Search results for "Scale"
showing 10 items of 5180 documents
Biology and behavior of Metaphycus angustifrons Compere (Hymenoptera: Encyrtidae), a newly discovered parasitoid of soft scale insects (Hemiptera: Co…
2011
Abstract Metaphycus angustifrons Compere has recently been found to be the most abundant parasitoid of brown soft scale, Coccus hesperidum L., in southern California. In laboratory experiments we examined several biological parameters of this species. M. angustifrons both oviposits and host feeds in brown soft scale and is a facultatively gregarious endoparasitoid of this soft scale insect. In contrast with other Metaphycus spp., M. angustifrons is a koinobiont parasitoid, allowing its host to grow up to 40% beyond its size at parasitism. Despite its high abundance on brown soft scale in the field, in the laboratory, high rates of parasitoid egg encapsulation are observed; about half of par…
Convergence et divergence comparées du salaire des enseignants du primaire dans l'échelle de développement économique
2008
Remunerations for primary teachers along the scale of economic development: convergence or divergence ?The relative distribution of wages at the aggregate level, without reference to individual characteristics, is linked both to structural aspects in local labour markets and the burden of history that makes that profession remains paid differently as compared to others. The teaching profession for the primary school has several characteristics of interest, it is a common profession, nearly one percent of labour force and whose conditions and qualifications are relatively close around the world. This text is dedicated to measure the relative pay off for teachers. Mainly, the position for a n…
Scale in ferro e ghisa. Esperienze costruttive tra ottocento e novecento
2016
A partire dalla seconda metà dell’Ottocento l’impiego delle scale in ferro ebbe in molti Paesi largo consenso e diffusione. Nuove esigenze abitative spinsero alla ricerca di soluzioni tecnologiche poco invasive, soprattutto per quelle strutture – quali i collegamenti verticali metallici – che potevano facilmente essere inserite nell’edilizia esistente, e che comportavano un contenuto ingombro volumetrico, oltre che minimi accorgimenti per l’ancoraggio alle strutture murarie. Nel Settecento si assistette ad una realizzazione di collegamenti verticali metallici piuttosto limitata, e molto più frequenti furono spesso le strutture miste in legno e ferro, nelle quali – comunque – il primo aveva …
Measuring soil erosion by field plots: Understanding the sources of variation
2006
Soil erosion plots of different types and sizes are widely used to investigate the geomorphological processes related to soil erosion. This field method has provided a variety of results, depending on the characteristics of the plots, on their suitability to reflect the ecosystem's characteristics and on the objectives of each particular research. The coupling of real soil loss at patch and slope scale within a landscape and the values obtained by field plots depend, among other things, on how good the methodology performs over a set of ecosystem properties, such as those related with temporal and spatial scale issues, disturbance and representation of natural conditions, and the ability to…
Le scale in pietra a vista nel Mediterraneo
2013
Il tema delle scale, apparentemente marginale, possiede un fascino del tutto peculiare: si tratta, infatti, di un ambito dove la ricerca formale si accompagna quasi sempre alla sapienza costruttiva. Nel Mediterraneo, dove le fabbriche in pietra a vista costituiscono una prassi diffusa e di lunga durata, le scale possono essere un significativo termometro per misurare il valore delle tradizioni e il ruolo delle invenzioni; i casi presentati in questa sede da studiosi di diversa provenienza confermano una plurisecolare consuetudine costruttiva, che accomuna tanti luoghi geograficamente distanti: il Levante iberico, l’Italia meridionale e diverse isole tra cui la Sicilia e Malta.
Deriving scaling laws in geodynamics using adjoint gradients
2018
Abstract Whereas significant progress has been made in modelling of lithospheric and crustal scale processes in recent years, it often remains a challenge to understand which of the many model parameters is of key importance for a particular simulation. Determining this is usually done by manually changing the model input parameters and performing new simulations. For a few cases, such as for folding or Rayleigh-Taylor instabilities, one can use thick-plate stability analysis to derive scaling laws to obtain such insights. Yet, for more general cases, it is not straightforward to do this (apart from running many simulations). Here, we discuss a numerically cheaper approach to compute scalin…
Aging in a free-energy landscape model for glassy relaxation
2005
The aging properties of a simple free-energy landscape model for the primary relaxation in supercooled liquids are investigated. The intermediate scattering function and the rotational correlation functions are calculated for the generic situation of a quench from a high temperature to below the glass transition temperature. It is found that the re-equilibration of molecular orientations takes longer than for translational degrees of freedom. The time scale for re-equilibration is determined by that of the primary relaxation as an intrinsic property of the model.
A Study on scale factor in distributed differential evolution.
2011
This paper proposes the employment of multiple scale factor values within distributed differential evolution structures. Four different scale factor schemes are proposed, tested, compared and analyzed. Two schemes simply employ multiple scale factor values and two also include an update logic during the evolution. The four schemes have been integrated for comparison within three recently proposed distributed differential evolution structures and tested on several various test problems. Numerical results show that, on average, the employment of multiple scale factors is beneficial since in most cases it leads to significant improvements in performance with respect to standard distributed alg…
Psychometric analysis of the Scale of Teacher's Perception of School Adjustment (PROF-A)
2015
La percepción del profesor del ajuste escolar de sus alumnos puede ser un importante indicador de su bienestar psicosocial y aportar información útil para el desarrollo de intervenciones encaminadas a mejorar su ajuste psicosocial. No obstante, para ello es fundamental considerar dentro del ajuste escolar no sólo el rendimiento académico del alumno sino también su nivel de integración social en el aula, la calidad de su relación con el profesor y el grado de implicación familiar en su educación. El objetivo de esta investigación es aportar un instrumento fiable para una medición completa del ajuste escolar y analizar su relación con dos importantes indicadores de ajuste psicosocial, el auto…
A multinational study exploring adolescent perception of school climate and mental health.
2021
School climate is a topic of increasing importance internationally. The current study investigated the established measurement invariance of an eight-factor school climate scale using a multinational sample of secondary students. School climate factor means across 14 international groups were compared and findings on the association between school climate factors and mental health were also investigated. Findings, from this study, illustrate several cross-national similarities regarding the ways in which secondary students perceive school climate and the influence of school climate on student mental health. These findings can support school psychologists' efforts to identify strategies and …