Enabling Outcomes for Students with Developmental Disabilities through Collaborative Consultation

Collaborative consultation has been widely adopted in school-based occupational therapy practice; however, limited research has examined how collaboration between educators and occupational therapists contributes to students’ outcomes. The purpose of this study was to describe the nature of collaborative working in two cases of school-based occupational therapy service delivery. This paper reports a cross-case analysis, comparing findings about the nature of a joint effort in each case study to identify workplace practices that facilitated educator-occupational therapist collaboration. Ethnographic case study methods (Stake, 1995; Wolcott, 2008) and socio-cultural activity theory (SCAT; Engeström, 2001) were used to examine multiple perspectives concerning school-based occupational therapy collaborative consultation for two students with developmental disability in one region of Ontario, Canada. Cross-case analysis (Stake, 2006) facilitated examination of the similarities and differences in teamwork. Specific ways that educator-occupational therapist collaboration can be facilitated were identified in three areas: (a) focus for educational programming; (b) communication practices; and (c) leadership practices of educators. SCAT provided a robust framework for describing the depth, quality, and context of interactions from multiple stakeholder perspectives. As such, this research contributes to the development of theoretical and empirical perspectives on the processes of collaborative working and the relationship of these processes to outcomes

Momentum space tomographic imaging of photoelectrons

We apply tomography, a general method for reconstructing 3-D distributions from multiple projections, to reconstruct the momentum distribution of electrons produced via strong field photoionization. The projections are obtained by rotating the electron distribution via the polarization of the ionizing laser beam and recording a momentum spectrum at each angle with a 2-D velocity map imaging spectrometer. For linearly polarized light the tomographic reconstruction agrees with the distribution obtained using an Abel inversion. Electron tomography, which can be applied to any polarization, will simplify the technology of electron imaging. The method can be directly generalized to other charged particles.Comment: Accepted by J. Phys.

The humanitarian emergency in Burundi: evaluation of the operational strategy for management of nutritional crisis

AbstractObjectiveTo evaluate the impact and appropriateness of programmes for the management and treatment of severe malnutrition in emergency situations.DesignA central unified database was set up with all data and statistics provided by nutritional centres (NC) active in Burundi.SettingThe paper describes the case of Burundi as an example of the response of the humanitarian community to nutritional crisis.SubjectsSince 1999, more than one million (1 054 210) severely malnourished patients were treated in NC established in Burundi.ResultsPeaks of beneficiaries were registered in 2000 and 2001; the admission rate started to decrease in 2002. In 2004, twenty therapeutic feeding centres (TFC) and 224 supplementary feeding centres (SFC) were active for the treatment of 127 420 beneficiaries. Nutritional programmes were present in every province with a coverage rate of 55 %. The most convincing impact of the nutritional programme in Burundi was the reduction of mortality rate in children under 5 years of age; an impact on the prevalence of acute malnutrition could not be demonstrated. Children under 5 years old accounted for 62 % of beneficiaries in TFC and 76 % in SFC. TFC performance indicators fulfilled the minimum standards in disaster response; the performance of SFC was not so optimal with a low recovery rate (69 % v. >80 %) and a high non-respondent rate (16 % v. <5 %). With the combination of coverage and cure rate, the programme met 44 % of the assessed needs in 2004.ConclusionsIn Burundi the stabilisation of security conditions permitted a combination of humanitarian responses ranging from emergency activities to strengthening of community-based initiatives that could correct the coverage and impact limitations

Alignment dependent enhancement of the photo-electron cutoff for multi-photon ionization of molecules

The multiphoton ionization rate of molecules depends on the alignment of the molecular axis with respect to the ionizing laser polarization. By studying molecular frame photo-electron angular distributions from N$_2$, O$_2$ and benzene, we illustrate how the angle-dependent ionization rate affects the photo-electron cutoff energy. We find alignment can enhance the high energy cutoff of the photo-electron spectrum when probing along a nodal plane or when ionization is otherwise suppressed. This is supported by calculations using a tunneling model with a single ion state.Comment: 4 pages, 4 figure

Methodology for extraction of space charge density profiles at nanoscale from Kelvin probe force microscopy measurements

International audienceTo understand the physical phenomena occurring at metal/dielectric interfaces, determination of the charge density profile at nanoscale is crucial. To deal with this issue, charges were injected applying a DC voltage on lateral Al-electrodes embedded in a SiN x thin dielectric layer. The surface potential induced by the injected charges was probed by Kelvin probe force microscopy (KPFM). It was found that the KPFM frequency mode is a better adapted method to probe accurately the charge profile. To extract the charge density profile from the surface potential two numerical approaches based on the solution to Poisson's equation for electrostatics were investigated: the second derivative model method, already reported in the literature, and a new 2D method based on the finite element method (FEM). Results highlight that the FEM is more robust to noise or artifacts in the case of a non-flat initial surface potential. Moreover, according to theoretical study the FEM appears to be a good candidate for determining charge density in dielectric films with thicknesses in the range from 10 nm to 10 μm. By applying this method, the charge density profile was determined at nanoscale, highlighting that the charge cloud remains close to the interface

Handling Geometric Features in Nanoscale Characterization of Charge Injection and Transport in thin Dielectric Films

International audienceDue to miniaturization and attractiveness of nanosized and/or nanostructured dielectric layers, characterization at the local scale of charge injection and transport phenomena comes to the fore. To that end the electric modes derived from Atomic Force Microscopy (AFM) are more and more frequently used. In this study, the influence of AFM tip-plane system configuration on the electric field distribution is investigated for homogeneous and heterogeneous (nanostructured) thin dielectric layers. The experimental and computing results reveal that the radial component of the electric field conveys the charge lateral spreading whereas the axial component of the electric field governs the amount of injected charges. The electric field distribution is slightly influenced by the heterogeneity of the material. Moreover, the interpretation of the current measurements requires consideration of the entire electric field distribution and not only the computed field at the contact point

Waiting and Residence Times of Brownian Interface Fluctuations

We report on the residence times of capillary waves above a given height $h$ and on the typical waiting time in between such fluctuations. The measurements were made on phase separated colloid-polymer systems by laser scanning confocal microscopy. Due to the Brownian character of the process, the stochastics vary with the chosen measurement interval $\Delta t$. In experiments, the discrete scanning times are a practical cutoff and we are able to measure the waiting time as a function of this cutoff. The measurement interval dependence of the observed waiting and residence times turns out to be solely determined by the time dependent height-height correlation function $g(t)$. We find excellent agreement with the theory presented here along with the experiments.Comment: 5 figure

Characterization of the Electrical Behaviour of Thin Dielectric Films at Nanoscale using Methods Derived from Atomic Force Microscopy: Application to Plasma Deposited AgNPs-Based Nanocomposites

International audienceRecent advances in the development of micro-and nano-devices call for applications of thin nanocomposite dielectric films (thickness less than few tens of nanometers) with tuneable electrical properties. For optimization purposes, their behaviour under electrical stress needs to be probed at relevant scale, i.e. nanoscale. To that end electrical modes derived from Atomic Force Microscopy (AFM) appear the best methods due to their nanoscale resolution and non-destructive nature which permits in-situ characterization. The potentialities of electrical modes derived from AFM are presented in this work. The samples under study consist of plasma processed thin dielectric silica layers with embedded silver nanoparticles (AgNPs). Charge injection at local scale, performed by using AFM tip, is investigated by Kelvin Probe Force Microscopy (KPFM). Modulation of the local permittivity induced by the presence of AgNPs is assessed by Electrostatic Force Microscopy (EFM)

Charge injection phenomena at the metal/dielectric interface investigated by Kelvin probe force microscopy

International audienceThe understanding of charge injection mechanism at metal/dielectric interface is crucial in many applications. A direct probe of such phenomenon requires a charge measurement method whose spatial resolution is compatible with the characteristic scale of phenomena occurring after injection, like charge trapping, and with the geometry of samples under investigation. In this paper, charge injection at metal/dielectric interface and their motion in silicon nitride layer under tunable electric field are probed at nanoscale using a technique derived from Atomic Force Microscopy. This was achieved by realizing embedded lateral electrode structures and using surface potential measurement by Kelvin Probe Force Microscopy (KPFM) to provide voltage, field and charge profiles close to the metal/dielectric interface during and after biasing the electrodes. The influence of electric field enhancement at the interface due to the electrode geometry was accounted for. Electron and hole mobility was estimated from surface potential profiles obtained under polarization. Charge dynamic was investigated during depolarization steps

Charges injection investigation at metal/dielectric interfaces by Kelvin Probe Force Microscopy

International audienceCharges injection at metal/dielectric interface and their motion in silicon nitride layer is investigated using samples with embedded lateral electrodes and surface potential measurement by Kelvin Probe Force Microscopy (KPFM). Bipolar charge injection was evidenced using this method. From surface potential profile, charge density distribution is extracted by using Poisson's equation. The evolution of the charge density profile with polarization bias and depolarization time was also investigated