Acute water shortages for large metropolitan regions are likely to become more frequent as climate changes impact historic precipitation levels and urban population grows. California and Los Angeles ...County have just experienced a severe four year drought followed by a year of high precipitation, and likely drought conditions again in Southern California. We show how the embedded preferences for distant sources, and their local manifestations, have created and/or exacerbated fluctuations in local water availability and suboptimal management. As a socio technical system, water management in the Los Angeles metropolitan region has created a kind of scarcity lock-in in years of low rainfall. We come to this through a decade of coupled research examining landscapes and water use, the development of the complex institutional water management infrastructure, hydrology and a systems network model. Such integrated research is a model for other regions to unpack and understand the actual water resources of a metropolitan region, how it is managed and potential ability to become more water self reliant if the institutions collaborate and manage the resource both parsimoniously, but also in an integrated and conjunctive manner. The Los Angeles County metropolitan region, we find, could transition to a nearly water self sufficient system.
Understanding mechanisms controlling fluid injection-triggered seismicity is key in defining strategies to ameliorate it. Recent triggered events (e.g. Pohang, Mw 5.5) have exceeded predictions of ...average energy release by a factor of >1000x, necessitating robust methodologies to both define critical antecedent conditions and to thereby constrain anticipated event size. We define maximum event magnitudes resulting from triggering as a function of pre-existing critical stresses and fluid injection volume. Fluid injection experiments on prestressed laboratory faults confirm these estimates of triggered moment magnitudes for varied boundary conditions and injection rates. In addition, observed ratios of shear slip to dilation rates on individual faults signal triggering and may serve as a measurable proxy for impending rupture. This new framework provides a robust method of constraining maximum event size for preloaded faults and unifies prior laboratory and field observations that span sixteen decades in injection volume and four decades in length scale.
The CCATT/enhancer binding protein alpha, C/EBPα, is a key transcription factor involved in late differentiation events of several cell types. Besides acting as a classical transcription factor, ...C/EBPα is also a well-characterized inhibitor of mitotic growth in most cell lines tested. In line with its anti-mitotic properties, C/EBPα has been shown to interact with, and alter the activities of, several cell cycle related proteins and a number of models as to the mechanistics of C/EBPα-mediated growth repression have been proposed. More recently, several reports have indicated that C/EBPα acts as a tumour suppressor in the hematopoietic system and that mutation within C/EBPα is sufficient to induce tumourigenesis. Here, we will review these data and probe the possibility that C/EBPα also act as a tumour suppressor in other C/EBPα-expressing tissues.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Acute myeloid leukemia (AML) develops via a multistep process involving several genetic and epigenetic events, which ultimately leads to the formation of a heterogeneous population of malignant ...cells, of which only a small subpopulation termed the leukemia initiating cell (LIC) is able to sustain the leukemia. The identity of the LIC is highly diverse and ranges from populations resembling hematopoietic stem cells or multipotent progenitors (MPPs) to more committed myeloid progenitors, and the question still remains whether this is a direct consequence of which cells are targets of the final transforming events. In this study, we use premalignant cells from a Cebpa mutant AML model, in which the LIC population resembles granulocyte-macrophage progenitors (GMPs), to show that premalignant GMPs undergo spontaneous immortalization with a high clonal frequency when cultured in vitro, suggesting that these cells constitute the target of the final transforming events. Furthermore, we show that premalignant GMPs are characterized by a distinct T cell gene expression signature correlating with an increased potential for differentiation toward the T cell lineage. These findings have implications for our understanding of the transcriptional wiring in premalignant myeloid progenitors and how this contributes to the development of AML.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
AbstractLos Angeles, which relies on large infrastructure systems that import water over hundreds of miles, faces a future of reduced imports. Within Los Angeles and its hundreds of water agencies, ...the capacity to adapt to future changes is influenced by laws, institutions, and hydrogeology. This paper presents a systems analysis of urban water management in metropolitan Los Angeles County to assess opportunities for increasing local water reliance. A network flow model was developed to investigate management tradeoffs across engineered, social, and environmental systems. With an aggressive regional demand target, increased stormwater capture (300%), and prioritized water reuse from existing facilities, imported water supplies can be cut by 30% while maintaining landscapes, economic productivity, and groundwater resources. Further reducing imports (by 40–50%) is possible through actions to promote additional reuse, recharge, conservation, and groundwater access. Reducing imported water without significant conservation results in likely groundwater overdraft. Fragmented networks of agencies in Los Angeles create an uneven landscape of vulnerability to water shortages. The paper discusses model applications, research needs, and policy implications of results for dry-climate cities.
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