Miracle-dz/UniFAR-FTUs huggingface dataset:
Principal Eigenvalues and Anti – Maximum Principle for Some Quasilinear Elliptic Equations on ℝN

We improve some previous existence and nonexistence results for positive principal eigenvalues of the problem —Δpu = λg(x)ψp(u), x ∈ ℝN, lim‖x‖+∞u(x) = 0. Also we discuss existence, nonexistence and antimaximum principle questions concerning the perturbed problem —Δpu = λg(x)ψp(u) + f(x), x∈ ℝN.
In situ and remote‐sensing measurements of the mean microphysical and optical properties of industrial pollution aerosol during ADRIEX

We present a summary of the principal physical and optical properties of aerosol particles using the FAAM BAE‐146 instrumented aircraft during ADRIEX between 27 August and 6 September 2004, augmented by sunphotometer, lidar and satellite retrievals. Observations of anthropogenic aerosol, principally from industrial sources, were concentrated over the northern Adriatic Sea and over the Po Valley close to the aerosol sources. An additional flight was also carried out over the Black Sea to compare east and west European pollution. Measurements show the single‐scattering albedo of dry aerosol particles to vary considerably between 0.89 and 0.97 at a wavelength of 0.55 µm, with a campaign mean within the polluted lower free troposphere of 0.92. Although aerosol concentrations varied significantly from day to day and during individual days, the shape of the aerosol size distribution was relatively consistent through the experiment, with no detectable change observed over land and over sea. There is evidence to suggest that the pollution aerosol within the marine boundary layer was younger than that in the elevated layer. Trends in the aerosol volume distribution show consistency with multiple‐site AERONET radiometric observations. The aerosol optical depths derived from aircraft measurements show a consistent bias to lower values than both the AERONET and lidar ground‐based radiometric observations, differences which can be explained by local variations in the aerosol column loading and by some aircraft instrumental artefacts. Retrievals of the aerosol optical depth and fine‐mode (<0.5 µm radius) fraction contribution to the optical depth using MODIS data from the Terra and Aqua satellites show a reasonable level of agreement with the AERONET and aircraft measurements. © Crown Copyright 2007. Reproduced with the permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd
Resilient Leaders: Resilient Determinants When Entering Principalship

The study examines factors that boost principals’ sense of resilience in their first year, as well as those that undermine it. 61 interviews were conducted with 21 school principals from five different districts throughout their first year in the role. Analysis revealed five categories of resilience-undermining factors. (1) Work overload that creates a sense of stress; (2) Difficulties in dealing with key players; (3) Lack of administrative knowledge; (4) Acceptance or rejection by the staff; and (5) Coping with the Covid-19 crisis. The analysis also revealed five categories of resilience-boosting factors: (1) Growth resulting from biographical events; (2) Short-term successes; (3) Supportive environment; (4) Drawing strength from the student environment; and (5) Acceptance by the staff. This study proposes ways of coping with the challenges of principalship through the prism of the resilience determinants of principals when entering their role.
Systematic errors of skin-friction measurements by oil-film interferometry

In recent years, the independent measurement of wall shear stress with oil-film or oil-drop interferometry has become a cornerstone of turbulent-boundary-layer research as many arguments depend critically on a precise knowledge of the skin friction ${\it\tau}_{w}^{\ast }$ . To our knowledge, all practitioners of oil-drop interferometry have so far used the leading-order similarity solution for asymptotically thin, wedge-shaped, two-dimensional oil films established by Tanner & Blows (J. Phys. E: Sci. Instrum., vol. 9, 1976, pp. 194–202) to relate the evolution of drop thickness to ${\it\tau}_{w}^{\ast }$ . It is generally believed that this procedure, if carefully implemented, yields the true time-averaged ${\it\tau}_{w}^{\ast }$ within $\pm 1\,\%$ or possibly better, but the systematic errors due to the finite thickness of the oil film have never been determined. They are analysed here for oil films with a thickness of the order of a viscous unit in a zero-pressure-gradient turbulent boundary layer. Neglecting spanwise surface curvature and surface tension effects, corrections due to the secondary air boundary layer above the oil film are derived with a linearised triple-layer approach that accounts for the turbulent shear-stress perturbation by means of modified van-Driest-type closure models. In addition, the correction due to processing oil drops with a slight streamwise surface curvature as if they were exact wedges is quantified. Both corrections are evaluated for oil-drop interferograms acquired in a zero-pressure-gradient turbulent boundary layer at a Reynolds number of around 3500, based on displacement thickness, and are shown to produce a reduction of the friction velocity relative to the basic Tanner and Blows theory of between $-0.1\,\%$ and $-1.5\,\%$ , depending on the mixing-length model. Despite the uncertainty about the true correction, the analysis allows the formulation of some guidelines on where and when to analyse interference fringes in order to minimise the error on the measured wall shear stress.
Inference When a Nuisance Parameter Is Not Identified under the Null Hypothesis

Many econometric testing problems involve nuisance parameters which are not identified under the null hypotheses. This paper studies the asymptotic distribution theory for such tests. The asymptotic distributions of standard test statistics are described as functionals of chi-square processes. In general, the distributions depend upon a large number of unknown parameters. We show that a transformation based upon a conditional probability measure yields an asymptotic distribution free of nuisance parameters, and we show that this transformation can be easily approximated via simulation. The theory is applied to threshold models, with special attention given to the so-called self-exciting threshold autoregressive model. Monte Carlo methods are used to assess the finite sample distributions. The tests are applied to U.S. GNP growth rates, and we find that Potter's (1995) threshold effect in this series can be possibly explained by sampling variation.
Inclusive social norms and nationals’ positive intergroup orientations toward refugees: The moderating role of initial prejudice and intergroup contact

Research on the interplay between inclusive norms and intergroup contact on improving intergroup orientations has yielded conflicting results, suggesting either that an experience of personal contact is necessary to have a positive effect of inclusive norms or that such personal experience is not always necessary. To clarify this issue, across four studies (N = 835), we investigated the influence of inclusive norms on positive intergroup orientations as a function of personal experiences of intergroup contact. Study 1 demonstrated that inclusive norms are more strongly correlated with experiences of personal contact with outgroups with whom opportunities of contact are more (i.e., immigrants) than less (i.e., refugees) frequent. Study 2 provided experimental evidence for this finding showing that inclusive norms increase prejudiced nationals’ willingness to engage in future contact with immigrants but not with refugees, suggesting that conformity to inclusive norms depends on varying contact opportunities with the outgroups. Studies 3 and 4 confirmed that prejudiced nationals conformed to inclusive norms specifically when experienced positive contact with a refugee (experimentally induced with the imagined contact paradigm), compared with no contact (Study 3) or negative contact (Study 4). We discuss the implications of these findings for research on intergroup contact, social influence, and intergroup relations.
Examining the Cross-Cultural Validity of the MUSIC Model of Academic Motivation Inventory in English Language Courses

This study examined whether the five scales of the MUSIC Model of Academic Motivation Inventory produced valid scores when used in university English language courses across four different countries. We surveyed 1,147 students in English language courses in Iran, Mexico, China, and Egypt and analyzed their responses by performing measurement invariance testing using multiple group confirmatory factor analysis. The internal consistency reliability of the five MUSIC Inventory scales was acceptable. The configural, metric, and scalar invariance held across the four countries, providing evidence of construct validity for the five scales. Relationships between the MUSIC Inventory scales and measures of behavioral engagement, disaffection, and achievement provided some evidence of criterion validity, but some inconsistencies with expected relationships were noted. Overall, this study provides validity evidence for using the inventory in English language courses.
Effect of glow discharge air plasma on grain crops seed

Oat and barley seeds have been exposed to both continuous and pulsed glow discharge plasmas in air to investigate the effects on germination and sprout growth. Statistical analysis was used to evaluate the effect of plasma exposure on the percentage generation and length of sprout growth. A stimulating effect of plasma exposure was found together with a strong dependence on whether continuous or pulsed discharges were used.
Machine learning model for building seismic peak roof drift ratio assessment

Abstract The peak roof drift ratio is one of the most important engineering parameters to describe the expected seismic damage in a building. A predictive model of the drift ratio was developed using a machine learning approach (Gaussian process regression model) on a dataset of approximately 11,800 records from 34 monitored buildings in Japan. Four predictors for ground motion and three predictors for building vulnerability are used in the machine-learning modelling. The residual analysis shows a reduction of 50% compared to the state of the art. The Gaussian process regression model is applied in a second analysis on an original dataset of approximately 4,500 records for 127 monitored buildings in Italy. A satisfactory comparison emerges by comparing the drift ratio prediction map with the observed damage pattern produced by satellite imagery for a test site in central Italy after the 2009 earthquake. The drift ratio map plays an important role in the simulation of an earthquake scenario at regional scale, which is needed by Civil Protection for emergency planning and management activities.
Intraoperative Scoring System to Assess the Difficult Laparoscopic Cholecystectomy: A Prospective Study From a Tertiary Care Centre

Background In comparison to a traditional cholecystectomy (open), the laparoscopic cholecystectomy approach provides a number of benefits and has been demonstrated in some studies to have a greater complication rate. The conversion rate from laparoscopic to open surgery ranged between 2% and 15%. A preoperative scoring or grading system (based on age, sex, history, clinical examination, laboratory, and sonographic results) was developed by Nassar et al., to anticipate the challenge of laparoscopic cholecystectomy. So, we conducted this study to assess the degree of difficulty in faced during laparoscopic cholecystectomy using an intraoperative scoring system and validate the same using the preoperative scoring system. Methods We conducted this study in the department of General Surgery among 105 patients who underwent laparoscopic cholecystectomy during the defined study period of one year. We performed the preoperative workup for all patients. A preoperative scoring or grading system developed by Nassar et al., in 2020 was used. In our study, laparoscopic cholecystectomy was performed by surgeons having a minimum of eight years of hands-on experience in laparoscopic surgeries. An intraoperative scoring or grading system for the degree of difficulty during laparoscopic cholecystectomy, developed by Sugrue et al., in 2015 was used. The Chi-square test was applied to assess the association between preoperative variables and the intraoperative score grading. We have also performed the receiver operating characteristic (ROC) curve analysis to validate the preoperative score in predicting the intraoperative findings. All tests were considered statically significant if the p-value was < 0.05. Results In our study, a total of 105 patients were included in the study and the mean age of patients was 57.6±16.4 years. The male patients were 58.1% and the remaining 41.9% were females. The primary diagnosis was cholecystitis among 44.8% of patients and 2.9% of patients were diagnosed with pancreatitis. Among enrolled patients, laparoscopic cholecystectomy was done on an emergency basis among 2.9% of subjects. During the laparoscopic cholecystectomy, among 21.0% and 30.5% of patients, there was a severe and extreme degree of difficulty respectively. In our study, the conversion rate from laparoscopic to open cholecystectomy was 8.6%. In our study, we found that at a preoperative score of 6, the sensitivity and specificity for predicting easy cases were 88.2% and 73.8%, respectively, and had an accuracy of 88.6% for easy cases and 68.5% for difficult cases. Conclusion When grading the difficulties of doing a laparoscopic cholecystectomy and determining the severity of cholecystitis, this intraoperative scoring system is effective and accurate. Additionally, it signifies the need for conversion from laparoscopic to open cholecystectomy in cases of severe cholecystitis.
Evidence for nonzero mass photons associated with a vacuum-induced dissipative red-shift mechanism

Laboratory observations that suggest a frequency anisotropy in the direction of the Leo constellation of delta nu / nu >or=10/sup -6/ can be interpreted in terms of a nonzero photon mass m/sub gamma / equivalent to 10/sup -65/ g. If one then accepts the theory of light (considered as real Maxwellian waves and photons simultaneously) of Einstein and de Broglie, the experimental justification of the existence of real Maxwellian displacement currents implies the existence of m/sub gamma />0 and of a vacuum dissipative mechanism which can interpret a part (or the totality) of Hubble's cosmological red shift. >
H∞ type problem for sampled-data control systems-a solution via minimum energy characterization

This paper aims at deriving a solution for H/sub /spl infin// type problem for sampled-data control systems. The solution is given in terms of an equivalent discrete-time H/sub /spl infin// problem. The reduction procedure is viewed and characterized from the viewpoint of minimum energy principle and J-unitary transformations. >
Cestode parasites of the Australian bustard, Ardeotis australis (Gray) (Aves: Gruiformes)

ABSTRACT Examination of museum collections of cyclophyllidean cestodes (families Paruterinidae and Davaineidae) from the Australian bustard, Ardeotis australis (Gray) (Aves: Gruiformes), revealed the presence of five species not previously reported from Australia: Ascometra vestita Cholodkovsky, 1912, Idiogenes kolbei Ortlepp, 1938, I. kori Ortlepp, 1938, I. nana Fuhrmann, 1925 and I. otidis Krabbe, 1868. All are known from a variety of genera and species of bustards from Africa and Eurasia. Minor differences were noted in the morphology of I. kori and I. nana from published descriptions, but these differences may be due to intraspecific variation.
A comparative analysis of two cash transfer programmes on how they influence the citizenship rights of beneficiaries.

Abstract In Ghana, barriers faced by people living in poverty exceed their ability to meet their daily needs. An effective way of addressing these barriers can be achieved by improving the uptake of citizenship rights among them. This article aims to determine whether cash transfer programmes promote the taking up of citizenship rights among beneficiaries. The article also examines the impact of conditions on the uptake of citizenship rights by the beneficiaries of cash transfer programme. Data collected from the field were used for this study. The results highlight how cash transfer programmes promote uptake of citizenship rights among beneficiaries. The research also shows that conditionality promotes the taking up of human capital development activities. These results make known that monitoring and enforcement of conditions have a higher effect on the promotion of uptake of citizenship rights among beneficiaries than non-enforcement.
An efficient method of solving the Navier–Stokes equations for flow control

A new method of solving the Navier–Stokes equations efficiently by reducing their number of modes is proposed in the present paper. It is based on the Karhunen–Loeve decomposition which is a technique of obtaining empirical eigenfunctions from the experimental or numerical data of a system. Employing these empirical eigenfunctions as basis functions of a Galerkin procedure, one can a priori limit the function space considered to the smallest linear subspace that is sufficient to describe the observed phenomena, and consequently reduce the Navier–Stokes equation defined on a complicated geometry to a set of ordinary differential equations with a minimum degree of freedom. The present algorithm is well suited for the problems of flow control or optimization, where one has to compute the flow field repeatedly using the Navier–Stokes equation but one can also estimate the approximate solution space of the flow field based on the range of control variables. The low-dimensional dynamic model of viscous fluid flow derived by the present method is shown to produce accurate flow fields at a drastically reduced computational cost when compared with the finite difference solution of the Navier–Stokes equation. © 1998 John Wiley & Sons, Ltd.
Distance and presence in interdisciplinary online learning. A challenge-based learning course on sustainable cities of the future

ABSTRACT Addressing complex sustainability issues in higher education requires the combination and integration of various disciplines, perspectives and approaches. Challenge-Based Learning (CBL) can support interdisciplinary collaboration on sustainability issues. It requires students to actively explore, discuss, reflect on and integrate information and methods from various disciplines. Online learning could enhance interdisciplinary collaboration since it is associated with greater geographical and educational flexibility and accessibility. Applying an active learning approach such as CBL in an online setting is believed to support interdisciplinary learning and collaboration. We present a case study that took place in a 10-week online interdisciplinary, inter-university undergraduate course on sustainability education. Our research is based on well-known online learning theories “Transactional distance” and “Community of Inquiry” (CoI). The aim of this study was to investigate how transactional distance, presence and (online) interdisciplinary learning are perceived by students. 23 undergraduate students from three universities were enrolled in the course. Quantitative survey data (N = 13) and qualitative data from student reflection papers and interviews (N = 15) were collected. Students perceived low levels of transactional distance and high levels of presence. Unexpectedly, a small increase in perceived distance between students was measured which could be explained by reported limitations of the course design. Students valued the open, interactive and creative character of the course and the online format was not perceived as hindering. Students reflected on interdisciplinary competences that they developed during the course. This study is a first step towards future national as well as international interdisciplinary, inter-university educational collaboration on sustainability issues.
Neuroprotective effect of quercetin and Zingiber officinale on sodium arsenate‐induced neurotoxicity in rats

Abstract The study was aimed at determining the ameliorative potential of quercetin and Zingiber officinale (ZO) against sodium arsenate‐induced neurotoxicity in male Wistar rats. Thirty adult animals were randomly allocated to five groups (n = 6). Group I served as control, groups II and IV were treated with ZO [300 mg/kg, PO (per os)/day], and group V animals were administered quercetin (50 mg/kg, PO/day) for 18 days. Groups III, IV, and V were injected with sodium arsenate (20 mg/kg, intraperitoneally/day) for 4 days starting from day 15. The administration of sodium arsenate resulted in a significant decrease in total antioxidant status, total thiols, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and aryl esterase in brain tissue of the animals compared with the control group. In addition, a significant increase was observed in malondialdehyde, advanced oxidation protein product and plasma nitric oxide levels, indicating oxidative stress‐mediated neuronal damage. However, these arsenic‐induced alterations were significantly reversed by quercetin or ZO in the treatment groups, indicating their ameliorative potential. These positive effects were further confirmed by histopathological examination of brain tissue revealing the suppression of severe neuronal injury, spongiosis and gliosis in the samples pretreated with quercetin and ZO. Our results suggest that inclusion of ZO and quercetin‐rich foods in the diet can help in preventing the neurotoxic effects in areas with elevated levels of arsenic in food chain and ground water.
Empirical bootstrap bias correction and estimation of prediction mean square error in small area estimation

We develop a method for bias correction, which models the error of the target estimator as a function of the corresponding estimator obtained from bootstrap samples, and the original estimators and bootstrap estimators of the parameters governing the model fitted to the sample data. This is achieved by considering a number of plausible parameter values, generating a pseudo original sample for each parameter and bootstrap samples for each such sample, and then searching for an appropriate functional relationship. Under certain conditions, the procedure also permits estimation of the mean square error of the bias corrected estimator. The method is applied for estimating the prediction mean square error in small area estimation of proportions under a generalized mixed model. Empirical comparisons with jackknife and bootstrap methods are presented. Copyright 2012, Oxford University Press.
A Simple Proof of an Identity Concerning Pfaffians of Skew Symmetric Matrices

Abstract In the present paper we prove an identity concerning Pfaffians similar to the well-known Grassmann-Plucker relations for determinants, using tools from multilinear algebra. More precisely, we shall derive the identity as a corollary to an equation concerning skew-symmetric bilinear forms and operators, acting on the exterior algebra Λ ( M ) of an R -module M over some fixed commutative ring R with 1 ∈ R .
UBVRI photometry of the Durham-AAT redshift survey

Using the PDS microdensitometer at the R oyal Greenwich Observatory, we have acquired U, B, V, R and I surface photometry from UK Schmidt photographic plates for all the galaxies with measured redshifts in the Durham ‐AAT redshift survey. By comparison with CCD photometry we show that such precision photographic photometry of galaxies off IIIa emulsions is capable of an accuracy as good as a few hundredths of a magnitude. We discuss the colour-related properties of these galaxies, and derive luminosity functions in each waveband. We show that when divided by colour, the faint-end slope of the luminosity function of the bluer galaxies is significantly steeper than that for the redder ones.