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CeAlGe, a proposed type-II Weyl semimetal, orders antiferromagnetically below 5 K. At 2 K, spin-flop and a spin-flip transitions to less than 1 $\mu_B$/Ce are observed in the $M(H)$ data below 30 kOe, ($\bf{H}\|\bf{a}$ and $\bf{b}$, and 4.3 kOe, $\bf{H}\|\langle110\rangle$, respectively, indicating a four-fold symmetry of the $M(H)$ data along the principal directions in the tetragonal $\it{ab}$ plane with $\langle110\rangle$ set of easy directions. However, anomalously robust and complex twofold symmetry is observed in the angular dependence of resistivity and magnetic torque data in the magnetically ordered state once the field is swept in the $\it{ab}$ plane. This twofold symmetry is independent of temperature and field hystereses and suggests a magnetic phase transition that separates two different magnetic structures in the $\it{ab}$ plane. The boundary of this magnetic phase transition and possibly the type of low-field magnetic structure can be tuned by an Al deficiency.

We present a comprehensive ultrasound study of the prototypical heavy-fermion material CeRhIn$_5$, examining the origin of the enigmatic 30 T transition. For a field applied at 2$^\circ$ from the $c$ axis, we observed two sharp anomalies in the sound velocity, at $B_m \approx$ 20 T and $B^* \approx$ 30 T, in all the symmetry-breaking ultrasound modes at low temperatures. The lower-field anomaly corresponds to the well-known first-order metamagnetic incommensurate-to-commensurate transition. The higher-field anomaly takes place at 30 T, where an electronic-nematic transition was previously suggested to occur. Both anomalies, observed only within the antiferromagnetic state, are of similar shape, but the corresponding changes of the ultrasound velocity have opposite signs. Based on our experimental results, we suggest that a field-induced magnetic transition from a commensurate to another incommensurate antiferromagnetic state occurs at $B^*$. With further increasing the field angle from the $c$ axis, the anomaly at $B^*$ slowly shifts to higher fields, broadens, and becomes smaller in magnitude. Traced up to 30$^\circ$ from the $c$ axis, it is no longer observed at 40$^\circ$ below 36 T., 9 pages, 10 figures. To be published in Phys. Bev. B

Spatial patterns of singing crickets in populations of Teleogryllus commodus are mapped and their development and regulation are analysed in terms of the migratory and acoustical behaviour of this species. Attraction of male and female crickets to the calling song followed by territorial spacing of the ♂♂ was established using singing crickets or loudspeakers as decoys. The time adult male crickets remain at their burrows has an upper limit of 14 days and most positions are occupied for one day or less, indicating readjustments to spacing with time. Zusammenfassung Raumliche Verteilungsmuster von singenden Teleogryllus commodus-♂♂ bei geringer und hoher Populationsdichte werden beschrieben. Die akustische Anlockung adulter Grillen beiderlei Geschlechts durch gekafigte, singende Grillen wird aufgezeigt und eine territoriale Verteilung von in der Nahe der Schallquellen freigelassenen ♂♂ demonstriert. Ein Verhaltensmechanismus, der bestimmt, wie Grillen sich raumlich verteilen, wird vorgeschlagen; er berucksichtigt die Wanderaktivitat und die anlockende, sowie abstandsfordernde Funktion des Lockgesangs. Der adaptive Wert des beobachteten Verhaltens wird diskutiert.

This paper discusses the ecological gradient as an organizing framework to assist understanding the complex interactions between societal and ecological processes underlying land-use change in East Africa. Detailed case studies on the gradients of the slopes of Mt Kilimanjaro, Kenya show how land-use change is responsive to the dynamics of both local and external driving forces. The study has shown that the distinct ecological conditions at the extremities of gradients are associated with specific land uses which may be different within livelihood systems such as for wet and dry season grazing. Access to water for cultivation, domestic use, livestock and wildlife is critical in determining the nature and distribution of livelihood systems. Land-use systems interact across the different ecological zones of the gradients characterized by vigorous spatial, cultural and economic interactions. Sometime conflicts occur between or within land-use/livelihood systems. There is strong evidence that the areas of higher economic potential remain advantaged compared with areas lower on the gradient. The ecological characteristics have been found to influence human activities and distribution. Interactions between societies are important in terms of trade, social relations and access to resources.

The tubulin dimers of microtubules are arranged in a crystalline lattice which is wrapped to form a long cylinder. Two different arrangements of monomers within the lattice have been postulated: the A-lattice and the B-lattice. Previous studies have assumed that both lattice types are hexagonal with each dimer surrounded by six nearest-neighbors. Based on recent biochemical studies I argue that both lattice types can also be formed with each dimer having four nearest-neighbors. This has important consequences for the overall behavior of the model. It is generally assumed that tubulin dimers possess a mobile electric dipole which can exist in one of two discrete Ising spin states: -1 (down) or +1 (up). The average of all these states within a microtubule is the mean polarization and is a measure of the dipole ordering within the lattice. Microtubule models with six nearest-neighbors behave like models of ferroelectric substances: at low temperatures the lattice is highly ordered with most (if not all) dipoles pointing in the same direction, but as the temperature increases, the degree of ordering decreases due to random thermal flipping of the dipoles. The mean polarization is particularly erratic at physiological temperatures. In contrast, when the microtubule lattice is modeled with four nearest-neighbors, the mean lattice polarization is quite stable and remains close to zero over a wide temperature range that includes 37°C (310K). This raises new questions about the biophysical role of microtubules.

Recent experiments on the Type I ELMy H-mode regime performed at JET with improved diagnostics have expanded the range of parameters for the study of Type I ELM energy and particle losses. Deviations from the standard behaviour of such losses in some areas of the Type I ELMy H-mode operating space have revealed that the ELM losses are correlated with the parameters (density and temperature) of the pedestal plasma before the ELM crash, while other global ELM characteristics (such as ELM frequency) are a consequence of the ELM-driven energy and particle flux and of the in-between ELM energy and particle confinement. The relative Type I ELM plasma energy loss (to the pedestal energy) is found to correlate well with the collisionality of the pedestal plasma, showing a weak dependence on the method used to achieve those pedestal plasma parameters: plasma shaping, heating, pellet injection and impurity seeding. Effects of edge plasma collisionality and transport along the magnetic field on the Type I ELM particle and energy fluxes onto the divertor target have also been observed. Two possible physical mechanisms that may give rise to the observed collisionality dependence of ELM energy losses are proposed and their consistency with the experimental measurements investigated: collisionality dependence of the edge bootstrap current with its associated influence on the ELM MHD origin and the limitation of the ELM energy loss by the impedance of the divertor target sheath to energy flow during the ELM event.

This paper discusses how the proximity to the L-H threshold affects the confinement of ELMy H-modes at high density. The largest reduction in confinement at high density is observed at the transition from the Type I to the Type III ELMy regime. At medium plasma triangularity, δ0.3 (where δ is the average triangularity at the separatrix), JET experiments show that by increasing the margin above the L-H threshold power and maintaining the edge temperature above the critical temperature for the transition to Type III ELMs, it is possible to avoid the degradation of the pedestal pressure with density, normally observed at lower power. As a result, the range of achievable densities (both in the core and in the pedestal) is increased. At high power above the L-H threshold power the core density was equal to the Greenwald limit with H970.9. There is evidence that a mixed regime of Type I and Type II ELMs has been obtained at this intermediate triangularity, possibly as a result of this increase in density. At higher triangularity, δ0.5, the power required to achieve similar results is lower.

Possible effects of kiore (Rattus exulans) on selected indigenous tree species in coastal forests ot northern New Zealand are surveyed from recent field sampling and a literature review Recruitment rates are compared on islands with and without kiore (i) on the same island before or at the time of rat eradication compared with recruitment some years later, and (II) on geographically separated islands with and without kiore In addition kiore‐proof exclosurcs enabled some comparisons to be made of seed germination and survival in the presence and absence of kiore There is evidence that kiore have substantially reduced recruitment of Pittosporum crassifohum, Poutena costata Streblus banksu, and Nestegis apetala by eating the seed Seed consumption and/or depressed recruitment is demonstrated for Rhopalostyhs sapida, Vitex lucens and Pisoma brunoniana, but the extent ot recruitment reduction is not yet clear No depressive effect by kiore on the recruitment ot some species, including Dysoxylum spectabde Beilchm...

The surfaces of aqueous HNO3 solutions and liquid HNO3 are examined using sum frequency generation (SFG). A molecular-level picture of these atmospherically relevant systems is developed. Consisten...

In a pilot study, the authors investigated how irrigation of secondary sewage effluent onto steeply sloping land affected soil physical, chemical, and biochemical properties, the composition of soil- and surface-waters and the vegetation of the site. The 3.36-ha site received up to 44 mm effluent/wk for 65 wk. Irrigation significantly improved total- and Olsen-P status of the soils and greatly enhanced nitrification potential. Respiration increased with increasing soil water content, but microbial biomass was not greatly affected by irrigation. Soil phosphatase activity decreased with increasing P fertility. Soil physical properties were not affected by effluent and hydraulic conductivities were sufficient to conduct water into and through the soil profiles. Soil- and surface-water NO{sub 3}{sup {minus}}-N concentrations increased markedly, especially in the second half of the trial when soil nitrification rates were also high. However, the streamwater NO{sub 3}{sup {minus}}-N concentrations remained well below the drinking water limit concentration of 11.3 g m{sup {minus}3}. In contrast, streamwater NH{sub 4}{sup +}-N and PO{sub 4}{sup 3{minus}}-P concentrations remained low and results indicated that concentrations of PO{sub 4}{sup 3{minus}}-P in river water, resulting from a full-scale irrigation scheme, would not exceed the target limit level of 0.0056 g m{sup {minus}3}. Irrigation accelerated natural successionalmore » changes in the vegetation, with a decline in undesirable fire-prone and shrubby species and an increase in native trees and tree ferns. These results demonstrated that, in the short term at least, a carefully designed and implemented irrigation scheme on steepland could renovate secondary sewage effluent, without adversely affecting soil properties and surface water quality.« less

The surface-specific vibrational spectroscopy, sum frequency generation, has been used to study the structure of water at air/liquid interfaces of inorganic, ionic solutions. The experiments suggest that ions in solution reorient surface water into a more structured, hydrogen-bonded network compared with the neat water/air interface. In more concentrated solutions, there is a high degree of ion association. A model based on Hard Soft Acid Base theory indicates that associated ions are able to penetrate closer to the air interface than unassociated ions. Associated ions incorporate surface water into the ion-pair hydration shell.

Strong onshore winds and airborne sea salt can gradually defoliate trees at the exposed margin of temperate pine stands in New Zealand and induce a slowly moving front of dieback and regeneration. Overcrowded mature stands are vulnerable to crown abrasion: abrasion affects trees 20 m ahead of the dieback front; suppressed trees 12 m ahead die before the front reaches them. At the stand margin, trees die from abrasion and salt wind induced dieback. The dieback zone lets sunlight enter the stand; light-demanding pine seedlings establish, but a gradient of increasing litter depth from the dieback front and summer dryness restrict successful seedling establishment to a narrow zone that moves parallel with the dieback front and 11-13 m ahead of it. Further seedlings establish for 4-10 years before the juveniles form a closed canopy; competing vegetation is partly suppressed by infrequent cattle browsing. Regenerating juvenile maritime pine (Pinus pinaster Ait.), show a strict age-related gradation from the dieback front and indicate that wind and salt deposition have been constant for 30 years. Stands further from the sea, with lower stocking rates and other pine species, did not have a clear-cut regeneration zone, because there were no strong gradients of litter depth and light intensity. Resume : De forts vents du large et des embruns salins peuvent graduellement defolier les arbres de la bordure exposee des pinedes en Nouvelle-Zelande et provoquer un front de deperissement et de regeneration qui se deplace lentement. Les peuplements murs d'une trop forte densite sont vulnerables a l'abrasion des cimes. Celle-ci affecte les arbres situes 20 m en avant du front, alors que les arbres supprimes, se trouvant 12 m en avant, meurent avant que le front de deperissement les ait atteints. En bordure du peuplement, les arbres meurent a cause de l'abrasion et a cause du deperissement provoque par le vent charge de sel. Dans la zone de deperissement, la lumiere penetre dans le peuplement permettant l'etablissement des semis du pin heliophile. Cependant, l'augmentation graduelle de l'epaisseur de la litiere a partir du front et la secheresse estivale limitent le succes de l'etablissement des semis a une etroite bande qui se deplace parallelement au front en le precedant de 11 a 13 m. De nouveaux semis s'installent pendant 4 a 10 ans avant que les jeunes sujets forment une canopee fermee. La vegetation qui concurrence les semis est partiellement eliminee par le broutage occasionnel du betail. A partir du front de deperissement, la jeune regeneration du pin maritime (Pinus pinaster Ait.) montre une gradation d'âge stricte, qui indique que le vent et la deposition du sel ont ete constants durant 30 ans. Les peuplements eloignes de la mer, de faible densite relative et composes d'autres especes de pin, n'avaient pas de zone de regeneration clairement delimitee, car ils ne possedaient pas de gradients prononces d'epaisseur de la litiere et d'intensite lumineuse. (Traduit par la Redaction) Campbell 960

The vibrational structure of water at the air/solution interface of an ionic solution has been obtained for the first time. Using vibrational sum frequency generation it is determined that ions in solution have a large orientational effect on the structure of the surface water. Electrolytic solutions, ionic in nature, cause water to be oriented into a more regular hydrogen-bonded network through an electric double layer at the interface. In electrolytic solutions where molecular or associated H 2 SO 4 or Cs 2 SO 4 species dominate, the surface water molecules are bound into hydrate complexes. These effects are explained using hard soft acid base (HSAB) theory.

Summary Soil compaction is a concern worldwide, particularly where compactible soils are used for intensive agriculture in a wet climate. We have investigated the impact of compaction and the associated changes in soil structural qualities on crop production and environmental pollution. The overall objective was to develop soil management systems that provide suitable conditions for crop growth and minimize environmental damage. We ran large-scale field experiments studying the preservation of structural quality in arable and permanent grassland, using management systems such as the control or elimination of field traffic and the application of conservation tillage and zero tillage. We measured bulk density, shear strength, cone resistance, macroporosity, relative diffusivity, air permeability and water infiltrability to identify soil qualities that could be used for selecting suitable soil management. Along with crop yield, we measured environmental impacts, such as the emissions of nitrous oxide from the soil, which require the interaction of soil structure and water content near the soil surface. Soil structure influenced wetness, which affected trafficability, compaction and nitrogen retention. Measurement of properties that affect fluid storage and transport, such as macroporosity, provided soil quality indices that helped in recommending suitable soil management systems. Spatial variation of structure associated with wheel-track locations could be estimated rapidly using a cone penetrometer. Variation was particularly important in determining crop yield consistency. Crop productivity and soil structural qualities were preserved best when field traffic was eliminated. A reduced ground-pressure system successfully minimized compaction in grassland but was less effective in an arable rotation. Unless traffic is eliminated, good timing of operations is the most effective way to preserve soil structural quality.

Structural data about water at the air/water interface of sulfuric acid solutions have been obtained with sum frequency generation spectroscopy. Sulfuric acid significantly affects the orientation of water at the interface. With as little as 0.01x (mole fraction) sulfuric acid, water is more highly oriented compared with the pure water surface. Surface water with one hydrogen free of hydrogen bonding, a “free OH”, decreases in concentration as the sulfuric acid concentration is increased. Finally, there are no sulfuric acid free OH groups projecting out of the surface for solutions from 0.01x to 0.9x sulfuric acid. Observations of the structure of water are consistent with the fact that sulfuric acid/water solutions change from ionic in nature at low concentrations ( 0.4x).

The OH and CH regions of glycerol/water mixtures in the concentration range 0.0−1.0 mole fraction have been investigated with vibrational sum frequency generation. Glycerol is found to partition to the surface of these solutions in all concentrations. Neat glycerol surfaces contain no free OH groups projecting into the vapor. The surface orientation of glycerol is constant through most of the concentration range.

JET has conducted extensive experiments in H-mode plasmas focusing on two broad aims. The first, involving the characterization of reactor-relevant aspects of the regime, encompasses the study of steady-state H-modes at plasma currents of up to 6 MA. In these plasmas, energy confinement is typically a factor of 1.8 - 2 greater than predicted by L-mode scalings and local transport varies with the ion Larmor radius, at least for input powers well above the H-mode threshold power. Using nitrogen impurity seeding, a regime has been developed in which good core confinement, with an enhancement of 1.5 relative to L-mode scaling, is combined with radiated power fractions of up to 80%. The second major goal is to optimize fusion power production by exploiting high-confinement ELM-free H-modes, which exhibit energy confinement enhancement factors of three or more relative to L-mode plasmas. In this regime, fusion power quotients have been achieved, though the highest fusion performance is transient.

Several studies have shown that lowering of blood pressure slows the rate of progression of diabetic renal disease. Some placebo-controlled studies have also shown that angiotensin-converting enzyme (ACE) inhibitors decrease or stabilize albuminuria in incipient nephropathy and slow the rate of progression of advanced nephropathy. However, it is not yet clear if prolonged treatment with ACE inhibitors or with other agents exerts a specific renoprotective effect in incipient diabetic nephropathy. It is proposed that such an effect should be independent from changes in systemic blood pressure and should be characterized by amelioration of the rate of rise of albumin excretion rate (AER) and the rate of fall of glomerular filtration rate (GFR) and independence from changes in other parameters known to influence AER (glycemic control, protein intake, sodium intake). In addition, there should be evidence that the potentially reversible effects of therapeutic intervention on AER and GFR are translated to long-term changes in renal function and structure. This paper reviews the evidence on which the concept of renoprotection is based, with particular reference to choice of end points, heterogeneity of study groups, and complexities of the disease process, and relates this evidence to the natural history of nephropathy in type I and type II diabetes. Based on the above, an assessment is made of the comparative effects of ACE inhibitors and other antihypertensive agents on AER and GFR. It is suggested that longitudinal intra-individual analysis of both variables may be necessary in order to determine whether ACE inhibitors exert greater renoprotection than calcium channel blockers or other antihypertensive agents.

Concentrations of prolactin were measured by an immunoradiometric assay in 26 matched samples of amniotic fluid, extraembryonic coelomic fluid and maternal serum from 9 to 12 weeks of pregnancy and in a further 131 amniotic fluid samples from 9 to 20 weeks. Low levels of prolactin (median 40 MU/l) were present in amniotic fluid from 9 to 12 weeks. Levels in the coelomic fluid were higher (median level 371 MU/l; P0.0001) than in amniotic fluid. From 13 weeks, there was a rapid rise in amniotic fluid prolactin to reach a peak at 19 weeks (median level 99,850 MU/l). The pattern of increase of prolactin in amniotic fluid is similar to, but occurs 2 weeks later than that for insulin-like growth factor-binding protein-1, another major decidual product.

Concentrations of IGF-binding protein-1 (IGFBP-1) were measured by radioimmunassay in 176 amniotic fluid samples from 9 to 20 and 36 to 42 weeks of pregnancy. Low levels of IGFBP-1 were present at 9 and 10 weeks (median values 35.0 and 45.0 μg/l respectively). After 10 weeks, the levels increased by four orders of magnitude to reach a peak at 16 weeks (median 145.2 mg/l). After 16 weeks levels fell. Near term, the levels (median 27.1 mg/l) were lower than in the second trimester. The rapid increase in IGFBP-1 shown by radioimmunoassay was confirmed by Western ligand blotting. The findings suggest that the regulatory role of IGFBP-1 in the growth or differentiation of the fetus or of its surrounding membranes may change as pregnancy advances.

The resonance hyper‐Raman (RHR) scattering of CH3I vapor is observed as blue incident radiation is tuned through two‐photon resonance with the ν2 vibronic absorption band of the predissociative B←X Rydberg transition in the UV. In analogy to linear resonance Raman spectroscopy, the RHR band shapes and polarization are found to be a sensitive function of the two‐photon resonant vibronic state lifetime and detuning. The dependence of these scattering characteristics on the two‐photon excited‐state dephasing constant provides a technique for determining subpicosecond predissociation rates via nonlinear spontaneous Raman scattering. Theoretical fits to the observed resonant rovibrational hyper‐Raman depolarization ratio dispersion curves are obtained for a vibronic B‐state lifetime of 0.5±0.2 ps. This lifetime value is in agreement with previous results obtained from linear resonance Raman scattering studies. The polarization analysis of RHR scattering, in particular, provides a technique for measuring excited‐state lifetimes of molecular transitions in the VUV.

The polarization-resolved resonance hyper-Raman (RHR) scattering of CH3I vapor is observed as blue incident radiation is tune through two-photon resonance with the origin absorption band of the predissociative ∼ ← ∼ Rydberg transition in the VUV (183–175 nm). These results demonstrate the ability of this nonlinear Raman technique to probe the ultrafast dynamics of molecular levels in the VUV. The C-state lifetime is determined to be 180±30 fs by fits of theory to the depolarization ratio excitation profile and rovibrational hyper-Raman bandshapes. Hence, predissociation is approximately three times faster on the C-state than the B-state surface of CH3I (τ = 500 fs). Additionally, the depolarization ratio dispersion and RHR bandshapes indicate mode specific predissociation effects, at least for the ν3 methyl iodine vibronic C-state level, just as found for the B state.

SUMMARY This paper describes the development of a constant cell volume triaxial compression testing machine. This apparatus features a method for applying the deviator load to a soil specimen contained in a conventional triaxial testing machine without altering the volume of the fluid jacket. The technique utilizes the stiffness or compliance of the closed hydraulic system to monitor the volume changes taking place in the soil sample during shear failure. This information is obtained from the pressure changes taking place in the closed fluid system. The behaviour of a prototype apparatus of this type in testing a normally consolidated soil sample is analysed in some detail. These results, and others not discussed in the paper, demonstrate that the method has considerable scope in the rapid acquisition of quantitative data on the strength and volume change behaviour of unsaturated soils. A mathematical model of the system is developed and used to evaluate its performance and exhibits good agreement with experimental observations. The model also highlights how the provision of a variable compliance facility extends the range of state paths that can be achieved by the system.

Insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-1 (IGFBP-1) were measured in amniotic fluid, extraembryonic coelomic fluid and maternal serum from 23 women with apparently normal first trimester pregnancies prior to termination. The levels of IGF-1 and IGFBP-1 were significantly higher in coelomic fluid than amniotic fluid (IGF-1, P = 0.006; IGFBP-1, P = 0.0008 (paired t-test)). The levels of IGFBP-1 were lower in amniotic fluid than in maternal serum (P = 0.017), a finding in sharp contrast to the situation in the second and third trimesters of pregnancy. There was a significant relation between levels of IGF-1 and IGFBP-1 in amniotic fluid (r = 0.43; P = 0.04) and in coelomic fluid (r = 0.81; P less than 0.001) but not in maternal serum. The finding that both the absolute levels of IGFBP-1 and the ratio to IGF-1 were low in amniotic fluid implies that there is a very high level of unbound, biologically active IGF-1 in this compartment in the first trimester. Thus, the regulatory role of IGFBP-1 may change as pregnancy advances.

The most crowded individuals in a population often compete for space and develop a regular pattern of spacing. Such regularity is not normally recognized because it occurs within high-density regions of a populated area showing overall aggregation. Thus competition for space, as reflected by spatial pattern, often goes undetected when standard tests for spatial randomness are used. The test described in this paper makes use of truncated samples of nearest-neighbour distances arranged in ascending order, so that only the pattern of spacing of the most crowded individuals is analysed. This is the basis of Pielou's test (1962, 1977) for spatial competition. An advantage of the approach described is that the density of the most crowded individuals is determined graphically. The graphical method also provides a means for choosing an appropriate, non-arbitrary, truncation point for the test. The test was applied to two samples of singing crickets to demonstrate the procedure. The biological significance of the spacing patterns identified is discussed.

A new sound trap for capturing male and female crickets attracted to the calling song of the male is described. Major advantages of the trap are its portability and effectiveness. It was designed to operate in conjunction with a previously described cricket-song generator. The trap is compared with other designs and the acoustic and migratory behaviour of crickets revealed by sound trapping are discussed.

Children restrained with lap belts may sustain severe injuries. We investigated the frequency of each type of injury associated with seatbelt contusions. The medical records of all trauma patients with ICD-9 codes for abdominal wall contusions from January 1, 1999, to December 31, 2001, were reviewed. All patients with seatbelt contusions were included in the study. Age, seat position, weight, restraint-type, sex, and mechanism of injury were noted. There were 1447 admissions for trauma over the 3-year period. Forty-six patients (ages 4-13) had a seatbelt contusion. Thirty-three wore lap belts, and 13 wore lap and shoulder harnesses. Twenty-two children required abdominal exploration. Small bowel injuries were the most common intra-abdominal injuries. Facial injuries were the most common associated injuries. Forty-eight per cent of children with seatbelt contusions in our institution required surgery. The smaller patients tend to have higher frequency of abdominal injuries. The presence of seatbelt contusion indicates the possibility of severe internal injuries.

2,2,5,5-Tetrakis(trimethylsilyl)-1,1,1,3,3,4,4,6,6,6-decamethylhexasilane, C 22 H 66 Si 10 , is a polysilane in which the longest chain is made up of six Si atoms and branching occurs at the second and fifth Si atoms. Each of the two central Si atoms is bonded to a tris(trimethylsilyl)silyl group in an anti arrangement. Bond lengths and angles are sufficiently close to normal to indicate that the molecule is relatively unstrained

Inhibitors of the renin-angiotensin system (RAS) are valuable therapeutic agents for a wide range of clinical conditions. Increasingly, consideration is being given to the combination of angiotensin-converting enzyme (ACE) inhibitors and angiotensin-II receptor (AR) antagonists to obtain more complete inhibition of the RAS than can be achieved by either agent alone. Beta-blockers also inhibit the RAS by inhibiting renin secretion. Whereas the combination of an ACE inhibitor and AR antagonist represents dual RAS inhibition, the combination of both of these agents with beta-blocker therapy represents triple RAS inhibition. Animal studies indicate that complete blockade of the RAS produces adverse effects. Moreover, post-hoc analysis of the recent Valsartan Heart Failure Trial study suggests that the combination of ACE inhibitor and AR antagonist therapies may have an adverse effect in heart failure when combined with beta-blocker therapy. There is therefore a need for caution in the combination of ACE inhibition and AR antagonism, particularly in patients receiving beta-blockers, until the impact of this strategy is evaluated.

Spiral tomography has been in use at the School of Dentistry, University of Otago, for 3 years. During this time over 140 examinations for radiographic workup prior to installation of implants have been undertaken. The cross-sectional spiral modality has proved to be of particular value for accurate assessment of bone. Its technical capabilities offer higher image quality compared with linear tomographic or computerised tomographic images. Imaging can be completed in one session, with minimal inconvenience to the patient and minimal radiation dose. High-quality images provide accurate information, contributing significantly to the long-term success of osseointegrated implants.

The T helper (Th) cell pool is composed of specialized cells with heterogeneous effector functions. Apart from Th1 and 2 cells, CXCR5+ T cells have been suggested to be another type of effector T cell specialized for B cell help. We show here that CXCR5+ T cells are heterogeneous, and we identify subsets of CXCR5+ CD4 T cells that differ in function and microenvironmental localization in secondary lymphoid tissues. CD57+CXCR5 T cells, hereafter termed germinal center Th (GC-Th) cells, are localized only in GCs, lack CCR7, and are highly responsive to the follicular chemokine B lymphocyte chemoattractant but not to the T cell zone EBI1-ligand chemokine. Importantly, GC-Th cells are much more efficient than CD57−CXCR5+ T cells or CXCR5− T cells in inducing antibody production from B cells. Consistent with their function, GC-Th cells produce elevated levels of interleukin 10 upon stimulation which, with other cytokines and costimulatory molecules, may help confer their B cell helper activity. Our results demonstrate that CXCR5+ T cells are functionally heterogeneous and that the GC-Th cells, a small subset of CXCR5+ T cells, are the key helpers for B cell differentiation and antibody production in lymphoid tissues.

Acute inflammation promotes the elimination of invading microorganisms and the repair of damaged tissues. While acute inflammation is clearly beneficial, there is evidence that inflammation may also cause tissue injury [1–4]. How inflammation causes tissue injury is poorly understood. A potential mechanism is cellular hypoxia following microvascular thrombosis. Endothelial cells activated by inflammatory mediators develop increased permeability and flood the interstitial spaces with fluid. With sustained activation, tissue factor and plasminogen activator inhibitor 1 (PAI 1) are expressed on the luminal surface of the endothelial cells [5, 6]. Tissue factor activates the extrinsic clotting cascade resulting in intra-vascular fibrin deposition [7], whereas PAI 1 neutralizes tissue plasminogen activator, thus preventing fibrinolysis of intra-vascular fibrin [8, 9]. Expression of tissue factor and PAI 1 may therefore transform the endothelium from an anti-coagulant to a pro-coagulant surface, thereby inducing the formation of microvascular thrombi. Microvascular thrombosis may result in cellular hypoxia, lactic acidosis and irreversible tissue injury [5, 7, 9–11].

To determine whether interstitial cystitis is associated with the increased release of substance P from the bladder wall into urine, by measuring urinary excretion rates of substance P and its metabolites in women with interstitial cystitis and in a control group of women with stress incontinence and normal bladder function.Catheter urine was collected from 13 patients and 10 controls during a water diuresis ( approximately 10 mL/min) before and after instilling the bladder with 100 mL of water. The contribution of the bladder wall to urinary substance P peptides was assessed by measuring the change in substance P peptide levels after 2 min of bladder stasis before and after instillation.Absolute substance P excretion rates were similar in patients with interstitial cystitis and controls; 2 min of bladder stasis reduced the substance P excretion rate (P = 0.03) and increased the excretion rate of substance P metabolites (P = 0.01).The release of substance P from the bladder wall was not increased in patients with interstitial cystitis.

Heart failure is a common cause of hospitalization and death across the industrialized world. Improving the diagnosis and care of patients with heart failure is therefore likely to have a major impact on morbidity, mortality, and health care costs.To determine the relation between cardiac function and plasma levels of amino-terminal brain natriuretic peptide precursor (NT-proBNP), plasma NT-proBNP levels and ventricular function (by radionucleotide ventriculography) were measured in healthy patients, patients with renal failure, patients with recent myocardial infarction, and patients investigated for cardiorespiratory symptoms. Plasma NT-proBNP levels were greater in healthy women (median, 1.5 fmol/mL; range, 1.0 to 13.8 fmol/mL; n = 34) than healthy men (median, 1.0 fmol/mL; range, 1.0 to 3.3 fmol/mL; n = 33; P = .012). NT-proBNP levels were elevated in subjects with renal failure (geometric mean, 314 fmol/mL; range, 18 to 5,800 fmol/mL) and were related to left ventricular ejection fraction (LVEF) (r = -0.86; P.0001; n = 19). NT-proBNP levels were also related to LVEF in patients with recent myocardial infarction (r = -0.62; P = .0003; n = 29) and those investigated for cardiorespiratory symptoms (r = -0.56; P.0001; n = 129). Applying an upper limit of normal of 5 fmol/mL for men and 15 fmol/mL for women (specificity, 100%), elevated plasma NT-proBNP levels had 100% sensitivity for the detection of LVEF less than 45% after myocardial infarction and 97% sensitivity for the detection of LVEF less than 45% in patients investigated for cardiorespiratory symptoms. NT-proBNP levels were also elevated in 87% of the patients with normal systolic function (LVEFor = 45%) after myocardial infarction and in 87% of the patients investigated for cardiorespiratory symptoms with heart failure and normal systolic function (LVEFor = 45%).Plasma NT-proBNP level is a sensitive indicator of cardiac dysfunction, both in the presence and absence of systolic dysfunction, and may prove to be a useful tool for the identification and management of cardiac dysfunction in the general community.

This case describes the experience of the Detroit Medical Center (DMC) in restructuring its governance and management. It provides a background on the DMC, examines the driving forces that led to modification of its structure, identifies key principles in guiding the change, and describes the strategies and specific steps taken in managing structural change. Finally, the critical lessons learned about leadership style, communication, agenda development, and relations with the board, medical staff, and management are discussed. This case study will help reduce the learning curve for any large, complex organization undertaking board and management restructuring to better meet its mission. At the time of DMC's restructuring there were no models to guide the effort. This case study attempts to reduce the gap in research on the management of structural change.

The combination of neutral endopeptidase 24.11 (NEP) and angiotensin converting enzyme (ACE) inhibition is a candidate therapy for hypertension and cardiac failure. Given that NEP and ACE metabolize angiotensin (Ang) and bradykinin (BK) peptides, we investigated the effects of NEP inhibition and combined NEP and ACE inhibition on the levels of these peptides. We administered the NEP inhibitor ecadotril (0, 0.1, 1, 10, 100 mg/kg per day), either alone or together with the ACE inhibitor perindopril (0.2 mg/kg per day), to rats by 12 hourly gavage for 7 days. Ecadotril produced diuresis, natriuresis, increased urine cyclic guanosine monophosphate and BK-(1-9) levels, increased Ang II and Ang I levels in plasma, and increased Ang I levels in heart. Perindopril reduced Ang II levels in kidney, and increased BK-(1-9) levels in blood, kidney and aorta. Combined NEP/ACE inhibition produced the summation of these effects of separate NEP and ACE inhibition. In addition, perindopril potentiated the ecadotril-mediated diuresis, natriuresis and decrease in urine BK-(1-7)/BK-(1-9) ratio, which is an index of BK-(1-9) metabolism. Moreover, combined NEP/ACE inhibition increased Ang II levels in plasma and lung. These data indicate that summation of the effects of separate NEP and ACE inhibition provides the basis for the therapeutic efficacy of their combination. Whereas potentiation by perindopril of the diuretic and natriuretic effects of ecadotril may contribute to the therapeutic effects, increased Ang II levels in plasma and lung may compromise the therapeutic effects of combined NEP/ACE inhibition.