Magneto-optical trapping and sub-Doppler cooling have been essential to most experiments with quantum degenerate gases, optical lattices, atomic fountains and many other applications. A broad set of ...new applications await ultracold molecules, and the extension of laser cooling to molecules has begun. A magneto-optical trap (MOT) has been demonstrated for a single molecular species, SrF, but the sub-Doppler temperatures required for many applications have not yet been reached. Here we demonstrate a MOT of a second species, CaF, and we show how to cool these molecules to 50 μK, well below the Doppler limit, using a three-dimensional optical molasses. These ultracold molecules could be loaded into optical tweezers to trap arbitrary arrays for quantum simulation, launched into a molecular fountain for testing fundamental physics, and used to study collisions and chemistry between atoms and molecules at ultracold temperatures.
Our research objective was to obtain a fundamental understanding of how ITO thin films layered on flexible polyethylene terephthalate (PET) substrates fail due to tensile, shear, and bending loading ...conditions. In our approach, we employed a nonlinear finite-element (FE) approach coupled with dislocation-density crystalline and hypoelastic material models and fracture approaches tailored for channel (film) cracking and interfacial delamination. These predictions were validated with mechanical experiments and characterization at different physical scales. Failure to strain and fracture predictions were used to account for interrelated mechanisms, such as channel and interfacial cracking nucleation and propagation along cleavage planes, interfaces, and within layers. Our predictions indicate that interfacial delamination occurred when channel cracks transitioned to interfacial cracks at the ITO/PET interface for tensile loading conditions. Furthermore, the thin film system, when subjected to three-point bending and shear loading conditions was more resistant to failure in comparison to systems subjected to tensile loading conditions.
Monitor lizards are emblematic reptiles that are widely distributed in the Old World. Although relatively well studied in vertebrate research, their biogeographic history is still controversial. We ...constructed a molecular dataset for 54 anguimorph species, including representatives of all families with detailed sampling of the Varanidae (38 species). Our results are consistent with an Asian origin of the Varanidae followed by a dispersal to Africa 41 (49–33) Ma, possibly via an Iranian route. Another major event was the dispersal of monitors to Australia in the Late Eocene–Oligocene 32 (39–26) Ma. This divergence estimate adds to the suggestion that Australia was colonized by several squamate lineages prior to the collision of the Australian plate with the Asian plate starting 25 Ma.
The endothelium of the adult vasculature is normally quiescent, with the exception of the vasculature of the female reproductive system. However, in response to appropriate stimuli (ie, wound ...healing, atherosclerosis, tumor growth and metastasis, arthritis) the vasculature becomes activated and grows new capillaries through angiogenesis. We have recently identified a novel endothelial-restricted gene,
Egfl7
, that encodes a 41-kd secreted protein (Fitch MJ, Campagnolo L, Kuhnert F, Stuhlmann H: Egfl7, a novel epidermal growth factor-domain gene expressed in endothelial cells. Dev Dyn 2004, 230:316–324).
Egfl7
is expressed at high levels early during mouse embryonic development and is strictly associated with the vascular bed. In this study, we investigated
Egfl7
expression in the quiescent adult vasculature, in the pregnant uterus, and in two different models of arterial injury, namely ballooning and ferric chloride injury. By RNA
in situ
hybridization,
Egfl7
expression in the vasculature was found to be restricted to the endothelium of the capillaries and mature vessels. In the pregnant uterus, increased vascularization was accompanied by up-regulation of
Egfl7
. On arterial injury,
Egfl7
expression was up-regulated in the regenerating endothelium, but not in the neointima. Importantly, the EGFL7 protein acted as a chemoattractant for embryonic endothelial cells and fibroblasts in a cell migration assay. Together, these results suggest that
Egfl7
functions in the formation and maintenance of endothelial integrity and that its up-regulation may be a critical component in the reorganization of the vascular bed in response to angiogenic stimuli.
We explore a technique for decelerating molecules using a static magnetic field and optical pumping. Molecules travel through a spatially varying magnetic field and are repeatedly pumped into a ...weak‐field seeking state as they move towards each strong field region, and into a strong‐field seeking state as they move towards weak field. The method is time‐independent and so is suitable for decelerating both pulsed and continuous molecular beams. By using guiding magnets at each weak field region, the beam can be simultaneously guided and decelerated. By tapering the magnetic field strength in the strong field regions, and exploiting the Doppler shift, the velocity distribution can be compressed during deceleration. We develop the principles of this deceleration technique, provide a realistic design, use numerical simulations to evaluate its performance for a beam of CaF, and compare this performance to other deceleration methods.
Escher meets Sisyphus: A deceleration technique for molecular beams is explored that relies on repeated optical pumping in a static, spatially varying, magnetic field. Molecules are pumped between weak‐ and strong‐field seeking states so that they are always climbing potential hills (see picture). The principles of this technique are developed, a design based on permanent magnets presented, and trajectory simulations used to study its performance for slowing a beam of CaF.
TNF‐α is a major inflammatory factor that is induced in response to injury, and it contributes to the normal regulatory processes of bone resorption. The role of TNF‐α during fracture healing was ...examined in wild‐type and TNF‐α receptor (p55−/−/p75−/−)‐deficient mice. The results show that TNF‐α plays an important regulatory role in postnatal endochondral bone formation.
Introduction: TNF‐α is a major inflammatory factor that is induced as part of the innate immune response to injury, and it contributes to the normal regulatory processes of bone resorption.
Methods: The role of TNF‐α was examined in a model of simple closed fracture repair in wild‐type and TNF‐α receptor (p55−/−/p75−/−)‐deficient mice. Histomorphometric measurements of the cartilage and bone and apoptotic cell counts in hypertrophic cartilage were carried out at multiple time points over 28 days of fracture healing (n = 5 animals per time point). The expression of multiple mRNAs for various cellular functions including extracellular matrix formation, bone resorption, and apoptosis were assessed (triplicate polls of mRNAs).
Results and Conclusions: In the absence of TNF‐α signaling, chondrogenic differentiation was delayed by 2–4 days but subsequently proceeded at an elevated rate. Endochondral tissue resorption was delayed 2–3 weeks in the TNF‐α receptor (p55−/−/p75−/−)‐deficient mice compared with the wild‐type animals. Functional studies of the mechanisms underlying the delay in endochondral resorption indicated that TNF‐α mediated both chondrocyte apoptosis and the expression of proresorptive cytokines that control endochondral tissue remodeling by osteoclasts. While the TNF‐α receptor ablated animals show no overt developmental alterations of their skeletons, the results illustrate the primary roles that TNF‐α function contributes to in promoting postnatal fracture repair as well as suggest that processes of skeletal tissue development and postnatal repair are controlled in part by differing mechanisms. In summary, these results show that TNF‐α participates at several functional levels, including the recruitment of mesenchymal stem, apoptosis of hypertrophic chondrocytes, and the recruitment of osteoclasts function during the postnatal endochondral repair of fracture healing.
This paper presents a Parzen-Windows (PW)-based classifier for transformer fault diagnosis, which is able to interpret transformer dissolved gas analysis (DGA) with a probabilistic scheme. A global ...optimizer, particle swarm optimizer (PSO), is employed to optimize the parameters of PW to improve fault classification accuracies. First, the essential concept of PW-based classification using PSO is introduced. This probabilistic classification approach is then extended from a simple PW method to classifying fault types on the evidence of various gas ratios. The proposed approach not only allows an intuitive interpretation of the transformer diagnosis, but also provides a DGA reviewer with quantified confidence to support decision making. It can be seen from the results that both the diagnosis accuracy and computational efficiency are improved compared with a number of fault classification techniques.
An optimal coordinated voltage controller (OCVC) is developed based on the spirit of model predictive control (MPC) method. The OCVC consists of three components, namely a predictor, a control ...candidate pool, and a selector. It has been used in secondary voltage control (SVC) to coordinate dissimilar control actions at different geographical locations in order to maintain desired voltage profiles in a global sense in emergencies. A single-stage Euler state predictor (SESP) is utilized, based on the system model, to predict voltage performance under selected control actions; the selection of the optimum control action from the pool is a complex optimization problem that is achieved by a pseudogradient evolutionary programming (PGEP) technique. Simulation results on a six-bus benchmark system and the New England 10-generator-39-bus system are given to show the potential of this method for online usage.
PDF
