nils-herrmann/clean_scirepeval huggingface dataset:
Influence of organic matter content and human activities on the occurrence of organic pollutants in antarctic soils, lichens, grass, and mosses.

Banned pesticides such as HCB and p,p'-DDE, and other legacy and ongoing pollutants such as PCBs and PAHs, were measured in different vegetation types and soil samples collected at selected areas from Antarctic Peninsula (Deception and Livingstone Islands, Southern Shetlands). Two Antarctic expeditions (in 2005 and 2009) were carried out to assess POPs levels at remote areas, and close to current and abandoned Antarctic research settlements, to assess potential sources of pollutants. Overall, the patterns in lichens, mosses, and grass were dominated by low molecular PCB congeners and PAHs and the presence of HCB and p,p'-DDE rather than heavier compounds, suggesting the importance of long-range atmospheric transport of POPs as the main vector for the introduction of these chemicals to Antarctica. Statistically significant correlations (p-level < 0.05) between concentrations in vegetation of PCBs, p,p'-DDE, and the more volatile PAHs with lipid content were found with r(2) of 0.22-0.52 for PCBs, 0.42 for p,p'-DDE, and 0.44-0.72 for the more volatile PAHs. Thus, lipid content is an important factor controlling POPs in Antarctic lichens, mosses, and grass. A strong significant dependence of HCB (r(2) = 0.83), p,p'-DDE (r(2) = 0.60), and PCBs (r(2) = 0.36-0.47) concentrations in soil on its organic carbon content was also observed, indicating the important role of soil organic matter (SOM) in the retention of PCBs and OCPs in Polar Regions, where SOM content is low. Penguin colonies enhance the SOM content in some areas which is reflected in higher concentrations of all POPs, especially of persistent compounds such as p,p'-DDE. Higher concentrations of PCBs and PAHs found at the currently active Byers Camp (in an Antarctic Specially Protected Area) were explained by higher SOM content, thus indicating that Antarctic regulations are being successfully fulfilled in this small research area. On the other hand, PAHs in soils proximate to current Juan Carlos I research station show that even small human settlements are an important source of PAHs to the local environment. Therefore, even though the concentrations in Antarctica are low, there is evidence of local hotspots of contamination.

Field of study: Environmental science
Up-regulation of a hydrogen peroxide-responsive pre-mRNA binding protein in atherosclerosis and intimal hyperplasia.

Multiple lines of investigation have implicated hydrogen peroxide (H(2)O(2)) as an important endogenous mediator of cell proliferation in the vessel wall. Heterogeneous nuclear ribonucleoprotein C (hnRNP-C), a nuclear pre-mRNA binding protein that plays roles in vertebrate cell proliferation and differentiation, has been identified as a component of a vascular cell signaling pathway activated by low physiologic levels of H(2)O(2). The expression of hnRNP-C in human arteries has not previously been assessed.



Segments of human proximal internal carotid arteries were evaluated for the expression of hnRNP-C by immunohistochemistry.



In normal proximal internal carotid arteries, hnRNP-C is expressed predominantly by the endothelium, with significantly lower expression by medial smooth muscle. In preatherosclerotic intimal hyperplasia, hnRNP-C is up-regulated in the artery wall, due to the robust expression by the intimal smooth muscle cells, without up-regulation in the medial smooth muscle cells. In arteries with atherosclerotic lesions, there is strong expression of hnRNP-C not only by intimal cells but also by medial smooth muscle cells.



The H(2)O(2) responsive pre-mRNA binding protein hnRNP-C is up-regulated in atherosclerosis and in preatherosclerotic intimal hyperplasia in humans, supporting the hypothesis that H(2)O(2) is a regulator of vascular cell proliferation in these conditions. These data also suggest that hnRNP-C may be useful as a marker of vascular cell activation.

Field of study: Biology, Medicine
THE TEMPERATURE DISTRIBUTION IN A CASE BONDED CYLINDRICAL ROCKET ASSEMBLY

Equations are presented for the temperature distribution in a case bonded propellant grain when the environmental temperature is suddenly changed. It is found that whenever the Biot modulus is relatively small, the temperature distribution is essentially independent of the radial coordinate but varies with the time coordinate only, at a rate which is dependent upon the geometry and the physical properties of the propellant grain as well as the heat transfer coefficients.

Field of study: Physics
How Nature builds the pigments of life

Vitamin B12 (1) is the anti-pernicious anaemia vitamin and the coenzyme form is used by several different enzymes to bring about remarkable rearrangements in living systems. The lecture will focus on the question "How is vitamin B12 biosynthesised". A very brief historical survey of what had been achieved earlier will be followed by a full account of the latest exciting advances. One take-home message is that any chemist aiming to solve the biosynthesis of a complex natural product must embrace genetics, molecular biology and enzymology whilst the biologists need the complementary strengths of the most advanced chemistry. A second theme will be to demonstrate the power of experiments, based on multiple labelling of biosynthetically generated intermediates, for studying natural pathways. The lecture will describe research involving molecular biology, enzymology, synthesis, isotopic labelling and the full panoply of modern NMR techniques. A family of coloured molecules including haem, chlorophyll, the cytochromes and vitamin B 12 are of such vital importance for living systems that they have become known as the Pigments of Life. The present lecture will focus on just one member, the anti-pernicious anaemia agent, vitamin B12 (1). It has a structure of considerable complexity and is often referred to as the Everest of biosynthetic problems. The question of how this structure is built in Nature has excited my group since we started on this problem in 1968 and happily much has been discovered about the biosynthetic pathway. I shall first outline very briefly what knowledge was available about those parts of the pathway which had been elucidated before 1990. Time does not allow this to be complete nor to include much detail; just the essential minimum information will be given to allow the reader to understand and enjoy the latest exciting developments. Full information and literature references are given in various reviews.

Field of study: Chemistry
Ordered-Defect Sulfides as Thermoelectric Materials

The thermoelectric behavior of the transition-metal disulfides n-type NiCr2S4 and p-type CuCrS2 has been investigated. Materials prepared by high-temperature reaction were consolidated using cold-pressing and sintering, hot-pressing in graphite dies or spark-plasma sintering in tungsten carbide dies. The consolidation conditions have a marked influence on the electrical transport properties. In addition to the effect on sample density, altering the consolidation conditions results in changes to the sample composition, including the formation of impurity phases. Maximum room-temperature power factors were 0.18 mW m−1 K−2 and 0.09 mW m−1 K−2 for NiCr2S4 and CuCrS2, respectively. Thermal conductivities of ca.

Field of study: Materials science
Comparative Analysis of the English Language Usage of Pupils in Public and Private Primary Schools in Ikere Local Government Area of Ekiti State, Nigeria

This study examined the English language usage of pupils in public and private primary schools. The sample used for the study consisted of fifty (50) teachers from public primary schools and fifty (50) from private primary schools. A simple self developed questionnaire was used to get information from the respondents regarding the extent to which pupils in primary school use English. Three research hypotheses were tested at 0.05 level of significance during the study. The findings indicated that there was significant difference between the level of exposure of pupils in public and private schools to English at home; the usage of English     language in teaching and learning in private and public schools; and the level of exposure to English language of pupils at school in public and private schools. The study, therefore recommended that government should make necessary review of language policy in order to make it workable in our primary schools. It should be noted that too much emphasis should not be placed on mother tongue education to the detriment of English and vice versa.

Field of study: Education
AN EFFICIENT SYNTHESIS OF 1,3,7-TRIAZASPIRO[4.4]NONANE-2,4-DIONE DERIVATIVES AND ANTIMICROBIAL ACTIVITY THEREOF

Разработаны эффективные методики синтеза производных 1,3,7-триазаспиро[4.4]нонан-2,4-диона с незамещенным пиррoлидиновым циклом, позволяющие получать не требующие дополнительной очистки полупродукты и целевые соединения с высокими выходами. Исследована противомикробная активность синтезированных соединений. Как ссылаться Krolenko, K. Yu.; Silin, O. V.; Vlasov, S. V.; Zhuravel, I. O.; Kovalenko, S. M. Chem. Heterocycl. Compd. 2015 , 51 , 472.

Field of study: Chemistry
Generation and characterization of murine monoclonal antibodies to recombinant 26-kDa periplasmic protein of Brucella abortus.

In the present study, hybridomas were developed for the production of monoclonal antibodies (MAb) against recombinant 26-kDa periplasmic protein (rBP26) of Brucella abortus. A set of six stabilized hybridoma cell lines were generated. Monoclonal antibodies secreted by all of these clones exhibited reaction for rBP26, as well as with the protein of 26-kDa, derived from whole cell lysate of B. abortus 544. Three out of six MAbs were IgG1, two were IgM, and one was IgG2b in nature. These MAbs did not show any cross-reaction with whole cell lysate of Yersinia enterocolitica O: 9, Vibrio cholerae, Salmonella typhimurium, and Escherichia coli O157 in Western blot analysis. Reactivity of these MAbs was further assessed with other organisms of Brucella species, namely, B. abortus 544, B. canis, B. melitensis 16M, and B. suis. Collectively, these data suggest that these MAbs may have the potential for their use in the detection of Brucella species with high specificity.

Field of study: Biology
Digital Africa (review)

Artists from varied African backgrounds have always looked to new forms of visual expression to represent and convey ideas. We have seen this in recent multimedia presentations of the arts and visual cultures of Africa such as Black President: The Art and tegacy of Tela Anikulapo-Kuti, in which several artists innovatively merged sight and sound. Those artists participating in the provocative exhibition, Digital Africa (presented at Electronic Arts Intermix) continue to push the envelope, exploring new technologies—from conceptual performance to interactive Web art—as a means of engaging and contesting a range of issues that comprise today's global media reality.

Field of study: Art
During HIV‐1 infection most blood dendritic cells are not productively infected and can induce allogeneic CD4+ T cells clonal expansion

We have considered the possibility that antigen‐presenting cells of the dendritic cell lineage may be infected in vivo and spread HIV‐1 at the time dendritic cells initiate the clonal expansion of antigen‐specific T cells. Dendritic cells were isolated from 25 HIV‐1–infected subjects (CDC stages II‐ IV). Fewer dendritic cells were recovered from most infected subjects. Reduced numbers of total non‐T cells were also found in these patients, so that preferential loss of dendritic cells did not occur. Dendritic cell function was assessed by stimulatory capacity for allogeneic CD4+ T cells in the mixed leucocyte reaction (MLR). Potent M LR stimulator activity was retained in the dendritic cell‐enriched populations from HIV‐infected patients. Seven out of nine patients without AIDS (asymptomatic, lymphadenopathy or ARC) and three out of six patients with AIDS had proliferative responses equivalent to those induced by dendritic cells from controls. Dendritic cells from HIV+ subjects were able to initiate the expansion of allogeneic CD4+ T cell clones with cloning efficiency not different from controls and without evidence of cytopathic effect in the expanding CD4+ clones. In situ hybridization of the different mononuclear cell populations with a gag‐specific riboprobe demonstrated positive cells in the T cell fractions of 12 of the 15 patients tested. None of the asymptomatic or ARC patients had riboprobe‐positive cells in the dendritic cell‐enriched populations. Four out of nine patients with AIDS had cells positive for HIV‐1 expression in the dendritic cell‐enriched fraction. However, the positive cells had the nuclear profile of lymphocytes, and by cytofluorography some residual low‐density T cells were present. By limiting dilution and polymerase chain reaction (PCR), CD4+ lymphocytes carried HIV provirus in inocula of 500–5000 cells, while provirus could only be detected in 50000 cells from the dendritic cell‐enriched fraction. The latter signal may be due to the demonstrated levels of T cell contamination. Our data indicate that productive or latent HIV‐1 infection of blood dendritic cells in vivo is rare, certainly no greater than in T lymphocytes, and that in vitro dendritic cell preparations from patients can expand CD4’ T cells efficiently and therefore may be able to expand T cells with immunotherapeutic activity.

Field of study: Biology, Medicine
Coxeter group actions on the complement of hyperplanes and special involutions

We consider both standard and twisted action of a (real) Coxeter group $G$ on the complement $\mathcal M_G$ to the complexified reflection hyperplanes by combining the reflections with complex conjugation. We introduce a natural geometric class of special involutions in $G$ and give explicit formulae which describe both actions on the total cohomology $H^*(\mathcal M_G, {\mathbb C})$ in terms of these involutions. As a corollary we prove that the corresponding twisted representation is regular only for the symmetric group $S_n$, the Weyl groups of type $D_{2m+1}$, $E_6$ and dihedral groups $I_2 (2k+1).$ We discuss also the relations with the cohomology of Brieskorn's braid groups.

Field of study: Mathematics
The Driving Force of Superconducting Transition in High Temperature Superconductors

We show that both the kinetic energy and the exchange energy of the t-J model can be read off from the optical data. We show that the optical data indicates that the superconducting transition in high temperature superconductors is kinetic energy driven and the exchange energy resist the transition. We also show that kinetic energy may also be the driving force of the pseudogap phenomenon.

Field of study: Physics
Observations on the effects of frost on beach sediments at Rimouski, lower St. Lawrence Estuary, Québec

Freezing of beach sediment during exposure to cold air and subsequent thawing upon immersion have been analyzed in a strong tidal environment, near Rimouski in the St. Lawrence Estuary (Quebec). Temperature data, recorded at different depths in the sediment over a 25-h period above the high water mark and following a sudden drop of air temperature to −6 °C, indicate that temperatures in the top 15 cm of the beach dropped below the freezing point of seawater (<−1.36 °C). At the mid-tide level station, which was alternately exposed to air and immersed, freezing temperatures were observed to a depth of approximately 5 cm. Observations show that the surface sediment became ice-cemented to a corresponding depth. Temperature changes on exposure to air and immersion were rapid in the surface sandy layer (about 5 cm) and slower in the underlying coarser sediment. Temperature changes were barely perceptible at low tide level and no ice-cemented sediment was observed. Observations on the frozen beach showed that wa...

Field of study: Environmental science
Heat pumps in the FRG

This report gives a brief survey of the development of heat pumps in the FRG. The description focusses on the market development during the last five years. The report is deliberately concise with respect to the engineering side. In this regard, as well as presenting comparisons with other heating systems, this Paper refers to the report of the ‘WEC ad hoc committee on combined heat and power and heat pumps’ presented in 1981. Although future trends have been outlined, these are not sufficiently reliable as to take this outlook to be a forecast.

Field of study: Engineering
A protein kinase C-activating phorbol ester enhances transcription of the human DBH gene through a cyclic AMP response element in SK-N-BE(2)C cells.

Protein kinase C (PKC) activation after treatment of human neuroblastoma SK-N-BE(2)C cells with phorbol 12-myristate 13-acetate (PMA) was found to enhance transcription of the human dopamine beta-hydroxylase (DBH) in those cells. To identify which cis-acting element is responsive to the PMA treatment during DBH gene expression, we employed transient transfection assays with serially deleted constructs of the human DBH gene's 5' upstream region fused to the chloramphenicol acetyltransferase (CAT) gene. Treatment of transfected cells with PMA resulted in an approximate threefold increase in CAT expression for all deletion constructs ranging from -978 bp to -262 bp, while the enhancement did not occur with a construct shortened to -114 bp. The region between -262 and -114 bp from the initiation site of transcription contains several cis-regulatory elements including a cyclic AMP response element (CRE) and putative AP1 and YY1 sequences. Site-directed mutagenesis of those cis-acting elements were performed to identify which of the elements mediated the PMA-induced transcriptional enhancement. Substitution of bases in the putative AP1 site containing in part a putative YY1 sequence did not effect the PMA inducibility. However, specific mutations in the CRE sequence abolished the PMA-inducible effect. Changing the CRE sequence into an authentic AP1 sequence (TGACGTCC --> TGACTCA) did not affect the PMA inducibility, suggesting that AP1 factors might interact with the new AP1 site upon PKC activation. A specific PKC inhibitor, GF109203X, completely inhibited the stimulatory effect of PMA on the expression of the human DBH gene. PMA induced an increase in the DBH mRNA level as detected by Northern blot analysis. Gel retardation showed that the binding of nuclear factors to CRE, putative YY1, and AP1 was sequence specific. Our data suggest that the enhancement of the human DBH gene expression by PMA treatment is mediated by the CRE motif in the 5' upstream region of the gene, and occurs via a PKC-dependent pathway.

Field of study: Biology
Dynamics of the Magnetization Vector during the 180° Pulsed Magnetization Reversal of Ferrite–Garnet Films with Complex Anisotropy

The regime of 180° pulsed magnetization reversal of ferrite-garnet films with planar anisotropy in the region of external fields, in which the mechanism of uniform rotation of the magnetization operates, is investigated for the first time. An analysis of numerical solutions of the Landau–Lifshitz equation and our experimental studies show that, as in the case of the 90° pulsed magnetization, the presence of biaxial anisotropy in real ferrite–garnet films also leads to the so-called “effect of delayed acceleration of the transient process.” In addition, it is found that under certain conditions it is possible to achieve two stable final positions of the magnetization vector that correspond to 180° and 90°.

Field of study: Physics
RTS noise due to lateral isolation related defects in submicron nMOSFETs

The results of a systematic study of the random telegraph signal (RTS) fluctuations in submicron W-array n metal-oxide semiconductor field-effect transistors (nMOSFETs) are presented and analysed. These results include the dependency of the RTS amplitude and of the capture and emission time constants, measured both in the standard transistor and in the diode configuration, on the gate, drain and substrate voltage. For the latter configuration, the drain-substrate (or source-substrate) diode of the transistor is forward biased. Application of this technique for measuring RTS noise allows us to distinguish the drain (source) traps from the well-known channel traps. It is found that besides the classical channel-related RTSs, another type occurs which is associated with lateral isolation related (or edge-related) oxide defects, located near the drain or the source contact. As will be shown, the coulomb blockade significantly affects the capture and emission kinetics of these defects. The specific properties of such RTSs are studied in detail, as they may reveal useful information on their identification.

Field of study: Engineering
Histoplasmosis prevalence among medical students of the faculty of Medicine Islamic University of North Sumatera and the association between pet animal and histoplasmin test.

A cross sectional study was conducted at the Faculty of Medicine, Islamic University of North Sumatera (FK MU) Medan with the population of 169 medical students. It was found that the prevalence of histoplasmosis was 13.61% and there was no correlation between the gender with the histoplasmin test reactivity. The most precipitating factor of the prevalence for the positive histoplasmin test was pet animal. The other precipitating factors were found such as in bat, cave adventure and contact with wood environment. There was significant association between pet animal and the reactivity of histoplasmin test. In conclusion, the prevalence of histoplasmosis with moderate category is found in the young adult population group. The pet animal has significant possibility as the precipitating factors and its role is needed for further attention.  histoplasmosis - histoplasmin test - prevalence - young adult - pet animal.

Field of study: Medicine
Modifications of glial metabolism of glutamate after serotonergic neuron degeneration in the hippocampus of the rat.

We have investigated the role of serotonergic neurons on the astrocytes catabolism of glutamate by analyzing glutamine synthetase (GS) and glutamate dehydrogenase (GDH) expression in the hippocampus after the degeneration of serotonergic neurons by a specific neurotoxin (5,7-DHT). 5,7-DHT caused reactive gliosis with hypertrophy (increase in glial fibrillary acidic protein (GFAP) expression) but not proliferation of astrocytes. Glutamate metabolism appeared preferentially regulated by a control of GDH expression rather than GS since the expression of GDH was specifically and significantly induced in the hippocampus whereas the level of GS remained unchanged. The inhibition of serotonin synthesis (by para-chlorophenylalanine (p-CPA) administration) produced no significant increase of GDH level. This suggests that serotonin is not the principal factor involved in this control of GDH expression.

Field of study: Biology
Rapid thermal low-pressure metalorganic chemical vapour deposition of local diffused W(Zn) contacts

Selective deposition of W(Zn) metallization, for formation of diffused ohmic contacts onto InP-based material, was realized by means of rapid thermal, low-pressure metalorganic chemical vapour deposition (RT-LPMOCVD). The W(Zn) layers were deposited using a reactive gas mixture that contained diethylzinc (DEZn), WF6, H2 and Ar, at temperatures of 450 to 550 degrees C and pressures in the of 2-3 Torr. Uniform and continuous layers of W(Zn), 30 to 120 nm thick, were obtained. These layers contained Zn at concentrations higher than 1*1018 cm-3, which was subsequently in-diffused into the underlying semiconductor layers to form highly doped semiconductor layers as thick as 0.2 mu m. As a result, the specific contact resistance of the W(Zn)/In0.53Ga0.47As contact was reduced to a minimum value of 5*10-6 Omega cm2. The W(Zn) films were found to be mechanically stable with a small compressive stress of 5*108 dyn cm-2, and were dry etched at rates of up to 90 nm min-1.

Field of study: Materials science