Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

1048 Prevalence Of Positional Obstructive Sleep Apnea (OSA) In Patients With OSA-COPD Overlap Syndrome

Introduction

Positional OSA (non-supine apnea-hypopnea index [AHI] < 5 events/hr) is present in 30% of patients with OSA. We demonstrated that in patients with OSA- COPD overlap syndrome the AHI inversely correlated with the degree of gas trapping, suggesting a stabilizing effect on the upper airway. We hypothesized that sleep position would be less important, resulting in a lower prevalence of positional OSA.

Methods

Patients underwent a polysomnogram that demonstrated OSA (AHI > 5 events/hr). To confirm COPD, patients had spirometry performed and a chest computed tomography for measurements of percent gas trapping.

Results

Sixteen patients [6 (38%) males, 55±7 years/old, FEV1 1.2±0.5 L, FEV1 % Predicted 45±19%, FVC 2.3±0.8 L, FVC % Predicted 69±20%, FEV1/FVC 51±12%, BMI 33±9 kg/m2)] were diagnosed with OSA (AHI 15±12 events/hour). Four patients (25%) had positional OSA (AHI 13±6 events/hr, non-supine AHI 1±1 event/hr) compared to 12 patients who were non-positional [AHI 16±13 events/hr (p=0.95)]. There was no difference in age [52±8 and 56±7 yrs (p=0.3)] or severity of obstruction in those with and without positional OSA [FEV1 1.4±4 L and 1.1±0.5 L, (p=0.3), FEV1 % predicted 50±17% and 44±20%, (p=0.7), FVC 2.9±0.8 L and 2.1±0.8 L (p=0.1), FVC % predicted 78±21% and 66±20%, (p=0.3), and FEV1/FVC 50±11% and 51±12%, (p=0.8), respectively]. However, patients with positional OSA were less heavy than those with non-positional OSA [BMI 23±3 and 37±8 kg/m2, respectively (p=0.005)]. Finally, there was no difference in the CT-Derived % Gas Trapping in those with and without positional OSA [48±37% and 36±25%, (p=0.6), respectively].

Conclusion

The prevalence of positional OSA in patients with OSA-COPD overlap is similar to OSA patients without COPD. Despite the presence of obstructive disease and gas trapping that may affect upper airway stability, other factors including body position and BMI remain important determinants for developing OSA in patients with COPD.

Support

R01-HL089856, R01-HL089897

0567 Hypoxic Burden and Apnea-Hypopnea Duration in Patients with Positional Obstructive Sleep Apnea

Introduction

Recently, the measurement of the hypoxic burden and apnea-hypopnea duration has been shown to correlate with mortality in patients with obstructive sleep apnea (OSA). We hypothesized that in patients with mild positional OSA (apnea-hypopnea index [AHI] < 5 events/hr in the non-supine position) the hypoxic burden would be increased and apnea-hypopnea duration shortened and similar to patients with non-positional OSA.

Methods

Fourteen patients with positional OSA and 24 patients non-positional OSA with similar severity of OSA based on the respiratory event index (REI) were included. All patients had a home sleep apnea test for suspected OSA. The hypoxic burden was calculated by the multiplication of REI and the mean area under the desaturation curves.

Results

Thirty-eight patients [12 (35%) males, 50±12 yrs, BMI 35±7 kg/m2, Epworth Sleepiness Scale (ESS) 11±8, REI 10±3 events/hr, apnea-hypopnea duration 19±4 sec, mean SaO2 94±2%, lowest SaO2 79±8%, % total sleep time (TST) SaO2 < 90% 11±16%, hypoxic burden 30±17 %min/hr] completed the study. Fourteen patients [9 (64%) males, 46±14 yrs, BMI 31±6 kg/m2, ESS 7±5, REI 9±3 events/hr, mean SaO2 94±2%, lowest SaO2 81±6%, %TST SaO2 < 90% 4±6%] had positional OSA (supine REI 16±7 events/hr, non-supine REI 3±1 events/hr) and 24 patients had non-positional OSA [3 (13%) males, 52±10 yrs, BMI 38±7 kg/m2, ESS 12±9, REI 10±3 events/hr, mean SaO2 94±2%, lowest SaO2 77±9%, %TST SaO2 < 90% 14±19%]. The hypoxic burden was elevated in both the positional and non-positional OSA patients with no difference between the groups (26±19 %min/hr and 32±15 %min/hr, respectively, p=0.13). The apnea-hypopnea duration was similar in positional and non-positional OSA patients (20±3 sec and 18±4 sec, respectively, p=0.08 sec).

Conclusion

In patients with mild positional OSA the hypoxic burden, which has been associated with cardiovascular mortality, is elevated and similar to patients with non-positional OSA.

Support

None

0610 Prevalence of Positional Obstructive Sleep Apnea Based on 3% Vs 4% Oxygen Desaturation Using Home Sleep Apnea Testing

Introduction

Approximately 30% of patient with obstructive sleep apnea (OSA) have positional OSA [non-supine apnea-hypopnea index (AHI) < 5 events/hr]. However, the prevalence is based on variable definitions for hypopneas related to the degree of oxygen desaturation. In addition, use of a home sleep apnea test (HSAT) to identify positional OSA is limited. We hypothesized that in patients evaluated with an HSAT, using a definition for hypopneas based on 4% compared to 3% oxygen desaturation will significantly decrease the percentage diagnosed with positional OSA.

Methods

Fourteen patients with positional OSA based on a non-supine respiratory event index (REI) < 5 events/hr were included. The initial diagnosis was determined based on a hypopnea definition of ≥ 3% oxygen desaturation. The studies were reanalyzed using a hypopnea definition of ≥ 4% oxygen desaturation.

Results

Fourteen patients [9 (64%) males, 46±14 yrs, BMI 31±6 kg/m2, ESS 7±5, REI 9±3 events/hr, mean SaO2 94±2%, lowest SaO2 81±6%, %TST SaO2 < 90% 4±6%] were identified with positional OSA (supine REI 16±7 events/hr, non-supine REI 3±1 events/hr) using a hypopneas definition of ≥ 3% oxygen desaturation. When reanalyzed using a hypopnea ≥ 4% oxygen desaturation there was a significant decrease in the REI to 7±2 events/hr (p<0.001). Three patients (21%) no longer were considered to have OSA. These patients were younger (32±14 vs. 50±11yrs, p=0.03) and had less severe OSA (REI 6±1 vs. 9±3 events/hr (p=0.04), but there was no difference in BMI (32±11 vs. 31±5 kg/m2, p=0.9) or mean and lowest SaO2 (96±0.4 vs. 94±2%, p=0.13, and 82±8 vs. 81±6%, p=0.9, respectively).

Conclusion

In patients with mild positional OSA, using a hypopnea definition of at least 4% vs. 3% oxygen desaturation on a HSAT will have a significant effect on the overall REI and often exclude patients who would otherwise be treated for OSA.

Support

None.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

Developmental programming: a new frontier for the poultry industry?

Increasing evidence that the maternal environment influences the programming of developing embryos and fetuses through epigenetic mechanisms has significant potential application in the broiler industry. The broiler breeder hen is subjected to restricted-feeding regimes to maximise egg quantity and quality, but the genetically high-intake potential of these birds makes this regime a stressful one. We propose that this stress is signalled to the developing embryo via changes in yolk composition as an evolutionary adaptation to changing environments, and that exposure to high levels of corticosteroids in ovo is associated with developmental reprogramming, which has effects on the behaviour, health and growth of the progeny. The present paper describes some preliminary results from a series of trials designed to elucidate the relationship between breeder hen diet and egg composition, and the growth, behaviour and immune function of the progeny. We conclude that manipulation of the breeder hen diet is an untapped opportunity to maintain the competitiveness of the chicken meat industry and further, that achieving improved productivity by this means may be compatible with improved animal welfare outcomes for the hen and her progeny.

Biological defleecing: intravenous infusion of amino acid mixtures lacking lysine and methionine creates a weakened zone in the wool staple, which is amenable to mechanical wool harvesting

Conventional shearing of sheep is labour-intensive, expensive and presents significant occupational health and safety risks. The only alternative at present is based on injection of epidermal growth factor, which severs the fibre at the follicle level. This technology cannot be used in pregnant animals and requires application of a net to retain the severed fleece. An alternative is to create a weakened zone within the wool staple, which would be sufficiently strong to retain the fleece on the sheep while a protective covering regrows, but sufficiently weak as to allow painless and automated removal of the fleece. We demonstrate that this approach is possible using mixtures of amino acids lacking lysine and methionine. Initially we demonstrate the relationships between staple strength, a subjective ‘harvestability’ score and a subjective ‘pain’ score, using fleeces from animals treated with varying levels of cortisol to create a wide range of strengths of wool attachment. We assigned a score to the ease with which we could manually break the staples, and also to the animal’s response to breaking the staples still attached to the skin. The relationships between these variables indicated that a staple was considered harvestable and could be removed with minimal skin flinch response at a staple strength of ~10–13 N/kTex. Staples within this range were then produced by intravenous infusion of mixtures of amino acids lacking in lysine and methionine for a 5-day period. The weak point was uniformly created across the entire fleece and when a prototype roller-pin device was applied to the weakened wool, it uniformly broke the fleece of the three sheep tested. The mode of action of the amino acid treatment on wool growth was studied. There was no effect of unbalanced amino acids on the rate of follicle bulb cell division, the number of active wool follicles, or the length of the keratinisation zone in the wool follicle. Fibre diameter was reduced by ~4 microns by treatment, and intrinsic fibre strength (strength relative to cross-sectional area of the wool fibres), was reduced by ~50%. Results of these trials are encouraging but further work is required to develop a practical, on-farm method of altering systemic amino acid supply and to design an automated, high-throughput system of severing the weakened wool.

Assembly of high-areal-density deuterium-tritium fuel from indirectly driven cryogenic implosions

The National Ignition Facility has been used to compress deuterium-tritium to an average areal density of ~1.0±0.1 g cm(-2), which is 67% of the ignition requirement. These conditions were obtained using 192 laser beams with total energy of 1-1.6 MJ and peak power up to 420 TW to create a hohlraum drive with a shaped power profile, peaking at a soft x-ray radiation temperature of 275-300 eV. This pulse delivered a series of shocks that compressed a capsule containing cryogenic deuterium-tritium to a radius of 25-35 μm. Neutron images of the implosion were used to estimate a fuel density of 500-800 g cm(-3).

Antibodies to metabotropic glutamate receptor 5 in the Ophelia syndrome

OBJECTIVE

To report the metabotropic glutamate receptor 5 (mGluR5) as the autoantigen of antibodies from 2 patients with Hodgkin lymphoma (HL) and limbic encephalopathy (Ophelia syndrome).

METHODS

Immunohistochemistry with brain tissue and cultures of rat hippocampal neurons were used to demonstrate antibodies. Immunoprecipitation, mass spectrometry, and mGluR5-null mice served to identify the antigen. HEK293 cells transfected with mGluR5 or mGluR1 were used to determine immunologic crossreactivity.

RESULTS

Both patients developed symptoms consistent with limbic encephalopathy; one had MRI findings typical of this disorder and the other had more extensive radiologic involvement, including parietal and occipital cortex. Patients' sera had antibodies that predominantly reacted with the neuropil of hippocampus and cell surface of live hippocampal neurons. Immunoprecipitation from cultured neurons and mass spectrometry demonstrated that the antigen was mGluR5, a receptor involved in processes of learning and memory. The reactivity of patients' sera was abrogated in brain of mGluR5-null mice, further confirming the antibody specificity. Studies with a large number of controls including 2 patients with cerebellar ataxia and mGluR1 antibodies showed that mGluR5 was only identified by sera of the 2 patients with the Ophelia syndrome, and that despite the homology of this receptor with mGluR1 each autoantigen was specific for a distinct syndrome.

CONCLUSIONS

Antibodies to mGluR5 should be considered in patients with symptoms of limbic encephalitis and HL (Ophelia syndrome). Recognition of this disorder is important because it can affect young individuals and is reversible.

Demonstration of ignition radiation temperatures in indirect-drive inertial confinement fusion hohlraums

We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 μm diameter hot core.

Ascorbic acid attenuates scopolamine-induced spatial learning deficits in the water maze

Vitamin C (ascorbate) has important antioxidant functions that can help protect against oxidative stress in the brain and damage associated with neurodegenerative disorders such as Alzheimer's disease. When administered parenterally ascorbate can bypass saturable uptake mechanisms in the gut and thus higher tissue concentrations can be achieved than by oral administration. In the present study we show that ascorbate (125 mg/kg) administered intraperitoneally (i.p.) 1-h before testing, partially attenuated scopolamine-induced (1 mg/kg i.p.) cognitive deficits in Morris water maze performance in young mice. Cumulative search error, but not escape latency nor path length, was significantly improved during acquisition in ascorbate plus scopolamine-treated mice although performance did not equal that of control mice. During the probe trial, scopolamine led to increased search error and chance level of time spent in the platform quadrant, whereas mice pre-treated with ascorbate prior to scopolamine did not differ from control mice on these measures. Ascorbate had no effect on unimpaired, control mice and neither did it reduce the peripheral, activity-increasing effects of scopolamine. Ascorbate alone increased acetylcholinesterase activity in the medial forebrain area but had no effect in cortex or striatum. This change, and its action against the amnestic effects of the muscarinic antagonist scopolamine, suggest that ascorbate may be acting in part via altered cholinergic signaling. However, further investigation is necessary to isolate the cognition-enhancing effects of ascorbate.

Understanding the alphaviruses: recent research on important emerging pathogens and progress towards their control

The alphaviruses were amongst the first arboviruses to be isolated, characterized and assigned a taxonomic status. They are globally very widespread, infecting a large variety of terrestrial animals, insects and even fish, and circulate both in the sylvatic and urban/peri-urban environment, causing considerable human morbidity and mortality. Nevertheless, despite their obvious importance as pathogens, there are currently no effective antiviral drugs with which to treat humans or animals infected by any of these viruses. The EU-supported project-VIZIER (Comparative Structural Genomics of Viral Enzymes Involved in Replication, FP6 PROJECT: 2004-511960) was instigated with an ultimate view of contributing to the development of antiviral therapies for RNA viruses, including the alphaviruses [Coutard, B., Gorbalenya, A.E., Snijder, E.J., Leontovich, A.M., Poupon, A., De Lamballerie, X., Charrel, R., Gould, E.A., Gunther, S., Norder, H., Klempa, B., Bourhy, H., Rohayemj, J., L'hermite, E., Nordlund, P., Stuart, D.I., Owens, R.J., Grimes, J.M., Tuckerm, P.A., Bolognesi, M., Mattevi, A., Coll, M., Jones, T.A., Aqvist, J., Unger, T., Hilgenfeld, R., Bricogne, G., Neyts, J., La Colla, P., Puerstinger, G., Gonzalez, J.P., Leroy, E., Cambillau, C., Romette, J.L., Canard, B., 2008. The VIZIER project: preparedness against pathogenic RNA viruses. Antiviral Res. 78, 37-46]. This review highlights some of the major features of alphaviruses that have been investigated during recent years. After describing their classification, epidemiology and evolutionary history and the expanding geographic distribution of Chikungunya virus, we review progress in understanding the structure and function of alphavirus replicative enzymes achieved under the VIZIER programme and the development of new disease control strategies.

Using localizing learning to improve supervised learning algorithms

Slow learning of neural-network function approximators can frequently be attributed to interference, which occurs when learning in one area of the input space causes unlearning in another area. To mitigate the effect of unlearning, this paper develops an algorithm that adjusts the weights of an arbitrary, nonlinearly parameterized network such that the potential for future interference during learning is reduced. This is accomplished by the reduction of a biobjective cost function that combines the approximation error and a term that measures interference. An analysis of the algorithm's convergence properties shows that learning with this algorithm reduces future unlearning. The algorithm can be used either during online learning or can be used to condition a network to have immunity from interference during a future learning stage. A simple example demonstrates how interference manifests itself in a network and how less interference can lead to more efficient learning. Simulations demonstrate how this new learning algorithm speeds up the training in various situations due to the extra cost function term.

Transient or occult HIV infections may occur more frequently than progressive infections: changing the paradigm about HIV persistence

Evidence of transient HIV infections was found in 8 subjects at high-risk for HIV infection among 47 longitudinally studied over 2-5 (average approximately 3.5) years, whereas only two subjects developed progressive infection. All of these subjects developed serum antibodies (Ab) to conformational epitopes of HIV gp41 (termed "early HIV Ab"), but the 8 transiently infected subjects lost this Ab within 4-18 months, and did not seroconvert to positivity in denatured antigen EIA or Western Blot (WB). However, the two progressively infected subjects eventually seroconverted in the EIA and WB tests within one to two months after the appearance of "early HIV Ab". HIV env and nef sequences were directly PCR amplified from the peripheral blood mononuclear cells (PBMCs) of two of the eight transiently infected subjects during the time of "early HIV Ab"-postivity, and these showed significant sequence divergence from the HIV strains in the laboratory, indicating that they were not laboratory contaminants. Genome identity typing ("paternity-typing") of PBMC samples obtained at the time of "early HIV Ab"-positivity, and later when Ab was absent from each of the 8 subjects, showed that blood samples were not mixed-up. This provides further evidence that transient or occult infection with HIV does occur, and perhaps at a greater frequency than do progressive infections.

Blockage of glucocorticoid, but not mineralocorticoid receptors prevents the persistent increase in circulating basal corticosterone concentrations following stress in the rat

Exposure to a single session of intense inescapable stressors results in elevations of plasma corticosterone levels selective to the trough of the circadian rhythm that last for several days after stressor cessation. In the present study, we examined whether this stress-induced alteration in the regulation of the circadian trough is dependent upon glucocorticoid and/or mineralocorticoid receptor activation during stress. Pre-treatment with the mineralocorticoid receptor (MR) antagonist, spironolactone (RU-28318; 50 mg/kg, s.c.), and/or the glucocorticoid receptor (GR) antagonist, mifepristone (RU-38486; 50 mg/kg, s.c.) 1 h before inescapable stress (40, 2.0-mA tail-shocks delivered over a 1 h period) had no effect on the acute plasma corticosterone response to inescapable stress. Treatment with the MR antagonist alone did not affect the appearance of basal corticosterone elevations in stressed rats. However, the elevated trough plasma corticosterone levels were no longer evident in rats treated previously with the GR antagonist either alone or in combination with the MR antagonist. GR activation during stressor exposure appears to be necessary for the development of subsequent basal corticosterone elevations.

Early environmental regulation of hippocampal glucocorticoid receptor gene expression: characterization of intracellular mediators and potential genomic target sites

Environmental conditions in early life permanently alter the development of glucocorticoid receptor gene expression in the hippocampus and hypothalamic-pituitary-adrenal responses to acute or chronic stress. In part, these effects can involve an activation of ascending serotonergic pathways and subsequent changes in the expression of transcription factors that might drive glucocorticoid receptor expression in the hippocampus. This paper summarizes the evidence in favor of these pathways as well as recent studies describing regulatory targets on the promoter region of the rat hippocampal glucocorticoid receptor gene.

Postnatal handling increases the expression of cAMP-inducible transcription factors in the rat hippocampus: the effects of thyroid hormones and serotonin

Postnatal handling increases glucocorticoid receptor expression in the rat hippocampus, thus altering the regulation of hypothalamic synthesis of corticotropin-releasing hormone and the hypothalamic-pituitary-adrenal response to stress. The effect on glucocorticoid receptor gene expression represents one mechanism by which the early environment can exert a long-term effect on neural development. The handling effect on hippocampal glucocorticoid receptor expression is dependent on peripheral thyroid hormone release and the activation of ascending serotonergic pathways. In primary hippocampal cell cultures, serotonin (5-HT) increases glucocorticoid receptor expression, and this effect appears to be mediated by increased cAMP levels. In the current studies we examined the in vivo effects of handling on hippocampal cAMP-protein kinase A (PKA) activity. In 7-d-old rat pups, we found that (1) postnatal handling increased adenylyl cyclase activity and hippocampal cAMP levels, (2) the effect of handling on cAMP levels was completely blocked by treatment with either propylthiouracil (PTU), a thyroid hormone synthesis inhibitor, or the 5-HT receptor antagonist, ketanserin, and (3) handling also increased hippocampal PKA activity. We then examined the effects of handling on cAMP-inducible transcription factors. Handling rapidly increased levels of the mRNAs for nerve growth factor-inducible factor A (NGFI-A) (zif268, krox24) and activator protein-2 (AP-2) as well as for NGFI-A and AP-2 immunoreactivity throughout the hippocampus. Finally, we found that the effects of handling on NGFI-A and AP-2 expression were significantly reduced by concurrent treatment with either PTU or ketanserin, effects that paralleled those on cAMP formation. NGFI-A and AP-2 have been implicated in the regulation of glucocorticoid receptor expression during development. Thus, these findings suggest that postnatal handling might alter glucocorticoid receptor gene expression via cAMP-PKA pathways involving the activation of NGFI-A and AP-2.

5'-heterogeneity of glucocorticoid receptor messenger RNA is tissue specific: differential regulation of variant transcripts by early-life events

Glucocorticoid receptor (GR) gene expression is regulated in a complex tissue-specific manner, notably by early-life environmental events that program tissue GR levels. We have identified and characterized several new rat GR mRNAs. All encode a common protein, but differ in their 5'-leader sequences as a consequence of alternate splicing of, potentially, 11 different exon 1 sequences. Most are located in a 3-kb CpG island, upstream of exon 2, that exhibits substantial promoter activity in transfected cells. Ribonuclease (RNase) protection analysis demonstrated significant levels of six alternate exons 1 in vivo in rat, with differences between liver, hippocampus, and thymus reflecting tissue-specific differences in promoter activity. Two of the alternate exons 1 (exons 1(6) and 1(10)) were expressed in all tissues examined, together present in 77-87% of total GR mRNA. The remaining GR transcripts contained tissue-specific alternate first exons. Importantly, tissue-specific first exon usage was altered by perinatal environmental manipulations. Postnatal handling, which permanently increases GR in the hippocampus, causing attenuation of stress responses, selectively elevated GR mRNA containing the hippocampus-specific exon 1(7). Prenatal glucocorticoid exposure, which increases hepatic GR expression and produces adult hyperglycemia, decreased the proportion of hepatic GR mRNA containing the predominant exon 1(10), suggesting an increase in a minor exon 1 variant. Such tissue specificity of promoter usage allows differential GR regulation and programming.

Topical use of papaya in chronic skin ulcer therapy in Jamaica

The objective of the study was to determine the prevalence of the use of the fruit (papaya) of Carica papaya as topical ulcer dressings by registered nurses in the Spanish Town Hospital (STH), Kingston Public Hospital (KPH) and the University Hospital of the West Indies (UHWI), Jamaica. A ten-item pretested self-administered questionnaire was distributed to 285 randomly selected registered nurses at the UHWI, KPH and STH. There was a 72% response rate. The prevalence of topical papaya use among the respondents was 75%. Comments from the users of papaya suggested that topical application of the unripe fruit promoted desloughing, granulation and healing and reduced odour in chronic skin ulcers. It was cost effective. Papaya was considered to be more effective than other topical applications in the treatment of chronic ulcers. There was some difficulty in preparation of the fruit and occasionally a sensation of burning was reported by the patients. There was concern about the use of a non-sterile, non-standardised procedure but there were no reports of wound infection from its use. Papaya is widely used by nurses as a form of dressing for chronic ulcers and there is need for standardisation of its preparation and application.

Optical BEAMTAP beam-forming and jammer-nulling system for broadband phased-array antennas

We present an approach to receive-mode broadband beam forming and jammer nulling for large adaptive antenna arrays as well as its efficient and compact optical implementation. This broadband efficient adaptive method for true-time-delay array processing (BEAMTAP) algorithm decreases the number of tapped delay lines required for processing an N-element phased-array antenna from N to only 2, producing an enormous savings in delay-line hardware (especially for large broadband arrays) while still providing the full NM degrees of freedom of a conventional N-element time-delay-and-sum beam former that requires N tapped delay lines with M taps each. This allows the system to adapt fully and optimally to an arbitrarily complex spatiotemporal signal environment that can contain broadband signals of interest, as well as interference sources and narrow-band and broadband jammers--all of which can arrive from arbitrary angles onto an arbitrarily shaped array--thus enabling a variety of applications in radar, sonar, and communication. This algorithm is an excellent match with the capabilities of radio frequency (rf) photonic systems, as it uses a coherent optically modulated fiber-optic feed network, gratings in a photorefractive crystal as adaptive weights, a traveling-wave detector for generating time delay, and an acousto-optic device to control weight adaptation. Because the number of available adaptive coefficients in a photorefractive crystal is as large as 10(9), these photonic systems can adaptively control arbitrarily large one- or two-dimensional antenna arrays that are well beyond the capabilities of conventional rf and real-time digital signal processing techniques or alternative photonic techniques.

Herpes varicella zoster encephalitis in immunocompromised patients

The authors describe specific MRI features that suggest the diagnosis of varicella zoster encephalitis. MRI initially revealed discrete, subcortical, nonenhancing lesions that coalesced and developed enhancement. Gray matter involvement was seen later. Autopsy revealed spherical lesions of demyelination and hemorrhagic cavitation confirmed as varicella zoster encephalitis. Characteristic MR features may suggest the diagnosis of varicella zoster encephalitis, enabling definitive diagnostic testing and early institution of antiviral treatment.

Motivation, attitudes and experience of donation: a follow-up of women donating eggs in assisted conception treatment

This paper reports a follow-up of 39 women who had donated eggs to an assisted conception unit. Their experience of donation and their motivation and attitudes were assessed. Comparisons were made with a group of semen donors who were attending a second unit. Female and male donors donated for altruistic reasons and neither group wished to have contact with recipients or donor offspring or have their identity revealed. Female donors were more involved in the donation process and more interested in the outcome of donation. They also appeared to be more motivated by 'helping' than male donors. The sample of female donors contained a small group of women who were donating to sisters and friends. In comparison with anonymous donors, these women reported more effects upon the family and issues of secrecy and openness were more apparent. The results are discussed in the light of previous studies and the legal framework for donation in the UK. Attention is drawn to the lack of social psychological analyses in this controversial medical area.

The effect of implicit and explicit motivation on recall among old and young adults

Seventy-six elderly subjects aged sixty-five to eighty-seven and seventy-seven young adults aged twenty-five to forty were compared on implicit and explicit motive levels and on recall of introductions and working memory. Significantly fewer of the elderly than the young participants scored high in the implicit motives, n Affiliation and n Power, confirming results from U.S. national surveys. The surveys also demonstrated a significant decline with age in high levels of n Achievement, a decline not found here. The elderly participants showed major recall deficits on both tasks, but all three of the implicit motives studied were shown to enhance recall for the elderly, but not for the young adults. Eight elderly women scoring high on at least two of the three motives showed no recall deficits compared to the young women on two memory tasks. In old age implicit motive deficits contribute to poor memory but explicit commitments to have a good memory had no effect on recall.

Wide angular aperture holograms in photorefractive crystals by the use of orthogonally polarized write and read beams

We demonstrate a method of simultaneous holographic recording and readout in photorefractive crystals that provides high write-read beam isolation and wide angular bandwidth. The method uses orthogonally polarized read and write beams and parallel tangent diffraction geometry near the equal curvature condition to provide spatially separable, orthogonally polarized diffracted output beams with high isolation and wide Bragg-matched angular bandwidth. The available angular bandwidth of this read-write technique is analyzed, simulated, and experimentally investigated. The measured angular bandwidth internal to the crystal is approximately 18° × 6° for our 45°-cut BaTiO(3) crystal, yet the entire hologram still demonstrates high Bragg selectivity. In contrast, traditional nonparallel-tangent geometries yield angular apertures of the order of 1° × 4°.

Sensory processing during early and late nocturnal sleep

The present experiments in 10 healthy men compared auditory evoked potentials (AEPs) and heart rate (HR) indicators of stimulus processing during early and late phases of nocturnal stage 2 sleep. Definition of early and late sleep relied on endocrine pituitary-adrenal secretory activity which is known to be inhibited during early nocturnal sleep but sharply increases during late sleep. AEPs and HR responses were recorded to trains of 10 tone pips (1000 Hz; interstimulus interval 15 s; intertrain interval > 3 min). On one night, tone pips were presented in the first part of sleep, on the other night tone presentation took place in the second part, with the order of conditions balanced across subjects. Amplitudes of N150 and N550 components of the AEP, and of acceleratory and deceleratory HR responses, were higher during the first than second part of nocturnal sleep (P < 0.05). Moreover, habituation of P240 and N550 amplitudes was slower during the first than second part of sleep (P < 0.05). In supplementary experiments, AEP and HR responses to the same stimuli did not differ between the first and second part of the night when subjects were waking during stimulation. Results indicate a reduced inhibitory control over cortical stimulus processing during early nocturnal sleep. This diminished inhibition of cortical processing together with other concomitant changes during early sleep (such as the enhanced inhibition of pituitary-adrenal secretion) may reflect a coordinated regulatory function of sleep possibly mediated by hippocampal mechanisms.