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1.
Phage (New Rochelle) ; 4(2): 82-89, 2023 Jun 01.
Article in English | MEDLINE | ID: mdl-37350996

ABSTRACT

Introduction: The rpoCY75N mutation in the zinc-binding domain of the ß' subunit of Escherichia coli RNA polymerase blocks the RNA-based mechanism of transcription antitermination utilized by bacteriophage HK022. Materials and Methods: Mutant phages that overcome the block imposed by the rpoCY75N mutation are described. These phages, designated "orc" (overcomes rpoC), carry mutations that create new promoters. Promoter activity was assessed by cloning the respective regions from the wild-type and orc phages into a promoterless lacZ reporter vector. Results: Reporter assays showed that the sequence originating from orc phages had significant promoter activity when compared with the equivalent sequence cloned from the parental phage. Conclusions: The newly created promoters facilitate the expression of phage genes that are essential for growth on the rpoCY75N strain by bypassing transcription terminators. The small plaque phenotype of orc phages, when grown on the mutant host, suggests that suppression of the rpoCY75N mutation is incomplete.

2.
Nat Commun ; 13(1): 2459, 2022 05 05.
Article in English | MEDLINE | ID: mdl-35513376

ABSTRACT

It is well established that nighttime radiance, measured from satellites, correlates with economic prosperity across the globe. In developing countries, areas with low levels of detected radiance generally indicate limited development - with unlit areas typically being disregarded. Here we combine satellite nighttime lights and the world settlement footprint for the year 2015 to show that 19% of the total settlement footprint of the planet had no detectable artificial radiance associated with it. The majority of unlit settlement footprints are found in Africa (39%), rising to 65% if we consider only rural settlement areas, along with numerous countries in the Middle East and Asia. Significant areas of unlit settlements are also located in some developed countries. For 49 countries spread across Africa, Asia and the Americas we are able to predict and map the wealth class obtained from ~2,400,000 geo-located households based upon the percent of unlit settlements, with an overall accuracy of 87%.


Subject(s)
Agriculture , Family Characteristics , Africa , Americas , Middle East , Population Dynamics
3.
Infect Drug Resist ; 14: 125-142, 2021.
Article in English | MEDLINE | ID: mdl-33500635

ABSTRACT

The spread of metallo-ß-lactamase (MBL)-producing Enterobacterales worldwide without the simultaneous increase in active antibiotics makes these organisms an urgent public health threat. This review summarizes recent advancements in diagnostic and treatment strategies for infections caused by MBL-producing Enterobacterales. Adequate treatment of patients infected with MBL-producing Enterobacterales relies on detection of the ß-lactamase in the clinic. There are several molecular platforms that are currently available to identify clinically relevant MBLs as well as other important serine-ß-lactamases. Once detected, there are several antibiotics that have historically been used for the treatment of MBL-producing Enterobacterales. Antimicrobials such as aminoglycosides, tetracyclines, fosfomycin, and polymyxins often show promising in vitro activity though clinical data are currently lacking to support their widespread use. Ceftazidime-avibactam combined with aztreonam is promising for treatment of infections caused by MBL-producing Enterobacterales and currently has the most clinical data of any available antibiotic to support its use. While cefiderocol has displayed promising activity against MBL-producing Enterobacterales in vitro and in preliminary clinical studies, further clinical studies will better shed light on its place in treatment. Lastly, there are several promising MBL inhibitors in the pipeline, which may further improve the treatment of MBL-producing Enterobacterales.

4.
Energy Res Soc Sci ; 44: 411-418, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30467534

ABSTRACT

As the world's most traded commodity, oil production is typically well monitored and analyzed. It also has established links to geopolitics, international relations, and security. Despite this attention, the illicit production, refining, and trade of oil and derivative products occur all over the world and provide significant revenues outside of the oversight and regulation of governments. A prominent manifestation of this phenomenon is how terrorist and insurgent organizations-including the Islamic State group, also known as ISIL/ISIS or Daesh-use oil as a revenue source. Understanding the spatial and temporal variation in production can help determine the scale of operations, technical capacity, and revenue streams. This information, in turn, can inform both security and reconstruction strategies. To this end, we use satellite multi-spectral imaging and ground-truth pre-war output data to effectively construct a real-time census of oil production in areas controlled by the ISIL terrorist group. More broadly, remotely measuring the activity of extractive industries in conflict-affected areas without reliable administrative data can support a broad range of public policy and decisions and military operations.

5.
Sci Adv ; 3(11): e1701528, 2017 11.
Article in English | MEDLINE | ID: mdl-29181445

ABSTRACT

A central aim of the "lighting revolution" (the transition to solid-state lighting technology) is decreased energy consumption. This could be undermined by a rebound effect of increased use in response to lowered cost of light. We use the first-ever calibrated satellite radiometer designed for night lights to show that from 2012 to 2016, Earth's artificially lit outdoor area grew by 2.2% per year, with a total radiance growth of 1.8% per year. Continuously lit areas brightened at a rate of 2.2% per year. Large differences in national growth rates were observed, with lighting remaining stable or decreasing in only a few countries. These data are not consistent with global scale energy reductions but rather indicate increased light pollution, with corresponding negative consequences for flora, fauna, and human well-being.

6.
Sci Adv ; 2(6): e1600377, 2016 06.
Article in English | MEDLINE | ID: mdl-27386582

ABSTRACT

Artificial lights raise night sky luminance, creating the most visible effect of light pollution-artificial skyglow. Despite the increasing interest among scientists in fields such as ecology, astronomy, health care, and land-use planning, light pollution lacks a current quantification of its magnitude on a global scale. To overcome this, we present the world atlas of artificial sky luminance, computed with our light pollution propagation software using new high-resolution satellite data and new precision sky brightness measurements. This atlas shows that more than 80% of the world and more than 99% of the U.S. and European populations live under light-polluted skies. The Milky Way is hidden from more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans. Moreover, 23% of the world's land surfaces between 75°N and 60°S, 88% of Europe, and almost half of the United States experience light-polluted nights.


Subject(s)
Environmental Pollution , Lighting , Maps as Topic , Africa , Americas , Asia , Conservation of Natural Resources , Europe , Models, Statistical
7.
Sensors (Basel) ; 10(4): 3961-88, 2010.
Article in English | MEDLINE | ID: mdl-22319336

ABSTRACT

We investigated the optimal spectral bands for the identification of lighting types and the estimation of four major indices used to measure the efficiency or character of lighting. To accomplish these objectives we collected high-resolution emission spectra (350 to 2,500 nm) for forty-three different lamps, encompassing nine of the major types of lamps used worldwide. The narrow band emission spectra were used to simulate radiances in eight spectral bands including the human eye photoreceptor bands (photopic, scotopic, and "meltopic") plus five spectral bands in the visible and near-infrared modeled on bands flown on the Landsat Thematic Mapper (TM). The high-resolution continuous spectra are superior to the broad band combinations for the identification of lighting type and are the standard for calculation of Luminous Efficacy of Radiation (LER), Correlated Color Temperature (CCT) and Color Rendering Index (CRI). Given the high cost that would be associated with building and flying a hyperspectral sensor with detection limits low enough to observe nighttime lights we conclude that it would be more feasible to fly an instrument with a limited number of broad spectral bands in the visible to near infrared. The best set of broad spectral bands among those tested is blue, green, red and NIR bands modeled on the band set flown on the Landsat Thematic Mapper. This set provides low errors on the identification of lighting types and reasonable estimates of LER and CCT when compared to the other broad band set tested. None of the broad band sets tested could make reasonable estimates of Luminous Efficacy (LE) or CRI. The photopic band proved useful for the estimation of LER. However, the three photoreceptor bands performed poorly in the identification of lighting types when compared to the bands modeled on the Landsat Thematic Mapper. Our conclusion is that it is feasible to identify lighting type and make reasonable estimates of LER and CCT using four or more spectral bands with minimal spectral overlap spanning the 0.4 to 1.0 um region.

8.
Sensors (Basel) ; 7(9): 1962-1979, 2007 Sep 21.
Article in English | MEDLINE | ID: mdl-28903208

ABSTRACT

We present the first global inventory of the spatial distribution and density ofconstructed impervious surface area (ISA). Examples of ISA include roads, parking lots,buildings, driveways, sidewalks and other manmade surfaces. While high spatialresolution is required to observe these features, the new product reports the estimateddensity of ISA on a one-km² grid based on two coarse resolution indicators of ISA - thebrightness of satellite observed nighttime lights and population count. The model wascalibrated using 30-meter resolution ISA of the USA from the U.S. Geological Survey.Nominally the product is for the years 2000-01 since both the nighttime lights andreference data are from those two years. We found that 1.05% of the United States landarea is impervious surface (83,337 km²) and 0.43 % of the world's land surface (579,703km²) is constructed impervious surface. China has more ISA than any other country(87,182 km²), but has only 67 m² of ISA per person, compared to 297 m² per person in theUSA. The distribution of ISA in the world's primary drainage basins indicates that watersheds damaged by ISA are primarily concentrated in the USA, Europe, Japan, China and India. The authors believe the next step for improving the product is to include reference ISA data from many more areas around the world.

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