52 research outputs found
DDoS Hide & Seek:On the effectiveness of a booter services takedown
Booter services continue to provide popular DDoS-as-a-service platforms and
enable anyone irrespective of their technical ability, to execute DDoS attacks
with devastating impact. Since booters are a serious threat to Internet
operations and can cause significant financial and reputational damage, they
also draw the attention of law enforcement agencies and related counter
activities. In this paper, we investigate booter-based DDoS attacks in the wild
and the impact of an FBI takedown targeting 15 booter websites in December 2018
from the perspective of a major IXP and two ISPs. We study and compare attack
properties of multiple booter services by launching Gbps-level attacks against
our own infrastructure. To understand spatial and temporal trends of the DDoS
traffic originating from booters we scrutinize 5 months, worth of inter-domain
traffic. We observe that the takedown only leads to a temporary reduction in
attack traffic. Additionally, one booter was found to quickly continue
operation by using a new domain for its website
Are Darknets All The Same? On Darknet Visibility for Security Monitoring
Darknets are sets of IP addresses that are advertised but do not host any client or server. By passively recording the incoming packets, they assist network monitoring activities. Since packets they receive are unsolicited by definition, darknets help to spot misconfigurations as well as important security events, such as the appearance and spread of botnets, DDoS attacks using spoofed IP address, etc. A number of organizations worldwide deploys darknets, ranging from a few dozens of IP addresses to large/8 networks. We here investigate how similar is the visibility of different darknets. By relying on traffic from three darknets deployed in different contintents, we evaluate their exposure in terms of observed events given their allocated IP addresses. The latter is particularly relevant considering the shortage of IPv4 addresses on the Internet. Our results suggest that some well-known facts about darknet visibility seem invariant across deployments, such as the most commonly contacted ports. However, size and location matter. We find significant differences in the observed traffic from darknets deployed in different IP ranges as well as according to the size of the IP range allocated for the monitoring
The measurement of regional cerebral blood flow during the complex cognitive task of meditation: a preliminary SPECT study
This study measured changes in regional cerebral blood flow (rCBF) during the complex cognitive task of meditation using single photon emission computed tomography. Eight experienced Tibetan Buddhist meditators were injected at baseline with 7 mCi HMPAO and scanned 20 min later for 45 min. The subjects then meditated for 1 h at which time they were injected with 25 mCi HMPAO and scanned 20 min later for 30 min. Values were obtained for regions of interest in major brain structures and normalized to whole brain activity. The percentage change between meditation and baseline was compared. Correlations between structures were also determined. Significantly increased rCBF (P\u3c0.05) was observed in the cingulate gyrus, inferior and orbital frontal cortex, dorsolateral prefrontal cortex (DLPFC), and thalamus. The change in rCBF in the left DLPFC correlated negatively (P\u3c0.05) with that in the left superior parietal lobe. Increased frontal rCBF may reflect focused concentration and thalamic increases overall increased cortical activity during meditation. The correlation between the DLPFC and the superior parietal lobe may reflect an altered sense of space experienced during meditation. These results suggest a complex rCBF pattern during the task of meditation
Potential of macrophytes for removing atrazine from aqueous solution.
The potential of three macrophytes, Azolla caroliniana, Salvinia minima, and Lemna gibba was assessed in this study to select plants for use in environmental remediation contaminated with atrazine. Experiments were carried out in a greenhouse over six days in pots containing Hoagland 0.25 strength nutritive solution at the following atrazineconcentrations: 0; 0.01; 0.1; 1.0; 10.0 mg L -1. Decrease in biomass accumulation was observed in the three macrophytes, as well as toxic effects evidenced by the symptomatology developed by the plants which caused their deaths. The chlorosis and necrosis allowed to observe in the plants the high sensitivity of the three species to the herbicide. Plants presented low potential for removal of atrazine in solution when exposed to low concentrations of the herbicide. However, at the 10.0 mg L-1 atrazine concentration, L. gibba and A. caroliniana showed potential to remove the herbicide from the solution (0.016 and 0.018 mg atrazine per fresh mass gram, respectively). This fact likely resulted from the processes of atrazine adsorption by the dead material. The percentage of atrazine removed from the solution by the plants decreased when the plants were exposed to high concentrations of the pollutant. Azolla caroliniana, S. minima, and L. gibba were not effective in removing the herbicide from solution. The use of these species to remedy aquatic environments was shown to be limitedNúmero especial
Afinidade de seis variedades cítricas sobre porta enxerto de limão rugoso nacional (Citrus limon).
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Adubação verde com espécies de fabáceas em monocultivo ou consorciadas ao milho no cultivo orgânico de abóbora.
Objetivou-se avaliar em três ciclos consecutivos o desempenho fitotécnico de fabáceas herbáceas cultivadas em monocultivo ou consorciadas ao milho e a produtividade de abóbora em sucessão. O delineamento estatístico foi em blocos casualizados em arranjo fatorial 2 (monocultivo ou consórcio) x 3 (espécies fabáceas) + 1 (monocultivo de milho). Os tratamentos consistiram em mucuna cinza em monocultivo; mucuna cinza consorciada ao milho; crotalária juncea em monocultivo; crotalária juncea consorciada ao milho; feijão-de-porco em monocultivo; feijão-de-porco consorciado ao milho; e milho em monocultivo. Após o corte das fabáceas e do milho, realizou-se o plantio de abóbora Itapuã 301. Constatou-se que os monocultivos das fabáceas alcançaram as maiores produtividades de biomassa seca, com destaque para a crotalária no primeiro e segundo ano e proporcionaram os maiores acúmulos de N, P e K. No primeiro ano, os pré-cultivos das fabáceas, independentemente do arranjo, proporcionaram um aumento de produtividade de abóbora superior em até 165,87% em relação ao pré-cultivo de milho, ao passo que, no segundo e terceiro anos não ocorreu a produção de abóbora associada ao monocultivo de milho. As três espécies de fabáceas apresentam potencial como adubo verde no cultivo de abóbora, quando comparadas com o pré-cultivo com milho
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