cssi/SciSciGPT-SciSciNet huggingface dataset:
RNA interference can rebalance the nitrogen sink of maize seeds without losing hard endosperm.

Background One of the goals of plant breeding is to create crops to provide better nutrition for humans and livestock. Insufficient intake of protein is one of the most severe factors affecting the growth and development of children in developing countries. More than a century ago, in 1896, Hopkins initiated the well-known Illinois long-term selection for maize seed protein concentration, yielding four protein strains. By continuously accumulating QTLs, Illinois High Protein (IHP) reached a protein level 2.5-fold higher than normal maize, with the most increased fraction being the zein protein, which was shown to contain no lysine soon after the long-term selection program initiated. Therefore, IHP is of little value for feeding humans and monogastric animals. Although high-lysine lines of non-vitreous mutants were based on reduced zeins, the kernel soft texture precluded their practical use. Kernel hardness in opaque 2 (o2) could be restored in quality protein maize (QPM) with quantitative trait loci called o2 modifiers (Mo2s), but those did not increase total protein levels. Methods The most predominant zeins are the 22- and 19-kDa α-zeins. To achieve a combination of desired traits, we used RNA interference (RNAi) against both α-zeins in IHP and evaluated the silencing effect by SDS-PAGE. Total protein, amino acid composition and kernel texture were analyzed. Conclusions The α-zeins were dramatically reduced, but the high total seed protein level remained unchanged by complementary increase of non-zein proteins. Moreover, the residual zein levels still allowed for a vitreous hard seed. Such dramatic rebalancing of the nitrogen sink could have a major impact in world food supply.
Counter-propagating edge modes and topological phases of a kicked quantum Hall system.

A periodically driven quantum Hall system in a fixed magnetic field is found to exhibit a series of phases featuring anomalous edge modes with the ``wrong'' chirality. This leads to pairs of counter-propagating chiral edge modes at each edge, in sharp contrast to stationary quantum Hall systems. We show that the pair of Floquet edge modes are protected by the chiral (sublattice) symmetry, and that they are robust against static disorder. The existence of distinctive phases with the same Chern and winding numbers but very different edge state spectra points to the important role played by symmetry in classifying topological properties of driven systems. We further explore the evolution of the edge states with driving using a simplified model, and discuss their experimental signatures.
Aromatization by the immature rhesus monkey ovary.

To determine the capacity of the ovary of the immature monkey to synthesize estrogens, incubations were performed on ovaries from 9 prepubertal (age 2–15 months) and 5 adult (greater than 4½ yr of age) rhesus monkeys utilizing3H-androstenedione (3H-Δ44) as substrate. Mean (±SEM)% conversion per 100 mg ovarian tissue of Δ4 to total estrone (E1) and 17β estradiol(E2) by immature monkey ovaries was not significantly different (p > 05) fromconversion by adult ovaries (7.0 ±1.38 vs 4.2 ± 0.28). Differences between immature and adult females for E1, E2, and E2:E1 ratio alsowere not significant (p > .05). These data indicate that the capacity for aromatization is present in the immature monkey ovary by at least 2 months of age, and is not significantly different from the adult ovary.(Endocrinology 94: 1181, 1974)
Aspects of the Feeding Behavior and Trophic Ecology of Suspension-Feeding Rotifers

While the evidence is not yet adequate to provide a general assessment of rotifer feeding in the dynamics of planktonic communities, there can be no question but that the feeding biology of this group is a rich and exciting field for freshwater ecologists and natural historians. Two recent reviews, those of Dumont (1977) and Pourriot (1977), provide ample evidence for this assertion, together summarizing some 70 years of research on rotifer feeding behavior. This paper is a further discussion of certain aspects of the feeding behavior and feeding ecology of free-swimming, suspension-feeding rotifers. I will deliberately omit consideration of sessile or predacious genera since the feeding biology of these forms has been reviewed very recently; sessile rotifers are examined by Wallace (1980) and the predacious genus Asplanchna by Gilbert (1979).
Convection-induced distortion of a solid-liquid interface

Measurements of convective flow fields and solid-liquid interface shapes during the solidification of a pure and a slightly alloyed transparent material reveal that the convective transport of solute can cause a macroscopic depression to develop in the solid-liquid interface. This effect occurs under conditions close to those which are predicted to produce morphological instability of a planar interface. A cellular or dendritic microstructure later develops within the interface depression. The convection is attributed to the effect of radial temperature gradients in the crystal growth apparatus.
Genetic Deletion of the Tumor Necrosis Factor Receptor p60 or p80 Abrogates Ligand-mediated Activation of Nuclear Factor-κB and of Mitogen-activated Protein Kinases in Macrophages

Tumor necrosis factor (TNF) is a pleiotropic cytokine known to regulate cell growth, viral replication, inflammation, immune system functioning, angiogenesis, and tumorigenesis. These effects are mediated through two different receptors, TNFR1 and TNFR2 (also called p60 and p80, respectively), with p60 receptor being expressed on all cell types and p80 receptor only on cells of the immune system and on endothelial cells. Although the role of p60 receptor in TNF signaling is well established, the role of p80 is less clear. In this report, by using macrophages derived from wild-type mice (having both receptors) and mice in which the gene for either p60 (p60−/−), or p80 (p80−/−), or both (p60−/− p80−/−) receptor have been deleted, we have redefined the role of these receptors in TNF-induced activation of nuclear factor (NF)-κB and of mitogen-activated protein kinases. TNF activated NF-κB in a dose- and time-dependent manner in wild-type macrophages but not in p60−/−, p80−/−, or p60−/−p80−/− macrophages. These results correlated with the IκBα degradation needed for NF-κB activation. We also found that TNF activated c-Jun N-terminal protein kinase in a dose- and time-dependent manner in wild-type macrophages but not in p60−/−, p80−/−, or p60−/−p80−/− macrophages. TNF activated p38 MAPK and p44/p42 MAPK in wild-type but not in p60−/−, p80−/−, or p60−/− p80−/−macrophages. TNF induced the proliferation of wild-type macrophages, but for p60−/− and p80−/− macrophages proliferation was lower, and in p60−/−p80−/− it was absent. Overall, our studies suggest that both types of TNF receptors are needed in macrophages for optimum TNF cell signaling.
Transport Rates Vary with Deposition Time in Dip-Pen Nanolithography

By patterning with dip-pen nanolithography using tip dwell times ranging from 15 s to 2 h over a period of 19 h, we show that the transport rate for smaller patterns is different than for larger ones. This transport behavior is found for both 1-octadecanethiol (ODT) and 16-mercaptohexadecanoic acid (MHDA) inks on gold substrates. Additionally, MHDA shows an overall decrease in transport rate as a function of total writing time during such experiments. These results indicate that measurements with short dwell times are insufficient to determine transport rates for larger features.
α/310-Helix transitions in α-methylalanine homopeptides: Conformational transition pathway and potential of mean force

The conformational transition between the alpha- and 3(10)-helical states of alpha-methylalanine homopeptides is studied with molecular mechanics. Conformational transition pathways for Ace-(MeA)n-NMe with n = 7, 9, and 11 are obtained with the algorithms of Elber and co-workers [R. Czerminski & R. Elber (1990) International Journal of Quantum Chemistry, Vol. 24, pp. 167-186; A. Ulitsky & R. Elber (1990) Journal of Chemical Physics, Vol. 92, pp. 1510-1511]. The free energy surface, or potential of mean force, for the conformational transition of Ace-(MeA)9-NMe is calculated from molecular dynamics simulations, and a method is presented for the decomposition of the free energy surface into the constituent energetic and entropic terms, via the calculation of the required temperature derivatives in situ. For the AMBER/OPLS model employed here, the conformational transition pathways each contain a single 3(10)-helical-like transition state, and the transition state potential energy relative to the 3(10)-conformation is 3 kcal/mol, independent of peptide length. Entropic stabilization in the barrier region significantly lowers the activation free energies for the forward and reverse transitions from the estimates of the barrier heights based simply on potential energy alone.
The origins of positron emission tomography

The development of positron emission tomography (PET) took place through the combination of the following recognitions: (1) a handful of short-lived, positron-emitting radionuclides, carbon-11, nitrogen-13, and oxygen-15, exhibit chemical properties that render them particularly suitable for the tracing of important physiological pathways, and (2) the radiation emitted as a result of the annihilation of positrons in matter exhibited physical properties that made it well-suited for nuclear medicine imaging, particularly for tomographic reconstruction. The scientific building blocks that were necessary for the structure of PET were contributed over a period of several decades by many investigators in physics, mathematics, chemistry, and fundamental biology.
CGS algorithms for constrained extremization of functions

CGS (conjugate Gram-Schmidt) algorithms are given for computing extreme points of a real-valued functionf(x) ofn real variables subject tom constraining equationsg(x)=0,M<n. The method of approach is to solve the system $$\begin{gathered} f'(x) + g'(x)*\lambda = 0 \hfill \\ g(x) = 0 \hfill \\ \end{gathered} $$ where λ is the Lagrange multiplier vector, by means of CGS algorithms for systems of nonlinear equations. Results of the algorithms applied to test problems are given, including several problems having inequality constraints treated by adjoining slack variables.
Effect of Addition Pattern on the Electrochemical and Spectroscopic Properties of Neutral and Reduced 1,2- and 1,4-(C6H5CH2)2C60 Isomers

The spectral and electrochemical properties of isomeric 1,2- and 1,4-adducts of fullerenes of the type R2C60 have been examined in their neutral, singly and/or doubly reduced forms. The first reduction potentials of 1,2- and 1,4-(C6H5CH2)2C60 in PhCN containing 0.1 M TBAP are the same within experimental error but the second and third reductions of the two isomers differ by 50 mV, with the 1,2-isomer being easier to reduce. Much larger differences, however, are seen in the near-IR spectra of the singly and doubly reduced organofullerene isomers. The monoanion of 1,2-R2C60 possesses an absorption band at about 1000 nm, while the dianion has a band at around 900 nm. The 1,4-R2C60 derivatives also show bands at similar wavelengths in their monoanionic and dianionic forms, but there is a second near-IR band at 1500 (monoanion) or 1300 nm (dianion).
Assessment of Etest as an Alternative to Agar Dilution for Antimicrobial Susceptibility Testing of Neisseria gonorrhoeae

ABSTRACT We studied whether the Etest can be used as an alternative to agar dilution to determine antimicrobial susceptibilities of ceftriaxone, cefixime, and cefpodoxime in Neisseria gonorrhoeae surveillance. One hundred fifteen clinical and laboratory isolates of N. gonorrhoeae were tested following the Clinical Laboratory Improvement Amendments (CLIA)-approved CLSI standard agar dilution method and, separately, by the Etest according to the manufacturer9s recommendations. The MICs were determined and compared. Ten laboratory-generated mutants were used to simulate substantially nonsusceptible specimens. The Etest and agar dilution methods were well correlated. Statistical tests produced regression R2 values of 88%, 82%, and 85% and Pearson correlation coefficients of 92%, 91%, and 92% for ceftriaxone, cefixime, and cefpodoxime, respectively. When paired comparisons were made, the two tests were 88.7%, 80%, and 87% within 1 log2 dilution from each other for ceftriaxone, cefixime, and cefpodoxime, respectively. The within-2-log2 agreements were 99.1%, 98.3%, and 94.8% for ceftriaxone, cefixime, and cefpodoxime, respectively. Notwithstanding the good correlations and the within-2-log2 general agreement, the Etest results produced slightly lower MICs than the agar dilution results. In conclusion, we found that the Etest can be effectively used as an alternative to agar dilution testing to determine the susceptibility of N. gonorrhoeae to ceftriaxone, cefixime, and cefpodoxime, although we recommend further research into extremely resistant isolates. For isolates within the typical range of clinical MICs, reexamination of the Etest interpretation of susceptible and nonsusceptible categories would likely allow for successful transition from agar dilution to the Etest.
Ex situ annealing method for c-axis oriented barium ferrite thick films

A barium hexaferrite (BaFe12O19, magnetoplumbite structure, BaM) multilayered film, with a total thickness of 0.63 μm, was deposited on a Si substrate by stacking several 0.09 μm layers using a rf sputtering technique. Each 0.09 μm layer was ex situ annealed at 800 °C for 10 min prior to deposition of the succeeding layer. A vibrating sample/torque magnetometer was employed to characterize the magnetic properties of both the BaM multilayered and a single layered film of the same thickness. The 0.63 μm thick BaM multilayered and single layered films show a squareness (SQ=Mr/Ms at 7 kOe) of 0.81 and 0.62, respectively. An anisotropy field (HA) was found to be 17 kOe for the BaM multilayered film and 14.5 kOe for the single layered film. A stacking of BaM layers, with ex situ annealing between each layer, improves the c-axis orientation and anisotropy field as compared to a single layered film with the same thickness. This is attributed to limiting the number of nucleation sites for randomly oriented BaM cry...
Designing Group Sequential Trials with Survival Endpoints

This paper discusses an algorithm to calculate information about the trial that is needed at the design stage implemented as an S-plus function. The function allows the user to specify arbitrary length of accrual, control, and treatment survival distributions; number and timing of interim analyses; stopping boundaries or an alpha-spending function; and which member of the Harrington-Fleming Gρ class of statistics it is. Three examples from real treatment protocols are presented.
Cis-platinum treatment for malignancy-associated humoral hypercalcemia in an athymic mouse model.

We have established a model for malignancy-associated humoral hypercalcemia (MAHH) in athymic mice, utilizing a human squamous cell lung carcinoma. In the present studies, we evaluated cis-platinum (DDP), a cytotoxic agent known to produce hypomagnesemia, and occasionally hypocalcemia, in the treatment of MAHH. Upon development of significant hypercalcemia, defined as serum calcium (Ca)⩾11.5 mg/dl, tumor-bearing mice received either normal saline (NS) alone (1.5 ml/day, i.p.), or NS+DDP. The DDP was given as a single dose of 6 µg/g body weight i.p. Serum Ca was determined on day 6 in surviving mice (6 of 10 survived in the NS-alone group; 7 of 10 survived in the NS+DDP group). Serum Ca (mean±SE) decreased from 14.3±0.46 to a nadir of 12.7±0.33 mg/dl in the NS-alone group, and from 13.5±0.46 to a nadir of 10.4±0.48 mg/dl in the NS+DDP group. Nadir serum Ca levels were significantly lower in the NS+DDP group (P=0.003). Three of 7 surviving NS+DDP mice achieved normocalcemia, whereas none of the NS-alone animals became normocalcemic. Tumor volumes increased in all animals. There was no change in the serum Ca in 5 tumor-free mice treated with NS+DDP. There were no significant differences in serum magnesium levels among groups of control mice, tumor-free mice treated with NS+DDP, tumor-bearing mice treated with NS+DDP, and tumor-bearing mice treated with NS-alone. We conclude that DDP is an effective agent for the treatment of MAHH, through a mechanism distinct from its antitumor cytotoxic effect and its potential to produce hypomagnesemia.
TICKS ON WHITE-TAILED DEER FAWNS FROM SOUTHERN ILLINOIS

Seventy-six white-tailed deer (Odocoileus virginianus (Zimmermann)) fawns captured on Crab Orchard National Wildlife Refuge in southern Illinois during June–July 1980–1983 were aged and examined for ticks. The prevalence of ticks (Amblyomma americanum (Linnaeus, 1758) and Dermacentor variabilis (Say, 1821)) was 80% intensity of infestation ranged from one to 123 ticks per fawn, averaging 21.6. Tick intensity correlated poorly with age suggesting that there were other, more important determinants of infestation rates. Packed cell volumes in blood of the fawns increased significantly with age, but were not significantly affected by existing tick intensities. Ticks were not directly or indirectly implicated in any of 16 mortalities that occurred among 61 radio-collared fawns monitored for approximately 6 mo post-partum, and were not considered a serious health problem for fawns on the study area.
Protein, cholesterol, acid phosphatase and aspartate aminotransaminase in the seminal plasma of turkeys (Meleagris gallopavo) producing normal white or abnormal yellow semen.

Turkeys which produce yellow semen have abnormal ductuli efferentes’ epithelial morphology, with b!ebbing of cytoplasmic material into the ductal lumen. This could possibly increase the activity or concentration of seminal plasma components. In the present study, seminal plasma from 270 Large White breeder turkeys was evaluated for protein and cholesterol concentrations and the activities of acid phosphatase and asparate aminotransaminase. In a separate experiment, protein concentrations of turkey seminal plasma were estimated by biuret or Bradford methods. Bradford estimates were 46.6% less than those obtained with the biuret assay, using bovine serum albumin as the standard. Estimates of seminal plasma protein concentration in the main study were obtained using the Bradford method, and should be adjusted accordingly when compared with other studies using the biuret technique. Abnormal yellow seminal plasma, compared to normal white seminal plasma, had elevated levels of total protein and cholesterol and increased activities of acid phosphatase and aspartate aminotransasninase. Overall means were: 14.3 mg/mI, 38.9 mg/dl, 232.6 lU/mI, 81.0 lU/mI, respectively. Correlation coefficients for cholesterol concentration, acid phosphatase and aminotransaminase activity with protein concentration were +0.65, 0.70 and 0.50 (P<0.0001), respectively. Specific activities of both enzymes showed a significant reduction as seminal plasma protein increased, indicating a disproportionate increase in proteins other than these enzymes in yellow seminal plasma.
Developing a Practical Forecasting Screener for Domestic Violence Incidents

In this article, the authors report on the development of a short screening tool that deputies in the Los Angeles Sheriff's Department could use in the field to help forecast domestic violence incidents in particular households. The data come from more than 500 households to which sheriff's deputies were dispatched in fall 2003. Information on potential predictors was collected at the scene. Outcomes were measured during a 3-month follow-up. Data were analyzed with modern data-mining procedures in which true forecasts were evaluated. A screening instrument was developed based on a small fraction of the information collected. Making the screening instrument more complicated did not improve forecasting skill. Taking the relative costs of false positives and false negatives into account, the instrument correctly forecasted future calls for service about 60% of the time. Future calls involving domestic violence misdemeanors and felonies were correctly forecast about 50% of the time. The 50% figure is important because such calls require a law enforcement response and yet are a relatively small fraction of all domestic violence calls for service.
Initial tree regeneration responses to fire and thinning treatments in a Sierra Nevada mixed-conifer forest, USA

Abstract Fire is a driver of ecosystem patterns and processes in forests globally, but natural fire regimes have often been altered by decades of active fire management. Following almost a century of fire suppression, many western U.S. forests have greater fuel levels, higher tree densities, and are now dominated by fire-sensitive, shade-tolerant species. These fuel-loaded conditions can often result in high-intensity crown fires replacing historic low- to moderate-intensity fire regimes. In the mixed-conifer forests of the California Sierra Nevada, thinning and prescribed fire are widely used to reduce fuels and shift future stand composition from shade-tolerant species to more fire-resistant pines (Pinus lambertiana and Pinus jeffreyi) that were historically more abundant. The impacts of these treatments, however, on forest regeneration composition and abundance are unclear. We examined the effects of prescribed fire and common thinning treatments (understory and overstory thinning) on microsite conditions, seed rain, and tree regeneration in an old-growth, mixed-conifer forest in the Sierra Nevada, California, USA. Treatments significantly altered environmental conditions, but there was substantial variation and overlap in conditions among treatments. Seed rain of shade-tolerant Abies concolor and Calocedrus decurrens was 5–26 times greater than P. jeffreyi and P. lambertiana, creating inertia in efforts to shift stands towards increased pine abundance. Survival of Pinus germinants was greatest in burned microsites. The burn-overstory thin treatment had both the highest mortality of advanced A. concolor and C. decurrens regeneration and the greatest increase in pine regeneration. Species occupied microsites gradating from low light/high moisture to high light/low moisture in the order: C. decurrens, A. concolor, P. lambertiana, and P. jeffreyi. Results suggest prescriptions may need to thin mature A. concolor and C. decurrens to significantly reduce their seed rain, create an abundance of burned open microsites, or plant Pinus seedlings to shift regeneration composition in treated stands.
Protein kinase C: Mediator or inhibitor of insulin action?

The role of protein kinase C in insulin signal transduction i s controversial It has been postulated that protein kinase C i s activated by insulin and that the kinase i s directly involved in insulin-mediated metabolic processes. In opposition to this view i s the hypothesis that protein kinase C is not activated by insulin and, more importantly, may be responsible for attenuation of the insulin signal The evidence for and against protein kinase C as a mediator of the insulin signal will be put in perspective followed by discussion of the possible role of the kinase in the pathogenesis of insulin resistance in type II diabetes.
There is no continuous projection from the measurable functions on the square onto the measurable functions on the interval

It is proved that the space of functions constant on vertical lines is not complemented in the space of all measurable functions on the unit square (with the topology of convergence in measure). The analogous results is proved for the space of all measurable functions on the product of two probability spaces, one of which is atomless.
A solution to the fundamental linear complex-order differential equation

This paper provides the solution to the complex-order differential equation, "0d"t^qx(t)=kx(t)+bu(t), where both q and k are complex. The time-response solution is shown to be a series that is complex-valued. Combining this system with its complex conjugate-order system yields the following generalized differential equation, "0d"t^2^R^e^(^q^)x(t)-k@?"0d"t^qx(t)-k"0d"t^q^@?x(t)+kk@?x(t)=p"0d"t^qu(t)+p@?"0d"t^q^@?u(t)-(k+k@?)u(t). The transfer function of this system is p(s^q-k)^-^1+p@?(s^q^@?-k@?)^-^1, having a time-response 2@?"n"="0^~t^(^n^+^1^)^u^-^1Repk^n@C((n+1)q)cos((n+1)vlnt)-Impk^n@C((n+1)q)sin((n+1)vlnt). The transfer function has an infinite number of complex-conjugate pole pairs. Bounds on the parameters u=Re(q),v=Im(q), and k are determined for system stability.
Computational design of a thermostable mutant of cocaine esterase via molecular dynamics simulations.

Cocaine esterase (CocE) has been known as the most efficient native enzyme for metabolizing naturally occurring cocaine. A major obstacle to the clinical application of CocE is the thermoinstability of native CocE with a half-life of only ∼11 min at physiological temperature (37 °C). It is highly desirable to develop a thermostable mutant of CocE for therapeutic treatment of cocaine overdose and addiction. To establish a structure–thermostability relationship, we carried out molecular dynamics (MD) simulations at 400 K on wild-type CocE and previously known thermostable mutants, demonstrating that the thermostability of the active form of the enzyme correlates with the fluctuation (characterized as the root-mean square deviation and root-mean square fluctuation of atomic positions) of the catalytic residues (Y44, S117, Y118, H287, and D259) in the simulated enzyme. In light of the structure–thermostability correlation, further computational modelling including MD simulations at 400 K predicted that the active site structure of the L169K mutant should be more thermostable. The prediction has been confirmed by wet experimental tests showing that the active form of the L169K mutant had a half-life of 570 min at 37 °C, which is significantly longer than those of the wild-type and previously known thermostable mutants. The encouraging outcome suggests that the high-temperature MD simulations and the structure–thermostability relationship may be considered as a valuable tool for the computational design of thermostable mutants of an enzyme.
Ground-Based Microwave Radiometric Observations of Precipitable Water Vapor: A Comparison with Ground Truth from Two Radiosonde Observing Systems

Abstract Dual-channel microwave radiometric measurements of precipitable water vapor are compared with values determined from two types of radiosondes. The first type is used in conventional soundings taken by the National Weather Service. The second is used by the CLASS system, as operated by the National Center for Atmospheric Research. The standard deviations of the two comparisons are nearly equal, being about 0.1 cm, but statistically significant biases occur between the radiometer and the radiosondes. A bias of 0.162 cm is present between radiometer and NWS values during the day and 0.075 cm during the night. The comparison shows that significant differences exist between the radiometer and the NWS moisture soundings when the relative humidity drops below 20 percent for pressures greater than 500 hPa. When this situation occurs, the NWS soundings contain a default dewpoint depression value of 30°C. After such data are removed from the comparisons, agreement between radiometer and NWS radiosonde data...
Interface characterization of high-k dielectrics on Ge substrates

Abstract High-k films are currently deposited on Ge substrate to compensate the mobility loss as Ge offers higher mobility compared to that of silicon. This work deals with the electrical characterization of high-k/Ge interface with Hf-based dielectrics on germanium substrate. Characteristics such as hysteresis, leakage current density, interface state density and flatband voltage shift using I–V, C–V and conductance measurements were performed on Ge/HfO 2 MOS capacitors. The results suggest that for thermally evaporated HfO 2 , the interface trap density at HfO 2 /Ge interface was found to be in the range of 10 12 –10 13 cm −2 eV −1 after 550 °C annealing in N 2 ambient even though significant improvements in hysteresis and leakage current were observed. Higher interface state density is attributed to the growth of interfacial layer. XPS analysis confirmed that after annealing, the gate dielectric was composed of both HfO 2 and GeO 2 . Furthermore, various interface treatments such as surface nitridation of Ge performed prior to HfO 2 deposition with an exposure to an atomic N beam from a remote RF source or introduction of SiO 2 by oxidizing a few monolayers of silicon deposited on Ge substrates, were considered. Even though improvements were observed, the surface nitrided devices demonstrated major dispersion in inversion region as a function of measured frequency as compared to non-nitrided devices. Introduction of SiO 2 seems to improve the interface quality marginally.
Gene Transfer into Loblolly Pine by Agrobacterium tumefaciens

We have demonstrated expression of bacterial genes transferred into cells of loblolly pine (Pinus taeda L.) by Agrobacterium tumefaciens. Whereas previous surveys found pines resistant to Agrobacterium, we found two wild type strains that produce galls. Callus proliferated from these galls synthesized specific opines. These results provide strong evidence for transfer and expression of bacterial genes in pine and extend the potential of genetic engineering to the world's most important genus for fiber production.
Hydroclimatic mechanisms of cholera transmission in the Bengal Delta

[1] Cholera, a deadly waterborne disease, remains a major threat in many areas of the world, including the Bengal Delta region. In this region, cholera outbreaks have two annual peaks; the first occurs during the dry season in the spring, and the second occurs in the fall following the wet season. However, the large-scale hydroclimatic processes underlying the propagation of the disease have not been well understood. Akanda et al. show that cholera outbreaks in the Bengal Delta region propagate from the coast to inland and from spring to fall following two distinct transmission cycles. The first outbreak begins in the spring near the coast when northward movement of plankton-rich seawater and increasing salinity promote the growth of cholera-causing bacteria in rivers, which are used for irrigation, sanitation, and consumption. The second outbreak begins in the fall, after summer floods and monsoons affect sanitation conditions that aid in bacterial transmission by contaminating waters over much of Bangladesh. (Water Resources Research, doi:10.1029/2010WR009914, 2011)
The Problem of the Ionized Hydrogen Molecule

The problem of the ionized hydrogen molecule was first treated by Pauli(1) who used the old quantum theory and obtained a result which was not in agreement with experiment. Niessen,(2) however, obtained the experimental value for the lowest energy level by introducing half-quantum numbers. The problem has now been treated by methods of wave-mechanics; thus Burrau(3) obtained a result in very good agreement with experiment by a numerical integration and a general discussion has been given recently by A. H. Wilson.(4) It is well known that the polynomial method of wave-mechanics, invented by Brillouin and Wentzel and developed by Sommerfeld,(5) gives, for a certain group of problems, the same result as the old quantum theory in approximation (0) and gives half-quantum numbers in approximation (1). It is shown in this paper that the present problem belongs to this group.
Concentration ratios for small mammals collected from the exposed sediments of a 137Cs contaminated reservoir

137Cs concentration ratios were computed for small mammals collected from the dried sediments of a partially drained, contaminated reservoir. Soil 137Cs activity concentrations were heterogeneous on small and large spatial scales and had a geometric mean of 253 (range 23–2110) Bq/kg dry weight. Mean 137Cs activity concentrations in composite cotton rat Sigmodon hispidus and cotton mouse Peromyscus gossypinus samples averaged 2480 (range 556–6670) and 471 (range 96–1000) Bq/kg whole body dry weight, respectively. About 50% of the variance in cotton rat tissue 137Cs activity was explained by variation in soil 137Cs activity. Soil-to-animal dry weight concentration ratios averaged 6.0 for cotton rats and 1.2 for cotton mice and were generally similar to 137Cs concentration ratios for herbivorous, homeothermic animals from other contaminated ecosystems. In the RESRAD-BIOTA dose model, the default wet-weight concentration ratio for 137Cs in terrestrial animals is 110 resulting in an estimate of internal and external radiation doses to terrestrial biota that is 44 times more than the dose calculated with the actual measured wet-weight concentration ratio for cotton rats (1.6). These results show that site-specific concentration ratios can significantly affect the estimation of dose.
Evidence of non-vascular land plants from the early Silurian (Llandoverian) of Virginia, U.S.A.

Abstract Evidence is presented for the earliest known occurrences of non-vascular land plants and of higher, septate fungi. Macerates of carbonaceous silstone lenses from the lower Massanutten Sandstone, early Silurian (Llandoverian) of Virginia, have yielded a diverse assemblage of microfossil elements. Parallel aligned, banded tubes with annular to spiral ribbing and rounded to papilliform ends, membranous cellular sheets, cuticles, trilete spores, small spore tetrads, and septate higher filamentous fungi were recovered from the macerates. The banded tubes are probably a significant analogue with supportive or conductive cell types, but are not considered tracheidal. The heterogeneous plant assemblage may represent a thalloid, non-vascular land plant, in part, with a tubular-filamentous (nematophytic) organization associated with a membranous cellular layer and cuticular covering. While no spores were established as nematophytic, the presence of trilete spores adds to the indirect evidence of multiple evolutionary convergence toward land-plant characters. This assemblage is interpreted as of land-plant origin, based on the inferred fluvial depositional model of the fossiliferous rocks. A glacio-eustatic sea-level drop in the late Ordovician is suggested as a stimulus to the advent of land plants in the early Silurian.
The Idea Factory: Learning to Think at MIT

This is a personal story of the educational process at one of the world's great technological universities. Pepper White entered MIT in 1981 and received his master's degree in mechanical engineering in 1984. His account of his experiences, written in diary form, offers insight into graduate school life in general -- including the loneliness and even desperation that can result from the intense pressure to succeed -- and the purposes of engineering education in particular. The first professor White met at MIT told him that it did not really matter what he learned there, but that MIT would teach him how to think. This, then, is the story of how one student learned how to think. There have of course been changes at MIT since 1984, but its essence is still the same. White has added a new preface and concluding chapter to this edition to bring the story of his continuing education up to date.
Magnetic reconnection and m = 1 oscillations in current carrying plasmas

The problem of magnetic field reconnection and the onset of instabilities resulting from it is analyzed for current carrying plasmas in high temperature regimes of thermonuclear interest. In order to compare our theoretical analysis of modes having azimuthal wave number m = 1 with present experimental observations and to predict those in future experiments producing high electron temperatures, we have developed a model that includes simultaneously the effects of finite electrical resistivity, ion gyroradius, electron drift wave frequency and ion-ion collisions. The viscous term arising from the last effect prevents the considered modes from developing a radial structure with typical “wavelength” shorter than the ion gyroradius and makes the moment equation description adequate for the regimes of interest. The relevant growth rates are found to be strongly decreasing functions of the electron temperature and, as the temperature increases, tend to achieve a form similar to that previously derived for higher m modes which can be found only in the presence of finite electrical resistivity. The relationship of these modes with the m = 1 ideal MHD internal kink mode is studied and the effects of toroidal geometry are briefly discussed.
Further exploration of M1 allosteric agonists: Subtle structural changes abolish M1 allosteric agonism and result in pan-mAChR orthosteric antagonism

This letter describes the further exploration of two series of M1 allosteric agonists, TBPB and VU0357017, previously reported from our lab. Within the TPBP scaffold, either electronic or steric perturbations to the central piperidine ring led to a loss of selective M1 allosteric agonism and afforded pan-mAChR antagonism, which was demonstrated to be mediated via the orthosteric site. Additional SAR around a related M1 allosteric agonist family (VU0357017) identified similar, subtle ‘molecular switches’ that modulated modes of pharmacology from allosteric agonism to pan-mAChR orthosteric antagonism. Therefore, all of these ligands are best classified as bi-topic ligands that possess high affinity binding at an allosteric site to engender selective M1 activation, but all bind, at higher concentrations, to the orthosteric ACh site, leading to non-selective orthosteric site binding and mAChR antagonism.
Cardioprotection via adaptation to hypoxia: expanding the timeline and targets?

Substantial effort and resources throughout the past fourdecades have been devoted to the investigation of novelparadigms to limit the damage caused to the heart bymyocardial ischemia and, more recently, the spectrum oflethal ischemia–reperfusion injury. The scope of thisintellectual and ﬁnancial investment is underscored by thefact that, as of December 2010, more than 9,600 publica-tions cited in PubMed include the term ‘cardioprotection’as a key word.A milestone in the ﬁeld of cardioprotection was pro-vided in 1986 by Murry et al. [14], who demonstrated thattransient exposure of the heart to a stressful stimulus (i.e.,antecedent ‘preconditioning’ ischemia) marshaled a pro-found, endogenous cardioprotective response and renderedthe myocardium resistant to a subsequent sustained ische-mic insult. Although this observation was, at the time,considered remarkable and viewed with some skepticism,the phenomenon of cardioprotection via adaptation tostress has been corroborated in a host of studies andexpanded from the initial paradigm of ischemic precondi-tioning to encompass multiple triggers including remoteischemia or ‘preconditioning at a distance’ [18, 27], mildhypothermia and hyperthermia [12, 23, 25, 29], endotoxinand endotoxin analogs [19, 30, 31], endoplasmic reticulumstress [17] and many others. There are, however, twoimportant caveats to the reduction of infarct size achievedwith ischemic preconditioning and other stressors: theprotective triggers are considered to delay (rather thanpreclude) cardiomyocyte death, and efﬁcacy is achievedwhen the triggers are applied as a pretreatment (beforeischemia) or, in some instances, during the initial seconds–minutes of reperfusion. That is: myocardial salvage istypically not obtained in the setting of permanent coronaryocclusion, and cardioprotective strategies are generallyineffective when administered hours–days following reliefof ischemia.In the current issue of Basic Research in Cardiology,Xuand colleagues [28] report that prolonged exposure of ratsto intermittent hypobaric hypoxia (IHH: barometric pres-sure of 404 mmHg and PO
Detecting singularities of piecewise deterministic (terminal) dynamics in experimental data

Piecewise deterministic (terminal) dynamics with singularities have been suggested as a model for many physical and biological systems. A difficulty, however, has been their detection in experimental situations. A method developed from recurrence-based Liapunov exponents is suggested. Practical implications for the detection of such dynamics is discussed.
A Semiempirical Computational Investigation of the Antipsoriatic Drug Anthralin

Abstract A series of computational studies was carried out, by using the highly successful Austin Model 1 (AM1) semiempirical method, to illuminate more completely the fundamental, molecular-level forces that affect the function and utility of the antipsoriatic drug anthralin. First, examination of the keto–enol tautomeric equilibrium by AM1 showed that the keto tautomer of the drug is 9.5 kcal/mol more stable than the enol form. Strong electrostatic forces involving the hydrogens on the hydroxy groups (a partial charge of +0.25 in both forms) and the keto oxygen (a partial charge of −0.40) apparently overcome the effects of the increased aromatic stabilization present in the enol form. Second, AM1 was applied to the degradation products of anthralin, 1,8-dihydroxy-9, 10-anthra-quinone, 1,8,1′,8′-tetrahydroxy-10,10′-dianthrone, and a further oxidized form of the dimer. These molecules have been implicated in some of the unpleasant side effects of anthralin. Third, AM1 was used to predict the preferred site of ionization of anthralin.
Analytical Homogenization for Microelectronic Substrates

Organic substrates used in microelectronic packages contain complex micro-via, plated-through-hole via, and copper networks in order to accommodate stringent electrical requirements of power delivery and I/O. These complex layouts can produce significant inhomogeniety in the in-plane and out-of-plane mechanical properties of the substrates. An analytical homogenization methodology has been established that uses substrate design geometries and material properties such as the copper density and via locations with two-phase micromechanics models to homogenize the substrate. In this paper the homogenization methodology is discussed and validated with experimental data. A comparison of the various two-phase micromechanics models commonly found in literature are reviewed and compared for their applicability to accurately homogenize organic substrates. Two case studies are provided to highlight the importance of accurately modeling the anisotropy of the substrates for temperature cycling and bend reliability predictions.Copyright © 2007 by ASME
In vitro fertilization availability and utilization in the United States: a study of demographic, social, and economic factors

Objective To characterize the demographic correlates of IVF availability and utilization. Design Demographic analysis of public data. Setting Each of the 50 states in the United States was used as a unit of analysis. Patient(s) Patients undergoing IVF, as demographically estimated. Intervention(s) Publicly available data were collected through the Society for Assisted Reproductive Technology and the Centers for Disease Control. The US Census Bureau data were collected by using software available from the Centers for Disease Control. Main Outcome Measure(s) The number of physicians performing IVF and the number of IVF cycles per 100,000 reproductive-age women were used to estimate IVF availability and utilization. Result(s) In 2005, 1,031 providers performed 98,242 fresh IVF cycles in 430 centers. Overall availability was 2.5 IVF physicians per 100,000, and utilization was 236 IVF cycles per 100,000. Availability and utilization of IVF were highly correlated. Mean IVF availability and utilization were significantly higher in states with IVF insurance coverage. In adjusted analyses, IVF availability correlated positively with mandated insurance coverage, percentage of single persons, and median income. Utilization of IVF correlated with IVF availability, percentage urbanization, and percentage of individuals ≥25 years of age who had a bachelor's degree. Conclusion(s) Lower rates of IVF utilization in some states are correlated with a lack of insurance coverage and decreased availability of physicians providing this service.
Synthesis and catalytic properties in olefin epoxidation of novel iron(II) complexes with pyridine-containing macrocycles bearing an aminopropyl pendant arm.

Three novel iron(II) complexes with pyridine-containing macrocycles bearing an aminopropyl pendant arm were synthesized and characterized. Crystal structures of two of the complexes revealed high-spin iron(II) centers coordinated to the five ligand nitrogen atoms with no coordination of either the solvent molecules or anions, resulting in an unusual square-pyramidal geometry. Related tetradentate ligand CRH formed a low-spin iron(II) complex (meso form was structurally characterized) with a planar arrangement of the four nitrogen atoms from the macrocycle and two axial acetonitrile molecules. Similarly to the corresponding nickel and copper complexes of the pentadentate ligands, the protonation of the amino group on the ligand arm in iron(II) complexes was found to be reversible. Spectral changes and magnetic susceptibility measurements indicated that a change in the geometry and spin state of the metal center is associated with this acid−base process. In the presence of noncoordinating acids (e.g., trifl...
Measurement of atmospheric boundary layer based on super-large-scale particle image velocimetry using natural snowfall

We present an implementation of super-large-scale particle image velocimetry (SLPIV) to characterize spatially the turbulent atmospheric boundary layer using natural snowfall as flow tracers. The SLPIV technique achieves a measurement area of ~22 m × 52 m, up to 56 m above the ground, with a spatial resolution of ~0.34 m. The traceability of snow particles is estimated based on their settling velocity obtained from the wall-normal component of SLPIV velocity measurements. The results are validated using coincident measurements from sonic anemometers on a meteorological tower situated in close proximity to the SLPIV sampling area. A contrast of the mean velocity and the streamwise Reynolds stress component obtained from the two techniques shows less than 3 and 12 % difference, respectively. Additionally, the turbulent energy spectra measured by SLPIV show a similar inertial subrange and trends when compared to those measured by the sonic anemometers.
AFM Mechanical Studies Of A Novel Form Of The Biopolymer Fibrin: Elastomeric Sheets

Fibrin is a gel-forming biopolymer that constitutes the supporting fiber network structure of blood clots within the vasculature. The structure and mechanical properties of these fiber networks have been extensively studied for decades, inspired both by their unusual materials properties as well as their profound biomedical importance. We have recently observed a previously unreported alternate form of polymerized fibrin: two dimensional sheets of molecular thickness. Structural data revealing the sheet structure collected with atomic force microscopy (AFM), SEM and TEM will be presented. When prepared on micropatterened surfaces, the fibrin sheets spontaneously polymerized to span channels or holes in the underlying substrate. Using a combination fluorescence/AFM system, we have manipulated the suspended sheets and collected strain and force data. Our results show that fibrin sheets are a novel biological material: continuous elastomeric films capable of supporting reversible strains well in excess of 100% with an elastic modulus in the few MPa range.