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In all cell types, mitochondrial biogenesis is balanced with mitophagy to maintain a healthy mitochondrial pool that sustains specific energetic demands. Cell types that have a higher energetic burden, such as skeletal muscle cells and cardiomyocytes, will subsequently develop high mitochondrial volumes. In these cells, calcium influx during activity triggers cascades leading to activation of the co-transcriptional regulation factor PGC-1α, a master regulator of mitochondrial biogenesis, in a well-defined pathway. Despite the advantages in ATP production, high mitochondrial volumes might prove to be perilous, as it increases exposure to reactive oxygen species produced during oxidative phosphorylation. Mechanosensory hair cells are highly metabolically active cells, with high total mitochondrial volumes to meet that demand. However, the mechanisms leading to expansion and maintenance of the hair cell mitochondrial pool are not well defined. Calcium influx during mechanotransduction and synaptic transmission regulate hair cell mitochondria, leading to a possibility that similar to skeletal muscle and cardiomyocytes, intracellular calcium underlies the expansion of the hair cell mitochondrial volume. This review briefly summarizes the potential mechanisms underlying mitochondrial biogenesis in other cell types and in hair cells. We propose that hair cell mitochondrial biogenesis is primarily product of cellular differentiation rather than calcium influx, and that the hair cell high mitochondrial volume renders them more susceptible to reactive oxygen species increased by calcium flux than other cell types.

This narrative review evaluates strength or resistance training on cardiorespiratory endurance, blood pressure, contractile function, contractile protein synthesis rate, bone turnover, gait and balance, and neuromuscular adaptations in elderly populations. Seventy-eight studies spanning from 1999 through 2020 were reviewed. Database sources including PubMed, Science Direct, Web of Knowledge and Google Scholar were searched in accordance with the purpose of the study. A majority of the studies reported that resistance training reduces blood pressure and increases contractile functions, contractile protein synthesis rate, bone turnover, gait and balance, cardiorespiratory endurance, and neuromuscular adaptations in the elderly. Furthermore, combined training (CT), also known as concurrent training (strength plus endurance training) may also be as effective as traditional endurance training or traditional strength/resistance training alone for improving cardiorespiratory endurance and functional performance. According to the evaluation of studies included in this review, we concluded that training modalities that involve low-load, high velocity strength training combined with endurance training might be the best training strategy in improving cardiovascular fitness, functional capacity and musculoskeletal health in the elderly populations. Elderly people should be encouraged to participate in a concurrent training or a combination of strength and endurance training to delay, or even reverse the negative effects of aging. Article visualizations

N-methyl-d-aspartate receptors (NMDARs) are fundamental coincidence detectors of synaptic activity necessary for the induction of synaptic plasticity and synapse stability. Adjusting NMDAR synaptic content, whether by receptor insertion or lateral diffusion between extrasynaptic and synaptic compartments, could play a substantial role defining the characteristics of the NMDAR-mediated excitatory postsynaptic current (EPSC), which in turn would mediate the ability of the synapse to undergo plasticity. Lateral NMDAR movement has been observed in dissociated neurons; however, it is currently unclear whether NMDARs are capable of lateral surface diffusion in hippocampal slices, a more physiologically relevant environment. To test for lateral mobility in rat hippocampal slices, we rapidly blocked synaptic NMDARs using MK-801, a use-dependent and irreversible NMDAR blocker. Following a 5-min washout period, we observed a strong recovery of NMDAR-mediated responses. The degree of the observed recovery was proportional to the amount of induced blockade, independent of levels of intracellular calcium, and mediated primarily by GluN2B-containing NMDA receptors. These results indicate that lateral diffusion of NMDARs could be a mechanism by which synapses rapidly adjust parameters to fine-tune synaptic plasticity. NEW & NOTEWORTHY N-methyl-d-aspartate-type glutamate receptors (NMDARs) have always been considered stable components of synapses. We show that in rat hippocampal slices synaptic NMDARs are in constant exchange with extrasynaptic receptors. This exchange of receptors is mediated primarily by NMDA receptors containing GluN2B, a subunit necessary to undergo synaptic plasticity. Thus this lateral movement of synaptic receptors allows synapses to rapidly regulate the total number of synaptic NMDARs with potential consequences for synaptic plasticity.

The sweetpotato vine borer, Omphisa anastomosalis (Guenée), is a primarily Asian pest of sweetpotato, Ipomoea batatas L. Damage by O. anastomosalis infestation can cause root yield losses of 30%–50%. A binary sex pheromone for O. anastomosalis, consisting of Type I [(10E,14E)-10,14-hexadecadienal (E10,E14-16:Ald)] and Type II [(3Z,6Z,9Z)-3,6,9-tricosatriene (Z3,Z6,Z9-23:H)] components, was identified in Vietnam from extracts of female pheromone glands. A structurally similar Type II compound [(3Z,6Z,9Z)-3,6,9-docosatriene (Z3,Z6,Z9-22:H)], not recovered from female pheromone glands, was also found to synergize the attractiveness of the Type I component. Additional field work has been needed to determine whether these synergistic enhancements of attractiveness also occur in other parts of the geographical distribution of this moth species. Herein, results of studies are reported which document that both Z3,Z6,Z9-23:H and Z3,Z6,Z9-22:H also synergistically enhance male response to E10,E14-16:Ald in Hawaii sweetpotato field populations. Trap catch tends to be enhanced with increase of dose and lower Type I:Type II ratios. Among the compound doses and ratios tested, trap catch increased with the addition of the Type II component by over 13 times relative to traps baited with the Type I component alone, which significantly enhanced sweetpotato vine borer detection. Using a 2.0 mg: 4.0 mg Type I: Type II loading, there was continued catch over 12 wk, during which time the Type I component weathered at a faster rate than the Type II component. This binary sex pheromone seems to have promise for both monitoring and suppression of field populations of O. anastomosalis throughout its geographical range.

This study provides a protocol for the isolation of high-quality DNA from sweetpotato weevils (Cylas formicarius elegantulus (Summers)) collected from pheromone-baited aerial funnel traps. This study was based on our discovery that a 2-wk collection interval of sweetpotato weevils from pheromone traps did not permit isolation of intact high-quality genomic DNA. To test the effect of collection methods, i.e., sample collection interval and preservation method, on quality of isolated DNA, we placed freshly killed male sweetpotato weevils into aerial funnel traps in the field and removed subsamples at several times thereafter. DNA yield from freshly isolated (day = 0) samples was significantly greater than samples preserved in 70% ethanol or at -20°C, whereas there was no difference between 70% ethanol and -20°C storage. Likewise, DNA yield from freshly isolated (day = 0) samples was significantly greater than for later sampling times. Quality assessment of genomic DNA through gel electrophoresis and polymerase chain reaction (PCR) indicated isolation of high molecular weight DNA for all samples collected at t ≤ 7 d, but that DNA quality was degraded by 14 d. Our goal was to develop a reliable method for isolation of genomic DNA from field-collected sweetpotato weevil suitable for direct use in PCR. We discovered that it is critical to collect specimens from traps at an interval of 1 wk or less. Our findings allow for scheduling of sampling at reasonable intervals without the need for special materials. This has the added benefit of allowing individuals without special training to collect and prepare sweetpotato weevil specimens for genetic studies.

Bactrocera latifrons (Hendel) (Diptera: Tephritidae) is a pest fruit fly species native to Oriental Asia which has invaded and established in Hawaii and Tanzania and has been recovered in detection trapping in California. It is largely non-responsive to the male lures cuelure and methyl eugenol. Alpha-ionol + cade oil is a moderately effective male B. latifrons attractant, but is not as attractive as cuelure or methyl eugenol are to other fruit fly species. An improved attractant is therefore desired. With the recent success in finding other non-responsive fruit fly species attracted to isoeugenol, methyl-isoeugenol, or dihydroeugenol in Australia and other countries, we wanted to assess whether B. latifrons might also respond to these “eugenol analogs.” Working with wild B. latifrons populations in Hawaii, we assessed the relative catch of B. latifrons in traps baited with the eugenol analogs with catch in traps baited with alpha-ionol, alpha-ionol + cade oil, or alpha-ionol + eugenol. Catch was significantly higher in traps baited with alpha-ionol + cade oil relative to traps with any of the other baits. There was, though, some male B. latifrons catch in traps baited with dihydroeugenol or isoeugenol but none in traps baited with methyl-isoeugenol.

Bactrocera cucurbitae (Coquillett) is a tephritid fruit fly native to the Indo-Malayan region. Its distribution, though, has extended to include Africa, temperate Asia, and a number of Pacific islands. It became established in Japan in 1919 in the Yaeyama Islands and spread north in the Southwestern Islands of Japan. It was subsequently eradicated from these islands by an eradication program that extended from 1972 to 1993. As part of an effort to develop a worldwide database on the status of fruits as hosts of melon fly, the infestation data gathered from host fruits collected in this eradication program, before the initiation of suppression activities, are summarized here. Bactrocera cucurbitae infestation was documented in 24 plant taxa of four plant families (Caricaceae, Cucurbitaceae, Moraceae, and Solanaceae), with the following four new hosts identified: Ficus erecta Thunb., F. pumila L. (Moraceae), Solanum erianthum D. Don (Solanaceae), and Zehneria liukiuensis Jeffrey ex Walker (Cucurbitaceae).