cssi/SciSciGPT-SciSciNet huggingface dataset:
The Ran GTPase cycle is required for yeast nuclear pore complex assembly

Here, we report the first evidence that the Ran GTPase cycle is required for nuclear pore complex (NPC) assembly. Using a genetic approach, factors required for NPC assembly were identified in Saccharomyces cerevisiae. Four mutant complementation groups were characterized that correspond to respective mutations in genes encoding Ran (gsp1), and essential Ran regulatory factors Ran GTPase–activating protein (rna1), Ran guanine nucleotide exchange factor (prp20), and the RanGDP import factor (ntf2). All the mutants showed temperature-dependent mislocalization of green fluorescence protein (GFP)-tagged nucleoporins (nups) and the pore-membrane protein Pom152. A decrease in GFP fluorescence associated with the nuclear envelope was observed along with an increase in the diffuse, cytoplasmic signal with GFP foci. The defects did not affect the stability of existing NPCs, and nup mislocalization was dependent on de novo protein synthesis and continued cell growth. Electron microscopy analysis revealed striking membrane perturbations and the accumulation of vesicles in arrested mutants. Using both biochemical fractionation and immunoelectron microscopy methods, these vesicles were shown to contain nups. We propose a model wherein a Ran-mediated vesicular fusion step is required for NPC assembly into intact nuclear envelopes.
Relationship of skeletal muscle glucose 6-phosphate to glucose disposal rate and glycogen synthase activity in insulin-resistant and non-insulin-dependent diabetic rhesus monkeys.

Reduced insulin action on skeletal muscle glycogen synthase activity and reduced whole-body insulin-mediated glucose disposal rates in insulin-resistant subjects may be associated with an alteration in muscle glucose transport (or phosphorylation) or with a defect distal to glucose 6-phosphate. To examine this issue we determined the glucose 6-phosphate concentration and glycogen synthase activity in muscle samples obtained under basal and euglycaemic hyperinsulinaemic clamp conditions in 27 rhesus monkeys (Macaca mulatta). They ranged from metabolically normal (n = 11) to insulin-resistant (n = 8) to overtly diabetic (non-insulin-dependent) (n = 8). The glucose 6-phosphate measured under insulin-stimulated conditions was inversely correlated to insulin-stimulated glycogen synthase independent activity (r = −0.54, p < 0.005), the change in glycogen synthase independent activity (insulin-stimulated minus basal) (r = −0.58, p < 0.002) and to whole-body insulin-mediated glucose disposal rate (r = −0.60, p < 0.002). The insulin-resistant and diabetic monkeys had significantly higher insulinstimulated glucose 6-phosphate concentrations (0.57 ± 0.11 and 0.62 ± 0.11 nmol/mg dry weight, respectively) compared to the normal monkeys (0.29 ± 0.05 nmol/mg dry weight) (p’s < 0.05). We conclude that under euglycaemic/hyperinsulinaemic conditions, a defect distal to glucose 6-phosphate is a major contributor to reduced whole-body insulin-mediated glucose disposal rates and to reduced insulin action on glycogen synthase in insulin-resistant and diabetic monkeys.
The effect of an unusual workshift on chemical toxicity. II. Studies on the exposure of rats to aniline.

Abstract Increasing numbers of workers in industry are working a novel or unusual 12-hr workshift in which the exposure time is longer and the recovery period is shorter than for a standard 8-hr workshift. Experiments were conducted to examine the effects of altering the exposure schedule of rats from 8 hr/day for 5 days to 12 hr/day for 4 days on the toxicity resulting from the inhalation of aniline at 10, 30, 50, and 150 ppm. When compared to the first day, methemoglobin (MetHb) levels, measured prior to and following the exposure, increased with the days of exposure at 50 ppm aniline. At 150 ppm aniline, the MetHb level determined prior to exposure to aniline increased with the days of exposure whereas the postexposure MetHb levels appeared to plateau after the second exposure. The MetHb levels determined prior to exposure were significantly different between the two groups at 50 or 150 ppm aniline whereas the postexposure MetHb levels were not. A residual MetHb level higher than the nonexposed control was observed in the 12 hr/day exposure group after a 3-day recovery period. There was an aniline concentration-dependent decrease in the hematocrit level when determined 1 week after the exposure started. Following a single exposure for 8 or 12 hr to 100 ppm aniline there was no difference in the maximum MetHb level, the peak aniline level in blood and fat, or the rate of aniline elimination from fat and blood. Repeated exposures to 100 ppm for 3 days did not produce a significant difference in aniline level in blood or fat between the 8 and 12 hr/day exposure groups immediately following the last exposure. However, the aniline level in blood was significantly higher in the 12 hr/day exposure group when determined on the morning following the last exposure. These results suggest that the residual burden resulting from previous exposures should be considered when the exposure limits are modified for longer workshifts in man.
Democratic consolidation and community policing: Conflicting imperatives in South Africa

Community policing is currently seen as essential to public policing in a democracy. Yet the consolidation of a new democracy poses potentially conflicting demands that may defeat efforts to move in this direction. The study reported here examines the rise and decline of Community Police Forums in South Africa, a high‐priority effort to democratize the state police during the 1994–1999 transition from apartheid to democracy. The South African experience of building a durable democracy suggests that once the legitimacy of the new government has been established the imperative of regime performance carries more weight than the need to deepen democracy, and that the high crime levels that often accompany greater political freedom are likely to determine a definition of police effectiveness antithetical to community policing. The author notes the irony that the democratization process set in motion political and social forces that increased the political utility of demonstrating the state's authority through ...
Rigid-band behavior in tellurium-rich liquid thallium-tellurium alloys

On carefully excluding data affected by ambipolar transport, we find that the behavior of the electrical conductivity $\ensuremath{\sigma}$ and thermopower $S$ in ${\mathrm{Tl}}_{x}{\mathrm{Te}}_{1\ensuremath{-}x}$ is in accord with a rigid-band model for $\ensuremath{\sigma}(E)$ in the range $0.2\ensuremath{\lesssim}x\ensuremath{\lesssim}0.6$. As a result, we are able to determine $\ensuremath{\sigma}(E)$ and the dependence of the Fermi energy on $x$ and $T$. Using the relation $\ensuremath{\sigma}(E)\ensuremath{\propto}{[N(E)]}^{2}$, we find that the density of states $N(E)\ensuremath{\propto}{E}^{\frac{1}{2}}$ for $E\ensuremath{\lesssim}0.25$ eV, and increases less rapidly than this at larger $E$. Combining this information, we have determined from experimental data the dependence of the hole concentration of $T$ and $x$ within an undetermined constant factor.
Formation and recovery of irradiation and mechanical damage in stabilized δ-plutonium alloys

Abstract Based on the results of thermal expansion measurements of aged δ-phase Pu–Ga alloys and comparisons with historical bulk density, thermal expansion, and X-ray diffraction data of δ-phase Pu–Al and Pu–Ga alloys, it is being proposed that Pu-solute atom mixed 〈1 0 0〉 dumbbell interstitials, generated by damage processes, induce volumetric swelling and impede δ → α′ Martensitic transformation in these alloys. Damage induced volumetric swelling in δ-phase Pu–Al and Pu–Ga alloys is distinct from swelling induced by He bubble formation in that it appears to saturate as a function of damage eventually reaching a constant value which is linearly dependent on solute element atomic concentration. Based on arguments offered in this work, each Pu-solute atom mixed 〈1 0 0〉 dumbbell interstitial creates a strain field of approximately 4.8 times the Pu atomic volume over some 20 A in extent. As the interstitial concentration increases with damage, so does the volumetric swelling up to the point of saturation with a concentration of 1% of the solute atomic concentration. These interstitials appear to anneal out at temperatures of 150 to 200 °C. This relatively high thermal stability is possibly due to an altered local bonding environment for the Pu-solute atom interstitial pair and first-nearest neighbors in response to reduced coordination number and lattice strain field.
On what crosses, and does not cross, our desks in early literacy

Book reviewed in this article: Language, Literacy and Cognitive Development: The Development and Consequences of Symbolic Communication. Edited by Eric Amsel & James P. Byrnes. 2002.
The effect of 2,3-DPG on red cell enzymes

Der Einfluss von 2,3-DPG auf die Erythrozytenenzyme PFK, 6-PGD, GPI und PK ist nochmals untersucht worden. Unterschiede zu bereits publizierten Ergebnissen werden auf Grund unterschiedlicher experimenteller Bedingungen und verschiedener kinetischer Eigenschaften der Enzyme erklart.
Autoantibodies that bind glomeruli: cross-reactivity with bacterial antigen.

Objective Systemic lupus erythematosus (SLE) is characterized by the production of multiple autoantibodies. Anti-DNA antibodies are associated with glomerulonephritis in SLE. It has been shown that anti-DNA antibodies cross-react with bacterial polysaccharide and, thus, might be elicited by microbial exposure. Non–DNA-binding antibodies also contribute significantly to the pathogenesis of lupus nephritis. The goal of this study was to characterize non–DNA-binding, kidney-binding antibodies. Methods We generated a combinatorial library derived from spleen cells of a patient with SLE who had just previously received pneumococcal vaccine. The phage library was used in an in vivo biopanning technique to identify non–DNA-binding, kidney-binding antibodies. Antibodies were then analyzed for binding to bacterial polysaccharide and to renal antigens. Results Eight antibodies were characterized that bound glomeruli, but not DNA. All antibodies isolated by this protocol were IgG class, suggesting that there is affinity maturation for glomerular binding. Four of the antibodies cross-reacted with pneumococcal polysaccharide. Six of the antibodies bound to renal antigens that have previously been reported to be cross-reactive with DNA; the other 2 bound to histone. Conclusion This study suggests that both DNA-binding and non–DNA-binding antibodies in SLE may be elicited by the same bacterial antigens.
Do diabetic patients have higher in-hospital complication rates when admitted from the emergency department for possible myocardial ischemia?

Objective: To compare in-hospital complication rates for diabetic and nondiabetic patients admitted from the emergency department (ED) for possible myocardial ischemia. Methods: This was a prospective, observational study of consecutive consenting patients presenting to a suburban university hospital ED during study hours with typical and atypical symptoms consistent with cardiac ischemia. Demographic, historical, and clinical data were recorded by trained research assistants using a standardized, closed-question, data collection instrument. Inpatient records were reviewed by trained data abstractors to ascertain hospital course and occurrence of complications. Final discharge diagnosis of acute myocardial infarction (AMI) was assigned by World Health Organization criteria. Categorical and continuous data were analyzed by chi-square and t-tests, respectively. All tests were two-tailed with alpha set at 0.05. Results: There were 1,543 patients enrolled who did not have complications at initial presentation; 283 were diabetic. The rule-in rate for AMI was 13.8% for nondiabetic patients and 17.7% for diabetic patients (p = 0.09). Times to presentation were similar for nondiabetic vs diabetic patients [248 minutes (95% CI = 231 to 266) vs 235 minutes (95% CI = 202 to 269); p = 0.32]. Nondiabetic patients tended to be younger [56.6 years (95% CI = 55.8 to 57.4) vs 61.6 years (95% CI = 60.2 to 63.1); p = 0.001] and were less likely to be female (34.3% vs 48.1%; p = 0.001). The two groups had similar prevalences for initial electrocardiograms diagnostic for AMI (5.5% vs 7.4%; p = 0.21). There was no significant difference between nondiabetic and diabetic patients for the occurrence of the following complications after admission to the hospital: congestive heart failure (1.3% vs 1.1%, p = 0.77); nonsustained ventricular tachycardia (VT) (1.3% vs 1.2%, p = 0.93); sustained VT (1.2% vs 1.1%, p = 0.85); supraventricular tachycardia (1.7% vs 3.2%, p = 0.12); bradydysrhythmias (1.9% vs 1.1%, p = 0.33); hypotension necessitating the use of pressors (0.9% vs 1.1%, p = 0.76); cardiopulmonary resuscitation (0.2% vs 0.7%, p = 0.10); and death (0.3% vs 0.7%, p = 0.34). One or more complications occurred with similar frequencies for patients in the two groups (6.3% vs 5.7%; p = 0.70). Conclusions: No statistically significant difference was found in the post-admission complication rates for initially stable diabetic vs nondiabetic patients admitted for possible myocardial ischemia. Based on these results, the presence or absence of diabetes as a comorbid condition does not indicate a need to alter admitting decisions with respect to risk for inpatient complications.
Tribological Properties for Cast Iron CrMo at High Temperature

The tribological properties on the friction and wear properties of cast iron CrMo and 38CrMoAlA materials under the load, temperature, sliding speed were investigated on a MMW-1 high temperature friction-wear tester. The worn surface morphology was observed and analyzed by scanning electron microscope (SEM). The results show that considering the impact of the three factors, the conclusion was that larger influence on adhesive wear was mainly test temperature and sliding speed, the influence of the load was minimal. The main influence of test temperature and sliding speed was adhesive wear. The abrasive wear and plough cut wear were mainly caused by the load. When the synergy of the load, temperature and sliding speed reach a certain condition.
Current Issues in Mechanical Ventilation for Respiratory Failure

The morbidity and mortality associated with respiratory failure is, to a certain extent, iatrogenic. Mechanical ventilation, although the mainstay of treatment for respiratory distress syndrome, can result in physical trauma to lung tissue (ventilator-induced lung injury [VILI]). Strategies to alleviate VILI are often termed lung-protective strategies and are aimed at reducing overstretching and shear stresses associated with repetitive alveolar collapse and reopening. Lower tidal volumes during ventilation, maintenance of positive-end expiratory pressure, and high-frequency ventilation are the best-studied lung-protective strategies that appear to reduce VILI. Faster withdrawal from mechanical ventilation could also improve outcomes and lower the costs associated with care. To enhance the success of weaning from mechanical ventilation, the cooperative efforts of physicians and respiratory therapists are needed. These efforts involve the initiation of spontaneous-breathing trials, implementation of systematic weaning protocols, and optimization of individual patient interventions.
Ethnicity and Religiousity: Some Selective Explorations Among College Seniors.

During the past several years there has been a growing interest in the impact of ethnic background upon attitudes and behavior. With few exceptions, social scientists generally have treated ethnicity and religiousity as demographic, and not social-psychological, variables. More recently however, Greeley of the Na? tional Opinion Research Center1 has made an impressive case for the need for more detailed investigations of how ethnic-religious background functions as a salient agent in the expressed attitudes and behaviors of individuals. Greeley's work suggests that ethnic identity and religious affiliation play roles in percep? tions of self and of others. Data reported in this article support the view that ethnic-religious variables are somehow an integral part of the socialization process. We can only say that ethnic-religious variables are "somehow" a part of the socialization process because our own research does not really indicate how these variables take hold. Our research instruments were not designed to identify the events which lead to individual recognition or internalization of specific or vague ethnic characteristics or attitudes, or to identify the time periods in which indi? viduals are made aware of their ethnic or religious origins. We are unable to say anything about the degree of ethnicity or religiousity felt by our respondents. What we can say is that when we control for the ethnic-religious backgrounds of these participants, we find dramatic and significant differences. In many instances these differences are far greater than those found when we control for social class, sex, or field of study.
Underestimation of cardiac output by thermodilution in patients with tricuspid regurgitation.

Abstract introduction: This study was done to assess the accuracy and reliability of the thermodilution technique in measuring cardiac output in patients with tricuspid regurgitation. patients and methods: In 30 subjects (17 men, 13 women, aged 50 ± 14 [mean ± SD] years), cardiac output was measured in close temporal proximity by thermodilution as well as Fick or indocyanine green dye, after which the presence and severity of tricuspid regurgitation were assessed by contrast right ventriculography or pulsed Doppler echocardiography. results: In the 13 patients without tricuspid regurgitation, there was excellent agreement between the results of thermodilution and Fick or indocyanine green dye cardiac output determinations (4.95 ± 1.19 liters/minute by thermodilution, 4.90 ± 1.11 liters/minute by Fick or indocyanine green dye; NS). In contrast, in the 17 patients with tricuspid regurgitation, the results of thermodilution were consistently lower than those of Fick or indocyanine green dye (4.22 ± 1.45 liters/minute by thermodilution, 4.99 ± 1.67 liters/minute by Fick or indocyanine green dye (4.22 ± 1.45 liters/minute by thermodilution, 4.99 ± 1.67 liters/minute by Fick or indocyanine green dye; p conclusion: Thus, the thermodilution technique of measuring cardiac output is inaccurate in patients with tricuspid regurgitation, yielding results that are consistently lower than the actual outputs.
Excretion of Vasopressin in the Hypoxic Lamb: Comparison between Fetus and Newborn

Top of pageAbstract Summary: The factors associated with increased renal excretion of vasopressin (VP) were examined in the hypoxic fetus and newborn. Studies were conducted on six chronically instrumented fetal (117-136 days gestation) and seven newborn lambs (2-6-dayold). Hypoxia was produced by administration of 10% oxygen to the ewe or neonate for 30 min. This procedure caused a 50% reduction in PaO2, no significant change in pHa in either fetus or neonate and a slight fall in PaCO2. Hypoxia caused an increase in VP concentrations in plasma from 1.3 ± 0.53 to 46.4 ± 4.71 pg/ml in the fetus and from 5.9 ± 2.80 to 50.2 ± 26.68 pg/ml in the neonate. After hypoxia there was a fall in urine output from 0.27 ± 0.045 to 0.17 ± 0.046 ml/(min·kg) in the fetus and from 0.15 ± 0.033 to 0.09 ± 0.022 ml/(min·kg) in the newborn. The corresponding values for urine osmolality were the following: 168 ± 30.8 to 325 ± 30.6 mOsm/kg in the fetus and 388 ± 65.4 to 523 ±51.8 mOsm/kg in the newborn. VP concentration in urine increased from 13 ± 9.4 to a maximum of 176 ± 32.4 pg/ml after 30 min of recovery in the fetus and 39 ± 4.6 to 278 ± 132.5 pg/ml after 1 h of recovery in the newborn. These levels remained high for at least 1 h after the end of hypoxia. There was a good linear correlation between plasma VP levels and the corresponding urine levels and excretion rates in both the fetus and newborn. No correlation was found between VP urinary excretion and either osmolar excretion or GFR. These results, therefore, indicate that urinary VP levels and excretion rates can be used as a reflection of levels in plasma after hypoxia.
Periodate-oxidized ATP stimulates the permeability transition of rat liver mitochondria.

Abstract Periodate-oxidized ADP (oADP) and periodate-oxidized ATP (oATP) stimulate the permeability transition in energized rat liver mitochondria measured as the Ca2+-efflux induced by Ca2+ and Pi. In the presence of Mg2+ and Pi, mitochondria lose intramitochondrial adenine nucleotides at a slow rate. oATP induces a strong decrease of the matrix adenine nucleotides which is inhibited by carboxyatractyloside. Under these conditions, Mg2+ prevents the opening of the permeability transition pore. EGTA prevents the Pi-induced slow efflux of adenine nucleotides, but is without effect on the oATP-induced strong decrease of adenine nucleotides. This oATP-induced strong adenine nucleotide efflux is inhibited by ADP. oATP reduces the increase of matrix adenine nucleotides occurring when the mitochondria are incubated with Mg2+ and ATP. This effect of oATP is also prevented by carboxyatractyloside. oATP is not taken up by the mitochondria. It is suggested that oATP induces a strong efflux of matrix adenine nucleotides by the interaction with the ADP/ATP carrier from the cytosolic side. The induction of the mitochondrial permeability transition by oADP and oATP is attributed to two mechanisms—a strong decrease in the intramitochondrial adenine nucleotide content, especially that of ADP, and a stabilization of the c-conformation of the ADP/ATP carrier.
Parameters affecting neutral-to-earth voltage along primary distribution circuits

It is essential to identify the type of primary distribution circuit and to have a thorough understanding of the sources of neutral-to-earth voltage in agricultural installations in order to achieve success when attempting to mitigate an elevated on-farm neutral-to-earth voltage level originating from off the farm. The authors discuss the primary electrical distribution system, describe the ways in which a neutral-to-earth voltage is produced by the various primary distribution systems, and present the expected change in level of neutral-to-earth voltage as a result of changes of various design parameters of the primary distribution system. It is shown that grounding isolation or step-down transformer banks installed on a line can have an effect upon the neutral-to-earth voltage of the line. >
Solitary waves, steepening and initial collapse in the Maxwell-Lorentz system

Abstract We present a numerical study of Maxwell’s equations in nonlinear dispersive optical media describing propagation of pulses in one Cartesian space dimension. Dispersion and nonlinearity are accounted for by a linear Lorentz model and an instantaneous Kerr nonlinearity, respectively. The dispersion relation reveals various asymptotic regimes such as Schrodinger and KdV branches. Existence of soliton-type solutions in the Schrodinger regime and light bullets containing few optical cycles together with dark solitons are illustrated numerically. Envelope collapse regimes of the Schrodinger equation are compared to the full system and an arrest mechanism is clearly identified when the spectral width of the initial pulse broadens beyond the applicability of the asymptotic behavior. We show that beyond a certain threshold the carrier wave steepens into an infinite gradient similarly to the canonical Majda–Rosales weakly dispersive system. The weak dispersion in general cannot prevent the wave breaking with instantaneous or delayed nonlinearities.
The structure and function of supported molybdenum nitride hydrodenitrogenation catalysts

A series of "y-Al20 s supported Mo nitrides were prepared by the temperature programmed reaction of supported molybdates with NH 3. Several loadings, heating rates, and space velocities were employed in an attempt to vary the properties of the nitride. The structure and composition of the supported nitrides depended on the structure of the precursor oxide and the conditions employed in nitriding the oxide. The ease with which the oxide was nitrided improved with increasing Mo loading. Nitride domains in the lowloaded materials (4 and 8 wt% Mo) were highly dispersed and Xray amorphous while the higher-loaded catalysts (16 wt% Mo) consisted of "y-Mo2N crystallites. The response of the high-loaded materials to the various nitriding conditions was similar to that observed for unsupported y-Mo2N. The supported Mo nitrides were active for the hydrodenitrogenation of pyridine. In fact, their activities were superior to that of a commercial sulfided Ni-Mo hydrotreating catalyst and comparable to those of the unsupported Mo nitrides. The catalytic properties of the supported Mo nitrides depended on the size and composition of the Mo nitride domains. We believe that the most active sites were located at the perimeters of two-dimensional, raft-like domains. Regions near the perimeter also appeared to be nitrogen deficient. Lower activity sites were associated with the -y-Mo2N crystallite surfaces, c, 1994 Academic Press, Inc. ployed (1). In addition, their catalytic properties were superior to those of a commercial sulfided Co-Mo hydrotreatment catalyst. A key observation from this study was that the activity decreased with increasing surface area. In fact, the highest surface area nitride had the lowest specific activity while the lowest surface area material had the highest activity. This was taken as evidence that HDN was structure-sensitive over the Mo nitrides. It also suggested that an effective catalyst could be prepared by reproducing the structures and stoichiometries present in the high activity nitrides on the surface of a high surface area support. To this end we prepared a series of supported Mo nitrides with different Ioadings using the TPR technique. Several different heating rates and space velocities were employed in an attempt to vary the properties of the nitride. In this paper we discuss the preparation and the structural, compositional, chemisorptive, and catalytic properties of y-AIzO 3 supported Mo nitrides. We also describe the structural and chemical character of the catalytically active species in these materials.
High dietary carbohydrates decrease gallbladder volume and enhance cholesterol crystal formation

Background Animal and human data suggest that a diet high in refined carbohydrates leads to gallstone formation. However, no data are available on the role of dietary carbohydrates on gallbladder volume or on cholesterol crystal formation. Therefore, we tested the hypothesis that a high carbohydrate diet would alter gallbladder volume and enhance cholesterol crystal formation. Methods At 8 weeks of age, 60 lean and 36 obese leptin-deficient female mice were fed a 45% carbohydrate diet while an equal number of lean and obese mice were fed a 75% carbohydrate diet for 4 weeks. All animals then underwent cholecystectomy, and gallbladder bile volume was recorded. Bile was pooled, filtered, and maintained in a water bath at 37°C for 14 days. Birefringent cholesterol crystals in bile were counted daily; crystal observation time and crystal mass were determined. Results The crystal observation time was significantly shortened in both lean and obese mice on the 75% diet compared with their counterparts on the 45% diet. The crystal mass was significantly increased in the lean mice on the 75% diet compared with the 45% diet. Gallbladder volumes were significantly reduced in both lean and obese mice on the 75% diet compared with their counterparts on the 45% diet. Conclusions These data suggest that a high carbohydrate diet decreases gallbladder volume, shortens cholesterol crystal observation time, and increases crystal mass. We conclude that dietary carbohydrates may play a role in cholesterol gallstone formation by altering biliary motility and by enhancing crystal formation.
Disturbance, emigration, and refugia: How the mud snail, Ilyanassa obsoleta (Say), affects the habitat distribution of an epifaunal amphipod, Microdeutopus gryllotalpa (Costa)☆

In the presence of the mud snail Ilyanassa obsoleta (Say), the tubicolous amphipod Microdeutopus gryllotalpa (Costa) emigrates to snail-free sediments, as demonstrated in laboratory and field experiments. Emigration occurs predominantly in the dark when the amphipod is most active. Unlike crevices, the thickness of sediments in which the amphipod is established offers no protection from snail disturbance. Emigration is shown to be caused by the disturbance generated by the snail's plowing and burrowing across the sediment surface, and not a response to a reduction in the shared microfloral food supply. The crawling and burrowing of the smaller mud snail, Hydrobia totteni Morrison, does not disturb Microdeutopus, supporting the hypothesis that relative body sizes affects the ability of bioturbators/burrowers to disturb tube-dwellers. As the burrows of Microdeutopus extend only ≈2 cm below the sediment surface, thick mud layers do not offer any refuge from Ilyanassa. However, very small solid surfaces (≈1–2 mm in relief) to which the amphipods build tubes do provide some protection from Ilyanassa. In soft-sediment benthic communities, such small structures may provide significant refuge for small epifauna and shallow burrowing infauna escaping from small-scale, biogenic disturbance.
Craft Retailers’ Criteria for Success and Associated Business Strategies

This research was designed to fill the void in understanding how art–related retailers define and achieve success. A two–phase data collection process was implemented. Preliminary personal interviews were conducted with 12 craft retailers followed by a mailed survey to 1000 craft retailers in nine southeastern U.S. states. Factor analysis was employed to reduce the number of items for defining success. Cluster analysis followed to develop empirical groupings of craft retail businesses based on the success factor scores, of which four different groups were identified. Multivariate analysis of variance (MANOVA) and analysis of variance (ANOVA) were used to compare retail clusters related to business strategy variables of competitive strategies, product assortment, pricing, and distribution strategies, and networking activities. Significant differences were found in the craft retailers’ business strategies used to achieve success. Craft retail entrepreneurs were found to define success with both traditional criteria such as profit and growth and also with intrinsic factors such as personal satisfaction and the opportunity to elevate the craft tradition. Successful small craft retail firms offered more focused product assortments of specialized craft products, implemented more differentiated strategies of stocking unique crafts in their assortments, as well as offering unique services to educate consumers about crafts, craft artisans, and a region’s culture. Craft retailers who reported greater success did not engage in competitive pricing. Collaborative strategies included networking among family, friends, and business peers.
Renal net acid excretion capacity is comparable in prepubescence, adolescence, and young adulthood but falls with aging.

OBJECTIVES: To evaluate whether renal net acid excretion capacity (NAEC) varies across different age groups and, specifically, whether it falls in elderly people. DESIGN: Cross-sectional observational study. SETTING: Community-based. PARTICIPANTS: Young participants were from the DOrtmund Nutritional and Anthropometric Longitudinally Designed Study, Dortmund, Germany; elderly participants were from Gothenburg, Sweden. MEASUREMENTS: Twenty-four-hour urine pH, net acid excretion (NAE), urinary phosphorus, total nitrogen excretion, and anthropometric data were measured in healthy elderly people (aged 55–75; n=85), young adults (aged 18–22; n=117), adolescents (aged 13–14; n=112), and prepubescent children (aged 6–7; n=217). NAEC was determined as 24-hour NAE adjusted for urine pH using the residual method. RESULTS: In elderly participants 24-hour urinary pH (5.9±0.53) was lower (P<.05) and NAE (60±27 mEq/d) higher (P<.05) than in the three other groups. In a regression model adjusted for age, sex, and body surface area, NAEC showed a clear decrease with age, with highest values in prepubescents and lowest in elderly participants. However, NAEC remained significantly lower only in elderly participants (P<.001) after the inclusion of total nitrogen excretion, a protein intake index, which was included because protein intake is known to modulate renal function. NAEC was approximately 8 mEq/d lower in healthy elderly participants than in young adults. CONCLUSION: The capacity to excrete net endogenous acid does not vary markedly from childhood to young adulthood but falls significantly with age, implying that elderly people may require higher daily alkalizing mineral intake to compensate for renal function losses.
Putting the software radio on a low-calorie diet

Modern software-defined radios are large, expensive, and power-hungry devices and this, we argue, hampers their more widespread deployment and use, particularly in low-power, size-constrained application settings like mobile phones and sensor networks. To rectify this problem, we propose to put the software-defined radio on a diet by redesigning it around just two core chips -- an integrated RF transceiver and a Flash-based, mixed-signal FPGA. Modern transceivers integrate almost all RF front-end functions while emerging FPGAs integrate nearly all of required signal conditioning and processing functions. And, unlike conventional FPGAs, Flash-based FPGAs offer sleep mode power draws measured in the microamps and startup times measured in the microseconds, both of which are critical for low-power operation. If our platform architecture vision is realized, it will be possible to hold a software-defined radio in the palm of one's hand, build it for $100, and power it for days using the energy in a typical mobile phone battery. This will make software radios deployable in high densities and broadly accessible for research and education.
A Column-Generation Approach to the Multiple Knapsack Problem with Color Constraints

In this paper, we study a new problem that we refer to as the multiple knapsack with color constraints (MKCP). Motivated by a real application from the steel industry, the MKCP can be formulated by generalizing the multiple knapsack problem. A real-life instance (called mkc) of this problem class is available through MIPLIB (Bixby 2004) and a larger instance (mkc7) is downloadable from the COIN site (IBM 2004). The focus of this paper is to present improved computational results for the two mentioned instances of this problem using a column-generation approach. We solve mkc to optimality and use Dantzig-Wolfe decomposition for upper bounding the other instance. Solving mkc to optimality took less time than it takes to solve the LP relaxation of the original formulation. The larger instance is solved to near optimality (within 0.5 of optimality) in a fraction of the time required to solve the original relaxed LP.
A note on the sensitivity of mantle convection models to composition‐dependent phase relations

Numerical simulations of mantle convection are highly sensitive to the dependence of phase relations upon pressure, temperature, and composition. Phase transitions in the (relatively silica-poor) olivine components of the mantle tend, with increasing iron content, to inhibit convective mass transfer between the upper and lower mantle. Those occurring in the (relatively silica-rich) non-olivine components fail to inhibit (and indeed promote) such mass transfer. Behavior in the real mantle must entail an interplay between such competing effects, with the finite width of multivariant phase fields acting to mitigate impediments to flow. Attempts to directly correlate computed flow or temperature fields with models derived from physical observables should be approached with caution, given the sensitivity of the former to compositional heterogeneity and uncertainties in phase relations.
Causal status as a determinant of feature centrality.

One of the major problems in categorization research is the lack of systematic ways of constraining feature weights. We propose one method of operationalizing feature centrality, a causal status hypothesis which states that a cause feature is judged to be more central than its effect feature in categorization. In Experiment 1, participants learned a novel category with three characteristic features that were causally related into a single causal chain and judged the likelihood that new objects belong to the category. Likelihood ratings for items missing the most fundamental cause were lower than those for items missing the intermediate cause, which in turn were lower than those for items missing the terminal effect. The causal status effect was also obtained in goodness-of-exemplar judgments (Experiment 2) and in free-sorting tasks (Experiment 3), but it was weaker in similarity judgments than in categorization judgments (Experiment 4). Experiment 5 shows that the size of the causal status effect is moderated by plausibility of causal relations, and Experiment 6 shows that effect features can be useful in retrieving information about unknown causes. We discuss the scope of the causal status effect and its implications for categorization research.
Using analogy to predict functional regions on genes

Describes a system to support prediction of functional regions (features) on genes using a form of reasoning by analogy. Analogy is a powerful tool in the study of biological systems, since analogous components typically have a biological correspondence based on evolution. The authors capitalize on this correlation between biotaxonomic relatedness and similarity of genetic structure to drive their predictions. By building a classification hierarchy whose members represent classes of related genes and classifying individual genes in this hierarchy, one can both form theories about the general structural characteristics of classes of genes, and generate hypotheses about the detailed structure of individual genes. >
A confidence interval for tail conditional expectation via two-level simulation

We develop and evaluate a two-level simulation procedure that produces a confidence interval for tail conditional expectation, otherwise known as conditional tail expectation. This risk measure is closely related to conditional value-at-risk, expected shortfall, and worst conditional expectation. The outer level of simulation generates risk factors and the inner level estimates each expected loss conditional on the risk factor. Our procedure uses the statistical theory of empirical likelihood to construct a confidence interval, and it uses tools from the ranking-and-selection literature to make the simulation efficient.
Intelligent curing of thick composites using a knowledge-based system

An expert-system-based tool was developed in order to operate the autoclave cure of a thick fiber reinforced thermosetting matrix composite laminate in an optimal manner. The best temperature profile is obtained using a novel model-based optimization technique. It incorporates known heuristics about the problem to prune the search space and reduce the dimensionality of the problem so as to converge to a near-optimum in a reasonable amount of time. The objective function used has components for minimizing the total cure time, reducing the temperature excursions during an exotherm and minimization of process-induced residual stresses in the laminate. The inevitable divergence between the process and the simulation precludes the direct application of such optimal profiles. We have devised a general methodology to address this issue of process-model mismatch, which allows for the implementation of model-based optimal profiles in real situations. This methodology is directed at ensuring that the actual cure fo...
How to Predict the Frequency of Voting Events in Actual Elections

Two commonly-used criteria for evaluating voting rules are how infrequently the rules provide opportunities for strategic voting and how infrequently they encounter voting paradoxes. The lack of ranking data from enough actual elections to determine these frequencies with reasonable accuracy makes it attractive to investigate ranking data simulated with Monte Carlo methods. But such simulations permit inferences about actual frequencies only if they are conducted through statistical models that generate ranking data with the same statistical properties as ranking data from actual elections. We offer statistical evidence that ranking data simulated with a spatial model of vote-casting are extremely similar to ranking data from actual elections.
The effects of analogues of thyroxine on the glycolysis and oxygen uptake of ascites tumor cells.

A number of analogues of thyroxine which stimulate aerobic glycolysis in Ehrlich ascites tumor cells have been studied. The most active compounds contained at least three iodine substituents and an acetic or propionic side chain (triiodothyroacetic acid, tetraiodothyroacetic acid and tetraiodothyropropionic acid). Activity was greatty reduced when iodine was replaced b}r bromine and was virtually abolished by the presence of amino or keto groups in the side chain. Stimulation of aerobic glycolysis by these compounds was observed only with intact cells and was associated with a decrease in oxygen consumption. The related compound, 2:6 diiodophenol, was a more potent stimulant of aerobic glycolysis than the above analogues and caused no depression of oxygen uptake. Substitution in the 4 position of this compound reduced its activity. The mechanism of these various effects is discussed.
Test of chiral recognition in the Salmonella typhimurium (TA100) mutagenicity of mucochloric acid-cysteine adducts.

A difference in biological response to enantiomers is not an uncommon observation and is, therefore, to be expected in various manifestations of genotoxicity. The bacterial mutagen mucochloric acid (2,3-dichloro-5-hydroxy-2(5H)-furanone) has one chiral center, at C-5, but this mutagen exists in racemic form because of the facile stereoisomerization occurring by the mechanism of ring-chain tautomerism. Two readily synthesized enantiomeric analogs of mucochloric acid, as well as the racemic form of the two, were prepared from mucochloric acid and (R)-(+)-, (S)-(-)-, and (R,S)-(+/-)-cysteine. Using Salmonella typhimurium (TA100), the enantiomeric compounds were assayed together in four dose/response assays along with mucochloric acid, the reference mutagen. In three of the same four assays, the racemic form was also assayed. Neither statistically significant differences in mutagenicity, as determined in slope responses, nor distinctions from the plotted curves were observed among the two enantiomers and their racemic form. Therefore, no enantiospecific interaction between enantiomers and chiral DNA or enzymes involved in repair or replication could be concluded. © 1993 Wiley-Liss, Inc.
Effects of endurance and resistance training on total daily energy expenditure in young women: a controlled randomized trial.

There exists considerable controversy regarding the impact of different modes of exercise training on total daily energy expenditure (TEE). To examine this question, young, nonobese women were randomly assigned to a supervised 6-month program of endurance training, resistance training, or control condition. TEE was measured before and 10 d after a 6-month exercise program was completed with doubly labeled water. Body composition was determined from dual energy x-ray absorptiometry, maximum aerobic capacity from a treadmill test to exhaustion, and muscular strength from onerepetition maximum tests. Results showed that body composition did not change in endurance-trained women, but maximum aerobic capacity increased by 18%. Resistance-trained women increased muscular strength and fat-free mass (1.3 kg). TEE did not significantly change when measured subsequent to the endurance or resistance training programs. Absolute resting metabolic rate increased in resistance-trained women but not when adjusted for fat-free mass. No change in physical activity energy expenditure was found in any of the groups. These results suggest that endurance and resistance training does not chronically alter TEE in free-living young women. Thus, the energy-enhancing benefits of exercise training are primarily derived from the direct energy cost of exercise and not from a chronic elevation in daily energy expenditure in young, nonobese women. (J Clin Endocrinol Metab 87: 1004 –1009, 2002)
Hormonal Actions on the Sexual Differentiation of the Genitalia and the Gonadotropin-Regulating Systems

In 1903, Bouin and Ancel proposed that substances produced by the testes controlled differentiation of the embryonic genital structures. Their observation that there was a very well-developed secretory interstitium in the testes of pig embryos at the time of genital tract differentiation indirectly supported this notion. The idea of hormonal regulation of the process of sexual differentiation was given further impetus by studies of a phenomenon known as free-martinism. Freemartinism occurs in cows, sheep, goats, and pigs (Short, 1972). Descriptions of the syndrome in cattle include the following: (a) the freemartin calf is a sexually abnormal chromosomal female born as a twin to an apparently normal male; (b) about 90% of female cattle born as twins to males are sterile; (c) external genitalia of the freemartin are of the female type, and there is mammary gland development; (d) there is variable development of the internal genital tracts; and (e) the gonads are atrophic but resemble testes more than they resemble ovaries (Burns, 1961). To account for the occurrence of freemartinism, a “hormone theory” was devised by Keller and Tandler (1916) and by Lillie (1917). According to this theory, androgenic hormones produced by the male fetus are able to reach the female twin because of fusion of some of the placental blood vessels that supply the twins.
Unsteady expansion of an ideal gas into a vacuum

The unsteady expansion of an ideal gas into a vacuum is studied in one-dimensional planar and spherical geometries. The free-molecular expansion of a Maxwell-distributed gas is compared to the continuum expansion of a perfect gas with for planar flow and tends to zero for spherical flow. Continuum thermodynamic temperature pulses, on the other hand, rise and fall in simple relation to continuum density. The far-field peak wall pressure in both Knudsen-number limits is found to decrease in inverse (or inverse cubic) proportion to the distance from the initial planar (or spherical) region. This result for the spherical case is at odds with the experiments of Ahrens, Allen & Kovach (1971) which indicate a more rapid (ξ−3.5) fall-off of peak overpressure with distance from a point source in a vacuum.