Vehicular Ad Hoc Networks

(First paragraph) Vehicular ad hoc networks (VANETs) have recently been proposed as one of the promising ad hoc networking techniques that can provide both drivers and passengers with a safe and enjoyable driving experience. VANETs can be used for many applications with vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications. In the United States, motor vehicle traffic crashes are the leading cause of death for all motorists between two and thirty-four years of age. In 2009, the National Highway Traffic Safety Administration (NHTSA) reported that 33,808 people were killed in motor vehicle traffic crashes. The US Department of Transportation (US-DOT) estimates that over half of all congestion events are caused by highway incidents rather than by rush-hour traffic in big cities. The US-DOT also notes that in a single year, congested highways due to traffic incidents cost over $75 billion in lost worker productivity and over 8.4 billion gallons of fuel. Some of the significant applications of VANETs are road safety applications including collision and other safety warning systems, driver convenience and information systems, and, in the future, intelligent traffic management systems

Fireside corrosion in oxy-fuel environments and the influence of fuel and ash characteristics on corrosion and deposition

The development of advanced techniques (such as carbon capture and storage) for future power plants and the implementation of retrofit technologies to existing ones (like biomass co-firing) in order to reduce pollutant emission, has raised several concerns for the power industry. One such problem, which also forms the basis of this thesis, is the effect of these measures on corrosion and deposition of the boiler heat transfer surfaces. This research work can be divided into two parts. The first part involved studying the corrosion behaviour of a typical waterwall and a superheater material under simulated oxy-fuel environments with and without the influence of an ash deposit. A custom-built, laboratory scale, corrosion rig with the ability to simulate a range of flue gas compositions and temperatures, in addition to generating a heat flux through the specimen, was set up for this purpose. The second part of this work deals with evaluating the properties of a UK power station coal and four biomass samples with the help of laboratory techniques and thermodynamic modelling in order to predict their fusion and deposit forming tendencies in combustion systems. A series of experiments were performed on the corrosion rig to assess the influence of individual variables on the rate of corrosion. The results indicated that the increased concentration of SO2 in oxy fuel combustion due to recycling of the flue gas, can lead to an increase in corrosion rates especially in the presence of reactive alkali containing deposits. Under the conditions studied, the presence of a biomass ash deposit aggravated the corrosive propensity of the environment while coal ash lessened it. With regard to predicting the fusion behaviour of different ashes, the standard ash fusion tests proved inadequate for explaining the relationship between high alkali constituents in biomass ash and the expected higher slagging and fouling tendencies. Simultaneous thermal analysis was more useful in assessing the physical & chemical changes taking place in the ash. Prediction of the fuel behaviour using FactSage thermodynamic analysis showed that ash melting commences at much lower temperatures than those predicted from laboratory techniques. This would help to explain the increased risk of deposition and corrosion linked with burning high alkali containing fuels

Microscopic Observation Drug Susceptibility Assay for Rapid Diagnosis of Lymph Node Tuberculosis and Detection of Drug Resistance.

In this study, 132 patients with lymphadenopathy were investigated. Fifty-two (39.4%) were diagnosed with tuberculosis (TB). The microscopic observation drug susceptibility (MODS) assay provided rapid (13 days), accurate diagnosis (sensitivity, 65.4%) and reliable drug susceptibility testing (DST). Despite its lower sensitivity than that of other methods, its faster results and simultaneous DST are advantageous in resource-poor settings, supporting the incorporation of MODS into diagnostic algorithms for extrapulmonary TB

Oligodendrocyte RasG12V Expressed in its Endogenous Locus Disrupts Myelin Structure Through Increased MAPK, Nitric Oxide, and Notch Signaling

Costello syndrome (CS) is a gain of function Rasopathy caused by heterozygous activating mutations in the HRAS gene. Patients show brain dysfunction that can include abnormal brain white matter. Transgenic activation of HRas in the entire mouse oligodendrocyte lineage resulted in myelin defects and behavioral abnormalities, suggesting roles for disrupted myelin in CS brain dysfunction. Here we studied a mouse model in which the endogenous HRas gene is conditionally replaced by mutant HRasG12V in mature oligodendrocytes, to separate effects in mature myelinating cells from developmental events. Increased myelin thickness due to decompaction was detectable within one month of HRasG12V expression in the corpus callosum of adult mice. Increases in active ERK and Nitric Oxide (NO) were present in HRas mutants and inhibition of NO synthase (NOS) or MEK each partially rescued myelin decompaction. In addition, genetic or pharmacologic inhibition of Notch signaling improved myelin compaction. Complete rescue of myelin structure required dual drug treatments combining MAPK, NO or Notch inhibition; with MEK + NOS blockade producing the most robust effect. We suggest that individual or concomitant blockade of these pathways in Costello syndrome patients may improve aspects of brain function

Genetically engineered minipigs model the major clinical features of human neurofibromatosis type 1.

Neurofibromatosis Type 1 (NF1) is a genetic disease caused by mutations in Neurofibromin 1 (NF1). NF1 patients present with a variety of clinical manifestations and are predisposed to cancer development. Many NF1 animal models have been developed, yet none display the spectrum of disease seen in patients and the translational impact of these models has been limited. We describe a minipig model that exhibits clinical hallmarks of NF1, including café au lait macules, neurofibromas, and optic pathway glioma. Spontaneous loss of heterozygosity is observed in this model, a phenomenon also described in NF1 patients. Oral administration of a mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitor suppresses Ras signaling. To our knowledge, this model provides an unprecedented opportunity to study the complex biology and natural history of NF1 and could prove indispensable for development of imaging methods, biomarkers, and evaluation of safety and efficacy of NF1-targeted therapies

Exchangeable zinc pool size at birth in Pakistani small for gestational age and appropriate for gestational age infants do not differ but are lower than in US infants

Objectives: Small for gestational age (SGA) infants are more susceptible to infectious morbidity and growth faltering compared to their appropriate for gestational age (AGA) counterparts. Zinc supplementation of SGA infants may be beneficial but the underlying susceptibility to zinc deficiency of SGA infants has not been examined.Methods: In a community-based, observational, longitudinal study in a peri-urban settlement of Karachi, Pakistan, we compared the size of the exchangeable zinc pools (EZPs) in term SGA and AGA infants at birth and at 6 months of age, hypothesizing that the EZP would be lower in the SGA group. To measure EZP size, a zinc stable isotope was intravenously administered within 48 hours of birth (n = 17 and 22) at 6 months (n = 11 and 14) in SGA and AGA infants, respectively. Isotopic enrichment in urine was used to determine EZP.Results: No significant difference was detected in the mean (±standard deviation) EZP between SGA and AGA infants at birth, with values of 9.8 ± 3.5 and 10.1 ± 4.1 mg/kg, respectively (P = 0.86), or at 6 months. Longitudinal EZP measurements demonstrated a significant decline in EZP relative to body weight in both groups at 6 months (P \u3c 0.001). Mean EZP (adjusted for body weight) size at birth for the combined Pakistani groups was significantly lower than AGA infants at birth in the United States (P = 0.017).Conclusions: These results did not support a difference in zinc endowment between SGA and AGA Pakistani infants. They, however, do suggest lower in utero zinc transfer to the fetus in a setting where poor maternal nutritional status may confer a high susceptibility to postnatal zinc deficiency

Histological Examination in Obtaining a Diagnosis in Patients with Lymphadenopathy in Lima, Peru.

The differential diagnosis for lymphadenopathy is wide and clinical presentations overlap, making obtaining an accurate diagnosis challenging. We sought to characterize the clinical and radiological characteristics, histological findings, and diagnoses for a cohort of patients with lymphadenopathy of unknown etiology. 121 Peruvian adults with lymphadenopathy underwent lymph node biopsy for microbiological and histopathological evaluation. Mean patient age was 41 years (Interquartile Range 26-52), 56% were males, and 39% were HIV positive. Patients reported fever (31%), weight loss (23%), and headache (22%); HIV infection was associated with fever (P < 0.05) and gastrointestinal symptoms (P < 0.05). Abnormalities were reported in 40% of chest X-rays (N = 101). Physicians suspected TB in 92 patients (76%), lymphoma in 19 patients (16%), and other malignancy in seven patients (5.8%). Histological diagnoses (N = 117) included tuberculosis (34%), hyperplasia (27%), lymphoma (13%), and nonlymphoma malignancy (14%). Hyperplasia was more common (P < 0.001) and lymphoma less common (P = 0.005) among HIV-positive than HIV-negative patients. There was a trend toward reduced frequency of caseous necrosis in samples from HIV-positive than HIV-negative TB patients (67 versus 93%, P = 0.055). The spectrum of diagnoses was broad, and clinical and radiological features correlated poorly with diagnosis. On the basis of clinical features, physicians over-diagnosed TB, and under-diagnosed malignancy. Although this may not be inappropriate in resource-limited settings where TB is the most frequent easily treatable cause of lymphadenopathy, diagnostic delays can be detrimental to patients with malignancy. It is important that patients with lymphadenopathy undergo a full diagnostic work-up including sampling for histological evaluation to obtain an accurate diagnosis