35 research outputs found
Seasonal and interannual variability in the hydrology and geochemistry of an outlet glacier of the Greenland Ice Sheet
No full textThesis: Ph. D., Joint Program in Chemical Oceanography (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2016.Cataloged from PDF version of thesis.Includes bibliographical references.In the spring and summer within the ablation zone of the Greenland Ice Sheet (GrIS), meltwater drains to the ice sheet bed through an evolving network of efficient channelized and inefficient distributed drainage systems. Distributed system drainage is a key component in stabilizing GrIS velocity on interannual time scales and controlling geochemical fluxes. During the spring and summer of 2011 and 2012, I conducted fieldwork at a large outlet glacier in southwest Greenland underlain by metamorphic silicate rocks. Data collected from a continuous 222Rn monitor in the proglacial river were used as a component of a mass balance model. I demonstrated that Jdis, the 222Rn fraction derived from the distributed system, was >90% of the 222Rn flux on average, and therefore, 222Rn can be used as a passive flow tracer of distributed system drainage. Supraglacial meltwater runoff estimated using two independent models was compared with ice velocity measurements across the glacier's catchment. Major spikes of Jdis, occurred after rapid supraglacial meltwater runoff inputs and during the expansion of the subglacial channelized system. While increases in meltwater runoff induced ice acceleration, they also resulted in the formation of efficient subglacial channels and increased drainage from the distributed system, mechanisms known to cause slower late summer to winter velocities. Sr, U, and Ra isotopes and major and trace element chemistry were used to investigate the impact of glacial hydrology on subglacial weathering. Analysis of partial and total digestions of the riverine suspended load (SSL) found that trace carbonates within the silicate watershed largely controlled the 'Sr/'Sr ratio in the dissolved load. Experiments and sampling transects downstream from the GrIS demonstrated that [delta]234U in the dissolved phase decreased with increasing interaction with the SSL. The (2 2 8Ra/2 26Ra) value of the dissolved load was significantly higher than that of the SSL and therefore, was not the result of the source rock material but of extensive mineral surface weathering and the faster ingrowth rate of 228Ra (t1 2=5.75 y) relative to 22 6Ra (t112=1600 y). In summary, extensive, repeated cycles of rapid supraglacial meltwater runoff to subglacial drainage networks leads to increased distributed system drainage and mineral weathering.by Benjamin Shawn Linhoff.Ph. D
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Geochemical evolution of uraniferous soda lakes in Eastern Mongolia
No full textExtremely high concentrations of U were discovered in hypersaline soda lakes in eastern Mongolia. The lakes are small, shallow (<1km², <1m), and terminal with variable salinity. The origin and fate of U in these lakes was investigated using geochemical analyses and modeling, using samples collected from lakes and lake pore waters, wells and a stream. Samples were analyzed for Sr and U isotopes, cations, trace metals, anions, total inorganic carbon (TIC), and unstable field parameters. A representative groundwater in the field area is dilute and alkaline, with pH=7.9, 10 mmol L⁻¹ of TIC and 5 mmol L⁻¹ Cl⁻. In contrast, a representative lake water is pH(similar to)10 with TIC and Cl⁻ each more than 1000 mmol L⁻¹. Uranium concentrations in lake waters range from 0.24 to more than 62.5 (Greek small letter mu)mol L⁻¹, possibly making these lakes the highest naturally occurring U concentrations ever reported in a natural water. Groundwater concentrations of U range from 0.03 and 0.43 (Greek small letter mu)mol L⁻¹. The U is natural and derived from groundwater discharging to stable closed basin lakes. Waters are concentrated by evaporation and U(VI) is chelated by CO₃⁻² to form the highly soluble UO₂(CO₃)₃⁻⁴. Two sets of well waters with corresponding lake discharge waters were analyzed for U isotopes. Unnatural concentrations of ²³⁵U were tested for, the presence of which would indicate fallout-derived U. The average of four samples was ²³⁸U/²³⁵U=136(plus or minus)2 indicating that the U is naturally derived. (Greek small letter delta)²³⁴U between one well and its corresponding discharge lake had similar (Greek small letter delta)²³⁴U values ([Greek small letter delta]²³⁴U=837.6- 858.5). The other sample pair however, revealed significant differences between the well and its discharge lake ([Greek small letter delta] ²³⁴U=303.6-1530). This suggests nuclide recoil is significantly enriching one of the lakes with ²³⁴U beyond secular equilibrium during alpha-decay of ²³⁸U in lake sediments or along the groundwater flow path. Modeled evaporation of lakes demonstrates that a U-mineral phase is likely to precipitate during evaporation. Strontium isotopes varied in groundwaters between ⁸⁷Sr/⁸⁶Sr= 0.706192-0.709776 and in lakes ⁸⁷Sr/⁸⁶Sr=0.708702-0.709432. Cretaceous mafic rocks likely account for low ⁸⁷Sr/⁸⁶Sr values while Cretaceous alkaline rhyolites account for the high ⁸⁷Sr/⁸⁶Sr values. High concentrations of U, Na, Cl⁻, and K correlate to radiogenic Sr in lake waters indicating that U is sourced from local Cretaceous alkaline rhyolites.Earth and Planetary Science
Lessons from an aftermath : recovery of the self through trans-disciplinary applied drama practice
No full textIncludes abstract.Includes bibliographical references (leaves [198]-223).The aftermath is a region that is often associated with disruption, disrepair and trauma. Taking as his departure point his witnessing of the specific aftermath of the September 11th attacks in New York– the author returns to South Africa to locations that are concerned with the aftermath of apartheid and the aftermath of the advent of HIV/AIDS i.e. education and public health. He attempts a method of extracting elements from an aftermath as a form of redemptive critical theory (see Walter Benjamin, Hannah Arendt, Jean L. Cohen and Andrew Arato, Maurizio Passerin D’Entreves) in order to apply a combination of elements into a dialogical method of dramatic practice that might provide opportunities for recovery. This he does through a practice that is based upon participatory research involving participants from a high school and an HIV/AIDS wellness clinic
Shifting ground: Can community development loan funds continue to serve the neediest borrowers?
No full textCommunity development financial institutions (CDFIs) are designed to improve economic conditions for low-income individuals and communities by providing a range of financial products and services that often are not available from mainstream lenders and financiers. ; Part I of this paper reviews CDLF origins, structures, and current activities. Part II discusses the field’s historic sources of subsidized capital and why they have shrunk. Part III reviews potential new sources of capital and the organizational ways that CDLFs are responding to their changed environment. The paper concludes with recommendations for CDLFs, funders, and policy makers.Community development ; Loans
Low-Cost Micrometeorology Instrument
No full textabstract: There is an interest in citizen scientist networks such as CoCoRaHS to develop an air temperature sensor with a solar shield that is both extremely low cost and user friendly for use in widespread data collection in order to analyze urban microclimates. This paper outlines work done to develop a low cost micrometeorology instrument to fulfill the design requirements set by CoCoRaHS. While the first two revisions of this technology had significant changes in development, a third revision was created as a proof of concept that low cost temperature sensors could be used in an array to accurately measure air temperature without solar radiation interference. Another technology, described as revision four, called the iButton was also evaluated and displayed promising ability to log temperatures, but costs too much for the ultra-low cost design goal. Additionally, work was done to design a radiation shield that will be prototyped and tested alongside commercial radiation shields. This controlled experiment will also include further evaluation of the iButton and the next revision of a custom microclimate temperature sensing unit to determine the best option for widespread field testing
Virtually real : problems of authenticity in religion on the internet
No full textBibliography: leaves 205-213.This study explores the vexed problem of authenticity in religion. In making that exploration, the study uses for its data the multitude of diverse and disparate religious formations found in the relatively disordered and anarchic spaces created with Internet technologies, formations that I have tentatively called virtual religions. The theoretical framework applied here is developed from the unique and original critical theory of Walter Benjamin. This study is therefore located at a number of important intersections: between religion and popular culture, between religion and politics, between religion and philosophy, and between religion and art. The argument is comprised of three major parts, corresponding to Chapters Two, Three and Four respectively. The first part approaches authenticity from the perspective of empiricism, with its scientific methods of verification and falsification. The keyword here is forensics because it implies both the scientific paradigm and police detection. This second implication is an important addition to the first because it draws attention to power in the vexed problem of religious authenticity
Financing rural innovation with community development venture capital: models, options and obstacles
No full textGrowing local companies is essential to the economic prosperity for many rural regions and residents. Rural economies, however, rarely attract traditional venture capital. Given the important role that patient capital plays in entrepreneurial development, the future economic vitality of rural communities rests, at least in part, on their ability to access such capital. Community development venture capital (CDVC) is a particularly adept model for overcoming the structural obstacles that rural geographies present for venture capital investors. Rubin explores some of the obstacles this model faces, along with options for sources of funding.Community development ; Venture capital
The Oakland Post 2010-11-10
No full textIn the Spotlight ; 6th Annual GrizzDance features 10 student films ; STAFF EDITORIAL Free service pays off ; You matter more than your school ; GUEST COLUMN Hold OUSC accountable ; Grizzlies grace silver screen: Annual campus film festival showcases student film works ; SCREEN CAPS ; Making security a priority: Personas Non-Grata list active to keep students on campus safe ; Men's club hockey hosts fundraiser for CF ; Award-winning author visits ; campus briefs Grizz Gang fan challenge ; Becoming a home to military veterans ; Putting sleep deprivation to rest ; Approved funding for Anti-Hate week ; Police Files Loot missing from safety box ; Grizzlies still kicking: Men's soccer secures a spot in the league tournament ; Women's soccer season ends in tournament ; Volleyball making tournament push ; GOLDEN GRIZZLIES GAME OF THE WEEK Changing of the guard ; Alternative dancing studio thrives in Madison Heights ; local briefs Forklift accident leaves one dead ; United States ; OP WEEKLY CROSSWORD Sponsored by Tonic Night Club ; Struggling to move around campus ; Staying S.A.F.E. and avoiding tickets ; 4.0 professor profiles: Weekly spotlight on OU professors ; Community showcases creative talent at Ferndale Film Festival: records & reels ; Bring on the global warming: Paper towels and vacuum cleaners make Michigan a tropical paradise ; Sand Watc
Juvenile homicide : a criminological study on the possible causes of juvenile homicidal delinquency in Jamaica
No full textJamaica, the so-called land of wood and water, normally is the embodiment of a dream holiday destination with white sandy beaches, tropical palm trees, dazzling sunshine and the typical Caribbean flair. Generally, murder and manslaughter are not associated with Jamaica. However, international comparisons of crime rates reveal that Jamaica has persistently had one of the highest homicide rates in the world. Jamaica has been described as the murder capital of the world in 2006 by the BBC news after more than 1’600 people were killed in the year 2005; a tally of at least five people murdered a day. The majority of the homicides are caused by young men. Despite the dimension and severity of the homicidal problem in Jamaica, it is astonishing that literature on this phenomenon in Jamaica is very sparse and the literature that is available either doesn’t conform to the current homicide situation in Jamaica anymore or is inconsistent with other studies. The aim of the present research study was thus to close this gap and to help the process of comprehending the problem of fatal juvenile delinquency by engaging empirical research in serious efforts to describe and explain the epidemic. According to the author, understanding juvenile homicidal delinquents and their actions and thus ascertaining a plausible explanation for their high homicide rate can only be achieved by going back to those whose acts are to be explained: The juvenile homicidal delinquents themselves. The findings of the present study are therefore based upon the data gathered by means of 20 face-to-face, semi-standardised interviews with young men who have committed at least one homicide during the last five years prior to the interview and were aged between 12 and 25 years at the time of the respective homicide(s). The author acts on the assumption that homicides by juveniles can be understood as a reaction that emerges situationally and is based on a complex bundle of causes which leads to an increased susceptibility to homicides. The aim of the present study was to generate a plausible and scientifically substantiated hypothesis to explain the high proportion of male juveniles responsible for the homicide rate in Jamaica. Three groupings were examined: The individual personality characteristics of the homicide delinquents, the social context influencing the individual’s thoughts and actions and the triggering factors in the homicide context.
The study comes to the conclusion that the homicides of the respondents of the present study – additionally to the basic prerequisites of the occurrence of homicides in general such as a life in deprivation and the failure of the institutions of socialisation to sufficiently socialise their members – can be explained in high gear by the widely dispread culture of violence. Within this culture, violence constitutes a part of every-day behaviour and killing is perceived as a legitimate form of dispute resolution to which one has adapted because it utterly works. This is an instrumental understanding of violent behaviour. This apparent culture of violence of the underclass society with the deeply embedded willingness to apply violence to solve even seemingly minor disputes is intensified by a high gun prevalence and easy firearm accessibility as well as the wide distribution of and attachment to gangs. Firearms as well as delinquent gangs are two powerful factors that accord power, a feeling of strength and superiority to the individual. Status, power and respect rank high within the impecunious underclass society in Jamaica. Violence is perceived as a necessary instrument to sustain the own identity, status and respect. Thus, the fight for respect in the street culture of Jamaica’s urban inner-city youth depicts an act in self-defence for the parties involved. And such an act in self-defence legitimises to kill
CDK12 Inhibition Reverses De Novo and Acquired PARP Inhibitor Resistance in BRCA Wild-Type and Mutated Models of Triple-Negative Breast Cancer
No full textSummaryAlthough poly(ADP-ribose) polymerase (PARP) inhibitors are active in homologous recombination (HR)-deficient cancers, their utility is limited by acquired resistance after restoration of HR. Here, we report that dinaciclib, an inhibitor of cyclin-dependent kinases (CDKs) 1, 2, 5, and 9, additionally has potent activity against CDK12, a transcriptional regulator of HR. In BRCA-mutated triple-negative breast cancer (TNBC) cells and patient-derived xenografts (PDXs), dinaciclib ablates restored HR and reverses PARP inhibitor resistance. Additionally, we show that de novo resistance to PARP inhibition in BRCA1-mutated cell lines and a PDX derived from a PARP-inhibitor-naive BRCA1 carrier is mediated by residual HR and is reversed by CDK12 inhibition. Finally, dinaciclib augments the degree of response in a PARP-inhibitor-sensitive model, converting tumor growth inhibition to durable regression. These results highlight the significance of HR disruption as a therapeutic strategy and support the broad use of combined CDK12 and PARP inhibition in TNBC
