISQ)] (2 a; where Tp=hydrotris(3,5-diphenylpyrazol-1-yl)borate and tBuISQ is the radical anion derived from 2-amino-4,6-di-tert-butylphenol). In the current manuscript, density functional theory (DFT) calculations and a wide variety of spectroscopic methods (electronic absorption, Mössbauer, magnetic circular dichroism, and resonance Raman) were employed to obtain detailed electronic-structure descriptions of 2 a and its one-electron oxidized derivative [3 a]+. In addition, we describe the synthesis and characterization of a parallel series of complexes featuring the neutral supporting ligand tris(4,5-diphenyl-1-methylimidazol-2-yl)phosphine (TIP). The isomer shifts of about 0.97 mm s−1 obtained through Mössbauer experiments confirm that 2 a (and its TIP-based analogue [2 b]+) contain FeII centers, and the presence of an ISQ radical was verified by analysis of the absorption spectra in light of time-dependent DFT calculations. The collective spectroscopic data indicate that one-electron oxidation of the FeII–ISQ complexes yields complexes ([3 a]+ and [3 b]2+) with electronic configurations between the FeIII–ISQ and FeII–IBQ limits (IBQ=iminobenzoquinone), highlighting the ability of o-amidophenolates to access multiple oxidation states. The implications of these results for the mechanism of APDOs and other ring-cleaving dioxygenases are discussed

Observing decoupling processes of NO2 pollution and GDP growth based on satellite observations for Los Angeles and Tokyo

Nitrogen dioxide (NO2) pollution is mainly caused by anthropogenic processes such as burning of fossil fuels. Due to its severe impact on health as well as the environment in general, it is important to monitor the amount of NO2 pollution especially in areas with a high population density. Therefore, the aim of this study is to investigate to what extent spatiotemporal fluctuations in the tropospheric NO2 column density can map variations in economic output. To do so, we analyzed satellite based tropospheric NO2 column observations obtained from the ERS-2, ENVISAT, MetOp-A and MetOp-B satellite missions covering the period from 1996 to 2017 for Tokyo, Japan and Los Angeles, United States. Within our studies, a harmonic analysis was carried out in order to exclude meteorological influences. Afterwards, the NO2 time series were further investigated through a wavelet analysis method to characterize the fluctuations, that is the temporal variability of the NO2. These fluctuations have been shown to be a particularly sensitive measure of the change in NO2 pollution. We further use the gross domestic product (GDP) for the metropolitan areas as an indicator for economic performance. The results for the study area of Los Angeles shows a substantial reduction in NO2 variability starting in 2007. The NO2 variability for the period during the global financial crisis (December 2007–April 2012), dropped by around 77% in comparison to the previous period (January 1997–November 2007). However, a second period from May 2012 to December 2016 presents a further reduction of the NO2 variability of around 82% in contrast to the period from 2007 to 2012. Contrary to this, continuous economic growth can be observed during the second period. A similar picture emerges for the metropolitan region of Tokyo. A significant decline in NO2 variability of around 73% can be detected from October 2003 to January 2012. Additionally, a second period with a strong decline in NO2 variability of around 80% can be identified from February 2012 to December 2016. A plunge in GDP during 2008 reflects that year's global financial crisis, but cannot independently explain the following sharp decline in NO2 variability. Those results suggest that Tokyo as well as Los Angeles managed to substantially decouple its NO2 pollution from the economic growth due to strict air quality policies