scholarly journals Structure of molluscan assemblages in sheltered intertidal unconsolidated environments

2005 ◽  
Vol 48 (5) ◽  
pp. 825-839 ◽  
Author(s):  
Márcia Regina Denadai ◽  
Antonia Cecilia Zacagnini Amaral ◽  
Alexander Turra

The molluscan macrofauna from 13 oceanic sheltered intertidal unconsolidated environments and its relationship with abiotic factors were studied in order to establish the degree of species richness and to understand the role environment plays in structuring such assemblages. Four distinct intertidal habitat types were recognized based on molluscan assemblage descriptors (diversity, richness and density) and abiotic characteristics. The mean grain size (in phy units) and the beach slope showed a negative relationship with the diversity, richness and density. Coarser sediments were favorable to molluscan fauna in the study areas, contrasting the well-known negative effect of this type of sand on fauna in typical oceanic beaches. The low-tide terraces, typical from tide-dominated areas, and the presence of physical (rocky fragments) and biogenic (gravel) structures, were also associated to the higher values of richness. The high richness in the study area as a whole seemed to be a direct consequence of its environmental heterogeneity, once it was composed by quite distinct habitat types.

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
S Cardoso Torres ◽  
CX Resende ◽  
PG Diogo ◽  
P Araujo ◽  
RA Pinto ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Adults with repaired aortic coarctation (CoA) require lifelong follow-up due to late complications, including left ventricular (LV) myocardial dysfunction. Age at the time of CoA repair is an important prognostic factor in these patients (pts). Purpose To evaluate LV size, ejection fraction (EF) and global longitudinal strain (GLS) values using 2D speckle tracking echocardiography (STE) in a population of adult pts with repaired CoA and to assess the relationship between these echocardiographic parameters and age at the time of CoA repair. Methods Retrospective analysis of adult pts with repaired CoA, followed in a Grown Up Congenital Heart Disease Centre. Pts with hemodynamically significant concomitant cardiac lesions were ruled out. Epidemiologic and clinical data were obtained from clinical records. Transthoracic echocardiograms were reviewed in order to assess GLS using 2DSTE (Echopac Software, GE). Results The study population consisted of 63 pts (61.9% male), with a mean age of 35.3 years at the time of the echocardiographic evaluation. The mean age at the time of the CoA repair was 117 months (95% CI 89.8-144.1 months). Surgical repair was performed in 46 pts (73%): resection with subclavian artery flap aortoplasty (n = 21); patch aortoplasty (n = 15) and head-to-head anastomosis (n = 10). In 10 pts there was no data regarding the type of surgical repair. Seven pts (11.1%) were submitted to percutaneous intervention (6 with aortic stent implantation and 1 with balloon aortic angioplasty). Mean LVEF was 63.4% (CI 95% 55.6 – 71.2%) and mean LV end-diastolic diameter (LVEDD) was 50mm (CI 95% 43-57mm). Mean GLS was - 17.3 (CI 95% 14.8- 19.8), which is inferior to the mean normal values reported for the software used. Age at the time of CoA repair had a statistically significant positive linear relationship with LVEDD (r= 0.282; p= 0.026) and a linear negative relationship with both GLS (r= -0,29; p= 0.022) and LVEF (r= -0.33; p= 0.05). Conclusion Older age at the time of CoA repair was associated with increased LVEDD and decreased GLS and LVEF. Also, GLS may be an important tool for the identification of subclinical LV dysfunction in adult pts with repaired CoA.


2008 ◽  
Vol 56 (3) ◽  
pp. 272 ◽  
Author(s):  
Zhi Y. Yuan ◽  
Han Y. H. Chen ◽  
Ling H. Li

Nitrogen use efficiency (NUE) can be divided into two components, i.e. N productivity (A) and the mean residence time (MRT). Controlled experiments indicate that there is not a trade-off between A and MRT within species, but this theory has not been well tested in field conditions. Here, we studied the A, MRT and NUE of Stipa krylovii Roshev. in a grassland over 4 years of N fertilisation experimentation. The three parameters (A, MRT and NUE) were significantly related to soil N supply and there was a negative relationship between A and MRT within this species (r = –0.775, P < 0.05), i.e. plants with higher A had lower MRT. Our results showed a trade-off between A and MRT within this Stipa species and this observed trade-off was attributed to different responses of A and MRT to soil fertility.


2021 ◽  
pp. 104346312110155
Author(s):  
Markus Tepe ◽  
Fabian Paetzel ◽  
Jan Lorenz ◽  
Maximilian Lutz

Income redistribution with an efficiency loss is expected to have a twofold negative effect on support for redistribution, as it lowers egoistic support for redistribution and activates efficiency preferences. This study tests whether such a negative relationship exists, increases with the size of efficiency loss and interacts with group communication and the income position. We present a laboratory experiment in which subjects receive a randomly allocated income and must coordinate on a majority tax rate using a deliberative communication tool. The rate of money lost as a part of the redistribution process is manipulated as a treatment variable (0%, 5%, 20%, or 60%). Experimental evidence shows that efficiency loss exerts a robust negative effect on support for redistribution. The effect shows a tipping point pattern, is stronger at the lower end of the income distribution and is not fully explained by egoistic preferences. Inefficiency matters mostly for the chosen tax rate after group communication. At an efficiency loss of 60%, however, group communication does not affect support for redistribution, which implies that inefficiencies tend to play a minor role in the context of redistribution as long as they are within a moderate range. JEL Classification: C91, C92, D63, D72


2021 ◽  
pp. 089976402199166
Author(s):  
Hans-Peter Y. Qvist

The nature of the relationship between the time people spend on paid work and volunteering remains debated in the social sciences. Time constraint theory suggests a negative relationship because people can allocate only as much time to volunteering as their work responsibilities permit. However, social integration theory suggests a more complex inverse U-shaped relationship because paid work not only limits people’s free time but also plays a key role in their social integration. Departing from these competing theories, this study uses two-wave panel data from Denmark to examine the relationship between hours of paid work and volunteering. In support of time constraint theory, the results suggest that hours of paid work have a significant negative effect on the total number of hours that people spend volunteering, not mainly because paid work hours affect people’s propensity to volunteer but because they affect the number of hours that volunteers contribute.


2021 ◽  
Vol 56 (19) ◽  
pp. 11237-11247 ◽  
Author(s):  
Johannes Pötschke ◽  
Manisha Dahal ◽  
Mathias Herrmann ◽  
Anne Vornberger ◽  
Björn Matthey ◽  
...  

AbstractDense (Hf, Ta, Nb, Ti, V)C- and (Ta, Nb, Ti, V, W)C-based high-entropy carbides (HEC) were produced by three different sintering techniques: gas pressure sintering/sinter–HIP at 1900 °C and 100 bar Ar, vacuum sintering at 2250 °C and 0.001 bar as well as SPS/FAST at 2000 °C and 60 MPa pressure. The relative density varied from 97.9 to 100%, with SPS producing 100% dense samples with both compositions. Grain size measurements showed that the substitution of Hf with W leads to an increase in the mean grain size of 5–10 times the size of the (Hf, Ta, Nb, Ti, V,)C samples. Vacuum-sintered samples showed uniform grain size distribution regardless of composition. EDS mapping revealed the formation of a solid solution with no intermetallic phases or element clustering. X-ray diffraction analysis showed the structure of mostly single-phase cubic high-entropy carbides. Hardness measurements revealed that (Hf, Ta, Nb, Ti, V)C samples possess higher hardness values than (Ta, Nb, Ti, V, W)C samples.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Bahareh Honari ◽  
Seyed Mehran Homam ◽  
Maryam Nabipour ◽  
Zahra Mostafavian ◽  
Arezou Farajpour ◽  
...  

Abstract Background Epilepsy is one of the most common neurological disorders with physical, emotional, and social consequences. Previous studies indicate that epilepsy symptoms can highly affect the epileptic patients’ satisfaction in life. The aim of the present study is to investigate the QOL of People with Epilepsy (PWE) in Khorasan Razavi province, Iran. Methods In this study, 100 patients were randomly selected. After confirmation of the diagnosis of epilepsy by neurologists and fulfilling the entrance criteria, patients completed the Quality of Life in Epilepsy-31 inventory (QOLIE-31) questionnaire. Finally, data was analyzed statistically by SPSS software. Results The study sample comprised 100 PWE, aged 18–74 years (34 ± 13), of whom 58 (58%) were females. Tonic-colonic seizure was the most common (60%) type of seizure. The obtained score of each subscale and the range of the QOLIE-31 total score was 16.40–79.18 with the mean of 50 (SD = 16). The energy-fatigue subscale score was significantly higher in patients younger than 35 (p = 0.018). The data analysis showed that the seizure worry subscale was significantly higher in single patients (p = 0.04). Duration of epilepsy had a positive correlation with QOLIE-31 total score (p = 0.038), and a negative relationship with energy-fatigue subscale (p = 0.018). In contrast with previous studies, which reported the frequency of the epileptic episodes as the most important predictor of QOL, our results showed no significant correlation between the number of the episodes and overall QOL score (p = 0.063). However, the number of episodes was significantly correlated with emotional well-being and cognition subscales. Furthermore, the results indicated that poor QOL score is correlated with depressed mood. Conclusion In fact, the ultimate and preferred outcome of all treatments and care interventions is the patient’s QOL. Thus, improvement of the QOL by means of obtaining more information about its contributing factors, in PWE should be one of the main goals in the patients’ treatment.


Author(s):  
Maty Konte ◽  
Gideon Ndubuisi

Abstract Several existing studies have documented a negative relationship between firm financial constraint and export activities but do not attempt to examine factors that could attenuate this relationship in Africa. In this paper, we examine the effect of financial constraint on exports in Africa and explore how the level of trust in countries where firms are located shapes this relationship. We combine the World Bank Enterprise Surveys with different measures of country-level personal and interpersonal trust computed from the Afrobarometer surveys of 19 African countries. Our results show that financial constraints negatively affect export activities. However, this negative effect is attenuated for firms that are located in trust-intensive societies. These findings are robust to different specifications. Interestingly, we find that small and medium-sized enterprises in Africa are more likely to be affected by financial constraints but also more likely to benefit from a higher level of both personal and interpersonal trust, while for larger firms only interpersonal trust matters.


2021 ◽  
pp. 1-19
Author(s):  
Maciej Sychowiec ◽  
Monika Bauhr ◽  
Nicholas Charron

Abstract While studies show a consistent negative relationship between the level of corruption and range indicators of national-level economic performance, including sovereign credit ratings, we know less about the relationship between corruption and subnational credit ratings. This study suggests that federal transfers allow states with higher levels of corruption to retain good credit ratings, despite the negative economic implications of corruption more broadly, which also allows them to continue to borrow at low costs. Using data on corruption conviction in US states and credit ratings between 2001 and 2015, we show that corruption does not directly reduce credit ratings on average. We find, however, heterogeneous effects, in that there is a negative effect of corruption on credit ratings only in states that have a comparatively low level of fiscal dependence on federal transfers. This suggest that while less dependent states are punished by international assessors when seen as more corrupt, corruption does not affect the ratings of states with higher levels of fiscal dependence on federal revenue.


2020 ◽  
Vol 96 (12) ◽  
Author(s):  
Hang Qian ◽  
Chunli Hou ◽  
Hao Liao ◽  
Li Wang ◽  
Shun Han ◽  
...  

ABSTRACT To seek how soil biotic and abiotic factors which might shape the Bdellovibrio-and-like-organisms community, we sampled paddy soils under different fertilization treatments including fertilization without nitrogen (Control), the nitrogen use treatment (N) and the nitrogen overuse one (HNK) at three rice growing stages. The abundances of BALOs were impacted by the rice-growing stages but not the fertilization treatments. The abundances of Bdellovibrionaceae-like were positively associated with soil moisture, which showed a negative relationship with Bacteriovoracaceae-like bacteria. High-throughput sequencing analysis of the whole bacterial community revealed that the α-diversity of BALOs was not correlated with any soil properties data. Network analysis detected eight families directly linked to BALOs, namely, Pseudomonadaceae, Peptostreptococcaceae, Flavobacteriaceae, Sediment-4, Verrucomicrobiaceae, OM27, Solirubrobacteraceae and Roseiflexaceae. The richness and composition of OTUs in the eight families were correlated with different soil properties, while the evenness of them had a positive effect on the predicted BALO biomass. These results highlighted that the bottom-up control of BALOs in paddy soil at least partially relied on the changes of soil water content and the diversity of bacteria directly linked to BALOs in the microbial network.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alejandro Gil-Betacur ◽  
Carmen Yulieth Mantilla-Gutiérrez ◽  
Jaiberth Antonio Cardona-Arias

AbstractThe effects of platelet donation by apheresis on different parameters of the erythrogram are still unclear. The objective was to meta-analyze the effect of plateletpheresis on hematocrit, hemoglobin, and erythrocyte count, with a systematic review with random effects meta-analysis of the mean difference. The PRISMA guidelines were considered, as well as 133 search strategies on four different databases. Reproducibility was guaranteed and methodological quality was evaluated. Heterogeneity was evaluated with Galbraith and DerSimonian-Laird’s, publication bias with a funnel plot and a Begg’s test, sensitivity analysis and a cumulative meta-analysis were also conducted. Eighteen (18) articles were included, 17 evaluated the effects on hematocrit in 2,564 donors; 13 on hemoglobin in 1,640 donors; and 4 on red blood cell count in 243 donors. A decrease of 2.26% (CI95% = 2.11–2.41) was observed in hematocrit, of 0.80 g/dL (CI95% = 0.75–0.86) in hemoglobin and −0.21 × 1012/L (CI95% = −0.13; −0.29) in red blood cell count. Plateletpheresis has a negative effect on the erythrogram parameters, explained by blood loss in the kits used for the procedure and cell lysis. Such evidence is relevant to secure the efficiency and safety of the procedure, improve selection processes or determine the number of donations that can be performed without affecting donors’ health.


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