Search

Due to the numerous side effects of synthetic pesticides, including environmental pollution, threats to human health, harmful effects on non-target organisms and pest resistance, the use of alternative healthy, available and efficient agents in pest management strategies is necessary. In this paper, the susceptibility of the cosmopolitan, polyphagous, stored-product pest Tribolium castaneum (red flour beetle) to the fumigation of the essential oils of two important medicinal and food additive plants, Satureja hortensis and S. intermedia, was investigated. The insecticidal properties of the essential oils were modeled and optimized using response surface methodology. It was found that a maximum significant mortality of 94.72% and 92.97% could be achieved within 72 h with the applications of 55.15 µL/L of S. hortensis (with the linear model) and 58.82 µL/L of S. intermedia (with the quadratic model), respectively. There were insecticidal terpenes and phenylpropanoids in both essential oils, including thymol (50.8%), carvacrol (11.2%) and p-cymene (13.4%), in the S. intermedia and estragole (68.0%) and methyl eugenol (5.6%) in the S. hortensis. It was suggested that the essential oils of S. hortensis and S. intermedia could be offered as promising pesticidal agents against T. castaneum for further studies in the management of such pests instead of detrimental synthetic pesticides. [ABSTRACT FROM AUTHOR]

This paper is concerned with the numerical solution of delay differential equations(DDEs). We focus on the stability behaviour of Runge-Kutta methods for nonlinear DDEs. The new concepts of GR(l)-stability, GAR(l)-stability and weak GAR(l)stability are further introduced. We investigate these stability properties for (k, l)algebraically stable Runge-Kutta methods with a piecewise constant or linear interpolation procedure. [ABSTRACT FROM AUTHOR]

Postharvest physiological deterioration (PPD) of fresh cassava roots limits their shelf-life to about 48 h. There is a demand for simple, cheap, and logistically feasible solutions for extending the shelf life of fresh cassava roots in industrial processes. In this study, three different types of bag materials were tested, namely woven polypropylene, tarpaulin, and jute as a potential storage solution for cassava roots with different levels of mechanical damage. Microclimate related to temperature, humidity, and carbon di-oxide (CO2) was monitored in order to understand the storage conditions for up to 12 days. The results showed that fresh cassava roots could be stored for 8 days, with minimal PPD and starch loss (2.4%). However, roots with significant mechanical damage in the form of cuts and breakages had a considerably shorter shelf life in the storage bag, compared to whole roots and roots with retained stalk (peduncle) where roots are connected to the main plant. Wetting of the roots and bag material were not significant factors in determining the shelf life and starch loss. Carbon dioxide concentration in the stores was significantly correlated with the starch loss in fresh cassava roots and is proposed as a possible method for continuously and remotely monitoring starch loss in large-scale commercial operations and reducing postharvest losses. [ABSTRACT FROM AUTHOR]

In a tropical rainforest environment, different storage strategies are often adopted in the preservation of primary processed food crops, such as maize, sorghum, etc., after drying and dehulling to increase shelf-life. For breadfruit seeds (Treculia Africana), the current challenge is identifying the most appropriate short-term storage and packaging methods that can retain the quality of stored products and extend shelf-life. In this regard, we compared the performance of a plastic container, a weaved silo bag and a locally developed silo bin for the short-term storage of parboiled, dehulled and dried breadfruit seeds treated with locally sourced and affordable alligator pepper (Zingiberaceaeaframomum melegueta) and bitter kola (garcinia) powder as preservatives. We show that the concentration of CO2 was lower in the silo bin treated with 150 g alligator pepper and higher in the silo bag-treated with 100 g bitter kola nut. A higher CO2 concentration resulted in limited oxygen availability, higher water vapor, and a higher heat release rate. Non-treated bag storage had the highest average mold count of 1.093 × 103 CFU/mL, while silo bin-stored breadfruit treated with 150 g of alligator pepper had the lowest mold count of 2.6 × 102 CFU/mL. The storage time and botanical treatments influenced both the crude protein and crude fiber content. Average insect infestations were low (0–4.5) in the silo bin with breadfruits treated with alligator pepper powder, as the seeds seemed to continue to desorb moisture in storage, unlike in other treatments. The obtained results revealed the high potential of alligator pepper (Zingiberaceaeaframomum melegueta) as a botanical insecticide in preventing insect infestation and mold growth in stored breadfruit instead of using synthetic insecticide. An aluminum silo bin with alligator pepper powder is recommended to store dried and dehulled breadfruit seeds as a baseline for other tropical crops. [ABSTRACT FROM AUTHOR]

Fruits and vegetables are highly nutritious agricultural produce with tremendous human health benefits. They are also highly perishable and as such are easily susceptible to spoilage, leading to a reduction in quality attributes and induced food loss. Cold chain technologies have over the years been employed to reduce the quality loss of fruits and vegetables from farm to fork. However, a high amount of losses (≈50%) still occur during the packaging, pre-cooling, transportation, and storage of these fresh agricultural produce. This study highlights the current state-of-the-art of various advanced tools employed to reducing the quality loss of fruits and vegetables during the packaging, storage, and transportation cold chain operations, including the application of imaging technology, spectroscopy, multi-sensors, electronic nose, radio frequency identification, printed sensors, acoustic impulse response, and mathematical models. It is shown that computer vision, hyperspectral imaging, multispectral imaging, spectroscopy, X-ray imaging, and mathematical models are well established in monitoring and optimizing process parameters that affect food quality attributes during cold chain operations. We also identified the Internet of Things (IoT) and virtual representation models of a particular fresh produce (digital twins) as emerging technologies that can help monitor and control the uncharted quality evolution during its postharvest life. These advances can help diagnose and take measures against potential problems affecting the quality of fresh produce in the supply chains. Plausible future pathways to further develop these emerging technologies and help in the significant reduction of food losses in the supply chain of fresh produce are discussed. Future research should be directed towards integrating IoT and digital twins for multiple shipments in order to intensify real-time monitoring of the cold chain environmental conditions, and the eventual optimization of the postharvest supply chains. This study gives promising insight towards the use of advanced technologies in reducing losses in the postharvest supply chain of fruits and vegetables. [ABSTRACT FROM AUTHOR]

This paper presents the field measured data of the ambient temperature profile and the heat stress occurrences directly underneath ground-mounted solar photovoltaic (PV) arrays (monocrystalline-based), focusing on different temperature levels. A previous study has shown that a 1 °C increase in PV cell temperature results in a reduction of 0.5% in energy conversion efficiency; thus, the temperature factor is critical, especially to solar farm operators. The transpiration process also plays an important role in the cooling of green plants where, on average, it could dissipate a significant amount of the total solar energy absorbed by the leaves, making it a good natural cooling mechanism. It was found from this work that the PV system's bottom surface temperature was the main source of dissipated heat, as shown in the thermal images recorded at 5-min intervals at three sampling times. A statistical analysis further showed that the thermal correlation for the transpiration process and heat stress occurrences between the PV system's bottom surface and plant height will be an important factor for large scale plant cultivation in agrivoltaic farms. [ABSTRACT FROM AUTHOR]

The purpose of this paper was to study the drying kinetic, quality, energy and exergy performance of green peas in a hot air-rotary drum dryer using the Adaptive Neuro-Fuzzy Inference System (ANFIS) model. The effect of air temperature and rotary rotation speed was examined. The drying tests were performed at three air temperature levels of 40, 55 and 70 "C and three rotation speeds of 5, 10 and 15 rpm. The modeling of kinetic, quality (color, shrinkage, and rehydration ratio), energy and exergy indices of the green pea drying was also investigated using the adaptive neuro-fuzzy inference system (ANFIS). The results showed that the energy utilization rate of the process varied in the range of 0.0121-0.1556 kj/s. The minimum and maximum values of energy utilization ratio were respectively obtained in the drying conditions at 70 °C and rotation speed ot 15 rpm, and at 40 *C and loLalion bpeed of 15 rpm. Reducing the drying temperature and speed of rotation reduced the quality properties. Minimum values of color (AE) and shrinkage was 64.95 ± 1.67 and 39.19 ± 1.05, respectively. The exergy loss rate and average exergy efficiency varied from 0.02 to 0.11 kj/s and from 0.5434 to 0.8382, respectively. The average rate of exergy improvement potential increased with increasing air temperature and rotary rotation speed. The highest R2 value for the pie-diction of moisture ratio, energy utilization, energy utilization ratio, exergy loss and exergy efficiency with the ANFIS model was 0.9996, 0.9999, 0.9995, 0.9989 and 0.9996, respectively. [ABSTRACT FROM AUTHOR]

Abstract Although silica aerogel is an excellent thermal insulation material, the poor mechanical property limits its application. The glass fiber reinforced silica aerogel with excellent mechanical property through facile sol-gel process is reported. Innovatively, during the experiments, ethanol was introduced as the main solvent in the water glass based silica sol through ion concentration adjustion to get rid of the conventional solvent exchange. To improve the mechanical property of the product, glass fiber was introduced during the gelation process. Catalyzed by hydrogen chloride, hexamethyldisiloxane was utilized as the modificaton agent. The glass fiber reinforced silica aerogel with low thermal conductivity (0.024 W/m·K) was obtained after ambient pressure drying. Three-point loading tests indicated excellent anti-flexure ability of the as-prepared glass fiber reinforced silica aerogel. Moreover, the entire preparation period can be reduced to ~20 h. Highlights • EtOH is introduced to the water glass based sol via ion concentration adjustion. • HCl/HMDSO system was conducted to modified the composite in a fast way. • Glass fiber/silica aerogel composite was obtained within 20 h. [ABSTRACT FROM AUTHOR]

Background Developing an efficient drying system with combined novel thermal and conventional hot-air drying of agricultural crops has become potentially a viable substitute for conventional drying techniques. Due to the synergistic effect, the total energy and time required can be drastically reduced, and the final quality of agricultural crops preserved. The growing interest and research in recent years have already shown that novel thermal with hot-air drying technology can adequately be used in the drying of agricultural crops. Scope and approach This review attempts to give a summary of recent advances in the research and applications of novel thermal combined hot-air drying technology for agricultural crops, with particular emphasis on the combination mode, process conditions, process-quality interaction, drying kinetics, energy demand and drying efficiency. Key findings and conclusions The combination of novel thermal with hot-air drying provides distinctive opportunities in the development of advanced agricultural crop drying technologies. The most significant advantages of using the above method were the reduction in the drying time and energy consumption as well as, an increase in the drying rate and overall efficiency. More so, the application of infrared and hot-air drying on agricultural crops is advantageous in obtaining dried products of better quality. In conclusion, the findings suggest that these technologies have great potentials. Therefore, more studies, especially in their industrial and commercial application are indispensable. [ABSTRACT FROM AUTHOR]

Moisture variation and fissure formation of rice kernels during multi-stage intermittent drying (MSID) were simulated and analyzed based on the experimental data obtained in a laboratory-scale infrared-assisted vibratory bed dryer. The variations of drying parameters included far-infrared radiation (FIR) intensity (0, 1000 and 2000 W m−2), inlet drying air temperature (30, 40 and 50 °C), drying duration (15, 30 and 40 min), and tempering ratio (0, 2, 4 and 6). Two-dimensional moisture distribution within individual kernel was predicted. Drying rate, percentage of the cracked kernel (PCK), and specific energy consumption (SEC) were also determined, experimentally. By assessing PCK and SEC and simulation results, it was found that the magnitude of 10% d.b. mm−1 was considered as an index for the critical value for moisture content gradient (MCG) to achieve the suitable drying and tempering duration. It was further recommended that the intermittent drying duration at each stage should be selected in such a way that the MCG value does not exceed the critical level and the shortest possible tempering duration should be chosen in a manner that at least 40% of critical level of MCG be eliminated. The suitable treatment for intermittent drying was selected at FIR intensity of 1000 W m−2, inlet air temperature in 40 °C, drying duration in 30 min, and tempering ratio in 4. [ABSTRACT FROM AUTHOR]

This research aims to explore the mechanism by which microRNAs may regulate the biological behavior of tumor cells in ALDH1+ fibrosarcoma. We identified differentially expressed miRNAs in ALDH + NMFH-1 cells, screened genes related to sarcoma metastasis in the TCGA database, and finally obtained key genes regulated by miRNAs that are involved in metastasis. The function and mechanism of these key genes were then validated at the cellular level. Using the ULCAN database, a significant correlation was found between hsa-mir-206 and mortality in sarcoma patients. WGCNA analysis identified 352 genes related to tumor metastasis. Through Venn diagrams, we obtained 15 metastasis-related genes regulated by hsa-mir-206. Survival analysis showed that SYNPO2 expression is significantly correlated with survival rate and is significantly underexpressed in multiple tumors. SYNPO2 showed a negative correlation with macrophages and a positive correlation with CD8+ T cells. After inhibiting the expression of hsa-mir-206 with siRNA plasmids, the mRNA expression of SYNPO2 was significantly upregulated. The results of CCK8 assay, scratch assay, and transwell assay showed that the proliferation and migration ability of NFMH-1 cells were promoted after SYNPO2 was inhibited. ALDH1+ tumor stem cells promote the proliferation and invasion of malignant fibrous histiocytoma cells by inhibiting SYNPO2 through hsa-mir-206. • SYNPO2 expression was low in many tumors. • SYNPO2 was negatively correlated with macrophages in the immune microenvironment. • Hsa-mir-206 promotes the progression of MFH by inhibiting SYNPO2 expression. [ABSTRACT FROM AUTHOR]

Abstract: A laser-discrete quenched steel (LDQS) substrate/as-deposited chromium (top high-contraction (HC) and underlying low-contraction (LC) chromium) system was investigated by dissolving coatings in order to reveal the mechanism that the service life of the coated parts is largely improved using the hybrid technique of laser pre-quenching plus chromium post-depositing. It was found that the surface characteristics of the substrate, LC and HC chromium layer can be simultaneously revealed owing to the dissolution edge effect of chromium coatings. Moreover, the periodical gradient morphologies of the LDQS substrate are clearly shown: the surfaces of laser transformation-hardened regions are rather smooth; a lot of fine micro-holes exist in the transition zones; there are many micro-dimples in the original substrate. Furthermore, the novel method of dissolving coatings with sharp interfaces may be used to reveal the structural features of a substrate/coating system, explore the effect of the substrate on the initial microstructure and morphologies of coatings, and check the quality of the coated-parts. [Copyright &y& Elsevier]

Abstract: The transient thermal stress problem of an inner-surface-coated hollow cylinder with multiple pre-existing surface cracks contained in the coating is considered. The transient temperature, induced thermal stress, and the crack tip stress intensity factor (SIF) are calculated for the cylinder via finite element method (FEM), which is exposed to convective cooling from the inner surface. As an example, the material pair of a chromium coating and an underlying steel substrate 30CrNi2MoVA is particularly evaluated. Numerical results are obtained for the stress intensity factors as a function of normalized quantities such as time, crack length, convection severity, material constants and crack spacing. [Copyright &y& Elsevier]

Abstract: The interfacial debonding of an inner-surface-coated hollow cylinder with multiple pre-existing surface cracks is presented. The cylinder is assumed to be exposed to convective heating at the inner surface while the outer surface is perfectly insulated. The failure criterion based on the adhesion strength is adopted, in which the interfacial stresses are considered to be responsible for interfacial debonding initiation. By using the finite element (FE) method, the transient temperature and induced interfacial stresses are calculated for the cylinder. Based on dimensional analysis, the sensitivity analysis of interfacial stresses is obtained as a function of various dimensionless parameters such as time, convection severity, material constants, crack depth as well as crack spacing. These results may provide some useful references for coating/substrate system design under thermal loading. [Copyright &y& Elsevier]

This study investigated the agronomic response and economic return of wheat grown in compacted and non-compacted soils to represent the conditions of non-controlled (non-CTF) and controlled traffic (CTF) systems, respectively. Yield-to-nitrogen responses were derived after application of urea, DMPP-treated urea, and UAN at rates between 0 and 300 kg ha−1 N. Soil properties were measured to guide parametrisation of APSIM, which was used to assess long-term (50 years) effects of CTF and non-CTF soil conditions on crop productivity, rainfall-use efficiency (RUE) and surface runoff. Grain yield and yield components were significantly higher in CTF compared with non-CTF. When N inputs were optimised, N use efficiency (NUE) was more than double in CTF (≈23%) compared with non-CTF (≈9%). RUE was about 15% higher in CTF, which concurrently reduced the amount of surface runoff compared with non-CTF. For years with average rainfall (240-mm in-crop), yield penalties of up 12% may be expected in non-CTF. APSIM simulations showed that increased productivity, and inter-annual yield stability, can increase gross margin of wheat by AUD30-50 ha−1 depending on in-crop rainfall and the tillage method used. In non-CTF systems, improvements in NUE and RUE are constrained by soil compaction. Enhanced efficiency fertilizers cannot compensate for other stresses caused by compaction and therefore cannot achieve the same NUE and RUE as the CTF system. Adoption of CTF in water-constrained environments improves profitability and resource-use efficiency. [ABSTRACT FROM AUTHOR]

The effect of seven drying methods (freeze (FD), hot air (HA), infrared (IR), microwave (MW), hot air‐infrared (HA‐IR), hot air‐microwave (HA‐MW), and sun drying (SD) methods on the drying time, the physical, qualitative and antioxidant properties, and the extraction of phenolic and flavonoid compounds in green peas was studied. Six mathematical models were also utilized to predict the moisture content of dried green peas. The results showed that the shortest and longest drying times were obtained by the HA‐MW and FD methods, respectively. For all drying methods, the Page model had the best ability in predicting the drying curve. The lowest amount of specific energy consumption was achieved by the MW method. The highest color changes and the lowest amount of shrinkage occurred in the FD method. The lowest rehydration ratio was 1.23 in the SD method. The highest pH value of 6.08 was also obtained in the SD method. The amount of antioxidant capacity changes and the total phenol and flavonoid contents varied between 42.47%–88.28%, 4.52–14.59 mg GAE/gDW, and 244.62–322.44 mg QE/gDW for different methods. The FD method was found to be the best way to preserve the product properties. It was further suggested that the HA‐MW method can be a promising technology for drying the green peas due to the relatively lower energy consumption, shorter drying time, and higher quality. Novelty impact statement: Seven drying methods are compared for the drying of green peas. It is found that freeze drying is the best in terms of the preservation of the product quality but it is also the most expensive drying method. High‐quality dried green peas can also be obtained using the combined hot air‐microwave drying method, with relatively lower energy consumption and shorter drying time. [ABSTRACT FROM AUTHOR]

• A novel hybrid system based on a concentrating CPC solar collector was proposed for drying purposes. • The drying time can be reduced as 83 min using hybrid operation. • The maximum value of vitamin C obtained after the drying procedure was recorded as 375.941 mg/100 g. • The daily average solar fraction can vary from near 30 to 100% depending on the operation mode. In this study, a hybrid drying system incorporating a compound parabolic concentrator (CPC) solar collector and an electric auxiliary heater was developed to make advances in sustainable tomato drying. The proposed dryer was designed to operate in a combined mode with solar energy as the prime source of energy, and the auxiliary unit was only used in the cases with the absence of solar radiation or limitation in generated solar power. Experimental tests were carried out to investigate the drying performance at different levels of sample thickness, airflow rate, and drying temperature. Using image processing and high-performance liquid chromatography (HPLC) techniques, the quality of the dried products was also evaluated in terms of the changes in color, shrinkage, and vitamin C content. Results indicated that the average drying time was about 231 min, while the shortest time was obtained as 83 min, suggesting an improved performance compared to similar works. It was found that drying temperature is the key factor influencing the rate of color changes, and shrinkage is only affected by the thickness of tomato slices. The experimental data further showed that the destruction of vitamin C was mostly influenced by the drying air temperature and sample thickness. The maximum energy and exergy efficiencies of the solar collector were determined as 25 and 6% at the maximum and minimum airflow rates, respectively. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNAs) serve as competing endogenous RNAs (ceRNAs) and indirectly regulate gene expression through shared microRNAs (miRNAs). However, the potential circRNAs functioning as ceRNAs in osteoporosis remain unclear. The bone marrow mesenchymal stem cells (BMSCs) were isolated from ovariectomy (OVX) mice and controls. We systematically analyzed RNA‐seq and miRNA‐microarray data, miRNA‐target interactions, and prominently coexpressed gene pairs to identify aberrantly expressed circRNAs, miRNAs, and messenger RNAs (mRNAs) between the OVX mice and controls. A total of 45 circRNAs, 22 miRNAs, and 548 mRNAs were significantly dysregulated (fold change > 1.5; p < 0.05). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were conducted for differentially expressed mRNAs, and subsequently a circRNA‐associated ceRNA network involved in osteoporosis was constructed. We identified two ceRNA regulatory pathways in this osteoporosis mouse model—novel circRNA 0020/miR-206-3p/Nnmt and circRNA 3832/miR-3473e/Runx3, which were validated by real-time PCR. This is the first study to elucidate the circRNA-associated ceRNA network in OVX and control mice using deep RNA-seq and RNA-microarray analysis. The data further expanded the understanding of circRNA-associated ceRNA networks, and the regulatory functions of circRNAs, miRNAs and mRNAs in the pathogenesis and pathology of osteoporosis. [ABSTRACT FROM AUTHOR]

Intermittent infrared and convective drying (IIRCD) is a novel drying method that can enhance energy efficiency and quality of dried product. The mechanism of drying using this method is not yet fully understood. Mathematical models that describe the drying process of IIRCD for agricultural crops do not exist. In this study, a physics based mathematical model was developed to understand the mechanism of drying sweet potato using IIRCD. The model was based on shrinkage dependent diffusivity and evaporation phenomenon. COMSOL Multiphysics finite element software was employed for the model simulation. The simulation results of moisture and temperature distribution were validated by experimental drying data. The results fitted closely with experimental data. Drying of sweet potato using IIRCD was found to be more efficient in terms of final product quality compared to convective hot-air drying method. © 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. [ABSTRACT FROM AUTHOR]

Abstract This study examined the performance of different combined infrared (IR) and hot-air drying (HAD) strategies for sweet potato. Experiments were conducted for simultaneous infrared and hot-air drying, two-stage sequential hot-air and infrared drying, two-stage sequential infrared and hot-air drying, and intermittent infrared and hot-air drying in a laboratory scale combined infrared and hot-air dryer. The drying air temperature varied between 50 and 70 °C, the infrared intensity was 1100 W/m2, the air-velocity was 1.5 m/s, and the pulse ratio (PR) ranged from 1 to 3. Results indicated that the drying rate, drying time, effective moisture diffusivity, shrinkage, specific energy consumption (SEC), colour attributes and phytochemical compounds of sweet potato were affected by the different drying combination strategies. The drying kinetics, product shrinkage, and sample temperature were also influenced by drying time and air temperature. The two-term exponential model adequately explained the drying behaviour of sweet potato for all the different combination strategies. The intermittent IR and HAD combination strategy proved to be the most suitable based on the combined effect of total drying time (113–120 min), SEC (27.67–41.44 kWh/kg), total colour change (17.15–26.48) and bioactive compounds. Highlights • Performance of different combined infrared (IR) and hot-air drying (HAD) strategies for sweet potato was studied. • Drying kinetics, shrinkage, specific energy consumption and colour attributes were affected by the combination strategy. • Drying air temperature and time significantly affected the efficacy of the different IR and HAD strategies. • Drying using intermittent IR and HAD was found to be the most suitable strategy for sweet potato. [ABSTRACT FROM AUTHOR]

The prevalence of diagnosed human immunodeficiency virus (HIV) infection among Hispanics/Latinos in the United States is approximately twice that of non-Hispanic whites (1). Barriers to, and experiences with, medical care have been found to vary by sex (2). Describing characteristics of Hispanics/Latinos in care by sex can help identify disparities and inform delivery of tailored services to this underserved population. Data from the 2013 and 2014 cycles of the Medical Monitoring Project (MMP) were analyzed to describe demographic, behavioral, and clinical characteristics among Hispanics/Latinos by sex. MMP is an annual cross-sectional, nationally representative surveillance system that, during 2013-2014, collected information about behaviors, medical care, and clinical outcomes among adults receiving outpatient HIV care. Hispanic/Latina women were significantly more likely than were men to live in poverty (78% versus 54%), report not speaking English well (38% versus 21%), and receive interpreter (27% versus 16%), transportation (35% versus 21%), and meal (44% versus 26%) services. There were no significant differences between Hispanic/Latino women and men in prescription of antiretroviral therapy (ART) (95% versus 96%) or sustained viral suppression (68% versus 73%). Although women faced greater socioeconomic and language-related challenges, the clinical outcomes among Hispanic/Latina women were similar to those among men, perhaps reflecting their higher use of ancillary services. Levels of viral suppression for Hispanics/Latinos are lower than those found among non-Hispanic whites (3) and lower than the national prevention goal of at least 80% of persons with diagnosed HIV infection. Providers should be cognizant of the challenges faced by Hispanics/Latinos with HIV infection in care and provide referrals to needed ancillary services. [ABSTRACT FROM AUTHOR]

This study investigated the drying kinetics, mass and heat transfer characteristics of sweet potato slices (0.4-0.6 cm thickness) during drying based on mid-infrared experimental set-up (intensity of 1100-1400 W/m2). Thin layer drying models were used to evaluate the drying kinetics of sweet potato slices. Two analytical models (Fick’s diffusion model, and Dincer and Dost model) were used to study the mass transfer behaviour of sweet potato slices with and without shrinkage during mid-infrared drying. The heat transfer flux between the emitter and sweet potato slices was also investigated. Results demonstrated that an increase in infrared intensity from 1100 W/m2 to 1400 W/m2 resulted in increased in average radiation heat flux by 3.4 times and a 15% reduction in the overall drying time. The two-term exponential model was found to be the best in predicting the drying kinetics of sweet potato slices during mid-infrared drying. The specific heat consumption varied from 0.91-4.82 kWh/kg. The effective moisture diffusivity with and without shrinkage using the Fick’s diffusion model varied from 2.632 × 10−9 to 1.596 × 10−8 m2/s, and 1.24 × 10−8 to 2.4 × 10−8 m2/s using Dincer and Dost model, respectively. The obtained values of mass transfer coefficient, Biot number and activation energy varied from 5.99 × 10−6 to 1.17 × 10−5 m/s, 0.53 to 2.62, and 12.83 kJ/mol to 34.64 kJ/mol, respectively. The values obtained for Biot number implied the existence of simultaneous internal and external resistances. The findings further explained that mid-infrared intensity of 1100 W/m2 did not significantly affect the quality of sweet potato during drying, demonstrating a great potential of applying low intensity mid-infrared radiation in the drying of agricultural crops. [ABSTRACT FROM AUTHOR]

This study seeks to investigate the potential of using combined computer vision (CV) and laser-induced backscattering imaging (LLBI) in monitoring the quality attributes of sweet potato during drying. CV and backscattered images of 4 mm thickness sweet potato slices were captured after every one-hour of drying, at drying temperatures of 50–70 °C. Reference quality properties, such as moisture content, L∗, a∗ and b∗ colour coordinates were measured hourly under the same drying conditions. Principal component analysis (PCA) and partial least square regression (PLS) were applied to the extracted combined CV (based on RGB) and backscattering imaging parameters to analyse the quality changes of sweet potato during drying. The results showed that there was significant effect of drying temperature and time on combined CV and backscattering imaging parameters. The combined optical method showed good correlation with moisture content and colour properties i.e L∗ and a∗ of sweet potato with R 2  > 0.7. Specifically, the redness (a∗) gave the highest coefficient of determination (R 2 ) of 0.80, while the moisture ratio (MR) showed the lowest root mean square error of validation (RMSEV) with the value of 0.18. Thus, this study has shown that combined CV and backscattering imaging parameters can serve as a non-destructive tool for detecting the changes in quality parameters of sweet potato during drying. [ABSTRACT FROM AUTHOR]

Osteoporosis (OP) is a systemic skeletal disorder with the characteristics of bone mass reduction and microarchitecture deterioration, resulting in bone fragility and increased fracture risk. A reduction in the osteoblast-differentiation of bone marrow mesenchymal stem cells (BMSCs) is considered as a basic pathogenesis of osteoporosis. miRNAs play a substantial role in the development and differentiation of BMSCs. In the present study, we found that miR-1-3p was significantly downregulated in the bones of Chinese osteoporotic patients (n = 29). Secreted frizzled-related protein 1 (SFRP1) was predicted as a target gene of miR-1-3p via the TargetScan and PicTar softwares and validated by dual-luciferase reporter assays. The findings revealed that the expression of SFRP1 was inversely correlated with miR-1-3p in osteoporotic patients. We induced mouse MSCs (mMSCs) to osteogenesis or adipogenesis and found that miR-1-3p was upregulated during osteogenesis but downregulated during adipogenesis. The overexpression of miR-1-3p stimulated osteogenesis and inhibited adipogenesis of mMSCs. In addition, ovariectomized (OVX) mice were tested and the function of miR-1-3p in vivo was explored. Immunohistochemistry and histomorphometric assays showed that in vivo inhibition of miR-1-3p increased the expression level of SFRP1 and reduced bone formation and bone mass. Furthermore, tartrate-resistant acid phosphatase (TRAP) staining indicated that the in vivo suppression of miR-1-3p promoted osteoclast activity, suggesting that miR-1-3p may influence bone mass by regulating bone resorption. It can be concluded that miR-1-3p plays a pivotal role in the pathogenesis of osteoporosis via targeting SFRP1 and may be a potential therapeutic target for osteoporosis. • miR-1-3p was significantly downregulated in bone of osteoporotic patients. • SFRP1 was a direct target gene of miR-1-3p. • Overexpression of miR-1-3p stimulated the osteogenesis and inhibited adipogenesis of mMSCs • In vivo inhibition of miR-1-3p increased expression level of SFRP1, and reduced bone formation and bone mass. • miR-1-3p influences bone mass by regulating bone resorption. [ABSTRACT FROM AUTHOR]

An imbalance between the adipogenesis and osteogenesis of bone marrow mesenchymal stem cells (BMSCs) is considered the basic pathogenesis of osteoporosis. Although actin cytoskeleton remodelling plays a crucial role in the differentiation of BMSCs, the role of actin cytoskeleton remodelling in the adipogenesis of BMSCs and postmenopausal osteoporosis (PMOP) has remained elusive. Glia maturation factor-beta (GMFB) has a unique role in remodelling the polymerization/depolymerization cycles of actin. We observed that GMFB expression was increased in bone tissue from both ovariectomized (OVX) rats and PMOP patients. GMFB knockout inhibited the accumulation of bone marrow adipocytes and increased bone mass in the OVX rat model. The inhibition of adipocyte differentiation in GMFB knockout BMSCs was mediated via actin cytoskeleton remodelling and the Ca 2+ -calcineurin-NFATc2 axis. Furthermore, we found that GMFB shRNA treatment in vivo had favourable effects on osteoporosis induced by OVX. Together, these findings suggest a pathological association of the GMFB with PMOP and highlight the potential of the GMFB as a therapeutic target for osteoporosis patients., Competing Interests: Competing interests The authors declare no competing interests. Ethics approval and consent to participate Informed consent was signed by all the patients for the collection of specimens, and the study protocol was approved by the Ethics Committee of Minhang Hospital of Fudan University (Approval Number: K2021-043). The animal care and experiments were approved by the Institutional Animal Care and Use Committee of Fudan University (Approval Number: 2020 Minhang Hospital JS-004). All methods were performed in accordance with the relevant guidelines and regulations., (© 2024. The Author(s).)

Orthopaedic medicine often treats intervertebral disc degeneration (IVDD), which is caused by nucleus pulposus (NP) tissue damage and mechanical stress. Bioactive glasses (BGs), widely used for bone regeneration, can incorporate therapeutic ions into their network. Manganese (Mn) activates human osteoblast integrins, proliferation, and spreading. The CMnBGNPs-NPMSCs are carboxymethyl cellulose hydrogels functionalized with MnBGsNPs and NP-derived mesenchymal stem cells to treat IVDD. To ensure stability and biocompatibility of CMnBGNPs-NPMSCs were characterized for rheological properties like gelation time and swelling ratio. Gene expression analysis of PAX1, FOXF1, CA12, HBB, and OVOS2 via qRT-PCR further assessed the hydrogel's characteristics. Rat models with induced IVDD had hydrogel-MSC composite injected into their intervertebral discs for in vivo studies. Histological examination, immunohistochemical staining for inflammation and disc regeneration markers, and disc height assessments assessed therapeutic efficacy. CMnBGNPs-NPMSCs show promising results for IVDD treatment, offering a novel therapeutic strategy with clinical implications for degenerative disc diseases., Competing Interests: Declaration of competing interest No conflict of interest exists, according to the author., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Reducing postharvest losses offers a significant opportunity to enhance food availability without requiring extra production resources. A substantial portion of cereal grain goes to waste annually due to a lack of science-based knowledge, unconscious handling practices, suboptimal technical efficiency, and inadequate infrastructure. This article extensively reviews losses occurring during postharvest operations across various crops, examining diverse postharvest operations in different countries. Recent advancements in postharvest technology research are thoroughly discussed. The primary obstacles and challenges hindering the adoption and implementation of postharvest technologies are also explored. The appropriate postharvest technology relies on specific factors, including the kind of crops, production locales, seasons, and existing environmental and socioeconomic conditions.

Background: Percutaneous kyphoplasty (PKP) is commonly used to treat severe osteoporotic vertebral compression fractures (OVCFs) by restoring vertebral height. However, its application in mild cases is not frequently discussed., Methods: The study retrospectively included 100 treated vertebral bodies of the 91 patients mentioned before, and efficacy was evaluated using visual analog scale (VAS) and Oswestry Disability Index (ODI) scores preoperatively, 2 days postoperatively, and at 1 and 6 months after treatment, as well as mean variation in vertebral body height. The study also examined complications such as pain recurrence, delayed vertebral fracture, and loss of vertebral height, and developed a scale to assess the shape and filling effect of cement (SFEC) and its impact on complications., Results: The results showed significant reductions in mean VAS and ODI scores from pre-to post-surgery and an increase in vertebral body height. However, complications occurred in 10 patients who received treatment for 11 vertebral bodies, including pain recurrence, fractures, and loss of vertebral height. Among the 10 patients with complications, 7 (63.6%) vertebral bodies had dissatisfied SFEC scores, compared with 22 (24.7%) vertebral bodies with dissatisfied SFEC scores in 81 patients without complications (89 vertebral bodies)., Conclusions: PKP is a safe and effective method for treating mild OVCFs, but attention should be paid to the shape and filling effects of cement during surgery to prevent later complications. The developed SFEC scale provides a specific and quantitative standards for evaluating the recovery status after PKP, which need further validations., (Copyright © 2024 Elsevier Inc. All rights reserved.)

This study aimed to elucidate the roles of microRNA (miR)-4738-3p and the collagen type I alpha 2 chain (COL1A2) gene in the pathogenesis of osteoarthritis (OA) through bioinformatics analysis and cellular assays. The GSE55235 dataset was analyzed using the weighted gene co-expression network analysis (WGCNA) method to identify gene modules associated with OA. Key overlapping genes were identified from these modules and the GSE55235-differential expressed genes (DEGs). The expression levels of selected genes were determined in C28/I2 cells using the quantitative real-time polymerase chain reaction (qRT-PCR). The interaction between miR-4738-3p and COL1A2 was examined in the context of interleukin 1 beta (IL-1β) induction. Exosome characterization was achieved through transmission electron microscopy (TEM), western blotting (WB), and other analyses. The study also investigated the functional relevance of miR-4738-3p in OA pathology through various molecular and cellular assays. Our findings revealed that the green module exhibited a strong correlation with the OA phenotype in the GSE55235 dataset, with COL1A2 emerging as a hub gene and miR-4738-3p as its key downstream target. IL-1β induction suggested that COL1A2 is involved in inflammation and apoptosis, while miR-4738-3p appeared to play an antagonistic role. The analysis of exosomes underscored the significance of miR-4738-3p in cellular communication, with an enhanced level of exo-miR-4738-3p antagonizing IL-1β-induced inflammation and promoting cell survival. Conversely, a reduction in exo-miR-4738-3p led to increased cell damage. This study established a clear regulatory relationship between miR-4738-3p and COL1A2, with the nuclear factor kappa B (NF-κB) signaling pathway playing a central role in this regulation. The miR-4738-3p significantly influences the OA-associated inflammation, primarily through modulation of COL1A2 and the NF-κB pathway. Therefore, targeting miR-4738-3p offers a potential therapeutic approach for OA, with exosome miR-4738-3p presenting a promising strategy.

In this study, the combustion characteristics of two wheat straw pellets (WSP) (T 1 : 100% wheat straw and T 5 : 70% wheat straw; 10% sawdust, 10% biochar; 10% bentonite clay) were performed at a heating rate 20 °C/min under a temperature from 25 to 1200 °C in air atmosphere. A thermogravimetric analyser (TGA) was used to investigate the activation energy ( E α ), pre-exponential factor ( A ), and thermodynamic parameters. The DTG/TG profile of WSP was evaluated by model-free and model-based methods and found the model-based method was suitable for WSP thermal characterisation. The result demonstrates that the thermal decomposition occurred in four stages, comprising four consecutive reaction steps. A→B→C→D→E→F. Further, the model-based techniques were best fitted with kinetic reaction models like Cn (nth - order reaction with auto-catalyst), F n (reaction of nth order), F2 (second-order phase interfacial reaction) and D3 (diffusion control). The average E α for Fn, Cn, D3 and F2 models were 164.723, 189.782, 273.88, and 45.0 kJ/mol, respectively, for the T 1 pellets. Alternatively, for T 5 pellets, the A was 1.17E+2, 1.76E+16, 5.5E+23, and 1.1E+3 (1/s) for F2, D3, Cn and Fn models. Overall, the thermodynamic properties showed that WSP thermokinetic reactions were complex and multi-point equilibrium, indicating a potentiality as a bioenergy feedstock., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Abstract: The use of chemical pesticides can have many detrimental side effects, including environmental pollution, and be a threat to human health. Carbon dioxide (CO2) treatment, a relatively new method for storage pest management, can replace harmful chemicals. Dates, an important food worldwide, contains many minerals, fiber, and a variety of vitamins and are an important dried fruit export from Iran annually. Thus, control of the pests of dried dates by using eco-friendly agents that do not affect quality features are critical. In this study, larval mortality of the Indian meal moth (Plodia interpunctella (Hübner)) and the greater wax moth (Galleria mellonella (L.)), two key pests of stored products, especially dried dates, was studied after exposure to different CO2 pressures within 24 h. Mortality percentages of the third-instar larvae of both pests were increased with an increase in CO2 pressure. Sensory tests on the qualitative characteristics of the dates revealed that CO2 pressures did not affect their aroma, color, sweetness, sourness, crispness, firmness, and overall acceptance. The highest tested pressure (33.4 mol%) of CO2 also had no significant effects on the chemical properties of the date samples, including moisture content, pH, acidity, Brix value, reducing sugar, and total sugar. We conclude that atmospheric CO2 gas can provide a cost-effective and environmentally friendly method for controlling the insect pests of dried dates in addition to preserving their sensory and quality properties., (Copyright ©, International Association for Food Protection.)

The repetitive part of the genome (the repeatome) contains a wealth of often overlooked information that can be used to resolve phylogenetic relationships and test evolutionary hypotheses for clades of related plant species such as Pelargonium. We have generated genome skimming data for 18 accessions of Pelargonium section Ciconium and one outgroup. We analyzed repeat abundancy and repeat similarity in order to construct repeat profiles and then used these for phylogenetic analyses. We found that phylogenetic trees based on read similarity were largely congruent with previous work based on morphological and chloroplast sequence data. For example, results agreed in identifying a "Core Ciconium" group which evolved after the split with P. elongatum. We found that this group was characterized by a unique set of repeats, which confirmed currently accepted phylogenetic hypotheses. We also found four species groups within P. sect. Ciconium that reinforce previous plastome-based reconstructions. A second repeat expansion was identified in a subclade which contained species that are considered to have dispersed from Southern Africa into Eastern Africa and the Arabian Peninsula. We speculate that the Core Ciconium repeat set correlates with a possible WGD event leading to this branch., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.)

Osteoporosis (OP) has the characteristics of a systematically impaired bone mass, strength, and microstructure. Long non-coding RNAs (lncRNAs) are longer than 200 nt, and their functions in osteoporosis is yet not completely understood. We first harvested the bone marrow mesenchymal stem cells (BMSCs) from ovariectomy (OVX) and sham mice. Then, we systematically analyzed the differential expressions of lncRNAs and messenger RNAs (mRNAs) and constructed lncRNA-mRNA coexpression network in order to identify the function of lncRNA in osteoporosis. Totally, we screened 743 lncRNAs (461 upregulated lncRNAs and 282 downregulated lncRNAs) and 240 mRNAs (128 upregulated and 112 downregulated) with significantly differential expressions in OP compared to normal. We conducted Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional analyses to investigate the functions and pathways of the differential expression of messenger RNAs (mRNAs), a coexpressed network of lncRNA/mRNA. Quantitative PCR (qPCR) validated that the expressions of NONMMUT096150.1, NONMMUT083450.1, and NONMMUT029743.2 were all downregulated, whereas NONMMUT026970.2, NONMMUT051734.2, NONMMUT003617.2, and NONMMUT034049.2 were all upregulated in the OVX group. NONMMUT096150.1, as a key lncRNA in OP, was identified to modulate the adipogenesis of BMSCs. Further analysis suggested that NONMMUT096150.1 might modulate the adipogenesis of BMSCs via the peroxisome proliferator-activated receptor (PPAR) signaling pathway, AMPK signaling pathway, and the lipolysis regulation in adipocyte and adipocytokine signaling pathway. Our study expands the understanding of lncRNA in the pathogenesis of OP., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Gu, Huang, Zhou, Chen, Bian, Xu and Yin.)

Osteoporosis (OP) is a disease characterized by bone mass loss, bone microstructure damage, increased bone fragility, and easy fracture. The molecular mechanism underlying OP remains unclear.In this study, we identified 217 genes associated with OP, and formed a gene set [OP-related genes gene set (OPgset)].The highly enriched GOs and pathways showed OPgset genes were significantly involved in multiple biological processes (skeletal system development, ossification, and osteoblast differentiation), and several OP-related pathways (Wnt signaling pathway, osteoclast differentiation, steroid hormone biosynthesis, and adipocytokine signaling pathway). Besides, pathway crosstalk analysis indicated three major modules, with first module consisted of pathways mainly involved in bone development-related signaling pathways, second module in Wnt-related signaling pathway and third module in metabolic pathways. Further, we calculated degree centrality of a node and selected ten key genes/proteins, including TGFB1, IL6, WNT3A, TNF, PTH, TP53, WNT1, IGF1, IL10, and SERPINE1. We analyze the K-core and construct three k-core sub-networks of OPgset genes.In summary, we for the first time explored the molecular mechanism underlying OP via network- and pathway-based methods, results from our study will improve our understanding of the pathogenesis of OP. In addition, these methods performed in this study can be used to explore pathogenesis and genes related to a specific disease.

Objective: To describe delivery of recommended HIV care and work satisfaction among infectious disease (ID) physicians, non-ID physicians, nurse practitioners (NPs), and physician assistants (PAs)., Data Sources: Medical Monitoring Project 2013-2014 HIV Provider Survey., Study Design: Population-based complex sample survey., Data Collection/analysis Methods: We surveyed 2208 HIV care providers at 505 US HIV care facilities and computed weighted percentages of provider characteristics, stratified by provider type. Rao-Scott chi-square tests and logistic regression used to compare characteristics of ID physicians with each other provider type., Principal Findings: The adjusted provider response rate was 64 percent. Among US HIV care providers, 45 percent were ID physicians, 35 percent non-ID physicians, 15 percent NPs, and 5 percent PAs. Satisfaction with administrative burden was lowest among non-ID physicians (27 percent). Compared with ID physicians, satisfaction with remuneration was lower among non-ID physicians and higher among NPs (37, 28, and 51 percent, respectively). NPs were more likely than ID physicians to report performing four of six services that are key to providing comprehensive HIV care, but more NPs planned to leave clinical practice within 5 years (19 vs 7 percent)., Conclusion: Addressing physician dissatisfaction with remuneration and administrative burden could help prevent a provider shortage. Strengthening the role of NPs may help sustain a high-quality workforce., (© Health Research and Educational Trust.)

Background: Drying is a method used to preserve agricultural crops. During the drying of products with high moisture content, structural changes in shape, volume, area, density and porosity occur. These changes could affect the final quality of dried product and also the effective design of drying equipment. Therefore, this study investigated a novel approach in monitoring and predicting the shrinkage of sweet potato during drying. Drying experiments were conducted at temperatures of 50-70 °C and samples thicknesses of 2-6 mm. The volume and surface area obtained from camera vision, and the perimeter and illuminated area from backscattered optical images were analysed and used to evaluate the shrinkage of sweet potato during drying., Results: The relationship between dimensionless moisture content and shrinkage of sweet potato in terms of volume, surface area, perimeter and illuminated area was found to be linearly correlated. The results also demonstrated that the shrinkage of sweet potato based on computer vision and backscattered optical parameters is affected by the product thickness, drying temperature and drying time. A multilayer perceptron (MLP) artificial neural network with input layer containing three cells, two hidden layers (18 neurons), and five cells for output layer, was used to develop a model that can monitor, control and predict the shrinkage parameters and moisture content of sweet potato slices under different drying conditions. The developed ANN model satisfactorily predicted the shrinkage and dimensionless moisture content of sweet potato with correlation coefficient greater than 0.95., Conclusion: Combined computer vision, laser light backscattering imaging and artificial neural network can be used as a non-destructive, rapid and easily adaptable technique for in-line monitoring, predicting and controlling the shrinkage and moisture changes of food and agricultural crops during drying. © 2017 Society of Chemical Industry., (© 2017 Society of Chemical Industry.)

The toxicity of superparamagnetic iron oxide nanoparticles (SPIONs) is still a vital topic of debate and the mechanisms remain unclear. In the present study, overdose SPIONs could induce osteosarcoma cell death and the effects were exaggerated when combined with spinning magnetic field (SMF). In the combination group, mitochondrial transmembrane potential decrease more obviously and reactive oxygen species (ROS) was found to generate much higher in line with that of the apoptosis ratio. Meantime, amount of autophagy was induced. Inhibiting the autophagy generation by 3-methyladenine (3-MA) increase cell viability but decrease the caspase 3/7 and caspase 8 activities in combination groups, and inhibiting apoptosis took the same effect. In the end, the SPIONs effects on xenograft mice was examed by intratumoral injection. The result showed that the combination group could greatly decrease the tumor volume and prolong the lifespan of mice. In sum, the result indicated that overdose SPIONs induced ROS generation, and excessive ROS induced by combination of SPIONs and SMF contribute to autophagy formation, which play a apoptosis-promoting role that formed as a platform to recruits initiate the caspase activities.

MicroRNAs (miRNAs) suppress targeting gene expression through blocking translation or triggering mRNA degradation and, in general, act in trans, through a partially complementary interaction with the 3' untranslated region (3' UTR) or coding regions of a target gene. Although it has been reported previously that some miRNAs suppress their target genes on the opposite strand with a fully complementary sequence (i.e., natural antisense miRNAs that act in cis), there is no report to systematically study such cis-antisense miRNAs in different animal species. Here we report that cis-antisense miRNAs do exist in different animal species: 48 in Caenorhabditis elegans, 17 in Drosophila, 36 in Mus musculus, and 52 in Homo sapiens using a systematical bioinformatics approach. We show that most of these cis-antisense miRNAs can efficiently reduce the expression levels of their target genes in human cells. We further investigate hsa-miR-3661, one of the predicted cis-antisense miRNAs, in detail and demonstrate that this miRNA directly targets the coding sequence of PPP2CA located on the opposite DNA strand and inhibits the PPP2CA expression. Taken together, these results indicate that cis-antisense miRNAs are conservative and functional in animal species including humans., (© 2015 Wang et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.)

At the onset of endospore formation in Bacillus subtilis the DNA-binding protein Spo0A directly activates transcription from promoters of about 40 genes. One of these promoters, Pskf, controls expression of an operon encoding a killing factor that acts on sibling cells. AbrB-mediated repression of Pskf provides one level of security ensuring that this promoter is not activated prematurely. However, Spo0A also appears to activate the promoter directly, since Spo0A is required for Pskf activity in a DeltaabrB strain. Here we investigate the mechanism of Pskf activation. DNase I footprinting was used to determine the locations at which Spo0A bound to the promoter, and mutations in these sites were found to significantly reduce promoter activity. The sequence near the -10 region of the promoter was found to be similar to those of extended -10 region promoters, which contain a TRTGn motif. Mutational analysis showed that this extended -10 region, as well as other base pairs in the -10 region, is required for Spo0A-dependent activation of the promoter. We found that a substitution of the consensus base pair for the nonconsensus base pair at position -9 of Pskf produced a promoter that was active constitutively in both deltaabrB and deltaspo0A deltaabrB strains. Therefore, the base pair at position -9 of Pskf makes its activity dependent on Spo0A binding, and the extended -10 region motif of the promoter contributes to its high level of activity.

The Bacillus subtilis AT (anti-TRAP) protein inhibits the regulatory protein TRAP (trp RNA-binding attenuation protein), thereby eliminating transcription termination in the leader region of the trp operon. Transcription of the AT operon is activated by uncharged tryptophan transfer RNA (tRNATrp). Here we show that translation of AT also is regulated by uncharged tRNATrp. A 10-residue coding region containing three consecutive tryptophan codons is located immediately preceding the AT structural gene. Completion of translation of this coding region inhibits AT synthesis, whereas incomplete translation increases AT production. Tandem sensing of uncharged tRNATrp therefore regulates synthesis of AT, which in turn regulates TRAP's ability to inhibit trp operon expression.