At-focus scanning ptychography for high resolution imaging with a wide field of view.

From manufacturing to medicine, there is a demand for phase-resolved, high resolution imaging of large samples. Here we present at-focus scanning ptychography (AFSP), a novel ptychographic metrology station designed for high resolution imaging over a large field of view. AFSP builds on scanning ptychography, but samples remain stationary during the imaging process, allowing for in-situ imaging.

Need for oxygen therapy and ventilatory support in premature infants in a hospital in Southern Brazil.

Background: Prematurity in newborns is a condition that is associated with worse hospital outcomes when compared to birth to term. A preterm infant (PI) is classified when gestational age (GA) < 37 wk.

Aim: To analyze prognostic indicators related to the use of oxygen therapy, non-invasive ventilation (continuous positive airway pressure) and mechanical ventilation (MV) in PI.

Recent climate change is creating hotspots of butterfly increase and decline across North America.

Some insect populations are experiencing dramatic declines, endangering the crucial ecosystem services they provide. Yet, other populations appear robust, highlighting the need to better define patterns and underlying drivers of recent change in insect numbers. We examined abundance and biodiversity trends for North American butterflies using a unique citizen-science dataset that has recorded observations of over 8 million butterflies across 456 species, 503 sites, nine ecoregions, and 26 years.

Variable effects of mycorrhizal fungi on predator-prey dynamics under field conditions.

Interactions between herbivores and their predators are shaped, in part, by plant phenotype. Consequently, ubiquitous symbionts of plants below-ground, such as arbuscular mycorrhizal fungi (AMF), may influence interactions above-ground between predators and their prey by altering plant phenotype. However, the ecological relevance of below-ground organisms on predator-prey interactions under field conditions remains unclear.

Host plants and shape the population genetics of sympatric herbivore populations.

Changing climate and land-use practices have the potential to bring previously isolated populations of pest insects into new sympatry. This heightens the need to better understand how differing patterns of host-plant association, and unique endosymbionts, serve to promote genetic isolation or integration. We addressed these factors in populations of potato psyllid, (Šulc), a generalist herbivore that vectors a bacterial pathogen ( Liberibacter solanacearum, causal pathogen of zebra chip disease) of potato ( L.

No net insect abundance and diversity declines across US Long Term Ecological Research sites.

Recent reports of dramatic declines in insect abundance suggest grave consequences for global ecosystems and human society. Most evidence comes from Europe, however, leaving uncertainty about insect population trends worldwide. We used >5,300 time series for insects and other arthropods, collected over 4-36 years at monitoring sites representing 68 different natural and managed areas, to search for evidence of declines across the United States.

Mycorrhizae Alter Constitutive and Herbivore-Induced Volatile Emissions by Milkweeds.

Plants use volatile organic compounds (VOCs) to cue natural enemies to their herbivore prey on plants. Simultaneously, herbivores utilize volatile cues to identify appropriate hosts. Despite extensive efforts to understand sources of variation in plant communication by VOCs, we lack an understanding of how ubiquitous belowground mutualists, such as arbuscular mycorrhizal fungi (AMF), influence plant VOC emissions.

The Role of Strain in the Homoaromatization of Semibullvalenes.

The low activation barrier to the Cope rearrangement of semibullvalenes has been attributed to the inherent ring-strain of this nucleus. Appropriate, Dewar-Hoffmann, substitution of semibullvalene results in the stabilization of the transition state and a further lowering of the Cope barrier. An alternative proposal for lowering/eliminating this barrier is the use of strain to destabilize the localized semibullvalene.

Comparing Personal Health Practices: Individuals with mental illness and the general Canadian population.

Objective: Individuals with mental illness often live in chronic poverty, which is associated with personal health practices such as tobacco use and poor nutrition that disrupt physical health. The purpose of our study was to examine whether differences exist in personal health and health practices - related to nutrition, physical activity, smoking, alcohol consumption and sleep - between a cohort of individuals with mental illness in southwestern Ontario and the general Canadian population.

Method: The study sample consisted of 250 individuals who had had a psychiatric diagnosis for at least one year.

Spatial-spectral characterization of focused spatially chirped broadband laser beams.

Proper alignment is critical to obtain the desired performance from focused spatially chirped beams, for example in simultaneous spatial and temporal focusing (SSTF). We present a simple technique for inspecting the beam paths and focusing conditions for the spectral components of a broadband beam. We spectrally resolve the light transmitted past a knife edge as it was scanned across the beam at several axial positions.

Broadband interferometric characterization of divergence and spatial chirp.

We demonstrate a spectral interferometric method to characterize lateral and angular spatial chirp to optimize intensity localization in spatio-temporally focused ultrafast beams. Interference between two spatially sheared beams in an interferometer will lead to straight fringes if the wavefronts are curved. To produce reference fringes, we delay one arm relative to another in order to measure fringe rotation in the spatially resolved spectral interferogram.

Nonlinear dynamics of double-pass cross-polarized wave generation in the saturation regime.

The conversion efficiency of cross-polarized wave (XPW) generation can be improved using two separate thinner nonlinear crystals versus a single thick one, due to the evolution of the beam sizes and individual phases after the first crystal. In this paper, we present an alternative scheme in which a curved mirror is used to reimage a plane just after the BaF2 crystal for a second pass. We also develop a simple analytic model for XPW conversion that describes the origin of a nonlinear phase mismatch and nonlinear lensing for both the fundamental wave and XPW.

Seeking and securing work: Individual-level predictors of employment of psychiatric survivors.

Background: For people with mental illness (psychiatric survivors), seeking and securing employment involves personal, social, and environmental factors. In Canada, psychiatric survivors are under-represented in the workforce, and services can help by tailoring their supports to help make the most gains in employment.

Objective: Determine whether individual socio-demographic and health factors predict seeking and securing employment among psychiatric survivors.

Measurement of energy contrast of amplified ultrashort pulses using cross-polarized wave generation and spectral interferometry.

We present a method using spectral interferometry (SI) to characterize a pulse in the presence of an incoherent background such as amplified spontaneous emission (ASE). The output of a regenerative amplifier is interfered with a copy of the pulse that has been converted using third-order cross-polarized wave generation (XPW). The ASE shows as a pedestal background in the interference pattern.