nils-herrmann/clean_scirepeval huggingface dataset:
Neuroprotective effects of nicardipine in a rat model of ischemia and reperfusion

A reversible middle cerebral artery occlusion was performed in rats to determine whether nicardipine, a dihydropyridine voltage-sensitive Ca++ channel (VSCC) antagonist, exerts neuroprotective effects when administered 10 minutes following an ischemic insult, and if it does, whether this is due to its vasodilatory action and effect on cerebral blood flow (CBF) or to direct blockade of Ca++ entry into ischemic brain cells. An increase in the intracellular calcium, [Ca++]i, plays a major role in neuronal injury during cerebral ischemia. Although a large amount of Ca++ enters neurons through the VSCC during ischemia, inconsistent neuroprotective effects have been reported with the antagonists of the VSCC. An intraperitoneal injection of nicardipine (1.2 mg/kg) was administered to rats at 10 minutes after the onset of ischemia, and 8, 16, and 24 hours after occlusion. Cortical CBF was determined by laser-Doppler flowmetry. Neurological and neuropathological examinations were performed after 72 hours. Neuron-s...

Field of study: Medicine
Frugality,personality and education

Frugality is the inner need of the humanity."No frugality,no humanity" is the basic principle of the human beings.Many diseases in our modern society,such as affluenza,the humanity commercialization,consumption fantasy,worship to the power and technology,the ecological and environmental crisis etc.are all the consequences that caused by the contraction of this basic principle.Modern schools,where tremendous hope is placed,do not preserve their own moral integrity and then became the tools to meet the needs of the school and students.Therefore,no matter it is for the sake of saving human beings or for the sake of saving the seriously endangered ecological environment,the education should reevaluate the value of frugality,and put the frugality education into practice.

Field of study: Education
Un siglo de deuda publica en Mexico (review)

This volume on Mexico’s foreign debt is part of a series devoted to Mexico’s economic history, and both students and the general public will find it useful, since the previously published articles reprinted here are difficult to access. The first two articles analyze the impact of the 1820 financial bubble on Mexico’s economy. Reinhard Liehr’s 1983 article concerning merchant bank houses offers an excellent analysis of the role they played in the negotiations of Mexico’s first British loan; Liehr interwines this with a discussion of loans and trade. The following article, published in 1980 by Jaime E. Rodríguez, focuses on the impact that foreign loans had on the Mexican political arena. Guadalupe Nava’s essay (originally published in 1971), as well as Geneviève Gilles’s 1965 article, contain precise information on the evolution of Mexico’s internal and foreign debt in the second third of nineteenth century. The last two essays offer explanations for the changes in the foreign debt at the moment that Mexico entered the international financial system. Carlos Marichal’s 1988 article sketches out certain hypotheses regarding the role of foreign debt on the development of Mexico’s infrastructure, mainly railways and public services. However, the most valuable essay of this volume is that of Jaime Enrique Zablowski (a chapter from his 1984 doctoral dissertation, which unfortunately remains unpublished). Zablowski uses different economic variables in order to provide a reflective explanation about the role of external financing in Mexico’s economic performance between 1880 and 1911. He also explains the benefits of Mexico’s return to the international financial system: loans were invested in new public goods and (once Mexico adopted the gold standard) transactions were widely facilitated by its participation in the multilateral international payment system. This, in turn, enabled the full development of its public finances and reduced transaction costs in Mexico’s foreign trade. One would have expected to find Luis Tellez Kuenzler’s excellent 1992 article on the relation between economic performance and credibility or realiability factor on the part of Mexico’s foreign bondholders in the second half of nineteenth century. Beyond a doubt, this volume is a good starting point on the topic, and it should encourage deeper and further research on an issue that is further explored in the recent volume edited by M. D. Bordo and R. Cortés Conde, Transferring Wealth and Power from the Old to the New World ( 2001). The collection has one drawback: the lack of a balanced bibliographic essay. Since its natural readers are students and the general public, one would have expected to find such bibliographical tool in order to provide critical insights and the intellectual tools to enable the nonspecialist to counterweigh and form an opinion concerning the longstanding demonization of foreign capital in Mexican historiography of development.

Field of study: History
Heart rate variability measurements and the prediction of ventricular arrhythmias.

Heart rate variability (HRV) is the temporal variation between sequences of consecutive heartbeats. On a standard electrocardiogram (ECG), the maximum upwards deflection of a normal QRS complex is at the peak of the R wave , and the duration between two adjacent R wave peaks is termed the R-R interval. The ECG signal requires editing before HRV analysis can be performed, a process requiring the removal of all non-sinus-node-originating beats. The resulting period between adjacent QRS complexes resulting from sinus node depolarizations is termed the N-N (normal-normal) interval.1 HRV is the measurement of the variability of the N-N intervals.  
The normal electrocardiogram with component waves labelled.



Although counter-intuitive, it is possible that HRV confers a survival advantage. Any system exhibiting intrinsic variability is primed to respond rapidly and appropriately to demands placed upon it.

HRV is a measure of the balance between sympathetic mediators of heart rate (HR) (i.e. the effect of epinephrine and norepinephrine, released from sympathetic nerve fibres, acting on the sino-atrial and atrio-ventricular nodes), which increase the rate of cardiac contraction and facilitate conduction at the atrio-ventricular node, and parasympathetic mediators of HR (i.e. the influence of acetylcholine, released by the parasympathetic nerve fibres, acting on the sino-atrial and atrio-ventricular nodes), leading to a decrease in the HR and a slowing of conduction at the atrio-ventricular node. Sympathetic mediators appear to exert their influence over longer time periods and are reflected in the low frequency power (LFP) of the HRV spectrum (between 0.04 Hz and 0.15 Hz.2,,3 Vagal mediators exert their influence more quickly on the heart, and principally affect the high frequency power (HFP) of the HRV spectrum (between 0.15 Hz and 0.4 Hz).4 Thus, at any point in time, the LFP:HFP ratio is a proxy for the sympatho-vagal balance.

Physiological and pathological process … 

Address correspondence to Dr M.J. Reed, Emergency Department, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA.

Field of study: Medicine
Oversampled Paraunitary DFT Filter Banks: A General Construction Algorithm and Some Specific Solutions

Oversampled filter banks are at the center of essential signal processing systems, either for source coding or for transmission applications. Among this class of filter banks (FBs), the case of oversampled discrete Fourier transform (DFT) filter banks is particularly important since it leads to efficient algorithm implementations. However, up to now, no general construction algorithm has been proposed to exhaustively cover the large set of the various solutions offered by this family of FBs. The paper recalls in detail the precise features of the rectangular paraunitary matrices that are specific of this type of systems. A parametrization method is proposed involving transformations, being either rotations or shifts, that depend upon the oversampling ratio and upon the prototype filter length. This shows that several factorizations exist leading to solutions of different dimension. Orthogonal and paraunitary patterns are introduced and, using a sequence of transformations applied to a pattern (STAP), an algorithm is derived that allows us to get the exhaustive set of solutions for various values of the oversampling ratio and prototype filter length. Furthermore, for some oversampling ratios, explicit expressions of some solutions are also provided that are valid whatever the maximum length of the prototype filter. Finally, design examples for linear and nonlinear phase prototype filters are presented.

Field of study: Engineering
Utility of an Inverse-Matrix Technique in the Fast Atom Bombardment Mass Spectrometry-Based Structural Determination of 2-Substituted 1,3-Bis(benzotriazolyl)isoindolines

Molecular ions (M+’s) of reactive synthetic intermediates (1,3-bis(benzotriazolyl)isoindolines) can be monitored with certainty through a new sample-sorting technique in the fast atom bombardment mass spectrometry (FABMS).

Field of study: Chemistry
Symptoms of autonomic dysfunction in chronic fatigue syndrome.

Chronic fatigue syndrome (CFS) is common and its cause is unknown.



To study the prevalence of autonomic dysfunction in CFS, and to develop diagnostic criteria.



Cross-sectional study with independent derivation and validation phases.



Symptoms of autonomic dysfunction were assessed using the Composite Autonomic Symptom Scale (COMPASS). Fatigue was assessed using the Fatigue Impact Scale (FIS). Subjects were studied in two groups: phase 1 (derivation phase), 40 CFS patients and 40 age- and sex-matched controls; phase 2 (validation phase), 30 CFS patients, 37 normal controls and 60 patients with primary biliary cirrhosis.



Symptoms of autonomic dysfunction were strongly and reproducibly associated with the presence of CFS or primary biliary cirrhosis (PBC), and correlated with severity of fatigue. Total COMPASS score >32.5 was identified in phase 1 as a diagnostic criterion for autonomic dysfunction in CFS patients, and was shown in phase 2 to have a positive predictive value of 0.96 (95%CI 0.86-0.99) and a negative predictive value of 0.84 (0.70-0.93) for the diagnosis of CFS.



Autonomic dysfunction is strongly associated with fatigue in some, but not all, CFS and PBC patients. We postulate the existence of a 'cross-cutting' aetiological process of dysautonomia-associated fatigue (DAF). COMPASS >32.5 is a valid diagnostic criterion for autonomic dysfunction in CFS and PBC, and can be used to identify patients for targeted intervention studies.

Field of study: Medicine
Continental weathering and redox conditions during the early Toarcian Oceanic Anoxic Event in the northwestern Tethys: Insight from the Posidonia Shale section in the Swiss Jura Mountains

The geochemistry and mineralogy of organic-rich sediments of the Rietheim succession in northern Switzerland were studied to evaluate the main impacts of the early Toarcian Oceanic Anoxic Event (T-OAE; ~ 183 Ma ago) on the depositional environment in the NW Tethys Ocean. The geochemical data obtained (notably, δ13Corg, δ13CCaCO3, Rock-Eval pyrolysis, TOCcff) support the hypothesis that the negative C-isotope excursion at the onset of the T-OAE mainly reflects a major perturbation in the global carbon cycle rather than local environmental changes (e.g., basinal restriction, productivity). Rock-Eval pyrolysis and δ13Corg-δ15Ntotal crossplots indicate that the organic matter was primarily of marine origin during the T-OAE, and deposited in an epicontinental sea setting. Detrital proxies [notably, detritus index, siliciclastic balance and Ln(Al2O3/Na2O)] suggest that the elevated pCO2 levels and greenhouse climate prevailing during the T-OAE induced significant acceleration of the hydrologic cycle and an increase in continental chemical weathering rates. Redox-sensitive proxies [relative pyrite contents, organic and sulfide balances, V/(V + Ni) ratios, trace elements enrichment factors, trace-element-TOC co-variation patterns and TOC/Ptotal molar ratios] indicate that the Rietheim Posidonia Shale sediments accumulated under oxic-to-dysoxic bottom-water conditions, with more reducing conditions during the T-OAE (anoxic and possibly euxinic). These changes in redox conditions were probably induced by substantial thermohaline stratification driven by enhanced freshwater input and the recurrent influx of brackish Arctic seawater into the NW Tethys through the Viking Corridor, in agreement with previous sedimentological and geochemical evidences from the NW Tethys Ocean. In the studied succession, such conditions were perhaps also responsible for sequestration of most of the regenerated P in the deeper water column by adsorption and/or co-precipitation into authigenic phases. Overall, the major palaeoenvironmental changes documented in this study provide a robust example of Earth’s possible responses to the rapid onset of extreme greenhouse conditions.

Field of study: Environmental science, Geography
The Changing Contours of Long-Term Unemployment: The Need for a More Radical Policy

Since the financial meltdown of 2007, unemployment has consistently been above 6.0 percent. On one level, long-term unemployment can be accounted for by structural changes. But, on another level, the problem of long-term unemployment is really no more complicated than the absence of effective demand. This study looks at the demographics of the long-term unemployed for the years 2007-2010, and compares them to the years 1991-1994 to see what changes have occurred specifically among the long-term unemployed. The data shows that, in terms of structural changes, the 1991-1994 and 2007-2010 periods were not much different. Rather, the nature of this recession resulted in an altered composition of the long-term unemployed. Because long-term unemployment in this recession is a function of a particularly deep recession, a new approach is needed. Based on the data, this study argues for a wage policy that would allow for people to increase their effective demand for goods and services.

Field of study: Economics
A New RF Stealth Performance Evaluation Method Based on PSCP

A new RF(radio frequency) stealth performance evaluation method of electronic equipment based on polarization status changing parameter is presented. By analyzing typical intercept receiving mechanism in electronic war, a key factor- the uncertainty of radiating signals of electronic equipment is extracted from “radiating-intercepting” scenario. A calculating formula is established to transfer this kind of uncertainty to RF stealth factor. This RF stealth factor can be used to evaluate electronic equipments RF stealth performance directly, without relying on traditional complex “radiating-intercepting” scenario. Simulation results show the effectiveness of this evaluation method.

Field of study: Engineering
Study of increased radiation when an x-ray tube is placed in a strong magnetic field.

When a fixed anode x-ray tube is placed in a magnetic field (B) that is parallel to the anode-cathode axis, the x-ray exposure increases with increasing B. It was hypothesized that the increase was caused by backscattered electrons which were constrained by B and reaccelerated by the electric field onto the x-ray tube target. We performed computer simulations and physical experiments to study the behavior of the backscattered electrons in a magnetic field, and their effects on the radiation output, x-ray spectrum, and off-focal radiation. A Monte Carlo program (EGS4) was used to generate the combined energy and angular distribution of the backscattered electrons. The electron trajectories were traced and their landing locations back on the anode were calculated. Radiation emission from each point was modeled with published data (IPEM Report 78), and thus the exposure rate and x-ray spectrum with the contribution of backscattered electrons could be predicted. The point spread function for a pencil beam of electrons was generated and then convolved with the density map of primary electrons incident on the anode as simulated with a finite element program (Opera-3d, Vector Fields, UK). The total spatial distribution of x-ray emission could then be calculated. Simulations showed that for an x-ray tube working at 65 kV, about 54% of the electrons incident on the target were backscattered. In a magnetic field of 0.5 T, although the exposure would be increased by 33%, only a small fraction of the backscattered electrons landed within the focal spot area. The x-ray spectrum was slightly shifted to lower energies and the half value layer (HVL) was reduced by about 6%. Measurements of the exposure rate, half value layer and focal spot distribution were acquired as functions of B. Good agreement was observed between experimental data and simulation results. The wide spatial distribution of secondary x-ray emission can degrade the MTF of the x-ray system at low spatial frequencies for B < 0.5 T.

Field of study: Medicine, Physics
Modeling the influence of attitudes and beliefs on recreational boaters' use of buoys in the Balearic Islands

Recreational boating is a globally significant nature-based industry, which can degrade sensitive benthic habitats through physical damage from anchors. Mooring buoys can eliminate this impact and lead to additional benefits such as more efficient use of space, increasing the well-being and safety of boaters, and generating revenue through user fees. Evidence that buoys positively influence the well-being of users, especially if this is reflected in a willingness to pay, may provide motivation to decision-makers to invest in this management measure yet, to the best of our knowledge, relatively little is known about what motivates boaters to use buoys. Based on the theory of reasoned action, this study uses the classification tree method to model the influence of behavioral and normative beliefs on two dependent variables; boaters’ perceived likelihood to use buoys and willingness to pay (WTP) in a Marine Protected Area (MPA) located in a heavily used Bay on the island of Mallorca in the Balearic Islands of Spain. This MPA was designated to protect Posidonia oceanica, an endemic seagrass in the Mediterranean, which has been significantly degraded by structural damage from anchors. Data were collected using a survey instrument administered to recreational boaters in the summer of 2011. The data showed overall user support for buoys, and a positive relationship between attitudes (associated with perceptions of safety, space, and minimizing impacts on P. oceanica) and WTP and behavioral intent. The data also indicated a positive influence of awareness of the potential negative impacts of anchoring on P. oceanica and the role of buoys in minimizing these effects on both dependent variables. Attitudes towards crowding in the study site had a very minor influence and normative beliefs did not feature as predictors in our models. The study is part of a larger research initiative to assess the physical, social, and environmental dimensions of recreational boating on the island of Mallorca. The theoretical framework, data collection and statistical assessment methods are broadly applicable to interdisciplinary research on use of coastal and marine space.

Field of study: Environmental science
Solvability based on E-property for the nonlinear symmetric cone complementarity problem

In this paper, we introduce some concepts of E-properties for nonlinear transformations defined on Euclidean Jordan algebras, such as E-property, quad E-property, uniform Jordan E-property, E 0 -property. And then we study the implications among these E-properties. In particular, the quad E-property is equivalent to the E-property. The K -copositive property implies the E 0 -property. The uniform Jordan E-property is proved to have the E 0 and R 0 -properties. Based on the E-properties, we get some sufficient conditions to guarantee the solution existence for the nonlinear symmetric cone complementarity problem.

Field of study: Mathematics
On the scalability of rendezvous-based location services for geographic wireless ad hoc routing

Geographic routing protocols allow stateless routing by taking advantage of the location information of mobile nodes and thus are highly scalable. A central challenge in geographic routing protocols is the design of scalable distributed location services that track mobile node locations. A number of location services have been proposed, but little is known about the relative performance of these location services. In this paper, we perform a detailed performance comparison of three rendezvous-based location services that cover a range of design choices: a quorum-based protocol (XYLS) which disseminates each node's location to O(N) nodes, a hierarchical protocol (GLS) which disseminates each node's location to O(logN) nodes, and a geographic hashing-based protocol (GHLS) which disseminates each node's location to O(1) nodes. We present a quantitative model of protocol overheads for predicting the performance tradeoffs of the protocols for static networks. We then analyze the performance impact of mobility on these location services. Finally, we compare the performance of routing protocols equipped with the three location services with two topology-based routing protocols, AODV and DSR, for a wide range of network sizes. Our study demonstrates that when practical mobile ad hoc network (MANET) sizes are considered, the constants matter more than the asymptotic costs of location service protocols. In particular, while GLS scales better asymptotically, GHLS transmits fewer control packets and delivers more data packets than GLS in MANETs of sizes considered practical today and in the near future. Additionally, in contrast to the complex GLS design, the simplicity of GHLS provides significant resilience to performance degradation from mobility. Finally, although XYLS has a comparable packet delivery ratio to GHLS, it achieves this ratio with a higher overhead.

Field of study: Computer science
Measurement and Torque Calculation of Magnetic Spur Gear Based on Quasi 3-D Analytical Method

This paper presents the torque characteristics analysis and torque measurement of a magnetic spur gear with a three-segment Halbach array based on the Quasi Three-Dimension (3-D) Analytical Method. It analyzes a magnetic spur gear that uses a Halbach array by employing an analytical method for torque calculation. In the analytical method, from the magnetic vector potential and a coordinate system conversion, analytical solutions are obtained for magnetic fields produced by source magnets. By using the derived magnetic field solutions, an analytical solution is obtained for the external magnetic flux density. The drive magnet is next reduced to the equivalent current densities, and the torque is computed from these currents in the external magnetic field, which is obtained from the second process. Finally, the leakage flux in the z-direction occurring in the magnetic gear is considered using the 3-D analytical method. Thus, an analytical result can be obtained. These results are validated by comparison with the finite element method.

Field of study: Physics