140 research outputs found
Climate Village Adaptation in Sindang Jaya Village and South Manokwari Waroser
The purpose of writing is to compare the implementation of climate village program adaptation activities in Sindang Jaya and Waroser villages, South Manokwari Regency. This study uses a descriptive method with multiple regression analysis to determine the factors that most influence the implementation of adaptation activities in these two adjacent villages. This study indicates that in Kampung Sindang Jaya and Kampung Waroser, there are several adaptation activities, including drought, flood, and landslide control, actions to increase food security, and disease control activities. The age variable is a value that partially negatively affects climate change adaptation activities in Sindang Village. In contrast, for Waroser Village, age, education, and information media variables significantly affect people's attitudes towards climate change adaptation activities
Climate Village Adaptation in Sindang Jaya Village and South Manokwari Waroser
The purpose of writing is to compare the implementation of climate village program adaptation activities in Sindang Jaya and Waroser villages, South Manokwari Regency. This study uses a descriptive method with multiple regression analysis to determine the factors that most influence the implementation of adaptation activities in these two adjacent villages. This study indicates that in Kampung Sindang Jaya and Kampung Waroser, there are several adaptation activities, including drought, flood, and landslide control, actions to increase food security, and disease control activities. The age variable is a value that partially negatively affects climate change adaptation activities in Sindang Village. In contrast, for Waroser Village, age, education, and information media variables significantly affect people's attitudes towards climate change adaptation activities
Performansi Pompa Air Dab Type Db-125b Yang Difungsikan Sebagai Turbin Air
The use of water pumps DAB type DB-125 as the impulse turbine functions for Micro Hydro Power Plant Lisrik (PLTMH) is the topic in this research. Water pump is used to suck water and deliver it to a certain height. In this application the water pumps used as turbines where water from a certain height will rotate the impeller pump and produces electricity. The testing is done in the laboratory of mechanical engineering of University of Sam Ratulangi. Turbine is driven by three pumps which are assembled in series and parallel, to get different head and flow (Q). Water flow and load on dinamometer ( ) have been set at the lowest rotation of the load on turbine. For the initial set of water flow Q = 33,5 litres/minute. The results showed that the different H and Q from curve turbine rounds, maximum power is at Q = 40 litres/minute, H = 33,5 m, and n = 910 rp
Theoretical approach to two-dimensional traffic flow models
In this paper we present a theoretical analysis of a recently proposed
two-dimensional Cellular Automata model for traffic flow in cities with the
novel ingredient of turning capability. Numerical simulations of this model
show that there is a transition between a freely moving phase with high
velocity to a jammed state with low velocity. We study the dynamics of such a
model starting with the microscopic evolution equation, which will serve as a
basis for further analysis. It is shown that a kinetic approach, based on the
Boltzmann assumption, is able to provide a reasonably good description of the
jamming transition. We further introduce a space-time continuous
phenomenological model leading to a couple of partial differential equations
whose preliminary results agree rather well with the numerical simulations.Comment: 15 pages, REVTeX 3.0, 7 uuencoded figures upon request to
[email protected]
Reciprocal regulation of PKA and rac signaling
Activated G protein-coupled receptors (GPCRs) and receptor tyrosine kinases relay extracellular signals through spatial and temporal controlled kinase and GTPase entities. These enzymes are coordinated by multifunctional scaffolding proteins for precise intracellular signal processing. The cAMP-dependent protein kinase A (PKA) is the prime example for compartmentalized signal transmission downstream of distinct GPCRs. A-kinase anchoring proteins tether PKA to specific intracellular sites to ensure precision and directionality of PKA phosphorylation events. Here, we show that the Rho-GTPase Rac contains A-kinase anchoring protein properties and forms a dynamic cellular protein complex with PKA. The formation of this transient core complex depends on binary interactions with PKA subunits, cAMP levels and cellular GTP-loading accounting for bidirectional consequences on PKA and Rac downstream signaling. We show that GTP-Rac stabilizes the inactive PKA holoenzyme. However, β-adrenergic receptor-mediated activation of GTP-Rac–bound PKA routes signals to the Raf-Mek-Erk cascade, which is critically implicated in cell proliferation. We describe a further mechanism of how cAMP enhances nuclear Erk1/2 signaling: It emanates from transphosphorylation of p21-activated kinases in their evolutionary conserved kinase-activation loop through GTP-Rac compartmentalized PKA activities. Sole transphosphorylation of p21-activated kinases is not sufficient to activate Erk1/2. It requires complex formation of both kinases with GTP-Rac1 to unleash cAMP-PKA–boosted activation of Raf-Mek-Erk. Consequently GTP-Rac functions as a dual kinase-tuning scaffold that favors the PKA holoenzyme and contributes to potentiate Erk1/2 signaling. Our findings offer additional mechanistic insights how β-adrenergic receptor-controlled PKA activities enhance GTP-Rac–mediated activation of nuclear Erk1/2 signaling
The diterpenoid alkaloid noroxoaconitine is a Mapkap kinase 5 (MK5/PRAK) inhibitor
The mitogen-activated protein kinase-activated protein kinase MK5 is ubiquitously expressed in vertebrates and is implicated in cell proliferation, cytoskeletal remodeling, and anxiety behavior. This makes MK5 an attractive drug target. We tested several diterpenoid alkaloids for their ability to suppress MK5 kinase activity. We identified noroxoaconitine as an ATP competitor that inhibited the catalytic activity of MK5 in vitro (IC50 = 37.5 μM; Ki = 0.675 μM) and prevented PKA-induced nuclear export of MK5, a process that depends on kinase active MK5. MK5 is closely related to MK2 and MK3, and noroxoaconitine inhibited MK3- and MK5- but not MK2-mediated phosphorylation of the common substrate Hsp27. Molecular docking of noroxoaconitine into the ATP binding sites indicated that noroxoaconitine binds more strongly to MK5 than to MK3. Noroxoaconitine and derivatives may help in elucidating the precise biological functions of MK5 and may prove to have therapeutic values
Generalized Boltzmann Equation for Lattice Gas Automata
In this paper, for the first time a theory is formulated that predicts
velocity and spatial correlations between occupation numbers that occur in
lattice gas automata violating semi-detailed balance. Starting from a coupled
BBGKY hierarchy for the -particle distribution functions, cluster expansion
techniques are used to derive approximate kinetic equations. In zeroth
approximation the standard nonlinear Boltzmann equation is obtained; the next
approximation yields the ring kinetic equation, similar to that for hard sphere
systems, describing the time evolution of pair correlations. As a quantitative
test we calculate equal time correlation functions in equilibrium for two
models that violate semi-detailed balance. One is a model of interacting random
walkers on a line, the other one is a two-dimensional fluid type model on a
triangular lattice. The numerical predictions agree very well with computer
simulations.Comment: 31 pages LaTeX, 12 uuencoded tar-compressed Encapsulated PostScript
figures (`psfig' macro), hardcopies available on request, 78kb + 52k
Serine residue 115 of MAPK-activated protein kinase MK5 is crucial for its PKA-regulated nuclear export and biological function
The mitogen-activated protein kinase-activated protein kinase-5 (MK5) resides predominantly in the nucleus of resting cells, but p38MAPK, extracellular signal-regulated kinases-3 and -4 (ERK3 and ERK4), and protein kinase A (PKA) induce nucleocytoplasmic redistribution of MK5. The mechanism by which PKA causes nuclear export remains unsolved. In the study reported here we demonstrated that Ser-115 is an in vitro PKA phosphoacceptor site, and that PKA, but not p38MAPK, ERK3 or ERK4, is unable to redistribute MK5 S115A to the cytoplasm. However, the phosphomimicking MK5 S115D mutant resides in the cytoplasm in untreated cells. While p38MAPK, ERK3 and ERK4 fail to trigger nuclear export of the kinase dead T182A and K51E MK5 mutants, S115D/T182A and K51E/S115D mutants were able to enter the cytoplasm of resting cells. Finally, we demonstrated that mutations in Ser-115 affect the biological properties of MK5. Taken together, our results suggest that Ser-115 plays an essential role in PKA-regulated nuclear export of MK5, and that it also may regulate the biological functions of MK5
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