87 research outputs found
Stellar: Network Attack Mitigation using Advanced Blackholing
© ACM 2018. This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in Proceedings of the 14th International Conference on Emerging Networking EXperiments and Technologies - CoNEXT ’18,
http://dx.doi.org/10.1145/3281411.3281413.Network attacks, including Distributed Denial-of-Service (DDoS), continuously increase in terms of bandwidth along with damage (recent attacks exceed 1.7 Tbps) and have a devastating impact on the targeted companies/governments. Over the years, mitigation techniques, ranging from blackholing to policy-based filtering at routers, and on to traffic scrubbing, have been added to the network operator’s toolbox. Even though these mitigation techniques pro- vide some protection, they either yield severe collateral damage, e.g., dropping legitimate traffic (blackholing), are cost-intensive, or do not scale well for Tbps level attacks (ACL filltering, traffic scrubbing), or require cooperation and sharing of resources (Flowspec).
In this paper, we propose Advanced Blackholing and its system realization Stellar. Advanced blackholing builds upon the scalability of blackholing while limiting collateral damage by increasing its granularity. Moreover, Stellar reduces the required level of cooperation to enhance mitigation effectiveness. We show that fine-grained blackholing can be realized, e.g., at a major IXP, by combining available hardware filters with novel signaling mechanisms. We evaluate the scalability and performance of Stellar at a large IXP that interconnects more than 800 networks, exchanges more than 6 Tbps tra c, and witnesses many network attacks every day. Our results show that network attacks, e.g., DDoS amplification attacks, can be successfully mitigated while the networks and services under attack continue to operate untroubled.EC/H2020/679158/EU/Resolving the Tussle in the Internet: Mapping, Architecture, and Policy Making/ResolutioNetDFG, FE 570/4-1, Gottfried Wilhelm Leibniz-Preis 201
Cross-Flow Filtration of Escherichia coli at a Nanofluidic Gap for Fast Immobilization and Antibiotic Susceptibility Testing
Infections with antimicrobial-resistant (AMR) bacteria are globally on the rise. In the future, multi-resistant infections will become one of the major problems in global health care. In order to enable reserve antibiotics to retain their effect as long as possible, broad-spectrum antibiotics must be used sparingly. This can be achieved by a rapid microfluidic phenotypic antibiotic susceptibility test, which provides the information needed for a targeted antibiotic therapy in less time than conventional tests. Such microfluidic tests must cope with a low bacteria concentration. On-chip filtering of the samples to accumulate bacteria can shorten the test time. By means of fluorescence microscopy, we examined a novel nanogap filtration principle to hold back Escherichia coli and to perform cultivation experiments with and without antibiotics present. Microfluidic chips based on the nanogap flow principle showed to be useful for the concentration and cultivation of E. coli. With a concentration of 106 cells/mL, a specific growth rate of 0.013 min−1 and a doubling time of 53 min were achieved. In the presence of an antibiotic, no growth was observed. The results prove that this principle can, in future, be used in fast and marker-free antimicrobial susceptibility testing (AST)
Bioelectric and biomagnetic measurements are differentially sensitive to spiral currents
Observations indicate that different information is contained in electrocardiograms and magnetocardiograms in both patients and healthy volunteers. Closed loop currents could explain this phenomenon. We hypothesized that open loops, such as the spirally shaped currents in the heart, also contribute to these differences. We modeled two types of open spiral-shaped loops, based on the heart geometry, using 12 artificial current dipoles in a physical torso phantom. The electric potentials and magnetic fields were measured simultaneously with increasing numbers of active dipoles in the spiral source geometries. We found a continuous increase in the measured amplitudes of the magnetic fields, up to a plateau value when 10 active dipoles were enabled. For the electric potentials, we found that the amplitudes increased when up to six or eight active dipoles had been enabled, and then decreased thereafter. We conclude that open loop currents also contribute to the experimentally observed differences in magnetocardiograms and electrocardiograms in both patients and healthy volunteers. Combined bioelectric and biomagnetic measurements should provide greater insight into heart activity than do single modality measurements
Nanofluidic Immobilization and Growth Detection of Escherichia coli in a Chip for Antibiotic Susceptibility Testing
Infections with antimicrobial resistant bacteria are a rising threat for global healthcare as
more and more antibiotics lose their effectiveness against bacterial pathogens. To guarantee the
long-term effectiveness of broad-spectrum antibiotics, they may only be prescribed when inevitably
required. In order to make a reliable assessment of which antibiotics are effective, rapid point-of-care
tests are needed. This can be achieved with fast phenotypic microfluidic tests, which can cope with
low bacterial concentrations and work label-free. Here, we present a novel optofluidic chip with
a cross-flow immobilization principle using a regular array of nanogaps to concentrate bacteria
and detect their growth label-free under the influence of antibiotics. The interferometric measuring
principle enabled the detection of the growth of Escherichia coli in under 4 h with a sample volume
of 187.2 µL and a doubling time of 79 min. In proof-of-concept experiments, we could show that
the method can distinguish between bacterial growth and its inhibition by antibiotics. The results
indicate that the nanofluidic chip approach provides a very promising concept for future rapid and
label-free antimicrobial susceptibility tests
Operationalizing multimorbidity and autonomy for health services research in aging populations - the OMAHA study
<p>Abstract</p> <p>Background</p> <p>As part of a Berlin-based research consortium on health in old age, the OMAHA (Operationalizing Multimorbidity and Autonomy for Health Services Research in Aging Populations) study aims to develop a conceptual framework and a set of standardized instruments and indicators for continuous monitoring of multimorbidity and associated health care needs in the population 65 years and older.</p> <p>Methods/Design</p> <p>OMAHA is a longitudinal epidemiological study including a comprehensive assessment at baseline and at 12-month follow-up as well as brief intermediate telephone interviews at 6 and 18 months. In order to evaluate different sampling procedures and modes of data collection, the study is conducted in two different population-based samples of men and women aged 65 years and older. A geographically defined sample was recruited from an age and sex stratified random sample from the register of residents in Berlin-Mitte (Berlin OMAHA study cohort, n = 299) for assessment by face-to-face interview and examination. A larger nationwide sample (German OMAHA study cohort, n = 730) was recruited for assessment by telephone interview among participants in previous German Telephone Health Surveys. In both cohorts, we successfully applied a multi-dimensional set of instruments to assess multimorbidity, functional disability in daily life, autonomy, quality of life (QoL), health care services utilization, personal and social resources as well as socio-demographic and biographical context variables. Response rates considerably varied between the Berlin and German OMAHA study cohorts (22.8% vs. 59.7%), whereas completeness of follow-up at month 12 was comparably high in both cohorts (82.9% vs. 81.2%).</p> <p>Discussion</p> <p>The OMAHA study offers a wide spectrum of data concerning health, functioning, social involvement, psychological well-being, and cognitive capacity in community-dwelling older people in Germany. Results from the study will add to methodological and content-specific discourses on human resources for maintaining quality of life and autonomy throughout old age, even in the face of multiple health complaints.</p
Prevalence of Age-Related Macular Degeneration in Europe: The Past and the Future
Purpose Age-related macular degeneration (AMD) is a frequent, complex disorder in elderly of European ancestry. Risk profiles and treatment options have changed considerably over the years, which may have affected disease prevalence and outcome. We determined the prevalence of early and late AMD in Europe from 1990 to 2013 using the European Eye Epidemiology (E3) consortium, and made projections for the future. Design Meta-analysis of prevalence data. Participants A total of 42 080 individuals 40 years of age and older participating in 14 population-based cohorts from 10 countries in Europe. Methods AMD was diagnosed based on fundus photographs using the Rotterdam Classification. Prevalence of early and late AMD was calculated using random-effects meta-analysis stratified for age, birth cohort, gender, geographic region, and time period of the study. Best-corrected visual acuity (BCVA) was compared between late AMD subtypes; geographic atrophy (GA) and choroidal neovascularization (CNV). Main Outcome Measures Prevalence of early and late AMD, BCVA, and number of AMD cases. Results Prevalence of early AMD increased from 3.5% (95% confidence interval [CI] 2.1%–5.0%) in those aged 55–59 years to 17.6% (95%
Neurological side effects of immunosupression therapy in patients after kidney transplantation
Mērķis: Neiroloģiskas blaknes dažādām imūnsupresīvām zālem nav daudz pētītas un iespējamo blakņu incidences un smaguma atšķirību identifikācia var palīdzēt optimizēt terapiju, lai palīdzētu uzlabot pacientu dzīves kvalitāti pēc transplatācijas. Šī pētījuma mērķis ir salīdzināt incidenci un smagumu neiroloģiskām blaknēm pacientiem, kuri saņem dažāda veida imūnsupresīvu terapiju pēc nieres pārstādīšanas un izvērtēt blakņu incidenci starp sieviešu un vīriešu dzimumiem. Metodes: Pētījums tika viekts Rīgas Paula Stradiņa Klīniskajā Universitātes Slimnīcā ambulatorajā nieru transplantāciju nodaļā. Pētījuma populācija sastāvēja no pacientiem, kuri vismaz sešus mēnešus pēc nieru transplantācijas saņēmuši terapiju ar Prednizolonu, Mikofenolāta Mofetilu un Ciklosporīnu A vai Takrolimu. Pacienti ar izmaiņām zāļu režīmā blakusslimību dēļ, kā vīrushepatītu C vai cukura diabēts, tika izslēgti no pētijuma. Visi pētījuma pacienti aizpildīja anketu ar 17 jautājumiem par blakņu biežumu un smagumu. Rezultāti: 37 dalībnieki tika iedalīti divās grupās, kur 18 saņēma Takrolima terapiju un 19 Ciklosporīnu A kā daļu no imūnsupresīvās terapijas. Divu blakņu incidence bija ar statistiski ticamu atšķirību. Pacienti pieredzēja krampjus, kas notika četriem pacientim (10,81%) Takrolima grupā salīdzinot ar 11 pacientiem (29,73%) Ciklosporīna A grupā ar p vērību 0.027. Muskuļu trīce tika novērota 19 pacientiem (51,35%), no kuriem lielākā daļa bija Takrolima grupā (32,43%) salīdzinot ar Ciklosporīna A grupu (18,92%). Būtiska atšķirība blakņu smagumā bija muskuļu trīcei un nogurumam. Nogurums tika vērtēts kā viegls = 9(47,37%), viegli-vidējs = 4 (21,05%), vidējs = 1 (5,26%) Ciklosporīna A grupā. Noguruma smagums Takrolima grupā viegls = 2 (11,11%),viegli-vidējs = 7 (38,89%), vidējs = 4 (22,22%), aprēķinātā P vērtība 0.043. Salīdznot simptomu atšķirības starp dzimumiem, palielināts muskuļu tonuss bija novērojams biežāk vīriešiem (28,3%) nekā sievietēm (8,10%) ar p=0.046. Polineiropātijas bija ar statistiski ticamu atšķirību zāļu grupās, 4 pacientiem saņemot Takrolimu un nevienam saņemot Ciklosporīnu A. Secinājumi: Autors secina, ka polineiropātijas kā imūnsupresīvās terapijas blakne ir ar statistiski ticamu biežuma atšķirība starp medikamentu grupām. Būtiska atšķirība smagumā un biežumā tika novērota muskuļu trīcei, nogurumam un krampjiem. Muskuļu krampji ietekmēja vīriešus ievērojami biežāk nekā sievietes. Ierobežotas pētījumu populācijas un retrospektīvās datu analīzes dēļ autors iesaka turpmāku izpēti par blakņu incidenci un to smaguma pakāpi.Aim: Neurologic side effects of different immunosuppression drugs have not been well studied. Therefore, identification of possible differences in side effects incidence and severity may help to optimize therapy, in order to improve quality of life of post-transplant patients. The aim of this study is to compare the incidence and severity of neurologic side effects of patients receiving different regimens of maintenance immunosuppression therapy after renal transplantation and to evaluate the incidence of side effects between male and female gender. Methods: The research was conducted in Pauls Stradins Clinical University Hospital´s ambulatory kidney transplantation ward. The study population consists of patients at least six months after renal transplantation receiving treatment regimens including Prednisolone, Mycophenolate Mofetil and either Cyclosporine A or Tacrolimus. Patients with changes in treatment regimen due to comorbidities, such as Hepatitis C or Diabetes Mellitus, were excluded. All patients received a questionnaire about severity and incidence of 17 side effects. Results: Out of 48 participants 37 were included and divided into two groups with 18 receiving Tacrolimus and 19 Cyclosporine A as part of their therapy. Patients experienced seizures, which occurred in four patients (10,81%) receiving Tacrolimus compared to 11 participants (29.73%) taking Cyclosporine A with a p-value of 0.027, respectively. Muscle trembling occurred with an incidence of 19 patients (51,35%) with the majority in the Tacrolimus regimen (32,43%) group compared to Cyclosporine-A (18,92%). Significant difference of severity of side effects was identified for muscle trembling and fatigue. Fatigue being most relevant compared at mild = 9 (47,37%), mild-moderate = 4 (21,05%), moderate = 1 (5,26%) for Cyc-A. Severity of fatigue showed the following distribution with Tacro: mild = 2 (11,11%), mild-moderate = 7 (38,89%), moderate = 4 (22,22%), p-value was calculated at 0.043, respectively. Comparing symptomatic difference among both genders, increased muscle tension showed higher incidence in males (28,3%) compared to females (8.10%) with p=0.046, respectively. Polyneuropathy showed significant difference in medication groups of four Tacrolimus receiving patients compared to no patients, who received Cyclosporine A. Conclusion: The author concluded that polyneuropathy has significant difference of incidence among both medication groups. Significant difference of severity and frequency of muscle trembling, fatigue and seizures could be identified as well. Furthermore, muscle tensions affected males significantly more often than females. Due to a limited study population and the retrospective nature of this study the author recommends further research about incidence and severity of side effects
How to use the Kaiser score as a clinical decision rule for diagnosis in multiparametric breast MRI: a pictorial essay
Abstract Due to its superior sensitivity, breast MRI (bMRI) has been established as an important additional diagnostic tool in the breast clinic and is used for screening in patients with an elevated risk for breast cancer. Breast MRI, however, is a complex tool, providing multiple images containing several contrasts. Thus, reading bMRI requires a structured approach. A lack of structure will increase the rate of false-positive findings and sacrifice most of the advantages of bMRI as additional work-up will be required. While the BI-RADS (Breast Imaging Reporting And Data System) lexicon is a major step toward standardised and structured reporting, it does not provide a clinical decision rule with which to guide diagnostic decisions. Such a clinical decision rule, however, is provided by the Kaiser score, which combines five independent diagnostic BI-RADS lexicon criteria (margins, SI-time curve type, internal enhancement and presence of oedema) in an intuitive flowchart. The resulting score provides probabilities of malignancy that can be used for evidence-based decision-making in the breast clinic. Notably, considerable benefits have been demonstrated for radiologists with initial and intermediate experience in bMRI. This pictorial essay is a practical guide to the application of the Kaiser score in the interpretation of breast MRI examinations. Teaching Points • bMRI requires standardisation of patient-management, protocols, and reading set-up. • Reading bMRI includes the assessment of breast parenchyma, associated findings, and lesions. • Diagnostic decisions should be made according to evidence-based clinical decision rules. • The evidence-based Kaiser score is applicable independent of bMRI protocol and scanner. • The Kaiser score provides high diagnostic accuracy with low inter-observer variability
- …