998 research outputs found
Kratkotrajno očuvanje sperme potočne pastrmke (salmo trutta macrostigma): delovanje ekstendera na pokretljivost
Cilj eksperimenta je bila procena spermatoloških parametara kratkotrajno čuvane sperme potočne pastrmke (Salmo trutta macrostigma) korišćenjem različitih ekstendera. Mleč je uzorkovan od odraslih mužjaka istiskanjem rukom, bez anestezije. Po određivanju najvažnijih karakteristika sperme (volumen, pokretljivost, trajanje pokretljivosti, gustina, pH) uzorci sperme koji su pokazali >80 pokretljivosti su prikupljeni i razblaženi u odnosu 1:3 sa tri različita ekstendera.
Razblažena sperma je čuvana 72 sata na 4°C. Tokom čuvanja na svaka 24 h je procenjivan motilitet spermatozoida (%). U zaključku, rezultati studije su pokazali da se ekstender I pokazao boljim od druga 2 za kratkotrajno očuvanje sperme potočne pastrmke
Projections Onto Convex Sets (POCS) Based Optimization by Lifting
Two new optimization techniques based on projections onto convex space (POCS)
framework for solving convex and some non-convex optimization problems are
presented. The dimension of the minimization problem is lifted by one and sets
corresponding to the cost function are defined. If the cost function is a
convex function in R^N the corresponding set is a convex set in R^(N+1). The
iterative optimization approach starts with an arbitrary initial estimate in
R^(N+1) and an orthogonal projection is performed onto one of the sets in a
sequential manner at each step of the optimization problem. The method provides
globally optimal solutions in total-variation, filtered variation, l1, and
entropic cost functions. It is also experimentally observed that cost functions
based on lp, p<1 can be handled by using the supporting hyperplane concept
Shortcuts through Colocation Facilities
Network overlays, running on top of the existing Internet substrate, are of
perennial value to Internet end-users in the context of, e.g., real-time
applications. Such overlays can employ traffic relays to yield path latencies
lower than the direct paths, a phenomenon known as Triangle Inequality
Violation (TIV). Past studies identify the opportunities of reducing latency
using TIVs. However, they do not investigate the gains of strategically
selecting relays in Colocation Facilities (Colos). In this work, we answer the
following questions: (i) how Colo-hosted relays compare with other relays as
well as with the direct Internet, in terms of latency (RTT) reductions; (ii)
what are the best locations for placing the relays to yield these reductions.
To this end, we conduct a large-scale one-month measurement of inter-domain
paths between RIPE Atlas (RA) nodes as endpoints, located at eyeball networks.
We employ as relays Planetlab nodes, other RA nodes, and machines in Colos. We
examine the RTTs of the overlay paths obtained via the selected relays, as well
as the direct paths. We find that Colo-based relays perform the best and can
achieve latency reductions against direct paths, ranging from a few to 100s of
milliseconds, in 76% of the total cases; 75% (58% of total cases) of these
reductions require only 10 relays in 6 large Colos.Comment: In Proceedings of the ACM Internet Measurement Conference (IMC '17),
London, GB, 201
SELF-REGULATION OF NOVICE MIDDLE SCHOOL MATHEMATICS TEACHERS IN THE PREPARATION PROCESS FOR TEACHING
This study analyses the self-regulation (goal setting and planning) of the novice middle school mathematics teachers during the preparation phase of teaching. The study is designed as a case study. The participants are six mathematics teachers with less than five-year teaching experience. The data were collected through interviews, observations and document analysis. In regard to the observations, the teaching of certain topics (e.g., basic elements of prisms) were observed to uncover the classroom behavior of the participants. In the semi-structured interviews carried out after the class observations, the participants were asked some questions about their goals and planning concerning the related teaching activities. The findings of the study indicate that the participants do not exhibit the goal setting and planning activities that are consistent with the conceptual learning covered in the mathematics education program. It is also found that they do not set clear goals and develop detailed planning in regard to teaching activities
Theory and analysis of electrode size optimization for capacitive microfabricated ultrasonic transducers
Cataloged from PDF version of article.Theoretical analysis and computer simulations of capacitive microfabricated ultrasonic transducers indicate that device performance can be optimized through judicious patterning of electrodes. The conceptual basis of the analysis is that electrostatic force should be applied only where it is most effective, such as at the center of a circular membrane. If breakdown mechanisms are ignored, an infinitesimally small electrode with an infinite bias voltage results in the optimal transducer, A more realistic design example compares the 3-dB bandwidths of a fully metalized transducer and a partially metalized transducer, each tuned with a lossless Butterworth network. It is found that the bandwidth of the optimally metalized device is twice that of the fully metalized device
Evaluating adult cor triatriatum with total anomalous pulmonary venous connections by multidetector computed tomography angiography
A 19-year-old female patient was admitted to our hospital with dyspnea, chest
pain, and shortness of breath. A chest radiograph showed mild cardiomegaly.
Echocardiography revealed an extra chamber in the heart. To evaluate this
abnormality, ECG-gated 16-detector-row computed tomography angiography
was performed. Multidetector computed tomography (MDCT), showing cor
triatriatum with total anomalous pulmonary venous connections (TAPVC), clearly
revealed cardiac and vascular anatomy. ECG-gated cardiac MDCT is a useful
tool for detection and characterisation of cor triatriatum and related anomalies.
(Folia Morphol 2011; 70, 4: 312–314
SOME ASPECTS OF ENERGY SAVING OF BURDEN MATERIAL IN THE BLAST FURNACE
To determine the possibility of self-stabilization effect for burden
surface texture and gas flow in operating blast furnace under the proper conditions
was experimentally proved for the first time, as well as the reasons of the effect
disruption
Photonuclear reactions with Zinc: A case for clinical linacs
The use of bremsstrahlung photons produced by a linac to induce photonuclear
reactions is wide spread. However, using a clinical linac to produce the
photons is a new concept. We aimed to induce photonuclear reactions on zinc
isotopes and measure the subsequent transition energies and half-lives. For
this purpose, a bremsstrahlung photon beam of 18 MeV endpoint energy produced
by the Philips SLI-25 linac has been used. The subsequent decay has been
measured with a well-shielded single HPGe detector. The results obtained for
transition energies are in good agreement with the literature data and in many
cases surpass these in accuracy. For the half-lives, we are in agreement with
the literature data, but do not achieve their precision. The obtained accuracy
for the transition energies show what is achievable in an experiment such as
ours. We demonstrate the usefulness and benefits of employing clinical linacs
for nuclear physics experiments
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