Measurement of the T + T neutron spectrum using the national ignition facility.

Neutron time-of-flight spectra from inertial confinement fusion experiments with tritium-filled targets have been measured at the National Ignition Facility. These spectra represent a significant improvement in energy resolution and statistics over previous measurements, and afford the first definitive observation of a peak resulting from sequential decay through the ground state of (5)He at low reaction energies E(c.m.) 100

Effects of systemic administration or intrabursal injection of serotonin on puberty, first ovulation and follicular development in rats.

To elucidate the role of serotonin in the onset of puberty, the effects of both systemic and in-ovarian bursa administration of serotonin on the neuroendocrine mechanism that modulates the onset of puberty, follicular development and first ovulation were evaluated. Two experiments were carried out. For the first, 25 or 37.5 mg kg⁻¹ of bodyweight of serotonin creatinine sulfate was administered by a subcutaneous route to 30-day-old female rats. In the second experiment, serotonin creatinine sulfate was administered directly into the ovarian bursa of 34-day-old female rats. Systemic administration of 25 or 37.5 mg kg⁻¹ of serotonin creatinine sulfate induced a delay in the ages of vaginal opening and first vaginal oestrus, a decrease in the number of ovulating animals, and serum concentrations of FSH, LH, oestradiol and progesterone. An increase in the number of Class 3 (>500 µm) and atretic follicles was observed in the ovaries of these animals. The administration of serotonin creatinine sulfate in the ovarian bursa did not modify the onset of puberty and ovulation, but a reduced serum concentration of oestradiol was observed. Our results suggest that serotonin acts on the components of the hypothalamus-hypophysis-ovary axis by modulating follicular development, ovarian functions and the onset of puberty.

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).

Variable region genes of anti-HIV human monoclonal antibodies: non-restricted use of the V gene repertoire and extensive somatic mutation.

The extent of the expressed human V gene repertoire for the most part has been derived from fetal cDNA libraries, autoantibodies, and myeloma proteins. In order to continue to explore the utilization of the VH and VL gene repertoire in response to exogenous viral antigens, the heavy and light chain cDNAs from four human anti-HIV monoclonal antibodies were PCR amplified from human-mouse heterohybridomas, cloned, and nucleotide sequence analysis performed. Of the monoclonals analyzed, three were directed against gp120 and one reacted with gp41. Three of the antibodies were of the IgG1 lambda isotype and one was an IgG1 kappa. Three of the four heavy chains were derived from VHI gene segments and one VHII was observed. D segments showed evidence of D-D joining and three JH4 and one JH5 gene were utilized. Two V lambda II lambda chains and one from the V lambda III gene family were observed and the single kappa chain sequenced was from the V kappa III family. DNA sequence comparison with known germline gene segments identified putative precursor V gene segments for one of the heavy chains and two light chains. Comparison of the expressed amino acid sequences with the predicted germline sequences indicated that changes were clustered in the CDRs and FR3 regions of the V gene segments. We reported previously the nucleotide sequences of five human monoclonal antibodies from HIV-infected individuals, three of which utilized VHIV, one VHV and one a VHI gene segment and also found extensive evidence of somatic mutation. Collectively, our results indicate that an antigen driven response is functioning following HIV infection and, surprisingly, to date we have not encountered a VHIII gene segment. Since VHIII is the largest human VH gene family, it may well be that this under-representation has both functional and clinical implications.

Absence of circadian variations in urinary porphyrin excretion in normal subjects.

The hypothesis that urinary porphyrins could be excreted in a circadian rhythm was examined. A group of 20 healthy subjects, 10 males and 10 females, aged 20-40 years, were used in this study. Urine was collected at 4-hr intervals over three 24-hr periods. Median porphyrin concentrations (microgram l-1 or microgram g-1 of creatinine) were similar in the six groups, but significant differences were observed in that excreted. Highest porphyrin excretion was detected in the afternoon (12.00-16.00 hr) and, in the evening (16.00-20.00 hr). pH values were also increased at evening but did not correlate with porphyrin excretion. Despite these temporal variations, no cycles indicating circadian periodicity were observed. Therefore, a 24-hr collection of urine is not necessary for the initial evaluation of porphyrin metabolism.

Correlation between levels of free and protein-bound plasma porphyrin and urinary porphyrins in porphyria cutanea tarda.

Porphyria cutanea tarda (PCT) is a disorder of porphyrin metabolism that leads to massive overproduction and excretion of uroporphyrin. Most plasma porphyrins are bound to albumin and hemopexin. The aim of this work was to analyze the relationship between the concentrations of serum albumin and hemopexin, the levels of total, free and protein-bound plasma porphyrins and the urinary coproporphyrin and uroporphyrin excretion, in PCT patients at different stages of the disease. Urinary porphyrins showed a stronger correlation with total plasma porphyrin levels (r = 0.863) than with the free fraction of plasma porphyrins (r = 0.608). Patients considered in an active stage of PCT, have a higher mean level of total plasma porphyrins (8.80 micrograms/dl +/- 8.75) and a lower mean percentage of free plasma porphyrins (12.79% +/- 11.21) than those patients on remission (0.71 +/- 0.5 microgram/dl and 44.3 +/- 35.3%, respectively). 30% of patients showed hypohemopexinaemia, presumably due to hepatic damage. Despite the high affinity of this protein for porphyrins, no significant correlation was found between plasma porphyrin levels and hemopexin or albumin. It is concluded that (i) the kidney is not merely a passive filter for free plasma porphyrins and (ii) that the formation of hemopexin-porphyrin complex occurs when plasma porphyrins concentrations are increased (i.e. in those patients in an active stage of PCT).

Characterization of the gene encoding superoxide dismutase of Bordetella pertussis and construction of a SOD-deficient mutant.

The Bordetella pertussis gene sodB, encoding superoxide dismutase (SOD), was cloned by complementation of an Escherichia coli sodAsodB double mutant. The nucleotide sequence of sodB predicted a 21-kDa protein with homology to manganese- and iron-containing SODs from other organisms. Examination of SOD activity on gels suggests that B. pertussis extracts have a single SOD containing Fe3+ as a prosthetic group. A SOD-deficient mutant was obtained by insertional inactivation of sodB in B. pertussis, confirming that there is only one SOD in this organism.

Salivary porphyrin concentration in porphyria cutanea tarda.

To assess the clinical utility of saliva samples, serum, urine and saliva porphyrin concentration were fluorometrically measured in 31 patients with porphyria cutanea tarda. In comparison with normal values, porphyrin mean levels were 20-fold increased in serum and urine but only 3-fold in saliva. Saliva porphyrin concentration exhibited significant but weak correlations with porphyrin levels in serum (r = 0.69) and urine (r = 0.67). However, saliva porphyrins were not more closely correlated with protein-unbound serum porphyrins (r = 0.57). This finding suggests that saliva porphyrin concentration does not simply correspond to the filtered free fraction of serum porphyrins. Nevertheless, measurement of saliva porphyrins could represent a valuable non-invasive alternative to serum porphyrins in the monitoring of patients with porphyria cutanea tarda.

Covert visual attention in schizophrenia spectrum personality disordered subjects: visuospatial cuing and alerting effects.

A recent study observed lateralized deficit in the disengagement of covert visual attention in schizophrenic patients. Subsequent attempts to replicate this finding have had mixed results. Differences in the neuroleptic treatment or other secondary factors associated with schizophrenia are some of the possible reasons for these inconsistent findings. In this study, we examined the ability to shift covert visual attention in neuroleptic-naive, schizophrenia spectrum personality disordered (SSPD; n = 35) subjects and normal controls (n = 34) under a variety of spatial cuing and alerting conditions. We hypothesized that SSPD subjects would have difficulty with disengagement of covert visual attention from an invalidly cued left visual field when the target appeared in the right visual field in comparison to the normal subjects. As predicted, schizophrenia spectrum personality disordered subjects had significantly longer latencies for the right visual field invalid targets than normals (p = .014). Under the remaining cue conditions, spectrum subjects performed normally. Consequently, the cost of left visual field invalid cueing for the right visual field target was significantly higher in spectrum personality subjects than in normals. The cost for the invalid right visual field cue and the benefits of valid cue in both fields were very similar in the two groups. The findings of an asymmetrical deficit in the disengagement and shift of covert visual attention in schizophrenia spectrum subjects are similar to the one's observed in patients with unilateral left hemisphere lesions.

Choroidal neovascular membrane after laser-induced chorioretinal anastomosis.

PURPOSE: To treat a patient who had a choroidal neovascular membrane after laser-induced chorioretinal anastomosis for nonischemic central retinal vein occlusion. METHODS: A 70-year-old man underwent successful formation of a chorioretinal anastomosis for nonischemic central retinal vein occlusion. He subsequently developed a choroidal neovascular membrane at the site of the chorioretinal anastomosis. RESULTS: The choroidal neovascular membrane at the site of the chorioretinal anastomosis was treated successfully with argon laser photocoagulation. The anastomosis remained functional. CONCLUSION: We recommend that patients who have undergone laser-induced chorioretinal anastomosis for nonischemic central retinal vein occlusion be followed up closely for choroidal neovascular membrane formation.

Porphyria cutanea tarda as a Predictor of Poor Response to Interferon Alfa Therapy in Chronic Hepatitis C.

BACKGROUND: Porphyria cutanea tarda (PCT) is sometimes associated with hepatitis C virus chronic infection. The aim of this study was to describe the effect of interferon alfa (IFN-a) in the treatment of patients with chronic hepatitis C and PCT. METHODS: We treated a total of 66 patients with chronic hepatitis C with IFN-a 2b (5 MU t.i.w.) for 12 months. Twenty-two of these patients suffered from PCT as well. These patients differed from patients without PCT in that they were men, past history of alcohol abuse and HFE gene mutations were more common and the source of infection was almost always unknown. RESULTS: Sustained virologie response was obtained in 19.7% of the 66 treated patients, 27.3% in the non-PCT group and 4.5% in the PCT group (P < 0.05). This difference could not be ascribed to the difference in sex of patients, history of alcohol abuse, HCV genotype or iron status. CONCLUSION: Multivariate logistic regression analysis revealed that PCT is independently and significantly associated with non-sustained response to IFNa therapy. In conclusion, patients with chronic hepatitis C and PCT rarely responded to IFNa treatment.

Experimental analyses of the structure and dynamics of mid-shore rocky intertidal communities in New South Wales.

At mid-shore levels on rocky shores in New South Wales, grazing gastropods are the dominant species in sheltered areas. Where wave-exposure is great, barnacles occupy most of the space. At intermediate levels of waveexposure, there are mixtures of grazing gastropods and barnacles, and the patterns of occupancy of space, and structure of the community change from time to time. The major species found in these areas are the coronuloid barnacle Tesseropora rosea, the patellid limpet Cellana tramoserica, the smaller acmaeid limpet, Patelloida latistrigata, which is mostly confined amongst barnacles, and the predatory whelk Morula marginalba. The roles of each of these species in determining the structure and persistence of intertidal communities were investigated by experimental manipulations of the densities of each of these organisms. In most experiments, a range of densities of limpets and barnacles was used, rather than the simple removal of all of one species.Recruitment of Cellana was negatively associated with increasing density of adult limpets, and with increasing density of barnacles. Growth and survival of juvenile Cellana were decreased by increasing densities of barnacles, probably because barnacles occupied space, preventing limpets from grazing. Morula had no effect on recruitment or survival of juvenile Cellana. Recruitment of juvenile Patelloida was not affected by different densities of barnacles, but survival to adult sizes was poor in areas where whelks are active. In areas where whelks were removed, Patelloida showed increased survivorship with increased cover of barnacles, probably because Patelloida amongst barnacles found refuge from the superior competitive effects of Cellana.The settlement and subsequent survival of Tesseropora were affected in complex ways by the activities of Cellana. At great densities, Cellana can have deleterious effects on newly-settled barnacles, probably by crushing them whilst grazing. In some areas, and at some densities, however, limpets can have beneficial effects on the recruitment and/or survival of Tesseropora. The limpets graze the juvenile stages of growth of foliose macroalgae, preventing them from growing up to pre-empt the rock-surface (thus preventing settlement of barnacles) or to smother alreadysettled barnacles. The effect of limpets on the recruitment and survival of barnacles in any area is a function of the densities of limpets and barnacles, and the height on the shore and local weather (the latter factors influence the rates of growth of algae).Increased cover of the rock-surface by adult barnacles caused reductions in the densities of Cellana. Limpets migrated away from areas of great cover of barnacles, and, if confined in such areas, starved and lost weight. The dispersion, as well as the density of the barnacles was important in determining the effects of barnacle cover. Where barnacles occupied half the space, but were scattered, leaving only small patches of bare rock, they had the same deleterious effects on Cellana as in areas where they were spread evenly to occupy most of the rock-surface. Thus, barnacles could invade areas dominated by limpets provided they recruited in sufficient numbers. They did not have to saturate an area to displace the Cellana.In these communities, all of the species can be considered to have important roles in the establishment and maintenance of community structure. We conclude that interpretations of the roles of individual species must be based on direct, experimental investigation. In this system, there was no indication that many of the species were functionally insignificant.The present experiments also revealed that the interactions among even a few species are very varied and complex; proper investigation requires considerable replication and repeated experimentation in different places and years.Finally, although the present studies allow reliable interpretations of observed patterns of occupancy and dominance on natural shores, the experiments did not provide a predictive framework to anticipate the future events in any area. This is because of great variability in the timing and intensity of recruitment of planktonic propagules of all the components in the system, and in the density and activity of predatory whelks in different areas. These results suggest that tightly co-evolved community relationships are not likely to be important, even if they appear to exist, in communities where most of the species have widely dispersed pelagic offspring and interact in diverse and complex ways at different densities.

Does pursuit abnormality in schizophrenia represent a deficit in the predictive mechanism?

Although an abnormality of smooth pursuit eye movement has been consistently noted in schizophrenia, the underlying ocular motor pathophysiology is unknown. It is unclear whether the abnormality represents deficits in processing of information provided by the moving target, generation of pursuit eye movements, or other ocular motor and related cognitive processes. To evaluate the ability to process information provided by a moving target, saccadic accuracies were studied in step-ramp and single step tasks. Schizophrenic (with and without tardive dyskinesia [TD]) and normal subjects made equally accurate initial corrective saccades to the moving target. Thus, when the target jumped and then smoothly moved (creating a position and a velocity error on the retina), the patients were able to process retinal motion information and generate a normally accurate saccadic response. After the initial corrective saccade, both groups followed the target with a combination of pursuit eye movements and occasional catch-up saccades. During this period, the retinal velocity error is minimal because the eye approximates the target motion, and the major source of target motion information both for the smooth pursuit and saccadic responses is extra-retinal (i.e., predictive mechanism). The accuracies of catch-up saccades were significantly lower in the schizophrenic patients than in the normal subjects. During this period, overall pursuit performance, measured by pursuit gain, was also significantly worse in the patients. Accuracies of subsequent catch-up saccades, but not initial corrective saccades, significantly predicted the pursuit gain. Low pursuit gain was associated with high numbers of saccades per time spent in pursuit, which were similar in both schizophrenic subgroups (i.e., with and without TD), but were only significantly higher in the patients with TD than in the normal subjects. These preliminary data suggest that schizophrenic patients are able to process retinal motion information but have difficulties in using extra-retinal motion information to generate an appropriate saccadic response.

[Prevalence of porphyria cutanea tarda in Madrid and relationship between urine porphyrin and ethanol intake in a multiple linear regression model]. / Prevalencia de porfiria cutánea tarda en Madrid y asociación entre la porfirinuria y el consumo de etanol en un modelo de regresión lineal múltiple.

BACKGROUND: The application of a simple fluorometric analytical method enabled us to quantify the urinary porphyrin excretion and to establish the prevalence of porphyria cutanea tarda (PCT) in the town of Madrid, Spain, in a cross-sectional study. PATIENTS AND METHODS: The study assessed 1,613 subjects from three districts in Madrid, in whom further variables potentially related to porphyrinuria such as ethanol intake or -in women-oral contraceptive use were measured and recorded. RESULTS: The estimated prevalence of the disease was 1.24 cases per 1,000 inhabitants (95% confidence interval 0.15-4.47 per thousand). After excluding from the study sample all cases with existent disease, an analysis was performed to ascertain an unilateral tolerance interval for urinary porphyrin concentration in the adult population; this level was established at 181.2 micrograms/l. The effect of ethanol intake on porphyrinuria was considered significant using a multiple linear regression model adjusted for the control variables gender, age and body mass index. In fertile women, contraceptive use did not attain statistical significance when that variable was included in a multiple regression model. CONCLUSIONS: A high prevalence has been estimated for PCT in the Madrid population. A significant association was further found between alcohol intake and porphyrinuria in non-porphyric adults.

Identification of Down's syndrome adults from prolonged vowel samples.

Special educators and speech pathologists were both able to distinguish adults with Down's syndrome from nonretarded adults with voice disorders based only on prolonged vowel samples. Listeners indicated that resonance differences may have helped them to identify Down's syndrome speakers. Differences in formant frequencies and perceived hypernasality between Down's syndrome and nonretarded speakers, however, were nonsignificant. Formant frequency measures and perceived nasality ratings obtained from Down's syndrome adults in the present study are in contrast to such measures obtained from Down's syndrome children in previously reported studies.

Relation between voice profile ratings and aerodynamic and acoustic parameters.

The present study sought to examine the relation between Wilson Voice Profile ratings and certain aerodynamic and acoustic variables. Subjects in this study were 20 adults with voice disorders and five adults with no voice disorders. A series of stepwise multiple correlations were used. The variance in perceptual ratings accounted for by aerodynamic and acoustic variables included in the present study ranged from 29% for tension ratings of connected speech to 81% for pitch ratings of connected speech for the female speakers. It is clear from the present findings that ratings on the Wilson Voice Profile are only partially accounted for by the variables included in the present study.

Succession management: a model for developing nursing leaders.

Succession management is critical to all healthcare organizations as they respond to the cost-cutting initiatives brought about by the prospective payment era. This personnel management system ensures that motivated individuals enter and ascend the management hierarchy consistently. Such stabilization is reflected in turnover vacancy rates of < 12 percent and < 9 percent, respectively, at a time of unprecedented competition for professional nurses. This provides not only greater professional advancement but also stability for patient care delivery.

A compact proton spectrometer for measurement of the absolute DD proton spectrum from which yield and ρR are determined in thin-shell inertial-confinement-fusion implosions.

A compact, step range filter proton spectrometer has been developed for the measurement of the absolute DD proton spectrum, from which yield and areal density (ρR) are inferred for deuterium-filled thin-shell inertial confinement fusion implosions. This spectrometer, which is based on tantalum step-range filters, is sensitive to protons in the energy range 1-9 MeV and can be used to measure proton spectra at mean energies of ∼1-3 MeV. It has been developed and implemented using a linear accelerator and applied to experiments at the OMEGA laser facility and the National Ignition Facility (NIF). Modeling of the proton slowing in the filters is necessary to construct the spectrum, and the yield and energy uncertainties are ±<10% in yield and ±120 keV, respectively. This spectrometer can be used for in situ calibration of DD-neutron yield diagnostics at the NIF.

Deuterium-tritium neutron yield measurements with the 4.5 m neutron-time-of-flight detectors at NIF.

The first several campaigns of laser fusion experiments at the National Ignition Facility (NIF) included a family of high-sensitivity scintillator∕photodetector neutron-time-of-flight (nTOF) detectors for measuring deuterium-deuterium (DD) and DT neutron yields. The detectors provided consistent neutron yield (Y(n)) measurements from below 10(9) (DD) to nearly 10(15) (DT). The detectors initially demonstrated detector-to-detector Y(n) precisions better than 5%, but lacked in situ absolute calibrations. Recent experiments at NIF now have provided in situ DT yield calibration data that establish the absolute sensitivity of the 4.5 m differential tissue harmonic imaging (DTHI) detector with an accuracy of ± 10% and precision of ± 1%. The 4.5 m nTOF calibration measurements also have helped to establish improved detector impulse response functions and data analysis methods, which have contributed to improving the accuracy of the Y(n) measurements. These advances have also helped to extend the usefulness of nTOF measurements of ion temperature and downscattered neutron ratio (neutron yield 10-12 MeV divided by yield 13-15 MeV) with other nTOF detectors.

Neutron spectrometry--an essential tool for diagnosing implosions at the National Ignition Facility (invited).

DT neutron yield (Y(n)), ion temperature (T(i)), and down-scatter ratio (dsr) determined from measured neutron spectra are essential metrics for diagnosing the performance of inertial confinement fusion (ICF) implosions at the National Ignition Facility (NIF). A suite of neutron-time-of-flight (nTOF) spectrometers and a magnetic recoil spectrometer (MRS) have been implemented in different locations around the NIF target chamber, providing good implosion coverage and the complementarity required for reliable measurements of Y(n), T(i), and dsr. From the measured dsr value, an areal density (ρR) is determined through the relationship ρR(tot) (g∕cm(2)) = (20.4 ± 0.6) × dsr(10-12 MeV). The proportionality constant is determined considering implosion geometry, neutron attenuation, and energy range used for the dsr measurement. To ensure high accuracy in the measurements, a series of commissioning experiments using exploding pushers have been used for in situ calibration of the as-built spectrometers, which are now performing to the required accuracy. Recent data obtained with the MRS and nTOFs indicate that the implosion performance of cryogenically layered DT implosions, characterized by the experimental ignition threshold factor (ITFx), which is a function of dsr (or fuel ρR) and Y(n), has improved almost two orders of magnitude since the first shot in September, 2010.