bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endemism and Invasion in the Great Lakes Diatom Community
Authors: Kreuger N. , Julius M. L. 
Published: March 2003

AbstractPopulation dynamics and health for individual Great Lakes diatom species is explored. Information dealing with how these taxa compete with introduced species and rapid environmental changes in modern times is examined. Diatomists have identified a number of these taxa, but discussion is limited with little or no information covering the ecological range of the taxa over time. Some of these include Cyclotella americana Fricke; C. bodanica var. stellata Skvortzow; and Stephanodiscus superiorensis Theriot. A number of taxa endemic to the Great Lakes undescribed in the literature also exist. These are species wedged into taxonomic categories from the European taxonomic system. Recent advances in the understanding of diatom species boundaries, suggest these names are inappropriately used for a number of taxa identified in paleolimnological investigations of the Great Lakes. This problem developed because taxonomic information outside of the European flora is not readily available to researchers, and because the focus of paleolimnological studies is primarily environmental reconstruction minimizing the time that can be spent unraveling taxonomically troublesome species. Examples of these are Cyclotella bodanica var. glabriscula and C. bodanica var. oligactis. Great Lakes populations of these taxa are significantly different from the original populations described from alpine lakes in Austria and Switzerland and merit taxonomic separation. Many of the endemic taxa are no longer present in the modern Great Lakes assemblages. The precise time of their disappearance from the system is not know, but modifications in Great Lakes diatom populations clearly coincided with the development of substantial European settlement of the Great Lakes region. C. americana, for example, was always limited to Lakes Erie and Ontario but disappeared from both of these lakes prior to 1900. With the disappearance of these taxa, came a number of introductions to the lakes. This work represents the first attempt to document these floristic changes.
Preservation of Nostocacean Hormogone Motility in Desiccated Calcium Carbonate Agar Patches
Authors: Lazaroff N. 
Published: March 2003

AbstractFilamentous nitrogen fixing cyanobacteria are resistant to desiccation, nutrient depletion, adverse temperature and challenging photic environments. This is generally thought to account for their role as pioneering forms of life on denuded strata. It has also lent credence to the possibility that cyanobacteria with prolonged viability may have been able to survive conditions of interplanetary space to implement a panspermian hypothesis for the origin of life on earth. Prolonged retention of viability had been noted in our collection of myxotrophically grown strains of nostocaceans cultured in liquid or solid media containing calcium carbonate. Such media permitted satisfactory recovery and regrowth after storage at low light intensities for 2 years or more. Moreover, even the oldest calcium carbonate cultures contained motile hormogonia when observed microscopically. This phenomenon can be used to advantage in sending cultures to other laboratories. Not only are organisms maintained during passage through the postal system but since the cultures formed hormogonia readily, it was possible to produce preservable homogeneous agar lawns that generated hormogonia as needed for demonstration or experiment. A practical technique consists of seeding axenic strains of Nostoc species grown in liquid shake culture under cool‐white fluorescent illumination into solid media containing 0.7% sucrose, 0.05% finely divided calcium carbonate and 1.4% purified agar. The preparations are incubated under red fluorescent illumination to produce several crops of hormogonia in successive cycles of development, within the agar. The heavily grown lawns are cut into disks or squares, then transferred to dishes and dried in desiccators with anhydrous calcium sulfate. The dry patches produce swarms of hormogonia in 2 or 3 h, depending upon the rate of rehydration. The patches are facile tools for purifying cultures through the isolation of hormogonia and studying cyanobacterial physiology by the rapid response of motile hormogonia.
Phylogeography of Batrachospermum Helminthosum (Rhodophyta) in North America
Authors: Chiasson W. B. , Machesky N. J. , Vis M. L. 
Published: March 2003

AbstractThe freshwater red alga, Batrachospermum helminthosum, is distributed primarily in streams of eastern North America. Although it is often an abundant and conspicuous component of the algal flora for many streams, little is known about the genetic relationship among populations throughout its range. The purpose of our study was to elucidate geographic patterns among populations to gain insight into the biogeographic distribution of this species and possible modes of dispersal. Individuals were sampled in 13 stream segments as follows: four locations in Ohio, two locations in Michigan and one location each in Indiana, North Carolina, Tennessee, Louisiana, Rhode Island, Massachusetts and Connecticut. The mitochondrial spacer region (371 bp) between the COX2 and COX3 genes was chosen because it is variable among individuals. This region was sequenced for 15 individuals from each location. Thirteen haplotypes were identified among the 13 locations with most locations having one or two haplotypes. Two of the haplotypes were dominant being recorded from six of the streams. The Indiana, Louisiana and first Michigan population had a unique haplotype. The second Michigan and fourth Ohio populations shared a unique haplotype. The Tennessee population had four haplotypes, three of which were closely related but the fourth haplotype was not and linked to the haplotypes from Michigan and Ohio. The relationships among these populations are very complex but there may have been a recent dispersal event via birds among various streams.
Interannual Variation in Coral Reef Plant Communities of Central Belize
Authors: Rhodes M. J. , Nelson T. A. 
Published: March 2003

AbstractAlgal and seagrass community composition were monitored biennially along three transect lines in Belize from 1997 through 2001. Two sites were on South Water Caye. The first was on the seaward side, between the reef crest and the caye. The second was on the landward side of the caye. The third site was on Long Caye, Glover's Reef Atoll. This transect line ran from a coral rubble filled embayment, through a small channel (formed by hurricane Hattie in 1960, bisecting Long Caye), and into a seagrass meadow in the interior of the atoll. After a 38‐year hiatus, hurricanes struck Belize in 1998, 2000 and 2001, giving us the opportunity to examine changes in plant community structure before and after the storm sequence. Minimal interannual changes were seen at South Water Caye. The seagrasses at Long Caye were nearly eliminated along the transect line due to burial by sand. Peak density of Thalassia testudinum at Long Caye was over 60 shoots/m2 in 1997 and less than 2 shoots/m2 in 1999 and 2001. Halodule wrightii and Syringodium filiforme were both completely eliminated between 1997 and 1999. Padina and Dictyota spp. flourished in the embayment following the hurricane, but had been virtually absent prior to the sequence of storms. Future monitoring will be conducted to follow recovery of the meadow and look for other long‐term changes.
Photoprotective Compounds in Rice‐Field Cyanobacteria
Authors: Sinha R. P. , Haeder D.‐P. 
Published: March 2003

AbstractCyanobacteria are cosmopolitan in distribution, forming a prominent component of microbial populations in both aquatic as well as terrestrial ecosystems. They are the dominant microflora in rice‐fields, where they significantly contribute to fertility as a natural biofertilizer. The fluence rates of UV‐B radiation impinging on the natural habitats is of major concern since being photoautotrophic organisms, cyanobacteria depend on solar radiation as the primary source of energy. UV‐B radiation causes reduction in growth, survival, pigment and protein content, heterocyst frequency and fixation of carbon and nitrogen in cyanobacteria. However, a number of cyanobacteria synthesize water soluble colorless mycosporine‐like amino acids (MAAs) and the lipid soluble yellow‐brown colored sheath pigment, scytonemin to counteract the damaging effects of UV‐B. Anabaena sp., Nostoc commune, Scytonema sp. and Lyngbya sp. were isolated from rice‐fields in India and screened for the presence of photoprotective compounds. Spectroscopic and biochemical analyses revealed the presence of shinorine, a bisubstituted MAA containing both glycine and serine group with an absorption maximum at 334 nm in all cyanobacteria except Lyngbya sp. There was a circadian induction in the synthesis of this compound by UV‐B. Polychromatic action spectra for the induction of MAAs in Anabaena sp. and N. commune show the induction to be UV‐B dependent peaking at 290 nm. Another photoprotective compound, scytonemin, with an absorption maximum at 386 nm (also absorbs significantly at 300, 278, 252 and 212 nm) was detected in all cyanobacteria except Anabaena sp. In addition, two unidentified, water‐soluble, yellowish and brownish compounds with an absorption maximum at 315 nm were recorded only in Scytonema sp. The spectral characteristics of these compounds neither matches with MAAs nor with scytonemin and seems to be a novel compound acting as an effective UV screens. In conclusion, a particular cyanobacterium having photoprotective compounds may be a potent candidate as biofertilizers for crop plants.
Primary Myelodysplasia: Management and Outcome at 3 Years in 45 Patients Age 65 and Older
Authors: Tilly‐Gentric A. , Malo J. P. , Marion V. 
Published: March 2003

OBJECTIVES:To study myelodysplasia in patients age 65 and older.SETTING:A French university hospital.PARTICIPANTS:Forty‐five patients age 65 and older with a diagnosis of myelodysplasia made in the hospital between January 1993 and December 1998.MEASUREMENTS:Clinical presentation, initial hematological features, type of myelodysplasia (French American British classification), treatment, and evolution at 36 months were studied.RESULTS:The mean age of the group was 78. Anemia was the initial hematological feature in 30 patients out of 45 and was symptomatic in 24 patients. Refractory anemia was diagnosed in 20 patients; 11 patients presented with refractory anemia with excess blast cells, eight with chronic myelomonocytic leukemia. Thirty‐one patients received erythrocyte transfusions, no patient received chemotherapy. At 36 months, 68.8% of the patients were dead. The median survival (22 months) was lower than in other reported series even in types of myelodysplasia with a classically better prognosis.CONCLUSION:Myelodysplasia is probably underdiagnosed in older people and has a poor prognosis (median survival 22 months), and no effective treatment is available in older patients. J Am Geriatr Soc 49:1358–1360, 2001.
Effect of Beta Blockers on Mortality and Morbidity in Persons Treated for Congestive Heart Failure
Authors: Aronow Wilbert S. 
Published: March 2003

PURPOSE: To determine the effect of metoprolol controlled release/extended release (CR/XL) administered once daily on mortality in patients with congestive heart failure (CHF) associated with abnormal left ventricular (LV) ejection fraction. BACKGROUND: CHF with abnormal LV ejection fraction despite treatment with diuretics plus angiotensin‐converting enzyme (ACE) inhibitors plus digoxin has a very high mortality. Previous data suggested that long‐term treatment with beta‐blockers, including metoprolol, could improve survival and improve hemodynamics in patients with CHF and abnormal LV ejection fraction. METHODS: Three thousand nine hundred and ninety‐one patients aged 40 to 80 years from 313 investigational sites in 13 European countries and in the United States with chronic CHF New York Heart Association (NYHA) functional class II, III, or IV and a LV ejection fraction of 40% or less were stabilized with optimum standard therapy. Of the 3,991 patients, 77% were men, 23% were women; 33% were younger than 60 years of age, 35% were 60 to 69 years of age, 32% were 70 to 80 years of age; 66% had ischemic heart disease; 91% were receiving diuretics, 96% were receiving ACE inhibitors or angiotesin II type 1 receptor antagonists, and 64% were receiving digitalis. Randomization was preceded by a 2‐week single‐blind placebo run‐in period. Following this, 1,990 patients were randomized to metoprolol CR/XL 12.5 mg daily if NYHA functional class III or IV CHF was present (59%) or to 25 mg daily if NYHA functional class II CHF was present (41%), and 2,001 patients were randomized to double‐blind placebo. The target dose was 200 mg once daily of metroprolol CR/XL and doses were up‐titrated over 8 weeks. The primary endpoint was all‐cause mortality analyzed by intention to treat. MAIN RESULTS: The study was stopped early on the recommendation of the independent safety committee. Mean follow‐up was 1 year. All‐cause mortality occurred in 145 of 1,990 patients (7.2%) treated with metoprolol versus 217 of 2,001 patients (11.0%) treated with double‐blind placebo (P= .0062; relative risk = 0.66, 95% confidence interval = 0.53–0.81). Compared with double‐blind placebo, metoprolol caused a significant reduction in total mortality by 34% (P= .0052), a significant decrease in cardiovascular mortality by 38% (P= .00003), a significant reduction in sudden cardiac death by 41% (P= .0002), and a significant decrease in death from worsening CHF by 49% (P= .0023). Mortality was significantly reduced by metoprolol in patients who were in the upper tertile of age as well as in the middle and lower tertiles of age. CONCLUSIONS: In patients with chronic CHF NYHA functional class II, III, or IV treated with optimum standard therapy, these data demonstrated that, compared with double‐blind placebo, metoprolol CR/XL 200 mg administered once daily caused significant reductions in all‐cause mortality by 34%, in cardiovascular mortality by 38%, in sudden cardiac death by 41%, and in death from worsening CHF by 49%.
Description of the National Pressure Ulcer Long‐Term Care Study
Authors: Horn Susan D. , Bender Stacy A. , Bergstrom Nancy , Cook Abby S. , Ferguson Maree L. , Rimmasch Holly L. , Sharkey Siobhan S. , Smout Randall J. , Taler George A. , Voss Anne C. 
Published: March 2003

OBJECTIVES: To describe and provide baseline data from The National Pressure Ulcer Long‐Term Care Study (NPULS).DESIGN: Retrospective cohort study of detailed resident characteristics, treatments, and outcomes using convenience sampling.SETTING: One hundred nine long‐term care facilities throughout the United States.PARTICIPANTS: Two thousand four hundred twenty adult residents aged 18 and older, with a length of stay of 14 days or longer and who were at risk of developing a pressure ulcer, as defined by a Braden Scale for Predicting Pressure Sore RiskMEASUREMENTS: More than 500 characteristics were obtained for each resident over a 12‐week period. This paper describes the NPULS database with respect to the resident (sex, age, diagnoses, severity of illness scores, Braden Scale score, activities of daily living, cognitive ability, mobility, bowel or bladder incontinence, laboratory values, nutritional assessment, and pressure ulcer assessment documentation), treatment (nutritional interventions, pressure relieving devices, incontinence interventions, protective devices, turning schedules, and pressure ulcer treatments), and outcome variables (pressure ulcer development and healing, pressure ulcer and systemic infection, changes in nutritional status, and discharge disposition) associated with pressure ulcers. Descriptive statistics and bivariate associations were used for preliminary analyses of resident, treatment, and outcome characteristics.RESULTS: The average age ± standard deviation was 79.7 ± 14.2; 70% of the residents were female. Fifty‐three percent of residents (n = 1,293) were at risk of developing a pressure ulcer but never developed one during the study (Group 1), 19% developed a new pressure ulcer during the study (n = 457) (Group 2), 22% had an existing pressure ulcer (n = 534) (Group 3), and 6% had an existing pressure ulcer and developed a new ulcer during the study (n = 136) (Group 4). Residents who developed a new pressure ulcer (Group 2) were more likely to be female, older, cognitively impaired, and immobile than residents who had an existing pressure ulcer (Group 3).CONCLUSIONS: This baseline study describes the NPULS database with respect to the resident, treatment, and outcome variables associated with pressure ulcers. Future studies will focus on multivariate analyses for risk factor prediction of pressure ulcer development and pressure ulcer healing. Research‐based pressure ulcer prevention and treatment protocols can then be developed.
The effect of mode of agitation and type of plastic bag on storage characteristics and in vivo kinetics of platelet concentrates
Authors: Snyder E. L. , Pope C. , Ferri P. M. , Smith E. O. , Walter S. D. , Ezekowitz M. D. 
Published: March 2003

We studied the characteristics of platelet concentrates stored for 5 days at 22°C. Platelets were prepared in three plastic bags (PL 732, PL 1240, and CLX) and stored on one of four platelet agitators, 1‐ or 6‐rpm elliptical and 2‐ or 6‐rpm circular rotators. A total of 76 studies were divided among 12 groups, each group being composed of a different storage bagrotator combination. In vivo recovery and survival were calculated using Indium‐111 oxine‐labeled platelets injected into autologous volunteers. Platelet recovery was assessed at 2 hours postinjection or as the y‐intercept of the multiple‐hit model survival curve. Survival was calculated using linear, exponential, and multiple‐hit computer models. Linear T 1/2 also was calculated as an index of platelet survival.At 5 days, the pH of all concentrates was above pH 7.0 and platelet counts were above 5.5 × 1010 per bag except for the PL 732 with the 6‐rpm elliptical rotator, which was 4.6 × 1010 per bag. This combination also showed a significantly higher poststorage lactic dehydrogenase (LDH) discharge compared to the mean of the other 11 groups (23.6 ± 5.4% vs. 10.4 ± 3.0%, p < 0.05); however, the β‐thromboglobulin (β‐TG) release was not statistically different. The lowest in vivo recovery and survival T 1/2 were found for the PL 732 with the 6‐rpm elliptical rotator: 2‐hour recovery of 28.0 ± 3.2 percent vs. 40.0 ± 10.6 percent for the other 11 groups (p < 0.05) and survival T 1/2 of 2.1 ± 1.4 days vs. 2.9 ± 0.6 days (p<0.05). Survivals using the three computer models, however, were similar for all 12 groups and were 7.2 ± 1.3 days (linear), 3.3 ± 0.9 days (exponential), 5.7 ± 2.0 days (multiple hit) (n = 76). The percent in vitro release of β‐TG or discharge of LDH during storage did not predict in vivo recovery. We conclude that storage of platelet concentrates for 5 days in PL 732 containers on a 6‐rpm elliptical rotator is the least desirable method of storage; all other combinations gave acceptable and similar results.
Changes in adenosine triphosphate, 2,3 diphosphoglycerate, and P50 of dog blood following transfusion of autologous red cells pretreated with phosphoenolpyruvate in vitro
Authors: Yonenaga K. , Todoroki H. , Tokunaga K. , Hamasaki N. 
Published: March 2003

Red cells treated with phosphoenolpyruvate (PEP) in vitro were reinfused into the donor dogs and were monitored for changes in adenosine triphosphate (ATP), 2,3 diphosphoglycerate (2,3 DPG), and P50. ATP and 2,3 DPG concentrations increased to 116 and 143 percent of control, respectively, when these cells were incubated with 60 mM PEP for 90 minutes at 37°C. The oxygen dissociation curve shifted to the right, and P50 increased from 24.5 to 30.6 torr as a result of the PEP treatment. When one‐half of the circulating red cell volume was treated with PEP and reinfused into the animal, the red cell 2,3 DPG increased to 120 percent of pretransfusion values. The 2,3 DPG level remained elevated during the following day and returned to near pretransfusion levels on the third day. The P50 of the circulating blood paralleled the variations in the red cell 2,3 DPG level, and the capacity for oxygen delivery was calculated to be raised by 13 to 38 percent for a period of 24 hours. In contrast, elevated red cell ATP returned to control values immediately after transfusion.In vivo viability, i.e., 24‐hour survival and one‐half disappearance time, of the cells pretreated with PEP were determined by a single‐isotope technique using 51Cr. The results showed that PEP treatment did not injure the red cells. In addition, there was neither acute toxicity nor a deleterious hemodynamic effect when large amounts of PEP were administered intravenously.These results suggest that PEP could be used clinically to improve the capacity of the circulating red cells to deliver oxygen to the tissues.
Effect of storage and ultraviolet B irradiation on CD14‐bearing antigen‐ presenting cells (monocytes) in platelet concentrates
Authors: FIEBIG E. , LANE T.A. 
Published: March 2003

BACKGROUND: Ultraviolet B (UVB) irradiation of platelet concentrate (PCs) reduces platelet alloimmunization, but the mechanism of the effect is unclear. Evidence suggests that UVB may downregulate the expression of surface adhesion molecules on passenger antigen‐ presenting cells in PCs.STUDY DESIGN AND METHODS: The effect of blood bank storage, platelet preparation from whole blood, and UVB irradiation on the quantitative expression of intercellular adhesion molecule‐1 (ICAM‐1, or CD54), HLA‐DR, CD45, and CD11c on CD14‐positive antigen‐presenting cells (monocytes) was studied by using two‐color flow cytometry.RESULTS: Blood bank storage for 4 days resulted in upregulation of ICAM‐1 and HLA‐DR and downregulation of CD14 but left the expression of CD11c and CD45 unchanged. Preparation of PCs from fresh whole blood was associated with a rapid increase in CD11c without upregulation of ICAM‐1 and HLA‐DR. UVB irradiation before storage inhibited the upregulation of ICAM‐1 and HLA‐DR, resulted in accelerated downregulation of CD14, and was associated with increased loss of monocytes. Agitation of the PC bag during irradiation was of critical importance, since omission of agitation resulted in largely uninhibited upregulation of ICAM‐1 but was still associated with significantly higher cell loss than that seen in unirradiated controls. CONCLUSION: UVB exposure nonspecifically affects monocytes in PCs, resulting in downregulation of surface molecules that are important for antigen presentation, as well as in significant cell loss