Nuclear Charge Radius of ^{26m}Al and Its Implication for V_{ud} in the Quark Mixing Matrix

Collinear laser spectroscopy was performed on the isomer of the aluminium isotope ^{26m}Al. The measured isotope shift to ^{27}Al in the 3s^{2}3p ^{2}P_{3/2}^{○}→3s^{2}4s ^{2}S_{1/2} atomic transition enabled the first experimental determination of the nuclear charge radius of ^{26m}Al, resulting in R_{c}=3.130(15)  fm. This differs by 4.5 standard deviations from the extrapolated value used to calculate the isospin-symmetry breaking corrections in the superallowed β decay of ^{26m}Al. Its corrected Ft value, important for the estimation of V_{ud} in the Cabibbo-Kobayashi-Maskawa matrix, is thus shifted by 1 standard deviation to 3071.4(1.0) s.

Human skeletal muscle tissue chip autonomous payload reveals changes in fiber type and metabolic gene expression due to spaceflight

Microphysiological systems provide the opportunity to model accelerated changes at the human tissue level in the extreme space environment. Spaceflight-induced muscle atrophy experienced by astronauts shares similar physiological changes to muscle wasting in older adults, known as sarcopenia. These shared attributes provide a rationale for investigating molecular changes in muscle cells exposed to spaceflight that may mimic the underlying pathophysiology of sarcopenia. We report the results from three-dimensional myobundles derived from muscle biopsies from young and older adults, integrated into an autonomous CubeLab™, and flown to the International Space Station (ISS) aboard SpaceX CRS-21 as part of the NIH/NASA funded Tissue Chips in Space program. Global transcriptomic RNA-Seq analyses comparing the myobundles in space and on the ground revealed downregulation of shared transcripts related to myoblast proliferation and muscle differentiation. The analyses also revealed downregulated differentially expressed gene pathways related to muscle metabolism unique to myobundles derived from the older cohort exposed to the space environment compared to ground controls. Gene classes related to inflammatory pathways were downregulated in flight samples cultured from the younger cohort compared to ground controls. Our muscle tissue chip platform provides an approach to studying the cell autonomous effects of spaceflight on muscle cell biology that may not be appreciated on the whole organ or organism level and sets the stage for continued data collection from muscle tissue chip experimentation in microgravity. We also report on the challenges and opportunities for conducting autonomous tissue-on-chip CubeLabTM payloads on the ISS.

Validation of Human Skeletal Muscle Tissue Chip Autonomous Platform to Model Age-Related Muscle Wasting in Microgravity

Microgravity-induced muscle atrophy experienced by astronauts shares similar physiological changes to muscle wasting experienced by older adults, known as sarcopenia. These shared attributes provide a rationale for investigating microgravity-induced molecular changes in human bioengineered muscle cells that may also mimic the progressive underlying pathophysiology of sarcopenia. Here, we report the results of an experiment that incorporated three-dimensional myobundles derived from muscle biopsies from young and older adults, that were integrated into an autonomous CubeLabâ"¢, and flown to the International Space Station (ISS) aboard SpaceX CRS-21 in December 2020 as part of the NIH/NASA funded Tissue Chips in Space program. Global transcriptomic RNA-Seq analysis comparing the myobundles in space and on the ground revealed downregulation of shared transcripts related to myoblast proliferation and muscle differentiation for those in space. The analysis also revealed differentially expressed gene pathways related to muscle metabolism unique to myobundles derived from the older cohort exposed to the space environment compared to ground controls. Gene classes related to inflammatory pathways were uniquely modulated in flight samples cultured from the younger cohort compared to ground controls. Our muscle tissue chip platform provides a novel approach to studying the cell autonomous effects of microgravity on muscle cell biology that may not be appreciated on the whole organ or organism level and sets the stage for continued data collection from muscle tissue chip experimentation in microgravity. Thus, we also report on the challenges and opportunities for conducting autonomous tissue-on-chip CubeLab TM payloads on the ISS.

An investigation of coaches' awareness of injury in elite adolescent rugby union in Northern Irish schools - A qualitative study

OBJECTIVES

To examine the decision-making processes employed by schools' Rugby coaches in the management of injured players and to explore the factors that influenced those decisions. A secondary objective was to gauge interest in an education focused toolkit for schools' Rugby coaches.

DESIGN

A qualitative study using one-to-one online interviews.

SETTING

Schools who compete in the Ulster Schools' Cup Rugby competition.

PARTICIPANTS

Eleven Rugby union coaches from four post primary schools.

OUTCOME MEASURES

A thematic analysis approach was used to examine the factors that influence schools' Rugby coaches' decision-making processes in the management of injured players.

RESULTS

Findings suggest coaches are influenced in their decision making by four primary factors: their experience and learning, their relationships with other stakeholders, their knowledge and understanding of the roles and responsibilities of medical staff, healthcare and health fitness professionals, and resources available to them.

CONCLUSIONS

Schools' Rugby coaches play a significant role in the supervision of injured adolescent Rugby players, often drawing from their playing and coaching experiences. Schools retain, or recommend the services, of healthcare professionals (HCPs) and health and fitness professionals (HFPs). The role of these healthcare and health and fitness professionals, along with their qualifications and experience is not fully understood by coaches. Coaches acknowledge that there is a need for further training and would welcome education initiatives aimed at increasing awareness of musculoskeletal injury in schoolboy Rugby players.

External Cueing Influences Drop Jump Performance in Trained Young Soccer Players

ABSTRACT

Oliver, JL, Barillas, SR, Lloyd, RS, Moore, I, and Pedley, J. External cueing influences drop jump performance in trained young soccer players. J Strength Cond Res 35(6): 1700-1706, 2021-Drop jump (DJ) characteristics provide insight on power production and injury risk. The purpose of this study was to investigate the effect of external cueing on DJ characteristics in young male soccer players. Fourteen academy soccer players performed DJs with 4 different conditions, control (CONT), contact cue (CC), height cue (HC), and quiet cue (QC). Performance measures were reactive strength index (RSI), jump height, ground contact time (GCT), and take-off impulse, with injury risk reflected by impact peak, impact timing, and landing impulse. Contact cue showed a very large significant reduction in GCT (effect size [ES] > 2.0, p < 0.05), and moderate to large increase in RSI, landing impulse, and push-off impulse (ES 0.70-1.55, p < 0.05) compared with all other conditions. Contact cue also moderately increased impact peak when compared with HC and QC (ES ≥ 0.78, p < 0.05). Height cue led to a significant increase in jump height that was moderately greater than other external cues (ES ≥ 0.87, p < 0.05), but with only a small nonsignificant increase compared (ES 0.54, p > 0.05) with CONT. The data showed that all cues provided a specific response; CC reduced GCT and increased RSI, HC increased jump height, and QC reduced outcomes associated with injury risk. Height cue may be advantageous for young soccer players with a low training age because it shows a small to moderate increase in jump height without increasing injury risk. Young players may need to be safely progressed to be able to use a CC to facilitate high reactive strength without being exposed to undue injury risk.

Variation in training requirements within general surgery: comparison of 23 countries

Background

Many differences exist in postgraduate surgical training programmes worldwide. The aim of this study was to provide an overview of the training requirements in general surgery across 23 different countries.

Methods

A collaborator affiliated with each country collected data from the country's official training body website, where possible. The information collected included: management, teaching, academic and operative competencies, mandatory courses, years of postgraduate training (inclusive of intern years), working‐hours regulations, selection process into training and formal examination.

Results

Countries included were Australia, Belgium, Canada, Colombia, Denmark, Germany, Greece, Guatemala, India, Ireland, Italy, Kuwait, the Netherlands, New Zealand, Russia, Saudi Arabia, South Africa, South Korea, Sweden, Switzerland, UK, USA and Zambia. Frameworks for defining the outcomes of surgical training have been defined nationally in some countries, with some similarities to those in the UK and Ireland. However, some training programmes remain heterogeneous with regional variation, including those in many European countries. Some countries outline minimum operative case requirement (range 60–1600), mandatory courses, or operative, academic or management competencies. The length of postgraduate training ranges from 4 to 10 years. The maximum hours worked per week ranges from 38 to 88 h, but with no limit in some countries.

Conclusion

Countries have specific and often differing requirements of their medical profession. Equivalence in training is granted on political agreements, not healthcare need or competencies acquired during training.

Discovery of an Exceptionally Strong β-Decay Transition of ^{20}F and Implications for the Fate of Intermediate-Mass Stars

A significant fraction of stars between 7 and 11 solar masses are thought to become supernovae, but the explosion mechanism is unclear. The answer depends critically on the rate of electron capture on ^{20}Ne in the degenerate oxygen-neon stellar core. However, because of the unknown strength of the transition between the ground states of ^{20}Ne and ^{20}F, it has not previously been possible to fully constrain the rate. By measuring the transition, we establish that its strength is exceptionally large and that it enhances the capture rate by several orders of magnitude. This has a decisive impact on the evolution of the core, increasing the likelihood that the star is (partially) disrupted by a thermonuclear explosion rather than collapsing to form a neutron star. Importantly, our measurement resolves the last remaining nuclear physics uncertainty in the final evolution of degenerate oxygen-neon stellar cores, allowing future studies to address the critical role of convection, which at present is poorly understood.

Large Impact of the Decay of Niobium Isomers on the Reactor ν[over ¯]_{e} Summation Calculations

Even mass neutron-rich niobium isotopes are among the principal contributors to the reactor antineutrino energy spectrum. They are also among the most challenging to measure due to the refractory nature of niobium, and because they exhibit isomeric states lying very close in energy. The β-intensity distributions of ^{100gs,100m}Nb and ^{102gs,102m}Nb β decays have been determined using the total absorption γ-ray spectroscopy technique. The measurements were performed at the upgraded Ion Guide Isotope Separator On-Line facility at the University of Jyväskylä. Here, the double Penning trap system JYFLTRAP was employed to disentangle the β decay of the isomeric states. The new data obtained in this challenging measurement have a large impact in antineutrino summation calculations. For the first time the discrepancy between the summation model and the reactor antineutrino measurements in the region of the shape distortion has been reduced.

Summation Calculations for Reactor Antineutrino Spectra, Decay Heat and Delayed Neutron Fractions Involving New TAGS Data and Evaluated Databases

Three observables of interest for present and future reactors depend on the β decay properties of the fission products: antineutrinos from reactors, the reactor decay heat and delayed neutron emission. In these proceedings, we present new results from summation calculations of the first two quantities quoted above, performed with evolved independent yields coupled with fission product decay data, from various nuclear data bases or models. New TAGS results from the latest experiment of the TAGS collaboration at the JYFL facility of Jyväskylä will be displayed as well as their impact on the antineutrino spectra and the decay heat associated to fission pulses of the main actinides.

The influence of aquaculture unit proximity on the pattern of Lepeophtheirus salmonis infection of anadromous Salmo trutta populations on the isle of Skye, Scotland

A total of 230 anadromous Salmo trutta (brown trout) were sampled in five sheltered coastal fjords (or sea lochs) on the Isle of Skye, Scotland, U.K., in 2016 at varying distances from active Atlantic salmon Salmo salar farms. Statistical models were developed to investigate potential correlations between salmon lice Lepeophtheirus salmonis burdens on S. trutta hosts and their proximity to S. salar farm cages. Significant correlations were found between lice burdens and fish fork length and proximity to the nearest S. salar farm. The probability of the presence of L. salmonis on fish hosts increased with fish host size and with distance from the nearest S. salar farm, but total lice burdens were highest in fish sampled near S. salar farms and decreased with distance. The proportion of different life-cycle stages of L. salmonis were also dependent on S. salar farm proximity, with higher juvenile lice numbers recorded at sites near S. salar farm cages. These results highlight the complexity of the relationship between S. trutta and L. salmonis infections on wild fish and emphasize the requirement of further research to quantify these effects to better inform conservation and management strategies, particularly in areas of active S. salar farm facilities.

Abstract P5-22-11: Enhanced intraoperative breast specimen assessment may reduce margin positivity and reoperation rates in breast cancer

Introduction: Partial mastectomy is the most commonly performed operation for breast cancer. Margin positivity throughout the nation ranges from 30-60%, of which 10-36% require reoperation. Data from the SHAVE trial showed that excising an additional 1 cm margin circumferentially can reduce margin positivity by 50%. We are concerned about the large volume of tissue that may be unnecessarily removed secondary to routine circumferential margin excision. We have practiced selective additional margin excision based on enhanced intraoperative margin assessment including gross specimen evaluation by pathology. We suggest that enhanced intraoperative specimen assessment may reduce margin positivity and reoperation rates.

Methods: This is a retrospective review of a prospectively maintained, single surgeon database of patients undergoing partial mastectomy between Feburary 2014 – December 2016 at Medstar Union Memorial Hospital. One hundred consecutive patients diagnosed with DCIS or invasive carcinoma undergoing partial mastectomy with the intention of margin negativity were included. Information regarding preoperative planning and intraoperative specimen assessment were collected from clinical notes and operative records. These data points included preoperative imaging studies, use of preoperative needle localization, intraoperative ultrasound to guide surgery, use of intraoperative Faxitron, and gross pathologic consultation. The data is analyzed to calculate margin positivity and reoperation rates in comparison to reported experiences.

Results: The average age was 62.3 years, ranging from 33-96 years. Of the 100 patients, 73 had invasive cancer, 19 had DCIS. The average lesion size was 14.17mm. There were 8/100 cases with a positive margin, of which 5 cases had re-excisions. An additional 3 cases had re-excision for positive cells &lt;1mm from margin. Faxitron was used in 89% of cases and gross consultation in 100% of cases. The average number of additional margins taken was 1.2. 22/100 cases did not have additional margins taken during the index operation.

Discussion: This is a hypothesis generating study that was prompted by our concern about the amount of tissue and the expense created by routine circumferential margin removal. The issue of variability among different institutions and the very high reoperation rates reported by many beg for an explanation. Many techniques have been proposed to reduce this unexplained variability but none has consistently shown the necessary improvement and many new technologies are costly. Our experience suggests that low margin positivity and reoperation rates may be achieved using inexpensive enhanced intraoperative specimen assessment. We can test this hypothesis by comparing information among the different hospitals in our system. A head to head prospective trial comparing routine shaves versus enhanced specimen assessment and selective additional margins would answer this question.

Conclusion: Enhanced intraoperative margin assessment and selective margin excision may provide a good alternative to routine shave margin while removing less breast tissue. Uniform specimen assessment algorithms may also help achieve reduced margin positivity and reoperation rates.

Citation Format: Tran H-T, Moore I, Patel N, Willey S, Farha M. Enhanced intraoperative breast specimen assessment may reduce margin positivity and reoperation rates in breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-22-11.

Concussion knowledge and experience among Welsh amateur rugby union coaches and referees

Background

Rugby union is a collision sport where participants are at high risk of sustaining a concussion. In settings where there is little qualified medical supervision, certain stakeholders (eg, coaches and officials) should possess sufficient knowledge in regard to the recognition and management of concussion.

Aim

The aim of this study was to assess the knowledge and experience of various aspects of concussion among coaches and referees involved in Welsh amateur rugby union.

Methods

A questionnaire was distributed to 1843 coaches and 420 referees.

Results

A total of 333 coaches and 283 referees completed the questionnaire (18% and 68% response rates, respectively). Participants exhibited greater knowledge of concussion symptom recognition relative to knowledge of both the consequences of concussion and associated return-to-play protocols, both of which could be considered poor. There were no differences in knowledge levels between coaches and referees or between participants with or without a history of concussion. Two-thirds of participants incorrectly believed that headgear could prevent concussion, and nearly 30% of coaches reported having witnessed other coaches allowing a potentially concussed player to continue playing.

Conclusions

Identification of several misconceptions indicates that concussion management within Welsh amateur rugby union needs to be improved, warranting a multi-faceted educational intervention.

Total Absorption Spectroscopy Study of (92)Rb Decay: A Major Contributor to Reactor Antineutrino Spectrum Shape

The antineutrino spectra measured in recent experiments at reactors are inconsistent with calculations based on the conversion of integral beta spectra recorded at the ILL reactor. (92)Rb makes the dominant contribution to the reactor antineutrino spectrum in the 5-8 MeV range but its decay properties are in question. We have studied (92)Rb decay with total absorption spectroscopy. Previously unobserved beta feeding was seen in the 4.5-5.5 region and the GS to GS feeding was found to be 87.5(25)%. The impact on the reactor antineutrino spectra calculated with the summation method is shown and discussed.

Enhanced γ-Ray Emission from Neutron Unbound States Populated in β Decay

Total absorption spectroscopy is used to investigate the β-decay intensity to states above the neutron separation energy followed by γ-ray emission in (87,88)Br and (94)Rb. Accurate results are obtained thanks to a careful control of systematic errors. An unexpectedly large γ intensity is observed in all three cases extending well beyond the excitation energy region where neutron penetration is hindered by low neutron energy. The γ branching as a function of excitation energy is compared to Hauser-Feshbach model calculations. For (87)Br and (88)Br the γ branching reaches 57% and 20%, respectively, and could be explained as a nuclear structure effect. Some of the states populated in the daughter can only decay through the emission of a large orbital angular momentum neutron with a strongly reduced barrier penetrability. In the case of neutron-rich (94)Rb the observed 4.5% branching is much larger than the calculations performed with standard nuclear statistical model parameters, even after proper correction for fluctuation effects on individual transition widths. The difference can be reconciled by introducing an enhancement of 1 order of magnitude in the photon strength to neutron strength ratio. An increase in the photon strength function of such magnitude for very neutron-rich nuclei, if it proves to be correct, leads to a similar increase in the (n,γ) cross section that would have an impact on r process abundance calculations.

Enteric colonization by staphylococcus delphini in four ferret kits with diarrhoea

Four, 1-to 4-week-old ferret kits were submitted to the Diagnostic Center for Population and Animal Health at Michigan State University for post-mortem examination. Grossly, multiple bowel loops in all ferret kits were distended by mucoid faecal material. Microscopically, there was no evidence of inflammation or notable alteration to the normal mucosal morphology. Gram-positive coccoid bacteria colonized variable segments of the small intestine. These bacteria were identified as Staphylococcus delphini by phenotypic and molecular analyses. Enzyme-linked immunosorbent assay for detection of Staphylococcus enterotoxins was positive and polymerase chain reaction detected the gene for Staphylococcus enterotoxin E in the isolates. The hypersecretory diarrhoea in these ferret kits may have been associated with colonization of the small intestine by S. delphini, cultures of which were shown in vitro to be potentially capable of producing enterotoxin E. The condition described in these ferrets is similar to ‘sticky’ kit syndrome in mink.

Sex pheromone components of the giant looper,Boarmia selenaria schiff. (Lepidoptera: Geometridae): Identification, synthesis, electrophysiological evaluation, and behavioral activity

(Z,Z)-6,9-cis-(3S,4R)-Epoxynonadecadiene9a and (Z,Z,Z)-3,6,9-nonadecatriene have been identified as sex pheromone components in female ovipositor extracts and effluvia of the geometridBoarmia selenaria. The identification was based on relative retention times on gas chromatographic columns, GC-MS, chemical enantioselective syntheses, EAG, wind-tunnel behavioral experiments, and field tests. A single female ovipositor extract contained an average of 42 ng of (Z,Z)-6,9-cis-3,4-epoxynonadecadiene and 2 ng of (Z,Z,Z)-3,6,9-nonadecatriene.EAG, wind-tunnel behavioral studies, and field tests demonstrated that maleB. selenaria exhibit preferential attraction for the (3S,4R)-enantiomer of (Z,Z)-6,9-cis-3,4-epoxynonadecadiene. Only in effluvia and ovipositor extracts of calling females was (Z,Z)-6,9-cis- 3,4-epoxynonadecadiene detected, whereas relatively high amounts of (Z,Z,Z)-3,6,9-nonadecatriene were found in noncalling females. Wind-tunnel behavioral studies showed that (Z,Z,Z)-3,6,9-nonadecatriene did not elicit any response in the males, and when tested in combination with a mixture of monoepoxynonadecadienes, (Z,Z,Z)-3,6,9-nonadecatriene decreased the observed behavioral responses. A possible precursor role for (Z,Z,Z)-3,6,9-nonadecatriene in the pheromonal system is discussed.

Postpartum aHUS secondary to a genetic abnormality in factor H acquired through liver transplantation

We report here a young female who underwent a successful deceased donor liver transplant for hepatic vein thrombosis. Five years after transplantation she developed postpartum atypical hemolytic uremic syndrome (aHUS). She did not recover renal function. Mutation screening of complement genes in her DNA did not show any abnormality. Mutation screening of DNA available from the donor showed a nonsense CFH mutation leading to factor H deficiency. Genotyping of the patient showed that she was homozygous for an aHUS CD46 at-risk haplotype. In this individual, the development of aHUS has been facilitated by the combination of a trigger (pregnancy), an acquired rare genetic variant (CFH mutation) and a common susceptibility factor (CD46 haplotype).

Organelle motility in plant cells: imaging golgi and ER dynamics with GFP

By the addition of plant or mammalian targeting sequences, green fluorescent protein (GFP) can be directed to the endoplasmic reticulum, the Golgi apparatus, or both organelles in plant cells. This unit describes the application of rapid Agrobacterium and virus-mediated transient expression systems in leaf tissue to permit visualization of ER and Golgi dynamics in vivo by epifluorescence or confocal microscopy.

Q values of the superallowed beta emitters 26Alm, 42Sc, and 46V and their impact on Vud and the unitarity of the Cabibbo-Kobayashi-Maskawa matrix

The beta-decay Q(EC) values of the superallowed beta emitters 26Alm, 42Sc, and 46V have been measured with a Penning trap to a relative precision of better than 8 x 10(-9). Our result for 46V, 7052.72(31) keV, confirms a recent measurement that differed from the previously accepted reaction-based Q(EC) value. However, our results for 26Alm and 42Sc, 4232.83(13) keV and 6426.13(21) keV, are consistent with previous reaction-based values. By eliminating the possibility of a systematic difference between the two techniques, this result demonstrates that no significant shift in the deduced value of Vud should be anticipated.

First precision mass measurements of refractory fission fragments

Atomic masses of 95-100Sr, 98-105Zr, and [corrected] 102-110Mo and have been measured with a precision of 10 keV employing a Penning trap setup at the IGISOL facility. Masses of 104,105Zr and 109,110Mo are measured for the first time. Our improved results indicate significant deviations from the previously published values deduced from beta end point measurements. The most neutron-rich studied isotopes are found to be significantly less bound (1 MeV) compared to the 2003 atomic mass evaluation. A strong correlation between nuclear deformation and the binding energy is observed in the two-neutron separation energy in all studied isotope chains.

An audit to assess the quality of necropsies performed on stillborn infants

AIMS

To determine the quality of stillbirth postmortem reports and their contribution to a final diagnosis following the introduction of explicit consent forms after the Alder Hey inquiry.

METHODS

Necropsy reports from 100 consecutive stillbirths were reviewed from 2001 onwards. A spreadsheet compiled data items that were considered essential in the Royal College of Pathologists guidelines. The type of consent (with permission for organs/tissue retention) was recorded to assess the impact on establishing a cause of death.

RESULTS

Consent for tissue retention was obtained in 95 cases, whereas consent for organ retention was significantly lower (52 cases). In two cases, permission was refused for tissue retention and three requested external examinations only. Of these five, four had an undetermined cause of death, compared with 35 of 95 cases where permission for tissue retention was granted. All data items considered essential were recorded in every report. In 65 cases, the necropsy provided useful information, helped clinical care, and addressed parental concerns.

CONCLUSIONS

There was no major impact of the type of necropsy consent on establishing a cause of death, apart from the case of limited necropsies without histological examination of tissue samples.

Case of interstitial 12q deletion in association with Wilms tumor

A 14-month-old boy presenting with Wilms tumor (WT) was found to have a small de novo deletion of the long arm of chromosome 12 (12q11-12q13.11). Microsatellite analysis of this region from constitutional DNA showed that the paternal allele was absent between the markers D12S331 and D12S1713 (inclusive). In the WT there was no evidence of loss of the maternal chromosome. Constitutional chromosome abnormalities can often point to the presence of genes that are important in disease, and the deletion of chromosome 12 in this patient may indicate a gene involved in WT. To determine whether a WT predisposition locus exists at 12q we examined the region in two familial Wilms tumor (FWT) pedigrees unlinked to the known FWT genes on chromosomes 17q (FWT1), 19q (FWT2), and 11p (WT1). In both families WT did not segregate with chromosome 12q markers located within the deletion boundaries.

Prevention of fat-induced insulin resistance by salicylate

Insulin resistance is a major factor in the pathogenesis of type 2 diabetes and may involve fat-induced activation of a serine kinase cascade involving IKK-beta. To test this hypothesis, we first examined insulin action and signaling in awake rats during hyperinsulinemic-euglycemic clamps after a lipid infusion with or without pretreatment with salicylate, a known inhibitor of IKK-beta. Whole-body glucose uptake and metabolism were estimated using [3-(3)H]glucose infusion, and glucose uptake in individual tissues was estimated using [1-(14)C]2-deoxyglucose injection during the clamp. Here we show that lipid infusion decreased insulin-stimulated glucose uptake and activation of IRS-1-associated PI 3-kinase in skeletal muscle but that salicylate pretreatment prevented these lipid-induced effects. To examine the mechanism of salicylate action, we studied the effects of lipid infusion on insulin action and signaling during the clamp in awake mice lacking IKK-beta. Unlike the response in wild-type mice, IKK-beta knockout mice did not exhibit altered skeletal muscle insulin signaling and action following lipid infusion. In summary, high-dose salicylate and inactivation of IKK-beta prevent fat-induced insulin resistance in skeletal muscle by blocking fat-induced defects in insulin signaling and action and represent a potentially novel class of therapeutic agents for type 2 diabetes.

Plant cytokinesis: KNOLLE joins the club

Dividing plant cells assemble a new intracellular compartment, the cell plate, which grows centrifugally by vesicle fusion to partition the cytoplasm. Genetic studies in Arabidopsis are revealing the molecular signals that specify this special membrane transport pathway.

In vivo platelet activation in atherothrombotic stroke is not determined by polymorphisms of human platelet glycoprotein IIIa or Ib

Platelet membrane glycoprotein polymorphisms are candidate risk factors for thrombosis, but epidemiological data are conflicting. Thus, demonstration of a genotype-dependent alteration in function is desirable to resolve these inconsistencies. We investigated in vivo platelet activation in acute thrombosis and related this to platelet genotype. Frequencies of the 1b and 2b alleles of the HPA 1a/1b and HPA 2a/2b platelet glycoprotein polymorphisms were determined in 150 (52 men/98 women, mean age 58.3 years) patients with atherothrombotic stroke, and the influence of genotype on markers of platelet activation was assessed. Platelet P-selectin (CD62P) expression and fibrinogen binding was measured using whole blood flow cytometry within 24 h of stroke and 3 months later in 77 patients who provided a repeat blood sample. Results were compared with matched controls. Neither the 1b allele [allele frequency 0.11 vs. 0.13, odds ratio (OR) confidence interval (CI) 0.8 (0.5-1.3)] nor the 2b allele [0.09 vs. 0.07, OR (CI) 1.4 (0.8-2.4)] was significantly over-represented in patients. Increased numbers of activated platelets were found following stroke (acute mean P-selectin expression 0.64% vs. control 0.35%, P < 0.001; acute mean fibrinogen binding 1.6% vs. control 0.9%, P < 0.001). Activation persisted in the convalescent phase (P < 0.001 and P = 0.005 vs. controls for P-selectin and fibrinogen respectively). Expression of P-selectin and fibrinogen was not influenced by either the HPA 1a/1b genotype (P > 0.95 for each marker, Scheffe's test) or the 2a/2b genotype (P > 0.95 for each). Although persisting platelet activation is seen in atherothrombotic stroke, it is independent of HPA 1a/1b and 2a/2b genotypes. These data suggest an underlying prothrombotic state, but do not support the polymorphisms studied as risk factors for thrombotic stroke in this population.