bluuebunny/crossref_metadata_2025 huggingface dataset:
On quantitative measures of indirect interactions
Authors: Okuyama Toshinori , Bolker Benjamin M.
Published: February 2007

Indirect effects, whether density‐mediated (DMII) or trait‐mediated (TMII), have been recognized as potentially important drivers of community dynamics. However, empirical studies that have attempted to detect TMII or to quantify the relative strength of DMII and TMII in short‐term studies have used a range of different metrics. We review these studies and assess both the consistency of a variety of different metrics and their robustness to (or ability to detect) ecological phenomena such as the dependence of forager behaviour on conspecific density. Quantifying indirect effects over longer time scales when behaviour and population density vary is more challenging, but also necessary if we really intend to incorporate indirect effects into predictions of long‐term community dynamics; we discuss some problems associated with this effort and conclude with general recommendations for quantifying indirect effects.
Vertical distribution of picoeukaryotic diversity in the Sargasso Sea
Authors: Not Fabrice , Gausling Rudolf , Azam Farooq , Heidelberg John F. , Worden Alexandra Z.
Published: February 2007

Eukaryotic molecular diversity within the picoplanktonic size‐fraction has primarily been studied in marine surface waters. Here, the vertical distribution of picoeukaryotic diversity was investigated in the Sargasso Sea from euphotic to abyssal waters, using size‐fractionated samples (< 2 μm). 18S rRNA gene clone libraries were used to generate sequences from euphotic zone samples (deep chlorophyll maximum to the surface); the permanent thermocline (500 m); and the pelagic deep‐sea (3000 m). Euphotic zone and deep‐sea data contrasted strongly, the former displaying greater diversity at the first‐rank taxon level, based on 232 nearly full‐length sequences. Deep‐sea sequences belonged almost exclusively to the Alveolata and Radiolaria, while surface samples also contained known and putative photosynthetic groups, such as unique Chlorarachniophyta and Chrysophyceae sequences. Phylogenetic analyses placed most Alveolata and Stramenopile sequences within previously reported ‘environmental’ clades, i.e. clades within the Novel Alveolate groups I and II (NAI and NAII), or the novel Marine Stramenopiles (MAST). However, some deep‐sea NAII formed distinct, bootstrap supported clades. Stramenopiles were recovered from the euphotic zone only, although many MAST are reportedly heterotrophic, making the observed distribution a point for further investigation. An unexpectedly high proportion of radiolarian sequences were recovered. From these, five environmental radiolarian clades, RAD‐I to RAD‐V, were identified. RAD‐IV and RAD‐V were composed of Taxopodida‐like sequences, with the former solely containing Sargasso Sea sequences, although from all depth zones sampled. Our findings highlight the vast diversity of these protists, most of which remain uncultured and of unknown ecological function.
Effect of salinity changes on the bacterial diversity, photosynthesis and oxygen consumption of cyanobacterial mats from an intertidal flat of the Arabian Gulf
Authors: Abed Raeid M. M. , Kohls Katharina , De Beer Dirk
Published: February 2007

The effects of salinity fluctuation on bacterial diversity, rates of gross photosynthesis (GP) and oxygen consumption in the light (OCL) and in the dark (OCD) were investigated in three submerged cyanobacterial mats from a transect on an intertidal flat. The transect ran 1 km inland from the low water mark along an increasingly extreme habitat with respect to salinity. The response of GP, OCL and OCD in each sample to various salinities (65‰, 100‰, 150‰ and 200‰) were compared. The obtained sequences and the number of unique operational taxonomic units showed clear differences in the mats' bacterial composition. While cyanobacteria decreased from the lower to the upper tidal mat, other bacterial groups such as Chloroflexus and Cytophaga/Flavobacteria/Bacteriodetes showed an opposite pattern with the highest dominance in the middle and upper tidal mats respectively. Gross photosynthesis and OCL at the ambient salinities of the mats decreased from the lower to the upper tidal zone. All mats, regardless of their tidal location, exhibited a decrease in areal GP, OCL and OCD rates at salinities > 100‰. The extent of inhibition of these processes at higher salinities suggests an increase in salt adaptation of the mats microorganisms with distance from the low water line. We conclude that the resilience of microbial mats towards different salinity regimes on intertidal flats is accompanied by adjustment of the diversity and function of their microbial communities.
Making literature searches easier: a rapid and sensitive search filter for retrieving randomized controlled trials from PubMed
Authors: Royle P. L. , Waugh N. R.
Published: February 2007

Aims  To develop and test the sensitivity and precision of a rapid and simple search filter (RSSF), suitable for busy clinicians wanting to find randomised controlled trials (RCTs) in PubMed. Ideally it should retrieve all the RCTs, but as few irrelevant studies as possible, and be easy to use.

Methods  The RSSF consisted of the search term ‘Randomized Controlled Trial’ limited to the Publication Type field. Journals that published the highest numbers of diabetes RCTs between 2000 and 2005 were identified, and then handsearched in order define a set of known RCTs. The sensitivity of the RSSF was tested by measuring the proportion of the known RCTs retrieved, and the precision by checking the proportion of the retrieved studies which were RCTs. The RSSF was compared to a highly sensitive search strategy (HSSS) developed for PubMed. Embase was checked for trials not in PubMed.

Results  Sixteen journals were found to contain half of all published RCTs in diabetes. 820 diabetes RCTs were identified by handsearching. Measured against these, the RSSF gave a sensitivity of 96.0% (95% CI, 94.8% to 97.1%), and a precision of 93.6% (95% CI 91.7% to 95.0%). Compared to the HSSS, the RSSF reduced the filtering required by 87%. An Embase search for diabetes RCTs found 36 (2.1%) not in PubMed.

Conclusions  A rapid simple search filter for PubMed can find almost all diabetes RCTs, while excluding most studies not required, thereby greatly reducing the time cost of searching and filtering results, and of searching other databases.
Nursing skill mix and outcomes: a Singapore perspective
Authors: Ayre T. C. , Gerdtz M. F. , Parker J. , Nelson S.
Published: February 2007

Aim:  To summarize key evidence on nursing skill mix in acute care hospitals and their limitations; and identify the gaps in current literature vis‐à‐vis Singapore’s nursing workforce.

Background:  Nursing skill mix has been theorized to be a factor influencing patient, nurse and organizational outcomes. While there is a growing body of literature explicating associations between nursing skill mix and positive outcomes, the evidence does not as yet provide firm directions in determining the best configuration. In addition, differences in nursing workforce characteristics also make it difficult to apply findings from one healthcare setting to another.

Conclusions:  In reviewing key evidence from the United States of America and Canada, this paper highlights three critical gaps in the nursing skill mix literature when examined in the context of Singapore’s nursing workforce. Issues related to the interface between local and foreign nurses, the impact of speciality education, and the possible effects that work roles and distribution may have on quality of care need to be further examined. This knowledge should provide a robust evidence base with which to inform national policy on skill mix and maximize nursing resources in order to achieve optimal outcomes.
Trends in nursing staff allocation: the nurse‐to‐patient ratio and skill mix issues in Israel
Authors: Rassin M. , Silner D.
Published: February 2007

Purpose:  This article describes a case study relating to trends in nurse‐to‐patient ratios and nursing staff mix in Israel.

Background:  In recent years, there has been a worldwide trend towards changing nurse‐to‐patient ratios and nursing staff mixes. On the one hand, the patient’s status has become more complex and requires a more professional nursing staff to maintain treatment, safety and quality, on the other hospitals have become more economically focused. In light of this, the need to re‐examine the issues of nurse‐to‐patient ratio and nursing staff mix are of primary importance to the health system. Legislation of nurse‐to‐patient ratios is being widely discussed in nursing circles, and nurse‐to‐patient ratios are now mandatory in the State of California, USA, and the State of Victoria, Australia.

Conclusion:  The trend in nursing staff mix in Israel has been towards increased hiring of academic registered nurses, leading to the clinical development of quality treatment programmes and decreased mortality rates. Subsequently, license practical nurses are phased out, and where necessary auxiliary staff, which represents a cheaper work force, provides unskilled care. Today, the staff mix distribution in Israeli general governmental hospitals consists of 73% registered nurses, 11% licensed vocational nurses, and 16% auxiliary staff. In addition, there is a special collective agreement related to the allocation of nursing positions, including a classification method involving 10 categories of inpatient wards.
On amphidromy, a distinct form of diadromy in aquatic organisms
Authors: McDowall R M
Published: February 2007

Amphidromy is a distinctive form of diadromy that involves some fish, decapod crustaceans and gastropod molluscs. Characteristic elements in amphidromy are: reproduction in fresh water, passage to sea by newly hatched larvae, a period of feeding and growing at sea usually a few months long, return to fresh water of well‐grown juveniles, a further period of feeding and growing in fresh water, followed by reproduction there. This life‐history strategy is observed in numerous fish species, primarily in islands of the tropics and subtropics (probably more than 75 species, especially sicydiine gobies), and extends to temperate countries as far as Japan in the north and New Zealand in the south. There has been considerable confusion about the nature of amphidromy and its distinctiveness from anadromy, another category of diadromy. The return to freshwater of small juveniles of amphidromous fishes is functionally and strategically different from the return of large mature adults, as happens in anadromy. The strategy is recognized as distinctive by numerous fish biologists who work with amphidromous fishes, although it has tended to be rejected or ignored by others, typically those who have no personal experience with them.
Chest pain is inversely associated with blood pressure during exercise among individuals being assessed for coronary heart disease
Authors: Ditto Blaine , D'Antono Bianca , Dupuis Gilles , Burelle Denis
Published: February 2007

Acute and chronic increases in blood pressure have been related to decreases in pain perception. This phenomenon has been studied primarily using acute experimental pain stimuli. To extend the literature to naturalistic pain and in particular the problem of silent cardiac ischemia, this study examined the relationship between blood pressure and chest pain during exercise stress testing. Nine hundred seven (425 men, 482 women) individuals undergoing exercise stress testing for diagnosis of possible myocardial ischemia completed the McGill Pain Questionnaire (MPQ) immediately afterward and other questionnaires before and after testing. Blood pressure was measured before, during, and after exercise. Systolic blood pressure at the end of exercise was inversely related to a number of measures of pain such as total score on the MPQ. The relationship could not be explained by individual differences in exercise duration, medication use, sex, or other measured variable. In sum, the inverse relationship between blood pressure and sensitivity to pain that has been observed in other populations in experimental and naturalistic conditions was observed for chest pain during exercise. Blood pressure may contribute to episodes of silent ischemia.
Music and emotion: Electrophysiological correlates of the processing of pleasant and unpleasant music
Authors: Sammler Daniela , Grigutsch Maren , Fritz Thomas , Koelsch Stefan
Published: February 2007

Human emotion and its electrophysiological correlates are still poorly understood. The present study examined whether the valence of perceived emotions would differentially influence EEG power spectra and heart rate (HR). Pleasant and unpleasant emotions were induced by consonant and dissonant music. Unpleasant (compared to pleasant) music evoked a significant decrease of HR, replicating the pattern of HR responses previously described for the processing of emotional pictures, sounds, and films. In the EEG, pleasant (contrasted to unpleasant) music was associated with an increase of frontal midline (Fm) theta power. This effect is taken to reflect emotional processing in close interaction with attentional functions. These findings show that Fm theta is modulated by emotion more strongly than previously believed.
Cerebral blood flow in essential hypotension during emotional activation
Authors: Stegagno Luciano , Patritti Denise , Duschek Stefan , Herbert Beate , Schandry Rainer
Published: February 2007

Variations of blood flow velocity in the left and right middle cerebral arteries (MCA) were measured in 20 hypotensive women and 20 normotensive control subjects during emotional stimulation using functional transcranial Doppler sonography (fTDS). The emotional stimuli were composed of three series (neutral, pleasant, and unpleasant) of 20 pictures from the International Affective Picture System (IAPS). Both groups exhibited greater increases in right than left MCA blood flow during emotional stimulation. However hypotensive subjects showed smaller increases in blood flow than did normotensive controls. Furthermore hypotensives exhibited lower MCA blood flow velocity in both hemispheres at rest than did normotensives. Nevertheless the hypotensive group rated the emotional pictures as more arousing than did the control group. Results suggest a decreased blood flow, in addition to peripheral, in the central nervous system (CNS) of hypotensives, which was associated with normal emotional responses for both valence and hemispherical asymmetry, but also with a general increase of arousal levels. This dissociation might be related to an increase in anterior cerebral arteries (ACA) blood flow and/or to hypotension‐mediated baroreceptors' up‐regulation to the reticular system.
Plasticity of 5‐HT1A receptor‐mediated signaling during early postnatal brain development
Authors: Mehta Mukti , Ahmed Zagloul , Fernando Suraj Shawn , Cano‐Sanchez Patricia , Adayev Tatyana , Ziemnicka Dorota , Wieraszko Andrzej , Banerjee Probal
Published: February 2007

The presence of serotonin 1A receptor (5‐HT1A‐R) in the hippocampus, amygdala, and most regions of the frontal cortex is essential between postnatal day‐5–21 (P5–21) for the expression of normal anxiety levels in adult mice. Thus, the 5‐HT1A‐R plays a crucial role in this time window of brain development. We show that the 5‐HT1A‐R‐mediated stimulation of extracellular signal‐regulated kinases 1 and 2 (Erk1/2) in the hippocampus undergoes a transition between P6 and P15. At P6, a protein kinase C (PKC) isozyme is required for the 5‐HT1A‐R ⇒Erk1/2 cascade, which causes increased cell division in the dentate gyrus. By contrast, at P15, PKCα participates downstream of Erk1/2 to augment synaptic transmission through the Schaffer Collateral pathway but does not cause increased cell division. Our data demonstrate that the 5‐HT1A‐R ⇒Erk1/2 cascade uses PKC isozymes differentially, first boosting the cell division to form new hippocampal neurons at P6 and then undergoing a plastic change in mechanism to strengthen synaptic connections in the hippocampus at P15.
Biological Soil Crust Rehabilitation in Theory and Practice: An Underexploited Opportunity
Authors: Bowker Matthew A.
Published: February 2007

Biological soil crusts (BSCs) are ubiquitous lichen–bryophyte microbial communities, which are critical structural and functional components of many ecosystems. However, BSCs are rarely addressed in the restoration literature. The purposes of this review were to examine the ecological roles BSCs play in succession models, the backbone of restoration theory, and to discuss the practical aspects of rehabilitating BSCs to disturbed ecosystems. Most evidence indicates that BSCs facilitate succession to later seres, suggesting that assisted recovery of BSCs could speed up succession. Because BSCs are ecosystem engineers in high abiotic stress systems, loss of BSCs may be synonymous with crossing degradation thresholds. However, assisted recovery of BSCs may allow a transition from a degraded steady state to a more desired alternative steady state. In practice, BSC rehabilitation has three major components: (1) establishment of goals; (2) selection and implementation of rehabilitation techniques; and (3) monitoring. Statistical predictive modeling is a useful method for estimating the potential BSC condition of a rehabilitation site. Various rehabilitation techniques attempt to correct, in decreasing order of difficulty, active soil erosion (e.g., stabilization techniques), resource deficiencies (e.g., moisture and nutrient augmentation), or BSC propagule scarcity (e.g., inoculation). Success will probably be contingent on prior evaluation of site conditions and accurate identification of constraints to BSC reestablishment. Rehabilitation of BSCs is attainable and may be required in the recovery of some ecosystems. The strong influence that BSCs exert on ecosystems is an underexploited opportunity for restorationists to return disturbed ecosystems to a desirable trajectory.
Plant Diversity, Production, Stability, and Susceptibility to Invasion in Restored Northern Tall Grass Prairies (United States)
Authors: Biondini Mario
Published: February 2007

This study investigated the relationship among plant diversity, production, stability, and susceptibility to invasion in restored northern tall grass prairies (United States). The experiment consisted of 50 species mixtures fertilized with N or P, at high or low levels. Results from the past 5 years were as follows: (1) aboveground biomass increased and year‐to‐year variability declined with increases in plant species and functional form richness, mostly as a result of substantial increases in minimum biomass (maximum biomass was unaffected). (2) Aboveground biomass and biomass stability increased when the species in the mixture had: (a) high relative growth rates, root density, root surface area per unit of root biomass, uptake rates of N or P per unit of root surface area, and N use efficiency and (b) low root to shoot ratio. (3) Invasion of nonseeded species declined with increases in plant species and functional form richness. (4) The results from this experiment did not provide a single specific criterion for selecting an optimal species mixture. However, if the objectives of the restoration were simply to achieve an aboveground biomass variability that is less than that of growing‐season precipitation, then the seed mixtures need to have a minimum of nine species and three functional forms.
EFFECTS OF SALINITY AND LIGHT INTENSITY ON THE RESUMPTION OF PHOTOSYNTHESIS IN REHYDRATED CYANOBACTERIAL MATS FROM BAJA CALIFORNIA SUR, MEXICO1
Authors: Fleming Erich D. , Bebout Brad M. , Castenholz Richard W.
Published: February 2007

Lyngbya mats in the intertidal of the Laguna Ojo de Liebre are metabolically active for only a few days every 2 weeks during spring tides, with environmental conditions varying greatly during these periods of hydration. Pulse amplitude modulated fluorometry (PAM) and oxygen measurements were used to measure photosynthetic activity during the first few hours after rehydration under various light intensities and salinities. Upon rehydration, a transitory maximum in respiratory activity (10–30 min) occurred before the resumption of photosynthesis, which could recover in about 2 h. Salinities outside the mats' natural range (35–50 psu) were detrimental to photosynthetic recovery. Both high (100 psu) and low (0–10 psu) salinities slowed recovery as well as lowered the overall photosynthetic yield. Photosynthesis was initiated earlier and recovered more rapidly with increasing light intensity. In addition, the positive effect of light on rates of recovery was disproportionately greater at lower salinities (10–25 psu) where high light (500 W·m−2) counteracted the negative effects of low‐salt stress early in recovery. However, higher light intensities became photoinhibitory later in recovery (>2 h). Photosynthesis did not recover uniformly within the mat. Filaments deeper in the mat most likely recovered later than those near the surface due to high light attenuation. The ability of the mats to tolerate desiccation and take advantage of hydration periods even when conditions are suboptimal enables these mats to predominate in the intertidal environment.
PHYLOGENY AND SYSTEMATICS OF THE GENUS MONOMORPHINA (EUGLENACEAE) BASED ON MORPHOLOGICAL AND MOLECULAR DATA1
Authors: Kosmala Sylwia , Milanowski Rafał , Brzóska Kamil , Pękala Małgorzata , Kwiatowski Jan , Zakryś Bożena
Published: February 2007

Morphological studies of 16 strains belonging to the genus Monomorphina revealed a single, parietal, orbicular chloroplast in their cells. The chloroplast has a tendency to be perforated and disintegrates in aging populations and thus may appear to be many chloroplasts under the light microscope. A single chloroplast in the cells of Cryptoglena skujae is also parietally located and highly perforated. It never forms a globular and closed structure, but is open from the side of the furrow, resembling the letter C. We have verified the Monomorphina pyrum group (M. pyrum–like) on the basis of phylogenetic analysis of SSU rDNA and morphological data. The strain CCAC 0093 (misidentified as M. reeuwykiana) diverges first on the SSU rDNA phylogenetic tree. The rest of the M. pyrum–like strains form a tight cluster, subdivided into several smaller ones. Because morphological differences between the M. pyrum–like strains (including the strain CCAC 0093) do not conform to the tree topology, we suggest that they all (except the strain CCAC 0093) belong to M. pyrum. We designate a new species, M. pseudopyrum, for the strain CCAC 0093, solely on the basis of molecular characters. We also suggest that M. reeuwykiana and similar species should stay in Phacus and Lepocinclis unless detailed molecular and morphological studies show otherwise. Emended diagnoses of the genera Monomorphina and Cryptoglena and the species M. aenigmatica are also proposed, as well as the delimitation of an epitype for M. pyrum, the type species for the genus Monomorphina.
SEASONAL GROWTH AND PHENOTYPIC VARIATION INPORPHYRA LINEARIS(RHODOPHYTA) POPULATIONS ON THE WEST COAST OF IRELAND1
Authors: Varela‐Álvarez Elena , Stengel Dagmar B. , Guiry Michael D.
Published: February 2007

The phenology and seasonal growth ofPorphyra linearisGrev. were investigated in two morphologically dissimilar populations from the west coast of Ireland. Thallus size and reproductive status of individuals were monitored monthly between June 1997 and June 1998. Both populations exhibited a similar phenology: gametophyte stages appeared on the shore in October, with spermatangial and zygotosporangial sori appearing the following February; the gametophyte stage began to degenerate in April and had disappeared completely by June. However, significant differences in growth and reproduction in the field and in cultures of plants from the two populations were observed. Thallus length and width of individuals from one population were significantly longer throughout the sample period, and reproduction and sporulation occurred 1 month earlier. Also,in siturelative growth rates (RGRs) of plants differed significantly and were correlated with different climatic factors (sunshine, day length, irradiance, rainfall, seawater temperature, and intertidal temperatures), suggesting that plants were affected by two different microhabitats. At one site, blades were more exposed to wave action, sunshine, and extreme minimum temperatures, while at the other site, blades were more protected in winter, spring, and early summer. In culture, RGRs of blades from the second site were higher than RGRs of blades from the first site under short days, corroborating the field results and suggesting a degree of phenotypic differentiation between the two populations. However, there were no sequence divergences of the RUBISCO spacer between strains of the twoP. linearispopulations.
BROAD THERMAL TOLERANCE OF THE SYMBIOTIC DINOFLAGELLATE SYMBIODINIUM MUSCATINEI (DINOPHYTA) IN THE SEA ANEMONE ANTHOPLEURA ELEGANTISSIMA (CNIDARIA) FROM NORTHERN LATITUDES1
Authors: Muller‐Parker Gisèle , Pierce‐Cravens Jessie , Bingham Brian L.
Published: February 2007

The sea anemone Anthopleura elegantissima (Brandt) hosts two species of symbiotic dinoflagellates, known as zooxanthellae, which coexist within the host at southern latitudes only. One of these species, Symbiodinium muscatinei LaJeunesse et Trench, has a broad latitudinal distribution, occurring in intertidal anemones from Washington state to Southern California. To investigate whether high thermal tolerance contributes to the ability of S. muscatinei to inhabit anemones from northern and southern regions, the upper thermal tolerance limit for photosynthesis of symbionts in northern (48°24′ N) populations of A. elegantissima was determined by subjecting anemones to a gradual increase in temperature from 12°C to 30°C over a 10‐week period. Light‐saturated photosynthetic rates of isolated zooxanthellae were the same over the range of 12°C–24°C and declined significantly at 26°C, which is 14°C and 5°C above average summertime seawater temperatures in northern Puget Sound and Southern California, respectively. At 28°C, zooxanthellae isolated from the anemones, and those expelled by their hosts, exhibited extremely low rates of photosynthesis and highly reduced chl content. The photosynthetic rates and chl content of expelled zooxanthellae were lower than those of retained zooxanthellae. The high thermal tolerance of S. muscatinei isolated from northern populations of anemones supports the broad latitudinal distribution of this symbiont, allowing it to coexist with S. californium (#383, Banaszak et al. 1993) in southern populations of anemones.
MICROSATELLITE MARKERS REVEAL POPULATION GENETIC STRUCTURE OF THE TOXIC DINOFLAGELLATE ALEXANDRIUM TAMARENSE (DINOPHYCEAE) IN JAPANESE COASTAL WATERS1
Authors: Nagai Satoshi , Lian Chunlan , Yamaguchi Sanae , Hamaguchi Masami , Matsuyama Yukihiko , Itakura Shigeru , Shimada Hiroshi , Kaga Shinnosuke , Yamauchi Hiroyuki , Sonda Yoshiko , Nishikawa Tetsuya , Kim Chang‐Hoon , Hogetsu Taizo
Published: February 2007

This is the first report to explore the fine‐scale diversity, population genetic structure, and biogeography of a typical planktonic microbe in Japanese and Korean coastal waters and also to try to detect the impact of natural and human‐assisted dispersals on the genetic structure and gene flow in a toxic dinoflagellate species. Here we present the genetic analysis of Alexandrium tamarense (Lebour) Balech populations from 10 sites along the Japanese and Korean coasts. We used nine microsatellite loci, which varied widely in number of alleles and gene diversity across populations. The analysis revealed that Nei's genetic distance correlated significantly with geographic distance in pair‐wise comparisons, and that there was genetic differentiation in about half of 45 pair‐wise populations. These results clearly indicate genetic isolation among populations according to geographic distance and restricted gene flow via natural dispersal through tidal currents among the populations. On the other hand, high P‐values in Fisher's combined test were detected in five pair‐wise populations, suggesting similar genetic structure and a close genetic relationship between the populations. These findings suggest that the genetic structure of Japanese A. tamarense populations has been disturbed, possibly by human‐assisted dispersal, which has resulted in gene flow between geographically separated populations.
DIVERSITY IN THE GENUS SKELETONEMA (BACILLARIOPHYCEAE): III. PHYLOGENETIC POSITION AND MORPHOLOGICAL VARIABILITY OF SKELETONEMA COSTATUM AND SKELETONEMA GREVILLEI, WITH THE DESCRIPTION OF SKELETONEMA ARDENS SP. NOV.1
Authors: Sarno Diana , Kooistra Wiebe H. C. F. , Balzano Sergio , Hargraves Paul E. , Zingone Adriana
Published: February 2007

Skeletonema costatum (Grev.) Cleve emend. Zingone et Sarno and S. grevillei Sarno et Zingone were known only from the type material collected from Hong Kong waters more than a century ago. Both species have now been collected as live material, and their morphology and phylogenetic position are investigated in this study. Eight Skeletonema strains isolated from Florida, USA; Uruguay; and Brazil are attributed to S. costatum, while one strain from Oman is ascribed to S. grevillei based on morphological similarity to the type material of these species. In addition, a new Skeletonema species, S. ardens Sarno et Zingone, is described for a strain from Singapore and two from northern Australian waters. Skeletonema ardens has terminal fultoportula processes ending in a tapered, undulate protrusion and long intercalary fultoportulae with 1:1 junctions. The rimoportula of terminal valves is located at the margin of the valve face. No major morphological variations were observed within S. grevillei and S. ardens along a salinity gradient, whereas in S. costatum, the processes shortened and the valves came into close contact at low salinities, as already described for S. subsalsum (Cleve) Bethge. Consistent with their morphology, Skeletonema costatum and Skeletonema subsalsum also had similar rDNA sequences. Skeletonema grevillei and S. ardens were distinct in the large subunit (LSU) phylogeny. Skeletonema ardens exhibited consistent intraspecific genetic differences in both the LSU and small subunit (SSU) rDNA.
Intracranial Hypotension Following Motor Vehicle Accident: An Overlooked Cause of Post‐Traumatic Head and Neck Pain?
Authors: Huntoon Marc A. , Watson James C.
Published: February 2007

Abstract:  Motor vehicle accidents result in many patients with chronic head and neck pain, some of which meet the criteria for a “whiplash syndrome.” The cervical zygapophysial joint synovium, muscular, and ligamentous strains and other anatomical sites are often implicated in the pathophysiology of these cases. Some patients have a characteristic constellation of vague neurological symptoms, often including headache, posterior neck discomfort, dizziness, nausea, and sometimes visual changes. Recently presented research has noted that some patients who have a whiplash‐associated disorder have imaging findings consistent with a low‐pressure cerebrospinal fluid leak. Some of these patients respond favorably to high‐volume epidural blood patch. The following case presentation focuses on the differential diagnosis of a post‐traumatic headache syndrome, specific imaging findings, and treatment strategies.
Blood use by inpatient elderly population in the United States
Authors: Anderson Steven A. , Menis Mikhail , O'Connell Kathryn , Burwen Dale R.
Published: February 2007

BACKGROUND: Our objective was to characterize inpatient blood use by the US elderly population during 2001. As the US population ages the demand for blood is expected to grow. There have been no comprehensive studies, however, detailing blood use by the elderly in the United States.

STUDY DESIGN AND METHODS: A descriptive cross‐sectional study of blood utilization was conducted with the 5 percent Medicare Provider Analysis and Review (MedPAR) data file obtained from the Centers for Medicare and Medicaid Services (CMS). Each record of the file represented a billing record of an inpatient stay. Blood use was identified by either a nonzero blood pints furnished quantity or a procedure code for transfusion of whole blood or red blood cells (RBCs).

RESULTS: Among 635,700 stays, 43,220 (6.8%) recorded transfusion of whole blood or RBCs. Blood use prevalence was approximately 4.5 times higher for stays with at least one medical procedure compared to stays without procedures. Of 15,579 stays with number of blood pints furnished recorded, the top 20 principal procedures with the largest quantities of blood accounted for about 56 percent of total blood pints furnished; however, these procedures represented only about 19 percent of all stays.

CONCLUSION: Our study shows a strong association between medical procedures and blood use among inpatient stays for the elderly. Some of the highest blood utilization occurred with surgical procedures. More precise information on blood utilization may serve as the basis for estimating risks associated with blood transfusion and may inform decisions that maintain an adequate supply of blood.
A revised classification scheme for acute transfusion reactions
Authors: Sanders Robert P. , Geiger Terrence L. , Heddle Nancy , Pui Ching‐Hon , Howard Scott C.
Published: February 2007

BACKGROUND: Although the standard classification system for acute transfusion reactions adequately describes the general features associated with the various types of reactions, it was not designed to provide strict criteria for diagnosis and classification. Consequently, its use to classify individual reactions can result in significant inter‐ and intraobserver variability, which can complicate patient management and clinical research.

STUDY DESIGN AND METHODS: A total of 595 transfusion reactions that occurred at a single institution between January 1, 1996, and December 31, 2003, were reviewed and were initially classified according to the established conventions of the AABB. Each reaction was then reclassified with a revised system that refines and clarifies reaction categories, adds severity grades in the format of the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE), and includes terminology to indicate the attribution or likelihood that the adverse event is related to the transfusion.

RESULTS: Comparison of the two approaches as applied to these 595 transfusion reactions showed clear advantages for the revised system. Of 128 reactions classified by AABB criteria as inconclusive, a mixture of reaction types, or otherwise qualified, all but 5 were accommodated by discrete categories within our revised scheme. In each case with a classifiable reaction, the severity of the reaction could be readily graded.

CONCLUSION: The advantages of this revised classification scheme for acute transfusion reactions warrant prospective evaluation and ultimately consideration of its incorporation into clinical practice.
Bacterial contamination of platelet concentrates: results of a prospective multicenter study comparing pooled whole blood–derived platelets and apheresis platelets
Authors: Schrezenmeier Hubert , Walther‐Wenke Gabriele , Müller Thomas H. , Weinauer Franz , Younis Adelheid , Holland‐Letz Tim , Geis Gabriele , Asmus Jens , Bauerfeind Ursula , Burkhart Jürgen , Deitenbeck Robert , Förstemann Elisabeth , Gebauer Wolfgang , Höchsmann Britta , Karakassopoulos Apostolos , Liebscher Ute‐Maja , Sänger Werner , Schmidt Michael , Schunter Friedrich , Sireis Walid , Seifried Erhard
Published: February 2007

BACKGROUND: The GERMS Group initiated a prospective multicenter study to assess prevalence and nature of bacterial contamination of pooled buffy‐coat platelet concentrates (PPCs) and apheresis platelet concentrates (APCs) by routine screening with a bacterial culture system.

STUDY DESIGN AND METHODS: In nine centers overall, 52,243 platelet (PLT) concentrates (15,198 APCs, 37,045 PPCs) were analyzed by aerobic and anaerobic cultures (BacT/ALERT, bioMérieux).

RESULTS: In 135 PLT concentrates (PCs; 0.26%), bacteria could be identified in the first culture (0.4% for APCs vs. 0.2% for PPCs; p < 0.001). In 37 (0.07%) of these PC units, the same bacteria strain could be identified in a second culture from the sample bag and/or the PC unit. The rate of confirmed‐positive units did not differ significantly between APC (0.09%; 1/1169) and PPC units (0.06%; 1/1544). Bacteria from skin flora (Propionibacterium acnes, Staphylococcus epidermidis) were the most prevalent contaminants. Median times to first positive culture from start of incubation were 0.7 and 3.7 days in aerobic and anaerobic cultures for confirmed‐positive units. With a “negative‐to‐date” issue strategy, most PC units (55%) had already been issued by time of the first positive culture.

CONCLUSION: The rate of confirmed bacterial contamination of PC units was low. Nevertheless, clinicians must be aware of this risk. The risk of bacterial contamination does not warrant universal preference of APCs. It must be questioned whether routine bacterial screening by a culture method can sufficiently prevent contaminated products from being transfused due to the delay until a positive signal in the culture system and due to false‐negative results.
In vitro evaluation of metabolic changes and residual platelet responsiveness in photochemical treated and gamma‐irradiated single‐donor platelet concentrates during long‐term storage
Authors: Apelseth Torunn O. , Bruserud Øystein , Wentzel‐Larsen Tore , Bakken Anne M. , Bjørsvik Solfrid , Hervig Tor
Published: February 2007

BACKGROUND: Photochemical treatment (PCT) prevents replication of pathogens in platelet concentrates (PCs) by cross‐linking nucleic acids and thus affects all cells containing DNA or RNA.

STUDY DESIGN AND METHODS: Fourteen double‐dose single‐donor PCs were divided into two study arms. The double‐dose PCs were split in two identical units, PCT and conventional control PCs. Study Arm A consisted of seven PCT PCs with corresponding untreated controls, whereas Study Arm B consisted of seven PCT PCs with corresponding gamma‐irradiated control. Metabolic changes and agonist‐induced platelet (PLT) response were evaluated during storage for up to 12 days.

RESULTS: Higher rate of PLT destruction, illustrated by reduced PLT content, increased lactate dehydrogenase levels, and higher CD61+ microparticle formation rate, were observed after PCT. Generally PCT accelerated metabolic changes in PCs and reduced agonist‐induced (collagen or thrombin receptor activator peptide [TRAP]) aggregation responses. Flow cytometric analysis of CD62P and CD42b (GPIbα) expression showed higher spontaneous PLT activation in PCT PCs from 5 days of storage. Correspondingly, a reduced capacity for up regulation of CD62P expression and down regulation of CD42b was observed in PCT PLTs after stimulation by the agonists ADP or TRAP.

CONCLUSION: Generally reduced in vitro PLT quality was observed after PCT during storage for up to 12 days, with marked reduction from 5 days of storage. Compared to conventional PCs, reduced agonist‐induced aggregation and glycoprotein expression were observed after PCT during storage, corresponding to significantly higher level of spontaneous PLT activation in PCT PCs. Clinical studies of efficacy and safety of PCT PCs stored for more than 5 days are recommended.
Inhabitants' and Experts' Assessments of Environmental Quality for Urban Sustainability
Authors: Bonnes Mirilia , Uzzell David , Carrus Giuseppe , Kelay Tanika
Published: February 2007

In the context of sustainable urban development, we discuss the assessment of residential environmental quality and the importance of considering inhabitants' perceptions of natural resources in urban areas. Two series of studies, conducted in Guildford (United Kingdom) and in Rome (Italy), addressed the correspondence, or contrast, between inhabitants' and experts' assessment of urban quality concerning two crucial natural resources: air quality and biodiversity. The Guildford study emphasized the accuracy of the assessment of urban air quality by experts and the public. The Rome study focused on the evaluative criteria employed by scientists and the public in assessing the quality of urban green spaces. The results from both studies shed more, albeit complex, light on the simple conventional wisdom about public versus expert understanding and assessment of environmental quality. Study implications are discussed for the support of programs, methods, and tools for urban development, particularly with regard to effective communication and better structuring of residents' participation in urban environmental decision making.
Literature, the Interpretive Mode, and Novice Learners
Authors: SCOTT VIRGINIA M. , HUNTINGTON JULIE A.
Published: February 2007

The qualitative study reported in this article analyzes how novice learners develop the interpretive mode (as outlined in Standard 1.2 of the Standards for Foreign Language Learning in the 21st Century, 1996, 1999) in a classroom setting when reading a literary text in a foreign language (FL). Using unmotivated looking through conversation analysis, we examined transcripts from video‐ and audiorecordings of students' discussions in a teacher‐moderated classroom setting and in small groups of 3 to 4 students. Our findings indicate that novice learners were able to interpret and understand a challenging literary text (in this case, a poem) if they were in the teacher‐moderated group. In addition, our findings suggest that use of the first language was effective in encouraging interpretive talk among students in the teacher‐moderated classroom but not among students in small groups. Ultimately, these findings indicate that the nature of the teacher‐moderated, yet distinctly student‐centered, interaction had a clear impact on developing the interpretive mode in novice learners.
Cardiac MRI Is an Important Complementary Tool to Doppler Echocardiography in the Management of Patients with Pulmonary Regurgitation
Authors: Sorrell Vincent L. , Altbach Maria I. , Kudithipudi Vijayasree , Squire Scott W. , Goldberg Stan J. , Klewer Scott E.
Published: February 2007

Cardiac MRI (CMR) is a noninvasive diagnostic tool with comprehensive capabilities similar to that of two‐dimensional echocardiography with Doppler. In addition to the ability to evaluate the etiology and severity of pulmonary valve regurgitation (PR), CMR is well designed to serially monitor the impact of the PR on the right ventricle (RV). Importantly, RV dilation and dysfunction is a critical determinate to time surgical intervention. CMR gives the silent RV, suffering from PR, a voice.
Cardiac Manifestations of Exhaustive Exercise in Nonathletic Adults: Does Cardiac Fatigue Occur?
Authors: Alshaher Motaz , El‐Mallakh Rif , Dawn Buddhadeb , Siddiqui Tariq , Longaker Rita A. , Stoddard Marcus F.
Published: February 2007

The aim of the study was to examine the impact of prolonged exercise leading to physical exhaustion on left ventricular (LV) systolic and diastolic function in untrained healthy subjects, and to examine cardiovascular determinants of exercise performance. Twenty‐four nonathletic healthy adults (14 males, 10 females; mean age 42 ± 11 years) were exercised on a treadmill at 70% of maximal oxygen consumption until physical exhaustion occurred after an average of 84 ± 39 minutes. Two‐dimensional and Doppler echocardiography was performed before and 15 minutes after exercise to assess LV function and geometry, and right ventricular (RV) systolic function. After prolonged exercise, LV ejection fraction and geometry were unchanged, but LV end‐diastolic volume, end‐systolic volume, and stroke volume decreased. However, due to a higher heart rate (HR), cardiac output increased at 15 minutes post exercise. RV fractional shortening was unchanged. LV peak early to atrial filling velocity ratio decreased post exercise, with an increase in percent atrial contribution. However, less preload‐dependent variables of LV diastolic function such as deceleration time, LV inflow propagation rate, mitral annular tissue Doppler and myocardial performance index were unchanged. Preexercise stroke volume and HR were the only predictors (r = 0.86, P < 0.01) of exercise duration. However, age, resting blood pressure, indices of systolic and diastolic function, and LV geometry were not predictors. Prolonged exercise leading to physical exhaustion is not associated with systolic or diastolic dysfunction. Reduced early LV diastolic filling and the relative increase in left atrial contribution seen with prolonged exercise are likely due to preload reduction rather than true diastolic dysfunction.
Identification of Tricuspid Valve Vegetation by Computed Tomography Scan
Authors: Panwar Sadik R. , Singh Satinder , Nanda Navin C. , Singh Anurag , Yelamanchili Pridhvi , Pothineni Koteswara R.
Published: February 2007

We report a patient with disseminated sepsis in whom a large vegetation involving the tricuspid valve was seen on a routine nongated computed tomography (CT) study emphasizing the potential role of CT scan in endocarditis.
Effects of V and Mn Colorants on the Crystallization Behavior and Optical Properties of Ce‐Doped Li‐Disilicate Glass–Ceramics
Authors: Rukmani Sandhya Jayaraman , Brow Richard K. , Reis Signo T. , Apel Elke , Rheinberger Volker , Höland Wolfram
Published: February 2007

The critical cooling rate and fluorescence properties of lithium (Li) disilicate glasses and glass–ceramics, doped with 2.0 wt% CeO2 and with up to 0.7 wt% V2O5 and 0.3 wt% MnO2 added as colorants, were investigated. The critical cooling rates, Rc, of glass melts were determined using differential thermal analysis and were found to be dependent on the relative concentrations of V2O5 and MnO2, decreasing from 25±3° to 16±3°C/min. Annealed glasses were heat treated first to 670°C, and then to 850°C to form Li metasilicate and Li disilicate glass–ceramics, respectively. The fluorescence intensities of the Ce‐doped glasses and glass–ceramics decrease by a factor of 100 with the addition of the transition metal oxides. This optical quenching effect is explained by the association of the Ce3+ ions with the transition metal ions in the residual glassy phase of the glass–ceramics.
Finite Element Modeling of a Donut Flextensional Transducer
Authors: Narayanan Manoj , Schwartz Robert W.
Published: February 2007

A new flextensional transducer based on the cymbal device was designed and fabricated. The endcap shape of this device, called the donut, was developed through finite element modeling using the commercially available software code ATILA®. Endcap dimensions that were studied in this research include cap thickness, flange width, and cavity depth. Other parameters considered included piezoelectric material type, thickness of the piezoelectric disk, epoxy thickness, and endcap metal. Fundamental flextensional resonance frequency and effective coupling coefficient, which are two important characteristics that determine the performance and the application opportunities of the transducer, were predicted. Finite element analysis coupled with experimental results suggest that these devices have higher flextensional resonance frequencies compared with cymbals of similar dimensions. Impedance spectroscopy of the donut devices also suggests that the effective electromechanical coupling coefficient is higher than cymbal devices of similar dimensions.