Low Input Levels Research Articles

The impact of boundary conditions on the acoustical behavior of lightweight granular particle stacks

The acoustical behavior of air-saturated granular stacks can differ significantly from that of more traditional sound absorbing materials such as fibrous webs and foams when tested in a standing wave tube. The latter materials can often be modeled as equivalent fluids by using one-dimensional theory, with the further assumption that their behavior does not depend on the input signal level. In contrast, level dependence of the response of lightweight granular materials such as glass bubbles has been consistently observed in previous studies. At low input levels, the absorption coefficient of glass bubble stacks shows solid-like behavior with multiple peaks associated with radial modes of the solid phase of the edge-constrained stack: i.e., the response is two-dimensional. In contrast, at high input levels, glass bubble stacks show one-dimensional fluid-like behavior, with the quarter wave depth resonance dominating the response. It is hypothesized here that at high input levels the particles slip axially at the circumferential boundary, thus showing a one-dimensional response, while at low levels, the particles are constrained to have zero axial velocity, thus creating a two-dimensional response. It is shown here that a two-dimensional finite difference implementation of the poro-elastic Biot theory can accurately reproduce the observed level-dependent behavior.

Review and Evaluate the Bioinformatics Analysis Strategies of ATAC-seq and CUT&Tag Data.

Efficient and reliable profiling methods are essential to study epigenetics. Tn5, one of the first identified prokaryotic transposases with high DNA-binding and tagmentation efficiency, is widely adopted in different genomic and epigenomic protocols for high-throughputly exploring the genome and epigenome. Based on Tn5, the Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) and the Cleavage Under Targets and Tagmentation (CUT&Tag) were developed to measure chromatin accessibility and detect DNA-protein interactions. These methodologies can be applied to large amounts of biological samples with low-input levels, such as rare tissues, embryos, and sorted single cells. However, fast and proper processing of these epigenomic data has become a bottleneck because massive data production continues to increase quickly. Furthermore, inappropriate data analysis can generate biased or misleading conclusions. Therefore, it is essential to evaluate the performance of Tn5-based ATAC-seq and CUT&Tag data processing bioinformatics tools, many of which were developed mostly for analyzing chromatin immunoprecipitation followed by sequencing (ChIP-seq) data. Here, we conducted a comprehensive benchmarking analysis to evaluate the performance of eight popular software for processing ATAC-seq and CUT&Tag data. We compared the sensitivity, specificity, and peak width distribution for both narrow-type and broad-type peak calling. We also tested the influence of the availability of control IgG input in CUT&Tag data analysis. Finally, we evaluated the differential analysis strategies commonly used for analyzing the CUT&Tag data. Our study provided comprehensive guidance for selecting bioinformatics tools and recommended analysis strategies, which were implemented into Docker/Singularity images for streamlined data analysis.

Usage and preservation of Mizo traditional medicine by the people of Chungtlang Village, Mamit District, Mizoram.

Diversity, flexibility, easy accessibility, broad continuing acceptance in developing countries and increasing popularity in developed countries, relative low cost, low levels of technological input, relative low side effects, and growing economic importance are some of the positive features of traditional medicine. In rural India, traditional medicine continues to be the only available form of care. Many communities continue to treat patients using their old methods, unaffected by contemporary medical advancements. Due to their accessibility, affordability, and ease of use, tribal tribes prefer to utilize and consult their own traditional healers. These are likewise thought to be highly effective and without any adverse effects. This paper aims to identify various traditional medicines used for treating illness and infirmities, by taking accounts from the residents of Chungtlang village, Mamit District, Mizoram. The objective here lies in discovering traditional knowledge of medicinal plants and their uses for various infirmities.

Improving Acacia smallholder plantation value chains in Thừa Thien Huế cooperative alliance, Vietnam

Acacia plantations in Vietnam have an important role in supplying the wood processing industry and generating income for small-scale forest owners. However, it is proving difficult to improve their incomes and reduce the vulnerabilities inherent to current production systems. To address this situation, a quantitative and qualitative value chain analysis was undertaken to understand the products and profits from small-scale Acacia plantations in Thừa Thiên Huế province in Vietnam. The results show that Acacia plantations are profitable, require low levels of inputs and have a short minimum rotation time of five years. Harvesting and transport costs account for a large proportion of total production costs. Traders play an important role in linking producers and processors. Most of the pro- ducts traded are Acacia logs for chipping and processing into other products and for saw-wood to produce timber for carpentry and domestic uses. Acacia logs with larger diameters of over 15 cm have a higher added value for wood processing companies producing furniture for export. Vulnerabilities include the highly fragmented value chain with little coordination and few information exchange mechanisms, and differences between ethnic groups that suggest a need for culturally sensitive intervention on value chains. Different options to increase profits – particularly for smallholder plantation owners – include product diversification, chain integration, and increased production to achieve efficiencies of scale.

Biological soil health indicators are sensitive to shade tree management in a young cacao (Theobroma cacao L.) production system

Cacao agroforestry systems can offer important benefits, such as greenhouse gas mitigation, microclimate regulation and improved soil health. The selection of tree species for cacao agroforestry systems is a critical step impacting cacao yields, as well as the environmental and economic sustainability of the production system. However, the effects of different tree species on soil processes and functions have been poorly studied. We assessed a series of soil health indicators in a five-year-old agroforestry trial located in the Ecuadorian Amazon. The following treatments: “control” (cacao monoculture), “timber” (cacao with Cedrelinga cateniformis Ducke; a leguminous tree), “fruit” (cacao with Bactris gasipaes), “N-fix” (cacao with Erythrina velutina Wild) and “mixed” (cacao with C. cateniformis + E. velutina) were replicated 3 times in randomized blocks. The experiment was managed organically with low levels of external inputs. We collected soil, litter and leaf samples of cacao trees at two different distances (∼2 m and ∼ 6 m) from the shade tree. Biological (potential soil respiration, and macrofauna abundance, richness and Shannon diversity), chemical (pH, CEC, total C and N, macro and micronutrients and Cd), and physical (bulk density and water holding capacity) soil health indicators were measured. Additionally, we analysed nutrients and Cd in cacao leaves and litter. Results showed positive effects of the “timber” and “mixed” treatments on biological soil health indicators, primarily earthworm abundance and potential respiration, as compared to cacao monocultures. Treatment effects on potential respiration showed different trends in litter versus soil, indicating that effects of shade trees on litter respiration do not transfer directly to soil respiration. Physical and chemical soil indicators, including available Cd which is irrelevant in the context of food safety regulations, did not show any differences among the treatments. Five years after establishment, no significant differences in yields were found among the control and any of the shade tree treatments.

PlateletSeq: A novel method for discovery of blood-based biomarkers.

Platelets are small circulating fragments of cells that play important roles in thrombosis, haemostasis, immune response, inflammation and cancer growth. Although anucleate, they contain a rich RNA repertoire which offers an opportunity to characterise changes in platelet gene expression in health and disease. Whilst this can be achieved with conventional RNA sequencing, a large input of high-quality RNA, and hence blood volume, is required (unless a pre-amplification step is added), along with specialist bioinformatic skills for data analysis and interpretation. We have developed a transcriptomics next-generation sequencing-based approach that overcomes these limitations. Termed PlateletSeq, this method requires very low levels of RNA input and does not require specialist bioinformatic analytical skills. Here we describe the methodology, from sample collection to processing and data analysis. Specifically, blood samples can be stored for up to 8days at 4°C prior to analysis. Platelets are isolated using multi-step centrifugation and a purity of≤1 leucocyte per 0.26x106 platelets is optimal for gene expression analysis. We have applied PlateletSeq to normal adult blood samples and show there are no age-associated variations and only minor gender-associated differences. In contrast, platelets from patients with myeloproliferative neoplasms show differences in platelet transcript profiles from normal and between disease subtypes. This illustrates the potential applicability of PlateletSeq for biomarker discovery and studying platelet biology in patient samples. It also opens avenues for assessing platelet quality in other fields such as transfusion research.

Ecosystem services in coffee agroforestry: their potential to improve labour efficiency amongst smallholder coffee producers

This paper investigates the potential labour efficiencies and socio-cultural benefits of agroforestry for coffee smallholders practising low input production strategies. Employing both qualitative and quantitative methods, our case study of coffee smallholders in the highlands of Papua New Guinea, shows that despite managing very small holdings of coffee trees (< 500 trees), productivity is challenged by labour shortages and by very low levels of farm inputs. Constraints on labour supply include barriers to mobilising women’s labour; competition for labour from alternative livelihoods; the absence of a market in hired labour; and the time, labour and income demands of the indigenous socio-economy. The indigenous social economy draws heavily on smallholders’ time, labour and coffee income, to the extent that there is little labour for coffee garden maintenance and little coffee income invested in other farm inputs. To address these input shortfalls we explore the potential of ecosystem services from shade-grown coffee to generate labour efficiencies to partly fill some of the unmet maintenance requirements of coffee gardens and to partly fill the role of other farm inputs. Coffee extension must become more holistic and consider smallholder families’ diverse livelihoods and recognise the enduring nature of the low input production strategy, its socio-cultural value, its role in determining life quality, and thus its resistance to change. Extension must align with, rather than challenge, the low input production strategy to promote the potential labour efficiencies and benefits of agroforestry to create more resilient, sustainable and culturally-enriching coffee-based farming systems.

Two motor neuron synergies, invariant across ankle joint angles, activate the triceps surae during plantarflexion.

Recent studies have suggested that the nervous system generates movements by controlling groups of motor neurons (synergies) that do not always align with muscle anatomy. In this study, we determined whether these synergies are robust across tasks with different mechanical constraints. We identified motor neuron synergies using principal component analysis (PCA) and cross-correlations between smoothed discharge rates of motor neurons. In part 1, we used simulations to validate these methods. The results suggested that PCA can accurately identify the number of common inputs and their distribution across active motor neurons. Moreover, the results confirmed that cross-correlation can separate pairs of motor neurons that receive common inputs from those that do not receive common inputs. In part 2, 16 individuals performed plantarflexion at three ankle angles while we recorded EMG signals from the gastrocnemius lateralis (GL) and medialis (GM) and the soleus (SOL) with grids of surface electrodes. The PCA revealed two motor neuron synergies. These motor neuron synergies were relatively stable, with no significant differences in the distribution of motor neuron weights across ankle angles (P=0.62). When the cross-correlation was calculated for pairs of motor units tracked across ankle angles, we observed that only 13.0% of pairs of motor units from GL and GM exhibited significant correlations of their smoothed discharge rates across angles, confirming the low level of common inputs between these muscles. Overall, these results highlight the modularity of movement control at the motor neuron level, suggesting a sensible reduction of computational resources for movement control. KEY POINTS: The CNS might generate movements by activating groups of motor neurons (synergies) with common inputs. We show here that two main sources of common inputs drive the motor neurons innervating the triceps surae muscles during isometric ankle plantarflexions. We report that the distribution of these common inputs is globally invariant despite changing the mechanical constraints of the tasks, i.e. the ankle angle. These results suggest the functional relevance of the modular organization of the CNS to control movements.

A Review of the Roles of Non- Coding RNAs Associated with Drought Stress Response in Cassava (Manihot esculenta Crantz)

Cassava is a tuberous root crop that offers food and nutrition security for vulnerable populations, especially in the developing world. The crop is climate-resilient, widely adaptable to varied environments, and tolerant to most abiotic stresses such as drought. It is easy to propagate and can produce significant yield under low input levels compared to other major crops. Cassava’s inherent tolerance to drought stress has been linked with various morpho-physiological and molecular mechanisms. Although major molecular pathways and genes activated under drought stress have been described, cassava drought stress tolerance mediated by non-coding RNAs (ncRNAs) such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) have not been exhaustively elucidated. This review, therefore, consolidates recent progress that has been made towards the discovery and characterization of miRNAs and lncRNAs in cassava response to drought stress. The review details the omics approaches used in various studies to discover miRNAs and lncRNAs and their over-arching functions in several physiological and molecular mechanisms in cassava under drought.

Soil organic carbon priming co-regulated by labile carbon input level and long-term fertilization history

Labile carbon (C) input and fertilization have important consequences for soil organic matter (SOM) decomposition via the priming effect (PE), thereby impacting soil fertility and C sequestration. However, it remains largely uncertain on how the labile C input levels interact with long-term fertilization history to control PE intensity. To clarify this question, soil samples were collected from a 38-year fertilization field experiment (including five treatments: chemical nitrogen fertilizer, N; chemical fertilizer, NPK; manure, M1; 200 % manure, M2; NPK plus M2, NPKM2), with strongly altered soil physiochemical properties (i.e., soil aggregation, organic C and nutrient availability). These soil samples were incubated with three input levels of 13C-glucose (without glucose, control; low, 0.4 % SOC; high, 2.0 % SOC) to clarify the underlying mechanisms of PE. Results showed that the PE significantly increased with glucose input levels, with values increasing from negative or weak (−2.21 to 3.55 mg C g−1 SOC) at low input level to strongly positive (5.62 to 8.57 mg C g−1 SOC) at high input level across fertilization treatments. The increased PE intensity occurred along with decreased dissolved total nitrogen (DTN) contents and increased ratios of dissolved organic C to DTN, implying that the decline in N availability largely increased PE via enhanced microbial N mining from SOM. Compared to N and NPK treatments, the PE was significantly lower in the manure-amendment treatments, especially for low input level, due to more stable SOM by aggregate protection and higher N and phosphorus availability. These results suggested that manure application could alleviate SOM priming via increased soil C stability and nutrient availability. Collectively, our findings emphasize the importance of long-term fertilization-driven changes in labile C inputs, SOM stability, and nutrient availability in regulating PE and soil C dynamics. This knowledge advances our understanding of the long-term fertilization management for soil C sequestration.

Unlocking the potential for yellow maize production and utilization in Homa-bay County, Kenya

Yellow maize is popular in Western Kenya especially in Homa-Bay County. However, it’s faced with myriad of challenges that has greatly limited its production and utilization. This study investigated yellow maize production, post-harvest handling and utilization practices and constraints while exploring opportunities. The study was conducted from September-November 2020 in three wards of Ndhiwa Sub-County, Homa-Bay County by conducting a cross-sectional survey using a structured questionnaire administered to 385 farmers. Results showed that yellow maize production was an important food security crop and source of livelihood for farmers. Yellow maize was continuously cultivated as a sole crop or intercropped with legumes in less than 1ha land sizes using locally sourced seed with low levels of farm inputs resulting in low yields of less than 1 t/ha. Yellow maize was preferred due to its early maturity (3 months), taste, tolerance to biotic and abiotic stresses. The main constraints included total lack of good quality seed, low soil fertility (71%), striga weed infestation (60%), low marketability (46%), pest/diseases prone (34%) and adverse weather (33%). About 68% sun dried their maize, with the dried grains stored in polypropylene bags (87%) kept mainly on raised platforms in their houses (90%) for approximately 3 months/year. Most of the respondents (95%) preferred to consume yellow maize compared to white maize mainly in form of ugali (stiff porridge) (97%) consumed twice daily (77%). The yellow maize potential is under-exploited and enhancing its productivity through research, improved seed system, soil amendments and awareness creation could lead to production increase and be among the pathways that can be used to develop the region and contribute to food and nutrition security in the country.

Status of rice-fish farming and rice field fisheries in Northern Laos

IntroductionRice-fish farming can play an important role in increasing food production in less developed countries. The Lao People’s Democratic Republic (Laos) is one of the least developed countries in the world, and rice is the most important crop in Laos.MethodsThe present study conducted field surveys in 2022 in order to get a better understanding of the status of rice-fish production systems in mountainous areas in Northern Laos. Rice-fish farming was defined as one form of aquaculture in the present study, characterized by seed stocking and feed input. Rice field fisheries is mainly the harvesting of wild fish with no seed and feed input.ResultsWe found that rice-fish production systems, including both integrated rice-fish farming and rice field fisheries, are still in resources poor status with low input levels of fertilizer and chemicals. Rice-fish farms generally have higher intensification levels in rice farming than that rice field fisheries farms. Rice-fish farms generate significantly more value output of rice than that rice field fisheries farms. Overall, rice-fish farms use land and labor more efficiently and generate higher land and labor productivity measured in value output than rice field fisheries farms.DiscussionWe suggest that more rice field fisheries farms can be intensified with extra seed and feed input to move to rice-fish farming to produce more aquatic products and more value output with the same rice field areas in Northern Laos.

Evaluation of epitranscriptome-wide N6-methyladenosine differential analysis methods.

RNA methylation has emerged recently as an active research domain to study post-transcriptional alteration in gene expression regulation. Various types of RNA methylation, including N6-methyladenosine (m6A), are involved in human disease development. As a newly developed sequencing biotechnology to quantify the m6A level on a transcriptome-wide scale, MeRIP-seq expands RNA epigenetics study in both basic and clinical applications, with an upward trend. One of the fundamental questions in RNA methylation data analysis is to identify the Differentially Methylated Regions (DMRs), by contrasting cases and controls. Multiple statistical approaches have been recently developed for DMR detection, but there is a lack of a comprehensive evaluation for these analytical methods. Here, we thoroughly assess all eight existing methods for DMR calling, using both synthetic and real data. Our simulation adopts a Gamma-Poisson model and logit linear framework, and accommodates various sample sizes and DMR proportions for benchmarking. For all methods, low sensitivities are observed among regions with low input levels, but they can be drastically boosted by an increase in sample size. TRESS and exomePeak2 perform the best using metrics of detection precision, FDR, type I error control and runtime, though hampered by low sensitivity. DRME and exomePeak obtain high sensitivities, at the expense of inflated FDR and type I error. Analyses on three real datasets suggest differential preference on identified DMR length and uniquely discovered regions, between these methods.

NPM1 Mutation Quantitation Evaluated By a Commercially Available Assay and the Cepheid Prototype‡ Xpert® NPM1 Mutation Assay

Aims The objective of this study was to compare the performance of the novel Cepheid Prototype Xpert® NPM1 Mutation Assay to the Qiagen ipsogen® NPM1 mut A, B&D MutaQuant Kits using samples contrived using cell line-spiked peripheral blood. Our goal was to evaluate the comparative performance of a faster and easier to use assay than commercially available products for use in the monitoring of minimal residual disease (MRD) in NPM1-positive AML patients. Background A common mutation in AML (20-30% of cases) is a four base pair insertion in the NPM1 gene.¹ NPM1 plays a role in ribosome biogenesis, maintaining genomic stability, and modulating growth suppression by binding and stabilizing p53.² NPM1 mutant A consists of about 80% of NPM1 mutations, while mutants B or D are present in a sizeable minority of patients.¹² Monitoring of NPM1 mutations can provide prognostic value and can assist with choice of treatment.³ Methods Three NPM1-positive cell lines, OCI-AML3 MutA, OCI-AML3 MutB, and OCI-AML3 MutD, which express NPM1 MutA, NPM1 Mut B, and NPM1 Mut D, respectively, were grown and isolated. After processing the cells into cell lysate, the cell-lysates were spiked into NPM1-negative EDTA whole blood lysate and serially diluted to target 13 or 14 NPM1/ABL levels from approximately 2500% (log reduction (LR) 1.4) to approximately 0.01% (LR -4.0). A subset of each level underwent hands-off sample preparation, total RNA extraction, and RT-qPCR all within the Cepheid GeneXpert automated cartridge system, and another subset had total RNA extracted using the Zymo Direct-zol™ RNA Miniprep Plus Kit. RNA was qualified and quantified using the Thermo Scientific NanoDrop™ 2000 Spectrophotometer before being tested per the comparator assay vendor's recommendations. The Cepheid Prototype assay utilized 4.5mL of lysate, whereas the Qiagen kits used 100 ng of RNA per test. Specimens spiked with cell lines expressing different NPM1 mutations were tested using the respective ipsogen kit designed for that mutation. The Cepheid Prototype assay was evaluated against the comparator assay for each subtype using Deming regressions. Bland-Altman plots were utilized to evaluate bias between assay quantitation outputs. Results Deming regressions and associated Bland-Altman plots showed a high degree of correlation and agreement between comparator assays and the Cepheid Prototype assay (Figure 1). Conclusions The novel Cepheid Prototype assay showed a high level of agreement with Qiagen kits in this study using whole blood EDTA lysate samples spiked with three NPM1-positive cell-lysates. Agreement tended to decline at low input levels, and a small but acceptable degree of nonlinearity was present in MutA and MutD. Total time to result (TTR) was minimized in the Cepheid Prototype assay to under 170 minutes, while the comparator assay had a TTR of approximately six hours plus RNA extraction. While RNA extraction is performed within Cepheid Prototype assay cartridge and is included in this 170-minute TTR, the Qiagen kit requires additional expensive and labor-intensive extraction steps that can last one-hour to multiple days, which are not included in the six-hour TTR estimate. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Assessing the potential for demographic restoration and assisted evolution to build climate resilience in coral reefs.

Interest is growing in developing conservation strategies to restore and maintain coral reef ecosystems in the face of mounting anthropogenic stressors, particularly climate warming and associated mass bleaching events. One such approach is to propagate coral colonies ex situ and transplant them to degraded reef areas to augment habitat for reef-dependent fauna, prevent colonization from spatial competitors, and enhance coral reproductive output. In addition to such "demographic restoration" efforts, manipulating the thermal tolerance of outplanted colonies through assisted relocation, selective breeding, or genetic engineering is being considered for enhancing rates of evolutionary adaptation to warming. Although research into such "assisted evolution" strategies has been growing, their expected performance remains unclear. We evaluated the potential outcomes of demographic restoration and assisted evolution in climate change scenarios using an eco-evolutionary simulation model. We found that supplementing reefs with pre-existing genotypes (demographic restoration) offers little climate resilience benefits unless input levels are large and maintained for centuries. Supplementation with thermally resistant colonies was successful at improving coral cover at lower input levels, but only if maintained for at least a century. Overall, we found that, although demographic restoration and assisted evolution have the potential to improve long-term coral cover, both approaches had a limited impact in preventing severe declines under climate change scenarios. Conversely, with sufficient natural genetic variance and time, corals could readily adapt to warming temperatures, suggesting that restoration approaches focused on building genetic variance may outperform those based solely on introducing heat-tolerant genotypes.

A Multifunctional Battery-Free Bluetooth Low Energy Wireless Sensor Node Remotely Powered by Electromagnetic Wireless Power Transfer in Far-Field.

This paper presents a multifunctional battery-free wireless sensing node (SN) designed to monitor physical parameters (e.g., temperature, humidity and resistivity) of reinforced concrete. The SN, which is intended to be embedded into a concrete cavity, is autonomous and can be wirelessly powered thanks to the wireless power transmission technique. Once enough energy is stored in a capacitor, the active components (sensor and transceiver) are supplied with the harvested power. The data from the sensor are then wirelessly transmitted via the Bluetooth Low Energy (BLE) technology in broadcasting mode to a device configured as an observer. The feature of energy harvesting (EH) is achieved thanks to an RF-to-DC converter (a rectifier) optimized for a low power input level. It is based on a voltage doubler topology with SMS7630-005LF Schottky diode optimized at −15 dBm input power and a load of 10 kΩ. The harvested DC power is then managed and boosted by a power management unit (PMU). The proposed system has the advantage of presenting two different power management units (PMUs) and two rectifiers working in different European Industrial, Scientific and Medical (ISM) frequency bands (868 MHz and 2.45 GHz) depending on the available power density. The PMU interfaces a storage capacitor to store the harvested power and then power the active components of the sensing node. The low power digital sensor HD2080 is selected to provide accurate humidity and temperature measurements. Resistivity measurement (not reported in this paper) can also be achieved through a current injection on the concrete probes. For wireless communications, the QN9080 system-on-chip (SoC) was chosen as a BLE transceiver thanks to its attractive features: a small package size and extremely low power consumption. For low power consumption, the SN is configured in broadcasting mode. The measured power consumption of the SN in a deep-sleep mode is 946 µJ for four advertising events (spaced at 250 ms maximum) after the functioning of sensors. It also includes voltage offset cancelling functionality for resistivity measurement. Far-field measurement operated in an anechoic chamber with the most efficient PMU (AEM30940) gives a first charging time of 48 s (with an empty capacitor) and recharge duration of 27 s for a complete measurement and data transmission cycle.

Direct-Drive Oscillation of KrF Excimer Laser Using Pulsed Power Generator Based on LTD

The excimer laser is a laser characterized by high output and high gain oscillation in the ultraviolet region. Utilizing these features, excimer lasers are currently in practical use as light sources for semiconductor lithography. We are aiming to improve the oscillation efficiency and to extend the lifetime of excimer lasers. In this article, we have evaluated the oscillation efficiency by directly driving the krypton fluoride (KrF) excimer laser using a pulsed power generator based on a linear transformer driver (LTD), which is one of the new pulsed power generation methods. As a result, we have demonstrated, for the first time, the direct pumping of KrF excimer laser using LTDs. However, although it is confirmed that the oscillation efficiency was improved by about 15% on the low-input level, it is observed that the laser output is significantly reduced on the high-input level, compared with the traditional method. It is concluded that the circuit and the pumping waveform need further optimization.

Thermo-fluidic characteristics and performance in a distribute heating bubble pump generator

In some thermally driven two-phase natural circulation systems, bubble pumps serve as the key driving powers for the cycles. Recently a type of distribute heating bubble pump generator (BPG) is gradually receiving attention due to its compact structure and great potentials to utilize solar energy and low-grade waste heat recovery. The BPG provides a variety of promising features (e.g., passive heat transfer, enhanced reliability), which can benefit the advancing of heat transfer technology. For the primary study, we performed an experiment in a distributed heating BPG. Through utilizing multiple lift tubes and partial visualization configurations, it provides accesses to observe the flow pattern transition and monitor the flow instability, and thus to explore some of the underlying mechanisms affecting BPG performance.Results showed that heat input and immersion height were crucial parameters to enable the operation of distribute heating BPG. With low heat input or high inlet water subcooling level, the flow within the pump was unstable with intermittent flow interruptions. As the heat input increased, the fluid flow became more stable, the vapor generation increased linearly, while the lifted liquid flow rate initially increased then decreased. Correspondingly, the flow pattern at the outlet section of lift tubes gradually changed from slug flow to churn flow, and then to annular flow. The higher of the immersion was, the higher heat input was needed for the flow pattern transition. It was in the churn flow regime at the outlet of lift tubes for the BPG to lift a maximum liquid. At lower immersion level, liquid reflux in the lift tubes was obvious and affected the flow stability as well as the lifting performance. At higher immersion level, the fluid flow was more stable and faster, which lifted more liquid while generated less vapor depending on the inlet subcooling. In general, the BPG showed better performance (both the lifted liquid and vapor generation increased) at smaller inlet subcooling level or lower system pressure. This study highlights the flow pattern evolution and flow stability, which is helpful to the reliable design and effective operation of the distributed heating BPG.

Enhanced regulation of prokaryotic gene expression by a eukaryotic transcriptional activator

Expanding the genetic toolbox for prokaryotic synthetic biology is a promising strategy for enhancing the dynamic range of gene expression and enabling new engineered applications for research and biomedicine. Here, we reverse the current trend of moving genetic parts from prokaryotes to eukaryotes and demonstrate that the activating eukaryotic transcription factor QF and its corresponding DNA-binding sequence can be moved to E. coli to introduce transcriptional activation, in addition to tight off states. We further demonstrate that the QF transcription factor can be used in genetic devices that respond to low input levels with robust and sustained output signals. Collectively, we show that eukaryotic gene regulator elements are functional in prokaryotes and establish a versatile and broadly applicable approach for constructing genetic circuits with complex functions. These genetic tools hold the potential to improve biotechnology applications for medical science and research.

Economic profitability of yellow passion fruit in organic cultivationunder different input levels and irrigation

The productivity of passion fruit is low compared to its productive potential which in organic system is due to rainfed cultivation and low input levels. The aim of this work was to evaluate the profitability of yellow passion fruit production in organic system under different input levels and irrigation. The experiment was carried out in Rio Branco - AC, at the Serido Ecological Site, conducted from November 2016 to August 2018. Randomized block design was used, arranged in a factorial scheme (3x2) with four replicates. The factors evaluated were: three input levels of inputs (fertilizers and alternative pesticides) and presence or absence of irrigation. Fertilization was carried out based on the nutrient content of the soil analysis and according to the yield estimate 5 t ha-1, 10 t ha-1 and 15 t ha-1. The irrigation used was with a micro sprinkler per plant. The production cost, profitability, simplified economic analysis, production for total and operating coverage were calculated based on capital depreciation, input level and labor during two cultivation years. The highest input level and irrigation increase productivity, total revenue and production requirements to cover total and operating costs. Fixed cost is higher when using combination of irrigation and input level 1; however, it provided positive economic yields.