Sustainable coffee supply chain management: a case study in Buon Me Thuot City, Daklak, Vietnam

This paper aims to analyze and discuss the evolution towards sustainable coffee supply chain and its management in Vietnam. Coffee is a major agricultural export commodity of Vietnam with the export value accounts for 3% of national GDP in 2014 and provides a livelihood for approximately 2.6 million people. However, the sector is facing enormous challenges as the current farming methods and processing infrastructure have been unsustainable resulting in many catastrophic impacts on the environment such as deforestation and soil degradation that have the potential to lead to a decrease in the quality of coffee beans. Using a case study in Buon Me Thuot City, Daklak, Vietnam, the paper analyses the key factors influencing the sustainable coffee supply chain management in Vietnam. Our analysis confirms that although productivity is high, and farmers have positive experiences in this sector, sustainability issues are emerging. For instance, the farmers have experienced soil erosion and a lack of water and as such are now more willing to incorporate sustainability initiatives in their production and processing

Features of trastuzumab-related cardiac dysfunction: deformation analysis outside left ventricular global longitudinal strain

BackgroundCancer therapy-related cardiac dysfunction due to trastuzumab has been well-known for many years, and echocardiographic surveillance is recommended every 3 months in patients undergoing trastuzumab treatment, irrespective of the baseline cardiotoxicity risk. However, the potential harm and cost of overscreening in low- and moderate-risk patients have become great concerns.ObjectivesThis study aimed to identify the incidence of early cancer therapy-related cardiac dysfunction (CTRCD) and the behaviours of left and right heart deformations during trastuzumab chemotherapy in low- and moderate-risk patients.MethodsWe prospectively enrolled 110 anthracycline-naïve women with breast cancer and cardiovascular risk factors who were scheduled to receive trastuzumab. The left ventricular ejection fraction (LVEF), left ventricular global longitudinal strain (LV-GLS), and right ventricular and left atrial longitudinal strains were evaluated using echocardiography at baseline, before every subsequent cycle and 3 weeks after the final dose of trastuzumab. The baseline risk of CTRCD was graded according to the risk score proposed by the Heart Failure Association (HFA) Cardio-Oncology Working Group and the International Cardio-Oncology Society (ICOS). CTRCD and its severity were defined according to the current European Society of Cardiology (ESC) guidelines.ResultsTwelve (10.9%) patients had asymptomatic CTRCD. All CTRCD occurred sporadically during the first 9 months of the active trastuzumab regimen in both low- and moderate-risk patients. While CTRCD was graded as moderate severity in 41.7% of patients and heart failure therapy was initiated promptly, no irreversible cardiotoxicity or trastuzumab interruption was recorded at the end of follow-up. Among the left and right heart deformation indices, only LV-GLS decreased significantly in the CTRCD group during the trastuzumab regimen.ConclusionsCTRCD is prevalent in patients with non-high-risk breast cancer undergoing trastuzumab chemotherapy. Low- and moderate-risk patients show distinct responses to trastuzumab. The LV-GLS is the only deformation index sensitive to early trastuzumab-related cardiac dysfunction

Low-Noise GaAs Quantum Dots for Quantum Photonics

Quantum dots are both excellent single-photon sources and hosts for single spins. This combination enables the deterministic generation of Raman-photons -- bandwidth-matched to an atomic quantum-memory -- and the generation of photon cluster states, a resource in quantum communication and measurement-based quantum computing. GaAs quantum dots in AlGaAs can be matched in frequency to a rubidium-based photon memory, and have potentially improved electron spin coherence compared to the widely used InGaAs quantum dots. However, their charge stability and optical linewidths are typically much worse than for their InGaAs counterparts. Here, we embed GaAs quantum dots into an $n$-$i$-$p$-diode specially designed for low-temperature operation. We demonstrate ultra-low noise behaviour: charge control via Coulomb blockade, close-to lifetime-limited linewidths, and no blinking. We observe high-fidelity optical electron-spin initialisation and long electron-spin lifetimes for these quantum dots. Our work establishes a materials platform for low-noise quantum photonics close to the red part of the spectrum.Comment: (19 pages, 12 figures, 1 table

Optically driving the radiative Auger transition

In a radiative Auger process, optical decay is accompanied by simultaneous excitation of other carriers. The radiative Auger process gives rise to weak red-shifted satellite peaks in the optical emission spectrum. These satellite peaks have been observed over a large spectral range: in the X-ray emission of atoms; close to visible frequencies on donors in semiconductors and quantum emitters; and at infrared frequencies as shake-up lines in two-dimensional systems. So far, all the work on the radiative Auger process has focussed on detecting the spontaneous emission. However, the fact that the radiative Auger process leads to photon emission suggests that the transition can also be optically excited. In such an inverted radiative Auger process, excitation would correspond to simultaneous photon absorption and electronic de-excitation. Here, we demonstrate optical driving of the radiative Auger transition on a trion in a semiconductor quantum dot. The radiative Auger and the fundamental transition together form a $\Lambda$-system. On driving both transitions of this $\Lambda$-system simultaneously, we observe a reduction of the fluorescence signal by up to $70\%$. Our results demonstrate a type of optically addressable transition connecting few-body Coulomb interactions to quantum optics. The results open up the possibility of carrying out THz spectroscopy on single quantum emitters with all the benefits of optics: coherent laser sources, efficient and fast single-photon detectors. In analogy to optical control of an electron spin, the $\Lambda$-system between the radiative Auger and the fundamental transitions allows optical control of the emitters' orbital degree of freedom.Comment: 8 pages, 6 figure

Charge Tunable GaAs Quantum Dots in a Photonic n-i-p Diode

In this submission, we discuss the growth of charge-controllable GaAs quantum dots embedded in an n-i-p diode structure, from the perspective of a molecular beam epitaxy grower. The QDs show no blinking and narrow linewidths. We show that the parameters used led to a bimodal growth mode of QDs resulting from low arsenic surface coverage. We identify one of the modes as that showing good properties found in previous work. As the morphology of the fabricated QDs does not hint at outstanding properties, we attribute the good performance of this sample to the low impurity levels in the matrix material and the ability of n- and p-doped contact regions to stabilize the charge state. We present the challenges met in characterizing the sample with ensemble photoluminescence spectroscopy caused by the photonic structure used. We show two straightforward methods to overcome this hurdle and gain insight into QD emission properties

Establishing and validating noninvasive prenatal testing procedure for fetal aneuploidies in Vietnam

Noninvasive prenatal testing (NIPT) for fetal aneuploidies has been widely adopted in developed countries. Despite the sharp decrease in the cost of massively parallel sequencing, the technical know-how and skilled personnel are still one of the major limiting factors for applying this technology to NIPT in low-income settings. Here, we present the establishment and validation of our NIPT procedure called triSure for detection of fetal aneuploidies.We established the triSure algorithm based on the difference in proportion of fetal and maternal fragments from the target chromosome to all chromosomes. Our algorithm was validated using a published data set and an in-house data set obtained from high-risk pregnant women in Vietnam who have undergone amniotic testing. Several other aneuploidy calling methods were also applied to the same data set to benchmark triSure performance.The triSure algorithm showed similar accuracy to size-based method when comparing them using published data set. Using our in-house data set from 130 consecutive samples, we showed that triSure correctly identified the most samples (overall sensitivity and specificity of 0.983 and 0.986, respectively) compared to other methods tested including count-based, sized-based, RAPIDR and NIPTeR.We have demonstrated that our triSure NIPT procedure can be applied to pregnant women in low-income settings such as Vietnam, providing low-risk screening option to reduce the need for invasive diagnostic tests

Extraction of anthocyanins from Butterfly pea (Clitoria ternatea L. Flowers) in Southern Vietnam: Response surface modeling for optimization of the operation conditions

In this paper, the Response Surface Methodology (RSM), in conjunction with Central Composite Design (CCD), was used to optimize the extraction of anthocyanins from Butterfly pea (Clitoria ternatea L.Flowers) cultivated in Southern Vietnam. The effect of extraction temperatures of solvent ethanol (50-70 °C), duration of extraction (40-50 min) and solid-liquid ratios (20:1-30:1) was measured as independent variables on the total extraction anthocyanins in the response function. The highest anthocyanin content of 132.756 mg/L of butterfly pea anthocyanin was collected at the solid liquid ratio of 23:1, extraction time of 46 min, and temperature 60.6°C. Butterfly pea anthocyanins yield detailed significant correlation with high F values, low P values (<0.0001), and desirable determination coefficient (R2 = 0.9994)

B-fields and Dust in Interstellar Filaments Using Dust Polarization (BALLAD-POL). I. The Massive Filament G11.11–0.12 Observed by SOFIA/HAWC+

We report the first measurement of polarized thermal dust emission toward the entire infrared dark cloud G11.11−0.12 taken by the polarimeter SOFIA/HAWC+ at 214 μm. The obtained magnetic fields (B-fields) from the polarized emission of the early-stage and massive filament tend to be perpendicular to its spine. We produce a map of B-field strengths for the center region of the filament. The strengths vary in the range of 100–600 μG and are strongest along the filament's spine. The central region is sub-Alfvénic and mostly subcritical, meaning that B-fields dominate over turbulence and are strong enough to resist gravitational collapse. The alignment and properties of dust grains in the filament are studied using radiative torque (RAT) theory. We find the decrease of polarization degree P with emission intensity I, i.e., depolarization effect, of the form P∝ I−α ∼ 0.8–0.9, implying a significant loss of grain alignment in the filament's spine. The depolarization can be explained by the decrease in RAT alignment efficiency toward the denser regions with weaker radiation field, which cannot be explained by B-field tangling. We study the effect of the enhanced magnetic relaxation by embedded iron inclusions on RAT alignment and find that the high polarization fraction P ∼ 20%–30% in the outer layer of the filament is potential evidence for the magnetically enhanced RAT alignment mechanism. This is the first time this effect is evaluated in a filament. Based on the polarization fraction and RAT alignment theory, we also find evidence for grain growth in the filament