scholarly journals Localized Augmentation of Net Precipitation to Shrubs: A Case Study of Stemflow Funneling to Hummocks in a Salinity-Intruded Swamp

2021 ◽  
Vol 4 ◽  
Author(s):  
Scott T. Allen ◽  
William H. Conner

The interception of precipitation by plant canopies can alter the amount and spatial distribution of water inputs to ecosystems. We asked whether canopy interception could locally augment water inputs to shrubs by their crowns funneling (freshwater) precipitation as stemflow to their bases, in a wetland where relict overstory trees are dying and persisting shrubs only grow on small hummocks that sit above mesohaline floodwaters. Precipitation, throughfall, and stemflow were measured across 69 events over a 15-months period in a salinity-degraded freshwater swamp in coastal South Carolina, United States. Evaporation of intercepted water from the overstory and shrub canopies reduced net precipitation (stemflow plus throughfall) across the site to 91% of gross (open) precipitation amounts. However, interception by the shrub layer resulted in increased routing of precipitation down the shrub stems to hummocks – this stemflow yielded depths that were over 14 times larger than that of gross precipitation across an area equal to the shrub stem cross-sectional areas. Through dimensional analysis, we inferred that stemflow resulted in local augmentation of net precipitation, with effective precipitation inputs to hummocks equaling 100–135% of gross precipitation. Given that these shrubs (wax myrtle, Morella cerifera) are sensitive to mesohaline salinities, our novel findings prompt the hypothesis that stemflow funneling is an ecophysiologically important mechanism that increases freshwater availability and facilitates shrub persistence in this otherwise stressful environment.

Author(s):  
Yongkai Zhou ◽  
Jie Zhu ◽  
Han Wei Teo ◽  
ACT Quah ◽  
Lei Zhu ◽  
...  

Abstract In this paper, two failure analysis case studies are presented to demonstrate the importance of sample preparation procedures to successful failure analyses. Case study 1 establishes that Palladium (Pd) cannot be used as pre-FIB coating for SiO2 thickness measurement due to the spontaneously Pd silicide formation at the SiO2/Si interface. Platinum (Pt) is thus recommended, in spite of the Pt/SiO2 interface roughness, as the pre-FIB coating in this application. In the second case study, the dual-directional TEM inspection method is applied to characterize the profile of the “invisible” tungsten residue defect. The tungsten residue appears invisible in the planeview specimen due to the low mass-thickness contrast. It is then revealed in the cross-sectional TEM inspection.


2021 ◽  
Vol 14 ◽  
pp. 194008292110281
Author(s):  
Elène Haave-Audet ◽  
Doris Audet ◽  
Michelle Monge-Velazquez ◽  
Eleanor Flatt ◽  
Andrew Whitworth

Introduction: Background and Research Aims: Assessing biodiversity recovery is key to determine whether the objectives of habitat restoration for conservation are met. Many restoration initiatives use cross-sectional comparisons of wildlife communities to infer restoration impact instead of longitudinal assessments from a baseline state. Using an indicator of biodiversity in the neotropics— bats— we demonstrate how assessing community diversity and composition in an area targeted for restoration prior to implementation, and when compared to surrounding intact forest, provides the groundwork to track changes in the community post-restoration. Methods We assessed bat communities by 1) using mist-net surveys to identify species in the family Phyllostomidae (leaf-nosed bats), and 2) conducting acoustic surveys to identify non-phyllostomid species (aerial insectivores). Results For both groups, we found that areas targeted for restoration had similar diversity as the surrounding forest, but the two habitat types differed in community composition. Phyllostomids were captured at higher rates in forest, but aerial insectivores were detected at higher rates in restoration habitat. Conclusion Our baseline assessment revealed unexpected diversity in areas targeted for restoration. The presence of all trophic groups in restoration habitat suggests that bats provide key ecosystem services in the restoration process, such as through seed dispersal, pollination and insect pest control. Implications for Conservation: Conducting a baseline survey of bats in areas targeted for restoration demonstrated that the community was not species poor at the baseline and was different from the surrounding forest, allowing us to better track restoration success and the effects of different restoration treatments.


2021 ◽  
Vol 14 ◽  
pp. 117863292110192
Author(s):  
Minh Van Hoang ◽  
Anh Tuan Tran ◽  
Trang Thu Vu ◽  
Tuan Kim Duong

This study examined the coronavirus disease 2019 (COVID-19) preparedness and response of the health system (HS) in Hanoi, Vietnam, and identified enabling factors and barriers. This cross-sectional, mixed-methods study was conducted in 4 urban and peri-urban districts that included some wards with COVID-19-positive cases and some without. The US Centers for Disease Control and Prevention (CDC) analytical frameworks were used. Overall, 10% of health facilities (HFs) failed to fully implement COVID-19 risk determination; 8.8% failed to fully implement stronger community partnerships with local stakeholders to support public health (PH) preparedness; 35% and 2.5% incompletely implemented and did not implement evaluation of PH emergency operations, respectively; 10% did not identify communication channels to issue public information, alerts, warnings, and notifications; 25% incompletely implemented identification, development of guidance, and standards for information; 72.5% had good preventive and treatment collaboration; and 10% did not fully implement procedures for laboratory testing and reporting results. Enablers included sufficient infrastructure and equipment, strong leadership, and good cross-public-sector collaboration with police and military forces. Barriers included workforce constraints, overburdened and inconsistent reporting systems, inappropriate financial mechanisms, ambiguous health governance, and lack of private-sector engagement. Nonetheless, the HS preparedness and response were satisfactory, although further coordinated efforts in evaluation, coordination, communication, and volunteering remain necessary.


2014 ◽  
Vol 6 (1) ◽  
pp. 128-148 ◽  
Author(s):  
Stephen K. Nkundabanyanga ◽  
Charles Omagor ◽  
Irene Nalukenge

Purpose – The purpose of this paper is to examine the effect of the fraud triangle, Machiavellianism, academic misconduct and corporate social responsibility (CSR) proclivity of students. Design/methodology/approach – The present study surveyed 471 university students. The study was cross-sectional and employed structural equation modelling in statistical modelling. Findings – The study provides evidence that perceived opportunity to cheat in examinations is the single most important factor accounting for significant variations in rationalization and academic misconduct. Similarly, low Machiavellians significantly get inclined to CSR ideals. The fraud triangle alone accounts for 36 per cent of the variations in academic misconduct, hence the error variance is 64 per cent of academic misconduct itself. This error variance increases to 78 per cent when a combination of perceived opportunity, rationalization, Machiavellianism is considered. Moreover, both Machiavellianism and academic misconduct account for 17 per cent of variations in students’ proclivity to CSR ideals. Research limitations/implications – Results imply that creating a setting that significantly increases a student's anticipated negative affect from academic misconduct, or effectively impedes rationalization ex ante, might prevent some students from academic misconduct in the first place and then they will become good African corporate citizens. Nevertheless, although the unit of analysis was students, these were from a single university – something akin to a case study. The quantitative results should therefore be interpreted with this shortcoming in mind. Originality/value – This paper contributes to the search for predictors of academic misconduct in the African setting and as a corollary, for a theory explaining academic misconduct. Those students perceiving opportunity to cheat in examinations are also able to rationalize and hence engage in academic misconduct. This rationalization is enhanced or reduced through Machiavellianism.


Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1166 ◽  
Author(s):  
Łukasz Przyborowski ◽  
Anna Łoboda ◽  
Robert Bialik

Long-duration measurements were performed in two sandy bed rivers, and three-dimensional (3D) flow velocity and bottom elevation changes were measured in a vegetated area and in a clear region of a river. Detailed flow velocity profiles downstream and upstream of a single specimen of Potamogeton pectinatus L. were obtained and the bed morphology was assessed. Potamogeton plants gathered from each river were subjected to tensile and bending tests. The results show that the existence of the plants was influenced by both bottom and flow conditions, as the plants were located where water velocity was lower by 12% to 16% in comparison to clear region. The characteristics of the flow and sand forms depended on the cross-sectional arrangement of the river, e.g., dunes were approximately four times higher in the middle of the river than in vegetated regions near the bank. Furthermore, the studied hydrophytes were too sparse to affect water flow and had no discernible impact on the sand forms’ movements. The turbulent kinetic energy downstream of a single plant was reduced by approximately 25%. Additionally, the plants’ biomechanical characteristics and morphology were found to have adjusted to match the river conditions.


2018 ◽  
Vol 4 (2) ◽  
pp. 1 ◽  
Author(s):  
Angelica Campigotto ◽  
Stephane Leahy ◽  
Ayan Choudhury ◽  
Guowei Zhao ◽  
Yongjun Lai

A novel, inexpensive, and easy-to-use strain sensor using polydimethylsiloxane (PDMS)  was developed. The sensor consists of a microchannel that is partially filled with a coloured liquid and embedded in a piece of PDMS. A finite element model was developed to optimize the geometry of the microchannel to achieve higher sensitivity. The highest gauge factor that was measured experimentally was 41. The gauge factor was affected by the microchannel’s square cross-sectional area, the number of basic units in the microchannel, and the inlet and outlet configuration. As a case study, the developed strain sensors were used to measure the rotation angle of the wrist and finger joints.


2017 ◽  
Vol 7 (4) ◽  
pp. 87
Author(s):  
James K. Sirite ◽  
Henry Ongori ◽  
Darius Bosire

The purpose of this study was to identify the challenges faced in quality service delivery to Turkana Central Sub-county citizens of Turkana County. The study used cross-sectional survey design. The sample size selected for the study was 261.  Data was collected using questionnaires and interview guides. Data was analyzed by descriptive statistics and presented in tables and figures for ease interpretation. The major findings of the study show that devolved governance faces some challenges. For instance the devolved governance is faced with corruption, lack of transparency and accountability and inadequate funds. This adversely   affects quality service delivery to its citizens. The findings of the study would inspire policy makers at the county and national government level to come up with appropriate strategies to mitigate the challenges identified in order to improve the quality of services offered by the county governments.


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