Publications

أسئلة علم الاجتماع في علم الاجتماع الانعكاسي

COVID-19: From Lockdown to Recovery

The Nature of Star-Like Nuclei in Late-Type Galaxies

A Simple Model of the Treloar—Kearsley Instability

The Treloar—Kearsley instability is studied in the framework of membrane theory. The phenomenon considered is the bifurcation of an equibiaxial stretch of a thin square elastic sheet, in equilibrium under equibiaxial dead loads, to a rectangle at a critical value of the load. The membrane setting, in which the sheet is regarded as an elastic surface, leads to sharper results on the stability of equilibria than those delivered by conventional elasticity theory. Further, definite conclusions can be drawn under weaker constitutive hypotheses. These are illustrated through the use of a particular strain-energy function which renders the analysis nearly trivial.

Supplementary Figure 3 from Centrosomal PKCβII and Pericentrin Are Critical for Human Prostate Cancer Growth and Angiogenesis

Supplementary Figure 3 from Centrosomal PKCβII and Pericentrin Are Critical for Human Prostate Cancer Growth and Angiogenesis

Dynamic manipulation and separation of individual semiconducting and metallic nanowires

DIC-calibrated mechanical testing data

The DIC related data

KAIT Discovery and Robotic Follow-up of a young SN Ia in NGC5669

The Anti-Inflammatory Effects of Chinese Herbs, Plants, and Spices

Of all the herbal pharmacopoeias of the many ancient civilizations, those from China have the longest history and form perhaps the most complex and intricate systems of all forms of empiric medicine. The Chinese pharmacopoeia is a treasure chest of pharmacological products, derived from plants, animals and minerals, which have been used to treat patients for over 5000 yr. In contrast to drugs used in Western medicine, which go through rigorous scientific study before being presented to the public, most of the herbal preparations or animal products used in Chinese medicine were developed by trial and error and have been handed down from physician to student, generation after generation. The enormity of this experience should not be lost on the reader. Thousands of products have been identified that have beneficial effects in thousands of diseases, without the help of the fundamental biochemical and biophysical knowledge and without the benefit of a double-blinded, placebo-controlled study method. Over the entire planet, other ancient civilizations have undergone the same evolution, from the Egyptians, to the Greeks, the Romans, Hindus, and American Indians. All of these cultures have their own collection of pharmaceutical and herbal products used in folklore medicine. Oftentimes, the same plant has been independently identified to work in the same disease states by cultures thousands of miles apart, separated in time by thousands of years, with completely different medical theories and doctrines.

Ultrahigh spontaneous emission quantum efficiency, 99.7% internally and 72% externally, from AlGaAs/GaAs/AlGaAs double heterostructures

Optically thin AlGaAs/GaAs/AlGaAs double heterostructures, (5000 Å), are floated off their substrates by the epitaxial liftoff technique and mounted on various high reflectivity surfaces. From the absolute photoluminescence intensity, we measure internal and external quantum efficiencies of 99.7% and 72%, respectively. High spontaneous emission quantum efficiency, is important for photon number squeezed light, diode lasers, single-mode light-emitting-diodes, optical interconnects, and solar cells.

Doubly-dendronized linear polymers

Doubly-dendronized polymers were synthesized by grafting polybenzyl ether dendrons onto a poly(hydroxy) styrene polymer with polyaliphatic esters.

The Effect of Alkali Metal Cations on The Structure of Dissolved Silicate Oligomers

Multiphoton vibrational pumping on optically prepared NO2 molecules

Hidden-Action in Network Routing

In communication networks, such as the Internet or mobile ad-hoc networks, the actions taken by intermediate nodes or links are typically hidden from the communicating endpoints; all the endpoints can observe is whether or not the end-to-end transmission was successful. Therefore, in the absence of incentives to the contrary, rational (i.e., selfish) intermediaries may choose to forward messages at a low priority or simply not forward messages at all. Using a principal-agent model, we show how the hidden-action problem can be overcome through appropriate design of contracts in both the direct (the endpoints contract with each individual router directly) and the recursive (each router contracts with the next downstream router) cases. We further show that, depending on the network topology, per-hop or per-path monitoring may not necessarily improve the utility of the principal or the social welfare of the system.

Magnetic phase diagram of a spin-1 condensate in two dimensions with dipole interaction

Several new features arise in the ground-state phase diagram of a spin-1\ncondensate trapped in an optical trap when the magnetic dipole interaction\nbetween the atoms is taken into account along with confinement and spin\nprecession. The boundaries between the regions of ferromagnetic and polar\nphases move as the dipole strength is varied and the ferromagnetic phases can\nbe modulated. The magnetization of the ferromagnetic phase perpendicular to the\nfield becomes modulated as a helix winding around the magnetic field direction,\nwith a wavelength inversely proportional to the dipole strength. This\nmodulation should be observable for current experimental parameters in\n$^{87}$Rb. Hence the much-sought supersolid state, with broken continuous\ntranslation invariance in one direction and broken global U(1) invariance,\noccurs generically as a metastable state in this system as a result of dipole\ninteraction. The ferromagnetic state parallel to the applied magnetic field\nbecomes striped in a finite system at strong dipolar coupling.\n

The Fourth Element

Reviews of Books

A review of AIMS MCGUINNESS. Path of Empire: Panama and the California Gold Rush. Ithaca, NY and London: Cornell University Press, 2008. Pp. xiii, 249. $35.00 (US).

Effect of copy number and mRNA processing and stabilization on transcript and protein levels from an engineered dual‐gene operon

Abstract To study the effect of mRNA stability and DNA copy number on protein production from a dual‐gene operon, a synthetic operon containing the reporter genes gfp and lacZ under the control of the araBAD promoter was placed in pMB1‐based (approximately 100 copies/cell) and F plasmid‐based (approximately 1 copy/cell) vectors. DNA cassettes encoding secondary structures were placed at the 5' and 3' ends of the genes and a putative RNase E site was placed between the two genes. Although the copy number of the pMB1‐based vectors was approximately 100‐fold greater than the copy number of the F plasmid‐based vectors, transcript and protein levels from the pMB1‐based vector were not 100‐fold greater than from the F plasmid‐based vectors. In identical plasmid backbones, different combinations of mRNA control elements were used to alter steady‐state levels of transcripts. Control elements that amplified the stability of one coding region relative to another amplified the ratio of protein produced from those transcripts. The effects of mRNA stability control elements were greater at low inducer concentrations, where mRNA levels limit protein production, than at high inducer concentrations. Although we can alter mRNA and protein levels through copy number, induction level, and mRNA stability control elements, some aspect of gene expression remains dependent on inherent characteristics of the coding region. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 78: 412–424, 2002.