bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparative Analysis of Mandated Benefit Laws, 1949–2002
Authors: Laugesen Miriam J. , Paul Rebecca R. , Luft Harold S. , Aubry Wade , Ganiats Theodore G.
Published: March 2006

Objective. To understand and compare the trends in mandated benefits laws in the United States.

Data Sources/Study Setting. Mandated benefit laws enacted in 50 states and the District of Columbia for the period 1949–2002 were compiled from multiple published compendia.

Study Design. Laws that require private insurers and health plans to cover particular services, types of diseases, or care by specific providers in 50 states and the District of Columbia are compared for the period 1949–2002. Legislation is compared by year, by average and total frequency, by state, by type (provider, health care service, or preventive), and according to whether it requires coverage or an offer of coverage.

Data Collection/Extraction Method. Data from published tables were entered into a spreadsheet and analyzed using statistical software.

Principal Findings. A total of 1,471 laws mandated coverage for 76 types of providers and services. The most common type of mandated coverage is for specific health care services (670 laws for 34 different services), followed by laws for services offered by specific professionals and other providers (507 mandated benefits laws for 25 types of providers), and coverage for specific preventive services (295 laws for 17 benefits). On average, a mandated benefit law has been adopted or significantly revised by 19 states, and each state has approximately 29 mandates. Only two benefits (minimum maternity stay and breast reconstruction) are mandated in all 51 jurisdictions and these were also federally mandated benefits. The mean number of total mandated benefit laws adopted or significantly revised per year was 17 per year in the 1970s, 36 per year in the 1980s, 59 per year in the 1990s, and 76 per year between 2000 and 2002. Since 1990, mandate adoption increased substantially, with around 55 percent of all mandated benefit laws enacted between 1990 and 2002.

Conclusions. There was a large increase in the number of mandated benefits laws during the managed care “backlash” of the 1990s. Many states now use mandated benefits to prescribe not only what services and benefits would be provided but how, where, and when services will be provided.
State‐Mandated Benefit Review Laws
Authors: Bellows Nicole M. , Halpin Helen Ann , McMenamin Sara B.
Published: March 2006

Objective. To determine which states have laws that require the review of mandated health insurance benefits and describe the various approaches states take in reviewing mandated benefits, as stated in the mandated benefit review (MBR) laws.

Data Sources. We queried online databases of the individual state statutes and reviewed the state statutes and state legislative agendas for all 50 states and Washington, DC to identify those states with active MBR laws as of September 2004.

Study Design. We reviewed the identified MBR laws to catalog their various components. The components chosen for this analysis include: general review strategy, designated reviewers, time frame for conducting reviews, criteria used in the review, requirements to use actuaries, sources of funding, and state data collection systems. Two of the authors independently created analysis categories and coded the MBR laws to document details on the major components of the laws.

Principal Findings. We identified 26 state MBR laws active as of September 2004. A majority of the MBR laws specified a prospective review approach and only one law used an exclusively retrospective review approach. A substantial amount of variation was found with regards to the designated reviewers, time frames for conducting reviews, and criteria used in the review. Few states specified the use of actuaries, sources of funding, and state data collection systems.

Conclusions. The number of states that have enacted MBR laws has increased substantially in recent years, however, different states have structured the review of mandated benefits differently, according to the values and perceived needs of the state legislatures. It is important that states increasingly consider a broader scope of review criteria so state decision makers can position themselves to mandate only those benefits that add real value to the state's health care system.
Changing Physician Knowledge, Attitudes, and Beliefs About Migraine: Evaluation of a New Educational Intervention
Authors: Patwardhan Meenal B. , Samsa Gregory P. , Lipton Richard B. , Matchar David B.
Published: March 2006

Objective.—Use a presurvey of primary care providers (PCPs) enrolled in a continuing medical education (CME) program on headache management to ascertain their existing knowledge, attitudes, and beliefs regarding migraine and use a postsurvey to determine the extent to which the CME program has brought participant knowledge, attitudes, and skills closer to conformance with best evidence.

Background.—Migraine is a common and debilitating condition, which PCPs may not always manage satisfactorily. In an effort to improve management, the American Headache Society has developed a CME program called BRAINSTORM that encourages PCPs to adopt the US Headache Consortium Guidelines for headache care.

Methods.—A 20‐item questionnaire was developed that covered the essential elements of migraine care. The questionnaire was administered before and after a BRAINSTORM presentation to 254 consenting primary care clinicians attending a medical meeting at 1 of 6 sites. A control group of 112 comparable physicians who did not attend the presentation completed the same questionnaire. Prepresentation scores of attendees were compared to scores of nonattendees to assess the generalizability of results. Prepresentation scores on selected questions were used to assess participant baseline knowledge, attitudes, and beliefs. Pre‐ and postpresentation scores for attendees at all sites were compared using the Mantel‐Haenszel statistic to assess the effectiveness of the BRAINSTORM CME. Pre‐ and postpresentation scores were compared by site using the Breslow‐Day test to evaluate any differential impact based on CME location.

Results.—Prepresentation scores of attendees and nonattendees were found to be similar. No significant difference in performance was noted across sites. A chi‐square analysis revealed a statistically significant difference between pre‐ and postpresentation scores for 16 of the test's 20 questions. In the pretest, all participants scored <66% on 2 questions related to prevalence, impact, and pathophysiology of migraine, 2 questions pertaining to history taking/physical examination, and 3 migraine management questions. Attendee scores improved to >66% posttest on all except 2 questions related to prevalence, impact, and pathophysiology of migraine.

Conclusion.—Our results indicate that PCPs need to acquire greater understanding about the epidemiology and pathophysiology of migraine and may require guidance in history taking and physical examination of migraine patients. Improvement in scores posttest confirms that the BRAINSTORM program has a significant immediate impact on the knowledge, beliefs, and attitudes of participants. The program could be strengthened to improve emphasis in some areas where posttest scores showed no improvement.
The Impact of Intensive Patient Education on Clinical Outcome in a Clinic‐Based Migraine Population
Authors: Rothrock John Farr , Parada Victoria A. , Sims Cheryl , Key Kristin , Walters Naomi S. , Zweifler Richard M.
Published: March 2006

Objective.—To determine whether the addition of patient education to routine medical management improves the clinical status of migraine patients and reduces their utilization of healthcare resources.

Background.—Optimal migraine management typically requires effective patient education. Such education often is difficult to accomplish in the busy clinic setting.

Methods.—One hundred consecutive patients with migraine presenting to an university‐based headache clinic were randomized to receive or not receive a standardized course of didactic instruction regarding migraine biogenesis and management. The course consisted of 3 classes taught by lay migraineurs who themselves previously had undergone intensive training. All patients were evaluated initially and at 1, 3, and 6 months by a neurologist blinded as to the results of randomization. Clinical variables examined included headache frequency/severity, migraine disability assessment (MIDAS) scores, patient compliance, presence versus absence of analgesic use/overuse, and headache‐related unscheduled visits or phone calls. Comparisons were made between baseline findings and findings at the 6‐month follow‐up visit, with the change in mean MIDAS score serving as the primary outcome variable.

Results.—At 6 months the group randomized to receive intensive education exhibited a significantly greater reduction in mean MIDAS score than the group randomized to routine medical management only (24 vs. 14 points; P < .05). Those patients also experienced a reduction in mean headache days per month and a greater reduction in functionally incapacitating headache days per month, exhibited less analgesic overuse and need for abortive therapy, were more compliant with prophylactic therapy prescribed, and made fewer headache‐related calls to the clinic or unscheduled visits.

Conclusion.—Intensive education of migraine patients by trained lay instructors may convey significant benefit to those patients and reduce their utilization of healthcare resources.
Migraine Prevention: What Patients Want From Medication and Their Physicians (A Headache Specialty Clinic Perspective)
Authors: Rozen Todd D.
Published: March 2006

Objective.—To document the results of a migraine patients survey, from a headache specialty clinic, in which patients were asked to rank, in order of importance, certain characteristics of migraine preventive treatment.

Methods.—A 10‐question survey was completed by 150 patients (114 females and 36 males) with a history of migraine who presented to the Michigan Head Pain & Neurological Institute. The patients were asked to rank, in order of importance, characteristics of migraine preventive treatment. Each characteristic was rated individually on a 1 to 10 scale (1 being of little importance and 10 being extremely important). The mean rating of each characteristic was then calculated and the results analyzed.

Results/Discussion.—From this migraine preventive treatment survey, the most important thing to migraineurs, from a headache specialty clinic population, is that the prescribing physician involves them in the decision making of choosing a preventive agent. The physician taking time to explain the possible medication side effects is the second most highly ranked characteristic. Migraine preventives with published efficacy in the medical literature are also deemed very important. Migraineurs do not mind using more than 1 preventive agent at one time if greater efficacy can be achieved. Agents that may affect weight and /or cause sedation may be important factors as to why patients (especially females) may not want to take a preventive medication. Natural therapies and once‐daily dosing are ranked lower overall but still are important characteristics of preventive treatment. Some gender differences are noted in the ranking of migraine preventive characteristics.
Migraine Headaches and Preeclampsia: An Epidemiologic Review
Authors: Adeney Kathryn L. , Williams Michelle A.
Published: March 2006

Objective.—To summarize and evaluate available empirical research on the relationship between migraines and gestational hypertension or preeclampsia and to provide direction for future research in this area.

Background.—Migraines affect a substantial proportion of reproductive‐aged women and have been associated with cardiovascular risk factors and ischemic disease in this population. Preeclampsia is a vascular disorder of pregnancy, also linked to adverse cardiovascular outcomes.

Methods.—Publications were identified by a MEDLINE search using keywords “migraine,”“preeclampsia,” and “gestational hypertension,” and by examination of the reference lists of identified articles.

Results.—The literature review yielded 10 studies addressing the association between migraines and preeclampsia or gestational hypertension. Of the 10 studies, 8 reported a positive association between the syndromes.

Conclusions.—Available evidence suggests that migraines and preeclampsia may reflect an underlying predisposition toward ischemic injury. More rigorous epidemiologic research is warranted, after consideration of several important methodologic issues.
IS THERE AN ECOPHYSIOLOGICAL EXPLANATION FOR THE GAMETOPHYTE–TETRASPOROPHYTE RATIO IN GELIDIUM SESQUIPEDALE (RHODOPHYTA)?1
Authors: Carmona Raquel , Santos Rui
Published: March 2006

In the fall, when 61% of the fronds of the Gelidium sesquipedale (Clem.) Born. et Thur. population located in Albufeira (southern Portugal) were reproductive, about 90% of these fronds were tetrasporophytes, whereas an equal percentage of female and male gametophytes was found (5%). The comparison of physiological performances of the reproductive phases (males, females and tetrasporophytes) did not reveal a physiological advantage of tetrasporic fronds. There were no significant differences either in the photosynthesis, nitrogen uptake, nitrate reductase activity, or biochemical composition of adult fronds. On the other hand, vegetative recruitment and spore production in the laboratory were significantly different. The re‐attachment to calcareous substrate and the subsequent rhizoidal growth were faster in tetrasporophytes. Particular levels of temperature, rather than irradiance, had an important effect on the phase differences in the spore release, attachment, and germination rates. Significant results were the higher release of carpospores at all irradiances at 17°C, and the higher attachment percentage of carpospores at 13°C versus tetraspores. Under higher temperatures (21°C), tetraspores showed higher attachment rates while carpospores germinated more. G. sesquipedale cystocarps released carpospores for 2 months, while tetrasporangia stopped shedding tetraspores after 1 month, resulting in a 3‐fold higher production of carpospores than tetraspores. Results showed that vegetative and spore recruitment may explain the low gametophyte–tetrasporophyte ratio of the studied population of G. sesquipedale as opposed to the physiological performance of phases.
CYTOPLASMIC MASSES PRESERVED IN EARLY HOLOCENE DIATOMS: A POSSIBLE TAPHONOMIC PROCESS AND ITS PALEO‐ECOLOGICAL IMPLICATIONS1
Authors: Tanimura Yoshihiro , Kato Megumi , Fukusawa Hitoshi , Mayama Shigeki , Yokoyama Kazumi
Published: March 2006

In Lake Suigetsu, central Japan, greenish/light‐brown granules identified as cytoplasmic masses had been preserved in siliceous cell walls of freshwater diatoms in annual layers of lacustrine muds since the early Holocene. The lacustrine muds consisted of alternating dark‐colored (rich in diatom valves, clay, and organic matter) and light‐colored (mainly diatom valves) laminae. The greenish/light‐brown granules were predominately preserved in frustules of the genus Aulacoseira preserved in the dark‐colored laminae. The dark‐colored laminae were inferred to have formed annually under stratified water caused by surface water warming in summer that caused the formation of an organic‐rich anoxic layer on the lake bottom that favored granule preservation. The good preservation of cytoplasmic masses in dark‐colored laminae suggested a cause for diatom assemblage periodicity, a phenomenon that was commonly noted in temperate lakes: the cells containing these masses could be potential seed stocks for subsequent spring blooms. Frustules of the most abundant granule‐containing species, Aulacoseira nipponica (Skvortzow) Tuji, in the dark‐colored laminae of the Early Holocene muds were abundant in the overlying light‐colored laminae, suggesting that these species reproduced abundantly in springtime yielding a massive diatom bloom.
EXTRACELLULAR MATRIX ASSEMBLY IN DIATOMS (BACILLARIOPHYCEAE). V. ENVIRONMENTAL EFFECTS ON POLYSACCHARIDE SYNTHESIS IN THE MODEL DIATOM, PHAEODACTYLUM TRICORNUTUM1
Authors: Abdullahi Abass S. , Underwood Graham J.C. , Gretz Michael R.
Published: March 2006

The effects of phosphate (P) limitation, varying salinity (5–65 psu), and solid media growth conditions on the polysaccharides produced by the model diatom, Phaeodactylum tricornutum Bohlin were determined. Sequential extraction was used to separate polymers into colloidal (CL), colloidal extracellular polymeric substances (cEPS), hot water soluble (HW), hot bicarbonate soluble (HB), and hot alkali (HA) soluble fractions. Media‐soluble polymers (CL and cEPS) were enriched in 4‐linked mannosyl, glucosyl, and galactosyl residues as well as terminal and 3‐linked xylosyl residues, whereas HW polymers consisted mainly of 3‐linked glucosyl as well as terminal and 2,4‐linked glucuronosyl residues. The HB fraction was enriched in terminal and 2‐linked rhamnosyl residues derived from the mucilage coating solubilized by this treatment. Hot alkali treatment resulted in the complete dissolution of the frustule releasing 2,3‐ and 3‐linked mannosyl residues. The fusiform morphotype predominated in standard and P‐limited cultures and cultures subjected to salinity variations, but growth on solid media resulted in an enrichment of the oval morphotype. The proportion and linkages of 15 residues, including neutral, uronic acid, and O‐methylated sugars, varied with environmental conditions. P limitation and salinity changes resulted in 1.5‐ to 2.5–fold increase in carbohydrate production, with enrichment of highly branched/substituted and terminal rhamnose, xylose, and fucose as well as O‐methylated sugars, uronic acids, and sulfate. The increased deoxy‐ and O‐methylated sugar content under unfavorable environments enhances the hydrophobicity of the polymers, whereas the anionic components may play important roles in ionic cross‐linking, suggesting that these changes could ameliorate the effects of salinity or P‐stress and that these altered polysaccharide characteristics may be useful as bioindicators for environmental stress.
ULTRASTRUCTURE AND LSU RDNA‐BASED PHYLOGENY OF ESOPTRODINIUM GEMMA (DINOPHYCEAE), WITH NOTES ON FEEDING BEHAVIOR AND THE DESCRIPTION OF THE FLAGELLAR BASE AREA OF A PLANOZYGOTE1
Authors: Calado António J. , Craveiro Sandra C. , Daugbjerg Niels , Moestrup Øjvind
Published: March 2006

A small, freshwater dinoflagellate with an incomplete cingulum, identified as Esoptrodinium gemma Javornický (=Bernardinium bernardinense sensu auctt. non sensu Chodat), was maintained in mixed culture and examined using light and serial section TEM. Vegetative flagellate cells, large cells with two longitudinal flagella (planozygotes), and cysts were examined. The cells displayed a red eyespot near the base of the longitudinal flagellum, made of two or three layers of pigment globules not bounded by a membrane. Yellow‐green, band‐shaped chloroplasts, bounded by three membranes and containing lamella with three thylakoids, were present in both flagellate cells and cysts. Most cells had food vacuoles, containing phagotrophically ingested chlamydomonads or chlorelloid green algae; ingestion occurred through the ventral area, involving a thin pseudopod apparently driven by the peduncle. The pusule was tubular, with numerous diverticula in its distal portion, and opened into the longitudinal flagellar canal. Three roots were associated with each pair of flagellar bases, both in vegetative cells and in a planozygote. The longitudinal microtubular root bifurcated around the longitudinal basal body. The planozygote contained a single peduncle and associated structures, and a single transverse flagellar canal with the two converging transverse flagella. Using two ciliates as outgroup species, phylogenetic analyses based on maximum parsimony, neighbor‐joining and posterior probability (Bayesian analysis) supported a clade comprising Esoptrodinium, Tovellia, and Jadwigia.
COMPARISON OF THREE COMMON MOLECULAR TOOLS FOR DISTINGUISHING AMONG GEOGRAPHICALLY SEPARATED CLONES OF THE DIATOM SKELETONEMA MARINOI SARNO ET ZINGONE (BACILLARIOPHYCEAE)1
Authors: Godhe Anna , McQuoid Melissa R. , Karunasagar Indrani , Karunasagar Iddya , Rehnstam‐Holm Ann‐Sofi
Published: March 2006

Skeletonema marinoi Sarno et Zingone is a planktonic marine diatom with a widespread geographic distribution. Different populations of this species may show distinct genetic signatures. We have evaluated the utility of three common molecular methods for distinguishing clones of S. marinoi from different geographic regions. Clonal cultures were isolated from the Canadian west coast, south west Portugal, and the east and west coasts of Sweden. All strains originated from resting stages in sediment. More than 90% of the individually isolated chains grew to densities suitable for DNA extraction. Genetic signatures of clones from each sample location were assessed by sequencing variable domains (D1–D3) of the nuclear large subunit (LSU) rRNA gene and internal transcriber spacer (ITS) (ITS‐1, 5.8S and ITS‐2) regions, and also by analysis of randomly amplified polymorphic DNA patterns. Analysis of molecular variance showed that strains from the four geographic areas were significantly separated by all three methods but that differences among European samples were best resolved by ITS 2 sequences.
ENDOLITHIC MICROFLORA ARE MAJOR PRIMARY PRODUCERS IN DEAD CARBONATE SUBSTRATES OF HAWAIIAN CORAL REEFS1
Authors: Tribollet Aline , Langdon Christopher , Golubic Stjepko , Atkinson Marlin
Published: March 2006

To quantify the contribution of endolithic phototrophs to primary production of dead carbonate substrates, experimental blocks of cleaned Porites lobata Dana skeleton were placed at three different sites in Kaneohe Bay, Hawaii: inshore, lagoonal, and oceanic. After 6 months of exposure, experimental blocks were colonized by communities characteristic of their estuarine (inshore, lagoonal) and oceanic (ocean) environments. Blocks were sub‐sampled; net photosynthesis (NP) and chl a concentrations of the whole blocks (epi‐ and endoliths) and scrapped blocks (only endoliths) were quantified. Green turf algae colonized predominantly inshore and lagoonal blocks, while encrusting corallines were the dominant epiliths colonizing oceanic blocks. Four main species of endolithic phototrophs were identified in all blocks: Mastigocoleus testarum Lagerheim, Plectonema terebrans Bornet and Flahault (cyanobacteria), Phaeophila dendroides Crouan and Crouan, and Ostreobium quekettii Bornet and Flahault (Chlorophytes). While epiliths were very different between sites, NP rates and chl a concentration of endoliths did not vary significantly and were positively correlated (191±25 mmol C·m−2·day−1 and 590±150 mg chl a·m−2 of reef, respectively). Assimilation numbers for whole communities, including both epilithic and endolithic communities, were similar to those measured for endolithic communities alone (average of 0.3 g C·g chl a·h−1). Under experimental conditions, the contribution of endolithic phototrophs to community NP rates of blocks ranged from 56% to 81%, and under natural conditions, we estimated that this contribution ranged between 32% and 46%. Thus, we showed that the endolithic phototrophs are one of the major primary producers in dead coral substrates in a wide range of coral reef environments.
IMPROVED DETECTION AND CHARACTERIZATION OF FUCOXANTHIN‐TYPE CAROTENOIDS: NOVEL PIGMENTS INEMILIANIA HUXLEYI(PRYMNESIOPHYCEAE)1
Authors: Airs Ruth L. , Llewellyn Carole A.
Published: March 2006

A new atmospheric pressure chemical ionization mass spectrometry (APCI‐LC/MS) method improved detection and aided characterization of fucoxanthin related carotenoids, revealing the coccolithophoridEmiliania huxleyi(Lohm.) Hay et Mohler (strain MBA 92, Plymouth) to contain a wider range of acyloxyfucoxanthins than reported previously. The diversity is confirmed as arising from differences in the length of the alkanoic acid substituent esterified at position C‐19′. Acyloxyfucoxanthins with substituents of between four and eight carbons at the C‐19′ position have been detected in a culture ofEmiliania huxleyi, where previously only 19′‐butanoyloxyfucoxanthin and 19′‐hexanoyloxyfucoxanthin have been reported in the literature. Novel fucoxanthinol derivatives were also found. The detection of these novel carotenoids inEmiliania huxleyipermits detailed studies of the impact of environmental factors on individual components of the complex pool of fucoxanthin‐type carotenoids in this organism.
EFFECT OF HISTONE DEACETYLASE INHIBITORS ON TUBULIN ACETYLATION AND DEVELOPMENT IN VOLVOX CARTERI (VOLVOCALES)1
Authors: Cheng Qian , Balzer Eric , Miller Stephen M. , Yoshida Minoru , Wong Jason C.
Published: March 2006

Volvox carteri f. nagariensis (Iyengar) possesses several thousand cells of just two types, gonida and somatic cells, that are set apart by asymmetric cell division. Because the division apparatus contains microtubules enriched in acetylated α‐tubulin, we wished to know whether acetylated tubulin plays any role in regulating division symmetry. Two different human histone deacetylases (HDACs) have been shown to deacetylate tubulin in vivo, thereby regulating cell motility. Here we set out to determine: (1) whether HDAC inhibitors that increase tubulin acetylation in animal cells have the same effect in V. carteri, (2) whether increasing acetylated tubulin affects microtubule stability, and (3) whether increasing acetylated tubulin affects division symmetry. Embryos exposed to two HDAC inhibitors, trichostatin A (TSA) and tubacin, accrued dramatically higher levels of acetylated tubulin (and more acetylated microtubules) and were significantly more sensitive to colchicine than controls. However, while TSA‐treated embryos cleaved aberrantly to produce adults with abnormal morphology, tubacin‐treated embryos developed normally. We conclude that increasing tubulin acetylation subtly alters microtubule stability, but does not appear to affect cell division in V. carteri.
GENETIC STRUCTURE OF NATURAL POPULATIONS IN THE RED ALGAEGELIDIUM CANARIENSE(GELIDIALES, RHODOPHYTA) INVESTIGATED BY RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD) MARKERS1
Authors: Bouza Nieves , Caujapé‐Castells Juli , González‐Pérez Miguel Ángel , Sosa Pedro A.
Published: March 2006

Random amplified polymorphic DNA (RAPD) marker variation was analyzed in female gametophytes in natural populations ofGelidium canariense(Grunow) Seoane‐Camba ex Haroun, Gil‐Rodríguez, Diaz de Castro et Prud'Homme van Reine from the Canary Islands to estimate the degree and distribution of genetic variability and differentiation. A total of 190 haploid individuals were analyzed with 60 polymorphic RAPDs bands which produced 190 distinct multilocus genotypes. A high level of polymorphism was detected in all populations analyzed. Within‐population gene diversity ranged from 0.156 to 0.264. The populations on the island of Gran Canaria showed higher genetic variation than the other populations analyzed. The partitioning of molecular variance by analysis of molecular variance showed that most genetic variation resides within populations (68.85%). These results suggest that sexual reproduction is the predominant mode of reproduction forG. canariensegametophytic populations, and the main determinant in reaching high levels of genetic diversity. The Neighbor‐Joining tree and FCA analysis displayed two subclusters that correspond to the populations from the western islands (Tenerife, La Palma, Gomera) and the eastern island (Gran Canaria). In addition, we have detected a significant relationship betweenFST/(1−FST) and geographical distance consistent with data on water circulation and age of islands. The results obtained agree with an isolation by distance model, with gene flow from eastern to the western islands, and a high level of genetic differentiation between populations (FST=0.311,P<0.001).
DIATOM COMMUNITY DYNAMICS IN STREAMS OF CHRONIC AND EPISODIC ACIDIFICATION: THE ROLES OF ENVIRONMENT AND TIME1
Authors: Passy Sophia I.
Published: March 2006

Community dynamics of epiphytic diatoms were studied for 3 years in a chronically and an episodically acidified tributary of Buck Creek, Adirondacks. Both streams experienced pulses of acidity during hydrologic events but these pulses were more pronounced in the episodically acidified stream, where pH decreased over two units (between 4.53 and 6.62) and the acid‐neutralizing capacity (ANC) became negative. In the chronically acidified stream, pH was below 4.9 and the ANC was negative 94% of the time. In this stream, high inorganic acidity following SO42− enrichment from snowmelt or rainstorms alternated with high organic acidity derived from a headwaters wetland during base flow. The fluctuating water chemistry generated shifts in diatom community composition: from exclusive dominance of Eunotia bilunaris (Ehrenberg) Mills during periods of high inorganic acidity to proliferation of several subdominant species during periods of high organic acidity. In the episodically acidified stream, the pulses of acidity were associated with high NO3− concentrations and the corresponding high ratios of inorganic monomeric Al (Alim) to organic monomeric Al (Alom). Diatom communities there were dominated exclusively by E. exigua (Brébisson) Rabenhorst year round; however, this species peaked during periods of low acidity. Periods of high acidity and Alim:Alom ratios were marked by a decline in E. exigua and a concomitant increase in the subdominant species. Variance partitioning into terms of environmental and temporal variance, and their covariance, suggested that diatom communities in the chronically acidic stream were governed primarily by environmental factors while in the episodically acidic stream environmental and temporal factors had equal contributions.
Recent Canadian experience with targeted hepatitis C virus lookback
Authors: Goldman Mindy , Patterson Lindsay , Long Anne
Published: March 2006

BACKGROUND:  Targeted hepatitis C virus (HCV) lookback studies have been performed in Canada since 1995. The yield of HCV lookback has not been reassessed since the introduction of improved HCV screening tests.

STUDY DESIGN AND METHODS:  Data were combined from the two Canadian blood suppliers to determine the yield of targeted HCV lookback performed on donors found to be HCV‐positive by antibody screening and/or nucleic acid testing (NAT) from the introduction of NAT in 1999 until January 1, 2005.

RESULTS:  Lookback was performed on 498 donations from 176 HCV‐seropositive and two NAT‐only‐positive donors; 494 components had been transfused, and 160 components were traced to living recipients who underwent HCV testing. Seventy‐two percent of recipients of components derived from donations given before the introduction of second‐generation enzyme immunoassay (EIA) testing were HCV‐seropositive. Four recipients of components derived from donations tested by second‐ or third‐generation EIA, with or without NAT, were HCV‐seropositive. Two of these recipients tested HCV‐seropositive before transfusion, and a third was probably infected by transfusions before the introduction of HCV testing. The fourth recipient likely received a noninfectious transfusion, since five other recipients of components from subsequent donations made by this donor were seronegative.

CONCLUSION:  When previous donations had been tested by second‐ or third‐generation EIA, the yield of HCV lookback was likely zero. Because HCV infection is relatively common in the general population and patients in Canada do not undergo pretransfusion testing, coincident infections in recipients may be erroneously attributed to transfusion. The regulatory requirement for HCV lookback should be reassessed.
Evaluation of the performance of 44 assays used in countries with limited resources for the detection of antibodies to hepatitis C virus
Authors: Scheiblauer Heinrich , El‐Nageh Mohamed , Nick Sigrid , Fields Howard , Prince Alfred , Diaz Susan
Published: March 2006

BACKGROUND:  This study was conducted by the International Consortium for Blood Safety (ICBS) and its Collaborating Center, the Paul Ehrlich Institute, to identify high‐quality, affordable assays for the detection of hepatitis C virus (HCV) antibodies and make available information on their performance for the benefit of developing countries.

STUDY DESIGN AND METHODS:  Forty‐four assays were evaluated for their sensitivity and specificity. The assays’ sensitivity was evaluated on a characterized panel of 200 anti‐HCV‐positive samples comprising major HCV genotypes 1 through 6. Three seroconversion panels were used to estimate sensitivity in the early infectious phase. Specificity was evaluated with a characterized ICBS‐negative panel of 181 verified negative samples.

RESULTS:  Sensitivity was 100 percent for 15 assays, 99.5 percent for 11 assays, 99.0 percent for 6 assays, and less than 99.0 percent for 12 assays. The false‐negative results found were not linked to the genotype. Anti‐HCV detection in the early infectious phase was, on average, 16.7 days later than for tests licensed in the European Union. Specificity in 25 tests was 100 percent, whereas 11 assays showed 1 false‐positive result (99.45%) and the other assays were nonspecific in 2 or more samples. Two assays were not supplied in sufficient quantity to test for specificity.

CONCLUSIONS:  On applying criteria for highest sensitivity (100%) and high specificity (≥99.5%), 11 tests met the criteria. An additional 19 tests reached a performance comparable to WHO’s criteria for human immunodeficiency virus antibody assays. The genotype diversity of HCV was found not to influence sensitivity of the assays.
Platelets photochemically treated with amotosalen HCl and ultraviolet A light correct prolonged bleeding times in patients with thrombocytopenia
Authors: Slichter Sherrill J. , Raife Thomas J. , Davis Kathryn , Rheinschmidt Margaret , Buchholz Donald H. , Corash Laurence , Conlan Maureen G.
Published: March 2006

BACKGROUND:  Photochemical treatment (PCT) with amotosalen HCl with ultraviolet A illumination inactivates pathogens and white blood cells in platelet (PLT) concentrates.

STUDY DESIGN AND METHODS:  In a Phase II crossover study, 32 patients with thrombocytopenia received one transfusion of PCT and/or one transfusion of untreated (reference) apheresis PLTs. Hemostatic efficacy was assessed with the cutaneous template bleeding time and clinical observations.

RESULTS:  Paired bleeding time data for PCT and reference transfusions were available for 10 patients. Mean pretransfusion bleeding times were 29.2 ± 1.6 minutes in the PCT group and 28.7 ± 2.5 minutes in the reference group. After transfusion of a dose of PLTs of at least 6.0 × 1011, mean 1‐hour posttransfusion template bleeding times corrected to 19.3 ± 9.5 minutes in the PCT group and 14.3 ± 6.5 minutes in the reference group (p = 0.25). In 29 patients receiving paired PCT and reference transfusions, mean 1‐hour posttransfusion PLT count increments were 41.9 × 109 ± 20.8 × 109 and 52.3 × 109 ± 18.3 × 109 per L for PCT and reference, respectively (p = 0.007), and mean 1‐hour posttransfusion PLT corrected count increments (CCIs) were 10.4 × 103 ± 4.9 × 103 and 13.6 × 103 ± 4.3 × 103 for PCT and reference, respectively (p < 0.001). The time to next PLT transfusion was 2.9 ± 1.2 days after PCT transfusions versus 3.4 ± 1.3 days after reference transfusions (p = 0.18). Clinical hemostasis was not significantly different after PCT and reference transfusions.

CONCLUSION:  PCT PLTs provided correction of prolonged bleeding times and transfusion intervals not significantly different than reference PLTs despite significantly lower PLT count increments and CCIs.
Prevalence of HLA antibodies in transfused patients with and without red cell antibodies
Authors: Buetens Orin , Shirey R. Sue , Goble‐Lee Mary , Houp Julie , Zachary Andrea , King Karen E. , Ness Paul M.
Published: March 2006

BACKGROUND:  Multiply transfused patients are at increased risk of developing red cell (RBC) antibodies, as well as antibodies to HLA. Although pretransfusion testing screens for RBC antibodies, no such testing is routinely performed for HLA antibodies. Determining which patients are more likely to make HLA antibodies may be important for patients undergoing elective surgery where platelets (PLTs) may be required. It is hypothesized that patients with RBC alloantibodies may be more likely to have HLA antibodies than previously transfused patients without RBC antibodies.

STUDY DESIGN AND METHODS:  Blood was collected from 53 adult male surgical patients with RBC alloantibodies and a control group of 69 similar male patients with a history of previous transfusions but no evidence of RBC alloimmunization. The samples were tested for the presence of immunoglobulin G Class I HLA antibodies by enzyme‐linked immunosorbent assay.

RESULTS:  Of the 53 samples from patients with RBC alloantibodies, 12 (22.6%) also had HLA antibodies, whereas only 7 (10.1%) of the 69 patients in the control group had HLA antibodies (p < 0.03).

CONCLUSIONS:  There is a significant difference between the rates of HLA alloimmunization in male patients with RBC antibodies versus multiply transfused patients without RBC antibodies. Screening for HLA antibodies may be warranted in patients with RBC alloantibodies who might require PLT transfusion support for elective surgery.
Platelet function in variable platelet split products intended for neonatal transfusion
Authors: Strasser Erwin F. , Stachel Daniel K. , Schwarzkopf Peter , Ringwald Jürgen , Weisbach Volker , Zimmermann Robert , Zingsem Jürgen , Eckstein Reinhold
Published: March 2006

BACKGROUND:  Only a few systematic studies have examined the effect of variable produced small platelet (PLT) aliquots on PLT function before transfusion to neonates. Although neonatal transfusion could be critical, no standardization of production or systematic quality controls have been introduced so far.

STUDY DESIGN AND METHODS:  PLT split products were prepared in three different ways (30‐ or 60‐mL bag, syringe aliquot) at different times from the parent unit (Days 1‐4) and stored for 2 or 4 hours. The measures of PLT function include pH, lactate, P‐selectin expression, and cytokines (β‐thromboglobulin [β‐TG], PLT‐derived growth factor AB [PDGF‐AB]). Additionally, syringe passage (0.5 mL/min) was assessed.

RESULTS:  High product variability of PLT content was found (40% deviation of PLT content from programmed target, 13%‐19% PLT loss by product distribution), which resulted in PLT concentrations of split units between 0.94 × 109 and 1.66 × 109 PLTs per mL. Different gas transfer rates (pCO2) of PLT containers caused different pH values of the product (Trima 7.47 ± 0.09 vs. COM.TEC 7.33 ± 0.08; p < 0.0001), but acceptable results of PLT metabolism were found in all split units (minimum pH, 7.09; maximum lactate content, 13.1 mmol/L). P‐selectin expression on PLTs increased by factor of 2 in the parent units stored for 4 days (16.9 ± 8.6% 32.2 ± 13.4%; p = 0.02). After Day 3, β‐TG and PDGF‐AB increased by twofold. PLTs stored during passage for 100 minutes in syringes dropped pO2 by 50 percent and caused 15 percent higher lactate levels.

CONCLUSION:  High variability of PLT content in split units requires at least additional PLT counts before transfusion in critical preterm or neonatal infants.
TheRHCEalleleceSL: the second example for D antigen expression without D‐specific amino acids
Authors: Chen Qing , Hustinx Hein , Flegel Willy A.
Published: March 2006

BACKGROUND: The example of ceRT proved that the expression of some D epitopes does not require D‐specific amino acids. This allele denoted asRHce(R154T) caused the “false‐positive” reactions that were observed in ccddee blood donors who typed positive for the D antigen with some monoclonal anti‐D. No other example exposing a similar molecular mechanism was known.

STUDY DESIGN AND METHODS: Eleven donor and 1 patient ccddee samples were collected in Switzerland that typed “false‐positive” with some monoclonal anti‐D in bromelain technique. TheirRHCEalleles were determined by nucleotide sequencing from genomic DNA and by a polymerase chain reaction with sequence‐specific priming. The D epitope profile was compared to ceRT. The population frequencies were estimated in Switzerland and Germany by serology or at the molecular level, respectively.

RESULTS: The “false‐positive” reactions were caused by theRHCEalleleRHce(S122L) occurring in thecdehaplotype. Its ceSL phenotype expressed few D epitopes that belonged to the D epitope 6 group. The frequency of ceSL among D– donors was about 1:675 in the region of Bern, Switzerland. No ceSL donors were found elsewhere in Switzerland or in southwestern Germany.

CONCLUSION: ceSL represented the second molecular mechanism for D antigen expression without any D‐specific amino acids. ceSL and ceRT were useful to delineate the molecular mechanisms of D expression by RhCE proteins carrying amino acids not representative for the RhD proteins. The ceSL population frequencies differed significantly among three Swiss and German populations.
ABO blood group in Kuwaitis: detailed allele frequency distribution and identification of novel alleles
Authors: Yip Shea Ping , Choi Pik Shan , Lee Sau Yin , Leung Kim Hung , El‐Zawahri Mokhtar M. , Luqmani Yunus A.
Published: March 2006

BACKGROUND:  The ABO blood group is clinically the most important blood group system and can now be genotyped easily by DNA‐based methods without family studies.

STUDY DESIGN AND METHODS:  Samples (n = 166) from a Kuwaiti population were phenotyped by standard serologic techniques for the ABO blood group and genotyped for the ABO locus by an established multiplex polymerase chain reaction protocol followed by single‐strand conformation polymorphism (SSCP) analysis. Nonstandard SSCP patterns were investigated by DNA sequencing of exons 6 and 7 and, if necessary intron 6.

RESULTS:  Standard SSCP patterns identified six classical alleles in this population: A101 (0.1115), A102 (0.0181), A201 (0.0301), B101 (0.1627), O101 (0.3103), and O201 (0.2500). One A, 1 B, and 8 O variant alleles were identified (total frequency, 0.1175). All variant alleles were each present in one or two chromosomes (≤0.0060) in our samples except O109 (0.0813). Three of these 10 variant alleles were novel alleles defined by newly identified single‐nucleotide polymorphisms in exon 7 (527G>A, 687C>T, and 1116G>A). One new base substitution result in amino acid change.

CONCLUSIONS:  This is the first study reporting the detailed distribution of ABO alleles and genotypes in Kuwaitis. Sixteen alleles were identified, including 3 novel alleles.
Production of Silicon Carbide Pieces by Immersion of Silicon Preforms in Carbonaceous Powders
Authors: Gómez Mónica , Pérez Antonio , Valcárcel Víctor , Cerecedo Carmen , Guitián Francisco
Published: March 2006

In this work a novel method for production of silicon carbide (SiC) pieces, which involves the heating of silicon (Si) preforms immersed in graphite powder is presented. Such preforms were obtained via low‐pressure injection molding (LPIM), although any other conformation route can be used. The process can be carried out at modest temperatures and gradients in standard furnaces used for processing other ceramics. These features make this process a simpler and cheaper alternative, when compared with other methods of SiC fabrication. The variables affecting the process have been identified, and an optimum‐heating ramp has been established. Under these conditions, the obtained SiC products show no remnant‐free Si, and their mechanical behavior allows their use in several less‐demanding SiC applications, for which expensive high‐performance SiC products are unaffordable. In the proposed chain of reactions, CO(g) is responsible for the carburization of the pieces. All phases present are identified, and their distribution is explained by means of competitive reactions. In our opinion, this novel method can be extended to an industrial scale because it is simple and involves cheap raw materials.
Morphologies‐Controlled Synthesis and Optical Properties of Bismuth Tungstate Nanocrystals by a Low‐Temperature Molten Salt Method
Authors: Xie Lijin , Ma Junfeng , Zhou Jun , Zhao Zhongqiang , Tian Hua , Wang Yonggang , Tao Jiantao , Zhu Xiaoyi
Published: March 2006

Well‐crystallized bismuth tungstate (Bi2WO6) powders with different morphologies were successfully synthesized via a low‐temperature molten salt method. The powders were characterized by X‐ray diffraction, transmission electron microscopy, and UV‐Vis, respectively. It was found that the variation of morphology of the obtained Bi2WO6 powder mainly depends on the different reaction temperatures and the weight ratio of LiNO3–NaNO3 salt to precursor. In addition, the UV‐Visible absorption spectra showed that the synthesized powders had strong light absorption properties not only in the ultraviolet light but also in the visible light region.
Encounters between aphids and their predators: the relative frequencies of disturbance and consumption
Authors: Nelson Erik H. , Rosenheim Jay A.
Published: March 2006

Ecologists may wish to evaluate the potential for predators to suppress prey populations through the costs of induced defensive behaviors as well as through consumption. In this paper, we measure the ratio of non‐consumptive, defense‐inducing encounters relative to consumptive encounters (henceforth the ‘disturbed : consumed ratio’) for two species of aphids and propose that these disturbed : consumed ratios can help evaluate the potential for behaviorally mediated prey suppression. For the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), the ratio of induced disturbances to consumption events was high, 30 : 1. For the cotton aphid, Aphis gossypii (Glover) (Homoptera: Aphididae), the ratio of induced disturbances to consumption events was low, approximately 1 : 14. These results indicate that the potential for predators to suppress pea aphid populations through induction of defensive behaviors is high, whereas the potential for predators to suppress cotton aphid populations through induced behaviors is low. In measuring the disturbed : consumed ratios of two prey species, this paper makes two novel points: it highlights the variability of the disturbed : consumed ratio, and it offers a simple statistic to help ecologists draw connections between predator–prey behaviors and predator–prey population dynamics.
Do I Contribute More When I Trust More? Differential Effects of Cognition- and Affect-Based Trust
Authors: Ng Kok-Yee , Chua Roy Y.J.
Published: March 2006

This study investigates the relationship between level of trust and cooperative behaviours in a social dilemma. We argue that this relationship should depend on the basis of trust (cognition- versus affect-based) and on beliefs about the equality of resource endowments. Results supported our prediction that increasing affect-based trust increases cooperation, but increasing cognition-based trust to a certain level can reduce cooperation because of free-riding tendency. Moreover, these effects of trust are stronger for individuals who believed that other group members had more resources than they did. Thus, our study demonstrates that higher levels of trust do not necessarily encourage cooperation. Implications of these findings are discussed.
Managerial Knowledge Sharing: The Role of Individual, Interpersonal, and Organizational Factors
Authors: Lu Lin , Leung Kwok , Koch Pamela Tremain
Published: March 2006

This paper describes two studies conducted in the People's Republic of China aimed at improving understanding of knowledge sharing among managers. Study 1 found evidence for the role of two individual factors: greed which reduced knowledge sharing, and self-efficacy which increased it. In addition, co-worker collegiality has an indirect influence on knowledge sharing by lowering greed and raising self-efficacy. Study 2 replicated the key findings of Study 1 and also identified the influence of organizational support on knowledge sharing. Organizational support led to higher utilization of information and communication technologies, resulting in more knowledge sharing, especially for explicit as opposed to implicit knowledge.