Improved detection of Probe Request Attacks : Using Neural Networks and Genetic Algorithm

The Media Access Control (MAC) layer of the wireless protocol, Institute of Electrical and Electronics Engineers (IEEE) 802.11, is based on the exchange of request and response messages. Probe Request Flooding Attacks (PRFA) are devised based on this design flaw to reduce network performance or prevent legitimate users from accessing network resources. The vulnerability is amplified due to clear beacon, probe request and probe response frames. The research is to detect PRFA of Wireless Local Area Networks (WLAN) using a Supervised Feedforward Neural Network (NN). The NN converged outstandingly with train, valid, test sample percentages 70, 15, 15 and hidden neurons 20. The effectiveness of an Intruder Detection System depends on its prediction accuracy. This paper presents optimisation of the NN using Genetic Algorithms (GA). GAs sought to maximise the performance of the model based on Linear Regression (R) and generated R > 0.95. Novelty of this research lies in the fact that the NN accepts user and attacker training data captured separately. Hence, security administrators do not have to perform the painstaking task of manually identifying individual frames for labelling prior training. The GA provides a reliable NN model and recognises the behaviour of the NN for diverse configurations

Environmental effects on progesterone profile measures of dairy cow fertility

Environmental effects on fertility measures early in lactation, such as the interval from calving to first luteal activity (CLA), proportion of samples with luteal activity during the first 60 days after calving (PLA) and interval to first ovulatory oestrus (OOE) were studied. In addition, traditional measurements of fertility, such as pregnancy to first insemination, number of inseminations per service period and interval from first to last insemination were studied as well as associations between the early and late measurements. Data were collected from an experimental herd during 15 years and included 1106 post-partum periods from 191 Swedish Holsteins and 325 Swedish Red and White dairy cows. Individual milk progesterone samples were taken twice a week until cyclicity and thereafter less frequently. First parity cows had 14.8 and 18.1 days longer CLA (LS-means difference) than second parity cows and older cows, respectively. Moreover, CLA was 10.5 days longer for cows that calved during the winter season compared with the summer season and 7.5 days longer for cows in tie-stalls than cows in loose-housing system. Cows treated for mastitis and lameness had 8.4 and 18.0 days longer CLA, respectively, compared with healthy cows. OOE was affected in the same way as CLA by the different environmental factors. PLA was a good indicator of CLA, and there was a high correlation (−0.69) between these two measurements. Treatment for lameness had a significant influence on all late fertility measurements, whereas housing was significant only for pregnancy to first insemination. All fertility traits were unfavourably associated with increased milk production. Regression of late fertility measurements on early fertility measurements had only a minor association with conception at first AI and interval from first to last AI for cows with conventional calving intervals, i.e. a 22 days later, CLA increased the interval from first to last insemination by 3.4 days. Early measurements had repeatabilities of 0.14–0.16, indicating a higher influence by the cow itself compared with late measurements, which had repeatabilities of 0.09–0.10. Our study shows that early fertility measurements have a possibility to be used in breeding for better fertility. To improve the early fertility of the cow, there are a number of important factors that have to be taken into account

Qualitative mineralogical analysis of Barracuda exploration well in the offshore Mannar Basin (the Indian Ocean) using FTIR and XRD techniques

The Mannar Basin plays a vital role in petroleum exploration in Sri Lanka, and its Barracuda exploration well was drilled up to 4206 m in depth. The objective of the current study is to identify mineralogy using Fourier-transform infrared (FTIR) and X-ray diffraction (XRD) analyses. The FTIR and XRD analyses confirm the presence of quartz, feldspar, clay minerals (e.g., kaolinite, montmorillonite), calcite, and hematite in all marlstone and mudstone samples. These sedimentary rocks can be identified as potential petroleum source rocks in the Mannar Basin. Quartz, carbonate, and hematite cementations are directly reduced porosity and permeability, and thus primary migration of hydrocarbons from potential source rocks. Clay minerals act as a seal for hydrocarbon migrations in the Mannar Basin. A variety of dominant clay mineral assemblages allows the reconstruction of several paleoclimatic chronozones in warm/wet and arid climates. In contrast, feldspar dissolution promotes the primary migration of hydrocarbon from potential petroleum source rocks. Consequently, this study concluded that common minerals such as quartz, carbonate, and hematite are associated with the trapping and binding processes of hydrocarbons

COVID-19 control in low-income settings and displaced populations: what can realistically be done?

COVID-19 prevention strategies in resource limited settings, modelled on the earlier response in high income countries, have thus far focused on draconian containment strategies, which impose movement restrictions on a wide scale. These restrictions are unlikely to prevent cases from surging well beyond existing hospitalisation capacity; not withstanding their likely severe social and economic costs in the long term. We suggest that in low-income countries, time limited movement restrictions should be considered primarily as an opportunity to develop sustainable and resource appropriate mitigation strategies. These mitigation strategies, if focused on reducing COVID-19 transmission through a triad of prevention activities, have the potential to mitigate bed demand and mortality by a considerable extent. This triade is based on a combination of high-uptake of community led shielding of high-risk individuals, self-isolation of mild to moderately symptomatic cases, and moderate physical distancing in the community. We outline a set of principles for communities to consider how to support the protection of the most vulnerable, by shielding them from infection within and outside their homes. We further suggest three potential shielding options, with their likely applicability to different settings, for communities to consider and that would enable them to provide access to transmission-shielded arrangements for the highest risk community members. Importantly, any shielding strategy would need to be predicated on sound, locally informed behavioural science and monitored for effectiveness and evaluating its potential under realistic modelling assumptions. Perhaps, most importantly, it is essential that these strategies not be perceived as oppressive measures and be community led in their design and implementation. This is in order that they can be sustained for an extended period of time, until COVID-19 can be controlled or vaccine and treatment options become available

Preliminary observations on the anopheline mosquitoes of gomadiyagala a village in the north western province of Sri Lanka

Investigations on anopheline mosquitoes were carried out in Gomadiyagaladuring January-December 1989, primarily to gather base-line data in relationtoa collaborative study between the Entomology Division, Anti-Malaria Campaignand the Department of Zoology, University of Sri Jayewardenepura on thepotential for a genetic approach for malaria control in Sri Lanka. Eight anophelinespecies were recordedfrom adult catches and lavae sampled. An. subpictusAn. culicifacies and An. varuna were the most predominant species.The only stream with two tributaries in the study area was the permanentand very productive anopheline breeding habitat. Larval and adult anophelinedensities were related to the rainfall received. The larval densities recorded indrought periods were observed to be significantly higher than those recorded inrainy periods (t=4.087, p<O.Ol). August, September and October that recordedrelatively low larval and adult An. culicifacies densities appear to be suitabletimes for field releases of genetically altered An.culicifacies in the area for malariacontrol

ASSESSMENT OF BIODIVERSITY IN THE MUTHURAJAWELA WETLAND SANCTUARY

Muthurajawela wetland. located as the west coast of Sri Lanka is the largestcoastal peal bag of the island. At present. the biodiversity of Muthurajawela isthreatened by unplanned development activities and growing human population.Therefore, an ecological survey was carried out in order to assess the presentstatus of biodiversity in Muthurajawela, and also to identify critical habitats forthe conservation and sustence of biodiversity. Field monitoring of fauna and florawas carried out at fortnightly intervals, using scientifically accepted rapidbiodiversity assessment techniques (fauna - line transects; flora - plots, Braun-Blanquet cover), The data was analysed using ecological indices(diversity/species richness), and critical habitats were identified using avifauna asa correlate of biodiversity. Ground truthing of vegetation maps was carried out todocument changes of major vegetation communities.The study enabled to identify 192 species of flora, distributed over seven majorvegetation communities at Muthurajawela; marsh, lentic flora, reed swamp, shortgrassland, scrubland, stream bank flora and mangrove swamp. The vertebratefauna documented included 40 species of fish, 14 species of amphibians, 31species of reptiles, 102 species of birds and 22 species of mammals. Among thetotal vertebrate species documented, 17 are endemic, 26 are considered asnationally threatened, while 36 are new records to Muthurajawela. The selectedinvertebrate species documented consisted of 48 species of butterflies and 22species odonates, the latter which turned out to be a useful indicator of habitatquality. The threats documented included direct exploitation (poaching, cutting oftrees), habitat degradation/modification (land reclamation, dumping of garbage,clearing of natural vegetation, pollution and eutrophication) and the spread ofseveral alien invasive species (including unmanaged domestic animals). Thenorthern part of the marsh serve as an ecotone, with a mixture of the above plantcommunities/habitat types which were relatively undisturbed. Analysis carriedout using ecological indices highlighted the northern region as a high biodiversityzone, which is critical for the conservation and future sustenance of biodiversity atMuthurajawela. Ground truthing of vegetation maps, supported with results of thevegetation survey showed that the composition of dominant flora has changedover a period of 10 years, in most places in the Muthurajawela Wetland, as aresult of human disturbances. Data on the avifauna also highlighted aconsiderable decrease in migrant birds at Muthurajawela, possibly due to habitatdeterioration.The findings have important conservation and managementimplications, in particular greater emphasis need to be placed on the more ciritcalareas of the marsh. An important policy implication would be the need

Prevalence of Oral Pain and Barriers to use of Emergency Oral Care Facilities Among Adult Tanzanians.

Oral pain has been the major cause of the attendances in the dental clinics in Tanzania. Some patients postpone seeing the dentist for as long as two to five days. This study determines the prevalence of oral pain and barriers to use of emergency oral care in Tanzania. Questionnaire data were collected from 1,759 adult respondents aged 18 years and above. The study area covered six urban and eight rural study clusters, which had been selected using the WHO Pathfinder methodology. Chi-square tests and logistic regression analyses were performed to identify associations.\ud Forty two percent of the respondents had utilized the oral health care facilities sometimes in their lifetime. About 59% of the respondents revealed that they had suffered from oral pain and/or discomfort within the twelve months that preceded the study, but only 26.5% of these had sought treatment from oral health care facilities. The reasons for not seeking emergency care were: lack of money to pay for treatment (27.9%); self medication (17.6%); respondents thinking that pain would disappear with time (15.7%); and lack of money to pay for transport to the dental clinic (15.0%). Older adults were more likely to report that they had experienced oral pain during the last 12 months than the younger adults (OR = 1.57, CI 1.07-1.57, P < 0.001). Respondents from rural areas were more likely report dental clinics far from home (OR = 5.31, CI = 2.09-13.54, P < 0.001); self medication at home (OR = 3.65, CI = 2.25-5.94, P < 0.001); and being treated by traditional healer (OR = 5.31, CI = 2.25-12.49, P < 0.001) as reasons for not seeking emergency care from the oral health care facilities than their counterparts from urban areas. Oral pain and discomfort were prevalent among adult Tanzanians. Only a quarter of those who experienced oral pain or discomfort sought emergency oral care from oral health care facilities. Self medication was used as an alternative to using oral care facilities mainly by rural residents. Establishing oral care facilities in rural areas is recommended