Acceleration and Particle Field Interactions of Cosmic Rays I: Formalism

The acceleration of ultra high energy cosmic rays is conjectured to occur through various interactions with the electromagnetic fields in different astrophysical objects, like magnetic matter clumps, besides the well-known shock and stochastic Fermi mechanisms. It is apparent that the latter are not depending on the particle's charge, quantitatively. Based on this model, a considerable portion of the dynamics, that derives a charged particle parallel to a magnetic field $\mathbf{B}$ and under the influence of a force $\mathbf{F}$, is assumed to be composed of an acceleration by a non-magnetic force $\mathbf{F}_{\parallel}$ and a gyromotion along $\mathbf{B}$ direction, plus drifts in the direction of $\mathbf{F}_{\perp}$. The model and its formalism are introduced. Various examples for drift motions and accelerating forces are suggested. The formalism is given in a non-relativistic version. Obviously, the translation into the relativistic version is standard. In a forthcoming work, a quantitative estimation of the energy gained by charged cosmic rays in various astrophysical objects will be evaluated.Comment: 9 pages, 2 EPS figure

Correlation of the Hippocampal theta rhythm to changes in hypothalamic temperature

Warming and cooling the preoptic anterior hypothalamic area in awake, loosely restrained rabbits was found to evoke theta rhythm. This is consistent with previous studies indicating that theta rhythm is a nonspecific response evoked by stimulation of several sensory modalities. Several studies have correlated theta rhythm with alertness. A neural pathway involving the hypothalamus, the hippocampus, the septal area, and the reticular formation is proposed. Thus, a role of this pathway may be to alert the animal to changes in its body temperature

Generation of Entangled Photon Holes using Quantum Interference

In addition to photon pairs entangled in polarization or other variables, quantum mechanics also allows optical beams that are entangled through the absence of the photons themselves. These correlated absences, or ``entangled photon holes'', can lead to counter-intuitive nonlocal effects analogous to those of the more familiar entangled photon pairs. Here we report an experimental observation of photon holes generated using quantum interference effects to suppress the probability that two photons in a weak laser pulse will separate at an optical beam splitter.Comment: 4 pages, color figures, submitted to Phys. Rev.

Correlation of hippocampal theta rhythm with changes in cutaneous temperature

A possible role for the hippocampus in alerting an animal to changes in cutaneous temperature was examined. Following local warming or cooling of the ears of unanesthetized, loosely restrained rabbits, theta waves (4-7 Hz EEG waves) were recorded from electrodes straddling the hippocampus. The onset of the hippocampal theta rhythm was correlated with changes in cutaneous temperature, an observation consistent with studies indicating that the theta rhythm is a nonspecific response evoked by stimulation of several sensory modalities. Additional data from cats and rabbits were correlated with specific neurons within the hippocampus, namely pyramidal cells. Post stimulus time histograms obtained by excitation of the dorsal fornix were interpreted in terms of excitatory and inhibitory inputs to pyramidal cells. Thus, the theta rhythm, which appears to be evoked by changes in cutaneous temperature, can be related to a specific type of hippocampal neuron which is in turn connected with other areas of the brain involved in temperature regulation

Non-diffracting Optical Beams in a Three-level Raman System

Diffractionless propagation of optical beams through atomic vapors is investigated. The atoms in the vapor are operated in a three-level Raman configuration. A suitably chosen control beam couples to one of the transitions, and thereby creates a spatially varying index of refraction modulation in the warm atomic vapor for a probe beam which couples to the other transition in the atoms. We show that a Laguerre-Gaussian control beam allows to propagate single Gaussian probe field modes as well as multi-Gaussian modes and non-Gaussian modes over macroscopic distances without diffraction. This opens perspectives for the propagation of arbitrary images through warm atomic vapors.Comment: 8 pages, 7 figure

Measuring the Impact of Higher Education in Promoting Sustainable Development Goals: Analysis of the Arab universities’ performance

Sustainability's global importance has amplified the role of universities in achieving the UN Sustainable Development Goals (SDGs) through research, education, and community engagement. Aim: This study aims to provide valuable insights into the role of Arab universities in promoting sustainability within the context of global higher education. Approach and methods: This study analyzes the performance of 200 universities from 15 Arab countries in the THE IMPACT Rankings. Their performance was compared to 135 universities from three of the leading world-class higher education systems: Canada, UK, and USA. Results: A global demand for sustainable development, Arab universities face challenges in improving their contributions to the SDGs and sustainability rankings. Despite the impressive growth in the participation of Arab universities in THE IMPACT Rankings yet lags in quality and impact of Arab universities contributions towards SDGs. Conclusion: The policy implications underscore the importance of institutional commitment to sustainability in Arab universities, urging the alignment of policies, funding, and curriculum with the United Nations Sustainable Development Goals (SDGs). Arab universities need to bridge performance gaps, promote green initiatives, and contribute effectively to the achievement of SDGs while recognizing the diverse socio-economic context and priorities of the Arab region.Globalne znaczenie zrównoważonego rozwoju spotęgowało rolę uniwersytetów w realizacji Celów Zrównoważonego Rozwoju (SDG) ONZ poprzez badania, edukację i zaangażowanie społeczności. Cel: Celem tego badania jest dostarczenie cennych spostrzeżeń dotyczących roli uniwersytetów arabskich w promowaniu zrównoważonego rozwoju w kontekście globalnego szkolnictwa wyższego. Podejście i metody: Badanie to analizuje wyniki 200 uniwersytetów z 15 krajów arabskich w rankingach THE IMPACT. Ich wyniki porównano z 135 uniwersytetami z trzech czołowych światowych systemów szkolnictwa wyższego: Kanady, Wielkiej Brytanii i USA. Wyniki: W obliczu globalnego zapotrzebowania na zrównoważony rozwój, uniwersytety arabskie napotykają wyzwania w poprawie swojego wkładu w SDG i rankingi zrównoważoności. Pomimo imponującego wzrostu udziału uniwersytetów arabskich w rankingach THE IMPACT, jest jeszcze wiele do zrobienia w zakresie jakości i wpływu ich wkładu w SDG. Wnioski: Implikacje polityczne podkreślają znaczenie zobowiązania instytucjonalnego do zrównoważonego rozwoju w uniwersytetach arabskich, nawołując do dostosowania polityk, finansowania i programów nauczania do Celów Zrównoważonego Rozwoju (SDG) ONZ. Uniwersytety arabskie muszą zniwelować luki w wynikach, promować inicjatywy zielone i efektywnie przyczyniać się do osiągnięcia SDG, uwzględniając różnorodny kontekst społeczno-ekonomiczny i priorytety regionu arabskiego. &nbsp