nils-herrmann/clean_scirepeval huggingface dataset:
Massive sulfide deposits of the Noranda area, Quebec. II. The Aldermac mine

The original Aldermac mine near Noranda contained several Cu–Zn massive sulfide lenses hosted by felsic to mafic volcanic rocks of the late Archean Blake River Group. The original Nos. 3–6 orebodies, which consisted of massive pyrite, with lesser magnetite, pyrrhotite, chalcopyrite, and sphalerite, contained 1.87 Mt of Cu–Zn ore that averaged 1.47% Cu (Zn was not recovered). The orebodies occurred within felsic breccias and tuffs up to 100 m thick that are stratigraphically overlain by an extensive dome of mainly massive rhyolite and rhyodacite (up to 250 m thick and at least 550 m across). Most of the volcanic rocks that laterally flank and overlie the felsic dome are dacitic to andesitic flows, breccia, and tuff, with minor rhyolites, and associated subvolcanic sills of quartz-feldspar porphyry and gabbro.The new massive sulfide deposit, discovered in 1988, lies 150–200 m east of the mined-out orebodies, at a similar stratigraphic level within altered felsic breccia and tuff. The sulfides are mainly in ...

Field of study: Environmental science
A new analytical model for the IEEE 802.15.4 CSMA-CA protocol

We give new analytical results for the performance of a wireless sensor network using the energy-conserving CSMA-CA MAC protocol of IEEE 802.15.4. We derive the throughput both under saturation and under a nonsaturation scenario in a star network involving periodic traffic, and validate the accuracy of our results using simulation for both acknowledgement and non-acknowledgement modes. Our analysis relies on the solution of a fixed point equation, and we prove the existence and uniqueness of the fixed point for the saturated case. The initial backoff window that maximizes saturation throughput is derived, and shown to be an approximately linear function of the number of active nodes. We also study the saturation model when the number of nodes tends to infinity, and obtain a simple expression for the asymptotic throughput.

Field of study: Computer science
Purification, crystallization and preliminary X-ray analysis of catabolic ornithine carbamoyltransferase from Pseudomonas aeruginosa.

The catabolic ornithine carbamoyltransferase (OTCase) from Pseudomonas aeruginosa exhibits allosteric behaviour, with two conformational states of the molecule: an active R form and an inactive T form. The enzyme is a dodecamer with a molecular mass of 455700 Da. Three crystal forms have been obtained. Crystals of allosteric state T are rhombohedral, belonging to the R3 space group, with hexagonal unit-cell parameters a = b = 180.6, c = 122.0 A. They diffract to a resolution of 4.5 A. Two crystal forms for allosteric state R have been obtained, with hexagonal and cubic symmetries. Hexagonal crystals, which diffract to a resolution of 3. 4 A, belong to the space group P6(3) with unit-cell parameters a = b = 140.8, c = 145.6 A. The cubic crystals belong to space group I23, with unit-cell parameter a = 134.32 A and diffract to a resolution better than 2.5 A. In all crystal forms, the dodecamer exhibits a 23 point-group symmetry.

Field of study: Chemistry
Synchrotron radiation sources - present capabilities and future directions.

Many of the more than 40 operational light sources around the world have achieved performance levels that exceed initial design goals. These accomplishments are reviewed, along with concepts and proposals for sources with performance levels exceeding those of present sources. These include storage rings with lower electron-beam emittance than present third-generation rings and free-electron lasers (FELs). It now appears that the highest performance sources will be based on linacs rather than storage rings. This is because emittance originates differently and scales differently with electron energy for rings and linacs, so that the lowest electron-beam emittance can be achieved in high-energy linacs equipped with high-brightness electron sources. Such electron beams can be used to provide X-ray beams with very high brightness and coherence in sub-picosecond pulses in a single pass through a small-gap short-period undulator by spontaneous emission, and with even higher beam brightness and coherence by stimulated coherent emission in an FEL. Designs for such FEL sources, and associated research and development, are underway at several laboratories.Work supported by the US Department of Energy, Office of Basic Energy Sciences, contract DE-AC03-76SF00515.

Field of study: Physics
MEASUREMENT OF CURRENT DENSITY DISTRIBUTION IN PROTON EXCHANGE MEMBRANE FUEL CELL WITH STRAIGHT CHANNELS FLOW FIELD

A modified subcell approach was used to measure the current density distribution of proton exchange membrane fuel cell (PEMFC) with straight channels flow field. For PEMFC with parallel channels flow field,subcells in inlet channels presented higher performance than those in middle channels,but showed lower performance than those in outlet channels. The experimental results with parallel channels flow field demonstrated that the current density distribution over the whole electrode was heterogeneous and was consistent with the velocity distribution from the mathematic model. Gas flow rate was one of prime factors to influence the current distribution of PEMFC cathode. With the decrease of reactant flow rate,the flooding process began at the flow field outlet region of a cell,and then propagated to the inlet area.

Field of study: Chemistry, Environmental science
A Fresh Look at the Tense-aspect System of Turkish

Turkish is one of the best described languages of the world. One should therefore expect a large consensus with regards to the way Turkish grammar is described. However, once we compare different grammatical descriptions of Turkish, we find an astonishing variation of analyses. One domain whose description is particularly unsatisfactory is the tense-aspect system. The paper will show that forms like okuyor, okur, okuyacak, and okumu? are participles marked for aspect, but not for tense. Failure to recognize the zero-exponence of present tense has lead to the erroneous analysis of aspectual morphemes as tense markers. Comparison with the tense marking on non-verbal predicates shows however that present tense is neither marked on the noun/adjective/adverbial/participle, nor part of the meaning of the subject cross-reference markers. It is marked by the absence of the other member of the tense paradigm, past tense. In addition to an inadequate semantic description of the progressive aspect suffix -iyor, many grammars present a diachronically motivated form -(I)yor, which requires elaborate morphophonological rules to produce the synchronically correct verb forms. This segmentation should be revised by acknowledging the morphological inclusion of the original linking vowel into the suffix, which allows for a much more elegant description. Finally, the paper will draw attention to the crosslinguistic confusion caused by the term ‘aorist’ and advocates the term ‘dispositive aspect’ instead. In the same vein, ‘prospective aspect’ is a more adequate term for participles in -ecek than ‘future tense’. An interesting consequence of the present analysis is that Turkish has a simple past marked by a cumulative morpheme -ti which fills both the aspectual and the temporal slot of the verb form, but no simple present, as all present tense forms require overt aspectual marking. Tense is thus an inflectional category of the predicate, be it verbal or non-verbal, while aspect is an inflectional category of verbs. The paper is relevant for linguists interested in Turkish in general as well as readers interested in tense and aspect, and may contribute to improvements in Turkish language education by providing a more consistent account of the morphological structure of temporal and aspectual forms and their use.

Field of study: Linguistics
Ricci Solitons in (ε,δ)-Trans-Sasakian Manifolds

We study Ricci solitons in (e,δ)-trans-Sasakian manifolds. It is shown that a symmetric parallel second order covariant tensor in a (e,δ)-trans-Sasakian manifold is a constant multiple of the metric tensor. Using this it is shown that if Vg + 2S is parallel where V is a given vector field, then (g,V) is Ricci soliton. Further, by virtue of this result, Ricci solitons for 3-dimensional (e,δ)-trans-Sasakian manifolds are obtained. Also an example of Ricci solitons in 3-dimensional (e,δ)-trans-Sasakian manifold is provided in the region where trans-Sasakian manifold is expanding (shrinking) the Lorentzian trans-Sasakian manifold is shrinking (expanding).

Field of study: Mathematics
Regional and developmental regulation of syntaphilin expression in the brain: a candidate molecular element of synaptic functional differentiation.

The conserved nature of the basic machinery underlying synaptic function makes it necessary to search for other factors--structural and molecular--that could account for the tremendous diversity found among synapses even within a single neuron. Syntaphilin is a presynaptic membrane protein previously described as a molecular clamp that controls free syntaxin-1A and dynamin-1 availability, and thereby regulates synaptic vesicle exocytosis and endocytosis at the nerve terminal. In this study, we report our finding that syntaphilin expression is developmentally regulated, and show that syntaphilin is expressed most prominently in the mature rat brain, in areas that have been previously characterized to undergo synaptic plastic change. We also find that syntaphilin undergoes divergent subcellular targeting to the mitochondrial outer membrane and the synaptic plasma membrane, giving rise to two neuronal subpopulations of the protein that are modified in their relative enrichment with synaptic maturation and with the formation of cell contacts. Finally, we demonstrate that syntaphilin expression is initiated with induction of neuronal differentiation in PC12 cells. Given its biochemical and functional properties, the spatially and temporally limited nature of syntaphilin expression provides evidence that syntaphilin could be a molecular element of synaptic functional differentiation.

Field of study: Biology
Residues of legacy organochlorine pesticides and DDT metabolites in highly consumed fish from the polluted Guanabara Bay, Brazil: distribution and assessment of human health risk

Organochlorine (OCP) pesticides were determined in samples of sardine (Sardinella brasiliensis), whitemouth croaker (Micropogonias furnieri), and mullet (Mugil liza) from Guanabara Bay (state of Rio de Janeiro, Brazil). OCP concentrations and fish consumption were linked with acceptable daily intake values in order to assess the human health risk for the Brazilian population. The total concentrations of OCPs (Σ OCP) was 6.6 ng/g f.w., 7.5 ng/g f.w., and 2.8 ng/g f.w. for sardines, corvina, and mullet, respectively. There was a significant difference (P < 0.05) among the species related to o,p’-DDD and o,p’-DDT concentrations. Both DDT-related compounds were 5 and 76 times more abundant in sardines than in whitemouth croaker and mullet. Newly discovered DDT metabolite, o-Cl-DDMU, was frequently detected in the fish. None of the samples exceeded the maximum limits for acceptable levels of OCP residues. According to the data of average intake of Brazilian population, none of three species exceeded toxicological parameter. The investigated fishes are considered as safe for human consumption in regard to exposure of the studied OCPs. However, fish may be a intake source of OCP metabolites such as o-Cl-DDMU whose toxicity is still unknown.

Field of study: Agricultural and Food sciences
Engineering Characteristics of Chemically Treated Water-Repellent Kaolin

Water-repellent soils have a potential as alternative construction materials that will improve conventional geotechnical structures. In this study, the potential of chemically treated water-repellent kaolin clay as a landfill cover material is explored by examining its characteristics including hydraulic and mechanical properties. In order to provide water repellency to the kaolin clay, the surface of clay particle is modified with organosilanes in concentrations (CO) ranging from 0.5% to 10% by weight. As the CO increases, the specific gravity of treated clay tends to decrease, whereas the total organic carbon content of the treated clay tends to increase. The soil-water contact angle increases with an increase in CO until CO = 2.5%, and then maintains an almost constant value (≈134.0°). Resistance to water infiltration is improved by organosilane treatment under low hydrostatic pressure. However, water infiltration resistance under high hydrostatic pressure is reduced or exacerbated to the level of untreated clay. The maximum compacted dry weight density decreases with increasing CO. As the CO increases, the small strain shear modulus increases, whereas the effect of organosilane treatment on the constrained modulus is minimal. The results indicate that water-repellent kaolin clay possesses excellent engineering characteristics for a landfill cover material.

Field of study: Materials science
You Can’t Always Do What You Want: Social Identity and Self-Presentational Determinants of the Choice to Work for a Low-Status Group

Group members’ choice to work on individual or on group status improvement was examined as a function of degree of ingroup identification (low, high) and accountability of responses (anonymous, accountable to the ingroup). In Experiment 1 (N = 73), in line with the authors’ predictions, accountability elicited progroup behavior among low identifiers, whereas individualistic behavior was displayed when participants were anonymous. No similar effect of accountability was observed for high identifiers, who always chose for group status improvement. Experiment 2(N = 118) replicated and extended these findings. Degree of identification with the ingroup was shown to determine which contextual cues are likely to influence group members’ responses. The integration of traditionally separate models of social influence (self-presentation and social identity) is proposed. It is suggested that degree of identification with a group functions as a moderator of which type of influence the group is able to exert.

Field of study: Psychology
Clearance of increased serum advanced glycosylation end products in patients with end stage renal disease by hemodialysis.

To study the effect of removal of hemodialysis using acetate membrane on serum advanced glycosylation end products (AGEP) in 36 patients (59.1 +/- 1.6) with end stage renal disease (ESRD).



Serum AGEP levels were determined with quantitative fluorescence spectrometry, flow injection analysis (FIA), and competitive enzyme-linked immunosorbent assay (ELISA) using a polyclonal antibody directed against AGEP.



The serum AGEP levels in patients with ESRD quantified by fluorescence spectrometry, FIA, and ELISA were higher than those in controls [(25 +/- 5) vs (7.5 +/- 1.5), (6.1 +/- 1.8) vs (1.4 +/- 0.5), and (37 +/- 20) vs (9 +/- 10) kU/L, respectively] and markedly reduced to [(22 +/- 6), (4.2 +/- 1.4), and (19 +/- 14) kU/L, respectively] after hemodialysis.



Increased serum AGEP levels in the circulation of patients with ESRD were reduced effectively by hemodialysis.

Field of study: Biology, Chemistry, Medicine
Effect of propylene carbonate as a plasticizer in high molecular weight PEOLiCF3SO3 electrolytes

The effect of propylene carbonate on the PEO-LiCF 3 SO 3 system was studied using infrared spectroscopy and ionic conductivity measurements. It has been observed that large amounts of propylene carbonate tend to decrease the degree of ionic association in polymer electrolytes, while the ionic conductivity increases by several orders of magnitude. Propylene carbonate interacts preferentially with the crystalline PEO phase relative to the (PEO) 3 LiCF 3 SO 3 compound present in the PEO-LiCF 3 SO 3 salt complexes.

Field of study: Materials science
[Relevance of brain prostaglandins to central effects of l-tetrahydropalmatine].

l-THP isa central depressant. It caused a marked sedation in various animals at 20—40 mg/kg (ip) and a profound sedation with catalepsy in rats at 70—100 mg/kg ( ip) . In this paper the interaction between brain prostaglandins (PGs) and l-THP was studied. 
 After ip l-THP10 mg/kg, the spontaneous locomotor activities (walking, washing and rearing) of rats were decreased, but no catalepsy was found. Previous intraventricular injection (icv) of PGE or PGFpotentiated significantly the depression on the spontaneous locomotor activities of l-THP and induced catalepsy. However, when the brain PGs level had been lowered by ip indomethacin 20 mg/kg×2, the depression of the locomotor activities caused by l-THP 10 mg/kg was not diminished, and catalepsy was facilitated. 
 The radioimmunoassay (sensitivity 0.01 ng) was used for measuring PGE or PGF in brain tissues. In rats or mice given ip l-THP 100 mg/kg, a considerable increment of brain PGF accompanying a profound central effects was observed. The endogenous biosynthesis of PGs in cortex homogenate was not influenced by l–THP (mice, ip 100 mg/kg) and (rats, mM), but was inhibited by indomethacin. The PGs levels in rabbits' CSF were not affected by im l-THP 40 mg/kg. 
 It is deduced that the central inhibitory effects of l-THP is not directly related to brain PGs.

Field of study: Biology, Chemistry, Medicine
Rhabdomyolysis and acute renal failure resulting from alcohol and drug abuse.

Rhabdomyolysis is a common cause of acute renal failure (ARF) associated with drug misuse. Abuse of the gel formulation of temazepam has been a particular problem in the West of Scotland. We performed a retrospective review of dialysis-dependent ARF from rhabdomyolysis and drug misuse in the West of Scotland, 1986-1997. We identified 76 patients, of whom 87% were male. Seventeen cases occurred in the first 6 years, compared with 59 in the subsequent 6 years. Median age was 32. Thirty cases followed intravenous drug misuse, 46 followed oral drug misuse. The substances most frequently misused were alcohol (54%), heroin (24%) and parenteral temazepam (17%). The temazepam cases all followed the introduction of the gel formulation. Three out of 4 patients requiring limb amputation had injected temazepam. Of intravenous drug misusers tested, 72% were hepatitis-C-positive. Some 43% of patients had deprivation scores in the worst category. ARF due to rhabdomyolysis from substance misuse is increasing in our area. Alcohol is frequently responsible. The introduction of the gel formulation of temazepam has contributed to the increase. Those at risk in this study were young, male, had a high incidence of hepatitis C and lived in the most deprived areas.

Field of study: Medicine
Competition between the conditioned rewarding effects of cocaine and novelty.

Access to novelty might provide an alternative learning history that competes with conditioned drug reward. We tested this suggestion in rats using a place conditioning procedure with cocaine and novelty. In Experiment 1, rats were conditioned with cocaine to prefer one side of an apparatus. In a subsequent phase, cocaine exposure continued; however, on the unpaired side, separate group of rats had access to novel objects, cocaine injections, or saline with no objects. Pairings with novel objects or cocaine shifted a preference away from the cocaine-paired environment during drug-free and drug-challenge tests. Experiment 2 tested novelty's impact when cocaine exposure was discontinued. The identical procedures were used except drug exposure ceased on the cocaine-paired side during the second phase. Both groups expressed a preference for the cocaine compartment. This preference was maintained for rats that did not have novel objects; however, rats that experienced novelty spent similar amounts of time in both compartments during both tests. Overall, the conditioned rewarding effects of novelty competed with those of cocaine as evidenced by a change in choice behaviors motivated by drug reward.

Field of study: Biology, Psychology
A Critical Analysis of School Principals’ Competence in Financial Management in Kenya: Accountability in Educational Planning and Management

This critical analysis seeks to explore the competence of the school Heads in Financial Management in Kenya. Competence is acquired through training and experience. On the other hand accountability is a moral issue acquired through schooling, theory and practice. It is believed that schools whose finances are well managed determine the overall performance of the school. In contrast, principals who involve themselves in misappropriation of funds, wastage, incompetence and are not responsible lacks moral authority in their duties and fails to achieve the set goals of the institution. The objective of the study was to analyze the principals’ competence and professionalism in managing school funds. The concept of financial management is critical in schools because it facilitates planning and utilizing of school funds economically and for the intended purposes. Principals in Kenyan schools are chief executive officers (CEO) as well as accounting officer who executes all school development plans and, he/she implements and controls school budgets. School administration realizes that school has an aspect of a business. As an investment, it aims at maximizing profit and wealth of the stakeholders- the students and parents which would pay dividends to the investors. The concept of accountability in a school tracks records and monitors the element of honesty and responsibility in using and spending school funds.  Competence, Financial Management, School, Accountability.

Field of study: Education
Quantitative analysis of glucosinolate of Chinese kale by HPLC-external standard method

The feasibility of glucosinolate quantitative analysis by Sinigrin as external standard and the glucosinolates in bolting stem of Chinese kale were studied. It was found that there was a positive correlation between the concentration of Sinigrin and peak area under the condition of 14.2 U sulfatase and HPLC measurement. The regression equation was y =3E -07x +0.001 and coefficient of regression is 0.9994. The standard recovery and comparison experiments indicated that Sinigrin external standard method is precise and can be used instead of the expensive internal standard Glucotropaeolin. 11 GS compounds in Chinese kale bolting stems were separated by HPLC and confirmed by electrospray mass spectrometry, including 7 kinds of aliphatic GSs and 4 kinds of indolyl GSs which accounted for 63.41% and 36.59% of total GSs content, respectively. Among them, Glucoerucin was detected in Chinese kale for the first time. The highest content GS in bolting stem of Chinese kale was Gluconapin, while the lowestcontent of GS was Glucoerucin.

Field of study: Agricultural and Food sciences