Solar plasma experiment

Solar plasma experiment by Mariner IV space prob

Perfect quantum transport in arbitrary spin networks

Spin chains have been proposed as wires to transport information between distributed registers in a quantum information processor. Unfortunately, the challenges in manufacturing linear chains with engineered couplings has hindered experimental implementations. Here we present strategies to achieve perfect quantum information transport in arbitrary spin networks. Our proposal is based on the weak coupling limit for pure state transport, where information is transferred between two end-spins that are only weakly coupled to the rest of the network. This regime allows disregarding the complex, internal dynamics of the bulk network and relying on virtual transitions or on the coupling to a single bulk eigenmode. We further introduce control methods capable of tuning the transport process and achieve perfect fidelity with limited resources, involving only manipulation of the end-qubits. These strategies could be thus applied not only to engineered systems with relaxed fabrication precision, but also to naturally occurring networks; specifically, we discuss the practical implementation of quantum state transfer between two separated nitrogen vacancy (NV) centers through a network of nitrogen substitutional impurities.Comment: 5+7 page

Ultrahigh Purcell factors and Lamb shifts using slow-light metamaterial waveguides

Employing a medium-dependent quantum optics formalism and a Green function solution of Maxwell's equations, we study the enhanced spontaneous emission factors (Purcell factors) and Lamb shifts from a quantum dot or atom near the surface of a %embedded in a slow-light metamaterial waveguide. Purcell factors of approximately 250 and 100 are found at optical frequencies for $p-$polarized and $s-$polarized dipoles respectively placed 28\thinspace nm (0.02\thinspace $\lambda_{0}$) above the slab surface, including a realistic metamaterial loss factor of $\gamma /2\pi =2 \mathrm{THz}$. For smaller loss values, we demonstrate that the slow-light regime of odd metamaterial waveguide propagation modes can be observed and related to distinct resonances in the Purcell factors. Correspondingly, we predict unusually large and rich Lamb shifts of approximately -1 GHz to -6 GHz for a dipole moment of 50 Debye. We also make a direct calculation of the far field emission spectrum, which contains direct measurable access to these enhanced Purcell factors and Lamb shifts

Quantification of Ophthalmic Changes After Long-Duration Spaceflight, and Subsequent Recovery

A subset of crewmembers are subjected to ophthalmic structure changes due to long-duration spaceflight (>6 months). Crewmembers who experience these changes are described as having Spaceflight Associated Neuro-Ocular Syndrome (SANS). Characteristics of SANS include optic disk edema, cotton wool spots, choroidal folds, refractive error, and posterior globe flattening. SANS remains a major obstacle to deep-space and planetary missions, requiring a better understanding of its etiology. Quantification of ocular, structural changes will improve our understanding of SANS pathophysiology. Methods were developed to quantify 3D optic nerve (ON) and ON sheath (ONS) geometries, ON tortuosity, and posterior globe deformation using MR imaging

Computer Augmented Learning: The Basisof Sustained Knowledge Management

The term learning organization (Senge 1990) has come into wideuse. Watkin (1996) reported that 300 organizations professed to be learning organizations, although many were not. Now the Knowledge Management movement has superseded the learning organization fad. In abandoning the learning organization, the fundamentalimportance of learning may also have been given short shrift. The purpose of this paper is to reinforce learning\u27s preeminent role in the building and sustaining of the knowledge management philosophy. The emphasis should be on the process that enhances knowledge: the capacity for effective action. New computer augmented learning applications can enhance the individual\u27s knowledge that leads to effective task performance. The technology embodied in user interfaces, computer memory, and data bases (or knowledge bases) has evolved so that it is now capable of doing what Doug Englebart (1963) envisioned with his term intellectual augmentation. New learning applications have been developed that have a critical and basic role in the achievement of knowledge management. Several examples of applications in widespread use are provided as evidence of the maturity of computer augmented learning systems. Many leading firms are employing systems that are aimed at capture of critical knowledge, placing it in knowledgebases, and facilitating access for those in the organization who need to learn from that knowledge. A review of some of these knowledge management developments underway and in research underscores the importance of this foundational approach

Giant aneurysmal bone cyst mimicking malignant tumor

Aneurysmal bone cyst (ABC) is a bone tumor which occurs mostly in young adults. Despite its benign character, it may sometimes locally turn malignant and can reach a significant size. Therefore, it is not uncommon for this disease to become similar to a malignant, destructive process and to be difficult to diagnose. We present a case of a 12-year-old girl with a rapidly growing mass in the region of the left hip joint. Imaging (X-ray, MRI, CT) showed a growing lesion in the proximal part of the femur that damaged the cortical layer of the bone. This suggested a presence of rhabdomyosarcoma. The lesion was removed surgically and the bone defects were filled with grafts. Two months after the surgery the patient reported pain in the area of the right groin and left knee. X-ray showed bone lesions in the right pubic bone and the left femoral bone. The biopsy showed no pathological lesions. One year after the surgery, lesions in the X-ray image of the right pubic bone and left femoral bone remitted spontaneously. Ten years after the diagnosis of the aneurysmal bone cyst no recurrence of the disease or other ailments was observed

APOE4 allele disrupts resting state fMRI connectivity in the absence of amyloid plaques or decreased CSF Aβ42

Identifying high risk populations is an important component of disease prevention strategies. One approach is examining neuroimaging parameters that differ in Alzheimer’s disease (AD), including functional connections known to be disrupted within the “default mode network” (DMN). We have previously shown these same disruptions in cognitively normal elderly, who have amyloid-beta (Aβ) plaques detected using PIB PET imaging, suggesting neuronal toxicity of plaques. Here we sought to determine if pathological effects of apolipoprotein E ε4 (APOE4) genotype could be seen independent of Aβ plaque toxicity by examining resting state fMRI functional connectivity (fcMRI ) in participants without preclinical fibrillar amyloid deposition (PIB−). Cognitively normal participants enrolled in longitudinal studies (n = 100, mean age = 62) who were PIB− were categorized into those with and without an APOE 4 allele and studied using fcMRI. APOE 4 allele carriers (E4+) differed significantly from E4− in functional connectivity of the precuneus to several regions previously defined as having abnormal connectivity in a group of AD participants. These effects were observed prior to any manifestations of cognitive changes and in the absence of brain fibrillar amyloid-beta (Aβ) plaque deposition, suggesting that early manifestations of a genetic effect can be detected using fcMRI and that these changes may antedate the pathological effects of fibrillar amyloid plaque toxicity

In Memoriam Professor Emeritus Egon Guttmon

When I think about Egon, the first thing that comes to mind are the memories when we met in 1982 at the Washington College of Law (WCL), where he was working as a full-time faculty member. I was coming at that time from my sabbatical in the Netherlands and as a Fulbright Scholar. From the beginning, Egon sought to provide me with a welcoming environment. He approached me, finding shared backgrounds and interests, which is always greatly appreciated, particularly when you are in a new institution. Egon noted that we both had an intellectual interest in international law. In addition to his teaching and research, Egon has had an important educational experience as a faculty member in Sudan and would often talk to me about the life-changing nature of that academic endeavor

Midday measurements of leaf water potential and stomatal conductance are highly correlated with daily water use of Thompson Seedless grapevines

A study was conducted to determine the relationship between midday measurements of vine water status and daily water use of grapevines measured with a weighing lysimeter. Water applications to the vines were terminated on August 24th for 9 days and again on September 14th for 22 days. Daily water use of the vines in the lysimeter (ETLYS) was approximately 40 L vine−1 (5.3 mm) prior to turning the pump off, and it decreased to 22.3 L vine−1 by September 2nd. Pre-dawn leaf water potential (ΨPD) and midday Ψl on August 24th were −0.075 and −0.76 MPa, respectively, with midday Ψl decreasing to −1.28 MPa on September 2nd. Leaf g s decreased from ~500 to ~200 mmol m−2 s−1 during the two dry-down periods. Midday measurements of g s and Ψl were significantly correlated with one another (r = 0.96) and both with ETLYS/ETo (r = ~0.9). The decreases in Ψl, g s, and ETLYS/ETo in this study were also a linear function of the decrease in volumetric soil water content. The results indicate that even modest water stress can greatly reduce grapevine water use and that short-term measures of vine water status taken at midday are a reflection of daily grapevine water us

Olbrzymia torbiel tętniakowata kości naśladująca nowotwór złośliwy

Torbiel tętniakowata kości (TTK) jest guzem kości, który występuje głównie u młodych dorosłych. Pomimo łagodnego charakteru, czasami jest lokalnie agresywny i może osiągnąć znaczną wielkość. Dlatego nierzadko choroba ta upodabnia się do złośliwego, destrukcyjnego procesu i sprawia trudności diagnostyczne. Przedstawiamy przypadek 12-letniej dziewczynki, u której zauważono gwałtownie rosnącą masę w okolicy stawu biodrowego lewego. W badaniach obrazowych (RTG, MRI, TK) stwierdzono w proksymalnej części kości udowej rozrastającą się zmianę, która uszkadzała warstwę korową kości. Sugerowało to obecność mięśniakomięsaka prążkowanokomórkowego. Zmianę usunięto operacyjnie, wypełniając ubytki kostne przeszczepami. Dwa miesiące po operacji chora zgłosiła dolegliwości bólowe okolicy prawej pachwiny oraz lewego kolana. W badaniu RTG stwierdzono zmiany kostne w prawej kości łonowej oraz lewej udowej. Biopsja nie wykazała zmian patologicznych. W rok od zabiegu operacyjnego zmiany w obrazie RTG prawej kości łonowej oraz lewej kości udowej wycofały się samoistnie. Po 10 latach od rozpoznania torbieli tętniakowatej nie zaobserwowano wznowy choroby ani innych dolegliwości