Mechanical and physical behavior of high-porosity chalks exposed to chemical perturbation

Extensive study on the effect of dissolution–precipitation on mechanical behavior of various high-porosity outcrop chalks (Liége, Aalborg, Kansas, Stevns Klint, and Mons) flooded with simplified aqueous chemistry at 130 °C under isotropic stress beyond the yield is performed. Chemical effects induced by injection of 0.219 M MgCl2 solutions into impure chalks (Liége, Aalborg, Kansas) lead to an immediate enhancement on the macroscopic creep with more than a factor of 2 larger than that of exposed to 0.657 M NaCl solutions. In pure chalks (Stevns Klint and Mons) however, the creep response is characterized by a time lag, where creep initially diminishes before a tertiary-like creep develops. Systematic correlation between calcite dissolution and the resulting creep strain is consistently demonstrated by all the different chalk types. The chemical effects are described as precipitation of Mg-bearing minerals and dissolution processes, which involve both the carbonate and non-carbonate phases. SEM-EDS, XRD, and BET (N2) analyses indicate newly formed Mg-bearing minerals primarily present as Magnesite, which precipitated in the pore space. Enhanced dissolution is shown by continuous production of Ca2+ measured in the core effluent. The time for the dissolution to overcome intergranular friction accounts for the delay in the creep acceleration in pure chalks (Stevns Klint and Mons). For impure chalks (Liége, Aalborg, Kansas) chemical alterations on the non-carbonate phases outweigh the intergranular friction. This additional effect accounts for the immediate impact in the creep deformation. The chemical effects are also demonstrated by marked reduction in the permeability. The porosity–permeability relationship measured at the end of creep test is shifted down from the initial correlation, indicating a dramatic increase in the chalk specific surface area.acceptedVersio

Cleavage of DNA by the Insulin-Mimetic Compound, NH4[VO(O2)2(phen)]

The kinetics and mechanism of cleavage of DNA by the insulin-mimetic peroxo-vanadate NH4[VO(O2)2(phen)], pV, are described. In the presence of low energy UV radiation or biologically common reducing agents, pV decomposes into the monomer, dimer, and tetramer of vanadate and an uncharacterized compound of V4+ as shown by 51V NMR, ESR, and absorption spectra. The rate of photodecomposition of pV is reduced in the presence of calf thymus DNA, indicating that a decomposition product of the peroxo-vanadate, that is important in the destruction pathway of the complex, is interacting with DNA. This species, probably a short-lived complex of V4+, may also be responsible for the observed catalytic decomposition of pV in the absence of DNA by ascorbate. If closed circular pBR322 DNA is present when the peroxo-vanadate is destroyed by either UV radiation or reducing agents, the polymer may have its sugar-phosphate backbone broken. Closed circular DNA (form I) is converted into nicked circular DNA (form II) and linear DNA (form III). The amounts of the various forms produced as a function of irradiation time and peroxo-vanadate concentration were fit to a kinetic model to derive rate constants for the conversions. The kinetic analysis shows that pV is a single-strand nicking agent which exhibits some base and/or sequence preference. Furthermore, the pH dependences of the rates for conversion of form I to form II and for conversion of form II to form III are different, indicating that the nature of the chemistry at the site of cleavage on DNA influences further cutting by activated pV. Reduced amounts of DNA breakage in the presence of various salts and metal binding ligands indicate that a short-lived reactive complex of V4+, not the V4+ species detected by ESR at long irradiation times, is important in the cleavage process. The susceptibility of pV to decomposition by biologically common reducing agents suggests that metabolites of the agent, and not the compound itself, are responsible for its insulin-mimetic effects

The spectrum of phenotypes associated with mutations in steroidogenic factor 1 (SF-1, NR5A1, Ad4BP) includes severe penoscrotal hypospadias in 46,XY males without adrenal insufficiency

OBJECTIVE. Hypospadias is a frequent congenital anomaly but in most cases an underlying cause is not found. Steroidogenic factor 1 (SF-1, NR5A1, Ad4BP) is a key regulator of human sex development and an increasing number of SF-1 (NR5A1) mutations are reported in 46,XY disorders of sex development (DSD). We hypothesized that NR5A1 mutations could be identified in boys with hypospadias. DESIGN AND METHODS. Mutational analysis of NR5A1 in 60 individuals with varying degrees of hypospadias from the German DSD network. RESULTS. Heterozygous NR5A1 mutations were found in three out of 60 cases. These three individuals represented the most severe end of the spectrum studied as they presented with penoscrotal hypospadias, variable androgenization of the phallus and undescended testes (three out of 20 cases (15%) with this phenotype). Testosterone was low in all three patients and inhibin B/anti-Müllerian hormone (AMH) were low in two patients. Two patients had a clear male gender assignment. Gender re-assignment to male occurred in the third case. Two patients harbored heterozygous nonsense mutations (p.Q107X/WT, p.E11X/WT). One patient had a heterozygous splice site mutation in intron 2 (c.103-3A/WT) predicted to disrupt the main DNA-binding motif. Functional studies of the nonsense mutants showed impaired transcriptional activation of an SF-1-responsive promoter (Cyp11a). To date, adrenal insufficiency has not occurred in any of the patients. CONCLUSIONS. SF-1 (NR5A1) mutations should be considered in 46,XY individuals with severe (penoscrotal) hypospadias, especially if undescended testes, low testosterone, or low inhibin B/AMH levels are present. SF-1 mutations in milder forms of idiopathic hypospadias are unlikely to be common

Homozygous disruption of P450 side-chain cleavage (CYP11A1) is associated with prematurity, complete 46,XY sex reversal, and severe adrenal failure

Disruption of the P450 side-chain cleavage cytochrome (P450scc) enzyme due to deleterious mutations of the CYP11A1 gene is thought to be incompatible with fetal survival because of impaired progesterone production by the fetoplacental unit. We present a 46, XY patient with a homozygous disruption of CYP11A1.The child was born prematurely with complete sex reversal and severe adrenal insufficiency. Laboratory data showed diminished or absent steroidogenesis in all pathways. Molecular genetic analysis of the CYP11A1 gene revealed a homozygous single nucleotide deletion leading to a premature termination at codon position 288. This mutation will delete highly conserved regions of the P450scc enzyme and thus is predicted to lead to a nonfunctional protein. Both healthy parents were heterozygous for this mutation.Our report demonstrates that severe disruption of P450scc can be compatible with survival in rare instances. Furthermore, defects in this enzyme are inherited in an autosomal-recessive fashion, and heterozygote carriers can be healthy and fertile. The possibility of P450scc-independent pathways of steroid synthesis in addition to the current concept of luteoplacental shift of progesterone synthesis in humans has to be questioned

Causes of Emotive Response to Artefacts

Emotions are one important aspect of how we experience artefacts. The question is what influences these emotions? As the first of a series of studies addressing this issue, a Focus Group session has been conducted. The participants were all adult consumers, men and women, in different ages. The topics investigated in the interviews concerned what emotions are associated with artefacts, and what product characteristics may have evoked these emotions, as well as more open-ended questions about other influencers of emotions. The results were descriptions of situations in which the participants had experienced emotions related to artefacts and the design of artefacts, as well as a list of factors expected to influence the emotive response to products. The results have been analysed in order to describe the source(s) of the emotion related to artefacts, i.e. whether the emotions may be attributed to the artefact or other factors. The participants’ comments tell us that the artefact in itself cannot always explain their experiences with products. The activity in which the products are used and contextual factors play an important role, as do the individual characteristics of the user

Negotiating identities : South German Catholics and the formation of national identity, 1871-1914

Includes bibliographical references (pages [427]-444).The following study investigates how Catholics in the southwestern German state of Baden reacted to German unification in 1871. Although Baden had a Catholic majority, during the Second Empire the state was governed by Protestant liberals, who often discriminated against the state’s Catholics. To understand how Badenese Catholics participated in the nation-building project from 1871 to 1914, this work analyzes Catholic reactions to the commemorative discourse that surrounded unification. This discourse was often tinged with anti-Catholic sentiments that alleged that Catholics had been opposed to the unification and that they harbored stronger loyalties to the Pope in Rome than they did to the German Emperor in Berlin. Despite being politically and economically disadvantaged, Badenese Catholics successfully contested this ideological message and instead created an alternative discourse that better represented their own version of Germanness. My analysis illustrates that these Catholics subscribed to a multifaceted version of German identity. Instead of being subsumed into a Protestantdominated national identity, they were able to maintain certain pre-1871 elements of their identity, which included loyalties to the Pope, Baden, their fellow Germans in Catholic A ustria, as w ell as E m peror W ilhelm I. This study also displays how central confessional elements were to the construction of German national identity during the Second Empire. Religious affiliation to a large extent determined how Germans lived their lives, and confessional loyalties became one of the key components in the new German national identity. Moreover, this work also demonstrates that Catholic and Protestant integration into the new German nation-state should be viewed as an ongoing debate about what constituted German. Although during the last two decades before the First World War, Catholics and Protestants did not clash as frequently over the definition of Germanness as they had during the first two decades of the Kaiserreich, they never completely agreed on the exact nature of their national identity. Thus, despite facing numerous political, economic, and social obstacles, Badenese Catholics were able to manifest successfully their own version of German identity throughout the Second German Empire.Ph.D. (Doctor of Philosophy

Disorders Of Sex Development And Hypogonadism: Genetics, Mechanism, And Therapies.

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