The Profiles of Bars in Spiral Galaxies

We present an analysis of major-axis surface-brightness profiles of bars in a volume-limited sample of 182 barred spiral galaxies, using Spitzer 3.6 micron images. Unlike most previous studies, we use the entire bar profile, and we classify profiles into four categories. These are "Peak+Shoulders" (P+Sh) -- updating the classic "flat bar" profile -- and three subtypes of the classic "exponential" profile: (true) Exponential, "Two-Slope" (shallow inner slope + steeper outer slope), and "Flat-Top" (constant inner region, steep outer slope). P+Sh profiles are preferentially found in galaxies with high stellar masses, early Hubble types, red colours, and low gas fractions; the most significant factor is stellar mass, and previous correlations with Hubble type can be explained by the tendency of higher-mass galaxies to have earlier Hubble types. The most common type of non-P+Sh profile is Exponential, followed by Flat-Top profiles; all non-P+Sh profiles appear to have similar distributions of stellar mass, Hubble type, colour, and gas fraction. We also morphologically classify the bars of an inclined subsample into those with and without boxy/peanut-shaped (B/P) bulges; as previously reported, the presence of a B/P bulge is very strong function of stellar mass. Essentially all bars with B/P bulges have P+Sh profiles; we associate the profile shoulders with the outer, vertically thin part of the bar. We find a small number of P+Sh profiles in bars without clear B/P bulges, which may indicate that P+Sh formation precedes the formation of B/P bulges.Comment: pdflatex, 21 pages, 12 figures; accepted by MNRAS. Data, code, and Jupyter notebooks available at https://github.com/perwin/barprofiles_pape

Role of vasopressin in impaired water excretion in conscious rats with experimental cirrhosis

Role of vasopressin in impaired water excretion in conscious rats with experimental cirrhosis. The present study was undertaken to study the mechanism of impaired water excretion in experimental cirrhosis in the rat. Conscious rats in whom histologically proven cirrhosis was induced with carbon tetrachloride and phenobarbital were compared with control rats given phenobarbital alone. Impaired water excretion in experimental cirrhosis was verified by a basal hyponatremia (138 vs. 147 mEq/liter, P < 0.005) and an impaired excretion of water load (minimal urinary osmolality, 262 vs. 100 mOsm/kg; 58 vs. 102% of water load excreted, P < 0.001). To clarify the mechanism of this impaired water excretion, we measured glomerular filtration rate (GFR), renal blood flow (RBF), and vasopressin (VP) levels. In cirrhosis, GFR was normal but RBF was decreased (4.5 vs 6.8 ml/min/g, P < 0.01). VP levels were found to be higher in cirrhotic rats (1.61 vs. 0.71 pg/ml, P < 0.025). The significance of the impaired renal hemodynamics and the increase in VP was assessed by inducing cirrhosis in VP-free Brattle-boro (diabetes insipidus; DI) rats. Despite histologic, biochemical, and renal hemodynamic changes that were comparable to cirrhotic rats with an intact neurohypophysis, cirrhotic DI rats had no impairment in water excretion. To determine the cause of increased VP in experimental cirrhosis, we determined blood volume and systemic hemodynamics. Although plasma volume was greater in experimental cirrhosis (4.3 vs. 3.0 ml/100 g, P < 0.05), cirrhotic rats had a significantly lower peripheral resistance (0.37 vs. 0.42mm Hg/ml/min/kg, P < 0.05) and mean arterial pressure (104 vs. 120mm Hg, P < 0.001) than did control rats. These results document that experimental cirrhosis in the rat is associated with impaired renal water excretion in association with both abnormal renal hemodynamics and increased VP levels. The impaired water excretion, however, is solely VP mediated. The nonosmolar stimulus for VP release may be due to abnormal systemic hemodynamics.Rôle de la vasopressine dans l'altération de l'excrétion de l'eau par le rat conscient atteint de cirrhose expérimentale. Cette étude a été entreprise pour élucider le mécanisme de l'altération de l'excrétion de l'eau au cours de la cirrhose du rat. Des rats conscients chez lesquels une cirrhose prouvée histologiquement a été induite par le tétrachlorure et le phénobarbital ont été comparés à des rats contrôles recevant seulement le phénobarbital. L'altération de l'excrétion de l'eau dans la cirrhose expérimentale a été vérifiée par l'hyponatrémie basale (138 vs. 147 mEq/litre, P < 0,005) et le défaut d'excrétion d'une charge en eau (osmolalité urinaire minimale 262 vs. 100 mOsm/kg; 58 vs. 102% de la charge d'eau sont excrétés, P < 0,001). Pour élucider le mécanisme de cette altération de l'excrétion de l'eau le débit de filtration glomérulaire (GFR), le débit sanguin rénal (RBF) et les concentrations de vasopressine (VP) ont été mesurés. Dans la cirrhose GFR est normal alors que RBF est diminué (4,5 vs. 6,8 ml/min/gm, P < 0,01). VP est plus élevée chez les rats cirrhotiques (1,61 vs. 0,71 pg/ml, P < 0,025). La signification des modifications de l'hémodynamique rénale et de l'augmentation de VP a été évaluée en créant des cirrhoses chez des rats sans VP de la souche Brattleboro (DI). Malgré des modifications histologiques, biochimiques et hémodynamiques rénales qui sont comparables à celles des rats dont la neurohypophyse est intacte, les rats DI cirrhotiques n'ont pas d'altération de l'excrétion de l'eau. Pour connaître la cause de l'augmentation de VP dans la cirrhose expérimentale le volume sanguin et l'hémodynamique systémique ont été étudiés. Quoique le volume plasmatique soit augmenté dans la cirrhose expérimentale (4,3 vs. 3,0 ml/100 g, P < 0,05) les rats cirrhotiques ont des résistances périphériques inférieures (0,37 vs. 0,42mm Hg/ml/min/kg, P < 0,05) et une pression artérielle moyenne inférieure (104 vs. 120mm Hg, P < 0,001) à celles des rats contrôles. Ces résultats indiquent que la cirrhose expérimentale du rat comporte une altération de l'excrétion de l'eau associée à une hémodynamique rénale anormale et à des concentrations de VP augmentées. L'altération de l'excrétion de l'eau, cependant, a la vasopressione comme seul médiateur. Le stimulus non osmolaire de la libération de VP pourrait être l'anomalie de l'hémodynamique systémique

Elective hospital admissions : secondary data analysis and modelling with an emphasis on policies to moderate growth

Background The English NHS faces financial pressures that may render the growth rates of elective admissions seen between 2001/2 and 2011/12 unsustainable. A better understanding of admissions growth, and the influence of policy, are needed to minimise the impact on health gain for patients. Objectives This project had several objectives: (1) to better understand the determinants of elective activity and policy to moderate growth at minimum health loss for patients; (2) to build a rich data set integrating health, practice and local area data to study general practitioner (GP) referrals and resulting admissions; (3) to predict patients whose treatment is unlikely to be cost-effective using patient-reported outcomes and to examine variation in provider performance; and (4) to study how policies that aim to reduce elective admissions may change demand for emergency care. The main drivers of elective admissions growth have increased either supply of or demand for care, and could include, for example, technical innovations or increased awareness of treatment benefits. Of the factors studied, neither system reform nor population ageing appears to be a key driver. The introduction of the prospective payment tariff ‘Payment by Results’ appears to have led to primary care trusts (PCTs) having increasingly similar lengths of stay. In deprived areas, increasing GP supply appears to moderate elective admissions. Reducing the incidence of single-handed practices tends to reduce referrals and admissions. Policies to reduce referrals are likely to reduce admissions but treatments may be particularly reduced in the lowest referring practices, in which resulting health loss may be greatest. In this model, per full-time equivalent, female and highly experienced GPs identify more patients admitted by specialists. Results It appears from our studies that some patient characteristics are associated with not achieving sufficient patient gain to warrant cost-effective treatment. The introduction of independent sector treatment centres is estimated to have caused an increase in emergency activity rates at local PCTs. The explanations offered for increasing elective admissions indicate that they are manageable by health policy. Conclusions Further work is required to understand some of the results identified, such as whether or not high-volume Clinical Commissioning Groups are fulfilling unmet need; why some practices refer at low rates relative to admissions; why the period effect, which results from factors that equally affect all in the study at a point in time, dominates in the age–period–cohort analysis; and exactly how the emergency and elective sections of hospital treatment interact. This project relies on the analysis of secondary data. This type of research does not easily facilitate the important input of clinical experts or service users. It would be beneficial if other methods, including surveys and consultation with key stakeholders, could be incorporated into future research now that we have uncovered important questions. Funding The National Institute for Health Research Health Services and Delivery Research programme

Extremely high He isotope ratios in MORB-source mantle from the proto-Iceland plume

The high &lt;sup&gt;3&lt;/sup&gt;He/&lt;sup&gt;4&lt;/sup&gt;He ratio of volcanic rocks thought to be derived from mantle plumes is taken as evidence for the existence of a mantle reservoir that has remained largely undegassed since the Earth's accretion. The helium isotope composition of this reservoir places constraints on the origin of volatiles within the Earth and on the evolution and structure of the Earth's mantle. Here we show that olivine phenocrysts in picritic basalts presumably derived from the proto-Iceland plume at Baffin Island, Canada, have the highest magmatic &lt;sup&gt;3&lt;/sup&gt;He/&lt;sup&gt;4&lt;/sup&gt;He ratios yet recorded. A strong correlation between &lt;sup&gt;3&lt;/sup&gt;He/&lt;sup&gt;4&lt;/sup&gt;He and &lt;sup&gt;87&lt;/sup&gt;Sr/&lt;sup&gt;86&lt;/sup&gt;Sr, &lt;sup&gt;143&lt;/sup&gt;Nd/&lt;sup&gt;144&lt;/sup&gt;Nd and trace element ratios demonstrate that the &lt;sup&gt;3&lt;/sup&gt;He-rich end-member is present in basalts that are derived from large-volume melts of depleted upper-mantle rocks. This reservoir is consistent with the recharging of depleted upper-mantle rocks by small volumes of primordial volatile-rich lower-mantle material at a thermal boundary layer between convectively isolated reservoirs. The highest &lt;sup&gt;3&lt;/sup&gt;He/&lt;sup&gt;4&lt;/sup&gt;He basalts from Hawaii and Iceland plot on the observed mixing trend. This indicates that a &lt;sup&gt;3&lt;/sup&gt;He-recharged depleted mantle (HRDM) reservoir may be the principal source of high &lt;sup&gt;3&lt;/sup&gt;He/&lt;sup&gt;4&lt;/sup&gt;He in mantle plumes, and may explain why the helium concentration of the 'plume' component in ocean island basalts is lower than that predicted for a two-layer, steady-state model of mantle structure

HTLV-III Serology in Hemophilia: Relationship with Immunologic Abnormalities

We investigated the relationship of the presence of antibodies to HTLV-III and immunologic abnormalities in patients with hemophilia. Serum antibodies to HTLV-III were analyzed by ELISA assay, immunoprecipitation of labeled cell extracts, and immunoprecipitation of purified HTLV-III p24. Thirty-four (61%) of the total group (n = 56) had antibody to HTLV-III; 34 (76%) of 45 patients given commercial factor VIII preparations were seropositive, compared with none of 11 patients treated exclusively with cryoprecipitate obtained from volunteer blood donors. Of patients who were seropositive for HTLV-III antibody, 94% had abnormal T4/T8 ratios, and 33% of those whose serum was antibody negative had abnormal T4/T8 ratios; five patients, each antibody positive, have lymphadenopathy syndrome. Sequential studies in a subset of patients indicate that there is a changing pattern of antibody production to HTLV-III antigens after seroconversion

HTLV-III Serology in Hemophilia: Relationship with Immunologic Abnormalities

We investigated the relationship of the presence of antibodies to HTLV-III and immunologic abnormalities in patients with hemophilia. Serum antibodies to HTLV-III were analyzed by ELISA assay, immunoprecipitation of labeled cell extracts, and immunoprecipitation of purified HTLV-III p24. Thirty-four (61%) of the total group (n = 56) had antibody to HTLV-III; 34 (76%) of 45 patients given commercial factor VIII preparations were seropositive, compared with none of 11 patients treated exclusively with cryoprecipitate obtained from volunteer blood donors. Of patients who were seropositive for HTLV-III antibody, 94% had abnormal T4/T8 ratios, and 33% of those whose serum was antibody negative had abnormal T4/T8 ratios; five patients, each antibody positive, have lymphadenopathy syndrome. Sequential studies in a subset of patients indicate that there is a changing pattern of antibody production to HTLV-III antigens after seroconversion

MitoNeoD:a mitochondria-targeted superoxide probe

Mitochondrial superoxide (O2⋅−) underlies much oxidative damage and redox signaling. Fluorescent probes can detect O2⋅−, but are of limited applicability in vivo, while in cells their usefulness is constrained by side reactions and DNA intercalation. To overcome these limitations, we developed a dual-purpose mitochondrial O2⋅− probe, MitoNeoD, which can assess O2⋅− changes in vivo by mass spectrometry and in vitro by fluorescence. MitoNeoD comprises a O2⋅−-sensitive reduced phenanthridinium moiety modified to prevent DNA intercalation, as well as a carbon-deuterium bond to enhance its selectivity for O2⋅− over non-specific oxidation, and a triphenylphosphonium lipophilic cation moiety leading to the rapid accumulation within mitochondria. We demonstrated that MitoNeoD was a versatile and robust probe to assess changes in mitochondrial O2⋅− from isolated mitochondria to animal models, thus offering a way to examine the many roles of mitochondrial O2⋅−production in health and disease

The secular growth of bars revealed by flat (peak + shoulders) density profiles

The major-axis density profiles of bars are known to be either exponential or ‘flat’. We develop an automated non-parametric algorithm to detect flat profiles and apply it to a suite of simulations (with and without gas). We demonstrate that flat profiles are a manifestation of a bar’s secular growth, producing a “shoulder” region (an overdensity above an exponential) in its outskirts. Shoulders are not present when bars form, but develop as the bar grows. If the bar does not grow, shoulders do not form. Shoulders are often accompanied by box/peanut bulges, but develop separately from them and are independent tracers of a bar’s growth. They can be observed at a wide range of viewing orientations with only their slope varying significantly with inclination. We present evidence that shoulders are produced by looped x1 orbits. Since the growth rate of the bar moderately correlates with the growth rate of the shoulder strength, these orbits are probably recently trapped. Shoulders therefore are evidence of bar growth. The properties of the shoulders do not, however, establish the age of a bar, because secondary buckling or strong spirals may destroy shoulders, and also because shoulders do not form if the bar does not grow much. In particular, our results show that an exponential profile is not necessarily an indication of a young bar

Effectiveness of a training-of-trainers model in a HIV counseling and testing program in the Caribbean Region

<p>Abstract</p> <p>Objectives</p> <p>To evaluate the effectiveness and sustainability of a voluntary counseling and testing (VCT) training program based on a training-of-trainers (TOT) model in the Caribbean Region, we gathered data on the percentage of participants trained as VCT providers who were providing VCT services, and those trained as VCT trainers who were conducting VCT training.</p> <p>Methods</p> <p>The VCT training program trained 3,489 providers in VCT clinical skills and 167 in VCT training skills within a defined timeframe. An information-monitoring system tracked HIV trainings conducted, along with information about course participants and trainers. Drawing from this database, a telephone survey followed up on program-trained VCT providers; an external evaluation analyzed data on VCT trainers.</p> <p>Results</p> <p>Almost 65% of trained VCT providers could be confirmed as currently providing VCT services. This percentage did not decrease significantly with time. Of the VCT trainers, 80% became certified as trainers by teaching at least one course; of these, 66% taught more than one course.</p> <p>Conclusion</p> <p>A TOT-based training program is an effective and sustainable method for rapid scale-up of VCT services and training capacity in a large-scale VCT program.</p