Analisi delle problematiche di sicurezza per lo sviluppo di applicazioni basate su WebRTC

WebRTC è una tecnologia open-source che permette lo scambio di dati multimediali in tempo reale direttamente all'interno del browser utilizzando canali peer-to-peer. Al momento è in fase di standardizzazione presso il W3C e l'IETF. Si tratta di un framework costruito per essere affidabile, flessibile, semplice e soprattutto, rispetto ai concorrenti, sicuro. Questa tesi analizza a tutti i livelli il funzionamento di WebRTC entrando nel dettaglio di come sia implementata la sicurezza. In particolare vengono studiati i protocolli utilizzati e il perchè sono stati scelti dal working group, come vengono implementate le diverse funzionalità nel browser tramite API sviluppate in Javascript, quali sono i suoi punti di forza e i suoi punti sensibili ad un attacco informatico di cui uno sviluppatore deve tenere conto quando decide di creare un'applicazione WebRTC e quali sono i possibili rischi a cui va incontro l'utente che utilizza un servizio di questo tipo, soprattutto dal punto di vista della privacy. Al termine della discussione WebRTC risulta sicuramente migliore rispetto alle possibilità che sono state utilizzate finora, candidandosi come uno standard destinato a durare a lungo nel mondo del Web

Targeted delivery of anti-inflammatory therapy to rheumatoid tissue by fusion proteins containing an IL-4-linked synovial targeting peptide

We provide first-time evidence that the synovial endothelium-targeting peptide (SyETP) CKSTHDRLC successfully delivers conjugated IL-4 to human rheumatoid synovium transplanted into SCID mice. SyETP, previously isolated by in vivo phage display and shown to preferentially localize to synovial xenografts, was linked by recombinant technology to hIL-4 via an MMP-cleavable sequence. Both IL-4 and the MMP-cleavable sequence were shown to be functional. IL-4-SyETP augmented production of IL-1ra by synoviocytes stimulated with IL-1[beta] in a dose-dependent manner. In vivo imaging confirmed increased retention of SyETP-linked-IL-4 in synovial grafts which was enhanced by increasing number of copies (one to three) in the constructs. Strikingly, SyETP delivered bioactive IL-4 in vivo as demonstrated by increased pSTAT6 in synovial grafts. Thus, this study provides proof of concept for peptide-tissue-specific targeted immunotherapy in rheumatoid arthritis. This technology is potentially applicable to other biological therapies providing enhanced potency to inflammatory sites and reducing systemic toxicity

Estradiol inhibition of catecholamine elicited eating in the female rat

Two experiments test the hypothesis that estradiol suppresses food intake by inhibiting [beta] dopamine hydroxylase in the anterior diencephalon where norepinephrine sensitive neurons activate feeding behavior. In the first experiment, dopamine or norepinephrine was injected intracerebrally in female rats during estrous and diestrous phases of the estrous cycle. Dopamine injections in the anterior diencephalon of rats elicited eating (pppp<0.05) only in the absence of circulating estradiol while the increases following norepinephrine were independent of estradiol treatment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33851/1/0000110.pd

A third ascending hypothalamopetal pathway

Electrolytic lesions centered in the reticular formation or partial hemisections of the brain stem were induced stereotaxically at various levels from the medulla to the diencephalon. Nauta and Fink-Heimer methods were used to reveal degenerated fibers ascending through the upper brain stem. Degenerated fibers coursing rostrally through the subthalamus and ventrally to enter the lateral hypothalamus at tuberal levels were observed after lesions at all levels rostral to the medulla. The trajectory of this ascending pathway through the midbrain and diencephalon was distinct from that of the dorsal longitudinal fasciculus which is medial and that of the medial forebrain bundle which is ventral. Several lines of evidence suggest the hypothesis that this pathway is a component of the ascending reticular system which carries sensory information into the hypothalamus for correlation with hypothalamic visceral and behavioral functions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33552/1/0000053.pd

The contact method: A simple technique for electrical self-stimulation without external leads

Electrical currents to reward areas of the brain were administered without the use of external leads by utilizing a method conceptually similar to that of the electronic drinkometer. A wire brush connected to the intracranial electrode protudes above the rat's head. By lifting its head the rat can make contact between the brush and a stimulation plate mounted horizontally overhead. The stimulation circuit is completed through the contact of the rat's feet with a grounded metal floor. Current thresholds and stimulation rates obtained by this method were identical to those obtained by the conventional method of stimulation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33792/1/0000047.pd

Effects of previous curare-immobilization on Pavlovian conditioned heart decelerations in the curarized rat

Recent evidence indicates that mechanisms other than the vagal-blocking properties of d-tubocurarine chloride (dTC) or inadequate respiration may account for the reports of invariant heart rate (HR) in curarized rats. Two experiments were conducted to determine if repeated dTC-paralysis facilitate acquisition of a Pavlovian HR conditioning in the dTC-paralyzed rat. In Experiment 1, Pavlovian HR conditioning was examined in curarized rats which had (1) experience with dTC-induced immobilization before conditioning, or (2) no experience with dTC-induced immobilization. The results showed that pronounced conditioned HR decelerations were observed only for the curare-experienced animals. Experiment 2 was conducted to determine if repeated curarization influenced tolerance to dTC-induced neuromuscular paralysis. No group differences in basal electromyographic (EMG) activity or time to recover from paralysis were found between the Non-Curare Adapted (NCA), and the Curare Adapted (CA) groups. The implications of the results are discussed in terms of the role of immobilization-induced stress on acquiring stimulus control over autonomic responses.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22116/1/0000543.pd

Comparison of DC and RF for lesioning white and grey matter

The morphology of brain lesions produced by anodal direct current and by radio frequency current was compared. The lesions were placed within or adjacent to number of myelinated fiber tracts of the forebrain and brain stem using a range of common current parameters. It was found that with the parameters used anodal current was relatively ineffective for destroying fiber tracts while radio frequency was equally effective for fiber tracts and cellular areas. Thus, differential applicabilities of these two lesion methods are indicated. Additional observations were made on the effect of cathode location upon the shape of anodal direct current lesions. There was a tendency for the anodal lesion to be drawn in the direction of the cathode but the effect was small and inconsistent and therefore its usefulness for controlling the shapes of anodal lesions seems minimal.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22350/1/0000796.pd

Glucocorticoid anorexia in rats

The effects of two mineralocorticoids, two glucocorticoids and a compound possessing both activities on ad lib food intake, water intake and salt intake were investigated. Dose response curves for d-aldosterone, DOCA, 9 alpha fluorocortisone, corticosterone and dexamethasone were obtained following subcutaneous injections in different groups of rats. Results support the conclusion of a clear separation between the mineralocorticoids and glucocorticoids in terms of their effects on salt intake and food intake respectively. In general (but with some notable exceptions) glucocorticoid activity was associated with anorexia while mineralocorticoid activity was associated with enhanced salt appetite, and the two effects appeared entirely independent of each other. Single doses of dexamethasone and 9 alpha flurocortisone significantly reduced (pp<0.001) increased salt intakes for 1 or more post injection days. The glucocorticoid data are discussed in terms of a possible modification of arterial-venous glucose utilization differences affecting hypothalamic sites or the possible activation of glucose sensitive hepatic cells.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22437/1/0000888.pd

Facilitation of Pavlovian conditioned cardiodecelerations following preshock in immobilized rats

Two experiments are reported that examine the effects of unsignalled, inescapable prior shock exposure (PSE) on shock-motivated Pavlovian conditioned heart rate (HR) decelerations in rats. Both studies involved 2 CS-US contingencies (paired and unpaired) and 2 preshock treatments (preshock and no preshock). The 2 designs differed in the type of immobilization procedures to which the rats were submitted and the number of conditioning sessions. In Experiment 1 rats were conditioned for 2 consecutive 35 trial sessions while physically restrained, whereas only one conditioning session was used in Experiment 2 on animals that were paralyzed with d-tubocurarine chloride (dTC). The results demonstrated that PSE augmented the magnitude of the HR conditioned response (CR) in both the physically restrained and paralyzed preparations. In addition, PSE improved the rate of acquisition of the conditioned cardiodeceleration in physically restrained rats and tended to facilitate reinstatement of the HR CR during the second conditioning session. These data support the notion that certain nonspecific stress processes that are relatively independent of the CS-US contingency but related to the occurrence of response suppression are intimately involved in Pavlovian HR conditioning.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21940/1/0000347.pd