1,506 research outputs found
Selective Regulation of Cytoskeletal Dynamics and Filopodia Formation by Teleost Leukocyte Immune-Type Receptors Differentially Contributes to Target Capture During the Phagocytic Process
Phagocytosis evolved from a fundamental nutrient acquisition mechanism in primitive unicellular amoeboids, into a dynamic and complex component of innate immunity in multicellular organisms. To better understand the cellular mechanisms contributing to phagocytic processes across vertebrates, our research has focused on characterizing the involvement of innate immune proteins originally identified in channel catfish (Ictalurus punctatus) called leukocyte immune-type receptors (IpLITRs). These unique teleost proteins share basic structural as well as distant phylogenetic relationships with several immunoregulatory proteins within the mammalian immunoglobulin superfamily. In the present study, we use a combination of live-cell confocal imaging and high-resolution scanning electron microscopy to further examine the classical immunoreceptor tyrosine-based activation motif (ITAM)-dependent phagocytic pathway mediated by the chimeric construct IpLITR 2.6b/IpFcRγ-L and the functionally diverse immunoreceptor tyrosine-based inhibitory motif-containing receptor IpLITR 1.1b. Results demonstrate that IpLITR 1.1b-expressing cells can uniquely generate actin-dense filopodia-like protrusions during the early stages of extracellular target interactions. In addition, we observed that these structures retract after contacting extracellular targets to secure captured microspheres on the cell surface. This activity was often followed by the generation of robust secondary waves of actin polymerization leading to the formation of stabilized phagocytic cups. At depressed temperatures of 27°C, IpLITR 2.6b/IpFcRγ-L-mediated phagocytosis was completely blocked, whereas IpLITR 1.1b-expressing cells continued to generate dynamic actin-dense filopodia at this lower temperature. Overall, these results provide new support for the hypothesis that IpLITR 1.1b, but not IpLITR 2.6b/IpFcRγ-L, directly triggers filopodia formation when expressed in representative myeloid cells. This also offers new information regarding the directed ability of immunoregulatory receptor-types to initiate dynamic membrane structures and provides insights into an alternative ITAM-independent target capture pathway that is functionally distinct from the classical phagocytic pathways
The Validity and Reliability of the Garmin Instinct in Measuring Heart Rate, Energy Expenditure, and Steps During Skipping
As the use of wearable technology to monitor physical activity increases, assessment of the validity and reliability of these devices are needed. A popular device brand is Garmin. Although not a common physical activity, skipping can be included in dynamic warm-ups. PURPOSE: Therefore, the purpose of this study was to determine the validity and reliability of the Garmin Instinct in measuring caloric energy expenditure (EE), average heart rate (HR), and steps while skipping. METHODS: Ten participants (5 female, age: 27±9 years) skipped at a self-selected pace for five minutes. During that time, HR, EE, and steps were measured by the Polar H10, Cosmed K5, and manual counting, respectively. Two Garmin Instincts simultaneously tracked all three variables. A step was defined as any time the foot leaves and hits the ground (stride x 4). Data was input into Google Sheets and summary statistics, t-test with Bonferonni corrections, and mean absolute percentage error (MAPE) were calculated. Additional validity and reliability tests were run in jamovi, including Lin’s concordance correlation coefficient (CCC), TOST tests, Bland-Altman bias, coefficient of variation (CV), and intraclass correlation coefficient (ICC). The pre-established validity criteria are as follows: CCC \u3e 0.7 and MAPE \u3c 10%. The pre-established reliability criteria are as follows: CV \u3c 10% and ICC \u3e 0.7. RESULTS: The Garmin Instinct had a MAPE of 19.2%, 28.5%, and 53.2% for HR, EE, and steps, respectively. It had a CCC of .06, .21, and .01 for HR, EE, and steps, respectively. The 2-tailed paired t-tests with corrections for multiple comparisons was significant for HR and steps. The TOST tests were violated for all 3 measurements (HR, EE, and steps). Bland-Altman analysis produced a bias estimate of 34.0, 0.6, and 1100 for HR, EE, and steps, respectively. The Garmin produced a CV of 11.2%, 14.8%, and 6.6% for HR, EE, and steps, respectively. It produced an ICC of .51, .64, and .81 for HR, EE, and steps, respectively. CONCLUSION: The Garmin Instinct did not meet the pre-established validity criteria for any measure (HR, EE, or steps). However, it did meet the pre-established reliability criteria for steps but not for HR or EE. Therefore, the Garmin Instinct cannot be expected to produce accurate estimates of HR, EE, or steps during skipping
Whole genome sequencing of \u3ci\u3eMoraxella bovis\u3c/i\u3e strains from North America reveals two genotypes with different genetic determinants
Background: Moraxella bovis and Moraxella bovoculi both associate with infectious bovine keratoconjunctivitis (IBK), an economically significant and painful ocular disease that affects cattle worldwide. There are two genotypes of M. bovoculi (genotypes 1 and 2) that differ in their gene content and potential virulence factors, although neither have been experimentally shown to cause IBK. M. bovis is a causative IBK agent, however, not all strains carry a complete assortment of known virulence factors. The goals of this study were to determine the population structure and depth of M. bovis genomic diversity, and to compare core and accessory genes and predicted outer membrane protein profiles both within and between M. bovis and M. bovoculi.
Results: Phylogenetic trees and bioinformatic analyses of 36 M. bovis chromosomes sequenced in this study and additional available chromosomes of M. bovis and both genotype 1 and 2 M. bovoculi, showed there are two genotypes (1 and 2) of M. bovis. The two M. bovis genotypes share a core of 2015 genes, with 121 and 186 genes specific to genotype 1 and 2, respectively. The two genotypes differ by their chromosome size and prophage content, encoded protein variants of the virulence factor hemolysin, and by their affiliation with different plasmids. Eight plasmid types were identified in this study, with types 1 and 6 observed in 88 and 56% of genotype 2 strains, respectively, and absent from genotype 1 strains. Only type 1 plasmids contained one or two gene copies encoding filamentous haemagglutinin- like proteins potentially involved with adhesion. A core of 1403 genes was shared between the genotype 1 and 2 strains of both M. bovis and M. bovoculi, which encoded a total of nine predicted outer membrane proteins.
Conclusions: There are two genotypes of M. bovis that differ in both chromosome content and plasmid profiles and thus may not equally associate with IBK. Immunological reagents specifically targeting select genotypes of M. bovis, or all genotypes of M. bovis and M. bovoculi together could be designed from the outer membrane proteins identified in this study
Associations of Dietary Bioactive Compounds with Maternal Adiposity and Inflammation in Gestational Diabetes: An Update on Observational and Clinical Studies
Gestational diabetes mellitus (GDM) is a common complication of pregnancy that adversely affects maternal and offspring health. Maternal obesity, oxidative stress, and inflammation have been implicated in GDM. In non-pregnant adults, intakes of dietary bioactive compounds inversely associate with insulin resistance and inflammation. However, associations of dietary bioactive compounds with biomarkers of adiposity, antioxidant vitamin and mineral status, oxidative stress, and inflammation in GDM have not been fully elucidated. We addressed this gap by conducting a semi-quantitative review of observational studies and randomized controlled trials published between 2010 and 2020 and retrieved from Google Scholar, Medline, and PubMed. Our analysis revealed that women with GDM are more likely to consume a pro-inflammatory diet before pregnancy and tend to consume fewer antioxidant vitamins and minerals during pregnancy than healthy pregnant women. Women with GDM also have lower blood levels of vitamins A, C, and D and certain adipokines. Several dietary bioactive compounds were noted to improve antioxidant status and biomarkers of inflammation. The Dietary Approaches to Stop Hypertension (DASH) diet and soybean oligosaccharides increased antioxidant enzyme levels. Supplementing n-3 fatty acids, probiotics, synbiotics, and trace elements increased antioxidant enzymes and reduced hs-CRP and MDA. Improvements in inflammation by vitamin D may be contingent upon co-supplementation with other dietary bioactive compounds
Determining Validity and Reliability of Caloric Expenditure Recorded by Wearable Technology While Walking and Running
With growing interest in tracking exercise progress, wearable technology is increasingly popular. While heart rate and step count are typically accurate for consumer-available devices, research from our laboratory indicates that caloric expenditure is not. PURPOSE: The current investigation aimed to evaluate the validity and reliability of caloric expenditure in multiple wearable devices during a self-paced walk and run. METHODS: Ten participants were tested (5F, 5M, age = 26.9± 9.43 years, body mass = 72.64± 7.73 kg, height = 168.66± 9.37 cm). Participants were asked to wear 5 devices: 2 Garmin Instinct watches (one on each wrist), 2 Polar Vantage M2 watches, and a K5 portable metabolic analysis system (criterion measure). Data was collected from all devices while participants completed a 5-minute self-paced walk, followed by a 5-minute rest period, then a 5-minute self-paced run. Validity was evaluated using the mean absolute percent error (MAPE) with a threshold of below 10 percent and Lin’s Concordance Correlation Coefficient (CCC) with significance above 0.7. Reliability was evaluated using the Intraclass Correlation Coefficient (ICC) and Coefficient of Variation (CV). RESULTS: For validity, neither device met the predetermined threshold for MAPE or CCC (see results table for reference). For reliability, only the Polar device during the running condition returned consistent results for both measures. CONCLUSION: These results indicate neither brand of watch produced valid energy expenditure estimates. Reliability was also poor. This poses a challenge to people relying on wearable devices to keep an accurate, consistent log of caloric expenditure. Our research does not indicate that technology is keeping up with how rapidly it is being developed and sold to the public
Validity and Reliability of the Garmin Instinct in Measuring Heart Rate during Pickleball
Playing a racquet sport called pickleball is increasing in popularity every day in the United States. Garmin is a popular brand that manufactures wearable fitness trackers capable of measuring heart rate (HR). Because HR is a common way to determe exercise intensity, the validity and reliability of wearables to provide accurate HR during pickleball is important. PURPOSE: This study aimed to analyze and assess the validity and reliability of HR from the Garmin Instinct vs. Polar H10 (criterion) during pickleball. METHODS: Eleven adults (2 female, 8 male, 1 prefer not to disclose; age = 28.1 ± 9.2 years; height = 176.0 ± 8.0 cm; mass = 73.2 ± 13.4 kg) were recruited to participate via convenience sampling. Participants were asked to play alternating intervals of five minutes of pickleball interspersed with five minutes of rest while wearing two Garmin Instinct watches on the same wrist and a Polar H10 chest strap. Outcome measures were average and maximum HR, recorded in beats per minute (bpm). Mean Absolute Percent Error (MAPE) and Lin’s Concordance Correlation Coefficient (CCC) were used to assess validity; MAPE ≤ 5% and CCC ≥ 0.90. Coefficient of Variation (CV) were used to assess reliability; CV ≤ 10% and ICC ≥ 0.70. RESULTS: The Garmin Instinct did not meet the CCC threshold for validity of average or maximum HR but met the thresholds for both reliability tests for average and maximum HR (see Table 1). CONCLUSION: These results indicate that, in the present study, the Garmin Instinct was only reliable for measuring average and maximum HR. This is challenging for those who wish to track their HR while playing racquet sports such as pickleball because the Garmin Instinct did not provide accurate average or maximum HR
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AAPM medical physics practice guideline 10.a.: Scope of practice for clinical medical physics.
The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline (MPPG) represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiation requires specific training, skills, and techniques as described in each document. As the review of the previous version of AAPM Professional Policy (PP)-17 (Scope of Practice) progressed, the writing group focused on one of the main goals: to have this document accepted by regulatory and accrediting bodies. After much discussion, it was decided that this goal would be better served through a MPPG. To further advance this goal, the text was updated to reflect the rationale and processes by which the activities in the scope of practice were identified and categorized. Lastly, the AAPM Professional Council believes that this document has benefitted from public comment which is part of the MPPG process but not the AAPM Professional Policy approval process. The following terms are used in the AAPM's MPPGs: Must and Must Not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. Should and Should Not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances
Does Hand Use Affect Metabolic Measures During Pickleball
Pickleball is one of the fastest up and coming sports in the United States today. This low impact sport has the combined elements of Ping-Pong, tennis, and badminton. Pickleball can be played with the dominant hand (DH) or non-dominant (NDH). Though many people enjoy the sport, it is under-researched. The metabolic demands of pickleball are not clear, nor is whether the demands differ by the hand used. PURPOSE: The aim of this study was to determine the differences in metabolic measures while playing pickleball with the DH and NDH. METHODS: Eleven people were recruited via convenience sampling and participated (2 female, 8 males, 1 prefer not to disclose; age = 28.1 ± 9.2 years; height = 176.0 ± 8.0 cm; mass = 73.2 ± 13.4 kg). Participants were connected to a COSMED K5 portable metabolic analysis system. Outcome measures were VO2 (ml/kg/min), Metabolic Equivalents (METS), Percent of Calories from Fat (FAT%), Percent of Calories from Carbohydrate (CHO%), and Respiratory Quotient (RQ). Participants played for five minutes with one hand, rested, and played for five minutes with the other hand. The hand order was counterbalanced. Data were analyzed using a paired t-test with significance accepted at p ≤ 0.05. RESULTS: A significant difference was observed for VO2 (DH = 27.3 ± 4.2, NDH = 24.7± 4.4, p = 0.03) and METS (DH = 7.8 ± 1.2, NDH = 7.1 ± 1.3, p = 0.03). No difference was noted for RQ (DH = 0.84 ± 0.07, NDH = 0.82 ± 0.07, p = 0.2), FAT% (DH = 54.9 ± 22.1%, NDH = 62.4 ± 20.9%, p = 0.2), or CHO% (DH = 45.1 ± 22.1%, NDH = 37.6 ± 20.9% p = 0.2) CONCLUSION: Pickleball players consume more oxygen while playing with their dominant hand, but the difference is not reflected in other metabolic measures associated with substrate utilization. While playing pickleball with the dominant hand may confer an advantage from a skill and intensity perspective, there is no statistical advantage when considering the fuels used during the activity. The practical implications, however, should be further explored
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