On-disc observations of flux rope formation prior to its eruption

Coronal mass ejections (CMEs) are one of the primary manifestations of solar activity and can drive severe space weather effects. Therefore, it is vital to work towards being able to predict their occurrence. However, many aspects of CME formation and eruption remain unclear, including whether magnetic flux ropes are present before the onset of eruption and the key mechanisms that cause CMEs to occur. In this work, the pre-eruptive coronal configuration of an active region that produced an interplanetary CME with a clear magnetic flux rope structure at 1 AU is studied. A forward-S sigmoid appears in extreme-ultraviolet (EUV) data two hours before the onset of the eruption (SOL2012-06-14), which is interpreted as a signature of a right-handed flux rope that formed prior to the eruption. Flare ribbons and EUV dimmings are used to infer the locations of the flux rope footpoints. These locations, together with observations of the global magnetic flux distribution, indicate that an interaction between newly emerged magnetic flux and pre-existing sunspot field in the days prior to the eruption may have enabled the coronal flux rope to form via tether-cutting-like reconnection. Composition analysis suggests that the flux rope had a coronal plasma composition, supporting our interpretation that the flux rope formed via magnetic reconnection in the corona. Once formed, the flux rope remained stable for two hours before erupting as a CME

Constraints on Jupiters from Observations of Galactic bulge microlensing events during 2000

Peer reviewe

Self-consistent solutions of canonical proper self-gravitating quantum systems

Generic self-gravitating quantum solutions that are not critically dependent on the specifics of microscopic interactions are presented. The solutions incorporate curvature effects, are consistent with the universality of gravity, and have appropriate correspondence with Newtonian gravitation. The results are consistent with known experimental results that indicate the maintenance of the quantum coherence of gravitating systems, as expected through the equivalence principle.Comment: 13 pages, 7 figure

Individualised internal and external training load relationships in elite wheelchair rugby players

Aim: The quantification and longitudinal monitoring of athlete training load (TL) provides a scientific explanation for changes in performance and helps manage injury/illness risk. The aim of the present study was to establish the relationship between measures of internal (heart rate (HR) and session RPE (sRPE)) and external TL specific to wheelchair rugby (WR). Methods: Fourteen international WR athletes (age = 29 ± 7 yrs; body mass = 58.9 ± 10.9 kg) were monitored during 18 training sessions over a 3 month period. Activity profiles were collected during each training session using a radio-frequency based indoor tracking system. External TL was quantified by total distance (m) covered as well as time spent and distance covered in a range of classification-specific arbitrary speed zones. Banister’s TRIMP, Edwards’s summated HR zone (SHRZ) and Lucia’s TRIMP methods were used to quantify physiological internal TL. sRPE was calculated as the product of session duration multiplied by perceived exertion using the Borg CR10 scale. Relationships between external and internal TL were examined using correlation coefficients and the 90% confidence intervals (90% CI). Results: sRPE (r=0.59) and all HR-based (r >0.80) methods showed large and very large relationships with the total distance covered during training sessions, respectively. Large and very large correlations (r =0.56-0.82) were also observed between all measures of internal TL and times spent and distances covered in low and moderate intensity speed zones. HR-based methods showed very large relationships with time (r=0.71-0.75) and distance (r=0.70-0.73) in the very high speed zone and a large relationship with the number of high intensity activities performed (r=0.56-0.62). Weaker relationships (r=0.32–0.35) were observed between sRPE and all measures of high intensity activity. A large variation of individual correlation co-efficient was observed between sRPE and all external TL measures. Conclusion: The current findings suggest that sRPE and HR-based internal TL measures provide a valid tool for quantifying volume of external TL during WR training but may underestimate high intensity activities. It is recommended both internal and external TL measures are employed for the monitoring of overall TL during court-based training in elite WR athletes

A comparison of speed profiles during training and competition in elite wheelchair rugby players

Purpose: To investigate the speed profiles of individual training modes in comparison to wheelchair rugby (WCR) competition across player classifications. Methods: Speed profiles of fifteen international WCR players were determined using a radio-frequency based indoor tracking system. Mean and peak speed (m∙s-1), work-rest ratios, the relative time spent (%)and the number of high speed activities performed were measured across training sessions (n = 464) and international competition (n = 34). Training was classified into one of four modes: conditioning (n = 71), skill-based (n = 133), game related (n = 151) and game-simulation drills (n = 109). Game-simulation drills were further categorised by the structured duration, which were 3-minute game-clock (n = 44), 8-minute game-clock (n = 39), and 10-minute running-clock (n = 26). Players were grouped by their International Wheelchair Rugby Federation classification as either low-point (≤ 1.5; n = 8) or high-point players (≥ 2.0; n = 7). Results: Conditioning drills were shown to exceed the demands of competition, irrespective of classification (P ≤ 0.005; effect size [ES] = 0.6-2.0). Skill-based and game related drills under-represented the speed profiles of competition (P ≤ 0.005; ES = 0.5-1.1). Mean speed and work-rest ratios were significantly lower during 3- and 8-minute game simulation drills in relation to competition (P ≤ 0.039; ES = 0.5-0.7). However, no significant differences were identified between the 10-minute running-clock and competition. Conclusions: Although game-simulation drills provided the closest representation of competition, the structured duration appeared important since the 10-minute running-clock increased training specificity. Coaches can therefore modify the desired training response by making subtle changes to the format of game-simulation drills

Individualised internal and external training load relationships in elite wheelchair rugby players

Aim: The quantification and longitudinal monitoring of athlete training load (TL) provides a scientific explanation for changes in performance and helps manage injury/illness risk. The aim of the present study was to establish the relationship between measures of internal (heart rate (HR) and session RPE (sRPE)) and external TL specific to wheelchair rugby (WR). Methods: Fourteen international WR athletes (age = 29 ± 7 yrs; body mass = 58.9 ± 10.9 kg) were monitored during 18 training sessions over a 3 month period. Activity profiles were collected during each training session using a radio-frequency based indoor tracking system. External TL was quantified by total distance (m) covered as well as time spent and distance covered in a range of classification-specific arbitrary speed zones. Banister’s TRIMP, Edwards’s summated HR zone (SHRZ) and Lucia’s TRIMP methods were used to quantify physiological internal TL. sRPE was calculated as the product of session duration multiplied by perceived exertion using the Borg CR10 scale. Relationships between external and internal TL were examined using correlation coefficients and the 90% confidence intervals (90% CI). Results: sRPE (r=0.59) and all HR-based (r >0.80) methods showed large and very large relationships with the total distance covered during training sessions, respectively. Large and very large correlations (r =0.56-0.82) were also observed between all measures of internal TL and times spent and distances covered in low and moderate intensity speed zones. HR-based methods showed very large relationships with time (r=0.71-0.75) and distance (r=0.70-0.73) in the very high speed zone and a large relationship with the number of high intensity activities performed (r=0.56-0.62). Weaker relationships (r=0.32–0.35) were observed between sRPE and all measures of high intensity activity. A large variation of individual correlation co-efficient was observed between sRPE and all external TL measures. Conclusion: The current findings suggest that sRPE and HR-based internal TL measures provide a valid tool for quantifying volume of external TL during WR training but may underestimate high intensity activities. It is recommended both internal and external TL measures are employed for the monitoring of overall TL during court-based training in elite WR athletes

A comparison of system monitoring methods, passive network monitoring and kernel instrumentation

This paper presents the comparison of two methods of system monitoring, passive network monitoring and kernel instrumentation. The comparison is made on the basis of passive network monitoring being used as a replacement for kernel instrumentation in some situations. Despite the fact that the passive network monitoring technique is shown to perform poorly as a direct replacement for kernel instrumentation, this paper indicates the areas where passive network monitoring could be used to the greatest advantage and presents methods by which the discrepancies between results of the two techniques could be minimised

Reconstitution of Targeted Deadenylation by the Ccr4-Not Complex and the YTH Domain Protein Mmi1

SummaryCcr4-Not is a conserved protein complex that shortens the 3′ poly(A) tails of eukaryotic mRNAs to regulate transcript stability and translation into proteins. RNA-binding proteins are thought to facilitate recruitment of Ccr4-Not to certain mRNAs, but lack of an in-vitro-reconstituted system has slowed progress in understanding the mechanistic details of this specificity. Here, we generate a fully recombinant Ccr4-Not complex that removes poly(A) tails from RNA substrates. The intact complex is more active than the exonucleases alone and has an intrinsic preference for certain RNAs. The RNA-binding protein Mmi1 is highly abundant in preparations of native Ccr4-Not. We demonstrate a high-affinity interaction between recombinant Ccr4-Not and Mmi1. Using in vitro assays, we show that Mmi1 accelerates deadenylation of target RNAs. Together, our results support a model whereby both RNA-binding proteins and the sequence context of mRNAs influence deadenylation rate to regulate gene expression

Modifications of the Fine Structure of the Incisor Pulp of the Guinea Pig during Fxperimental Scurvy

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68076/2/10.1177_00220345660450030301.pd

Voluntary running exercise protects against sepsis-induced early inflammatory and pro-coagulant responses in aged mice

Background: Despite many animal studies and clinical trials, mortality in sepsis remains high. This may be due to the fact that most experimental studies of sepsis employ young animals, whereas the majority of septic patients are elderly (60 - 70 years). The objective of the present study was to examine the sepsis-induced inflammatory and pro-coagulant responses in aged mice. Since running exercise protects against a variety of diseases, we also examined the effect of voluntary running on septic responses in aged mice. Methods: Male C57BL/6 mice were housed in our institute from 2-3 to 22 months (an age mimicking that of the elderly). Mice were prevented from becoming obese by food restriction (given 70-90% of ad libitum consumption amount). Between 20 and 22 months, a subgroup of mice ran voluntarily on wheels, alternating 1-3 days of running with 1-2 days of rest. At 22 months, mice were intraperitoneally injected with sterile saline (control) or 3.75 g/kg fecal slurry (septic). At 7 h post injection, we examined (1) neutrophil influx in the lung and liver by measuring myeloperoxidase and/or neutrophil elastase in the tissue homogenates by spectrophotometry, (2) interleukin 6 (IL6) and KC in the lung lavage by ELISA, (3) pulmonary surfactant function by measuring percentage of large aggregates, (4) capillary plugging (pro-coagulant response) in skeletal muscle by intravital microscopy, (5) endothelial nitric oxide synthase (eNOS) protein in skeletal muscle (eNOS-derived NO is putative inhibitor of capillary plugging) by immunoblotting, and (6) systemic blood platelet counts by hemocytometry. Results: Sepsis caused high levels of pulmonary myeloperoxidase, elastase, IL6, KC, liver myeloperoxidase, and capillary plugging. Sepsis also caused low levels of surfactant function and platelet counts. Running exercise increased eNOS protein and attenuated the septic responses. Conclusions: Voluntary running protects against exacerbated sepsis-induced inflammatory and pro-coagulant responses in aged mice. Protection against pro-coagulant responses may involve eNOS upregulation. The present discovery in aged mice calls for clinical investigation into potential beneficial effects of exercise on septic outcomes in the elderly