Strong Negative Trend Research Articles

EXPLAINING THE [C II]157.7 μm DEFICIT IN LUMINOUS INFRARED GALAXIES—FIRST RESULTS FROM AHERSCHEL/PACS STUDY OF THE GOALS SAMPLE

We present the first results of a survey of the [CII]158um emission line in 241 luminous infrared galaxies (LIRGs) comprising the Great Observatories All-sky Survey (GOALS) sample, obtained with the PACS instrument on board Herschel. The [CII] luminosities of the LIRGs in GOALS range from ~10^7 to 2x10^9 Lsun. We find that LIRGs show a tight correlation of [CII]/FIR with far-IR flux density ratios, with a strong negative trend spanning from ~10^-2 to 10^-4, as the average temperature of dust increases. We find correlations between the [CII]/FIR ratio and the strength of the 9.7um silicate absorption feature as well as with the luminosity surface density of the mid-IR emitting region (Sigma_MIR), suggesting that warmer, more compact starbursts have substantially smaller [CII]/FIR ratios. Pure star-forming (SF) LIRGs have a mean [CII]/FIR ~ 4x10^-3, while galaxies with low 6.2um PAH equivalent widths (EWs), indicative of the presence of active galactic nuclei (AGN), span the full range in [CII]/FIR. However, we show that even when only pure SF galaxies are considered, the [CII]/FIR ratio drops by an order of magnitude, from 10^-2 to 10^-3, with Sigma_MIR and Sigma_IR, implying that the [CII] luminosity is not a good indicator of the star formation rate (SFR) for most LIRGs, for it does not scale linearly with the warm dust emission. Moreover, even in LIRGs in which we detect an AGN in the mid-IR, the majority (2/3) of galaxies show [CII]/FIR >= 10^-3 typical of high 6.2um PAH EW sources, suggesting that most AGNs do not contribute significantly to the far-IR emission. We provide an empirical relation between the [CII]/FIR and the specific SFR (SSFR) for SF LIRGs. Finally, we present predictions for the starburst size based on the observed [CII] and far-IR luminosities which should be useful for comparing with results from future surveys of high-redshift galaxies with ALMA and CCAT.

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Introduction: In 2005, the Veterans Health Administration implemented a program that provides automated quarterly reports for every VA intensive care unit (ICU) and supports targeted local ICU improvement. The reports track process measures (adherence to practices to reduce central line associated blood stream infections [CLABSI] and ventilator associated pneumonia [VAP], venous thromboembolism prophylaxis, hypo/hyperglycemia rates) and outcomes (risk adjusted and unadjusted hospital and 30-day mortality, ward transfer mortality, length of stay, and CLABSI and VAP rates). Hypothesis: We asked if implementation of this quality improvement infrastructure was associated with changes in 30-day mortality. Methods: We constructed a cohort composed of all patients (505,007) admitted to VA ICU’s from 2006 through 2010, and accounted for differences in patient severity using a validated risk method that predicted mortality at 30 days. Sensivitivity analyses varied the populations, stratifying by types of ICUs and regions. Standardized mortality ratios (SMR30) and 95% confidence intervals (CI) calculated with bootstrapping, compared outcomes. Quality improvement projects included reduction in CLABSI and VAP, Flow improvement, the surgical care improvement project. Results: The VA admits 101,001 ± 715.4 patients annually to its 132 hospitals and 173 ICUs. Annual unadjusted mortality did not change significantly from 206 to 2010 (10.00% to 9.64%); predicted mortality increased (9.4% to 10.2%). From 2006 to 2010, SMR30 fell from 1.07(95% CI 1.04, 1.08) to 0.94 (95%CI 0.923, 0.961). SMR30 was significantly reduced across 1) large and small ICUs, 2) MICUs, MICU/CCU, SICU, but not CCUs, 3) 11/23 VA regions, 4) among patients admitted with cardiovascular, gastrointestinal, metabolic, renal, respiratory, and infectious diagnoses, and 5) all groups stratified by severity. Trend plots by ICU show a strong negative trend in SMR and variance. Conclusions: Implementation of a quality infrastructure and multiple quality improvement projects was temporally associated with 13% reduction in risk adjusted mortality, but not unadjusted mortality. Severity of illness in the ICU increased.

Mitral annular systolic velocity as a marker of preclinical systolic dysfunction among patients with arterial hypertension

BackgroundThe aim of this study was to investigate early changes in left ventricular longitudinal systolic function in patients with hypertension (HTN) with and without concomitant diastolic dysfunction (DD) and the clinical implications of these findings.MethodWe enrolled 299 patients with HTN and 297 age-matched patients with HTN and DD and compared both groups with an age-matched control group consisting of 100 healthy subjects. The long axis systolic function was investigated by determining the average peak systolic velocity of the septal and lateral mitral sites (Smavg) using spectral pulsed wave tissue Doppler imaging (TDI).ResultsWe found a strong negative trend toward the reduction of velocity, which is dependent on the grade of HTN, on the magnitude of DD, and also on the gender and age of the subjects (r=−0.891/-0.580; p<0.0001). The data showed that the beginning and evolution of HTN are related to a slight but significant reduction in the long axis systolic function (10.2-10.0 cm/s; p<0.0001), and DD worsens this initial finding (9.8-8.8 cm/s; p<0.0001).ConclusionThe strength of the study is the analysis of incremental changes in longitudinal contraction in patients with different stage of HTN but not so many the classification of the degree of systolic dysfunction. The importance of our results lies in the fact that these initial changes in systolic contraction could be used as an early sign that should prompt optimization of the treatment of HTN.

MAKING A LIVELIHOOD IN (AND BEYOND) THE AFRICAN CITY: THE EXPERIENCE OF ZIMBABWE

ABSTRACTThe formal labour markets and economies of many cities in sub-Saharan Africa have been very weak for decades and this has led to significant adaptations in the nature of the livelihoods of most urban households. The lack of formal and reasonably paid jobs has also had a strong impact on population growth in cities, although this is often not recognized. This article reviews some of these trends and illustrates them with case study material from Harare, Zimbabwe. There, many urban residents have increasingly struggled to get by and their perceptions of the city and their future within it show a strong negative trend. Links to rural areas and the possibility of making livelihoods there in the future have become more important. These adaptations build on the long history of rural–urban linkages in sub-Saharan Africa but contemporary practices, including patterns of circular migration, are influenced by the harsh realities of African urban economies. The decisions and future plans of some migrants may not, therefore, fit with their aspirations – and the degree and nature of this mismatch are influenced by factors such as gender, age and position in the urban household, and links to rural areas. It is suggested that it helps to analyse the consequent migration patterns in terms of a framework in which migrants’ decisions to stay in the city or leave it are conceptualized as either willing or reluctant.

Percepção da qualidade de vida no trabalho dos neurocirurgiões em São Paulo

Resumo Contexto: Estudos da percepção da qualidade de vida no trabalho (QVT) permitem estimar a percepção de uma classe profissional inteira, identificar desequilíbrios específicos e proporcionar políticas de desenvolvimento profissional. Objetivo: Avaliar a percepção da QVT dos neurocirurgiões que trabalham em Serviços de Emergência em São Paulo usando instrumentos de validação disponíveis na língua portuguesa. Método: A percepção da QVT dos neurocirurgiões da cidade de São Paulo (Capital) foi estudada com questionário validado para língua portuguesa. Resultados: Cinquenta e oito neurocirurgiões responderam ao questionário. A análise revelou fortes tendências negativas na maioria das áreas de QVT. As áreas com forte tendência negativa deveriam ser tratadas com políticas específicas. Conclusão: Há fortes tendências negativas em quase todos os domínios da QVT.

Evapotranspiration paradox at a semi-arid location in India

Paradox of decreasing evaporation and evapotranspiration under increasing temperature conditions in the semi-arid tropics assumes greater importance as agriculture in these areas is more vulnerable to climate change. Trends in annual reference crop evapotranspiration (ETo) at Patancheru, Andhra Pradesh indicated a reduction of about 200 mm from 1850 mm to 1650 mm during the past 35 years. Contribution of energy balance term to the total ETo has shown an increasing trend while aerodynamic term has a decreasing trend. Wind speed has shown a strong negative trend leading to the dramatic fall of the aerodynamic term and consequently the ETo. Rate of reduction in evapotranspiration demand was about 10% for kharif (Jun-Oct) and about 14% for rabi (Nov-Feb). At Patancheru, measured temperature and solar radiation showed opposite trends and at locations where no measured solar radiation data available and if solar radiation is estimated from air temperature alone for use as an input in crop modelling, outputs under such conditions need to be interpreted with caution. Present study highlights the need for climate change impact studies at a local level in addition to those based on regional and global circulation models.

Understanding changes over time in workers' compensation claim rates using time series analytical techniques

ObjectiveThe objective of this study is to better understand the inter-temporal variation in workers' compensation claim rates using time series analytical techniques not commonly used in the occupational health and...

Present status, possibilities and perspective of development of goat production in Republic of Serbia

The paper analyzes the state of goat production in the Republic of Serbia, with special emphasis on the general overview of conditions and problems that accompany this branch of animal husbandry with the proposed solutions and recommendations with the aim of increasing the productive capacity of the existing breeds of goats. Goat Serbia is characterized by a negative state, especially strong negative trend over the number of goats. Production of goat milk and meat past few years has stagnated at very low levels. As a small producer of these foods, our country can not meet the needs of its population in them, nor to any one market may not emerge as a serious bidder. For these reasons, imposes itself as a priority in the agricultural policy of our country, the constant application and approval of new incentives in the goat in order to create as many commodity producers of milk and meat, especially of kid meat intended for export. Serbia goat development opportunities exist and are available through the agricultural areas, where special emphasis should be placed on individual farms, their size, and to deal with the goat as the primary production in the highlands, and in some areas and the plains, where land and soil suitable for meadows and pastures. However, evaluation of the potential and benefits is very low, and the prosperity of goats farms not possible without a transformation of the wider economic and social environment.

Re-Visiting the Easterlin Hypothesis: Marriage in the U.S. 1968-2010

This study tests the effect of relative income – younger people's earning potential relative to their aspirations, as approximated by older families' income – on the proportions married, by sex, in the first fifteen years out of school. It finds that relative income has become a better measure to use, than relative cohort size, because of a disconnect that has developed between the two as a result of rising female labor force participation among older women that has inflated older families’ income faster than older men's earnings. The results are highly supportive of the Easterlin relative income hypothesis, finding a dominant negative effect of older family income that extends due to postponement effects even into groups 11-15 years out of school. But in addition it finds a strong but changing effect of the female wage: positive among women 0-5 years out of school, although slowly declining over time, but negative among the older women with a dominant positive time trend that has produced a positive effect in the last decade. The elasticity with respect to older family income suggests that it was responsible for 16% of the observed decline in the proportion of women 0-5 years out of school who were married, and 23% of the proportion for the men in the same group. There is in addition, however, a very strong negative time trend.

Statistical analysis of eight surface ozone measurement series for various sites in Ireland

Data from various stations having different measurement record periods between 1988 and 2007 are analyzed to investigate the surface ozone concentration, long‐term trends, and seasonal changes in and around Ireland. Time series statistical analysis is performed on the monthly mean data using seasonal and trend decomposition procedures and the Box‐Jenkins approach (autoregressive integrated moving average). In general, ozone concentrations in the Irish region are found to have a negative trend at all sites except at the coastal sites of Mace Head and Valentia. Data from the most polluted Dublin city site have shown a very strong negative trend of −0.33 ppb/yr with a 95% confidence limit of 0.17 ppb/yr (i.e., −0.33 ± 0.17) for the period 2002−2007, and for the site near the city of Cork, the trend is found to be −0.20 ± 0.11 ppb/yr over the same period. The negative trend for other sites is more pronounced when the data span is considered from around the year 2000 to 2007. Rural sites of Wexford and Monaghan have also shown a very strong negative trend of −0.99 ± 0.13 and −0.58 ± 0.12, respectively, for the period 2000−2007. Mace Head, a site that is representative of ozone changes in the air advected from the Atlantic to Europe in the marine planetary boundary layer, has shown a positive trend of about +0.16 ± 0.04 ppb per annum over the entire period 1988−2007, but this positive trend has reduced during recent years (e.g., in the period 2001−2007). Cluster analysis for back trajectories are performed for the stations having a long record of data, Mace Head and Lough Navar. For Mace Head, the northern and western clean air sectors have shown a similar positive trend (+0.17 ± 0.02 ppb/yr for the northern sector and +0.18 ± 0.02 ppb/yr for the western sector) for the whole period, but partial analysis for the clean western sector at Mace Head shows different trends during different time periods with a decrease in the positive trend since 1988 indicating a deceleration in the ozone trend for Atlantic air masses entering Europe.

Twentieth century trends in tree ring stable isotopes (δ13C and δ18O) of Larix sibirica under dry conditions in the forest steppe in Siberia

Tree ring width, density, and ratio of stable isotopes (13C/12C and 18O/16O) in wood and cellulose were determined for larch (Larix sibirica Ledeb.) growing under water deficit conditions in the forest steppe zone in central Siberia (54°24′N, 89°57′E) for the period 1850–2005. Dendroclimatic analysis of the chronologies indicated precipitation to be the most important factor determining indicated parameters. Precipitation of June is significantly correlated with tree ring width and maximum density (r = 0.36 and 0.43, p &lt; 0.05, respectively). Relations of δ13C and δ18O to precipitation are similar, but the most important month is July (r = −0.47, p &lt; 0.05 for δ13C; r = −0.29, p &lt; 0.05 for δ18O). Further, δ18O is positively related to the mean temperatures of July (r = 0.30, p &lt; 0.05). Carbon and oxygen isotope ratios in wood and cellulose showed strong negative trends for the last 100 years. The reason for this decrease could be the observed shift of the beginning of the vegetation period to earlier dates (up to 1 week) in spring and the increased use of precipitation water stored in the soil from October of the previous year, although other explanations cannot be excluded (in particular the physiological effect of increasing atmospheric CO2 also responsible for lower δ13C values). Thus, an earlier start of the vegetation period could lead to tree ring formation during a period with higher water availability, resulting in stronger isotopic fractionation and 13C depletion, also reflected in a higher earlywood to latewood ratio. At the same time, highly 18O depleted water from October precipitation of the previous year is absorbed. The incorporation of this isotopically lighter water during photosynthesis is reflected in the wood and cellulose of tree rings.

Trends in Volatile Substance Abuse

ABSTRACT The purpose of this article is to evaluate whether social, geographic, and demographic factors have a relationship to trends in volatile substance abuse. Two datasets were obtained. Dataset 1 was all patients reported to U.S. poison centers with inhalation abuse of a non-pharmaceutical substance between 2000 and 2005. Dataset 2 was annual data from the U.S. Dept of Labor and U.S. Census Bureau for each of the 50 states for the years 2000 through 2005 for unemployment rate, population density, poverty rate, high school graduation rate and percentage of population with bachelor degree. The two datasets were compared for geographic (by state) and temporal (by year) relationships using U.S. government demographic categories. The U.S. poison centers state that 12,428 patients with volatile substance abuse have been reported over the 6 year period of 2000–2005, with a mean of 2,071 patients annually. A strong negative trend was found between volatile substance abuse and population density, with volatile substance abuse increasing as population density decreased. This trend remained consistent over the 6 years of evaluation. A negative trend was found with percentage of population with a bachelor's degree and volatile substance abuse. No trend was found when comparing volatile substance abuse and poverty rate, unemployment rate, or high school graduation rate. Volatile substance abuse appears to increase as population density decreases, following a previously suggested relationship with a rural setting. Volatile substance abuse appears to increase as percentage of population with a bachelor's degree decreases.

The greening and browning of Alaska based on 1982–2003 satellite data

AbstractAim To examine the trends of 1982–2003 satellite‐derived normalized difference vegetation index (NDVI) values at several spatial scales within tundra and boreal forest areas of Alaska.Location Arctic and subarctic Alaska.Methods Annual maximum NDVI data from the twice monthly Global Inventory Modelling and Mapping Studies (GIMMS) NDVI 1982–2003 data set with 64‐km2 pixels were extracted from a spatial hierarchy including three large regions: ecoregion polygons within regions, ecozone polygons within boreal ecoregions and 100‐km climate station buffers. The 1982–2003 trends of mean annual maximum NDVI values within each area, and within individual pixels, were computed using simple linear regression. The relationship between NDVI and temperature and precipitation was investigated within climate station buffers.Results At the largest spatial scale of polar, boreal and maritime regions, the strongest trend was a negative trend in NDVI within the boreal region. At a finer scale of ecoregion polygons, there was a strong positive NDVI trend in cold arctic tundra areas, and a strong negative trend in interior boreal forest areas. Within boreal ecozone polygons, the weakest negative trends were from areas with a maritime climate or colder mountainous ecozones, while the strongest negative trends were from warmer basin ecozones. The trends from climate station buffers were similar to ecoregion trends, with no significant trends from Bering tundra buffers, significant increasing trends among arctic tundra buffers and significant decreasing trends among interior boreal forest buffers. The interannual variability of NDVI among the arctic tundra buffers was related to the previous summer warmth index. The spatial pattern of increasing tundra NDVI at the pixel level was related to the west‐to‐east spatial pattern in changing climate across arctic Alaska. There was no significant relationship between interannual NDVI and precipitation or temperature among the boreal forest buffers. The decreasing NDVI trend in interior boreal forests may be due to several factors including increased insect/disease infestations, reduced photosynthesis and a change in root/leaf carbon allocation in response to warmer and drier growing season climate.Main conclusions There was a contrast in trends of 1982–2003 annual maximum NDVI, with cold arctic tundra significantly increasing in NDVI and relatively warm and dry interior boreal forest areas consistently decreasing in NDVI. The annual maximum NDVI from arctic tundra areas was strongly related to a summer warmth index, while there were no significant relationships in boreal areas between annual maximum NDVI and precipitation or temperature. Annual maximum NDVI was not related to spring NDVI in either arctic tundra or boreal buffers.

A Comparison of Aprotinin and Lysine Analogues in High-Risk Cardiac Surgery

Antifibrinolytic agents are commonly used during cardiac surgery to minimize bleeding and to reduce exposure to blood products. We sought to determine whether aprotinin was superior to either tranexamic acid or aminocaproic acid in decreasing massive postoperative bleeding and other clinically important consequences. In this multicenter, blinded trial, we randomly assigned 2331 high-risk cardiac surgical patients to one of three groups: 781 received aprotinin, 770 received tranexamic acid, and 780 received aminocaproic acid. The primary outcome was massive postoperative bleeding. Secondary outcomes included death from any cause at 30 days. The trial was terminated early because of a higher rate of death in patients receiving aprotinin. A total of 74 patients (9.5%) in the aprotinin group had massive bleeding, as compared with 93 (12.1%) in the tranexamic acid group and 94 (12.1%) in the aminocaproic acid group (relative risk in the aprotinin group for both comparisons, 0.79; 95% confidence interval [CI], 0.59 to 1.05). At 30 days, the rate of death from any cause was 6.0% in the aprotinin group, as compared with 3.9% in the tranexamic acid group (relative risk, 1.55; 95% CI, 0.99 to 2.42) and 4.0% in the aminocaproic acid group (relative risk, 1.52; 95% CI, 0.98 to 2.36). The relative risk of death in the aprotinin group, as compared with that in both groups receiving lysine analogues, was 1.53 (95% CI, 1.06 to 2.22). Despite the possibility of a modest reduction in the risk of massive bleeding, the strong and consistent negative mortality trend associated with aprotinin, as compared with the lysine analogues, precludes its use in high-risk cardiac surgery. (Current Controlled Trials number, ISRCTN15166455 [controlled-trials.com].).

Climatic trends in E-region critical frequency and virtual height above Tromsø (70° N, 10° E)

Abstract. We have examined the long time series of observations of E-region virtual height (1948–2006) and critical frequency (1935-2006) hitherto made by the Tromsø ionosonde at 70° N, 19° E. Combining a simplistic trend analysis with a rigorous treatment of errors we identify a negative trend in critical frequency. While a similar analysis of the virtual height h'E also suggests a negative trend, a closer examination reveals a possible weak positive trend prior to ~1975 and a strong negative trend from ~1975 to present. These two metrics of essentially the same feature of the ionosphere do not exhibit the same signature since critical frequency is controlled by photochemistry within the E-layer while height is controlled by pressure level. We further find that the trend in critical frequency is a daylight/summer phenomenon, no significant trend being evident in the winter subset of the data. On the other hand, the trends in virtual height are independent of season/daylight.

BAX mutations are associated with an adverse prognosis in Lynch syndrome-associated colorectal cancer

Lynch syndrome-associated colorectal cancer (CRC) is associated with a favorable prognosis compared to sporadic CRC, yet prognostic factors for Lynch syndrome-associated CRC are poorly investigated. We analyzed 70 colorectal neoplasms with high levels of microsatellite instability from 65 patients for frameshift mutations in the coding regions in the TGFBR2, ACVR2, BAX, MSH3, MSH6, AIM2, SEC63L genes as well as for P53 overexpression and loss of SMAD4 expression. In order to minimize selection bias, we restricted the evaluation of the prognostic value to 45 patients in whom MSI testing was initiated within 6 months after tumor diagnosis. TGFBR2, ACVR2, BAX, MSH3, MSH6, AIM2, and SEC63 frameshift mutations were detected in 55%, 87%, 52%, 23%, 30%, 25%, and 26%, respectively. Overexpression of P53 was detected in 64%, whereas loss or reduction of SMAD4 expression was observed in 7% and 33% respectively. MSH6 mutations occurred more frequently in MSH2 or MSH6 mutation carriers than in MLH1 mutation carriers (57% vs.11%, p=0.04). In addition SEC63L mutations were observed more frequently in right-sided CRC as compared to left-sided CRC (40% vs. 9%, p=0.02). No further correlations with sex, age at diagnosis, inclusion criteria (Amsterdam vs. Bethesda), mutation status, location or stage of the CRC, and resection status were observed. The median follow-up of the 45 patients evaluated for prognosis was 37 months with a total of 1839 person months. Seven patients died during the follow-up period: 5 due to CRC, 1 due to pancreatic cancer, 1 due to myocardial infarction. In univariate analysis BAX mutations, T stage (T3/4), positive nodal status (N+), metastatic disease (M1), resection status (non-R0), and UICC stage were significantly associated with an adverse overall (OS) and disease-specific survival (DSS). A strong negative trend was observed for TGFBR2 mutations.

20th-century glacier recession and regional hydroclimatic changes in northwestern Patagonia

This paper documents the occurrence of significant glacier and hydroclimatic changes in northwestern Patagonia during the past century. Drastic, widespread glacier recession is documented by repeat photography of some of the earliest glacier images from southern South America. Linear trends in regionally-averaged annual and seasonal temperature and precipitation records indicate significant warming and decreasing precipitation over the 1912–2002 interval. A climatic index is developed, based on winter precipitation and summer temperature records, that mimics glacier mass balance relationships and shows a strong negative trend which agrees with the drastic glacier recession shown by the photographic comparisons. Short positive periods of this climatic index broadly correspond with known evidence of glacier advances in the region. Regionally-averaged mean annual streamflow records east of the mountains were used in an independent verification check of the climatic series used in this study. This regional runoff record shows a strong negative trend, remarkable similarities with the climatic index, and highly significant positive (negative) correlations with the regional precipitation (temperature) series. This highlights the existence of a strong, regionally coherent hydroclimatic signal across this region and supports the utility of these records as environmental indicators for northwestern Patagonia between ca. 38° and 45°S. Given the significant socio-economic importance of rivers and glaciers in this area, further research is needed to evaluate the full range of natural hydroclimate variability and improve understanding of potential impacts of the future warmer and drier climates projected for this region.

Chemical reaction pathways affecting stratospheric and mesospheric ozone

Catalytic cycles and other chemical pathways affecting ozone are normally estimated empirically in atmospheric models. In this work we have automatically quantified such processes by applying a newly developed analysis package called the “Pathway Analysis Program” (PAP). It used modeled chemical rates and concentrations as input. These were supplied by the “Module Efficiently Calculating the Chemistry of the Atmosphere” MECCA box model, itself initialized by the Free University of Berlin Climate Middle Atmosphere Model with Chemistry. We analyzed equatorial, midlatitude and high‐latitude locations over 24‐hour periods during spring in both hemispheres. We present results for locations in the lower stratosphere, upper stratosphere and midmesosphere. Oxygen photolysis dominated (&gt;99%) in situ ozone production in the equatorial lower stratosphere, in the upper stratosphere and in the mesosphere. In the lower stratosphere midlatitudes the “ozone smog cycle” (already established in the troposphere) rivaled oxygen photolysis as an in situ ozone source in both hemispheres. However, absolute ozone production rates in midlatitudes were rather slow compared with at the equator, typically 16–50 ppt ozone/day. In the equatorial lower stratosphere, five catalytic sinks were important (each contributing at least 5% to chemical ozone loss): a HOx cycle, a HOBr cycle and its HOCl analog, a water‐HOx cycle and a mixed chlorine‐bromine cycle. Important in midlatitudes were the HOx cycle, a NOx cycle, the HOBr cycle and the mixed chlorine‐bromine cycle. In lower‐stratosphere high latitudes, the chlorine dimer cycle and the mixed chlorine‐bromine cycle dominated in both hemispheres. A variant on the latter, involving BrCl formation, also featured. In the upper stratosphere high latitudes (where strong negative ozone trends are observed), a nitrogen cycle, a chlorine cycle, and a mixed chlorine‐nitrogen cycle were found. In the mesosphere, three closely related HOx cycles dominated ozone loss.

Ozone laminae: Comparison of the Southern and Northern Hemisphere, and tentative explanation of trends

The measured ozone profiles often exhibit narrow layers of enhanced ozone concentration (positive laminae) or depleted ozone (negative laminae). Here we deal with the ozone laminae characteristics in the Southern Hemisphere in comparison with earlier studied laminae characteristics in the Northern Hemisphere. There are large differences between the ozone laminae characteristics in the Northern and Southern Hemisphere. The overall ozone content (deficit) in the positive (negative) laminae per profile and the number of laminae is much smaller in the Southern Hemisphere compared with the Northern Hemisphere. No detectable trend in these two lamina characteristics was found in the Southern Hemisphere contrary to a strong negative trend with a reversal to strong positive trend in the mid-1990s in the Northern Hemisphere. Pattern of trends in the ozone content in one lamina is quite different; no trend except for a slight negative trend in the Northern American sector. Some dynamical factors, mainly the degree of stability of the polar vortex, are suggested as contributing (or not) to the long-term behavior of lamina characteristics.

RELATIONSHIPS AND UNDERWRITER SPREADS IN THE EUROBOND FLOATING RATE NOTE MARKET

AbstractWe examine the role of issuer‐underwriter relationships in determining underwriter spreads for Eurobond floating rate notes from 1992 to 2002. Financial and nonfinancial firms with long‐term relationships pay a higher underwriter spread. Financial issuers that switch underwriters receive a discounted spread that is invariant to the underwriter's reputation and quality of the issue. However, the discount is not evident for nonfinancial firms. For both financial and nonfinancial firms, spreads are higher for noninvestment grade issues and, within investment grade, increase as quality declines. We also find higher spreads when underwriting is syndicated, and a strong negative time trend consistent with increasing competitive pressures.