46 research outputs found
Earthquake-triggered landslides and Environmental Seismic Intensity: insights from the 2018 Papua New Guinea earthquake (Mw 7.5)
On the 25 February 2018, an earthquake of magnitude M(w)7.5 struck the region of Porgera in Papua New Guinea (PNG), triggering numerous landslides. Planetscope images are used to derive a partial inventory of 2941 landslides in a cloud-free area of 2686 km(2). The average area of landslides in the study area is 18,500 m(2). We use the Environmental Seismic Intensity (ESI) scale to assess the damage due to the triggered landslides. Local intensity values are assigned to individual landslides by calculating their volume using various area-volume relations. We observe that different empirical relations yield similar volume values for individual landslides (local ESI intensity & GE; X). The spatial variation of landslide density and areal coverage within the study area in cells of 1 km(2) is investigated and compared to the probability predicted by the USGS model. We observe that high probability corresponds to a significant number of landslides. An ESI epicentral intensity of XI is estimated based on primary and secondary effects. This study represents the first application of the ESI scale to an earthquake in PNG. The Porgera earthquake fits well with past case studies worldwide in terms of ESI scale epicentral intensity and triggered landslide number as a function of earthquake magnitude
HIV reverse transcriptase: Structural interpretation of drug resistant genetic variants from India
The reverse transcriptase (RT) enzyme is the prime target of nucleoside/ nucleotide (NRTI) and non-nucleoside (NNRTI) reverse transcriptase
inhibitors. Here we investigate the structural basis of effects of drug-resistance mutations in clade C RT using three-dimensional structural
modeling. Apropos the expectation was for unique mechanisms in clade C based on interactions with amino acids of p66 subunit in RT molecule.
3-D structures of RT with mutations found in sequences from 2 treatment naïve, 8 failed and one reference clade C have been modeled and
analyzed. Models were generated by computational mutation of available crystal structures of drug bound homologous RT. Energy minimization
of the models and the structural analyses were carried out using standard methods. Mutations at positions 75,101,118,190,230,238 and 318
known to confer drug resistance were investigated. Different mutations produced different effects such as alteration of geometry of the drugbinding
pocket, structural changes at the site of entry of the drug (into the active site), repositioning the template bases or by discriminating the
inhibitors from their natural substrates. For the mutations analyzed, NRTI resistance was mediated mainly by the ability to discriminate between
inhibitors and natural substrate, whereas, NNRTI resistance affected either the drug entry or the geometry of the active site. Our analysis
suggests that different mutations result in different structural effects affecting the ability of a given drug to bind to the RT. Our studies will help
in the development of newer drugs taking into account the presence of these mutations and the structural basis of drug resistance
Earthquake-triggered landslides and Environmental Seismic Intensity: insights from the 2018 Papua New Guinea earthquake (Mw 7.5)
ABSTRACTOn the 25th of February 2018, an earthquake of magnitude Mw7.5 struck the region of Porgera in Papua New Guinea (PNG), triggering numerous landslides. Planetscope images are used to derive a partial inventory of 2941 landslides in a cloud-free area of 2686 km2. The average area of landslides in the study area is 18,500 m2. We use the Environmental Seismic Intensity (ESI) scale to assess the damage due to the triggered landslides. Local intensity values are assigned to individual landslides by calculating their volume using various area-volume relations. We observe that different empirical relations yield similar volume values for individual landslides (local ESI intensity ≥ X). The spatial variation of landslide density and areal coverage within the study area in cells of 1 km2 is investigated and compared to the probability predicted by the USGS model. We observe that high probability corresponds to a significant number of landslides. An ESI epicentral intensity of XI is estimated based on primary and secondary effects. This study represents the first application of the ESI scale to an earthquake in PNG. The Porgera earthquake fits well with past case studies worldwide in terms of ESI scale epicentral intensity and triggered landslide number as a function of earthquake magnitude
Vi-specific latex agglutination for early and rapid detection of Salmonella serotype typhi in blood cultures
Latex particles coated with rabbit antisera against Salmonella serotype typhi (S. typhi) Vi and O (STO) antigens were used in slide agglutination tests for the rapid identification of S. typhi in blood culture broths as soon as Gram-negative bacilli (GNB) were detected in them. Among 231 consecutive blood cultures showing GNB tested for Vi, and a subset of 163 tested for STO, by latex agglutination (LA), 125 and 32, respectively, were positive. The GNB in 127 blood cultures were confirmed by conventional methods as S. typhi, 125 (98.4%) of which had been identified by the Vi LA test. In the subset of 163, 81 grew S. typhi, of which only 32 (39.5%) had been identified by the STO LA tests. Thus, the sensitivity of the Vi and STO LA tests was 98.4% and 39.5%, respectively, whereas the specificity was 100% for both tests. Of the S. typhi isolates, 38 (30.4%) were detected by the Vi LA test on day 2 and 73 (58.4%) on day 3, day 1 being the date of inoculation of the blood culture broths. Thus, the Vi LA test is suitable for the early and rapid confirmation of S. typhi in blood culture
Viral Diseases of Public Health Importance in India: Current Priorities with Special Emphasis on Prevention
India faces problems with both communicable and non
communicable diseases. The major non communicable
diseases are cancer, cardiovascular disease and
diabetes mellitus. This article focuses on communicable
diseases (infectious diseases) especially viral
infections of public health importance. The infections
include bacterial, parasitic and viruses. It could be said
that fungal infections by the nature of the spread are
not of public health concern. The viral infections are
transmitted by the respiratory route, water and food
borne route, vectors and blood and blood products,
sexual route and are of major concern. Efforts are
aimed at early detection, prevention by use of vaccines
and sentinel surveillance. For the success of public
health programmes sentinel surveillance of diseases is
mandatory. India has got several programme
initiatives addressing the problem. The programs
include IDSP, VBDCP and NACO. The approximate
cumulative annual prevalence of infectious disease in
India ranges from 100 to 200 million individuals
affected in one year. India should aim to improve case
detection by strengthening laboratory services with
manpower training and nationwide quality control
scheme, sentinel surveillance activity and prevention
by improving the efficiency and scope of UIP. Also,
creation of a single portal of infectious disease data
handling hub to collect information from different
sources will help avoid overlap and duplication of
reporting