Compact 20-pass thin-disk amplifier insensitive to thermal lensing

We present a multi-pass amplifier which passively compensates for distortions of the spherical phase front occurring in the active medium. The design is based on the Fourier transform propagation which makes the output beam parameters insensitive to variation of thermal lens effects in the active medium. The realized system allows for 20 reflections on the active medium and delivers a small signal gain of 30 with M$^2$ = 1.16. Its novel geometry combining Fourier transform propagations with 4f-imaging stages as well as a compact array of adjustable mirrors allows for a layout with a footprint of 400 mm x 1000 mm.Comment: 7 pages, 6 figure

Proximate factors influencing the spatial distribution of a high altitude copepod : Hesperodiaptomus shoshone

Spatial distribution shapes almost every aspect of the ecology of populations. Even though the importance of spatial distribution to the ecology of zooplankton is established, little is known about the factors that generate and maintain these aggregations (Megard et al . 1997). The role that environmental variables, specifically light intensity, and pond substrate coloration play on the formation and maintenance of aggregations was investigated in the freshwater calanoid Hesperodiaptomus shoshone . The spatial distribution of H. shoshone was determined using traditional methods (i.e. the Morisita's index of dispersion) and spatial methods--trend analyses and autocorrelations--with the aim of clarifying distribution dynamics during a 24hr point interval sampling period. Copepods were found to be aggregated through the day and night with the highest aggregation levels at midday. Spatial patterns were not consistent either between the two ponds studied or between sampling times of the day. Partial regression analyses were used to identify the relative contribution of environmental and spatial factors structuring H. shoshone spatial distributions. Although the results were not consistent between the two ponds, light intensity and proximity to logs were two proximate factors influencing the observed copepod heterogeneity. Furthermore results showed that background colours of pond substrate were found to influence the aggregation behaviour of copepods in the water column

Relevance of the speed and direction of pulling in simple modular proteins

A theoretical analysis of the unfolding pathway of simple modular proteins in length- controlled pulling experiments is put forward. Within this framework, we predict the first module to unfold in a chain of identical units, emphasizing the ranges of pulling speeds in which we expect our theory to hold. These theoretical predictions are checked by means of steered molecular dynamics of a simple construct, specifically a chain composed of two coiled-coils motives, where anisotropic features are revealed. These simulations also allow us to give an estimate for the range of pulling velocities in which our theoretical approach is valid.Comment: Accepted for publication in J. Chem. Theory Comput.; only one PDF file with the main text and the supporting information (generated from a docx file

Phylogeny, phylogeography and genetic structure of the North American diaptomid copepod, Hesperodiaptomus shoshone (Copepoda: Calanoida)

The freshwater diaptomid copepod Hesperodiaptomus shoshone (S.A. Forbes, 1882) occurs in high altitudes of Western North America, ranging from British Columbia to Colorado in the Rocky Mountains, and in the Sierra Nevada of California. I examined the genetic variation of H. shoshone at different spatial scales to determine the extent of current demographic processes and historical events shaping the distribution and dispersal of this species. First, I examined the phylogenetic relationships within the genus Hesperodiaptomus based upon nuclear ribosomal DNA gene sequences. Phylogenetic reconstructions supported the monophyletic origin of the genus and revealed two clades supported by morphological characters. Second, I carried out a phylogeographic study using partial DNA sequences of the cytochrome oxidase I gene and from nuclear ribosomal DNA gene sequences from 51 populations representing the current distribution range of the species. The genetic divergence among populations was high, and indicates a low level of dispersal among populations. The data revealed the presence of two geographically distinct deep lineages (North/South), with further genetic sub-structuring within each region. I hypothesize that the observed patterns of genetic diversity and structure reflect historical dispersal events and episodic range displacement due to glaciations. Finally, I characterized three microsatellite markers for this species and carried out a population genetic study to examine the genetic structure among 12 neighbouring populations in the Gunnison area of Colorado. The results indicated that H. shoshone have significant population differentiation and high genetic divergence suggesting a limited gene flow even at relatively small spatial scales

Developing an IF panel to examine Cyclin and CDK interactions in a Pancreatic Adenocarcinoma Patient Derived Xenograph.

https://openworks.mdanderson.org/sumexp22/1084/thumbnail.jp

Switching from Electron to Hole Transport in Solution-Processed Organic Blend Field-Effect Transistors

Organic electronics became an attractive alternative for practical applications in complementary logic circuits due to the unique features of organic semiconductors such as solution processability and ease of large-area manufacturing. Bulk heterojunctions (BHJ), consisting of a blend of two organic semiconductors of different electronic affinities, allow fabrication of a broad range of devices such as light-emitting transistors, light-emitting diodes, photovoltaics, photodetectors, ambipolar transistors and sensors. In this work, the charge carrier transport of BHJ films in field-effect transistors is switched from electron to hole domination upon processing and post-treatment. Low molecular weight n-type N,N′-bis(n-octyl)-(1,7&1,6)-dicyanoperylene-3,4:9,10-bis(dicarboximide) (PDI8-CN2) was blended with p-type poly[2,5-bis(3-tetradecylthiophene-2-yl)thieno[3,2-b]thiophene] (PBTTT-C14) and deposited by spin-coating to form BHJ films. Systematic investigation of the role of rotation speed, solution temperature, and thermal annealing on thin film morphology was performed using atomic force microscopy, scanning electron microscopy, and grazing incidence wide-angle X-ray scattering. It has been determined that upon thermal annealing the BHJ morphology is modified from small interconnected PDI8-CN2 crystals uniformly distributed in the polymer fraction to large planar PDI8-CN2 crystal domains on top of the blend film, leading to the switch from electron to hole transport in field-effect transistors

Effect of CORONA treatment on finishing processes of linen fabrics

Application of CORONA technology for finishing processes of cellulosic fabric is an innovation in European textile industry. A CORONA discharge is created between two electrodes with high voltage and a frequency of 20 – 40 kHz affecting the surface of a fabric running continuously at ambience pressure and temperature. The paper presents the newest results of research refer to linen fabrics properties without and after CORONA treatment. Fabrics after Corona get new better properties, what makes finishing processes much easier. Quality of fabrics after Corona can be highly improved in important aspects concerning safety of users. Corona treatment improves significantly wettability of cellulosic fabrics. New stage – CORONA treatment – apply in finishing process in line allows for eliminating initial washing without detriment to quality of finished fabric. Instead of washing applied, CORONA ensures good results in bleaching and evenness of dyeing by some kinds of dyes. Corona gives a chance to get better end properties at lower costs and less environmental aggressio

Distortion or Clarification: Defining Highly Qualified Teachers and the Relationship between Certification and Achievement

Recent studies of the relationship between teacher preparation pathways and student achievement have resulted in similar statistics but contradictory conclusions. These studies as a group have several limits: they sometimes focus on student-level indicators when many policy decisions are made with indicators at the school-level or above, are limited to specific urban locations or grade levels, or neglect the potential influence of building type, as defined as the grade-levels serviced. Using statewide data from the 2004-2005 school year, we examined the relationships between school-level indicators of student achievement on nationally-normed tests and proportions of alternatively certified teachers, while controlling for building type and other relevant covariates. Our findings indicate that the relationship between teacher preparation and student achievement at the school level depends on whether the building mixes multiple grade levels (e.g., elementary and middle). The implications of Missouri's policy change for research and school improvement are discussed with respect to the current high-stakes testing environment