Search Results (34)

This study employs molecular dynamics (MD) simulations to investigate the mechanical response and fracture behavior of penta-graphene, a novel two-dimensional carbon allotrope composed entirely of pentagonal rings with mixed sp²–sp³ hybridization and pronounced mechanical anisotropy. Atomistic simulations are carried out to evaluate the impact of structural defects on mechanical performance and to elucidate crack propagation mechanisms. The results reveal that void defects involving sp³-hybridized carbon atoms cause a more significant degradation in mechanical strength compared to those involving sp² atoms. During fracture, local atomic rearrangements and bond reconstructions lead to the formation of energetically favorable ring structures—such as hexagons and octagons—at the crack tip, promoting enhanced energy dissipation and fracture resistance. A central focus of this work is the evaluation of the critical stress intensity factor (SIF) under mixed-mode (I/II) loading conditions. The simulations demonstrate that the critical SIF is influenced by the loading phase angle, with pure mode I exhibiting a higher SIF than pure mode II. Notably, penta-graphene shows a critical SIF significantly higher than that of graphene, indicating exceptional fracture toughness that is rare among ultra-thin two-dimensional materials. This enhanced toughness is primarily attributed to penta-graphene’s capacity for substantial out-of-plane deformation prior to failure, which redistributes stress near the crack tip, delays crack initiation, and increases energy absorption. Additionally, the study examines crack growth paths as a function of loading phase angle, revealing that branching and kinking can occur even under pure mode I loading. Full article

In light of the current global challenges, such as climate change, the overexploitation of natural resources, and increasing food demand, drought-tolerant forage crops present substantial potential for development in dryland regions. However, there is a notable gap in research that integrates yield improvement, nutritional quality enhancement, and resistance to pests and diseases in the production of forage crops in semi-arid areas. Therefore, selecting oat forage varieties that exhibit high yield, superior quality, and enhanced pest resistance can substantially advance the forage industry and animal husbandry in semi-arid regions. In this study, ten oat varieties, including both domestic and international cultivars, were cultivated in a semi-arid region (Weiqi town, Gansu Province) during the 2023–2024 growing season. A comprehensive analysis was performed to assess the yield, quality, and pest resistance of these varieties. All ten oat varieties successfully completed their growth cycles. Among them, Everleaf 126 exhibited a shorter plant height compared to the other varieties, measuring 103.32 cm and 115.14 cm over two years. However, its superior leaf area and tiller number led to the highest hay yields (11,819.33 kg/ha and 13,550.67 kg/ha) and seed yields (4913.20 kg/ha and 5242.33 kg/ha). Additionally, Everleaf 126 demonstrated significantly higher leaf–stem ratios (0.35 and 0.41), crude protein content (8.52% and 9.13%), and crude fat content (2.19% and 2.69%) relative to other oat varieties (p < 0.05). Furthermore, it showed the best resistance to powdery mildew (MR), red leaf disease (HR), leaf spot disease (MR), and aphids (R). The plant height of Kona was the lowest, measuring 81.22 cm and 87.16 cm, respectively, with the fewest number of tillers and the smallest leaf area. Baler II exhibited the lowest hay yield at 8770.10 kg/ha and 7898.33 kg/ha, as well as the lowest seed yield at 3409.33 kg/ha and 3323.90 kg/ha. Kona also had the lowest leaf–stem ratio (0.19 and 10.13) and crude protein content (5.74% and 6.58%), while exhibiting the highest neutral detergent fiber (NDF) and acid detergent fiber (ADF) values. Furthermore, Kona showed the poorest resistance to powdery mildew (MS) and leaf spot (MS). Finally, based on the comprehensive evaluation analysis of the membership function, in the semi-arid region, Everleaf 126 achieved the highest overall performance based upon a comprehensive evaluation, followed by Molasses and Longyan No.3. In comparison, Kona received the poorest performance. Full article

Historical trauma has been established as a determinant of health among all Hawaiians, but limited research exists on how Wāhine (Native Hawaiian women) uniquely experience historical trauma. A phenomenological qualitative study was conducted to primarily understand how historical trauma, trauma response, and the transmission and modes of intergenerational trauma intersect with sexism and patriarchy among contemporary Wāhine, as described in the Historical Trauma Conceptual Model. With partnership and approval of the Waimānalo Pono Research Hui, interviews were conducted with 13 Wāhine from various generations in Hawai’i. The structural, institutional, interpersonal, and internal levels of ‘Eha (loosely translated as hurt/suffering/to inflict pain/cause hurt or suffering) were generated as prominent themes from the data. Findings from this project communicate the urgency for change to heal Wāhine with radical aloha and to support them in reimagining a world that is inclusive of their needs. Full article

The project “Optimizing Selection Pressures and Pest Management to Maximize Cultivation Yield” (OSPREY, award #DE-EE08902) was undertaken to enhance the annual productivity, stability, and quality of algal production strains for biofuels and bioproducts. The foundation of this project was the year-round cultivation of a Nannochloropsis strain across three outdoor systems in California, Hawaii, and New Mexico. We aimed to leverage environmental selection pressures to drive strain improvement and use metagenomic techniques to inform pest management tools. The resulting dataset includes environmental and biological parameters from these cultivation campaigns, captured in a single CSV file. This dataset aims to serve a wide range of end users, from biologists to algal farmers, addressing the scarcity of publicly available data on algae cultivation. Further data releases will include 16S rRNA amplicon sequencing and shotgun sequencing datasets. Full article

Explosion monitoring is performed by infrasound and seismoacoustic sensor networks that are distributed globally, regionally, and locally. However, these networks are unevenly and sparsely distributed, especially at the local scale, as maintaining and deploying networks is costly. With increasing interest in smaller-yield explosions, the need for more dense networks has increased. To address this issue, we propose using smartphone sensors for explosion detection as they are cost-effective and easy to deploy. Although there are studies using smartphone sensors for explosion detection, the field is still in its infancy and new technologies need to be developed. We applied a machine learning model for explosion detection using smartphone microphones. The data used were from the Smartphone High-explosive Audio Recordings Dataset (SHAReD), a collection of 326 waveforms from 70 high-explosive (HE) events recorded on smartphones, and the ESC-50 dataset, a benchmarking dataset commonly used for environmental sound classification. Two machine learning models were trained and combined into an ensemble model for explosion detection. The resulting ensemble model classified audio signals as either “explosion”, “ambient”, or “other” with true positive rates (recall) greater than 96% for all three categories. Full article

In this case study, the current situation faced by coffee growers attempting to control coffee leaf rust (Hemileia vastatrix) in Hawaii is reported. CLR is considered the most devastating disease affecting coffee crops worldwide and was detected in Hawaii in 2020. Three small coffee farms from the South Kona district of Hawaii Island were selected. The goals of this case study were to: (1) assist coffee growers in the early detection of CLR incidence, and consequently support farmers with recommendations for control, (2) record agronomic information and management practices, and (3) estimate the cost to control CLR during 2021 and 2022 seasons. Low CLR incidence (<4%) was initially observed at all farms (January–June 2021), but increased as the harvest began, ending the season (December 2021) at 77%, 21% and 6% incidence at farms 1, 2 and 3, respectively. At the end of 2022 season (December), CLR incidence reached 43%, 20% and 3% at farms 1, 2 and 3, respectively. The number of sprays per season (5–10), the type of fungicides applied (preventive, curative), the timing of sprays, the efficacy of applications and weather conditions all played a role in determining the infection rates at each farm. Effective control of CLR is possible in Hawaii if the sprays of fungicides are carried out with the right products, appropriate timing and good coverage. Full article

In the face of an increasing world population and a subsequent need for an increase in sustainable and healthy food production, low trophic species, such as oysters, emerge as a promising alternative. However, regional variations in oyster production techniques, market dynamics, and consumption patterns create challenges for both the global and local industry’s growth. In this study, a descriptive qualitative analysis of oyster markets across seven Atlantic regions was carried out. The Pacific oyster (Crassostrea gigas) was found to be farmed in most Atlantic regions except the US but is classified as invasive in Sweden and potentially invasive in South Africa. Other farmed and/or harvested species include native species (C. gasar and C. rhizophorae) in Brazil, the American cupped oyster (C. virginica) in the US, and the European flat oyster (Ostrea edulis) in France, Sweden, and the US. In Irish farms, Pacific oysters are primarily for export to European markets. The marine aquaculture sectors of Sweden, South Africa, and Namibia, as well as Brazil’s farming for C. gasar, were found to be underdeveloped. This study also observed a variation in licensing, property rights, and regulatory frameworks. Financial challenges for small businesses, ecological implications of seed production techniques, biosecurity risks, and public health considerations are emphasized as critical areas for attention. This study offers valuable insights into the selected markets and can serve as a useful resource for policymakers, aquaculture practitioners, and stakeholders in optimizing global shellfish industry strategies. Full article

To create carbon efficient sources of bioenergy feedstocks and feedstuff for aquaculture and terrestrial livestock, it is critical to develop and commercialize the most efficient seaweed cultivation approach with a sustainable nutrient input supply. Here, we present data for a novel, onshore tropical macroalgae cultivation system, based on influent deep seawater as the nutrient and carbon sources. Two red algal species were selected, Agardhiella subulata and Halymenia hawaiiana, as the basis for growth optimization. Highest productivity in small-scale cultivation was demonstrated with A. subulata in the 10% deep seawater (64.7 µg N L⁻¹) treatment, growing at up to 26% specific growth rate day⁻¹ with highest yields observed at 247.5 g m⁻² day⁻¹ fresh weight. The highest yields for H. hawaiiana were measured with the addition of 10% deep seawater up to 8.8% specific growth rate day⁻¹ and yields at 63.3 g fresh weight m⁻² day⁻¹ equivalent. Biomass should be culled weekly or biweekly to avoid density limitations, which likely contributed to a decrease in SGR over time. With a measured 30–40% carbon content of the ash-free dry weight (20–30% of the dry weight) biomass, this translates to an almost 1:1 CO₂ capture to biomass ratio. The compositional fingerprint of the high carbohydrate content of both Agardhiella and Halymenia makes for an attractive feedstock for downstream biorefinery applications. By focusing on scaling and optimizing seaweed farming technologies for large-scale onshore farms, the opportunities for yield potential, adaptability to cultivation conditions, and meeting global sustainability goals through novel, carbon-negative biomass sources such as seaweed can be realized. Full article

Coffee is an important agricultural crop for the State of Hawaii. Developing new coffee cultivars with resistance to damaging pests and diseases is crucial for improving production and maintaining the profitability of the industry. With the recent discovery of Hemileia vastatrix, coffee leaf rust (CLR), to Hawaii there is a strong interest in replanting with CLR-resistant germplasm. However, when selecting an appropriate cultivar for replanting, susceptibility to other pathogens, such as plant-parasitic nematodes, should be taken into consideration. Meloidogyne konaensis, the Kona coffee root-knot nematode, causes severe destruction of the root system, reducing the yield and causing the mortality of susceptible Coffea arabica cv. Typica trees. Fortunately, resistance to root-knot nematodes has been found in some C. arabica germplasm. In this study, accessions of wild Ethiopian C. arabica and two CLR-resistant C. arabica cultivars, Tupi-HI and Obata, were evaluated for resistance to M. konaensis in a greenhouse bioassay. All Ethiopian accessions retained high levels of resistance, resulting in reproductive factors (Rfs) lower than 1.0, and low root-rot ratings. Tupi-HI was highly susceptible to M. konanensis, with an Rf value of 7.12, whereas Obata was slightly susceptible, with an Rf value of 2.33. Both cultivars had high root-rot ratings, suggesting intolerance to the nematode. Hybridizing Ethiopian C. arabica with Tupi-HI or Obata may result in new elite cultivars, resistant to both H. vastatrix and M. konaensis. Full article

COVID-19 lockdown measures appreciably affected patients’ lifestyles, negatively impacting on their health. This includes patients with Type 2 Diabetes Mellitus (T2DM). Care of these patients was also negatively impacted due to a priority to treat patients with COVID-19, certainly initially, within hospitals and clinics in Bangladesh, combined with a lack of access to clinics and physicians due to lockdown and other measures. This is a concern in Bangladesh with growing rates of T2DM and subsequent complications. Consequently, we sought to critically analyze the situation among patients with T2DM in Bangladesh during the initial stages of the pandemic to address this information gap and provide future direction. Overall, 731 patients were recruited by a simple random sampling method among patients attending hospitals in Bangladesh, with data collected over 3 timescales: before lockdown, during the pandemic, and after lockdown. Data extracted from patients’ notes included current prescribed medicines and key parameters, including blood sugar levels, blood pressure, and comorbidities. In addition, the extent of record keeping. The glycemic status of patients deteriorated during lockdown, and comorbidities as well as complications related to T2DM increased during this period. Overall, a significant proportion of key datasets were not recorded in patients’ notes by their physician before and during lockdown. This started to change after lockdown measures eased. In conclusion, lockdown measures critically affected the management of patients with T2DM in Bangladesh, building on previous concerns. Extending internet coverage for telemedicine, introduction of structured guidelines, and appreciably increasing data recording during consultations is of the utmost priority to improve the care of T2DM patients in Bangladesh. Full article

Coffee berry borer (CBB), Hypothenemus hampei, is a damaging insect pest of coffee worldwide. CBB has recently been introduced to Hawaii, so management techniques are still being developed for sustainable and cost-efficient approaches for the effective control of this pest. Field trials were conducted to evaluate the use of spinetoram on CBB infestation and bean damage compared to Beauveria bassiana and an untreated control. Initial CBB infestations were similar, and the treatments resulted in no detectable differences in subsequent new infestations. Damage to the coffee beans was reduced by both spinetoram and B. bassiana compared to controls as the mortality of adult beetles resulting from the treatments prevented them from moving into the bean (C/D position) from the berry (A/B position). The mortality of adult beetles also prevented reproduction, subsequently reducing future CBB populations in the field. When applied to infested berries, spinetoram reduced live beetle populations in the A/B position by 73% and CBBs in the C/D position by 70% compared to the water control, whereas applications of B. bassiana reduced beetles in the C/D position by 37% but had no effect on the live A/B population. An integrated pest management program is recommended for the effective control of CBBs, and the use of spinetoram applications when adult beetles are in the A/B position appears to have potential as another management tool. Full article

In the United States, besides the US territory Puerto Rico, Hawai‘i is the only state that grows commercial coffee. In Hawai’i, coffee is the second most valuable agricultural commodity. Health benefits associated with moderate coffee consumption, including its antioxidant capacity, have been correlated to its bioactive components. Post-harvest techniques, coffee variety, degree of roasting, and brewing methods significantly impact the metabolites, lipids, minerals, and/or antioxidant capacity of brewed coffees. The goal of our study was to understand the impact of roasting and brewing methods on metabolites, lipids, biogenic amines, minerals, and antioxidant capacity of two Hawai‘i-grown coffee (Coffea arabica) varieties, “Kona Typica” and “Yellow Catuai”. Our results indicated that both roasting and coffee variety significantly modulated several metabolites, lipids, and biogenic amines of the coffee brews. Furthermore, regardless of coffee variety, the antioxidant capacity of roasted coffee brews was higher in cold brews. Similarly, total minerals were higher in “Kona Typica” cold brews followed by “Yellow Catuai” cold brews. Hawai‘i-grown coffees are considered “specialty coffees” since they are grown in unique volcanic soils and tropical microclimates with unique flavors. Our studies indicate that both Hawai‘i-grown coffees contain several health-promoting components. However, future studies are warranted to compare Hawai‘i-grown coffees with other popular brand coffees and their health benefits in vivo. Full article

The constant-Q Gabor atom is developed for spectral power, information, and uncertainty quantification from time–frequency representations. Stable multiresolution spectral entropy algorithms are constructed with continuous wavelet and Stockwell transforms. The recommended processing and scaling method will depend on the signature of interest, the desired information, and the acceptable levels of uncertainty of signal and noise features. Selected Lamb wave signatures and information spectra from the 2022 Tonga eruption are presented as representative case studies. Resilient transformations from physical to information metrics are provided for sensor-agnostic signal processing, pattern recognition, and machine learning applications. Full article

Daily exposure to bisphenols can affect reproductive functions due to their pseudo-estrogenic and/or anti-androgenic effects. Testicular lipids contain high levels of polyunsaturated fatty acids necessary for sperm maturity, motility, and spermatogenesis. Whether prenatal exposure to bisphenols alters testicular fatty acid metabolism in adult offspring is unknown. Pregnant Wistar rats were gavaged from gestational day 4 to 21 with BPA and BPS (0.0, 0.4, 4.0, 40.0 μg/kg bw/day). Despite increased body and testis weight, the total testicular cholesterol, triglyceride, and plasma fatty acids were unaffected in the offspring. Lipogenesis was upregulated by increased SCD-1, SCD-2, and expression of lipid storage (ADRP) and trafficking protein (FABP4). The arachidonic acid, 20:4 n-6 (ARA) and docosapentaenoic acid, 22:5 n-6 (DPA) levels were decreased in the BPA-exposed testis, while BPS exposure had no effects. The expression of PPARα, PPARγ proteins, and CATSPER2 mRNA were decreased, which are important for energy dissipation and the motility of the sperm in the testis. The endogenous conversion of linoleic acid,18:2 n-6 (LA), to ARA was impaired by a reduced ARA/LA ratio and decreased FADS1 expression in BPA-exposed testis. Collectively, fetal BPA exposure affected endogenous long-chain fatty acid metabolism and steroidogenesis in the adult testis, which might dysregulate sperm maturation and quality. Full article

Aquaponics has the potential to contribute to food security in urban Nepal, where agricultural land near cities is rapidly being converted for other uses. This technology’s use is expanding in Nepal, but the relatively high cost of commercial fish food is a hindrance. As a result, some aquaponics operators are resorting to alternative, less expensive fish foods. Since the primary input of nutrients to the plants grown in aquaponics comes from the fish food, an evaluation of the impact of fish foods on plant and fish growth is needed to help operators evaluate the costs and benefits of commercial compared to alternative fish diets. This study evaluated the growth of lettuce and common carp, the most common species of plant and fish used in aquaponics in Nepal, with three fish diets (commercial fish food, commercial chicken food, and a homemade diet with mustard oil cake and rice bran) at a commercial aquaponics farm with nine identical systems allowing for three replicates of the three fish food treatments. There were no significant differences in the measurements of lettuce growth (stem length, root length, and stem mass) and few differences in nutrient concentrations in leaf tissue. The specific growth rate of the carp fingerlings was lowest for the fish in the systems fed with the homemade diet (0.21) compared to those fed commercial fish food or commercial chicken food (0.31 and 0.28, respectively). These findings suggest that aquaponics operators who have been buying the more expensive commercial fish food with fish meal as its protein source can save 50–95% of the related costs by using commercial chicken food or the homemade diet defined in this study. This could potentially encourage the expansion of aquaponics systems in Nepal. Full article