nils-herrmann/clean_scirepeval huggingface dataset:
Synchrotron radiation sources in the news and JSR goes online

With this issue, we celebrate the ®fth anniversary of the journal. Since the launch, approximately 850 papers and 3800 pages have appeared. The journal has published the proceedings of two main synchrotron radiation conferences, SRI'97 (May 1998 issue) and XAFS X (May 1999 issue), where new standards for these proceedings have been set. The journal now features in the top 17% of the Science Citation Index (4800 journals). Its impact factor is greater than that of Rev. Sci. Instrum.,   C, and is approaching that of Phys.  A major development for JSR this year has been the launch in August 1999 of the new and innovative electronic journal service, Synchrotron Radiation Online. This gives easy access to the complete text of all regular 1999 articles. The articles are available in HTML and PDF formats, and are richly hyperlinked for easy navigation within and between articles. The service also provides search mechanisms, e-mail alerting and immediate access to supplementary data. Access is free to the service during 1999, but will require a subscription to the journal in 2000. We ask you to visit http://journals.iucr.org/s/ journalhomepage.html to see the service for yourself. The ®rst Nobel prize for synchrotron radiation-based work, awarded to Sir John Walker of the MRC's Laboratory of Molecular Biology (see Editorial, November 1998), was marked by a dedicated issue on structural biology (Vol. 6, Part 4). The issue gathered together several excellent articles from the leaders in the ®eld demonstrating the transformation in structural biology brought about by synchrotron radiation. The importance of synchrotron radiation for structural biology is recognized by the funding agencies around the world. In the USA, NIH has increased its commitment to the synchrotron radiation sources by providing an extra injection of funds to several US facilities. In the UK, the Wellcome Trust, a large medical charity, provided ~$160M last year towards the replacement of the SRS Daresbury. The UK government had been expected to provide the remainder of the cost but, in August, French Science Minister Claude AlleAgre announced the participation of the French government in the UK's DIAMOND project . He also announced the abandonment of the French project SOLEIL . AlleAgre has argued that money spent on large `big science' facilities should be rerouted into research projects. The announcement by AlleAgre has angered a wide spectrum of scientists in France. Some of this anger was witnessed at the recent SRS Users Meeting where senior of®cials of the UK Ministry of Science and Technology were present. The decision to make DIAMOND the single source for the two 1069

Field of study: Physics
Immobilized β-galactosidase: Preparation and Characterization

A new enzyme support consisting of magnetic composite microspheres was prepared using artemisia seed gum, chitosan and magnetic fluid as a source, and characterized. The microspheres contained reactive aldehyde groups that react with the free amino groups of the enzymes. The β-galactosidase was largely immobilized by covalent binding to the surface of the activated magnetic carriers. The factors controlling the relative activity and the enzymic properties of the immobilized β-galactosidase were compared with those of its soluble counterpart, for which ONPG (o-nitrophenol β-D-galactopyranoside) was chosen as a substrate. The pH and thermal stability of the immobilized β-galactosidase were higher than those of the soluble one. The Michaelis constant, Km, was evaluated both for the immobilized β-galactosidase and for the soluble enzyme. The immobilized type exhibited better environmental adaptability and re-usability than the soluble one.

Field of study: Materials science
Hot carrier and soft breakdown effects on LNA performance for ultra wideband communications

This paper systematically investigates the hot carrier (HC) and soft breakdown (SBD) effects on CMOS low noise amplifier (LNA) for the ultra wide-band (UWB) of 3.1 to 7 GHz. After the MOSFET device RF parameter degradations due to HC and SBD effects are experimentally extracted, the HC and SBD induced performance degradations of the LNA for UWB are evaluated for 0.16 μm CMOS technology, including s-parameters, noise figure, and stability factor. This work can help RF designers to design more reliable LNA circuits for upcoming UWB applications.

Field of study: Engineering
Using instrumental variables for selecting the order of arma models

A methodology is developed for selecting the order of an ARMA representation of a short realization. The methodology is based on an extension of the Instrumental Variables technique and its theoretical logic is supported by the characteristic of extended Yule-Walker equations and Toeplitz matrices. The methodology is a modification of the Cormer Method and tries to identify a set of orders instead of a single order. The strength of the methodology is evaluated by comparing its numerical findings with that from the Corner Method and the Extended Sample Autocorrelation Function Method. The numerical results imply that (i) the proposed method performs, on the average better than the Corner Method and both methods outperform Extended Sample Autocorrelation Function method, and (ii) the selection of a set of orders provides more reliable results than the selection of a single order.

Field of study: Mathematics
The Impact of Chinese Investment in Africa

The purpose of this paper is to explore the increasingly important economic and business relationship between the People’s Republic of China and the countries of Africa. Our focus is on how this partnership manifests itself in investments. The research questions are: first, how has the relationship changed over time and second, from an African perspective has this relationship been beneficial? Finally, how has the recent economic downturn affected their partnership? Our investigation shows that Chinese investment has been motivated by a desire to access critical resources (oil, bauxite, etc.). The Chinese approach was been to downplay political issues (e.g., human rights). Although recipient African nations have received investment inflows, they have come with certain drawbacks. For instance, they have negatively impacted local trade and commerce. Also, in some cases African labor has not benefited from Chinese investment.

Field of study: Business
Paleohydrology of a Canadian Shield lake inferred from 18O in sediment cellulose

Oxygen- and carbon-isotope analyses on cellulose in the postglacial sediment of Weslemkoon Lake, southern Ontario, show that the cellulose came mainly from aquatic plants or algae, rather than from terrestrial sources. If a wholly aquatic source is assumed, the oxygen-isotope content permits inferences of lake-water δ18O values over the past 10 000 years by accounting for the isotopic fractionation that occurs during cellulose synthesis. Chronological control is provided by pollen analysis and six 14C dates. Our reconstruction shows lake-water δ18O fluctuated from about 5‰ lower than present in the early postglacial to 5‰ or more above present values during the mid-postglacial. These broad, secular shifts reflect a combination of fluctuating mean annual δ18O of local precipitation, evaporative isotopic enrichment of surface waters, and snowmelt-bypass effects. The first two factors reflect the changing paleotemperature and paleohydrology, respectively, whereas the third factor is a more speculative interp...

Field of study: Environmental science
Analysis and simulation of blurring effect for CCD image system in high-energy radiography

It is pointed out that the depth of focus,diffraction from aperture and radiation scattering are three main sources for image blurring of CCD receiving system.The radiation scattering is studied by MCNP simulation.The distributions of energy deposition in CsI:Tl crystal under different energy spectrum and depth of screen are given.It is shown that energy deposition increases linearly with the depth of screen increasing.The blurring from radiation scattering is related with the spectrum of photons.Furthermore,the blurring caused by the hardened spectrum changing with the depth of screen is less than that by non-hardened spectrum.It can be seen that the radiation scattering is the main source for image blurring,and the blurring from radiation scattering is different from the Gaussian blurring.

Field of study: Physics
The structure and dynamics of enzyme-substrate reaction intermediates determined by resonance Raman spectroscopy

The two principal means of obtaining the resonance Raman (RR) spectra of enzyme-substrate complexes are discussed. The first employs substrates which contain extended ¶-electron systems, such as cinnamic or furylacrylic acid. The spectral data for these substrates bound to serine or cysteine proteinases can be interpreted in terms of a model in which the delocalised it-electrons become polarised. The second method of employing the RR technique creates a dithioester chromophore at the point where the substrate is covalently linked, for a short time, to the enzyme. By this means it is possible to obtain the vibrational spectrum associated with those bonds undergoing catalytic transformation. The RR spectra provide detailed information on the conformation of the enzyme-bound substrate and allow us to discuss conformer selection and substrate distortion and strain. Combined X-ray crystallographic and Raman studies on suitable model compounds are important in setting up the spectra-structure correlations needed for spectral interpretation. These studies also introduce a dynamical concept by suggesting how structural changes occur along the reaction pathway. Complementary dynamical information is elicited from combined kinetic and RR data; the data from these two techniques provide a very detailed structure-kinetic correlation and show how the breaking of a single atom-atom contact in the active site is associated with an individual rate constant for the reaction. Papain is the archetype enzyme used for the dithioester work, but the approach has been extended to other plant cysteine proteinases and to the mammalian enzyme cathepsin B.

Field of study: Chemistry
Opportunity to Learn and Achievement in Three Subject Matter Areas.

In surveys of educational achievement some teachers frequently complain that a centrally constructed test underestimates the real achievement of their students, since they did not have an opportunity to study topics covered by some items. An attempt has been made to find out the relationship between opportunity to study a topic or skill in the school and proficiency in it. It was found that such relationship exists; nevertheless the rank order of a particular class is not really changed when assessed on those items only which they studied in comparison to their rank order on the total test score.

Field of study: Education
Delocalization by disorder in layered systems.

Motivated by anomalously large conductivity anisotropy in layered materials, we propose a simple model of randomly spaced potential barriers (mimicking stacking faults) with isotropic impurities in between the barriers. We solve this model both numerically and analytically by utilizing an exact solution for the conductivity of a one-dimensional disordered system. In the absence of bulk disorder, electron motion in the out-of-plane direction is localized. Bulk disorder destroys one-dimensional localization. As a result, the out-of-plane conductivity is finite and scales linearly with the scattering rate by bulk impurities until planar and bulk disorder become comparable. The ac out-of-plane conductivity is of a manifestly non-Drude form: the real part starts from finite value at zero frequency and has a maximum at the frequency corresponding to the scattering rate by potential barriers.

Field of study: Physics
Lung function and within-breath changes in resistance in patients who have had a laryngectomy.

We describe the construction of a simple device which may be used to connect a patient with a tracheostomy to standard lung function testing equipment. We compared the lung function of nine patients after laryngectomy with nine patients matched for similar degrees of airflow obstruction, and found that peak flow rate (as per cent predicted) was significantly lower than predicted FEV1 in the patients with tracheostomy. This suggests that the larynx may normally affect production of peak flow. We then compared the change in resistance over the normal tidal volume in the two groups, finding no significant difference, and obtained similar results from paired studies in two patients before and after laryngectomy. We conclude that, while the laryngeal aperture varies during tidal breathing, it plays no major part in the overall resistance changes which occur during a normal breath.

Field of study: Medicine
Many-to-many feature matching in object recognition: a review of three approaches

The mainstream object categorisation community relies heavily on object representations consisting of local image features, due to their ease of recovery and their attractive invariance properties. Object categorisation is therefore formulated as finding, that is, `detecting`, a one-to-one correspondence between image and model features. This assumption breaks down for categories in which two exemplars may not share a single local image feature. Even when objects are represented as more abstract image features, a collection of features at one scale (in one image) may correspond to a single feature at a coarser scale (in the second image). Effective object categorisation therefore requires the ability to match features many-to-many. In this paper, we review our progress on three independent object categorisation problems, each formulated as a graph matching problem and each solving the many-to-many graph matching problem in a different way. First, we explore the problem of learning a shape class prototype from a set of class exemplars which may not share a single local image feature. Next, we explore the problem of matching two graphs in which correspondence exists only at higher levels of abstraction, and describe a low-dimensional, spectral encoding of graph structure that captures the abstract shape of a graph. Finally, we embed graphs into geometric spaces, reducing the many-to-many graph-matching problem to a weighted point matching problem, for which efficient many-to-many matching algorithms exist.

Field of study: Computer science
The significance of the theropod collections of the Royal Tyrrell Museum of Palaeontology to our understanding of Late Cretaceous theropod diversity1

Significant specimens of theropod dinosaurs were part of the collections that were transferred to the Royal Tyrrell Museum of Palaeontology when it split off from the Provincial Museum of Alberta in 1981. Collecting activity of the institution increased dramatically in the period leading up to the opening of the building and displays in 1985, and resulted in the recovery and preparation of many fine theropod skeletons. New specimens have been added to the collection every year since the museum opened. Several (mostly small) taxa are only represented by isolated bones, partial skeletons, and (or) teeth. Theropod specimens also include footprints, coprolites, eggs, and feathers in amber. Although theropods are relatively rare in comparison with herbivorous dinosaurs, the Tyrrell has managed to build one of the finest research collections of Late Cretaceous forms. Thirty-seven species of theropods in the Tyrrell are currently accepted as being valid, of which 30 are from the Upper Cretaceous deposits of Alberta.

Field of study: Environmental science
(Aminoethinyl)metallierungen, 61) Umsetzungen von (Silylethinyl)‐ und (Germylethinyl)aminen mit Ketoketenen

Die β-silylierten und β-germylierten Inamine 1 addieren die Ketoketene 2 bevorzugt zu den (3-Siloxy- bzw. (3-Germyloxy-3-alken-1-inyl)aminen 4. Nebenprodukte sind die Cycloaddukte 5i und 5j sowie das C-silylierte Acylinamin 6k. Bei der sauren Hydrolyse von 4a–f erhalt man die 3-Siloxy-3-butenamide 9, die Acetoacetamide 10 und in einigen Fallen die Cyclisierungsprodukte 12; die basische Hydrolyse liefert Acylinamine wie 13. Das Eninamin 4d reagiert mit Sulfonylaziden 7 uber die Diazoverbindungen 15 unter Stickstoffabspaltung und intramolekularer Sauerstoffverschiebung zu den 2-Oxo-3-siloxy-N2-sulfinyl-3-butenamidinen 16. Mit Ketenen liefern die Eninamine 4 Cyclobutenone vom Typ 17. 
 
 
 
(Aminoethynyl)metallations, 61). – Reactions of (Silylethynyl)-and (Germylethynyl)amines with Ketoketenes 
 
 
 
The β-silylated and β-germylated ynamines 1 add the ketoketenes 2 to give preferentially the (3-siloxy- and (3-germyloxy-3-alken-1-ynyl)amines 4, respectively. By-products are the cycloadducts 5i and j and the C-silylated acylynamine 6k. Acid hydrolysis of 4a–f affords the 3-siloxy-3-butenamides 9, the acetoamides 10, and – in few cases – the cyclization products 12; base hydrolysis furnishes acylynamines, e.g. 13. Reaction of 4d with the sulfonyl azides 7 via diazo compounds 15 gives on elimination of nitrogen and intramolecular migration of oxygen the 2-oxo-3-siloxy-N2-sulfinyl-3-butenamidines 16. Ketenes react with the enynamines 4 to yield cyclobutenones of type 17.

Field of study: Chemistry
Reconstructing the foraging environment of the latest titanosaurs (Fumanya dinosaur tracksite, Catalonia)

The analysis of depositional environments associated with sauropod dinosaurs has been revealed as a key element for assessing their palaeoecology. A detailed study of the sedimentology, plant taphofacies and titanosaur ichnology at the Fumanya localities (early Maastrichtian, Catalonia) reveals that two distinct palaeoenvironments existed within the coastal wetlands. These settings are correlated with the occurrence of two distinct track and plant remains distributions, which correspond to a) a marginal brackish lagoon environment where no vegetation grew and titanosaurs roamed, during a short time span, without apparently any preferential purpose, and b) a freshwater swamp area around charophyte lakes with evidence of vegetation growth (charophytes, palms, and probably ferns and cheirolepidiacean conifers) where titanosaurs congregated and fed actively during a long time span. These data indicate that titanosaurs trampled the muddy substrates of freshwater wetlands in order to forage according to the availability of plants.

Field of study: Environmental science, Geography
Change in sign of the Hall coefficient from Fermi surface curvature in underdoped high Tc copper oxide superconductors

It has recently been proposed that the Fermi surface of underdoped high Tc copper oxide materials within the charge-ordered regime consists of a diamond-shaped electron pocket constructed from arcs connected at vertices. We show here that on modeling the in-plane magnetotransport of such a Fermi surface using the Shockley-Chambers tube integral approach and a uniform scattering time, several key features of the normal state in-plane transport of the underdoped copper oxide systems can be understood. These include the sign reversal in the Hall coefficient, the positive magnetoresistance and magnetic quantum oscillations in the Hall coefficient.

Field of study: Physics
The extraction of collagen from eel bone using acetic acid and pepsin

The technology of extracted collagen from eel bone was studied in this paper.Acetic acid and pepsin were adopted on the extraction technology including immersion time,quantity of enzymes,acid concentration and the liquid-solid ratio.The result showed that the optimal processing condition was eel bone immersing in 0.5 mol/L acetic acid for 28 hours at 37 ℃,and 0.10 g pepsin added,and the solid-liquid ratio was 1:45.The recovery of eel bone collagens was 80.80%.

Field of study: Agricultural and Food sciences
From Spectrum Pooling to Space Pooling: Opportunistic Interference Alignment in MIMO Cognitive Networks

We describe a noncooperative interference alignment (IA) technique which allows an opportunistic multiple input multiple output (MIMO) link (secondary) to harmlessly coexist with another MIMO link (primary) in the same frequency band. Assuming perfect channel knowledge at the primary receiver and transmitter, capacity is achieved by transmiting along the spatial directions (SD) associated with the singular values of its channel matrix using a water-filling power allocation (PA) scheme. Often, power limitations lead the primary transmitter to leave some of its SD unused. Here, it is shown that the opportunistic link can transmit its own data if it is possible to align the interference produced on the primary link with such unused SDs. We provide both a processing scheme to perform IA and a PA scheme which maximizes the transmission rate of the opportunistic link. The asymptotes of the achievable transmission rates of the opportunistic link are obtained in the regime of large numbers of antennas. Using this result, it is demonstrated that depending on the signal-to-noise ratio and the number of transmit and receive antennas of the primary and opportunistic links, both systems can achieve transmission rates of the same order.

Field of study: Engineering
Recovery Of Endosulfan From Pigeonpea, Chickpea, And Groundnut After Spraying With Different Appliances

The recovery from pigeonpea [Cajanus cajan], chickpea [Cicer arietinum] and groundnut following application of endosulfan at 1.16 g a.i./m² with a hand-operated knapsack sprayer (500 litres spray liquid/ha), a motorized knapsack sprayer (250 litres/ha) and a hand-held spinning disc controlled droplet applicator (CDA) (10 litres/ha) were determined in studies in Andhra Pradesh, India. The percentage recovery of endosulfan on all crops was higher with the CDA (79-85%) than with the motorized knapsack (60-73%) or the hand-held knapsack (38-57%).

Field of study: Biology
Domestic violence in primary care: The psychologist's role

This paper highlights the difficulties facing medical and mental health professionals in helping families in which there is violence. Emphasis is placed on how domestic violence presents in primary care medical settings. Physician and patient characteristics that interfere with domestic violence detection are reviewed. A role is outlined for psychologists in primary care settings to facilitate detection and treatment. Facilitative efforts include educating physicians through collaboration and serving as an on-site resource for information and consultation.

Field of study: Psychology