cssi/SciSciGPT-SciSciNet huggingface dataset:
CFTR dysfunction increases endoglin and TGF-β signaling in airway epithelia

Endoglin (ENG) regulates signaling by transforming growth factor-β (TGF-β), a genetic modifier of cystic fibrosis (CF) lung disease severity. We hypothesized that ENG mediates TGF-β pathobiology in CF airway epithelia. Comparing CF and non-CF human lungs, we measured ENG by qPCR, immunoblotting and ELISA. In human bronchial epithelial cell lines (16HBE), we used CFTR siRNA knockdown and functional inhibition (CFTRINH -172) to connect loss of CFTR to ENG synthesis. Plasmid overexpression of ENG assessed the direct effect of ENG on TGF-β transcription and signal amplification in 16HBE cells. We found ENG protein to be increased more than fivefold both in human CF bronchoalveolar fluid (BALF) and human CF lung homogenates. ENG transcripts were increased threefold in CF, with a twofold increase in TGF-β signaling. CFTR knockdown in 16HBE cells tripled ENG transcription and doubled protein levels with corresponding increases in TGF-β signaling. Plasmid overexpression of ENG alone nearly doubled TGF-β1 mRNA and increased TGF-β signaling in 16HBE cells. These experiments identify that loss of CFTR function increases ENG expression in CF epithelia and amplifies TGF-β signaling. Targeting ENG may offer a novel therapeutic opportunity to address TGF-β associated pathobiology in CF.
On a problem of George Andrews concerning partitions with even parts below odd parts

Recently, George Andrews gave a detailed study of partitions with even parts below odd parts in which only the largest even part appears an odd number of times. In this note, we provide a combinatorial proof of a generating function identity related to such partitions. This answers a problem of Andrews.
Adolescent and Parent Management of Controlled Prescription Medications.

AbstractBackground: Most adolescents who misuse controlled prescription medications acquire them from home settings. However, little is known regarding household management (storage, administration...
CONSERVATION AND NATURAL RESOURCES Department of Natural Resources: Establish Minimum Standards and Procedures for Protection of Mountains and River Corridors

The Act provides for protection of certain mountain slopes and river corridors by limiting development and placing restrictions on the land owners. The mountain protection portion of the bill protects all mountain slopes at an elevation of over 2,200 feet with a grade of more than twenty-five percent. The river corridor protection portion of the bill restricts development within 100 feet of rivers having a flow rate of over 400 cubic feet per second, limiting permissible structures to single family residences and necessary infrastructure. A natural vegetative cover must be maintained in the buffer area. Both sections provide exemptions for land use plans developed before the effective date of the Act.
From Digital Library to Open Datasets

This article discusses the burgeoning “collections as data” movement within the fields of digital libraries and digital humanities. Faculty at the University of Utah’s Marriott Library are developing a collections as data strategy by leveraging existing Digital Library and Digital Matters programs. By selecting various digital collections, small- and large-scale approaches to developing open datasets are explored. Five case studies chronicling this strategy are reviewed, along with testing the datasets using various digital humanities methods, such as text mining, topic modeling, and GIS (geographic information system).
Computer Mediated Communication

Computer-mediated communication (CMC) involves sending messages through computer networks such as the Internet. Research on the social impacts of text-based CMC began with a cues-filtered-out perspective, highlighting the loss of social information due to the absence of face-to-face, nonverbal cues. More recent theories focus on how message senders exploit the CMC medium in order to create messages and relationships actively. A sender-receiver-message-channel-feedback model of communication reveals how CMC affects social dynamics.
Technical Note: Assessment of two methods for estimating bone ash in pigs.

Data from three experiments conducted to evaluate the effects of increasing available P in swine diets were used to compare two different bone processing methods. Our objective was to determine if the procedures influenced treatment differences and the ability to detect changes in the percentage bone ash. In each experiment, pigs (nursery pigs in experiments 1 and 2, and finishing pigs in experiment 3) were fed a wide range of available phosphorus levels provided from either increasing monocalcium P or added phytase. At the completion of each experiment, a subset of pigs was euthanized, and either fibulas (experiments 1 and 2) or metacarpals (experiment 3) were collected to determine the percentage bone ash. Bones were processed by cleaning away all soft tissues followed by ether extraction for 7 d (defatted), or no lipid extraction (non-defatted), and then ashed. In nursery and finishing pigs, defatted bones had increased (P 0.10) for nursery pigs; however, a linear interaction was detected (P < 0.05) in percentage bone ash for grow-finish pigs. This response was minimal and likely due to increased variation observed in grow-finish pigs when bones were not defatted. The processing method did not affect the ability to detect differences among treatments as a result of changing dietary P concentrations in the nursery or grow-finish pigs. In summary, either non-defatted or defatted bone processing methods can be used to determine bone ash weight and percentage bone ash as a way to assess bone mineralization and dietary treatment differences in nursery pigs; however, the increased variation observed in mature pigs suggests that defatted bone processing is the preferred method for grow-finish pigs.
Development of supervised machine learning algorithms for prediction of satisfaction at 2 years following total shoulder arthroplasty.

Background Patient satisfaction after primary anatomic and reverse total shoulder arthroplasty (TSA) represents an important metric for gauging patients' perception of their care and surgical outcomes. Although TSA confers improvement in pain and function for most patients, inevitably some will remain unsatisfied postoperatively. The purpose of this study was to (1) train supervised machine learning (SML) algorithms to predict satisfaction after TSA and (2) develop a clinical tool for individualized assessment of patient-specific risk factors. Methods We performed a retrospective review of primary anatomic and reverse TSA patients between January 2014 and February 2018. A total of 16 demographic, clinical, and patient-reported outcomes were evaluated for predictive value. Five SML algorithms underwent 3 iterations of 10-fold cross-validation on a training set (80% of cohort). Assessment by discrimination, calibration, Brier score, and decision-curve analysis was performed on an independent testing set (remaining 20% of cohort). Global and local model behaviors were evaluated with global variable importance plots and local interpretable model-agnostic explanations, respectively. Results The study cohort consisted of 413 patients, of whom 331 (82.6%) were satisfied at 2 years postoperatively. The support vector machine model demonstrated the best relative performance on the independent testing set not used for model training (concordance statistic, 0.80; calibration intercept, 0.20; calibration slope, 2.32; Brier score, 0.11). The most important factors for predicting satisfaction were baseline Single Assessment Numeric Evaluation score, exercise and activity, workers' compensation status, diagnosis, symptom duration prior to surgery, body mass index, age, smoking status, anatomic vs. reverse TSA, and diabetes. The support vector machine algorithm was incorporated into an open-access digital application for patient-level explanations of risk and predictions, available at https://orthopedics.shinyapps.io/SatisfactionTSA/ . Conclusion The best-performing SML model demonstrated excellent discrimination and adequate calibration for predicting satisfaction following TSA and was used to create an open-access, clinical decision-making tool. However, rigorous external validation in different geographic locations and patient populations is essential prior to assessment of clinical utility. Given that this tool is based on partially modifiable risk factors, it may enhance shared decision making and allow for periods of targeted preoperative health-optimization efforts.
Diversity and Metabolic Potential of Microbial Communities in a Serpentinite-Hosted Spring at the Tablelands

The geochemical process of serpentinization releases energy and organic carbon: two of the basic requirements needed to support life. Sites of active serpentinization in the deep subsurface provide the intriguing possibility of a non-photosynthetically-supported biosphere. However, serpentinization also creates conditions, such as high pH and limited electron acceptors, which may limit microbial growth and diversity. Gaining an understanding of the identity and metabolic potential of microbes that thrive in these environments may provide insight as to whether serpentinization is sufficient to independently support life. Tablelands Ophiolite in Gros Morne National Park, Newfoundland, Canada is a continental site of serpentinization where serpentinite springs form surface pools. These pools provide easy sampling access to subsurface fluids and may allow for sampling of the subsurface microbial community. However, identification of members of the subsurface community in these pools is complicated by both surface contamination and contamination by organisms that inhabit the transition zone where hydrogen-rich subsurface fluids meet oxygen-rich surface fluids. This study was designed to distinguish among these potential sources of microorganisms by using a sampling technique that more effectively samples subsurface fluids. Community dissimilarity comparisons using environmental 16S rRNA gene sequencing indicate that the sampling design led to more direct access to subsurface fluids. These results are supported by metagenomic analyses that show metabolic pathways consistent with non-photosynthetic carbon fixation in the samples expected to represent subsurface fluids and that show hydrogen oxidation pathways in samples associated with the surface sources. These results provide a clearer picture of the diversity and metabolic potential of microbial communities potentially inhabiting subsurface, serpentinite-hosted habitats.
Crops better when grown together

Sustainability and resilience are priorities in agriculture. A new analysis of four experiments with a combined 46 years of data shows that intercropping — growing multiple crops together — can increase yields, yield stability and soil fertility.
400 Postneonatal cerebral palsy – timing and origin

Cerebral palsy (CP) is most common severe neurodevelopmental disorder, affecting 2-3/1000 live borns. Postneonatal cerebral palsy is a rare and distinct form of CP in which damage to immature brain occurs after the newborn period until the age of 24 months. Surveillance of Cerebral Palsy in Europe (SCPE) is European project encompassing 26 currently active centers from 21 European countries. Common database of children with CP is one of the main assets, providing better insight even in the rare CP types. Croatian SCPE register is enrolled since 2012 as „C28 RCP-HR Register of cerebral palsy of Croatia’, and is affiliated to Children’s Hospital Zagreb. Object of this study is to address children with postneonatal origin of CP in our national Register and the main causes of this rare CP. This population-based study included 502 children from C28 RCP-HR born 2003-2009, living at the area of Register at point of registration, with postneonatal cause of cerebral palsy. Patients were stratified according to the timing and origin of the lesion. Out of total of 502 children with CP (total CP prevalence 2.11/1000), 11 had postneonatal origin, presenting 2.19% of total CP population or 0.46/10000 live borns. Most common causes were vascular episodes (5/11) and infection of central nervous system (3/11), while others, including the head trauma, accounted for one case respectively. Most usual time of onset was during first trimester (6/11), while timing in other five children was distributed quite equally until the age of two years of life. Postneonatal cerebral palsy is rare and possibly unrecognised form of cerebral palsy, in our Register, as well as common SCPE register (proportion of 7.69% of total CP population; prevalence of 1.26/10000). Recognition of this state is important since it is partly preventable, epidemiologically relevant in large scale studies, but most importantly, on individual level, for planning and establishing the special care each CP patient should have.
Principles of Genetic Analysis

The basic unit of hereditary material is the gene. “The word ‘gene’ does not imply any hypothesis; it expresses only the established fact that many properties of the organism have their origins in some particular, distinctive and thereby independent elements . . . present in the gametes” (Johannsen 1909, p. 130). This definition, provided in 1909 by W. Johannsen, who introduced the term gene into modern biology, is, admittedly, a vague one. But in the 65 years since this proposal, geneticists have failed to agree on any more exact description; consequently, it may be best to preserve the original denotation of the gene as an abstract unit of genetic information. The term sometimes used as a substitute for gene is cistron, defined as a segment of nucleic acid coding for one polypeptide chain.
Surveillance of Feral Cats for Influenza A Virus in North Central Florida

Please cite this paper as: Gordy JT et al. (2012) Surveillance of feral cats for influenza A virus in North Central Florida. Influenza and Other Respiratory Viruses 6(5), 341–347. Background Transmission of highly pathogenic avian influenza and the recent pandemic H1N1 viruses to domestic cats and other felids creates concern because of the morbidity and mortality associated with human infections as well as disease in the infected animals. Experimental infections have demonstrated transmission of influenza viruses in cats. Objectives An epidemiologic survey of feral cats was conducted to determine their exposure to influenza A virus. Methods Feral cat sera and oropharyngeal and rectal swabs were collected from November 2008 through July 2010 in Alachua County, FL and were tested for evidence of influenza A virus infection by virus isolation, PCR, and serological assay. Results and conclusions No virus was isolated from any of 927 cats examined using MDCK cell or embryonated chicken egg culture methods, nor was viral RNA detected by RT-PCR in 200 samples tested. However, 0.43% of cats tested antibody positive for influenza A by commercial ELISA. These results suggest feral cats in this region are at minimal risk for influenza A virus infection.
Chapter 9 A new model of letter string encoding: simulating right neglect dyslexia

Publisher Summary The chapter describes a theoretical model of oral reading that is developed to be consistent with experimental data from normal subjects and with existing neurobiological theory. Computer simulations based on this model can be lesioned to reproduce an error pattern obtained from a group of adult patients with left hemisphere lesions. The development of this model forced explicit consideration of a number of issues concerning normal word processing, especially the important issue of how letter order is encoded in words. The chapter also describes the genesis of the model, including the motivation for modifications made during its development, to illustrate the value of computational modeling for studying cognitive processes and their impairments. The main purpose for developing a model of written word processing can accommodate the finding that, patients with focal left hemisphere lesions tend to substitute words that overlap the first few letters of the target.
Lymph node retrieval from colorectal resection specimens for adenocarcinoma: is it worth the extra effort to find at least 12 nodes?

Aim Retrieval of a minimum of 12 lymph nodes has been recommended for adequately staging a node-negative colorectal cancer (CRC). This study was designed to determine whether the extra effort expended to recover more nodes for histological examination improves the accuracy of staging. Method Pathology reports, histology worklists, and haematoxylin and eosin (H&E) slides of 334 CRC resections were reviewed. The total number of nodes and the number of positive nodes harvested from the first and additional searches were recorded for each patient. Results The number of nodes retrieved from the 334 resections at the first search ranged from 0 to 57 (mean: 14.2), with 195 patients (58.4%) having ≥ 12 nodes. Nodal metastasis was found in 122 (33.6%) patients. Additional searches were performed on 115 patients, including 91 with < 12 nodes. The mean number of nodes recovered in these patients increased significantly, from 9.1 to 14.2 (P < 0.0001). Thirty-one additional positive nodes were found in 19 patients following the further searches, and 12 (63.2%) of the 19 patients were upstaged using the American Joint Committee on Cancer (AJCC) 6th edition (2002) staging criteria. The total number of nodes retrieved and the probability of obtaining ≥ 12 nodes correlated negatively with the age of the patient and the rectosigmoid location of the tumours, but positively with the specimen length, the pericolic/perirectal fat width, female gender and tumour size. Conclusion Although a number of patient and specimen variables influence the number of lymph nodes retrieved, our observations support the importance of a thorough search for nodes in CRC specimens in order to achieve accurate tumour staging.
Vector quantization of contextual information for lossless image compression

The authors present a new pruned tree structured vector quantization (TSVQ) algorithm, called incremental tree growing (ITG), which incrementally grows and quantizes the context tree locally on a level by level basis, thus drastically reducing both the memory requirements and the computational complexity. After the incremental tree growing is completed, terminal branches are globally vector quantized again, which is possible due to significant reduction of the number of initial branches. Using a technique similar in spirit to the mean removed VQ (MRVQ) of Baker and Gray (1983), significant reduction in the number of probability tables is achieved. In one of their simulations, they reduced the number of probability tables from 262 K(=2/sup 18/) to 108 by using the ITG algorithm, and from 108 to 10 using the modified MRVQ at the conditional entropy increase of only 1.26%. In summary, the proposed ITG algorithm combined with a modified MRVQ provides an efficient framework for the design of context-trees with reduced memory and computational requirements. >
The Relativity and Equivalence Principles for Self-gravitating Systems

I criticise the view that the relativity and equivalence principles are consequences of the small-scale structure of the metric in general relativity, by arguing that these principles also apply to systems with non-trivial self-gravitation and hence non-trivial spacetime curvature (such as black holes). I provide an alternative account, incorporating aspects of the criticised view, which allows both principles to apply to systems with self-gravity.
Synthesis and near infrared luminescence of a tetrametallic Zn2Yb2 architecture from a trinuclear Zn3L2 Schiff base complex

Near infrared luminescence is observed in tetrametallic [Zn2Yb2L2(µ-OH)2Cl4]·2MeCN which is obtained from the Zn3 Schiff-base complex [Zn3L2(NO3)2]·MeOH, (H2L = N,N′-bis(5-bromo-3-methoxysalicylidene)propylene-1,3-diamine).
Outcomes After Laparoscopic Roux-en-Y Gastric Bypass for Morbid Obesity

Objective To evaluate the short-term outcomes for laparoscopic Roux-en-Y gastric bypass in 275 patients with a follow-up of 1 to 31 months. Background Data The Roux-en-Y gastric bypass is a highly successful approach to morbid obesity but results in significant perioperative complications. A laparoscopic approach has significant potential to reduce perioperative complications and recovery time. Methods Consecutive patients (n = 275) who met NIH criteria for bariatric surgery were offered laparoscopic Roux-en-Y gastric bypass between July 1997 and March 2000. A 15-mL gastric pouch and a 75-cm Roux limb (150 cm for superobese) was created using five or six trocar incisions. Results The conversion rate to open gastric bypass was 1%. The start of an oral diet began a mean of 1.58 days after surgery, with a median hospital stay of 2 days and return to work at 21 days. The incidence of early major and minor complications was 3.3% and 27%, respectively. One death occurred related to a pulmonary embolus (0.4%). The hernia rate was 0.7%, and wound infections requiring outpatient drainage only were uncommon (5%). Excess weight loss at 24 and 30 months was 83% and 77%, respectively. In patients with more than 1 year of follow-up, most of the comorbidities were improved or resolved, and 95% reported significant improvement in quality of life. Conclusion Laparoscopic Roux-en-Y gastric bypass is effective in achieving weight loss and in improving comorbidities and quality of life while reducing recovery time and perioperative complications.
The significance of axial stresses and out-of-plane restraints on the design of rotors

Abstract The importance of axial stresses in rotors and the effect of out-of-plane restraints at the hub, on the in-plane stresses are investigated by using the finite element technique, with a hexahedral isoparametric element. The stresses in a non-dimensional form are compared with the plane stress solution. The probable mode of deformation of rotors of various axial thicknesses is given. The use of the above method in the analysis of an asymmetric rotor is also demonstrated.
LOCAL FUND RAISING: DEMONSTRATING THE VALUE OF LIBRARIES

Fifteen years ago, when I became a city library director, my highest priority was to increase the percentage of city residents who used the library to 100 percent. During my first six months on the job, I did a community needs assessment and also looked at the other locally funded city services. One of the startling realizations I had was not all city services were striving for that all‐important 100 percent utilization.
Evidence for synaptic potentiation in a cortical network during learning

Abstract The connections between the lateral olfactory tract (LOT) and layer I of the piriform cortex were used to test the idea that certain forms of learning involve potentiation of cortical synapses. Rats were trained on a series of two-odor discriminations over a period of several days after which patterned electrical stimulation (short, high frequency bursts with 5–6 bursts per second) of the LOT was used as a discriminative cue. The animals reacted to the stimulation as though it were an odor and quickly learned to respond appropriately and to distinguish between ‘positive’ and ‘negative’ electrodes. Comparisons of the monosynaptic responses in the piriform cortex evoked by single pulse stimulation of the LOT before and after learning revealed that the population synaptic responses were substantially potentiated by the training. This effect was present in an unchanged form 24 h later. Responses elicited by control stimulating electrodes were slightly or not at all affected by training to stimulation with another electrode. Synaptic potentiation was not found in a small group of rats that did not learn to respond to patterned stimulation and was also absent when the stimulation was applied to naive rats. These results provide evidence that rapid learning of a specific cue potentiates cortical synapses in a defined terminal field.
A mouse model of the fragile X premutation: effects on behavior, dendrite morphology, and regional rates of cerebral protein synthesis

Carriers of FMR1 premutation alleles have 55-200 CGG repeats in the 5' untranslated region of the gene. These individuals are at risk for fragile X associated primary ovarian insufficiency (females) and, in late life, fragile X associated tremor and ataxia syndrome (males, and to a lesser extent, females). Premutation carrier status can also be associated with autism spectrum disorder, attention deficit hyperactivity disorder, and some cognitive deficits. In premutation carriers, FMR1 mRNA levels are often higher than those with normal sized alleles. In contrast, in subjects with full mutation alleles, (>200 repeats) the FMR1 gene is silenced and FMR1 mRNA and its product, FMRP, are absent. We have studied a male knock-in (KI) mouse model of the fragile X premutation (120-140 repeats) during young adulthood. In comparison to wild type, KI mice were hyperactive, exhibited less anxiety in both the open field and the elevated zero maze, were impaired on the passive avoidance test, and showed some subtle deficits on a test of social interaction. Motor learning as assessed by the rotarod test was normal. Dendritic arbors were less complex and spine densities and lengths increased in medial prefrontal cortex, basal lateral amygdala, and hippocampus compared with wild type. Regional rates of cerebral protein synthesis measured in vivo in KI mice were increased. KI mice also had elevated levels of Fmr1 mRNA and decreased levels of FMRP. Our results highlight similarities in phenotype between KI and Fmr1 knockout mice and suggest that the decreased concentration of FMRP contributes to the phenotype in young adult KI mice.
Towards a Pedagogy for the Application of Empathy in Culturally Diverse Classrooms.

Empathy is theorized to improve the teaching effectiveness of teachers in urban and multicultural classroom settings. However, the field has few models useful for training and preparing teachers to cultivate empathy as a professional disposition. This study examines the academic, behavioral, and social/relational interactions of four White female high school teachers with their Black male students. Findings suggest that empathy, as a professional disposition applied by teachers to negotiate interactions with students, requires two phases of implementation. Phase 1 is the acquisition of new knowledge. Phase 2 is the strategic negotiation of that knowledge and interpretation of student feedback to make the necessary pedagogic adjustments in subsequent student–teacher interactions. Implications for teacher education and professional development are discussed.
A shock tube study of H + HNCO → NH2 + CO

The reaction of atomic hydrogen with isocyanic acid (HNCO) to produce the amidogen radical (NH2) and carbon monoxide, has been studied in shock-heated mixtures of HNCO dilute in argon. Time-histories of the ground-state NH2 radical were measured behind reflected shock waves using cw, narrowlinewidth laser absorption at 597 nm, and HNCO time-histories were measured using infrared emission from the fundamental v2-band of HNCO near 5 μm. The second-order rate coefficient of reaction (2(a)) was determined to be: cm3 mol−1 s−1, where f and F define the lower and upper uncertainty limits, respectively. An upper limit on the rate coefficient of was determined to be:
Quantitative analyses of changes in cell shapes during bending of the avian neural plate

It is widely believed that changes in cell shapes play important roles in the bending or folding of epithelial sheets, but few studies have actually examined cell shapes in such systems. We have determined the percentages of four types of neuroepithelial cells (i.e., spindle, flask, inverted flask, and globular) present during bending of the avian neural plate. Serial transverse plastic sections through seven craniocaudal levels of the neuroepithelium were examined. Four distinct periods of bending were chosen based on the morphology of the neuroepithelium: period I, flat neural plate; period II, midline furrow without elevation of the neural folds; period III, midline furrow with elevation; and period IV, bilateral furrows with convergence of the neural folds. We compared statistically the percentages of different cell types in bending (furrowed) and nonbending regions of the neuroepithelium, as well as changes in cell shapes with time. Our results demonstrate that dramatic changes in cell shapes occur in the midline and bilateral furrows during bending of the neural plate, such that as many as 70% of the neuroepithelial cells in the midline and 55% in the bilateral furrows are wedge shaped by the end of bending. In contrast, less than 35% of the neuroepithelial cells are wedge shaped outside of the three morphological loci of bending. These results support the hypothesis that localized changes in cell morphologies have roles in bending and shaping of the neural plate, but exactly how cells change shapes and what precise roles such changes play in bending remain to be determined.
A Thermoelectric Blood Flow Recorder in the Form of a Needle

The needle flow recorder described here was primarily designed to measure rate of blood flow through the internal jugular vein of man. Preliminary work on animals has shown that the device possesses certain characteristics that would seem to promise it a sphere of usefulness in a variety of problems where blood flow is an important variable. The advantages of the device are as follows: Its use entails only a minimal trauma. It can be applied to the study of flow through relatively inaccessible structures. The method makes it possible to measure qualitatively the changes in blood flow through a vascular tissue without isolating or cannulizing the afferent or efferent vessels, and thus enables one to study the blood flow through a tissue or organ, the blood supply of which is not capable of being completely isolated. It also makes possible relative determinations of the blood flow through various parts of the same organ or region. This has not been possible by any method previously described. The thermoelec...
Nicotine tolerance in rats; role of dose and dose interval.

In experimentally naive rats, nicotine reduced spontaneous locomotor activity in a dose-related manner. After a single pretreatment with nicotine, acute tolerance developed; this was shown by a shift of the dose-response curve, such that the dose of nicotine required to produce a given decrement in activity was multiplied by a factor of about 2.4. In a second experiment, a range of doses of nicotine was found to induce tolerance, but the dose inducing the maximum degree of tolerance was rather critical. The results demonstrated the importance of using a range of pretreatment and challenge doses when assessing tolerance to nicotine. However, frequently repeated doses were not necessary, since tolerance developed when nicotine was administered to rats only once in every 3 days. In terms of tolerance liability in rats, it seems that nicotine is not discriminable from other drugs upon which dependence can be established.
Aspartic acid racemisation in dentine as a measure of ageing.

THE L-amino acids initially present in bone protein undergo slow racemisation over geological time at a rate which is proportional to temperature1,2. We have shown3 that at the human body temperature of ∼37°C aspartyl residues in tooth enamel protein also undergo racemisation at a rate which corresponds to an enrichment in the D-aspartic acid content of ∼0.1% per year. No D-aspartic acid increase was detected in haemoglobin, a protein with a more rapid turnover. We concluded that D-aspartyl residues accumulate in the metabolically stable protein in tooth enamel during the human lifetime as a result of in situ racemisation. We proposed that the irreversible first-order rate equation calculated from the enamel results could be used to deduce the age of any stable protein from a long lived mammal and thus the age of the organism itself. The error among samples from old individuals was large, however, probably because attrition and caries reduce the amount of uncontaminated enamel, and thus tend to limit the usefulness of tooth enamel for age determinations. In this report, we show that tooth dentine is a more suitable material, and the extent of aspartic acid racemisation in this fraction can be used as a reliable indicator of mammalian age.
Level-2 cache for high performance /390 μ-processors

Abstract A L2 cache chip design for high performance /390 μ-processors in a multiprocessor environment is presented. Design objectives, logic and technological implementation as well as measured results are discussed. The design features a 96 k Bytes L2 cache-, its associated directory- and LRU arrays, dataflow and control logic integrated on one CMOS standard cell chip with more than 6 million transistors. Its nominal operating frequency is 75 Mhz. 16 bytes wide memory and PU busses are serviced by operating two L2-cache chips in parallel.
Turboprop interior noise studies

The modal theory of acoustoelasticity is applied to the determination of the sound levels caused by a prescribed external sound excitation which is transmitted through a cylindrical shell. A circumferential traveling pressure wave excitation is studied as representative of a propeller sound field. It is shown how other excitations such as point mechanical loading, plane wave and reverberation random may be synthesized by superposition of circumferential waves. Representative numerical results illustrate the importance of structural and acoustic frequency matching in the determination of interior sound levels and clarify the role of the cylindrical shell ring frequency. An exploratory study of a double wall geometry is conducted.
A bounding surface model for concrete

Abstract A rate-independent, three-dimensional bounding surface model for concrete is developed. The model adopts a scalar representation of the damage related to the strain and stress states of the material. The salient features of the model are: (1) a bounding surface in stress space that shrinks uniformly as damage accumulates, and (2) material parameters that depend on damage and the distance between the current stress point and the bounding surface. Satisfactory prediction is obtained of the multiaxial compression behavior of concrete in monotonic and cyclic loadings. The model is relatively simple and incrementally linear, and its finite element implementation appears promising.
ONE HAT TOO MANY: KEY EXECUTIVE PLURALITY AND SHAREHOLDER WEALTH

Tracing backward the career paths of the key executives of Business Week’s 1990 listing of the 1000 most valuable publicly held companies, we empirically examined the impact of announced changes in key executive plurality on stockholder returns. We found the more complete the position consolidation, the more negative were the shareholder responses. To attempt to gain further understanding, the additional variables of executive’s origin, the size of the board of directors of the firm, the proportion of outsiders on the board, and prior firm performance were examined. © 1997 by John Wiley & Sons, Ltd.
Species-Specific Inhibition of Inosine 5‘-Monophosphate Dehydrogenase by Mycophenolic Acid†

IMPDH catalyzes the oxidation of IMP to XMP with the concomitant reduction of NAD+ to NADH. This reaction is the rate-limiting step in de novo guanine nucleotide biosynthesis. Mycophenolic acid (MPA) is a potent inhibitor of mammalian IMPDHs but a poor inhibitor of microbial IMPDHs. MPA inhibits IMPDH by binding in the nicotinamide half of the dinucleotide site and trapping the covalent intermediate E-XMP*. The MPA binding site of resistant IMPDH from the parasite Tritrichomonas foetus contains two residues that differ from human IMPDH. Lys310 and Glu431 of T. foetus IMPDH are replaced by Arg and Gln, respectively, in the human type 2 enzyme. We characterized three mutants of T. foetus IMPDH: Lys310Arg, Glu431Gln, and Lys310Arg/Glu431Gln in order to determine if these substitutions account for the species selectivity of MPA. The mutation of Lys310Arg causes a 10-fold decrease in the Ki for MPA inhibition and a 8−13-fold increase in the Km values for IMP and NAD+. The mutation of Glu431Gln causes a 6-fold...
Polynomial estimation of eigenvalues

In estimating the eigenvalues of the covariance matrix of a multivariate normal population, the usual estimates are the eigenvalues of the sample covariance matrix. It is well known that these estimates are biased. This paper investigates obtaining improved eigenvalue estimates through improved estimates of the characteristic polynomial, which is a function of the sample eigenvalues. A numerical study investigates the improvements evaluated under both a square error and an entropy loss function.
Additive Manufacturing of Metal Cellular Structures: Design and Fabrication

With the rapid development of additive manufacturing (AM), high-quality fabrication of lightweight design-efficient structures no longer poses an insurmountable challenge. On the other hand, much of the current research and development with AM technologies still focuses on material and process development. With the design for additive manufacturing in mind, this article explores the design issue for lightweight cellular structures that could be efficiently realized via AM processes. A unit-cell-based modeling approach that combines experimentation and limited-scale simulation was demonstrated, and it was suggested that this approach could potentially lead to computationally efficient design optimizations with the lightweight structures in future applications.
COMPARISON OF TRAINING MODALITIES FOR PERFORMING LAPAROSCOPIC RADICAL PROSTATECTOMY: EXPERIENCE WITH 1,000 PATIENTS

ABSTRACTPurpose: We report a detailed analysis of different training modalities on the transferability of laparoscopic radical prostatectomy to generations of surgeons.Material and Methods: The first generation surgeon with experience with 600 cases and the second generation surgeon with 150 were trained in open retropubic radical prostatectomy and laparoscopy, whereas the third generation surgeon with 150 cases was trained only laparoscopically. The fourth generation of surgeons with a total of 50 cases was trained in our fellowship program. We analyzed groups of 50 operations. The groups were comparable with respect to patient age, prostate weight and pathological tumor stage.Results: We observed a continual decrease in operative time between (322 to 247 minutes.) and within (332 to 196 minutes.) the analyzed groups. This result was also expressed in a decrease in the time required for anastomosis. A significant decrease was observed for the initial transfusion rate (4% to 10%). No difference was found ...
Sex differences in the gross size of the rat neocortex.

The pervasiveness of sex differences in the size of the rat cerebral cortex was investigated in ten littermate pairs of socially housed Long-Evans hooded rats at 90 days of age. Overall, the cortex was longer and wider in male than in female rats. Sex differences were detected in most cortical regions with this sample size; the exception was the temporal cortex. While some asymmetries were found, they did not vary with the sex of the animal nor were they consistently in one direction. The contribution of the cortical layers to sex differences in cortical thickness was examined in four locations: the primary motor cortex, the forelimb area of the sensorimotor cortex and the monocular and the binocular areas of the visual cortex. The layers that showed sex differences varied among the areas but were confined to layers II–III, V and VI. Sex differences in cortical size were widespread in the adult rat but showed some regional and laminar specificity. © 1992 Wiley-Liss, Inc.
Interactions of Organozinc Compounds with Crown Ethers and Cryptands: Formation of R2Zn(18-crown-6) Rotaxanes

Several pieces of evidence indicate that R2Zn(18-crown-6) rotaxanes are components of solutions prepared from some R2Zn (R = alkyl or aryl) compounds and 18-crown-6, and crystal structures show that Et2Zn(18-crown-6) and Ph2Zn(18-crown-6) solids that precipitate from such solutions have rotaxane structures. By contrast, the R2Zn compounds do not form rotaxanes with 15-crown-5 or its nitrogen equivalent, 1,4,7,10,13-pentamethyl-1,4,7,10,13-pentaazacyclopentadecane. Disproportionation of R2Zn by macrocycles to form coordinated RZn+ cations and R3Zn- anions is less favorable than the corresponding reaction with R2Mg, although Tol2Zn (Tol = p-methylphenyl) and 2,1,1-cryptand do form TolZn(2,1,1-cryptand)+Tol3Zn-.
Thrombin receptor function and cardiovascular disease

Thrombin, a multifunctional protease generated at sites of vascular injury, is a powerful agonist fora variety of cellular processes important in cardiovascular disease. A recently cloned thrombin receptor has provided a framework for understanding how thrombin, a protease rather than a classic ligand, activates cells. It has also yielded new tools for defining the role of thrombin and its receptor in cellular events. This review discusses a working model for how thrombin activates platelets and other cells, and possible roles for the thrombin receptor in thrombotic, proliferative, and inflammatory processes.
APPROPRIATE SAMPLE SIZES FOR SELECTING THE POPULATION WITH THE LARGEST VALUE OF π FROM AMONG κ BINOMIAL POPULATIONS

Bechhofer's (1954) procedure for selecting the population with the largest mean from among κ normal populations with known variances is discussed as it applies to the problem of selecting the population with the largest value of π from among κ binomial populations. Tables of appropriate sample sizes are provided and an example is discussed concerning their use in which one might wish to select such a population at a specified probability level.
The polishability of posterior composites

The polishability of six brands of posterior composites was evaluated by means of a stylus profile instrumentation and scanning electron microscopy and was compared with that of an anterior microfilled composite. A sedigraphic study was performed to estimate the size and distribution of their inorganic particles. The extent of the filler loading as well as the hardness values were also assessed to determine any relevant characteristics. Some of the findings indicated that posterior composites with large particles produced significantly higher surface roughness than those with small fiber particles. A direct correlation was also found between the hardness value and surface roughness value, indicating that a composite with higher hardness value yielded a higher roughness value.
Automated designation of tie-points for image-to-image coregistration.

Image-to-image registration requires identification of common points in both images (image tie-points; ITPs). Here, we describe software implementing an automated, area-based technique for identifying ITPs. The ITP software was designed to follow two strategies: (1) capitalize on human knowledge and pattern-recognition strengths, and (2) favour robustness in many situations over optimal performance in any one situation. We tested the software under several confounding conditions, representing image distortions, inaccurate user input, and changes between images. The software was robust to additive noise, moderate change between images, low levels of image geometric distortion, undocumented rotation, and inaccurate pixel size designation. At higher levels of image geometric distortion, the software was less robust, but such conditions are often visible to the eye. Methods are discussed for adjusting parameters in the ITP software to reduce error under such conditions. For more than 1600 tests, median time n...
Dynamical Constraints on Alternatives to Supermassive Black Holes in Galactic Nuclei

The compelling dynamical evidence for massive dark objects in galactic nuclei does not uniquely imply massive black holes (BHs). To argue convincingly that these objects are BHs we must rule out alternatives to a BH, and the alternative to a point mass is a cluster of some sort of nonluminous objects, such as a cluster of brown dwarfs or stellar remnants. We use simple physical considerations to derive the maximum possible lifetime of a dark cluster that may consist of any plausible form of nonluminous gravitating objects?from brown dwarfs and very low mass objects of cosmic composition to white dwarfs, neutron stars, and black holes. The lower this limit relative to the galaxy age, the more implausible the cluster hypothesis is, thus arguing for a point mass. A cluster with a lifetime much shorter than 10 Gyr is unacceptable, since observing it at the present epoch would be highly improbable. Since the goal is to rule out a dark cluster by showing that its lifetime must be very short, we make the most generous assumptions possible under the observational constraints to allow for its survival. We find that the lifetime of such a hypothetical cluster must be much shorter than the galaxy age only in the cases of NGC 4258 and our Galaxy, thus strongly arguing for a point mass. In all other galaxies, the case of a massive BH, although compelling, is not yet watertight. We also note that there are two exotic alternatives to a massive BH that cannot be ruled out even in the cases of NGC 4258 and the Galaxy: clusters of elementary particles (e.g., bosons), and clusters of very low mass (0.04 M?) BHs. We point out, however, serious difficulties with these alternatives, and argue that they are highly implausible.
A Brief Statistical Review of the United States-Mexico Screw-Worm Eradication Program

The first experiments which showed that native populations of the screw-worm fly, Cochliomyia hominivorax (Coquerel), could be reduced under practical field conditions through the release of laboratory-reared sterilized (irradiated) flies were made on Sanibel and adjacent islands off the coast of Florida in 1952–53 by one of us (G.W.E.) and co-workers (unpublished data). The first actual eradication of the fly was accomplished on the island of Curacao some 64 km off the coast of Venezuela (Baumhover et al. 1955). A more impressive demonstration of the effectiveness of the sterile-male technique was the eradication of the screw-worm fly from the southeastern United States (Knipling 1960, Baumhover 1966). A review of these programs as well as a report on the eradication program in the southwestern United States and Mexico during 1962–65 (Baumhover 1966) included statistics concerning numbers of flies released, screw-worm cases, program costs, losses caused by the fly, and savings resulting from the program's operation. The most recent review of the status of the screw-worm eradication program in the southwest and Mexico was given by Hightower (1970). Our paper deals mainly with areas of infestations, screwworm cases reported, and the numbers of sterile flies released in the United States and Mexico during 1962 through 1969.
Time-dependent permeabilities of hydrophobic, pH-sensitive hydrogels exposed to pH gradients

pH-dependent changes in permeability to glucose of a poly(N-isopropylacrylamide-co-methacrylic acid) hydrogel membrane were measured with the membrane clamped between two cells. The donor cell was maintained at pH 7.0 and the receptor cell was subjected to a set of ramps in pH. Starting with the membrane in a state of high permeability to glucose, a ramp of decreasing pH led ultimately to shutoff of glucose flux. With passage of time at a fixed, low pH, however, permeability was restored to an intermediate value. Upon ramping pH back to its initial value, the initial permeability was restored. Based on light microscopy, the nonstationary permeability behavior is attributed to lateral stress-induced morphological changes that occur in a collapsed,,skin formed on the side of the membrane facing the acidic donor solution.