67 research outputs found
The Response of Thalassiosira pseudonana to Long-Term Exposure to Increased CO2 and Decreased pH
The effect of ocean acidification conditions has been investigated in cultures of the diatom Thalassiosira pseudonana CCMP1335. Expected end-of-the-century pCO2 (aq) concentrations of 760 µatm (equivalent to pH 7.8) were compared with present-day condition (380 µatm CO2, pH 8.1). Batch culture pH changed rapidly because of CO2 (aq) assimilation and pH targets of 7.8 and 8.1 could not be sustained. Long-term (∼100 generation) pH-auxostat, continuous cultures could be maintained at target pH when cell density was kept low (<2×105 cells mL−1). After 3 months continuous culture, the C:N ratio was slightly decreased under high CO2 conditions and red fluorescence per cell was slightly increased. However, no change was detected in photosynthetic efficiency (Fv/Fm) or functional cross section of PS II (σPSII). Elevated pCO2 has been predicted to be beneficial to diatoms due to reduced cost of carbon concentration mechanisms. There was reduced transcription of one putative δ-carbonic anhydrase (CA-4) after 3 months growth at increased CO2 but 3 other δ-CAs and the small subunit of RUBISCO showed no change. There was no evidence of adaptation or clade selection of T. pseudonana after ∼100 generations at elevated CO2. On the basis of this long-term culture, pH change of this magnitude in the future ocean may have little effect on T. pseudonana in the absence of genetic adaption
Effect of ocean acidification and elevated fCO2 on trace gas production from the Baltic Sea summer phytoplankton community.
The Baltic Sea is a unique environment as the largest body of brackish water in the world. Acidification of the surface oceans due to absorption of anthropogenic CO2 emissions is an additional stressor facing the pelagic community of the already challenging Baltic Sea. To investigate its impact on trace gas biogeochemistry, a large-scale mesocosm experiment was performed off Tvärminne Research Station, Finland, in summer 2012. During the second half of the experiment, dimethylsulfide (DMS) concentrations in the highest-fCO2 mesocosms (1075–1333 µatm) were 34 % lower than at ambient CO2 (350 µatm). However, the net production (as measured by concentration change) of seven halocarbons analysed was not significantly affected by even the highest CO2 levels after 5 weeks' exposure. Methyl iodide (CH3I) and diiodomethane (CH2I2) showed 15 and 57 % increases in mean mesocosm concentration (3.8 ± 0.6 increasing to 4.3 ± 0.4 pmol L−1 and 87.4 ± 14.9 increasing to 134.4 ± 24.1 pmol L−1 respectively) during Phase II of the experiment, which were unrelated to CO2 and corresponded to 30 % lower Chl a concentrations compared to Phase I. No other iodocarbons increased or showed a peak, with mean chloroiodomethane (CH2ClI) concentrations measured at 5.3 (±0.9) pmol L−1 and iodoethane (C2H5I) at 0.5 (±0.1) pmol L−1. Of the concentrations of bromoform (CHBr3; mean 88.1 ± 13.2 pmol L−1), dibromomethane (CH2Br2; mean 5.3 ± 0.8 pmol L−1), and dibromochloromethane (CHBr2Cl, mean 3.0 ± 0.5 pmol L−1), only CH2Br2 showed a decrease of 17 % between Phases I and II, with CHBr3 and CHBr2Cl showing similar mean concentrations in both phases. Outside the mesocosms, an upwelling event was responsible for bringing colder, high-CO2, low-pH water to the surface starting on day t16 of the experiment; this variable CO2 system with frequent upwelling events implies that the community of the Baltic Sea is acclimated to regular significant declines in pH caused by up to 800 µatm fCO2. After this upwelling, DMS concentrations declined, but halocarbon concentrations remained similar or increased compared to measurements prior to the change in conditions. Based on our findings, with future acidification of Baltic Sea waters, biogenic halocarbon emissions are likely to remain at similar values to today; however, emissions of biogenic sulfur could significantly decrease in this region
Dermatoglyphic patterns in children with chronic constipation
Analysis of the fine ridge configurations on the digits of the palms and soles (dermatoglyphics) may sometimes help in the diagnoses of certain medical disorders. Dermatoglyphic patterns have been reported to be associated with congenital anomalies, such as congenital heart disease, duodenal ulcer, abdominal pain, and constipation. The palmar dermatoglyphic patterns of 77 children with constipation (39 functional and 38 organic constipation) were recorded. The control group consisted of 84 children with inguinal hernia. Those patients with at least one arch identified on any digit of either hand were termed arch positive. There was no significant correlation between arch positivity and constipation (functional or organic), or inguinal hernia (chi square, P =0.9211). Therefore, the presence of palmar arches cannot be used as a screening device for children with chronic constipation, especially of organic etiology.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44424/1/10620_2005_Article_BF02285186.pd
The supernatural characters and powers of sacred trees in the Holy Land
This article surveys the beliefs concerning the supernatural characteristics and powers of sacred trees in Israel; it is based on a field study as well as a survey of the literature and includes 118 interviews with Muslims and Druze. Both the Muslims and Druze in this study attribute supernatural dimensions to sacred trees which are directly related to ancient, deep-rooted pagan traditions. The Muslims attribute similar divine powers to sacred trees as they do to the graves of their saints; the graves and the trees are both considered to be the abode of the soul of a saint which is the source of their miraculous powers. Any violation of a sacred tree would be strictly punished while leaving the opportunity for atonement and forgiveness. The Druze, who believe in the transmigration of souls, have similar traditions concerning sacred trees but with a different religious background. In polytheistic religions the sacred grove/forest is a centre of the community's official worship; any violation of the trees is regarded as a threat to the well being of the community. Punishments may thus be collective. In the monotheistic world (including Christianity, Islam and Druze) the pagan worship of trees was converted into the worship/adoration of saints/prophets; it is not a part of the official religion but rather a personal act and the punishments are exerted only on the violating individual
Long‐run effects of teachers in developing countries
How persistent are teacher effects on student outcomes? In this paper we present estimates of teacher effects on long‐run student outcomes from two low‐ and middle‐ income countries. We first estimate teacher value‐added using the Young Lives School Survey data from Ethiopia and Vietnam. We then track students taught by these teachers 2 and 5 years later and use data from the Young Lives Household Surveys to estimate the effects of teacher quality. We find no persistent effect after 2 years, but better mathematics (0.08σ) and reading (0.06σ) test scores after 5 years, from being taught by a 1σ better Grade 5 teacher. We find no persistent effects of good teachers on measures of more “generalized” cognitive ability, aspirations, well‐being, or “grit.
Pulmonary rehabilitation in group 3 pulmonary hypertension: An evaluation of clinical outcomes, adherence and safety
Background: Pulmonary Rehabilitation (PR) may improve exercise tolerance and health status in patients with pulmonary hypertension groups 1 and 4 (Morris, N. et al. Cochrane database, 2017). Little is known about the effectiveness, safety or feasibility of PR in patients with group 3 pulmonary hypertension (that which is associated with lung disease), who access PR due to their underlying respiratory pathology.
Aims: To describe clinical outcomes, adherence and safety in patients with group 3 pulmonary hypertension attending a standard United Kingdom-based PR programme.
Method: A retrospective casenote review was conducted for patients with group 3 pulmonary hypertension attending PR over a 3-year period (2016-2019). Data included pre- and post-PR six-minute walk distance (6MWD), Medical Research Council breathlessness scale (MRC), COPD assessment test (CAT), patient health questionnaire-9 (PHQ-9) and generalised anxiety disorder-7 (GAD-7). Adherence and adverse events were collected.
Results: Thirty-one patients with group 3 pulmonary hypertension were enrolled in PR. There was a significant improvement in 6MWD (median change 30m; 95%CI 5, 70m p=0.023;) and MRC (median change -1.0; 95%CI -1.0, -0.5; p=0.005) following PR but no change in CAT, PHQ-9 or GAD-7.
PR completion rate was 65%. Low to medium risk adverse events did occur, most commonly, oxygen desaturation below 80%.
Conclusion: In patients with group 3 pulmonary hypertension, PR is feasible and low-risk. Significant improvements in 6MWD were achieved, although the impact on health status was less clear. The occurrence of adverse events suggests the need for extra monitoring in this patient group
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