Northeastern State University

About: Northeastern State University is a education organization based out in Tahlequah, Oklahoma, United States. It is known for research contribution in the topics: Wireless sensor network & Computer science. The organization has 477 authors who have published 831 publications receiving 21482 citations. The organization is also known as: NSU.

Inhibition of Bacillus anthracis metallo-β-lactamase by compounds with hydroxamic acid functionality

Abstract: Metallo-β-lactamases (MBLs) that catalyze hydrolysis of β-lactam antibiotics are an emerging threat due to their rapid spread. A strain of the bacterium Bacillus anthracis has its ability to produce and secrete a MBL, referred to Bla2. To address this challenge, novel hydroxamic acid-containing compounds such as 3-(heptyloxy)-N-hydroxybenzamide (compound 4) and N-hydroxy-3-((6-(hydroxyamino)-6-oxohexyl)oxy)benzamide (compound 7) were synthesized. Kinetic analysis of microbial inhibition indicated that the both sides of hydroxamic acids containing compound 7 revealed a reversible, competitive inhibition with a Ki value of 0.18 ± 0.06 μM. The result has reflected that the both sides of dihydroxamic acids in a molecule play a crucial role in the binding affinity rather than monohydroxamic containing compound 4 which was unable to inhibit Bla2. In addition, in silico analysis suggested that compound 7 was coordinated with a zinc ion in the active site of enzyme. These observations suggest that the dih...

An Integral Data Gathering Framework for Supervisory Control and Data Acquisition Systems in Green IoT

Abstract: In Green Internet of Things, energy consumption research is a hot topic. Our research focuses on Supervisory Control And Data Acquisition (SCADA) system, and it is a system consisting of a plurality of self-organized sensing networks. Live data gathering from numerous Sub-connected SCADA (S-SCADA) networks to make unified decisions based on collected data is one of pivot problem, which has not been well studied. In this article, an integral data-gathering framework is proposed to prolong network lifetime by using sink rotating and Unmanned Aerial Vehicles (UAV) path planning. In the proposed Sink Rotating joint UAV Data Gathering (SR-UAV-DG) framework, the data gathering process is divided into two organic components: (a) S-SCADA in-network data collection. The energy consumption of the network is balanced by selecting the node with the least energy consumption as the sink node. (b) Use UAV for data collection between S-SCADA networks. The theoretical analysis results show that the SR-UAV-DG framework proposed in this article reduces the maximum energy consumption of nodes in the network by 99.21% after 1000 rounds of data. The flight time of UAV is reduced by 16.83%. In the case of unreliable communication links, the data reception rate is guaranteed to reach 91.94%.

Perceived direction of gaze from eyes with dark vs. light irises.

Abstract: PURPOSE: Much of the previous research on the perceived direction of gaze has not specified eye color or pupil visibility. This study tests whether the lightness or darkness of a gazer's irises (typically brown vs. blue) affects their perceived direction of gaze. METHODS: Twenty-five observers judged the direction of horizontal gaze from a model whose LCD-imaged head gazed toward points on the plane of the observer's face. The model's head was displayed with its natural brown irises and also with its irises digitally altered to look blue without pupils, blue with centered pupils, and blue with nasally decentered pupils. True gaze location was compared with the judged gaze location for each type of iris. RESULTS: For all iris types, observers judged that monocular gaze was biased outward from its true direction for all gaze locations, including central, whereas binocular gaze was close to centered and had a greater slope. Blue eyes with no pupil and blue eyes with a centered pupil exaggerated this perceived outward deviation for monocular gaze but binocular gaze remained the same. When the pupils were nasally decentered by a typical amount, straight monocular as well as binocular gaze appeared to be centered. CONCLUSIONS: The direction of monocular gaze from eyes that differ in the darkness of their irises is perceived differently, and, within the blue irises, small differences in pupil centration made surprisingly large differences in the perceived directions of gaze.

Intertester agreement in refractive error measurements.

Abstract: Purpose—To determine the inter-tester agreement of refractive error measurements between lay and nurse screeners using the Retinomax Autorefractor (Retinomax) and the SureSight Vision Screener (SureSight). Methods—Trained lay and nurse screeners measured refractive error in 1452 preschoolers (3- to 5-years old) using the Retinomax and the SureSight in a random order for screeners and instruments. Inter-tester agreement between lay and nurse screeners was assessed for sphere, cylinder and spherical equivalent (SE) using the mean difference and the 95% limits of agreement. The mean inter-tester difference (lay minus nurse) was compared between groups defined based on child’s age, cycloplegic refractive error, and the reading’s confidence number using analysis of variance. The limits of agreement were compared between groups using the Brown-Forsythe test. Inter-eye correlation was accounted for in all analyses. Results—The mean inter-tester differences (95% limits of agreement) were −0.04 (−1.63, 1.54) Diopter (D) sphere, 0.00 (−0.52, 0.51) D cylinder, and −0.04 (1.65, 1.56) D SE for the Retinomax; and 0.05 (−1.48, 1.58) D sphere, 0.01 (−0.58, 0.60) D cylinder, and 0.06 (−1.45, 1.57) D SE for the SureSight. For either instrument, the mean inter-tester differences in sphere and SE did not differ by the child’s age, cycloplegic refractive error, or the reading’s confidence number. However, for both instruments, the limits of agreement were wider when eyes had significant refractive error or the reading’s confidence number was below the manufacturer’s recommended value. Conclusions—Among Head Start preschool children, trained lay and nurse screeners agree well in measuring refractive error using the Retinomax or the SureSight. Both instruments had similar inter-tester agreement in refractive error measurements independent of the child’s age. Significant refractive error and a reading with low confidence number were associated with worse inter-tester agreement.