cssi/SciSciGPT-SciSciNet huggingface dataset:
Single-Phase Cryogenic Flows Through Microchannel Heat Sinks

Cryogenic fluids are used widely in several thermal management applications such as in regenerative cooling of rocket engine combustor liners, missile warning receivers, satellite tracking systems and cryo-adsorbent hydrogen storage systems. Single phase laminar flow and heat transfer rate of liquid nitrogen in microchannels is studied experimentally in this paper.The performance of two distinct geometries of microchannel heat sinks are evaluated and compared for simultaneous developing laminar flow in the Reynolds number range from 180 to 610. The first geometry pertains to parallel microchannels while the second corresponds to a staggered microscale pin fin array. Two parallel microchannel geometries having identical widths of 140μm and identical laminar thermal resistances but with different aspect ratios of 4.7 and 7.6 are compared. The pin fin heat sink consisted of square pins of 395μm side and oriented at 45 degrees to the flow. All three heat sinks have identical heat source surface area.Results are presented in a non-dimensional form in terms of the friction factor, Nusselt, Reynolds numbers and compared with the predictions of existing correlations in the literature for parallel microchannels and micro pin fin heat sinks.© 2014 ASME
Studies on the incorporation of sn-[1,3-14C]glycerol 3-phosphate into glycerolipids by intestinal mucosa.

Abstract Intestinal mucosal microsomes from several animal species (non-fasted) were used to study the formation of glycerolipids from sn-[1,3-14C]glycerol 3-phosphate and palmitoyl-CoA. Rates of glycerolipid biosynthesis were species dependent, since mouse and rat were quite low compared to hamster, guinea pig and man. Under the usual incubation conditions, guinea pig intestinal microsomes formed primarily phosphatidic acid (85–90%). However, when Mg2+ was added to incubations containing intestinal microsomes prepared in the presence of 5 mM EDTA, there was a marked increase in neutral lipid biosynthesis (5–10-fold). These results suggest that intestinal microsomes contain Mg2+-dependent phosphatidate phosphohydrolase (EC 3.1.3.4) which is involved in glycerolipid biosynthesis. All divalent cations studied increased sn-glycerol-3-phosphate acyltransferase (EC 2.3.1.15) activity; however, Ca2+, Ba2+, Zn2+, Cd2+, Ni2+, and Mn2+ antagonized the Mg2+-dependent rise in neutral lipid formation. In all cellular preparations studied, the ratio of neutral lipid (diacylglycerol + triacylglycerol) to total lipid (phosphatic acid + neutral lipid) was low, suggesting that phosphatidate phosphohydrolase may be rate limiting in intestinal neutral glycerolipid biosynthesis.
The comparative submicroscopic morphology of the ring gland of Drosophila melanogaster during the second and third larval instars.

A description is given of the ultrastucture of the ring gland of late second and late third instar larvae of Drosophila melanogaster. The organ contains tissues of four types: (1) corpus allatum cells, (2) prothoracic gland cells, (3) corpus cardiacum cells, and (4) tracheal cells. Axons bearing spherical neurosecretory granules pass from the corpus cardiacum to the corpus allatum. Ecdysone and juvenile hormone are thought to be manufactured by smooth surfaced endoplasmic reticulum contained in the prothoracic gland cell and the corpus allatum cell, respectively. The morphology of these cells at the two developmental stages studied suggests that the switch over from larval to pupal development is preceded during the third larval stage by an increasing hormone secretion by the prothoracic gland cells and a decreasing secretion by the cells of the corpus allatum.
Relationship between Ballistocardiographic Forces and Certain Events in the Cardiac Cycle

The temporal relationships of the various waves of the ballistocardiogram have been studied by means of simultaneously recorded electrocardiograms, femoral pulses, and electrokymograms of the great vessels and heart chambers. A modification of the Dock type of electromagnetic, undamped, direct ballistocardiograph has been employed in this study of 23 normal individuals. The total duration of mechanical systole in the great vessels has been found to correspond closely to the H-L interval. The HIJKL complex of the ballistocardiogram appears to be entirely related to the events of ventricular systole. The M, N and O waves represent after-waves occurring during diastole.
Degradation of graphite/bismaleimide laminates with multiple embedded fiber-optic sensors

This paper summarizes the reduction in mechanical properties of graphite/bismaleimide (Gr/BMI) laminates due to the presence of multiple embedded fiber-optic sensors. Previous work has shown that small quantities of optical fibers embedded parallel to the loading direction have only a negligible effect on the tension behavior of laminated structures. This work establishes the significance of larger quantities of embedded optical fibers on the tensile and compressive behavior of composite laminates. Experimental strength and modulus data from six test groups of seven tension and seven compression specimens are compared to a control group. All specimens were fabricated from G40-600/5245C Gr/BMI pre-preg tape to form a [°3/9o2/°]s stacking sequence. The quantity of optical fibers embedded parallel to the loading direction was varied in the different test groups. Uniaxial compression testing using an IITRI fixture and uniaxial tension testing were performed in accordance with ASTM Standards. Catastrophic failure was induced by fiber fracture. Results indicate that large quantities of embedded optical fibers reduce the static tensile strength up to 4% and stiffness up to 9%, while reducing the static compressive strength up to 24% and stiffness up to 20%. It is concluded that large quantities of embedded optical fibers result in significant degradation of the compressive strength of laminated composite structures, but do not significantly affect the tensile behavior.
Photoabsorption cross sections of OH at 115–183 nm

The absorption spectrum for OH was obtained in the 115-183 nm region. The OH radicals were produced by a pulse discharge of trace H2O in few torr of Ar. Absorption cross sections were obtained by calibration with absorption of the OH (X 2 Pi to A 2 Sigma +) transition. The features in the absorption spectrum are correlated with the excited states 1 2 Sigma -, D 2 Sigma -, 1 2 Delta, B 2 Sigma + and possibly others calculated by van Dishoeck, Langhoff, and Dalgarno. The measured cross sections are comparable with the calculated values.
The Effect of Pressure Upon the Elastic Parameters of Isotropic Solids, According to Murnaghan's Theory of Finite Strain

Murnaghan's theory of finite deformations is applied to a discussion of the effect of hydrostatic pressure upon the elastic coefficients of an isotropic body, for small strains superposed on the hydrostatic strain. Stress‐strain equations for the small strains, and the equations of small motion, are shown to have the same form as those of the classical theory, with elastic parameters which depend upon the pressure. Using a form of elastic potential identical with that of the classical theory, explicit results are found for the pressure coefficients of compressibility, Young's modulus, rigidity and so on; these are compared with such experimental results as are available, with good agreement. A single‐constant formula is derived which gives the volume change of such compressible materials as sodium and cesium up to the highest experimental pressure, 45,000 kg/cm2, within the experimental error.
Surface Integrity of Biodegradable Magnesium-Calcium (Mg-Ca) Alloy by Low Plasticity Burnishing

When a device is implanted into the body, into either hard or soft tissue, the body will respond. While the bulk material of the device is often important for integrity and mechanical success, the device surface is at the interface with biology. Major effort has been spent modifying a biomaterial surface in order to elicit or inhibit a biological response. Metallic biodegradable Magnesium-Calcium (Mg-Ca) alloys have attracted an increased attention for orthopedic fixation applications. This research focuses on low plasticity burnishing (LPB) as a novel surface modification technique that is added to the surface to control biodegradation as a biological response. The effects of burnishing pressure as an important process parameter on surface integrity characteristics such as surface roughness, surface topography, and residual stresses are investigated. Burnished surface roughness is smaller than the machined ones. However, some amount of waviness is observed which might be due to large diameter of the burnishing ball and sever plastic deformation. High compressive residual stresses are measured on the burnished surface.Copyright © 2010 by ASME
Boundary element method solutions for elastic wave scattering in 3D

Time-harmonic elastic wave scattering problems such as those encountered in ultrasonic non destructive evaluation are solved by the boundary element method (BEM). Selected results for spherical and spheroidal shaped voids and inclusions are compared with analytical and other numerical solutions. Results for ellipsoids, which require a full three-dimensional formulation, are provided as a benchmark for comparison when other numerical methods would be developed for this problem class in the future. The modelling of cracklike defects with this formulation is discussed. Recent theoretical findings regarding the fictitious eigenfrequency difficulty (FED) are confirmed by a numerical study.
AS ALWAYS, PROVOCATIVE

Whether or not you concur with Gene V Glass's view of the educational world, you simply must concede that he's provocative. He seems to take special delight in tangling with widely espoused views, and his current assault on standard setting follows that iconoclastic tradition. The verve and skill with which he takes on the educational establishment in this instance commands my admiration, even though at several key points I think his analysis is several kilometers off target. Before quarreling with the Glass position, I should note that his Standards and Criteria paper has already stimulated the kind of dialogue among measurement and evaluation specialists which, in the long run, should sharpen our skills in dealing with the standard-setting enterprise. If that were to be the only consequence of this Glass paper, then I would toss a plaudit or two his way without remorse. But there is another possible consequence of Standards and Criteria that is not so pleasant to contemplate. He has argued emphatically that all standard setting must be mindless and capricious, hence even educators who are attempting to do a decent job in setting performance standards are destined to end up with arbitrary and indefensible standards. Faced with that prophecy of gloom, some well-intentioned standard setters may abandon the very processes that, with care, might have yielded an acceptable answer to the question: "How good is good enough?" There is no reason to dispute Glass's claim that most past standard-setting efforts have been blatantly arbitrary, even if abetted by the naive quantitative schemes that he so deftly slaps around in his analysis. But he goes well beyond castigating prior practices. Indeed, he tells us that we will always be incapable of coming up with standards that are not capricious. That's where he and I part company.
Audio amplifier distortion analysis and measurement

Some of the fundamental techniques for recognizing, measuring, and reducing unwanted distortion in the electronic amplifiers of audio systems are discussed. Three chief sources of electronic distortion—tube nonlinearity, circuit reactances, and random interference—are dealt with in some detail
Hematopoietic changes in mice following Bordetella pertussis vaccine.

SummaryCytologic and ferrokinetic studies in mice following a single injection of B. pertussis endotoxin reveal a marked increase in splenic erythropoiesis accompanied by a decrease in bone marrow erythropoiesis. It is suggested that the intense leukocyte stimulation noted at the site of injection as well as in the bone marrow and spleen, may be responsible for this shift in erythropoiesis.
Regulation of ACTH and cortisol in depression

Disturbances of hypothalamic-pituitary-adrenal regulation are frequently observed in a subgroup of patients suffering from major depression. The mechanism of hypothesized pituitary and hypothalamic involvement in this dysregulation remains relatively uncharacterized. In this paper we investigated the response of adrenocorticotropin (ACTH), as well as cortisol, to dexamethasone inhibition and characterized the dynamic response of ACTH to a one-hour infusion of cortisol in normal subjects and patients suffering from depression. A paradoxical increase in ACTH in response to cortisol is noted in one patient.
Epidermal Growth Factor is a Positive in Vivo Regulator of CTP: Cholinephosphate Cytidylyltransferase

CTP: cholinephosphate cytidylyltransferase (CT) is a key enzyme required for surfactant phosphatidylcholine synthesis, and its activity is regulated by lung lipids. This study evaluated the effect of epidermal growth factor (EGF) on the phospholipid content and the expression of CT in the lung following direct in vivo administration to the newborn rat. EGF caused an increase in cytidylyltransferase activity by 58% in lung cytosol. The increase in cytosolic activity was not mediated by a corresponding increase in enzyme mass. Further, these changes in cytidylyltransferase activity were associated with a significant increase in total lung phospholipid and phosphatidylcholine content. The results suggest that EGF may have important maturational effects on lung surfactant metabolism.
NMDA Receptors Activated by Subventricular Zone Astrocytic Glutamate Are Critical for Neuroblast Survival Prior to Entering a Synaptic Network

Summary Even before integrating into existing circuitry, adult-born neurons express receptors for neurotransmitters, but the intercellular mechanisms and their impact on neurogenesis remain largely unexplored. Here, we show that neuroblasts born in the postnatal subventricular zone (SVZ) acquire NMDA receptors (NMDARs) during their migration to the olfactory bulb. Along their route, neuroblasts are ensheathed by astrocyte-like cells expressing vesicular glutamate release machinery. Increasing calcium in these specialized astrocytes induced NMDAR activity in neuroblasts, and blocking astrocytic vesicular release eliminated spontaneous NMDAR activity. Single-cell knockout of NMDARs using neonatal electroporation resulted in neuroblast apoptosis at the time of NMDAR acquisition. This cumulated in a 40% loss of neuroblasts along their migratory route, demonstrating that NMDAR acquisition is critical for neuroblast survival prior to entering a synaptic network. In addition, our findings suggest an unexpected mechanism wherein SVZ astrocytes use glutamate signaling through NMDARs to control the number of adult-born neurons reaching their final destination.
Use of in situ pericardium for surgical relief of pulmonary venous obstruction following Mustard's operation.

Abstract A technique is described for relief of pulmonary venous obstruction following the Mustard procedure. The functional left atrium is enlarged by using the pericardium in situ. This is expected to allow for growth of the pericardial patch and to avoid recurrent obstructions. This technique has also been used in reoperations for systemic venous obstruction after enlargement of the systemic venous baffle with a patch.
Non-ionic Surfactants as Drag Reducing Additives

THE addition of small amounts of certain materials to fluids undergoing turbulent flow causes a reduction on pressure drop called drag reduction. Polymer solutions, soap solutions and solid suspensions in liquids and gases have all demonstrated this phenomenon1.
Rapid induction of prostaglandin synthesis in piglet astroglial cells by interleukin 1α

Abstract We examined effects of interleukin 1α (IL-1α) on prostaglandin production in piglet cultured astroglia. Immuno-and morphologically identified polymorphic and process-bearing astrocytes were collected from cerebral cortex and white matter from piglets (1–3 days of age). Levels of Prostaglandins were determined using enzyme immunoassay. Baseline levels for prostaglandin (PG) F 2α , were 631 ± 332 pg/ml and increased to 1417 ± 353 pg/ml 20 min after addition of 11 μg/ml IL-1α ( p p n = 7). Only small amounts of 6-ketoPGF 2α or PGE 2 were detected in medium under baseline conditions or in the presence of IL-1α. Medium alone did not change PGF 2α levels ( n = 3). Coapplication of cycloheximide (10 −3 M) blocked the increase in PGF 2α ( n = 3). We conclude that IL-1α causes a rapid increase in prostaglandin production by astroglia, and this process involves a step requiring continued or increased protein synthesis.
Interlimb muscle and fat comparisons in persons with lower-limb amputation.

Abstract Sherk VD, Bemben MG, Bemben DA. Interlimb muscle and fat comparisons in persons with lower-limb amputation. Objectives To investigate differences in muscle and fat tissue between amputated and intact limbs in subjects with transfemoral and transtibial amputations and to determine the effect of amputation level on limb differences. We hypothesized that the amputated limb would have a higher relative amount of fat than the intact limb, and transfemoral amputees would have greater limb differences in muscle size than transtibial amputees. Design Cross-sectional, repeated-measures design. Setting Laboratory. Participants Subjects included persons with unilateral transfemoral (TF) (n=5) and transtibial (TT) (n=7) amputations and age- and sex-matched nonamputation controls (n=12). Interventions Not applicable. Main Outcome Measures Muscle cross-sectional areas and fat cross-sectional areas of the end of residual limbs were compared with similar cross-sectional sites of the intact limb by using peripheral quantitative computed tomography scans. Thigh and lower-leg fat mass (FM) and bone-free lean body mass were measured by dual-energy x-ray absorptiometry. Results There was a 93% to 117% difference between limbs in muscle cross-sectional areas for TF and TT. TT had a between-limb difference of 39% for fat cross-sectional areas. Thigh bone-free lean body masses and FM were significantly ( P P Conclusions Muscle atrophy was prevalent in the residual limb with larger relative amounts of fat in the thighs, especially in TF subjects.
Relating inhomogeneous deformation to local texture in zirconium through grain-scale digital image correlation strain mapping experiments

Abstract The effect of local texture on inhomogeneous plastic deformation is studied in zirconium subjected to uniaxial compression. Cross-rolled commercially pure Zr 702 plate that had a strong basal (0 0 0 1) texture through the plate thickness, and a non-basal texture in cross-section, was obtained. At a compressive strain rate of 1 s −1 , samples loaded either in the through-thickness or in-plane directions exhibited significant differences in yield strength, hardening response and failure mechanisms. These macroscopic differences are related to microstructural features by combining information from electron backscattered diffraction with real time in situ imaging and subsequent full-field strain measurements obtained using digital image correlation. Experimental results indicate that the through-thickness loaded zirconium samples, which show a strong basal-texture in the loading direction, do not deform homogeneously – implying the lack of a representative volume element. The detailed surface deformation fields provided by digital image correlation allow for a qualitative and quantitative analysis of the relationship between grain orientation and patterns of deformation bands that form as the precursors to development of an adiabatic shear band in the through-thickness loaded sample. For the in-plane loaded samples, inhomogeneities still exist at the microscale, but the collective behavior of several grains leads to a homogeneous response at the macroscale. It is observed that local texture for hcp polycrystals, which are significantly slip restricted, can directly affect both local and global response, even at low to moderate plastic strains.
Sail flap excision for the iguana neck deformity

Summary A method of recontouring the lax submental tissues of the sagging neck is discussed.
The role of radiosurgery and particulate embolization in the treatment of dural arteriovenous fistulas.

✓ Over the past 5 years 29 patients with dural arteriovenous fistulas (AVFs) were treated by the authors using the Leksell radiosurgical gamma knife unit. Within 2 days after radiosurgery, 17 patients with AVFs that exhibited retrograde pial or cortical venous drainage (12 patients) and/or produced intractable bruit (eight patients) underwent particulate embolization of external carotid feeding vessels. The rationale for this treatment strategy was that radiosurgery was expected to cause obliteration of most fistulas after 12 to 36 months. In patients with bruit, ocular symptoms, or in those at risk for hemorrhage, treatment with embolization after radiosurgery kept the fistulas angiographically visible for radiosurgical targeting yet offered palliation of symptoms and temporary, partial protection from hemorrhage during the latency period. In 12 patients, preobliteration embolization immediately reduced (10 patients) or eliminated (two patients) retrograde pial venous drainage. To date, no lesion has hem...
Cerebral endothelial cell culture. II. Adenylate cyclase response to prostaglandins and their interaction with the adrenergic system.

Abstract The response of endothelial adenylate cyclase (AC) to prostaglandins (PGE 1 , PGE 2 , PGF 1α , PGF 2α , PGD 2 and PGI 2 ) and the relationship of PGE 2 to adrenergic systems were investigated in cerebrovascular endothelial cultures. E-type prostaglandins and PGI 2 were more effective in stimulating endothelial AC (EC 50 = 3 × 10 −7 M, and 3 × 10 −7 M, respectively) than prostaglandins of the F-series and PGD 2 which activated AC at high doses only. A modulation of endothelial AC response to either PGE 2 or norepinephrine (NE) was observed in the presence of both agents in the system. It was manifested by a dose-dependent NE inhibition of the PGE 2 -stimulated formation of cAMP, which was partially restored by phentolamine. Alpha and β-adrenergic agonists (α, clonidine and 6-fluoronorepinephrine; β, isoproterenol) also partly blocked while forskolin and PGE 2 synergistically stimulated the production of cAMP in the endothelial cultures. These findings strongly suggest that the interaction of prostaglandins and α- and β-adrenergic agonists with the AC system in cerebrovascular endothelium may play a role in the regulation of the cerebral microcirculation and/or blood pressure.
Variations in gene expression among different types of human skeletal muscle

There is a consistent variation in the response of different skeletal muscle groups to mutations in genes known to cause muscular dystrophy, yet these muscles appear histologically similar. To better understand these phenotypic differences, we analyzed gene expression patterns in control muscle specimens obtained from four sites at autopsy: deltoid, quadriceps, gastrocnemius, and tibialis anterior (TA). A total of 35 muscle samples from nine individuals (four pediatric and five geriatric) were studied. Factors potentially influencing gene expression in the different samples included individuality, age, muscle type, gender, cause of death, postmortem interval, and ethnicity. The first three factors, in decreasing order, were found to have a significant impact on the stratification of muscle specimens. A novel analytic method, using a second round of normalization, was used to elicit differences between muscle types. This approach may be extended to a broader survey, potentially elucidating a molecular classification of the skeletal muscles.
Child support awards: differentials and trends by race and marital status.

This paper examines differentials in the award of child support by race and marital status and evaluates the impact of the child support enforcement program, begun in 1975, on child support awards. According to data from the 1979 and 1982 March/ April Match Files of the Current Population Survey, never-married mothers are significantly less likely than ever-married mothers to have a child support award; which do, however, cannot readily be explained by our model. Ever-disrupted black marriages resulted in awards considerably less frequently than nonblack marriages, although the enforcement program has had a positive effect.
ADHD status and degree of positive illusions: moderational and mediational relations with actual behavior.

OBJECTIVE Past research suggests that many children with behavior problems display overly positive self-views ("positive illusions"); some researchers have hypothesized that these positive illusions may prevent these children from improving their behavior. This research investigates positive illusions in the behavioral domain as a moderator and mediator of the relation between ADHD status and behavior in a summer program setting. METHOD Boys with ADHD and comparison boys rated their own behavioral competence; discrepancies between these self-ratings and the reports of boys' teachers served as an index of behavioral positive illusions. Dependent variables were derived from a behavioral point system that provided specific data about boys' positive and negative behaviors and from counselor ratings of behavior. RESULTS/CONCLUSION Hierarchical multiple regression and analyses revealed no evidence supporting a moderational association, although ADHD status and behavioral positive illusions were additive predictors of the dependent variables. Post hoc analyses revealed a pattern of mediational effects that were strongest for dependent variables assessing conduct problem behaviors.
A Coupled Tube-Tissue Model for Frequency Calculation of Arterial Tubes With Tissue

Vibro-acoustography is a new noncontact imaging method based on the radiation force of ultrasound. We extend this new technique for tissue characterization of arterial vessels by vibration techniques. In this paper a theoretical model for vibration analysis of arterial vessel with tissue is developed. Experimental studies were carried out on a silicone rubber tube embedded in a cylindrical gelatin phantom of larger radius, which simulates a large artery and the tissue body. The fundamental mode is well excited by the radiation force of ultrasound. The fundamental frequency was measured 81.8 Hz for a tube-phantom structure that is quite close to our theoretical prediction of 83.3 Hz.© 2003 ASME
Selection of the Best from Lognormal Populations Using Type-II Censored Data: Unknown σi 2 Case

Abstract We consider the problem of selecting the best from k lognormal populations using type-II censored samples. The selection parameter is taken to be a linear combination, a μ + b σ2, since many quantities of interest associated with lognormal can be expressed as exp(a μ + b σ2). Since the known case has been dealt with elsewhere, the case of unknown is the focus of this paper. Two-stage procedures are proposed, one for the equal case and the other for the unequal case. The procedure for the equal case, with a simple modification for the subcase when there is no censoring, is comparable to the procedure of Bechhofer et al. (1954), and the comparison is discussed. A discussion on the optimality of the procedures is also included. Recommended by M. Aoshima
Mechanics from Aristotle to Einstein

Michael J. Crowe, Mechanics from Aristotle to Einstein. Santa Fe: Green Lion Press, 2007. 331 pp. $17.95 (pbk). ISBN-13 978-1-888-00932-3. It is always a pleasure to peruse a new work by Michael J....
Intrinsic triggering mechanisms in focal paroxysmal discharges.

SUMMARY Studies were made on neurons of the motor cortex of cats before and after topically applied strychnine evoked focal paroxysmal discharges. No obvious changes were found in “epileptic” neurons in resting conditions, especially in their membrane resting potentials and input resistance. After strychnine application, decrease and inversion of IPSPs were observed in a group of pyramidal tract and non-identified cells which also showed characteristic “epileptiform” burst discharges. The hypothesis of a strychnine altered IPSP equilibrium potential which could account for the observed changes in IPSP was supported by the results of conductance measurements during the IPSPs (and during the same period when the IPSPs were decreased, abolished or inverted). These measurements revealed no changes in IPSP “strength”; i.e., in the post-synaptic conductance increase generated by the synaptic action. The findings were discussed in connection with possible triggering mechanisms of neuronal epileptiform discharges. RESUME Cette etude porte sur des neurones du cortex moteur du chat avant et apres l'application locale de strychnine provoquant des decharges focales paroxystiques. Aucune modification evidente n'a ete trouvee au niveau des neurones epileptiques dans des conditions de repos, notamment il n'existait pas de modifications du potentiel de membrane de repos et de la resistance d'entree. Apres l'application de strychnine une diminution et une inversion des IPSP ont ete observees au niveau d'un groupe de cellules du faisceau pyramidal, ainsi qu'au niveau d'autres cellules non identifiees mais qui montraient des decharges en bouffees de type epileptique caracteristiques. L'hypothese qu'une aletration du potentiel de membrane due a la strychnine pourrait etre tenue pour responsable des modifications observees au niveau de l'IPSP, etait soutenue par les mesures de conductance pendant les IPSP (et pendant la meme periode quand les IPSP etaient diminuees, abolies ou inversees). Ces mesures n'ont pas montre de modifications dans I'IPSP “en puissance” c'est-a-dire au niveau de l'action postsynaptique. Ces resultats sont discutes en relation avec la possibilite de mecanismes de declenchement des decharges neuroniques de type epileptique.
A high-quality cross-sectioning method: Examples of applications in optimizing solar cell contact firing

A damage-free polishing method is developed to prepare a high-quality cross-section of a large length of a solar cell. A 1-inch-long sample is diced from the solar cell and embedded in wax using a specially designed chuck. The sample edge is sequentially polished by progressively reducing the grit sizes. The final polishing is done by Chemical Mechanical Polishing (CMP). This polishing procedure produces a highly flat edge, with excellent interfaces between metal contacts and the Si cell. The planarity of the wafer edge makes it possible to perform a variety of analyses of various regions and the interfaces of the cell, using optical microscopy, EDX, scanning electron microscopy (SEM), and conductive AFM (C-AFM). Here, we will discuss some details of the chuck and the polishing procedure, and present some applications for optimizing the contact firing process. This method has an added advantage of delineating the back surface field for optical observation.
Trigeminal neuralgia and vascular compression in patients with trigeminal schwannomas

OBJECTIVE Trigeminal neuralgia (TN) is often associated with neurovascular compression. However, intracranial tumors are occasionally observed, particularly when symptoms are atypical. We describe three patients with Type-1 TN and trigeminal schwannoma diagnosed by magnetic resonance imaging, with concomitant arterial compression of the trigeminal nerve. CLINICAL PRESENTATION All three patients had Type-1 TN with spontaneous onset, paroxysm-triggered pain, and response to antiepileptic medication. Contrast-enhanced T1-weighted magnetic resonance imaging scans demonstrated an ipsilateral enhancing perineural mass consistent with a schwannoma. Two of the three patients had previously undergone gamma knife radiosurgery without improvement. Subsequent high-resolution magnetic resonance imaging in all three patients revealed obvious compression of the trigeminal nerve by an arterial structure. INTERVENTION Two patients underwent retrosigmoid craniectomy followed by microvascular decompression and remain pain-free. One patient elected not to pursue surgical intervention. CONCLUSION Although intracranial tumors are occasionally observed in patients with TN, neurovascular compression must still be considered as an etiology, especially if typical TN symptoms are reported.
Famine, Impoverishment and the Creation of a Labor Reserve in Central Tanzania

An often under-recognized response to drought by members of pastoral and mixed farming communities in Africa is semi-regular migration in search of wage employment. Among the Gogo of the Dodoma and Singida Regions of central Tanzania this strategy has increasingly, since the 1940s, been the response of individuals to a cycle of drought, loss of livestock, and impoverishment. Before World War II hardly any people left Ugogo for wage labor; by 1955 20 per cent of the population was estimated to be absent at any particular time, with the proportion rising sharply during years of drought. Today, local stereotypes depict the Wagogo as beggars and casual laborers throughout Tanzania. The transitional period between 1942 and 1955 was marked by four major famines in which thousands of people died of malnutrition and associated diseases. These famines also marked a dramatic change in the distribution of livestock ownership as wealthy cattle owners no longer used livestock to control the labor of food deficit households and individuals found themselves forced into migrant labor. Colonial policy during and after the war helped precipitate these changes through labor conscription and the demand for labor from the Groundnut Scheme in the Kongwa area of the region.
Thermoelasticity of weak polyelectrolyte networks

The thermoelastic behavior of poly(vinyl alcohol)–poly(acrylic acid) networks was evaluated in pure water and CaCl2 solution. The ratio fe/f of the energy component of the force to the total force, evaluated without taking into account polymer–diluent specific interactions, ranged from −0.75 for networks swollen in pure water to −5.7 in 0.1M CaCl2. However, an analysis based on Flory's theory of polyelectrolyte gels yields fe/f constant at −1.32 when specific interactions are accounted for. In addition, the variation of In (r2)0 with CaCl2 concentration is 2000 times that with water. In neither pure water nor CaCl2 solution can specific interactions be neglected.
ABSTRACT BIOLOGICAL SYSTEMS AS SEQUENTIAL MACHINES. II. STRONG CONNECTEDNESS AND REVERSIBILITY.

It was previously shown that the abstract biological systems called. (ℳ, ℛ)-systems could be regarded formally as sequential machines, and that when this was done, the reversibility of environmentally induced structural changes in these systems was closely related to the strong connectedness of the corresponding machines. In the present work it is shown that the sequential machines arising in this way are characterized by the property that the size of the input alphabet is very small compared with the size of the set of states of the machine. It is further shown that machines with this property almost always fail to be strongly connected. Therefore, it follows that one of the following alternatives holds: either most environmentally induced structural alterations are not environmentally reversible, or else many mappings in the category from which the (ℳ, ℛ)-systems are formed must not be physically realizable.
A MULTITAXONOMIC APPROACH TO UNDERSTANDING LOCAL‐ VERSUS WATERSHED‐SCALE INFLUENCES ON STREAM BIOTA IN THE LAKE CHAMPLAIN BASIN, VERMONT, USA

Twenty-one stream reaches in northwestern Vermont were surveyed to assess the relative influence of local- and watershed-scale variables on stream biotic assemblages including fish, aquatic macroinvertebrates and birds. Data were collected during the summers of 2003 and 2004 and included quantitative and qualitative geomorphic and habitat assessments (local-scale) and land-use characterization and modelled annual flow and sediment loading (watershed-scale). Biotic assemblages were surveyed to capture characteristics related to abundance, diversity and composition. Principal components analysis (PCA) was used to generate sets of factors representing unique scenarios of geophysical data derived from various spatial extents within the watershed. These factors were then used as the independent variables in multiple regression models using the biotic data as the dependent variables. Forty significant models were built from the combination of the eight scenarios and 11 dependent variables. Fish assemblage diversity and composition were influenced by a combination of local-scale and watershed-scale variables; however, the qualitative local data were more predictive than the quantitative data. Local-scale data and sediment (model-derived) were important factors in building significant macroinvertebrate models. Bird abundance and species richness were best predicted using local geomorphic characteristics and the qualitative local data. Our results reinforce the concept that whereas both local- and watershed-scale variables affect stream biota, their relative influence depends upon the individual ecology of each taxon. In order to address these issues, comprehensive watershed management, restoration and conservation plans would benefit from assessments at multiple scales and from geomorphological, watershed and multitaxonomic perspectives. Copyright © 2010 John Wiley & Sons, Ltd.
Vesicle size and stability of biomimetic liposomes from 3′-sulfo-Lewis a (SuLea) containing glycolipids

Abstract We report on the use of a natural Lewis type saccharide ligand, 3′-sulfo-Lewis a (SuLe a ) for glycocalyx-mimetic surface modification of liposomes. Two SuLe a -containing glycolipids, monovalent SuLe a -lipid and trivalent SuLe a (TSuLe a )-lipid, were synthesized, and used with 1,2-distearoyl- sn -glycero-3-phosphocholine (DSPC) and cholesterol to prepare unilaminar vesicles (ULVs) by a freeze–thaw and extrusion method. The effects of the glycolipid concentrations and the pore sizes of extrusion membranes on vesicle size and stability were investigated by photon correlation spectroscopy (PCS). Glycoliposomes, with 5% SuLe a - or TSuLe a -lipids obtained by 50 nm extrusion, had 25–30% more vesicles less than 100 nm in diameter compared with the 100 nm extrusion. TSuLe a -liposomes always produced larger vesicle size than SuLe a -liposomes, which we attribute to the larger TSuLe a headgroup. Both SuLe a - and TSuLe a -liposomes increased their vesicle size with increasing glycolipid concentration from 5% to 15%, and demonstrated good stability at room temperature for over 1 month. Further increasing the glycolipid concentration to 20% resulted in large vesicle aggregation after 5 days for TSuLe a -liposomes, while the SuLe a -liposomes remained stable for 10 days. SuLe a - and TSuLe a -liposomes with 15% glycolipids demonstrated better stability due to the electrostatic effect from the negatively charged SuLe a and TSuLe a headgroups. The results indicate that the biomimetic liposomes with SuLe a - and TSuLe a -lipids with 5 to 15% incorporation are sufficiently stable for the potential applications in targeted drug delivery.
An X-ray beam position monitor based on the photoluminescence of helium gas

Abstract A new method for white beam position monitoring for both bend magnet and wiggler synchrotron X-ray radiation has been developed. This method utilizes visible light luminescence generated as a result of ionization by the intense X-ray flux. In video beam position monitors (VBPMs), the luminescence of helium gas at atmospheric pressure is observed through a view port using a CCD camera next to the beam line. The beam position, profile, integrated intensity and FWHM are calculated from the distribution of luminescence intensity in each captured image by custom software. Misalignment of upstream apertures changes the image profile making VBPMs helpful for initial alignment of upstream beam line components. VBPMs can thus provide more information about the X-ray beam than most beam position monitors (BPMs). A beam position calibration procedure, employing a tilted plane-parallel glass plate placed in front of the camera lens, has also been developed. The accuracy of the VBPM system was measured during a bench-top experiment to be better than 1 μm. The He-luminescence-based VBPM system has been operative on three CHESS beam lines (F hard-bend and wiggler, A-line wiggler and G-line wiggler) for about a year. The beam positions are converted to analog voltages and used as feedback signals for beam stabilization. In our paper we discuss details of VBPM construction and describe further results of its performance.
Preliminary x-ray characterization of authentic providence virus and attempts to express its coat protein gene in recombinant baculovirus

Providence Virus (PrV) is a non-envoloped, T = 4 icosahedral beta-tetravirus that undergoes autocatalytic cleavage of its coat protein precursor after capsid assembly. This is also a well characterized function of Nudaurelia capensis ω virus (NωV), a member of the related omegatetraviruses, whose x-ray structure has been determined. Virus-like particle (VLP) production of PrV in a recombinant baculovirus expression system was attempted to obtain high VLP yields for comparison of structural and autocatalytic active site properties between these virus groups. This resulted in insoluble aggregates of PrV coat protein even though NωV VLPs have been successfully produced in the same system. Betatetraviruses may be more dependent on compartmentalization and availability of their full-length genome for proper folding and assembly. However, crystals were grown of limited quantities of authentic PrV produced in cell culture and a partial X-ray data set collected to 3.8 A resolution. The virus particle position and orientation in the unit cell was determined by space group consideration and rotation function analysis. A phasing model, based on NωV, was developed to initiate the structure solution of PrV.
Vulnerable populations in the underuse of the US Health Care System by persons with diabetes mellitus and diabetic macular edema.

Vulnerable Populations in the Underuse of the US Health Care Systemby PersonsWith Diabetes Mellitus andDiabeticMacular Edema To the Editor We read with great interest the recent article by Bressler et al1 describing the current state of diabetic eye care in the United States. The lack of clinical eye care being provided to patients with diabetes mellitus is both alarming and concerning, especially in light of advances in visionpreserving treatment for diabetic macular edema (DME). Diabetes, amongother chronicdiseases, is increasingat an alarming rate in the United States. Ample evidence demonstrates thatwithin theUnitedStates and internationally,more than 40% of cases (sometimes as many as 70%) may go undiagnosed.2Theproblemofunderdiagnosis isgreaterwithin socioeconomicallydeprivedandethnicminoritygroups.3Given the case definition in this article (self-reported diabetes from theNationalHealthandNutritionExaminationSurveysample), it is likely that a substantialnumberof cases in the samplehave beenoverlooked.The scaleofunderscreeningandundertreatment of DMEmay be even greater than we think. The data from Bressler and colleagues’ study suggest a greater relative proportion of ethnic minorities and populations with lower socioeconomic status among the diabetic groups with diabetic retinopathy (DR) and DME.1 Patients of lower socioeconomic status have previously been shown to have reduced access to vision-preserving services.3 Thismay explain, at least in part, the increased relative prevalence of DR and DME among these vulnerable groups. The Patient Protection and Affordable Care Act and Medicaid expansion in many states may help alleviate this access issue. The Patient Protection and Affordable Care Act mandates zerocost diabetic screenings to patients, reducing financial barriers to diagnosis. Additionally, new quality initiatives may push clinicians to optimize visual outcomes among diabetic patients. Thepercentage of patientswithDRandDME in this study whowere told byphysicians that theyhad retinopathy is startlingly low. New and innovative strategies, alongwith proper education of both patients and physicians, must be adopted to ensure timely diagnosis and effective management of DR andDME to prevent long-term visual complications of diabetes. Previous studieshave successfullyuseddemographic factors to predict patients at risk for not attending DR screening visits with health care professionals.4 While this important study estimates the current undertreatment of DME, ongoing health care reform in the United Statesandtheanticipatedchanges incoverage for themostvulnerablepopulationsnecessitate reassessmentof access to care aswell as outcomes of screening and treatment following full implementationof thePatient Protection andAffordableCare Act. We eagerly anticipate the results of these studies.
Ultrasound-guided caudal and sacroiliac joint injections

Caudal epidural steroid injection and sacroiliac joint injection are two very commonly employed interventions at any pain clinic. These injections are traditionally performed under fluoroscopic guidance, but recently the use of ultrasound (US) guidance has been reported. We will review the relevant anatomy, sonoanatomy, and the US-guided technique.
e-Ana and e-Mia: A Content Analysis of Pro–Eating Disorder Web Sites

Objectives. The Internet offers Web sites that describe, endorse, and support eating disorders. We examined the features of pro–eating disorder Web sites and the messages to which users may be exposed.Methods. We conducted a systematic content analysis of 180 active Web sites, noting site logistics, site accessories, “thinspiration” material (images and prose intended to inspire weight loss), tips and tricks, recovery, themes, and perceived harm.Results. Practically all (91%) of the Web sites were open to the public, and most (79%) had interactive features. A large majority (84%) offered pro-anorexia content, and 64% provided pro-bulimia content. Few sites focused on eating disorders as a lifestyle choice. Thinspiration material appeared on 85% of the sites, and 83% provided overt suggestions on how to engage in eating-disordered behaviors. Thirty-eight percent of the sites included recovery-oriented information or links. Common themes were success, control, perfection, and solidarity.Conclusions. Pro–eat...
Understanding the mechanisms of sickle cell disease by simulations with a discrete particle model

Sickle cell disease (SCD) is an inherited blood disorder characterized by rigid, sickle-shaped red blood cells (RBCs). Because of their rigidity and shape, sickle cells can get stuck in smaller blood vessels, causing blockages and depriving oxygen to tissues. This study develops and applies mathematical models to better understand the mechanism of SCD. Two-dimensional models of RBCs and blood vessels have been constructed by representing them as discrete particles interacting with different forces. The nonlinear, elastic property of healthy RBCs could be adequately reproduced using a cosine angle bending force and a worm-like chain spring force. With the ability to deform, RBCs can squeeze through narrow blood vessels. In modeling sickle cells as rigid bodies and applying repelling and friction forces from the blood vessel, this study shows that geometrical factors (dimensions of the sickle cell and blood vessels) as well as rigidity and adhesiveness of the sickle cell all play an important role in determining how, and if, sickle cells become trapped within narrow blood capillaries. With lack of data to validate the model, this study primarily provides a sensitivity analysis of factors influencing sickle cell occlusion and identified critical data to support future modeling.