scholarly journals Palynological analysis of faecal matter in African Forest Elephants Loxodonta cyclotis (Mammalia: Proboscidea: Elephantidae) at Omo Forest Reserve, Nigeria

2019 ◽  
Vol 11 (10) ◽  
pp. 14309-14317
Author(s):  
Okwong John Walter ◽  
Olusola Helen Adekanmbi ◽  
Omonu Clifford
Keyword(s):  
Large Scale ◽  
Epidermal Cells ◽  
Xylem Vessel ◽  
Quantitative Composition ◽  
Palynological Analysis ◽  
Factors Affecting ◽  
Faecal Matter ◽  
Foraging Preferences ◽  
Vessel Elements ◽  
Forest Elephants

The factors affecting African Forest Elephants include food availability, demand for ivory and changes in land-use. In order to survive, they tend to traverse considerable distances in search of food; on such occasions they are trapped and killed for their ivory.  This present study is aimed at assessing the faecal matter of elephants, and at providing information on the season of ingestion and foraging preferences of these elephants.  Faecal matter was collected at nine different locations for one year before being processed and subjected to standard palynological laboratory procedures.  The analyses showed that the samples had moderately abundant and diversified palynomorphs.  A total of 27 palynomorphs belonging to 22 families with a total count of 2,895 accounting for 94.34% were found to be eaten, while other plant fragments (epidermal cells, xylem vessel elements, and seeds) accounted for 5.66%.  The wet and dry seasons accounted for 73.26% and 26.74% respectively.  Epidermal cells and xylem vessel elements recorded (70.76%) and (29.2%) during the dry and wet seasons, respectively.  In the palynological analysis, pollen of Balanites wilsoniana, Desplatsia subericarpa, Chrysophyllum albidum, among others were recovered in the faecal matter.  Pollen analysis of faecal matters provided no information about the quantitative composition of the natural vegetation of elephants, but rather valuable information about their diet. It is recommended that these preferentially foraged parent plants should be cultivated on a large scale.  This would potentially reduce competition for food and movement of these animals to other greener areas, consequently leading to poaching.  

scholarly journals Structure and Biomechanics during Xylem Vessel Transdifferentiation in Arabidopsis thaliana

2020 ◽  
Author(s):  
Eleftheria Roumeli ◽  
Leah Ginsberg ◽  
Robin McDonald ◽  
Giada Spigolon ◽  
Rodinde Hendrickx ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Walls ◽  
Large Scale ◽  
Turgor Pressure ◽  
Plant Cells ◽  
Building Blocks ◽  
Xylem Vessel ◽  
Primary Cell Wall ◽  
Individual Plant ◽  
Vessel Elements

Individual plant cells are the building blocks for all plantae and artificially constructed plant biomaterials, like biocomposites. Secondary cell walls (SCWs) are a key component for mediating mechanical strength and stiffness in both living vascular plants and biocomposite materials. In this paper, we study the structure and biomechanics of cultured plant cells during the cellular developmental stages associated with SCW formation. We use a model culture system that induces transdifferentiation of Arabidopsis thaliana cells to xylem vessel elements, upon treatment with dexamethasone (DEX). We group the transdifferentiation process into three distinct stages, based on morphological observations of the cell walls. The first stage includes cells with only a primary cell wall (PCW), the second covers cells that have formed a SCW, and the third stage includes cells with a ruptured tonoplast and partially or fully degraded PCW. We adopt a multi-scale approach to study the mechanical properties of cells in these three stages. We perform large-scale indentations with a micro-compression system and nanoscale indentations through atomic force microscopy (AFM), in three different osmotic conditions. We introduce a spring-based model to deconvolve the competing stiffness contributions from turgor pressure, PCW, SCW and cytoplasm in the stiffness of differentiating cells. Prior to triggering differentiation, cells in hypotonic pressure conditions are significantly stiffer than cells in isotonic or hypertonic conditions, highlighting the dominant role of turgor pressure. Plasmolyzed cells with a SCW reach similar levels of stiffness as cells with maximum turgor pressure. The stiffness of the PCW in all of these conditions is lower than the stiffness of the fully-formed SCW. Our results provide the first experimental characterization of the mechanics of SCW formation at single cell level.

scholarly journals On the geophysical processes impacting palaeo-sea-level observations

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yusuke Yokoyama ◽  
Anthony Purcell
Keyword(s):  
Sea Level ◽  
Large Scale ◽  
Global Climate ◽  
Sea Level Change ◽  
Sea Level Changes ◽  
Factors Affecting ◽  
Ice Volume ◽  
Level Change ◽  
Recent Developments ◽  
Geophysical Processes

AbstractPast sea-level change represents the large-scale state of global climate, reflecting the waxing and waning of global ice sheets and the corresponding effect on ocean volume. Recent developments in sampling and analytical methods enable us to more precisely reconstruct past sea-level changes using geological indicators dated by radiometric methods. However, ice-volume changes alone cannot wholly account for these observations of local, relative sea-level change because of various geophysical factors including glacio-hydro-isostatic adjustments (GIA). The mechanisms behind GIA cannot be ignored when reconstructing global ice volume, yet they remain poorly understood within the general sea-level community. In this paper, various geophysical factors affecting sea-level observations are discussed and the details and impacts of these processes on estimates of past ice volumes are introduced.

scholarly journals Progress in Research on Carbon Nanotubes Reinforced Cementitious Composites

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Qinghua Li ◽  
Jintao Liu ◽  
Shilang Xu
Keyword(s):  
Carbon Nanotubes ◽  
Large Scale ◽  
High Strength ◽  
Cementitious Composites ◽  
Scale Production ◽  
Multiwalled Carbon ◽  
Factors Affecting ◽  
Environment And Health ◽  
Research Activities ◽  
Major Factors

As one-dimensional (1D) nanofiber, carbon nanotubes (CNTs) have been widely used to improve the performance of nanocomposites due to their high strength, small dimensions, and remarkable physical properties. Progress in the field of CNTs presents a potential opportunity to enhance cementitious composites at the nanoscale. In this review, current research activities and key advances on multiwalled carbon nanotubes (MWCNTs) reinforced cementitious composites are summarized, including the effect of MWCNTs on modulus of elasticity, porosity, fracture, and mechanical and microstructure properties of cement-based composites. The issues about the improvement mechanisms, MWCNTs dispersion methods, and the major factors affecting the mechanical properties of composites are discussed. In addition, large-scale production methods of MWCNTs and the effects of CNTs on environment and health are also summarized.

Species Responses to Grazing and Environmental-Factors in an Arid Halophytic Shrubland Community

1987 ◽  
Vol 35 (2) ◽  
pp. 135 ◽  
Author(s):  
RB Hacker
Keyword(s):  
Environmental Factors ◽  
Soil Salinity ◽  
Large Scale ◽  
Chemical Properties ◽  
Grazing Pressure ◽  
Aerial Photographs ◽  
Small Scale ◽  
Factors Affecting ◽  
Species Responses

Species responses to grazing and environmental factors were studied in an arid halophytic shrubland community in Western Australia. The grazing responses of major shrub species were defined by using reciprocal averaging ordination of botanical data, interpreted in conjunction with a similar ordination of soil chemical properties and measures of soil erosion derived from large-scale aerial photographs. An apparent small-scale interaction between grazing and soil salinity was also defined. Long-term grazing pressure is apparently reduced on localised areas of high salinity. Environmental factors affecting species distribution are complex and appear to include soil salinity, soil cationic balance, geomorphological variation and the influence of cryptogamic crusts on seedling establishment.

Factors affecting post-fire seedling establishment of selected mallee understorey species

2000 ◽  
Vol 48 (1) ◽  
pp. 59 ◽  
Author(s):  
J. S. Cohn ◽  
R. A. Bradstock
Keyword(s):  
Large Scale ◽  
Prescribed Burning ◽  
New South ◽  
Eucalyptus Species ◽  
Factors Affecting ◽  
Acacia Species ◽  
Introduced Herbivores ◽  
South Wales ◽  
Rabbit Grazing ◽  
Seedling Germination

Factors affecting the survival of post-fire germinants in mallee communities, in central western New South Wales, were examined. Experiments compared the relative effects of native and introduced herbivores (kangaroos, goats, rabbits), after small- and large-scale fires (20–50 and > 10 000 ha, respectively), with particular emphasis on edge effects, seedling clustering, topography and eucalypt canopy presence. The experiments (1985–1997) focused on common understorey species Acacia rigens Cunn. ex Don, A. wilhelmiana F.Muell. and Triodia scariosa N.T.Burb. subsp. scariosa, in mallee dominated by Eucalyptus species. Following a large fire (1985), high spring rainfall and rabbit grazing on A. rigens only, survival of Acacia species and T. scariosa remained relatively high 4 years later (60–70%). After small burns (1987, 1988), low spring rainfall and grazing by rabbits and kangaroos, survival of Acacia species declined to between 0 and 30% of the germinants by the second summer. In most cases, local extinction had occurred within 8 years. After small burns (1988, 1989) and low spring rainfall, the survival of T. scariosa declined to between 0 and 35% of germinants by the second summer (effect of grazing unknown). No consistent effect of edge, topography and eucalypt canopy was found. Survival of clustered Acacia seedlings was between 10 and 20% lower than unclustered seedlings. Given the high frequency of low rainfall and its interaction with grazing, prescribed burning of mallee for wildfire control and nature conservation may require the local elimination of rabbits and a reduction in kangaroo numbers, especially in the first spring and summer following seedling germination.

scholarly journals Analysis of Factors Influencing Effective Utilization Coefficient of Irrigation Water in the Manas River Basin

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 189
Author(s):  
Lili Yang ◽  
Tong Heng ◽  
Guang Yang ◽  
Xinchen Gu ◽  
Jiaxin Wang ◽  
...  
Keyword(s):  
Irrigation Water ◽  
Large Scale ◽  
Grey Model ◽  
Analytic Hierarchy ◽  
Effective Utilization ◽  
Factors Affecting ◽  
Factors Influencing ◽  
Utilization Coefficient ◽  
Using Data ◽  
Effective Use

The factors influencing the effective utilization coefficient of irrigation water are not understood well. It is usually considered that this coefficient is lower in areas with large-scale irrigation. With this background, we analyzed the effective utilization coefficient of irrigation water using the analytic hierarchy process using data from 2014 to 2019 in Shihezi City, Xinjiang. The weights of the influencing factors on the effective utilization coefficient of irrigation water in different irrigation areas were analyzed. Predictions of the coefficient’s values for different years were made by understanding the trends based on the grey model. The results show that the scale of the irrigation area is not the only factor determining the effective utilization coefficient of irrigation water. Irrigation technology, organizational integrity, crop types, water price management, local economic level, and channel seepage prevention are the most critical factors affecting the effective use of irrigation water. The grey model prediction results show that the effective utilization coefficient of farmland irrigation water will continuously increase and reach 0.7204 in 2029. This research can serve as a reference for government authorities to make scientific decisions on water-saving projects in irrigation districts in terms of management, operation, and investment.

The State of Irrigation Infrastructure in Ghana: The Way Forward

2018 ◽  
Vol 1 (1) ◽  
pp. 54-67
Author(s):  
P. Glitse ◽  
B. V. Nyamadi ◽  
K. W. Darkwah ◽  
K. A. Mintah
Keyword(s):  
Water Management ◽  
Large Scale ◽  
Irrigated Agriculture ◽  
Energy Access ◽  
Agricultural Water ◽  
Agricultural Water Management ◽  
Irrigation Development ◽  
Factors Affecting ◽  
Cost Of Energy ◽  
Irrigation Infrastructure

The Ghana Irrigation Development Authority (GIDA) is a public sector organization established to promote agricultural growth through the provision of irrigation infrastructure and other agricultural water management techniques. Irrigated agriculture in Ghana is categorized into formal, informal or smallholder and large-scale commercial irrigation. Over the years, irrigation development in the country has been faced with a number of challenges, which necessitated the development of the National Irrigation Policy, Strategies and Regulatory Measures and the Ghana Agricultural Water Management Pre-Investment Reform Action Framework. A number of factors affecting irrigation development in the country include lack of capital, commitment by successive governments, cost of energy, access to land and credit, lack of technical know-how and encroachment, among others. Analysis of budget provided by government for public irrigation development was carried out using simple linear regression. Results indicate a bright prospect of irrigation development, with reforms under implementation. A minimum of GHS 633.43 million is required for release into the sub-sector by government together with investments from private sector in the next ten years to shift the balance towards positive growth. To solve the problem of inadequate funding of the sub-sector activities, it is recommended that the GIDA collaborates with Development Partners to fund projects and activities in line with their objectives. GIDA should develop effective programmes for building capacity of contractors involved in development of infrastructure. GIDA should deepen its collaboration with private investors under PPPs and convert electric and diesel/petrol powered irrigation pumps to solar powered ones.

Neurofeedback for Opioid Dependent Patients in an Outpatient Setting: A Pilot Feasibility Study

2021 ◽  
Author(s):  
Helena A. Rempala ◽  
Justin A. Barterian
Keyword(s):  
Large Scale ◽  
The United States ◽  
Outpatient Setting ◽  
Opioid Use Disorder ◽  
High Rate ◽  
Treatment Center ◽  
Opioid Use ◽  
Treatment As Usual ◽  
Factors Affecting ◽  
Study Approach

Abstract Background: Neurofeedback (NF) has been described as “probably efficacious” when used in conjunction with other interventions for substance use disorders, including the most recent studies in population of individuals with opioid use disorder. Despite these promising outcomes, the seriousness of the opioid epidemic, and the high rate of relapse even with the most effective medication-assisted maintenance treatments NF continues to be an under-researched treatment modality. This article explores factors that affected the feasibility of adding Alpha/Theta Neurofeedback to treatment as usual for opioid dependence in an outpatient urban treatment center. The study strived to replicate previous research completed in Iran that found benefits of NF for opioid dependence.Methods: Out of approximately two dozen patients eligible for Alpha/Theta NF, about 60% (n=15) agreed to participate; however, only 2 participants completed treatment. The rates of enrollment in response to active treatment were monitored. Results: The 4 factors affecting feasibility were: 1) the time commitment required of participants, 2) ineffectiveness of standard incentives to promote participation, 3) delayed effects of training, and 4) the length and number of treatments required.Conclusion: The findings indicate a large scale study examining the use of NF for the treatment of opioid use disorder in the United States will likely be difficult to accomplish without modification to the traditional randomized control study approach and suggests challenges to the implementation of this treatment in an outpatient setting.

scholarly journals Epilithic community development on artificial reefs deployed along a cross-shelf environmental gradient off Paraná state, southern Brazil

2011 ◽  
Vol 59 (spe1) ◽  
pp. 43-53 ◽  
Author(s):  
Frederico Brandini ◽  
Ariel Scheffer da Silva
Keyword(s):  
Large Scale ◽  
Diversity Index ◽  
Artificial Reef ◽  
Larval Abundance ◽  
Percent Cover ◽  
Southern Brazil ◽  
Factors Affecting ◽  
Hydrographic Conditions ◽  
One Year ◽  
General Community

Concrete modules were deployed on the bottom of the 11, 18 and 30 meters isobaths along a cross-shelf hydrographic gradient off Paraná State, Southern Brazil, with the purpose of studying the colonization of sessile epilithic macroinvertebrates on artificial surfaces. After one year of submersion a total of 63 species of epilithic organisms were identified, dominated by Ostrea puelchana, Chthamalus bisinuatus, Balanus cf spongicola, Astrangia cf rathbuni, Didemnum spp, poryphers and bryozoans. Diversity index and percent cover at reef stations placed at 11, 18 and 30 meters isobaths were respectively 2.28 and 66.7%, 2.79 and 96.6% and 1.66 and 77.4%. Differences of general community structure among the three assemblages were not clearly related to the general environmental conditions at the bottom layers near the reef stations. Turbidity and larval abundance are discussed as important factors affecting colonization processes. Results indicate that depths between 15-20 meters are more suitable for the implementation of large scale artificial reef systems in the inner shelf off Paraná and, possibly, throughout the inner shelves off southern Brazil with similar hydrographic conditions.

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