Effects Of Starvation Research Articles

The Psychological, Cognitive, and Behavioural Effects of Starvation in Humans: A Scoping Review.

Research has highlighted the physical complications of starvation, but there is less research examining the psychological effects of starvation in humans. This scoping review synthesises literature on the non-physical effects of starvation in humans. Following PRISMA-ScR guidelines, we searched MEDLINE, PsycINFO, and Global Health for studies published between 1946 and 2023 examining the non-physical effects of starvation in individuals aged 2-79years, including those who were starved, malnourished, stunted, wasted, underweight, had a restrictive eating disorder, or were raised in famine conditions. From 16,555 abstracts, 851 articles on the effects of malnutrition were reviewed, and 318 were included. Among these, 35% focused on children and adolescents, 25.5% on adults with comorbid illnesses, 17% on older adults, 13% on those with eating disorders, 6% on adults without comorbidities, and 3.5% on famine survivors. Cognitive impairments were the most frequently reported effects in children. In adults and older adults, depression and anxiety were common, along with reduced cognitive functioning, reduced quality of life, social withdrawal, impaired sleep and impaired sexual functioning. Individuals with eating disorders experienced depression, anxiety, obsessive-compulsive symptoms, emotion regulation difficulties, and cognitive impairment. There is extensive evidence showing the detrimental non-physical consequences of starvation in children and adults. These findings should inform research, clinical interventions, and educational materials addressing the effects of insufficient nutrition, including in those with restrictive eating disorders.

Effects of prolonged starvation on body mass and respiratory physiology of the New Zealand abalone or pāua, Haliotis iris

Context Subtidal, adult pāua experience irregular food supply. The effects of prolonged starvation have not been examined. Aim To examine effects of 105-day starvation on body mass, respiration and haemolymph proteins. Methods Pāua, maintained at 15°C, were divided into groups that were either fed Macrocystis pyrifera, or starved; each group was further divided between pāua whose haemolymph was sampled at intervals and those sampled only at the beginning and end of the experimental period. Body mass, condition, oxygen uptake and gonad index were measured at the start and end. Key results Total mass of both fed and starved groups did not change significantly. The condition of the starved individuals decreased significantly. Haemocyanin accounts almost entirely for haemolymph proteins. The haemolymph haemocyanin concentration in fed abalone fell by 17–27% over 105 days, and by 49–63% in starved individuals. Final normoxic oxygen uptake was similar in starved and fed pāua and declined similarly during hypoxia. Conclusions Pāua may survive extended periods of starvation by metabolising body tissues and haemocyanin, with only minor changes in their mass, condition and aerobic respiration. Implications These primitive gastropods have mechanisms to survive stressors associated with low food availability. Maintenance of body volume in this osmoconformer supports gill perfusion and the functioning of the hydraulic skeleton in locomotion.

Effect of nutritional stress and serum starvation on the optical absorbance of normal and malignant epithelial cell lines.

This brief report aimed to investigate the optical absorbance spectra of normal, dysplastic, and malignant epithelial cell lines under normal and nutritional stress conditions. HaCAT (keratinocyte), DOK (oral dysplastic), and oral squamous cell carcinoma (OSCC) cell lines (CA1, Luc4, SCC9) were evaluated regarding their optical absorbance after culture with 0-10% fetal bovine serum. Absorbance measurements indicated that HaCAT under serum starvation exhibited higher absorbance at blue (430nm) and near-infrared (906nm) wavelengths. DOK showed absorption at 440nm and 945nm. OSCC cells showed absorption peaks at blue (400-428nm) and near-infrared. These findings highlight the importance of tailoring PBM parameters to individual needs to achieve optimal absorption and effectiveness. Moreover, the higher absorption peaks in the blue region support further studies to elucidate the potential use of blue light in oral dysplastic lesions and OSCC.

Effect of tryptophan starvation on inclusion membrane composition and chlamydial-host interactions.

Chlamydia is an obligate intracellular bacterial pathogen that develops within a membrane-bound vacuole called an inclusion. Throughout its developmental cycle, Chlamydia modifies the inclusion membrane (IM) with type III secreted (T3S) membrane proteins, known as inclusion membrane proteins (Incs). Via the IM, Chlamydia manipulates the host cell to acquire lipids and nutrients necessary for its growth. One key nutrient is tryptophan (Trp). As a Trp auxotroph, Chlamydia is very sensitive to Trp starvation and, in response to low Trp levels induced by the immune response, enters a viable but nonreplicating state called persistence. To maintain viability during persistence, Chlamydia must necessarily maintain both the integrity of the IM and its ability to modify host cell responses, but how Trp starvation affects IM composition and subsequent interactions with the host cell remains poorly understood. We hypothesize that, under Trp starvation conditions, Inc expression/stability or T3S function during persistence alters IM composition but that key host-Chlamydia interactions will be preserved. To examine host-Chlamydia interactions during persistence, we examined sphingomyelin, cholesterol, and transferrin trafficking to the inclusion, as well as localization of host proteins that bind to specific Incs. We identified IM composition changes during persistence by monitoring endogenous Inc abundance at the IM. Chlamydial T3S is generally functional during persistence. Specific changes in Inc composition in the IM can be linked to Trp content of a specific Inc or effector-specific defects in chlamydial T3S. Overall, our findings reveal that critical host-Chlamydia interactions are maintained during persistence mediated by Trp starvation.

Life Stage- and Sex-Specific Sensitivity to Nutritional Stress in a Holometabolous Insect.

Over lifetime, organisms can be repeatedly exposed to stress, shaping their phenotype. At certain, so-called sensitive phases, individuals might be more receptive to such stress, for example, nutritional stress. However, little is known about how plastic responses differ between individuals experiencing nutritional stress early versus later in life or repeatedly, particularly in species with distinct ontogenetic niches. Moreover, there may be sex-specific differences due to distinct physiology. Larvae of the holometabolous turnip sawfly, Athalia rosae, consume leaves and flowers, while the adults take up nectar. We examined the effects of starvation experienced at different life stages on life-history, adult behavioural and metabolic traits to determine which stage may be more sensitive and how specific these traits respond. We exposed individuals to four nutritional regimes, either no, larval, adult starvation or starvation periods as larvae and adults. Larvae exposed to starvation had a prolonged development, and starved females reached a lower initial adult body mass than non-starved individuals. Males did not differ in initial adult body mass regardless of larval starvation, suggesting the ability to conform well to poor nutritional conditions. Adult behavioural activity was not significantly impacted by larval or adult starvation. Individuals starved as larvae had similar carbohydrate and lipid (i.e., fatty acid) contents as non-starved individuals, potentially due to building up energy reserves during development, while starvation during adulthood or at both stages led to reduced energy reserves in males. This study indicates that the sensitivity of a life stage to stress depends on the specific trait under consideration. Life-history traits were mainly affected by larval stress, while activity appeared to be more robust and metabolism mostly impacted by the adult conditions. Individuals differed in their ability to conform to the given environment, with the responses being life stage- and sex-specific.

Effects of Long-Term Serum Starvation on Autophagy, Metabolism, and Differentiation of Porcine Skeletal Muscle Satellite Cells.

This study investigated the effects of long-term serum starvation on autophagy, metabolism, and differentiation of porcine skeletal muscle satellite cells (SMSCs) and elucidated the role of autophagy in skeletal muscle development. Our findings provide a theoretical basis for improving meat production in domestic pigs. The SMSCs isolated and preserved in our laboratory were revived and divided into six groups based on the culture medium serum concentration to simulate varying levels of serum starvation: 20% serum (control group), 15% serum (mild serum starvation group), 5% serum (severe serum starvation group), and their autophagy inhibition groups supplemented with 3-methyladenine. After 96 h of culture, the apoptosis rate, mitochondrial membrane potential, reactive oxygen species, and ATP were measured to evaluate the effects of serum starvation on the SMSCs' metabolism. Additionally, the levels of autophagy-related proteins, autophagosomes, and autolysosomes were measured to investigate the impact of long-term serum starvation on autophagy. The expression of proteins associated with myogenic and adipogenic differentiation (MHC, MyoD1, peroxisome proliferator-activated receptor γ, and lipoprotein lipase) as well as lipid content were also determined to investigate the effects of long-term serum starvation on SMSC differentiation. The results showed that long-term serum starvation induced autophagy through the AMPK/mTOR signaling pathway, accelerated cell metabolism and apoptosis, exacerbated reactive oxygen species accumulation, and inhibited myogenic and adipogenic differentiation of SMSCs. Moreover, these effects were positively correlated with the level of serum starvation. In addition, serum starvation-induced autophagy moderately promoted the myogenic and adipogenic differentiation of SMSCs; however, these effects were insufficient to counteract the inhibition of cell differentiation by long-term serum starvation. This study provides insight into leveraging serum starvation as a stressor to regulate muscle growth and metabolism in domestic pigs.

Effect of Phosphate Starvation on Gene Expression in Komagataella phaffii Cells.

Phosphorus is a key nutrient for all organisms. The study of phosphate metabolism and its regulation is important for understanding the evolutionary processes of regulatory systems in eukaryotic cells. The methylotrophic yeast Komagataella phaffii is an efficient producer organism, and it is actively used in biotechnological production. The high practical importance of K. phaffii has stimulated active research to find new tools to work with this yeast and optimize its cultivation conditions. In this work, we observed the effect of phosphate starvation on gene expression in K. phaffii at the transcriptome level. Phosphate starvation had a significant effect on general cell metabolism. K. phaffii cells demonstrated a response to this macronutrient deficiency through an altered gene expression of carbon and amino acid metabolism. We observed the activation of phosphate and polyphosphate metabolism gene expression. In this case, there was a suppression of ribosome biogenesis genes and genes involved in fatty acid beta-oxidation and translation processes.

Effect of starvation and crowding on some physiological parameters of young common carp (Cyprinus carpio L. )

Fish frequently undergo stress during aquaculture or experimental operations, which can change any physiological parameter and have an impact on the success of rearing the fish or the outcomes of the research.The purpose of this study was to investigate how different stressors affected some physiological parameters of common carp (Cyprinus carpio L.). A total of 162 common carp with body weights ranging from 60.4 to 62.8 g which were evenly distributed in plastic aquaria were subjected to three stressor factors: crowding, starvation, and a combination of starvation and crowding for durations of 24, 72, and 144 hours. Cortisol levels were 167.55, 183.8, 212.8 nmol/L, and 222.65 nmol/L, respectively, for control, crowding, starvation and (crowding+starvation). Unlike haematocrit, which was consistently lower in starved fish, hemoglobin content did not appear to be influenced by starvation. Stressors such as starvation, crowding, and their combination had a substantial influence on typical automotive physiological measures such as cortisol level, blood glucose and hematocrit.

Nanozyme as Tumor Energy Homeostasis Disruptor to Augment Cascade Catalytic Therapy.

Breaking the balance of the tumor microenvironment and reshaping it sustainably remain major challenges in lung cancer treatment. Here, a "tumor energy homeostasis disruptor", the Cu2O@Au nanozyme was developed, which exhibits excellent glucose oxidase-like activity, enabling it to be used for starvation therapy and as a mimic peroxidase for chemodynamic therapy (CDT), producing •OH. Cu2O@Au nanozymes consume glucose at the tumor site to block the tumor's energy supply, produce H2O2 continuously, and lower the pH to enhance the efficiency of CDT, initiating a cascade reaction that leads to a storm of reactive oxygen species (ROS). Furthermore, Cu2O@Au nanozyme consumes glutathione and reduces the expression of the SLC7A11 (xCT) protein to decrease cancer cell uptake of cysteine, further enhancing the burst of ROS, resulting in lipid peroxidation in tumor cells and ultimately leading to ferroptosis. The excellent photothermal performance of Cu2O@Au can further enhance CDT. Additionally, Cu2O@Au nanozyme also has computed tomography (CT) and photothermal imaging capabilities. In conclusion, Cu2O@Au nanozymes, acting as tumor energy homeostasis disruptor, can effectively inhibit tumor growth and successfully achieve the synergistic effects of starvation therapy/CDT/photothermal therapy (PTT). This multifunctional nanozyme holds promise for providing valuable insights and therapeutic strategies for cancer treatment.

Effect of tryptophan starvation on inclusion membrane composition and chlamydial-host interactions.

Chlamydia is an obligate intracellular bacterial pathogen that develops within a membrane-bound vacuole called an inclusion. Throughout its developmental cycle, Chlamydia modifies the inclusion membrane (IM) with type III secreted (T3S) membrane proteins, known as inclusion membrane proteins (Incs). Via the IM, Chlamydia manipulates the host cell to acquire lipids and nutrients necessary for its growth. One key nutrient is tryptophan (Trp). As a Trp auxotroph, Chlamydia is very sensitive to Trp starvation and, in response to low Trp levels induced by the immune response, enters a viable but nonreplicating state called persistence. To maintain viability during persistence, Chlamydia must necessarily maintain both the integrity of the IM and its ability to modify host cell responses, but how Trp starvation affects IM composition and subsequent interactions with the host cell remains poorly understood. We hypothesize that, under Trp starvation conditions, Inc expression/stability or T3S function during persistence alters IM composition but that key host- Chlamydia interactions will be preserved. To examine host- Chlamydia interactions during persistence, we examined sphingomyelin, cholesterol, and transferrin trafficking to the inclusion, as well as localization of host proteins that bind to specific Incs. We identified IM composition changes during persistence by monitoring endogenous Inc abundance at the IM. Chlamydial T3S is generally functional during persistence. Specific changes in Inc composition in the IM can be linked to Trp content of a specific Inc or effector-specific defects in chlamydial T3S. Overall, our findings reveal that critical host- Chlamydia interactions are maintained during persistence mediated by Trp starvation.

Effect of Prolonged Starvation of Nacella concinna, Odontaster validus, and Sterechinus neumayeri on Their Body Composition and the Enrichment of the Aquatic Environment with Nitrogen and Phosphorus

The seasonal availability of food for Antarctic zoobenthic consumers affects, among other factors, the levels of excreted metabolites that can serve as a source of nitrogen (N) and phosphorus (P) for autotrophs. This study tested the effects of prolonged starvation on N and P excretion by Nacella concinna, Odontaster validus, and Sterechinus neumayeri, as well as changes in their body chemistry. In all animals starved for 65 days, a significant decrease in body protein content was observed (33% for S. neumayeri and approximately 23% for N. concinna and O. validus). Nitrogen excretion rates were higher than phosphorus, with mean values (in µmol N or P h−1 100 g−1) of 1.351 and 0.094 for N. concinna, 0.779 and 0.037 for O. validus, and 0.538 and 0.075 for S. neumayeri, respectively. Ammonium nitrogen accounted for 50% to 69% of total nitrogen, while total reactive phosphorus represented 35% to 42% of total phosphorus. The study confirmed the natural adaptation of zoobenthos to prolonged food scarcity and demonstrated that (i) protein was the primary energy source during starvation, (ii) excretion rates were negatively correlated with invertebrate body size and were higher for N than P, and (iii) the excreted N and P loads may serve as a source of nutrients for autotrophs and act as chemical signals in trophic chemoreception.

Magnetic Field Analysis for State of Health Monitoring of PEM Electrolyzer Stacks

The expected increase in the number of installed PEM electrolyzers during their industrialization in the upcoming years highlights the need for suitable non-destructive diagnostic methods for state of health monitoring and anomaly detection to ensure reliability and durability while reducing lifetime costs. The inner electrical current density distribution significantly impacts the efficiency and lifetime of a PEM electrolyzer stack. During operation, various degradation phenomena and inhomogeneities, including inhomogeneous water and cooling management, starvation effects, contact pressure, and delamination, influence its electric conductivity and current density distribution. These, in turn, affect the generated vectorial magnetic field distribution inside and outside the stack.This work examines the use of non-destructive magnetic field analysis (MFA) to identify changes in the outer magnetic field distribution and, thus, local current density distributions within PEM electrolyzer stacks. The magnetic field distribution is analyzed in all three spatial directions to trace electrical currents and identify electrical defects during different operating conditions. Accordingly, signatures in magnetic field images allow for the distinction between normal and abnormal system behavior. For initial investigations, creating a parameterized stack model using the finite element method (FEM) enabled the analysis of different stack geometries and their outer magnetic fields. The following examinations evaluated the effect of electric inhomogeneities on the magnetic field signatures, showing unique patterns depending on defect location and current density distribution. Both results were used to determine resolution limits, which enable the development of suitable sensor hardware and measurement concepts for industrial operating conditions. These concepts were initially tested and validated using a test stack designed to emulate the electrical behavior of an operational PEM electrolyzer stack without electrochemical reactions. Figure 1 shows one stylized measurement plane, along with the Bx, By, and Bz magnetic field component scans of the test stack in a non-defective state. Following these measurements, artificial defects are induced. After repeated experiments with an electrochemical operating stack, the work presents, compares, and discusses the resulting magnetic fingerprints of both stacks. Additionally, an overview of expected resolvable current-related defects is provided.Magnetic field simulations and measurements conducted on a PEM electrolyzer test stack show systematic differences depending on defect location and current density distribution, resulting in characteristic magnetic field images. In addition, comparative experiments with an operating stack are presented and discussed, determining the potential and limitations of the method. Furthermore, enhancing Magnetic Field Analysis for industrial applications using machine learning methods will be assessed. These initial results suggest that MFA is potentially useful as a non-destructive diagnostic state of health monitoring method for industrial PEM electrolyzer stacks. Figure 1

Microbiome-Metabolomics Analysis Insight into the Effects of Starvation and Refeeding on Intestinal Integrity in the Juvenile Largemouth Bass (Micropterus salmoides).

The effects of starvation and refeeding on the gut condition of juvenile largemouth bass (Micropterus salmoides) remain unclear. Therefore, our research aimed to explore these effects. Amylase and lipase activities were remarkably decreased in the starvation (ST) group, yet prominently increased in the refeeding (RE) group (p < 0.05). In addition to the malondialdehyde (MDA) level, catalase (CAT) and superoxide dismutase (SOD) activities were significantly upregulated in the ST group (p < 0.05) in marked contrast to those in the controls; however, the RE group showed no substantial variations in CAT and SOD activities or the MDA level (p > 0.05). During starvation, the expression of Nrf2-Keap1 pathway-associated genes was significantly upregulated (p < 0.05). The comparative levels of TNF-α, IL-1β, and IL-15 were highly increased, with the levels of TGF-β1 and IL-10 apparently downregulated in the ST group; in contrast, these levels were restored to their original values in the RE group (p < 0.05). In contrast to the controls, the ST group showed significantly lower height and width of the villi, muscle thickness, and crypt depth and a higher goblet cell number; however, these values were recovered to some extent in the RE group (p < 0.05). The dominant bacterial phyla in the intestines of both groups were Proteobacteria, Firmicutes, Bacteroidetes, Acidobacteria, and Actinobacteria, with marked inter-group differences in the genera Serratia and Lactobacillus. Metabolomics analysis showed that amino acid metabolism is disrupted during starvation and is restored after refeeding. In summary, this study expands our comprehension of the interaction between oxidative stress and antioxidant defenses among juvenile largemouth bass subjected to starvation and refeeding.

Biomimetic Single-Atom Nanozyme for Dual Starvation-Enhanced Breast Cancer Immunotherapy.

Cold exposure (CE) therapy is an innovative and cost-efficient cancer treatment that activates brown adipose tissue to compete for glucose uptake, leading to metabolic starvation in tumors. Exploring the combined antitumor mechanisms of CE and traditional therapies (such as nanocatalysis) is exciting and promising. In this study, a platelet membrane biomimetic single-atom nanozyme (SAEs) nanodrug (PFB) carrying bis-2-(5-phenylacetamido-1, 2, 4-thiadiazol-2-yl) ethyl sulfide (BPTES) is developed for use in cancer CE therapy. Owing to the platelet membrane modification, PFB can effectively target tumors. Upon entering cancer cells, the dual starvation effect induced by CE treatment and BPTES can significantly diminish intracellular glucose and ATP levels, resulting in a substantial reduction in cellular (glutathione) GSH, which can enhance the cytotoxic efficacy of reactive oxygen species generated by SAEs. This strategy not only boosts ROS production in tumors, but also strengthens immune responses, particularly by increasing memory T-cell abundance and suppressing distant tumor growth and tumor metastasis. Compared with SAEs therapy alone, this combined approach offers superior benefits for tumor immunotherapy. This study achieves a combination of CE and nanomedicines for the first time, providing new ideas for future nanomedicine combination therapy modalities.

"Terminal Anorexia", Treatment Refusal and Decision-Making Capacity.

Whether anorexic patients should be able to refuse treatment when this refusal potentially has a fatal outcome is a vexed topic. A recent proposal for a new category of "terminal anorexia" suggests criteria when a move to palliative care or even physician-assisted suicide might be justified. The author argues that this proposed diagnosis presents a false sense of certainty of the illness trajectory by conceptualizing anorexia in analogy with physical disorders and stressing the effects of starvation. Furthermore, this conceptualization is in conflict with the claim that individuals who meet the diagnostic criteria for terminal anorexia have decision-making capacity. It should therefore be rejected.

Effect of Starvation and Refeeding on Gamete Quality and Fertilization in Rainbow Trout (Oncorhynchus mykiss) Broodstock

In this study, the impact of starvation and refeeding on broodstocks was observed by examining quality parameters of gametes and fertilization. While the control group fish were fed every day, the male and female members of the group were fed one week apart and placed in starvation after a week of feeding. Weight gain in the control group was the highest. The feed conversion ratio was normal in all groups (0.9-1.3%). Relative fecundity was (935±62 eggs/kg) in control group females; it was found to be (1317±241 eggs/kg) in starving females and statistically different in the groups (p &amp;lt; .05). The egg diameter of the group receiving intermittent feeding for a week (3.36±0.2 mm) was found to be the lowest. All spermatological parameters were similar between groups, except for sperm volume. The most sperm count was seen in the group that received one-week intermittent feeding (46.9± 20 ml). The results of fertilization with the control female in the fertilization study based on male individuals showed similarity for the male individuals of the trial group, the highest fertilization rate was seen in fertilization using the control female and control male.

Starvation increases susceptibility to bacterial infection and promotes systemic pathogen proliferation in Drosophila melanogaster females

Defense against pathogens and parasites requires substantial investment of energy and resources on part of the host. This makes the host immune function dependent on availability and accessibility of resources. A resource deprived host is therefore expected to be more susceptible to infections, although empirical results do not always align with this prediction. Limiting host access to resources can additionally impact within-host pathogen numbers, either directly by altering the amount of resources available to the pathogens for proliferation or indirectly by altering the efficiency of the host immune system. We tested for the effects of host starvation (complete deprivation of resources) on susceptibility to bacterial pathogens, and within-host pathogen proliferation, in Drosophila melanogaster females. Our results show that starvation increases post-infection mortality of the host, but in a pathogen-specific manner. This increase in mortality is always accompanied by increased within-host pathogen proliferation. We therefore propose that starvation compromises host resistance to bacterial infections in Drosophila melanogaster females thereby increasing susceptibility to infections.

Unravelling the effects of short-term starvation and pH disturbances in stable volatile fatty acids production

The successful upscaling of anaerobic fermentation (AF) still relies on ensuring the stable production of volatile fatty acids (VFAs) in high concentrations and yields. The unforeseen events taking place at industrial scale can compromise the AF stability, thereby decreasing the cost-effectiveness of the process. To assess process stability against disturbances and identify AF failure indicators, this investigation explored the effect of starvation and pH control failure in a continuous reactor. The starvation disturbance did not affect AF performance and methanogenesis was not restored, confirming the relevance of selecting proper conditions (25 °C and pH 6.5) to ensure methanogenesis suppression. By contrast, the uncontrolled pH provoked a pH drop to 4.5, limiting the acidogenesis metabolisms and modifying the metabolites profile due to microbiome reshape. Lactobacillus, and members of Lactobacillaceae, Lactobacillales, and Bifidobacteriaceae dominated the microbiome in the pH disturbance, revealing lactic, succinic and oxalic acids as warning indicators of the acidogenesis failure. Nevertheless, the AF was completely recovered after the disturbances evidencing the microbiome robustness against pH range between 4.5 and 5.

Case study on the relationship between transmission of antibiotic resistance genes and microbial community under freeze-thaw cycle on cold-region dairy farm

Freeze-thaw cycle (FTC) is a naturally occurring phenomenon in high-latitude terrestrial ecosystems, which may exert influence on distribution and evolution of microbial community in the soil. The relationship between transmission of antibiotic resistance genes (ARGs) and microbial community was investigated upon the case study on the soil of cold-region dairy farm under seasonal FTC. The results demonstrated that 37 ARGs underwent decrease in the abundance of blaTEM from 80.4 % for frozen soil to 71.7 % for thawed soil, and that sul2 from 8.8 % for frozen soil to 6.5 % for thawed soil, respectively. Antibiotic deactivation was identified to be closely related to the highest relative abundance of blaTEM, and the spread of sulfonamide resistance genes (SRGs) occurred mainly via target modification. Firmicutes in frozen soil were responsible for dominating the abundance of ARGs by suppressing the native bacteria under starvation effect in cold regions, and then underwent horizontal gene transfer (HGT) among native bacteria through mobile genetic elements (MGEs). The TRB-C (32.6–49.1 %) and tnpA-06 (0.27–7.5 %) were significantly increased in frozen soil, while Int3 (0.67–10.6 %) and tnpA-04 (11.1–19.4 %) were up-regulated in thawed soil. Moreover, the ARGs in frozen soil primarily underwent HGT through MGEs, i.e. TRB-C and tnpA-06, with increased number of Firmicutes serving as carrier. The case study not only demonstrated relationship between transmission of ARGs and microbial community in the soil under practically relevant FTC condition, but also emphasized the importance for formulating better strategies for preventing FTC-induced ARGs in dairy farm in cold regions.

Simplified Wear Model for Power Cylinder under Engine Operating Conditions

A simple numerical approach is developed to predict the wear and friction of piston ring pack and cylinder liner during the break-in period and under transient speed conditions. In the model, a solution of mixed lubrications using the load-shearing concept is presented based on the selected elastic-plastic equations of asperity contacts in conjunction with well-established elastohydrodynamic equations. The model takes shear-thinning, thermal effects in elastohydrodynamic lubrication (EHL) and lubricant starvation effects into account. Modified Archard’s wear coefficient to describe the piston ring against cylinder liner wear is introduced. The approach is valid for the calculations of the asperity pressure at low values of the ratio of oil film thickness to combined roughness of the interacting surfaces, that is, less than 0.5. Applications are discussed, including association of piston side thrust force on wear and friction characteristics of piston ring/cylinder bore, gas blowby through the ring pack on the cylinder liner wear, a strong coating dependence for the piston ring wear, and wear distribution across the stroke under engine operating conditions. A good agreement between the experimental and analytical data indicates that the proposed model can be used to predict the wear and friction of the piston ring pack sliding against cylinder liner.