296 research outputs found
Saline Conversion and Ice Structures from Artificially Grown Sea Ice
The environment of cold regions is generally viewed as inhospitable, primarily
due to application of ideal processes and techniques suitable to temperate
zones. The work herein is a step toward solving two environmental problems.
The first involves the supply of inexpensive, potable water in Arctic regions,
the lack of which is a severe detriment to development. Although water does
exist in the Arctic, it is neither available in potable form during many months
of the year nor does it occur in sufficient quantity near the point of use. Principally,
this lack is caused by the aridness of the Arctic and the shallowness
of fresh water sources which, for all practical purposes, do not exist but
freeze completely each winter season. The remaining liquid water source is
the sea. Arctic problems are then similar to other arid regions where the
conversion of sea water to potable water or the transmission of potable water
to desired locations is necessary. Cold temperatures generally preclude
transmission except over very short distances.
Desalination by freezing sea water is a much reported process and has been
included among the desalination processes under study worldwide. The
advantage of this method in the Arctic is the cold winter-time temperature
for freezing and the existence of adequate solar energy in the summer for
melting self purified ice. Power requirements are greatly reduced using these
natural phenomena.
The second aspect of this study concerns the use of artificially grown sea ice
as a structural material, thinking primarily in terms of coastal facilities such
as docks, jetties, islands, platforms, etc. At sufficiently high latitudes, the
summer ablation can be controlled to the point where major structures can be
maintained intact during the summer. The unit cost of material is quite low
because of low energy requirements.
The results of this study show that each of these sea water uses have considerable
promise. Desalination to potable level was accomplished. Ice growth
rates were obtained which indicate that ice structures of substantial size can
be built.This project was accomplished under a matching grant between the Office of
Water Resources Research, Department of the Interior, and the University
of Alaska, Arctic Environmental Engineering Laboratory. Funds available
under this grant purposefully did not anticipate the heavy logistic expense
in moving the project and equipment from Fairbanks to Kotzebue, Alaska.
Therefore, a major third contributor was the Alaska Air National Guard,
Kulis Air Force Base, Alaska. The support offered by the officers and men
of the Alaska Air National Guard was excellent and greatly appreciated
A Program for the Collection, Storage, and Analysis of Baseline Environmental Data for Cook Inlet, Alaska
The scope of this report is to provide a general, yet comprehensive,
description of the Cook Inlet System which will serve as a
basis for understanding the interrelated natural and man-made factors
governing its future; to present a program of field research studies
for the estuarine environment that will describe the existing state of
the Inlet with respect to the water quality and biota; to provide a
framework whereby the program of studies can be evaluated and redirected
in light of the preliminary results; and, to provide a method of storing
and analyzing the data from the investigations so that it can be made
available to interested parties in the most efficient manner possible.This report was prepared by the Institute of Water Resources of the
University of Alaska for the Alaska Water Laboratory, Federal Water
Pollution Control Administration under Contract No. 14-12-449
Core compressor exit stage study, 2
A total of two three-stage compressors were designed and tested to determine the effects of aspect ratio on compressor performance. The first compressor was designed with an aspect ratio of 0.81; the other, with an aspect ratio of 1.22. Both compressors had a hub-tip ratio of 0.915, representative of the rear stages of a core compressor, and both were designed to achieve a 15.0% surge margin at design pressure ratios of 1.357 and 1.324, respectively, at a mean wheel speed of 167 m/sec. At design speed the 0.81 aspect ratio compressor achieved a pressure ratio of 1.346 at a corrected flow of 4.28 kg/sec and an adiabatic efficiency of 86.1%. The 1.22 aspect ratio design achieved a pressure ratio of 1.314 at 4.35 kg/sec flow and 87.0% adiabatic efficiency. Surge margin to peak efficiency was 24.0% with the lower aspect ratio blading, compared with 12.4% with the higher aspect ratio blading
Study of blade aspect ratio on a compressor front stage
A single stage, low aspect ratio, compressor with a 442.0 m/sec (1450 ft/sec) tip speed and a 0.597 hub/tip ratio typical of an advanced core compressor front stage was tested. The test stage incorporated an inlet duct which was representative of an engine transition duct between fan and high pressure compressors. At design speed, the rotor stator stage achieved a peak adiabatic efficiency of 86.6 percent at a flow of 44.35 kg/sec (97.8 lbm/sec) and a pressure ratio of 1.8. Surge margin was 12.5 percent from the peak stage efficiency point
Associating ground magnetometer observations with current or voltage generators
A circuit analogy for magnetosphere‐ionosphere current systems has two extremes for drivers of ionospheric currents: ionospheric electric fields/voltages constant while current/conductivity vary—the “voltage generator”—and current constant while electric field/conductivity vary—the “current generator.” Statistical studies of ground magnetometer observations associated with dayside Transient High Latitude Current Systems (THLCS) driven by similar mechanisms find contradictory results using this paradigm: some studies associate THLCS with voltage generators, others with current generators. We argue that most of this contradiction arises from two assumptions used to interpret ground magnetometer observations: (1) measurements made at fixed position relative to the THLCS field‐aligned current and (2) negligible auroral precipitation contributions to ionospheric conductivity. We use observations and simulations to illustrate how these two assumptions substantially alter expectations for magnetic perturbations associated with either a current or a voltage generator. Our results demonstrate that before interpreting ground magnetometer observations of THLCS in the context of current/voltage generators, the location of a ground magnetometer station relative to the THLCS field‐aligned current and the location of any auroral zone conductivity enhancements need to be taken into account.Key PointsConductivity and location assumptions used to interpret ground magnetic perturbations yield conflicting resultsHigh‐latitude currents associated with voltage generators may instead be associated with current generators, and vice versaWithout better constraints on conductivity/station location relative to currents, conflicts will not be resolvedPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138366/1/jgra53632.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138366/2/jgra53632_am.pd
Cre-dependent DNA recombination activates a STING-dependent innate immune response
Gene-recombinase technologies, such as Cre/loxP-mediated DNA recombination, are important tools in the study of gene function, but have potential side effects due to damaging activity on DNA. Here we show that DNA recombination by Cre instigates a robust antiviral response in mammalian cells, independent of legitimate loxP recombination. This is due to the recruitment of the cytosolic DNA sensor STING, concurrent with Cre-dependent DNA damage and the accumulation of cytoplasmic DNA. Importantly, we establish a direct interplay between this antiviral response and cell-cell interactions, indicating that low cell densities in vitro could be useful to help mitigate these effects of Cre. Taking into account the wide range of interferon stimulated genes that may be induced by the STING pathway, these results have broad implications in fields such as immunology, cancer biology, metabolism and stem cell research. Further, this study sets a precedent in the field of gene-engineering, possibly applicable to other enzymatic-based genome editing technologies
Cre-dependent DNA recombination activates a STING-dependent innate immune response
Gene-recombinase technologies, such as Cre/loxP-mediated DNA recombination, are important tools in the study of gene function, but have potential side effects due to damaging activity on DNA. Here we show that DNA recombination by Cre instigates a robust antiviral response in mammalian cells, independent of legitimate loxP recombination. This is due to the recruitment of the cytosolic DNA sensor STING, concurrent with Cre-dependent DNA damage and the accumulation of cytoplasmic DNA. Importantly, we establish a direct interplay between this antiviral response and cell-cell interactions, indicating that low cell densities in vitro could be useful to help mitigate these effects of Cre. Taking into account the wide range of interferon stimulated genes that may be induced by the STING pathway, these results have broad implications in fields such as immunology, cancer biology, metabolism and stem cell research. Further, this study sets a precedent in the field of gene-engineering, possibly applicable to other enzymatic-based genome editing technologies
ANALISIS DETERMINAN KEJADIAN STUNTING PADA BALITA
INTRODUCTION the problem of nutrition the impact on human resources is still going on in Indonesia. The number of children who experience stunting as much as 27.5% in 2016. This means that 1 in 3 children are experiencing a stunting. The purpose of this research is to analyze the factors giving of nutrition, LOW BIRTH WEIGHT, fetal growth and income against Gen. stunting on toddlers.
RESEARCH METHODOLOGY the study was observational, analytic. Variables include low birth weight, the height of the fundus uteri, gift of nutrition and income. The sample is selected by sampling a number of exposure fix 150 with comparison 1:2. Data collection using keusioner, and medical record (KIA).
The RESULTS there are influences of nutrition (b = 2.54; CI = 1.63 up 3.44; p = 0.001), LBW < (b =-2.10; CI = 1.33-to-2.87; p = 0.001), growth < fetal (b = 5.95; CI = 3.88 to 8.03; p = 0.001) and income < against Gen. stunting in toddlers (b =-1.38; CI = 2.28 to-0.48; p = 0.003).
DISCUSSION of the causes of the incidence of stunting in toddlers is a complex thing. The incidence of stunting begins from malnutrition during pregnancy and diperberat with malnutrition in the first five years the growth of toddlers.
CONCLUSION there is influence the granting of nutrition, LOW BIRTH WEIGHT, fetal growth and income against Gen. stunting on toddlers.
PENDAHULUAN permasalahan gizi yang berdampak pada sumber daya manusia masih terjadi di Indonesia. Jumlah anak yang mengalami stunting sebanyak 27.5% pada tahun 2016. Hal ini dapat diartikan bahwa 1 dari 3 anak mengalami stunting. Tujuan penelitian ini menganalisis faktor pemberian nutrisi, BBLR, pertumbuhan janin dan pendapatan terhadap kejadian stunting pada balita.
METODOLOGI PENELITIAN studi ini analitik observasional. Variabel meliputi berat badan lahir rendah, tinggi fundus uteri, pemberian nutrisi dan pendapatan. Sampel dipilih secara fix exposure sampling sejumlah 150 dengan perbandingan 1:2. Teknik pengumpulan data menggunakan keusioner, dan rekam medis (buku KIA).
HASIL ada pengaruh nutrisi (b= 2.54; CI= 1.63 sampai 3.44; p= <0.001), BBLR (b= -2.10; CI= -2.87 sampai -1.33; p= <0.001), pertumbuhan janin (b= 5.95; CI= 3.88 sampai 8.03; p= <0.001) dan pendapatan terhadap kejadian stunting pada balita (b= -1.38; CI= 2.28 sampai -0.48; p= 0.003).
DISKUSI penyebab kejadian stunting pada balita merupakan hal yang kompleks. Kejadian stunting dimulai dari kondisi kekurangan gizi saat kehamilan dan diperberat dengan kekurangan gizi pada lima tahun pertama pertumbuhan balita.
KESIMPULAN ada pengaruh pemberian nutrisi, BBLR, pertumbuhan janin dan pendapatan terhadap kejadian stunting pada balita
Sequence-dependent off-target inhibition of TLR7/8 sensing by synthetic microRNA inhibitors
Anti-microRNA (miRNA) oligonucleotides (AMOs) with 2\u27-O-Methyl (2\u27OMe) residues are commonly used to study miRNA function and can achieve high potency, with low cytotoxicity. Not withstanding this, we demonstrate the sequence-dependent capacity of 2\u27OMe AMOs to inhibit Toll-like receptor (TLR) 7 and 8 sensing of immunostimulatory RNA, independent of their miRNA-targeting function. Through a screen of 29 AMOs targeting common miRNAs, we found a subset of sequences highly inhibitory to TLR7 sensing in mouse macrophages. Interspecies conservation of this inhibitory activity was confirmed on TLR7/8 activity in human peripheral blood mononuclear cells. Significantly, we identified a core motif governing the inhibitory activity of these AMOs, which is present in more than 50 AMOs targeted to human miRNAs in miRBaseV20. DNA/locked nucleic acids (LNA) AMOs synthesized with a phosphorothioate backbone also inhibited TLR7 sensing in a sequence-dependent manner, demonstrating that the off-target effects of AMOs are not restricted to 2\u27OMe modification. Taken together, our work establishes the potential for off-target effects of AMOs on TLR7/8 function, which should be taken into account in their therapeutic development and in vivo application
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