Turf wars: The livelihood and mobility frictions of motorbike taxi drivers on Hanoi's streets

In Vietnam's capital city Hanoi, the growing popularity of application based (app-based) motorbike taxis has offered many inhabitants new opportunities to pursue a mobile livelihood with ride-hailing platforms. Nonetheless, as this influx of app-based drivers has hit the city's streets, specific livelihood and mobility frictions have emerged, notably with informal, ‘traditional’ motorbike taxi drivers, or xe ôm. In this paper we analyse these evolving sites and moments of friction and their impacts on driver livelihoods and mobilities for both driver groups. We draw conceptually on debates regarding mobility, platform economies, and urban livelihoods, while specifically interrogating the concept of friction to highlight three possible analytical applications. Methodologically, we interpret static and ride-along interviews completed with over 130 drivers. We highlight a range of tactics ‘traditional’ and app-based motorbike taxi drivers have employed to respond to rising frictions, defend their ‘turf’, and maintain their street-based livelihoods. Driver responses reveal differing access to distinctive forms of social capital and social networks, and contrasting levels of agency regarding their mobilities. By conceptually teasing apart the notion of friction, we wish to expand and deepen understandings of the experiences of vulnerability, precarity, and other impacts of platformisation for different motorbike taxi driver cohorts.     

Testing the yield of a pilot‐scale bubble column photobioreactor for cultivation of the microalga Rhodomonas salina as feed for intensive calanoid copepod cultures

A dual column photobioreactor (PBR) (2 × 47 L) with mixed CO₂/air bubbling was tested for cultivation of the microalga Rhodomonas salina as food for live feed copepods. In the continuous growth phase, the cell density was relatively stable at 2.40 ± 0.13 × 10⁶ cells/ml at an average dilution rate of 0.46 ± 0.02 per day throughout the 30‐day experiment. The produced algae had a high content of both total fatty acids (TFA) and free amino acids (FAA). Especially, the harvested algae contained a high proportion of poly‐unsaturated fatty acids that made up 80% of the TFA and of essential amino acids (35% of all FAA), implicating desirable components as feed for copepods. The current PBR was sufficient to feed a culture of the calanoid copepod Acartia tonsa at a density of 2,500 adult/L in ca. 500 L culture with a daily yield of approximately 17 × 10⁶ eggs. To be able to sustain the integrated copepods production, the suggested volume of the algae cultures should be ca. 20% of the copepod culture volume.     

Variability in Osmotic Stress Tolerance of Starch Potato Genotypes (Solanum tuberosum L.) as Revealed by an In Vitro Screening: Role of Proline,Osmotic Adjustment and Drought Response in Pot Trials

Solanum tuberosum (potato) as a drought sensitive plant is also one of the most promising plants to meet the demands for food and starch of a growing population. Distinguishing genotypes into tolerant and susceptible is therefore of utmost interest. We subjected eighteen potato genotypes and two wild species, S. tarijense and S. chacoense, to osmotic stress applied in vitro by addition of 0.2 m sorbitol to a solid medium. Here, we report that a ratio of root:shoot dry mass (DM) together with the SSI (stress susceptibility index, equivalent to drought susceptibility index by Fischer and Maurer, Aust. J. Agron. Res., 29, 1978) of shoot DM were found to be relevant parameters to characterize genotypes in vitro for their osmotic stress tolerance. Drought stress data from pot trials in a rainout shelter (2013 and 2015) correlated poorly with the data obtained in in vitro experiments. However, the most tolerant and most sensitive genotypes in vitro were also categorized to be more tolerant or sensitive than the average to drought stress in vivo. Both, under in vitro and in vivo conditions, proline displayed an increase under osmotic stress conditions in nearly all potatoes tested, but no direct correlations were found to stress tolerance. However, a genotype classified as tolerant displayed earlier proline accumulation. Proline is thought of as one factor for plants to withstand stressful conditions, but cannot be used to distinguish potato genotypes for their stress tolerance to osmotic stress in vitro. Analysis of the osmotic potential of in vitro and in vivo stressed plants displayed a general increase compared to the control.     

Tuber Position in the Ridge in Relation to the Planting Depth with the Technology of Simultaneous Planting and Final Ridge Formation

Simultaneous planting and final ridge formation using a deeper planting depth is necessary in order to achieve good soil cover of tubers and fewer green tubers. Three planting depths were used: planting depth 1 (the shallowest), planting depth 2 (the medium), and planting depth 3 (the deepest). Planting depth 3 led to the largest minimum distance of tubers from the ridge side, and the smallest percentage of tubers in the upper layer of the ridge (0 to 5 cm). However, the highest yield and percentage of green tubers and the smallest marketable yield occurred at the shallowest planting depth (1). The tuber cluster covers 80 to 90% of the area of the ellipse. Empty spaces surrounding the tuber cluster in the ridge also affect the percentage of green tubers in the ridge, which predominantly occur at planting depth 3 and are the rarest at planting depth 1.     

Muscle activity monitoring with fabric stretch sensors

In this paper, development of a fabric stretch sensor embedded system has been proposed for muscle activity monitoring. It is expected that this product will be proper for monitoring a wide range of human activities mainly due to the characteristics of light-weight and high sensitivity. The fabric sensors developed can be easily attached to almost any types of clothing due to their thin and stretchable natures. The mechanism and performance of the sensors have been characterized by measuring the mechanical and electrical performance along with stretch ratio or strain percent. The data collected would be successfully transmitted to mobile phones through low power consumption BLE connection, and thus muscle activities in real time. As expected, the resultant smart muscle pants could achieve realistic goals through monitoring body movements without any significant loss of wear comforts in normal clothing. This work significantly contributed in enhancing the utility of strain/stretch sensors for development of e-textiles and intended to be a starting point for data collection and analysis of smart fabric embedded sensing technologies.     

Insights to the clarification of sugar cane juice expressed from sugar cane stalk and trash

Processing of juice expressed from green sugar cane containing all the trash (i.e., tops and leaves, the nonstalk component) of the sugar cane plant during sugar manufacture has been reported to lead to poor clarified juice (CJ) quality. Studies of different liming techniques have been conducted to identify which liming technique gives the best clarification performance from juice expressed from green cane containing half of all trash extracted (GE). Results have shown that lime saccharate addition to juice at 76 °C either continuous or batchwise gives satisfactory settling rates of calcium phosphate flocs (50-70 cm/min) and CJ with low turbidity and minimal amounts of mineral constituents. Surprisingly, the addition of phosphoric acid (≤ 300 mg/kg as P?O?), prior to liming to reduce juice turbidity (≤ 80%), increased the Mg (≤ 101%) and Si (≤ 148%) contents particularly for clarified GE juices. The increase was not proportional with increasing phosphoric acid dose. The nature of the flocs formed, including the zeta potential of the particles by the different liming techniques, has been used to account for the differences in clarification performance. Differences between the qualities of the CJ obtained with GE juice and that of burnt cane juices with all trash extracted (BE) have been discussed to provide further insights into GE processing.     

Characterization of a Novel Conus bandanus Conopeptide Belonging to the M-Superfamily Containing Bromotryptophan

A novel conotoxin (conopeptide) was biochemically characterized from the crude venom of the molluscivorous marine snail, Conus bandanus (Hwass in Bruguière, 1792), collected in the south-central coast of Vietnam. The peptide was identified by screening bromotryptophan from chromatographic fractions of the crude venom. Tandem mass spectrometry techniques were used to detect and localize different post-translational modifications (PTMs) present in the BnIIID conopeptide. The sequence was confirmed by Edman’s degradation and mass spectrometry revealing that the purified BnIIID conopeptide had 15 amino acid residues, with six cysteines at positions 1, 2, 7, 11, 13, and 14, and three PTMs: bromotryptophan, γ-carboxy glutamate, and amidated aspartic acid, at positions “4”, “5”, and “15”, respectively. The BnIIID peptide was synthesized for comparison with the native peptide. Homology comparison with conopeptides having the III-cysteine framework (–CCx₁x₂x₃x₄Cx₁x₂x₃Cx₁CC–) revealed that BnIIID belongs to the M-1 family of conotoxins. This is the first report of a member of the M-superfamily containing bromotryptophan as PTM.     

Effect of burning and high temperature on survival of Xanthomonas translucens pv. pistaciae in infected pistachio branches and twigs

This paper reports the efficacy of burning and heat‐treating pistachio branches and twigs as a means of disposing of prunings from trees infected with Xanthomonas translucens pv. pistaciae (Xtp). Burning of pistachio wood, naturally infected with Xtp, was conducted twice under field conditions. Viable Xtp was detected in some non‐burned wood, but not in charcoal, ash or partially burned wood. Controlled laboratory experiments were conducted with pure cultures of Xtp and naturally and artificially infected pistachio wood. In liquid culture, 65°C was lethal to Xtp, whereas survival at 60°C or less varied with culture medium and duration of exposure. Xtp survived in infected wood exposed to 40–55°C for at least 60 min but was killed by exposure to 60°C for 15 min or more. Overall, the results of burning and heat treatment were consistent, and confirmed that burning was a reliable eradication technique to dispose of infected wood, such as prunings, providing the pathogen was exposed to a temperature of 60°C or greater for at least 15 min.