4,060 research outputs found
The effect of genetic background on phosphorus utilization for growth and bone integrity in pigs
Concern over the environmental impact of phosphate (P) excretion from pig production has led to reduced dietary P supplementation to these animals. These reductions may cause minor dietary P deficiency, a problem also seen in segments of the human populace. To examine how genetics influences P utilization, ninety-four gilts sired by two different genetic lines (PIC337 and PIC280) were fed either a P adequate diet or a 20% P deficient diet for 14 wk. Blood samples were collected and BW recorded monthly following an overnight fast. Upon completion of the study, radial bones with attached ulnae, intermediate carpals, and kidney tissue samples were collected. After 12 wk on the experimental diets, an additional 28 pigs (approximately 100 kg BW) produced by the same breeding strategy as described above, were moved into individual stainless steel metabolism crates (1.2 m x 2.4 m). Twice daily, feces and urine were collected from each metabolism crate for P balance analysis. Dietary treatment, sire, and their interaction significantly affected plasma 1, 25 (OH) 2 vitamin D and PTH concentrations, growth performance, bone strength, and gene expression in the kidney. The PIC337 sired pigs consumed more feed and gained more weight than their PIC280 sired counterparts (P \u3c 0.05). Regardless of sire line, pigs fed the P deficient diet had lower (P \u3c 0.05) plasma P concentrations and were less efficient at converting feed to BW (P \u3c 0.05). The P deficient pigs had increased (P \u3c 0.05) plasma concentrations of 1, 25 (OH)2 vitamin D and decreased concentrations of PTH after 4 wk. While plasma 1, 25 (OH)2 vitamin D concentrations were elevated (P \u3c 0.05) in all the P deficient animals, this increase was larger among the PIC337 sired pigs. As expected, P deficiency resulted in weaker bones with lower percent ash (P \u3c 0.05). Among the P adequate pigs, the bones of PIC337 sired pigs were stronger (P \u3c 0.05) and had higher (P \u3c 0.05) ash percentage compared to PIC280 sired pigs. Increased (P \u3c 0.05) levels of the CYP27B1 and PTHR mRNA were seen in P deficient pigs. Those animals housed in metabolism crates fed the P deficient diet had lower dietary P intakes, as well as lower fecal P excretion compared to pigs fed the P adequate diet (P \u3c 0.01), though there were no significant differences based on sire line or the interaction of sire line and dietary P in any of the P balance indices measured. These data suggest differing mechanisms of regulation of P utilization between these genetic lines.;In order to examine the impact of a single nucleotide polymorphism in the calcitonin receptor gene (CALCR) previously shown to be associated with bone integrity on P utilization in growing pigs, forty-two gilts were fed either a P adequate diet or a 20% P deficient diet for 14 wk. Plasma P concentrations of animals receiving the adequate diet were higher than their deficient counterparts at 8 wk and subsequent samplings until trial completion (P \u3c 0.05). P adequacy also resulted in increased concentrations of 1, 25 (OH)2 vitamin D and decreased PTH concentrations at 8 wk (P \u3c 0.05). P deficiency reduced bone strength and mineral content, regardless of genotype (P \u3c 0.05). Among pigs fed the P adequate diet, the 11 and 22 genotypes had higher bone modulus and ash percentage compared to their P deficient counterparts (P \u3c 0.05). However, these differences were not observed within animals having the 22 genotype. Neither dietary treatment nor CALCR genotype effected growth performance. These data suggest that this CALCR SNP is associated with the regulation of P utilization. Elucidating the genetic mechanisms responsible for P utilization would have important implications to for both animal and human health
Recommended from our members
Application of the Moore rearrangement to the synthesis of 1,4-dioxygenated xanthones and efforts toward the total synthesis of lundurine B
textA novel application of the Moore rearrangement was successfully developed and applied to the synthesis of 1,4-dioxygenated xanthones that would have been difficult to obtain otherwise. The 1,4-dioxygenated xanthone moiety is found in several naturally occurring, biologically active compounds. Several methods by which to obtain the 1,4-dioxygenated xanthone core have been reported; however, high step counts, low yields, and harsh reaction conditions preclude the use of these methods to complex xanthone natural products. Using the Moore rearrangement as a key step in the synthetic sequence has allowed us to prepare several xanthone natural products quickly and more efficiently than what is possible with the prior art.
Using the Martin group’s prior experience with the application of ring closing metathesis (RCM) to the field of alkaloid natural product synthesis, the preparation of lundurine B was undertaken. Key features of the proposed synthesis to lundurine B include the formation of a cyclopropane ring by the formation pyrazoline intermediate via [3+2] dipolar cycloaddition followed by dinitrogen extrusion. A second key step in the proposed sequence to lundurine B is a double RCM to form a five- and eight-membered ring in a single operation. While double RCM strategies have been applied to several elegant natural product syntheses, the formation of a five- and eight-membered ring in a single sequence has not been reported. Should the double RCM strategy prove successful for lundurine B, the conditions could in principle be applied to other structurally related natural products.Chemistr
Middle and elementary school students’ changes in self-determined motivation in a basketball unit taught using the Tactical Games Model
Studies examining student motivation levels suggest that this is a significant factor in students’ engagement in physical education and may be positively affected when teachers employ alternative pedagogical models such as game-centered approaches (GCAs). The aim of this study was to investigate changes in self-determined motivation of students as they participated in a GCA-basketball unit taught using the Tactical Games Model (TGM). Participants were 173 students (84 girls), 79 middle school (45 girls) and 94 (39 girls) elementary school students from four seventh and five fourth/fifth grade co-educational classes. Two teachers taught 32 (middle) and 33 (elementary) level one TGM basketball lessons. Need satisfaction and self-determined motivation data were collected using a previously validated instrument, while lesson context and teacher behavior data were recorded using systematic observation instruments. Repeated measures MANOVAs were employed to examine pre-posttest differences. Results revealed a significant main effect for time in need satisfaction for both middle (relatedness increased) and elementary school students (autonomy decreased) and a significant main effect in self-determined motivation for middle school students only (introjected regulation, external regulation, and amotivation all increased). Approximately 48%/42% (middle/elementary) of lesson time was game play, 22%/22% skill practice, 17%/17% management, and 13%/19% knowledge. The primary teacher behaviors used were instruction, management, specific observation, corrective feedback and modelling. Results indicate that it is important for future research to pay greater attention to the contextual factors associated with the application of the TGM, such as the students’ previous exposure to TGM lessons, and the teachers’ training and experience in utilizing the TGM. Indeed, results of the present study demonstrate that a longer-term commitment to the TGM is necessary to reduce controlling teacher behaviors, which will lead to positive changes in students’ need satisfaction and self-determined motivation. Future research is therefore needed to embrace this challenge to provide an increased evidence-base for GCAs such as the TGM
Biological Control of the Raspberry Eriophyoid Mite Phyllocoptes gracilis Using Entomopathogenic Fungi
There is an urgent need to develop biological control methods against the eriophyoid mite, Phyllocoptes gracilis, which causes significant losses in organic raspberry production in Europe. The use of entomopathogenic fungi (EF) is a sustainable alternative to conventional chemical pesticides, reducing the risks of pesticide resistance and other negative environmental impacts of agriculture. The objective of this study was to assess the pathogenicity of three strains of EF, two of Beauveria bassiana and one of Metarhizium anisopliae, on P. gracilis under laboratory conditions. Fungal spore suspensions (1 × 107 spores per mL) were sprayed on detached leaves infested with P. gracilis. Treated mites were kept under controlled conditions (25 ± 3 °C, 72 ± 10% relative humidity and photoperiod of 16:8 (light/dark)) and mite mortality was assessed three, five and seven days after inoculation. At all three measurement points (days after inoculation), the mortality of P. gracilis was highest for B. bassiana strain BB 1.1 and M. anisopliae strain MA 10.1. Our data demonstrate that EFs are promising candidates for the development of biological control agents against P. gracilis in raspberry crops
High Resolution Helioseismic Imaging of Subsurface Structures and Flows of A Solar Active Region Observed by Hinode
We analyze a solar active region observed by the Hinode CaII H line using the
time-distance helioseismology technique, and infer wave-speed perturbation
structures and flow fields beneath the active region with a high spatial
resolution. The general subsurface wave-speed structure is similar to the
previous results obtained from SOHO/MDI observations. The general subsurface
flow structure is also similar, and the downward flows beneath the sunspot and
the mass circulations around the sunspot are clearly resolved. Below the
sunspot, some organized divergent flow cells are observed, and these structures
may indicate the existence of mesoscale convective motions. Near the light
bridge inside the sunspot, hotter plasma is found beneath, and flows divergent
from this area are observed. The Hinode data also allow us to investigate
potential uncertainties caused by the use of phase-speed filter for short
travel distances. Comparing the measurements with and without the phase-speed
filtering, we find out that inside the sunspot, mean acoustic travel times are
in basic agreement, but the values are underestimated by a factor of 20-40%
inside the sunspot umbra for measurements with the filtering. The initial
acoustic tomography results from Hinode show a great potential of using
high-resolution observations for probing the internal structure and dynamics of
sunspots.Comment: accepted for publication in Ap
Evaluating the Intra-Rater and Inter-Rater Reliability of Fixed Tension Scale Instrumentation for Determining Isometric Neck Strength
International Journal of Exercise Science 14(3): 563-577, 2021. PURPOSE: The purpose of this study was to evaluate the reliability of a fixed tension scale instrumentation, comparing the intra-rater and inter-rater reliability between seating and standing measurement techniques. Instrumentation developed from this study will be utilized to assess isometric neck strength in future studies comparing neck strengthening protocols. METHODS: Isometric neck strength for eight movements (cervical/capital flexion, cervical/capital extension, left/right lateral flexion, left/right cervical rotation) as well as anthropometric measurements were evaluated for thirty-one participants through the use of a novel neck strength assessment protocol. RESULTS: The fixed tension scale instrumentation and methods used in this study demonstrated good to excellent intra-rater reliability (ICC range from 0.78 to 0.97) as well as moderate to excellent inter-rater reliability (ICC range from 0.73 to 0.91) for both measurement techniques. PRACTICAL APPLICATIONS: This study will provide foundational knowledge for the reliable assessment of neck strength. Additionally, the findings will provide a cost-effective, portable, and reliable instrument for measuring isometric neck strength. CONCLUSIONS: Seated and standing measurement techniques demonstrated similar intra and inter-rater reliability. Inter-rater reliability tended to be lower with motions (capital flexion and extension) that required the participants to face directly towards or away from the instrumentation. This could be due to participant positioning or unfamiliarity with those specific movements. The assessment protocol utilized in this study demonstrated comparable inter-rater reliability to another cost-effective method for evaluating isometric neck strength
The Effects of Species Exposure on Chemical Communication Behavior in Beetles
The Tribolium castaneum genome sequence contains a large number of odorant receptor (Or) genes when compared to the olfactory genomes of other insects (Engsontia et al., 2007). Evolved populations of the red flour beetle differ in their ability to detect chemical senses (Boake & Wade, 1984). Red flour beetles have been noted to release compounds via glands on their femurs (Olsson et al., 2006). This study observes the effects of chemical communication on behavior in beetles by comparing the response of the red flour beetles to areas predisposed to the chemical communication of other species. The purpose of this research is to study the effects of chemical communication in beetles by comparing the behavior of beetles exposed to life with only members of their own species to life in a group setting exposed to other species. If members of the species, Tribolium castaneum, were exposed to living with other species of beetles, then these beetles would be more likely to be present in areas predisposed to the other species. When accounting for edge behavior tendencies in beetles, this study observed that 80% of the tested individuals from the single species environment visited the red flour beetle chemical communication patch, while only 50% of individuals exposed to the group of multiple species were found on the patch chemically marked by species of red flour beetles. Results of this study support the notion that living alongside other species likely influences chemical communication preferences in beetles
A Case Study: Examining Biological Sex Differences in a 14-Week Neck Strength Protocol for Optimal Neuromuscular Indicators to Reduce the Incidence of Traumatic Brain Injury
Topics in Exercise Science and Kinesiology Volume 4: Issue 1, Article 9, 2023. The primary aim of this research was to analyze potential biological sex differences to determine if a variation in dynamic and isometric neck strength existed following a 14-week novel neck strengthening protocol. College-aged healthy participants who did not have a previous history of head or neck trauma were recruited for this study. A pre- and post-assessment was conducted to gather initial isometric and dynamic neck strength values. The neck strengthening intervention utilized a novel dynamic neck strength device for 14-weeks. 14-week neck strength protocol used in this study did increase dynamic and isometric neck strength in participants. After analysis, the authors discovered an increased gain in dynamic neck strength in males over females. According to the pre- and post-assessment data, males gained an extra 8.821 lbs/rev of clockwise strength and 8.135 lbs/rev of counterclockwise strength over females. The change over time (COT) values revealed males gained an extra 3.69 lb./rev of rate of force development (RFD) in the clockwise direction and 3.92 lb./rev of rate of force development in the counterclockwise direction. There was no statistical difference in isometric strength gain in males versus females; however, both groups improved. Dynamic and isometric neck strength increased for all participants after the 14-week neck strength protocol. Males exhibited a greater increase in dynamic neck strength. Extra gain in male dynamic neck strength may be due to differences between male and female dynamic neck musculature size, abundance of type II muscle fiber type, or rate of adaptation
- …