cssi/SciSciGPT-SciSciNet huggingface dataset:
Biodegradable Drug Delivery Systems Based on Polypeptides

A new dimension to the use of polymeric materials as drug delivery devices is the incorporation of biodegrability into the system. A number of degradable polymers are potentially useful for this purpose, including synthetic and natural substances. A number of such substances are described in this chapter. However, major emphasis is placed on synthetic poly(α-amino acids). These polymers are useful for matrix and reservoir-type delivery systems and, in addition, when difunctional amino acids, such as glutamic acid, are utilized, polymer/drug conjugates represent another new dimension. In polymer/drug conjugates, the drug is covalently bonded directly to the polymeric “backbone” or to a spacer group between the drug and polymer. The bond must be of a type which hydrolyzes more rapidly than the amide bonds in the polymeric backbone. A number of such conjugates have been synthesized and evaluated for in vitro and in vivo hydrolysis and for potential toxicity. It appears that this concept can be utilized to advantage in the development of delivery systems for a wide variety of bioactive substances.
Abstract P016: Preventing Heart Disease, Stroke, and Related Chronic Diseases in the Mississippi Delta Region: Clinical Community Health Worker Initiative

Background: Community Health Workers (CHW) are increasingly being used to address chronic disease prevention, but knowledge of their use in underserved rural settings is limited. CHW can be instrumental in linking underserved populations to clinical care and navigating the health care system. We report on the influence of our Clinical Community Health Worker Initiative (CCHWI) intervention program on clinical risk factors for heart disease and stroke in the Mississippi Delta region. Methods: Patients diagnosed with hypertension, diabetes or high cholesterol, and ≥18 years and consented to participate in the CCHWI were referred to a CHW for follow-up. CHW conducts an initial home visit, a follow-up phone call 7 to 10 days after the initial visit, a second home visit after 30-45 days and a subsequent recurring 90-day follow-up home visit. CHW activities include appointment scheduling and transportation arrangement, interpretation of health information, demonstrating proper procedures in monitoring blood pressure and blood glucose and encouraging patients to keep monitoring logs, assisting patients in documenting questions or concerns regarding medication and/or treat regimens for next doctors visit, assisting patients in setting nutrition target and goals, explaining the benefits of changing lifestyle habits, performing height, weight, and blood pressure measurements, encouraging patient to enroll in chronic disease self-management classes, and arranging referral for counseling to tobacco cessation treatment programs. Clinical data from 432 participants contacted by CHWs during home visits and phone calls from August 2012 to August 2014 were evaluated. We used paired t tests to assess changes from baseline for the following clinical measures: blood pressure, hemoglobin A1c, total blood cholesterol, high density lipoprotein cholesterol, low density lipoprotein (LDL) cholesterol, triglycerides, and body mass index. Results: Mean age of participants was 57.6 (range 20-89) years; 71.1% were female, and 91.9% were black. The majority of the participants were diagnosed with hypertension (82.4%) and diabetes (72.0%) and more than half (57.2%) with high cholesterol. One in five (21.1%) participants had only one condition, 46.3% had two conditions and a third (32.6%) had all three conditions. We observed statistically significant improvements (baseline vs most recent value) for diastolic blood pressure (p=0.0045), total cholesterol (p=0.0014), LDL cholesterol (p=0.0117), and triglycerides (p=0.0255). Conclusion: The use of CHW may help improve heart disease and stroke clinical risk factors among rural underserved populations.
The Faint End of the Luminosity Function in the Field

I review the current observational status of the faint end of the optical luminosity function of field galaxies at low redshift. There is growing evidence for an excess number of dwarf galaxies that is not well fit by a single Schechter function. These dwarf galaxies tend to be of late morphological and spectral type, blue in colour, of low surface brightness and currently undergoing significant star formation.
Progressive deterioration of β-cell function in obese youth with type 2 diabetes

The pathophysiology of type 2 diabetes (T2DM) in youth involves impairments in insulin sensitivity and β-cell function, translating to around 86% lower insulin secretion relative to insulin sensitivity, compared with non-diabetic controls of similar body composition and abdominal adiposity (1, 2). Progressive deterioration of β-cell function is a well-recognized feature of the disease in adults (3, 4) and is a major challenge in maintaining glycemic control (3). Given the novelty of the disease and the paucity of patients in the pediatric age group, there are limited longitudinal data regarding the natural history of T2DM in youth (5–7). These reports indicate rapid deterioration of β-cell function (6) during the course of treatment (7) compared to what is reported in adult large epidemiologic (3, 4) and cohort studies (8). In youth with recent onset T2DM, residual β-cell function is a significant determinant of glycemic control in small- (1) and large-scale studies such as the treatment options for type 2 diabetes in youth (TODAY) study (9). Glycemic control is an important factor to avert the comorbidities and complications of diabetes (10), which are identified in youth even at the time of diagnosis (11–13). However, data are sparse with respect to the rate of deterioration of β-cell function in youth with T2DM. Thus, we aimed to investigate prospectively the changes in insulin secretion and sensitivity in obese adolescents with T2DM. On the basis of our previous case reports (5, 6), we hypothesized that youth with T2DM will demonstrate accelerated deterioration in β-cell function compared with published data in adults.
Utilising malariometric data in Real Time: a strategy to roll back malaria and sustain local elimination

Current scale up strategies for malaria control are based on massive input of resources as well as expertise from major donors from a variety of sources but long term sustainability is insecure. Objectives are not always based on public health principles, and outcomes are measured on an immediate scale of demographic or logistic estimates rather than epidemiological indices. If the objective is to reduce transmission as well as to reduce mortality and disease in endemic communities, new strategies sustained through local infrastructure and expertise must be developed. There is a need to focus on empowering local infrastructure to collect data from rural areas, process them in real time, analyze for outbreak conditions and mobilize the local health system to intervene strategically in place and time. In Zambia, the rural health service is doing this on a pilot scale. In endemic areas where transmission is less than holoendemic (or stable), transmission is seasonal with peaks during the rainy season and troughs when the weather is cold or hot and dry. During the peak malaria season malaria is widespread, but during the low transmission season malaria can be quite restricted and focal with a high proportion of asymptomatic infections. If a major vector control intervention is implemented, then transmission becomes reduced both during the peak but also during the dry season. This has been show clearly in the Macha district of Zambia where data on malaria case incidence rates has been collected weekly since August 2008. Staff at 14 rural health centres (RHC) report weekly by SMS texting to the research institute at Macha the number of cases diagnosed positive by rapid diagnostic test (RDT) during the previous week. During the low transmission season, it becomes clear just where residual foci occur and what appear to be salient risk factors for low season transmission. It is also clear how and when the case positivity rate spreads after the advent of the rains. Using GIS it is clear where the foci persist and where the parasite reservoir would be vulnerable to attack. These foci were identified by following cases diagnosed in RHC during the low transmission period in 2010 to their homestead, and by examining other residents of the homestead by RDT and PCR for asymptomatic cases. There were significantly more malaria infections detected at these homesteads than in homes selected randomly. We propose to target such foci in real time using RHC staff on bicycle during low transmission and treat all contacts with regular anti malaria treatment without additional diagnosis. This will concentrate the attack in place and time. With preparation, this paradigm can be integrated into the health system, would be locally sustained and in time will eliminate foci and the parasite reservoir and reduce dependence on major donations from other countries and donors whose priorities may change.
Thrombophilia testing patterns amongst patients with acute venous thromboembolism

Abstract Background Thrombophilia testing has limited value in determining the selection and duration of anticoagulation therapy for venous thromboembolism (VTE), yet is commonly performed. This study describes the patterns and appropriateness of thrombophilia testing in a large cohort of patients with acute VTE. Materials and methods This was a retrospective study of a random sample of patients with a validated diagnosis of acute VTE diagnosed between January 1, 2004 and December 31, 2010. Events were identified from administrative data and verified via manual review. Patients were grouped by thrombophilia testing status and compared on patient characteristics and thrombophilia testing results and appropriateness. Results Of 1314 patients with validated VTE, 315 (24%) underwent thrombophilia testing, 62 (20%) of whom had ≥ 1 positive test. Tested patients were younger and more likely to have had a family history of VTE. Factor V Leiden (17%) and prothrombin G20210A mutation (4%) were the most commonly detected thrombophilias. Only 31 (10%) of tested patients met eligibility criteria for thrombophilia testing (i.e., at least one strong thrombophilic risk factor present) and were tested at least 90 days following unprovoked index VTE. Conclusions Thrombophilia is commonly evaluated in patients without a clear indication for testing and during times where results may be unreliable. Future studies are needed to assess interventions aimed at reducing inappropriate thrombophilia testing without adversely affecting patient outcomes.
A novel way for dealing with time-varying harmonic distortions: the concept of evolutionary spectra

The concept of harmonic decomposition can only be applied to steady state, periodic waveform functions. In real life however, voltage and currents are constantly changing with time. The pragmatic way of dealing with time-varying functions is to extend the time window and capture the variations along the time. However, this method can have some significant limitations and loss of physical meaning depending on the time-varying nature of the waveform analyzed. This paper suggests the application of some spectral analysis and probability distribution concepts, in an integrated way, for a better understanding of the nature of time-varying harmonics and possibly as a more precise way to treat time-varying harmonics and validate harmonic summation studies.
Defective Selection of Thymic Regulatory T Cells Accompanies Autoimmunity and Pulmonary Infiltrates in Tcra-Deficient Mice Double Transgenic for Human La/Sjögren’s Syndrome-B and Human La-Specific TCR

A human La/Sjogren's syndrome-B (hLa)-specific TCR/hLa neo-self-Ag double-transgenic (Tg) mouse model was developed and used to investigate cellular tolerance and autoimmunity to the ubiquitous RNA-binding La Ag often targeted in systemic lupus erythematosus and Sjogren's syndrome. Extensive thymic clonal deletion of CD4(+) T cells occurred in H-2(k/k) double-Tg mice presenting high levels of the I-E(k)-restricted hLa T cell epitope. In contrast, deletion was less extensive in H-2(k/b) double-Tg mice presenting lower levels of the epitope, and some surviving thymocytes were positively selected as thymic regulatory T cells (tTreg). These mice remained serologically tolerant to hLa and healthy. H-2(k/b) double-Tg mice deficient of all endogenous Tcra genes, a deficiency known to impair Treg development and function, produced IgG anti-hLa autoantibodies and displayed defective tTreg development. These autoimmune mice had interstitial lung disease characterized by lymphocytic aggregates containing Tg T cells with an activated, effector memory phenotype. Salivary gland infiltrates were notably absent. Thus, expression of nuclear hLa Ag induces thymic clonal deletion and tTreg selection, and lymphocytic infiltration of the lung is a consequence of La-specific CD4(+) T cell autoimmunity.
Spatial patterns, processes and predictions in ecohydrology: integrating technologies to meet the challenge

Spatial organization is the pre-eminent challenge of ecohydrology as a geospatial science. Ecohydrological patterns emerge as a result of interactions of fine-scale processes and functions that are difficult to observe, quantify and predict. As a result, an integrated approach to the study of spatial patterns in ecohydrology requires a more focused engagement of sampling, sensing and computational tools that are presently available to the scientific community. Here, an incremental and iterative process is proposed consisting of field experiments sequenced with distributed ecohydrological modelling aimed at identifying emergent spatial patterns. In this commentary, three case studies are presented that illustrate how the integration of spatial technologies can provide new insights into the ecohydrological patterns of arid and semiarid ecosystems. The search for emergent ecohydrological behaviour arising from cross-scale interactions can also yield improved process understanding, predictive capabilities and relevance to societal needs. Copyright © 2012 John Wiley & Sons, Ltd.
A Test System for Computer Controlled Thermomechanical Fatigue Testing

This paper describes a computer controlled testing system which is capable of performing thermomechanical fatigue tests. Three different tests have been developed: (i) high temperature compression (HTC) tests in which the gauge length of the specimen is held at constant length and the mechanical strain is totally imposed by the triangular temperature cycle, (ii) high temperature tension (HTT) tests in which the mechanically imposed length change is exactly double the thermally induced length change, and (iii) multiple isothermal deformation (MID) tests for which the deformations occur isothermally and the temperature is changed every half cycle while maintaining constant mechanical strain. The need for these tests is shown by comparing the results of isothermal low cycle fatigue tests with results from TMF for several steels (304 Stainless Steel, 316 Stainless Steel, Alloy 800, and Modified 9Cr-1Mo Steel). We show that universal assumptions of TMF behavior are inappropriate and may lead to non-conservative design rules. Computer controlled TMF tests of the types described here are required to establish the response of each alloy considered for application. 8 refs., 9 figs., 1 tab.
Vancomycin Trough Concentration as a Predictor of Clinical Outcomes in Patients with Staphylococcus aureus Bacteremia: A Meta-analysis of Observational Studies

Study objective To determine the strength of evidence for better clinical outcomes in patients with Staphylococcus aureus bacteremia who had vancomycin trough levels of 15-20 mg/L. Design Meta-analysis of 14 observational cohort studies. Patients A total of 1677 patients, representing geriatric and unspecified inpatients, who received standard dosing of vancomycin for the treatment of S. aureus bacteremia and who had trough level goals of 15-20 mg/L. Measurements and main results The treatment variables examined in the analysis were vancomycin trough concentrations and 24-hour area under the concentration-time curve to minimum inhibitory concentration ratio (AUC:MIC) values. The outcomes of interest were mortality, persistent bacteremia, and treatment failure. Mortality was defined as 30-day mortality, in-hospital mortality, or a comparable measure; persistent bacteremia was defined as bacteremia lasting at least 7 days after the initiation of vancomycin; treatment failure was defined as a composite end point that included at least persistent bacteremia and mortality, as previously defined. Higher vancomycin trough levels (15 mg/L or greater or based on MIC) were not associated with significantly reduced treatment failure, persistent bacteremia, or mortality. Higher AUC:MIC values were associated with significantly reduced treatment failure (odds ratio [OR] 0.41, 95% confidence interval [CI] 0.31-0.53), persistent bacteremia (OR 0.53, 95% CI 0.33-0.86), and mortality (OR 0.47, 95% CI 0.33-0.65). The weighted mean ± SD AUC:MIC threshold defined by regression analyses in the included studies was 418 ± 88 hours, which supports the current goal of 400 hours or more. Conclusion Vancomycin trough concentrations do not have sufficient evidence to support their use as the primary guide in vancomycin dosing. Dosing should instead focus on AUC:MIC values, which have strong evidence of benefit.
Observation of a rigid body from measurement of a principal axis

A method for observing the attitude of a freely rotating spacecraft by measuring one of its principal axes is given. A method of determining the angular velocity from the trajectory of one of its coordinates is also given. >
The Staining of the Metachromatic Granules in Corynebacterium Diphtheriae

The metachromatic granules, which sometimes are regarded as characteristic of the diphtherial species, are more easily differentiated when the basic dye is made up in a solution of which the reaction is quite acid. Of the usual stains employed for demonstrating the granules, the Neisser stain proves to give the best results.
CBX8, a component of the Polycomb PRC1 complex, modulates DOT1L-mediated gene expression through AF9/MLLT3.

AF9 is known to interact with multiple proteins including activators and repressors of transcription. Our data indicate that other AF9 binding proteins compete with the histone methyltransferase DOT1L for AF9 binding thus diminishing its ability to methylate lysine 79 of histone 3. Specifically, we show that AF9 is part of a protein multimer containing members of Polycomb group (PcG) PRC1 complex, CBX8, RING1B, and BMI1. Interaction with CBX8 precludes AF9–DOT1L binding. Knockdown of CBX8 with short-hairpin RNA (shRNA) leads to decreased expression of the AF9 target gene ENaCα. In contrast, CBX8 overexpression results in increased ENaCα mRNA levels and this effect can be partially overcome by co-overexpression of AF9.
Accuracy of Self-Reported Physical Activity as an Indicator of Cardiovascular Fitness Depends on Education Level

Abstract Gerrard P. Accuracy of self-reported physical activity as an indicator of cardiovascular fitness depends on education level. Objective To determine whether there is a relationship between the level of education and the accuracy of self-reported physical activity as a proxy measure of aerobic fitness. Design Data from the National Health and Nutrition Examination from the years 1999 to 2004 were used. Linear regression was performed for measured maximum oxygen consumption (Vo 2 max) versus self-reported physical activity for 5 different levels of education. Setting This was a national survey in the United States. Participants Participants included adults from the general U.S. population (N=3290). Interventions None. Main Outcome Measure Coefficients of determination obtained from models for each education level were used to compare how well self-reported physical activity represents cardiovascular fitness. These coefficients were the main outcome measure. Results Coefficients of determination for Vo 2 max versus reported physical activity increased as the level of education increased. Conclusions In this preliminary study, self-reported physical activity is a better proxy measure for aerobic fitness in highly educated individuals than in poorly educated individuals.
Postnatal tolerance to NO2 toxicity

Abstract Nursing neonatal rats (10 days old) are remarkably resistant to the cytotoxic effects of nitrogen dioxide (NO 2 ). They survive well when exposed continuousty to 50 ppm, exhibiting only minor injury of the proximal alveolar Type 1 cells. Moderate injury and loss of ciliated cells and moderate accumulation of alveolar edema are observed in the distal airways; however, both are well within tolerable levels. By comparison, maturing 60-day-old animals exposed to the same level of NO 2 have difficulty surviving for more than 8 hr. Extensive epithelial cell injury and loss occur both in the distal airways and in the proximal alveolar regions. Death results from massive alveolar edema. When exposure of 60-day-olds is reduced to 25 ppm, the animals are able to survive; however, evidence of injury and repair is still much greater than that in the neonate exposed to 50 ppm.
Impact of esophageal acid exposure on the endoscopic reversal of Barrett’s esophagus

Abstract OBJECTIVE: Normalization of esophageal acid exposure had been assumed to be necessary for the reversal of Barrett’s esophagus with endoscopic therapy. This assumption is examined by evaluating the esophageal pH in a group of patients undergoing reversal therapy with fixed high-dose proton pump inhibitor therapy and endoscopic multipolar electrocoagulation (MPEC). METHODS: Patients with Barrett’s esophagus of 2–6 cm in length were treated with omeprazole (40 mg b.i.d. ). They underwent 24-h esophageal pH monitoring 5 cm above the upper margin of the lower esophageal sphincter determined by a water-perfused catheter. They then underwent MPEC therapy to an endpoint of elimination of Barrett’s (reversal) by both endoscopy and biopsy 6 months after the last MPEC session or failure to achieve visual (endoscopic) reversal after six treatment sessions. RESULTS: Twenty patients had 24-h pH testing and reached a reversal endpoint. Three patients had abnormal pH tests, two total and supine and one supine only. These patients had documented reversal. The remaining 17 patients had normal pH testing but five failed reversal therapy. CONCLUSION: Barrett’s esophagus can be completely reversed with endoscopic therapy despite abnormal esophageal acid exposure. Also, patients can fail reversal even with normal esophageal acid exposure. The necessary reduction of esophageal acid exposure for reversal therapy has yet to be defined.
Three dimensional x-projection method (with acceleration techniques) for solving systems of linear equations

Abstract The solution of linear systems of equations using a 3-dimensional x -projection method is presented. At each step of the iterative process the approximate solution vector is projected to a point in the intersection of three of the hyperplanes of the linear system. Nonsingularity of the coefficient matrix is the only requirement for convergence. An algorithm is presented to select triples of hyperplanes to project the approximate solution vector at each step. The algorithm is quasi-optimal since the hyperplanes, which are determined by the row vectors of the coefficient matrix, are selected a priori . This is shown to significantly reduce the number of cycles required for convergence. We observe that in some cases the ratio of the change vectors of the approximate solution vectors after some number of cycles becomes a constant. Thus, when this occurs a simple geometric acceleration can be applied to calculate the solution directly. Geometric acceleration can significantly reduce computation time and improve the accuracy of the solution by orders of magnitude. The 3-dimensional x -projection method was tested against the 2-dimensional x -projection method using random and Hilbert coefficient matrices and proved superior (less C.P.U. time required) in nearly every case.
Evaluating problem solving based on the use of history findings in a standardized-Patient examination

PURPOSE To evaluate a novel item format for assessing clinical problem solving in a standardized-patient examination (SPE). METHOD In 1992-93 a key-findings item format was included in two versions of three stations in an SPE (given in the style of an objective structured clinical examination) that was taken by 198 third-year students at the end of their three-month internal medicine clerkship at the University of Texas Medical Branch at Galveston. Each of the stations involved an extended matching question that listed ten to 12 findings. The students were told to select as many or as few findings as they wished that were key in leading them to their diagnosis of the standardized patient's (SP's) problem. The findings fell into three categories: (1) key to the diagnosis, (2) provided by the SP but not key to the diagnosis, and (3) not provided by the SP. RESULTS A total of 169 students (85%) identified at least one of the findings determined to be key in each of the stations. Correctly identifying key findings was related to correctly diagnosing the SP's problem. A total of 145 students (73%) indicated at least one finding across the three cases as key to their diagnosis but not given by the SP. Selecting nonexistent findings as key to diagnosis was not found to be related to performance on the SPE. It was hypothesized that once a diagnosis was made, the students had difficulty differentiating key findings that had led them to the diagnosis from other key features of their cognitive model of illness. CONCLUSION The students were generally able to obtain and recognize at least some of the key information they needed to formulate appropriate differential diagnoses, and the ability to identify key findings was shown to be related to identifying the most appropriate diagnosis. The key-findings item format has potential both in assessment and for gaining a better understanding of the clinical problem-solving process.
Microemulsion liquid membranes. I: Cobalt transport in a surfactant-dodecane system

Abstract Cobalt transport across supported microemulsion liquid membranes containing reversed micelles of dinonylnaphthalenesulfonic acid (HDNNS) was measured as a function of organic phase composition, aqueous phase composition, stirring rate and temperature. A microporous polypropylene film served as the membrane support. The membrane phase was characterized by interfacial tension and viscosity measurements. Stirring speed and temperature effects suggest that diffusion processes play a major role in the transfer of cobalt across the membrane. The experimental results at relatively low carrier concentration are explained by a membrane transport model involving counter-diffusion of HDNNS reversed micelles and metal-reversed micelle complexes.
The fine structure of myocytes in the sponges microciona prolifera (Ellis and Solander) and tedania ignis (Duchassaing and Michelotti).

Myocytes are long, fusiform cells found in the osculum and other contractile areas of many sponges. Myocytes in the oscular sphincter of Tedania ignis and the osculum and dermal membrane of Microciona prolifera were studied with light- and electron-microscopes to compare their structure to that of muscles. Salient points of similarity between myocytes and smooth muscles were their long, fusiform shape, their red color after staining with Mallory's triple stain, and the presence of filaments running longitudinally in the cytoplasm. Microciona myocytes have thick filaments of 150–250 A diameter and thin filament of 50–70 A diameter, and in transverse sections the thin filaments occasionally appear as a ring of dots around a thick filament. Longitudinal sections of Tedania myocytes show only one type of filament, which varies from 100 A to 200–300 A diameter in thick regions of the filament. Although transverse sections show light material around the dense filaments, a distinct pattern of thick and thin filaments is not seen in Tedania. Due to infrequent contacts between cells, the large extra-cellular space observed with the electron microscope (49% in Tedania, 57% in Microciona), and the absence of nerves, each myocyte probably acts as an independent contractile unit.
New year's eve party?

Abstract Sometimes companies attempt to inflate reported earnings and assets by recording dubious transactions near the end of the fiscal year. Auditors often refer to such transactions as “New Year's Eve Parties”. This case study is based on reports in the business press about what appears to be a classic “New Year's Eve Party”. At the end of 1993 Bausch & Lomb (B&L) recorded some very questionable sales, which in essence involved B&L forcing distributors to take large shipments of inventory. The case, which is designed for use in auditing courses, requires students to consider indications of risks and to evaluate several accounting and auditing questions from the perspectives of an audit manager, a partner in charge, a controller, and a member of a quality review team.
Retinoic Acid Selectively Stimulates Growth Hormone Secretion and Messenger Ribonucleic Acid Levels in Rat Pituitary Cells

Hydrocortisone (HCT) is known to stimulate rat GH gene expression. As the retinoic acid receptor cDNA bears a 15% homology to the hydrocortisone receptor cDNA, the effects of retinoic acid were tested in GH3 rat pituitary cells. Retinoic acid selectively stimulated GH secretion after 24 h. Maximal induction of basal GH secretion (220% of controls) was achieved with 1 microM retinoic acid after 72 h. HCT (50 nM) alone stimulated GH secretion 3.5-fold during 72-h incubation, and retinoic acid (1 microM) with HCT caused a further 7-fold increase in GH secretion. The stimulating effects of retinoic acid on GH were observed when cells were incubated in defined serum-free medium, 4% fetal calf serum, or Dulbecco's Modified Eagle's Medium containing HCT. Northern gel hybridization showed that steady state levels of GH mRNA transcripts in these cells were also selectively induced by retinoic acid. PRL secretion and mRNA levels, however, were not appreciably altered by retinoic acid. The results show that retinoic acid selectively stimulates basal and HCT-induced GH secretion and mRNA levels in these cells in a dose- and time-dependent manner. This selective action of retinoic acid appears to occur independently of the presence of serum in the culture medium.
Optimization of the Storage Process for a Cool Thermal Storage System

The storage process for a static-water ice-on-coil cool thermal storage system is difficult to model analytically, based on the dynamic behavior of ice production. Systems that utilize a vapor-compression cycle, with the tank acting as an evaporator, further complicate an analytical model due to the two-phase heat transfer throughout the storage tank. This analysis presents a simplified model of the storage process for a static-water ice-on-coil storage tank acting as an evaporator in a vapor-compression cycle. Specifically, the storage process is optimized by minimizing the amount of compressor work required to freeze water at 0°C. Optimization variables are refrigerant evaporating temperatures and tank heat exchanger sizing. The dynamics of ice production and two-phase heat transfer are simplified by assuming the overall heat transfer coefficient remains constrant throughout the storage process. An average value for the overall heat transfer coefficient may be substituted and still provide useful results. A second law analysis utilizing the irreversebility developed during cool storage is also presented. The model is then used in side-by-side comparisons of compressor work, tank heat exchanger efficiency, and irreversibility, as functions of evaporating temperature, for several heat exchanger sizes.
Influence of Sand in Redds on Survival and Emergence of Brook Trout (Salvelinus fontinalis)

Abstract Alevins of brook trout (Salvelinus fontinalis) were buried in laboratory troughs in spawning gravel containing 0 to 25% sand. Sand slowed emergence and reduced the number of fry emerging. Weight of fry was not related to proportion of sand in the gravel, but was related to time; the fry were heaviest near the time of peak emergence, and lighter before and after the peak. Survival was estimated to be 84% from egg deposition to hatching for brook trout in Lawrence Creek, Wisconsin, and 70% from hatching to emergence, providing a total estimate for survival from egg deposition to emergence of 59%.
Raman spectroelectrochemistry of a single-wall carbon nanotube bundle

Abstract Raman microscopy and spectroelectrochemistry with polymer electrolyte gating is developed to study the effect of charging on Raman spectra of individual single-wall carbon nanotubes (SWCNTs) and bundles. The Raman spectra of a small bundle, consisting of well-separated features from a metallic and a semiconducting SWCNT, have been obtained at different electrochemical charging levels. The broad Fano peak of the metallic SWCNT exhibits an appreciable frequency upshift and simultaneous line narrowing when the charging level, either positive or negative, is increased, in agreement with the presence of a Kohn anomaly in metallic SWCNTs. The radial breathing mode of the metallic tube also shows a similar but much weaker dependence on the charging potential. While the G mode frequencies of the semiconducting SWCNT also increase with the increasing charging level, the magnitude of such change is much smaller than in the metallic SWCNT. At high negative charging potentials the G− peak of the semiconducting SWCNT exhibits a larger upshift than its G+ peak, leading to the observation of merging of these two peaks. However, both G+ and G− peaks of the semiconducting SWCNT become broader at high charging levels, which are not predicted from previous theoretical studies.
Step-Mother's Model of Identification in Relation to Mourning in the Child

Three models of identification are proposed for the step-mother which might clarify and consequently ease her interactions with her step-children. These are: (1) “primary” mother, (2) “other” mother, and (3) “friend.” Selection among these could be made on the basis of the child's mourning of his biological mother. If the child's mourning is incomplete and his mother is still psychologically alive to him, then the role of “friend,” model (3), seems to have advantages. But if the child's mourning of his biological mother is complete, i.e., she is psychologically dead for him, then the step-mother's adopting model (1), “primary” mother, seems to fit the needs of the situation. Model (2), “other” mother, does not appear to have advantages over other models under any circumstances considered.
Cytoplasmic structure and contractility: the solation-contraction coupling hypothesis

We have briefly described our studies of cytoskeletal and contractile elements in intact cells, in cell extracts, and in mixtures of purified proteins. Changes in the concentration of calcium and of protons have been found to modulate both gelation and contraction in all of these preparations. The distribution of calcium, protons and actin has been studied in intact amoeboid cells. Using these results, we have refined our working model of the relation of cytoskeletal and contractile proteins: the solation-contraction coupling hypothesis. The model is also supported by quantitative analysis of the rates of contraction in a soluble extract of Dictyostelium discoideum amoebae allowed to gel in a capillary and stimulated by the addition of calcium ions at one end. A plausible interpretation of the most prominent cytological features of amoeboid locomotion is obtained by application of the principles of our model. In addition, we propose that the solation-contraction coupling hypothesis may be useful in further study of a variety of motile phenomena observed in many types of cells.
The recovery from anaerobic metabolism in invertebrates

The duration and completeness of recovery from anaerobic metabolism is of important functional consequence in invertebrates. Two basic processes occur during recovery: (1) recharging of the phosphagen and ATP pools and (2) disposal of end products by excretion, oxidation, or conversion back to anaerobic substrates. The recovery process in invertebrates is largely aerobic, as is evidenced by the near universality of the oxygen debt phenomenon. However, there is often a lack of correlation between end product accumulation and the magnitude of the oxygen debt. Typically, ATP and phosphagen levels are recharged very rapidly during recovery–ATP (0.25 to 1.0 hr) and phosphagens (0.5 to 4 hr). Excretion of propionate, acetate, and, occasionally succinate, is relatively common in annelids and has also been observed in a number of bivalve molluscs. Nitrogen-containing end products do not appear to be excreted. Cephalopods and large arthropods show elevated hemolymph end product levels following anoxia/hypoxia. In arthropods, these end products display a protracted return to control levels during recovery. In cephalopods, some octopine may be rapidly taken up and metabolized by the heart, brain, and gill. The sites of lactate metabolism in arthropods are unclear. In contrast to the situation in cephalopods and arthropods, most end products in the adductor muscles of bivalve molluscs do not appear to be exported, but are metabolized within the tissue itself. End ducts such as octopine, succinate, and alanine thus appear to be metabolized at the site of their production. Octopine and lactate appear to be gluconeogenic substrates in cephalopods and arthropods, respectively. Although many of the enzymes involved in gluconeogenesis are present in bivalve molluscs, this process has not been demonstrated in this group. Recovery from anaerobic metabolism remains a fruitful area for future research. Of special interest is the identification of sites of gluconeogenesis in the larger, more active species.
Electronic interactions between iron and the bound semiquinones in bacterial photosynthesis. EPR spectroscopy of oriented cells of Rhodopseudomonas viridis

Abstract Electron paramagnetic resonance (EPR) spectroscopy of the iron-semiquinone complex in photosynthetic bacterial cells and chromatophores of Rhodopseudomonas viridis is reported. Magnetic fields are used to orient the prolate ellipsoidal-shaped cells which possess a highly ordered internal structure, consisting of concentric, nearly cylindrical membranes. The field-oriented suspension of cells exhibits a highly dichroic EPR signal for the iron-semiquinone complex, showing that the iron possesses a low-symmetry ligand field and exists in a preferred orientation within the native reaction-center membrane complex. The EPR spectrum is analyzed utilizing a spin hamiltonian formalism to extract physical information describing the electronic structure of the iron and the nature of its interaction with the semiquinones. Exact numerical solutions and analytical expressions for the transition frequencies and intensities derived from a perturbation theory expansion are presented, and a computer-simulated spectrum is given. It has been found that, for a model which assumes no preferred orientation within the plane of the membranes, the orientation of the Fe2+ ligand axis of largest zero-field splitting (Z, the principal magnetic axis) is titled 64±6° from the membrane normal. The ligand field for Fe2+ has low symmetry, with zero-field splitting parameters of |D1|=7.0±1.3 cm−1 and |E1|=1.7±0.5 cm−1 and | E 1 D 1 |=0.26 for the redox state Q1−Fe2+Q2−. The rhombic character of the ligand field is increased in the redox state Q1Fe2+Q−2, where 0.33>| E 2 D 2 |>0.26 . This indicates that the redox state of the quinones can influence the ligand field symmetry and splitting of the Fe2+. There exists an electron-spin exchange interaction between Fe2+ and Q−1 and Q−2, having magnitudes |J1|=0.12±0.03 cm−1 and |J 2 |⋍0.06 cm −1 , respectively. Such weak interactions indicate that a proper electronic picture of the complex is as a pair of immobilized semiquinone radicals having very little orbital overlap (probably fostered by superexchange) with the Fe2+ orbitals. The exchange interaction is analyzed by comparison with model systems of paramagnetic metals and free radicals to indicate an absence of direct coordination between Fe2+ and Q−1 and Q−2. Selective line-broadening of some of the EPR transitions, involving Q− coupling to the magnetic sublevels of the Fe2+ ground state, is interpreted as arising from an electron-electron dipolar interaction. Analysis of this line-broadening indicates a distance of 6.2–7.8 Ȧ between Fe2+ and Q−1, thus placing Q1 outside the immediate coordination shell of Fe2+.
Is NHEJ a tumor suppressor or an aging suppressor

Tumor suppressors are longevity assurance genes that ensure early life fitness. Genes are defined as tumor suppressors if their mutation predisposes the animal to cancer (a phenotype-based definition). Tumor suppressors fall into two categories: caretakers and gatekeepers. Caretakers suppress cancer by repairing damaged DNA while gatekeepers suppress cancer by halting the cell cycle long enough to repair damaged DNA. If the damage is irreparable, gatekeepers induce either apoptosis or senescence. These responses are deleterious to the cell but protect the organism. p53 is the best-known gatekeeper because it is mutated in over half of all cancers. Nonhomologous end joining (NHEJ) is considered a caretaker since it repairs DNA double-strand breaks that would otherwise lead to gross chromosomal rearrangements (GCRs). NHEJ-mutant mice display increased GCRs, but without increased cancer. Instead these mice show early aging. This commentary focuses on the role NHEJ has on aging and cancer. I propose that NHEJ evolved to reduce GCRs and moderate gatekeeper responses that would otherwise cause early aging. Furthermore, NHEJ did not evolve to suppress tumors and any observed tumor suppression is merely circumstantial to unnatural laboratory conditions coupled with human bias that favors defining all DNA repair pathways as caretakers.
Becoming Savage: Western Representations and Cultural Identity in a Sepik Society

This paper examines the impact of European representations on identity in a Papua New Guinean village. Local leaders reinforce their authority by echoing a colonial rhetoric portraying Melanesians as "ignoble savages." On other occasions the same leaders praise local society as orderly, showing that they do not entirely subscribe to European views. But villagers have internalized the European view that Melanesians are violent, an assumption that helps to keep villagers poor and powerless. Language: en
Half channels mediating H(+) transport and the mechanism of gating in the Fo sector of Escherichia coli F1Fo ATP synthase.

H(+)-transporting F1Fo ATP synthase catalyzes the synthesis of ATP via coupled rotary motors within Fo and F1. H(+) transport at the subunit a-c interface in trans-membranous Fo drives rotation of the c-ring within the membrane, with subunit c being bound in a complex with the γ and e subunits extending from the membrane. Finally, the rotation of subunit γ within the α3β3 sector of F1 mechanically drives ATP synthesis within the catalytic sites. In this review, we propose and provide evidence supporting the route of proton transfer via half channels from one side of the membrane to the other, and the mechanism of gating H(+) binding to and release from Asp61 of subunit c, via conformational movements of Arg210 in subunit a. We propose that protons are gated from the inside of a four-helix bundle at the periplasmic side of subunit a to drive protonation of cAsp61, and that this gating movement is facilitated by the swiveling of trans-membrane helices (TMHs) 4 and 5 at the site of interaction with cAsp61 on the periphery of the c-ring. Proton release to the cytoplasmic half channel is facilitated by the movement of aArg210 as a consequence of this proposed helical swiveling. Finally, release from the cytoplasmic half channel is mediated by residues in a complex of interacting extra-membraneous loops formed between TMHs of both subunits a and c. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference.
Deoxyribonucleic acid of mung bean embryonic axes

Abstract A technique is developed for the isolation of highly polymerized DNA from mung bean embryonic axes. The isolated DNA has a buoyant density of 1.694 g/cm 3 , suggesting that it is a nuclear DNA. Using DNA-RNA hybridization technique, about 1 % of the total DNA is found to be hybridizable with ribosomal [ 3 H]RNA. Analysis of DNA fractions from CsCl gradient and DNA-rRNA hybridization reveals a slight separation of rDNA from the main DNA.
Endothelial cell lumen and vascular guidance tunnel formation requires MT1-MMP–dependent proteolysis in 3-dimensional collagen matrices

Here we show that endothelial cells (EC) require matrix type 1-metalloproteinase (MT1-MMP) for the formation of lumens and tube networks in 3-dimensional (3D) collagen matrices. A fundamental consequence of EC lumen formation is the generation of vascular guidance tunnels within collagen matrices through an MT1-MMP-dependent proteolytic process. Vascular guidance tunnels represent a conduit for EC motility within these spaces (a newly remodeled 2D matrix surface) to both assemble and remodel tube structures. Interestingly, it appears that twice as many tunnel spaces are created than are occupied by tube networks after several days of culture. After tunnel formation, these spaces represent a 2D migratory surface within 3D collagen matrices allowing for EC migration in an MMP-independent fashion. Blockade of EC lumenogenesis using inhibitors that interfere with the process (eg, integrin, MMP, PKC, Src) completely abrogates the formation of vascular guidance tunnels. Thus, the MT1-MMP-dependent proteolytic process that creates tunnel spaces is directly and functionally coupled to the signaling mechanisms required for EC lumen and tube network formation. In summary, a fundamental and previously unrecognized purpose of EC tube morphogenesis is to create networks of matrix conduits that are necessary for EC migration and tube remodeling events critical to blood vessel assembly.
Organogenesis of the endocrine pancreas

Organogenesis of the endocrine pancreas. Embryonic pancreatic primordia transplanted into diabetic animal hosts undergo selective endocrine differentiation in situ and normalize glucose tolerance. Pancreatic primordia can be transplanted across isogeneic, allogeneic, and both concordant (rat to mouse) and highly disparate (pig to rodent) xenogeneic barriers. This review explores the therapeutic potential for pancreatic organogenesis posttransplantation of embryonic primordia.
Validating the Efficacy-Based Change Model

Abstract The purpose of this paper was to empirically validate the Efficacy-Based Change Model as a theoretical model of change. The model suggests that as participants are involved in an innovation, they move through stages of implementation, in the process expressing different concerns that are related to the efficacy process and are further influenced by ascribed attributions. Data analysis strongly supported the role of self-efficacy as it related to expressed concerns (those with higher efficacy expressed concerns associated with later stages). High efficacy was predicted by success attributions for effort; regression analysis for outcome expectation and value also yielded significant models.