TRIDEnT: Building Decentralized Incentives for Collaborative Security

Sophisticated mass attacks, especially when exploiting zero-day vulnerabilities, have the potential to cause destructive damage to organizations and critical infrastructure. To timely detect and contain such attacks, collaboration among the defenders is critical. By correlating real-time detection information (alerts) from multiple sources (collaborative intrusion detection), defenders can detect attacks and take the appropriate defensive measures in time. However, although the technical tools to facilitate collaboration exist, real-world adoption of such collaborative security mechanisms is still underwhelming. This is largely due to a lack of trust and participation incentives for companies and organizations. This paper proposes TRIDEnT, a novel collaborative platform that aims to enable and incentivize parties to exchange network alert data, thus increasing their overall detection capabilities. TRIDEnT allows parties that may be in a competitive relationship, to selectively advertise, sell and acquire security alerts in the form of (near) real-time peer-to-peer streams. To validate the basic principles behind TRIDEnT, we present an intuitive game-theoretic model of alert sharing, that is of independent interest, and show that collaboration is bound to take place infinitely often. Furthermore, to demonstrate the feasibility of our approach, we instantiate our design in a decentralized manner using Ethereum smart contracts and provide a fully functional prototype.Comment: 28 page

Oxidative environments decrease tenderization of beef steaks through inactivation of μ-calpain

This study was designed to test the hypothesis that oxidative conditions in postmortem (PM) tissue decrease calpain activity and proteolysis, subsequently minimizing the extent of tenderization. To achieve different levels of oxidation, the diets of beef cattle were supplemented with vitamin E for the last 126 d on feed, and beef steaks were irradiated early PM. Ten steers were fed a finishing diet with the inclusion of vitamin E at 1,000 IU per steer daily (VITE). Another 10 beef steers were fed the same finishing diet without added vitamin E (CON). At 22 to 24 h PM, strip loins from each carcass were cut into 2.54-cm-thick steaks and individually vacuum packaged. Within 26 h PM, steaks were irradiated at 0 or 6.4 kGy and then aged at 4°C for 0, 1, 3, 7, and 14 d postirradiation. Steaks from each time point were used to determine Warner-Bratzler shear force (WBSF) and calpain activity, and for western blotting of sarcoplasmic proteins and myofibrillar proteins. Calpastatin activity was determined at 0, 3, and 14 d postirradiation. At 1, 3, 7, and 14 d postirradiation, WBSF values of irradiated steaks were higher (P \u3c 0.03) than for nonirradiated steaks. Western blots of troponin-T and desmin showed decreased proteolysis in irradiated samples compared with nonirradiated samples. At 2 d PM, troponin-T degradation products were more evident (P \u3c 0.03) in nonirradiated steaks supplemented with VITE than nonirradiated steaks from the CON diet. Similarly, VITE treatment resulted in steaks with lower (P \u3c 0.05) calpastatin activity at 1 d PM than in steaks from steers fed the CON diet. Irradiation diminished the rate of calpastatin inactivation. Irradiated samples, regardless of diet, had no detectable levels of intact titin or nebulin. Irradiation decreased μ-calpain activity and autolysis, whereas m-calpain activity was not affected by diet or irradiation. Inactivation of μ-calpain by oxidation during early times PM decreased the amount of myofibrillar proteolysis, thereby decreasing the extent of tenderization of beef steaks

Effect of pH and ionic strength on μ- and m-calpain inhibition by calpastatin

The objectives of this study were to determine the extent to which pH and ionic strength influence μ- and m-calpain activity and the inhibition of calpains by calpastatin. Calpastatin, μ-calpain, and m-calpain were purified from at-death porcine semimembranosus. μ-Calpain or m-calpain (0.45 U) were incubated with the calpain substrate Suc-Leu-Leu-Val-Tyr-7-amino-4-methyl coumarin in the presence of calpastatin (0, 0.15, or 0.30 U of calpain inhibitory activity) under the following pH and ionic strength conditions: pH 7.5 and 165 mM NaCl or 295 mM NaCl; pH 6.5 and 165 mM NaCl or 295 mM NaCl; and pH 6.0 and 165 mM NaCl or 295 mM NaCl. The reactions were initiated with addition of 100 μM (μ-calpain) or 1 mM CaCl2 (m-calpain), and calpain activity was recorded at 30 and 60 min. μ-Calpain had the greatest (P \u3c 0.01) activity at pH 6.5 at each ionic strength. Higher ionic strength decreased μ-calpain activity (P\u3c 0.01) at all pH conditions. Inhibition percent of μ-calpain by calpastatin was not affected by pH; however, it was influenced by ionic strength. Inhibition of μ-calpain by calpastatin was higher (P \u3c 0.01) at 295 mM NaCl than at 165 mM NaCl when 0.3 units of calpastatin were included in the assay. Activity of m-calpain was greater (P \u3c 0.01) at pH 7.5 than at pH 6.5. m-Calpain activity was not detected at pH 6.0. Inhibition of m-calpain was greater (P \u3c 0.01) when 0.15 and 0.3 U calpastatin were added at pH 6.5 than 7.5 at 165 mM NaCl, whereas percentage inhibition of m-calpain was greater (P \u3c 0.01) at 295 mM than 165 mM NaCl at pH 7.5 and 6.5. These observations provide new evidence that defines further the influence of pH decline and increased ionic strength on μ-calpain, m-calpain, and calpastatin activity, thereby helping to more accurately define a role for these enzymes in the process of postmortem tenderization

Effect of oxidation, pH, and ionic strength on calpastatin inhibition of μ- and m-calpain

The objective of this study was to evaluate the effect of oxidation on μ- and m-calpain activity at varying pH and ionic strength conditions in the presence of calpastatin. In 2 separate experiments, purified porcine skeletal muscle μ- or m-calpain (0.45 units of caseinolytic activity) was incubated in the presence of calpastatin (0, 0.15, or 0.30 units) at pH 7.5, 6.5, or 6.0 with either 165 or 295 mM NaCl. The reactions were initiated with the addition of CaCl2 (100 μM for μ-calpain; 1 mM for m-calpain). In Experiment 1, μ- or m-calpain was incubated with the calpain substrate Suc-Leu-Leu-Val-Tyr-AMC (170 μM). Either 0 or 16 μ μM H2O2 was added to each assay. Activity was measured at 60 min. In Experiment 2, calpain was incubated with highly purified porcine myofibrils (4 mg/mL) under conditions described. Either 0 or 100 μM H2O2 was added immediately prior to the addition of calpain. Degradation of desmin was determined on samples collected at 2, 15, 60, and 120 min. Results from Experiment 1 indicated that oxidation decreased (P \u3c 0.01) activity of μ-calpain. μ-Calpain had the greatest (P \u3c 0.01) activity at pH 6.5, and m-calpain had the greatest (P \u3c 0.01) activity at pH 7.5 at 60 min. m-Calpain activity was not detected at pH 6.0. μ- and m-calpain activity were lower (P \u3c 0.01) at 295 mM NaCl than at 165 mM NaCl at all pH conditions. Oxidation lowered (P \u3c 0.01) calpastatin inhibition of μ-and m-calpain at all pH and ionic strength combinations. In Experiment 2, oxidation decreased proteolytic activity of μ-calpain against desmin at pH 6.0 (P \u3c 0.05 at 15, 60, and 120 min) and decreased m-calpain at all pH conditions. However, desmin degradation by μ-calpain was not as efficiently inhibited by calpastatin at pH 7.5 and as at pH 6.5 (P = 0.03 at 60 min) when oxidizing conditions were created. This is consistent with the results from Experiment 1, which indicated that oxidation decreased the ability of calpastatin to inhibit μ-calpain. These studies provide evidence that oxidation influences calpain activity and inhibition of calpains by calpastatin differently under varying environmental conditions. The results suggest that, at the higher pH conditions used, calpastatin may limit the possibility of oxidation-induced inactivation of μ-calpain

Using degraded music quality to encourage a health improving walking pace : BeatClearWalker

Meeting the target of 8000 steps/day, as recommended by many national governments and health authorities, can provide considerable physical and mental health benefits and is seen as a key target for reducing obesity levels and improving public health. However, to optimize the health benefits, walking should be performed at a "moderate" intensity. While there are numerous mobile fitness applications that monitor distance walked, none directly support walking at this cadence nor has there been any research into live feedback for walking cadence. We present a smartphone fitness application to help users learn how to walk at a moderate cadence and maintain that cadence. We apply real-time audio effects that diminish the audio quality of music when the target walking cadence is not being reached. This provides an immersive and intuitive application that can easily be integrated into everyday life as allows users to walk while listening to their own music and encourages eyes-free interaction. In this paper, we introduce our approach, design, initial lab evaluation and a controlled outdoor study. Results show that using music degradation decreases the number of below-cadence steps, that users felt they worked harder with our player and would use it while exercise walking

Using degraded music quality to encourage a health improving walking pace : BeatClearWalker

Meeting the target of 8000 steps/day, as recommended by many national governments and health authorities, can provide considerable physical and mental health benefits and is seen as a key target for reducing obesity levels and improving public health. However, to optimize the health benefits, walking should be performed at a “moderate” intensity. While there are numerous mobile fitness applications that monitor distance walked, none directly support walking at this cadence nor has there been any research into live feedback for walking cadence. We present a smartphone fitness application to help users learn how to walk at a moderate cadence and maintain that cadence. We apply real-time audio effects that diminish the audio quality of music when the target walking cadence is not being reached. This provides an immersive and intuitive application that can easily be integrated into everyday life as allows users to walk while listening to their own music and encourages eyes-free interaction. In this paper, we introduce our approach, design, initial lab evaluation and a controlled outdoor study. Results show that using music degradation decreases the number of below-cadence steps, that users felt they worked harder with our player and would use it while exercise walking

Influence of harvest processes on pork loin and ham quality

The purpose of this study was to determine the specific effects of extending the interval between dwell time and the duration of scalding on pork quality attributes. Sixty-four Duroc × Yorkshire pigs were randomly assigned to a 2 × 2 factorial treatment arrangement. Treatments included extending the dwell duration from 5 to 10 min and extending the scald duration from 5 to 8 min. All carcasses entered the cooler 50 min after exsanguination. At exsanguination, blood was collected for three 1-min intervals and then for a final 2-min period. Temperature and pH of the LM and semimembranosus muscle (SM) were measured at 45 min, and at 2, 4, 6, and 24 h postmortem (PM). Hunter L*, a*, and b* values were determined on the LM, SM, and biceps femoris (BF). Purge loss was measured on the SM, BF, and the sirloin end of the loin. Drip loss was measured in duplicate from LM chops after 1 and 5 d of storage. Warner-Bratzler shear force (WBS) measurements were determined on LM chops aged 1, 3, 5, and 7 d PM. Over 99% of the collected blood was obtained during the first 3 min after sticking. Carcasses scalded for 8 min had greater (P \u3c 0.05) semi-membranosus 2 h temperature (28.8°C) than carcasses scalded 5 min (27.3°C). An 8-min scald process resulted in longissimus dorsi chops with lower hue angle and greater WBS values than the 5-min scald process. Increasing dwell time from 5 to 10 min resulted in biceps femoris chops with greater hue angle and loin chops with greater WBS values at 3 d PM. Harvest processes did not significantly affect subjective quality scores, Hunter L* values, purge or drip loss. Lengthening the duration of dwell and scalding may result in a more rapid PM pH decline. Reducing the duration of scalding may lead to increased time for manual removal of hair. Because of differences in facilities, it is recommended that individual facilities monitor dwell and scald durations to determine how to best minimize time of entry into the cooler

Influence of early postmortem protein oxidation on beef quality

The objective of this study was to examine the effect of early postmortem protein oxidation on the color and tenderness of beef steaks. To obtain a range of oxidation levels, the longissimus lumborum muscles (LM) from both strip loins of 20 steers fed either a finishing diet with vitamin E (1,000 IU per steer daily, minimum of 126 d [VITE]; n = 10 steers) or fed the same finishing diet without vitamin E (CON; n = 10 steers) were used. Within 24 h after slaughter, the LM muscle from each carcass was cut into 2.54-cm-thick steaks and individually vacuum packaged. Steaks from each steer were assigned to a nonirradiated group or an irradiated group. Steaks were irradiated within 26 h postmortem, and were aged at 4°C for 0, 1, 3, 7, and 14 d after irradiation. Steaks from each diet/irradiation/aging time treatment were used to determine color, shear force, and degree of protein oxidation (carbonyl content). Steaks from steers fed the VITE diet had higher (P \u3c 0.01) α-tocopherol contents than steaks from steers fed the CON diet. Immediately following irradiation, steaks that had been irradiated had lower (P \u3c 0.05) L* values regardless of diet. Irradiated steaks, regardless of diet, had lower a* (P \u3c 0.05) and b* (P \u3c 0.01) values than nonirradiated steaks at all aging times. Carbonyl concentration was higher (P \u3c 0.05) in proteins from irradiated steaks compared to nonirradiated steaks at 0, 1, 3, and 7 d postirradiation. Immunoblot analysis showed that vitamin E supplementation decreased the number and extent of oxidized sarcoplasmic proteins. Protein carbonyl content was positively correlated with Warner-Bratzler shear force values. These results indicate that increased oxidation of muscle proteins early postmortem could have negative effects on fresh meat color and tenderness

Dedication to David Dean

This special volume is dedicated to David H. Dean who passed away on August 11th, 2013. This dedication describes David's impact on the academic research on disability and, most notably, the vital interaction between research and policy. It discusses his influence in shaping perspectives on evaluating the effectiveness of programs to increase employment. Finally, it describes David as a person and why he was influential as a researcher and college professor

The variable relationship between arm and hand use: a rationale for using finger magnetometry to complement wrist accelerometry when measuring daily use of the upper extremity.

Wrist-worn accelerometers are becoming more prevalent as a means to assess use of the impaired upper extremity in daily life after stroke. However, wrist accelerometry does not measure joint movements of the hand, which are integral to functional use of the upper extremity. In this study, we used a custom-built, non-obtrusive device called the manumeter to measure both arm use (via wrist accelerometry) and hand use (via finger magnetometry) of a group of unimpaired subjects while they performed twelve motor tasks at three intensities. We also gave the devices to four stroke subjects and asked them to wear them for six hours a day for one month. From the in-lab testing we found that arm use was a strong predictor of hand use for individual tasks, but that the slope of the relationship varied by up to a factor of ~12 depending on the task being performed. Consistent with this, in the daily use data collected from stroke subjects we found a broad spread in the relationship between arm and hand use. These results suggest that analyzing the spread of the relationship between daily hand and arm use will give more insight into upper extremity recovery than wrist accelerometry or finger magnetometry alone, because the spread reflects the nature of the daily tasks performed as well as the amount of upper extremity use