cssi/SciSciGPT-SciSciNet huggingface dataset:
A postmortem correlation of four techniques of assessment of osteoporosis with force of bone compression.

Prosected vertebrae and phalanges from 32 cadavera were examined using noninvasive methods commonly used for assessment of osteoporosis. Bone measures were then compared with a strength variable obtained by mechanically crushing or breaking the bones. All of the phalangeal density assessment techniques were found to be significantly correlated with the bone strenght. The highest correlations were between bone mineral content and strength. In vertebral samples (cubes with 2 cm sides), bone mineral content corrected for bone width (BMC/BW) was significantly correlated with the force at the first deviation from linearity. Correlations between the computed tomography number and bone strength were negligible. Bone strength of the vertebrae was significantly correlated to that of the fingers. Photon absorptometric (SPA) measurements of the vertebrae correlated significantly with corresponding measures of the phalanges. BMC/BW appeared as the first or second variable selected as a predictor of bone strength in the multiple regression analysis. Throughout this entire study, BMC or MBC/BW were the only variables that were consistently related to the strength variables.
Making the step from chemistry to biology and back.

There is a gap between the nanoscale level of molecular structure and the micron-sized level of cellular ultrastructure that is difficult to probe experimentally. New techniques and simulated images are revealing its secrets.
Crop colonisation, feeding, and reproduction by the predatory beetle, Hippodamia convergens, as indicated by stable carbon isotope analysis

Habitat management to enhance natural enemy populations in agricultural systems may help regulate levels of crop pests, but little research addresses the behaviour of immigrating beneficial insects. 2. Stable carbon isotopes were used in complementary laboratory and field studies to examine colonisation behaviour of an ephemeral agricultural habitat by the lady beetle, Hippodamia convergens Guerin-Meneville. 3. Under laboratory conditions, H. convergens carbon isotope ratios, d 13 C, changed after its food supply was shifted from a C4 -t o aC 3-based diet of aphids produced on grain sorghum or cotton respectively. Final isotope ratios of adult H. convergens were closer to that of the new C3-based diet, with most change in d 13 C occurring within 3 days after the diet shift. 4. The carbon isotope ratios of lady beetle adults collected in cotton fields suggested that grain sorghum was a continuous source for H. convergens until many nearby sorghum fields matured and senesced. 5. When cotton aphid (Aphis gossypii Glover) prey were absent, carbon isotope ratios of beetle populations did not change over time and virtually no egg produc- tion by H. convergens was detected. This indicates that beetles were feeding little on non-aphid resources originating in cotton. 6. With cotton aphids present, beetle isotope ratios decreased towards the carbon isotope ratio of cotton, indicating adult feeding in cotton. As a result, egg masses produced had carbon isotope ratios in the C3 range of values. 7. The results suggest that some predator species may be retained in habitats without large prey populations, a quality essential in controlling pests in agricul- tural systems.
Bedside Pulmonary Angiography Utilizing an Existing Swan-Ganz Catheter

A single view, wedge, pulmonary angiogram was performed at bedside in nine patients using a Swan-Ganz catheter which had been inserted previously for other indications. Criteria for consideration of a bedside study were as follows: (1) a clinical suspicion of significant, acute pulmonary embolism; (2) the inability or inadvisability of transferring the patient for definitive studies; and (3) a Swan-Ganz catheter in situ.Seven of the nine patients subsequently died. Of five patients who underwent necropsy, three positive studies and one negative, were confirmed. No post-mortem evidence for embolism could be demonstrated in one patient with a positive study. Of the two patients who survived, one negative study was confirmed with a negative radionuclide perfusion lung scan. There was no morbidity or mortality associated with the procedure. These data suggest that this technique is safe and has a role in the early diagnosis of significant pulmonary embolism in selected critically ill patients.
Inorganic polymer resists for EUVL

The uniqueness in extreme ultraviolet (EUV) Lithography is encouraging the development of new polymer platform as a resist material. The absorbance characteristic of materials at the EUV region demands the use of polymers containing highly transparent silicon atoms. Also very low level of outgassing is required due to the vacuum environment during exposure and the extremely high cost of the EUV tools. To fulfill those requirements, two types of silicon backbone polymers were studied; chemically amplifiable polysilanes and polysilsesquiazanes. In the former case, the direct incorporation of acid sensitive groups into the polymer backbone allows for a solubility switch upon exposure. In the later system, this nitrogen-containing silicon polymer can be cleaved upon exposure to induce a solubility switch. These polymers possess many essential properties including low absorbance, low outgassing, and high sensitivity. Polymers having different substituents and branching ratios were synthesized. The properties of the polymers will be discussed relating to their lithographic performances.
Perinatal clinical and imaging features of CLOVES syndrome

We report a neonate with antenatal imaging features suggestive of CLOVES syndrome. Postnatal clinical and imaging findings confirmed the diagnosis, with the constellation of truncal overgrowth, cutaneous capillary malformation, lymphatic and musculoskeletal anomalies. The clinical, radiological and histopathological findings noted in this particular phenotype help differentiate it from other overgrowth syndromes with complex vascular anomalies.
Problems in Estimating the Value of Household Services

Current estimates of the value of household services (VHS) as a percent of Gross National Product(GNP) are overestimations, it is contended. They are based on a zero (or low) supply price whereas if such services by family members usually commanded a price, the quantity demanded might be substantially less. Also the total output of goods and services (real GNP) against which VHS is measured is GNP sans VHS; if measurement is justified, it should be GNP plus VHS, yielding a smaller percentage.
Design and Operation Water-Cooled Pyrolytic Graphite Targets at LAMPF

Design considerations and actual operating experience are reported for water-cooled pyrolytic graphite targets at the Clinton P. Anderson Meson Physics Facility (LAMPF). Emphasis is placed on the use of finite element computer calculations to determine target temperatures and stresses, which can then be evaluated to judge the usefulness of a particular design. Consideration is also given to the swelling of the target following irradiation, and to the measures taken to prolong target lifetime.
γ-Glutamyltranspeptidase: A tumour cell marker with a pharmacological function

The distribution of γ-glutamyltranspeptidase activity (γGT) in adult, foetal, and neoplastic tissues in rats and humans is reviewed. The normal adult kidney, pancreas, and jejunum are high in this activity. Around the time of birth, γGT activity increases transiently in the liver, colon, and skin; many tumours of these organs often have elevated activity as well. Although this activity in tumour tissue may reflect a general expression of onco-foetal genes, subpopulations of cells having abnormally high γGT may have a selective growth advantage over their normal counterparts. We explore this latter possibility by considering the pharmacological function this enzyme may play. γGT may facilitate the detoxification of electrophiles by glutathione conjugation, so that cells can survive in an otherwise toxic environment. This growth advantage may be particularly important to the development of liver tumours in rats during chemical carcinogenesis.
Chaos in a periodically perturbed CSTR

The occurrence of chaotic behavior is analyzed in a periodically perturbed dynamic nonisothermal CSTR with first-order exothermic chemical reaction A→B and an Arrhenius expression for the rate constant. When sinusoidal forcing functions for the cooling-fluid temperature and the volumetric feed rate are applied to the unperturbed part of the system, period-doubling behavior leading to a strange attractor is observed as the amplitude of the perturbation in the cooling-fluid temperature is increased. Chaos and period-doubling are also verified through Fourier spectra analysis, adherence to the Feigenbaum Theory, and analysis of the Poincare return map The basis for obtaining chaotic behavior in the reactor system is the Melnikov theory, which slates that chaos can be obtained in a periodically perturbed system if the phase plot of the unperturbed system closely corresponds to that of a homoclinic orbit (a phase trajectory which contains the stable and unstable separatrices of a saddle). From linear stability...
Soft-tissue sarcomas: MR imaging findings after treatment in three pediatric patients.

PURPOSE: To characterize the skeletal and bone marrow magnetic resonance (MR) imaging changes during and after treatment of childhood soft-tissue tumors. MATERIALS AND METHODS: Three boys with soft-tissue sarcomas of the popliteal fossa underwent surgery, radiation therapy, and chemotherapy. Plain radiographic and MR imaging findings were correlated with the effect of treatment. RESULTS: After radiation therapy, MR images revealed findings that resembled those of rickets at sites of irradiation in the three patients. These findings included metaphyseal sclerosis, metaphyseal fraying, and epiphyseal plate widening. Bone marrow imaging changes were temporally related to therapy. During chemotherapy, reconversion to hematopoietic marrow was noted in nonirradiated areas in two patients, but after cessation of all treatment, these areas converted back to fatty marrow. Irradiated areas of bone marrow remained fatty throughout therapy in the three patients. CONCLUSION: Awareness of the MR imaging findings relate...
Cross-sectional geometry of the human forefoot.

The human forefoot presents an interesting biomechanical problem of clinical importance because loads are distributed unequally across multiple bones. The fact that long bones typically have a several-fold safety factor relative to peak loads suggests that metatarsal strengths should be related to their peak loads. This study is the first to systematically examine the cross-sectional geometric properties of the human forefoot and their relationship to external loads during walking and running. We report midlength cross-sectional geometric properties (CA, Ix, Iy, Imax, Imin, J, Zx, and Zy) of metatarsals (1–5) and the hallucial proximal phalanx of a shod industrial population (n = 40) obtained using computed tomography. We then examine the relationship between these measures of shaft strength and published plantar pressure data sets recorded during the following functional activities: standing, at the push-off stage of the walking cycle, the full walking cycle, and running. Cross-sectional geometric properties of the first ray are greater than those of other rays, even when scaled to bone length. This pattern corresponds to the high pressures recorded for the first ray during most activities. The relationships between cross-sectional geometric properties of the lateral metatarsals and peak plantar pressure data are more complex. Metatarsals 2–4 are weakest in most cross-sectional geometric properties. However, metatarsal 2, and to a lesser extent metatarsal 3, experience relatively high peak pressures. On average, geometric measures of axial and bending strengths (adjusted relative to body size) are lower in females than males, and in European Americans than in African Americans, which corresponds to the respective rates of general metatarsal stress fracture in these groups. The discrepancy between strength and plantar pressure values in metatarsals 2 and 3 is consistent with the high incidence of stress fractures in these bones and underscores the importance of soft tissues, such as the plantar fascia and flexor musculature, in moderating metatarsal shaft strain.
An expression for the correlation energy of an electron gas

Abstract A new expression for the ground state energy, and in particular the correlation energy, of an inhomogeneous electron gas in an external field is found using an effective action method. The result is given in terms of the density matrix of the gas. In general the expression should be evaluated numerically, but analytic results for the homogeneous case are given which agree well with previous calculations.
The Effect of Passive Smoking and Tobacco Exposure Through Breast Milk on Sudden Infant Death Syndrome

Objective. —To examine the relationship between sudden infant death syndrome (SIDS) and smoking during pregnancy; postnatal tobacco smoke exposure from the mother, father, live-in adults, and day care providers; and postnatal smoke exposure from breast-feeding. Design. —Case-control study. Setting. —Five counties in Southern California. Participants. —A total of 200 white, African-American, Hispanic, and Asian parents of infants who died of SIDS between 1989 and 1992 were compared with 200 control parents who delivered healthy infants. Case infants were matched to control infants on the basis of birth hospital, birth date, gender, and race. All information was obtained from a detailed telephone interview and validated with medical records. Main Outcome Measures. —Risk of SIDS associated with passive smoking by the mother, father, live-in adults, and day care providers; smoking in the same room as the infant; total number of cigarettes smoked by all adults; and maternal smoking during the time period of breast-feeding. Results. —Conditional logistic regression resulted in overall adjusted odds ratios (ORs) for SIDS associated with passive smoke from the mother of 2.28, the father of 3.46, other live-in adults of 2.18, and all sources of 3.50 (95% confidence interval, 1.81 to 6.75), while simultaneously adjusting for birth weight, sleep position, prenatal care, medical conditions at birth, breast-feeding, and maternal smoking during pregnancy. A dose-response effect was noted for SIDS associated with increasing numbers of cigarettes, as well as total number of smokers. Breast-feeding was protective for SIDS among nonsmokers (OR=0.37) but not smokers (OR=1.38), when adjusting for potential confounders. Conclusions. —Passive smoking in the same room as the infant increases the risk for SIDS. Physicians should educate new and prospective parents about the risks of tobacco smoke exposure during pregnancy and the first year of the infant's life. ( JAMA . 1995;273:795-798)
Synthesis in vitro of corticosteroid-binding globulin from rat liver messenger ribonucleic acid.

To show that corticosteroid-binding globulin (CBG), a plasma glycoprotein, is synthesized in the liver as well as to develop a tool with which to study the hormonal factors which control its synthesis, we undertook to translate rat CBG mRNA in vitro. Rat liver mRNA was translated in the presence of [35S]methionine in both a rabbit reticulocyte lysate (cell-free) system and a Xenopus laevis oocyte (whole cell) system. A monospecific antibody against highly purified rat CBG was used to precipitate a single 35S-labeled product from the mixture of newly synthesized hepatic proteins in the two systems. In the rabbit reticulocyte lysate system, the protein migrated with an apparent molecular weight of 41,000 on sodium dodecyl sulfategel electrophoresis; CBG isolated from rat serum migrated as a doublet with apparent molecular weights of 56,000 and 62,500. Since proteins synthesized by a cell-free system are not glycosylated, the difference in molecular weight can probably be accounted for by the carbohydrate co...
Band transitions in wurtzite GaN and InN determined by valence electron energy loss spectroscopy

Abstract Valence electron energy loss spectroscopy (VEELS) was applied to determine band transitions in wurtzite InN, deposited by molecular beam epitaxy on (0001) sapphire substrates or GaN buffer layers. The GaN buffer layer was used as VEELS reference. At room temperature a band transition for wurtzite InN was found at (1.7±0.2 eV) and for wurtzite GaN at (3.3±0.2 eV) that are ascribed to the fundamental bandgap. Additional band transitions could be identified at higher and lower energy losses. The latter may be related to transitions involving defect bands. In InN, neither oxygen related crystal phases nor indium metal clusters were observed in the areas of the epilayers investigated by VEELS. Consequently, the obtained results mainly describe the properties of the InN host crystal.
Manipulation Effects, Open-Field Experience and Digestive Transit Time in Wistar Male and Female Rats

Summary.-14 male and 16 female Wistar (DAB) 113-day-old rats were observed in an open-fie:d situation, in their home cages after manipulation, and in home cages without manipulation. Incidences of defecation and urination, locomotor activity, and digestive transit time were recorded during 4-min. sessions for 6 days. Animals were more likely to eliminate in the open-field situation than in their hornc cages, and more rats eliminated in this group than in the other two groups. It appears that the effect of the open-field situation on eliminative behavior is not related to that of manipulation incident to the observation of the animal in the open field. The decrease in digestive transit rime of animals placed in the open field further suggests that the open-field situation is more effective than manipulation in modifying digestive transit time.
Retaining the Online Learner: Profile of Students in an Online MBA Program and Implications for Teaching Them

Research regarding student cohorts entering the Georgia WebMBA$$ program (an online MBA program in the University System of Georgia) shows consistent demographic characteristics as well as students' reasons for joining the program, experience with online learning, and perceptions of teamwork. The program has a high retention rate, and in this article the authors focus on retaining online learners. They discuss the profile of program students and the teaching approaches that have been successful in addressing potential attrition issues with these learners. To retain virtual learners, the program provides a cohort- and team-based learning experience with extensive faculty feedback and interaction to address isolation concerns, provide application-based content and activities, and help students meet expectations for personal and professional growth. The authors also stress the need to offer a well-managed program and faculty members who are both interested and competent in teaching in the online learning env...
A review of flatfish behavior relative to trawls

Trawls harness the innate avoidance behavior of fish to affect their capture. As such, effective bycatch reduction relies, in part, upon knowledge of behavioral differences between target and non-target species. The behavior of flatfish during herding, net entry and passage through trawls differs substantially from that of many roundfish. These differences result from the unique body morphology of flatfish and the constraints this morphology places upon their natural predator avoidance and evasion tactics. Paramount, in this regard, is the intimate association between flatfish and the seafloor. Flatfish utilize a detection minimization strategy that combines burial, highly evolved cryptic capabilities and low activity. Additionally, the maximum sustained swimming speeds and endurance of flatfishes are low compared to most roundfish. As a result, flatfish typically respond to trawl ground-gear at shorter distances, remain closer to the seafloor during herding and herd in the net mouth for a shorter time, prior to net entry, than roundfish. As is the case for roundfish species, light and temperature influence flatfish reactivity and herding behavior. At low ambient light levels herding behavior in flatfish breaks down, as fish initially respond to ground-gear by rising off the bottom, which removes them from the ground-gear's zone of influence. Similarly, at low temperatures some flatfish display reduced herding. Differences in behavior between flatfish and roundfish have spurred development of selective flatfish trawls, with low rise head ropes and/or open or large mesh intermediates that allow rising roundfish to exit the net opening, while flatfish remain close to the net floor, passing into the net and back to the codend. Lastly, a conceptual design for a counter-herding device is presented, which takes advantage of the longer reactive distances of roundfish, and their tendency to herd farther of the seafloor, thereby allowing them to be herded out of the path of the net, while not influencing the normal inward herding of flatfish.
An Integrated Laboratory Approach toward the Preparation of Conductive Poly(phenylenevinylene) Polymers

Poly(phenylene vinylene) (PPV) represents an important class of conjugated, conducting polymers that have been readily exploited in the preparation of organic electronic materials. In this experiment, students prepare a PPV polymer via a facile multistep synthetic sequence with robust spectroscopic evaluation of synthetic intermediates and the final product. The synthetic sequence could be applied by university instructors as a capstone project for an undergraduate organic chemistry laboratory or as a centerpiece project for either a polymer or integrated laboratory course. The initial synthetic step could be segmented and used as a modular piece in the traditional introductory organic chemistry laboratory. In either case, the resultant PPV polymer is analyzed by UV–vis and fluorescence spectroscopy to determine the quantum yield which promotes enhanced student understanding of the photophysical properties of the material. In addition, GPC analysis is completed to reveal the molecular weight and polydispe...
Absolute Configuration of cis- and trans-2-(o-Bromophenyl)cyclohexanols and (+)-cis-2-(o-Bromophenyl)cyclohexylamine

The absolute configurations of (-)-trans-2-(o-bromophenyl)cyclohexanol (V), (+)-cis-2-(o-bromophenyl)cyclohexanol (VII), and (+)-cis-2-(o-bromophenyl)cyclohexylamine (X) have been chemically related to that of (2S)-(-)-2-(o-bromophenyl)-cyclohexanone (VI), whose absolute configuration can be reliably assigned from its optical rotatory dispersion and circular dichroism spectra.
Use of Dicalcium Phosphate Dihydrate as a Probe in an Approach for Accurate Calculations of Solution Equilibria in Buffered Calcium Phosphate Systems

Both synthetic and biological carbonated apatites have been shown to possess metastable equilibrium solubility (MES) distributions. Investigation of their MES behavior requires accurate knowledge of the activities of the relevant ions over a range of solution compositions. This in turn requires that the activity coefficients for these ions and the stability constants for the various solution complexes be accurately known. Since the solubility of dicalcium phosphate dihydrate (DCPD) can be easily determined, it can be used as a probe to study the appropriateness of proposed sets of stability constants and activity coefficients. In the present study, the solubility of DCPD was determined in acetate buffer solutions at pHs ranging from 4.5 to 6.5 and this allowed for the determination and evaluation of the stability constants of the NaHPO(-)(4), CaHPO(0)(4), CaH(2)PO(+)(4), and CaAc(+) complexes. The activity coefficients were calculated by a modification of the extended Debye-Huckel method and also by Bockris and Reddy's method, in which the activity of water and the hydration numbers of ions are also considered. The solution conditions were controlled to simulate the dissolution media used for the determination of MES distributions of apatites in our laboratory. Both methods of activity coefficient determination gave very consistent DCPD solubility product (K(DCPD)) values, and values for the stability constants of the relevant complexes determined using the two methods were close to each other. This approach of determining the stability constants under a set of conditions similar to those in apatite dissolution studies offers an effective set of parameters which, though not necessarily always exactly correct in absolute terms, are internally consistent and should allow for the quantitative characterization of the MES behavior of apatites. Copyright 1999 Academic Press.
A Drosophila melanogaster hobo‐white+ vector mediates low frequency gene transfer in D. virilis with full interspecific white+ complementation

Transformation of a Drosophila virilis white mutant host strain was attempted using a hobo vector containing the D. melanogaster mini-white(+) cassette (H[w(+), hawN]) and an unmodified or heat shock regulated hobo transposase helper. Two transformant lines were recovered with the unmodified helper (HFL1), one containing only the white(+) marked vector, and a sibling line containing the vector as well as an HFL1 helper integration. An approximate total transformation frequency of 1% is deduced. A high frequency of wing and eye morphology mutants were also observed, suggesting that hobo may have mobilized a related element in D. virilis. The data reaffirms a relatively low transformation vector activity for the hobo transposon in D. virilis; however, nearly full interspecific expression white(+) marker supports its possible function in other species as well.
Facile synthesis of vesicle templated hollow germania nanospheres

Well-organised hollow germania nanospheres were grown using lipid vesicles as templates. We investigated lipids of varying surface charge, and studied their efficacy as templates for the growth of the nanospheres in the presence and absence of the co-surfactant octadecylamine. From the studies conducted, we found that the surface charges as well as the chemical structures of the templates are important factors for the growth of the nanospheres. We observed that in the case of anionic vesicles, the incorporation of the co-surfactant was crucial for the formation of the nanospheres. The germania nanospheres were constructed by layer by layer deposition of germania onto the templates. Hollow nanospheres were obtained upon calcining the products, thereby removing the lipid templates. The materials obtained were examined by electron microscopy, dynamic light scattering, XRD, FTIR, DTA/TGA, and zeta potential analysis. This method can be applicable for developing hollow nanospheres of controlled size and shape of various metal oxides. Such hollow germania nanospheres may have potential applications in photonics, catalysis and for the development of optical nanosensors.
Broadband picosecond transient absorption spectroscopy at MHz repetition rates

Abstract We demonstrate broadband picosecond transient absorption spectroscopy at MHz repetition rates using stimulated Raman scattering from a single-mode polarization-preserving optical fiber. We use the output of the fiber to probe the absorption of the excited state of the cyanine dye DODCI.
Undergraduate and Postgraduate Teaching in Diseases of the Chest: A Report of the Joint Program of the New York Medical College and the Municipal Tuberculosis Sanatorium of the City of New York

It is our hope that eventually the teaching of tuberculosis will accompany the student throughout the four years of his medical school, not as an elective, but as a required course correlated with all his other subjects. In this instance, familiarity will breed not contempt but knowledge of, and respect for, a disease that thrives on ignorance. The success of the courses given was due directly to the enthusiasm and wholehearted cooperation of the Dean and Medical Board of the New York Medical College and the Medical Staff of the Municipal Tuberculosis Sanatorium.
Aids education in black America

As Aids continues to hit American black communities at alarmingly dispropor tionate rates, both black Americans themselves, and the American mass media must begin to confront the realities of the problem, and devise a plan of action to educate blacks about health risks and prevention, argues Dr Gayle.
A fast spectroscopic imaging method using a blipped phase encode gradient.

Many methods of chemical shift imaging have been described recently. In most cases, these methods couple resolution and imaging time. The most flexible methods use time-varying gradients to cover a large region of k space on each excitation. We present here a new time-varying gradient method that offers a decrease in scan time (when SNR is sufficient), simplifies the reconstruction problem by retaining an essentially rectilinear sampling grid, and makes efficient use of scan time by minimizing gradient reversals. Implementation on a standard high-field imaging system (GE Signa) is discussed, and experimental results are shown. An application of the method to the generation of water reference data sets is described. © 1989 Academic Press, Inc.
Psoriasis and pregnancy.

Background: Women comprise half of all psoriasis patients and because the majority of psoriasis cases present before age 40 the disease affects women who may become pregnant. Information regarding the heritability of psoriasis can be used in counseling patients who inquire about the potential risk to their children. Patients with psoriasis who become pregnant will likely notice an associated improvement of their symptoms if any change is noted at all. Objective: Because of potential fetal effects, the treatment of chronic psoriasis in pregnancy involves prudent consideration of whether the severity of the disease warrants treatment and selection of the safest treatments available. Conclusion: Topical corticosteroids and topical calcipotriene as well as topical anthralin and topical tacrolimus appear to be safe choices for control of localized psoriasis in pregnancy. UVB is the safest treatment for extensive psoriasis during pregnancy, particularly when topical application of other agents is not practical. Short-term use of cyclosporine during pregnancy is probably the safest option for management of severe psoriasis that has not responded to topical or UVB treatment.
The ionospheric outflow feedback loop

Abstract Following a long period of observation and investigation beginning in the early 1970s, it has been firmly established that Earth׳s magnetosphere is defined as much by the geogenic plasma within it as by the geomagnetic field. This plasma is not confined to the ionosphere proper, defined as the region within a few density scale heights of the F-region plasma density peak. Rather, it fills the flux tubes on which it is created, and circulates throughout the magnetosphere in a pattern driven by solar wind plasma that becomes magnetically connected to the ionosphere by reconnection through the dayside magnetopause. Under certain solar wind conditions, plasma and field energy is stored in the magnetotail rather than being smoothly recirculated back to the dayside. Its release into the downstream solar wind is produced by magnetotail disconnection of stored plasma and fields both continuously and in the form of discrete plasmoids, with associated generation of energetic Earthward-moving bursty bulk flows and injection fronts. A new generation of global circulation models is showing us that outflowing ionospheric plasmas, especially O + , load the system in a different way than the resistive F-region load of currents dissipating energy in the plasma and atmospheric neutral gas. The extended ionospheric load is reactive to the primary dissipation, forming a time-delayed feedback loop within the system. That sets up or intensifies bursty transient behaviors that would be weaker or absent if the ionosphere did not “strike back” when stimulated. Understanding this response appears to be a necessary, if not sufficient, condition for us to gain accurate predictive capability for space weather. However, full predictive understanding of outflow and incorporation into global simulations requires a clear observational and theoretical identification of the causal mechanisms of the outflows. This remains elusive and requires a dedicated mission effort.
Increased excitability of the human corticospinal system with hyperventilation

Abstract Objectives : Hyperventilation is effective in inducing generalized spike-wave discharges in patients with absence seizures and improves visual function and normalizes visual function in patients with multiple sclerosis. Hyperventilation increases the excitability of cutaneous and motor axons. In experimental animals, hyperventilation increases excitability of hippocampal neurons. There is however no direct evidence of a hyperventilation-induced increase in neuronal excitability within the central nervous system in humans. In this study we determined the effects of hyperventilation on the human corticospinal system. Methods : We studied the effects of hyperventilation on (1) motor evoked potentials (MEPs) induced by transcranial magnetic pulse stimulation of the motor cortex and (2) F-wave responses. Six subjects were studied. Results : Hyperventilation resulting in an end-tidal pCO 2 of 15 mm Hg or less enhanced the amplitude of the MEP and resulted in a shortened onset latency. F-wave amplitudes were enhanced without any change in onset latency. Conclusions : These findings indicate that hyperventilation increases the excitability of the human corticospinal system. A hyperventilation-induced increase in excitability within the central nervous system may account for clinical phenomena such as facilitation of spike-wave discharges.
Artificial neural networks for acoustic target recognition

Acoustic sensors can be used to detect, track and identify non-line-of-sight targets passively. Attempts to alter acoustic emissions often result in an undesirable performance degradation. This research project investigates the use of neural networks for differentiating between features extracted from the acoustic signatures of sources. Acoustic data were filtered and digitized using a commercially available analog-digital convertor. The digital data was transformed to the frequency domain for additional processing using the FFT. Narrowband peak detection algorithms were incorporated to select peaks above a user defined SNR. These peaks were then used to generate a set of robust features which relate specifically to target components in varying background conditions. The features were then used as input into a backpropagation neural network. A K-means unsupervised clustering algorithm was used to determine the natural clustering of the observations. Comparisons between a feature set consisting of the normalized amplitudes of the first 250 frequency bins of the power spectrum and a set of 11 harmonically related features were made. Initial results indicate that even though some different target types had a tendency to group in the same clusters, the neural network was able to differentiate the targets. Successful identification of acoustic sources under varying operational conditions with high confidence levels was achieved.
Physiology and morphology of Pinus sylvestris seedlings from diverse sources under cyclic drought stress

Abstract We examined seed source variation in drought tolerance characteristics of Pinus sylvestris seedlings from 12 diverse geographic origins representing a longitudinal transect across the species range. The seedlings were subjected to three dry-down cycles in raised water-use efficiency in a greenhouse experiment. We measured pre-dawn needle water potential ( Ψ n ) and instantaneous water-use efficiency (WUE) ( W ) during the cyclic droughts. Seedling survival, growth, biomass allocation to roots, and carbon isotope ratio ( δ 13 C) were measured at the end of the experiment. The seed sources varied ( P δ 13 C. In general, seedlings from the drier central Asian seed sources survived longer under drought than seedlings from more mesic European and coastal seed sources. Seedlings from the Asian seed sources were smaller, allocated more biomass to roots, and had higher integrative water-use efficiency (as indicated by higher δ 13 C) than the seedlings from the European sources. Seed source variation in Ψ n and W was not significant ( P >0.05). Carbon isotope ratio was correlated with precipitation at the seed origin ( r =−0.75, P
Aspects of investigative inquiry in evaluation

A description of the characteristics of investigative inquiry can illuminate examples of evaluation practice that are increasingly investigative.
A distributed admission control model for QoS assurance in large-scale media delivery systems

Conventional admission control models incur some performance penalty. First, admission control computation can overload a server that is already heavily loaded. Also, in large-scale media systems with geographically distributed server clusters, performing admission control on each cluster can result in long response latency, if the client request is denied at one site and has to be forwarded to another site. Furthermore, in prefix caching, initial frames cached at the proxy are delivered to the client before the admission decisions are made. If the media server is heavily loaded and, finally, has to deny the client request, forwarding a large number of initial frames is a waste of critical network resources. In this paper, a novel distributed admission control model is presented. We make use of proxy servers to perform the admission control tasks. Each proxy hosts an agent to coordinate the effort. Agents reserve media server's disk bandwidth and make admission decisions autonomously based on the allocated disk bandwidth. We develop an effective game theoretic framework to achieve fairness in the bandwidth allocation among the agents. To improve the overall bandwidth utilization, we also consider an aggressive admission control policy where each agent may admit more requests than its allocated bandwidth allows. The distributed admission control approach provides the solution to the stated problems incurred in conventional admission control models. Experimental studies show that our algorithms significantly reduce the response latency and the media server load.
Direct Analysis of Single Cells by Mass Spectrometry at Atmospheric Pressure

Analysis of biochemicals in single cells is important for understanding cell metabolism, cell cycle, adaptation, disease states, etc. Even the same cell types exhibit heterogeneous biochemical makeup depending on their physiological conditions and interactions with the environment. Conventional methods of mass spectrometry (MS) used for the analysis of biomolecules in single cells rely on extensive sample preparation. Removing the cells from their natural environment and extensive sample processing could lead to changes in the cellular composition. Ambient ionization methods enable the analysis of samples in their native environment and without extensive sample preparation.1 The techniques based on the mid infrared (mid-IR) laser ablation of biological materials at 2.94 μm wavelength utilize the sudden excitation of water that results in phase explosion.2 Ambient ionization techniques based on mid-IR laser radiation, such as laser ablation electrospray ionization (LAESI) and atmospheric pressure infrared matrix-assisted laser desorption ionization (AP IR-MALDI), have successfully demonstrated the ability to directly analyze water-rich tissues and biofluids at atmospheric pressure.3-11 In LAESI the mid-IR laser ablation plume that mostly consists of neutral particulate matter from the sample coalesces with highly charged electrospray droplets to produce ions. Recently, mid-IR ablation of single cells was performed by delivering the mid-IR radiation through an etched fiber. The plume generated from this ablation was postionized by an electrospray enabling the analysis of diverse metabolites in single cells by LAESI-MS.12 This article describes the detailed protocol for single cell analysis using LAESI-MS. The presented video demonstrates the analysis of a single epidermal cell from the skin of an Allium cepa bulb. The schematic of the system is shown in Figure 1. A representative example of single cell ablation and a LAESI mass spectrum from the cell are provided in Figure 2.
Effects of E2 transitions in the Coulomb dissociation of 8B

We examine the Coulomb dissociation of aB in a model that has both E1 and E2 matrix elements. We find that the interference between El and E2 amplitudes produces large asymmetries in the angular and momentum distributions of the emitted protons and 7Be fragments. By measuring these asymmetries one may be able to put constraints on the E2 component and thereby improve the accuracy of the E1 strength that can be extracted from Coulomb dissociation experiments. We also investigate the effect of higher-order dynamical processes and find that they reduce the asymmetries in reactions on high-Z targets. They also reduee the effect of E2 transitions on the dissociation probability and on the peak height of the decay energy spectrum compared to predictions of first-order perturbation theory.
Designating the driver: Establishing a cooperative distribution network in Japan*

This article is an exploratory case study, which describes the recent evolution of a distribution network for ice cream in Japan and explores the forces behind that evolution. The case incorporates the perspectives of actors at the manufacturing, wholesaling, and retail levels. In examining how a particular distribution structure evolved among these parties, we suggest that the resulting structure was a response to environmental changes. We identify power and efficiency as driving forces behind the network architecture, and we identify mechanisms used to facilitate trust between the parties.
Nonstationary learning characteristics of the LMS algorithm

Upper and lower bounding first-order linear recursions for the mean-squared error realized with the LMS algorithm subjected to a sequence of independent nonstationary training vectors are derived. These bounds coincide to give the exact evolution of mean-squared error for the problem of identification of a nonrecursive time-varying system with white-noise excitation. This leads to an exact formula for time-averaged mean-squared error that is used to study optimization of the step-size parameter for minimum time-average misadjustment. New results on dependence of the minimal step size and the minimum misadjustment on the degree of nonstationarity are obtained.
A self-structuring patch antenna

In this paper we have presented a design for a self-structuring patch antenna. This antenna has been shown through simulation to have tunable single-frequency operation with a VSWR of no more than 1.087 over a band from 2 GHz to 9 GHz, and multiple-frequency operation with up to four frequencies at once over the same band. The multiple-frequency mode can be used to enhance the bandwidth of the self-structuring patch antenna, with instantaneous bandwidths of up to .78 GHz (16%) obtained.
Towards Optimal Resource Provisioning for Running MapReduce Programs in Public Clouds

Running MapReduce programs in the public cloud introduces the important problem: how to optimize resource provisioning to minimize the financial charge for a specific job? In this paper, we study the whole process of MapReduce processing and build up a cost function that explicitly models the relationship between the amount of input data, the available system resources (Map and Reduce slots), and the complexity of the Reduce function for the target MapReduce job. The model parameters can be learned from test runs with a small number of nodes. Based on this cost model, we can solve a number of decision problems, such as the optimal amount of resources that can minimize the financial cost with a time deadline or minimize the time under certain financial budget. Experimental results show that this cost model performs well on tested MapReduce programs.
A general solution of the "inverse-system realization" problem for linear dynamical systems with waveform-structured inputs

A new theory and realization methodology for real-time inverse-systems is developed. This new theory, based on the assumption of a linearized dynamical system and uncertain, waveform-structured input signals s(t), effectively overcomes the long-standing difficulties of realizing inverse-systems for systems that have "more poles than zeros" and/or have "zeros in the right-half plane". The results obtained here are derived also for time-varying linear dynamical systems with vector input signals s(t)=(s/sub 1/(t), ..., s/sub r/(t)) and/or vector output measurements y(t)=(y/sub 1/(t), ..., y/sub m/(t)). >
Facilitating transformations in a human genome project database

Human Genome Project databases present a confluence of interesting database challenges: rapid schema and data evolution, complex data entry and constraint management, and the need to integrate multiple data sources and software systems which range over a wide variety of models and formats. While these challenges are not necessarily unique to biological databases, their combination, intensity and complexity are unusual and make automated solutions imperative. We illustrate these problems in the context of the Philadelphia Genome Center for Human Chromosome 22, and describe a new approach to a solution for these problems, by means of a deductive language for expressing database transformations and constraints.
Melting of stress-crystallized polyethylene

Abstract The fusion behavior of lightly cross-linked polyethylene films isothermally crystallized at various temperatures and extensions has been examinedonadifferential scanning calorimeter (DSC). Ameans to hold the specimen at fixed elongation during the melting was devised. At large extensions, a separate higher-temperature endotherm was observed in addition to the major peak, indicating a two-phase nature of the crystal morphology. In addition, crystallization experiments performed on the DSC show the crystallization process to consist of two stages. In contrast to reported results for natural rubber and polychloroprene, the melting temperature for polyethylene was not found to be strongly dependent on crystallization temperature or extension. The reason for the differences between polymers is not presently understood, but they may reflect variations in morphological details.