Safe Preservation Research Articles

A meta-analysis to observe silage microbiome differentiated by the use of inoculant and type of raw material.

Silage fermentation is naturally carried out by lactic acid bacteria (LAB) to mainly produce lactic acid (LA) and other organic acids as preservatives. Along with fermentation time, the growth of LAB will replace and suppress undesirable microorganisms. This meta-analysis study aimed to explore silage microbiome differentiated by LAB inoculants and type of raw materials. A total of 37 articles with 185 studies and 475 datasets were used for building up the meta-database. Data were subjected to the mixed model methodology. The parameters observed were silage quality and silage microbiome post-ensiling process. Results revealed that four bacterial genera along with Weissella dominated the post-ensiling process. The addition of lactic acid inoculants in the silage has increased the abundance of Lactobacillus spp. and decreased the Shannon index significantly. Moreover, the abundance of both L. plantarum and L. buchneri increased, and subsequently, Weissella, Pseudomonas, Proteobacteria, pH value, ammoniacal nitrogen (NH3-N), coliforms, and the yeasts were decreased significantly due to the addition of LAB inoculants in silage (p < 0.05). Environmental factors such as temperature affected the existence of Pseudomonas, Exiguobacterium, and Acinetobacter. However, the dry matter, LA, acetic acid (AA), the ratio of LA to AA, and the LAB population were enhanced significantly (p < 0.05). Among the LAB types, the lowest abundance of Pseudomonas was due to the LAB group, while the lowest abundance of Weissella and Proteobacteria was due to the addition of the combined LAB group. In conclusion, the addition of LAB is effectively enhancing the silage microbiome and silage quality by altering bacterial diversity and the metabolic products of the silage materials for safe preservation.

Advances in the Role and Mechanisms of Essential Oils and Plant Extracts as Natural Preservatives to Extend the Postharvest Shelf Life of Edible Mushrooms

China has a large variety of edible mushrooms and ranks first in the world in terms of production and variety. Nevertheless, due to their high moisture content and rapid respiration rate, they experience constant quality deterioration, browning of color, loss of moisture, changes in texture, increases in microbial populations, and loss of nutrition and flavor during postharvest storage. Therefore, this paper reviews the effects of essential oils and plant extracts on the preservation of edible mushrooms and summarizes their mechanisms of action to better understand their effects during the storage of mushrooms. The quality degradation process of edible mushrooms is complex and influenced by internal and external factors. Essential oils and plant extracts are considered environmentally friendly preservation methods for better postharvest quality. This review aims to provide a reference for the development of new green and safe preservation and provides research directions for the postharvest processing and product development of edible mushrooms.

Antimicrobial Effect of Moringa oleifera Leaves Extract on Foodborne Pathogens in Ground Beef.

Consumers nowadays are becoming more aware of the importance of using only meat products containing safe and natural additives. Hence, using natural food additives for extending the shelf life of meat along with delaying microbial growth has become an urgent issue. Given the increasingly popular view of Moringa oleifera leaves as a traditional remedy and also the scarcity of published data concerning its antimicrobial effect against foodborne pathogens in meat and meat products, we designed the present study to investigate the antimicrobial effect of Moringa oleifera leaves aqueous extract (0.5%, 1%, and 2%) on ground beef during refrigerated storage at 4 °C for 18 days. MLE revealed potent antimicrobial properties against spoilage bacteria, such as aerobic plate count and Enterobacteriaceae count. MLE 2% showed a significant (p < 0.01) reduction in the counts of E. coli O157:H7, Salmonella enterica serovar Typhimurium, and Staphylococcus aureus artificially inoculated to ground beef by 6.54, 5.35, and 5.40 log10 CFU/g, respectively, compared to control, by the 18th day of storage. Moringa leaves extract (MLE) had no adverse effect on the overall acceptability and other sensory attributes; moreover, it induced a slight improvement in the tenderness and juiciness of treated ground beef, compared to the control. Therefore, MLE can be used as a healthy, natural, and safe preservative to increase meat products' safety, quality, and shelf stability during cold storage. A promising approach for using natural food additives rather than chemical preservatives could begin new frontiers in the food industry, as they are more safe and do not constitute health risks to consumers.

Cross-linked alginate edible coatings incorporated with hexyl acetate: Film characteristics and its application on fresh-cut rose apple

Edible coatings, as carriers of antimicrobial compounds, have been proposed as an alternative method to preserve fresh-cut products. This research focused to improve the shelf life of fresh-cut rose apples by applying an edible coating based on alginate cross-linked with calcium chloride (SAC)-enriched hexyl acetate (HA) as a natural antimicrobial compound. The SAC with HA in 0.01, 0.03, and 0.05% (v/v) (SAC-HA) solution was evaluated for its film properties and applied to fresh-cut rose apples, and compared with the unmodified SAC coating. Postharvest quality and microbial contamination were determined every 2 days during 10 days of storage at 4 °C. The film thickness, tensile strength, and elongation at break increased with the high concentrations of HA added. Films containing 0.03% HA had lower oxygen permeability (from 1.57 to 0.04 × 10−7 cm3 μm m−2 day−1 kPa−1), as well as water vapor permeability (from 0.03 to 0.01 g mm m−2 day−1 kPa−1), compared to the unmodified SAC film. Moreover, the greater coating uniformity and thickness were supported by scanning electron microscopy and Fourier transform infrared spectroscopy. The developed edible SAC coatings with 0.03% HA successfully preserved the physicochemical quality and extended the shelf life of fresh-cut rose apples for 10 days at 4 °C by retarding the respiration rate, inhibiting browning, and preventing microbial growth. Therefore, the using of SAC-HA in fresh-cut products is a promising and safe preservation technique to extend shelf life.

Maintenance of postharvest storability and overall quality of 'Jinshayou' pummelo fruit by salicylic acid treatment.

The loss of postharvest storability of pummelo fruit reduces its commodity value for long run. To maintain its storability, the effects of postharvest dipping treatment by salicylic acid (SA) with different concentrations (0, 0.1, 0.2, or 0.3%) were investigated on pummelo fruit (Citrus maxima Merr. cv. Jinshayou) during the room temperature storage at 20 ± 2°C for 90d. Among all treatments, pre-storage SA treatment at 0.3% demonstrated the most significant ability to reduce fruit decay incidence, decrease weight loss, delay peel color-turned process, and inhibit the declines in total soluble solids (TSS) as well as titratable acid (TA) content. The increases in electrolyte leakage, hydrogen peroxide (H2O2), and malondialdehyde (MDA) content of the 0.3% SA-treated pummelo fruit were reduced compared to the control (dipped in distilled water). Pummelo fruit treated with 0.3% SA exhibited the most outstanding ability to excess reactive oxygen species (ROS) accumulation, as evidenced by promoted the increases in glutathione (GSH), total phenolics and flavonoids contents, delayed the AsA decline, and enhanced the activities of antioxidant enzymes and their encoding genes expression. Pre-storage treatment dipped with SA, particularly at 0.3%, can be used as a useful and safe preservation method to maintain higher postharvest storability and better overall quality of 'Jinshayou' pummelo fruit, and thus delaying postharvest senescence and extend the storage life up to 90d at room temperature.

RESEARCH PROGRESS OF SALT REDUCTION: FROM INITIATIVES TO TECHNOLOGICAL INNOVATIONCTION

Salt is one of the most widely used condiments in the home cooking and the food industry. It not only contains an essential micronutrient for human beings (sodium), but also is an important and safe preservative in food processing sector. Excessive salt intake is linked to the high prevalence of hypertension and other related diseases such as cardiovascular diseases and stroke. A reduction in salt intake across the whole population will be conducive to improvements in public health. However, reducing the salt content in foods is not a simple but a challenging task, since salt not only impacts the flavor and texture of the final products, but also plays an important role in processing and preservation of foods. The present review introduced the salt reduction actions around the world and different approaches for sodium reduction in foods, and further summarized emerging technologies that utilized in salt reduction in foods.

Preservation of muscle tissue with a formaldehyde-free borax solution for gross anatomy lessons

It is known that formaldehyde has serious toxicological effects on medical students, laboratory workers and environmental health. Recently various scientists search for a safe preservation fluid instead of the formaldehyde. One of them and the famous one is the Thiel’s embalming solution. However, it has been realized that it causes deterioration in muscle tissues. It was determined that this deterioration was caused by the boric acid. In the present study, previously formalin fixed muscle tissues were stored into the alkali form of boron during 40 days. At the end of the trial the appearance of the borax stored cadavers was quite similar to the formalin stored cadavers. In cross-sections taken from the muscle tissues, no deterioration could observe. Additionally, there was no putrid odor; on the contrary, a slight level of formaldehyde odor. In microbiological tests, there was a slight insignificant increase in the total number of bacteria in borax solutions. As a result, it was concluded that borax could be used as a cadaveric storage solution, and it can be more appropriate to use borax instead of boric acid in Thiel's solution.

Ultrasound Measurement of the Distance between the Breast Tumor and the Skin: A Cut-Off Value for Safe Skin Preservation – Diagnostic Accuracy Study

Background: In superficial tumors of the breast, it is necessary to plan the thickness of surgical skin flaps, and whether skin can be preserved for esthetics results. This study aimed to find an ultrasound-measured cut-off distance between tumor and skin (TSD) that allows patients to have the skin over the tumor spared. Methods: This is a diagnostic accuracy study comparing preoperative ultrasound TSD with pathological TSD and the thickness of the skin flaps. We recruited all consecutive women diagnosed with breast cancer between January 2017 and December 2019 whose surgical planning allowed to have the tumor and overlying skin to be removed in bloc (reconstruction procedures, situations where skin removal would not lead to esthetic problems, and superficially located tumors). Measurements were made: preoperatively (by ultrasound), during surgery (using a metal caliper to obtain the thickness of surgical skin flap), and after surgery (pathological). A pathological tumor-skin distance greater than surgical skin flap thickness would indicate preservation of skin above the tumor. Results: We evaluated 95 consecutive patients with 102 lesions. The average surgical flap thickness was 5.5 mm (3–10 mm). The ultrasound-measured cut-off TSD of 2.1 mm obtained 96.0% accuracy in predicting free anterior margin, considering a 5-mm-thick surgical flap. Conclusion: In breast superficial tumors, a cut-off distance of 2.1 mm or more measured preoperatively by ultrasound allows safe preservation of the skin above the tumor. Future studies need to follow up for longer the women submitted to skin preservation surgeries, especially those not undergoing radiotherapy.

Antifungal activity of natamycin against kiwifruit soft rot caused by Botryosphaeria dothidea and potential mechanisms

Soft rot caused by Botryosphaeria dothidea leads to massive economic losses in the kiwifruit industry. Natamycin is a natural antimicrobial preservative that effectively prevents postharvest decay and preserves fruit quality. However, the ability to control kiwifruit soft rot and potential antifungal mechanisms have not been explored. In this study, the inhibitory impact of natamycin against soft rot caused by B. dothidea, as well as its putative action mechanisms were investigated. The results indicated that 2 mg L−1 natamycin effectively inhibited mycelial growth and spore germination of B. dothidea in vitro. Natamycin caused B. dothidea hypha to shrink and deform, along with vacuolation and plasmolysis in hypha cells, as observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Likewise, natamycin stimulated the accumulation of reactive oxygen species (ROS) in the hypha. The inhibition effect of natamycin on B. dothidea inoculated in kiwifruit was dose-dependent, with 500 mg L−1 natamycin significantly decreasing the incidence of soft rot to 35%. Furthermore, natamycin induced disease resistance in kiwifruit tissue by activating the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), increasing the antioxidant compound total phenol, maintaining a low level of malondialdehyde (MDA), and repressing the activity of four cell wall degrading enzymes, as well as gene expression of β-galactosidase (β-Gal) and polygalacturonase (PG). Further field research revealed that pre-harvest treatment combined with the postharvest natamycin application significantly reduced the natural decay incidence of kiwifruit while having no negative effect on soft-ripe quality. In conclusion, our findings proved that natamycin has an antifungal effect on B. dothidea and may be applied as a safe preservative to reduce soft rot.

Effect of chitosan‐based melatonin composite coating on the quality of minimally processed pomegranate aril‐sacs during cold storage

AbstractThe current study evaluated the potential of chitosan‐based melatonin (CH‐MT) composite coating to maintain quality and delay senescence of minimally processed pomegranate aril‐sacs during refrigerated storage. Mature pomegranate fruit (cv. Wonderful) without physical defects were processed into aril‐sacs. Subsequently, the following treatments were applied; distilled water (control), CH 0.5% (w/v), CH+0.1 mM MT, CH+0.4 mM MT, CH+0.8 mM MT, and CH+1 mM MT. Each treatment was applied by immersing the aril‐sacs in the coating solution for 3 min and allowed to dry at room temperature. Aril‐sacs were then packed in polyethene terephthalate punnets (three to four aril‐sacs/punnet) and stored at 5°C and 85% RH for 21 days. Aril color, weight loss, respiration rate, ascorbic acid content, total anthocyanins, browning index, and antioxidant capacity were monitored during storage at 3 days intervals. The study results showed that the CH‐MT coating treatments significantly (p &lt; 0.05) delayed the increase in aril‐sacs weight loss and respiration rate. These treatments also retained higher aril chroma, ascorbic acid, anthocyanin content, DPPH‐radical scavenging activity, and aril‐sacs antioxidant power (FRAP). In addition, surface browning development was significantly suppressed in the coated aril‐sacs compared with control sacs. However, the effectiveness of CH‐MT treatments in maintaining the quality of aril‐sacs was concentration‐dependent, with CH+0.8–1 mM MT treatments showing the best results. Therefore, CH+0.8–1 mM MT treatments are recommended to suppress the development of physiological disorders and maintain the quality of minimally processed pomegranate aril‐sacs.Novelty Impact StatementThis study focuses on the development and application of chitosan‐melatonin composite coating (CH‐MT) as an active and functional formulation to maintain quality and extend the storage life of minimally processed pomegranate aril‐sacs. The results showed that incorporating melatonin with chitosan improved the effectiveness of chitosan base coating. This was demonstrated by the CH‐MT coating's enhanced retention of ascorbic acid, anthocyanins, radical scavenging activity, and antioxidant power. Further, delaying the increase in aril‐sacs surface browning, weight loss, and respiration rate. The study findings are valuable in the commercial adoption of safe preservation technologies to maintain the quality and maximize the storability of minimally processed products.

Is the Organ Care System (OCS) Still the First Choice With Emerging New Strategies for Donation After Circulatory Death (DCD) in Heart Transplant?

The scarcity of donor hearts continues to be a challenge in transplants for advanced heart failure patients. With an increasing number of patients on the waiting list for a heart transplant, the discrepancy in the number between donors and recipients is gradually increasing and poses a new challenge that plagues the healthcare systems when it comes to the heart. Several technologies have been developed to expand the donor pool in recent years. One such method is the organ care system (OCS). The standard method of organ preservation is the static cold storage (SCS) method which allows up to four hours of safe preservation of the heart. However, beyond four hours of cold ischemia, the incidence of primary graft dysfunction increases significantly. OCS keeps the heart perfused close to the physiological state beyond the four hours with superior results, which allows us to travel further and longer distances, leading to expansion in the donor pool. In this review, we discuss the OCS system, its advantages, and shortcomings.

Antifungal Activity of Nanoemulsion of Iranian Tarragon (Artemisia dracunculus L.) Essential Oil

Background: Despite the considerable activity of herbal Essential Oils (EOs) as safe food preservatives, problems such as high volatility, low water solubility, and low stability in adverse environmental conditions restrict their use in food products. This work aimed to investigate in vitro antifungal activity of oil-in-water nanoemulsion of Iranian Artemisia dracunculus L. (tarragon) EO.&#x0D; Methods: Nanoemulsion of tarragon EO was formed by ultrasound method through blending 10 wt% of tarragon EO, 85 wt% water, and the mixture of 5 wt% surfactants (Tween® 80/Span® 80). The droplet size and zeta potential were measured. The antifungal activity was evaluated against four different fungi, Aspergillus niger, Penicillium spp., Fusarium spp., and Saccharomyces cerevisiae through determining Minimum Inhibitory Concentration (MIC), Minimum Fungicidal Concentration (MFC), and mycelial growth test. Data were statistically analyzed by the software of SPSS 22.0.&#x0D; Results: Main fragments of tarragon EO found to be beta-cis-ocimene, estragole, and beta-trans-ocimene. Nanodroplets had a zeta potential of -30 mV and an average diameter of 50 nm. For A. niger, Penicillium spp., Fusarium spp., and S. cerevisiae, the MIC and MFC values of nanoemulsion were identical and obtained at 1.50, 2.05, 1.61, and 1.14 µg/ml, respectively, while these values of free EO were higher and as follows: 2.81, 4.52, 3.75, and 2.40 µg/ml, respectively. Mycelial growth showed that encapsulated EO had the most fungitoxic potential against A. niger (inhibition 41%) and S. cerevisiae (inhibition 68%). Also, Penicillium spp. was the most resistant against both EO and nanoemulsion.&#x0D; Conclusion: The growth inhibitory activity of tarragon was significantly enhanced when encapsulated as nanoemulsion.

Breeding of a High-Nisin-Yielding Bacterial Strain and Multiomics Analysis

Nisin is a green, safe and natural food preservative. With the expansion of nisin application, the demand for nisin has gradually increased, which equates to increased requirements for nisin production. In this study, Lactococcus lactis subsp. lactis lxl was used as the original strain, and the compound mutation method was applied to induce mutations. A high-yielding and genetically stable strain (Lactobacillus lactis A32) was identified, with the nisin titre raised by 332.2% up to 5089.29 IU/mL. Genome and transcriptome sequencing was used to analyse A32 and compare it with the original lxl strain. The comparative genomics results show that 107 genes in the A32 genome had mutations and most base mutations were not located in the four well-researched nisin-related operons, nisABTCIPRK, nisI, nisRK and nisFEG: 39 single-nucleotide polymorphisms (SNPs), 34 insertion mutations and 34 deletion mutations. The transcription results show that the expression of 92 genes changed significantly, with 27 of these differentially expressed genes upregulated, while 65 were downregulated. Our findings suggest that the output of nisin increased in L. lactis strain A32, which was accompanied by changes in the DNA replication-related gene dnaG, the ABC-ATPase transport-related genes patM and tcyC, the cysteine thiometabolism-related gene cysS, and the purine metabolism-related gene purL. Our study provides new insights into the traditional genetic mechanisms involved nisin production in L. lactis, which could provide clues for a more efficient metabolic engineering process.

Study on the antifungal mechanism of Chinese herbal extract on Botryosphaeria dothidea

Botryosphaeria dothidea is a main post-harvest pathogen of kiwifruit, causing fruit decay and health problems. In this study, the effect of Chinese herbal extract compound (CHEC) on the antifungal assay, the SEM (scanning electron microscope) observation, fluorescence microscopy observation, transcriptional profile, and physiological characters of B. dothidea was measured. CHEC (0.6 to 0.8 mg/ml) significantly inhibited mycelium growth, reduced the formation and germination of spores, and decreased the content of sugar and protein in the mycelium. The activity of SOD, CAT, POD, NADP-malate dehydrogenase, succinate dehydrogenase, cellulase, and glucanase was significantly reduced, while the content of malondialdehyde in the mycelium was significantly increased. In addition, there was a significant decrease in DNA content and mitochondrial membrane potential and a significant increase in ROS. The mycelium appeared thicker, the top of the mycelium was significantly larger, the cell membrane of spores began to contract and bend, and the nucleus gradually disappeared. Transcriptome data showed that a total of 20,510 differentially expressed genes (DEGs) were obtained, including 19,139 down-regulated and 1371 up-regulated genes. Both RNA-seq data and qRT-PCR showed that the genes of remarkable down-regulation were included in the membrane pathway, cell pathway, oxidoreductase activity pathway, transport and catabolism, and carbohydrate metabolism. Practical applications CHEC is a mixture of several extracts with strong antifungal effects. It is a green and safe antifungal agent. CHEC has a strong antifungal effect by destroying mycelial cell structure, inhibiting gene expression and mycelial growth and metabolism. These findings provided additional useful information on the antifungal mechanism of CHEC at the molecular and genetic levels, and suggested that CHEC was a potential candidate to control B. dothidea. Moreover, our data provided novel insights into the green and safe preservation of kiwifruit.

Hydrocolloids is a new trend as meat preservative

Meat eating aids in the absorption of proteins and vital amino acids, as well as vitamins and minerals such as vitamin B, vitamin A, zinc, and iron, all of which are required for a balanced diet. This evaluation looked into the many types of hydrocolloids and whether they may be used as a new, safe natural meat preservative. Natural, semi-synthetic, and synthetic hydrocolloids are classified according to their origin. Hydrophilic polymers generated from natural sources such as plants, animals, microbes, and seaweeds are known as natural hydrocolloids. Semi-synthetic hydrocolloids, on the other hand, are modifications of naturally formed hydrocolloids, whereas synthetic hydrocolloids are chemically manufactured from petroleum-derived base materials to produce a product with a structure comparable to natural polysaccharides. In recent years, natural hydrocolloids have been widely preferred in the food industry for improving the stability, functionality, quality, safety, nutritional and health benefits of various food products over semi-synthetic and synthetic hydrocolloids due to: Extracted from renewable sources, readily available and easy to handle, Biocompatible, Non-toxic, Capable of physical and chemical modification, Eco-friendly and cost-effective, More acceptance by the general public. According to the study, the growth is a direct outcome of the increased use of hydrocolloids. In the food industry, functional qualities are still the most common application of hydrocolloids.

Antibacterial activity of antimicrobial peptide gcDefb1 against foodborne pathogenic bacteria and its application in pork storage.

The online version contains supplementary material available at 10.1007/s10068-022-01060-9.

Design and construction of a desiccant air dryer for seeds and vegetables

The object of this research is the design of an affordable desiccant dryer for local farmers for seed and vegetable drying. The subsequent increase in food production has led to an accompanying need for easy, safe, and affordable preservation methods. This has led to a substantial increase in the number of driers, which are expensive for local farmers to acquire. Seeds and certain vegetables do not do well, under the high heat used in most dryers for drying as the drying process is often used as a final production step before packaging and selling agricultural products. Desiccant drying is hygienic, low energy, low cost, and safe method of drying agricultural products without degrading them or reducing their nutritional quality. A desiccant air dryer for seeds and vegetables was designed and constructed, and its performance was tested using bitter leaves (Vernonia amygdalina). Desiccant dryer materials were carefully sourced and selected based on the cost of the materials, availability, strength, lightness (weight), and resistance to rust. The desiccant dryer chamber has external dimensions of 43 cm by 30 cm and internal dimensions of 28 cm by 25 cm. The drying chamber is divided into five layers; each layer is 48 cm by 44 cm with a total surface area of 0.2112 m2.&#x0D; Results showed significant moisture loss in the dried sample in 26 hours from 167 g to 54.1 g when compared with ambient air drying values. Proximate analysis of the desiccant dried bitter leaf higher values across all parameters when compared with the sample dried using ambient air. From the results obtained, it was therefore concluded that the desiccant dryer dried the samples faster than the common air-drying method. It was recommended that seed and vegetables should be dried in a desiccant dryer in other to increase shelf life and reduce perishability.

Development of a Formulation of Vanishing Cream Containing Wheat Germ Oil with Safe Preservation, and Measurement of Antioxidants in the Cream by a Rapid Method

Introduction: Wheat germ is a by-product of the wheat mill and contains 10 to 15% of the oil. The use of wheat germ oil in cosmetics is because this oil contains ceramide that prevents skin aging and can preserve the skin.&#x0D; Material and Methods: A vanishing oil in water (O/W) cream based on wheat germ oil was made and formulated. The antioxidants of the cream were extracted, and the best extraction conditions were obtained by the Taguchi method. Four factors of temperature, time, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and round per minute (RPM) were investigated at three levels. To maintain consumer health, carcinogenic preservatives such as parabens were removed from the formulation, and a new composition of methylpropanediol, capryl glycol, and phenylpropanoldiol (OMP) was used in the formulation. At microbial testing, two standard strains of Staphylococcus aureus and Pseudomonas aeruginosa were selected as representative of gram-positive and gram-negative bacteria. The stability of the antioxidants of wheat germ oil in the cream structure was studied.&#x0D; Results: In the extraction of the antioxidants from the cream structure, the highest impact was related to the DPPH factor (78%) and temperature (14%), respectively. A growth inhibition zone of 24mm diameter was observed for S. aureus and 16mm for P. aeruginosa. The wheat germ oil cream was completely stable at 37°C after 30 days.&#x0D; Conclusion: A vanishing herbal cream was formulated base on OMP composition with a very good antimicrobial activity. A rapid extraction and measurement method of the cream antioxidants was established and optimized based on DPPH.

Filmic memory texts: Seeing America’s archeological turn from salvage to conservation in Spadework for History

Over two decades in mid-century America, the professional approach to sites endangered by post-war construction and development projects was to excavate and “save the data” from certain loss. Archeologists led such salvage efforts from 1945 to 1970, first meeting the increased demand for their labor and skills. Then, in seeing the permanence of destruction, they shifted by extending their concept of safe preservation into the future: an early conservationist archeology. One broad impact of the River Basin Surveys was in memorializing tribal histories and relationships to the land environment by the recovery of large swaths of biological, ecological, palynological, and geological data from excavations coordinated from branch offices in Nebraska, Oregon, California, Washington, D.C., and Texas. With funding from the National Science Foundation, Texas professor E. Mott Davis created a meticulous record of such archeological practices through a film series which captures that shift from the perspective of one of its practitioners. Spadework for History (1964), subtitled “Salvaging American History,” seeks to document the country’s anthropological archeology through a pioneering academic collaboration between film and archeology. Weighing scholarship on the production of archives—including an awakening to power in their production of history—this article considers the power of film in creating a memory text. In retelling Davis’s contribution, evidence from the films’ reception and memory studies perspectives together expand the temporal framework available to support further audiovisual collection-based analyses of professional work.

A sequential hybridization of ETLBO and IPSO for solving reserve‐constrained combined heat, power and economic dispatch problem

The explosive demand for electricity and ecological concerns has necessitated the operation of power networks in a more cost-effective approach. In recent years, the integration of combined heat and power units has presented a potential answer to these problems; nevertheless, a new difficult challenge has emerged: finding an optimal solution for simultaneous dispatch of power and heat. Therefore, to tackle this problem, this work presents an intelligent sequential algorithm based on a hybridization of an enthusiasm-aided teaching and learning-based optimization algorithm (ETLBO) with an improved version of particle swarm optimization (IPSO). The proposed method can simultaneously minimize total generating costs while considering a variety of physical and operational limitations. In addition, this research designed an adaptive violation constraint management approach combined with the formulated hybridized optimization algorithm to ensure system constraints' safe preservation during the optimization process. Finally, the performance of the proposed method is compared to the recently developed metaheuristic algorithms as well as Knitro and IPOPT (industrially used optimization packages), in which the ETLBO-IPSO outperforms all the other methods.