cssi/SciSciGPT-SciSciNet huggingface dataset:
The Active Site in α-Chymotrypsin ABSOLUTE CONFIGURATION AND KINETICS OF HYDROLYSIS OF METHYL 3,4-DIHYDROISOCOUMARIN-3-CARBOXYLATE

Abstract The active site of α-chymotrypsin is considered to be composed of parts complementary to the parts of a small molecule natural substrate, l-ethyl N-acetyl β-phenylalaninate, in a conformation in which the β-aryl and hydrolyzing ester groups are transoid: (a) the ar site, a cavity or fold into the enzyme at which the β-aryl substituent provides the primary associative effect; (b) the am site, at or near the enzyme surface, at which the α-acylamido group associates by hydrogen bonding; (c) the h site of restricted volume into which the α-hydrogen atom or other small substituent may fit; (d) the hydrolytic site, n, at or near the enzyme surface, at which the group to be hydrolyzed must be placed if an association is to be effective. High reactivity of noncyclized substrates requires binding at am and ar which restricts rotation about Cα—Cβ and Cβ—Cphenyl (Cφ), and a fit at h, placing the group to be hydrolyzed at n. d Enantiomers hydrolyze (a) when the α substituents associate at ar, and β substituents fit at am or are absent, and (b) when the α substituent may fit at h. Effective association and hydrolysis of d enantiomers lead to absence of or inversion of stereospecificity. dl-Methyl 3,4-dihydroisocoumarin-3-carboxylate (I) [see PDF for structure] has been prepared. It is hydrolyzed rapidly by α-chymotrypsin, leading to l(+)-unhydrolyzed Ester I, and d(-)-Acid VI. The acid l(+)-VI was prepared, stereospecifically, from [see PDF for structure] l(-)-phenyllactic acid, establishing the preferred enzymic hydrolysis of d(-)-I. A convenient stereospecific synthesis of d(-)-1-keto-3-carbomethoxytetrahydroisoquinoline (II) [see PDF for structure] from d(+)-β-phenylalanine has also been developed. Kinetic parameters for hydrolysis by α-chymotrypsin are: d(-)-I, kcat = 42 sec-1, Km = 0.0007 m, kcat:Km = 6.0 x 104 m-1 sec-1; l(+)-I, kcat = 1.8 sec-1, Km = 0.028 m, kcat:Km = 64 m-1 sec-1. The cyclic ester group of d(-)-I may not utilize the am site effectively, and it is concluded that the cyclic amide group of d(-)-II also does not utilize the am site. The α-heteroatoms of d(-)-I and d(-)-II fit at h, the aryl groups at ar, leading to hydrolysis of the d enantiomers. The heterocyclic rings of d(-)-I and d(-)-II lead to high reactivity by restricting rotations at Cα—Cβ and Cβ—Cφ. This, coupled with association of the phenyl ring at ar, places the carbalkoxyl group at n. The lesser reactivity of l-cyclized substrates appears related to diminished access of the aryl group to the ar site when the cyclic amide or ester group in II and I associates or lies at am. The proposal that the carbalkoxyl group in d(-)-I and d(-)-II is more nearly equatorial in the reacting conformation is discussed and supported. The usefulness of cyclized substrates with respect to information about the ar and h sites and their limitation with respect to the am site are indicated.
Sum rules and properties in time-dependent density-functional theory

Time-dependent quantal density-functional theory (Q-DFT) is a description of the s-system of noninteracting fermions with electronic density equivalent to that of Schr\"odinger theory, in terms of fields whose sources are quantum-mechanical expectations of Hermitian operators. The theory delineates and defines the contribution of each type of electron correlation to the local electron-interaction potential ${\ensuremath{\nu}}_{\mathrm{ee}}(\mathbf{r},t)$ of the s system. These correlations are due to the Pauli exclusion principle, Coulomb repulsion, correlation-kinetic, and correlation-current-density effects, the latter two resulting, respectively, from the difference in kinetic energy and current density between the interacting Schr\"odinger and noninteracting systems. We employ Q-DFT to prove the following sum rules and properties of the s system: (i) the components of the potential due to these correlations separately exert no net force on the system; (ii) the torque of the potential is finite and due solely to correlation-current-density effects; (iii) two sum rules involving the curl of the dynamic electron-interaction kernel defined as the functional derivative of ${\ensuremath{\nu}}_{\mathrm{ee}}(\mathbf{r},t)$ are derived and shown to depend on the frequency dependent correlation-current-density effect. Furthermore, via adiabatic coupling constant (\ensuremath{\lambda}) perturbation theory, we prove: (iv) the exchange potential ${\ensuremath{\nu}}_{x}(\mathbf{r},t)$ is the work done in a conservative field representative of Pauli correlations and lowest-order $O(\ensuremath{\lambda})$ correlation-kinetic and correlation-current-density effects; (v) the correlation potential ${\ensuremath{\nu}}_{c}(\mathbf{r},t)$ commences in $O({\ensuremath{\lambda}}^{2}),$ and, at each order, it is the work done in a conservative field representative of Coulomb correlations and correlation-kinetic and correlation-current-density effects; (vi) we derive the integral virial theorem relating ${\ensuremath{\nu}}_{\mathrm{ee}}(\mathbf{r},t)$ to the electron-interaction and correlation-kinetic energy for arbitrary coupling constant strength \ensuremath{\lambda}, and show there are no explicit correlation-current-density contributions to the energy. From this integral virial theorem we (vii) obtain the fully interacting $(\ensuremath{\lambda}=1)$ and exchange-only $(\ensuremath{\lambda}=0)$ integral virial theorems as special cases, the latter showing there is no explicit correlation-kinetic contribution to the exchange energy; and (viii) write expressions for the electron-interaction and correlation-kinetic actions for arbitrary coupling constant \ensuremath{\lambda} in terms of the corresponding fields.
Intrahepatic levels and replicative activity of covalently closed circular hepatitis B virus DNA in chronically infected patients

Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is responsible for viral persistence in the natural course of chronic HBV infection and during prolonged antiviral therapy and serves as the template for the production of HBV pregenomic RNA (pgRNA), the primary step in HBV replication. In this study, we have developed and applied sensitive and specific quantitative real-time polymerase chain reaction (PCR) assays for the measurement of intrahepatic concentration, pgRNA production, and replicative activity of cccDNA in liver biopsy samples from 34 non-treated patients with chronic hepatitis B (CHB); 12 hepatitis B e antigen (HBeAg)(+) and 22 HBeAg(-). Median copy number for cccDNA was 1.5 per cell and for pgRNA significantly higher, 6.5 copies per cell, with a good correlation between cccDNA and pgRNA levels in all samples. In HBeAg(-) patients, median values of cccDNA and pgRNA levels were 10-fold and 200-fold lower than in HBeAg(+), respectively, reflecting the differences in viral activity and clinical characteristics of the two groups. Furthermore, the replicative activity of intrahepatic cccDNA was significantly lower in HBeAg(-) patients harboring mutant HBV strains than in HBeAg(+) patients: median 3.5 versus 101 pgRNA copies per cccDNA molecule. In conclusion, the levels of both HBV cccDNA, a marker of HBV persistence, and pgRNA, an indicator of viral replication, in the liver of chronically infected patients correlate with viral activity and the phase of HBV infection. The combined measurement of cccDNA and pgRNA levels provides valuable information on the presence and replicative activity of intrahepatic HBV cccDNA.
Phosducin and βγ-Transducin Interaction I: Effects of Post-translational Modifications

Abstract The interaction between phosducin and βγ-transducin plays regulatory roles in light adaptation of photoreceptors. Both phosducin and βγ-transducin undergo post-translational modifications, with phosducin modified by phosphorylation and the γ subunit of βγ-transducin by farnesylation and carboxylmethylation. In this study we exploited the electrophoretic mobilities of these native proteins to develop a micro binding assay and examined the effects of post-translational modifications on binding affinities. It was found that decarboxylmethylation of γ-transducin increased the mobility of βγ-transducin during native gel electrophoresis, but decreased the apparent affinity for phosducin by about 2-fold. Phosphorylation of phosducin by protein kinase A increased the mobility but decreased the apparent affinity for βγ-transducin by at least 3-fold.
Individual and Community Impact of Influenza

Influenza has been recognised as a distinct entity for centuries because of its profound effect on respiratory morbidity and mortality, although the full burden of the disease has been difficult to determine. The population groups most affected by influenza morbidity and mortality have also been recognised for years and are strongly related to the viral type or subtype circulating. Studies in the US suggest that the traditional pneumonia and influenza (P&I) mortality rate underestimates the total impact of influenza on mortality by a factor of approximately 3.8. Observations in different parts of the world confirm that mortality associated with P&I is not limited to specific countries. Vaccination not only reduces the severity of illness and death from P&I, but also reduces all-cause mortality, thus confirming these observations. Estimates of overall morbidity vary widely, depending on the methods used in various observational studies. The actual impact of influenza is likely to be within this range of estimates, but recent vaccination studies suggest the possibility of much higher rates of morbidity than previously estimated.
Conversion of Green Fluorescent Protein into a Toxic, Aggregation-prone Protein by C-terminal Addition of a Short Peptide

A non-natural 16-residue "degron" peptide has been reported to convey proteasome-dependent degradation when fused to proteins expressed in yeast (Gilon, T., Chomsky, O., and Kulka, R. (2000) Mol. Cell. Biol. 20, 7214-7219) or when fused to green fluorescent protein (GFP) and expressed in mammalian cells (Bence, N. F., Sampat, R. M., and Kopito, R. R. (2001) Science 292, 1552-1555). We find that expression of the GFP::degron in Caenorhabditis elegans muscle or neurons results in the formation of stable perinuclear deposits. Similar perinuclear deposition of GFP::degron was also observed upon transfection of primary rat hippocampal neurons or mouse Neuro2A cells. The generality of this observation was supported by transfection of HEK 293 cells with both GFP::degron and DsRed(monomer)::degron constructs. GFP::degron expressed in C. elegans is less soluble than unmodified GFP and induces the small chaperone protein HSP-16, which co-localizes and co-immunoprecipitates with GFP::degron deposits. Induction of GFP::degron in C. elegans muscle leads to rapid paralysis, demonstrating the in vivo toxicity of this aggregating variant. This paralysis is suppressed by co-expression of HSP-16, which dramatically alters the subcellular distribution of GFP::degron. Our results suggest that in C. elegans, and perhaps in mammalian cells, the degron peptide is not a specific proteasome-targeting signal but acts instead by altering GFP secondary or tertiary structure, resulting in an aggregation-prone form recognized by the chaperone system. This altered form of GFP can form toxic aggregates if its expression level exceeds the capacity of chaperone-based degradation pathways. GFP::degron may serve as an instructive "generic" aggregating control protein for studies of disease-associated aggregating proteins, such as huntingtin, α-synuclein, and the β-amyloid peptide.
Space-time beamforming for randomly distributed sensors

We briefly review the signal processing architecture of a wireless MEM sensor system for source detection, signal enhancement, localization, and identification. A blind beamformer using only the measured data of randomly distributed sensor to form a sample correlation matrix is proposed. The maximum power collection criterion is used to obtain array weights from the dominant eigenvector of the sample correlation matrix. An effective blind beamforming estimation of the time delays of the dominant source is demonstrated. Source localization based on a novel least-squares method for time delay estimation is also given. Array system performance based on analysis, simulation, and measured acoustical/seismic sensor data is presented. Applications of such a system to multimedia, intrusion detection, and surveillance are briefly discussed.
Current-input current-output CMOS logarithmic amplifier based on translinear Ohm's law

State-of-the-art logarithmic amplifiers use a transimpedance technique based on the exponential dependence between input current and output voltage as exhibited by p-n junction diodes, bipolar transistors and MOS transistors in the subthreshold region. Presented is a CMOS current-input current-output logarithmic amplifier based on a translinear Ohm's law principle which involves a floating voltage source and a passive resistor embedded within a translinear loop. It is demonstrated that the input–output range of the proposed logarithmic amplifier can be controlled using a reference bias and the response of the amplifier can be temperature compensated using a PTAT and a resistive cancellation technique.
Sulfur-Containing Derivatives of Amphetamine: Thioureas Methanesulfonamides Trifluoromethanesulfonamides

N-Methylthiourea, methanesulfonamide, and trifluoro- methanesulfonamide derivatives of amphetamine, 4-nitroamphetamine, and 4-aminoamphetamine were synthesized. The N-methylthiourea derivative of amphetamine, as well as the triethylammonium salt of the dithiocarbamate, produced significant depressor effects in normo- tensive dogs. N,N′-Bis(methanesulfonyl)-l-methyl-2-(4:amino- phenyl)ethylamine and N-trifluoromethanesulfonyl-l-methyl-2-phe- nylethylamine, but not N-methanesulfonyl-l-methyl-2-phonylethylamme and N-trifluoroacetyl-1-methyl-2-(4-trifluoromethanesulfonamidophenyl)ethylamine, showed significant antiobesity effects in rats.
Maternal Weight, Hemodynamics, and Preeclampsia

Objectives: To evaluate the relationship between the obesity, elevated cardiac output, and the development of preeclampsia.Methods: Maternal weight, mean arterial pressure, and cardiac output were ...
Scaling of Hydrophobic Solvation Free Energies

We have calculated the free energy of solvation for hard sphere solutes, as large as 20 A in diameter, in two simple-point-charge models of water. These results were obtained using umbrella sampling of ensembles with fixed, ambient temperature and pressure. For the same water models, we have also calculated the surface tension of a liquid−vapor interface at room temperature. Analogous calculations were carried out for three thermodynamic states of the Lennard-Jones (LJ) fluid near liquid−vapor coexistence. For both water and the LJ fluid at the conditions we have simulated, extrapolation of our results suggests that the planar interface between coexisting liquid and vapor phases has the same surface tension as the planar limit of hard sphere solvation. We expect this correspondence to be a general result for fluids at thermodynamic states close to phase coexistence, as measured by the difference in chemical potential between bulk liquid and vapor phases, and far from the critical point. The solvation free...
Prediction of a bcc–hcp phase transition for Sn: A first-principles study

Abstract The high-pressure structural transformation of elemental Sn is studied using an ab initio density functional theory implementation of the metadynamics method that predicts with sufficient compression, Sn will transform from the bcc structure into an hcp structure. The low-free-energy pathway associated with this phase transition is characterized as the Burgers transition mechanism. The superconducting properties of Sn under pressure are also investigated. Both bcc and hcp structures of Sn exhibit very weak electron–phonon coupling and therefore would not sustain superconductivity at high pressure.
Delivery of nitroxide spin label to cultured cells by liposomes.

The positively charged nitroxide spin label, 2,2,6,6-tetramethyl-piperidine-N-oxyl-4- trimethylammonium (Cat1), was encapsulated in two types of liposomes, phosphatidylserine/phosphatidylcholine (PS/PC) and phosphatidylserine/distearoylphosphatidylcholine/dipalmitoylphosphatidylcholine (PS/DSPC/DPPC). The liposomes were incubated with mouse thymus-bone marrow (TB) cells to study the uptake and metabolism of nitroxides entrapped in Iiposomes. The effects of temperature, metabolic inhibitors, and fixation of cells were investigated. The results indicate that different mechanisms are involved in the uptake of these two types of liposomes. PS/PC liposomes interact predominately with the plasma membrane of TB cells and release Cat1 continuously, whereas the majority of PS/DSPC/DPPC liposomes are taken into the cells intact via endocytosis. These findings suggest that it may be possible to deliver nitroxides selectively, either to the membrane of cells or to their interior by manipulating the lipid com- position of the liposomes. This study also found that the rate of reduction of Cat 1 delivered using liposomes was increased under hypoxic conditions. Thus, the use of liposomes for in vivo delivery of nitroxides has the potential to provide NMR contrast that reflects different metabolic conditions. © 1988 Academic Press, Inc.
Comparing functional results one year and ten years after ileal pouch-anal anastomosis for chronic ulcerative colitis.

Proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the treatment of choice for most patients with chronic ulcerative colitis. Long-term results, however remain undefined; the major concern is that function may deteriorate. PURPOSE: The aim of this study was to assess functional outcome in a subgroup of patients who have an IPAA for chronic ulcerative colitis for >10 years. METHODS: Among 1400 IPAA patients, 75 consecutive subjects (31 females and 44 males; median age 31 at operation) were identified who had the procedure prior to 1982. All patients had functional results recorded 1 year and 10 years following ileostomy closure. RESULTS: There were four deaths during the follow-up period; none were pouch related. Two patients refused ileostomy closure. Of the remaining 69 patients, there were 8 (11 percent) failures, leaving 61 subjects available for study. Stool frequency (7±3, mean±SD) remained unchanged. Of the 50 subjects with initially excellent daytime continence, 39 (78 percent) remained the same, 10 (20 percent) developed minor incontinence, and 1 developed poor control after 10 years. Four of 10 subjects (40 percent) with initial minor daytime incontinence remained unchanged, 4 (40 percent) improved, and 2 (20 percent) worsened. The one subject with poor control at one year was unchanged. Nocturnal fecal spotting increased over the 10-year period but not significantly (38 percentvs.52 percent;P=0.08). CONCLUSIONS: After IPAA, functional results in terms of stool frequency and rate of fecal incontinence did not deteriorate with time.
Patient care classification systems: A study in home care:

The author shares the results of a study that was conducted to determine the relationship between complexity of patients at home, nurses' estimated level of complexity, and the length of time per visit. While the study results indicate the need for more investigation, they can help agencies distribute human resources more evenly.
Martian climatic events on timescales of centuries: Evidence from feature morphology in the residual south polar ice cap

Flat-floored, quasi-circular depressions on the southern residual cap of Mars have been observed to expand rapidly. Analysis of the size distribution combined with modeling of the growth process yields information about the ages of these features. We report on properties of a population of these features within a selected study area. We find a narrow size distribution that indicates a common formation time and a finite period during which new features were forming. Some change in environmental conditions occurred during this period, which we date at several Martian decades to centuries ago depending on modeled growth rates. We report on THEMIS data that reveals the nature of larger features outside our study area. Underlying water ice is exposed on the flat floors of these depressions near the outer walls. These features may record more than one growth phase, indicating that conditions conducive to growth may switch on and off with characteristic timescales of Martian centuries.
Essential Closures and AC Spectra for Reflectionless CMV, Jacobi, and Schrödinger Operators Revisited

We provide a concise, yet fairly complete discussion of the concept of essential closures of subsets of the real axis and their intimate connection with the topological support of absolutely continuous measures. As an elementary application of the notion of the essential closure of subsets of R we revisit the fact that CMV, Jacobi, and Schrodinger operators, reflectionless on a set ∈ of positive Lebesgue measure, have absolutely continuous spectrum on the essential closure ⋶^e of the set ∈ (with uniform multiplicity two on ∈). Though this result in the case of Schrodinger and Jacobi operators is known to experts, we feel it nicely illustrates the concept and usefulness of essential closures in the spectral theory of classes of reflectionless differential and difference operators.
Consumer Magazine Advertisement Portrayal of Models by Race in the US: An Assessment

This study examined the frequency of portrayal, positive or negative depiction, relative hierarchy position, and relative social authority status of African American, Asian American, Hispanic American, and White American models in a sample of consumer magazine advertisements, utilizing content analysis. A longitudinal framework was employed in the study to determine if the patterns of depiction have stabilized or have experienced meaningful change over a ten‐year period. In contrast to previous studies, the results were generally that minority group models were frequently featured, relative to their proportion in the total US population, and they were depicted in a favorable manner, relative to White models, during the periods under consideration.
Actions of serotonin and substance P on myenteric neurons of guinea-pig distal colon.

Abstract Intracellular methods were used to study the effects of serotonin and substance P (SP) on the electrical behavior of myenteric neurons in guinea-pig distal colon in vitro. Serotonin evoked either a short-duration transient depolarization, a long-lasting depolarization or a multiphasic response consisting of a rapid depolarization followed by a short duration hyperpolarizing potential and then a long-lasting depolarization. Application of SP evoked a long-lasting depolarization. Depolarizing potentials to both substances were accompanied by enhaced excitability that was reflected by repetitive spike discharge. Long-lasting depolarizations were associated with increased input resistance. The responses to serotonin or SP were unaltered by the presence of tetrodotoxin, hexamethonium or elevated extracellular Mg2+ and reduced Ca2+. Some neurons responded to both serotonin and SP indicating that both receptors coexisted on the same neuron. The putative SP antagonist, [D-Arg1, D-Phe5,D-Trp7,9,Leu[11]SP did not affect the responses to SP. It did suppress the slow-depolarizing response to serotonin, while the fast response was unaffected. The responses to serotonin and SP in myenteric neurons of guinea-pig colon resembled the responses reported by others for small intestinal myenteric neurons.
Development of a duplex quantitative polymerase chain reaction assay for detection of bovine herpesvirus 1 and bovine viral diarrhea virus in bovine follicular fluid

The objective of this study was to develop a duplex quantitative polymerase chain reaction (qPCR) assay for simultaneous detection of bovine herpesvirus 1 (BoHV-1) and bovine viral diarrhea virus (BVDV) type I and type II. Follicular fluid was collected from a BoHV-1 acutely infected heifer, a BVDV I persistently infected heifer, and from 10 ovaries recovered from an abattoir. Both the BoHV-1 and BVDV contaminated follicular fluid were diluted 1:5 to 1:107 using the pooled, abattoir-origin follicular fluid. Each dilution sample was analyzed using the duplex qPCR, virus isolation, reverse transcription-nested PCR (RT-nPCR), and BoHV-1 qPCR. The duplex qPCR was able to simultaneously detect BoHV-1 and BVDV I in the fluid diluted to 1:100 and 1:1000, respectively. These results corresponded with the reverse transcription-nested PCR and BoHV-1 qPCR. Therefore, the duplex qPCR might be used for quality assurance testing to identify these two viruses in cells, fluids and tissues collected from donor animals and used in reproductive technologies.
Neural mechanisms for serial order in a stereotyped behaviour sequence

A single, transient sensory stimulus can evoke a complex behavioural response in which several behavioural units occur in a serially ordered manner. For stereotyped behavioural sequences, two alternative neural mechanisms have been proposed to account for the serial ordering of behavioural units: chain reflexes1, which depend on peripheral feedback, and central pattern generators2, which attribute the sequence to interactions among central neural elements. Although long thought to be mutually exclusive, both alternatives were recently shown to contribute to simple crayfish escape responses3–5. We now demonstrate that the integration of these simple, serially ordered escape responses into the compound escape sequence of the crayfish is mediated by a third mechanism for serial order, namely the parallel activation by the same sensory stimulus of two separate behavioural units with different intrinsic reaction times.
VitalSim® Versus SimMan®: A Comparison of BSN Student Test Scores, Knowledge Retention, and Satisfaction

Abstract Background Students voice satisfaction with human patient simulation (HPS) however the costs associated with it must be balanced against measurable learning outcomes. Test scores are one measure of interest to faculty as licensure is awarded based on scores on a multiple-choice exam. Methods A 3 X 3 factorial repeated measures design was used with three groups (lecture only, SimMan® and lecture and VitalSim® and lecture, and three time points (a pretest, posttest 1 at two weeks, and posttest 2 at six months). Results Findings indicated significant increases in knowledge for all groups at posttest 1 and significant decreases in knowledge for all groups at posttest 2, six months later. Compensatory rivalry may have played a role in the initial posttest findings. There was no difference in simulation satisfaction by fidelity level. This study was funded by a Carl M. Hansen grant from Washington State University.
The role of adjunctive postchemotherapy surgery for nonseminomatous germ-cell tumors: current concepts and controversies.

Adjunctive surgical resection of residual disease after chemotherapy is a critical part of the comprehensive management of patients with advanced nonseminomatous germ-cell tumor (NSGCT). Surgical resection is indicated in the presence of residual radiographic abnormalities and normal serum tumor markers. Necrosis, teratoma, and viable carcinoma can be found at any resected site. After induction chemotherapy, necrosis comprises approximately 50% of histologic findings, teratoma 40%, and viable GCT the remaining 10%. A number of investigators have attempted to predict the presence of necrosis in an effort to obviate surgery. A number of variables predictive of necrosis have been identified and tested prospectively, including: degree of tumor shrinkage, size of pre- and posttreatment mass(es), prechemotherapy markers, and teratomatous components in the orchiectomy specimen. However, the risk for a false-negative prediction remains approximately 20%. The most rigorous approach remains a retroperitoneal lymph node dissection (RPLND). Furthermore, the histologic discordance between different sites ranges from 29% to 46%; thus, all sites of residual disease should be resected. The patient's prognosis is influenced by: (1) completeness of resection, and (2) biology of the tumor (histology of residual mass(es), marker status at the time of RPLND, and prior burden of therapy). Surgical boundaries and completeness of dissection should not be compromised in an attempt to preserve ejaculation.
Characterizing structural conditions in mature managed red pine: Spatial dependency of metrics and adequacy of plot size

Abstract Restoration of the range of forest types and stages that once composed the landscape mosaic of the Upper Great Lakes region of North America will involve manipulating managed red pine stands to recreate now rare structural conditions. Because many of the attributes used to characterize structural condition depend upon spatial arrangement, sampling schemes to assess condition must match sampling extent to attribute variability. To evaluate the metrics and scales appropriate for characterizing structural complexity in managed red pine, we applied metrics that incorporated one-, two-, and three-dimensional structural attributes to eight 1.0 ha mature stem-mapped stands. Most metrics were also calculated within simulated moving windows of 0.05–1.0 ha in sampling extent (“plot size”) within each stand. Two standards were used to evaluate the adequacy of plot sizes for these metrics: (1) estimates were precise, varying less than 10% among moving windows for a given scale, and (2) estimates were accurate to within 10% of the 1.0 ha value at both the 5th and 95th percentiles of the moving window distributions. Necessary sample sizes to achieve precise and accurate estimates were also calculated for each scale. Stands were relatively homogeneous in metrics commonly used in traditional timber management (basal area, mean diameter, total density), which were precisely and accurately estimated in 0.50 ha or larger plots. Metrics capturing attributes associated with old stands (number of large trees, number of snags) were more variable and required larger plots sizes (0.75–1.0 ha). A single 0.50 ha plot would be adequate to estimate mean tree size, the variation in tree size, basal area, and the density of all trees, but the minimum plot size for characterizing structural attributes commonly associated with old-growth appears to be 0.75–1.0 ha in managed red pine. The two-dimensional spatial arrangement (Ripley’s K) and the structural complexity index (SCI) were satisfactorily estimated in plots of 0.50 ha in extent. These early transition phase stands were characterized by smaller trees, greater red pine dominance, density-dependent dispersion, and lower SCI than old-growth. This suggests that relatively large plot sizes may be necessary to evaluate structural condition of stands with increasingly “old-growth” structural conditions.
The Magnetic Moment of the Proton

The magnetic moment of the proton has been measured by a method depending on the deflection of a beam of neutral hydrogen atoms in weak magnetic fields of sufficient inhomogeneity. When the field is of such magnitude that the nuclear spin is only partially decoupled from the electron spin the nuclear moment can be evaluated by measuring the atomic magnetic moments of the magnetic levels. Detection was effected on a molybdenum oxide coated plate and the results evaluated by the measurement of the widths and separation of the traces produced. A novel method of great convenience and simplicity for producing the proper magnetic field is described. The value of the proton moment obtained is 3.25\ifmmode\pm\else\textpm\fi{}10 percent.
Technology and the Engineering Method for Non-Engineering Students

This paper describes the structure, material, and techniques used in a course that introduces non-engineering students to the tasks and tools of the engineering profession. The primary components of the course include differentiation between engineering and science, heuristic and computational problem solving, experimentation, conservation principles, and a design experience.
Absolute quantification of five phytochrome transcripts in seedlings and mature plants of tomato (Solanum lycopersicum L.)

Described here are the first quantitative measurements of absolute amounts of mRNAs transcribed from individual members of a phytochrome gene (PHY) family. The abundances of PHY mRNAs were determined for dry seed and for selected organs of greenhouse-grown tomato (Solanum lycopersicum L.) seedlings and mature plants. With a PhosphorImager, absolute amounts of PHY A, PHYB1, PHYB2, PHYE and PHYF transcripts were measured with reference to standard curves prepared from mRNA fragments synthesized in vitro. Methodology was developed permitting the use of polymerase chain reaction (PCR)-generated probes derived from a highly conserved region of PHY, obviating the necessity to clone cDNAs and to isolate probes derived from their 3′ non-coding regions. In dry seeds, PHYB1 mRNA appeared to be most abundant (4–5 μmol/mol mRNA) while in all other instances PHYA mRNA predominated. In seedlings, PHYB1, PHYB2, PHYE, and PHYF mRNAs were most abundant in the shoot (25–87 μmol/mol mRNA) while PHYA mRNA was most abundant in the root (325 umol/mol mRNA). In adult plants, the levels of PHYA, PHYB1 and PHYE mRNAs were relatively uniform among different organs (approx. 100, 75, and 10 μmol/ mol mRNA, respectively). In contrast, PHYB2 and PHYF were expressed preferentially in ripening fruits (35 and 47 μmol/mol mRNA, respectively), indicative of a possible role in fruit ripening for the phytochromes they encode. In general, the order of decreasing abundance of the five mRNAs for both seedlings and mature plants was PHYA, PHYB1, PHYE, PHYB2 and PHYF. Based upon observations that relatively modest changes in the extent of PHY expression result in changes in phenotype, the differential expression of each of the five tomato PHY described here is predicted to impact upon the spatial expression of biological activity of each phytochrome.
Attachment issues and the cocaine exposed dyad

Through the theoretical lens of attachment theory, the relationship between substance abusing parents and their children exposed prenatally to drugs is explored. Attachment theory, the quality of attachment, attachment classifications, internal working models of attachment, and correlates of attachment classifications are discussed. Case studies of two schoolaged children exposed prenatally to cocaine are presented and interpreted in light of attachment theory set within a social-ecological perspective. Implications for practice and the use of federal policy for this population are explored.
Designing a symmetry-protected molecular device

Realizing a quantum transistor built of molecules or quantum dots has been one of the most ambitious challenges in nanotechnology. Even though remarkable progress has been made, being able to gate and control nanometer-scale objects, as well to interconnect them to achieve scalability, remains extremely difficult. Most experiments concern a single quantum dot or molecule, and they are made at ultralow temperature to avoid decoherence and tunneling. We propose to use canonical transformations to design quantum devices that are protected by symmetry and therefore may be operational at high temperatures. We illustrate the idea with examples of quantum-transistor architectures that can be connected both in series and parallel.
Health Search Behavior of Parents in Rural Bangladesh: An Empirical Study

In this paper, the health seeking behavior of parents in a rural area of Bangladesh who were unsuccessful in their attempt to save their child's life is dealt with. With use of univariate and multivariate techniques, the role of some selected socioeconomic, demographic, cultural, and spatial factors on the utilization of qualified doctors of modern medicine is examined. The analysis of data indicates that demographic, cultural, and spatial factors have stronger effects on the health search behavior of the parents than the socioeconomic conditions of the parents. The parents' preference for boys emerges as the strongest factors followed by distance to qualified doctors and parity. Implications of the findings are also discussed.
Non-autonomous logistic equations as models of populations in a deteriorating environment

Abstract The non-autonomous logistic equation d x(t) d t = r(t)x(t)[1 − x(t) K(t) ] is studied under conditions that include an environment which is completely deteriorating. In this setting, when the population's growth rate, r, is large on the average, solutions track the environment with a consequent extinction of the population. However, when both r and rK−1 are small in the sense that they are in L1[0,∞) then an asymptotic equivalence, where all solutions tend to positive limits as t approaches infinity, results and the population is persistent, independent of initial density. The asymptotic equivalence produces an unreasonable overshoot of carrying capacity which leads to concern about employing the logistic equation in the above form as a population model when growth rates are close to zero. A re-interpretation of the parameters of the logistic equation leads to the alternative logistic formulation d x(t) d t = x(t)[r(t) − c B(t) x(t)], (c > 0) . A biological interpretation of the parameters is presented and this equation is compared with the classical logistic model in the case where the parameters are constant. If the alternative logistic model is applied in a situation with time-varying parameters, then a deteriorating environment always leads to extinction of the population regardless of the behavior of r. Similarly, a growth rate which is small on the average results in extinction regardless of the behavior of B. Furthermore, r and B have limiting values as t approaches infinity then so does x and the terminal value of x is equal to the terminal value of the carrying capacity of the population. In general, the alternative formulation seems to be the more reasonable model in situations where perturbations lead to severe decreases in environmental quality and growth rates.
Generating 3D views of facial expressions from frontal face video based on topographic analysis

In this paper, we report our newly developed 3D face modeling system with arbitrary expressions in a high level of detail using the topographic analysis and mesh instantiation process. Given a sequence of images of facial expressions at frontal views, we automatically generate 3D expressions at arbitrary views. Our face modeling system consists of two major components: facial surface representation using topographic analysis and generic model individualization based on labeled surface features and surface curvatures. The realism of the generated individual model is demonstrated through 3D views of facial expressions in videos. This work targets the accurate modeling of face and face expression for human computer interaction and 3D face recognition.
Automated data-member layout of heap objects to improve memory-hierarchy performance

We present and evaluate a simple, yet efficient optimization technique that improves memory-hierarchy performance for pointer-centric applications by up to 24% and reduces cache misses by up to 35%. This is achieved by selecting an improved ordering for the data members of pointer-based data structures. Our optimization is applicable to all type-safe programming languages that completely abstract from physical storage layout; examples of such languages are Java and Oberon. Our technique does not involve programmers in the optimization process, but runs fully automatically, guided by dynamic profiling information that captures which paths through the program are taken with that frequencey. The algorithm first strives to cluster data members that are accessed closely after one another onto the same cache line, increasing spatial locality. Then, the data members that have been mapped to a particular cache line are ordered to minimize load latency in case of a cache miss.
The influence of maternal cigarette smoking on placental pathology in pregnancies complicated by abruption.

Objective The purpose of this study was to evaluate the effect of maternal cigarette smoking on placental histology in women with abruption. Study Design Data were derived from the New Jersey-Placental Abruption Study (NJ-PAS)—an ongoing, case-control study, conducted since August 2002 in 2 large hospitals in NJ. Abruption cases were identified based on a clinical diagnosis. Histologic evaluations were performed by 2 perinatal pathologists who were blinded to the abruption status. Maternal smoking during pregnancy was determined based on patient’s self-report. Among abruption cases, histologic findings were compared between smokers and nonsmokers, and the association expressed as odds ratio (OR) with 95% confidence interval (CI). All analyses were adjusted for potential confounders. Results A total of 189 abruption cases were available for analysis, of which 10.6% (n = 20) were smokers. Intervillous thrombus was more common in women who smoked (20%) than in nonsmokers (3.0%) (OR, 17.5; 95% CI, 3.1-99.4). However, placental infarcts were seen less frequently among smokers than nonsmokers (10.0% vs 32.5%; OR, 0.2; 95% CI, 0.1-0.8). Conclusion These findings suggest that different pathologic mechanisms may be responsible for the histologic findings between smokers and nonsmokers diagnosed with placental abruption.
Site-Specific Arylation of Rat Glutathione S-Transferase A1 and A2 by Bromobenzene Metabolites in Vivo

The hepatotoxicity of bromobenzene (BB) derives from its reactive metabolites (epoxides and quinones), which arylate cellular proteins. Application of proteomic methods to liver proteins from rats treated with a hepatotoxic dose of [ 14 C]-BB has identified more than 40 target proteins, but no adducted peptides have yet been observed. Because such proteins are known to contain bromophenyl- and bromodihydroxyphenyl derivatives of cysteine, histidine, and lysine, the failure to observe modified peptides has been attributed to the low level of total covalent binding and to the "dilution" effect of multiple metabolites reacting at multiple sites on multiple proteins. In this work glutathione S-transferase (GST), a well-known and abundant BB-target protein, was isolated from liver cytosol of rats treated with 14 C-BB by use of a glutathione (GSH)-agarose affinity column and further resolved by reverse-phase high-performance liquid chromatography (HPLC) into subunits Ml, M2, Al, A2 and A3. The subunits were identified by a combination of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), whole-molecule mass spectrometry, and peptide mass mapping and found to contain radioactivity corresponding to 0.01-0.05 adduct per molecule of protein. Examination of tryptic digests of these subunits by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) and electrospray ionization mass spectrometry (ESI-MS) failed to reveal any apparent adducted peptides despite observed sequence coverages up to 87%. However, use of HPLC-linear ion-trap quadrupole Fourier transform mass spectrometry (LTQ-FTMS) to search for predicted modified tryptic peptides revealed peaks corresponding, with a high degree of mass accuracy, to a bromobenzoquinone adduct of peptide 89-119 in both GSTA1 and A2. The identity of these adducts and their location at Cys-111 was confirmed by tandem mass spectrometry (MS-MS). No evidence for the presence of any putative BB-adducts in GST Ml, M2, or A3 was obtained. This work highlights the challenges involved in the unambiguous identification of reactive metabolite adducts formed in vivo.
Bilateral Scapular Fractures from Low.Voltage Electrical Injury

Bilateral, characteristically distributed fractures of the scapula occur from low-voltage electrical injury due to tetanic muscle contraction involving the upper extremities and shoulder girdles. We present the case of a 43-year-old man who sustained bilateral scapular fractures after exposure to a 440-volt, 60 cycle-per-second current passing briefly through his upper extremities. Conservative management, consisting of shoulder immobilization, analgesia, and progressive physical therapy, led to healing of the fractures over six weeks with essentially normal shoulder function after a follow-up period of six months. The absence of an associated fall or other direct trauma should not dissuade the physician from the diagnosis of scapular fractures in electrical injury.
Toward the re‐enchantment of psychotherapy: Stories as container

Abstract Storytelling by a therapist to clients may serve to increase clients’ ability to bear pain, to increase self‐complexity, and expand clients’ senses of the allowable. A model delineating the therapeutic impact of therapist storytelling in psychotherapy is proposed. Stories may change clients’ selves so that they may accommodate traumatic experiences and internal complexity. Stories increase clients’ capacity to tolerate painful experience and therefore serve as a container of tragic life experiences. The artistry of therapeutic story selection is defined as choosing stories consonant with clients’ strengths, rather than with the nature of the trauma. The power of story‐listening to alter consciousness in pleasant ways (storystoned) increases its usefulness as an intervention that is neither anxiety provoking nor re‐traumatizing.
Quantifying transgene flow rate in transgenic Sclerotinia-resistant peanut lines

Abstract Multi-year transgenic field trials were conducted to assess the extent of pollen-mediated transgenic flow in Virginia to support a petition requesting deregulated status for Blight Blocker peanuts from USDA Animal and Plant Health Inspection Service (APHIS) Biotechnology Regulatory Services (BRS). We measured transgene flow from transgenic lines to their non-transgenic parental cultivars. A colorimetric method based on quantification of hydrogen peroxide released from oxalic acid in the presence of the oxalate oxidase was used to screen seed embryos from non-transgenic rows at various distances from the transgenic source. The overall transgene flow rate in three cultivars was 0.2094% based on screening over 85,000 seeds. In general, the transgene flow rate greatly declined past 10 m from the transgene source. However, a transgene flow rate of less than 0.05% did occur sporadically at greater distances than 10 m. In conclusion, transgene flow in peanut can be spatially confined to provide negligible rates using relatively short separation distances. The extremely low rate of transgene flow at greater distance was dependent on ecological and environmental contexts, particularly on foraging patterns and flight distance of pollinators.
An electromyographic analysis of muscular behavior in mandibular movements from rest position

Summary Mandibular movements on either side of the rest position were electromyographically evaluated in subjects wearing dentures. It was found that a correct vertical dimension of occlusion coupled with an adequate interocclusal distance between the teeth of the upper and lower dentures is essential to maintain the muscles of mastication at their most efficient functional length. When vertical overclosure obtained, there was loss of muscle tension which frequently caused spontaneous hyperactivity. When the vertical dimension was excessive, muscle tension increased. An interocclusal space, to be adequate, must be sufficient to permit muscles to function within their physiologic length. For edentulous patients this was found to be in the neighborhood of 4 mm.