611 research outputs found
Author response image 1.
No full textNeurotransmitter is released at synapses by fusion of synaptic vesicles with the plasma membrane. To sustain synaptic transmission, compensatory retrieval of membranes and vesicular proteins is essential. We combined capacitance measurements and pH-imaging via pH-sensitive vesicular protein marker (anti-synaptotagmin2-cypHer5E), and compared the retrieval kinetics of membranes and vesicular proteins at the calyx of Held synapse. Membrane and Syt2 were retrieved with a similar time course when slow endocytosis was elicited. When fast endocytosis was elicited, Syt2 was still retrieved together with the membrane, but endocytosed organelle re-acidification was slowed down, which provides strong evidence for two distinct endocytotic pathways. Strikingly, CaM inhibitors or the inhibition of the Ca2+-calmodulin-Munc13-1 signaling pathway only impaired the uptake of Syt2 while leaving membrane retrieval intact, indicating different recycling mechanisms for membranes and vesicle proteins. Our data identify a novel mechanism of stimulus-and Ca2+-dependent regulation of coordinated endocytosis of synaptic membranes and vesicle proteins
N=2 supersymmetric dynamics for pedestrians
No full textUnderstanding the dynamics of gauge theories is crucial, given the fact that all known interactions are based on the principle of local gauge symmetry. Beyond the perturbative regime, however, this is a notoriously difficult problem. Requiring invariance under supersymmetry turns out to be a suitable tool for analyzing supersymmetric gauge theories over a larger region of the space of parameters. Supersymmetric quantum field theories in four dimensions with extended N=2 supersymmetry are further constrained and have therefore been a fertile field of research in theoretical physics for quite some time. Moreover, there are far-reaching mathematical ramifications that have led to a successful dialogue with differential and algebraic geometry. These lecture notes aim to introduce students of modern theoretical physics to the fascinating developments in the understanding of N=2 supersymmetric gauge theories in a coherent fashion. Starting with a gentle introduction to electric-magnetic duality, the author guides readers through the key milestones in the field, which include the work of Seiberg and Witten, Nekrasov, Gaiotto and many others. As an advanced graduate level text, it assumes that readers have a working knowledge of supersymmetry including the formalism of superfields, as well as of quantum field theory techniques such as regularization, renormalization and anomalies. After his graduation from the University of Tokyo, Yuji Tachikawa worked at the Institute for Advanced Study, Princeton and the Kavli Institute for Physics and Mathematics of the Universe. Presently at the Department of Physics, University of Tokyo, Tachikawa is the author of several important papers in supersymmetric quantum field theories and string theory
Seven connection patterns between the author research areas.
No full textSeven connection patterns between the author research areas.</p
Effects of phytic acid sorption on iron polymerization and at the ferrihydrite-water interface
No full textPhytic acid is the most predominant organic phosphorus species in soils. Its stability in soils is mainly due to its high affinity for soil colloids, especially Fe (oxyhydr)oxides. They have been acknowledged as mobile/reactive adsorbents for P in soil-water environments. Although several sorption mechanisms were proposed, it is not clear how multi phosphate groups of phytic acid contribute to the surface complexation and/or precipitation processes. In this study, sorption behavior of phytic acid in ferrihydrite was examined using experimental geochemistry, solution 31P nuclear magnetic resonance spectroscopy, X-ray diffraction and scanning electron microscopy. The results indicated inner-sphere surface complexation via P1,3 and P2 functional groups under both pH 5 and 8.5. Under alkaline pH, an additional P5 functional group became active. Coprecipitation experiments showed evidence of the formation of Fe(III)-phytate-like bulk precipitates when the initial phytic acid/Fe(III) molar ratio was high (0.45-0.5). At the low phytic acid/Fe(III) (<0.1), the formation of ferrihydrite was unaffected, but further transformation was still inhibited. The study suggests a new role of phytic acid in the formation of Fe oxyhydroxide minerals.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2021-05-01The student, Ai Chen, accepted the attached license on 2019-03-22 at 09:27.The student, Ai Chen, submitted this Thesis for approval on 2019-03-22 at 09:39.This Thesis was approved for publication on 2019-03-25 at 10:06.DSpace SAF Submission Ingestion Package generated from Vireo submission #13441 on 2019-08-22 at 16:20:26Made available in DSpace on 2019-08-23T20:44:35Z (GMT). No. of bitstreams: 2
CHEN-THESIS-2019.pdf: 1920983 bytes, checksum: 29cd594d8d0011039bf498f5ec805648 (MD5)
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Previous issue date: 2019-03-25Embargo set by: Seth Robbins for item 112265
Lift date: 2021-08-23T20:44:50Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 112265
Lift date: 2021-08-23T20:46:41Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 112265
Lift date: 2021-08-23T20:47:38Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 112265
Lift date: 2021-08-23T20:48:32Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 112265 on 2021-08-24T09:15:10Z
OBSERVATION OF THE BULB TYPE TILTMETER IN THE LANDSLIDES
No full textIn this paper, the author had studied thr relationship between variation of tiltineter andlandslide movement observing bulb type tiltmeters~ in the creep type landslides. From the resultsof them, the variation of tiltmeter in landslide is related with the landslide movement of creep type.When we make judge the landslide movement from variation of inclination on the soil surface, it is usefull to confer the standard curves that was maked by observational facts.The critical inclination for soil movement, is assumed about 4"/day as N-S and E-W com-ponent respectivelly.In this paper, the author had studied thr relationship between variation of tiltineter andlandslide movement observing bulb type tiltmeters~ in the creep type landslides. From the resultsof them, the variation of tiltmeter in landslide is related with the landslide movement of creep type.When we make judge the landslide movement from variation of inclination on the soil surface,it is usefull to confer the standard curves that was maked by observational facts.The critical inclination for soil movement, is assumed about 4"/day as N-S and E-W com-ponent respectivelly
Mesotomisation of Diammine=dinitro=oxalo=cobalt Complex and Determination of the Configurations of this Complex and of Diammine=tetranitro=cobalt Complex
No full text1. Diammine-dinitro-oxalo-cobalt complex [Co(NH3)2(NO2)2C2O4]Me has been resolved into the optically active isomers by fractionation of the salts of brucine, strychinine and cinchomine. 2. In the fractionation of the alkaloid salts of the complex, either the l-alkaloid-l-cobalt complex or d-alkaloid-d-cobalt complex was always found to separate out as the least soluble fraction, while either the l-alkaloid-d-cobalt complex or d-alkaloid-l-cobalt complex always contituted the most easily soluble fraction. 3. The specific rotations of potassium and ammonium diammine-dinitro-oxalo-cobaltiates, which have been obtained by replacing the alkaloid molecules with potassium-and ammonium ions respectively, were measured, and found to have the values of ca±115°, using sodium light. 4. As a results of the mesotomisation of diammine-dinitro-oxalo-cobalt complex, the configurations of this complex and also of its mother substance, diammine-tetranitro-cobalt complex, have been made clear, the possibility of mesotomisation indicating that the complex ion [Co(NH2)2(NO2)2C2O4] is constructed asymmetrically, which means that the two ammonia molecules in this complex ion occupy the adjacent spacial position. As to the two nitro-groups, their position was previously determined, by one of the authors (Shibata), by a spectroscopic study. 5. The molecular asymmetry of the above mentioned complex ion, which is the first example of a mesotomised complex anion containing a cobalt atom, belongs to a new type and has been introduced into the stereochemistry of the metal complexes, calling it the type of molecular asymmetry III, in extension of Werner\u27s classification. The senior author, Yuji Shibata, has profound sorrow in recording here the death of his collaborator Mr. Toshio Maruki, Rigakushi, which occurred during the progress of the investigation recorded in this paper. At the same time, he has much pleasure in expressing his hearty thanks to Messrs. K. Matsuno, Rigakushi, and S. Mitsukuri for the great assistance they have given him in completing this work
Depth sequence distribution and reactivity of phosphorus in intensively managed agricultural soils in East-Central Illinois
No full textThis Thesis was approved for publication on 2019-04-08 at 15:57.DSpace SAF Submission Ingestion Package generated from Vireo submission #13519 on 2019-08-22 at 16:20:52Made available in DSpace on 2019-08-23T20:44:40Z (GMT). No. of bitstreams: 2
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Previous issue date: 2019-04-08Embargo set by: Seth Robbins for item 112286
Lift date: 2021-08-23T20:44:50Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemSubsurface loss of phosphorus (P) in agricultural soils in the Midwestern U.S. has been receiving attention in the last few decades because of its negative environmental impacts to aquatic ecosystems such as eutrophication and hypoxia. Thus, there is a great interest in understanding the distribution and reactivity of P in the soils influencing the subsurface P loss. In this study, the depth sequence distribution, speciation, reactivity of P, and soil physicochemical properties were investigated in intensively managed agricultural soils in East-Central Illinois using chemical extraction/digestion, batch desorption experiments, infiltrometer measurements, Nuclear Magnetic Resonance spectroscopy, and X-ray diffraction analysis. The results suggested several sources of P contributing to subsurface P loss. During the growing season when the water table is low, calcium P (Ca-P: P adsorbed by calcite/dolomite and/or apatites) in subsoils is likely to be the main source of labile P (>70% of total inorganic phosphorus (IP) in subsoils). Both P desorption from calcite/dolomite and dissolution of Ca-P precipitates contribute to the concentration of labile P in subsoils. Although the amount of other IP species such as Fe-occluded P and non-occluded P was low, P desorption from amorphous Fe oxyhydroxides should not be excluded. During the wet spring season, surface soils becomes an additional source of P. In surface soils, Ca-P was a major IP species (~40-70% of total IP in topsoils) followed by non-occluded P (9-40% of total IP in topsoils) and Fe-occluded P (6-30% of total IP in topsoils). The labile P via dissolution and/or desorption of these IP pools and mineralized organic P in the surface soils can be translocated to tile lines through preferential flow paths. All of these findings should help the Illinois Nutrient Reduction Strategy Plan to develop the strategy to reduce the agricultural nutrient loss to Illinois waters and the Gulf of Mexico.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2021-05-01The student, Suwei Xu, accepted the attached license on 2019-04-08 at 14:17.The student, Suwei Xu, submitted this Thesis for approval on 2019-04-08 at 14:34.Embargo set by: Seth Robbins for item 112286
Lift date: 2021-08-23T20:46:41Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 112286
Lift date: 2021-08-23T20:47:38Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 112286
Lift date: 2021-08-23T20:48:32Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 112286 on 2021-08-24T09:15:31Z
No Spring Chicken: Quantifying the Lifespan of Exploits in IoT Malware Using Static and Dynamic Analysis
No full textThe Internet of things (IoT) is composed by a wide variety of software and hardware components that inherently contain vulnerabilities. Previous research has shown that it takes only a few minutes from the moment an IoT device is connected to the Internet to the first infection attempts. Still, we know little about the evolution of exploit vectors: Which vulnerabilities are being targeted in the wild, how has the functionality changed over time, and for how long are vulnerabilities being targeted? Understanding these questions can help in the secure development, and deployment of IoT networks. We present the first longitudinal study of IoT malware exploits by analyzing 17,720 samples collected from three different sources from 2015 to 2020. Leveraging static and dynamic analysis, we extract exploits from these binaries to then analyze them along the following four dimensions: (1) evolution of infection vectors over the years, (2) exploit lifespan, vulnerability age, and the time-to-exploit of vulnerabilities, (3) functionality of exploits, and (4) targeted IoT devices and manufacturers. Our descriptive analysis uncovers several patterns: IoT malware keeps evolving, shifting from simply leveraging brute force attacks to including dozens of device-specific exploits. Once exploits are developed, they are rarely abandoned. The most recent binaries still target (very) old vulnerabilities. In some cases, new exploits are developed for a vulnerability that has been known for years. We find that the mean time-to-exploit after vulnerability disclosure is around 29 months, much longer than for malware targeting other environments.Organisation & Governanc
Reaction condition effects on Re(VII) sorption kinetics at the zerovalent iron-water interface
No full textLong lived technetium-99 (99Tc) (t1/2: 2.1 x 105 yr) is one of the major radionuclide risk drivers in low level radioactive waste (LLW) at U.S. Department of Energy sites. Cementitious waste technology (CWT)is presently being used to immobilize LLW. Blast furnace slag is presently being added to the CWT formulation to promote reductive precipitation of the dominant risk driver, pertechnetate, 99Tc(VII)O4- to the sparing soluble 99Tc(IV). Some previous studies show that a variety of hazardous elements immobilized by slag can still remain mobile and leach out of the cement systems. Therefore, use of additional reducing agents should be tested. Because LLW is in caustic brine (high nitrate) solutions, it is a challenging task to reduce 99Tc(VII)O4-. This study evaluated the reducing capacity of zero valent iron (ZVI) as a potential reducing agent in the CWT. Using perrhenate (Re(VII)O4-) as a chemical analogue for 99Tc(VII)O4-, batch Re(VII) sorption experiments were conducted in ZVI as a function of pH (8.2-10.2) and nitrate concentration (0-0.1M). Zero valent iron was effective in reducing Re(VII) to Re(IV), and the initial (< few hrs.) Re sorption was rapid at the ZVI-water interface followed by a slow uptake. Although the extent of Re sorption decreased with increasing pH and nitrate concentration, ZVI immobilized Re(VII) by as much as 10% at pH 10.2. The results suggest that ZVI can be a potential reducing agent to improve the performance of CWT to immobilize 99Tc(VII)O4-.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2018-05-01The student, Brian Lenell, accepted the attached license on 2016-03-24 at 13:23.The student, Brian Lenell, submitted this Thesis for approval on 2016-03-24 at 13:28.This Thesis was approved for publication on 2016-03-25 at 10:09.DSpace SAF Submission Ingestion Package generated from Vireo submission #9120 on 2016-07-07 at 14:16:19Made available in DSpace on 2016-07-07T21:14:26Z (GMT). No. of bitstreams: 2
LENELL-THESIS-2016.pdf: 2452635 bytes, checksum: 3c68aa6874ede8d506c6c4feeed704bf (MD5)
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Previous issue date: 2016-03-25Embargo set by: Seth Robbins for item 93229
Lift date: 2018-07-07T21:14:52Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 93229
Lift date: 2018-07-07T21:18:16Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 93229 on 2018-07-08T09:15:33Z
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