Global observations of magnetospheric high-m poloidal waves during the 22 June 2015 magnetic storm.

We report global observations of high-m poloidal waves during the recovery phase of the 22 June 2015 magnetic storm from a constellation of widely spaced satellites of five missions including Magnetospheric Multiscale (MMS), Van Allen Probes, Time History of Events and Macroscale Interactions during Substorm (THEMIS), Cluster, and Geostationary Operational Environmental Satellites (GOES). The combined observations demonstrate the global spatial extent of storm time poloidal waves. MMS observations confirm high azimuthal wave numbers (m ~ 100). Mode identification indicates the waves are associated with the second harmonic of field line resonances. The wave frequencies exhibit a decreasing trend as L increases, distinguishing them from the single-frequency global poloidal modes normally observed during quiet times. Detailed examination of the instantaneous frequency reveals discrete spatial structures with step-like frequency changes along L. Each discrete L shell has a steady wave frequency and spans about 1 RE , suggesting that there exist a discrete number of drift-bounce resonance regions across L shells during storm times.

Venous thromboembolism following colorectal resection.

AIM: The study investigated the rate of significant venous thromboembolism (VTE) following colorectal resection during the index admission and over 1 year following discharge. It identifies risk factors associated with VTE and considers the length of VTE prophylaxis required. METHOD: All adult patients who underwent colorectal resections in England between April 2007 and March 2008 were identified using Hospital Episode Statistics data. They were studied during the index admission and followed for a year to identify any patients who were readmitted as an emergency with a diagnosis of deep venous thrombosis or pulmonary embolism. RESULTS: In all, 35 997 patients underwent colorectal resection during the period of study. The VTE rate was 2.3%. Two hundred and one (0.56%) patients developed VTE during the index admission and 571 (1.72%) were readmitted with VTE. Following discharge from the index admission, the risk of VTE in patients with cancer remained elevated for 6 months compared with 2 months in patients with benign disease. Age, postoperative stay, cancer, emergency admission and emergency surgery for patients with inflammatory bowel disease (IBD) were all independent risk factors associated with an increased risk of VTE. Patients with ischaemic heart disease and those having elective minimal access surgery appear to have lower levels of VTE. CONCLUSION: This study adds to the benefits of minimal access surgery and demonstrates an additional risk to patients undergoing emergency surgery for IBD. The majority of VTE cases occur following discharge from the index admission. Therefore, surgery for cancer, emergency surgery for IBD and those with an extended hospital stay may benefit from extended VTE prophylaxis. This study demonstrates that a stratified approach may be required to reduce the incidence of VTE.

A comparative study of dipolarization fronts at MMS and Cluster.

We present a statistical study of dipolarization fronts (DFs), using magnetic field data from MMS and Cluster, at radial distances below 12 RE and 20 RE , respectively. Assuming that the DFs have a semicircular cross section and are propelled by the magnetic tension force, we used multispacecraft observations to determine the DF velocities. About three quarters of the DFs propagate earthward and about one quarter tailward. Generally, MMS is in a more dipolar magnetic field region and observes larger-amplitude DFs than Cluster. The major findings obtained in this study are as follows: (1) At MMS ∼57 % of the DFs move faster than 150 km/s, while at Cluster only ∼35 %, indicating a variable flux transport rate inside the flow-braking region. (2) Larger DF velocities correspond to higher Bz  values directly ahead of the DFs. We interpret this as a snow plow-like phenomenon, resulting from a higher magnetic flux pileup ahead of DFs with higher velocities.

Ion-scale secondary flux ropes generated by magnetopause reconnection as resolved by MMS.

New Magnetospheric Multiscale (MMS) observations of small-scale (~7 ion inertial length radius) flux transfer events (FTEs) at the dayside magnetopause are reported. The 10 km MMS tetrahedron size enables their structure and properties to be calculated using a variety of multispacecraft techniques, allowing them to be identified as flux ropes, whose flux content is small (~22 kWb). The current density, calculated using plasma and magnetic field measurements independently, is found to be filamentary. Intercomparison of the plasma moments with electric and magnetic field measurements reveals structured non-frozen-in ion behavior. The data are further compared with a particle-in-cell simulation. It is concluded that these small-scale flux ropes, which are not seen to be growing, represent a distinct class of FTE which is generated on the magnetopause by secondary reconnection.

Transient, small-scale field-aligned currents in the plasma sheet boundary layer during storm time substorms.

We report on field-aligned current observations by the four Magnetospheric Multiscale (MMS) spacecraft near the plasma sheet boundary layer (PSBL) during two major substorms on 23 June 2015. Small-scale field-aligned currents were found embedded in fluctuating PSBL flux tubes near the separatrix region. We resolve, for the first time, short-lived earthward (downward) intense field-aligned current sheets with thicknesses of a few tens of kilometers, which are well below the ion scale, on flux tubes moving equatorward/earthward during outward plasma sheet expansion. They coincide with upward field-aligned electron beams with energies of a few hundred eV. These electrons are most likely due to acceleration associated with a reconnection jet or high-energy ion beam-produced disturbances. The observations highlight coupling of multiscale processes in PSBL as a consequence of magnetotail reconnection.

Bile duct reconstruction following laparoscopic cholecystectomy in England.

OBJECTIVES: To determine the incidence of bile duct reconstruction (BDR) following laparoscopic cholecystectomy (LC) and to identify associated risk factors. BACKGROUND: Major bile duct injury (BDI) requiring reconstruction is a serious complication of cholecystectomy. METHODS: All LC and attempted LC operations in England between April 2001 and March 2013 were identified. Patients with malignancy, a stone in bile duct or those who underwent bile duct exploration were excluded. This cohort of patients was followed for 1 year to identify those who underwent BDR as a surrogate marker for major BDI. Logistic regression was used to identify factors associated with the need for reconstruction. RESULTS: In total, 572,223 LC and attempted LC were performed in England between April 2001 and March 2013. Five hundred (0.09 %) of these patients underwent BDR. The risk of BDR is lower in patient that do not have acute cholecystitis [odds ratio (OR) 0.48 (95 % CI 0.30-0.76)]. The regular use of on-table cholangiography (OTC) [OR 0.69 (0.54-0.88)] and high consultant caseload >80 LC/year [OR 0.56 (0.39-0.54)] reduced the risk of BDR. Patients who underwent BDR were 10 times more likely to die within a year than those who did not require further surgery (6 vs. 0.6 %). CONCLUSIONS: The rate of BDR following laparoscopic cholecystectomy in England is low (0.09 %). The study suggests that OTC should be used more widely and provides further evidence in support of the provision of LC services by specialised teams with an adequate caseload (>80).

A phase Ib/II translational study of sunitinib with neoadjuvant radiotherapy in soft-tissue sarcoma.

BACKGROUND: Preoperative radiotherapy (RT) is commonly used to treat localised soft-tissue sarcomas (STS). Hypoxia is an important determinant of radioresistance. Whether antiangiogenic therapy can 'normalise' tumour vasculature, thereby improving oxygenation, remains unknown. METHODS: Two cohorts were prospectively enrolled. Cohort A evaluated the implications of hypoxia in STS, using the hypoxic tracer (18)F-azomycin arabinoside (FAZA-PET). In cohort B, sunitinib was added to preoperative RT in a dose-finding phase 1b/2 design. RESULTS: In cohort A, 13 out of 23 tumours were hypoxic (FAZA-PET), correlating with metabolic activity (r(2)=0.85; P<0.001). Two-year progression-free (PFS) and overall (OS) survival were 61% (95% CI: 0.44-0.84) and 87% (95% CI: 0.74-1.00), respectively. Hypoxia was associated with radioresistance (P=0.012), higher local recurrence (Hazard ratio (HR): 10.2; P=0.02), PFS (HR: 8.4; P=0.02), and OS (HR: 41.4; P<0.04). In Cohort B, seven patients received sunitinib at dose level (DL): 0 (50 mg per day for 2 weeks before RT; 25 mg per day during RT) and two patients received DL: -1 (37.5 mg per day for entire period). Dose-limiting toxicities were observed in 4 out of 7 patients at DL 0 and 2 out of 2 patients at DL -1, resulting in premature study closure. Although there was no difference in PFS or OS, patients receiving sunitinib had higher local failure (HR: 8.1; P=0.004). CONCLUSION: In STS, hypoxia is associated with adverse outcomes. The combination of sunitinib with preoperative RT resulted in unacceptable toxicities, and higher local relapse rates.

Observational evidence of ring current in the magnetosphere of Mercury.

The magnetic gradient and curvature drift of energetic ions can form a longitudinal electric current around a planet known as the ring current, that has been observed in the intrinsic magnetospheres of Earth, Jupiter, and Saturn. However, there is still a lack of observational evidence of ring current in Mercury's magnetosphere, which has a significantly weaker dipole magnetic field. Under such conditions, charged particles are thought to be efficiently lost through magnetopause shadowing and/or directly impact the planetary surface. Here, we present the observational evidence of Mercury's ring current by analysing particle measurements from MErcury Surface, Space Environment, GEochemistry, and Ranging (MESSENGER) spacecraft. The ring current is bifurcated because of the dayside off-equatorial magnetic minima. Test-particle simulation with Mercury's dynamic magnetospheric magnetic field model (KT17 model) validates this morphology. The ring current energy exceeds [Formula: see text] J during active times, indicating that magnetic storms may also occur on Mercury.

Inner southern magnetosphere observation of Mercury via SERENA ion sensors in BepiColombo mission.

Mercury's southern inner magnetosphere is an unexplored region as it was not observed by earlier space missions. In October 2021, BepiColombo mission has passed through this region during its first Mercury flyby. Here, we describe the observations of SERENA ion sensors nearby and inside Mercury's magnetosphere. An intermittent high-energy signal, possibly due to an interplanetary magnetic flux rope, has been observed downstream Mercury, together with low energy solar wind. Low energy ions, possibly due to satellite outgassing, were detected outside the magnetosphere. The dayside magnetopause and bow-shock crossing were much closer to the planet than expected, signature of a highly eroded magnetosphere. Different ion populations have been observed inside the magnetosphere, like low latitude boundary layer at magnetopause inbound and partial ring current at dawn close to the planet. These observations are important for understanding the weak magnetosphere behavior so close to the Sun, revealing details never reached before.

Expression of genes involved in lipogenesis is not increased in patients with HCV genotype 3 in human liver.

Hepatitis C virus (HCV) infection is frequently associated with hepatic steatosis, particularly in patients with HCV genotype-3 (HCVGT3). It has variously been hypothesized, largely from in-vitro studies, to be the result of increased synthesis, decreased metabolism and export of triglycerides. We measured by real-time PCR the expression of genes involved in lipid metabolism [acetyl-Coenzyme A carboxylase alpha, apolipoprotein B (APOB), diacylglycerol O-acyltransferase 2, fatty acid-binding protein 1, fatty acid synthase, microsomal triglyceride transfer protein (MTTP), peroxisome proliferator-activated receptor alpha (PPARA), peroxisome proliferator-activated receptor gamma (PPARG), protein kinase AMP-activated alpha 1 catalytic subunit (PRKAA1) and sterol regulatory element-binding transcription factor 1 (SREBF1)] in liver biopsies from patients infected with HCV genotype-1 (HCVGT1), HCVGT3 and Hepatitis B (HBV) using ß-glucuronidase (GUSB) and splicing factor arginine/serine-rich 4 (SFRS4) as housekeeping genes. Patients infected with HCVGT3 were younger than those infected with HCVGT1 (36.3 ± 2.5 vs 45.6 ± 1.5, P < 0.05, Mann-Whitney) and were more likely to have steatosis (69.2%vs 11.8%). No significant difference was found in the expression of genes involved in lipogenesis or transport in patients infected with HBV or HCV of either genotype. Contrary to expectation, given the greater degree of steatosis in HCVGT3-infected liver, expression of enzymes involved in lipogenesis was not elevated in HCVGT3 compared with HCVGT1 or HBV-infected liver. Significantly less mRNA for SREBF1 was found in HCVGT3-infected liver tissue compared with HCVGT1-infected liver (1.00 ± 0.06 vs 0.70 ± 0.15 P < 0.05). These results suggest that steatosis in patients infected with HCVGT3 is not the result of a sustained SREBF1 driven increase in expression of genes involved in lipogenesis. In addition, a significant genotype-independent correlation was found between the expression of APOB, MTTP, PRKAA1 and PPARA, indicating that these networks are functional in HCV-infected liver.

SERENA: Particle Instrument Suite for Determining the Sun-Mercury Interaction from BepiColombo.

The ESA-JAXA BepiColombo mission to Mercury will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric particle dynamics at Mercury as well as their interactions with solar wind, solar radiation, and interplanetary dust. The particle instrument suite SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) is flying in space on-board the BepiColombo Mercury Planetary Orbiter (MPO) and is the only instrument for ion and neutral particle detection aboard the MPO. It comprises four independent sensors: ELENA for neutral particle flow detection, Strofio for neutral gas detection, PICAM for planetary ions observations, and MIPA, mostly for solar wind ion measurements. SERENA is managed by a System Control Unit located inside the ELENA box. In the present paper the scientific goals of this suite are described, and then the four units are detailed, as well as their major features and calibration results. Finally, the SERENA operational activities are shown during the orbital path around Mercury, with also some reference to the activities planned during the long cruise phase.

Loop ileostomy following anterior resection: is it really temporary?

INTRODUCTION: A temporary loop ileostomy is often created to minimize the impact of peritoneal sepsis if anastomotic dehiscence occurs following low colorectal anastomosis. Although it has been suggested that a loop ileostomy should be reversed within 12 weeks of formation, this is often not the case. We set out to analyse the use of loop ileostomy following elective anterior resection in England and to identify factors associated with non and delayed reversal. METHOD: Hospital episode statistics for the years 2001-2006 were obtained from the Department of Health. Patients undergoing elective anterior resection with a loop ileostomy for a primary diagnosis of rectal or recto-sigmoid cancer between April 2001 and March 2003 were identified as the study cohort. This cohort was followed until March 2006 to identify patients undergoing reversal of an ileostomy in an English NHS Hospital. RESULTS: A total of 6582 patients had an elective anterior resection between April 2001 and March 2003, of which 964 (14.6%) also had an ileostomy. Seven hundred and two (75.1%) patients were reversed before March 2006. Advancing age and comorbidity were statistically related to nonreversal. Median time to reversal was 207 days (Interquartile range 119-321.5 days). Postoperative chemotherapy and comorbidity significantly delayed reversal. CONCLUSIONS: One in four loop ileostomies performed to defunction an elective anterior resection is not reversed, and in the presence of significant comorbidity one in three is not reversed. Only 12% is reversed within 12 weeks.

Comparative Analysis of the Vlasiator Simulations and MMS Observations of Multiple X-Line Reconnection and Flux Transfer Events.

The Vlasiator hybrid-Vlasov code was developed to investigate global magnetospheric dynamics at ion-kinetic scales. Here we focus on the role of magnetic reconnection in the formation and evolution of magnetic islands at the low-latitude magnetopause, under southward interplanetary magnetic field conditions. The simulation results indicate that (1) the magnetic reconnection ion kinetics, including the Earthward pointing Larmor electric field on the magnetospheric side of an X-point and anisotropic ion distributions, are well-captured by Vlasiator, thus enabling the study of reconnection-driven magnetic island evolution processes, (2) magnetic islands evolve due to continuous reconnection at adjacent X-points, "coalescence" which refers to the merging of neighboring islands to create a larger island, "erosion" during which an island loses magnetic flux due to reconnection, and "division" which involves the splitting of an island into smaller islands, and (3) continuous reconnection at adjacent X-points is the dominant source of magnetic flux and plasma to the outer layers of magnetic islands resulting in cross-sectional growth rates up to + 0.3 RE 2/min. The simulation results are compared to the Magnetospheric Multiscale (MMS) measurements of a chain of ion-scale flux transfer events (FTEs) sandwiched between two dominant X-lines. The MMS measurements similarly reveal (1) anisotropic ion populations and (2) normalized reconnection rate ~0.18, in agreement with theory and the Vlasiator predictions. Based on the simulation results and the MMS measurements, it is estimated that the observed ion-scale FTEs may grow Earth-sized within ~10 min, which is comparable to the average transport time for FTEs formed in the subsolar region to the high-latitude magnetopause. Future simulations shall revisit reconnection-driven island evolution processes with improved spatial resolutions.

Effect of fructans, prebiotics and fibres on the human gut microbiome assessed by 16S rRNA-based approaches: a review.

The inherent and diverse capacity of dietary fibres, nondigestible oligosaccharides (NDOs) and prebiotics to modify the gut microbiota and markedly influence health status of the host has attracted rising interest. Research and collective initiatives to determine the composition and diversity of the human gut microbiota have increased over the past decade due to great advances in high-throughput technologies, particularly the 16S ribosomal RNA (rRNA) sequencing. Here we reviewed the application of 16S rRNA-based molecular technologies, both community wide (sequencing and phylogenetic microarrays) and targeted methodologies (quantitative PCR, fluorescent in situ hybridisation) to study the effect of chicory inulin-type fructans, NDOs and specific added fibres, such as resistant starches, on the human intestinal microbiota. Overall, such technologies facilitated the monitoring of microbiota shifts due to prebiotic/fibre consumption, though there are limited community-wide sequencing studies so far. Molecular studies confirmed the selective bifidogenic effect of fructans and galactooligosaccharides (GOS) in human intervention studies. Fructans only occasionally decreased relative abundance of Bacteroidetes or stimulated other groups. The sequencing studies for various resistant starches, polydextrose and beta-glucan showed broader effects with more and different types of gut microbial species being enhanced, often including phylotypes of Ruminococcaceae. There was substantial variation in terms of magnitude of response and in individual responses to a specific fibre or NDO which may be due to numerous factors, such as initial presence and relative abundance of a microbial type, diet, genetics of the host, and intervention parameters, such as intervention duration and fibre dose. The field will clearly benefit from a more systematic approach that will support defining the impact of prebiotics and fibres on the gut microbiome, identify biomarkers that link gut microbes to health, and address the personalised response of an individual's microbiota to prebiotics and dietary fibres.

Magnetospheres of the galilean satellites.

The plasma and field perturbations of magnetospheres that would surround magnetized galilean satellites embedded in the corotating jovian plasma differ from those produced by interaction with an unmagnetized conductor. If the intrinsic satellite dipole is antiparallel to that of Jupiter, the magnetosphere will be open. It is predicted that Io has an internal magnetic field with a dipole moment of 6.5 x 10(22) gauss-cubic centimeters antiparallel to Jupiter's, and Io's special properties can be interpreted on the basis of a reconnecting magnetosphere.

Initial pioneer venus magnetic field results: nightside observations.

Initial observations by the Pioneer Venus magnetometer on the nightside of Venus frequently reveal moderately strong fields from 20 to 30 nanoteslas. However, there is little evidence that thesefields arise from an internal dynamo since they are mainly horizontal and vary from orbit to orbit. Determining a precise upper limit to the intrinsic moment awaits further processing. This limit is expected to be much less than 10(22) gauss-cubic centimeters.

Initial pioneer venus magnetic field results: dayside observations.

Initial observations by the Pioneer Venus mangnetometer in the sunlit ionosphere reveal a dynamic ionosphere, very responsive to external solar-wind conditions. The localtions of the bow shock and ionosphere are variable. The strength of the magnetic field just olutside the ionopause is in approximate pressure balance with the thermal plasma of the ionosphere and changes markedly from day, to day in response to changes in solar wind pressure. The field strength in the ionosphere is also variable from day to day. The field is often weak, at most a few gammas, but reaching many tens of gammas for periods of the order of seconds. These field enchantments are interpreted as due to the passage of spacecraft through flux ropes consisting of bundles of twisted field lines surrounded by the ionospheric plasma. The helicity of the flux varies through the flux tube, with lows pitch angles on the inside and very lage angles in the low-field outer edges of the ropes. These ropes may have external or internal sources. Consistent with previous results, the average position of the bow shock is much closer to the planet than would be expected if the solar wnd were completely deflected by the planet. In total, these observations indicate that the solar wind plays a significant role in the physics of the Venus ionosphere.

Use of Hartmann's procedure in England.

INTRODUCTION: Hartmann's procedure is widely used in the management of complicated diverticular disease and for colorectal cancer. Very little national data are available about the reasons for performing this procedure and the reversal rate. METHOD: Hospital episode statistics data were obtained from The Department of Health and exported to an Access database for analysis. A cohort of patients who underwent a Hartmann's procedure between April 2001 and March 2002 were identified and followed until April 2006 to identify patients undergoing reversal of Hartmann's. RESULTS: Approximately 3950 Hartmann's procedures were performed between April 2001 and March 2002, 2853 as an emergency and 1097 as an elective procedure. Most emergency Hartmann's were performed for benign disease (2067, 72.5%) whereas a majority of the elective Hartmann's were performed for cancer (756, 68.9%). Seven hundred and thirty six (23.3%) of these patients underwent reversal during the study period. The median time interval between a Hartmann's procedure and reversal was 284.5 days (interquartile range 181-468.25). CONCLUSION: This study represents the single largest cohort in whom outcome after Hartmann's procedure has been studied. A majority of Hartmann's are performed as an emergency for benign diseases and most of them are not reversed.

Conversion after laparoscopic cholecystectomy in England.

BACKGROUND: Laparoscopic cholecystectomy is the procedure of choice for the treatment of symptomatic gallstones. Conversion to open surgery is reported to be necessary in 5-10% of cases. This study aimed to define those factors associated in English hospitals with the need to convert a laparoscopic cholecystectomy to an open procedure. These included patient-related and particularly nonpatient-related factors. METHODS: Using data derived from a national administrative database, Hospital Episode Statistics, patients undergoing cholecystectomy in acute National Health Service (NHS) hospitals in England during the financial years 2004-2006 were studied. The individual surgeon caseload and the hospital conversion rate were calculated using data from the first (baseline) year. Factors affecting the need for conversion were analyzed using data from the second (index) year. RESULTS: The study included 43,821 laparoscopic cholecystectomies undertaken from 2005 to 2006 in English hospitals. The overall conversion rate was 5.2%: 4.6% for elective procedures and 9.4% for emergency procedures. Patient-related factors that were good predictors of conversion included male sex, emergency admission, old age, and complicated gallstone disease (p < 0.001). Nonpatient-related factors that were good predictors of conversion included the laparoscopic cholecystectomy caseload of individual consultant surgeons and the overall hospital conversion rate in the previous year (all p < 0.001). CONCLUSIONS: Conversion after laparoscopic cholecystectomy is less common as consultant caseload increases. This suggests that operation should be undertaken only by surgeons with an adequate caseload. There is a wide variation in conversion rates among hospitals. This has important implications for training as well as for the organization and accreditation of cholecystectomy services on a national basis.

A review of the role of soluble fiber in health with specific reference to wheat dextrin.

Dietary fiber is widely recognized to have a beneficial role in overall health, but only at adequate levels (25 - 38 g/day for healthy adults). Wheat dextrin in particular is a soluble fiber that can easily be added to the diet and is widely used in the food industry. There is some debate about whether increased intake of soluble fibers leads to health benefits. This paper reviews the evidence regarding the physiological effects and potential health benefits of the addition of soluble dietary fibers, with specific reference to wheat dextrin, based on a search of PubMed. The evidence suggests that soluble fibers help to regulate the digestive system, may increase micronutrient absorption, stabilize blood glucose and lower serum lipids, may prevent several gastrointestinal disorders, and have an accepted role in the prevention of cardiovascular disease. It is concluded that supplementation with soluble fibers (e.g. wheat dextrin) may be useful in individuals at risk of a lower than recommended dietary fiber intake.