nils-herrmann/clean_scirepeval huggingface dataset:
Fitting a Semi-Parametric Mixture Model for Competing Risks in Survival Data

A model for survival analysis is studied that is relevant for samples which are subject to multiple types of failure. In comparison with a more standard approach, through the appropriate use of hazard functions and transition probabilities, the model allows for a more accurate study of cause-specific failure with regard to both the timing and type of failure. A semiparametric specification of a mixture model is employed that is able to adjust for concomitant variables and allows for the assessment of their effects on the probabilities of eventual causes of failure through a generalized logistic model, and their effects on the corresponding conditional hazard functions by employing the Cox proportional hazards model. A carefully formulated estimation procedure is presented that uses an EM algorithm based on a profile likelihood construction. The methods discussed, which could also be used for reliability analysis, are applied to a prostate cancer data set.

Field of study: Mathematics
Design considerations for a single tube gamma camera

It is pointed out that many potentially practical applications for nuclear medicine diagnostic procedures are difficult or impossible to perform because of the physical size of existing mobile gamma cameras. With the commercial availability of position sensitive photomultiplier tubes (PSPMTs) the development of an instrument ideally suited to these applications now appears to be practical. The major components necessary to construct such a camera have been tested, and a circuit configuration designed to provide a high level of clinical performance in such a device is proposed. Spatial resolution and linearity data from a developmental prototype are provided. Measurements have shown that by using conventional sum and difference analog circuits only, a 76-mm/sup 2/ PSPMT has good linearity and therefore uniformity of sensitivity over only the central 60% of its absolute field of view. It is believed that this high-quality imaging area can be increased to virtually the full field of view by implementing a digital geometric correction scheme using a position vector lookup table.

Field of study: Physics
Polymer Flexible Joint as a Repair Method of Concrete Elements: Flexural Testing and Numerical Analysis

Polymer Flexible Joint (PFJ) is a method for repairs of concrete elements, which enables carrying loads and large deformations effectively. This article presents the possibility of applying PFJ on beams subjected to bending and describes the influence of such joints on concrete elements. An experimental investigation was conducted to determine the behavior of concrete in a four-point bending test. The research program included flexural tests of plain concrete elements with a notch, as well as tests of elements which were repaired with PFJ after failure. Based on the experimental results, the numerical characteristics of analyzed polymer and concrete were calibrated. A nonlinear numerical model is developed, which describes the behavior of concrete elements and polymer in the experiments. The model is used to numerically analyze deformations and stresses under increasing load. The influence of flexible joint on concrete elements is described and behavior of elements repaired with PFJ is compared to original elements. Particular attention was paid to the stress redistribution in concrete. The application of flexible joint positively influences load capacity of the connected concrete elements. Furthermore, because of stress redistribution, connected elements can bear larger deformations than original ones. PFJ can therefore be considered an efficient repair method for connecting concrete elements.

Field of study: Materials science
Autonomic dysreflexia: recognizing a common serious condition in patients with spinal cord injury.

To raise family physicians' awareness of autonomic dysreflexia (AD) in patients with spinal cord injury (SCI) and to provide some suggestions for intervention.



MEDLINE was searched from 1970 to July 2011 using the terms autonomic dysreflexia and spinal cord injury with family medicine or primary care. Other relevant guidelines and resources were reviewed and used.


MAIN MESSAGE
Family physicians often lack confidence in treating patients with SCI, see them as complex and time-consuming, and feel undertrained to meet their needs. Family physicians provide a vital component of the health care of such patients, and understanding of the unique medical conditions related to SCI is important. Autonomic dysreflexia is an important, common, and potentially serious condition with which many family physicians are unfamiliar. This article will review the signs and symptoms of AD and offer some acute management options and preventive strategies for family physicians.



Family physicians should be aware of which patients with SCI are susceptible to AD and monitor those affected by it. Outlined is an approach to acute management. Family physicians play a pivotal role in prevention of AD through education (of the patient and other health care providers) and incorporation of strategies such as appropriate bladder, bowel, and skin care practices and warnings and management plans in the medical chart.

Field of study: Medicine
Droë-koeibehandeling - deel 1 : langs die drukgang

'n Produsent het my onlangs vertel dat hy dit wel doen, maar hy wou weet hoe ons die koste van droe-koeibehandeling wetenskaplik kan regverdig - ek deel graag my antwoord aan hom ook met die lesers van The Dairy Mail. Deel 1 handel oor die stadiums van die droe periode en in die volgende uitgawe kyk ons na die behandelingsbeginsels.

Field of study: Agricultural and Food sciences
The imbalance of CD4~+ CD25~+ Foxp3~(high) regulatory T cells/Thl7 cells in infant with sepsis

To further explore the pathogenesis of disturbed adaptive immune response in infants with sepsis.  Forty-eight infants with sepsis and 26 age-matched healthy infants were enrolled in this study. The HLA-DR expression of CD14~+ monocyte, the proportion of CD4~+ CD25~+ Foxp3~(high) Tr cells and the proportion of Thl7 cells were measured by flow cytometry. Cytokines (IL-1β, IL-6, TNF-α, IL-10, TGF-β and IL-17A) were measured by ELISA. Real-time PCR were used to evaluate the mRNA levels of Foxp3, ROR-γt in CD4-positive cells and IL-17A. Forty-eight infants with sepsis were divided into two groups according to HLA-DR expression of CD14~+ monocyte: DR-H group ( ＞ 30% ) and DR-L group ( ＜ 30% ).  The ratio of IL-10/TNF-α in DR-L group was higher than that in healthy control or DR-H group(P ＜0.05). The proportion of CD4~+ CD25~+ Foxp3~(high) Tr cells and mRNA expression of transcription factor Foxp3 in DR-L group was found to be significantly higher than that in healthy control or DR-H group(P＜0.05). The proportion of Thl7 cells, Serum concentration of IL-17A, the mRNA expression of IL-17A and transcription factor ROR-γt were significantly increased in DR-H group and DR-L group (P ＜ 0.05) , while there is no significant difference between DR-H and DR-L group( P ＞0.05). Serum levels of Th17-inducing cytokine such as IL-1β, IL-6 were significantly elevated in DR-H group and DR-L group (P＜0.05), while there is no significant difference between DR-H and DR-L group( P＞0.05). Serum level of CD4~+ CD25~+ Foxp3~(high) Tr-inducing cytokine TGF-p in DR-L group was higher than that in DR-H or healthy control group(P＜0. 05).  Over-activation of Th17 cells may be one of the factors causing aberrant increase of pro-inflammatory cytokine/chemotatic factor in infant with sepsis. The imbalance of CD4~+ CD25~+ Foxp3~(high) Tr cells/Th17 cells may be contributed to the pathogenic mechanism of mixed antagonist response syndrome ( MARS) in infant with sepsis. The changes of cytokine environment in infants with sepsis may be one of the factors causing the imbalance of CD4~+ CD25~+ Foxp3~(high) Tr cells/Th17 cells. 
 
 
Sepsis;  HLA-DR;  CD4~+ CD25~+ Foxp3~(high) regulatory T cells;  Thl7 cells;  Infant

Field of study: Biology
Research of dealing EMI modes for 4×2 multi-segment amplifier power system

The paper analyzes several EMI modes during the charging and discharging periods of the power system of the 4×2 multi-segment amplifiers. In order to deal these EMI modes, the methods of grounding one terminal of the capacitor, single grounding of the whole power system, pre-ionization shielding, optic fiber isolation and other measures were adopted. The whole system runs more safely, stably and reliably after adopting these measures.

Field of study: Physics
NUMERICAL SIMULATION OF FALLING FILM EVAPORATION OF BINARY MIXTURE

A model of falling film evaporation of binary mixture on the inside wall of a vertical tube and corresponding numerical Solution are presented.Heat and mass transfer are closely conjugated in this model.The effects of mass transfer on heat transfer are taken into account.It is found that mass transfer significantly affects heat transfer.Neglecting the effects of mass transfer in heat transfer will bring great error for predicting heat transfer coefficient.

Field of study: Chemistry, Environmental science
Decimation in Time and Space of Finite-Difference Time-Domain Schemes: Standard Isotropic Lossless Model

Finite-difference time-domain (FDTD) schemes permit changes in the grid density on selected regions of the wave propagation domain, which can reduce the computational load of the simulations. One possible alternative to varying the spatial density is to change the simulation temporal rate. This idea looks attractive when the wave signals exhibit pronounced bandwidth fluctuations across time. This is particularly true in sound synthesis, where a physically based acoustic resonator can be conveniently modeled using such schemes. To overcome the computational constraints that must be met by real-time distributed resonator models, this paper deals with the decimation in time and space of isotropic lossless finite-difference time-domain schemes holding conventional Nyquist-Shannon limits on the bandwidth of the wave signals. Formulas for the reconstruction of these signals at runtime over the interpolated grid are provided for both the 1D and 2D orthogonal case, depending on the ideal boundary conditions (either Neumann or Dirichlet) holding at each side of the grid in connection with the domain side lengths (either even or odd). Together, the boundaries and size determine the type of Discrete Cosine Transform used in the corresponding interpolation formula. Numerical artifacts arising as a consequence of decimating in space in 2D are discussed in terms of dispersion error and aliasing. Considerations concerning the temporal reconstruction of components lying at the decimated Nyquist frequency are addressed in the conclusion.

Field of study: Engineering
Giulio Genoino.Memoriale dal carcere al Re di Spagna. Ed. and trans. Rosario Villari. Fondazione Luigi Firpo Centro di studi sul pensiero politico: Studi e testi 34. Florence: Leo S. Olschki, 2012. xvi + 64 pp. €14. ISBN: 978-88-222-6227-1.


Field of study: History
Complexation of cadmium by a rhamnolipid biosurfactant.

The potential of microbially-produced surfactants (biosurfactants) to complex heavy metals was investigated in this study. Batch solution studies using a model metal, cadmium, and an anionic monorhamnolipid biosurfactant produced by Pseudomonas aeruginosa ATCC 9027 showed that complexation of the metal and biosurfactantwas rapid and stable and achieved high reductions in the free Cd 2+ concentration. For example 92% of Cd 2+ (0.72 mM) was complexed by 7.3 mM rhamnolipid, and 97% of Cd 2+ (0.36 mM) was complexed by 3.9 mM rhamnolipid. Under the experimental conditions used, the maximum complexation capacity of the rhamnolipid was 0.2 Cd 2+ /rhamnolipid on a molar basis

Field of study: Environmental science
Entrepreneurship Education versus Sustainable Economic Development in 21st Century Africa

Entrepreneurship education constitutes a vital curriculum instrument which could be employed in addressing issues and problems which lead to Economic Development in Africa. As most of our tertiary education grandaunts currently appear to be marginalized in the scheme of socio economic and developmental endeavours in this continent, entrepreneurial skills germane for generating self-employment could be explored as a very good alternative to wage employment. This line of thought could go a long way, not only in arresting the soaring unemployment rate in the Africa but could also contribute in enabling African countries overcome or solve a number of problems or issues which are at stake in the course of our march towards sustainable development. This paper does claim to be conclusive but presents important issues for careful reflection, to provoke discussion on the discourses on the relevancy of entrerpreneuship education to economic development of Africa. The paper is not empirical but it is located in sound knowledge and careful observation within African economic development in a global world as viewed by the writer. The paper raises issues around entrepreneurship education and economic development in Africa. Thus it has examined the concept of entrepreneurship education and its relationship economic development particularly in this age of globalization in Africa. It equally analyses the entrepreneurship role in contending Socio-economic development in African countries and made some recommendation on how to utilise this variable to make African Educational system achieve its Socio-economic aims and objectives and make African Countries grate in the nearest future. Methodically, the paper is a product of careful observation and reflections on direct participation in Higher education production and conclusion from studies in the fields of entrepreneurship education and human values in Africa. DOI: 10.5901/jesr.2014.v4n5p155

Field of study: Education, Sociology
Arginine-Depleting Enzymes – An Increasingly Recognized Treatment Strategy for Therapy-Refractory Malignancies

Arginine auxotrophy occurs in certain tumor types and is usually caused by the silencing of argininosuccinate synthetase 1 or arginine lyase genes. Such tumors are often associated with an intrinsic chemoresistance and thus a poor prognosis. Arginine auxotrophy however renders these tumors vulnerable to treatment with arginine-degrading enzymes. Among the most frequently applied arginine-degrading agents are bacterial arginine deiminases (ADI). The anti-cancerous effects of ADI derived from different bacteria were extensively studied in numerous preclinical cell culture and xenograft models. Mycoplasma-derived ADI-PEG20 is most commonly used and is currently under clinical investigation as a single agent therapeutic as well as in combination with different antineoplastic compounds. Mechanistically, ADI is capable of reducing metabolic activity in tumor cells, contributing to autophagy, senescence and apoptosis in arginine auxotrophic cells. Although clinical trials are promising, the resistance development upon initial treatment response is an increasing challenge. Furthermore, interference of ADI with the tumor microenvironment is poorly understood. In the present review, we outline recent experimental ADI-based treatment approaches and their translation into the clinic. Furthermore, we summarize new insights into the molecular mechanisms underlying the anti-cancer effects of ADI that might facilitate the refinement of ADI-based combination therapy approaches.

Field of study: Biology, Chemistry
Some analytic approximations for neutral stochastic functional differential equations

We consider an analytic iterative method to approximate the solution of a neutral stochastic functional differential equation. More precisely, we define a sequence of approximate equations and we give sufficient conditions under which the approximate solutions converge with probability one and in p th moment sense, p  ⩾ 2, to the solution of the initial equation. We introduce the notion of the Z -algorithm for this iterative method and present some examples to illustrate the theory. Especially, we point out that the well-known Picard method of iterations is a special Z -algorithm.

Field of study: Mathematics
MODELING OF SUGARBEET QUALITY VARIABLES FROM CANOPY SPECTRAL INDICES IN A FERTILITY TRIAL

Sugarbeet quality varies inversely with N fertility, while gross yield varies positively with N. Existing models of 
yield from remotely sensed data do not consider crop quality. A fertility trial was used as the basis for a canopy reflectance 
study to correlate quality variables to canopy characteristics. Sugarbeet canopy reflectance and radiance were measured with 
a portable spectroradiometer, and from airborne images of the trial plots. Canopy data were collected five times from early 
August to early October of 1999. Linear regression models were used to correlate canopy indices to sugarbeet quality 
variables on each date. Both a green NDVI and the conventional NDVI indices showed strong correlation to recoverable 
sucrose concentration in sugarbeet roots. Correlations to harvest quality in October were highest in spectral measurements 
taken in early to mid–August. Other quality variables including root concentrations of sodium, potassium, and amino–N were 
poorly correlated to spectral properties of the canopy. The results suggest that a single image of a field in August could provide 
spatial indication of variability in root quality.

Field of study: Agricultural and Food sciences
Continuous affinity-based selection: rapid screening and simultaneous amplification of bacterial surface-display libraries.

A new method for continuous biopanning has been developed. We have combined the power of affinity chromatography with the fecundity of bacteria in a unique process that mimics clonal selection. Mixed populations of bacteria were applied to a fermenter containing the immobilized ligand of interest. Bacteria retained in this affinity fermenter were allowed to grow under continuous washout conditions, such that weakly bound organisms were selectively lost. Those initially rare founder bacteria expressing a receptor for the immobilized ligand (R+ve) were thus enriched and amplified simultaneously. From an initial culture containing 1 x 10(10) R-ve cells spiked with fewer than 30 R+ve bacteria (<1 in 10(8)), final ratios of R+ve/R-ve bacteria as high as 1 in 12 were observed, representing an enrichment factor of 55 million-fold. This technology has considerable potential for rapid screening of bacterial surface-display libraries and in facilitating directed-evolution studies.

Field of study: Biology, Computer science
New constructions of fuzzy identity-based encryption

In this paper we construct two new fuzzy identity-based encryption (IBE) schemes in the random oracle model. Not only do our schemes provide public parameters whose size is independent of the number of attributes in each identity (used as public key) but they also have useful structures which result in more efficient key extraction and/or encryption than the random oracle version of Sahai and Water's fuzzy IBE scheme, considered recently by Pirretti et al. We prove that the confidentiality of the proposed schemes is relative to the Bilinear Decisional Bilinear Diffie-Hellman problem.

Field of study: Computer science, Mathematics
The hypoglycemic mechanism of catalpol involves increased AMPK-mediated mitochondrial biogenesis

Mitochondria serve as sensors of energy regulation and glucose levels, which are impaired by diabetes progression. Catalpol is an iridoid glycoside that exerts a hypoglycemic effect by improving mitochondrial function, but the underlying mechanism has not been fully elucidated. In the current study we explored the effects of catalpol on mitochondrial function in db/db mice and C2C12 myotubes in vitro. After oral administration of catalpol (200 mg·kg −1 ·d −1 ) for 8 weeks, db/db mice exhibited a decreased fasting blood glucose level and restored mitochondrial function in skeletal muscle. Catalpol increased mitochondrial biogenesis, evidenced by significant elevations in the number of mitochondria, mitochondrial DNA levels, and the expression of three genes associated with mitochondrial biogenesis: peroxisome proliferator-activated receptor gammaco-activator 1 (PGC-1α), mitochondrial transcription factor A (TFAM) and nuclear respiratory factor 1 (NRF1). In C2C12 myotubes, catalpol significantly increased glucose uptake and ATP production. These effects depended on activation of AMP-activated protein kinase (AMPK)-mediated mitochondrial biogenesis. Thus, catalpol improves skeletal muscle mitochondrial function by activating AMPK-mediated mitochondrial biogenesis. These findings may guide the development of a new therapeutic approach for type 2 diabetes.

Field of study: Biology, Chemistry, Medicine
A view from inside iron-based superconductors

Muon spin spectroscopy is one of the most powerful tools to investigate the microscopic properties of superconductors. In this paper, an overview on some of the main achievements obtained by this technique in iron-based superconductors (IBS) are presented. It is shown how the muons allow to probe the whole phase diagram of IBS, from the magnetic to the superconducting phase, along with their sensitivity to unravel the modifications of the magnetic and the superconducting order parameters, as the phase diagram is spanned either by charge doping, by an external pressure or by introducing magnetic and non-magnetic impurities. Moreover, it is highlighted that the muons are unique probes for the study of the nanoscopic coexistence between magnetism and superconductivity taking place at the crossover between the two ground-states.

Field of study: Physics
Quaternary Sedimentation on the Amazon Continental Margin: A Model

Sedimentation on the Amazon continental margin occurred in two distinct patterns during the Quaternary Period. During interglacials, when sea level was high (as at present), most of the sediment contributed by the Amazon River was deposited near the river mouth, then transported northwest along the innermost shelf by longshore currents. Apparently, little Amazon sediment escaped the nearshore environment. As sea level fell in response to glacial advance, the sedimentation pattern remained roughly similar, resulting in construction of an extensive prograding shoreline. Once the sea fell more than −60 to −80 m relative to present sea level, however, most Amazon sediment was channeled directly to the deep sea. Shoreline accretion stopped, but prograded sediments were preserved as a mud wedge that presently occupies the inner shelf seaward of the Amazon River. This model also explains the accumulation of large quantities of arkosic sands throughout the western Equatorial Atlantic deep sea during Pleistocene glacial epochs. These arkosic sediments appear to have been derived mostly from the Andes Mountains via the Amazon River.

Field of study: Geology