Filamentation of a relativistic proton bunch in plasma.

We show in experiments that a long, underdense, relativistic proton bunch propagating in plasma undergoes the oblique instability, which we observe as filamentation. We determine a threshold value for the ratio between the bunch transverse size and plasma skin depth for the instability to occur. At the threshold, the outcome of the experiment alternates between filamentation and self-modulation instability (evidenced by longitudinal modulation into microbunches).

Hosing of a Long Relativistic Particle Bunch in Plasma.

Experimental results show that hosing of a long particle bunch in plasma can be induced by wakefields driven by a short, misaligned preceding bunch. Hosing develops in the plane of misalignment, self-modulation in the perpendicular plane, at frequencies close to the plasma electron frequency, and are reproducible. Development of hosing depends on misalignment direction, its growth on misalignment extent and on proton bunch charge.

Double aortic arch: implications of antenatal diagnosis, differential growth of arches during pregnancy, associated abnormalities and postnatal outcome.

Objectives: To evaluate the prenatal characteristics of double aortic arch (DAA), assess the relative size of the arches and their growth during pregnancy, describe associated cardiac, extracardiac and chromosomal/genetic abnormalities and review postnatal presentation and clinical outcome.

Methods: This was a retrospective cohort study of all fetuses with a confirmed diagnosis of DAA seen in five specialized referral centers in London, UK, between October 2012 and November 2019. Cases were identified from the hospitals' fetal databases.

Cherenkov Radiation in Optical Fibres as a Versatile Machine Protection System in Particle Accelerators.

Machine protection systems in high power particle accelerators are crucial. They can detect, prevent, and respond to events which would otherwise cause damage and significant downtime to accelerator infrastructure. Current systems are often resource heavy and operationally expensive, reacting after an event has begun to cause damage; this leads to facilities only covering certain operational modes and setting lower limits on machine performance.

Controlled Growth of the Self-Modulation of a Relativistic Proton Bunch in Plasma.

A long, narrow, relativistic charged particle bunch propagating in plasma is subject to the self-modulation (SM) instability. We show that SM of a proton bunch can be seeded by the wakefields driven by a preceding electron bunch. SM timing reproducibility and control are at the level of a small fraction of the modulation period.

Transition between Instability and Seeded Self-Modulation of a Relativistic Particle Bunch in Plasma.

We use a relativistic ionization front to provide various initial transverse wakefield amplitudes for the self-modulation of a long proton bunch in plasma. We show experimentally that, with sufficient initial amplitude [≥(4.1±0.

Proton Bunch Self-Modulation in Plasma with Density Gradient.

We study experimentally the effect of linear plasma density gradients on the self-modulation of a 400 GeV proton bunch. Results show that a positive or negative gradient increases or decreases the number of microbunches and the relative charge per microbunch observed after 10 m of plasma. The measured modulation frequency also increases or decreases.

A novel simulation and analysis algorithm for high resolution optical transition radiation imaging.

The use of optical transition radiation (OTR) for charged particle beam imaging is a well-established and commonly used technique. As such, simulations of the images expected from an arbitrary transverse beam profile are important in both the design of such OTR imaging systems and the analysis of the data. However OTR image simulations of high-energy, low-emittance particle beams, that are becoming commonplace within accelerator physics, can be extremely challenging to produce and limited in their account of practical factors.

Sarcoptic mange in wombats-A review and future research directions.

Sarcoptic mange is caused by the mite Sarcoptes scabiei and has recently been recognized as an emerging infectious disease of wildlife worldwide. The mite is one of the main causes of population decline in southern hairy-nosed (Lasiorhinus latifrons) and bare-nosed wombats (Vombatus ursinus). This review focuses on Sarcoptes scabiei infestations in wombats and provides insights into why the disease may be so prevalent in wombats.

Flecainide versus digoxin for fetal supraventricular tachycardia: Comparison of two drug treatment protocols.

Background: The optimal treatment for fetal supraventricular tachycardia (SVT) with 1:1 atrioventricular relationship is unclear.

Objective: We compared the effectiveness of transplacental treatment protocols used in 2 centers.

Methods: Pharmacologic treatment was used in 84 fetuses.

Track and trigger system for use in community hospitals.

Aim: To adapt and promote a relevant track and trigger system based on modified early warning systems (MEWS) for use in rural community hospitals in Powys, Wales.

Method: Track and trigger systems, including MEWS, were reviewed, compared and developed by senior nursing and medical staff using PDSA (Plan Do Study Act) cycles.

Results: A track and trigger system was developed, piloted and rolled out to all ten community hospitals in Powys.

Obliteration of left superior caval vein draining to the left atrium during spontaneous closure of ventricular septal defect.

Persistent left-sided superior caval veins (SVC) are present in 0.4% of the population. In the majority of cases, the persistent left SVC drains into the right atrium via the coronary sinus, but direct connection to the left atrium is also recognized.

Myocardial tissue Doppler and long axis function in the fetal heart.

Unlabelled: Current echocardiographic assessment of fetal ventricular function uses relatively crude measures and this has led to inconsistencies in assessment of diastolic function. Long axis parameters may be more insightful.

Objective: To describe fetal long axis cardiac function and construct reference ranges.

Can atrioventricular septal defects exist with intact septal structures?

The hallmark of an atrioventricular septal defect (AVSD) is a common atrioventricular junction, giving rise to a trileaflet left atrioventricular valve. AVSDs have the potential for interatrial shunting alone, interventricular shunting alone, or both. AVSDs without interatrial or interventricular communications have been identified at postmortem examination, but there are no reports of AVSDs with intact septal structures diagnosed in life.

Increased periconceptual maternal glycated haemoglobin in diabetic mothers reduces fetal long axis cardiac function.

Objective: To compare ventricular long axis function in fetuses of diabetic mothers (FDM) with contemporaneously studied normal controls (N) and to assess the effect of pre-pregnancy diabetic control on these measurements.

Design: Long axis function was compared in 41 FDM and 159 N fetuses in a cross sectional observational study.

Setting: Fetal medicine unit.

Influence of twin-twin transfusion syndrome on fetal cardiovascular structure and function: prospective case-control study of 136 monochorionic twin pregnancies.

Objective: To test the hypothesis that identical twins show no inter-twin differences in cardiovascular structure or physiology in fetal life unless there has been twin-twin transfusion syndrome.

Design: Unselected prospective case-control observational study of fetoplacental haemodynamics including echocardiography at a median of 24 (16.7 to 32.

Root production and turnover and carbon budgets of two contrasting grasslands under ambient and elevated atmospheric carbon dioxide concentrations.

Monoliths of two contrasting vegetation types, a species-rich grassland on a brown earth soil over limestone and species-poor community on a peaty gley, were transferred to solardomes and grown under ambient (350 μ 1 ) and elevated (600 μ11 ) CO for 2 yr. Shoot biomass was unaltered but root biomass increased by 40-50% under elevated CO . Root production was increased by elevated CO in the peat soil, measured both as instantaneous and cumulative rates, but only the latter measure was increased in the limestone soil.

Effects of elevated CO2 and nutrient supply on the seasonal growth and morphology of Agrostis capillaris.

Responses to elevated CO2 have been studied using an upland grass species, Agrostis capillaris L. The plants were grown in sand culture with a range of N, P and K concentrations, in 'Solardome' growth chambers with either ambient air or a CO2 concentration of 250μmol CO2 mol(-1) above ambient The interactive effects of high CO2 and nutrient supply (in plant growth and morphology were monitored throughout the growing season. A.

Nitrogen, phosphorus and potassium uptake and demand in Agrostis capillaris: the influence of elevated CO and nutrient supply.

Responses to elevated CO have been studied using Agrostis capillaris L., an upland grass which is abundant on nutrient-poor soils. Plants were grown in sand culture with a wide range of nitrogen, phosphorus and potassium concentrations, and the impact of CO on the demand for nutrients was determined using isotopic root bioassays.

Effects of summer ozone on membrane lipid composition during subsequent frost hardening in Norway spruce [Picea abies (L.) Karst].

Norway spruce trees [Picea abies (L.) Karst] were exposed to ozone during the summers of three consecutive years and the fatty acid composition of the chloroplast membrane lipid, monogalactosyl diglyceride (MCDG) was analysed over the last 14 months. Significant variations in the degree of unsaturation and the percentage of linolenic acid (18:3) were not found, either on a seasonal basis or in relation to ozone treatment.

Regional variation in surface properties of Norway spruce and scots pine needles in relation to forest decline.

Measurements of leaf wettability (contact angle), amounts of epicuticular wax and of surface dust are reported for Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L) Karst) trees growing at 12 sites in Europe from SW Germany to NE Scotland. At each site, three year classes (current year, 1 and 2-year-old) of needles were sampled from the mid-crown of up to 12 trees.

CELLULAR READJUSTMENT OF BARLEY SEEDLINGS TO SIMULATED ACID RAIN.

No changes in buffer capacity at any range of pH were detected in either the shoots or roots of 9 d old hydroponically-grown barley seedlings which had been grown in dilute acid (pH 3 or 4) for the last 4 days of growth. Similar lack of change in buffer capacity was observed in barley which had been intermittently sprayed with acidic mists (pH 3 or 4) as compared to those sprayed with pH 56 media for the last 2 or 4 d of growth. Acidic treatments, especially growth in acidic media or 2 d of occasional spraying, caused significant increases in the levels of plastidic sulphate, as measured by high performance ion chromatography but no changes in the plastidic concentrations of other anions occurred.

The effect of ovariectomy on liver metabolism and maintenance energy requirement of hens.

Six pullets from each of an egg-producing and meat-producing strain were ovariectomised at 12 weeks of age. Ovarian regrowth occurred in two of the egg-producing and four of the meat-producing strain. 2.

Studies of fatty liver and kidney syndrome in chickens: dynamics of glucose metabolism.

1. Fatty liver and kidney syndrome (FLKS) was induced in a proportion of a group of 4-week-old chickens by giving a diet of meat meal and wheat; inclusion in the diet of animal tallow for 54 h substantially reduced the occurrence of FLKS. 2.