nils-herrmann/clean_scirepeval huggingface dataset:
Structure of the wild-type TEM-1 beta-lactamase at 1.55 A and the mutant enzyme Ser70Ala at 2.1 A suggest the mode of noncovalent catalysis for the mutant enzyme.

One of the best-studied examples of a class A beta-lactamase is Escherichia coli TEM-1 beta-lactamase. In this class of enzymes, the active-site serine residue takes on the role of a nucleophile and carries out beta-lactam hydrolysis. Here, the structures of the wild-type and the S70G enzyme determined to 1.55 and 2.1 A, respectively, are presented. In contrast to the previously reported 1.8 A structure, the active site of the wild-type enzyme (1.55 A) structure does not contain sulfate and Ser70 appears to be in the deprotonated form. The X-ray crystal structure of the S70G mutant has an altered Ser130 side-chain conformation that influences the positions of water molecules in the active site. This change allows an additional water molecule to be positioned similarly to the serine hydroxyl in the wild-type enzyme. The structure of the mutant enzyme suggests that this water molecule can assume the role of an active-site nucleophile and carry out noncovalent catalysis. The drop in activity in the mutant enzyme is comparable to the drop observed in an analogous mutation of the nucleophilic serine in alkaline phosphatase, suggesting common chemical principles in the utilization of nucleophilic serine in the active site of different enzymes.

Field of study: Chemistry
Land surface anomalies preceding the 2010 Russian heat wave and a link to the North Atlantic oscillation

The Eurasian wheat belt (EWB) spans a region across Eastern Ukraine, Southern Russia, and Northern Kazakhstan; accounting for nearly 15% of global wheat production. We assessed land surface conditions across the EWB during the early growing season (April–May–June; AMJ) leading up to the 2010 Russian heat wave, and over a longer-term period from 2000 to 2010. A substantial reduction in early season values of the normalized difference vegetation index occurred prior to the Russian heat wave, continuing a decadal decline in early season primary production in the region. In 2010, an anomalously cold winter followed by an abrupt shift to a warmer-than-normal early growing season was consistent with a persistently negative phase of the North Atlantic oscillation (NAO). Regression analyses showed that early season vegetation productivity in the EWB is a function of both the winter (December–January–February; DJF) and AMJ phases of the NAO. Land surface anomalies preceding the heat wave were thus consistent with highly negative values of both the DJF NAO and AMJ NAO in 2010.

Field of study: Environmental science
Code-based Cryptosystem from Quasi-Cyclic Elliptic Codes

With the fast development of quantum computation, codebased cryptography arises public concern as a candidate of post quantum cryptography. However, the large key-size becomes a main drawback such that the code-based schemes seldom become practical although they performed pretty well on the speed of both encryption and decryption algorithm. Algebraic geometry codes was considered to be a good solution to reduce the size of keys, but because of its special construction, there have lots of attacks against them. In this paper, we propose a public key encryption scheme based on elliptic codes which can resist the known attacks. By using automorphism on the rational points of the elliptic curve, we construct quasi-cyclic elliptic codes, which reduce the key size further. We apply the list-decoding algorithm to decryption thus more errors beyond half of the minimum distance of the code could be correct, which is the key point to resist the known attacks for AG codes based cryptosystem.

Field of study: Computer science, Mathematics
A Parametric Test of Perfect Ranking in Balanced Ranked Set Sampling

Many techniques based on data which are drawn by Ranked Set Sampling (RSS) scheme assume that the ranking of observations is perfect. Therefore it is essential to develop some methods for testing this assumption. In this article, we propose a parametric location-scale free test for assessing the assumption of perfect ranking. The results of a simulation study in two special cases of normal and exponential distributions indicate that the proposed test performs well in comparison with its leading competitors.

Field of study: Mathematics
The effect of inter-Landau-band mixing on extended states in quantum Hall system

The effect of inter-Landau-band mixing on electron localization in an integer quantum Hall system is studied. We find that mixing of localized states with opposite chirality tends to delocalize the states. This delocalization effect survives the quantum treatment. Extended states form bands because of this mixing, as we show through a numerical calculation on a two-channel network model. Based on this result, we propose a new phase diagram with a narrow metallic phase that separates any neighboring QH phases from each other and also separates each of them from the insulating phase. We reanalyzed the data from recent non-scaling experiments, and show that they are consistent with our theory.

Field of study: Physics
Cerebral dural arteriovenous fistulas and aneurysms.

OBJECT
The association of aneurysms and cerebral arteriovenous malformations is well established in the literature. Aside from a small number of case reports and small patient series, this association has not been well explored with cerebral dural arteriovenous fistulas (DAVFs). This study was designed to elucidate this relationship in the authors' own patient cohort with DAVFs.



Cerebral angiograms of 56 patients with 70 DAVFs were reviewed for the presence of cerebral aneurysms. Background patient demographics, mode of presentation, and DAVF and aneurysm angiographic characteristics were noted.



Twelve patients (21%) had aneurysms in addition to their DAVF. Three patients had multiple aneurysms. Of a total of 15 aneurysms, 5 (33%) occurred on DAVF feeding arteries and 10 (67%) were in remote locations. These patients more commonly presented with hemorrhage (58% vs 20% for those without aneurysms). Aneurysms were associated with DAVFs in any location (feeding artery or remote), but flow-related feeding artery aneurysms were more likely to be associated with Borden Type III DAVFs.



Twenty-one percent of patients with cerebral DAVFs also had aneurysms in this patient cohort. It is thus prudent to perform 6-vessel digital subtraction angiography on patients with DAVFs to rule out potential feeding artery and remote aneurysms. This association may be explained by flow-related phenomena, the initial inciting event leading to DAVF formation, as well as a potential genetic component or predisposition to develop these lesions.

Field of study: Medicine
An Improved Nonlinear Model for Load and Capacity

A nonlinear model of load and capacity is established to study the robustness of complex networks. The influences of load parameters and capacity parameters on cascading invulnerability of complex networks is analyzed following the principle load redistribution of local nearest neighbor. Furthermore, the invulnerability of complex networks is analyzed under the constraints of networks cost and survivability. Simulation results on complex networks show that the proposed nonlinear model can enhance the networks resistance to cascading failures with a limited cost.

Field of study: Engineering
Mathematical Model for Air Flow from Perforated Circular Ducts with Annular Corrugations

A mathematical model has been developed for the prediction of air flow and pressures in perforated corrugated ducts. Experimental tests have demonstrated the validity of this model for ducts with annular corruga-tions. Additional refinements in the model are needed to produce accurate predictions for ducts with helical cor-rugations. Dimensional analysis techniques were used to generalize the results. These results may be used in the design or analysis of air distribution systems for agricultural storages.

Field of study: Agricultural and Food sciences
CTLA‐4 blockade inhibits induction of Helicobacter pylori‐associated gastritis in mice

The balance between Th1 and Th2 response determines the outcome of Helicobacter pylori infection. Interferon (IFN)‐γ plays an inductive role in gastric inflammation, whereas interleukin (IL)‐4 counterbalances Th1 response and suppresses the development of gastritis. Th cell response is regulated by co‐stimulatory factors. A co‐stimulatory molecule, cytotoxic T lymphocyte‐associated antigen‐4 (CTLA‐4), plays an inhibitory role in IL‐2‐dependent cell growth and mediates an optimal inhibitory signal to Th1 and Th2 cells. We administered anti‐CTLA‐4 monoclonal antibody (MoAb), which blocks CTLA‐4 signalling, to examine the relative role for this signalling during maturation of Th1 and Th2 cells in H. pylori infection in mice. Mice treated by anti‐CTLA‐4 MoAb within the first week of infection showed an inhibition of gastric inflammation, accompanied by an increasing ratio of H. pylori‐specific IgG1/IgG2a  in  serum  following  infection.  Furthermore,  the  treatment  resulted  in  the higher ratio of IL‐4/IFN‐γ by splenocytes in response to H. pylori antigen at 6 weeks after infection, compared with untreated mice. These results suggest that the predominance of Th2 response by CTLA‐4 blockade leads to an inhibition of the development of gastric inflammation. CTLA‐4 signalling could contribute to the regulation of Th subsets and the development of gastric inflammation in H. pylori infection.

Field of study: Biology, Medicine
Isotopic hydrology and paleohydrology of the Madagi (Kenya)-Natron (Tanzania) basin during the late quaternary

Three generations of stromatolites mark the recent extension of paleolakes in the Magadi-Natron basin on the border between Tanzania and Kenya. The last two generations are observed some 50 m above the modern lakes' level; they are respectively attributed to the beginning of the last interglacial and to the Pleistocene-Holocene transition. Analysis of the morphology and texture of the stromatolites reveals an ecological zonation between 0 and 10–14 m below the shoreline. Their relatively high δ18O and δ13C values reflect a long residence time for the paleolake water, which would have been favorable to the establishment of an isotopic equilibrium between atmospheric CO2 and the dissolved inorganic carbon, despite deep carbon inputs in relation to carbonititic volcanism. A study of the 18O, 2H and 13C contents in the hydrothermal springs, perennial rivers and lacustrine brines indicates that, during the last period of significant renewal of the deep saline groundwater, precipitation was depleted in heavy isotopes when compared to modern precipitation. This difference corresponds to a drop of about 600–1000 m in altitudinal “hydroclimatic” zones. Finally, a comparison between the modern and paleohydrological data leads us to believe that the stabilization of the paleolake shorelines at the same altitude can be attributed to control by the water table level in the aquifer of the basaltic plateaus east of the basin.

Field of study: Environmental science, Geography
Recent Australian suicide trends for males and females at the national level: has the rate of decline differed?

In keeping with international public health policy development, suicide prevention in Australia has received increasing attention. The mid to late 1990s saw the introduction of a range of co-ordinated national prevention programmes. Since 1997, suicides have decreased, but the comparative rates of decline for males and females have not been well studied at the national level.



Standardised suicide rates were calculated for males and females, using data from 1997 to 2005. Linear models (ordinary least squares) were used to calculate rates of decline, with trends compared for males and females.



Male suicides appear to have fallen more rapidly than female suicides.



Australian males, an 'at risk' demographic, appear to be experiencing benefits from the existence of current national suicide prevention strategies and related social changes. It is recommended that greater consideration be given to researching risk factors such as intimate partner violence, sexual abuse, and substance dependence, for Australian female suicide.

Field of study: Medicine, Political science
The Value of Phenotypes in Knee Osteoarthritis Research

Over the past decade, phenotypes have been used to help categorize knee osteoarthritis patients relative to being subject to disease, disease progression, and treatment response. A review of potential phenotype selection is now appropriate. The appeal of using phenotypes is that they most rely on simple physical examination, clinically routine imaging, and demographics. The purpose of this review is to describe the panoply of phenotypes that can be potentially used in osteoarthritis research.  A search of PubMed was used singularly to review the literature on knee osteoarthritis phenotypes.  Four phenotype assembly groups were based on physical features and noninvasive imaging. Demographics included metabolic syndrome (dyslipidemia, hypertension, obesity, and diabetes). Mechanical characteristics included joint morphology, alignment, the effect of injury, and past and present history. Associated musculoskeletal disorder characteristics included multiple joint involvement, spine disorders, neuromuscular diseases, and osteoporosis. With the knee as an organ, tissue characteristics were used to focus on synovium, meniscus, articular cartilage, patella fat pad, bone sclerosis, bone cysts, and location of pain.  Many of these phenotype clusters require further validation studies. There is special emphasis on knee osteoarthritis phenotypes due to its predominance in osteoarthritic disorders and the variety of tissues in that joint. More research will be required to determine the most productive phenotypes for future studies.  The selection and assignment of phenotypes will take on an increasing role in osteoarthritis research in the future.

Field of study: Medicine
TESS: a high-luminosity high-resolution twin-etalon scanning spectrometer.

This section was established to reduce the lead time for the publication of Letters containing new, significant material in rapidly advancing areas of optics judged compelling in their timeliness. The author of such a Letter should have his manuscript reviewed by an OSA Fellow who has similar technical interests and is not a member of the author's institution. The Letter should then be submitted to

Field of study: Physics
Numerical investigations of dispersive shocks and spectral analysis for linearized quantum hydrodynamics

In this paper we perform the analysis of spectral properties of the linearized system around constant states and dispersive shock for a 1-D compressible Euler system with dissipation--dispersion terms. The dispersive term is originated by the quantum effects described through the Bohm potential, as customary in Quantum Hydrodynamic models. The analysis performed in this paper includes the computation of the linearized operator and the spectral stability through the Evans function method.

Field of study: Mathematics
TAXATION AND THE ECONOMY: A BUSINESS VIEW ON SOME IMPORTANT ISSUES

Australia is facing major economic problems. The overseas debt is uncomfortably high and we, like other countries, are having to face up to problems associated with the ageing of our population. 
 
 
 
To overcome these problems we need to save through superannuation and otherwise. Furthermore, we need to encourage further development of overseas operations by Australian companies and remove existing constraints. 
 
 
 
Taxation plays an important role. A consumption tax/income tax trade-off warrants thorough investigation. The benefits appear significant. 
 
 
 
We should avoid unnecessary restrictions on business activities as complexities lead to inefficiencies. We should seek to clarify and hopefully simplify the taxation code; a major review of the Income Tax Assessment Act would seem in order.

Field of study: Political science
Analysis of human Per4.

The molecular mechanism of the circadian pacemaker depends on the oscillatory expression of clock gene constituents. The Drosophila period gene is central to the clock mechanism in these animals. Three homologs of this gene identified in mice (mPer1-3) and humans (hPer1-3) display rhythmic expression and are important for normal clock function. Recently, analysis of the draft sequence of the human genome has revealed the presence of a fourth Per gene family member. Surprisingly, the deduced hPer4 cDNA has no open reading frame encoding a full-length PER-like protein. This sequence is characterized by numerous deletions, insertions, frame shifts and base pair changes, and its genomic structure is devoid of introns. The presence of an MER-2 mobile element fossil within the Per4 locus predicted that this gene would also be present in non-human primates. Rhesus monkey Per4 displays similar sequence anomalies and is 92.8% identical to hPer4. Sequence comparisons indicate that Per4 originated from a Per3 predecessor and that it is relatively new to the Period gene family. We conclude that hPer4 and RmPer4 are pseudogenes and descended from the retrotransposition of an ancestral Per3 gene.

Field of study: Biology
Idea,education idea and education system——An analysis based on new institutional economics

Education idea plays an important institutional role,but the elites play important roles in education institutional formation and its changes.The elites pass the education to spreads,set up notionally,and acquire social people responses,according to main current education ideas,pushing the construction activity of the education institutional arrangements.In education institutional arrangements of the construction process,exist different types of changing paths: change from the latent opportunity of an education institution for causing improvements of the efficiency;be competed by exterior pressures;the causable education institution changes due to the thought idea inside with target self-contradiction;the causable education institution changes due to ultimate end value in mankind in institutional result violation.

Field of study: Education
PPARγ-Induced Stimulation of Amiloride-Sensitive Sodium Current in Renal Collecting Duct Principal Cells is Serum and Insulin Dependent

Thiazolidinediones (TZDs), such as rosiglitazone or pioglitazone, are peroxisome proliferator-activated receptor gamma (PPARγ) agonists currently used in the treatment of type 2 diabetes. However, their clinical applicability is limited by common and severe side effects including strong water retention, edema and cardiac stroke. The precise mechanisms leading to these disorders are not clearly understood and remain controversial. While the nature of the disorders due to TZDs points to an increase in ENaC-mediated sodium reabsorption in the aldosterone-sensitive distal nephron, some studies suggested that this channel was not targeted by PPARγ agonists.  Mouse cortical collecting duct cells were incubated in different types of culture medium and treated with or without rosiglitazone. Transepithelial Na+ current was measured and the changes in SGK and Nedd4 expression were determined by immunoblotting.  Herein we demonstrate that rosiglitazone stimulates the amiloride-sensitive transepithelial sodium current in Collecting Duct Principal Cells after 3h and 24h treatment. This activation was dependent of both serum and insulin in culture medium and was mediated by SGK1/Nedd4-2 pathway stimulation. In these conditions, rosiglitazone induced SGK1 expression, Nedd4-2 phosphorylation and thus abolished ubiquitylation and internalization of ENaC channels. This mechanism explains most of the side effects of thiazolidinediones previously observed in humans and animals.  Our data show an increase in transepithelial sodium amiloride-sensitive current induced by a PPARγ agonist in presence of serum and insulin, thus confirming some in-vitro and in-vivo experiments while providing explanations for previous conflicting findings.

Field of study: Biology, Chemistry
Development of a 630 kVA Three-Phase HTS Transformer With Amorphous Alloy Cores

This paper describes design and operation of a three-phase HTS power transformer with capacity of 630 kVA operated in liquid nitrogen of 77 K for primary/secondary voltages of 10.5 kV/0.4 kV. The windings were wound by hermetic stainless steel-enforced multifilamentary Bi2223/Ag tapes. The structures of primary and secondary windings are solenoid and double-pancake respectively. Cryostat is made from electrical insulating materials with room temperature bore for commercial amorphous alloy core. Fundamental characteristics of the transformer are obtained by standard short-circuit and no-load tests. The ac losses were calculated and measured by method of conventional transformer. The HTS power transformer successfully operated in a live power grid.

Field of study: Physics
Review of Meetings of the Government of the Russian Federation in 2012

In October 2012, at the meetings of the Presidium of the Government of the Russian Federation the following issues were discussed: organization of a step-by-step provision of state and municipal services on the basis of a “single window” principle; draft Federal Law on Amendment of the Federal Law of the Russian Federation on the Customs Tariff; fulfillment of the forecast plan (program) of privatization of federal property in the 2011–2013 period and measures on limitation of purchasing of shares and interests of business entities by companies with state participation.

Field of study: Economics
High Performance Complementary Circuits Based on p-SnO and n-IGZO Thin-Film Transistors

Oxide semiconductors are regarded as promising materials for large-area and/or flexible electronics. In this work, a ring oscillator based on n-type indium-gallium-zinc-oxide (IGZO) and p-type tin monoxide (SnO) is presented. The IGZO thin-film transistor (TFT) shows a linear mobility of 11.9 cm2/(V∙s) and a threshold voltage of 12.2 V. The SnO TFT exhibits a mobility of 0.51 cm2/(V∙s) and a threshold voltage of 20.1 V which is suitable for use with IGZO TFTs to form complementary circuits. At a supply voltage of 40 V, the complementary inverter shows a full output voltage swing and a gain of 24 with both TFTs having the same channel length/channel width ratio. The three-stage ring oscillator based on IGZO and SnO is able to operate at 2.63 kHz and the peak-to-peak oscillation amplitude reaches 36.1 V at a supply voltage of 40 V. The oxide-based complementary circuits, after further optimization of the operation voltage, may have wide applications in practical large-area flexible electronics.

Field of study: Materials science
Oxidation of S(IV) in Atmospheric Water by Photooxidants and Iron in the Presence of Copper.

We have simulated some of the reactions that result in oxidation of S(IV) and production of secondary photooxidants in cloud droplets, using γ-radiation to generate hydroperoxyl (HO 2 ), superoxide (O 2 - ), and hydroxyl (OH . ) radicals in oxygenated, formate-containing solutions. In the absence of transition metals, HO 2 /O 2 - undergoes disproportionation to form hydrogen peroxide (H 2 O 2 ). S(IV) oxidation can be accounted for entirely by reactions with H 2 O 2 and OH . in such systems, and contrary to earlier reports, the oxidation of S(IV) by HO 2 /O 2 - is unimportant. In solutions containing dissolved Fe, oxidation of S(IV) also occurs through Fe(III)-catalyzed reactions with O 2

Field of study: Environmental science
Research Status and Development Trends of Precision Forging Process for Spiral Bevel Gear

The flow,features and superiority of precision forging process for spiral bevel gears have been described;the precision forging technology for Gears in China and abroad have been introduction;the research status and development trends of precision forging process for spiral bevel gears have been summarized according to the precision forging process,research methods and numerical simulation technology.

Field of study: Materials science