1,265 research outputs found
Edge Roman domination on graphs
An edge Roman dominating function of a graph is a function satisfying the condition that every edge with
is adjacent to some edge with . The edge Roman
domination number of , denoted by , is the minimum weight
of an edge Roman dominating function of .
This paper disproves a conjecture of Akbari, Ehsani, Ghajar, Jalaly Khalilabadi
and Sadeghian Sadeghabad stating that if is a graph of maximum degree
on vertices, then . While the counterexamples having the edge Roman domination numbers
, we prove that is an upper bound for connected graphs. Furthermore, we
provide an upper bound for the edge Roman domination number of -degenerate
graphs, which generalizes results of Akbari, Ehsani, Ghajar, Jalaly Khalilabadi
and Sadeghian Sadeghabad. We also prove a sharp upper bound for subcubic
graphs.
In addition, we prove that the edge Roman domination numbers of planar graphs
on vertices is at most , which confirms a conjecture of
Akbari and Qajar. We also show an upper bound for graphs of girth at least five
that is 2-cell embeddable in surfaces of small genus. Finally, we prove an
upper bound for graphs that do not contain as a subdivision, which
generalizes a result of Akbari and Qajar on outerplanar graphs
THE ACUTE EFFECT OF UPPER EXTREMITY PLYOMETRIC TRAINING
The purpose of this study was to probe the acute effect of the performance of upper extremity muscle groups after the plyometric training intervention. The participants were 13 healthy male college students. The force transducers (300kg, 200 Hz) and EMG sensor (1000 Hz) were taken to diagnose the acute effects of strength and muscle activation done by upper extremity pre and post plyometric training (load :24kg, 12 repetiiion times Iset, 3 set), and pair t-test was taken to test the significance(a=.05). The result showed that the strength after the upper extremity plyometric training intervention obviously had decreased 8% (
A Simple Model for Cavity Enhanced Slow Lights in Vertical Cavity Surface Emission Lasers
We develop a simple model for the slow lights in Vertical Cavity Surface
Emission Lasers (VCSELs), with the combination of cavity and population
pulsation effects. The dependences of probe signal power, injection bias
current and wavelength detuning for the group delays are demonstrated
numerically and experimentally. Up to 65 ps group delays and up to 10 GHz
modulation frequency can be achieved in the room temperature at the wavelength
of 1.3 m. The most significant feature of our VCSEL device is that the
length of active region is only several m long. Based on the experimental
parameters of quantum dot VCSEL structures, we show that the resonance effect
of laser cavity plays a significant role to enhance the group delays
Rdzeniowy zespół twarzowo-palcowy: częsty zespół w nietypowej lokalizacji
Background and purpose
Cheiro-oral syndrome (COS) is an established neurological entity characterized by a sensory impairment confined to the mouth angle and ipsilateral finger(s)/ hand. The current understanding of localization is a concomitant involvement of the spinothalamic and trigeminothalamic tract between the cortex and pons. The cervical spinal cord has not been mentioned in this situation yet, and this unusual location may heretofore increase the risk of misdiagnosis.
Material and methods
Six patients who presented with unilateral COS due to cervical cord disorder are reported.
Results
All patients were women and their age ranged between 42 and 70 years. Their neurological deficits included unilateral paraesthesiae restricted to cheiro-oral distribution, positive radicular sign, and mild change of tendon reflex. Cervical spinal stenosis at middle/lower cervical spine with variable magnitude of cord compression and intrinsic cord damage was found. A diagnostic dilemma obviously arises from the lack of tangible neurological signs or typical pattern of myelopathy, in addition to the previous concept of cerebral involvement. A benign course ensued in all reported patients.
Conclusions
Cheiro-oral syndrome can be an early neurological sign for cervical cord disorder; it further suggests that it is a strong neurological but weak localizing sign. A reciprocal influence of multiple factors is considered to generate COS at the cervical cord. Therefore, an absence of brain pathology should lead to a thorough examination of the cervical cord in case of COS.Wstęp i cel pracy
Zespół twarzowo-palcowy (ZTP) jest znanym zespołem neurologicznym, który cechuje się niedoczulicą ograniczoną do kącika ust i palców ręki lub ręki po tej samej stronie. Bieżący stan wiedzy dotyczący lokalizacji uszkodzenia w tym zespole wskazuje na jednoczesne zajęcie dróg rdzeniowo-wzgórzowej i trójdzielno-wzgórzowej pomiędzy mostem i korą mózgową. W tym kontekście nie wymieniano dotąd uszkodzenia rdzenia kręgowego w odcinku szyjnym, a taka nietypowa lokalizacja uszkodzenia może zwiększyć ryzyko błędnego rozpoznania miejsca uszkodzenia.
Materiał i metody
W pracy przedstawiono dane dotyczące 6 pacjentek z jednostronnym ZTP spowodowanym występowaniem nieprawidłowości w obrębie rdzenia kręgowego.
Wyniki
Zakres wieku pacjentek wynosił od 42 do 70 lat. Objawy neurologiczne obejmowały jednostronne parestezje ograniczone do obszaru twarzy i ręki, objaw korzeniowy i niewielkie nieprawidłowości w zakresie odruchów głębokich. Stwierdzono występowanie zwężenia kanału kręgowego w środkowej lub dolnej części odcinka szyjnego z uciskiem rdzenia kręgowego i uszkodzeniem wewnątrz rdzenia kręgowego. Wątpliwości diagnostyczne wynikały z braku typowych objawów neurologicznych mielopatii i stwierdzenia lokalizacji zmian nieodpowiadającej wcześniejszym opiniom na temat mózgowego pochodzenia zespołu. U wszystkich opisywanych pacjentek przebieg schorzenia był łagodny.
Wnioski
Zespół twarzowo-palcowy może być wczesnym objawem neurologicznym nieprawidłowości w obrębie rdzenia kręgowego. Stanowi istotny objaw neurologiczny, ale jego wartość lokalizacyjna jest niewielka. Powstawanie ZTP wskutek uszkodzenia rdzenia kręgowego wynika z wzajemnych oddziaływań wielu czynników. W razie braku uchwytnej patologii mózgu należy w przypadkach ZTP przeprowadzić szczegółowe badania rdzenia kręgowego w odcinku szyjnym
The Liquid Sensor Using Thin Film Bulk Acoustic Resonator with C-Axis Tilted AlN Films
Dual-mode thin film bulk acoustic resonator (TFBAR) devices are fabricated with c-axis tilted AlN films. To fabricate dual-mode TFBAR devices, the off-axis RF magnetron sputtering method for the growth of tilted piezoelectric AlN thin films is adopted. In this report, the AlN thin films are deposited with tilting angles of 15° and 23°. The frequency response of the TFBAR device with 23° tilted AlN thin film is measured to reveal its ability to provide dual-mode resonance. The sensitivities of the longitudinal and shear modes to mass loading are calculated to be 2295 Hz cm2/ng and 1363 Hz cm2/ng with the mechanical quality factors of 480 and 287, respectively. The sensitivities of the longitudinal and shear modes are calculated to be 0 and 15 Hz cm2/μg for liquid loading
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