Polarity-dependent reversible resistance switching in Ge–Sb–Te phase-change thin films

In this paper, we demonstrate reversible resistance switching in a capacitorlike cell using a Ge–Sb–Te film that does not rely on amorphous-crystalline phase change. The polarity of the applied electric field switches the cell resistance between lower- and higher-resistance states, as was observed in current-voltage characteristics. Moreover, voltage pulses less than 1.25 V showed this switching within time scales of microseconds with more than 40% contrast between the resistance states. The latter are found to be nonvolatile for months. The switching could also be achieved at nanoscales with atomic force microscopy with a better resistance contrast of three orders of magnitude.

Repertoire Development and the Control of Cytotoxic/Effector Function in Human γδ T Cells

T cells develop into two major populations distinguished by their T cell receptor (TCR) chains. Cells with the αβ TCR generally express CD4 or CD8 lineage markers and mostly fall into helper or cytotoxic/effector subsets. Cells expressing the alternate γδ TCR in humans generally do not express lineage markers, do not require MHC for antigen presentation, and recognize nonpeptidic antigens. We are interested in the dominant Vγ2Vδ2+ T cell subset in human peripheral blood and the control of effector function in this population. We review the literature on γδ T cell generation and repertoire selection, along with recent work on CD56 expression and defining a cytotoxic/effector lineage within the phosphoantigen-reactive Vγ2Vδ2 cells. A unique mechanism for MHC-independent repertoire selection is linked to the control of effector function that is vital to the role for γδ T cells in tumor surveillance. Better understanding of these mechanisms will improve our ability to exploit this population for tumor immunotherapy

Ultra high density scanning electrical probe phase-change memory for archival storage

The potential for using probe-based phase-change memories for the future archival storage at densities of around 1 Tbit/in.² is investigated using a recording medium comprising a Si/TiN/DLC/GeSbTe/diamond-like carbon (DLC) stack together with a conductive PtSi tip for writing and reading. Both experimental and computational simulation results are presented. The simulations include a physically-realistic threshold switching model, as well as the effects of thermal boundary resistance and electrical contact resistance. The simulated bit size and shape correspond closely to that written experimentally

Ultra-high density scanning electrical probe phase-change memory for archival storage.

In our work, we investigate the recording and readout performance of such phase-change memories and demonstrate experimental and simulation results which are based on a particular medium stack (Si/TiN/DLC/GST/DLC). The recording is achieved by injecting electrical current from a conductive tip to the storage medium to cause phase transformation through Joule heating, while readout is realised by sensing the current variation due to the significant differences in the electrical resistivity between the amorphous and crystalline phases. The experimental results clearly show that a crystalline bit with approximately 30nm diameter can be produced and readback, in good agreement with the corresponding simulations of the write/read processes

Pengaruh Sistem Olah Tanah Dan Aplikasi Mulsa Bagas Terhadap Biomassa Karbon Mikroorganisme Tanah (C-mik) Pada Lahan Pertanaman Tebu (Saccharum Officinarum L.) Tahun Ke-5

Upaya yang dilakukan untuk memperbaiki kualitas lahan yang telah terdegradasi antara lain dengan penerapan sistem tanpa olah tanah (TOT) dan pemberian mulsa bagas. Penelitian ini bertujuan untuk Penelitian ini bertujuan untuk mengetahui pengaruh olah tanah dan aplikasi mulsa bagas terhadap biomassa karbon mikroorganisme tanah (C-mik). Penelitian ini dilakukan dengan menggunakan rancangan petak terbagi dan disusun secara split plot dengan 5 ulangan. Sebagai petak utama adalah perlakuan sistem olah tanah (T) yaitu: T 0 = tanpa olah tanah; T 1 = olah tanah intensif dan anak petak dalam penelitian ini adalah penggunaan limbah pabrik gula (M) yaitu: M 0 = tanpa mulsa ; M 1 = mulsa bagas 80 ton ha -1 . Semua perlakuan diaplikasikan pupuk anorganik NPK, dan aplikasi bahan organik BBA 80 t ha -1 . Data yang diperoleh diuji homogenitasnya dengan Uji Bartlet dan aditivitasnya dengan Uji Tukey, serta uji lanjut dengan Uji Beda Nyata Terkecil (BNT).Hasil penelitian menunjukkan bahwa, sistem olah tanah tidak berpengaruh terhadap C-mik tanah, pada perlakuan aplikasi mulsa bagas hasil C-mik tanah lebih tinggi dibandingkan dengan perlakuan tanpa mulsa bagas pada waktu pengamatan 0, 3 dan 9 BST dan tidak terdapat interkasi antara sistem olah tanah dan aplikasi mulsa bagas terhadap C-mik tanah. Terdapat korelasi antara pH tanah dan suhu tanah dengan C-mik tanah, namun C-organik tanah dan kadar air tanah tidak berkorelasi nyata dengan C-mik tanah

Terrestrial mammals of a sheep-grazing property on Bruny Island, Tasmania

Land-based mammals were surveyed in a mosaic of dry sclerophyll forests and pasture on a sheep-grazing property on Bruny Island, Tasmania, using a range of methods in August 2010. 'This is the first mammal survey of a sheep-grazing property in Tasmania and the first large-scale survey of mammals on Bruny Island. Ten species were recorded comprising seven native and three introduced species. The Little Forest Bat, Vespadelus vulturnus, and the Black Rat, Rattus rattus, were recorded for the first time on Bruny Island, although both are probably long-term residents. No mammal species listed as rare or threatened under Tasmanian or Australian legislation were found on the property. Large numbers of Eastern Quolls, Dasyurus viverrinus, Brushtail Possums, Trichosurus vulpecula, Tasmanian Pademelons, Thylogale billardierii, and Bennetts Wallabies, Macropus rufogriseus, were recorded in a range of dry sclerophyll forests and in pasture. Longnosed Potoroos, Potorous tridactylus, were recorded widely on the property in native vegetation with relatively thick ground cover. Eastern Quoll capture rates were highest in pasture areas and in Eucalyptus ovata forest. Brushtail Possums, Long-nosed Potoroos, Tasmanian Pademelons and Bennetts Wallabies were virtually unrecorded from E. tenuiramis forest and woodlands. Given the level of survey effort and their potential to occur on the property it was remarkable that no Tasmanian Bettong, Bettongia gaimardi, Eastern Barred Bandicoot, Perameles gunnii, Southern Brown Bandicoot, lsoodon obesulus, or introduced House Mouse, Mus musculus, were recorded. We found that camera trapping was more cost-efficient than cage trapping for detecting the presence of mammals on "Murrayfield". Recommendations for ongoing management and monitoring of mammals are provided

Clonal Selection and Population Dynamics of Vγ2/Vδ2 T Cells in Macaca Fascicularis

HIV infection increases the susceptibility to new M. tuberculosis (Mtb) infections, the risk of reactivating latent infections and the risk of rapid TB progression. γδ T cells, in particular the Vγ2Jγ1.2 subset, are thought to be part of the innate immune response to both HIV and Mtb. Importantly, both HIV and Mtb perturb gd T cells homeostasis, causing a profound and highly specific depletion of the Vγ2Jγ1.2 subset

Influence of TRPV1 on diabetes-induced alterations in thermal pain sensitivity

A common complication associated with diabetes is painful or painless diabetic peripheral neuropathy (DPN). The mechanisms and determinants responsible for these peripheral neuropathies are poorly understood. Using both streptozotocin (STZ)-induced and transgene-mediated murine models of type 1 diabetes (T1D), we demonstrate that Transient Receptor Potential Vanilloid 1 (TRPV1) expression varies with the neuropathic phenotype. We have found that both STZ- and transgene-mediated T1D are associated with two distinct phases of thermal pain sensitivity that parallel changes in TRPV1 as determined by paw withdrawal latency (PWL). An early phase of hyperalgesia and a late phase of hypoalgesia are evident. TRPV1-mediated whole cell currents are larger and smaller in dorsal root ganglion (DRG) neurons collected from hyperalgesic and hypoalgesic mice. Resiniferatoxin (RTX) binding, a measure of TRPV1 expression is increased and decreased in DRG and paw skin of hyperalgesic and hypoalgesic mice, respectively. Immunohistochemical labeling of spinal cord lamina I and II, dorsal root ganglion (DRG), and paw skin from hyperalgesic and hypoalgesic mice reveal increased and decreased TRPV1 expression, respectively. A role for TRPV1 in thermal DPN is further suggested by the failure of STZ treatment to influence thermal nociception in TRPV1 deficient mice. These findings demonstrate that altered TRPV1 expression and function contribute to diabetes-induced changes in thermal perception

Anomalous Proximity Effect in Underdoped YBaCuO Josephson Junctions

Josephson junctions were photogenerated in underdoped thin films of the YBa$_2$Cu$_3$O$_{6+x}$ family using a near-field scanning optical microscope. The observation of the Josephson effect for separations as large as 100 nm between two wires indicates the existence of an anomalously large proximity effect and show that the underdoped insulating material in the gap of the junction is readily perturbed into the superconducting state. The critical current of the junctions was found to be consistent with the conventional Josephson relationship. This result constrains the applicability of SO(5) theory to explain the phase diagram of high critical temperature superconductors.Comment: 11 pages, 4 figure