Electric potential gradient and current during steady precipitation

An outdoor site adjoining Durham Observatory was instrumented to measure the atmospheric potential gradient and precipitation current at the ground during periods of steady, quiet precipitation. A system was constructed to automatically record these quantities and to present the data in a form suitable for input to a computer. Examination of most periods of quiet precipitation between January and June 1972 shows that rain is usually positively charged, with the potential gradient being negative, while during snow these signs are reversed. There is nearly always significant correlation between the two electrical quantities, with during rain variations in potential gradient most often leading those in precipitation current by several minutes; during snow the precipitation current leads by a similar amount. These two effects correspond to the so-called "inverse relation" and "mirror-image- effect" often quoted in previous work. These results are shown to be consistent with the precipitation charge being due to two charging processes, one acting on solid precipitation within the cloud, and the second occurring during the melting of snow to rain. Examination of aerological data shows that the time lags between corresponding variations of the electrical quantities can be explained during rain by the effects of the wind shear between the cloud and the ground on the falling precipitation. The different electrical behaviour of a few periods of precipitation can be explained by ,the effects of a slow-moving cloud where electrical development is taking place, rather than by a passing cloud with constant electrical activity. Comparison of periods of quiet precipitation with "disturbed" periods, when the electrical activity is much greater, suggests that the transition to disturbed precipitation occurs when the rate of electrical sign reversals exceeds 2 per hour and the precipitation rate exceeds 1-0 mm hr ,^ The connection between the degrees of electrical and meteorological activity agrees with the suggestion that the electrical activity reflects the degree of atmospheric stability within the cloud

Compliant Air Skates, An Experiment

There is currently a gap in the market of train levitation systems: wheeled trains and MagLev trains exist, but none utilize the low friction and high efficiency aspect of trains levitated by air skates. An air skate, is an air bearing that uses a pressure difference along its annular body to create a thin flow of air which is strong enough to levitate the weight of the skate. We have designed a compliant air skate that can glide over 0.04[in] defects in surfaces without touching down. After having made compliant skirts out of fiberglass and silicone, our setup of three air skates was easily capable of levitating 300[lb] while maintaining 3[psi] evenly split at the skates with an equivalent air flowrate of 3 [ft^3/min]

Adeno-Associated Virus-Mediated Rescue of the Cognitive Defects in a Mouse Model for Angelman Syndrome

Angelman syndrome (AS), a genetic disorder occurring in approximately one in every 15,000 births, is characterized by severe mental retardation, seizures, difficulty speaking and ataxia. The gene responsible for AS was discovered to be UBE3A and encodes for E6-AP, an ubiquitin ligase. A unique feature of this gene is that it undergoes maternal imprinting in a neuron-specific manner. In the majority of AS cases, there is a mutation or deletion in the maternally inherited UBE3A gene, although other cases are the result of uniparental disomy or mismethylation of the maternal gene. While most human disorders characterized by severe mental retardation involve abnormalities in brain structure, no gross anatomical changes are associated with AS. However, we have determined that abnormal calcium/calmodulin-dependent protein kinase II (CaMKII) regulation is seen in the maternal UBE3A deletion AS mouse model and is responsible for the major phenotypes. Specifically, there is an increased αCaMKII phosphorylation at the autophosphorylation sites Thr286 and Thr305/306, resulting in an overall decrease in CaMKII activity. CaMKII is not produced until after birth, indicating that the deficits associated with AS are not the result of developmental abnormalities. The present studies are focused on exploring the potential to rescue the learning and memory deficits in the adult AS mouse model through the use of an adeno-associated virus (AAV) vector to increase neuronal UBE3A expression. These studies show that increasing the levels of E6-AP in the brain using an exogenous vector can improve the cognitive deficits associated with AS. Specifically, the associative learning deficit was ameliorated in the treated AS mice compared to the control AS mice, indicating that therapeutic intervention may be possible in older AS patients

Experimental Plans for Accident Studies of Highway Design Elements: Encroachment Accident Study

DTFH61-92-C-00172This report documents an investigation into the feasibility of using accident data to derive estimates of the rate at which errant vehicles unintentionally encroach into the roadside on level, tangent sections of two-lane rural roads. In addition, issues related to estimating the percentage of unreported accidents were also investigated. The report discusses results from the literature and an analysis of hit-utility-pole accident cases from the National Accident Sampling System (NASS). A pilot study involving 56 km (35 mi) of tangent, two-lane rural road sections in Idaho is also documented. For that pilot study, detailed roadside data were collected and accident and traffic data were obtained. Based on an analysis of that data, the resulting encroachment rate estimates were determined to be of the same order of magnitude as the encroachment rates that had been developed from previous research. It was concluded that the methodology is feasible, although it is limited by the current state of the knowledge with respect to data on the trajectories of vehicles involved in run-off-the-road and hit-fixed-object crashes. An experimental plan for future research that would produce improved estimates of roadside encroachment rates is also presented. Because the plan depends on the availability of detailed sign maintenance and roadside inventory data in electronic media, it is recommended that the plan not be implemented immediately. When and if it is implemented, the latest results from other research on trajectory data should be integrated into the plan

Factors underlying metastatic breast cancer patients' perceptions of symptom importance: a qualitative analysis

The symptom literature in cancer has primarily examined symptom severity, frequency and distress. Assessing cancer patients' perceptions of symptom importance-how important it is for them to see improvement in a symptom following an intervention-and factors influencing these judgments would also inform patient-centred care, but this analysis has not been undertaken. This qualitative study aimed to identify factors underlying perceptions of symptom importance among 25 symptomatic metastatic breast cancer (MBC) patients. Participants were recruited from a cancer centre in the Midwestern USA. Semi-structured interviews focused on patients' rationale for considering common symptoms (i.e., anxiety, sadness, sleep problems, pain or fatigue) to be important. Thematic analyses revealed five interrelated factors underlying MBC patients' perceptions of symptom importance: activity restriction, concentration difficulties, exacerbation of other physical symptoms, symptom-related long-term health concerns and negative impact on their relationships with others. Patients most frequently stated that a physical or psychological symptom was important because of the resulting activity restriction. Additionally, some patients considered pain to be important because it signalled potential long-term health concerns, such as worsening metastatic disease. Findings suggest that clinicians should take into account MBC patients' perceptions of symptom importance and factors underlying these judgments when making shared treatment decisions

Show Racism The Red Card: potential barriers to the effective implementation of the anti-racist message

This discussion paper focuses on anti-racist groups associated with British Association football (soccer) and the barriers that they face in relation to effective implementation of the anti-racism message and aspirational cultural change. In order to address those issues (above) this essay draws on the educational charity Show Racism the Red Card (SRTRC) and their work to educate individuals in Great Britain though football. It takes an overview of the work of the charity, specifically focusing on three key areas relating to the group’s mission statement. Concluding comments are made on the current position of SRTRC in light of recent high-profile racist incidents

Reticular dysgenesis-associated AK2 protects hematopoietic stem and progenitor cell development from oxidative stress.

Adenylate kinases (AKs) are phosphotransferases that regulate the cellular adenine nucleotide composition and play a critical role in the energy homeostasis of all tissues. The AK2 isoenzyme is expressed in the mitochondrial intermembrane space and is mutated in reticular dysgenesis (RD), a rare form of severe combined immunodeficiency (SCID) in humans. RD is characterized by a maturation arrest in the myeloid and lymphoid lineages, leading to early onset, recurrent, and overwhelming infections. To gain insight into the pathophysiology of RD, we studied the effects of AK2 deficiency using the zebrafish model and induced pluripotent stem cells (iPSCs) derived from fibroblasts of an RD patient. In zebrafish, Ak2 deficiency affected hematopoietic stem and progenitor cell (HSPC) development with increased oxidative stress and apoptosis. AK2-deficient iPSCs recapitulated the characteristic myeloid maturation arrest at the promyelocyte stage and demonstrated an increased AMP/ADP ratio, indicative of an energy-depleted adenine nucleotide profile. Antioxidant treatment rescued the hematopoietic phenotypes in vivo in ak2 mutant zebrafish and restored differentiation of AK2-deficient iPSCs into mature granulocytes. Our results link hematopoietic cell fate in AK2 deficiency to cellular energy depletion and increased oxidative stress. This points to the potential use of antioxidants as a supportive therapeutic modality for patients with RD