Characterization of a planar microcoil for implantable microsystems

This paper discusses the modelling, design and characterization of planar microcoils to be used in telemetry systems that supply energy to miniaturized implants. Parasitic electrical effects that may become important at a.c. frequencies of several megahertz are evaluated. The fabrication process and electrical characterization of planar receiver microcoils will be described, and it will be shown that a power of a few milliwatts is feasible.\u

The Effects of Carrier Ligands on Cisplatin Binding to Cysteine and Methionine

We have reacted several derivatives of the anticancer drug cisplatin with N-acetyl-Lcysteine (N-AcCys) and N-acetyl-L-methionine (N-AcMet), which are two of the primary amino acid targets of platinum. NMR spectroscopy was used to monitor the reactions and determine the effect the different ligands would have on the platinum reactivity. Several of the platinum compounds were tested at pH of 4 and 7, and with platinum:amino acid ratios of 1:1, 2:1 and 1:2. Competition reactions between cysteine and methionine were done to confirm which would react with the platinum compound first. [Pt(dien)(NO3)]+ reacts faster with methionine than with cysteine at both pH 4 and 7 at a 1:1:1 ratio. [Pt(N,N,N\u27,N\u27,N -pentamethyldiethylenetriamine)(NO3)]+ reacts with methionine faster at pH 4 but with cysteine faster at pH 7. This is most likely due to the thiol in the cysteine starting to deprotonate around pH 7. [Pt(Me4en)(NO3)2] (Me4en = N,N,N\u27,N\u27-tetramethylethylenediamine) forms several products with N-AcCys at both pH 4 and 7, with the amounts of the products varying depending on the ratio of platinum and Cys. Mass spectrometry indicated one product as {[Pt(Me4en)(H2O)]2(N-AcCys)}2+, with two platinum compounds coordinated to a single cysteine. Lastly Pt[(en)(NO3)2] when reacting with N-AcCys at a ratio of 1:1 will coordinate with 2 different Cys molecules. With an excess of Pt the complex prefers to bind to only 1 Cys

Observations of the "Thermal Offset" in Near-Surface Mean Annual Ground Temperatures at Several Sites near Mayo, Yukon Territory, Canada

Temperature profiles in the surface layers of the ground were measured frequently over a 12-month period beginning in May 1984 at seven sites near Mayo, Yukon Territory. Permafrost is present at six of the sites. The mean annual ground temperature profile at each site displays a thermal offset, with measured mean annual temperatures in the active layer up to 1.7 degrees C higher than in permafrost. Similar mean annual soil temperature profiles are presented from other stations in northern Canada and the U.S.S.R. Such near-surface inflections are not included in conventional models of the thermal regime of permafrost. The data indicate that equilibrium or aggrading permafrost may be present at sites where the mean annual ground surface temperature is above 0 degrees C.Key words: permafrost, soil temperatureMots clés: pergélisol, température du so

Biodiversity of nematode assemblages from the region of the Clarion-Clipperton Fracture Zone, an area of commercial mining interest

BACKGROUND: The possibility for commercial mining of deep-sea manganese nodules is currently under exploration in the abyssal Clarion-Clipperton Fracture Zone. Nematodes have potential for biomonitoring of the impact of commercial activity but the natural biodiversity is unknown. We investigate the feasibility of nematodes as biomonitoring organisms and give information about their natural biodiversity. RESULTS: The taxonomic composition (at family to genus level) of the nematode fauna in the abyssal Pacific is similar, but not identical to, the North Atlantic. Given the immature state of marine nematode taxonomy, it is not possible to comment on the commonality or otherwise of species between oceans. The between basin differences do not appear to be directly linked to current ecological factors. The abyssal Pacific region (including the Fracture Zone) could be divided into two biodiversity subregions that conform to variations in the linked factors of flux to the benthos and of sedimentary characteristics. Richer biodiversity is associated with areas of known phytodetritus input and higher organic-carbon flux. Despite high reported sample diversity, estimated regional diversity is less than 400 species. CONCLUSION: The estimated regional diversity of the CCFZ is a tractable figure for biomonitoring of commercial activities in this region using marine nematodes, despite the immature taxonomy (i.e. most marine species have not been described) of the group. However, nematode ecology is in dire need of further study

Productivity of Loessal Grasslands in the Kluane Lake Region, Yukon Territory, and the Beringian "Production Paradox"

The Beringian "Production Paradox" is posed by abundant evidence that large ungulates populated unglaciated portions of northwestern North America and adjacent northeast Asia during the late Pleistocene, while botanical data from the same period suggest a poorly productive tundra environment. It is not clear how the large animals sustained themselves, but portions of Beringia, locally in receipt of loess, may have harbored sufficient forage-producing plants to nourish these animals. Loessal soils in the region today are warm and dry in summer, and are often used as rangelands. The loessal hypothesis was examined on grasslands in the Kluane Lake area, southwest Yukon Territory, at sites which have recently received loess blown from the Slims River delta. The biomass and species diversity of grasslands around the lake increase with the quantity of silt in the soil. Likewise, soil fertility indices, including total nitrogen, available nitrogen (NH4), and total carbon, increase with silt content, particularly at sites where the soil surface has been stable for some time, and a "humified" loess (Ahk) horizon has developed. These results support the hypothesis that sites in receipt of loess may have played a significant role in the vegetative productivity of the Beringian ecosystem.Le paradoxe de production Béringien signale que de nombreux indices témoignent de la présence de larges ongulés dans des régions non-glaciées du nord-ouest de l'Amérique du Nord et du nord-est de l'Asie adjacente durant le Pléistocène supérieur, alors que des données botaniques datant de la même époque suggèrent l'existence d'une toundra peu productive. Comment d'aussi larges animaux ont pu subvenir à leurs besoins n'est pas absolument clair mais certaines portions de la Béringie recevant des apports en loess ont pu récéler suffisamment de plantes fourragères pour les nourrir. Aujourd'hui, les sols loessiques de la région sont chauds et secs durant l'été et sont souvent utilisés comme pâturages. L'hypothèse loessique est examinée pour les prairies des environs du lac Kluane, en particulier dans les sites où des loess provenant du delta de la rivière Slims se sont récemment accumulés. La biomasse et la diversité des espèces dans les prairies avoisinant le lac accroissent avec la quantité de silt contenue dans le sol. De même, les indices de fertilité du sol, incluant l'azote total, l'azote libre (NH4) et le carbone total accroissent avec le contenu en silt, particulièrement dans les sites où la surface est demeurée stable durant un certain temps et où un horizon loessique humifié (Ahk) s'est developpé. Ces résultats confirment l'hypothèse que les sites ayant eu des apports en loess ont pu jouer un rôle significatif dans la productivité végétale de l'écosystème Béringien

The Midspan studies

No abstract available

Effects of supplementing methionine and lysine in a lactation diet containing high concentrations of corn by-products

Ninety-six lactating Holstein cows were used to determine the effects of using commercial supplements to supply additional lysine and methionine in diets containing large proportions of corn by-products. Cows were assigned to 1 of 8 pens. Pens were offered rations formulated to differ in metabolizable lysine and methionine supply. The study was divided into 2 periods. During period 1, cows received similar diets, but the treatment diet supplied supplemental lysine and methionine. During period 2, the treatment diet was modified to reduce dietary crude protein. Feed intake and production were monitored daily, and milk components were analyzed 3 days per week for 4 weeks. Diet did not alter feed intake or milk production. During period 2, dietary crude protein and milk urea nitrogen (MUN) were decreased without sacrificing performance.; Dairy Day, 2011, Kansas State University, Manhattan, KS, 2011; Dairy Research, 2011 is known as Dairy Day, 201

Q-switched laser damage of infrared nonlinear materials

Q-switched laser-damage thresholds have been determined for six materials (proustite – Ag3AsS3, pyrargyrite – Ag3SbS3, cinnabar – HgS, silver thiogallate – AgGaS2, tellurium – Te, and gallium arsenide – GaAs) of interest for nonlinear optics in the medium infrared. Four TEM00 mode lasers were employed with outputs at wavelengths of 694 nm, 1.06, 2.098, and 10.6 µm. Damage has been found to be confined to the surface of the crystals and occurs for radiation intensities between 3 and 75 MW/cm2. Particular care is needed in the cutting and polishing of tellurium crystals if a high-damage threshold is to be achieved

Statistics of soliton-bearing systems with additive noise

We present a consistent method to calculate the probability distribution of soliton parameters in systems with additive noise. Even though a weak noise is considered, we are interested in probabilities of large fluctuations (generally non-Gaussian) which are beyond perturbation theory. Our method is a further development of the instanton formalism (method of optimal fluctuation) based on a saddle-point approximation in the path integral. We first solve a fundamental problem of soliton statistics governing by noisy Nonlinear Schr\"odinger Equation (NSE). We then apply our method to optical soliton transmission systems using signal control elements (filters, amplitude and phase modulators).Comment: 4 pages. Submitted to PR