262 research outputs found
Comparison Of Butterfly Diversity In Natural, Semi-Natural And Human-Modified Ecosystems At Kundamankadavu,Thiruvananthapuaram, Kerala, South India .
Among insects, butterflies are the most taxonomically studied group and play key role in ecosystem as pollinators and bioindicator species. The diversity of butterflies inhabiting at Kundamankadavu, Vilavoorkal Panchayath, Thiruvananthapuram was recorded through a Pollard walk method by traversing slowly and observing within 5m radius of the observer for the period of November 2019 to March 2020. Three different ecosystems such as natural, semi-natural and human-modified ecosystems were evaluated for analysis of the diversities of butterfly species. The maximum diversity was observed in the natural ecosystem. A total of 15 species were observed across the three habitat types during the study period. Maximum number of butterflies were observed in natural ecosystem (6) followed by human-modified (5) and minimum in semi-natural ecosystem (4) respectively. Out of these, members belonging to the family Nymphalidae was the most common with 6 species being recorded accounting for 34% of total species. The study area is rich in butterfly diversity and further research could be conducted to obtain more details and documentation on butterfly diversity for the conservation and butterfly park. As the population of these insects decline rapidly due to human activities, habitat destruction, uses of pesticides and unawareness of people about the importance of butterflies, appropriate measures should be adopted for their protection
EFFECT OF PRE EXAMINATION STRESS ON OLFACTORY SENSITIVITY IN COLLEGE STUDENTS.
Ă‚Â Objective: The present study was undertaken to assess the effect of pre-examination stress on olfactory sensitivity in college students.Methods: A total of 80 apparently healthy males and females were included in the study after obtaining written informed consent. Blast injection method was used to measure the olfactory sensitivity.Result: In the present study, we have observed decrease in the olfactory sensitivity in both males and females during pre-examination stress. However, it is not statistically significant.Conclusion: We recommend further detailed studies for better understanding the links between stress and olfaction.Ă‚
Distinct Regulation of pH in the Cytosol and in Acidic Organelles by a Subunit Isoforms of V-ATPase in Human Cancer Cells
Assessment of rainwater management practices and land use land cover changes in the Meja watershed of Ethiopia
Poor rainwater management (RWM) practices and resultant problems of land degradation and low water productivity are severe problems in the rural highlands of Ethiopia. The current study was undertaken at Meja watershed, which is located in the Jeldu district of Oromia region. The study investigated rainwater management practices and associated socio-economic and biophysical conditions in the watershed. The existing RWM interventions, their extent and the nature of changes in land use and land cover (LULC) conditions were mapped and evaluated. Results indicated that over the two decades between 1990 and 2010 there was an increase in the extent of cultivated land and large expansion in eucalyptus plantation at the expense of natural forest and grazing lands. Results indicate that, with few exceptions of RWM interventions practised, there were mainly poor and inefficient rainwater management practices. The overall effect leads to inadequacy of water for household consumption, livestock and for intensifying agricultural production via small scale irrigation systems. Deforestation and poor resource management resulted in soil degradation, reduction of hydrological regimes and water productivities in the watershed
Effects of Traditional Range Enclosures and Seasonality on Herbaceous Plants Biodiversity in Southern Ethiopia
Urban Termites of Recife, Northeast Brazil (Isoptera)
This study surveyed the termite fauna in urban properties of the city of Recife, state of Pernambuco, northeastern Brazil. Six-hundred properties were inspected in search for termites or signs of their activity, such as abandoned nests, galleries on walls, and fecal pellets. Seven termite species, belonging to seven genera and three families (Kalotermitidae, Rhinotermitidae, and Termtidae) were found causing some type of damage. Nasutitermes corniger and Cryptotermes dudleyi were the most frequent species within buildings (82.4% and 9.5 %, respectively). Such species, along with Coptotermes gestroi, were responsible for the greatest damage recorded. With the exception of Cryptotermes dudleyi and Coptotermes gestroi, all of the species are native and relatively common in northeastern Brazil’s Atlantic forest
Genetic diversity and population structure among sorghum (Sorghum bicolor, L.) germplasm collections from Western Ethiopia
The Western Ethiopian region harbors a unique set of sorghum germplasm adapted to conditions not conventional to sorghums grown in other parts of the world. Accessions from the region possess unique resistance to multiple leaf and grain diseases. This study is aimed at exploring the extent of genetic variation and population structure among accessions of this region. A total of 123 accessions comprising 111 from Western Ethiopia (62 from Asosa and 49 from Pawe) and 12 U.S. adapted lines were genotyped using 30 sorghum simple sequence repeat markers (SSR). Genetic diversity and population structure were analyzed using PowerMarker and STRUCTURE software, respectively, based on 23 polymorphic SSR markers. Principal component analysis (PCA) was performed to view the variability in multi-dimensional space. Population structure analysis revealed considerable admixtures between Pawe and Asosa accessions, while the PowerMarker analysis grouped the accessions into three distinct clusters largely based on collection regions. The PCA did not clearly differentiate Asosa and Pawe accessions, but U.S. adapted lines were clearly separated from the rest. The study indicated the presence of marked genetic variability among accessions from Western Ethiopia and also provided clues on shared genetic events among accessions adapted to the two areas in Western Ethiopia.Keywords: Sorghum, genetic diversity, population structure, SSR, Ethiopi
Autocrine Production of β-Chemokines Protects CMV-Specific CD4+ T Cells from HIV Infection
Induction of a functional subset of HIV-specific CD4+ T cells that is resistant to HIV infection could enhance immune protection and decrease the rate of HIV disease progression. CMV-specific CD4+ T cells, which are less frequently infected than HIV-specific CD4+ T cells, are a model for such an effect. To determine the mechanism of this protection, we compared the functional response of HIV gag-specific and CMV pp65-specific CD4+ T cells in individuals co-infected with CMV and HIV. We found that CMV-specific CD4+ T cells rapidly up-regulated production of MIP-1α and MIP-1β mRNA, resulting in a rapid increase in production of MIP-1α and MIP-1β after cognate antigen stimulation. Production of β-chemokines was associated with maturational phenotype and was rarely seen in HIV-specific CD4+ T cells. To test whether production of β-chemokines by CD4+ T cells lowers their susceptibility to HIV infection, we measured cell-associated Gag DNA to assess the in vivo infection history of CMV-specific CD4+ T cells. We found that CMV-specific CD4+ T cells which produced MIP-1β contained 10 times less Gag DNA than did those which failed to produce MIP-1β. These data suggest that CD4+ T cells which produce MIP-1α and MIP-1β bind these chemokines in an autocrine fashion which decreases the risk of in vivo HIV infection
Direct Fabrication of Atomically Defined Pores in MXenes
Controlled fabrication of nanopores in atomically thin two-dimensional
material offers the means to create robust membranes needed for ion transport,
nanofiltration, and DNA sensing. Techniques for creating nanopores have relied
upon either plasma etching or direct irradiation using electrons or ions;
however, aberration-corrected scanning transmission electron microscopy (STEM)
offers the advantage of combining a highly energetic, sub-angstrom sized
electron beam for atomic manipulation along with atomic resolution imaging.
Here, we utilize a method for automated nanopore fabrication with real-time
atomic visualization to enhance our mechanistic understanding of beam-induced
transformations. Additionally, an electron beam simulation technique,
Electron-Beam Simulator (E-BeamSim) was developed to observe the atomic
movements and interactions resulting from electron beam irradiation. Using the
2D MXene Ti3C2Tx, we explore the influence of temperature on nanopore
fabrication by tracking atomic transformation pathways and find that at room
temperature, electron beam irradiation induces random displacement of atoms and
results in a pileup of titanium atoms at the nanopore edge. This pileup was
confirmed and demonstrated in E-BeamSim simulations around the small, milled
area in the MXene monolayer. At elevated temperatures, the surface functional
groups on MXene are effectively removed, and the mobility of atoms increases,
which results in atomic transformations that lead to the selective removal of
atoms layer by layer. Through controllable manufacture using e-beam milling
fabrication, the production and then characterization of the fabricated defects
can be better understood for future work. This work can lead to the development
of defect engineering techniques within functionalized MXene layers.Comment: Experimental and simulations on the electron beam interactions with
MXene monolayers to form nanopores as a function of temperatur
Deep Learning for Automated Experimentation in Scanning Transmission Electron Microscopy
Machine learning (ML) has become critical for post-acquisition data analysis
in (scanning) transmission electron microscopy, (S)TEM, imaging and
spectroscopy. An emerging trend is the transition to real-time analysis and
closed-loop microscope operation. The effective use of ML in electron
microscopy now requires the development of strategies for microscopy-centered
experiment workflow design and optimization. Here, we discuss the associated
challenges with the transition to active ML, including sequential data analysis
and out-of-distribution drift effects, the requirements for the edge operation,
local and cloud data storage, and theory in the loop operations. Specifically,
we discuss the relative contributions of human scientists and ML agents in the
ideation, orchestration, and execution of experimental workflows and the need
to develop universal hyper languages that can apply across multiple platforms.
These considerations will collectively inform the operationalization of ML in
next-generation experimentation.Comment: Review Articl
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