cssi/SciSciGPT-SciSciNet huggingface dataset:
Microheterogeneity evaluation of polycyclic aromatic hydrocarbons in particulate standard reference materials

With the emergence of highly sensitive analytical techniques, the microanalysis of natural-matrix materials employing smaller sample sizes is increasingly more common, which subsequently warrants a homogeneity assessment for the individual components at the appropriate sampling level. Pressurized liquid extraction (PLE) in combination with gas chromatography/mass spectrometry (GC/MS) has been used to determine the sampling constants and evaluate the relative homogeneity of trace levels of polycyclic aromatic hydrocarbons (PAHs) for two previously certified particulate standard reference materials, SRM 1649a Urban Dust and SRM 1650b Diesel Particulate Matter, in the milligram sampling range. Fluoranthene, pyrene, benz[a]anthracene and benzo[e]pyrene within SRM 1650b Diesel Particulate Matter were deemed to be homogeneous, based on relatively small sampling constants (K (S) 100 mg) obtained for all PAHs in SRM 1649a Urban Dust suggest more material heterogeneity. The material heterogeneity of ten individual PAHs (phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, benzo[k]fluoranthene, benzo[e]pyrene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene and benzo[ghi]perylene) was also described via nonlinear relationships (i.e., power law) between subsampling error S (s) (%) and sample mass, which are used to predict analyte-specific minimum sample masses that result in a specific level of analytical uncertainty.
The Association Between Stimulant, Opioid, and Multiple Drug Use on Behavioral Health Care Utilization in a Safety-Net Health System.

ABSTRACTBackground: Prior studies show an association between drug use and health care utilization. The relationship between specific drug type and emergent/urgent, inpatient, outpatient, and behavioral health care utilization has not been examined. We aimed to determine if multiple drug use was associated with increased utilization of behavioral health care. Methods: To assess health care utilization, we conducted a retrospective cohort study of patients who accessed health care at a safety-net medical center and affiliated clinics. Using electronic health records, we categorized patients who used stimulants, opioids, or multiple drugs based on urine toxicology screening tests and/or International Classification of Diseases, 9th Revision (ICD-9). Remaining patients were categorized as patients without identified drug use. Health care utilization by drug use group and visit type was determined using a negative binomial regression model. Associations were reported as incidence rate ratios. Utilization was ...
Noradrenergic innervation does not affect chronic regulation of [125I]pindolol receptors in fetal rat brain transplants or host neocortex.

Abstract Fetal (E15–16) somatosensory cortex (n = 15) or cerebellum (n = 9) were placed into the somatosensory cortex (SmI) of adult rat hosts to study the relative importance of tissue origin versus host milieu on graft β-adrenoceptor regulation. Autoradiographic studies of [125I]pindolol ([125I]pin) binding in the presence of 3 μM serotonin were performed as an index of β-receptor binding in both intact hosts and those with ipsilateral locus coeruleus (LC) lesions and/or ipsilateral superior cervical ganglionectomy. [125I]pin binding within fetal grafts was highly variable with areas of highest specific binding in cortical grafts ((Kd = 209 ± 30pM, Bmax = 106 ± 7fmol/mg protein) being comparable to host cortex (Kd = 211 ± 41pM, Bmax = 111 ± 9fmol/mg protein). Average total binding in whole cortical grafts was 73% and in cerebellar grafts was 60% of that in comparable adult cortex. Host cortex had 66–73% and cerebellum had 4–8%β1-receptors while cortical grafts had 59% and cerebellar grafts had 43%β1-receptors as determined by competitive binding with ICI 89406 and 118551. Noradrenergic fibers derived from both the host LC and superior cervical ganglion grew into fetal cortical grafts. Binding to high affinity uptake sites ([3H]desmethylimipramine, [3H]DMI) on noradrenergic terminals in cerebellar grafts was 28% higher than that in cortical grafts; superior cervical ganglionectomy decreased [3H]DMI binding in cortical grafts by 37% but had no effect on cerebellar grafts. Neither ganglionectomy nor LC lesions affected total specific binding or binding to β-receptor subtypes in the grafts or host cortex 3–6 months after removal. Therefore, anatomic site of origin appeared to be the predominant factor in determining the development of β-adrenoceptors in fetal cortical tissue. In ectopically placed cerebellar grafts, β-receptor subtypes did not develop comparably to host cerebellar receptors suggesting that host milieu may be of critical importance in receptor development in this tissue.
Oberfläche und katalytische Aktivität von Nickel‐Magnesiumoxyd‐Mischkontakten nach LANGENBECK. II

Es wird der Einflus der Temperatur der reduzierenden Zersetzung von Nickel-Magnesiumformiat-Mischkristallen und Nickel-Magnesiumoxalat-Mischkristallen auf die Oberflachengrose und die katalytische Aktivitat der so hergestellten Nickel-Magnesiumoxydkatalysatoren untersucht.
Nitrogen and amino acid composition of three species of anoplocephalid cestodes: Moniezia expansa, Thysanosoma actinioides, and Cittotaenia perplexa.

Abstract 1. 1. The distribution of nitrogen in five tissue fractions of M. expansa, T. actinioides, and C. perplexa has been determined. M. expansa and T. actinioides are distinct with respect to the amount of nitrogen in these fractions. T. actinioides and C. perplexa are closely related with regard to these nitrogen determinations. 2. 2. The amino acids of the non-protein and protein fractions of M. expansa, T. actinioides, and C. perplexa were determined qualitatively by paper chromatography on buffered papers. Nineteen amino acids were identified as common to the protein fractions of all three species. From seventeen to twenty-two amino acids were identified in the non-protein fractions of these cestodes. Certain qualitative differences between species were found in this fraction. This is the first report of β-alanine, β-aminoisobutyric acid, and γ-aminobutyric acid in cestodes. The possible roles of these amino acids in the metabolism of tapeworms is discussed. 3. 3. The amino acids present in sheep bile which are available to T. actinioides were determined. Bile as an environment for parasitic helminths is discussed as well as its contribution to the intestinal environment.
Student Activist and Establishment Orientations: Conflict of Values or Misperception?

Self-defined “activist” and “establishment” oriented students differed significantly in their perception of each other's value systems. The results suggested that the apparent conflict is over which means are to be employed to reach mutually held endstates.
Chaos in a Forced Dry-Friction Oscillator: Experiments and Numerical Modelling

Abstract The chaotic dynamics of a harmonically forced spring-mass system with dry friction is studied experimentally and numerically. The friction in the experiment was designed to vary linearly with displacement. A one-dimensional single-humped map is shown to underly the dynamics. Three friction laws are examined during the numerical modeling: the discontinuous Coulomb model, a continuous version of the Coulomb model, and a state-variable friction law. Using experimental Poincare maps, the qualitative features of the chaotic attractor in the three-dimensional phase space were discovered and used to evaluate the friction models. Each friction model produces the main qualitative features of the dynamics observed in the experiment. The state-variable friction law produces one feature that was found in the experimental system, but not in the simulations with simple friction laws.
Application of Ultrasonic Backscattering for Level Measurement and Process Monitoring of Expanded‐Bed Adsorption Columns

Expanded-bed adsorption is a newly commercialized technique for the purification of proteins from cellular debris in downstream processing. An expanded bed presents the possibility of protein recovery in a single step, eliminating the often costly clarification processing steps such as ultrafiltration, centrifugation, and precipitation. A major obstacle to the successful commercialization of this technology is the inability to accurately monitor and control the bed height in these systems. Fluctuations in the feedstock viscosity are common during normal operation and tend to make the operation and control of expanded beds for biological applications complex and difficult. We develop a level measurement technique based upon ultrasonics. It is shown that this technique has great promise for bed-height measurement in expanded-bed adsorption systems. Furthermore, the bed-height measurement can be used in feedback control strategies for bed-height regulation. The proposed ultrasonic sensor is also capable of monitoring for plugging and bubbling in the column.
Retraining Climate as a Predictor of Retraining Success and as a Moderator of the Relationship between Cross-Job Retraining Time Estimates and Time to Proficiency in the New Job

The limited empirical research on lateral cross-job retraining supports the idea that analysis of employee transferability of skills is related to retraining success in the new assignment. The pres...
Monitoring permeable paver runoff with an open-innovation geospatial sensor network

Sensor networks are an essential tool for environmental scientists. As scientists and engineers are beginning to utilize these new methods and devices in their fieldwork, they need to be actively involved in the future of sensor-networking development. Continued sensor network innovation is important for improved standardization, affordability, and interoperability. This article uses a storm water case study to outline an end-to-end open-innovation sensor network. Open innovation by scientists, engineers, and entities is the collaborative process of creating value for this project in permeable paver runoff data and advances within sensor networking. This article focuses on the technical implementation of the near–real-time location and temporally aware sensor network. Data are streamed in near–real-time with subliter precision to the cloud using common off-the-shelf routers. The sensors use Maxim's 1-wire™ protocol, and the unique digital serial numbers confirm the data. The data retrieved compare residen...
Impact of mammary grafts on coronary bypass operative mortality and morbidity

Abstract The internal mammary artery is frequently used as a coronary artery bypass graft conduit because of superior long-term patency. The purpose of this study was to determine if there was also an advantage to the internal mammary artery in terms of operative mortality and morbidity. The Department of Veterans Affairs Cardiac Surgery Database was reviewed for two separate time periods, April 1987 through March 1989 and October 1990 through September 1991. During these periods, 14,172 patients underwent coronary artery bypass grafting. Univariate and multivariate logistic regression analyses were used to determine preopetative variables predictive of operative mortality and morbidity, with the independent variable of use of the internal mammary artery added to previously determined indicators. The total group was analyzed in risk quartiles according to expected mortality. Univariate analysis revealed an operative mortality of 6.8% in the early period and 6.5% in the latter period for the saphenous vein groups compared with 3.7% and 3.2%, respectively, for the internal mammary artery groups ( p = 0.000). Multivariate analysis revealed an odds ratio of operative death with use of the internal mammary artery graft versus use of vein grafts of 0.78 during the first period and 0.72 during the second period, reductions of 22% and 28%, respectively. There were 29% and 37% reductions in the odds of operative mortality in the highest-risk quartile group of patients using the internal mammary artery graft. The odds ratio of developing mediastinitis with one internal mammary artery graft was 1.84 ( p p = not significant). However, with multiple mammary bypass grafts, the odds ratios were 3.70 ( p p
The role of causal criteria in causal inferences: Bradford Hill's "aspects of association".

As noted by Wesley Salmon and many others, causal concepts are ubiquitous in every branch of theoretical science, in the practical disciplines and in everyday life. In the theoretical and practical sciences especially, people often base claims about causal relations on applications of statistical methods to data. However, the source and type of data place important constraints on the choice of statistical methods as well as on the warrant attributed to the causal claims based on the use of such methods. For example, much of the data used by people interested in making causal claims come from non-experimental, observational studies in which random allocations to treatment and control groups are not present. Thus, one of the most important problems in the social and health sciences concerns making justified causal inferences using non-experimental, observational data. In this paper, I examine one method of justifying such inferences that is especially widespread in epidemiology and the health sciences generally – the use of causal criteria. I argue that while the use of causal criteria is not appropriate for either deductive or inductive inferences, they do have an important role to play in inferences to the best explanation. As such, causal criteria, exemplified by what Bradford Hill referred to as "aspects of [statistical] associations", have an indispensible part to play in the goal of making justified causal claims.
Prediction of complications following nonemergency percutaneous coronary interventions.

Previous models for prediction of complications after percutaneous coronary interventions (PCIs) have included in-hospital mortality and major in-hospital complications. In general, these models have excluded elevated cardiac biomarkers as a complication. We sought to determine whether a risk model could predict complications, including biomarker elevation, in patients undergoing nonemergency PCI. We examined the outcomes of nonemergency PCI performed on patients at Mayo Clinic from 2000 to 2003. The primary end point was in-hospital complications of death, myocardial infarction (MI) (Q-wave MI, or post-PCI creatine kinase-MB elevation ≥3 times the upper limit of normal), emergency coronary artery bypass grafting, or stroke. We used the Hosmer-Lemeshow test to demonstrate the adequacy of the model fit, and the c-index for discriminatory ability of the model. Of 2,894 nonemergency PCIs, the end point was noted in 232 (8%). The final prediction model included vein graft intervention (odds ratio [OR] 2.19), angiographic thrombus (OR 2.12), preprocedure stenosis of a minor (OR 1.98) or major (OR 1.62) side branch, and type C lesion (OR 1.48). The model had modest ability to discriminate between event and nonevent patients (c = 0.641). In the 500 bootstrap samples for internal validation, the c-index was 0.642 ± 0.020, indicating only fair discriminatory ability. The average number of observed events was 232.0 ± 14.7 compared with 232.1 ± 2.5 expected events (average difference −0.06 ± 14.5). In conclusion, the 5 risk variables associated with an increased risk of complications in patients undergoing elective PCI included vein graft intervention, presence of angiographic thrombus, stenosis of a major or minor side branch, and type C lesion; however, the discriminatory ability of the model derived from the variables was only modest.
Polarization enhanced optical transmission through plasmonic metal films with high aspect ratio apertures

The effects of period, geometry, and thickness on optically thick metal films perforated with subwavelength apertures have been an area of recent investigation, both experimentally and theoretically. It has been shown that the spectra of these films can be scaled proportionally to the period. Different geometries can change peak positions, and the thickness of a metal film can determine the degree of transmission for the entire spectrum. This tunability allows the positioning of a single peak to a wavelength of interest, but the position of all other peaks are dependent on the peak of interest and cannot be positioned independently. Further, the peak intensities are all related. This lack of individual control over specific peaks limits the future applicability of plasmonic films in optoelectronic and photonic devices. Transmission spectra that can be tuned by the polarization of the incident light can be fabricated with novel array structures. Further, control over the transmission spectra can be gained by using highly anisotropic apertures to modifying specific surface plasmon polariton modes and their associated peaks. Surface plasmon polariton modes that are not in the direct path of these anisotropic apertures are not significantly affected. This allows for controlled engineering of the intensity of peaks within the visible, greatly increasing the tailorability of the spectral characteristics of plasmonic films.
THE ULTRASTRUCTURE OF MITOSIS IN MYXAMOEBAE AND PLASMODIA OF PHYSARUM FLAVICOMUM

diploid plasmodia of the myxomycete Physarum avicomum Berk. reveal dissimilar spinidle apparatus during mitosis in the two cell types. Myxainoebae exhibit an astral type of mitosis with centrioles at the poles and nuclear envelope breakdown during prophase. Plasmodial nuclei lack centrioles at mitosis and have an intranuclear spindle, with nuclear envelope persisting during
Structurally characterized group 4 metal alkoxides modified with the pyridyl-based ligands 2-mercapto pyridine n-oxide and 3,3′-dihydroxy-2,2′-bipyridine

Abstract An investigation of a series of substituted pyridyl-based ligands was undertaken using 2-mercapto pyridine n-oxide (H-2MPO) and 3,3′-dihydroxy-2,2′-bipyridine (H2-OBPy) as the modifying reagents of a series of titanium alkoxides. The resultant products were identified as (2MPO)2Ti(OR)2 [OR = OCHMe2 (1), OCH2CMe3 (2), OCMe3 (3)] and [(OR)2M(μc-OBPy)]3 where M⧹OR = Ti⧹OCH2CMe3 (4) along with Zr⧹OCMe3 (5) from Zr(OCMe3)4 (μc = chelating bridging). The structure of 1–3 were found to adopt similar monomeric structures with octahedrally (Oh) bound Ti metal centers using two terminal OR and two chelating 2MPO derivatives. Switching to the OBPy ligand, cyclic trinuclear species with Oh bound metals that employed two terminal OR and two μc-OBPy ligands were isolated. The two rings of the bridging OBPy were rotated such that one O and one N from different rings chelate to a single metal. The synthesis and characterization of these compounds and comparison to appropriate literature species are presented.
Jitter-Free Signal Averaging Streak Camera

A streak camera with 2 ps shot-to-shot jitter and zero drift in timing has been developed. A picosecond high power switch which is DC-biased and operated at room temperature is used. In this article, we discuss recent sweep modeling and measurement results and some applications in picosecond fluorescence kinetics experiments.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Stability of symptoms of autism spectrum disorders in toddlers: An examination using the Baby and Infant Screen for Children with aUtIsm Traits–Part 1 (BISCUIT)

Objective: The diagnostic stability of Autism Spectrum Disorders (ASD) at very young ages continues to be debated, despite empirical evidence that ASDs can be reliably diagnosed in children under the age of 3 years. This topic is of the upmost importance given that early intervention increases long-term outcomes in this population.Methods: The goal of the current study was to examine the stability of symptoms of ASD between two assessment times for 114 toddlers. The following was compared from the first to second assessment: diagnostic classification stability, correlations between scores and the impact of time between the first and second assessment.Results: Significant correlations were found for toddlers as young as 18 months of age. In addition, even with up to a year between assessment intervals, symptoms of ASD were relatively stable prior to 3 years of age.Conclusions: Implications of the current findings are discussed.
Cerebral laterality and emotion: The neurology of depression

Abstract Differential specialization of the cerebral hemispheres for cognitive functioning is well established. A converging body of clinical and experimental studies conducted with brain-damaged patients, normal subjects, and psychiatric patients is reviewed which indicates that there is also hemispheric asymmetry in the regulation of emotional behavior. These data indicate that the right hemisphere may be uniquely specialized for the perception, experience, and expression of emotion. Theories to account for this hemispheric asymmetry are reviewed and a right-hemisphere dominance model is proposed. Future studies are outlined to further our understanding of the neuroanatomic basis of emotion. The recognition that the right hemisphere may be specialized for mediating emotion may have clinical implications.
Dynamics of the Ukrainian state-territory nexus

This paper addresses questions concerning the territorial sovereignty of present day Ukraine in light of established concepts in political geography, international relations, and international law. A template is derived from that literature to examine the particulars of the Ukrainian state extant insofar as its origins are concerned, especially as they relate to issues of the state and territory. An argument is made for the legitimacy of Ukraine as a bona fide entrant into the international system of states and, accordingly, its rights to territorial integrity. Finally, the challenges confronting Ukraine owing to its Soviet geographical heritage and ethnographic landscape are discussed, especially in light of its neighboring regional hegemon, Russia.
Continuous-Wave Terahertz Spectroscopy of Plasmas and Biomolecules

Continuous-wave linear-absorption spectroscopy based on THz radiation generated by solid-state photomixers has been applied to the investigation of the dynamics of biomolecules in polyethylene matrices and to line shape studies of HF for diagnostics of semiconductor etching plasmas. The THz spectra of biotin and myoglobin have been obtained using a variable-temperature, cryogenic sampling system. The spectrum of biotin displays a small number of discrete absorptions over the temperature range from 4.2 K to room temperature while the spectrum of myoglobin has no obvious resonance structure at the >10% fractional absorption level. Spectral predictions from the lowest energy ab initio conformations of biotin are in poor agreement with experiment, suggesting the need to include condensed-phase environmental interactions for qualitative predictions of the THz spectrum. Vibrational anharmonicity is used to model the line shapes that result from drastic changes in vibrational sequence level populations of biotin over this temperature range. Anharmonicity factors (χeωe/ωe) at the levels of 0.1% to 0.8% are obtained from non-linear least squares fits of the observed resonances and illustrate their important for refining model predictions. Application of the photomixer system to line shape studies in etching plasmas has been used to study the formation efficiency and translational temperature of HF at 1.2 THz under different operating conditions. These results will aid in understanding the chemistry of industry-standard fluorocarbon and oxygenated fluorocarbon etching plasmas.
Family Themes: Transmission and Transformation

This article describes a method for doing therapy that uses multisystemic themes that combine meaning and action to facilitate therapeutic change. By identifying central themes that operate at the individual, dyadic, triadic, whole family, intergenerational, and sociocultural levels, the therapist is able to develop effective interview questions and design useful interventions. In this method, behavioral symptoms are framed as a current manifestation of an overarching theme. This orientation enables family and therapist to de-pathologize symptoms and work collaboratively toward change. Case examples from a wide variety of families with differing presenting problems, interactional patterns, three-generational histories, and cultural backgrounds, illustrate the efficacy of the method.
Tunneling study of the superconducting proximity effect in the thin-normal limit

We report the tunneling characteristics of Pb-Zn-oxide-Pb junctions in which the average Zn thickness is approximately one atomic layer. This thin layer is produced either by indirect evaporation of Zn or by dissociation of ZnS upon evaporation. The tunneling characteristics show an added current shoulder just above the gap-edge voltage similar to that frequently reported for Nb junctions and several other systems, but unexplained until recently. We discuss the McMillan theory of the proximity effect in relation to earlier experiments using thicker normal films. We then use the theory to demonstrate that the observed current shoulder results from the proximity effect, involving a much thinner normal layer than in any previous experiments. A similar effect can explain the observations with Nb and other materials.
Nucleosome-depleted regions in cell-cycle-regulated promoters ensure reliable gene expression in every cell cycle.

Summary Many promoters in eukaryotes have nucleosome-depleted regions (NDRs) containing transcription factor binding sites. However, the functional significance of NDRs is not well understood. Here, we examine NDR function in two cell cycle-regulated promoters, CLN2pr and HOpr , by varying nucleosomal coverage of the binding sites of their activator, Swi4/Swi6 cell-cycle box (SCB)-binding factor (SBF), and probing the corresponding transcriptional activity in individual cells with time-lapse microscopy. Nucleosome-embedded SCBs do not significantly alter peak expression levels. Instead, they induce bimodal, "on/off" activation in individual cell cycles, which displays short-term memory, or epigenetic inheritance, from the mother cycle. In striking contrast, the same SCBs localized in NDR lead to highly reliable activation, once in every cell cycle. We further demonstrate that the high variability in Cln2p expression induced by the nucleosomal SCBs reduces cell fitness. Therefore, we propose that the NDR function in limiting stochasticity in gene expression promotes the ubiquity and conservation of promoter NDR. PaperClip
Clinical diagnosis of dysplastic melanocytic nevi: A clinicopathologic correlation

A prospective, community practice-based, clincopathologic correlation was undertaken in 165 melanocytic nevi excised from a group of forty-three patients, each patient having previously had at least one clinically suspected and histologically confirmed dysplastic melanocytic nevus. Eighty-two percent of seventy-two lesions with histologic evidence of mild dysplasia had been diagnosed correctly as such clinically. The accuracy of clinical diagnosis of moderate dysplasia was low (20%); however, all cases of severe dysplasia with or without in situ melanoma were diagnosed correctly. In 75% of all cases in which dysplasia of any degree was diagnosed clinically, histologic evidence of dysplasia was found. In order to investigate further the clinical features of these nevi, 175 color enlargements of histologically confirmed dysplastic melanocytic nevi were examined. The following clinical features were found to be most common: ill-defined border (90%), irregularly distributed pigmentation (84%), maximum diameter greater than 5.0 mm (72%), erythema (64%), and accentuated skin markings (63%). Increasing darkness and confluence of pigmentation in these dysplastic melanocytic nevi correlated with increasing severity of dysplasia. We conclude that careful clinical examination of individual melanocytic nevi will separate severe dysplasia with or without in situ melanoma from low-grade (mild or moderate) dysplasia in a high percentage of nevi from patients with the dysplastic nevus syndrome. Clinical examination will yield a diagnosis of dysplasia in approximately 75% of nevi from such patients in whom histologic evidence of dysplasia is present. Clinical examination constitutes a practical and sufficiently reliable method for the assessment of melanocytic nevi in patients with the dysplastic nevus syndrome.
Phenotypic Evolution of Therapeutic Salmonella enterica Serovar Typhimurium after Invasion of TRAMP Mouse Prostate Tumor

Salmonella has been of interest in cancer research due to its intrinsic ability to selectively target and colonize within tumors, leading to tumor cell death. Current research indicates promising use of Salmonellain regular administrations to re- move tumors in mouse models while minimizing toxic side effects. However, selection of mutants during such long-term tumor colonization is a safety concern, and understanding selection of certain phenotypes within a tumor is an important consider- ation in predicting the long-term success of bacterium-based cancer treatment strategies. Thus, we have made an initial exami- nation of selected phenotypes in a therapeutic Salmonella enterica serovar Typhimurium population developed from an archival wild-type LT2 strain and intraperitoneally injected into a 6-month-old TRAMP (transgenic adenocarcinoma of mouse prostate) mouse. We compared the original injected strain to isolates recovered from prostate tumors and those recovered from the spleen and liver of non-tumor-bearing TRAMP mice through phenotypic assessments of bacteriophage susceptibility, motility, growth rates, morphology, and metabolic activity. Tumor isolate traits, particularly the loss of wild-type motility andflagella, reflect the selective pressure of the tumor, while the maintenance of bacteriophage resistance indicates no active selection to remove this robust trait. We posit that the Salmonella population adopts certain strategies to minimize energy consumption and maximize survival and proliferation once within the tumor. Wefind these insights to be nonnegligible considerations in the development of cancer therapies involving bacteria and suggest further examinations into the evolution of therapeutic strains during passage through tumors. IMPORTANCE Salmonella is of interest in cancer research due to its intrinsic abilities to selectively target, colonize, and replicate within tumors, leading to tumor cell death. However, mutation of strains during long-term colonization within tumors is a safety concern, and understanding their evolution within a tumor is an important consideration in predicting the long-term suc- cess of bacterium-based cancer treatment strategies. Thus, we have made an initial examination of phenotypically diverse Salmo- nellacolonies recovered from a therapeutic Salmonellastrain that we developed and injected into prostate tumor-bearing mice. We compared the bacteriophage susceptibility, motility, growth rates, morphology, and metabolic activity of the original thera- peutic strain to those of strains recovered from prostate tumors of tumor-bearing mice and the liver and spleen of non-tumor- bearing mice. Our results suggest that the Salmonella population adopts certain strategies to minimize energy consumption and maximize survival and proliferation once within the tumor, leading to phenotypic changes in the strain.
Lung abscess in adults: clinical comparison of immunocompromised to non-immunocompromised patients

Abstract Information related to the clinical characteristics and isolated microbes associated with lung abscesses comparing immunocompromised (IC) to non-immunocompromised (non-IC) patients is limited. A retrospective review for 1984–1996 identified 34 consecutive adult cases of lung abscess (representing 0·2% of all cases of pneumonia), including 10 non-IC and 24 IC patients. Comparison of age, gender, tobacco use, pre-existing pulmonary disease or recognized aspiration risk factors were not significantly different between the two groups. Upper lobe involvement accounted for the majority of cases, although multi-lobe involvement was limited to IC patients. There were no differences in the need for surgical intervention, and mortality was very low for both groups. Anaerobes were the most frequent isolates for non-IC patients (30%), whereas aerobes were the most frequent isolate for IC patients (63%). Importantly, certain organisms were exclusively isolated in the IC group and multiple isolates were obtained only from the IC patients. Thus, comparing non-IC to IC patients, clinical characteristics may be similar whereas important differences may exist in the microbiology associated with lung abscess. These findings have important implications for the clinical management of these patient groups, and support a strategy to aggressively identify microbial agents in abscess material.
The case for a systematic approach to wireless mobile network simulation

The goal of this paper is to develop a systematic approach to conducting simulations in wireless cellular networks. Performance analysis in such networks is a non-trivial task for the following reasons. First, there are a lot of parameters whose combined effect needs to be understood. Second, there are no benchmarks or widely accepted realistic values. As a result, different studies use different scenarios, and this makes the results of these studies incomparable. How can we make network scenarios and results easier to interpret and compare? We start with the observation that absolute parameter values are meaningless. Instead, we propose the use of relative parameters. These parameters combine multiple parameters into fewer parameters; e.g., user speed and diameter of cell are combined into the cell latency parameter. Thus, we reduce the total parameter space, but more importantly, we capture the combined effect of parameters that affect the performance. We show how using relative units of time and space and relative parameters such as cell latency and average number of cells visited can provide better insight than absolute parameters such as session duration or absolute units such as seconds, miles, etc. In addition, we propose the use of steady state utilization, a novel metric that captures the inherent capacity of a mobile network. We show that steady state utilization can become the reference point with which we can conduct meaningful simulations and interpret results more effectively. Finally, we describe a case study to illustrate our methodology. We evaluate the effect of bandwidth reservations on network performance. Our results show how reservations can actually hurt network performance.
A slot timing detection method with multiple-symbol differential detection for MDPSK burst signals

This paper presents a slot timing detection method with multiple-symbol differential detection (MSDD) that offers improved transmission efficiency and mitigates the performance deterioration caused by carrier frequency offset. The method is applicable for burst wireless systems with short burst M-differential phase shift keying (MDPSK) signals and low symbol rates, which suits radio-frequency identifications (RF-IDs) or other ubiquitous wireless applications. Computer simulations show that the proposed method improves slot timing detection and error rate performances and yields robust demodulation of data symbols against carrier frequency offset.
Developmental Outcomes after Early or Delayed Insertion of Tympanostomy Tubes

background To prevent later developmental impairments, myringotomy with the insertion of tympanostomy tubes has often been undertaken in young children who have persistent otitis media with effusion. We previously reported that prompt as compared with delayed insertion of tympanostomy tubes in children with persistent effusion who were younger than three years of age did not result in improved developmental outcomes at three or four years of age. However, the effect on the outcomes of school-age children is unknown.
Can complex technology be explained to lay decision makers

An attempt is made to answer the question of whether technically complex systems can be explained to the layman. Using the examples of a jogger, a bicycle, and a passenger car as modern means of transportation, the clarity of message, the quality of the transmission, and the necessary knowledge of the receiver are illustrated. It is concluded that successful communication will take place when technologists have been educated under a system which accepts the challenge to insist that they must be competent communicators of technology as well as competent practitioners. Lay people, i.e., all those not trained in any one technology, must still have sufficient knowledge of technical matters to understand the technologist, lest they become disenfranchised in making the important choices for their own future. In societies which permit such a system to take root, the technologist then becomes technocrat. He dictates his own version of technical progress to society, rather than serving society with his technological expertise. >
Amonabactin-mediated iron acquisition from transferrin and lactoferrin by Aeromonas hydrophila : direct measurement of individual microscopic rate constants

The effectiveness and mechanism of iron acquisition from transferrin or lactoferrin by Aeromonas hydrophila has been analyzed with regard to the pathogenesis of this microbe. The ability of A. hydrophila's siderophore, amonabactin, to remove iron from transferrin was evaluated with in vitro competition experiments. The kinetics of iron removal from the three molecular forms of ferric transferrin (diferric, N- and C-terminal monoferric) were investigated by separating each form by urea gel electrophoresis. The first direct determination of individual microscopic rates of iron removal from diferric transferrin is a result. A. hydrophila 495A2 was cultured in an iron-starved defined medium and the growth monitored. Addition of transferrin or lactoferrin promoted bacterial growth. Growth promotion was independent of the level of transferrin or lactoferrin iron saturation (between 30 and 100%), even when the protein was sequestered inside dialysis tubing. Siderophore production was also increased when transferrin or lactoferrin was enclosed in a dialysis tube. Cell yield and growth rate were identical in experiments where transferrin was present inside or outside the dialysis tube, indicating that binding of transferrin was not essential and that the siderophore plays a major role in iron uptake from transferrin. The rate of iron removal from diferric transferrin shows a hyperbolic dependence on amonabactin concentration. Surprisingly, amonabactin cannot remove iron from the more weakly binding N-terminal site of monoferric transferrin, while it is able to remove iron from the more strongly binding C-terminal site of monoferric transferrin. Iron from both sites is removed from diferric transferrin and it is the N-terminal site (which does not release iron in the monoferric protein) that releases iron more rapidly! It is apparent that there is a significant interaction of the two lobes of the protein with regard to the chelator access. Taken together, these results support an amonabactin-dependent mechanism for iron removal by A. hydrophila from transferrin and lactoferrin. The implications of these findings for an amonabactin-dependent mechanism for iron removal by A. hydrophila from transferrin and lactoferrin are discussed.
The Effect of Ovariectomy and Estradiol on Rabbit Bladder Smooth Muscle Contraction and Morphology

ABSTRACTPurpose: The bladder can be considered a target organ for the actions of estrogen. Decreases in circulating estrogen after menopause have been associated with bladder dysfunctions, including incontinence and detrusor instability. We determined the effects of estrogen on rabbit bladder contractile function and morphology.Materials and Methods: Female New Zealand White rabbits were ovariectomized or sham operated and treated with vehicle or estradiol (1 mg/kg weekly) for 5 weeks. Serum estradiol concentration was monitored every 2 weeks. After treatment each rabbit was anesthetized, the bladder was catheterized, cystometry was performed, and the bladder was removed for contractile and morphological studies. Apoptosis in paraffin embedded rabbit bladder tissue was detected using in situ end-labeling, specifically terminal deoxynucleotidyl-transferase nick end labeling or the TUNEL assay.Results: Ovariectomy resulted in a 50% decrease in circulating estrogen and estradiol treatment resulted in a 5-fol...
Bicriterion Optimization of an M/G/1 Queue with A Removable Server

This paper studies bicriterion optimization of an M/G/1 queue with a server that can be switched on and off. One criterion is an average number of customers in the system, and another criterion is an average operating cost per unit time. Operating costs consist of switching and running costs. We describe the structure of Pareto optimal policies for a bicriterion problem and solve problems of optimization of one of these criteria under a constraint for another one.
Verifying the Evolution of Probability Distributions Governed by a DTMC

We propose a new probabilistic temporal logic, iLTL, which captures properties of systems whose state can be represented by probability mass functions (pmfs). Using iLTL, we can specify reachability to a state (i.e., a pmf), as well as properties representing the aggregate (expected) behavior of a system. We then consider a class of systems whose transitions are governed by a Markov Chain-in this case, the set of states a system may be in is specified by the transitions of pmfs from all potential initial states to the final state. We then provide a model checking algorithm to check iLTL properties of such systems. Unlike existing model checking techniques, which either compute the portions of the computational paths that satisfy a specification or evaluate properties along a single path of pmf transitions, our model checking technique enables us to do a complete analysis on the expected behaviors of large-scale systems. Desirable system parameters may also be found as a counterexample of a negated goal. Finally, we illustrate the usefulness of iLTL model checking by means of two examples: assessing software reliability and ensuring the results of administering a drug.
High efficiency MILO

Summary form only given. The magnetically insulated line oscillator (MILO) is a low impedance, highly powerful source of coherent RF radiation. It is also compact and relatively simple. MILO's RMS efficiency however is not very high. This is due to the fact that a large fraction of the DC input current goes into the generation of the azimuthal magnetic field needed to guide the initially radial beam into an axial flow. It has been shown that providing the azimuthal magnetic field through an external means, will not interfere with the MILO operation. This can be achieved through an independent circuit flowing an axial current near the cathode. Building upon this finding, we have designed a new MILO that operates with a significantly less input power while producing the same output as the conventional MILO. The new design has a higher impedance and provides no particle current for self-insulation. Results of the numerical simulations, carried out using the PIC code MAGIC will be presented.
Fertilization in vitro of feline ova by spermatozoa from the ductus deferens.

Sperm recovered from the ductus deferens of male cats were capable of fertilizing recently ovulated feline ova in vitro without in vivo capacitation. No difference was found in the ability of the two defined culture media tested, a medium described for mouse ova culture by Biggers et al. and modified Ham’s F-b, to support in vitro fertilization. Seventy-nine percent of the ova exposed to sperm cleaved to the two-cell stage and many developed further in culture, some to the blastocyst stage. Cleavage was not observed in any of the control ova which were not exposed to spermatozoa.
MENINGITIS IN MAN CAUSED BY A FILTERABLE VIRUS : II. IDENTIFICATION OF THE ETIOLOGICAL AGENT.

Evidence was presented substantiating the idea that our active agent is a virus. The reactions produced in laboratory animals by the active agent were described, and a comparison of it with other viruses was made. The results of experiments indicating the immunological identity of our virus, Armstrong and Lillie's virus of lymphocytic choriomeningitis, and Traub's virus were given in detail. Finally, the evidence in regard to its natural host and its importance as a factor in diseases of human beings was presented and discussed.
David S. Baldwin, MD: a legacy in nephrology.

A third-year medical student sat in the 17 W workstation at University Hospital in the spring of 1975 after meeting a patient with acute illness, taking a history, and performing a physical examination. This medical student had been very well prepared in the second-year course to understand clinical
The mediating role of health perceptions in the relation between physical and mental health: a study of older residents in assisted living facilities.

Objective: Responding to the increased need for research on older residents in assisted living facilities (ALFs), this study assessed the connections between physical and mental health among 150 older residents in ALF settings. Method: The major focus of the study was to explore whether individuals' subjective perceptions of their own health mediate the associations between health-related variables (chronic conditions and functional disability) and depressive symptoms. Results: The analyses showed that the adverse effects of chronic conditions and functional disability on depressive symptoms were not only direct but also indirect through negative health perceptions. Discussion: The findings that health perceptions serve as an intervening step between physical and mental health provide important implications for promotion of mental well-being among older residents in ALFs. In addition to disease/disability prevention and health promotion efforts, attention should be paid to ways to enhance older individual...
Anaerobic benzene degradation in petroleum-contaminated aquifer sediments after inoculation with a benzene-oxidizing enrichment

Sediments from the sulfate-reduction zone of a petroleum-contaminated aquifer, in which benzene persisted, were inoculated with a benzene-oxidizing, sulfate-reducing enrichment from aquatic sediments. Benzene was degraded, with apparent growth of the benzene-degrading population over time. These results suggest that the lack of benzene degradation in the sulfate-reduction zones of some aquifers may result from the failure of the appropriate benzene-degrading sulfate reducers to colonize the aquifers rather than from environmental conditions that are adverse for anaerobic benzene degradation.