bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physiological and Biochemical Responses of Two Seaweeds to Nutrient or Light Deprivation
Authors: Lourenço S. O. , Berges J. A. 
Published: March 2003

AbstractThe algae Fucus vesiculosus (brown) and Enteromorpha compressa (green) were cultured in long‐term experiments in which natural seawater without nutrient enrichment was used, or in which the plants were kept in complete darkness. Measurements of variable fluorescence (Fv/Fm), an indicator of photosynthetic competence, showed a gradual decrease of Fv/Fm in nutrient‐deprivation experiments, varying from 0.64 to 0.25 (E. compressa) and from 0.65 to 0.40 (F. vesiculosus) after 6 months of cultivation. F. vesiculosus was virtually unaffected after more than 2 months in darkness, showing values of Fv/Fm around 0.65 throughout the experiments, but cultures of E. compressa collapsed after 45 days in darkness. In both species lower concentrations of chlorophyll a resulted of nutrient‐deprivation experiments, decreasing three times in F. vesiculosus and 25 times in E. compressa by the end of the experiments. F. vesiculosus cultured in darkness showed 50% more chlorophyll a than the control, while plants of E. compressa kept in dark and in light showed similar values of chlorophyll a during the first 30 days of cultivation. The tissue‐N content of both species decreased dramatically in nutrient‐deprivation experiments, establishing variations in C : N ratio from 20 : 1 to 79 : 1 (F. vesiculosus) and from 8.6 : 1 to 75 : 1 (E. compressa). The algae showed small variations in C : N ratio throughout the experiments in darkness. Such as previously identified for phytoplanktonic species, the variations in the physiological responses exhibited by the seaweeds tested suggest that these conventional diagnostics of limitations may be misleading in natural algal assemblages, which are composed by mixed species. Gel electrophoretic is currently being performed to identify possible proteins that may respond specifically to these experimental conditions.
Distribution and Morphology of Diatoms in High Altitude Streams on Kauai (Hawaii)
Authors: Main S. P. 
Published: March 2003

AbstractDiatom samples collected from Kawaikoi Stream differ in species composition and relative abundance from those in Kokee Stream. Kuwaikoi collects drainage from the Alakai Swamp, which developed on a 1200–1500 m elevation ridge of Mt. Waialeale extending at a right angle to the NE winds. Kokee lies about 2000 m further west at about 1100 m elevation. Frustulia and Eunotia species characteristic of low conductivity waters predominate. Greater diversity of Achnanthes, Navicula, Pinnularia and Surirella taxa occurs in the somewhat more conductive waters of Kokee. The morphological species observed bear a close, but not exact, resemblance to mainland taxa described in the literature. Morphological variations are documented using light and scanning electron microscopy.
Survival of Chlamydomonas Subsequent to Cryopreservation is Prevented by a Substance Released from Damaged Cells
Authors: Piasecki B. , Fan Yang , Diller K. R. , Brand J. J. 
Published: March 2003

AbstractStorage of algae in liquid nitrogen offers a convenient way to permanently preserve many cultures with minimum genetic drift. We have successfully cryopreserved over 1400 strains in the Culture Collection of Algae at the University of Texas (UTEX), but over one‐fourth of UTEX cultures remain recalcitrant. Our previous studies demonstrate that unicellular algae frozen at a high cell density (>2000000 cells/mL) do not survive cryopreservation well. We now show that viability during cryopreservation of Chlamydomonas reinhardtii UTEX #89 at high cell densities is not affected by the physical proximity of cells. Instead, when cells are damaged, a small organic molecule(s) is produced and released into the medium preventing cryopreservation of other cells in the culture. Healthy C. reinhardtii cultures were treated with extracts prepared from damaged cells or culture medium separated from damaged cells, then cryopreserved by a standard method (Crutchfield et al. (1999) Eur J Phycol 34: 43–52). Viability was measured after thawing by the ability of a cell wall to preclude Evan's blue dye, and was confirmed by quantitative agar plating. The inhibitory substance from these fractions appears to affect living cells only during cryopreservation, but can be produced from cells by a variety of treatments. The inhibitor is heat‐stable, but heating cells to 80 °C precludes its production. The substance is stable when separated from cellular particulate matter, but gradually becomes inactive in the presence of cell membrane fractions. The inhibitor is a water‐soluble and heat‐stable organic compound(s), with a molecular mass less than or equal to 3500. Characterizing the inhibitory substance and the pathway that leads to its formation may explain why most multicellular algae remain recalcitrant to cryopreservation, and lead to protocols that allow the cryopreservation of a broader range of organisms.
Tracing Invasions of Caulerpa Taxifolia with Molecular Markers
Authors: Stam W. T. , Meusnier I. , Destombe C. , Valero M. , Olsen J. L. 
Published: March 2003

AbstractComparative sequence data from the rDNA ITS have proven very useful in species identification and identifying major biogeographic groups of Caulerpa taxifolia. However, the low variability of the sequence, and the need to screen hundreds of samples has limited its utility for population level studies. Here we report on the performance of two new markers suitable for population level screening: the chloroplast rDNA 16S intron‐2 and intersimple‐sequence‐repeat fingerprints (ISSRs). A new analysis of ITS1 insertion–deletion patterns was also conducted using all available sequences. A number of new insights have emerged. First, the invasive aquarium strain (Mediterranean, California) is clearly from Brisbane, but the Brisbane populations themselves may be the result of an introduction from Northern Australia. Second, an analysis of the new data in conjunction with an ITS1‐insertion–deletion analysis further suggests that the Mediterranean populations may be the result of not one, but two separate introductions. Third, intrapopulation genetic diversity between invasive Mediterranean and ‘native’ Australian populations revealed the occurrence of two divergent and widespread clades. The first clade grouped nontropical invasive populations with coastal inshore populations of Australia while the second clustered all offshore/oceanic populations so far studied. C. taxifolia, therefore exists as a complex of independent ecotypes that probably represent nascent species. Fourth, despite our finding of nine distinct nuclear and five distinct chloroplast profiles, strong linkage disequilibrium was found in most specimens, which indicates a predominance of asexual reproduction. However, nucleo‐cytoplasmic recombination was detected in one case, supporting hybridization both within and between populations.
Ultrastructure and Phylogeny of a New Species Belonging to the Prymnesiophyceae
Authors: Tanczos M. A. , Bailey J. C. , Andersen R. A. 
Published: March 2003

AbstractUltrastrucural and molecular data were used to examine a new alga (CCMP2000) collected from the Arabian Sea. Nonmotile vegetative cells are typically oblong to ovate, solitary and lack a gelatinous envelope. Ultrastructural analyses of these cells revealed the presence of a nucleus located in the posterior portion of the cell. A single large Golgi body with numerous cisternae is located anterior to the nucleus as are numerous profiles of mitochondria possessing tubular cristae. Two peripheral plastids are present having immersed pyrenoids that are traversed by one or more thylakoids. In some cells, the plastids are conspicuously lobed forming finger‐like extensions. Nonmotile vegetative cells possess reduced mature and immature flagella as well as a haptonema that are 1 micron long or less. A distinct internal covering and external wall surround the cell protoplasm. The outer wall is apparently composed of simple scales, but the composition (organic or mineralized?) of these scales is unknown. The outer wall may form a protuberance, or ‘foot’, at the posterior end of nonmotile cells. Interestingly, many vegetative cells are infected by a labyrinthulid. Flagellate stages have been observed and possess roughly equal length flagella and a haptonema. Phylogenetic analyses of nuclear 18S rRNA and plastid‐encoded rbcL genes indicate CCMP2000 is most closely related to Phaeocystis. However, CCMP2000 does not fit the description of Phaeocystis, and therefore, probably warrants recognition as a new taxon.
Aspiration Pneumonia: Dental and Oral Risk Factors in an Older Veteran Population
Authors: Terpenning Margaret S. , Taylor George W. , Lopatin Dennis E. , Kerr Connie Kinder , Dominguez B. Liza , Loesche Walter J. 
Published: March 2003

OBJECTIVES: To investigate the importance of medical and dental factors in aspiration pneumonia in an older veteran population.DESIGN: Prospective enrollment of subjects with retrospective analysis of data.SETTING: Department of Veterans Affairs outpatient clinic, inpatient ward, and nursing home.PARTICIPANTS: 358 veterans age 55 and older; 50 subjects with aspiration pneumonia.MEASUREMENTS: Demographic and medical data; functional status; health‐related behaviors; dental care utilization; personal oral hygiene; comprehensive dental examination; salivary assays including IgA antibodies; and cultures of saliva, throat, and dental plaques.RESULTS: Two logistic regression models produced estimates of significant risk factors. One model using dentate patients included: requiring help with feeding (odds ratio (OR) = 13.9), chronic obstructive pulmonary disease (COPD) (OR = 4.7), diabetes mellitus (OR = 3.5), number of decayed teeth (OR = 1.2), number of functional dental units (OR = 1.2), presence of important organisms for decay, Streptococcus sobrinus in saliva (OR = 6.2), and periodontal disease, Porphyromonous gingivalis in dental plaque (OR = 4.2), and Staphylococcus aureus presence in saliva (OR = 7.4). The second model, containing both dentate and edentulous patients included: requiring help with feeding (OR = 4.7), COPD (OR = 2.5), diabetes mellitus (OR = 1.7), and presence of S. aureus in saliva (OR = 8.3).CONCLUSION: This study supports the significance of oral and dental factors while controlling for established medical risk factors in aspiration pneumonia incidence.
Prevalence of Tooth Loss and Dental Service Use in Older Mexican Americans
Authors: Randolph Whitney M. , Ostir Glenn V. , Markides Kyriakos S. 
Published: March 2003

OBJECTIVES: To describe the prevalence of tooth loss, to examine risk factors for having fewer teeth or no teeth, and to describe the use of dental services in an older Mexican‐American population.DESIGN: Data from the baseline phase of the Hispanic Established Population for the Epidemiological Study of the Elderly survey conducted from 1993 to 1994, a cross‐sectional survey of older Mexican Americans.SETTING: Five southwestern states: Texas, California, Arizona, New Mexico, and Colorado.PARTICIPANTS: 3,050 noninstitutionalized Mexican Americans age 65 to 99.RESULTS: Twenty‐seven percent of the sample was completely edentulous and 22% reported visiting or speaking with a dental care professional in the preceding year. Logistic regression analyses showed that being older or being female was significantly associated with tooth loss, adjusting for education, income, smoking status, and diabetes mellitus. Current smokers (odds ratio (OR) = 1.69; 95% CI = 1.31–2.20) and diabetics (OR = 1.53; 95% CI = 1.27–1.84) were more at risk for tooth loss, as were persons of lower socioeconomic status.CONCLUSIONS: The prevalence of tooth loss and use of dental services in this population of older Mexican Americans is lower than what has been previously found among older people in the general population.
Effects of Supporting Community‐Living Demented Patients and Their Caregivers: A Randomized Trial
Authors: Eloniemi‐Sulkava Ulla , Notkola Irma‐Leena , Hentinen Maija , Kivelä Sirkka‐Liisa , Sivenius Juhani , Sulkava Raimo 
Published: March 2003

OBJECTIVES:To determine whether community care of demented patients can be prolonged by means of a 2‐year support program based on nurse case management.DESIGN:Randomized controlled intervention study with 2‐year follow‐up.SETTING:Demented patients entitled to payments from the Social Insurance Institution for community care, in five municipalities in eastern Finland.PARTICIPANTS:One hundred demented patients, age 65 and older, living at home with the primary support of informal caregivers, allocated at random to the intervention (n = 53) or control group (n = 47).INTERVENTION:Intervention patients and their caregivers were provided with a 2‐year intervention program of systematic, comprehensive support by a dementia family care coordinator.MEASUREMENTS:Time to institutionalization (period in community care) from enrollment of patients in the study to their placement in long‐term institutional care.RESULTS:During the first months, the rate of institutionalization was significantly lower in the intervention group than in the control group (P = .042), but the benefit of the intervention decreased with time (P = .028). Estimated probability of staying in community care up to 6, 12, and 24 months was 0.98, 0.92, and 0.63 in the intervention group and 0.91, 0.81, and 0.68 in the control group, respectively. Results also suggest that the intervention used in the study might be especially beneficial to patients with severe dementia and those with problems threatening the continuity of community care.CONCLUSIONS:The placement of demented patients in long‐term institutional care can be deferred with the support of a dementia family care coordinator. However, by the end of the 2‐year intervention, the number of patients institutionalized was similar in the intervention and control group. It seems to be beneficial to direct this type of intensive support at severely demented patients and their caregivers. On the basis of our experiences, we suggest that intervention by a dementia family care coordinator should be targeted especially at patients with problems threatening the continuity of community care. J Am Geriatr Soc 49:1282–1287, 2001.
Use of Anticholinergic Medications by Older Adults with Dementia
Authors: Roe Catherine M. , Anderson Michael J. , Spivack Barney 
Published: March 2003

OBJECTIVES: To compare the prevalence of anticholinergic use in older adults with probable dementia with that of a matched comparison group of older adults who were unlikely to have dementia and to examine the extent to which patients taking donepezil concomitantly use anticholinergic medications.DESIGN: Retrospective study.SETTING: Community‐based older adults receiving medications through a pharmacy benefit management company.PARTICIPANTS: Eight hundred thirty‐six patients aged 65 and older. Patients taking donepezil (n = 418) constituted the treatment group. Patients not taking donepezil (n = 418) constituted the comparison group. Each treatment group member was matched with a comparison group member on the basis of age, sex, and number of drugs taken for chronic conditions.MEASUREMENTS: The prevalence of anticholinergic use was compared in the treatment and comparison groups over a 3‐ to 12‐month follow‐up period using pharmacy claims data. The proportion of follow‐up period days that treatment group members concomitantly used donepezil and anticholinergics was also examined.RESULTS: Older adults with probable dementia were more likely to use anticholinergics than matched comparison group patients (33.0% vs 23.4%; P = .001). Of treatment group members receiving anticholinergics, 26.1% used multiple anticholinergic medications. Treatment group members who received anticholinergics used those drugs concomitantly with donepezil on a mean of 28.4% of follow‐up period days.CONCLUSIONS: Community‐based, commercially insured, older adults with probable dementia are more likely to take anticholinergics than matched controls. Patients taking donepezil frequently use an anticholinergic medication concomitantly. This study suggests that prescribing for older adults with dementia could be improved, especially if cognitive enhancing agents are being considered.
Deciding on Anticoagulating the Oldest Old with Atrial Fibrillation: Insights from Cost‐Effectiveness Analysis
Authors: Desbiens Norman A. 
Published: March 2003

OBJECTIVES: To better understand the tradeoffs between the efficacy of anticoagulation with warfarin and its side effects in the oldest old with nonrheumatic atrial fibrillation (AF).DESIGN: Cost‐effectiveness analysis.SETTING: Published literature, including meta‐analyses when available, and web‐based sources.PARTICIPANTS: Those aged 65 to 100 with AF.INTERVENTION: Anticoagulation with warfarin.MEASUREMENTS: Quality‐adjusted life expectancy and cost.RESULTS: Anticoagulation is not effective in persons with AF who do not have other risk factors, even in the oldest old. The best argument for its use (prolongation of life at an acceptable cost) can be made in those at major risk for stroke because of previous stroke or transient ischemic attack, diabetes mellitus, and hypertension, but poor quality of life before anticoagulation and comorbidities that carry their own risks of dying diminish benefits.The decision to anticoagulate the oldest old with AF must take into consideration the risk of hemorrhagic stroke and of death from hemorrhagic stroke that existed before anticoagulation, the increased risk of hemorrhagic stroke and of death from hemorrhagic stroke while anticoagulated, and the efficacy of anticoagulation. Cost‐effectiveness is also influenced by the cost of warfarin, the risk of major extracranial bleeding, the risk (natural and anticoagulated) of death from hemorrhagic stroke, the rate of ischemic stroke, the cost of major extracranial bleeding and hemorrhagic strokes, the cost of nursing home care, and the fraction of patients with stroke who need nursing home care.CONCLUSION: There is no compelling evidence to date that anticoagulation prolongs quality‐adjusted life expectancy in the oldest old with nonrheumatic AF. More studies that better estimate the risk of intracranial bleeding with and without anticoagulation in the oldest old are needed before recommendations can be made. The oldest old who are most likely to benefit are those who have a high risk of stroke secondary to risk factors other than age alone, although quality of life and life expectancy related to these risk factors limit obtained benefit. Recommendations that all older persons with AF should be anticoagulated are premature.
Predicting Cognitive Impairment in High‐Functioning Community‐Dwelling Older Persons: MacArthur Studies of Successful Aging
Authors: Chodosh Joshua , Reuben David B. , Albert Marilyn S. , Seeman Teresa E. 
Published: March 2003

OBJECTIVES: To examine whether simple cognitive tests, when applied to cognitively intact older persons, are useful predictors of cognitive impairment 7 years later.DESIGN: Cohort study.SETTING: Durham, North Carolina; East Boston, Massachusetts; and New Haven, Connecticut, areas that are part of the National Institute on Aging Established Populations for Epidemiological Studies of the Elderly.PARTICIPANTS: Participants, aged 70 to 79, from three community‐based studies, who were in the top third of this age group, based on physical and cognitive functional status.MEASUREMENTS: New onset of cognitive impairment as defined by a score of less than 7 on the Short Portable Mental Status Questionnaire (SPMSQ) in 1995.RESULTS: At 7 years, 21.8% (149 of 684 subjects) scored lower than 7 on the SPMSQ. Using multivariate logistic regression, three baseline (1988) cognitive tests predicted impairment in 1995. These included two simple tests of delayed recall—the ability to remember up to six items from a short story and up to 18 words from recall of Boston Naming Test items. For each story item missed, the adjusted odds ratio (AOR) for cognitive impairment was 1.44 (95% confidence interval (CI) = 1.16–1.78, P < .001). For each missed item from the word list, the AOR was 1.20 (95% CI = 1.09–1.31, P < .001). The Delayed Recognition Span, which assesses nonverbal memory, also predicted cognitive impairment, albeit less strongly (odds ratio = 1.06 per each missed answer, 95% CI = 1.003–1.13, P = .04).CONCLUSIONS: This study identifies measures of delayed recall and recognition as significant early predictors of subsequent cognitive decline in high‐functioning older persons. Future efforts to identify those at greatest risk of cognitive impairment may benefit by including these measures.
Screening for Alzheimer's Disease: The Memory Impairment Screen Versus the Conventional Three‐Word Memory Test
Authors: Kuslansky Gail , Buschke Herman , Katz Mindy , Sliwinski Martin , Lipton Richard B. 
Published: March 2003

OBJECTIVES:To improve screening for Alzheimer's disease (AD) with the Memory Impairment Screen (MIS), a 4‐minute, four‐item delayed free and cued recall memory test with controlled learning and high discriminative validity. To assess the discriminative validity of the MIS for AD and to compare it with the conventional three‐word memory test, a delayed free recall task, widely recommended as a dementia‐screening test in clinical practice.DESIGN:Cross‐sectional validation study nested within a longitudinal study of aging and dementia. The MIS and the standard three‐word memory task were administered as part of a comprehensive neurological and neuropsychological evaluation.SETTING:Einstein Aging Study at the Albert Einstein College of Medicine, Bronx, New York.PARTICIPANTS:Two hundred forty community‐dwelling older adults.MEASUREMENTS:Sensitivity, specificity, and positive predictive value (PPV) were calculated for the MIS and three‐word memory test as screening tests for AD.RESULTS:In comparison with the three‐word memory task, the MIS had higher sensitivity (.86 vs .65), higher specificity (.97 vs .85), and greater PPV (.80 vs .37) as a screen for AD.CONCLUSIONS:The MIS had high discriminative validity as a screening test for AD and substantially outperformed the three‐word memory task. Given its validity and brevity, the MIS has important advantages as an AD screen for use in primary care.