Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at sqrt[s]=510 GeV in p[over →]+p[over →] Collisions

We present measurements of the cross section and double-helicity asymmetry A_{LL} of direct-photon production in p[over →]+p[over →] collisions at sqrt[s]=510  GeV. The measurements have been performed at midrapidity (|η|<0.25) with the PHENIX detector at the Relativistic Heavy Ion Collider. At relativistic energies, direct photons are dominantly produced from the initial quark-gluon hard scattering and do not interact via the strong force at leading order. Therefore, at sqrt[s]=510  GeV, where leading-order-effects dominate, these measurements provide clean and direct access to the gluon helicity in the polarized proton in the gluon-momentum-fraction range 0.02<x<0.08, with direct sensitivity to the sign of the gluon contribution.

Simulated Performance of Laser-Machined Metamaterial Anti-reflection Coatings

Lenslet-coupled antenna arrays have been used in CMB experiments and are the baseline technology for the next-generation satellite missions such as LiteBIRD and PICO. Lenslets are small hemispherical lenses mounted on the focal plane that couple light to the detectors and are typically made of silicon or alumina due to their high focusing power and low absorption loss. To minimize reflection at the vacuum-dielectric interface, lenslets require anti-reflection (AR) coatings. Metamaterials have been used in large microwave optical components because they avoid any mismatch on the thermal expansion between the lens and its coating, but so far they have only been machined on surfaces of comparatively large radius of curvature. As a first step to understand the feasibility of machining metamaterial AR layers in lenslets through laser-etching for the LiteBIRD mission, a model in ANSYS HFSS was developed. The goal of the simulation was to optimize transmission in three frequency bands while meeting assumed laser machinability constraints and optical requirements. Simulation results from flat silicon show that an AR metamaterial coating made under the assumed conditions is feasible, and the baseline parameters for further curved-surface studies are provided.

Pseudorapidity Dependence of Particle Production and Elliptic Flow in Asymmetric Nuclear Collisions of p+Al, p+Au, d+Au, and ^{3}He+Au at sqrt[s_{NN}]=200 GeV

Asymmetric nuclear collisions of p+Al, p+Au, d+Au, and ^{3}He+Au at sqrt[s_{NN}]=200  GeV provide an excellent laboratory for understanding particle production, as well as exploring interactions among these particles after their initial creation in the collision. We present measurements of charged hadron production dN_{ch}/dη in all such collision systems over a broad pseudorapidity range and as a function of collision multiplicity. A simple wounded quark model is remarkably successful at describing the full data set. We also measure the elliptic flow v_{2} over a similarly broad pseudorapidity range. These measurements provide key constraints on models of particle emission and their translation into flow.

Centrality-Dependent Modification of Jet-Production Rates in Deuteron-Gold Collisions at √[s(NN)]=200 GeV

Jet production rates are measured in p+p and d+Au collisions at sqrt[s_{NN}]=200  GeV recorded in 2008 with the PHENIX detector at the Relativistic Heavy Ion Collider. Jets are reconstructed using the R=0.3 anti-k_{t} algorithm from energy deposits in the electromagnetic calorimeter and charged tracks in multiwire proportional chambers, and the jet transverse momentum (p_{T}) spectra are corrected for the detector response. Spectra are reported for jets with 12<p_{T}<50  GeV/c, within a pseudorapidity acceptance of |η|<0.3. The nuclear-modification factor (R_{dAu}) values for 0%-100% d+Au events are found to be consistent with unity, constraining the role of initial state effects on jet production. However, the centrality-selected R_{dAu} values and central-to-peripheral ratios (R_{CP}) show large, p_{T}-dependent deviations from unity, challenging the conventional models that relate hard-process rates and soft-particle production in collisions involving nuclei.

Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV

We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

Exploiting intrinsic triangular geometry in relativistic (3)He+Au collisions to disentangle medium properties

Recent results in d+Au and p+Pb collisions at RHIC and the LHC provide evidence for collective expansion and flow of the created medium. We propose a control set of experiments to directly compare particle emission patterns from p+Pb, d+Au, and ^{3}He+Au or t+Au collisions at the same sqrt[s_{NN}] . Using a Monte Carlo Glauber simulation we find that a ^{3}He or triton projectile, with a realistic wave function description, induces a significant intrinsic triangular shape to the initial medium. If the system lives long enough, this survives into a significant third-order flow moment v_{3} even with viscous damping. By comparing systems with one, two, and three initial hot spots, one could disentangle the effects from the initial spatial distribution of the deposited energy and viscous damping. These are key tools for answering the question of how small a droplet of matter is necessary to form a quark-gluon plasma described by nearly inviscid hydrodynamics.

High levels of HIF-2alpha highlight an immature neural crest-like neuroblastoma cell cohort located in a perivascular niche

High HIF-2alpha protein levels in the sympathetic nervous system-derived childhood tumour neuroblastoma as well as immature phenotype correlate to unfavourable outcome. Here we show that a small subset of perivascularly located, strongly HIF-2alpha-positive tumour cells (MYCN amplified) lacks expression of differentiation markers, but expresses neural crest and early sympathetic progenitor marker genes such as Notch-1, HES-1, c-Kit, dHAND, and vimentin. HIF-2alpha- and CD68-positive tumour-associated macrophages were frequently found close to the immature and HIF-2alpha-positive neuroblastoma cells and as VEGF levels are high in the perivascular niche, we hypothesize that neuroblastoma neural crest-like cells and macrophages cooperate to facilitate angiogenesis and thereby contribute to the aggressive neuroblastoma phenotype.

Arsenic trioxide-induced neuroblastoma cell death is accompanied by proteolytic activation of nuclear Bax

Arsenic trioxide (As(2)O(3)) is toxic to multidrug-resistant neuroblastoma cells in vivo and in vitro. In neuroblastoma, As(2)O(3) does not exert its cell death-promoting effects via a classical apoptotic pathway. A death mechanism involving proteolytic cleavage of Bax to a p18 form seems to be of importance, because inhibition of Bax cleavage coincides with diminished cell death. As existing models of cell death implicate Bax in the intrinsic apoptotic pathway, triggering death after Bax translocation to the mitochondria, we investigated the cellular localization of p18 Bax by subcellular fractionation. After As(2)O(3) treatment, p18 Bax was only present in nuclei-enriched, mitochondria-depleted fractions. Cytoplasmic p21 Bax levels decreased, whereas total (p21 and p18) nuclear Bax increased. Overexpressed p21 Bax localized to the cytoplasm and nuclei, whereas overexpressed p18 Bax localized to extra-nuclear structures only. The inability of overexpressed p18 Bax to locate to the nucleus, and the As(2)O(3)-induced reduction of p21 Bax in the cytosol, suggest an As(2)O(3)-induced mechanism where p18 Bax gets cleaved and 'trapped' in the nucleus. This model is strengthened by the observation that calpain, the protease responsible for p18 Bax generation, is present in the nuclei, and that nuclear calpain is induced by increasing As(2)O(3) and Ca(2+) levels.

Professional liability in a neonatal intensive care unit: a review of 20 years' experience

OBJECTIVE

To examine neonatal intensive care unit (NICU) malpractice claims and identify common characteristics likely to result in malpractice.

STUDY DESIGN

A retrospective study (1972 to 1992) at a tertiary care children's hospital examining malpractice claims involving NICU infants.

RESULTS

A total of 31 cases of malpractice out of 9367 NICU admissions (incidence 0.33%) were found. Although not statistically significant, the incidence of legal action increased with NICU growth from 0.19% (1972 to 1974) to 0.39% (1980 to 1992). Infants who were significantly over-represented in malpractice cases compared with the general NICU population included those who were full-term, white, privately insured, and those with neurologic conditions. Families' motives for legal action included (1) treatment error/delay (48%), (2) missed/delayed diagnosis (16%), (3) equipment malfunction/misuse (6%), and (4) general improper care (30%).

CONCLUSION

Based on this research, three factors may be associated with increased risk of malpractice in the NICU: (1) increased unit growth, (2) parental perceptions of negligence, and (3) full-term infants with diagnoses associated with neurologic conditions.

Radiation injury & mercury deposits in internal organs as a result of thallium-201 chloride intravenous injection for SPECT imaging; additional biochemical information obtained in the images of organs from SPECT or PET scans; & potential injury due to radiation exposure during long distance flights

In order to study functional as well as anatomical aspects of various internal organs, SPECT (Single Photon Emission Computerized Tomography) has been used extensively for evaluation of these organs. For SPECT study, intravenous injection of radioactive substances such as technetium-99m (20 millicuries) & thallium-201 chloride (3 millicuries) is commonly used. Although the physical half-life of thallium-201 chloride is 73 hours, its biological half-life is often more than 3.5 times that. Following intravenous injection of thallium-201 chloride it is concentrated in the heart, liver, kidneys, pancreas, thyroid gland, testes or ovaries, and then eventually decays to mercury. Because of its relatively long physical & biological half-lives, thallium-201 chloride may produce mild radiation injury while it remains radioactive. Similar injuries may be induced by technetium-99m (often used for brain SPECT), which radiates Gamma rays (140 KeV), but since its physical half-life is only 6 hours, the side effects are not as significant as those of thallium-201 chloride. Since the main component of thallium-201 chloride radiation is X-ray (68-82 KeV), which consists of photons with a very short wavelength and a high penetrating power, prolonged exposure can induce electromagnetic field-induced injury. As a previous study of the principal author on electromagnetic field exposure indicated, electromagnetic field-induced injury causes the change of L-amino acids to D-amino acids. 2 days after SPECT study of the heart with intravenous injection of thallium-201 chloride, the principal author experienced shortness of breath, loss of appetite, dizziness, fever, and general malaise within the week, and found a progressively significant increase in D-glutamic acid and decrease in L-glutamic acid peaking 2 weeks after the initial injection but lasting for many weeks after in organs such as the heart, liver, kidneys, pancreas, thyroid gland & testes, where radioactive substances had accumulated and radiation was at an average of about 400 counts/min. Even 2 months after the initial injection, the abnormal ratio of D-amino acids and L-amino acids had not returned to normal (in the radiation exposed heart, L-amino acids: 6 mg/dl with D-amino acids: 5 mg/dl; normal tissue, L-amino acids: 10 mg/dl with D-amino acids < 1 mg/dl). The principal author tried to find a safe method of reducing possible radiation injury and accelerating the elimination of the already deposited mercury.(ABSTRACT TRUNCATED AT 400 WORDS)

The functional affinities of antibodies of different IgG subclasses to dietary antigens in mothers and their babies

The quantity and functional affinities of IgG1 and IgG4 antibodies to the dietary antigens casein and ovalbumin were measured in unselected mothers and their 1-year-old infants. In these infants, the titre of IgG antibodies to both antigens was highest in the IgG1 subclass, while in their mothers the titre of IgG1 and IgG4 antibodies to these foods was similar. High affinity IgG4 responses to both casein and ovalbumin were frequently found in mothers, whilst IgG1 responses, particularly to ovalbumin, were of low functional affinity. By contrast, in the 1-year-old infants, the functional affinity of IgG1 antibody to ovalbumin was substantially higher than in their mothers (Student's paired t-test, P < 0.001), indicating that higher affinity IgG1 antibody was produced on first exposure to ovalbumin rather than following chronic exposure. The effect of antigenic load on affinity maturation was further investigated by comparing the affinity of IgG1 antibody to casein in bottle, mixed and breast fed infants. Bottle fed infants had significantly higher-affinity IgG1 antibodies to casein compared with breast or mixed fed infants (Student's unpaired t-test, P < 0.01 and 0.02), suggesting that antigen exposure via the gut was able to drive the affinity maturation process. In studying the immune response it is clear that account must be taken of the affinity as well as of the titre of the antibody produced.

[Drug therapy of depression in general practice]

The authors advocate use of the Montgomery-Asberg Depression Rating Scale in general practice as a screening instrument for depression. A score of 20 and above for more than two weeks indicates a need for treatment with antidepressant drugs. The treatment should continue with full dosage for at least two months after the patient has been cured. In order to maintain the patient's quality of life, reduce risk of drug-related toxicity and improve compliance, we recommend alfa-2-receptor blocker, a selective 5HT-re-uptake inhibitor or a selective monoamino-oxidase A inhibitor as the first drug choice for treatment of depression by general practitioners. Monitoring serum levels of the drug may be helpful, especially in persons who do not respond to treatment.

HIV isolation and antigen detection in infected individuals and their seronegative sexual partners

We have examined 39 couples, each consisting of one HIV-seropositive index case and one seronegative sexual partner. HIV isolations, HIV antigen (HIV-Ag) tests and HIV antibody tests were performed on samples from these 78 individuals. Results were compared with those of 68 unselected individuals. Neither HIV, nor HIV-Ag was detected in any of the seronegative individuals. HIV-Ag tests, but not HIV isolations showed positive results with a significantly lower frequency in symptomatic index cases than in unselected patients with symptoms. This indicates that the absence of HIV-Ag in the serum may be correlated with a low level of contagiousness.

HIV transmission by blood transfusions in Stockholm 1979-1985: nearly uniform transmission from infected donors

Thirty-five out of approximately 800 known HIV-seropositive people in Stockholm by mid-1986 were blood donors during the period 1979-1986. Almost all, i.e. 349 recipients of their blood components (red blood cells, platelets, plasma) could be traced. One hundred and eighty were still alive and 112 of these on further analysis, were suspected of being infected. They were contacted and all but one agreed to be tested for HIV antibodies. Fifty recipients were found to be seropositive. They had been transfused with blood components from 14 of the 35 donors. The earliest observed transmission occurred in June 1982. The patterns of HIV transmission showed, with only one exception, that each donor who had transmitted HIV to one recipient had also transmitted it to all later recipients. Appropriate preserved sera and clinical records from five of the donors who had not transmitted the virus were found and analysed. The result indicated that these donors had acquired their HIV infection after their last blood donation. In conclusion, our study indicates that every antibody-positive donor transmits HIV to almost every recipient.

Comparison of two enzyme immunoassays and an immunofluorescence test for detection of Chlamydia trachomatis

Three rapid methods for the detection of Chlamydia trachomatis were compared: one immunofluorescence test and two enzyme immunoassays. Cervical and urethral specimens were obtained from 75 women in an outpatient clinic for therapeutic abortions and from 50 women in a sexually transmitted disease clinic. Urethral specimens were also obtained from 154 men in the same clinic. One hundred and nineteen cervical and 272 urethral specimens of a total 391 specimens were tested by the three methods. The direct immunofluorescence test detected Chlamydia trachomatis in 8% and the two enzyme immunoassays in 10% and 12% of the patients. The sensitivity of the immunofluorescence test was 76% compared to 91% and 80% for the two enzyme immunoassay tests. All three tests had a specificity of 99%. Dilution experiments confirmed that one immunoassay test, Chlamydiazyme, detected most of the positive specimens. The rapid and easily automated enzyme immunoassays are a valuable complement to the culture technique.