Mass spectrometric characterization of BCl3/SF6 plasmas

This is the published version. Copyright © 2000 American Institute of PhysicsSignificant increases in the etch rates of both GaAs and GaN have been observed with the addition of SF6 to BCl3plasmas. Mass spectrometric characterization of neutrals in these gas mixtures shows that increasing the SF6 percentage in the flow enhances the dissociation of BCl3, resulting in nearly 100% dissociation at 70% SF6. This increased dissociation is believed to be due to electron attachment heating. Both Cl and Cl2 mass intensities also maximize at 70% SF6. The detection of BClF and BCl2F suggest the possibility of reactions occurring between BCl and BCl2 radicals and fluorine, which may inhibit the recombination of Cl

Caregivers knowledge, practices about childhood diarrhea and pneumonia and their perceptions of lady health worker program; findings from NIGRAAN implementation research project

Background: Despite 60% coverage by Lady Health Worker (LHW) Program, 30% of child deaths in Pakistan are still due to diarrhea and pneumonia. Caregivers are an important stakeholder yet there is little information on their case management practices and utilization of LHW Program. This study explored caregivers’ knowledge and practices about childhood diarrhea and pneumonia and utility of LHW services before and after a supportive supervision intervention.Methods: Cross sectional surveys were conducted with caregivers’ (mothers) pre and post intervention in project NIGRAAN. The intervention aimed to improve LHSs clinical and supervisory skills of lady health supervisors in order to improve LHW performance and ultimately impact caregiver practices. 4250 households were surveyed. Questionnaire was adapted from PDHS 2012-13. Differences between intervention and control groups were assessed using chi square test. P-value of Results: Comparing baseline to end line, there were significant overall improvements in caregivers’knowledge of loose motion (62 to 84%) and dehydration (12 to 18%) as signs and symptoms of childhood diarrhea. There was also a significant overall increase in caregivers’ knowledge of presenting features of pneumonia- i.e. fever (58 to 86%), cough (51 to 61%) and breathing problems (25 to 57%). The proportion of caregivers seeking advice for diarrhea from public sector significantly improved in intervention arm from 20% to 29%. Private sector however remained overall preferred choice for care seeking. There was significant overall improvement in awareness about LHWs functioning (93 to 99%) and household visits (91 to 98%). Actual care seeking from LHWs however stayed low (≤ 0.3%) Conclusion: In order to improve utility and expand coverage of LHW Program interventions aimed at providing supportive supervision have the potential to improve caregiver practices and utilization of available services and decrease childhood deaths due to preventable illnesses

From START to FINISH : the influence of osmotic stress on the cell cycle

Peer reviewedPublisher PD

Evaluation of a subunit H5 vaccine and an inactivated H5N2 avian influenza marker vaccine in ducks challenged with Vietnamese H5N1 highly pathogenic avian influenza virus

The protective efficacy of a subunit avian influenza virus H5 vaccine based on recombinant baculovirus expressed H5 haemagglutinin antigen and an inactivated H5N2 avian influenza vaccine combined with a marker antigen (tetanus toxoid) was compared with commercially available inactivated H5N2 avian influenza vaccine in young ducks. Antibody responses, morbidity, mortality, and virus shedding were evaluated after challenge with a Vietnamese clade 1 H5N1 HPAI virus [A/VN/1203/04 (H5N1)] that was known to cause a high mortality rate in ducks. All three vaccines, administered with water-in-oil adjuvant, provided significant protection and dramatically reduced the duration and titer of virus shedding in the vaccinated challenged ducks compared with unvaccinated controls. The H5 subunit vaccine was shown to provide equivalent protection to the other two vaccines despite the H5 antibody responses in subunit vaccinated ducks being significantly lower prior to challenge. Ducks vaccinated with the H5N2 marker vaccine consistently produced antitetanus toxoid antibody. The two novel vaccines have attributes that would enhance H5N1 avian influenza surveillance and control by vaccination in small scale and village poultry systems

Comparison of two different models for pile thermal response test interpretation

Thermal response tests (TRTs) are regularly used to characterise the thermal resistance of borehole heat exchangers and to assess the thermal conductivity of the surrounding ground. It is becoming common to apply the same in situ testing technique to pile heat exchangers, despite international guidance suggesting that TRTs should be limited to hole diameters of 152 mm (6 in.). This size restriction arises from the increased thermal inertia of larger diameter heat exchangers, which invalidates the assumption of a steady state within the concrete needed to interpret the test data by traditional line source analysis techniques. However, new methods of analysis for pile heat exchangers have recently been developed that take account of the transient behaviour of the pile concrete. This paper applies these new methods to data from a multi-stage TRT conducted on a small diameter test pile. The thermal conductivity and thermal resistance determined using this method are then compared with those from traditional analytical approaches based on a line source analysis. Differences between the approaches are discussed, along with the observation that the thermal resistance may not be constant over the different test stages

The influence of injection molding parameter on properties of thermally conductive plastic

Thermally conductive plastic is the composite between metal-plastic material that is becoming popular because if it special characteristic. Injection moulding was regarded as the best process for mass manufacturing of the plastic composite due to its low production cost. The objective of this research is to find the best combination of the injection parameter setting and to find the most significant factor that effect the strength and thermal conductivity of the composite. Several parameter such as the volume percentage of copper powder, nozzle temperature and injection pressure of injection moulding machine were investigated. The analysis was done using Design Expert Software by implementing design of experiment method. From the analysis, the significant effects were determined and mathematical models of only significant effect were established. In order to ensure the validity of the model, confirmation run was done and percentage errors were calculated. It was found that the best combination parameter setting to maximize the value of tensile strength is volume percentage of copper powder of 3.00%, the nozzle temperature of 195oC and the injection pressure of 65%, and the best combination parameter settings to maximize the value of thermal conductivity is volume percentage of copper powder of 7.00%, the nozzle temperature of 195oC and the injection pressure of 65% as recommended

Cholesterol catalyses Aβ42 aggregation through a heterogeneous nucleation pathway in the presence of lipid membranes.

Alzheimer's disease is a neurodegenerative disorder associated with the aberrant aggregation of the amyloid-β peptide. Although increasing evidence implicates cholesterol in the pathogenesis of Alzheimer's disease, the detailed mechanistic link between this lipid molecule and the disease process remains to be fully established. To address this problem, we adopt a kinetics-based strategy that reveals a specific catalytic role of cholesterol in the aggregation of Aβ42 (the 42-residue form of the amyloid-β peptide). More specifically, we demonstrate that lipid membranes containing cholesterol promote Aβ42 aggregation by enhancing its primary nucleation rate by up to 20-fold through a heterogeneous nucleation pathway. We further show that this process occurs as a result of cooperativity in the interaction of multiple cholesterol molecules with Aβ42. These results identify a specific microscopic pathway by which cholesterol dramatically enhances the onset of Aβ42 aggregation, thereby helping rationalize the link between Alzheimer's disease and the impairment of cholesterol homeostasis

Search for psi(2S)--> eta_c pi^+ pi^- pi^0

Using 5.63 pb^-1 of data accumulated at the psi(2S) resonance with the CLEO III and CLEO-c detectors corresponding to 3.08 million psi(2S) decays, a search is performed for the decay psi(2S) -> eta_c pi^+pi^-pi^0 to test a theoretical prediction based upon the assumption that the c \bar c pair in the psi(2S) does not annihilate directly into three gluons but rather survives before annihilating. No signal is observed, and a combined upper limit from six eta_c decay modes is determined to be B(psi(2S) -> eta_c pi^+pi^-pi^0) < 1.0 x 10^-3 at 90% C.L. This upper limit is about an order of magnitude below the theoretical expectation.Comment: 8 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2006

First Observation of Upsilon(3S) --> tau tau and Tests of Lepton Universality in Upsilon Decays

Using data collected with the CLEO-III detector at the CESR e+e- collider, we report on a first observation of the decay of the Upsilon(3S) to tau tau, and precisely measure the ratio of branching fractions of Upsilon(nS),n=1,2,3 to tau tau and mu mu final states, finding agreement with expectations from lepton universality. We derive absolute branching fractions for these decays, and also set a limit on the influence of a low mass CP-odd Higgs boson in the decay of the Upsilon(1S).Comment: 9 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2006