272 research outputs found
Analysis of financial planning requirements in transportation planning
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1995.Includes bibliographical references (leaves 175-179).by D. Tilly Chang.M.S
Disruption of the US pre-exposure effect and latent inhibition in two-way active avoidance by systemic amphetamine in C57BL/6 mice
Rationale: Pre-exposure to either one of the two to-be-associated stimuli alone is known to reduce the efficiency of the learning of their association when they are subsequently paired explicitly. In classical conditioning, pre-exposure to the conditioned stimulus (CS) gives rise to latent inhibition (LI); and pre-exposure to the unconditioned stimulus (US) results in the US pre-exposure effect (USPEE). Considerable evidence supports an important role of central dopamine in the regulation and modulation of LI; it has been suggested that the USPEE may be similarly controlled by dopamine, but this parallelism has only been directly demonstrated in the conditioned taste aversion paradigm. Objective: The present study tested this hypothesis by comparing the efficacy of systemic amphetamine treatment to affect the expression of LI and the USPEE in a two-way active avoidance paradigm. Methods: C57BL/6 male mice were tested in active avoidance using a tone CS and a foot-shock US. Twenty-four hours before, they were pre-exposed to 100 presentations of the CS or the US, or to the test apparatus only. Amphetamine (2.5mg/kg) or saline was administered before stimulus pre-exposure and conditioned avoidance test, in which the mice learned to avoid the shock by shuttling in response to the tone. Results: Amphetamine disrupted both stimulus pre-exposure effects, thus, lending further support to the hypothesis that the USPEE is similar to LI in its sensitivity to dopamine receptor agonist. Hence, the USPEE paradigm may represent a valuable addition to the study of dopamine-sensitive processes of selective learning currently implicated in LI and Kamin blockin
TNCs & Congestion
From the executive summary:
This document: Identifies common measures of roadway congestion; Discusses factors that contribute to roadway to congestion; and Quantifies the relative contributions of different factors, including population, employment, road network changes and TNCs, to observed changes in congestion in San Francisco between 2010 and 2016, by location and time of day.
The report utilizes a unique TNC trip dataset provided to the Transportation Authority by researchers from Northeastern University in late 2016, as well as INRIX data, a commercial dataset which combines several real-time GPS monitoring sources with data from highway performance monitoring systems. These data are augmented with information on network changes, population changes, and employment changes provided by local and regional planning agencies, which are used as input to the Transportation Authority’s activity-based regional travel demand model SF-CHAMP
Enhanced Planning Review of the Salt Lake and Ogden Metropolitan Area
ISTEA significantly changed the law governing metropolitan transportation planning. In response to the changes introduced by ISTEA, FHWA and FTA issued revised planning regulations on October 28, 1993, setting new requirements for the transportation planning processes. The requirements are presented in 23 CFR Part 450 and 49 CFR Part 613, Statewide and Metropolitan Planning Final Rule. The Clean Air Act Amendments of 1990 (CAAA) also imposed rigorous new transportation planning requirements in metropolitan areas, particularly those that are designated nonattainment or maintenance areas for air quality. In support of the implementation of the revised regulations, FHW A and FTA jointly established a schedule of EPRs. The EPRs are intended to determine the impact of planning on transportation investment processes. The EPRs also provide a technical assessment of the transportation planning and programming processes, including consideration of the six focal points identified by the FHW A and FTA Administrators for certification. The six focal points are: Financial Constraint and Financial Planning, Major Investment Studies, Congestion Management Systems, the Planning Process, and Links to the Conformity Requirements of the Clean Air Act Amendments of 1990; the Public Involvement Process; and the IS TEA Fifteen Planning Factors. 1 Of equal importance, EPRs will provide a forum for dialogue and the exchange of information on perspectives and concerns related to IS TEA between FT A and FHW A headquarters and field staff, and state and local officials responsible for metropolitan area transportation planning. Additionally, EPRs will provide information for future long-term federal policy-making, including possible legislative and regulatory changes; identify national issues and trends; and document national case studies of best professional practice. This information will also be used to help identify how future federal technical assistance programs can best assist MPOs and other planning agencies in carrying out the requirements of ISTEA. Finally, EPRs are intended to support progress toward meeting ISTEA requirements
Borrelia burgdorferi bb0426 encodes a 2′-deoxyribosyltransferase that plays a central role in purine salvage
Borrelia burgdorferi is an obligate parasite with a limited genome that severely narrows its metabolic and biosynthetic capabilities. Thus survival of this spirochaete in an arthropod vector and mammalian host requires that it can scavenge amino acids, fatty acids and nucleosides from a blood meal or various host tissues. Additionally, the utilization of ribonucleotides for DNA synthesis is further complicated by the lack of a ribonucleotide reductase for the conversion of nucleoside-5′-diphosphates to deoxynucleosides-5′-diphosphates. The data presented here demonstrate that B. burgdorferi must rely on host-derived sources of purine bases, deoxypurines and deoxypyrimidines for the synthesis of DNA. However, if deoxyguanosine (dGuo) is limited in host tissue, the enzymatic activities of a 2′-deoxyribosyltransferase (DRTase, encoded by bb0426), IMP dehydrogenase (GuaB) and GMP synthase (GuaA) catalyse the multistep conversion of hypoxanthine (Hyp) to dGMP for DNA synthesis. This pathway provides additional biochemical flexibility for B. burgdorferi when it colonizes and infects different host tissues
Genetic and cellular aspects of the establishment of histocompatible stem cells: information gained from an animal model
The establishment of patient-specific histocompatible stem cells may be an alternative for overcoming current limitations in stem cell engineering. We are developing an animal model to assist the establishment of histocompatible, autologous stem cells. In this process, we obtained valuable information on establishing and characterizing stem cells. As an initial step, we succeeded in establishing histocompatible stem cells using preantral follicle cultures and subsequent parthenogenetic activation. The gene expression profile of the established stem cells was similar to that of embryonic stem cells (ESCs) derived from normal fertilization. On the other hand, we propose a way to derive histocompatible, ESC-like cells by co-culturing ovarian stromal cells with feeder fibroblasts, which may allow the derivation of stem cells from somatic tissue. However, more progress regarding the establishment and elucidation on origination of established cell lines is necessary to use this genetic manipulation-free procedure. Nevertheless, relevant information on the process will help to stimulate preclinical research on cell transformation into differentiated, undifferentiated, and even cancerous cells, as well as clinical studies on the application of induced pluripotent cells
ortho-Lithiation Reactions of O-(3,n-Dihalophenyl) N,N-Diethylcarbamates: Synthesis of Dihalosalicylamides and 2,3,n-Trihalophenol Derivatives
New dihalosalicylamides and trihalophenol derivatives have been synthesized from easily available O-(3,n-dihalophenyl) N,N-diethylcarbamates by using a directed ortho-metalation (DoM) strategy. The o-lithiation reactions with sBuLi take place regioselectively at the doubly activated C-2 position, which demonstrates the ability of O-carbamates as directed metalating groups. In addition, highly functionalized arylnitriles were accessed from organolithium intermediates by using a tandem transnitrilation/SNAr reaction sequence.Junta de Castilla y León (Consejería de
Educación) and FEDER (BU237U13 and BU076U16) as well as
the Ministerio de Economía y Competitividad (MINECO) and
FEDER (CTQ2013-48937-C2-1-P
Rentier Statebuilding in a Post-Conflict Economy: The Case of Kosovo
Kosovo has been under various forms of international administration since 1999. Although the political dimension of this international experience has been widely studied by scholars — especially those associated with the critical theory of liberal peacebuilding — the economic dimension of international rule has received less attention. This article explores the economic dimension by linking insights from rentier theory with critical approaches to liberal peacebuilding and statebuilding. The postulate informing this article is that the sources of a state's income have an impact on its institutional development. The article discusses liberal peacebuilding through the lens of rentier theory, it analyses the economic management in the early years of the international administration of Kosovo, and describes and explores some of the unintended consequences of this massive international presence in Kosovo for the local economy
The cyclic-di-GMP signaling pathway in the Lyme disease spirochete,
In nature, the Lyme disease spirochete Borrelia burgdorferi cycles between the unrelated environments of the Ixodes tick vector and mammalian host. In order to survive transmission between hosts, B. burgdorferi must be able to not only detect changes in its environment, but also rapidly and appropriately respond to these changes. One manner in which this obligate parasite regulates and adapts to its changing environment is through cyclic-di-GMP (c-di-GMP) signaling. c-di-GMP has been shown to be instrumental in orchestrating the adaptation of B. burgdorferi to the tick environment. B. burgdorferi possesses only one set of c-di-GMP-metabolizing genes (one diguanylate cyclase and two distinct phosphodiesterases) and one c-di-GMP-binding PilZ-domain protein designated as PlzA. While studies in the realm of c-di-GMP signaling in B. burgdorferi have exploded in the last few years, there are still many more questions than answers. Elucidation of the importance of c-di-GMP signaling to B. burgdorferi may lead to the identification of mechanisms that are critical for the survival of B. burgdorferi in the tick phase of the enzootic cycle as well as potentially delineate a role (if any) c-di-GMP may play in the transmission and virulence of B. burgdorferi during the enzootic cycle, thereby enabling the development of effective drugs for the prevention and/or treatment of Lyme disease
Maternal Undernutrition Significantly Impacts Ovarian Follicle Number and Increases Ovarian Oxidative Stress in Adult Rat Offspring
BACKGROUND: We have shown recently that maternal undernutrition (UN) advanced female pubertal onset in a manner that is dependent upon the timing of UN. The long-term consequence of this accelerated puberty on ovarian function is unknown. Recent findings suggest that oxidative stress may be one mechanism whereby early life events impact on later physiological functioning. Therefore, using an established rodent model of maternal UN at critical windows of development, we examined maternal UN-induced changes in offspring ovarian function and determined whether these changes were underpinned by ovarian oxidative stress. METHODOLOGY/PRINCIPAL FINDINGS: Our study is the first to show that maternal UN significantly reduced primordial and secondary follicle number in offspring in a manner that was dependent upon the timing of maternal UN. Specifically, a reduction in these early stage follicles was observed in offspring born to mothers undernourished throughout both pregnancy and lactation. Additionally, antral follicle number was reduced in offspring born to all mothers that were UN regardless of whether the period of UN was restricted to pregnancy or lactation or both. These reductions were associated with decreased mRNA levels of genes critical for follicle maturation and ovulation. Increased ovarian protein carbonyls were observed in offspring born to mothers UN during pregnancy and/or lactation and this was associated with peroxiredoxin 3 hyperoxidation and reduced mRNA levels; suggesting compromised antioxidant defence. This was not observed in offspring of mothers UN during lactation alone. CONCLUSIONS: We propose that maternal UN, particularly at a time-point that includes pregnancy, results in reduced offspring ovarian follicle numbers and mRNA levels of regulatory genes and may be mediated by increased ovarian oxidative stress coupled with a decreased ability to repair the resultant oxidative damage. Together these data are suggestive of maternal UN potentially contributing to premature ovarian ageing in offspring
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