Size Control and Fluorescence Labeling of Polydopamine Melanin-Mimetic Nanoparticles for Intracellular Imaging.

As synthetic analogs of the natural pigment melanin, polydopamine nanoparticles (NPs) are under active investigation as non-toxic anticancer photothermal agents and as free radical scavenging therapeutics. By analogy to the widely adopted polydopamine coatings, polydopamine NPs offer the potential for facile aqueous synthesis and incorporation of (bio)functional groups under mild temperature and pH conditions. However, clear procedures for the convenient and reproducible control of critical NP properties such as particle diameter, surface charge, and loading with functional molecules have yet to be established. In this work, we have synthesized polydopamine-based melanin-mimetic nanoparticles (MMNPs) with finely controlled diameters spanning ≈25 to 120 nm and report on the pH-dependence of zeta potential, methodologies for PEGylation, and the incorporation of fluorescent organic molecules. A comprehensive suite of complementary techniques, including dynamic light scattering (DLS), cryogenic transmission electron microscopy (cryo-TEM), X-ray photoelectron spectroscopy (XPS), zeta-potential, ultraviolet-visible (UV-Vis) absorption and fluorescence spectroscopy, and confocal microscopy, was used to characterize the MMNPs and their properties. Our PEGylated MMNPs are highly stable in both phosphate-buffered saline (PBS) and in cell culture media and exhibit no cytotoxicity up to at least 100 μg mL-1 concentrations. We also show that a post-functionalization methodology for fluorophore loading is especially suitable for producing MMNPs with stable fluorescence and significantly narrower emission profiles than previous reports, suggesting they will be useful for multimodal cell imaging. Our results pave the way towards biomedical imaging and possibly drug delivery applications, as well as fundamental studies of MMNP size and surface chemistry dependent cellular interactions

Information Technology Offshoring: Prospects, Challenges, Educational Requirements, and Curriculum Implications

Offshore provision of information systems/information technology-related services has been growing rapidly in recent years and seems firmly set to continue. This trend is fueled by the many advantages of offshore service procurement; however, there are dangers in this practice. Furthermore, offshoring requires adaptation of the IS function and IS management. This in turn suggests modifications of IS curricula in order to prepare graduates for the new environment. The advantages of offshoring are those of outsourcing in general: allowing the organization to focus on its core activities and cost savings. The main dangers include loss of business intelligence and reliance on remote suppliers who may suffer a major failure. The loss of jobs due to offshoring also introduces political considerations. Offshore operations are generally supervised by an organization’s CIO. This management responsibility requires awareness of cultural and legal differences and of risks associated with offshoring and outsourcing in general. Offshoring has an effect on job opportunities for graduates of information systems programs. The number of some jobs will shrink, but new positions with new responsibilities are likely to emerge. Training students to function in an environment of offshored operations will introduce new IS specializations and require adaptation of IS curricula; a framework for considering modifications is suggested

A diagnosis of the development of a winter anticyclone over North America

This paper examines the 48-h life cycle of a winter anticyclone occurring over North America from 18 to 20 January 1979 using Goddard Laboratory for Atmospheres FGGE level 3b (SOP 1) global analyses on a 4 deg latitude by 5 deg longitude grid. Applying the relatively new methodology of the Zwack-Okossi equation, results show that anticyclonic vorticity advection and cold-air advection acted to develop the anticyclone, while adiabatic warming in the descending air opposed development. Other forcing processes made only small contributions to anticyclone changes. Vertical profiles of the development quantities reveal that vorticity and temperature advections, as well as the adiabatic warming, maximized in the 200-300-mb layer

IT OFFSHORING: History, Prospects and Challenges

Offshore provision of IS/IT related services has been growing rapidly in recent years and seems firmly set to continue. This trend is fueled by the many advantages of offshore service procurement; however, there are dangers in this practice. Furthermore, offshoring requires adaptation of the IS function and IS management. This, in turn suggests the need for modifications of IS curricula in order to prepare graduates for the new environment. The advantages of offshoring are those of outsourcing in general – cost saving and allowing the organization to focus on its core activities. The main dangers include loss of possibly-important business skills and reliance on remote suppliers who face risks that are unfamiliar to the client firm. The loss of jobs due to offshoring also introduces political considerations. Offshore IS activities are generally the responsibility of an organization’s CIO. This management responsibility requires awareness of cultural and legal differences and of risks associated with offshoring and outsourcing in general. Offshoring has an effect on job opportunities for graduates of information systems programs. The number of some jobs will shrink, but new positions with new responsibilities are likely to emerge. Training of students in the U.S. and other countries in the developed world to function in an environment of offshored operations will introduce new IS roles and skills and require the adaptations of IS curricula

Drought Scenario Analysis Using RiverWare: A Case Study in Urumqi River Basin, China

In this study, we applied RiverWare modeling approach to evaluate the management decisions on surface water and groundwater diversions in the agricultural watershed of the Urumqi River Basin of Xinjiang in Northwestern China. A rule-based daily time step RiverWare model was developed to simulate the hydrologic effects of different water management alternatives considering irrigation and drainage systems, crop water use, and diversion rules at the diversion dams within the basin. Daily data period from 2005 to 2009 was used to calibrate the model and 2010-2012 was used to validate the model. A calibrated daily RiverWare model was then used to evaluate the management decisions under different drought scenarios that generated by using the snowmelt runoff model (SRM) that developed to simulate inflow from upstream of Yingxiongqiao gaging station. Two drought scenarios (reduced precipitation and increased temperature) analysis were performed, and the corresponding hydrological variables were compared to the baseline scenario. The results indicated that the model adequately reproduced the historical inflows for the Wulabo Reservoir. The scenario analysis results suggest that the reduced precipitation led to increased groundwater pumping for irrigation both in the spring and summer. The increased temperature induces a significant increase in surface runoff in the basin and leads to increased crop water demand within the irrigation district, and however does not necessarily reduce the groundwater pumpage. Water operation policies from RiverWare provide guidelines for conjunctive use of groundwater and surface water resources within the basin under different water supply scenarios in the future

PIWI Homologs Mediate Histone H4 mRNA Localization to Planarian Chromatoid Bodies

The well-known regenerative abilities of planarian flatworms are attributed to a population of adult stem cells called neoblasts that proliferate and differentiate to produce all cell types. A characteristic feature of neoblasts is the presence of large cytoplasmic ribonucleoprotein granules named chromatoid bodies, the function of which has remained largely elusive. This study shows that histone mRNAs are a common component of chromatoid bodies. Our experiments also demonstrate that accumulation of histone mRNAs, which is typically restricted to the S phase of eukaryotic cells, is extended during the cell cycle of neoblasts. The planarian PIWI homologs SMEDWI-1 and SMEDWI-3 are required for proper localization of germinal histone H4 (gH4) mRNA to chromatoid bodies. The association between histone mRNA and chromatoid body components extends beyond gH4 mRNA, since transcripts of other core histone genes were also found in these structures. Additionally, piRNAs corresponding to loci of every core histone type have been identified. Altogether, this work provides evidence that links PIWI proteins and chromatoid bodies to histone mRNA regulation in planarian stem cells. The molecular similarities between neoblasts and undifferentiated cells of other organisms raise the possibility that PIWI proteins might also regulate histone mRNAs in stem cells and germ cells of other metazoans

Un-Haunting From the Ghost We Killed: IS Research and Education in the Post-Industrial Economy

The field of management emerged in response to the challenges of the industrial age that is now coming to an end. Since its inception, the information systems (IS) research community has argued that the information technology will bring fundamental challenges to the forces that underpin the way we organize our work. The IS discipline played a significant role in bringing the end of the industrial age, fulfilling its early promises. However, the IS community is struggling to find a way to move beyond the powerful institutional and intellectual hegemony based on the industrial-age organization. The proposed panel will take up this challenge and debate several ways of going beyond the hegemony of industrial age organization that has dominated both research and education of the field

Quantifying allo-grooming in wild chacma baboons (Papio ursinus) using tri-axial acceleration data and machine learning

Quantification of activity budgets is pivotal for understanding how animals respond to changes in their environment. Social grooming is a key activity that underpins various social processes with consequences for health and fitness. Traditional methods use direct (focal) observations to calculate grooming rates, providing systematic but sparse data. Accelerometers, in contrast, can quantify activity budgets continuously but have not been used to quantify social grooming. We test whether grooming can be accurately identified using machine learning (random forest model) trained on labelled acceleration data from wild chacma baboons (Papio ursinus). We successfully identified giving and receiving grooming with high precision (81% and 91%) and recall (87% and 79%). Giving grooming was associated with a distinct rhythmical signal along the surge axis. Receiving grooming had similar acceleration signals to resting, and thus was more difficult to assign. We applied our machine learning model to n = 680 collar data days from n = 12 baboons and found that grooming rates obtained from accelerometers were significantly and positively correlated with direct observation rates for giving but not receiving grooming. The ability to collect continuous grooming data in wild populations will allow researchers to re-examine and expand upon long-standing questions regarding the formation and function of grooming bonds

The Welfare Caseload, Economics Growth and Welfare-to-Work Policies: An Analysis of Five Urban Areas

This paper uses quarterly data on AFDC (later TANF) recipients in five major urban areas to examine the relative importance of policy reform and economic conditions in explaining the dynamics of the welfare caseload and the employment experiences of welfare leavers. We find that changes in both welfare exits and entries played an important role in the caseload declines of the 1990s. Policy changes were primary in causing changes in these flows, with economic conditions of secondary importance. Although welfare reforms were accompanied by substantial increases in the employment of those leaving welfare, this appears to be largely the result of an increasingly tight labor market rather than the reforms