853 research outputs found
Extremal maps of the universal hyperbolic solenoid
We show that the set of points in the Teichmuller space of the universal
hyperbolic solenoid which do not have a Teichmuller extremal representative is
generic (that is, its complement is the set of the first kind in the sense of
Baire). This is in sharp contrast with the Teichmuller space of a Riemann
surface where at least an open, dense subset has Teichmuller extremal
representatives. In addition, we provide a sufficient criteria for the
existence of Teichmuller extremal representatives in the given homotopy class.
These results indicate that there is an interesting theory of extremal (and
uniquely extremal) quasiconformal mappings on hyperbolic solenoids.Comment: LaTeX, 15 page
Experiments on the stability and transition of two-dimensional and three-dimensional boundary layers with suction
The preliminary experimental development work directed towards the understanding of transition in boundary layers with suction is presented. The basic stability experiment was established and the facility was certified
Discovery of Infection Associated Metabolic Markers in Human African Trypanosomiasis
Peer reviewedPublisher PD
Assessing the quality of care at primary health care level in two pilot regions of Albania
The quality of care (QoC) of primary health care (PHC) services in Albania faces challenges on multiple levels including governance, access, infrastructure and health care workers. In addition, there is a lack of trust in the latter. The Health for All Project (HAP) funded by the Swiss Agency for Development and Cooperation therefore aimed at enhancing the population's health by improving PHC services and implementing health promotion activities following a multi-strategic health system strengthening approach. The objective of this article is to compare QoC before and after the 4 years of project implementation. A cross-sectional study was implemented at 38 PHC facilities in urban and rural locations in the Diber and Fier regions of Albania in 2015 and in 2018. A survey measured the infrastructure of the different facilities, provider-patient interactions through clinical observation and patient satisfaction. During clinical observations, special attention was given to diabetes and hypertensive patients. Infrastructure scores improved from base- to endline with significant changes seen on national level and for rural facilities (p < 0.01). Facility infrastructure and overall cleanliness, hygiene and basic/essential medical equipment and supplies improved at endline, while for public accountability/transparency and guidelines and materials no significant change was observed. The overall clinical observation score increased at endline overall, in both areas and in rural and urban setting. However, infection prevention and control procedures and diabetes treatment still experienced relatively low levels of performance at endline. Patient satisfaction on PHC services is generally high and higher yet at endline. The changes observed in the 38 PHC facilities in two regions in Albania between 2015 and 2018 were overall positive with improvements seen at all three levels assessed, e.g., infrastructure, service provision and patient satisfaction. However, to gain overall improvements in the QoC and move toward a more efficient and sustainable health system requires continuous investments in infrastructure alongside interventions at the provider and user level
Modeling Fibrillogenesis of Collagen-Mimetic Molecules
One of the most robust examples of self-assembly in living organisms is the formation of collagen architectures. Collagen type I molecules are a crucial component of the extracellular matrix, where they self-assemble into fibrils of well-defined axial striped patterns. This striped fibrillar pattern is preserved across the animal kingdom and is important for the determination of cell phenotype, cell adhesion, and tissue regulation and signaling. The understanding of the physical processes that determine such a robust morphology of self-assembled collagen fibrils is currently almost completely missing. Here, we develop a minimal coarse-grained computational model to identify the physical principles of the assembly of collagen-mimetic molecules. We find that screened electrostatic interactions can drive the formation of collagen-like filaments of well-defined striped morphologies. The fibril axial pattern is determined solely by the distribution of charges on the molecule and is robust to the changes in protein concentration, monomer rigidity, and environmental conditions. We show that the striped fibrillar pattern cannot be easily predicted from the interactions between two monomers but is an emergent result of multibody interactions. Our results can help address collagen remodeling in diseases and aging and guide the design of collagen scaffolds for biotechnological applications
Lipid membrane-mediated attraction between curvature inducing objects
The interplay of membrane proteins is vital for many biological processes, such as cellular transport, cell division, and signal transduction between nerve cells. Theoretical considerations have led to the idea that the membrane itself mediates protein self-organization in these processes through minimization of membrane curvature energy. Here, we present a combined experimental and numerical study in which we quantify these interactions directly for the first time. In our experimental model system we control the deformation of a lipid membrane by adhering colloidal particles. Using confocal microscopy, we establish that these membrane deformations cause an attractive interaction force leading to reversible binding. The attraction extends over 2.5 times the particle diameter and has a strength of three times the thermal energy (−3.3 kBT). Coarse-grained Monte-Carlo simulations of the system are in excellent agreement with the experimental results and prove that the measured interaction is independent of length scale. Our combined experimental and numerical results reveal membrane curvature as a common physical origin for interactions between any membrane-deforming objects, from nanometre-sized proteins to micrometre-sized particles
Some Slaughter and Carcass Traits of the Lambs of Dalmatian Pramenka Reared in Three Different Fattening Systems
In order to determine the impact of different fattening system (I - milk, pasture; II - indoors, milk, grains, III - milk, pasture, concentrate) on slaughter value and carcass quality of the lambs of Dalmatian Pramenka, 18 lambs (100 ± 5 days old), 6 in each group, were slaughtered. Lambs of one group were from the same flock and selected by birth weight (2.00 ± 0.20 kg). After slaughtering and cutting the carcasses into halves, in order to determine the share of legs and shoulders as well as certain tissues in the halves, the legs and shoulders were separated from the halves and total dissection was made. The significant differences (P<0.05) of slaughter weight (I - 21.17 kg, II - 23.25 kg, III - 26.25 kg) and hot carcass weight (I - 9.98 kg, II - 11.92 kg, III - 12.92 kg) among three groups were found. The legs II (1.65 kg) and III (1.71 kg) were significantly heavier (P<0.001) than legs I (1.32 kg), as well as shoulders (I - 0.52 kg, II - 0.65 kg, III - 0.69 kg; P<0.01). Total dissection of the halves established these tissues ratio: muscle 51.25 %, fat 10.18 %, connective 13.93%, bone 23.04% and other tissues 2.32%. The biggest quantity of muscle tissue was found in halves III (3.27 kg) what was more (P<0.05) than in halves II (2.83 kg) and I (2.50 kg). However, the biggest quantity of fat was found in halves II (0.85 kg) what was more (P<0.01) than in halves I (0.33 kg) and III (0.52 kg). Therefore, the addition of concentrate in pasture fattening system (III) increased the muscularity, without significantly increasing the amount of fat in the lamb carcass
Consumer perception on purchase decision factors and health indicators related to the quality and safety of meat sold in dibiteries in Dakar, Senegal
Accelerated socio-economic and demographic changes have led to the transformation of eating habits in sub-Saharan African cities including Dakar, Senegal. The result is the proliferation of informal fast-food establishments, such as the 'dibiteries' serving braised sheep meat. However, owing to poor hygiene practices, consumption of dibiterie meat poses a public health concern. It was unclear how the dibiterie meat quality and safety were perceived among customers who define their own purchasing social norms. A total of 165 meat consumers were randomly selected and interviewed, from 165 dibiteries sampled by convenience in the Dakar region using a structured questionnaire. Results showed that purchase decisions were guided by trust in the salesperson's expertise, the taste of the product, perceived risk of meat contamination, tenderness, price, the nutritional value, the smell and the colour and freshness of the meat. The perceived quality and safety of dibiterie meat was expressed by the 'organoleptic quality', 'environment and service' and 'price and trust of the product's safety' factors. The majority of consumers (61%) were 'less concerned' about the safety of dibiterie meat, and the acceptable price range of the product was between 7.62. As this food product is gaining popularity in Dakar and the majority of our participating consumers do not show high levels of concern, we suggest stricter standards
The Effect of Acoustic Forcing on Instabilities and Breakdown in Swept-Wing Flow over a Backward-Facing Step
Instability interaction and breakdown were experimentally investigated in the flow over a swept backward-facing step. Acoustic forcing was used to excite the Tollmien-Schlichting (TS) instability and to acquire phase-locked results. The phase-averaged results illustrate the complex nature of the interaction between the TS and stationary cross flow instabilities. The weak stationary cross flow disturbance causes a distortion of the TS wavefront. The breakdown process is characterized by large positive and negative spikes in velocity. The positive spikes occur near the same time and location as the positive part of the TS wave. Higher-order spectral analysis was used to further investigate the nonlinear interactions between the TS instability and the traveling cross flow disturbances. The results reveal that a likely cause for the generation of the spikes corresponds to nonlinear interactions between the TS, traveling cross flow, and stationary cross flow disturbances. The spikes begin at low amplitudes of the unsteady and steady disturbances (2-4% U (sub e) (i.e. boundary layer edge velocity)) but can achieve very large amplitudes (20-30 percent U (sub e) (i.e. boundary layer edge velocity)) that initiate an early, though highly intermittent, breakdown to turbulence
- …