A general multivariate latent growth model with applications in student careers Data warehouses

The evaluation of the formative process in the University system has been assuming an ever increasing importance in the European countries. Within this context the analysis of student performance and capabilities plays a fundamental role. In this work we propose a multivariate latent growth model for studying the performances of a cohort of students of the University of Bologna. The model proposed is innovative since it is composed by: (1) multivariate growth models that allow to capture the different dynamics of student performance indicators over time and (2) a factor model that allows to measure the general latent student capability. The flexibility of the model proposed allows its applications in several fields such as socio-economic settings in which personal behaviours are studied by using panel data.Comment: 20 page

The dynamics of measuring attachment

Comments on the paper by P. R. Shaver and M. Mikulciner (see record 2002-08087-002) about research and assessment related to the psychodynamics of adult attachment. The current authors specifically address the adult attachment interview (AAI) compared with self-report methods in measuring the dynamics of attachment. They noted the benefits of the AAI, but are also persuaded by Shaver and Mikulciner\u27s article that self-reports of adult attachment are predictive of attachment-related dynamic processes. It is suggested that the joint use of self-reports and interviews would provide a useful way to further the study of attachment dynamics

The potential of 1 h refractivity changes from an operational C-band magnetron-based radar for numerical weather prediction validation and data assimilation

Refractivity changes (ΔN) derived from radar ground clutter returns serve as a proxy for near-surface humidity changes (1 N unit ≡ 1% relative humidity at 20 °C). Previous studies have indicated that better humidity observations should improve forecasts of convection initiation. A preliminary assessment of the potential of refractivity retrievals from an operational magnetron-based C-band radar is presented. The increased phase noise at shorter wavelengths, exacerbated by the unknown position of the target within the 300 m gate, make it difficult to obtain absolute refractivity values, so we consider the information in 1 h changes. These have been derived to a range of 30 km with a spatial resolution of ∼4 km; the consistency of the individual estimates (within each 4 km × 4 km area) indicates that ΔN errors are about 1 N unit, in agreement with in situ observations. Measurements from an instrumented tower on summer days show that the 1 h refractivity changes up to a height of 100 m remain well correlated with near-surface values. The analysis of refractivity as represented in the operational Met Office Unified Model at 1.5, 4 and 12 km grid lengths demonstrates that, as model resolution increases, the spatial scales of the refractivity structures improve. It is shown that the magnitude of refractivity changes is progressively underestimated at larger grid lengths during summer. However, the daily time series of 1 h refractivity changes reveal that, whereas the radar-derived values are very well correlated with the in situ observations, the high-resolution model runs have little skill in getting the right values of ΔN in the right place at the right time. This suggests that the assimilation of these radar refractivity observations could benefit forecasts of the initiation of convection

Effects of Solids Removal on Water Quality and Channel Catfish Production in a Biofloc Technology Production System

Total suspended solids control was evaluated in a channel catfish (Ictalurus punctatus) biofloc technology production system. Settling chamber flow rates were 0.9 (LO) or 2.9 (HI) L/min to reduce total suspended solids to 300 mg/L; solids were not removed from control tanks. Channel catfish yields (7.6–8.7 kg/m3) were not affected significantly, but control fish were skewed toward smaller size classes. Control treatment channel catfish tolerated 1,410 mg/L total suspended solids without adverse effects. LO- and HI-treatment fillet geosmin concentrations were high enough to be designated as off-flavor. Water quality results suggested that nitrification was affected by solids removal

Study of techniques and applications of satellite imagery to small scale mapping

There are no author-identified significant results in this report

Effect of Stocking Biomass on Solids, Phytoplankton Communities, Common Off-Flavors, and Production Parameters in a Channel Catfish Biofloc Technology Production System

The effect of initial channel catfish (Ictalurus punctatus, Rafinesque, 1818) fingerling biomass (1.4, 1.8, or 2.3 kg m-3) on phytoplankton communities, common off-flavours and stocker catfish production parameters was evaluated in biofloc technology production tanks. Stocker catfish size (145.5–172.6 g fish-1) at harvest did not differ among treatments, but net yield increased linearly as initial biomass increased (R2 = 0.633). Mean total feed consumption increased linearly with initial catfish biomass (R2 = 0.656) and ranged from 10.7 to 15.8 kg m -3. Total suspended solids (TSS) in all treatments increased linearly with total feed addition, and high TSS appeared to impact negatively daily feed consumption. Initial phytoplankton populations were dominated by small colonial green algae and diatoms, and later transitioned to populations dominated by a small, filamentous cyanobacteria and diatoms. Low, variable concentrations of 2-methylisoborneol and geosmin were present in biofloc tank water during most of the study and two tanks yielded catfish with 2-methylisoborneol or geosmin concentrations that might be classified as off-flavour. One isolate of actinomycete was isolated sporadically from some biofloc tanks, but its abundance was not correlated with 2-methylisoborneol concentration in tank waters. The microbial sources of 2-methylisoborneol and geosmin in biofloc tanks remain unidentified

Assessing the effect of Liquid Petroleum Gas ( LPG ) car conversion system in petrol car by local Artisans in Ghana.

Conversion of petrol to LPG fuelled vehicles is often carried out by mechanics who are not professionally trained in Ghana. Therefore this study was carried out to assess the effects of conversion systems of petrol cars to LPG by local artisans.  Data was collected through three techniques namely observation (i.e. Fifteen LPG installation garages), survey (112 questionnaires) and interviews with LPG installation expert from Don Bosco Training Centre in Tema, and local workshop owners. A total of 112 questionnaires were administered to LPG installation mechanics and drivers sampled randomly from the study area. The study clearly shows that most of the apprenticeship trainings were carried out by unprofessionally trained LPG installers under trees and in open garages which were not standard automobile repair workshops. Most of the vehicles do not have any safety detectors installed in them. According to the drivers, it was very difficult to detect leakage unless they smell the odour of the gas. Keywords: LPG, LPG conversion, Vehicles, Local artisans, Ghan

Evolution of level density step structures from 56,57-Fe to 96,97-Mo

Level densities have been extracted from primary gamma spectra for 56,57-Fe and 96,97-Mo nuclei using (3-He,alpha gamma) and (3-He,3-He') reactions on 57-Fe and 97-Mo targets. The level density curves reveal step structures above the pairing gap due to the breaking of nucleon Cooper pairs. The location of the step structures in energy and their shapes arise from the interplay between single-particle energies and seniority-conserving and seniority-non-conserving interactions.Comment: 9 pages, including 5 figure

Optical Line Width Broadening Mechanisms at the 10 kHz Level in Eu3+:Y2O3 Nanoparticles

We identify the physical mechanisms responsible for the optical homogeneous broadening in Eu3+:Y2O3 nanoparticles to determine whether rare-earth crystals can be miniaturized to volumes less than λ3 whilst preserving their appeal for quantum technology hardware. By studying how the homogeneous line width depends on temperature, applied magnetic field, and measurement time scale the dominant broadening interactions for various temperature ranges above 3 K were characterized. Below 3 K the homogeneous line width is dominated by an interaction not observed in bulk crystal studies. These measurements demonstrate that broadening due to size-dependent phonon interactions is not a significant contributor to the homogeneous line width, which contrasts previous studies in rare-earth ion nanocrystals. Importantly, the results provide strong evidence that for the 400 nm diameter nanoparticles under study the minimum line width achieved (45±1 kHz at 1.3 K) is not fundamentally limited. In addition, we highlight that the expected broadening caused by electric field fluctuations arising from surface charges is comparable to the observed broadening. Under the assumption that such Stark broadening is a significant contribution to the homogeneous line width, several strategies for reducing this line width to below 10 kHz are discussed. Furthermore, it is demonstrated that the Eu3+ hyperfine state lifetime is sufficiently long to preserve spectral features for timescales up to 1 s. These results allow integrated rare-earth ion quantum optics to be pursued at a sub-micron scale and hence, open up directions for greater scaling of rare-earth quantum technology

Assessing the Expression of Astrocytic Markers in Retinal Ganglion Cell Projection of LCR/HCR Rats

Metabolic Syndrome is a human condition that presents with various metabolic issues such as abnormal distribution of body fat, high blood pressure, and a prothrombotic state, among other problems (Alberti,et al, 2005). This syndrome is a risk factor for visual disorders, such as glaucoma, and is often associated with increased levels of neuroinflammation. Currently, the animal model used to replicate this syndrome is The Low Capacity Runner and High Capacity Runner Rat Model. These rats have been bred based on their running capacities for 30+ generations to have drastic metabolic differences. We assessed key areas of the retinal ganglion cell projection (optic nerve, superior colliculus, and retina) and other important thalamic nuclei in Metabolic Syndrome such as the arcuate nuclei and inferior colliculus, in the rats for expression of glial fibrillary acidic protein and Aquaporin 4. We expected to find elevated glial fibrillary acidic protein and Aquaporin 4 in key visual structures of Low Capacity Runner compared to High Capacity Runner rats. We found that in the superior colliculi of the Low Capacity Runner rats there was significantly a greater percent area fraction of glial fibrillary acidic protein than in the High Capacity Runner rats; as there was little Aquaporin 4 staining in many of the regions assessed, that data was inconclusive and it appears Aquaporin 4 plays a negligible role in stress-related changes associated with the Metabolic Syndrome phenotype. In this research, we provide novel evidence that Low Capacity Runner rats express an elevated immune response compared to their High Capacity Runner counterparts and that this response is partially specific to visual structures, as the inferior colliculus, an auditory-related thalamic nuclei, shoed to astroglial differences between High Capacity Runners and Low Capacity Runners. These findings could lead to a better understanding of the metabolic underpinnings of optic neuropathies and present new avenues for their treatment