cssi/SciSciGPT-SciSciNet huggingface dataset:
An Urban Project in Rural Crisis: Responding to Coronavirus in Bulgarian Villages

The unprecedented situation of COVID-19 has created a unique response from village-based projects in rural Bulgaria. My research from 2019-2020 followed three projects that facilitate urban-rural intergenerational connection as a form of rural reinvestment. With project planning uncertain and interactions between generations discouraged due to the pandemic, my research, and the cultural work I am following, took an unexpected turn. Rather than fulfilling their core missions of connecting young and old, rural and urban people together to pass on rural culture, these projects transformed their rhetoric and practices to support the elderly in a time of crisis. By drawing on my experiences in the field throughout Bulgaria’s early onset of pandemic and lockdown measures as well as “virtual ethnography” (being in the virtual spaces where communication and online events are happening), I explore how two of the intergenerational projects aimed at heritage-based rural reinvestment in Bulgaria have adapted and organized to fill different needs in a time of crisis. During the coronavirus pandemic, these projects served as a well-poised mechanism for responding quickly to shifting needs and contexts.
Belt Slip Measurements on Human Volunteers and the Part 572 Dummy in Low -G x Impact Acceleration

A series of volunteer and dummy impact experiments was performed on a Hyge-type (accelerator) sled to study the relative motion between the upper torso restraint and the torso surface. Kinematic measurements were made using a three-dimensional photogrammetric analysis of high-speed film data. Belt slip was found to be in the range of approximately 10 to 30 mm with more slip experienced by volunteers than the dummy. The dummy showed a slight change in amount of slip with acceleration level and all slip takes place within the first 80 ms of belt loading. For the covering abstract of the conference see HS-036 716. (Author/TRRL)
Principles and philosophy of modeling in biomedical research

Despite widespread applications in biomedical research, the role of models and modeling is often controversial and ill understood. It is usual to find that fundamental definitions, axioms, and postulates used in the modeling process have become tacit assumptions. What is essential, however, is a clear vision of the fundamental principles of modeling. This is even more compelling for new and emerging interdisciplinary fields that use techniques from previously separate scientific disciplines. This article outlines and reviews the central nature and philosophy of modeling, the rules that govern it, and its underlying key integral relationship to the ‘scientific method’. A comprehensive understanding of these issues is indispensable to successful research and meaningful progress in all facets of biomedicine.—Massoud, T. F., Hademenos, G. J., Young, W. L., Gao, E., Pile-Spellman, J., Vinuela, F. Principles and philosophy of modeling in biomedical research. FASEB J. 12, 275–285 (1998)
Production of 5-(chloromethyl)furan-2-carbonyl chloride and furan-2,5-dicarbonyl chloride from biomass-derived 5-(chloromethyl)furfural (CMF)

Acid chloride derivatives of 5-(chloromethyl)furan-2-carboxylic acid and furan-2,5-dicarboxylic acid (FDCA) can be produced in high yield by treatment of the precursor aldehydes 5-(chloromethyl) furfural (CMF) and 2,5-diformylfuran (DFF) with tert-butyl hypochlorite, which is inexpensively prepared from commercial bleach and tert-butanol. 5-(Chloromethyl)furan-2-carbonyl chloride (CMFCC) and furan-2,5-dicarbonyl chloride (FDCC) are highly useful intermediates for the production of furoate ester biofuels and polymers of FDCA.
Complex regulation of heat shock- and glucose-responsive genes in human cells.

The authors isolated a human genomic clone that encodes the glucose-responsive protein GRP78 and have used this cloned gene probe, together with a cloned HSP70 gene, to study the expression of both stress-induced genes in response to inhibitors of cellular metabolism. On the basis of the effects of this group of chemicals on GRP78 and HSP70 expression, the authors identified three classes of stress gene inducers. The first class induces GRP78 expression and includes inhibitors of glycoprotein processing. The second class results in coordinate activation of both GRP78 and HSP70 synthesis and includes amino acid analogs and heavy metals. Chemicals in the third class coordinately induce GRP78 and repress HSP70 expression; this class includes the calcium ionophore A23187 and the glucose analog 2-deoxyglucose. Whereas induction of GRP78 or HSP70 expression is primarily due to transcriptional activation, chemicals that repress HSP70 expression act through posttranscriptional regulation. These results reveal that the regulation of GRP78 and HSP70 expression is complex and may be dependent on the specificity and magnitude of physiological damage.
Low-Cost Rapid TLE Updating Method For Nano-Satellites Using Doppler Signature

The goal of this research is to provide a simple solution that enables mission operators to have the ability to accomplish self satellite tracking and orbit determination by correcting the satellite states with their own ground station, especially during the early stages of the mission after the first Two-Line Element set is released from the launch provider. The algorithm was tested under various modeling error conditions at the USC ground station using a spectrum analyzer and a self-developed data acquisition method.
ATV use, safety practices, and injuries among Indiana's youth

Abstract Limited data exist on ATV-related injuries and the associated behavioral practices of youths who operate ATVs. A questionnaire was administered to 2,098 Indiana youths to gather baseline data on the ATV operational and safety practices that would provide guidance in the development of a youth ATV safety program. Over two-thirds of the respondents had operated an ATV and nearly 80% had been either an operator or a passenger. The most frequently cited source of safety training was a “friend”. Helmets were the most commonly used personal protective safety equipment being used by 40% of youths who operated ATVs. Over 7% of youths indicated that they had suffered an ATV injury requiring medical treatment in the last year.
Auditory Thresholds in the Rat Measured by an Operant Technique

An adaptation of the Ratliff and Blough technique has been developed for auditory measurement in rats. Thresholds for a 2000-cy/sec tone were determined over a period of weeks. Kanamycin, an ototoxic agent, was then administered, and the gradual rise in threshold was followed.
Hot-working of graphite for graphite-matrix nuclear fuels

Abstract Hot-working reduces the porosity of artificial graphites. The possibility of using hot-working in the fabrication of graphite-matrix fuel bodies for nuclear application was investigated by compressing specimens of fuel-matrix graphite, both with and without a dispersion of ZrC particles, in the temperature range 2350–2950°C. Studies were made of the effects of changing the temperature and strain of hot-working, and the pitch content and method of fabrication of the starting material, on the deformation during hot-working and the properties of the hot-worked material. The activation energy for flow during hot-working was about 200 kcal/mole for matrix graphite either with or without ZrC particles present, but the deformation rates at a given temperature and strain were much higher with the carbide particles present. The most striking results of hot-working were the production of a strong preferred orientation and an increase in density in all the samples. Except in the case of bodies containing ZrC particles, hot-working also sharply reduced the permeability of the samples, especially when the initial pitch content was high. The favorable properties of hot-worked graphite of high initial pitch content and its behavior during hot-working make this material the most promising candidate for the further development of hot-worked nuclear fuel-matrix graphite.
Induction of thymidine−3h incorporation in multinucleated myotubes by rous sarcoma virus

During the differentiation of skeletal muscle, mononucleated myoblasts fuse to form multinucleated myotubes. After fusion, both DNA synthesis and nuclear division cease. When clones of chick embryonic leg muscle consisting of both myoblasts and myotubes are infected with Rous sarcoma virus, DNA synthesis (as measured by thymidine-3H incorporation) is induced in the nuclei of myotubes within 24 hours. On the other hand, nuclear division is not reactivated. These findings indicate that the restriction of DNA synthesis which attends the formation of myotubes is not irreversible since RSV, an RNA virus, reactivates DNA synthesis in mature myotubes. Induction, Par le Virus du Sarcome de Rous, de L'incorporation de Thymidine Tritiee dans la Fibre Musculaire Striee Pendant la differentiation des muscles du squelette, les myoblastes mononuclees fusionnent pour donner des fibres musculaires multinucleees. Apres la fusion, la synthese d'ADN et la division du noyau cessent. Si l'on infecte, avec le virus du sarcome de Rous, des clones musculaires de la patte d'embryon de poulet composes a la fois de myeloblastes et de fibres musculaires, la synthese de l'ADN (mesuree par incorporation de thymidine tritiee) est provoquee dans les noyaux des fibres dans les 24 heures. Par contre, la division nucleaire n'est pas reactivee. Ces observations montrent que l'arrět de la synthese d'ADN qui accompagne la formation des fibres n'est pas irreversible puisque le virus du sarcome de Rous (qui appartient au groupe des virus a ARN) reactive cette synthese dans les fibres arrivees a maturite.
Intolerance, Forgiveness, and Promise in the Rhetoric of Conversion: Italian Women Defy the Mafia.

The fight against the Mafia in Italy took a new turn in the past decade as former Mafia women turned state's evidence, uncovering invaluable information about the Mafia. As they tell their stories of conversion, from women of the Mafia to citizens who believe in civil justice, the women use the topoi of intolerance, forgiveness and promise to describe their process of conversion, to translate private experiences into public testimonies, and to persuade others to follow in their footsteps. Their stories provide inspiration for other anti‐Mafia groups and legitimize the Italian government's fight against the Mafia.
Alveolar ridge changes in patients congenitally missing mandibular second premolars

This study investigated changes in ridge width over time in patients who were congenitally missing mandibular second premolars. Data were obtained from stone casts and radiographs of 35 edentulous sites on 22 patients representing three time periods: (1) before extraction of the primary mandibular second molar, (2) completion of orthodontic treatment, and (3) long-term evaluation. The findings indicate that ridge width decreases 25% within 3 years after primary molar extraction. The rate of decrease diminishes to 4% over the next 3 years. The change in ridge width had a weak association with the age of the patient at the time of the extraction but a small predictive value. No correlation was found between changes in ridge width and height and the time since the extraction or the age of the patient at the time of extraction.
Determination of the single interstitial migration energy from stored energy and thermal resistivity changes in irradiated graphite

Abstract The model used to evaluate the single interstitial migration energy from property changes due to interstitials is extended to account for vacancy contributions. The annealing function obtained can be used to determine the relative contributions of the defects and is sufficiently sensitive to distinguish vacancy effects that are an order of magnitude less than interstitial effects. Application of the model to stored energy and thermal resistivity data yields the same values of the activation energy and temperature independent term obtained from c -axis and macroscopic length expansion rates. The results indicate that the stored energy associated with the di-interstitial is at least ten times greater than the stored energy associated with the vacancy. The minor role of vacancies in phonon scattering is discussed. The annealing function obtained from electrical resistivity changes in irradiated graphite is explained by assuming that the ratio of charge-carriers to scattering centers varies with irradiation temperature below 55°C. Above this temperature the changes are attributed to equal contributions from vacancies and interstitials.
Sensitivity to alcohol in mice with an altered brain fatty acid composition

Abstract Ethanol-induced sleep onset times, sleep times and blood alcohol levels upon awakening were measured in mice fed an essential fatty acid deficient, Purina Chow or unsaturated fat diet for nine months. These values in animals fed the essential fatty acid deficient and Purina Chow diets did not differ, but mice fed the unsaturated fat diet had longer sleep times and lower blood alcohol levels upon awakening than mice fed essential fatty acid deficient or Purina Chow diets. Crude brain mitochondrial fractions isolated from mice fed the essential fatty acid deficient diet had decreased levels of docosahexaenoic [22:6(n-3)] and increased levels of eicosatrienoic [20:3(n-9)], docosatrienoic [22:3(n-9)] and docosapentaenoic [22:5(n-6)] acids compared to mice fed the Purina Chow diet. The unsaturated fat diet decreased 22:6(n-3) and increased 22:5(n-6) compared to the Purina Chow dietary regimen. The longer sleep times and lower blood alcohol levels found in mice fed the unsaturated fat diet probably resulted from an artifact due to the obesity of the mice fed this diet and from the hinderance of obesity to the righting reflex (our measure of ethanol potency). We conclude that the alteration of several polyunsaturated fatty acid components in the brain has little or no influence on the sensitivity of the nervous system to alcohol.
Differences between the lowest-order mode and quasi-TEM mode in ferrite-filled coaxial line

The propagation constant and the general conditions for the existence of a quasi-TEM mode in ferrite-filled coaxial line are re-examined in view of recent results.
Combination therapy with zidovudine and dideoxycytidine in patients with advanced human immunodeficiency virus infection. A phase I/II study.

OBJECTIVE To evaluate the safety and immunologic and antiviral effects of combination therapy with zidovudine and dideoxycytidine (ddC) in patients with advanced human immunodeficiency virus type 1 (HIV) infection. DESIGN A phase I/II open-label, dose-ranging study. SETTING Two AIDS Clinical Trials Group units. PATIENTS Patients (56) with advanced HIV disease. INTERVENTIONS Patients were randomly assigned to one of three paired regimens of zidovudine and ddC. We evaluated six dosing regimens, each involving oral administration of the study drugs at 8-hour intervals. MEASUREMENTS Pharmacokinetics, toxicity, CD4 counts, p24 antigenemia and clinical end points. MAIN RESULTS The median follow-up period was 40.6 weeks (range, 0.3 to 70 weeks). Neither drug affected the pharmacokinetic profile of the other. Episodes of serious hematologic toxicity were infrequent, occurring in only 17.9% of patients, and did not differ among the regimens (P = 0.15). Severe sensory peripheral neuropathy occurred in two patients (one patient each in regimens 1 and 4). One patient receiving regimen 4 died. The mean maximal increase in CD4 counts exceeded 109 cells/mm3, and 69% of patients receiving combinations containing 300 or 600 mg of zidovudine daily had an increase in CD4 counts of 50 cells/mm3 or greater. Regimens containing 600 mg of zidovudine daily (regimens 2 and 5) were also more likely to result in persistent increases in CD4 counts above pretreatment values than were the two lowest dose regimens (P = 0.003). The decline in CD4 counts was more rapid, and the suppression of the p24 antigenemia was less rapid and less sustained in patients receiving the lowest zidovudine dose alone (regimen 6). The addition of ddC to regimen 6 (regimen 3) resulted in a slower decline in the CD4 counts (P = 0.06). CONCLUSIONS Combination therapy with zidovudine and ddC at the doses tested was well tolerated and did not result in toxicity. A daily oral dose of 150 mg of zidovudine appeared to produce a suboptimal effect on p24 antigenemia and CD4 counts. Combination therapy with ddC and higher doses of zidovudine produced greater and more persistent effects in patients with advanced HIV infection compared with other study regimens and with the results of previous trials of zidovudine monotherapy.
Comparison of length of hospital stay to mortality rate in a regional burn center.

Data were collected prospectively from 196 patients admitted to our regional burn center during a 10-month period. Fifteen patients died during hospitalization, for a mortality rate of 7.7%. The mean hospital stay of the 181 patients who survived was 13.9 days (+/- 13.7 SD), ranging from 2 to 89 days. The mean burn size was 9.2% (+/- 11% SD), ranging from 0.5% to 60% total body surface area. One hundred ten patients received at least 1 day of antibiotic treatment, and 22 patients required ventilatory support during hospitalization. Hospital stay was longer for those requiring antibiotics (18.6 days vs 7 days) or ventilatory support (34.4 days vs 11.2 days). When these and other variables were entered into a linear regression model, the most powerful predictors of hospital stay were burn size and duration of antibiotic use (p = 0.0001), followed next by the presence of other traumatic injuries (p = 0.047). Language: en
Wind tunnel measurements of the resuspension of ideal particles

Abstract Resuspension of spherical particles was studied in a small diameter wind tunnel having a smooth resuspension surface. Resuspension was measured at wind velocities from 5 to 22 m s−1 with fully developed turbulent flow in the experimental section of the tunnel. A long inlet (L/D of 36) provided a thick boundary layer in simulation of the atmospheric boundary layer. Resuspension rates and vertical flux were determined for monolayers of
Muscle strength in Osteoporotic versus normal women

Strong back muscles contribute to good posture and skeletal support. Osteoporosis, being a metabolic bone disease, should not affect muscle strength. In this study we were interested in comparing the back extensor strength (BES) of osteoporotic and normal women. Fifty-five women ages 40–85 years who had a documented diagnosis of osteoporosis and were referred for initiation of proper exercise programs were included in our study after meeting the inclusion criteria. They all had evaluation of their posture, back and upper extremity strength, and physical activity score through our Rehabilitation of Osteoporosis Program -Exercise (ROPE). In addition, to avoid the interference of pain on application of maximal effort, we did not include subjects with acute back pain or those who experienced back pain with maximal effort during the testing trial. BES for osteoporotic women ranged from 16 to 65 lb (mean ± SD, 36.5±15.5) for ages 40–59 years, 9 to 55 lb (mean ± SD, 29.9±10.6) for ages 60–69 years, 6 to 52 lb (mean ± SD, 24.3±10.2) for ages 70–79 years, and 17 to 27 lb (mean ± SD, 21.2±4.2) for ages 80 years or older. Comparison of these data with the BES of 25 normal women, with statistical adjustment for age, demonstrated that the osteoporotic women had significantly lower BES than the normal women. A longitudinal study of a larger group of women would be of great interest for clarifying whether the weakness of back extensors precedes and, indeed, contributes to compression fractures of the spine.
Blissfully productive: grouping and cooperation in world of warcraft instance runs

Gaming has attracted growing interest in both CSCW and HCI in recent years. We contribute to this line of research by analyzing collaboration in 5-person instance runs in World of Warcraft, an aspect of the game that is considered routine and mundane work by players yet remains largely unexamined in current literature. Using a combination of ethnographic observation, interview, chat and video log analysis, we unpack the conditions under which players can produce the most effective outcomes while having fun, and offer a three-level model of successful instance runs.
Reabsorption of lithium and phosphate by the rat kidney: role of the parathyroids.

Reabsorption of lithium and phosphate by the rat kidney: Role of the parathyroids. Because of the possibility that lithium reabsorption may parallel proximal tubular reabsorption in general, the fractional excretions of lithium (FELi), phosphate (FEP) and sodium (FENa) were compared in rats preloaded intraperitoneally with lithium during hydropenia and during stepwise NaCl/HCO3 volume expansion at 150 and 600 µl/min. In intact rats, all three indexes increased significantly during volume expansion. After acute parathyroidectomy, FEP values during hydropenia were 93% less than in the intact animals. Again, FELi, FEP and FENa all increased significantly during progressive volume expansion, but the increase in FEP was less than 1% of the increase in the intact rats. When chronically parathyroidectomized rats were studied, FELi and FENa again increased during volume expansion. However, FEP values did not increase, but remained at very low levels similar to those in the acutely parathyroidectomized animals. Calcium and magnesium infusion, separately and together, in other acutely parathyroidectomized volume-expanded rats did not decrease FELi. The results indicate that lithium reabsorption in the rat is not affected by the functional status of the parathyroid glands or the presence of parathyroid hormone. Parathyroidectomy dissociates changes in lithium and phosphate reabsorption during volume expansion. Reabsorption du lithium et du phosphate par le rein de rat: Role parathyroides. En fonction de la possibilite que la reabsorption du lithium puisse etre parallele a la reabsorption proximale en general, les excretions fractionnelles du lithium (FELi), de phosphate (FEP) et du sodium (FENa) ont ete comparees, chez des rats prealablement charges en lithium par voie intra-peritoneale, au cours de l'hydropenie et durant une expansion progressive par NaCl/HCO3 a 150 et 600 µl/min. Chez les rats normaux les trois valeurs augmentent significativement durant l'expansion. Apres parathyroidectomie aigue les valeurs de FEP en hydropenie sont inferieures de 93% a celles des animaux intacts. FELi, FEP et FENa ont augmente significativement durant l'expansion, mais l'augmentation est de moins de 1% de celle des rats intacts. Chez des rats parathyroidectomises chroniques FELi et FENa augmentent pendant l'expansion mais FEP n'augmente pas, sa valeur reste tres basse, semblable a celle des animaux parathyroidectomises aigus. Des infusions de calcium et de magnesium, simultanees ou separees, n'ont pas diminue FELi chez d'autres animaux parathyroidectomises aigus soumis a l'expansion. Les resultats indiquent que la reabsorption du lithium chez le rat n'est pas affectee par l'etat fonctionnel des glandes parathyroids ou la presence d'hormone parathyroidienne. La parathyroidectomie dissocie les modifications des reabsorptions du lithium et du phosphate au cours de l'expansion.
Human dermal microvasculature: I. Its segmental differentiation. Light and electron microscopic study.

SUMMARY Light microscopic examination of 1 μm thick epoxy resin sections of human skin preserved in fixative normally used for electron microscopy allows division of the microvasculature of the reticular and superficial dermis into several distinct segments. More precise delineation of these components can be achieved by correlative study using electron microscopy. Measurement of vessel diameter in tissue sections is of limited value in vessel classification because there is a wide overlap between different vascular segments and the results are influenced by the type of fixative used for processing the tissue. Detailed observation of the morphological characteristics of the endothelium and its investment, including the elastic and basal laminae, is considered preferable for identifying individual vascular segments. Differences in body region do not appear to have any obvious influence on vessel structure although there are regional differences in vessel density and arrangement. In comparison with earlier studies on animal tissues or human skin, no structures resembling arteriovenous shunts or precapillary sphincters were observed in the present investigation. However, closed fenestrae and other structures thought to be transendothelial channels were often found at the tips of capillary loops adjacent to the epidermis.
Ocular surface epithelia express mRNA for human beta defensin-2.

Human skin, lung and trachea produce human beta defensin-2 (hBD-2), an inducible, transcriptionally regulated antibiotic peptide with activity against gram negative bacteria, which may explain the unusual resistance of these tissues to infection. Since an intact corneal epithelium is also highly resistant to infection, we examined whether human ocular surface epithelia might produce hBD-2. Conjunctival epithelial cells were obtained from a human cadaver eye, while corneal epithelial cells were obtained from both a cadaver eye and the eye of a living human patient. Using reverse transcription-polymerase chain reaction and custom primers for hBD-2, a 257 bp sequence was amplified from both human corneal and conjunctival epithelial cell cDNA, and the amino acid sequence of this DNA band was computer-matched with the known gene sequence of hBD-2 available through GenBank (Z71389). To determine whether bacterial by-products upregulate hBD-2 mRNA expression, we stimulated confluent SV 40-immortalized human corneal epithelial cells with bacterial culture supernatant prepared from either wild-type P. aeruginosa strain PAO1 or two different lipopolysaccharide (LPS) mutants of PAO1. Both of these mutants, strains AK1012 and PAO1 algC::tet, are deficient in phosphomannomutase activity which is required for the synthesis of both a complete polysaccharide core and the O side chain structures of the LPS molecule. Neither of these mutations affects the lipid A portion of LPS. Cells treated with P. aeruginosa wild-type PAO1 bacterial culture supernatant demonstrated strong upregulation of hBD-2 mRNA expression, whereas cells stimulated with culture supernatant produced by either of the LPS mutants showed little or no change in hBD-2 gene expression. LPS extracted from the bacterial culture supernatant was used to demonstrate that upregulation of hBD-2 is caused by LPS. Genistein blocked this upregulation suggesting that protein tyrosine kinase activity is involved. Thus, both human corneal and conjunctival epithelium express mRNA for hBD-2, and this expression is upregulated by bacterial LPS. Data obtained from LPS mutants suggest that lipid A, which is responsible for initiating a number of the pathophysiological manifestations induced by endotoxin in mammals, is not required. Stimulation of endogenous hBD-2 production via the active portion of LPS might have therapeutic potential.
Meta-analysis of surgical treatments for temporomandibular articular disorders.

Abstract Purpose: Temporomandibular joint articular disorders may cause severe pain and dysfunction. We addressed the following questions. Can any surgical procedures effectively treat these disorders? If so, which procedures are most effective? Materials and Methods: We performed meta-analyses of surgical trial results to determine whether certain surgical procedures are effective in specific patient groups. To compensate for the lack of parallel control groups in published studies and for the improvement that has been observed in untreated patients, we used historical data from nonsurgical trials to derive 3 estimates of historical control group improvement (0%, 37.5%, and 75%). To our knowledge, this is the first meta-analytic evaluation of surgical treatments for temporomandibular joint disorders. Results: Among patients refractory to nonsurgical therapies, surgical arthrocentesis and arthroscopy were effective for patients with disc displacement without reduction at all assumed control group improvement rates. Disc repair/repositioning had a statistically significant effect at all but the highest improvement rate. In patients with disc displacement with reduction, arthroscopy and disc repair/repositioning had statistically significant effects at all but the highest assumed rate of control group improvement. There were no statistically significant differences between the effects of any treatments. Conclusions: Surgical treatments appear to provide some benefit to patients refractory to nonsurgical therapies. The most reliable evidence supports the effectiveness of arthrocentesis and arthroscopy for patients with disc displacement without reduction. Better designed trials are needed before one can accurately determine the magnitude of the benefits of surgery. © 2003 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 61:3-10, 2003
An anti-plane crack in a nonhomogeneous viscoelastic body

A quasi-static analysis of an anti-plane strain crack in a radially inhomogeneous viscoelastic material is carried out. Laplace and Mellin transform methods are used to construct explicit expressions for the stress and displacement fields. Results show that the stress field may exhibit both logarithmic and power-law type singularities and for special cases of material inhomogeneity the asymptotic behavior at the crack tip is determined by a logarithmic singularity. The effects of time and material inhomogeneity upon the stresses and displacements are numerically illustrated.
SWI/SNF Chromatin Remodeling Requires Changes in DNA Topology

ySWI/SNF complex belongs to a family of enzymes that use the energy of ATP hydrolysis to remodel chromatin structure. Here we examine the role of DNA topology in the mechanism of ySWI/SNF remodeling. We find that the ability of ySWI/SNF to enhance accessibility of nucleosomal DNA is nearly eliminated when DNA topology is constrained in small circular nucleosomal arrays and that this inhibition can be alleviated by topoisomerases. Furthermore, we demonstrate that remodeling of these substrates does not require dramatic histone octamer movements or displacement. Our results suggest a model in which ySWI/SNF remodels nucleosomes by using the energy of ATP hydrolysis to drive local changes in DNA twist.
Is lipid bilayer binding a common property of inhibitor cysteine knot ion-channel blockers?

Recent studies of several ICK ion-channel blockers suggest that lipid bilayer interactions play a prominent role in their actions. Structural similarities led to the hypothesis that bilayer interactions are important for the entire ICK family. We have tested this hypothesis by performing direct measurements of the free energy of bilayer partitioning (ΔG) of several peptide blockers using our novel quenching-enhanced fluorescence titration protocol. We show that various ICK peptides demonstrate markedly different modes of interaction with large unilamellar lipid vesicles. The mechanosensitive channel blocker, GsMTx4, and its active diastereomeric analog, D-GsMTx4, bind strongly to both anionic and zwitterionic membranes. One potassium channel gating modifier, rHpTx2gs, interacts negligibly with both types of vesicles at physiological pH, whereas another, SGTx1, interacts only with anionic lipids. The slope of ΔG dependence on surface potential is very shallow for both GsMTx4 and D-GsMTx4, indicating complex interplay of their hydrophobic and electrostatic interactions with lipid. In contrast, a cell-volume regulator, GsMTx1, and SGTx1 exhibit a very steep ΔG dependence on surface potential, resulting in a strong binding only for membranes rich in anionic lipids. The high variability of 5 kcal/mole in observed ΔG shows that bilayer partitioning is not a universal property of the ICK peptides interacting with ion channels.
Constructing biomolecular motor-powered hybrid NEMS devices

The recognition of many enzymes as nanoscale molecular motors has allowed for the potential creation of hybrid organic/inorganic nano-electro-mechanical (NEMS) devices. The long-range goal of this research is the integration of F1-ATPase with NEMS to produce useful nanoscale devices. A thermostable F1-ATPase coding sequence has been isolated, cloned, and engineered for high-level protein expression. Precise positioning, spacing, and orientation of single F1-ATPase molecules were achieved using patterned nickel arrays. An efficient, accurate, and adaptable assay was developed to assess the performance of single F1- ATPase motors, and confirmed a three-step mechanism of (gamma) subunit rotation during ATP hydrolysis. Further evaluation of the bioengineering and biophysical properties of F1-ATPase currently are being conducted, as well as the construction of an F1-ATPase-powered, hybrid NEMS device. The evolution of this technology will permit the creation of novel classes of nanoscale, hybrid devices.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Chemonucleolysis versus laminectomy. A cohort comparison of effectiveness and charges

Study Design. A prospective cohort study was done comparing 100 consecutive chemonucleolysis patients with 100 consecutive laminectomy patients. Objectives. The effectiveness and cost of chymopapain chemonucleolysis was compared with that of laminectomy to manage herniated lumbar discs. Summary of Background Data. Although the efficacy of chemonucleolysis has been established, controversly regarding the relative benefits of chemonucleolysis and laminectomy continues to arise. The relative cost-effectiveness of the two procedures has not been evaluated previously in a cohort study. Methods. Patients in both treatment groups were of comparable age, height and weight, and worker's compensation status. Patients with migrated disc were not considered for chemonucleolysis. Improvement in pain, paresthesia, straight-leg raising, reflexes, motor loss, and sensory function, self-reported overall improvement, ability to maintain employment, and charge of treatment were used to measure treatment success. Results. Clinical assessment after 6 weeks showed 92% of laminectomy patients compared with 82% of chemonucleolysis patients has successful results (P=0.058). Chemonucleolysis patients had greater improvement in numbness (P=0.014) and sensory and motor functions (P=0.002). After 6 months, 88% of chemonucleolysis patients and 85% of laminectomy patients had successful results, with a greater improvement in sensory status or chemonucleolysis patients (P<0.001). After 1 year, 87% of chemonucleolysis patients and 82% of laminectomy patients had successful results, and more chemonucleolysis patients than laminectomy patients were employed. Based on similar therapeutic results, the average charge savings for chemonucleolysis patients was $5365 when chemonucleolysis was performed instead of laminectomy. Conclusion. This study shows that chemonucleolysis is as effective as laminectomy in appropriately selected patients but a lower charge and can contribute substantially to reducing short- and long-term health costs.
Tumour necrosis factor alpha in gingival crevicular fluid as a possible indicator of periodontal disease in humans.

Abstract The suitability of using the cytokine TNF as an indicator of periodontal disease was assessed. Gingival crevicular fluid was collected from 162 sites on filter strips and analysed for TNF by ELISA. About 21% of the sites contained TNF: the amount recovered per site ranged from 0.2 to 998.8 fmol with a median value of 3.7 fmol. The periodontal disease status of each site was documented by recording the gingival and plaque indices, and by measuring pocket depth. About 62% of TNF-containing sites had a gingival index of 1, 76% had a plaque index of 0 or 1, and 47% had pockets of 3 mm or less. When the periodontal status of sites with and without TNF was compared by χ 2 analysis, no significant differences were found. These findings suggest that TNF may be found in sites prior to clinically observable disease and therefore may prove to be a suitable indicator for periodontal disease.
Curvature estimation of arbitrary discrete 3D surfaces using partial derivatives based on distance maps

This work investigates curvature estimation of level surfaces in 3D voxel images. We discuss features of a widely used curvature computation scheme developed by Thirion. It is shown that the locality of the implicit function theorem destroys the smoothness of the reference unit normal; the specialty of Monge patch restricts the derived curvature formulas. By explicitly choosing the normalized gradient of the level function as the reference unit normal, a curvature computation scheme is developed and reported here, in which consistent geometrical meaning of curvature sign is maintained. In order to estimate the curvature efficiently for arbitrary discrete surfaces, a scheme based on distance mapping is proposed. This method was tested on simple 2D objects. It was shown that our method gives accurate curvature estimation similar to Gaussian filtering method, but with much less computational cost.
Nutrients in soil water under three rotational cropping systems, Iowa, USA

Abstract Subsurface nutrient losses differ between annual and perennial crops; however, nutrient losses from cropping systems that rotate annual and perennial crops are poorly documented. This study tracked NO 3 -N and P in soil water under three cropping systems suited for the U.S. Midwest, including two-year (corn–soybean; 2YS), three-year (corn–soybean–small grain/red clover; 3YS), and four-year (corn–soybean–small grain/alfalfa–alfalfa; 4YS) systems. Nutrient applications were based on soil-test results, and solely comprised inorganic fertilizers to 2YS corn, whereas, in the 3YS and 4YS systems, nutrients were provided by legume residues, and a managed balance of composted manure, and inorganic fertilizers. Soil water was collected from 2004 through 2011 using suction samplers. The 4YS system had smaller concentrations of NO 3 -N and a lower frequency of P detection ( p 3 -N were 1.1 mg NO 3 -N L −1 under alfalfa and 6.5 mg NO 3 -N L −1 under the following 4YS corn crop, compared to average concentrations between 8.7 and 18.1 mg NO 3 -N L −1 among all other crop-years. Seasonal NO 3 -N dynamics among the three systems were explainable based on mineralization and – immobilization of N from decomposing crop residues. Large P concentrations (0.23–1.02 mg P L −1 ) occurred in one plot that occasionally ponded, indicating P transport to depth by preferential flow is a risk in some soils on this landscape. Among the remaining plots, the proportion of samples with detectable P concentrations (i.e., >0.02 mg L −1 ) was less ( p
TAXANE DITERPENES 5 : SYNTHESIS OF THE A- AND C-RINGS : AN UNUSUAL REARRANGEMENT OF AN N-HYDROXYIMINO LACTONE

Ring A of taxol was synthesized from the bromodiene 5 and acryloyl chloride to give 6, which was resolved by separation of diastereomers 7. Allylic oxidation of 7 gave 8, which on deprotection, esterification and reduction gave 11. Heating 11 followed by reduction and protection gave 13. The C-ring component was made using asymmetric Birch reduction methodology combined with standard functional group manipulations to give 28. Combining 13 and 28 gave 29, which was converted into 33. Thermolysis of 33 did not generate a nitrile oxide but rather ionized to an oxydienyl cation, eventually leading to 34.
New Melastomataceae from Peru and Bolivia

The following new species of Melastomataceae from Peru and Bolivia are described:Tibouchina wasshausenii, Miconia rimachii, M. boomii, M. histothrix, M. thysanophylla, and Topobea pascoensis.
Biochemical alterations in multiple sclerosis lesions and normal‐appearing white matter detected by in vivo 31P and 1H spectroscopic imaging

The goals of the current study were threefold: first, to confirm previous single volume proton (1H) magnetic resonance spectroscopy results of reduced N-acetyl aspartate (NAA, a putative marker of neurons) in multiple sclerosis (MS) white matter lesions using multiple volume 1H magnetic resonance spectroscopic imaging (MRSI); second, to measure the phospholipid metabolites phosphomonoesters and phosphodiesters in such lesions using phosphorus (31P) MRSI; and third, to test the hypothesis that biochemical changes occur in the normal-appearing (on spin echo T2-weighted magnetic resonance images) white matter in patients with MS. Thirteen subjects with clinically definite MS were studied with both 1H and 31P MRSI, and 19 controls were studied with either 1H MRSI, 31P MRSI, or both. MS lesion, MS normal-appearing white matter, and region-matched control spectra from the centrum semiovale were analyzed. The major findings of this study were that in both white matter lesions and normal-appearing white matter in patients with MS, the metabolite ratio NAA/creatine and the total 31P peak integrals were significantly reduced compared with controls. In addition, in MS lesions NAA/choline and phosphodiesters/total 31P were significantly reduced compared with controls, and in MS normal-appearing white matter there was a trend for NAA/choline to be reduced compared with controls. In normal-appearing white matter in patients with MS, total creatine and phosphocreatine were significantly increased compared to controls, as detected with both 1H (total creatine peak integrals) and 31P (phosphocreatine/total 31P) MRSI techniques. These results suggest reduced neuronal density and altered phospholipid metabolites in white matter lesions in patients with MS.(ABSTRACT TRUNCATED AT 250 WORDS)
Coqui frog invasions change invertebrate communities in Hawaii.

The Puerto Rican coqui frog (Eleutherodactylus coqui) invaded Hawaii in the late 1980s. Because the coqui reaches high densities and consumes large quantities of invertebrates, it was hypothesized to change invertebrate communities where it invades. Previous research found that coquis can change invertebrate communities, but these studies used highly manipulative, small-scale experiments. The objective of this research was to determine whether coquis create community-level changes in invertebrate communities at the landscape scale. We collected leaf litter, flying, and foliage invertebrates on both sides of 15 coqui invasion fronts across the island of Hawaii. Multivariate analyses show that coquis are associated with changes in leaf-litter communities, primarily reductions in Acari, but are not associated with overall changes in flying or foliage communities. Across sites, coquis reduced the total number of leaf-litter invertebrates by 27%, specifically by reducing Acari by 36%. Across sites, coquis increased flying Diptera by 19%. Changes were greater where coqui densities were higher. We suggest that coquis changed leaf-litter communities primarily through direct predation, but that they increased Diptera through the addition of frog carcasses and excrement. Results support previous studies conducted in more controlled settings, but add to our understanding of the invasion by showing that coqui effects on invertebrate communities are measurable at the landscape scale.
An expert system for design for robotic assembly

In recent years, due to the various advantages associated with automation and robotics, much work has been done in developing robotic systems for assembly operations. Since part design plays a major role in assembly, this paper deals with the design of parts for ease of robotic assembly. Considerable knowledge is available in the form of design for robotic assembly rules. In addition, a large amount of data is required for decisions regarding suitability of parts for robotic assembly. The implementation of design for robotic assembly rules would be much easier with the help of an expert system, which would guide the designer toward choosing the design alternative that can best facilitate ease of assembly from a robotic point of view.
Evidence for Baseline Retinal Pigment Epithelium Pathology in the Trp1-Cre Mouse

The increasing popularity of the Cre/loxP recombination system has led to the generation of numerous transgenic mouse lines in which Cre recombinase is expressed under the control of organ- or cell-specific promoters. Alterations in retinal pigment epithelium (RPE), a multifunctional cell monolayer that separates the retinal photoreceptors from the choroid, are prevalent in the pathogenesis of a number of ocular disorders, including age-related macular degeneration. To date, six transgenic mouse lines have been developed that target Cre to the RPE under the control of various gene promoters. However, multiple lines of evidence indicate that high levels of Cre expression can be toxic to mammalian cells. In this study, we report that in the Trp1-Cre mouse, a commonly used transgenic Cre strain for RPE gene function studies, Cre recombinase expression alone leads to RPE dysfunction and concomitant disorganization of RPE layer morphology, large areas of RPE atrophy, retinal photoreceptor dysfunction, and microglial cell activation in the affected areas. The phenotype described herein is similar to previously published reports of conditional gene knockouts that used the Trp1-Cre mouse, suggesting that Cre toxicity alone could account for some of the reported phenotypes and highlighting the importance of the inclusion of Cre-expressing mice as controls in conditional gene targeting studies.
Two-dimensional electron gas in a magnetic field : the non-degenerate limit.

The thermodynamical properties of a two-dimensional electron gas (2DEG) in a magnetic field with an arbitrary level broadening are discussed in the nondegenerate limit first proposed by Zawadzki. It is concluded that experimental measurements in the non-degenerate regime may open a new avenue for investigations on the density of states of a 2DEG in a magnetic field.
The SGB/NP hydration free energy model based on the surface generalized born solvent reaction field and novel nonpolar hydration free energy estimators

The development and parameterization of a solvent potential of mean force designed to reproduce the hydration thermodynamics of small molecules and macromolecules aimed toward applications in conformation prediction and ligand binding free energy prediction is presented. The model, named SGB/NP, is based on a parameterization of the Surface Generalized Born continuum dielectric electrostatic model using explicit solvent free energy perturbation calculations and a newly developed nonpolar hydration free energy estimator motivated by the results of explicit solvent simulations of the thermodynamics of hydration of hydrocarbons. The nonpolar model contains, in addition to the more commonly used solvent accessible surface area term, a component corresponding to the attractive solute-solvent interactions. This term is found to be important to improve the accuracy of the model, particularly for cyclic and hydrogen bonding compounds. The model is parameterized against the experimental hydration free energies of a set of small organic molecules. The model reproduces the experimental hydration free energies of small organic molecules with an accuracy comparable or superior to similar models employing more computationally demanding estimators and/or a more extensive set of parameters.