1,346 research outputs found
Recent Developments of Electrochemical Wall Mass Transfer Probes and Their Application to Drag-Reducing Polymers
Electrochemical mass transfer probes are used to measure the velocity gradient at a wall. Recent advances in their application are reviewed. These include corrections for the time response of the probe, the simultaneous measurement at a number of locations of the two components of the fluctuating velocity gradient and a study of the influence of drag reducing polymers on turbulence. It is found that drag-reducing polymers cause an increase in the scale of flow oriented eddies in the viscous sublayer
Dalle Province all’area vasta: un’incoerenza italiana
La storia della delimitazione regionale in Italia ci aiuta a capire quanto artificiale possa essere la rappresentazione che di esse hanno i diversi governi regionali. In questo capitolo si procede a una comparazione con quella provinciale, ben più antica, che ci permetta anche di mostrarne il ruolo nella programmazione attuale.The history of regional borders in Italy cans show the artificial representation that their governments propose. For this reason the comparison with the provincial delimitations, older than the first, can help to explain why it is important a deeper reflection about the question to renounce to this institutional level
PENGETAHUAN, SIKAP DAN TINDAKAN PENCEGAHAN PENYAKIT SCHISTOSOMIASIS MASYARAKAT DI DESA DODOLO KECAMATAN LORE UTARA KABUPATEN POSO
Schistosomiasis merupakan penyakit parasit akut dan kronis yang disebabkan oleh schistosomiasis darah (Schistosomiasis Trematoda) dari genus Schistosoma. Schistosomiasis merupakan penyakit endemis yang terdapat di Provinsi Sulawesi Tengah. Transmisi Schistosomiasis terjadi melalui air yang mengandung serkaria cacing Schistosoma dan Keong air Oncomelania. Penelitian ini bertujuan untuk mengetahui hubungan antara pengetahuan dan sikap tentang schistosomiasis dengan tindakan pencegahan penyakit schistosomiasis masyarakat di Desa Dodolo Kecamatan Lore Utara Kabupaten Poso. Penelitian ini merupakan penelitian survei analitik dengan desain studi potong lintang dengan menggunakan total populasi sebesar 111 responden. Instrumen yang digunakan untuk penelitian ini adalah kuesioner. Penelitian ini dilaksanakan di Desa Dodolo Kecamatan Lore Utara Kabupaten Poso Provinsi Sulawesi Tengah. Analisis data bivariat dengan menggunakan uji Chi Square. Hasil Penelitian menunjukkan bahwa sebagian besar responden memiliki pengetahuan yang baik tentang Schistosomiasis yaitu sebesar (62,2%). Sebagian besar responden memiliki sikap yang baik tentang Schistosomiasis (51,4%) dan sebagian besar responden memiliki tindakan pencegahan Schistosomiasis yang baik (64,0%). Analisis bivariat menggunakan uji chi-square hubungan pengetahuan dengan tindakan pencegahan Schistosomiasis p value = 0,170, sedangkan hubungan sikap dan tindakan pencegahan Schistosomiasis p value = 0,000. Berdasarkan penelitian ini dapat disimpulkan bahwa tidak terdapat hubungan antara pengetahuan dengan tindakan pencegahan Schistosomiasis dan terdapat hubungan antara sikap dengan tindakan pencegahan Schistosomiasis.Kata Kunci: Schistosomiasis, pengetahuan, sikap, tindakan pencegahanABSTRACTSchistosomiasis is an acute and chronic parasitic disease caused by blood schistosomiasis (Schistosomiasis Trematoda) of the genus Schistosoma. Schistosomiasis is an endemic disease in Central Sulawesi Province. Schistosomiasis transmission occurs through water containing Schistosoma cercariae and Oncomelania water conch. This research aims to determine the relationship between knowledge and attitudes of schistosomiasis with preventive practice of schistosomiasis disease in Dodolo Village, North Lore District, Poso Regency. This research was an analytical survey research with cross sectional study design with a total of population amounted to 111 respondents. The instrument used in this research was questionnaire. This research was conducted in Dodolo Village, North Lore District, Poso Regency, Central Sulawesi Province. Bivariate data analysis used Chi Square test. Research results show that most respondents have good knowledge about Schistosomiasis which is (62.2%). Most respondents have a good attitude about Schistosomias which is (51.4%) and the majority of respondents who have good preventive practice for Schistosomiasis (64.0%). Bivariate analysis with the chi-square test to analyze the relationship between knowledge and preventive practice of Schistosomiasis p value = 0.170, while the relationship between attitudes and preventive practice of Schistosomiasis p value = 0,000. Based on this research, it can be concluded that there is no relationship between knowledge and preventive practice of Schistosomiasis and there is a relationship between attitudes and preventive practice of Schistosomiasis.Keywords: Schistosomiasis, knowledge, attitude, preventive practic
Mycoheterotrophic plants preferentially target arbuscular mycorrhizal fungi that are highly connected to autotrophic plants
How mycoheterotrophic plants that obtain carbon and soil nutrients from fungi are integrated in the usually mutualistic arbuscular mycorrhizal networks is unknown. Here, we compare autotrophic and mycoheterotrophic plant associations with arbuscular mycorrhizal fungi and use network analysis to investigate interaction preferences in the tripartite network.
We sequenced root tips from autotrophic and mycoheterotrophic plants to assemble the combined tripartite network between autotrophic plants, mycorrhizal fungi, and mycoheterotrophic plants. We compared plant-fungal interactions between mutualistic and antagonist networks, and searched for a diamond-like module defined by a mycoheterotrophic and an autotrophic plant interacting with the same pair of fungi to investigate whether pairs of fungi simultaneously linked to plant species from each interaction type were overrepresented throughout the network.
Mycoheterotrophic plants as a group interacted with a subset of the fungi detected in autotrophs but are indirectly linked to all autotrophic plants, and fungi with high overlap in autotrophic partners tend to interact with a similar set of mycoheterotrophs. Moreover, pairs of fungi sharing the same mycoheterotrophic and autotrophic plant species are overrepresented in the network.
We hypothesize that the maintenance of antagonistic interactions is maximized by targeting well-linked mutualistic fungi, thereby minimizing the risk of carbon supply shortages
JAK2V617F allele burden is associated with thrombotic mechanisms activation in polycythemia vera and essential thrombocythemia patients
The clinical courses of polycythemia vera (PV) and essential thrombocythemia (ET) are characterized by thrombohemorrhagic diathesis. Several groups have suggested an association between JAK2V617F mutation and thrombosis. We hypothesized a relationship between JAK2V617F allele burden, cellular activation parameters, and thrombosis. We evaluated a group of PV and ET patients using flow cytometry: platelet CD62P, CD63, and dense granules, platelet-leukocyte aggregates (PLA), leukocyte CD11b and monocyte tissue factor (TF) expression. All patients had increased baseline platelet CD62P and CD63 expression (p 50 % presented higher levels of leukocyte activation. In ET, thrombosis was associated with JAK2V617F mutation (p < 0.05, χ (2) = 5.2), increased monocyte CD11b (p < 0.05) and with platelet-PMN aggregates (p < 0.05). In ET patients, hydroxyurea does not significantly reduce the activation parameters. Our data demonstrate that JAK2V617F allele burden is directly correlated with activation parameters that drive mechanisms that favor thrombosis.info:eu-repo/semantics/publishedVersio
Hubbard band or oxygen vacancy states in the correlated electron metal SrVO?
We study the effect of oxygen vacancies on the electronic structure of the
model strongly correlated metal SrVO. By means of angle-resolved
photoemission (ARPES) synchrotron experiments, we investigate the systematic
effect of the UV dose on the measured spectra. We observe the onset of a
spurious dose-dependent prominent peak at an energy range were the lower
Hubbard band has been previously reported in this compound, raising questions
on its previous interpretation. By a careful analysis of the dose dependent
effects we succeed in disentangling the contributions coming from the oxygen
vacancy states and from the lower Hubbard band. We obtain the intrinsic ARPES
spectrum for the zero-vacancy limit, where a clear signal of a lower Hubbard
band remains. We support our study by means of state-of-the-art ab initio
calculations that include correlation effects and the presence of oxygen
vacancies. Our results underscore the relevance of potential spurious states
affecting ARPES experiments in correlated metals, which are associated to the
ubiquitous oxygen vacancies as extensively reported in the context of a
two-dimensional electron gas (2DEG) at the surface of insulating
transition metal oxides.Comment: Manuscript + Supplemental Material, 12 pages, 9 figure
Anatypical active cell death process underlies the fungicidal activity of ciclopiroxolamine against the yeast Saccharomyces cerevisiae
Ciclopirox olamine (CPO), a fungicidal agent widely used in clinical practice,
induced in Saccharomyces cerevisiae an active cell death (ACD) process characterized
by changes in nuclear morphology and chromatin condensation associated
with the appearance of a population in the sub-G0/G1 cell cycle phase and an arrest
in the G2/M phases. This ACD was associated neither with intracellular reactive
oxygen species (ROS) signaling, as revealed by the use of different classes of ROS
scavengers, nor with a terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive phenotype. Furthermore, CPO-induced cell death
seems to be dependent on unknown protease activity but independent of the apoptotic regulators Aif1p and Yca1p and of autophagic pathways involving
Apg5p, Apg8p and Uth1p. Our results show that CPO triggers in S. cerevisiae an
atypical nonapoptotic, nonautophagic ACD with as yet unknown regulators
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Phase Composition and Microstructure of Cast Al-6%Mg-2%Ca-2%Zn Alloy with Fe and Si Additions
Data Availability Statement:
Not applicable.Investigating the effect of Fe and Si is essential for any new Al-based composition, as these impurities can be easily found both after primary production and recycling. This study is dedicated to filling the gap in revealing the phase composition of an Al-6%Mg-2%Ca-2%Zn alloy after the combined and separate addition of Fe and Si. This was addressed by permanent mold casting and solid solution heat treatment. The investigation of slowly solidified samples also contributed to understanding potential phase transitions. It was found that the alloy containing 0.5%Fe can have nearly spherical intermetallics after heat treatment, whereas a higher Fe content brought the formation of a needle-shaped Al3Fe intermetallic. We explain this by the formation of a ternary α-Al + Al10CaFe2 + Al4Ca eutectic, which is more compact in as-cast condition compared to divorced binary α-Al + Al4Ca and α-Al + Al3Fe eutectics. Similarly, 0.5%Si readily incurred the formation of a needle-shaped Al2CaSi2 intermetallic, probably also by a binary reaction L → α-Al + Al2CaSi2. In the solidified samples, no Mg2Si phase was found, even in slowly solidified samples. This is contrary to the thermodynamic calculation, which suggests a peritectic reaction L + Al2CaSi2 Mg2Si. Interestingly, the addition of 0.5%Si caused an even coarser microstructure compared to the addition of 1%Fe, which caused the appearance of a primary Al3Fe phase. We conclude that the new alloy is more tolerable to Fe rather than Si. Specifically, the addition of 0.5%Fe can be added while maintaining a fine morphology of the eutectic network. It was suggested that the morphology of eutectic and solid solution hardening governed the mechanical properties. The strength of the alloys containing separate 0.5%Fe (UTS = 215 ± 8 MPa and YS 146 ± 4 = MPa) and the combined 0.5%Fe and 0.5%Si additions (UTS = 195 ± 14 MPa and YS ± 1 = 139 MPa) was not compromised compared to the alloy containing 0.5%Si (UTS 201 ± 24 = MPa and YS = 131 ± 1 MPa).Russian Science Foundation (Project No. 23-79-01055 https://rscf.ru/project/23-79-01055/) (SEM, XRD analysis, hardness, tensile tests); Moscow Polytechnic University within the framework of the grant named after Pyotr Kapitsa (Conceptualization, SEM, TEM, Thermo-Calc calculations, discussion); the results were obtained by using the equipment of the Center for Collective Use, “Materials Science and Metallurgy”, with the financial support of the Ministry of Science and Higher Education of the Russian Federation (#075-15-2021-696)
High-density two-dimensional electron system induced by oxygen vacancies in ZnO
We realize a two-dimensional electron system (2DES) in ZnO by simply
depositing pure aluminum on its surface in ultra-high vacuum, and characterize
its electronic structure using angle-resolved photoemission spectroscopy. The
aluminum oxidizes into alumina by creating oxygen vacancies that dope the bulk
conduction band of ZnO and confine the electrons near its surface. The electron
density of the 2DES is up to two orders of magnitude higher than those obtained
in ZnO heterostructures. The 2DES shows two -type subbands, that we compare
to the -like 2DESs in titanates, with clear signatures of many-body
interactions that we analyze through a self-consistent extraction of the system
self-energy and a modeling as a coupling of a 2D Fermi liquid with a Debye
distribution of phonons.Comment: Article + Supplementary Material, 12 pages, 3 main figures, 6
supplementary figure
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