Spatial and temporal pulse shaping for lateral and depth resolved two-photon excited fluorescence contrast

We report combined temporal and spatial laser pulse shaping to perform lateral and depth dependent two-photon excited fluorescence of dyes. For generating the specific spatially and temporally phase tailored pulses a temporal pulse shaper and a subsequent spatial pulse shaper are employed. Simultaneous spatial and temporal shaping is presented for two-photon excited fluorescence by applying temporal third order phase functions on spatially different light field components. Moreover, the prospects of spatial shaping are demonstrated by applying various lateral two-photon fluorescence pattern. In particular, a depth dependent excitation of different dyes is performed which leads to a high axially resolved fluorescence contrast. The introduced spatial and temporal shaping technique provides new perspectives for biophotonic imaging applications

An analysis of the relationship between economic development and demographic characteristics in the United States

Over the past several decades there has been extensive research done in an attempt to determine what demographic characteristics affect economic growth, measured in GDP per capita. Understanding what influences the growth of a country will vastly help policy makers enact policies to lead the country in a positive direction. This research focuses on isolating a new variable, women in the work force. As well as isolating a new variable, this research will modify a preexisting variable that was shown to be significant in order to make the variable more robust and sensitive to recessions. The intent of this thesis is to explore the relationship between several demographic characteristics and their effect on the growth rate of GDP per capita. The first step is to reproduce the work done by Barlow (1994) to ensure that the United States follows similar rules as the countries in his research. Afterwards, we will introduce new variables into the model, comparing the goodness of fit through the methods of R-squared, AIC and BIC. There have been several models developed to answer each of the research questions independently

Soil and vegetation recovery on abandoned paved roads in a humid tropical rain forest, Puerto Rico

I examined soil and vegetation characteristics on a 60 yr chronosequence of abandoned paved roads in Puerto Rico. Rapid recovery obscured successional changes in soil regeneration. Littermass, bulk density, soil moisture, soil organic matter, and total Kjeldahl nitrogen reached forest levels within 11 yr of road abandonment despite residual pavement. Road soil pH showed a clear successional trend, and approached the more acidic forest soils within 60 yr. Pool sizes were similar to the forest by ≥30 yr; Road revegetation displayed strong successional trends across the chronosequence. Vegetation on roads abandoned for ≥30 yr reached a mature forest state for stem count, species richness, canopy height, and canopy cover characteristics. Basal area, understory cover, and diversity measures reached adjacent forest levels within 60 yr. Species composition remained disparate between road and forest. Adjacent forest conditions were the most significant in determining both soil and vegetation recovery trajectories

Tunable steady-state domain wall oscillator with perpendicular magnetic anisotropy

We theoretically study domain wall oscillations upon the injection of a dc current through a geometrically constrained wire with perpendicular magnetic anisotropy. The oscillation frequency spectrum can be tuned by the injected current density, but additionally by the application of an external magnetic field independent of the power. The results of analytical calculations are supported by micromagnetic simulations based on the Landau-Lifshitz-Gilbert equation. The simple concept of our localized steady-state oscillator might prove useful as a nanoscale microwave generator with possible applications in telecommunication or for rf-assisted writing in magnetic hard drives.Comment: 10 pages, 3 figure

Types and correlates of school non-attendance in students with autism spectrum disorders

School non-attendance in autism spectrum disorders (ASD) has received very little attention to date. The study aimed to provide a comprehensive description of school non-attendance in students with ASD. Through an online survey, parents of 486 children (mean age 11 years) reported on school attendance over one month, and reasons for instances of non-attendance. On average, students missed five days of school of a possible 23 days. Persistent non-attendance (absent on 10%+ of available sessions) occurred among 43% of students. School non-attendance was associated with child older age, not living in a two-parent household, parental unemployment and, especially, attending a mainstream school. School refusal accounted for 43% of non-attendance. School exclusion and school withdrawal each accounted for 9% of absences. Truancy was almost non-existent. Non-problematic absenteeism (mostly related to medical appointments and illness) accounted for 32% of absences. Non-problematic absenteeism was more likely among those with intellectual disability, school refusal was more likely among older students, and school exclusion was more likely among students from single-parent, unemployed, and well educated households. Findings suggest school non-attendance in ASD is a significant issue, and that it is important to capture detail about attendance patterns and reasons for school non-attendance

Combined temporal and spatial laser pulse shaping for two-photon excited fluorescence contrast improvement

We report on combined simultaneous temporal and spatial laser pulse shaping by utilizing light polarization properties. Thereto, a setup comprising a temporal pulse shaper, a waveplate, and a spatial shaper was developed and characterized by comparison with simulations. This enables to simultaneously shape one polarization component temporally and spatially while the perpendicular polarization component is modified temporally. The spatially and temporally modulated light fields were recorded and visualized by suitable contour plots, which was particularly demonstrated for cylindrically symmetric pulse profiles. Moreover, temporally and spatially shaped pulses were applied for two-photon excited fluorescence of dyes. These measurements were conducted by scanning third order phase functions for specific spatial pulse components which yields an enhanced contrast difference between fluorescing dyes. The presented temporal and spatial shaping method of ultrashort laser pulses has a high potential for biophotonic applications

The prehatch period and larval survival of Boophilus decoloratus (Koch, 1844) (Acarina: Ixodidae) under natural conditions in the Transvaal, South Africa

Studies were made on the duration of the prehatch period of Boophilus decoloratus and on the subsequent survival and viability of larvae under natural conditions. The length of the prehatch and larval survival periods was found to be inversely dependent on increased temperature. A high initial temperature at the time of female drop decreased the prehatch period further, resulting in synchronous hatching of eggs laid at different times. Oviposition occurred but no eggs hatched during mid-winter months with mean temperatures below 10°C. Eggs laid after mid-winter hatched because of the higher temperatures during subsequent months. Diapause occurs at the egg stage in areas with mean winter temperatures below 10°C. Larvae survived for 10 - 35 weeks during periods of high and low seasonal temperatures respectively. Larval viability decreased concomitantly with larval survival. The results suggest that pasture spelling alone would be impractical as a control measure for this tick species.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

A survey of Karoo tick paralysis in South Africa

Recent research interest in Karoo tick paralysis and its vector, Ixodes rubicundus, prompted this survey to determine the economic implications of this disease. The survey indicated relatively high losses caused by the condition, identified the stock involved and provided data on the incidence of paralysis and on the control methods employed. Recommendations are made to institute chemical control earlier in the season to attempt better containment of the problem.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201

Signposts for school refusal interventions, based on the views of stakeholders

School refusal (SR) signals a young person’s difficulty attending school. It jeopardizes their development, often contributes to distress for parents, and places an extra burden on school personnel. Reviews of empirical studies indicate that intervention for SR helps to increase school attendance, but not for all youths. This practice-based manuscript aims to support practitioners and organisations addressing the needs of youths and families affected by SR. Specifically, we present 14 signposts for the development and delivery of intervention for SR. The signposts represent important conditions for effective intervention based on key findings from the Knowing What Works project in the Netherlands. During that project, 76 professionals shared their views about the important elements in SR interventions they delivered, and 39 youths and 86 parents shared their views about the helpful elements in SR interventions in which they participated. These 201 stakeholders were variously associated with 21 SR interventions across 9 of the 12 Dutch provinces, most situated in mainstream or special education settings. Their responses informed the development of the 14 signposts presented here, supported by the extant literature on SR intervention. Wedescribe the essence of each signpost and conclude with suggestions for using the signposts and evaluating their utility.Pathways through Adolescenc