cssi/SciSciGPT-SciSciNet huggingface dataset:
Individual differences in the retention of maps

Abstract Individual differences effecting the way in which general reference maps are retained and organized in memory were assessed in 173 university undergraduate students. Learners were instructed to encode map features in memory by clustering them together, either by their semantic or spatial relationship. The degree to which either directive influenced map processing, in conjunction with the individual's cognitive style and gender, was examined in learners. The encoding tactic that learners used while processing the map significantly predicted performance on both organization and retention in memory. Interaction effects were also observed with cognitive style and gender significantly influencing some, but not all, indices of map processing. The findings are discussed in terms of their theoretical, as well as instructional, implications in explaining the ways in which maps are processed in learners.
Skeletal muscle in idiopathic cardiomyopathy

Abstract Six patients in whom a diagnosis of idiopathic cardiomyopathy was made and who showed no evidence of complicating diseases known to affect skeletal muscle were selected for this report. The skeletal muscle was evaluated clinically, by electromyography (EMG) and by biopsy. Four patients showed selective atrophy of type II fibres and in 1 there was also evidence of neurogenic involvement. One patient had pronounced non-selective myopathy with internalization of capillaries in the muscle fibres. One other had hypotrophy of type I fibres and also clinical evidence of muscle disease. No such abnormalities were found in patients with other forms of heart disease. It is suggested that idiopathic cardiomyopathy is sometimes a more generalized disorder and that the genetic or environmental etiological factors responsible for some cardiomyopathies may also involve skeletal muscle.
Sequential item selection: Optimal and heuristic policies

Abstract This paper considers testing in which the goal is to minimize the number of test items required to establish a learner's state of ability. Focus is on optimal or near optimal selection over a well-defined universe of items or stimuli. Selection policies are determined for the case in which the items have hierarchical or partial hierarchical relationships. Derivation of an optimal policy rests upon techniques from dynamic programming. For situations in which an optimal policy may be too costly to compute, two heuristic approximations are offered. One heuristic counts the hypothetical estimates of ability that remain tenable following a response to each item and chooses the item that minimizes the expectation of that number. The other selects the item that maximizes the statistic of information.
The cytology of encapsulated nerve endings in the rat penis.

The specialized encapsulated nerve endings found in the superficial dermis of the rat penis have been studied by light and electron microscopy. The nerve fiber in these endings lose their myelin sheath and become associated with specialized encapsulating cells termed laminar cells. This cell provides the cellular investment of the unmyelinated neurite and the successive thin cytoplasmic sheets which envelope the neurite. These lamellae are separated by reduplicated basement membranes. The separation between successive lamellae is remarkably constant and remains so when a process of a capsular cell intervenes between successive lamellae. Capsular cells lack basement membranes and appear similar to fibroblasts. Small unmyelinated neurites in a single Schwann cell investment are also found in these endings. These endings are similar to those described by Dogiel and Krause as genital end bulbs.
Correlation Coefficient and the Isotope Effect for the Diffusion of Zinc in Silver

The correlation factor ${f}_{i}$ for the diffusion of zinc in silver has been obtained from measurements of the diffusion of ${\mathrm{Zn}}^{65}$ and ${\mathrm{Zn}}^{69}$ in silver single crystals. ${f}_{i}$ increases from 0.47 at 697\ifmmode^\circ\else\textdegree\fi{}C to 0.56 at 952\ifmmode^\circ\else\textdegree\fi{}C. The values of ${f}_{i}$ and their temperature dependence agree with those calculated by LeClaire. The self-diffusion coefficients of silver in silver-zinc alloys containing 0 to 4 at.% zinc have been measured at 747 and 880\ifmmode^\circ\else\textdegree\fi{}C. The relative jump frequencies of the zinc atoms and the silver atoms, which are neighbors of the zinc atom, have been calculated from these data, using the theory of Howard and Manning and the results of the isotope-effect experiments. Values of ${f}_{i}$ calculated from these data by means of Lidiard's theory are also in agreement with the values obtained from the isotope effect.
The effect of thrombin and trypsin on calcium uptake by calf platelet membranes

Abstract The ATP-dependent calcium uptake activity of isolated platelet membranes is used as a model system to examine the effects of thrombin and trypsin on a platelet membrane function specifically related to calcium flux. Calcium uptake is completely insensitive to dialyzed or column-purified thrombin in a wide range of concentrations. This observation is in contrast to the effect of commercial thrombin, which produces an apparent decrease in calcium uptake because of a high level of contaminating calcium. Pre-treatment of whole platelets with 100 units dialyzed thrombin has no effect on calcium uptake activity of subsequently prepared membrane fractions. Treatment of the isolated membranes with 0.025–0.25 mg/ml trypsin reduces calcium uptake activity to 15–30% of control levels. Pre-treatment of whole platelets with 0.25 mg/ml trypsin results in some loss of calcium uptake activity in subsequently isolated membranes, but not as great as when the membranes are treated directly. The thrombin insensitivity of calcium uptake suggests that thrombin neither acts directly on calcium transport sites nor produces a general membrane permeability to calcium. The difference in effect of trypsin depending on whether the isolated membranes or the whole platelets are treated suggests that the membranes involved in ATP-dependent transport of calcium may have an internal location in the intact platelet.
Outcomes of strabismus surgery with or without trainee participation as surgeon.

Purpose To compare success rates of strabismus surgery that involves trainees versus those performed solely by staff surgeons. Design Retrospective, comparative case series. Subjects Patients undergoing eye muscle surgery for primarily horizontal deviations. Methods Retrospective comparative case series of 543 patients (921 eyes) undergoing eye muscle surgery, with or without trainee participation, for horizontal deviations. Main Outcome Measures Success in surgery defined as residual horizontal deviations of 10 prism diopters or less. Results Trainees were involved in surgeries on 396 patients (672 eyes), whereas only staff surgeons operated on 147 patients (249 eyes). After minimum follow-up of 8 weeks, there was no overall significant difference between the success rates of procedures that involved trainees as surgeons and those that did not ( P = 0.59). Conclusions The involvement of trainees as operators in surgeries on horizontal eye muscles does not result in a worse outcome than surgeries exclusively performed by staff. With a shift toward competency-based education and more scrutiny of patient outcomes, these data further support the quality of surgical care provided by trainees.
Prophages in marine bacteria: dangerous molecular time bombs or the key to survival in the seas?

Prophages in marine bacteria: dangerous molecular time bombs or the key to survival in the seas?
Development of uterine artery compliance in pregnancy as detected by Doppler ultrasound

Abstract Uterine artery velocimetry was performed by means of a continuous-wave Doppler ultrasound. Serial studies were done on 12 nonpregnant and 79 normal pregnant women. Measurements were made on both uterine arteries and averaged. From the proliferative phase of the menstrual cycle through 40 weeks of pregnancy, four developmental phases are described. These changes are based on the calculation of the systolic-diastolic ratio and the disappearance of the early diastolic notch in the velocity wave. The ratio after 26 weeks averaged 2 ± 0.3. These data provide a foundation for the study of pregnancies in which these normal evolutionary changes do not occur.
The cardiac response of the ponderous ark clam, Noetia ponderosa, to reduced oxygen levels☆

Abstract 1. 1. Heart rates in N. ponderosa decrease slowly as the p O 2 declines from 159 to 4 torr. 2. 2. Neither the flow rate nor the periods of ventilation change over a broad range of water p O 2 . 3. 3. Blood p O 2 declines when water p O 2 is reduced, but the change in hemoglobin oxygenation and thus the volume of O 2 carried in the blood remains stable. 4. 4. The bradycardia and the increased transport function of the hemoglobin explain the observed constancy of O 2 extraction at reduced water p O 2 .
Cleavage Efficiency of the Novel Aspartic Protease Yapsin 1 (Yap3p) Enhanced for Substrates With Arginine Residues Flanking the P1 Site: Correlation With Electronegative Active-Site Pockets Predicted by Molecular Modeling

Yapsin 1, a novel aspartic protease with unique specificity for basic residues, was shown to cleave CCK13-33 at Lys23. Molecular modeling of yapsin 1 identified the active-site cleft to have negative residues close to or within the S6, S3, S2, S1, S1‘, S2‘, and S3‘ pockets and is more electronegative than rhizopuspepsin or endothiapepsin. In particular, the S2‘ subsite has three negative charges in and close to this pocket that can provide strong electrostatic interactions with a basic residue. The model, therefore, predicts that substrates with a basic residue in the P1 position would be favored with additional basic residues binding to the other electronegative pockets. A deletion of six residues close to the S1 pocket in yapsin 1, relative to rhizopuspepsin and other aspartic proteases of known 3D structure, is likely to affect its specificity. The model was tested using CCK13-33 analogues. We report that yapsin 1 preferentially cleaves a CCK13-33 substrate with a basic residue in the P1 position since...
The prospects for enhanced international polar-orbiting satellite cooperation

Abstract With robust polar satellite missions demonstrated and/or operational in the USA, Europe, Japan, China, Russia, India, and Brazil, and with other nations also likely to develop such capability, this paper examines the prospects for as well as the potential challenges to closer and perhaps more formal international polar satellite cooperation. In suggesting that now is the time to explore the development of a coordinated polar observing system, the present paper identifies potential contributors, assesses the relevance of existing space-based Earth observation international coordination mechanisms, and considers three potential models for a future system.
Radiotherapy of malignant subdaphragmatic implants in advanced ovarian carcinoma: A new technique

Abstract We report the development of a new technique using remote afterloading intraoperative radiation therapy to deliver a tumoricidal dose to diaphragmatic tumor implants. A multi-positional lucite applicator was designed based on anatomic studies of the diaphragmatic surface to accommodate a high dose rate iridium source in a series of, needles placed 1.5 cm apart. The applicator curvature can vary from planar to full accommodation of the diaphragmatic surface with a constant source to surface distance of 0.5 cm. The applicator has been piloted in three patients with ovarian carcinoma with residual subdiaphragmatic disease found at second look laparotomy, to deliver a dose of 1,500 to 2,000 cGy at 0.5 cm. Tolerance of the diaphragm and hepatic surface has been excellent. There were no postoperative complications and no deterioration in liver function studies. The additional postoperative external beam irradiation directed with the aid of surgically placed clips and gated to respiratory movements permits achievement of a tumoricidal dose while limiting the treated volume and related toxicities.
The effects of radiotherapy for the treatment of contralateral breast cancer

Radiotherapy following breast-conserving surgery for the treatment of first primary breast cancer is the standard of care and is widely used despite its small survival benefit. The effects of radiotherapy in metachronous contralateral breast cancer are unknown. We examined the use of radiotherapy and its effect on cause-specific and all-cause mortality among women with metachronous contralateral breast cancer treated with breast-conserving surgery in community settings. Using data from the 1985-2000 Surveillance, Epidemiology, and End Results program, we identified women with stage 0-III metachronous contralateral breast cancer that occurred at least six months after stage 0-III first primary breast cancer. Cause-specific and all-cause mortality of women age 40-69 who did and who did not receive radiotherapy following breast-conserving surgery for metachronous contralateral breast cancer were compared in proportional hazard models using propensity scores to balance covariates by radiotherapy use. We adjusted for misclassification of radiotherapy use. Based on misclassification-corrected analyses, 43.2 percent of 1,083 women with metachronous contralateral breast cancer did not receive radiotherapy after BCS. After adjustment for propensity scores and radiotherapy misclassification, women who did not receive radiotherapy had 2.2 times greater risk of cause-specific and 1.7 times greater risk of all-cause mortality. In community settings, a high percentage of women with stage 0-III metachronous contralateral breast cancer did not receive radiotherapy following breast-conserving surgery. Unlike the small survival benefit of radiotherapy after first primary breast cancer, omission of radiotherapy after metachronous contralateral breast cancer significantly increased the risk of cause-specific and all-cause mortality.
Targeting FOXO Kills Two Birds with One Stone

PTEN deficiency activates Akt signaling and results in a variety of human malignancies. Encouragingly, recent studies demonstrate that small molecules can regulate FOXO1a, an Akt target, to suppress tumor growth, and FOXO1a is therefore a promising anticancer drug target.
A comparison of cardiopulmonary and anesthetic effects of an induction dose of alfaxalone or propofol in dogs

Abstract Objective To compare the physiological parameters, arterial blood gas values, induction quality, and recovery quality after IV injection of alfaxalone or propofol in dogs. Study design Prospective, randomized, blinded crossover. Animals Eight random-source adult female mixed-breed dogs weighing 18.7 ± 4.5 kg. Methods Dogs were assigned to receive up to 8 mg kg−1 propofol or 4 mg kg−1 alfaxalone, administered to effect, at 10% of the calculated dose every 10 seconds. They then received the alternate drug after a 6-day washout. Temperature, pulse rate, respiratory rate, direct blood pressure, and arterial blood gases were measured before induction, immediately post-induction, and at 5-minute intervals until extubation. Quality of induction, recovery, and ataxia were scored by a single blinded investigator. Duration of anesthesia and recovery, and adverse events were recorded. Results The mean doses required for induction were 2.6 ± 0.4 mg kg−1 alfaxalone and 5.2 ± 0.8 mg kg−1 propofol. After alfaxalone, temperature, respiration, and pH were significantly lower, and PaCO2 significantly higher post-induction compared to baseline (p Conclusions and clinical relevance There were no clinically significant differences in cardiopulmonary effects between propofol and alfaxalone. A single bolus of propofol resulted in shorter recovery times and fewer adverse events than a single bolus of alfaxalone.
Altered peptide ligands can modify the Th2 T cell response to the immunodominant 161–175 peptide of LACK (Leishmania homolog for the receptor of activated C kinase)

Abstract Following Leishmania major infection, the early LACK ( Leishmania homolog of receptors for activated C kinase)-induced IL-4 response appears to determine disease susceptibility in BALB/c mice. Therefore, we sought to manipulate the pathogenic T cell responses to the immunodominant epitope with the use of altered peptide ligands (APLs). Conservative and non-conservative substitutions for each amino acid of the LACK 161-175 peptide determinant were tested for their stimulatory capacity in four different LACK-reactive T cell systems. From these results, we propose a likely LACK 163-171/I-A d core peptide register and show that APLs with changes at putative T cell receptor (TCR) contacts provide the greatest potential for immune deviation. In particular, the TCR-contact H164V APL expanded Th1 cells upon in vitro recall of naive splenocytes from LACK-specific BV4 T cell receptor transgenic mice and stimulated IFN-γ secretion from a Th2-committed LACK-reactive T cell line. We also observed that non-conservative substitutions flanking the core determinant had strong agonistic effects for proliferation and Th1/Th2 modulation. However, upon immunization, the H164V APL considerably downregulated proliferation and cytokine responses to the wild type LACK 161-175 peptide, while immunization with the weak agonist, MHC contact APL S171K, increased the IFN-γ/IL-4 ratio to the wild type peptide. In these instances, a hyporesponsive T cell response to the wild-type peptide was achieved by immunizing with an APL possessing non-conservative substitutions at TCR contact sites, while immune deviation was accomplished using a weak-agonist APL that retained the core determinant. Thus, certain LACK-APLs are able to induce T cell responses with a protective phenotype in an infectious disease such as leishmaniasis.
Application of Stepwise Regression to Non-Linear Estimation

This paper reviews three basic methods of non-linear least squares estimation and the best known modifications to the popular Gauss-Newton procedure. With regard to the Gauss-Newton procedure the paper identifies the problem of poor parameterization and gives simple examples to show how it may arise. A simple example is also given to show that one popular method of handling constrained boundaries can lead to erroneous results. A modification, based on stepwise linear regression techniques, to handle both of these problems is presented and discussed and an example is given to illustrate its effectiveness. The required fundamentals of stepwise linear regression are reviewed.
Nonequilibrium and many-body Coulomb effects in the relaxation oscillation of a semiconductor laser

A treatment of the dynamics in a semiconductor laser that is based on the coupled Maxwell–semiconductor– Bloch equations is described. It is shown that intraband carrier dynamics and interband Coulomb interactions significantly affect the damping of relaxation oscillations. The specific case of a vertical-cavity surface-emitting laser is treated.
Lives in Transition: Bilingual Writers on Identity and Creativity

Lives in Translation: Bilingual Writers on Identity and Creativity. Isabelle de Courtivron. editor. Palgrave Macmillan: New York, NY. 2003. 192 pp. ISBN-4039-6066-6 (paper)
Regulation of the forkhead transcription factor FKHR, but not the PAX3-FKHR fusion protein, by the serine/threonine kinase Akt

Akt, a proto-oncogene that encodes a cytosolic serine/threonine kinase, can phosphorylate and modulate the activity of several proteins involved in cellular metabolism and survival. Recently, two mammalian highly related forkhead transcription factors FKHRL1 and AFX and their nematode homologue Daf-16 have been found to be targets of this kinase. Here we show that Akt, but not inactive Akt, represses the transcriptional activity of FKHR, another member of the forkhead family. FKHR mutants with alanine substitutions at three Akt phosphorylation consensus sites (T24, S256 and S319) were inhibited by Akt, but mutation of all three sites rendered FKHR resistant to suppression. By contrast, the transcriptional activity of the oncogenic PAX3 – FKHR fusion protein, containing two consensus phosphorylation sites, was not inhibited by Akt. Importantly, Akt inhibited the translocation of FKHR to the nucleus, providing a mechanism by which Akt might regulate the transcriptional activity of FKHR. Consistent with this model, the localization of the PAX3 – FKHR fusion protein was nuclear and was not altered by Akt. These results provide evidence that Akt inhibits the transcriptional activity of FKHR by controlling its trafficking into the nucleus and that oncogenic PAX3 – FKHR can escape this negative regulation by Akt.
Structural Features of Membrane-bound Glucocerebrosidase and α-Synuclein Probed by Neutron Reflectometry and Fluorescence Spectroscopy

Mutations in glucocerebrosidase (GCase), the enzyme deficient in Gaucher disease, are a common genetic risk factor for the development of Parkinson disease and related disorders, implicating the role of this lysosomal hydrolase in the disease etiology. A specific physical interaction exists between the Parkinson disease-related protein α-synuclein (α-syn) and GCase both in solution and on the lipid membrane, resulting in efficient enzyme inhibition. Here, neutron reflectometry was employed as a first direct structural characterization of GCase and α-syn·GCase complex on a sparsely-tethered lipid bilayer, revealing the orientation of the membrane-bound GCase. GCase binds to and partially inserts into the bilayer with its active site most likely lying just above the membrane-water interface. The interaction was further characterized by intrinsic Trp fluorescence, circular dichroism, and surface plasmon resonance spectroscopy. Both Trp fluorescence and neutron reflectometry results suggest a rearrangement of loops surrounding the catalytic site, where they extend into the hydrocarbon chain region of the outer leaflet. Taking advantage of contrasting neutron scattering length densities, the use of deuterated α-syn versus protiated GCase showed a large change in the membrane-bound structure of α-syn in the complex. We propose a model of α-syn·GCase on the membrane, providing structural insights into inhibition of GCase by α-syn. The interaction displaces GCase away from the membrane, possibly impeding substrate access and perturbing the active site. GCase greatly alters membrane-bound α-syn, moving helical residues away from the bilayer, which could impact the degradation of α-syn in the lysosome where these two proteins interact.
An Interesting Case of Late Age at Onset of Narcolepsy with Cataplexy

The usual age at onset of narcolepsy with cataplexy is in the second or third decade. In cases with late onset narcolepsy with cataplexy, symptoms are usually mild with relatively less severe daytime sleepiness and less frequent cataplexy. Here we present a case of narcolepsy with cataplexy with onset of symptoms around sixty years of age. This case is unique, with severe daytime sleepiness both by subjective report as well as on objective Multiple Sleep Latency Test and having multiple cataplexy episodes in a day.
The relationship of age and satisfaction with physician–patient communication from the 2009 Medical Expenditure Panel Survey (MEPS)

The purpose of this study was to determine the relationship between age and satisfaction with patient–physician communication. Data were obtained from the 2009 Medical Expenditure Panel Survey. Guided by the Communication Predicament Model, chi square analyses were run to examine the relationship of age and satisfaction with physician–patient communication for persons in general and those in fair to poor health. Regression analyses were run to determine whether older age (65+) increases the likelihood of experiencing communication issues of the physician listening to the older adult's medical concerns, explaining treatment so that the patient understood, treating the patient with respect and spending enough time with the patient. A significant relationship was found between age and dissatisfaction with physician communication. Persons who are 65 and older are 1.35–1.71 times as likely to perceive problems with physician communication. Other factors that increased the likelihood of perceived communication ...
A conserved hydrophobic tetrad near the C terminus of the secretory Na+-K+-2Cl- cotransporter (NKCC1) is required for its correct intracellular processing.

Little is known about the intracellular folding and trafficking of integral membrane proteins. Here we identify a hydrophobic amino acid tetrad (ILLV) close to the C terminus of the secretory Na+-K+-2Cl- cotransporter (NKCC1) that is important for the proper intracellular processing of this protein. This tetrad appears in a C-terminal sequence pattern that is conserved across species in a number of members of the NKCC1 gene family (slc12) of electroneutral salt transporters. We studied the effects of various mutations of these amino acids on NKCC1 transiently transfected into HEK-293 cells. Our results show that mutation of two of these residues to alanine leads to a >50% reduction in expression and complex glycosylation levels and that multiple mutations to alanine have cumulative effects. By contrast, scrambling of these amino acids, or mutation of other nearby conserved C-terminal residues, has little effect on these parameters. Mutation of ILLV to AAAA reduces complex glycosylation of NKCC1 by ∼90% and results in a protein that does not form stable dimers and is retained in the endoplasmic reticulum in a highly aggregated state. Our results are consistent with the hypothesis that mutation of the hydrophobic tetrad ILLV to AAAA leads to the ab initio misfolding and concomitant aggregation of this NKCC1 mutant, resulting in its retention in the endoplasmic reticulum.
A study of slow‐mode structures in the dayside magnetosheath

Recent observations indicate that a region of enhanced plasma pressure and decreased magnetic field intensity frequently occurs in front of the plasma depletion layer at the dayside magnetopause (Song et al., 1990). This inverse relationship is characteristic of a slow-mode wave. This phenomenon was simulated with a two-dimensional incompressible MHD simulation code. When a normal component of the interplanetary magnetic field is present (Bx not equal to 0), the total magnetic field intensity tends to decrease in front of the depletion layer due to the bending of the magnetic field lines, and the plasma pressure is enhanced in this region. On the other hand, when Bx = 0, this slow-mode structure is not present in the simulation and only the plasma depletion layer is observed.
High frame-rate simultaneous bilateral breast DCE-MRI.

A simultaneous bilateral back-projection method for 3D dynamic contrast-enhanced (DCE)-MRI of the breasts was developed and evaluated. Using a double-side band modulation of the RF slab excitation pulse, discontinuous volumes that included both breasts were simultaneously selected. The number of slice phase-encoding steps was undersampled by a factor of 2, and the resulting signal aliasing from one volume to the other was removed using SENSE processing. In-plane encoding was performed with an interleaved radial acquisition reconstructed using dynamic k-space-weighted image contrast (KWIC) temporal filtering. Image resolution was 0.5 × 0.5 × 3.0 mm3 with an effective temporal resolution of 15 s for both breast volumes. Combined with the 2× acceleration from SENSE encoding, this is a 16× acceleration factor over a conventional MR bilateral breast scan. An initial evaluation of these methods was performed on a cohort of women who presented with palpable or mammographically visible breast abnormalities. A total of 73 abnormalities were found in 45 of the 54 bilateral examinations that were performed. In 11 of these cases there was a significant finding in the contralateral breast. DCE images of both breasts can be acquired simultaneously, resulting in high-resolution images as well as rapid sampling of the contrast kinetics. Magn Reson Med 57:220–225, 2007. © 2006 Wiley-Liss, Inc.
Gas-Phase Transport and Redeposition of Nano- and Micro-Particulates During Laser Cleaning from Solid Substrates

Theoretical modeling and experimental studies were performed to investigate basic processes underlying transport of model submicron spherical particles in still air and thin liquid layers of variable thickness after their laser-assisted detachment from dry and 2-propanol–dosed Si surfaces. Viscous drag and diffusive Brownian motion were found to mostly affect transport of nano- and micro-particles removed from solid substrates in the used or other viscous media removed by laser cleaning, resulting in their undesirable redeposition. A crucial parameter of particle transport—lift-off distances—has been experimentally measured as a function of laser fluence for these particles using thin 2-propanol layers, and the distances can be scaled for other viscous media accounting for their corresponding viscosities. Experimental and theoretical results of this work can be related to optimization of transport processes in laser cleaning and laser-induced forward transfer applications for nano- and micro-features of a...
Land use and first birth timing in an agricultural setting

The dramatic changes in the earth’s landscape have prompted increased interest in the links between population, land use, and land cover. Previous research emphasized the notion of population pressure (population pressure increases demands on natural resources causing changes in land use), overlooking the potentially important effects of changes in land use on humans. Using multiple data sets from the Chitwan Valley Family Study in Nepal, we test competing hypotheses about the impact of land use on first birth timing. We argue that while agricultural land should encourage early childbearing, land area devoted to public infrastructure should discourage it. The results show that individuals from neighborhoods with larger proportions of land under agriculture experienced first birth at rates higher than those from neighborhoods with smaller proportions. On the other hand, individuals from neighborhoods with larger proportions of land under public infrastructure experienced first birth at rates lower than those from neighborhoods with smaller proportions. However, the effects of public infrastructure are not as strong as the land area devoted to agriculture.
SOLO: a meiotic protein required for centromere cohesion, coorientation, and SMC1 localization in Drosophila melanogaster

Sister chromatid cohesion is essential to maintain stable connections between homologues and sister chromatids during meiosis and to establish correct centromere orientation patterns on the meiosis I and II spindles. However, the meiotic cohesion apparatus in Drosophila melanogaster remains largely uncharacterized. We describe a novel protein, sisters on the loose (SOLO), which is essential for meiotic cohesion in Drosophila. In solo mutants, sister centromeres separate before prometaphase I, disrupting meiosis I centromere orientation and causing nondisjunction of both homologous and sister chromatids. Centromeric foci of the cohesin protein SMC1 are absent in solo mutants at all meiotic stages. SOLO and SMC1 colocalize to meiotic centromeres from early prophase I until anaphase II in wild-type males, but both proteins disappear prematurely at anaphase I in mutants for mei-S332, which encodes the Drosophila homologue of the cohesin protector protein shugoshin. The solo mutant phenotypes and the localization patterns of SOLO and SMC1 indicate that they function together to maintain sister chromatid cohesion in Drosophila meiosis.
A New Piece in the Puzzle of Lithium/Air Batteries: Computational Study on the Chemical Stability of Propylene Carbonate in the Presence of Lithium Peroxide

The electrolyte role in non-aqueous lithium/air batteries is attracting a lot of attention in several research groups, because of its fundamental importance in producing the appropriate reversible electrochemical reduction. While recent published works identify the lithium superoxide as the main degrading agent for propylene carbonate (PC), there is no clear experimental evidence that the oxygen at the cathode interface layer does not reduce further to peroxide before reacting with PC. Here, we investigate the reactivity of lithium peroxide versus propylene carbonate and find that Li(2)O(2) irreversibly decomposes the carbonate solvent, leading to alkyl carbonates. We also show that, compared with a single Li(2)O(2) unit in PC, a crystalline surface of Li(2)O(2) exhibits an enhanced reactivity. Our findings support the possibility that in lithium/air cells, oxygen may still be reduced to peroxide, with the formation of solid Li(2)O(2), which degrades by decomposing PC.
Complications of Radical Cystectomy For Nonmuscle Invasive Disease: Comparison With Muscle Invasive Disease

ABSTRACTPurpose: Radical cystectomy is gold standard treatment for muscle invasive bladder cancer and is an option for many patients with nonmuscle invasive disease at high risk for disease progression. We assessed the early complications of radical cystectomy among patients with nonmuscle invasive compared to those with muscle invasive disease.Materials and Methods: We reviewed the records of 304 consecutive patients who underwent radical cystectomy from December 1995 to July 2000. We evaluated complications that occurred within 30 days of the procedure. Cases were stratified into nonmuscle invasive (PO, Pa, P1 and PIS, N0) or muscle invasive (P2–4, N0–3) tumors based on final specimen pathology. The 2 groups were then compared with respect to age, gender, race, American Society of Anesthesiologists score, type of urinary diversion, estimated blood loss, operative time and length of stay, and major and minor complications.Results: Of the 293 available patients 105 (36.8%) had nonmuscle invasive specimen ...
Mechanism of RNA Recombination in Carmo- and Tombusviruses: Evidence for Template Switching by the RNA-Dependent RNA Polymerase In Vitro

RNA recombination occurs frequently during replication of tombusviruses and carmoviruses, which are related small plus-sense RNA viruses of plants. The most common recombinants generated by these viruses are either defective interfering (DI) RNAs or chimeric satellite RNAs, which are thought to be generated by template switching of the viral RNA-dependent RNA polymerase (RdRp) during the viral replication process. To test if RNA recombination is mediated by the viral RdRp, we used either a purified recombinant RdRp of Turnip crinkle carmovirus or a partially purified RdRp preparation of Cucumber necrosis tombusvirus. We demonstrated that these RdRp preparations generated RNA recombinants in vitro. The RdRp-driven template switching events occurred between either identical templates or two different RNA templates. The template containing a replication enhancer recombined more efficiently than templates containing artificial sequences. We also observed that AU-rich sequences promote recombination more efficiently than GC-rich sequences. Cloning and sequencing of the generated recombinants revealed that the junction sites were located frequently at the ends of the templates (end-to-end template switching). We also found several recombinants that were generated by template switching involving internal positions in the RNA templates. In contrast, RNA ligation-based RNA recombination was not detected in vitro. Demonstration of the ability of carmo- and tombusvirus RdRps to switch RNA templates in vitro supports the copy-choice models of RNA recombination and DI RNA formation for these viruses.
Ethylene Oxide and Some Factors Affecting the Mutagen Sensitivity of Sister Chromatid Exchange in Humans

In our laboratory, we consider mutagenesis and the factors surrounding a mutagenic event as a series of barrier systems (Fig. 1), any one of which can affect a final biological outcome in humans. For example, a mutagen can only exert an effect if it indeed has access to a portal of entry. Physical parameters such as solubility affect skin absorption (1). Particle size will determine whether a particulate is respirable (2). Taken together, the physical/chemical barriers at the portal of entry limit carcinogen access to an organism. Beyond this point, the extracellular fluid (e.g., blood plasma) may limit or augment a mutagenic effect. In our studies shown here and elsewhere in this volume, we (Wiencke, et al.) demonstrate that sister chromatid exchange (SCE) mutagen effects can be modulated by blood plasma (3). Indeed, Lambert et al. (4) have indicated this possibility earlier. The complex environment of peripheral blood presents a myriad of cell types (erythrocytes, other mononuclear cells, neutrophils, and platelets) which may alter the mutagen response in phytohemagglutinin (PHA)-stimulated lymphocytes. An elegant series of studies (5) shows quite clearly that erythrocytes activate at least 1 carcinogen, styrene, which otherwise is inactive in purified lymphocyte cultures, i.e., the target cell.
The effect of radiation on nuclear waste forms

Radioactive decay within solidified nuclear wastes leads to physical and chemical changes that can alter the rate at which radionuclides are released to the biosphere. Under current policy, the geologic repository for such wastes is relied upon to meet federal release-rate regulations. If these regulatory and acceptance criteria cannot be achieved or are tightened, it may become necessary to rely more heavily on the physical and chemical durability of the waste form itself. Although radiation effects are known to degrade nuclear waste forms, the mechanisms and extent of the degradation are neither well understood nor under current investigation.
Spring remigration of the monarch butterfly, Danaus plexippus (Lepidoptera: Nymphalidae) in north‐central Florida: estimating population parameters using mark‐recapture

Abstract Monarch butterflies ( Danaus plexippus ) of the eastern North American population migrate each fall from the northern U.S.A. and southern Canada to overwintering sites in Mexico and return the following spring to the southeastern U.S.A. where they lay eggs and then die. The spring remigration is the least studied phase in the annual migration cycle. We therefore conducted a mark-recapture study and examined population recolonization dynamics and residence time in a north-central Florida pasture where the monarch's milkweed host plant ( Asclepias humistrata ) was abundant. Beginning in late March 1995 two waves of monarchs arrived, their numbers peaked at 71 individuals by mid-April, and the butterflies disappeared in early May. After arriving, the adults remained for 3–5 days, laid eggs and then continued to migrate. We also compared population sizes and arrival times in 1994 and 1996. We found no evidence of a second spring generation, which was also consistent with the deteriorating quality of the A. humistrata plants. Individuals of the new spring generation disappear shortly after eclosion. The arriving population was approximately nine times greater in 1995 than in 1996. Our findings support two recent hypotheses: (1) the bird-like migration of the monarch butterfly in North America evolved with the northward expansion and phenology of milkweeds; and (2) monarchs appear to be migratory throughout their annual cycle of several generations. By lingering for only a short time at each milkweed patch they encounter, the old monarchs returning from Mexico locate the resurgent milkweed flora over an extensive area in the southern states. Then, within less than a month, their fresh offspring continue the migration and exploit the unfolding cornucopia of milkweeds as the spring advances northward. The more we discover about the biology of this insect, the more remarkable is its annual migratory, breeding and overwintering cycle.
A Case Study in Performance Appraisal System Development: Lessons from a Municipal Police Department:

This paper describes the development, implementation and evaluation of a successful performance appraisal system for probationary police officers for a medium-sized (330,000) Mid-Atlantic city. The case study summarizes the factors that contributed to the adoption of the performance appraisal system and the elements that contributed to the system's effectiveness. These factors include significant user participation in the system's development; thorough rater training; a clear articulation of the system's rationale, goals, and objectives; a rating format that is compatible with the organization's culture and congruent with the objectives of the appraisal system.
Mycoplasma gallisepticum infection dynamics in a house finch population: seasonal variation in survival, encounter and transmission rate

Summary 1. We considered the impact of an emerging pathogen ( Mycoplasma gallisepticum Edward and Kanarek) on apparent survival, encounter and transition rates in a population of a novel host (the house finch, Carpodacus mexicanus Muller). We used a multistate analysis of mark‐encounter data from individually marked birds. Individual birds were categorized to a particular disease ‘state’; transition rates among states, conditional on apparent survival, were analogous to rates of new infection and recovery from infection. We hypothesized that M. gallisepticum infection would reduce the apparent survival of infected individuals, and that the magnitude of this reduction would vary as a function of the physiological condition of the host (which was characterized in our analyses by including a demographic and an environmental surrogate as covariates). 2. We found consistent support for the hypothesis that M. gallisepticum infection resulted in lower apparent survival among infected individuals, and that recovery rates (from infected to non-infected) were greater than infection rates in this population. We also found strong evidence indicating that infected individuals were less likely to be encountered than were non-infected individuals. Although we predicted that both sex and temperature (proxies for physiological condition) would explain a significant proportion of the variation in our data, only marginal influences of both factors on apparent survival, encounter and state transition rates were detected. 3. Our analyses identified several factors that may be important to studies of disease in the wild. First, disease state assignment may be uncertain, which can complicate parameter estimation. Secondly, encounter rate for infected individuals in our study was low relative to that for non-infected individuals, reflecting possible behavioural changes in infected individuals. Low encounter rates reduces precision of estimated parameters, especially for multistate models. Finally, our results (and mark‐recapture models in general) assume independence among individual birds. However, we are aware that there is a social structuring in house finches (and in general for many bird species). Accounting for such non-independence may be especially important for situations where the state transitions are directly related to the pattern of social contact.
The Actual Role of CT and Ventilation–Perfusion Scanning in Workup for Suspected Pulmonary Embolism: Evidence From Hospitals

OBJECTIVE. Over the past two decades, CT has been found valuable in the diagnosis of pulmonary embolism (PE). We sought to ascertain the relative roles of CT and ventilation–perfusion (V/Q) scanning, the previously preferred technique, in the diagnosis of PE in recent practice and whether there is variation among hospital types.MATERIALS AND METHODS. Using the Medicare anonymized 5% of beneficiaries complete claims file for 2005, we studied the use of relevant CT and V/Q scanning in the evaluation of patients with a diagnosis of PE and of patients with symptoms that might have been due to PE (chest pain, syncope, difficulty breathing). In 2008, we surveyed the radiology departments of Pennsylvania hospitals about the use of CT and V/Q scanning for PE, service availability hours, and what equipment was used.RESULTS. In all data, we found that CT was used approximately six times as frequently as V/Q scanning. In the Medicare data, only small differences in frequency of use of CT and V/Q scanning were associ...
Distinct DNA sequence and structure requirements for the two steps of V(D)J recombination signal cleavage

Cleavage of V(D)J recombination signals by purified RAG1 and RAG2 proteins permits the dissection of DNA structure and sequence requirements. The two recognition elements of a signal (nonamer and heptamer) are used differently, and their cooperation depends on correct helical phasing. The nonamer is most important for initial binding, while efficient nicking and hairpin formation require the heptamer sequence. Both nicking and hairpin formation are remarkably tolerant of variations in DNA structure. Certain flanking sequences inhibit hairpin formation, but this can be bypassed by base unpairing, and even a completely single-stranded signal sequence is well utilized. We suggest that DNA unpairing around the signal-coding border is essential for the initiation of V(D)J combination.
Low bit rate video coding using robust motion vector regeneration in the decoder

In this paper, we present a novel coding technique that makes use of the nonstationary characteristics of an image sequence displacement field to estimate and encode motion information. We utilize an MPEG style codec in which the anchor frames in a sequence are encoded with a hybrid approach using quadtree, DCT, and wavelet-based coding techniques. A quadtree structured approach is also utilized for the interframe information. The main objective of the overall design is to demonstrate the coding potential of a newly developed motion estimator called the coupled linearized MAP (CLMAP) estimator. This estimator can be used as a means for producing motion vectors that may be regenerated at the decoder with a coarsely quantized error term created in the encoder. The motion estimator generates highly accurate motion estimates from this coarsely quantized data. This permits the elimination of a separately coded displaced frame difference (DFD) and coded motion vectors. For low bit rate applications, this is especially important because the overhead associated with the transmission of motion vectors may become prohibitive. We exploit both the advantages of the nonstationary motion estimator and the effective compression of the anchor frame coder to improve the visual quality of reconstructed QCIF format color image sequences at low bit rates. Comparisons are made with other video coding methods, including the H.261 and MPEG standards and a pel-recursive-based codec. >
Network-wide deployment of intrusion detection and prevention systems

Traditional efforts for scaling network intrusion detection (NIDS) and intrusion prevention systems (NIPS) have largely focused on a single-vantage-point view. In this paper, we explore an alternative design that exploits spatial, network-wide opportunities for distributing NIDS and NIPS functions. For the NIDS case, we design a linear programming formulation to assign detection responsibilities to nodes while ensuring that no node is overloaded. We describe a prototype NIDS implementation adapted from the Bro system to analyze traffic per these assignments, and demonstrate the advantages that this approach achieves. For NIPS, we show how to maximally leverage specialized hardware (e.g., TCAMs) to reduce the footprint of unwanted traffic on the network. Such hardware constraints make the optimization problem NP-hard, and we provide practical approximation algorithms based on randomized rounding.