304 research outputs found
Preparing Initial Teacher Education students for Flexible Learning Programs
In Australia, there is currently no official training pathway or qualification required for working in Flexible Learning Programs (FLPs). This causes a problem for both new teachers wishing to work in this area and for employers who have no way of knowing whether a new teacher has the appropriate skills or knowledge to teach in this alternative context. To address this problem, we designed and implemented a program during which Initial Teacher Education (ITE) students were given the opportunity to experience teaching in a FLP. Here we report on the experiences and perceptions of the preparation program from the perspectives of the key stakeholders, including the ITE students, FLP staff, and the young people attending the FLP. All stakeholders perceived the project to be a success in enabling the ITE students to gain valuable theoretical knowledge and practical experience of the FLP context
Precise Flow-Control Using Photo-Actuated Hydrogel Valves and Pid-controlled LED Actuation
Herein we demonstrate remarkable control of flow within fluidic channels using photo-actuated hydrogel valves. By polymerizing the valves in situ it has been possible to create highlyreproducible valves. Through the use of an LED platform and a PID algorithm we have generated extremely accurate flow control and created prototype devices to document their potential application within the microfluidics field
Synaptotagmin 1 oligomers clamp and regulate different modes of neurotransmitter release
Release of neurotransmitters relies on submillisecond coupling of synaptic vesicle fusion to the triggering signal: AP-evoked presynaptic Ca2+ influx. The key player that controls exocytosis of the synaptic vesicle is the Ca2+ sensor synaptotagmin 1 (Syt1). While the Ca2+ activation of Syt1 has been extensively characterized, how Syt1 reversibly clamps vesicular fusion remains enigmatic. Here, using a targeted mutation combined with fluorescence imaging and electrophysiology, we show that the structural feature of Syt1 to self-oligomerize provides the molecular basis for clamping of spontaneous and asynchronous release but is not required for triggering of synchronous release. Our findings propose a mechanistic model that explains how Syt1 oligomers regulate different modes of transmitter release in neuronal synapses
Loop Corrections and Naturalness in a Chiral Effective Field Theory
The loop expansion is applied to a chiral effective hadronic lagrangian; with
the techniques of Infrared Regularization, it is possible to separate out the
short-range contributions and to write them as local products of fields that
are already present in our lagrangian. (The appropriate field variables must be
re-defined at each order in loops.) The corresponding parameters implicitly
include short-range effects to all orders in the interaction, so these effects
need not be calculated explicitly. The remaining (long-range) contributions
that must be calculated are nonlocal and resemble those in conventional
nuclear-structure calculations. Nonlinear isoscalar scalar and
vector meson interactions are included, which incorporate
many-nucleon forces and nucleon substructure. Calculations are carried out at
the two-loop level to illustrate these techniques at finite nuclear densities
and to verify that the coupling parameters remain natural when fitted to the
empirical properties of equilibrium nuclear matter. Contributions from the
tensor coupling are also discussed.Comment: 22 pages, 6 figure
Monoamniotic twin pregnancy discordant for body stalk anomaly: a case report
Body stalk anomaly, also known as limb-body syndrome, is a rare and lethal congenital anomaly. It presents a major abdominal wall defect and severe kyphosis with either a rudimentary or absent umbilical cord. We present a case of monoamniotic twin discordant for body stalk anomaly diagnosed at 27 weeks. Ultrasound findings demonstrated a normal Twin A, but Twin B was abnormal with a large ventral wall defect and severe kyphoscoliosis. The pregnancy was managed conservatively and concluded with an emergency caesarean section at 31 weeks on account of preterm labour. The unaffected twin survived with no significant morbidity. This case highlights some of the challenges posed to the obstetrician in managing such a rare anomaly in twin pregnancy
Myo4p and She3p are required for cortical ER inheritance in Saccharomyces cerevisiae
Myo4p is a nonessential type V myosin required for the bud tip localization of ASH1 and IST2 mRNA. These mRNAs associate with Myo4p via the She2p and She3p proteins. She3p is an adaptor protein that links Myo4p to its cargo. She2p binds to ASH1 and IST2 mRNA, while She3p binds to both She2p and Myo4p. Here we show that Myo4p and She3p, but not She2p, are required for the inheritance of cortical ER in the budding yeast Saccharomyces cerevisiae. Consistent with this observation, we find that cortical ER inheritance is independent of mRNA transport. Cortical ER is a dynamic network that forms cytoplasmic tubular connections to the nuclear envelope. ER tubules failed to grow when actin polymerization was blocked with the drug latrunculin A (Lat-A). Additionally, a reduction in the number of cytoplasmic ER tubules was observed in Lat-Aâtreated and myo4Î cells. Our results suggest that Myo4p and She3p facilitate the growth and orientation of ER tubules
Synaptotagmin-1 membrane binding is driven by the C2B domain and assisted cooperatively by the C2A domain
Synaptotagmin interaction with anionic lipid (phosphatidylserine/phosphatidylinositol) containing membranes, both in the absence and presence of calcium ions (Ca2+), is critical to its central role in orchestrating neurotransmitter release. The molecular surfaces involved, namely the conserved polylysine motif in the C2B domain and Ca2+-binding aliphatic loops on both C2A and C2B domains, are known. Here we use surface force apparatus combined with systematic mutational analysis of the functional surfaces to directly measure Syt1-membrane interaction and fully map the site-binding energetics of Syt1 both in the absence and presence of Ca2+. By correlating energetics data with the molecular rearrangements measured during confinement, we find that both C2 domains cooperate in membrane binding, with the C2B domain functioning as the main energetic driver, and the C2A domain acting as a facilitator.Fil: Gruget, ClĂ©mence. Ecole Normale SupĂ©rieure; FranciaFil: Bello, Oscar Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mendoza. Instituto de HistologĂa y EmbriologĂa de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias MĂ©dicas. Instituto de HistologĂa y EmbriologĂa de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Coleman, Jeff. University of Yale. School of Medicine; Estados UnidosFil: Krishnakumar, Shyam S.. University of Yale. School of Medicine; Estados UnidosFil: Perez, Eric. Ecole Normale SupĂ©rieure; FranciaFil: Rothman, James E.. University of Yale. School of Medicine; Estados UnidosFil: Pincet, Frederic. Ecole Normale SupĂ©rieure; Francia. University of Yale. School of Medicine; Estados UnidosFil: Donaldson, Stephen H.. Ecole Normale SupĂ©rieure; Franci
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