2,069 research outputs found
MAC OS X Forensics: Password Discovery
OS X provides a password-rich environment in which passwords protect OS X resources and perhaps many other resources accessed through OS X. Every password an investigator discovers in an OS X environment has the potential for use in discovering other such passwords, and any discovered passwords may also be useful in other aspects of an investigation, not directly related to the OS X environment. This research advises the use of multiple attack vectors in approaching the password problem in an OS X system, including the more generally applicable non-OS X-specific techniques such as social engineering or well-known password cracking techniques such as John the Ripper or other versions of dictionary attacks and Rainbow table attacks. In some successful approaches the components of the attack vector will use more OS X specific techniques such as those described here: application-provided password revealing functions, a Javascript attack, an “Evil Website” attack, system file scavenging, exploitation of the keychain, and an OS X install disk attack.
Keywords: OS X, password, password discovery, social engineering, sleepimage, keychai
Expanded Hematopoietic Progenitor Cells Reselected for High Aldehyde Dehydrogenase Activity Demonstrate Islet Regenerative Functions
Human umbilical cord blood (UCB) hematopoietic progenitor cells (HPC) purified for high aldehyde dehydrogenase activity (ALDHhi) stimulate islet regeneration after transplantation into mice with streptozotocin-induced β cell deletion. However, ALDHhi cells represent a rare progenitor subset and widespread use of UCB ALDHhi cells to stimulate islet regeneration will require progenitor cell expansion without loss of islet regenerative functions. Here we demonstrate that prospectively purified UCB ALDHhi cells expand efficiently under serum-free, xeno-free conditions with minimal growth factor supplementation. Consistent with the concept that ALDH-activity is decreased as progenitor cells differentiate, kinetic analyses over 9 days revealed the frequency of ALDHhi cells diminished as culture time progressed such that total ALDHhi cell number was maximal (increased 3-fold) at day 6. Subsequently, day 6 expanded cells (bulk cells) were sorted after culture to reselect differentiated progeny with low ALDH-activity (ALDHlo subset) from less differentiated progeny with high ALDH-activity (ALDHhi subset). The ALDHhi subset retained primitive cell surface marker coexpression (32.0% ± 7.0% CD34+/CD38- cells, 37.0% ± 6.9% CD34+/CD133+ cells), and demonstrated increased hematopoietic colony forming cell function compared with the ALDHlo subset. Notably, bulk cells or ALDHlo cells did not possess the functional capacity to lower hyperglycemia after transplantation into streptozotocin-treated NOD/SCID mice. However, transplantation of the repurified ALDHhi subset significantly reduced hyperglycemia, improved glucose tolerance, and increased islet-associated cell proliferation and capillary formation. Thus, expansion and delivery of reselected UCB cells that retain high ALDH-activity after short-term culture represents an improved strategy for the development of cellular therapies to enhance islet regeneration in situ
Developing Conceptual and Methodological Foundations in Community Engagement
We describe the efforts of two related undergraduate projects to promote lasting social change in marginalized communities in the Dominican Republic and Nicaragua. The projects represent a test of the premise that undergraduate projects can engage academically based strategies and transcend good intentions to achieve effective community partnerships to improve health and health care. The projects proceed from a perspective and theory of marginalization and its consequences. Specifically, marginalization undermines individual and collective capacity to meet basic needs and efforts to thrive. Through strengthening social infrastructure, communities can overcome the effects of marginalization. Project work begins with annual medical clinics and, with the permission of community residents, team members conduct ethnographic descriptions of the communities and their health and health care concerns and resources. We use social network analysis (SNA) and geographic information system (GIS) techniques to describe social infrastructure. Working from those foundations, both projects have enabled increased social infrastructure. To date, we have observed increased communication among community residents, facilitated the development of community-endorsed five-year plans, and established partnerships with regional and international groups
Expansion of Umbilical Cord Blood Aldehyde Dehydrogenase Expressing Cells Generates Myeloid Progenitor Cells that Stimulate Limb Revascularization
Uncompromised by chronic disease-related comorbidities, human umbilical cord blood (UCB) progenitor cells with high aldehyde dehydrogenase activity (ALDHhi cells) stimulate blood vessel regeneration after intra-muscular transplantation. However, implementation of cellular therapies using UCB ALDHhi cells for critical limb ischemia, the most severe form of severe peripheral artery disease, is limited by the rarity (\u3c0.5%) of these cells. Our goal was to generate a clinically-translatable, allogeneic cell population for vessel regenerative therapies, via ex vivo expansion of UCB ALDHhi cells without loss of pro-angiogenic potency. Purified UCB ALDHhi cells were expanded \u3e18-fold over 6-days under serum-free conditions. Consistent with the concept that ALDH-activity is decreased as progenitor cells differentiate, only 15.1% ± 1.3% of progeny maintained high ALDH-activity after culture. However, compared to fresh UCB cells, expansion increased the total number of ALDHhi cells (2.7-fold), CD34+/CD133+ cells (2.8-fold), and hematopoietic colony forming cells (7.7-fold). Remarkably, injection of expanded progeny accelerated recovery of perfusion and improved limb usage in immunodeficient mice with femoral artery ligation-induced limb ischemia. At 7 or 28 days post-transplantation, mice transplanted with expanded ALDHhi cells showed augmented endothelial cell proliferation and increased capillary density compared to controls. Expanded cells maintained pro-angiogenic mRNA expression and secreted angiogenesis-associated growth factors, chemokines, and matrix modifying proteins. Coculture with expanded cells augmented human microvascular endothelial cell survival and tubule formation under serum-starved, growth factor-reduced conditions. Expanded UCB-derived ALDHhi cells represent an alternative to autologous bone marrow as an accessible source of pro-angiogenic hematopoietic progenitor cells for the refinement of vascular regeneration-inductive therapies. Stem Cells Translational Medicine 2017;6:1607–1619
Impact of Cultural Exposure and Message Framing on Oral Health Behavior: Exploring the Role of Message Memory.
BACKGROUND: Health messages are more effective when framed to be congruent with recipient characteristics, and health practitioners can strategically choose message features to promote adherence to recommended behaviors. We present exposure to US culture as a moderator of the impact of gain-frame versus loss-frame messages. Since US culture emphasizes individualism and approach orientation, greater cultural exposure was expected to predict improved patient choices and memory for gain-framed messages, whereas individuals with less exposure to US culture would show these advantages for loss-framed messages. METHODS: 223 participants viewed a written oral health message in 1 of 3 randomized conditions-gain-frame, loss-frame, or no-message control-and were given 10 flosses. Cultural exposure was measured with the proportions of life spent and parents born in the US. At baseline and 1 week later, participants completed recall tests and reported recent flossing behavior. RESULTS: Message frame and cultural exposure interacted to predict improved patient decisions (increased flossing) and memory maintenance for the health message over 1 week; for example, those with low cultural exposure who saw a loss-frame message flossed more. Incongruent messages led to the same flossing rates as no message. Memory retention did not explain the effect of message congruency on flossing. LIMITATIONS: Flossing behavior was self-reported. Cultural exposure may only have practical application in either highly individualistic or collectivistic countries. CONCLUSIONS: In health care settings where patients are urged to follow a behavior, asking basic demographic questions could allow medical practitioners to intentionally communicate in terms of gains or losses to improve patient decision making and treatment adherence
Self-affirmation theory in educational contexts
Self-affirmation, operationalized as value-affirmation interventions, can have long-term beneficial effects on the academic performance and trajectories of members of negatively stereotyped groups, thus reducing achievement gaps. Yet, there is significant heterogeneity in the effectiveness of value affirmations, and we do not yet have a clear understanding of why. In this introduction to the special issue, we review the literature on self-affirmation theory in educational contexts, providing overviews of the heterogeneity in the effectiveness of affirmation interventions, the methods of implementation, potential moderators, and underling processes. We identify several questions that are important for researchers to address, the answers to which would progress the field towards being able to more confidently implement value-affirmations in contexts in which, and/or for groups for whom, they are most likely to produce benefits. We then introduce the articles included in this special issue, which showcase several of the latest theoretical and empirical advances to self-affirmation theory in educational contexts
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