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Showing papers by "University of Miami published in 1996"


Journal ArticleDOI
TL;DR: In this article, the authors show that service quality relates to retention of customers at the aggregate level, as other research has indicated, and evidence of its impact on customers' behavioral responses should be detectable.
Abstract: If service quality relates to retention of customers at the aggregate level, as other research has indicated, then evidence of its impact on customers’ behavioral responses should be detectable. Th...

10,574 citations


Journal ArticleDOI
10 Oct 1996-Nature
TL;DR: Observations provide unequivocal support for the hypothesis that phytoplankton growth in this oceanic region is limited by iron bioavailability.
Abstract: The seeding of an expanse of surface waters in the equatorial Pacific Ocean with low concentrations of dissolved iron triggered a massive phytoplankton bloom which consumed large quantities of carbon dioxide and nitrate that these microscopic plants cannot fully utilize under natural conditions. These and other observations provide unequivocal support for the hypothesis that phytoplankton growth in this oceanic region is limited by iron bioavailability.

1,318 citations


Journal ArticleDOI
TL;DR: It is suggested that in postmenopausal women the intake of vitamin E from food is inverse- ly associated with the risk of death from coronary heart disease and that such women can lower their risk without using vitamin supplements.
Abstract: Background The role of dietary antioxidant vitamins in preventing coronary heart disease has aroused considerable interest because of the knowledge that oxidative modification of low-density lipoprotein may promote atherosclerosis. Methods We studied 34,486 postmenopausal women with no cardiovascular disease who in early 1986 completed a questionnaire that assessed, among other factors, their intake of vitamins A, E, and C from food sources and supplements. During approximately seven years of follow-up (ending December 31, 1992), 242 of the women died of coronary heart disease. Results In analyses adjusted for age and dietary energy intake, vitamin E consumption appeared to be inversely associated with the risk of death from coronary heart disease. This association was particularly striking in the subgroup of 21,809 women who did not consume vitamin supplements (relative risks from lowest to highest quintile of vitamin E intake, 1.0, 0.68, 0.71, 0.42, and 0.42; P for trend = 0.008). After adjustment for p...

883 citations


Journal ArticleDOI
TL;DR: Present evidence suggests that the leading factors responsible for large-scale coral reef bleaching are elevated sea temperatures and high solar irradiance (especially ultraviolet wavelengths), which may frequently act jointly.
Abstract: Coral reef bleaching, the temporary or permanent loss of photosynthetic microalgae (zooxanthellae) and/or their pigments by a variety of reef taxa, is a stress response usually associated with anthropogenic and natural disturbances Degrees of bleaching, within and among coral colonies and across reef communities, are highly variable and difficult to quantify, thus complicating comparisons of different bleaching events Small-scale bleaching events can often be correlated with specific disturbances (eg extreme low/high temperatures, low/high solar irradiance, subaerial exposure, sedimentation, freshwater dilution, contaminants, and diseases), whereas large scale (mass) bleaching occurs over 100s to 1000s of km2, which is more difficult to explain Debilitating effects of bleaching include reduced/no skeletal growth and reproductive activity, and a lowered capacity to shed sediments, resist invasion of competing species and diseases Severe and prolonged bleaching can cause partial to total colony death, resulting in diminished reef growth, the transformation of reef-building communities to alternate, non-reef building community types, bioerosion and ultimately the disappearance of reef structures Present evidence suggests that the leading factors responsible for large-scale coral reef bleaching are elevated sea temperatures and high solar irradiance (especially ultraviolet wavelengths), which may frequently act jointly

819 citations


Journal ArticleDOI
TL;DR: In this paper, the authors provide a replication with professional knowledge worker jobs, different measures of effectiveness, and work units that varied in the degree to which members identified as a team.
Abstract: Previous research has demonstrated that work team characteristics can be related to effectiveness (Campion, Medsker, & Higgs, 1993). This study provides a replication with professional knowledge worker jobs, different measures of effectiveness, and work units that varied in the degree to which members identified as a team. Data were collected from 357 employees, 93 managers, and archival records for 60 teams in a financial services organization. Team characteristics were measured with questionnaires completed by employees and managers. Effectiveness measures included immediate manager judgments at two points in time, senior and peer manager judgments, employee judgments, and archival records of employee satisfaction and performance appraisals. Results were similar to previous findings in that most team characteristics were related to most effectiveness criteria. Relationships were strongest for process characteristics, followed by job design, context, interdependence, and other characteristics. Further, work units higher on single-team identity were higher on many team characteristics and effectiveness measures.

802 citations


Journal ArticleDOI
01 Sep 1996-Stroke
TL;DR: Reversible MCAo in which a poly-L-lysine-coated intraluminal suture was used proved to be a reliable and effective modification of this technique, yielding consistently larger infarcts and greatly reduced interanimal variability.
Abstract: Background and Purpose The purpose of the present study was to evaluate a modified method of intraluminal suture occlusion of the middle cerebral artery (MCA) on the volume of brain infarction and on neurobehavioral function in rats subjected to a temporary focal ischemic insult. Methods Male Sprague-Dawley rats were anesthetized with halothane and subjected to 60 minutes or 2 hours of temporary MCA occlusion (MCAo) by an intraluminal thread. In one group of rats, the suture was coated with poly-l-lysine, while in a second group, a conventional uncoated suture was used. Behavioral function was evaluated at 50 to 60 minutes after occlusion and during a 3-day period after MCAo. Three days after MCAo, brains were perfusion-fixed and infarct volumes were measured. Results In rats with 60-minute MCAo, only 3 of 7 animals with uncoated sutures had infarcts, whereas in the group with poly-l-lysine–coated sutures, all rats (n=7) exhibited infarction (P=.009, Fisher's exact test). With 2 hours of MCAo, total infar...

761 citations


Journal ArticleDOI
TL;DR: It is demonstrated that, like TGF-beta, CTGF can induce connective tissue cell proliferation and extracellular matrix synthesis.

752 citations


Journal ArticleDOI
TL;DR: A placebo-controlled trial has shown that treatment with zidovudine reduces the rate at which human immunodeficiency virus type 1 (HIV-1) is transmitted from mother to infant as discussed by the authors.
Abstract: Background and Methods A placebo-controlled trial has shown that treatment with zidovudine reduces the rate at which human immunodeficiency virus type 1 (HIV-1) is transmitted from mother to infant. We present data from that trial showing the number of infected infants at 18 months of age and the relation between the maternal viral load, the risk of HIV-1 transmission, and the efficacy of zidovudine treatment. Viral cultures were obtained, and HIV-1 RNA was measured by two assays in samples of maternal blood obtained at study entry and at delivery. Results In 402 mother–infant pairs, the rate of transmission of HIV-1 was 7.6 percent (95 percent confidence interval, 4.3 to 12.3 percent) with zidovudine treatment and 22.6 percent (95 percent confidence interval, 17.0 to 29.0 percent) with placebo (P<0.001). In the placebo group, a large viral burden at entry or delivery or a positive culture was associated with an increased risk of transmission (the transmission rate was greater than 40 percent in the highe...

728 citations


Journal ArticleDOI
TL;DR: Although symptoms of posttraumatic stress disorder (PTSD) declined over time, a substantial level of symptomatology was observed up to 10 months after the disease and all 5 factors in the conceptual model were predictive of children's PTSD symptoms 7 and 10 months postdisaster.
Abstract: The authors examined symptoms of posttraumatic stress in 3rd-5th grade children during the school year after Hurricane Andrew. From a conceptual model of the effects of traumatic events, 442 children were evaluated 3, 7, and 10 months postdisaster with respect to (a) their exposure to traumatic events during and after the disaster, (b) their preexisting demographic characteristics, (c) the occurrence of major life stressors, (d) the availability of social support, and (e) the type of coping strategies used to cope with disaster-related distress. Although symptoms of posttraumatic stress disorder (PTSD) declined over time, a substantial level of symptomatology was observed up to 10 months after the disease. All 5 factors in the conceptual model were predictive of children's PTSD symptoms 7 and 10 months postdisaster. Findings are discussed in terms of the potential utility of the model for organizing thinking about factors that predict the emergence and persistence of PTSD symptoms in children.

689 citations



Journal ArticleDOI
TL;DR: In this paper, the applicability of lexicographic shellability to nonpure posets is discussed, and an edge-labeling λ of L(F) is defined as follows.
Abstract: This is a direct continuation of Shellable Nonpure Complexes and Posets. I, which appeared in Transactions of the American Mathematical Society 348 (1996), 1299-1327. 8. Interval-generated lattices and dominance order In this section and the following one we will continue exemplifying the applicability of lexicographic shellability to nonpure posets. Let F = {I1, I2, . . . , In} be a family of intervals of integers, by which is meant sets of the form [a, b] = {a, a + 1, . . . , b}, a ≤ b. We assume that there are no containments among these intervals, and that they are ordered so that their left and right endpoints are increasing. Let L(F) be the lattice of all sets that are unions of subfamilies of F , ordered by inclusion. Such interval-generated lattices L(F) were introduced and studied by Greene [G]. Define an edge-labeling λ of L(F) as follows. If A → B is a covering and a = max(B \A), then λ(A→ B) = { −a, if (a+ 1) ∈ A and a is the left endpoint of some I ∈ F ,

Journal Article
TL;DR: Northern blot and run-on transcription assays indicate that TGF-beta directly activates transcription of the CTGF gene, and analysis of deletion mutants indicated that an important T GF-beta regulatory element is located between positions -162 and -128 of theCTGF promoter sequence.
Abstract: We reported previously that transforming growth factor beta (TGF-beta) selectively induced high levels of connective tissue growth factor (CTGF) mRNA and protein in human skin fibroblasts In this study, we investigated the molecular mechanism for TGF-beta regulation of CTGF gene expression Northern blot and run-on transcription assays indicate that TGF-beta directly activates transcription of the CTGF gene Fragments of the 5'flanking region of the human CTGF gene were linked to luciferase reporter constructs TGF-beta induced a 25-30 fold increase in luciferase activity in NIH/3T3 fibroblasts that had been transfected with this construct compared with nontreated cells after 24 h incubation Other growth factors, such as platelet derived growth factor or fibroblast growth factor, caused only a 2-3-fold induction This response to TGF-beta occurred only in human skin fibroblasts, fetal bovine aortic smooth muscle cells, and NIH/3T3 fibroblasts but not in the epithelial cell lines tested Analysis of deletion mutants indicated that an important TGF-beta regulatory element is located between positions -162 and -128 of the CTGF promoter sequence A fragment of the promoter containing this region conferred TGF-beta induction to a SV40 enhanceriess promoter Methylation interference and competition gel shift assays mapped a unique 13-nucleotide sequence delineating a novel TGF-beta cis-regulatory element Point mutations in this region result in a complete loss of the TGF-beta induction, identifying this sequence as a new TGF-beta response element

Journal ArticleDOI
23 Aug 1996-Science
TL;DR: Seismic reflection profiles and piston cores show that the lake not only was at a low stand but dried up completely during the Late Pleistocene, before 12,400 carbon-14 years before the present, implying that the rate of speciation of cichlid fish in this tropical lake has been extremely rapid.
Abstract: Lake Victoria is the largest lake in Africa and harbors more than 300 endemic species of haplochromine cichlid fish. Seismic reflection profiles and piston cores show that the lake not only was at a low stand but dried up completely during the Late Pleistocene, before 12,400 carbon-14 years before the present. These results imply that the rate of speciation of cichlid fish in this tropical lake has been extremely rapid.

Journal ArticleDOI
TL;DR: The authors used an integrative conceptual model to examine the emergence of posttraumatic stress disorder symptoms in 568 elementary school-age children 3 months after Hurricane Andrew, and suggest that the conceptual model may be helpful to organize research and intervention efforts in the wake of natural disasters.
Abstract: The authors used an integrative conceptual model to examine the emergence of posttraumatic stress disorder (PTSD) symptoms in 568 elementary school-age children 3 months after Hurricane Andrew. The model included 4 primary factors: Exposure to Traumatic Events, Child Characteristics, Access to Social Support, and Children's Coping. Overall, 62% of the variance in children's self-reported PTSD symptoms was accounted for by the 4 primary factors, and each factor improved overall prediction of symptoms when entered in the analyses in the order specified by the conceptual model. The findings suggest that the conceptual model may be helpful to organize research and intervention efforts in the wake of natural disasters.

Journal ArticleDOI
07 Mar 1996-Nature
TL;DR: In this paper, the authors present high-resolution records of laminated sediments of the last deglaciation from the Cariaco basin (tropical Atlantic Ocean) which show many abrupt subdecade to century-scale oscillations in surface-ocean biological productivity that are synchronous with climate changes at high latitudes.
Abstract: THE climate system is capable of changing abruptly from one stable mode to another1–3. Rapid climate oscillations—in particular the Younger Dryas cold period during the last deglaciation—have long been recognized from records throughout the North Atlantic region4–14, and the distribution of these records at mostly high latitudes suggests that the changes were caused by rapid reorganizations of the North Atlantic thermohaline circulation6,8,10,15. But events far from the North Atlantic region that are synchronous with the Younger Dryas16–19 raise the possibility that a more global forcing mechanism was responsible20. Here we present high-resolution records of laminated sediments of the last deglaciation from the Cariaco basin (tropical Atlantic Ocean) which show many abrupt sub-decade to century-scale oscillations in surface-ocean biological productivity that are synchronous with climate changes at high latitudes. We attribute these productivity variations to changes in or duration of up-welling rate (and hence nutrient supply) caused by changes in trade-wind strength, which is in turn influenced by the thermo-haline circulation through its effect on sea surface temperature6,21. Abrupt climate changes in the tropical Atlantic during the last deglaciation are thus consistent with a North Atlantic circulation forcing mechanism.

Journal ArticleDOI
TL;DR: In this article, a sensitive quantitative fluorescence method was used to explore the time course and regional pattern of blood-brain barrier (BBB) opening after transient middle cerebral artery occlusion (MCAo).

Journal ArticleDOI
11 Jan 1996-Nature
TL;DR: In this article, salinity, temperature and chemical-tracer data from the Indonesian seas are reported, which show that the throughflow is dominated by two components: low-salinity, well ventilated North Pacific water through the upper thermocline of the Makassar Strait, and the other of more saline South Pacific waters through the lower thermoclinic of the eastern Indonesian seas.
Abstract: THE physical structure of the Pacific and Indian oceans is substantially affected by the inter-ocean transport of excess fresh water from the North Pacific Ocean through the Indonesian seas1,2. The efficiency of this transport is an important regulator of the meridional overturning of these oceans1,2, and hence perhaps of the global thermohaline circulation3; in addition, the seepage of warm water out of the Pacific affects the volume of the western Pacific warm pool, and thus may influence EI Nino events24. But the sources, pathways and physical properties of the Indonesian throughflow are not well enough characterized to allow its influence on ocean circulation and the climate system to be quantified. Here we report salinity, temperature and chemical-tracer data from the Indonesian seas which show that the throughflow is dominated by two components: one of low-salinity, well ventilated North Pacific water through the upper thermocline of the Makassar Strait, and the other of more saline South Pacific water through the lower thermocline of the eastern Indonesian seas. Seasonal (monosonal) variations in the ratio of these components, perhaps modulated by EI Nino conditions, imply the existence of potentially important variable feedbacks to the ocean circulation and climate system.

Journal ArticleDOI
TL;DR: A set of minimum clinical guidelines for use by primary care physicians in the evaluation and management of patients with thyroid nodules or thyroid cancer was developed by consensus by an 11-member Standards of Care Committee of the American Thyroid Association.
Abstract: A set of minimum clinical guidelines for use by primary care physicians in the evaluation and management of patients with thyroid nodules or thyroid cancer was developed by consensus by an 11-member Standards of Care Committee (the authors of the article) of the American Thyroid Association, New York, NY. The participants were selected by the committee chairman and by the president of the American Thyroid Association based on their clinical experience. The committee members represented different geographic areas within the United States, to reflect different practice patterns. The guidelines were developed based on the expert opinion of the committee participants, as well as on previously published information. Each committee participant was initially assigned to write a section of the document and to submit it to the committee chairman, who revised and assembled the sections into a complete draft document, which was then circulated among all committee members for further revision. Several of the committee members further revised and refined the document, which was then submitted to the entire membership of the American Thyroid Association for written comments and suggestions, many of which were incorporated into a final draft document, which was reviewed and approved by the Executive Council of the American Thyroid Association.


Journal ArticleDOI
X Zhu1, M Ohtsubo1, R M Böhmer1, J M Roberts1, Richard K. Assoian1 
TL;DR: It is shown here that cell adhesion and growth factors jointly regulate the cyclin D1- and E- dependent kinases, establishing the cell cycle basis for explaining the combined requirement for growth factors and the extracellular matrix in transit through the Rb checkpoint, entry into S phase, and anchorage-dependent growth.
Abstract: Growth factors and cell anchorage jointly regulate transit through G1 in almost all cell types, but the cell cycle basis for this combined requirement remains largely uncharacterized. We show here that cell adhesion and growth factors jointly regulate the cyclin D1- and E-dependent kinases. Adhesion to substratum regulates both the induction and translation of cyclin D1 mRNA. Nonadherent cells fail to phosphorylate the retinoblastoma protein (Rb), and enforced expression of cyclin D1 rescues Rb phosphorylation and entry into S phase when G1 cells are cultured in the absence of substratum. Nonadherent cells also fail to activate the cyclin E-associated kinase, and this effect can be linked to an increased association of the cdk inhibitors, p21 and p27. These data describe a striking convergence in the cell cycle controls used by the two major signal transduction systems responsible for normal and abnormal cell growth. Taken together with our previous studies showing adhesion-dependent expression of cyclin A, they also establish the cell cycle basis for explaining the combined requirement for growth factors and the extracellular matrix in transit through the Rb checkpoint, entry into S phase, and anchorage-dependent growth.

Journal ArticleDOI
TL;DR: In this paper, the authors explored the factors that contribute to the explanation of FDI in the United States by country of origin of investment, and found that the main significant positive influences are home country's exports to the USA and home country market size.
Abstract: Given the large size and rapid growth of foreign direct investment in the United States, this subject is a central concern of U.S. firms and U.S. government policymakers. This study explores the factors that contribute to the explanation of FDI in the United States by country of origin of investment. Evidence from the past twelve years shows that the main significant positive influences are home country's exports to the United States and home country market size. Significant negative influences include the home country's imports from the United States, the cultural and geographic distances of the home country from the United States, and the exchange rate (fx/$).

Journal ArticleDOI
TL;DR: Receptors for nucleotides and nucleosides could represent a novel target for the development of therapeutic strategies to treat incurable diseases of the nervous system, including trauma- and ischemia-associated neurodegeneration, demyelinating and aging-associated cognitive disorders.

Journal ArticleDOI
TL;DR: The findings reinforce a correlation between CTGF gene expression and skin sclerosis and support the hypothesis that transforming growth factor-beta plays an important role in the pathogenesis of fibrosis, as it is the only inducer for CTGF identified to date.

Journal ArticleDOI
TL;DR: The importance of an ecological approach to the problem of academic underachievement within the African American community is highlighted, as neighborhood risk was examined as a moderator of the effects of parenting and peer support.
Abstract: Using a 1-year prospective design, this study examined the influence of family status variables (family income, parental education, family structure), parenting variables (maternal support and restrictive control), peer support, and neighborhood risk on the school performance of 120 African American junior high school students. In addition to main effects of these variables, neighborhood risk was examined as a moderator of the effects of parenting and peer support. Family status variables were not predictive of adolescent school performance as indexed by self-reported grade point average. Maternal support at Time 1 was prospectively related to adolescent grades at Time 2. Neighborhood risk was related to lower grades, while peer support predicted better grades in the prospective analyses. Neighborhood risk also moderated the effects of maternal restrictive control and peer support on adolescent grades in prospective analyses. These findings highlight the importance of an ecological approach to the problem of academic underachievement within the African American community.

Journal ArticleDOI
TL;DR: The distribution of HCV genotypes in distinct geographic regions of the United States was evaluated and the clinical characteristics of and response to interferon therapy in patients with one of several HCV Genotypes was determined.
Abstract: Objective To study 1) the geographic distribution and clinical significance of hepatitis C virus (HCV) genotypes in the United States and 2) the influence of HCV genotypes on response to interferon therapy. Design Hepatitis C virus genotype was determined in 179 stored serum samples obtained from patients who were positive for antibody to HCV and for HCV RNA by using polymerase chain reaction. Setting Tertiary referral centers in four geographic regions of the United States. Patients Patients who visited medical centers in the Midwest (50 patients), Northeast (42 patients), Southeast (35 patients), and West (52 patients). Measurements Chaotropic lysis and isopropanol precipitation were used to extract RNA from serum. Polymerase chain reaction was done on the NS5 region and was followed by automated direct sequencing and genotyping of desalted amplification products. Results 104 patients (58%) had subtype 1a; 38 (21%) had subtype 1b; 4 (2%) had subtype 2a; 23 (13%) had subtype 2b; 8 (5%) had subtype 3a; and 2 (1%) had subtype 4a. Examination of the known risk factors for acquiring HCV showed no association between genotype and mode of acquisition (blood transfusion, injection drug use, employment at a health care facility) or histologic findings at presentation (mild active hepatitis, moderately active hepatitis, or cirrhosis). Sixty-eight percent of patients with genotype 1a, 80% of patients with genotype 1b, and 37% of patients with genotype 2a or 2b had severe hepatitis. Thirteen of 46 (28%) patients with genotype 1a and 4 of 15 (26%) patients with genotype 1b had a complete biochemical response after 6 months of interferon therapy. In contrast, 10 of 14 (71%) patients with genotype 2a or 2b had a complete response to interferon therapy. Five of 39 (13%) patients with genotype 1a, 1 of 14 (7%) patients with genotype 1b, and 2 of 11 (18%) patients with genotype 2a or 2b had a sustained biochemical response. Conclusions In the United States, HCV genotypes 1a and 1b are the predominant genotypes in patients with chronic hepatitis C. Genotype is not correlated with mode of virus acquisition or with histologic findings at presentation. Patients with HCV genotype 1a or 1b had more severe liver disease and lower rates of response to interferon therapy than did patients with HCV genotype 2a or 2b. These findings may have implications for predicting outcome and selecting patients for interferon treatment.

Journal Article
TL;DR: The results substantiate the importance of careful evaluation, educational planning, and medical intervention for CNS-related complications in children with sickle cell disease.
Abstract: Objective Brain magnetic resonance imaging (MRI) and neuropsychological evaluations were conducted to determine whether neuroradiographic evidence of infarct in children with sickle cell disease between ages 6 and 12 years would result in impairment in cognitive and academic functioning Method and Design Children enrolled in the Cooperative Study of Sickle Cell Disease were evaluated with brain MRI and neuropsychological evaluation Completed studies were obtained for 194 children, 135 with HbSS MRIs were categorized according to the presence of T2-weighted, high-intensity images suggestive of infarct and were further categorized on the basis of a clinical history of cerebrovascular accident (CVA) An abnormal MRI but no clinical history of CVA was classified as a silent infarct Neuropsychological evaluations included assessment of both global intellectual functioning and specific academic and neuropsychological functions Results Central nervous system (CNS) abnormalities were identified on MRI in 179% of the children (222% of children homozygous for HbS), and a clinical history of CVA (N = 9, 46%) was identified in only children with HbSS disease Subsequent analyses examined only children with HbSS Children with a history of CVA performed significantly poorer than children with silent infarcts or no MRI abnormality on most neuropsychological evaluation measures Children with silent infarcts on MRI performed significantly poorer than children with no MRI abnormality on tests of arithmetic, vocabulary, and visual motor speed and coordination Conclusions These results substantiate the importance of careful evaluation, educational planning, and medical intervention for CNS-related complications in children with sickle cell disease

Journal ArticleDOI
TL;DR: Within the sparse, apparently simple plot of the story, O’Connor constructs a world torn between renewal and emptiness, natural beauty and crass materialism, compassion and cruelty; the protagonist must choose between these extremes and attempt to experience the grace of God’s love.
Abstract: 1953 Like much of Flannery O’Connor’s short fiction, ‘‘The Life You Save May Be Your Own’’ is set in the American South and contains characters whose most notable feature seems to be their ordinariness. Through imagery, dialogue, and moments of revelation, O’Connor explores the themes of morality and religion, both frequent concerns in her work. The story evoked critical praise upon its publication in the Kenyon Review in the spring of 1953. Within the sparse, apparently simple plot of the story, O’Connor constructs a world torn between renewal and emptiness, natural beauty and crass materialism, compassion and cruelty. In the end, O’Connor’s protagonist must choose between these extremes and attempt to experience the grace of God’s love.

Journal ArticleDOI
04 Apr 1996-Nature
TL;DR: In this paper, the authors report measurements of the light-scattering properties of North African dust delivered to Barbados by the North Atlantic trade winds and conclude that African mineral dust should be the dominant lightscattering aerosol throughout the tropical and subtropical North Atlantic region.
Abstract: ATMOSPHERIC aerosols can affect climate by scattering and absorbing solar radiation1–3. Most recent studies of such effects have focused largely on anthropogenic sulphate aerosols, which are believed to exert a substantial cooling influence2. Mineral dust aerosols have been largely ignored, because it was thought that their scattering efficiency and concentrations were too low to have a substantial effect on climate. Here we report measurements of the light-scattering properties of North African dust delivered to Barbados by the North Atlantic trade winds. Although the mass scattering efficiency of the dust is only about a quarter of that of non-seasalt sulphate over the North Atlantic5, the annual-mean dust concentration in Barbados trade-wind air is 16 times that of non-seasalt sulphate6. The net scattering by mineral dust is therefore about four times that by non-seasalt sulphate aerosols. African mineral dust should therefore be the dominant light-scattering aerosol throughout the tropical and subtropical North Atlantic region. Our observations suggest that mineral dust could be an important climate-forcing agent over this ocean region and in other regions where dust concentrations are high7,8.

Journal ArticleDOI
TL;DR: The incidence of bleb-associated endophthalmitis after guarded filtering surgery performed with adjunctive mitomycin is higher than the reported rate in eyes undergoing filtering surgery without the use of antifibrotic agents, and inferior limbal trabeculectomy carries the highest risk of infection.
Abstract: Objective: To identify the incidence, causative organisms, and clinical outcomes of eyes with bleb-associated endophthalmitis after glaucoma filtering procedures with adjunctive mitomycin. Methods: Retrospective analysis of 773 consecutive eyes that underwent glaucoma filtering surgery at the Bascom Palmer Eye Institute, Miami, Fla. The course of 609 eyes from 485 patients with a minimum of 3 months of follow-up were reviewed. Results: Mean follow-up was 16.0±11.5 months (range, 3-48 months). Of the 609 eyes, 13(2.1%) developed bled-associated endophthalmitis an average of 18.5±13.2 months after surgery (range, 1-45 months). The incidence of bleb-associated endophthalmitis was significantly greater after inferior trabeculectomy (7.8% per patient-year) than after superior trabeculectomy (1.3% per patient-year) by Kaplan-Meier estimates ( P =.02, log rank test). The cumulative incidence was 13% for inferior limbal blebs and 1.6% for superior limbal blebs. Nine (69.2%) of the 13 eyes were culture positive. Streptococcus sanguis and Haemophilus influenzae (6/13 [46.2%]) were the most frequent causative organisms. The mean increase in intraocular pressure after endophthalmitis treatment was 1.2 mm Hg, with a mean decrease in visual acuity of 1.42 log MAR units. Eight (61.5%) of the 13 eyes had a final acuity of 20/400 or better. Conclusions: The incidence of bleb-associated endophthalmitis after guarded filtering surgery performed with adjunctive mitomycin is higher than the reported rate in eyes undergoing filtering surgery without the use of antifibrotic agents (0.2%-1.5%). Inferior limbal trabeculectomy carries the highest risk of infection. Eyes with mitomycin blebs maintained excellent filtration capacity. However, after treatment of the infection, the visual outcomes were generally poor.

Book ChapterDOI
TL;DR: In this paper, atmospheric chemical models are used to estimate the deposition rate of various inorganic oxides of nitrogen (NOy), reduced nitrogen species (NHx), and mineral dust to the North Atlantic Ocean (NAO).
Abstract: Atmospheric chemical models are used to estimate the deposition rate of various inorganic oxides of nitrogen (NOy), reduced nitrogen species (NHx) and mineral dust to the North Atlantic Ocean (NAO). The estimated deposition of NOy to the NAO (excluding the coastal ocean) and the Caribbean is 360 × 109 Moles-N m-2 yr-1 (5.0 Tg N); this is equivalent to about 13% of the estimated global emission rate (natural and anthropogenic) and a quarter of the emission rate from sources in North America and Europe. In the case of NHx, 258 Moles-N m-2 yr-1 (3.6 Tg N) are deposited to the NAO and the Caribbean; this is about 6% of the global continental emissions. There is relatively little data on the deposition rate of organic nitrogen species; nonetheless, this evidence suggests that concentrations and deposition rates are comparable to those for inorganic nitrogen.