A study of the chemical components of aerosols and snow in the Kashmir region.

Atmospheric aerosols in surface air were sampled for a total period of 2 weeks, from February 25 to March 11, 1971, during the winter season, at Gulmarg and Srinagar. Snow samples were also collected on days of snow occurrence during the period. Aerosols were sampled using cascade impactor and millipore filter assembly. Samples collected through impactor were categorized into hygroscopic and non-hygroscopic nuclei while chloride, ice-forming and total nuclei were evaluated from millipore filters.Analysis of the aerosol data showed higher counts for all the nuclei at Srinagar with respect to Gulmarg. Fractions of chloride, hygroscopic and ice-forming nuclei among the total nuclei were larger at Gulmarg. Aerosol counts during the days were higher as compared to the corresponding night values. All the chemical constituents, except Cl−, gradually reduced from the initial to the end stage of the snowfall. Snow sample from Srinagar indicated higher cation concentrations. Variations of aerosols under different weather conditions have been discusse

Calibration for measurements of droplet size distributions of ground based clouds - a laboratory investigation

Water droplets of varying sizes, released through an atomizer, were collected on glass slides coated with uniform layers of magnesium oxide or carbon soot and silicone oil. Assuming that the droplets retain their original shapes in the oil film, calibrations were obtained for their spreading on oxide and soot layers of known thickness. The calibrations have been further applied to evaluate droplet size distributions of ground-based clouds

Reducing Time to Reset a Stateful System Under Test (SUT)

The qualification of continuously running, stateful systems requires a full reset to initial state due to the state-altering nature of a finite workload. A full reset entails teardown and restart of the system to a known initial state, which can cause the workload to experience long downtimes for the duration of the reset. This disclosure describes techniques that reduce reset durations that occur in the context of testing stateful systems. In a one-time operation, an initial state is maintained in persistent storage, e.g., in cloud-based virtual disks. The system under test (SUT) is reset using the stored initial image. The time saved in the obviated teardown-and-restart procedure directly translates to reduced startup and qualification times and obviates other time-consuming procedures such as reinstalling dependent libraries and software. The techniques generally reduce interruptions in testing and are especially useful for narrow rollout windows

Effects of anxiety on neurocognitive performance in HIV positive adults

Objective: To examine the effects of anxiety on neuropsychological performance among HIV positive adults in Lusaka, Zambia.Design: A cross-sectional study with a sample of 263 participants of who 107 (40.7%) were males and 156 (59.3%) were females.Measures: The International Neurobehavioural Test Battery and Beck Anxiety Inventory were used to assess cognitive performance and anxiety levels respectively.Results: Severe anxiety showed a weak positive correlation (r=.148, p=0.472), but the result did not reach statistical significance. Participants who were not able to perform instrumental activities of daily living independently were more likely to be anxious (p<0.05).Conclusion: Results obtained from this study imply that there are minimal differences in performance between non anxious and anxious HIV positive individuals on neurocognitive performance. However, anxiety showed an effect on instrumental activities of daily living of the participants.Key Words: Anxiety, HIV, instrumental activities of daily living, Cognitive Performanc

Clinical characteristics of epilepsy in resource‐limited communities in Punjab, Northwest India

Objectives: To describe clinical characteristics of a community‐based epilepsy cohort from resource‐limited communities in Punjab, Northwest India. / Methods: The cohort was gathered following a two‐stage screening survey. We cross‐sectionally examined and followed up the cohort for one year. A panel of neurologists assigned seizure types, syndromes, and putative etiologies and categorized drug responsiveness. / Results: The cohort of 240 included 161 (67.1%) men, 109 (45.4%) illiterates and 149 (62.1%) unemployed. Current age was >18 years in 155 (64.6%) but age at epilepsy onset was <18 years in 173 (72.1%). Epilepsies due to structural and metabolic causes were diagnosed in 99 (41.3%), but syndromic assignments were not possible in 97 (40.4%). After one year, drug‐resistant epilepsy was established in 74 (30.8%). Perinatal events (n = 35; 14.6%) followed by CNS infections (n = 32; 13.3%) and traumatic brain injury (n = 12; 5.0%) were common risk factors. Most of those with CNS infections (n = 19; 63.3%), perinatal antecedents (n = 23; 76.7%), and other acquired risk factors (n = 27; 90.0%) presented with epilepsy due to structural and metabolic causes. Perinatal events were the putative etiology for nearly 40.7% of generalized epilepsies due to structural and metabolic causes and 28.2% of all epilepsies with onset <10 years. / Significance: Existing classifications schemes should be better suited to field conditions in resource‐limited communities in low‐ and middle‐income countries. The finding of drug‐resistant epilepsy in nearly at least a third in a community‐based sample underscores an unmet need for enhancing services for this segment within healthcare systems. Perinatal events, CNS infections, and head injury account for a third of all epilepsies and hence preventative interventions focusing on these epilepsy risk factors should be stepped up

Altered expression of microRNA in the airway wall in chronic asthma: miR-126 as a potential therapeutic target

Background: The role of microRNAs (miRNAs) in regulating gene expression is currently an area of intense interest. Relatively little is known, however, about the role of miRNAs in inflammatory and immunologically-driven disorders. In a mouse model, we have previously shown that miRNAs are potentially important therapeutic targets in allergic asthma, because inhibition of miR-126, one of a small subset of miRNAs upregulated in the airway wall, effectively suppressed Th2-driven airway inflammation and other features of asthma. In the present study, we extended investigation of the therapeutic potential of miRNA inhibition to our well-established model of chronic asthma. Methods: Female BALB/c mice were systemically sensitised with ovalbumin (OVA) and chronically challenged with low mass concentrations of aerosolised OVA for up to 6 weeks. Airway tissue was obtained by blunt dissection and RNA was isolated for miRNA profiling. On the basis of the results obtained, animals were subsequently treated with either an antagomir to miR-126 (ant-miR-126) or a scrambled control antagomir once weekly during the 6 weeks of chronic challenge, and the effects on airway inflammation and remodelling were assessed using established morphometric techniques. Results: Compared to naïve mice, there was selective upregulation of a modest number of miRNAs, notably miR-126, in the airway wall tissue of chronically challenged animals. The relative increase was maximal after 2 weeks of inhalational challenge and subsequently declined to baseline levels. Compared to treatment with the scrambled control, ant-miR-126 significantly reduced recruitment of intraepithelial eosinophils, but had no effect on the chronic inflammatory response, or on changes of airway remodelling. Conclusions: In this model of chronic asthma, there was an initial increase in expression of a small number of miRNAs in the airway wall, notably miR-126. However, this later declined to baseline levels, suggesting that sustained changes in miRNA may not be essential for perpetuation of chronic asthma. Moreover, inhibition of miR-126 by administration of an antagomir suppressed eosinophil recruitment into the airways but had no effect on chronic inflammation in the airway wall, or on changes of remodelling, suggesting that multiple miRNAs are likely to regulate the development of these lesions

Influence of a knot on the strength of a polymer strand

Many experiments have been done to determine the relative strength of different knots, and these show that the break in a knotted rope almost invariably occurs at a point just outside the `entrance' to the knot. The influence of knots on the properties of polymers has become of great interest, in part because of their effect on mechanical properties. Knot theory applied to the topology of macromolecules indicates that the simple trefoil or `overhand' knot is likely to be present with high probability in any long polymer strand. Fragments of DNA have been observed to contain such knots in experiments and computer simulations. Here we use {\it ab initio} computational methods to investigate the effect of a trefoil knot on the breaking strength of a polymer strand. We find that the knot weakens the strand significantly, and that, like a knotted rope, it breaks under tension at the entrance to the knot.Comment: 3 pages, 4 figure

Surface topography of hydroxyapatite affects ROS17/2.8 cells response

Hydroxyapatite (HA) has been used in orthopedic, dental, and maxillofacial surgery as a bone substitute. The aim of this investigation was to study the effect of surface topography produced by the presence of microporosity on cell response, evaluating: cell attachment, cell morphology, cell proliferation, total protein content, and alkaline phosphatase (ALP) activity. HA discs with different percentages of microporosity (< 5%, 15%, and 30%) were confected by means of the combination of uniaxial powder pressing and different sintering conditions. ROS17/2.8 cells were cultured on HA discs. For the evaluation of attachment, cells were cultured for two hours. Cell morphology was evaluated after seven days. After seven and fourteen days, cell proliferation, total protein content, and ALP activity were measured. Data were compared by means of ANOVA and Duncan’s multiple range test, when appropriate. Cell attachment (p = 0.11) and total protein content (p = 0.31) were not affected by surface topography. Proliferation after 7 and 14 days (p = 0.0007 and p = 0.003, respectively), and ALP activity (p = 0.0007) were both significantly decreased by the most irregular surface (HA30). These results suggest that initial cell events were not affected by surface topography, while surfaces with more regular topography, as those present in HA with 15% or less of microporosity, favored intermediary and final events such as cell proliferation and ALP activity

Prediction of landing gear loads using machine learning techniques

This article investigates the feasibility of using machine learning algorithms to predict the loads experienced by a landing gear during landing. For this purpose, the results on drop test data and flight test data will be examined. This article will focus on the use of Gaussian process regression for the prediction of loads on the components of a landing gear. For the learning task, comprehensive measurement data from drop tests are available. These include measurements of strains at key locations, such as on the side-stay and torque link, as well as acceleration measurements of the drop carriage and the gear itself, measurements of shock absorber travel, tyre closure, shock absorber pressure and wheel speed. Ground-to-tyre loads are also available through measurements made with a drop test ground reaction platform. The aim is to train the Gaussian process to predict load at a particular location from other available measurements, such as accelerations, or measurements of the shock absorber. If models can be successfully trained, then future load patterns may be predicted using only these measurements. The ultimate aim is to produce an accurate model that can predict the load at a number of locations across the landing gear using measurements that are readily available or may be measured more easily than directly measuring strain on the gear itself (for example, these may be measurements already available on the aircraft, or from a small number of sensors attached to the gear). The drop test data models provide a positive feasibility test which is the basis for moving on to the critical task of prediction on flight test data. For this, a wide range of available flight test measurements are considered for potential model inputs (excluding strain measurements themselves), before attempting to refine the model or use a smaller number of measurements for the prediction

Optical Detection of Ultrasound by Two-Wave Mixing in Photorefractive Semiconductor Crystals Under Applied Field

The optical detection of transient surface motion has many practical applications which include, in particular, the vibration monitoring of engineering structures (aircraft, power plants,...) and the detection of ultrasound produced by piezoelectric transducer or by pulse laser excitation. This last application where ultrasound is generated and detected by lasers, presents many advantages over conventional piezoelectric based methods. First, laser-ultrasonics is a remote sensing technique. Consequently it can be used, for example, for inspecting hot materials and products moving on a production line. Second, surfaces of complex shapes can also very easily be probed. For many applications, these advantages compensate the usually lower sensitivity of the laser-based technique compared to piezoelectric transduction