Anomalous electron mobility modeling in Hall thrusters

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76339/1/AIAA-2005-4057-695.pd

Computation of the interior and near-field flow of a 2-kW class Hall thruster

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76759/1/AIAA-2001-3321-274.pd

Traditional Medicine Practices among Community Members with Diabetes Mellitus in Northern Tanzania: An ethnomedical Survey.

Diabetes is a growing burden in sub-Saharan Africa where traditional medicines (TMs) remain a primary form of healthcare in many settings. In Tanzania, TMs are frequently used to treat non-communicable diseases, yet little is known about TM practices for non-communicable diseases like diabetes. Between December 2013 and June 2014, we assessed TM practices, including types, frequencies, reasons, and modes, among randomly selected community members. To further characterize TMs relevant for the local treatment of diabetes, we also conducted focus groups and semi-structured interviews with key informants. We enrolled 481 adults of whom 45 (9.4 %) had diabetes. The prevalence of TM use among individuals with diabetes was 77.1 % (95 % CI 58.5-89.0 %), and the prevalence of using TMs and biomedicines concurrently was 37.6 % (95 % CI 20.5-58.4 %). Many were using TMs specifically to treat diabetes (40.3 %; 95 % CI 20.5-63.9), and individuals with diabetes reported seeking healthcare from traditional healers, elders, family, friends, and herbal vendors. We identified several plant-based TMs used toward diabetes care: Moringa oleifera, Cymbopogon citrullus, Hagenia abyssinica, Aloe vera, Clausena anisata, Cajanus cajan, Artimisia afra, and Persea americana. TMs were commonly used for diabetes care in northern Tanzania. Individuals with diabetes sought healthcare advice from many sources, and several individuals used TMs and biomedicines together. The TMs commonly used by individuals with diabetes in northern Tanzania have a wide range of effects, and understanding them will more effectively shape biomedical practitices and public health policies that are patient-centered and sensitive to TM preferences

A New Means To Identify Type 3 Secreted Effectors: Functionally Interchangeable Class IB Chaperones Recognize a Conserved Sequence

Many Gram-negative bacteria utilize specialized secretion systems to inject proteins (effectors) directly into host cells. Little is known regarding how bacteria ensure that only small subsets of the thousands of proteins they encode are recognized as substrates of the secretion systems, limiting their identification through bioinformatic analyses. Many of these proteins require chaperones to direct their secretion. Here, using the newly described protein interaction platform assay, we demonstrate that type 3 secretion system class IB chaperones from one bacterium directly bind their own effectors as well as those from other species. In addition, we observe that expression of class IB homologs from seven species, including pathogens and endosymbionts, mediate the translocation of effectors from Shigella directly into host cells, demonstrating that class IB chaperones are often functionally interchangeable. Notably, class IB chaperones bind numerous effectors. However, as previously proposed, they are not promiscuous; rather they recognize a defined sequence that we designate the conserved chaperone-binding domain (CCBD) sequence [(LMIF)1XXX(IV)5XX(IV)8X(N)10]. This sequence is the first defined amino acid sequence to be identified for any interspecies bacterial secretion system, i.e., a system that delivers proteins directly into eukaryotic cells. This sequence provides a new means to identify substrates of type III secretion systems. Indeed, using a pattern search algorithm for the CCBD sequence, we have identified the first two probable effectors from an endosymbiont, Sodalis glossinidius

Angiogenic Factors Stimulate Growth of Adult Neural Stem Cells

The ability to grow a uniform cell type from the adult central nervous system (CNS) is valuable for developing cell therapies and new strategies for drug discovery. The adult mammalian brain is a source of neural stem cells (NSC) found in both neurogenic and non-neurogenic zones but difficulties in culturing these hinders their use as research tools.Here we show that NSCs can be efficiently grown in adherent cell cultures when angiogenic signals are included in the medium. These signals include both anti-angiogenic factors (the soluble form of the Notch receptor ligand, Dll4) and pro-angiogenic factors (the Tie-2 receptor ligand, Angiopoietin 2). These treatments support the self renewal state of cultured NSCs and expression of the transcription factor Hes3, which also identifies the cancer stem cell population in human tumors. In an organotypic slice model, angiogenic factors maintain vascular structure and increase the density of dopamine neuron processes.We demonstrate new properties of adult NSCs and a method to generate efficient adult NSC cultures from various central nervous system areas. These findings will help establish cellular models relevant to cancer and regeneration

Enhancing wind erosion monitoring and assessment for U.S. rangelands

Wind erosion is a major resource concern for rangeland managers because it can impact soil health, ecosystem structure and function, hydrologic processes, agricultural production, and air quality. Despite its significance, little is known about which landscapes are eroding, by how much, and when. The National Wind Erosion Research Network was established in 2014 to develop tools for monitoring and assessing wind erosion and dust emissions across the United States. The Network, currently consisting of 13 sites, creates opportunities to enhance existing rangeland soil, vegetation, and air quality monitoring programs. Decision-support tools developed by the Network will improve the prediction and management of wind erosion across rangeland ecosystems. © 2017 The Author(s)The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information

High Temperature Phase Transition in Two-Scalar Theories

Two-scalar theories at high temperature exhibit a rich spectrum of possible critical behaviour, with a second or first order phase transition. In the vicinity of the critical temperature one can observe critical exponents, tricritical points and crossover behaviour. None of these phenomena are visible to high temperature perturbation theory.Comment: 39 pages, macro equation.sty included, 11 uuencoded figures

Confining Properties of the Homogeneous Self-Dual Field and the Effective Potential in SU(2) Yang-Mills Theory

We examine in non-Abelian gauge theory the heavy quark limit in the presence of the (anti-)self-dual homogeneous background field and see that a confining potential emerges, consistent with the Wilson criterion, although the potential is quadratic and not linear in the quark separation. This builds upon the well-known feature that propagators in such a background field are entire functions. The way in which deconfinement can occur at finite temperature is then studied in the static temporal gauge by calculation of the effective potential at high temperature. Finally we discuss the problems to be surmounted in setting up the calculation of the effective potential nonperturbatively on the lattice.Comment: 31 pages, LaTeX, expanded discussion and derivations in Sections 2 and

Collagen density promotes mammary tumor initiation and progression

<p>Abstract</p> <p>Background</p> <p>Mammographically dense breast tissue is one of the greatest risk factors for developing breast carcinoma. Despite the strong clinical correlation, breast density has not been causally linked to tumorigenesis, largely because no animal model has existed for studying breast tissue density. Importantly, regions of high breast density are associated with increased stromal collagen. Thus, the influence of the extracellular matrix on breast carcinoma development and the underlying molecular mechanisms are not understood.</p> <p>Methods</p> <p>To study the effects of collagen density on mammary tumor formation and progression, we utilized a bi-transgenic tumor model with increased stromal collagen in mouse mammary tissue. Imaging of the tumors and tumor-stromal interface in live tumor tissue was performed with multiphoton laser-scanning microscopy to generate multiphoton excitation and spectrally resolved fluorescent lifetimes of endogenous fluorophores. Second harmonic generation was utilized to image stromal collagen.</p> <p>Results</p> <p>Herein we demonstrate that increased stromal collagen in mouse mammary tissue significantly increases tumor formation approximately three-fold (<it>p </it>< 0.00001) and results in a significantly more invasive phenotype with approximately three times more lung metastasis (<it>p </it>< 0.05). Furthermore, the increased invasive phenotype of tumor cells that arose within collagen-dense mammary tissues remains after tumor explants are cultured within reconstituted three-dimensional collagen gels. To better understand this behavior we imaged live tumors using nonlinear optical imaging approaches to demonstrate that local invasion is facilitated by stromal collagen re-organization and that this behavior is significantly increased in collagen-dense tissues. In addition, using multiphoton fluorescence and spectral lifetime imaging we identify a metabolic signature for flavin adenine dinucleotide, with increased fluorescent intensity and lifetime, in invading metastatic cells.</p> <p>Conclusion</p> <p>This study provides the first data causally linking increased stromal collagen to mammary tumor formation and metastasis, and demonstrates that fundamental differences arise and persist in epithelial tumor cells that progressed within collagen-dense microenvironments. Furthermore, the imaging techniques and signature identified in this work may provide useful diagnostic tools to rapidly assess fresh tissue biopsies.</p