Galaxy Formation In The Reionization Epoch As Hinted By Wide Field Camera 3 Observations Of The Hubble Ultra Deep Field

We present a large sample of candidate galaxies at z~7--10, selected in the HUDF using the new observations made by the HST/WFC3. Our sample is composed of 20 z-dropouts, 15 Y-dropouts, and 20 J-dropouts. The surface densities of the z-dropouts are close to what predicted by earlier studies, however, those of the Y- and J-dropouts are quite unexpected. While no Y- or J-dropouts have been found at AB < 28.0 mag, their surface densities seem to increase sharply at fainter levels. While some of these candidates seem to be close to foreground galaxies and thus could possibly be gravitationally lensed, the overall surface densities after excluding such cases are still much higher than what would be expected if the luminosity function does not evolve from z~7 to 10. Motivated by such steep increases, we tentatively propose a set of Schechter function parameters to describe the LFs at z~8 and 10. As compared to their counterpart at z~7, here L* decreases by ~ 6.5x and Phi* increases by 17--90x. Although such parameters are not yet demanded by the existing observations, they are allowed and seem to agree with the data better than other alternatives. If these LFs are still valid beyond our current detection limit, this would imply a sudden emergence of a large number of low-luminosity galaxies when looking back in time to z~10, which, while seemingly exotic, would naturally fit in the picture of the cosmic hydrogen reionization. These early galaxies could easily account for the ionizing photon budget required by the reionization, and they would imply that the global star formation rate density might start from a very high value at z~10, rapidly reach the minimum at z~7, and start to rise again towards z~6. In this scenario, the majority of the stellar mass that the universe assembled through the reionization epoch seems still undetected by current observations at z~6. [Abridged]Comment: accepted for publication in Research in Astronomy and Astrophysic

Digital Three-Dimensional Atlas of Quail Development Using High-Resolution MRI

We present an archetypal set of three-dimensional digital atlases of the quail embryo based on microscopic magnetic resonance imaging (µMRI). The atlases are composed of three modules: (1) images of fixed ex ovo quail, ranging in age from embryonic day 5 to 10 (e05 to e10); (2) a coarsely delineated anatomical atlas of the µMRI data; and (3) an organ system–based hierarchical graph linked to the anatomical delineations. The atlas is designed to be accessed using SHIVA, a free Java application. The atlas is extensible and can contain other types of information including anatomical, physiological, and functional descriptors. It can also be linked to online resources and references. This digital atlas provides a framework to place various data types, such as gene expression and cell migration data, within the normal three-dimensional anatomy of the developing quail embryo. This provides a method for the analysis and examination of the spatial relationships among the different types of information within the context of the entire embryo

Settlement, Growth, And Survival Of Eastern Oysters On Alternative Reef Substrates

Restoration of the native eastern oyster (Crassostrea virginica) has been severely hindered by the dwindling supply and rising costs of fossil and new oyster shell (OS) for use in reef restoration. Consequently, emphasis has shifted to the use of alternative oyster reef materials, which need to be tested for their effectiveness as settlement substrate. Furthermore, low recruitment of wild larvae has also impeded restoration, indicating a need to assess the potential of field setting of cultured larvae. We experimentally examined oyster settlement, growth and survival on unconsolidated OS, vertically embedded oyster shell (ES) in concrete, and concrete Oyster Castles (OC) in field and mesocosm experiments. In addition, we examined settlement success of cultured larvae in the mesocosm experiment. In the field experiment, juvenile recruitment was 3 higher on castles and unconsolidated shell than on embedded shell. Castles retained 4Xthe number of oysters and hosted 5Xthe biomass than embedded shell, and retained 1.5Xthe oysters and hosted 3Xthe biomass than unconsolidated shell. The proportion of live oyster recruits on castles was 1.5Xthat on both embedded and unconsolidated shell. In the mesocosm experiment (90-d postlarval deployment), the castles recruited, retained, and hosted an oyster biomass 4Xhigher than that of unconsolidated and embedded shell. This study confirms that artificial reef materials, such as OC, are suitable alternative substrates for oyster restoration, and remote setting of larvae can be effective under controlled environmental conditions. Future restoration efforts should consider use of alternative reef substrates and field setting of larvae, where recruitment is limited, to maximize oyster recruitment, while simultaneously minimizing the cost of reef restoration

The Effect of Media Selection on the Membrane Characteristics and Fatty Acid Composition of Staphylococcus Aureus

The cellular membrane is a vital structure to a microorganism and impacts important aspects of environmental regulation and growth. The physical structure of cellular membranes plays a key role in bacterial growth at low temperatures, membrane permeability and susceptibility to membrane active molecules as well as broader aspects of bacterial physiology and pathogenesis. Mueller Hinton medium is the required medium for antimicrobial susceptibility testing in the US, but there are many other types of media used in staphylococcal research. Different media vary in their nutrient compositions, and the effect of media composition on bacterial physiology is incompletely understood. The aim of this study is to elucidate possible mechanisms underlying alterations to important membrane characteristics of Staphylococcus aureus when grown in different nutrient media. The characteristics of interest in this study are fatty acid composition, membrane fluidity and carotenoid content of the cellular membrane. Each of these characteristics plays an important role in S. aureus growth, virulence and resistance to antibiotics. S. aureus cells of different strains will be grown on a number of media types and their membrane characteristics investigated using previously tested methodologies. Changes in bacterial physiology attributed to media selection could cause a rethinking of which types of media are used for antimicrobial susceptibility testing as well as other important experimental procedures

Joint Expansion Planning for Natural Gas and Electric Transmission with Endogenous Market Feedbacks

The recent and rapid shift towards the increased use of natural gas for power generation has convinced both power grid operators and regulators that additional coordination between electric power and natural gas transmission is needed to ensure the reliable operation of both systems. We report on an ongoing modeling effort for joint gas-grid expansion planning. We develop a Combined Electricity and Gas Expansion (CEGE) planning model that determines least-cost network expansions for power and gas transmission in a way that endogenizes the effects of expansion decisions on locational costs for electric power and natural gas deliveries. The CEGE model, which leverages recent advances in convex approximations for large-scale nonlinear systems, is illustrated on a new gas-grid test system topologically similar to the Northeastern United States. We show that the CEGE model is computationally tractable, and how the model might be used to jointly plan infrastructures to avoid extreme events such as the coincident gas-electric peaks experienced during the 2014 polar vortex

In a digitally connected world through likes, hashtags and followers - advancing surgical research through a social media: A narrative review

In this era of modern information technology, the world is now digitally connected through various platforms on social media, which has changed the way medical professionals work, communicate and learn. The use of social media in surgery is expanding, and it is now becoming an essential tool for surgical training, research and networking. Articles, journal clubs and surgical conferences are within reach of everyone regardless of geographical location worldwide. Electronic publications have now resoundingly replaced printed editions of journals. Collaborative research through social media platforms helps collect diverse data, enhancing the research\u27s global generalisability. The current narrative review was planned to discuss the importance of social media in advancing surgical research and the use of different social media applications in the context of promoting and disseminating surgical research alongside its evolving ethical challenges

Organic Indoor Location Discovery

We describe an indoor, room-level location discovery method based on spatial variations in "wifi signatures," i.e., MAC addresses and signal strengths of existing wireless access points. The principal novelty of our system is its organic nature; it builds signal strength maps from the natural mobility and lightweight contributions of ordinary users, rather than dedicated effort by a team of site surveyors. Whenever a user's personal device observes an unrecognized signature, a GUI solicits the user's location. The resulting location-tagged signature or "bind" is then shared with other clients through a common database, enabling devices subsequently arriving there to discover location with no further user contribution. Realizing a working system deployment required three novel elements: (1) a human-computer interface for indicating location over intervals of varying duration; (2) a client-server protocol for pre-fetching signature data for use in localization; and (3) a location-estimation algorithm incorporating highly variable signature data. We describe an experimental deployment of our method in a nine-story building with more than 1,400 distinct spaces served by more than 200 wireless access points. At the conclusion of the deployment, users could correctly localize to within 10 meters 92 percent of the time

The environment under the knife: A review of current eco-surgical strategies and recommendations for Pakistan

The healthcare sector at its core is based on the fundamentals belief to do no harm and bring about betterment in the lives of the people. Paradoxically, hospitals are one of the leading contributors to pollution, greenhouse gas (GHG) emissions and toxic waste material worldwide. Surgical care delivery is quite resource intensive, consuming significant amount of energy and equipment as well as producing large quantities of waste. With climate change being a global priority, it is crucial that hospitals re-evaluate the environmental impact of such practices. The current review was planned to identify areas of improvement in surgical care in terms of sustainability, as well as describe efficient and innovative strategies for hospitals in Pakistan to lessen their impact on the environment. The implementation of the 5 R\u27s strategy for surgical care (Reduce, Reuse, Recycle, Rethink and Research) as well as general measures to improve energy efficiency, waste management and inter-sectoral collaboration will provide significant benefits to the environment and advance efforts to creating a more sustainable future for surgical healthcare in Pakistan