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Livestock production has increased in many emerging economies, but productivity is often substantially impaired by infectious diseases. The first step towards improved livestock health and productivity is to map the presence of livestock diseases. The objective of this review was to summarize studies conducted on such diseases in an emerging economy, Vietnam, and thereby identifying knowledge gaps that may inform the design of surveillance and control programs. Few studies were found to evaluate the distribution of infectious livestock diseases other than avian influenza. Also, many regions with dense livestock populations had received little attention in terms of disease investigation. A large proportion of the studies dealt with zoonoses and food-borne infections which might be due to funding agencies priorities. On the contrary, studies targeting infections that affect livestock and their productivity were few. We think that this limitation in scientific reports on infectious diseases that only affect livestock productivity is a common phenomenon in low and lower middle income countries. More science-based data on such diseases would help policymakers to prioritize which livestock diseases should be subject to animal health programs aimed to support rural livelihoods and economic development.
where $p>0$ and $ 0<s<1 $. We establish a Liouville-type theorem for positive solutions in the case $p>1$ and give a uniform lower bound of positive solutions when $0<p\leq 1$. In particular, when v is independent of the time variable, we obtain a similar result for the fractional elliptic Lichnerowicz equation
We first establish a family of sharp Caffarelli–Kohn–Nirenberg type inequalities (shortly, sharp CKN inequalities) on the Euclidean spaces and then extend them to the setting of Cartan–Hadamard manifolds with the same best constant. The quantitative version of these inequalities also is proved by adding a non-negative remainder term in terms of the sectional curvature of manifolds. We next prove several rigidity results for complete Riemannian manifolds supporting the Caffarelli–Kohn–Nirenberg type inequalities with the same sharp constant as in the Euclidean space of the same dimension. Our results illustrate the influence of curvature to the sharp CKN inequalities on the Riemannian manifolds. They extend recent results of Kristály (J. Math. Pures Appl. 119 (2018), 326–346) to a larger class of the sharp CKN inequalities.
This study compared the plan dosimetry between the intensity-modulated radiation therapy (IMRT) and field-in-field (FIF) technique for head-and-neck cancer using the Elekta Monaco treatment planning system (TPS).
Materials and methods:
A total of 20 head-and-neck cancer patients were selected in this study. IMRT and FIF plans for the patients were created on the Monaco TPS (ver. 5.11.02) using the 6-MV photon beam generated by the Elekta Synergy linear accelerator. The dose–volume histograms, maximum doses, minimum doses, mean doses of the target volumes and organs-at-risk (OARs), conformity index (CI), homogeneity index (HI) and monitor units (MUs) were determined for each IMRT and FIF plan. All IMRT plans passed the patient-specific quality assurance tests from the 2D diode array measurements (MatriXX Evolution System, IBA Dosimetry, Germany).
The results showed that the dose distribution to the target volumes of IMRT plans was better than FIF plans, while the dose (mean or max dose) to the OAR was significantly lower than FIF plan, respectively. IMRT and FIF resulted in planning target volume coverage with mean dose of 71·32 ± 0·76 and 73·12 ± 0·62 Gy, respectively, and HI values of 0·08 ± 0·01 (IMRT) and 0·19 ± 0·06 (FIF). The CI for IMRT was 0·98 ± 0·01 and FIF was 0·97 ± 0·01. For the spinal cord tolerance (maximum dose < 45 Gy), IMRT resulted in 39·85 ± 2·04 Gy compared to 41·37 ± 2·42 Gy for FIF. In addition, the mean doses to the parotid grand were 27·27 ± 7·48 and 48·68 ± 1·62 Gy for the IMRT and FIF plans, respectively. Significantly more MUs were required in IMRT plans than FIF plans (on average, 846 ± 100 MU in IMRT and 467 ± 41 MU in FIF).
It is concluded that the IMRT technique could provide a better plan dosimetry than the FIF technique for head-and-neck patients.
For a vibration system, the best designed spring is compliant to a desired vibration mode while it is robust to other undesired modes. There are several types of spring design for displacing the proofmass along the x and y axes, however, very few designs of spring compliant to the z axis are introduced. Therefore, we propose a z axis microactuator in which the suspending spring is designed so that it is only compliant to vibration along the z axis. The suspending spring consists of straight beam stages mechanically coupled with each other via frames which are symmetrically designed around a center plate. The operation characteristics of the microactuator is investigated by theoretical expresses and numerical simulation. The frequency split between the z axis mode and undesired modes can obtain more than 45%. The operation frequency can be modified in a wide range, from 68 kHz to 400 kHz, by changing the dimensional parameters of spring beams. The spring beams can be lengthened to increase displacement in the z axis while the mode cross-talk is still suppressed. Compared to the previously reported researches, the current microactuator shows robustness to undesired vibration modes, which is potential for integration in low mode cross-talk multi-axis micro-stages and low-noise mechanical sensors.
The effects of CaTiO3 (CT) and BaZrO3 (BZ) modification upon the crystal structure and electromechanical properties of lead-free Bi0.5Na0.5TiO3–SrTiO3 piezoelectric ceramics were compared within a doping range of 0–4 mol%. The different effects of CT and BZ modification upon the phase transition are clearly observed in the polarization and strain hysteresis loops. The CT-modified specimens maintain strong ferroelectricity without any abnormal enhancement in the electric field-induced strain. However, the addition of as little as 1 mol% BZ induces a transition from a nonergodic relaxor phase to an ergodic relaxor phase, thus resulting in disruption of the ferroelectric order and the generation of a high field-induced strain. The present authors believe that the substitution of large ions (such as Zr4+) into the B-sites, rather than the A-sites, of the Bi0.5Na0.5TiO3-based ceramics plays a significant role in the phase transition behavior.
Background: Antibiotic overuse has led to increasing rates of antibiotic resistant infections and unnecessary antibiotic costs. Clinical pharmacists can play a key role in optimizing appropriate use of antimicrobials and reducing antimicrobial resistance. However, the role of clinical pharmacists in antimicrobial stewardship is new and not well established in Viet Nam. Objective: We evaluated the use of clinical pharmacists for improved antimicrobial prescribing. Methods: We assembled an antibiotic stewardship program (ASP) team consisting of a clinical pharmacist and a specialist in infection prevention and control in a 60-bed medical intensive care unit (MICU) at Hue Central Hospital in central Viet Nam. During January–September 2018, the ASP team collected baseline antibiotic prescribing days of therapy (DOT) for all antibiotics administered in the MICU. Then, from October 2018 through June 2019, the ASP team reviewed daily positive clinical bacterial cultures and susceptibility results for all patients present in the MICU. They reviewed medical charts, including antimicrobial prescriptions, during week days and only if patient was still in the ICU at the time of ASP rounds. The team recommended changes to antibiotic therapy verbally to physicians and left the decision to change antibiotic therapy to their discretion. The ASP team documented whether their recommendations were accepted or rejected. Statistical significance was determined using the Student t test. Results: The ASP team reviewed 160 medical charts and made 169 ASP recommendations: 122 (72%) to continue current treatment; 24 (14%) to monitor drug levels or obtain diagnostic tests; 10 (6%) to discontinue therapy; 6 (4%) to de-escalate therapy; 5 (3%) to adjust doses; and 2 (1%) to broaden therapy. Only 8 of the recommended changes (5%) were declined by the clinicians. The average monthly DOT for all types of antibiotics declined significantly from 2,213 to 1,681 (24% decrease; P = .04). Reductions in DOT for the most common broad-spectrum antibiotics included colistin from 303 to 276 (P = .75); imipenem-cilastatin 434 to 248 (P = .06); doripenem 150 to 144 (P = .85). Piperacillin-tazobactam increased from 122 to 142 (P = 0.75). Conclusions: We demonstrated that daily review of cultures and antibiotic use decreased overall antibiotic prescribing. Given that few recommendations included discontinuation of therapy, ASP rounds likely raised awareness for clinicians to optimize antibiotic use.
This chapter examines women's mobility as presented in Vietnamese revolutionary cinema in its heyday following the Gulf of Tonkin incident (in 1964). Focusing on Ngọc Quỳnh's On Top of the Wave, on Top of the Wind, it argues that this film offers a timely reflection upon the reality of fighting and the labour of the Vietnamese people in the American War. Through the film's spatial narrative and visuality of cultural and physical geography, the filmmaker conflates nation and home, blurring the separation of domestic and public spaces and creating a national/ familial space for both sexes. Yet while this narrative invokes patriotism and mobilizes women's participation in the national struggle, it also limits women's agency and subjectivity after the war.
Keywords: Vietnamese war documentaries, women and war, spatial mobility, gender and nation, and socialist cinema
On 2 August 1964, President Johnson reported that the North Vietnamese attacked US boats in the Gulf of Tonkin, triggering expanded US involvement in the Vietnam War. To punish the Việt Minh and curtail the increasing reputation of revolutionary forces in the South, President Johnson quickly launched a siege named Operation Rolling Thunder, which stretched from early 1965 to late 1968. This incursion, unlike most previous sieges, took advantage of high-tech US Air Force equipment to devastatingly drop bombs throughout the North. In response, Hồ Chí Minh publicly called for the whole country to rise up against US imperialism in 1966. Echoing the national struggle against the US Army, documentaries and newsreels were produced to mobilize the people for the ‘sacred resistance against Americans in Vietnam’ (Cuộc kháng chiến chống Mỹ thần thánh). Engaging with the Gulf of Tonkin incident, Ngọc Quỳnh's ĐẦU SÓNG NGỌN GIÓ (ON TOP OF THE WAVE, ON TOP OF THE WIND, 1967) weaves together a story about an island (in an unidentified location in North Vietnam) and its role against the US forces with a theme of women's changing roles. The film documents the process of women's transformation cinematically portrayed as a journey of women leaving private spaces for entry into the public realm.
The median duration of hospital stays due to COVID-19 has been reported in several studies on China as 10−13 days. Global studies have indicated that the length of hospitalisation depends on different factors, such as the time elapsed from exposure to symptom onset, and from symptom onset to hospital admission, as well as specificities of the country under study. The goal of this paper is to identify factors associated with the median duration of hospital stays of COVID-19 patients during the second COVID-19 wave that hit Vietnam from 5 March to 8 April 2020.
We used retrospective data on 133 hospitalised patients with COVID-19 recorded over at least two weeks during the study period. The Cox proportional-hazards regression model was applied to determine the potential risk factors associated with length of hospital stay.
There were 65 (48.9%) females, 98 (73.7%) patients 48 years old or younger, 15 (11.3%) persons with comorbidities, 21 (16.0%) severely ill patients and 5 (3.8%) individuals with life-threatening conditions. Eighty-two (61.7%) patients were discharged after testing negative for the SARS-CoV-2 virus, 51 were still in the hospital at the end of the study period and none died. The median duration of stay in a hospital was 21 (IQR: 16–34) days. The multivariable Cox regression model showed that age, residence and sources of contamination were significantly associated with longer duration of hospitalisation.
A close look at how long COVID-19 patients stayed in the hospital could provide an overview of their treatment process in Vietnam, and support the country's National Steering Committee on COVID-19 Prevention and Control in the efficient allocation of resources over the next stages of the COVID-19 prevention period.
Non-typhoidal Salmonella (NTS) serovars, sequences types and antimicrobial susceptibility profiles have specific associations with animal and human infections in Vietnam. Antimicrobial resistance may have an effect on the manifestation of human NTS infections, with isolates from asymptomatic individuals being more susceptible to antimicrobials than those associated with animals and human diarrhoea.
In this chapter, we have introduced existing solutions in the literature aiming to improve the performance of ambient backscatter communication systems (ABCSs). We have first provided the reviews on several multiple access schemes that allows multiple transmitters backscatter data to the receiver. Then, solutions focusing on improving the communication range, bitrate, reliability, and robustness are presented in details. Finally, we have discussed challenges and future research directions to further improve the performance of ABCSs.
In this chapter, we have provided an overview of ambient backscatter communication systems. Firstly, we have introduced the fundamentals of modulated backscatter and its three main configurations, i.e., monostatic, bistatic, and ambient backscatter communication systems. Then, key channel-coding and modulation techniques in modulated backscatter communication systems are discussed. Two major types of backscatter communication channels and their link budgets are also introduced. Next, theoretical analyses and experimental measurements of backscatter channels are reviewed. Finally, we have discussed some research challenges of backscatter communication systems, especially ambient backscatter communication systems.
This chapter discussed open issues and potential research directions for future developemnt of ambient backscatter communication. Many emerging research directions are presented in this chapter such as full-duplex ambient backscatter, ultra-wideband backscatter, visible-light backscactter, and millimeter-wave backscatter.
The performance analysis for ambient backscatter communication systems is fundamentally different from that of traditional communication systems. The carrier signal of backscatter communication is opportunistically exploited from the existing active radio-frequency communication systems. As it is vulnerable to channel variations, different detection and encoding mechanisms have been proposed and analyzed to improve the system throughput or ergodic capacity. In this chapter, we have focused on the analysis of signal detection and bit-error rate (BER) performance for backscatter communication. We have reviewed the different system models for backscatter communication systems and various signal detection approaches under different resource and physical constraints.