41 research outputs found
Assessing spectral similarities between rainfed and irrigated croplands in a humid environment for irrigated land mapping
Deriving accurate spatial assessments of the distribution of irrigated crops has become more important in recent years for water resource planning, particularly where irrigation water resources are constrained. However, this is easier in arid climates than in humid areas such as eastern England. The challenges in using alternative vegetation indices derived from remote sensing to discriminate between irrigated and rainfed crops in a humid climate are described, focusing on potato (Solanum tuberosum L.), the most important irrigated crop in England. Three techniques were evaluated: (a) temporal profile comparisons using the Normalized Difference Vegetation Index (NDVI); (b) cluster analysis combining the NDVI and the Normalized Difference Water Index (NDWI); and (c) identifying differences in chlorophyll content using green and near infrared bands. However, the study confirmed that the spectral signatures of irrigated and rainfed potato in England during a typical summer are very similar, presumably due to frequent rainfall events which reduce differences in water stress and chlorophyll content. The implications for using remote sensing to estimate irrigated areas in humid climates are discussed
Secure System? Challenge Accepted: Finding and Resolving Security Failures Using Security Premortems
Risk-driven approaches are dominant in secure systems design; these aim to elicit and treat vulnerabilities and the threats exploiting them. Such approaches, however, are so focused on driving risks out of system design, they fail to recognise the usefulness of failure as a vehicle for security innovation. To explore the role of failure as a design tool, we present the security premortem: a participative design technique where participants assume that a system has been exploited, and plausible reasons are given for explaining why. We describe this approach and illustrate how software tools can be used to support it
Oxidative stress in cigarette smoker and smokeless tobacco user among ethnic group north-eastern population of Uttar Pradesh, India
Background: Cigarette smoking and other form of tobacco abusing habits are high prevalence in India at present which can be compare the oxidative level among them. This study aimed to measure the oxidative level among different cigarette smoke and other form of users in north-eastern, Uttar Pradesh of India.Methods: Total of 934 male and female subjects were selected in which 387 were controls (Group I), 140 were active smokers (Group II), 105 were passive smokers (group III), 182 were tobacco users (Group IV) and 120 were active smokers plus tobacco users (group V). Cigarette smoker and tobacco user prevalence 10/day for 5 years’ duration were collected. MDA, SOD, GR and CAT were measured.Results: Cigarette smoker and tobacco user prevalence is high in >10 cigarette/day for 5 years, Mean and SD value in oxidative stress in cigarette smokers and tobacco users MDA level 1314±330.1µmol/mg is increased, whereas SOD, GR and CAT level 2.229±0.248 units/ml, 0.0152±0.0071mg/ml and 0.345±0.046mg/ml respectively were reduced in active smoker plus tobacco users.Conclusions: Present study concluded that cigarette smoker and tobacco user showed their increased MDA and decreased SOD, GR and CAT which represented the significantly increased oxidative stress in north-eastern of Uttar Pradesh, India
Ethical Hazards and Safeguards in Penetration Testing
Penetration testing entails attacking a system to identify and report insecurity, but doing so without harming
the system nor encroaching on the dignity of those affected by it. To improve the interaction between
penetration testers and their processes and technology, we need to understand the factors that affect
decisions they make with ethical import. This paper presents four ethical hazards faced by penetration
testers, and three safeguards that address them. We also present preliminary results validating the hazards
and safeguards
Difficulties in using spectral properties to map irrigated areas in a temperate climate: A case study of potatoes in England
Irrigation in England is supplemental to rainfall and only used on a small proportion of the cultivated land, notably on high value vegetable and potato crops. However, it is a significant water user as most of the irrigated area is located in the driest part of England. The existing data on irrigated areas are based on government and industry surveys. Recently these datasets have been used with Geographic Information Systems (GIS) to produce irrigated maps, but these can only be published at catchment level due to confidentiality constraints on the datasets. To assess the possibility of using remote sensing data for mapping the irrigated area, one Landsat image for the summer 2003 was used to compare the spectral signature between irrigated and non-irrigated potato fields in the East of England. ISODATA algorithm was used to perform unsupervised classification, and 50 spectral classes were created. A ground truth dataset was then used to identify the most representative spectral class for irrigated and nonirrigated fields. The result showed that categories both fall into the same spectral class, suggesting there are no significant differences between their spectral properties. Therefore, using satellite imagery may not yet be an appropriate method or need more research for mapping irrigated area in temperate climates such as England. The summer rainfall reduces the water stress differences between irrigated and non-irrigated potato fields such that these satellite sensors cannot yet differentiate the crops
Nematopsis sp. (Apicomplexa: Porosporidae) infection in Crassostrea madrasensis and its associated histopathology
The present study forms the first report of Nematopsis sp. infection in the
edible oyster, Crassostrea madrasensis from India. The study was carried
out as part of a detailed pathological investigation of C. madrasensis
along the southwest coast of India. Sporozoites of Nematopsis sp. were
found in samples collected from two locations. Light microscopic
observation revealed ellipsoidal oocysts measuring 16.63±2.40 μm in
length and 11.11± 2.49 μm in width (n=30) in the connective tissues
of gills, mantle, visceral mass and gonads. Prevalence of infection
ranged from 11 to 27%. Apparent pathological changes included
compression of adjacent digestive diverticulae in visceral connective
tissue infections and presence of phagocytosed oocysts in water
channels in the case of gill infections. With relevance to the expanding
culture of C. madrasensis, monitoring potential pathogens of this species
in its natural habitat is important for developing suitable health
management packages
Finding and Resolving Security Misusability with Misusability Cases
Although widely used for both security and usability concerns, scenarios used in security design may not necessarily inform the design of usability, and vice- versa. One way of using scenarios to bridge security and usability involves explicitly describing how design deci- sions can lead to users inadvertently exploiting vulnera- bilities to carry out their production tasks. This paper describes how misusability cases, scenarios that describe how design decisions may lead to usability problems sub- sequently leading to system misuse, address this problem. We describe the related work upon which misusability cases are based before presenting the approach, and illus- trating its application using a case study example. Finally, we describe some findings from this approach that further inform the design of usable and secure systems
Two instances of gonadal abnormalities in Indian mackerel
The Indian mackerel Rastrelliger kanagurta is
known to be dioecious with male and female gonads
in separate individuals. However, gonadal
abnormalities such as hermaphroditism and other
aberrations have been observed in a few instances.
Gonadal abnormalities in mackerel observed during
regular biological sampling from fish samples
collected from the landing centre is reported here.
For the histological analysis, the gonads were fixed
in 10% neutral buffered formalin, dehydrated in
ethanol series and the cleared samples were
embedded in paraffin wax and made into blocks
POSYDON: A General-Purpose Population Synthesis Code with Detailed Binary-Evolution Simulations
Most massive stars are members of a binary or a higher-order stellar systems,
where the presence of a binary companion can decisively alter their evolution
via binary interactions. Interacting binaries are also important astrophysical
laboratories for the study of compact objects. Binary population synthesis
studies have been used extensively over the last two decades to interpret
observations of compact-object binaries and to decipher the physical processes
that lead to their formation. Here, we present POSYDON, a novel, binary
population synthesis code that incorporates full stellar-structure and
binary-evolution modeling, using the MESA code, throughout the whole evolution
of the binaries. The use of POSYDON enables the self-consistent treatment of
physical processes in stellar and binary evolution, including: realistic
mass-transfer calculations and assessment of stability, internal
angular-momentum transport and tides, stellar core sizes, mass-transfer rates
and orbital periods. This paper describes the detailed methodology and
implementation of POSYDON, including the assumed physics of stellar- and
binary-evolution, the extensive grids of detailed single- and binary-star
models, the post-processing, classification and interpolation methods we
developed for use with the grids, and the treatment of evolutionary phases that
are not based on pre-calculated grids. The first version of POSYDON targets
binaries with massive primary stars (potential progenitors of neutron stars or
black holes) at solar metallicity.Comment: 60 pages, 33 figures, 8 tables, referee's comments addressed. The
code and the accompanying documentations and data products are available at
https:\\posydon.or