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Background There is growing recognition of metagenomic next-generation sequencing (mNGS) as a valuable diagnostic tool capable of providing unbiased pathogen detection, but data on performance in low-resource settings remains scant. Here, we use mNGS of nasopharyngeal (NP) swabs taken from subjects in Cambodia to identify potential pathogens causing acute febrile illness. Methods Febrile subjects aged 2 months to 65 years were enrolled in a cross-sectional study conducted across 4 tertiary hospitals in Cambodia. NP swabs were collected at hospital presentation. Depending on reported symptom constellations, sera was also taken in a subset of subjects for comparison of mNGS results. RNA was isolated from biosamples, converted to cDNA libraries, and sequenced on a NextSeq2000 (Illumina). Raw sequence reads were stripped for host reads and aligned to NCBI nucleotide and protein databases using a cloud-based bioinformatics platform (CZID). Results NP swabs were collected from 97 subjects between April 2020 and June 2021. Subjects were predominantly male (53.6%) and young (median age 3 years [IQR 1-25]). Pathogens were identified in 42 (43.2%) NP swabs; of these, 26 (61.9%) were respiratory viruses including 9 rhinovirus, 7 coronavirus (1 SARS-CoV-2), and 5 respirovirus cases. Co-infection was identified in 3 subjects with coronavirus and respirovirus (N=2) and coronavirus and rhinovirus (N=1). Of subjects with paired sera and NP samples (N=61), 18 (29.5%) had positive NP swabs but negative sera, 7 (11.5%) had negative NP swabs but positive sera, 12 (19.7%) had positive NP swabs and sera, and 24 (39.3%) had negative NP swabs and sera. Pathogen hits correlated in NP swabs and sera in 10 of 12 subjects, including six subjects with chikungunya. Conclusion mNGS can be successfully implemented in low-resource settings to identify emerging pathogens and common respiratory pathogens, including co-infecting pathogens, from NP swabs of febrile patients. mNGS may also be able to detect chikungunya from NP swab alone, raising the possibility of non-invasive diagnostics for infections associated with high viremic states. Disclosures All Authors: No reported disclosures.

Information on causative diarrheal pathogens and their associated antimicrobial susceptibility remains limited for Cambodia. This study describes antimicrobial resistance patterns for Shigella and nontyphoidal Salmonella isolates collected in Cambodia over a 5-year period. Multidrug resistance was shown in 98% of Shigella isolates, with 70%, 11%, and 29% of isolates being resistant to fluoroquinolones, azithromycin, and cephalosporin, respectively. As many as 11% of Shigella isolates were resistant to nearly all oral and parenteral drugs typically used for shigellosis, demonstrating extreme drug resistance phenotypes. Although a vast majority of nontyphoidal Salmonella isolates remained susceptible to cephalosporins (99%) and macrolides (98%), decreased susceptibility to ciprofloxacin was found in 67% of isolates, which is notably higher than previous reports. In conclusion, increasing antimicrobial resistance of Shigella and nontyphoidal Salmonella is a major concern for selecting empirical treatment of acute infectious diarrhea in Cambodia. Treatment practices should be updated and follow local antimicrobial resistance data for the identified pathogens.

Information on causative diarrheal pathogens and their associated antimicrobial susceptibility remains limited for Cambodia. This study describes antimicrobial resistance patterns for Shigella and nontyphoidal Salmonella isolates collected in Cambodia over a 5-year period. Multidrug resistance was shown in 98% of Shigella isolates, with 70%, 11%, and 29% of isolates being resistant to fluoroquinolones, azithromycin, and cephalosporin, respectively. As many as 11% of Shigella isolates were resistant to nearly all oral and parenteral drugs typically used for shigellosis, demonstrating extreme drug resistance phenotypes. Although a vast majority of nontyphoidal Salmonella isolates remained susceptible to cephalosporins (99%) and macrolides (98%), decreased susceptibility to ciprofloxacin was found in 67% of isolates, which is notably higher than previous reports. In conclusion, increasing antimicrobial resistance of Shigella and nontyphoidal Salmonella is a major concern for selecting empirical treatment of acute infectious diarrhea in Cambodia. Treatment practices should be updated and follow local antimicrobial resistance data for the identified pathogens.

The latest well completions developments for extended-reach wells include advanced techniques to improve the effectiveness of production and optimization solutions to achieve sustainable well production. Monitoring systems installed during the completion use real-time distributed temperature sensing (DTS), distributed acoustic sensing (DAS), and downhole gauge data to obtain better reservoir insight throughout the life of the well. This enables informed decision making to achieve optimal well production and gas injection. Permanent downhole gauges (PDGs) with dual sensors (tubing + tubing) are installed, along with hybrid cable as part of the upper completion string. The hybrid cable has an electrical conductor and two fiber-optic lines for DTS and DAS measurements. The cable is clamped onto the tubing at each coupling and passes through the upper completion subassemblies, which include gas lift mandrels (GLMs) and tubing-retrievable safety valves (TRSVs). An intermediate completion is run before the upper completion, which comprises a two-trip permanent packer and remote actuated barrier device (multicycle). Completions monitoring with hybrid cables provides an advantage over conventional gauge-only systems, with only a slight increase in completion costs. Using a single cable provides more run-in-hole (RIH) efficiency, fewer lines to manage, and a smaller equipment footprint. PDG data are used by production engineers, field development personnel, and subsurface personnel to determine pressure drawdown and optimize surface production choke size. Distributed fiber-sensing technology determines the effectiveness of gas lift operations to optimize injection rates, which effectively optimizes pumping rates and flow from surface. Fiber-sensing technology also helps identify tubing and annulus leaks, monitor the health of the completion during the life of the well, and minimize wellbore damage. This type of completion has been installed successfully in 64 wells (60 production and 4 injection), and all systems are operational with data accessible from all wells. This approach benefits the industry by highlighting best practices, providing advanced technology options for evaluating data and reservoir productivity, and providing completion and drilling effectiveness for extended deep-reach wells.

Rapid terrestrial locomotion is a fascinating but difficult problem that roboticists face. Considerations must be made towards dynamics, controls, estimation, the environment, electronics, and mechanical design. Wheeled and legged robots have been heavily researched and have gained much success, however they still have their limitations, especially when ground contact is lost.Inspired by the high performance of lizards actively using their tails to stabilize perturbations and rapidly reorient their body, we propose to add an active inertial appendage to terrestrial robots that will greatly improve their stability and maneuverability.In this dissertation we present three main focus areas. We first develop the capabilities of a novel tailed robot with an active single degree-of-freedom (DOF) tail. We then discuss the single degree of freedom orientation sensing developed for this robot. Finally, we construct a nonlinear controller to enable reorientation of the body of a 2-link robot in three-dimensions while being constrained to a tail that only has two DOF of actuation.The first 177 (g) active tailed robot, Tailbot, has a single DOF of actuation and contains attitude inertial sensors. By utilizing both contact forces and zero net angular momentum maneuvering, this tailed robot can rapidly right itself in a fall, avoid flipping over after a large perturbation, and smoothly transition between surfaces of different slopes. We used a modeling approach to show that a tail-like design offers significant advantages to other alternatives, including reaction wheels, when the speed of response is important.In order to provide the reliable orientation sensing for the single DOF robot we design a novel time varying complementary filter. Complementary filtering (CF) is a signal processing methodthat is commonly used for the fusion of gyroscope and accelerometer measurements in order to robustly estimate the attitude of a rigid body. The traditional CF uses linear time invariant filters to combine the two different measurements of the same physical quantity. Here we present an extension to the CF method with time-varying filters. A fuzzy logic method is developed to adjust the parameters. Stability analysis as well as experimental results are presented to verify the proposedmethod.Finally, we propose a nonlinear control scheme for attitude control of a falling, two link active tailed robot with only two DOF of actuation. We derive a simplified expression for the robot's angular momentum and invert this expression to solve for the shape velocities that drive the body'sangular momentum to a desired value. By choosing a body angular velocity vector parallel to the axis of error rotation, the controller steers the robot towards its desired orientation. The proposed scheme is accomplished through feedback laws as opposed to feedforward trajectory generation, is fairly robust to model uncertainties, and is simple enough to implement on a low power microcontroller.We verify our approach by implementing the controller on a small 175 (g) robot platform, enabling rapid maneuvers approaching the spectacular capability of animals.

Introduction: The burden of influenza in Cambodia is not well known, but it would be useful for understanding the impact of seasonal epidemics and pandemics and to design appropriate policies for influenza prevention and control. The severe acute respiratory infection (SARI) surveillance system in Cambodia was used to estimate the national burden of SARI hospitalizations in Cambodia. Methods: We estimated age-specific influenza-associated SARI hospitalization rates in three sentinel sites in Svay Rieng, Siem Reap and Kampong Cham provinces. We used influenza-associated SARI surveillance data for one year to estimate the numerator and hospital admission surveys to estimate the population denominator for each site. A national influenza-associated SARI hospitalization rate was calculated using the pooled influenza-associated SARI hospitalizations for all sites as a numerator and the pooled catchment population of all sites as denominator. National influenza-associated SARI case counts were estimated by applying hospitalization rates to the national population. Results: The national annual rates of influenza-associated hospitalizations per 100 000 population was highest for the two youngest age groups at 323 for < 1 year and 196 for 1–4 years. We estimated 7547 influenza-associated hospitalizations for Cambodia with almost half of these represented by children younger than 5 years. Discussion: We present national estimates of influenza-associated SARI hospitalization rates for Cambodia based on sentinel surveillance data from three sites. The results of this study indicate that the highest burden of severe influenza infection is borne by the younger age groups. These findings can be used to guide future strategies to reduce influenza morbidity.

To understand transmission of avian influenza A (H5N1) virus, we conducted a retrospective survey of poultry deaths and a seroepidemiologic investigation in a Cambodian village where a 28-year-old man was infected with H5N1 virus in March 2005. Poultry surveys were conducted within a 1-km radius of the patient's household. Forty-two household flocks were considered likely to have been infected from January through March 2005 because >60% of the flock died, case-fatality ratio was 100%, and both young and mature birds died within 1 to 2 days. Two sick chickens from a property adjacent to the patient's house tested positive for H5N1 on reverse transcription–PCR. Villagers were asked about poultry exposures in the past year and tested for H5N1 antibodies. Despite frequent, direct contact with poultry suspected of having H5N1 virus infection, none of 351 participants from 93 households had neutralizing antibodies to H5N1. H5N1 virus transmission from poultry to humans remains low in this setting.

Human infections with influenza A(H5N1) virus in Cambodia increased sharply during 2013. Molecular characterization of viruses detected in clinical specimens from human cases revealed the presence of mutations associated with the alteration of receptor-binding specificity (K189R, Q222L) and respiratory droplet transmission in ferrets (N220K with Q222L). Discovery of quasispecies at position 222 (Q/L), in addition to the absence of the mutations in poultry/environmental samples, suggested that the mutations occurred during human infection and did not transmit further.

The authors report a rare case of hepatoid adenocarcinoma of the stomach, presenting initially with spleen and lymph node metastases.

Invasive squamous carcinoma of the uterine cervix (CC) arises from sequential progression of low-grade (L) and high-grade (H) squamous intraepithelial lesions (SILs). In clinical observations, these lesions are frequently found as synchronous multiple foci. The nature and evolutionary mechanism of these lesions are largely unknown. We have performed allelotyping of three 3p markers (at 3p14, 3p22–24, and 3p25) on 22 LSILs and 15 HSILs microdissected from patients with multiple (n = 21) or uniform (n = 6) cervical lesions. The results were analyzed together with our previous allelotyping of 57 deeply invasive CCs. Loss of heterozygosity at one of the three markers was observed in 23%, 27%, and 31% of LSILs, HSILs, and CCs, respectively. Frequent and early allelic loss was noted (in 30% of LSILs and 50% of HSILs) at 3p14, which may harbor tumor suppressor genes involved in early stages of cervical carcinogenesis. A high frequency of microsatellite alteration (MA) was found in LSIL (41%) and HSIL (67%) but not in CC (5.3%). In particular, MA was more frequently found in low-grade lesions in association with invasive cancers (75%, 6/8) than in those associated with SILs (29%, 4/14) (P < 0.05). Together with the finding of a monoclonal origin of premalignant and malignant cervical lesions, the present results allow us to propose a model of local field effect of genomic instability that progressively affects the clonal evolution of SIL of uterine cervix. Genes Chromosomes Cancer 24:127–134, 1999. © 1999 Wiley-Liss, Inc.

Abstract Pressure maintenance support in mature fields where permeability heterogeneity is present requires proper distribution of injected water into the respective zones of interest. This process can be extremely challenging, if no method for allocating the proper amount of water into each zone is available. An operator in the South China Sea, who had initiated a water injection project using legacy single-string two-zone completion technology, found himself in this predicament since no selective control for pressure maintenance had been considered for the project. During the past few years, the application of intelligent completion (IC) technology has increased rapidly. This acceptance has been due primarily to its proven capabilities for reservoir monitoring and corresponding optimization of well performance without well interventions. Historically, the majority of IC applications have been in production wells; however, an increasing number of operators have started adopting IC technology for their injector wells. This paper presents a case study in which IC technology was successfully applied in an offshore field in the South China Sea to provide an efficient water-injection method for optimizing pressure support as well as sweep. The operator selected this technology, as it presented a solution for optimizing the water injection. In addition to eliminating problems experienced with the incapability of the legacy completion technology to monitor water allocation and pressure maintenance for each zone, the IC technology would allow selective well testing for each zone. By evaluating the reservoir properties and characteristics of each zone independently, an intelligent completion would provide another key benefit to the operator, since it would comply with the platform size restrictions for the pumping equipment. The paper will discuss field objectives, the conceptual design, the design obstacles, and the operational challenges experienced during the job execution. Introduction Water-flooding experiences and lessons-learned regarding this area of the South China Sea have been documented and presented (Dang, et al, 2010). The injection well discussed in this paper was in a mature field that had been producing for approximately seven years, and the production rates in other wells in this field had experienced a relatively steep production decline. Wellhead pressures varied in the injection wells in this field anywhere from 500 to 2300 psi. The variation being experienced in the wellhead injection pressures was a qualitative testament to the heterogeneity that was being observed in the reservoirs of this field. With a conventional single-string completion, the operator knew that the heterogeneity of the formation would prevent the desired distribution injection rates from entering Zones P and Q of the proposed well, since previously used legacy completion designs (see Figure 1) did not offer controlled zonal injection. The total injection rate was only 5,000 BWPD, and the operator knew that if a single string completion with uncontrolled zonal injection was used, the injection rate would probably end up with 4000 BWPD into 1 zone and only 1000 BWPD into another. This would affect pressure maintenance for the field, since they would have no injection control, and subsequently, no way to control water distribution. With this situation, it was very likely that reservoir pressure could not be sustained, much less increased. As a result, the production in the oil wells in the field for those zones would continue to decline at a higher rate than desired.

BACKGROUND: We conducted investigations in 2 villages in Cambodia where outbreaks of influenza H5N1 occurred among humans and poultry to determine the frequency of and risk factors for H5N1 virus transmission. METHODS: During May 2006, approximately 7 weeks after outbreaks of influenza H5N1 among poultry occurred, villagers living near households of 2 patients with influenza H5N1 were interviewed about potential H5N1 exposures and had blood samples obtained for H5N1 serological testing by microneutralization assay. A seropositive result was defined as an influenza H5N1 neutralizing antibody titer of 1:80, with confirmation by Western blot assay. A case-control study was conducted to identify risk factors for influenza H5N1 virus infection. Control subjects, who had seronegative results of tests, were matched with H5N1-seropositive persons by village residence, households with an influenza H5N1-infected poultry flock, sex, and age. RESULTS: Seven (1.0%) of 674 villagers tested seropositive for influenza H5N1 antibodies and did not report severe illness; 6 (85.7%) were male. The 7 H5N1-seropositive persons, all of whom were aged

In Cambodia, epidemiology and disease burden of leptospirosis were not addressed as they do not have an existing surveillance system and have limitations on their laboratory diagnosis.Define the existence of leptospirosis and determine the antibodies to serovars of leptospires in Cambodia.One hundred and twenty-one suspected cases of leptospirosis were enrolled in this cross-sectional study, between September 8 and November 30, 2003 from Takeo Provincial Hospital in Doun Keo District, Cambodia.Common clinical manifestations were fever (96%), headache (92%), and myalgia (87%). Common risk behaviors were throwing garbage on the ground (84%), pulling out sprouts (77%), fertilizing (49%), and plowing (47%). Microscopic agglutination test result confirmed four cases and polymerase chain reaction test result confirmed seven cases. Two cases each showed antibodies to serovars Javanica and Australis. An estimated annual incidence of leptospirosis in Takeo province was 7.65 per 100,000 populations. Further studies to define epidemiology and burden of disease are needed.Increasing awareness and knowledge on leptospirosis among people are necessary to decrease the impact of leptospirosis in Cambodia.

One important functionality provided by a context-aware infrastructure is to derive high-level contexts on behalf of context-aware applications. High-level contexts are summary descriptions about users' states and surroundings which are generally inferred from low-level, explicit contexts directly provided by hardware sensors and software programs. In Semantic Space, an ontology-based context-aware infrastructure, high-level contexts are derived using context reasoning. In this paper, we present another approach to deriving high-level contexts in Semantic Space, event-driven context interpretation. We show how event-driven context interpretation can leverage on the context model and dynamic context acquisition/representation in Semantic Space as well as easily integrate into Semantic Space. Differing from the context reasoning approach, our proposed event-driven context interpreter offers better performance in terms of flexibility, scalability and processing time. We also present a prototype of the event-driven context interpreter we are building within Semantic Space to validate the feasibility of the new approach.

We report a rare case of metastatic adenocarcinoma of the sigmoid colon that presented as Pancoast's disease.

Two unique characteristics of geostationary satellite links impact the performance of ATM connections. These are satellite errors (which usually come in bursts) and long propagation delay. Many satellite links also have a limited bandwidth compared to terrestrial optical fibre links. This paper identifies important performance issues that should be considered when implementing ATM over satellite including: ATM services via VSAT; physical layer framing; bandwidth efficiency; bit scrambling; error effects on performance of ATM layer and ATM service; and effect of satellite on user applications.