Isospin Symmetry at High Spin Studied via Nucleon Knockout from Isomeric States.

One-neutron knockout reactions have been performed on a beam of radioactive ^{53}Co in a high-spin isomeric state. The analysis is shown to yield a highly selective population of high-spin states in an exotic nucleus with a significant cross section, and hence represents a technique that is applicable to the planned new generation of fragmentation-based radioactive beam facilities. Additionally, the relative cross sections among the excited states can be predicted to a high level of accuracy when reliable shell-model input is available. The work has resulted in a new level scheme, up to the 11^{+} band-termination state, of the proton-rich nucleus ^{52}Co (Z=27, N=25). This has in turn enabled a study of mirror energy differences in the A=52 odd-odd mirror nuclei, interpreted in terms of isospin-nonconserving (INC) forces in nuclei. The analysis demonstrates the importance of using a full set of J-dependent INC terms to explain the experimental observations.

Evolution of collectivity in 72Kr: evidence for rapid shape transition.

The transition rates from the yrast 2+ and 4+ states in the self-conjugate 72Kr nucleus were studied via lifetime measurements employing the GRETINA array with a novel application of the recoil-distance method. The large collectivity observed for the 4+→2+ transition suggests a prolate character of the excited states. The reduced collectivity previously reported for the 2+→0+ transition was confirmed. The irregular behavior of collectivity points to the occurrence of a rapid oblate-prolate shape transition in 72Kr, providing stringent tests for advanced theories to describe the shape coexistence and its evolution.

Quadrupole transition strength in the (74)Ni nucleus and core polarization effects in the neutron-rich Ni isotopes.

The reduced transition probability B(E2;0(+)→2(+)) has been measured for the neutron-rich nucleus (74)Ni in an intermediate energy Coulomb excitation experiment performed at the National Superconducting Cyclotron Laboratory at Michigan State University. The obtained B(E2;0(+)→2(+))=642(-226)(+216) e(2) fm(4) value defines a trend which is unexpectedly small if referred to (70)Ni and to a previous indirect determination of the transition strength in (74)Ni. This indicates a reduced polarization of the Z=28 core by the valence neutrons. Calculations in the pfgd model space reproduce well the experimental result indicating that the B(E2) strength predominantly corresponds to neutron excitations. The ratio of the neutron and proton multipole matrix elements supports such an interpretation.

Nuclear structure towards N = 40 60Ca: in-beam γ-ray spectroscopy of 58,60Ti.

Excited states in the neutron-rich N = 38, 36 nuclei (60)Ti and (58)Ti were populated in nucleon-removal reactions from (61)V projectiles at 90 MeV/nucleon. The γ-ray transitions from such states in these Ti isotopes were detected with the advanced γ-ray tracking array GRETINA and were corrected event by event for large Doppler shifts (v/c ∼ 0.4) using the γ-ray interaction points deduced from online signal decomposition. The new data indicate that a steep decrease in quadrupole collectivity occurs when moving from neutron-rich N = 36, 38 Fe and Cr toward the Ti and Ca isotones. In fact, (58,60)Ti provide some of the most neutron-rich benchmarks accessible today for calculations attempting to determine the structure of the potentially doubly magic nucleus (60)Ca.

Mirror energy differences at large isospin studied through direct two-nucleon knockout.

The first spectroscopy of excited states in 52Ni (T(z)=-2) and 51Co (T(z)=-3/2) has been obtained using the highly selective two-neutron knockout reaction. Mirror energy differences between isobaric analogue states in these nuclei and their mirror partners are interpreted in terms of isospin nonconserving effects. A comparison between large-scale shell-model calculations and data provides the most compelling evidence to date that both electromagnetic and an additional isospin nonconserving interactions for J=2 couplings, of unknown origin, are required to obtain good agreement.

Quadrupole collectivity in neutron-rich Fe and Cr isotopes.

Intermediate-energy Coulomb excitation measurements are performed on the N ≥ 40 neutron-rich nuclei (66,68)Fe and (64)Cr. The reduced transition matrix elements providing a direct measure of the quadrupole collectivity B(E2;2(1)(+) → 0(1)(+)) are determined for the first time in (68)Fe(42) and (64)Cr(40) and confirm a previous recoil distance method lifetime measurement in (66)Fe(40). The results are compared to state-of-the-art large-scale shell-model calculations within the full fpgd neutron orbital model space using the Lenzi-Nowacki-Poves-Sieja effective interaction and confirm the results of the calculations that show these nuclei are well deformed.

Comparison of cryoprecipitate with fibrinogen concentrate for acquired hypofibrinogenaemia.

BACKGROUND: The benefits of fibrinogen concentrate in hypofibrinogenaemia have been established in congenital and has been used in acquired disorders. Most European countries have already changed their practice, using fibrinogen concentrate. METHODS: We compared the use of fibrinogen concentrate in acquired hypofibrinogenaemia to cryoprecipitate, which continues to be the standard of care in the UK. We undertook a retrospective analysis of fibrinogen increment in patients treated for acquired hypofibrinogenaemia. RESULTS: Sixty four transfusion episodes receiving cryoprecipitate and 36 episodes receiving fibrinogen concentrate were compared. The median increment following 10 donor pools (two bags) of cryoprecipitate was 0.26 g/l, compared to 0.44 g/l following 2g of fibrinogen concentrate. CONCLUSION: With its superior safety profile from infectious diseases, this provides further evidence to support the use of fibrinogen concentrate.

Structural evolution in the neutron-rich nuclei ¹°6Zr and ¹°8Zr.

The low-lying states in ¹°6Zr and ¹°8Zr have been investigated by means of ß-γ and isomer spectroscopy at the radioactive isotope beam factory (RIBF), respectively. A new isomer with a half-life of 620 ± 150 ns has been identified in ¹°8Zr. For the sequence of even-even Zr isotopes, the excitation energies of the first 2⁺ states reach a minimum at N = 64 and gradually increase as the neutron number increases up to N = 68, suggesting a deformed subshell closure at N = 64. The deformed ground state of ¹°8Zr indicates that a spherical subshell gap predicted at N = 70 is not large enough to change the ground state of ¹°8Zr to the spherical shape. The possibility of a tetrahedral shape isomer in ¹°8Zr is also discussed.

ß-decay half-lives of very neutron-rich Kr to Tc isotopes on the boundary of the r-process path: an indication of fast r-matter flow.

The ß-decay half-lives of 38 neutron-rich isotopes from (36)Kr to (43)Tc have been measured; the half-lives of (100)Kr, (103-105)Sr, (106-108)Y, (108-110)Zr, (111,112)Nb, (112-115)Mo, and (116,117)Tc are reported here. The results when compared with previous standard models indicate an overestimation in the predicted half-lives by a factor of 2 or more in the A≈110 region. A revised model based on the second generation gross theory of ß decay better predicts the measured half-lives and suggests a more rapid flow of the rapid neutron-capture process (r-matter flow) through this region than previously predicted.

New superheavy element isotopes: ²4²Pu(48Ca,5n) ²85114.

The new, neutron-deficient, superheavy element isotope ²85114 was produced in 48Ca irradiations of ²4²Pu targets at a center-of-target beam energy of 256 MeV (E*=50 MeV). The α decay of ²85114was followed by the sequential α decay of four daughter nuclides, 281Cn, 277Ds, 273Hs, and 269Sg. 265Rf was observed to decay by spontaneous fission. The measured α-decay Q values were compared with those from a macroscopic-microscopic nuclear mass model to give insight into superheavy element shell effects. The²4²Pu (48Ca,5n²)²85114 cross section was 0.6(-0.5)+0.9 pb.

Development and organization of outpatient surgery units: the hospital's perspective.

Many indicators suggest continued growth in the ambulatory surgery arena. Economic pressures, technology, and third-party payers are contributing to this trend. Hospital admissions and inpatient stays are declining. The patient base is shifting to more economical settings. The impact of these factors has been considered throughout this discussion. These occurrences have prompted hospitals to diversify and to create organizational structures that provide opportunities for a total health care business approach. The success of ambulatory surgery programs developed by hospitals has been a major contributor to the continuation of these reorganization efforts. Acceptance on the part of patients and physicians is the major contributing factor to the continued growth of outpatient surgery units. Marketing techniques and consumer-oriented programs, coupled with efficiency and reduced costs, also assure that the ambulatory surgery phenomenon is here to stay.

Accreditation of ambulatory surgery centers.

Accreditation is required for outpatient surgery facilities not only to assure quality patient care but also to obtain a facility fee reimbursement from many insurance companies. General guidelines concerning subjects considered by the JCAH and the AAAHC in the accreditation process have been reviewed. Because actual physical construction features may affect accreditation, those planning office-based and other types of outpatient surgery facilities should be aware of accreditation requirements before construction is begun.

Weighted least-squares criteria for electrical impedance tomography.

Methods are developed for the design of electrical impedance tomographic reconstruction algorithms with specified properties. Assuming a starting model with constant conductivity or some other specified background distribution, an algorithm with the following properties is found. (1) The optimum constant for the starting model is determined automatically. (2) The weighted least-squares error between the predicted and measured power dissipation data is as small as possible. (3) The variance of the reconstructed conductivity from the starting model is minimized. (4) Potential distributions with the largest volume integral of gradient squared have the least influence on the reconstructed conductivity, and therefore distributions most likely to be corrupted by contact impedance effects are deemphasized. (5) Cells that dissipate the most power during the current injection tests tend to deviate least from the background value. For a starting model with nonconstant conductivity, the reconstruction algorithm has analogous properties.

Dispersion in poroelastic systems.

We address one key source of the known discrepancies between theory and experiment in poroelasticity, i.e., the fact that Gassmann's equations for the bulk and shear moduli predict that the shear modulus is independent of the saturating fluid properties, whereas it is observed on the contrary that at high enough frequencies the shear modulus can in fact depend on the fluid's elastic properties in many porous materials. One clue to understanding this behavior comes from effective medium theory, which shows that the shear modulus does depend on the fluid properties in many circumstances. In comparison to values predicted by effective medium theory, Gassmann's equations predict different, smaller values for both the effective bulk and shear moduli of porous media. Sorting through these apparent (but not actual) disagreements among theory and theory, and theory and experiment is the main thrust of the paper.

The effects of training in nonaversive behavior management on the attitudes and understanding of direct care staff.

Recent developments in behavior therapy for persons with developmental disabilities and behavior disorders emphasize positive treatment designs that focus on understanding the causes of behavior, teaching functional alternatives, and enhancing the quality of daily experiences, rather than simple contingency management. There is little information on how well direct care staff can support these nonaversive strategies. This study examined the effects of training in traditional (positive) behavior management versus nonaversive principles on the understanding and attitudes of direct care staff. Overall, nonprofessional level staff receiving the nonaversive training showed increased sophistication in understanding the range of possible causes of behavior and were able to generate treatment suggestions based on skill development and environmental change. The effectiveness of staff in implementing state-of-the-art behavior therapy procedures is likely to be an important component of the continued success of behavior therapy, especially in residential settings, both institutional and community-based.

Polioencephalomalacia and photosensitization associated with Kochia scoparia consumption in range cattle.

Cattle consuming only Kochia scoparia in a pasture southeastern Colorado became ill. Clinical signs were lacrimation, depression, anorexia, nystagmus, head pressing, and recumbency. Some cattle died acutely, with the only clinical signs being recumbency, nystagmus, and occasionally opisthotonos. Pathologic findings were pulmonary edema and congestion, hepatic necrosis and fibrosis, necrosis of proximal convoluted tubular epithelium in the kidneys, epidermal necrosis of lightly pigmented areas, and laminar cerebrocortical necrosis. When the cattle were removed from the pasture, the problem ceased.

Pet owner attitudes to pets and people: a psychological study.

A preliminary attempt was made to assess how pet owners view their relationships with their pets and how pet relationships compare with human relationships. In the sample studied there was a marked variation between individuals in their perceptions but two group trends emerged. First, the pet relationship was most similar to the relationship to the individual's own child and, secondly, the pet relationship was frequently valued because of the attributes of 'dependency', 'fun/play' and 'relaxation based on absence of demands'. It is suggested that the personal meaning of pets for people needs to be further explored.