466 research outputs found
Global and Multiplexed Dendritic Computations under In Vivo-like Conditions.
Dendrites integrate inputs nonlinearly, but it is unclear how these nonlinearities contribute to the overall input-output transformation of single neurons. We developed statistically principled methods using a hierarchical cascade of linear-nonlinear subunits (hLN) to model the dynamically evolving somatic response of neurons receiving complex, in vivo-like spatiotemporal synaptic input patterns. We used the hLN to predict the somatic membrane potential of an in vivo-validated detailed biophysical model of a L2/3 pyramidal cell. Linear input integration with a single global dendritic nonlinearity achieved above 90% prediction accuracy. A novel hLN motif, input multiplexing into parallel processing channels, could improve predictions as much as conventionally used additional layers of local nonlinearities. We obtained similar results in two other cell types. This approach provides a data-driven characterization of a key component of cortical circuit computations: the input-output transformation of neurons during in vivo-like conditions
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Operations aspects of the Fermilab Central Helium Liquefier facility
The Fermilab Central Helium Liquefier (CHL) facility consists of helium and nitrogen reliquefier plants operated 24 hours-a-day to supply LHe at 4.6 K and LN{sub 2} for the Fermilab Tevatron superconducting proton-antiproton collider ring and to recover warm return gases. Operating aspects of CHL, including different equipment and systems reliability, availability, maintenance experience, safety concerns, and economics aspects are discussed
Quantum dot-based multiphoton fluorescent pipettes for targeted neuronal electrophysiology
Targeting visually identified neurons for electrophysiological recording is a fundamental neuroscience technique; however, its potential is hampered by poor visualization of pipette tips in deep brain tissue. We describe quantum dot-coated glass pipettes that provide strong two-photon contrast at deeper penetration depths than those achievable with current methods. We demonstrated the pipettes' utility in targeted patch-clamp recording experiments and single-cell electroporation of identified rat and mouse neurons in vitro and in vivo
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Operations aspects of the Fermilab Central Helium Liquefier Facility
The Fermilab Central Helium Liquefier (CHL) facility consists of helium and nitrogen reliquefier plants operated 24 hours-a-day to supply LHe at 4.6{degrees}K and LN{sub 2} for the Fermilab Tevatron superconducting proton-antiproton collider ring and to recover warm return gases. Operating aspects of CHL, including different equipment and systems reliability, availability, maintenance experience, safety concerns, and economics aspects are discussed
Primary Mathematics Teachers’ Assessment Practices in the Context of the Integrated Primary Curriculum in Lesotho
ArticleThe purpose of this research was to investigate primary mathematics teachers’ assessment practices in the
context of the new integrated primary curriculum. This was a case study in which data were collected
through classroom observations and interviews. Findings from the study revealed that teachers were
able to use some of the assessment for learning strategies in their classrooms. These were
communicating learning intentions and success criteria at the beginning of the lessons, making use of
peer and self-assessment by learners. The study established that the use of success criteria can
promote learners’ self-reflective ability, regardless of their age. Findings also revealed that teachers were
not providing learners with descriptive feedback that showed their strengths and weaknesses.
Furthermore, the results of the study revealed that teachers encountered challenges in the
implementation of assessment for learning in their classrooms. Some of the challenges encountered
were a shortage of resources, high teacher–learner ratio, increased workload and reduced teaching time
Detection of virulence factors in α-haemolytic Escherichia coli strains isolated from various clinical materials
ABSTRACTIn total, 201 α-haemolytic Escherichia coli isolates from various clinical materials (urine samples and vaginal and rectal swabs) were examined by PCR for the presence of genes for the virulence factors α-haemolysin (hly), cytotoxic necrotising factor type 1 (cnf1), P-fimbriae (pap), S/F1C-fimbriae (sfa/foc), aerobactin (aer) and afimbrial adhesin (afaI). Among vaginal isolates, 96% were positive for cnf1, compared with 80% of urine strains (p 0.02) and 63% of rectal strains (p 0.0001). Similarly, sfa/foc-specific DNA sequences were found in 97% of vaginal isolates compared with 75% of rectal strains (p 0.004). The afa1 and aer genes were associated more with rectal a-haemolytic E. coli strains than with extra-intestinal isolates. The results suggested that CNF1 and/or S/F1C-fimbriae contribute to colonisation and persistence of a-haemolytic E. coli strains in the vaginal environment
Computed tomographic features of feline sino-nasal and sino-orbital aspergillosis
Feline upper respiratory tract aspergillosis (URTA) occurs as two distinct anatomic forms, sinonasal aspergillosis (SNA) and sino-orbital aspergillosis (SOA). An emerging pathogen, Aspergillus felis is frequently involved. The pathogenesis of URTA, in particular, the relationship between the infecting isolate and outcome, is poorly understood. Computed tomography was used to investigate the route of fungal infection and extension in 16 cases (SNA n=7, SOA n=9) where the infecting isolate had been identified by molecular testing. All cases had nasal cavity involvement except one cat with SNA that had unilateral frontal sinus changes. A strong association between the infecting species and anatomic form was identified. A. fumigatus infections remained within the sino-nasal cavity. Cryptic species infections were associated with orbital and paranasal soft-tissue involvement and with orbital lysis. These species were further associated with a mass in the nasal cavity, paranasal sinuses or nasopharynx. Orbital masses showed heterogeneous contrast enhancement, with central coalescing hypoattenuating foci and peripheral rim enhancement. Severe, cavitated turbinate lysis, typical of canine SNA, was present only in cats with SNA. These findings support that the nasal cavity is the portal of entry for fungal spores in feline URTA and that the route of extension to involve the orbit is via direct naso-orbital communication from bone lysis. Additionally, a pathogenic role for A. wyomingensis and a sinolith in a cat with A. udagawae infection are reported for the first time. Keywords: Aspergillus felis; Aspergillosis; Cats; Sino-nasal; Sino-orbita
Computed tomographic features of feline sino-nasal and sino-orbital aspergillosis
Feline upper respiratory tract aspergillosis (URTA) occurs as two distinct anatomic forms, sinonasal aspergillosis (SNA) and sino-orbital aspergillosis (SOA). An emerging pathogen, Aspergillus felis is frequently involved. The pathogenesis of URTA, in particular, the relationship between the infecting isolate and outcome, is poorly understood. Computed tomography was used to investigate the route of fungal infection and extension in 16 cases (SNA n=7, SOA n=9) where the infecting isolate had been identified by molecular testing. All cases had nasal cavity involvement except one cat with SNA that had unilateral frontal sinus changes. A strong association between the infecting species and anatomic form was identified. A. fumigatus infections remained within the sino-nasal cavity. Cryptic species infections were associated with orbital and paranasal soft-tissue involvement and with orbital lysis. These species were further associated with a mass in the nasal cavity, paranasal sinuses or nasopharynx. Orbital masses showed heterogeneous contrast enhancement, with central coalescing hypoattenuating foci and peripheral rim enhancement. Severe, cavitated turbinate lysis, typical of canine SNA, was present only in cats with SNA. These findings support that the nasal cavity is the portal of entry for fungal spores in feline URTA and that the route of extension to involve the orbit is via direct naso-orbital communication from bone lysis. Additionally, a pathogenic role for A. wyomingensis and a sinolith in a cat with A. udagawae infection are reported for the first time. Keywords: Aspergillus felis; Aspergillosis; Cats; Sino-nasal; Sino-orbita
Installation, commissioning, and testing of the HB650 CM at PIP2IT
The Proton Improvement Plan-II (PIP-II) is a major upgrade to the Fermilab
accelerator complex, featuring a new 800-MeV Superconducting Radio-Frequency
(SRF) linear accelerator (LINAC) powering the accelerator complex to provide
the world's most intense high-energy neutrino beam. This paper describes the
conversion of the PIP-II Injector Test Facility (PIP2IT) cryogenic system into
a test stand for PIP-II High-Beta 650 MHz (HB650) cryomodules at Fermilab's
Cryomodule Test Facility (CMTF). A description of the associated mechanical,
electrical, and controls modifications necessary for testing HB650 cryomodules
are provided. The cooldown and warmup requirements, procedures and associated
controls logic is described.Comment: 2023 Cryogenic Engineering Conference and International Cryogenic
Materials Conference (CEC/ICMC
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