792 research outputs found
Parking and the visual perception of space
Using measured data we demonstrate that there is an amazing correspondence
among the statistical properties of spacings between parked cars and the
distances between birds perching on a power line. We show that this observation
is easily explained by the fact that birds and human use the same mechanism of
distance estimation. We give a simple mathematical model of this phenomenon and
prove its validity using measured data
MR imaging of meniscal tears
Background: Menisci transmit the forces across the joint and cushion the mechanical loading of the joint. Thus, it is important to identify meniscal tear. A thorough understanding of normal meniscal anatomy and surrounding structure is critical for diagnosis. Magnetic resonance imaging is the current modality of choice providing fine resolution and multi-planar imaging for identifying the meniscal injuries and the various pattern of tear, helping to plan the subsequent management. The purpose of the work was to study the role of MRI in classifying the meniscal injuries.Methods: MRI Knee of 136 patients with meniscal injuries was studied. All the MR imaging scans were performed on 1.5-T MR system (Siemens magnetom Essenza).Results: A total of 136 patients were studied in which majority of the patient’s i.e. 90.44 % had medial meniscal tear while 18.38 % patients had lateral meniscal tear. Both medial and lateral meniscal tears were found in 8.82 % patients. Among the different types of tears, horizontal tear was the most common tear in both medial and lateral meniscus comprising 52.8 % and 52 % respectively. The tears being most common in the age group 41-50years. There were associated injuries to the other ligaments of the knee joint along with meniscal tear, ACL tear being the most common and was seen in 50% of patients.Conclusions: MRI is a good modality for classifying meniscal injury and evaluation of injuries to the associated ligaments. Secondary signs are good predictors of underlying meniscal tear in equivocal cases
Effect of lopping intensity on tree growth and stand productivity in Tropical Forests
Effects of various intensities of lopping on the growth of trees, production of leafy biomass (leaves + shoots) and grass biomass production were investigated in the forests of the Western Ghats, India. Frequent complete lopping of trees resulted in a rapid drain of stored reserves leading to reduction in growth of tree girth and production of leafy biomass. Relatively greater increase in girth at the breast height of trees that were subjected to partial lopping, i.e. less than 50% intensity, was considered to be mainly the result of stimulation of remaining leaves to higher rates of photosynthesis. Opening of canopy increased the grass production in lopped quadrats. In two species, Aporosa lindleyana and Terminalia paniculata, the growth rate of girth and the yearly production of leafy biomass showed positive correlation up to 75% lopping intensity indicating that these two species can withstand lopping to some extent. For managing the forests and trees on an ecologically sustainable basis, the desired option recommended is to restrict lopping to less than 50% of the crown portion. Intensive long term studies, however, are required to suggest management practices
Recommended from our members
Conservation screening curves to compare efficiency investments topower plants: Applications to commercial sector conservationprograms
This paper describes a simplified methodology to compare supply and demand-side resources. The screening curve approach supplements with load shape information the data contained in a supply curve of conserved energy. In addition, a screening curve contains information on competing supply technologies, such as annualized capital costs, variable costs, and cost per delivered kWh. The information in the screening curve allows policymakers to promptly and conveniently compare the relevant parameters affecting supply and demand-side investment decisions. While many sophisticated computer models have evolved to account for the load shape impacts of energy efficiency investments, this sophistication has, by and large, not trickled down to spreadsheet-level or 'back-of-the-envelope' analyses. Our methodology allows a simple summary of load shape characteristics based on the output of the more complicated models. It offers many advantages, principal of which is clarity in analyzing supply and demand-side investment choices. This paper first describes how supply-side screening curves have been used in the past, and develops the conceptual tools needed to apply integrated supply/demand screening curves in the least-cost utility planning process. It then presents examples of supply-side technologies and commercial sector demand-side management programs, and plots them on representative screening curves
Comparison of LC and LC/MS methods for quantifying N-glycosylation in recombinant IgGs
Recommended from our members
CONSERVATION OPTIONS IN RESIDENTIAL ENERGY USE: STUDIES USING THE COMPUTER PROGRAM TWOZONE
A computer model called TWOZONE, which differentiates between the thermal behavior of the north and south zones of a house, is used to study the heating and cooling loads of single-family residences. The model agrees well with the available field data and with the NBSLD (NBSFAST) computer program. In this paper we resolve the furnace output into component loads. We show that depending on the climate, there is an optimum glass area and location in the house from the viewpoint of minimizing the yearly heating bill. The effectiveness of several window management strategies is studied. The energy savings and cost effectiveness of various retrofit measures such as ceiling and wall insulation, storm windows, and clock thermostat are evaluated for two different climates
Chapter 9 - Buildings
This chapter aims to update the knowledge on the building sector since the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) from a mitigation perspective. Buildings and activities in buildings are responsible for a significant share of GHG emissions, but they are also the key to mitigation strategies. In 2010, the building sector accounted for approximately 117 Exajoules (EJ) or 32% of global final energy consumption and 19% of energy-related CO2 emissions; and 51% of global electricity consumption. Buildings contribute to a significant amount of F-gas emissions, with large differences in reported figures due to differing accounting conventions, ranging from around an eighth to a third of all such emissions. The chapter argues that beyond a large emission role, mitigation opportunities in this sector are also significant, often very cost-effective, and are in many times associated with significant co-benefits that can exceed the direct benefits by orders of magnitude. The sector has significant mitigation potentials at low or even negative costs. Nevertheless, without strong actions emissions are likely to grow considerably - and they may even double by mid-century - due to several drivers. The chapter points out that certain policies have proven to be very effective and several new ones are emerging. As a result, building energy use trends have been reversed to stagnation or even reduction in some jurisdictions in recent years, despite the increases in affluence and population.
The chapter uses a novel conceptual framework, in line with the general analytical framework of the contribution of Working Group III (WGIII) to the IPCC Fifth Assessment Report (AR5), which focuses on identities as an organizing principle
Parental spoken scaffolding and narrative skills in crowd-sourced storytelling samples of young children
A novel crowdsourcing project to gather children’s storytelling based language samples using a mobile app was undertaken across the United Kingdom. Parents’ scaffolding of children’s narratives was observed in many of the samples. This study was designed to examine the relationship of scaffolding and young children’s narrative language ability in a story retell context which is analysed at the macro-structural (total macro-structure score), the micro-structural (mean length of utterances in morphemes) and verbal productivity (total number of utterances) levels. Young children with and without scaffolding were statistically compared. The interaction between the level of scaffolding support, the grammar complexity and the narrative structure was explored. A bidirectional relationship was observed between scaffolding and young children’s narrative language ability. Young children with better performance were observed to receive less scaffolding from parents. Scaffolding was shown to support early narrative development of young children and was more able to benefit those with low-level grammatical complexity skills. It is crucial to encourage parental scaffolding to be well-attuned to the child’s narrative ability
Glycan shifting on hepatitis C virus (HCV) E2 glycoprotein is a mechanism for escape from broadly neutralizing antibodies
Hepatitis C virus (HCV) infection is a major cause of liver disease and hepatocellular carcinoma. Glycan shielding has been proposed to be a mechanism by which HCV masks broadly neutralizing epitopes on its viral glycoproteins. However, the role of altered glycosylation in HCV resistance to broadly neutralizing antibodies is not fully understood. Here, we have generated potent HCV neutralizing antibodies hu5B3.v3 and MRCT10.v362 that, similar to the previously described AP33 and HCV1, bind to a highly conserved linear epitope on E2. We utilize a combination of in vitro resistance selections using the cell culture infectious HCV and structural analyses to identify mechanisms of HCV resistance to hu5B3.v3 and MRCT10.v362. Ultra deep sequencing from in vitro HCV resistance selection studies identified resistance mutations at asparagine N417 (N417S, N417T and N417G) as early as 5 days post treatment. Comparison of the glycosylation status of soluble versions of the E2 glycoprotein containing the respective resistance mutations revealed a glycosylation shift from N417 to N415 in the N417S and N417T E2 proteins. The N417G E2 variant was glycosylated neither at residue 415 nor at residue 417 and remained sensitive to MRCT10.v362. Structural analyses of the E2 epitope bound to hu5B3.v3 Fab and MRCT10.v362 Fab using X-ray crystallography confirmed that residue N415 is buried within the antibody–peptide interface. Thus, in addition to previously described mutations at N415 that abrogate the β-hairpin structure of this E2 linear epitope, we identify a second escape mechanism, termed glycan shifting, that decreases the efficacy of broadly neutralizing HCV antibodies
- …