Gastropods are an important component of subtidal Antarctic communities including in common association with macroalgae. Nonetheless, limited data exist detailing their abundance and distribution on macroalgal species. This study documents the abundance and species composition of gastropod assemblages on the two largest, blade-forming Antarctic macroalgae, Himantothallus grandifolius and Sarcopeltis antarctica, sampled across two depths (9 and 18 m) at four sites for each species off Anvers Island, Antarctica. Gastropods were also enumerated on Desmarestia anceps, Desmarestia antarctica and Plocamium sp. but were not included in the main analyses because of small sample sizes. There were major differences between the gastropod assemblages on deep vs shallow H. grandifolius and S. antarctica with much higher numbers of individuals and also greater numbers of gastropod species at the greater depth. Differences between the gastropod assemblages on H. grandifolius and S. antarctica across sampling sites were apparent in non-parametric, multivariate analyses, although depth contributed more than site to these differences. Within common sites, assemblages on H. grandifolius were significantly different from those on S. antarctica at 18 m depth but not at 9 m depth, indicating that the host species can be but is not always more important than site in influencing the gastropod assemblages.

The social world contains institutions (nations, clubs), groups (races, genders), objects (talismans, borders), and more. This essay explores a puzzle about the essences of social items. There is widespread consensus against social essences because of problematic presuppositions often made about them. But it is argued that essence can be freed from these presuppositions and their problems. Even so, a puzzle still arises. In a Platonic spirit, essences in general seem detached from the world. In an Aristotelian spirit, social essences in particular seem embedded in the world. The puzzle is that these inclinations are individually plausible but jointly incompatible. The essay has four aims: to clarify and refine the puzzle; to explore the puzzle's implications for essence in general and for social essences in particular; to illustrate the fruitfulness of the general distinction between detached and embedded; and to develop this distinction to sketch a novel solution to the puzzle.

Simon Evnine’s Making Objects and Events: A Hylomorphic Theory of Artifacts develops amorphic hylomorphism. I critically discuss three of its main themes. One theme is its attempt to do the work of form without forms. A second theme is the requirement that hylomorphs have ‘metabolisms at work’. A third theme is the use of artifacts as the paradigms for hylomorphs. I will raise some criticisms of each of these themes. Although the themes might at first appear disconnected, I believe the third underwrites the first two. So the criticisms of the third theme also bear on the rest.

We investigated the positive predictive value (PPV) of a solitary positive immunoglobulin M (IgM) phase II response for the serodiagnosis of acute Q fever detected with either an indirect immunofluorescence assay (IFA) or an enzyme-linked immunosorbent assay (ELISA). Initial and follow-up sera from patients suspected of acute Q fever were included if initially only IgM phase II tested positive with IFA in 2008 (n=92), or ELISA in 2009 (n=85). A seroconversion for Q fever was defined as an initial sample being IgG phase II negative but positive in the follow-up sample. The PPV of an initial isolated IgM phase II result detected by IFA or ELISA was 65% and 51%, respectively, and therefore appeared not to adequately predict acute Q fever. For this reason it cannot be used as a diagnostic criterion nor should it be included in public health notification without confirmation with other markers or a follow-up serum sample.

On account of the serious complications of hepatitis C virus (HCV) infection and the improved treatment possibilities, the need to improve HCV awareness and case-finding is increasingly recognized. To optimize a future national campaign with this objective, three pilot campaigns were executed in three regions in The Netherlands. One campaign was aimed at the general population, a second (similar) campaign was extended with a support programme for primary care and a third campaign was specifically aimed at hard-drug users. Data from the pilot campaigns were used to build a mathematical model to estimate the incremental cost-effectiveness ratio of the different campaigns. The campaign aimed at the general public without support for primary care did not improve case-finding and was therefore not cost-effective. The similar campaign accompanied by additional support for primary care and the campaign aimed at hard-drug users emerged as cost-effective interventions for identification of HCV carriers.

Results obtained from previous longitudinal studies of reading difficulties indicate that reading deficits are generally stable. However, little is known about the etiology of this stability. Thus, the primary objective of this first longitudinal twin study of reading difficulties is to provide an initial assessment of genetic and environmental influences on the stability of reading deficits. Data were analyzed from a sample of 56 twin pairs, 18 identical (monozygotic, MZ) and 38 fraternal (dizygotic, DZ), in which at least one member of each pair was classified as reading-disabled in the Colorado Learning Disabilities Research Center, and on whom follow-up data were available. The twins were tested at two time points (average age of 10.3 years at initial assessment and 16.1 years at follow-up). A composite measure of reading performance (PIAT Reading Recognition, Reading Comprehension and Spelling) was highly stable, with a stability correlation of .84. Data from the initial time point were first subjected to univariate DeFries-Fulker multiple regression analysis and the resulting estimate of the heritability of the group deficit (h2g) was .84 (± .26). When the initial and follow-up data were then fitted to a bivariate extension of the basic DF model, bivariate heritability was estimated at .65, indicating that common genetic influences account for approximately 75% of the stability between reading measures at the two time points.

Microstreaming from oscillating bubbles is known to induce vigorous vortex flow. Here we show how to harness the power of bubble streaming in an experiment to achieve directed transport flow of high velocity, allowing design and manufacture of microfluidic MEMS devices. By combining oscillating bubbles with solid protrusions positioned on a patterned substrate, solid beads and lipid vesicles are guided in desired directions without microchannels. Simultaneously, the flow exerts controlled localized forces capable of opening and reclosing lipid membranes.

Background: The aim of this study was to perform a systematic review and meta-analysis of the literature regarding the incidence of delirium following orthopedic surgery.

Methods: Relevant papers were sourced from online databases and gray literature. Included studies used a validated diagnostic method to measure the incidence of delirium in a prospective sample of adult/elderly orthopedic patients. Data were subject to meta-analysis after stratification by type of surgery (elective v. emergency) and inclusion/exclusion of pre-existing cognitive impairment. A funnel plot assessed for publication bias.

Results: 26 publications reported an incidence of postoperative delirium of 4–53.3% in hip fracture samples and 3.6–28.3% in elective samples. Significant heterogeneity was evident, and this persisted despite stratification. Hip fracture was associated with a higher risk of delirium than elective surgery both when the cognitively impaired were included in the sample (random effects pooled estimate = 21.7% [95% CI = 14.6–28.8] vs. 12.1% [95% CI = 9.6–14.6]), and when the cognitively impaired were excluded (random effects pooled estimate = 25% [95% CI = 15.7–34.7] vs. 8.8% [95% CI = 4.1–13.6]). The funnel plot showed a deficit of small studies showing low risk and large studies showing high risk. In eight hip fracture studies, the proportion of delirium cases with a preoperative onset ranged from 34 to 92%.

Conclusions: Delirium occurs more commonly with hip fracture than elective surgery, and frequently has a preoperative onset when associated with trauma. Recommendations are made with the aim of standardizing future research in order to further explore and reduce the heterogeneity and possible publication bias observed.

The variable pressure neck chamber has provided an invaluable research tool for the non-invasive assessment of carotid baroreflex (CBR) function in human investigations. The ability to construct complete stimulus-response curves and define specific parameters of the reflex function curve permits statistical comparisons of baroreflex function between different experimental conditions, such as rest and exercise. Results have convincingly indicated that the CBR stimulus-response curve is reset during exercise in an intensity-dependent manner to functionally operate around the prevailing pressure elicited by the exercise workload. Furthermore, both at rest and during exercise, alterations in stroke volume do not contribute importantly to the maintenance of arterial blood pressure by the carotid baroreceptors, and therefore, any reflex-induced changes in cardiac output (Q) are the result of CBR-mediated changes in heart rate. However, more importantly, the CBR-induced changes in mean arterial pressure (MAP) are primarily mediated by alterations in vascular conductance with only minimal contributions from Q to the initial reflex MAP response. Thus, the capacity of the CBR to regulate blood pressure depends critically on its ability to alter vascular tone both at rest and during exercise. This review will emphasize the utility of the variable pressure neck chamber to assess CBR function in human experimental investigations and the mechanisms by which the CBR responds to alterations in arterial blood pressure both at rest and during exercise. Experimental Physiology (2003) 88.6, 671-680.

Although square-wave sustained and R wave-triggered pulsatile stimuli have been used to assess carotid baroreflex (CBR) function in humans, it remains unclear whether these different stimulus protocols elicit comparable responses and whether CBR responses adapt during prolonged stimulation. Thus, we measured muscle sympathetic nerve activity (MSNA), heart rate (HR) and mean arterial pressure (MAP) in response to +30 Torr neck pressure (NP) and -30 Torr neck suction (NS) delivered for 20 s either as a sustained or pulsatile stimulus. CBR-mediated changes in MSNA, HR and MAP were similar with sustained and pulsatile stimuli. The time course of MSNA and HR responses identified that significant changes occurred during the initial 5 s and were better maintained over 20 s with NP than with NS. Changes in MAP exhibited a slower onset with the peak increase during NP occurring at 10 s (sustained, 7 ± 1 mmHg; pulsatile, 7 ± 1 mmHg; P > 0.05) and the nadir during NS occurring at 20 s (sustained, -7 ± 1 mmHg; pulsatile, -9 ± 2 mmHg; P > 0.05). These data demonstrate that sustained and pulsatile NP and NS produce comparable CBR-mediated responses. Furthermore, despite MSNA and HR returning towards baseline during NS, CBR-mediated changes in MAP are well maintained over 20 s of NS and NP. Experimental Physiology (2003) 88.5, 595-601.

The bed-forming brittlestars Ophiothrix fragilis, Ophiocomina nigra and Amphiura chiajei from Oban Bay, Scotland were studied using methods previously employed to study chemoautotrophic symbioses. Ophiothrix fragilis and A. chiajei both contain symbiotic bacteria (SCB) while Ophiocomina nigra is non-symbiotic. Samples were taken of Ophiothrix fragilis at approximately two-week intervals for one year. Symbiotic bacteria numbers were determined by direct counting of homogenates of the arms of 50 individual brittlestars. Water samples were analysed for chlorophyll content. Stable isotope ratios for carbon and nitrogen were determined for each homogenate sample. Regular SCB counts were made on the infaunal brittlestar A. chiajei. Homogenate samples of Ophiothrix fragilis, A. chiajei and the non-symbiotic Ophiocomina nigra were analysed to produce fatty acid profiles for each species. Symbiotic bacteria count varied by up to one order of magnitude in both Ophiothrix fragilis and A. chiajei with no evidence of seasonality in this variation. Symbiotic bacteria number was inversely correlated with δ15N but no relationship was established with δ13C. 16:1ω7 and 18:1.ω7 fatty acids were used as putative bacterial markers. Both symbiotic species had higher percentages of 16:1ω7 than the non-symbiotic Ophiocomina nigra. However, only Ophiothrix fragilis appeared to receive appreciable quantities of 18:1ω7 from its SCB. The SCB are heterotrophic and may contribute to the nitrogen budget of the host. The two symbiotic species studied here derive the bulk of their nutrition from conventional feeding but SCB make significant, additional contributions.

Variation in stomatal development and physiology of mature leaves from Alnus glutinosa plants grown under reference (current ambient, 360 μmol mol−1 CO2) and double ambient (720 μmol mol−1 CO2) carbon dioxide (CO2) mole fractions is assessed in terms of relative plant growth, stomatal characters (i.e. stomatal index and density) and leaf photosynthetic characters. This is the first study to consider the effects of elevated CO2 concentration on the distribution of stomata and epidermal cells across the whole leaf and to try to ascertain the cause of intraleaf variation. In general, a doubling of the atmospheric CO2 concentration enhanced plant growth and significantly increased stomatal index. However, there was no significant change in relative stomatal density. Under elevated CO2 concentration there was a significant decrease in stomatal conductance and an increase in assimilation rate. However, no significant differences were found for the maximum rate of carboxylation (Vcmax) and the light saturated rate of electron transport (Jmax) between the control and elevated CO2 treatment.