cssi/SciSciGPT-SciSciNet huggingface dataset:
Spinal neurogenesis and axon projection: A correlative study in the rat

The purpose of the present study was to determine the relationship between the duration of a spinal neuron's neurogenic period and the length of its axon or level of projection. Spinal segment L1 was chosen for examination and neurons were divided into four projection groups: (1) supraspinal projection (SSp), (2) long ascending propriospinal (LAPr), (3) short ascending propriospinal (SAPr), and (4) descending propriospinal (DPr). To determine the duration of the neurogenic period for each group, 3H-thymidine was administered to fetal rats during the proliferative period for spinal neuroblasts on one of embryonic (E) days E13 through E16. Between 50 and 100 days after birth neurons in each group were labeled with the retrograde fluorescent tracer Fluoro-Gold. To demonstrate nerve cells with SSp projections, spinal cords were hemisected at spinal segment C3 in one group of animals and Fluoro-Gold was applied to the sectioned surface of the cord. Three additional sets of animals were used to label nerve cells with LAPr, SAPr, and DPr projections by injecting Fluoro-Gold into the gray matter at spinal segments C6, T12, and L5, respectively. Neurons labeled with both Fluoro-Gold and 3H-thymidine and neurons labeled with Fluoro-Gold alone in each animal in each group were counted and the data statistically analyzed. Results showed that within each spinal lamina neurons with different projections were generated, i.e., completed cell division, at significantly different rates. Neurons with the longest axons, those with SSP projections, were generated first. These were followed by those with LAPr projections, and finally those with SAPr and DPr projections. In most laminae there was no significant difference between the neurogenic periods of rostrally projecting short propriospinal (SAPr) neurons versus caudally projecting short propriospinal (DPr) neurons. It was concluded that the duration of the neurogenic period for a given group of neurons within each spinal lamina is inversely related to the distance between the nerve cell and its projection site regardless of the direction of its projection. © 1993 Wiley-Liss, Inc.
HADRON SPECTROSCOPY AT CLAS

Meson photoproduction was studied at the CEBAF Large Acceptance Spectrometer (CLAS) utilizing a 5.5 GeV/c photon beam incident on a hydrogen target. Here we report on the partial wave analyzes (PWA) performed on the exclusive final states π+π+π-n and K+K-π+n. In addition, CLAS has data on the final state π+π0π-p which will be reported in the near future. The analysis of the π+π+π- system shows clearly the a2(1320), as well as evidence for the a1(1260) and the π2(1670). The π1(1600), previously observed in π-p interactions, is seen very weakly here. In the K+K-π+n channel there is is evidence for the Θ+(1540) S=+1 baryon pentaquark. The PWA of this system gives an excellent description of the background which rules out mesonic reflection as a source of the signal.
The significance of QS deflections in the right-sided precordial leads: Autopsy correlation

Abstract 1. 1. The hearts of 55 patients in whom the electrocardiograms displayed QS deflections in the right-sided precordial leads were studied at autopsy for disease of the septum and overlying anterior wall myocardium. 2. 2. The electrocardiograms were divided into 4 groups on the basis of the initial QRS deflections in Ve and V6. 3. 3. QS deflections in the right precordial leads were associated with anterior myocardial infarction and septal myocardial infarction. With one exception, a myocardial lesion was present when there was a QS deflection in Ve. 4. 4. The highest incidence of septal infarction was associated with initial negativity in Ve, i.el, QS or qR deflections. 5. 5. Left bundle branch block occurred only in Group 1, i.e., in electrocardiograms in which initial positivity of the QRS complex was displayed in Ve, V6, and aVF. In this group q waves were common in aVL and rarely present in Lead I, and initial negativity was invariably registered in aVR. When myocardial infarction was present, it was concealed by the pattern of left bundle branch block. 6. 6. There was a positive correlation between the type of electrocardiogram and septal myocardial infarction, but no specific fraction of septum appeared to be crucial in the genesis of the electrocardiographic pattern of septal infarction. 7. 7. There is no relationship between involvement of the anterior wall overlying the septum and the electrocardiographic pattern, but involvement of this portion of the myocardium is most common in anterior wall infarction.
The Oldest Vertebrate Fossil

NOTICING in your issue of April 11 a reference to the discovery of specimens of Cyathaspis in the Silurian of Gotland in strata equivalent to the English Wenlock, and with it the statement that these fossils are “for the present the oldest known vertebrates,” I am led to call your attention to the species described by myself from Silurian strata in Pennsylvania in 1885 (p. 48), and again in 1892 (p. 542), in the Quarterly Journal of the Geological Society. I forward with this a copy of the paper, from which it will be seen that the Salina (Ononduga) beds that yielded Palaeaspis are older than the Ludlow (or Lower Helderberg), and that the Clinton are older than the Wenlock (or Niagara). Consequently Onchus Clintoni of the latter group is thus far the oldest vertebrate.
Evidence that 4‐aminobiphenyl, benzidine, and benzidine congeners produce genotoxicity through reactive oxygen species

4-Aminobyphenyl (4-Ab), benzidine (Bz), and Bz congeners were evaluated for their ability to induce genotoxicity through an oxidative mechanism. The mutagenicity of these compounds was tested in the presence and absence of Aroclor 1254-induced rat S9 mix using Salmonella typhimurium tester strain TA102, which is sensitive to agents producing reactive oxygen species (ROS). In the presence of S9, 4-Ab, Bz, N-acetyl-benzidine, and 3,3 0 -dimethoxybenzidine were strongly mutagenic in TA102, whereas, 3,3 0 ,5,5 0 -tetra-methylbenzidine, 3,3 0 -dimethylbenzidine (O-tolidine), and N,N 0 -diacetylbenzidine were not mutagenic. In addition, 3,3 0 -dichlorobenzidine and 4,4 0 -dinitro-2-biphenylamine were directly mutagenic in TA102. Incorporation of the free radical and metal scavengers, catalase, superoxide dismutase (SOD), butylated hydroxytolune (BHT), and ethylenediamine tetraacetic acid (EDTA) reduced the mutagenic responses of 4-Ab and Bz, whereas heat-inactivated catalase and SOD had no effect. 4Ab and Bz also induced lipid peroxidation in the presence of S9 mix as shown using the thiobarbituric acid reactive substances assay. The results of this study indicate that 4-Ab and Bz induce mutations through the induction of ROS. Environ. Mol. Mutagen. 48:000–000, 2007. V C 2007 Wiley-Liss, Inc.
STRUCTURE OF TYPE 5 ADENOVIRUS. I. ANTIGENIC RELATIONSHIP OF VIRUS-STRUCTURAL PROTEINS TO VIRUS-SPECIFIC SOLUBLE ANTIGENS FROM INFECTED CELLS.

Type 5 adenovirus was purified by fluorocarbon (freon 113) treatment followed by banding in a CsCl equilibrium density gradient. This method permitted separation of virus from normal host cell materials and virus-specific soluble antigens. Virus banded in CsCl with a mean bouyant density of 1.3349 gm/cm3. The three virus-specific soluble antigens (group- and type-specific antigens and toxin) banded together with a mean bouyant density of 1.2832 gm/cm3. The group-specific antigen was the predominant antigen of the purified virus particle, whereas the group- and type-specific antigens were present in equal titers in the antigen band. Infectious virus particles were inactivated by prolonged dialysis at pH 10.5. Centrifugation of inactivated virus preparations in a CsCl equilibrium density gradient resulted in separation of virus DNA from specific antigen: the antigens banded with a mean bouyant density of 1.2832 gm/cm3 and the DNA sedimented to the bottom of the tube. The predominant antigen derived from purified virus particles was the group-specific antigen and it was in the same relative proportion to the type-specific antigen as measured in intact particles. The antigens derived from disrupted virus were immunologically identical with the soluble virus antigens present in infected cells.
Making Computer Games and Design Thinking A Review of Current Software and Strategies

This article provides an overview of computer software and instructional strategies intended to engage young people in making computer games, to achieve a variety of educational goals. It briefly describes the most popular of such programs and compares their key features, including the kinds of games that can be created with the software, the types of communities and resources that are associated with each program, claims made for learning outcomes resulting from use of the software, and the results of empirical research (if any) on the application and outcomes of the software in formal or informal educational settings. A key finding is that existing software and educational applications stress the goal of teaching users about computer programming and place little or no emphasis on teaching concepts related to game design. It concludes by discussing the potential value of explicit attention to “design thinking” as goal of game making in education.
The theory of capillary excess viscosities

A general phenomenological theory of capillary excess or surface viscosities is developed from considerations of momentum balance in the neighbourhood of a fluid phase boundary. It is assumed that a coordinate system may be erected in the interfacial region for which the constitutive equations are anisotropic in the normal direction but tangentially isotropic. This anisotropy together with certain assumptions regarding the continuity of the velocity vector and its derivatives leads to the identification for incompressible fluids of four surface viscosity coefficients $\kappa$, $\eta$, $\kappa\_N$ and $\eta\_N$. The first two have been recognized since the time of Boussinesq, and experimental data regarding them are accumulating. The second two appear to be new, and experiments to measure them are only in a preliminary stage. In all cases, the surface viscosity coefficients are formally identified as integrals taken through the interfacial region from one bulk phase to the next. The theory is limited to interfacial regions whose curvatures are small with respect to the reciprocal thickness of the transition zone and of greater than ultra-low surface tension.
Prostaglandin E2 Inhibits BMP Signaling and Delays Chondrocyte Maturation

While cyclooxygenases are important in endochondral bone formation during fracture healing, mechanisms involved in prostaglandin E2 (PGE2) regulation of chondrocyte maturation are incompletely understood. The present study was undertaken to determine if PGE2 effects on chondrocyte differentiation are related to modulation of the bone morphogenetic protein (BMP) signaling pathway. In primary murine sternal chondrocytes, PGE2 differentially regulated genes involved in differentiation. PGE2 induced type II collagen and MMP-13, had minimal effects on alkaline phosphatase, and inhibited the expression of the maturational marker, type X collagen. In BMP-2-treated cultures, PGE2 blocked the induction of type X collagen. All four EP receptors were expressed in chondrocytes and tended to be inhibited by BMP-2 treatment. RCJ3.1C5.18 chondrocytes transfected with the protein kinase A (PKA) responsive reporter, CRE-luciferase, showed luciferase induction following exposure to PGE2, consistent with activation of PKA signaling and the presence of the EP2 and EP4 receptors. Both PGE2 and the PKA agonist, dibutyryl cAMP, blocked the induction of the BMP-responsive reporter, 12XSBE, by BMP-2 in RCJ3.1C5.18 chondrocytes. In contrast, PGE2 increased the ability of TGF-beta to activate the TGF-beta-responsive reporter, 4XSBE. Finally, PGE2 down-regulated BMP-mediated phosphorylation of Smads 1, 5, and 8 in RCJ3.1C5.18 cells and in primary murine sternal chondrocytes. Altogether, the findings show that PGE2 regulates chondrocyte maturation in part by targeting BMP/Smad signaling and suggest an important role for PGE2 in endochondral bone formation.
Social structure and helping behavior in captive elephants

Selective pressures on individual behavior serve to mold social structure and subsequent levels of cooperation in social species, including elephants. Adult Asian (Elephas maximus) and African (Loxodonta africana) elephants have complex social societies that differ markedly between the sexes. Elephant social structure and cooperative behavior may have evolved in part to prepare young elephants to meet the challenges of an expansive environment, predators and parasites. In captivity, such forces are relaxed or eliminated, yet captive elephants display a similar repertoire of behaviors as their wild counterparts. Elephants live in herds of related adult females from several generations. This female social unit is centered on calves and the matriarch. Adult males reside in bachelor herds, singly, or frequent female groups, depending on male age and reproductive condition. In captivity, female elephants are usually housed together, although group size is smaller than in the wild, whereas adult males are generally housed separately from other elephants. Beyond these general similarities between wild and captive settings, captive elephants are housed in a wider range of group sizes, degrees of relatedness, and age structures than would be typical in the wild. This variation in social structure can be used to explore questions about cooperative behavior. Following a comparison of wild and captive social structures for elephants, three such potential avenues for study are discussed. Specifically, research with captive elephants could shed light on the development of social behavior, the functional significance of allomothering, and the ability of elephants to recognize kin or social group members. Beside the potential theoretical implications and insight into wild elephant behavior, the examination of social behavior also has important ramifications for the management of animals in captivity. Zoo Biol 19:447–459, 2000. © 2000 Wiley-Liss, Inc.
Resurrection of the Pronotocrepini Knight, with Revisions of the Nearctic Genera Orectoderus Uhler, Pronotocrepis Knight, and Teleorhinus Uhler, and Comments on the Palearctic Ethelastia Reuter (Heteroptera: Miridae: Phylinae)

ABSTRACT The Nearctic genera Orectoderus Uhler, Pronotocrepis Knight, and Teleorhinus Uhler are revised. One new species from Texas, Teleorhinus crataegi, sp. nov., is described. Teleorhinus oregoni Knight, 1968 is transferred to Orectoderus Uhler. The following new synonyms are proposed (senior synonym first): O. arcuatus Knight = O. schuhi Knight; O. montanus Knight = O. utahensis Knight, O. Salicis Knight, and O. cockerelli Knight; O. obliquus Uhler = O. ruckesi Knight; P. clavicornis Knight = P. ribesi Knight and P. ruber Knight; T. cyaneus Uhler = T. brindleyi Knight and T. nigricornis Knight; T. tephrosicola Knight = T. floridanus Blatchley and T. utahensis Knight; O. bakeri Knight = T. oregoni Knight Orectoderus and Teleorhinus are transferred from the Hallodapini Van Duzee to the Pronotocrepini Knight. The Palearctic genus Ethelastia Reuter, 1876, is reviewed and transferred from the Phylini to the Pronotocrepini. A rediagnosis for the tribe Pronotocrepini, a key to the included genera, keys to ma...
Polarization In Remote Sensing

Various aspects of polarization in remote sensing are presented including mathematical treatments and selected experimental observations. The observations are of the percent polarization from Haleakala volcanic ash, basalt powder, rhyolytic oumice. rose quartz, niccolite, ilmenite, black oak leaves. dried red pine needles, a New Haven red pine stand, moist soil, the sky above Mauna Loa Observatory, the sky above Long Island in summer and winter, and cirrus clouds. Also, space based shuttle photographic observations of polarization are described. Instrumental polarization from a Cassegrainian telescope is described as well as the design of an imaging soectropolarimeter for remote sensing. A list is presented of twelve polarimetric properties associated with remote sensing.
Children with Autism in the Inclusive Preschool Classroom: A Systematic Review of Single-Subject Design Interventions on Social Communication Skills

Changes in legislation have led to an increased push for children with autism spectrum disorder to be educated in classrooms with typically developing peers. This systematic review of the literature between the years of 2005 and 2012 aimed to identify effective interventions to support the children with autism spectrum disorder in the inclusive preschool classroom. Single-subject studies concerning the improvement of social communication skills for children with autism spectrum disorder in inclusive preschools were identified through systematic searches of electronic databases using key terms, journal hand searches, and ancestral searches of identified articles. Data were extracted from the resulting 16 articles to (a) examine rigor of design, (b) evaluate intervention effectiveness using visual analysis and percentage non-overlapping data (PND), and (c) determine evidence-based practices. Results suggest a range of effective interventions to improve the social communication skills for children with autism spectrum disorder in inclusive preschool classrooms. Suggestions for future research are discussed.
Postural Tachycardia Syndrome Perspectives for Patients

When a person stands up, he or she assumes that the body will automatically make any changes necessary to compensate for the increased gravitational stress this change of position brings. Indeed, standing causes gravity to try to pull nearly one quarter of the body’s blood downward toward the lower arms, legs, and abdomen, reducing the amount of blood available to keep the brain supplied with oxygen. To maintain a constant oxygen supply to the brain and upper body, standing is normally accompanied by an automatic increase in heart rate and the force with which the heart contracts and, most important, a tightening of the blood vessels in the lower part of the body. The combination of these 3 actions pushes blood upward against the force of gravity, thereby maintaining an uninterrupted flow of blood to the brain. The aspect of the nervous system that governs these …
Passive flow switching valves on a centrifugal microfluidic platform

In this paper we present two different methods for a passive flow switching valve on a centrifugal microfluidic platform, which controls the direction of a flowing liquid at a junction where a common inlet and two outlet channels meet. Switching of the flow can be performed either by relying on the Coriolis force that changes its pointing direction, perpendicular to the flow direction, with the rotational direction of a disk in a double layered arrangement at a symmetrical junction, or by means of the fluidic capacitance of an air pocket trapped between two fluids at a non-symmetric junction. This flow-switching valve, when combined with affinity-based separation techniques (e.g., adsorption of DNA on a silica matrix, followed by elution), has great potential in rapid bioassays and biomedical diagnostic applications that require the extraction of specific target biomoleclues.
Apical Ballooning Resulting from Limbic Encephalitis

Abstract Background Neurogenic stunned myocardium is an increasingly recognized cause of left ventricular apical ballooning, or takotsubo cardiomyopathy. We report the first case of neurogenic stunned myocardium as a result of limbic encephalitis. Methods This 73-year-old woman with anterograde and retrograde amnesia was investigated using electrocardiography, magnetic resonance imaging, and left ventricular angiography. Results Electrocardiography showed deep T-wave inversions in multiple leads, magnetic resonance imaging demonstrated increased signal on fluid-attenuated inversion recovery images symmetrically within the medial temporal lobes consistent with limbic encephalitis. Left ventricular angiography showed apical ballooning. Conclusions Because the insula has extensive interconnections with limbic structures, limbic encephalitis could lead to alterations in the sympathetic regulation of the insular cortex resulting in neurogenic stunned myocardium.
Serotonin targets the DAF-16/FOXO signaling pathway to modulate stress responses

Stress response is a fundamental form of behavioral and physiological plasticity. Here we describe how serotonin (5HT) governs stress behavior by regulating DAF-2 insulin/IGF-1 receptor signaling to the DAF-16/FOXO transcription factor at the nexus of development, metabolism, immunity, and stress responses in C. elegans. Serotonin-deficient tph-1 mutants, like daf-2 mutants, exhibit DAF-16 nuclear accumulation and constitutive physiological stress states. Exogenous 5HT and fluoxetine (Prozac) prevented DAF-16 nuclear accumulation in wild-type animals under stresses. Genetic analyses imply that DAF-2 is a downstream target of 5HT signaling and that distinct serotonergic neurons act through distinct 5HT receptors to influence distinct DAF-16-mediated stress responses. We suggest that modulation of FOXO by 5HT represents an ancient feature of stress physiology and that the C. elegans is a genetically tractable model that can be used to delineate the molecular mechanisms and drug actions linking 5HT, neuroendocrine signaling, immunity, and mitochondrial function.
A new device for sampling small volumes of water from marine micro-environments

Abstract Recent developments in microelectrode technology provide more sensitive measurement of biologically relevant redox species and require less water than traditional wet chemical techniques. To fully exploit the power of this new technology, water samplers capable of collecting small volumes (1–10 ml) from discrete micro-environments were developed. We have designed a new, low-cost water sampler (SIPPER) to draw small volume water samples from discrete locations at deep-sea hydrothermal vents. The sampler successfully operated with the deep submergence vehicle (DSV) ALVIN at 2600 m depth to extract water samples from the fragile tube dwellings of a small polychaete. These samples were electrochemically analyzed on board ship for the presence of biologically important redox species inside the worm tube. Although designed specifically for this study, the sampler can be readily modified for application in a variety of disciplines requiring discrete samples within aquatic micro-environments.
Workshop zeroes in on processes in space plasma transport

One of the outstanding issues in space plasma physics is the role of plasma waves and instabilities in the transport of mass, momentum, and energy mediated by plasma flow in space. The large-scale plasma flow in space creates conditions that generate plasma waves at relatively small spatial and temporal scales. The spatial scales of the waves are typically from a few centimeters to a few tens of meters and the corresponding temporal scales are from a few microseconds to less than a second. On the other hand, large-scale plasma flows have scale lengths from a few thousands of kilometers to several Earth radii, and the temporal scales range from about an hour to days. Do the smallscale waves (microprocesses) modify the large-scale flows? Is the modification significant enough to affect the transport of mass, momentum, and energy? And if it is significant enough, how do we incorporate the microprocesses in theoretical models of space plasma flows?
To Western Woods : The Breckinridge Family Moves to Kentucky in 1793

To Western Woods focuses on the John and Mary Cabell Breckinridge family's move across the Appalachian Mountains in the late eighteenth century through letters, diaries, and newspaper excerpts about events of the time.
Stimulation of maternal responsiveness after pregnancy termination in rats: Effect of time of onset of behavioral testing☆☆☆

Abstract To assess the effects of varying the time interval between surgical pregnancy termination and onset of behavioral testing on the expression of maternal behavior, both responsiveness to foster young and nest building-were measured in rats ovariectomized (O), hysterectomized (H), ovariectomized and hysterectomized (OH), or sham-operated (I) on Day 17 of pregnancy at 10:00 and first tested for maternal responsiveness 6, 24, or 48 hr after surgery. When behavioral testing was started 6 hr after surgery O and OH groups responded maternally to foster pups faster than H or I groups, and H females responded maternally faster than I animals (O = OH
"I'm Not an Activist!": Animal Rights vs. Animal Welfare in the Purebred Dog Rescue Movement

Purebred dog rescuers are doing their part to reduce the problems of homeless pets and pet overpopulation. The volunteers studied are doing the daily and invisible work of saving dogs. Because of their perception of the animal rights movement, however, they do not consider themselves part of the animal welfare or animal rights movement, nor do they care to be. Dog rescue organizations agree with academics and activist organizations on the cause of the problem of homeless pets and pet overpopulation, but they differ on the theoretical, political, and ideological solutions to the problem. This paper focuses on the disagreements between rescue workers, activists, and academics and asks whether there is a place for rescue workers within the larger animal protection movement.
Automated Two-Column Purification of Iminobiotin and BrdU-Labeled PCR Products for Rapid Cloning: Application to Genes Synthesized by Polymerase Chain Assembly

Polymerase chain assembly (PCA) is a powerful tool for basic biological research and biotechnology applications. During the last several years, major advances have been made in de novo gene synthesis. However, there is still a need for fast and reproducible methods to automatically purify the synthesized genes. Upon completion of PCA, the subsequent PCR-amplified product mixture still contains undesired shorter DNA fragments that hinder cloning efforts. To avoid tedious gel purification, an automated two-column purification has been developed and used in conjunction with rapid PCA. The system enables fast synthesis and isolation of the full-length DNA of interest, important for facile cloning of desired DNA fragments. During the PCR amplification step, forward and reverse primers tagged with iminobiotin and bromodeoxyuridine labels, respectively, were used. The automated purification was then performed on the PCR mixture using two affinity/immunocapture columns in series to isolate only the desired full-length product. The procedure has been applied to the pUC19 β-lactamase gene (929 bp). Follow-up PCR of the purified product, cloning, and sequencing demonstrated the technique's effectiveness in obtaining the pure full-length gene. The purification has also been performed on other synthesized genes, indicating its utility as a general approach.
The predictive value of cytologic testing in women with the human immunodeficiency virus who have low-grade squamous cervical lesions: a substudy of a randomized, phase III chemoprevention trial.

Abstract Objective: The purpose of this study was to determine whether the progression of low-grade squamous intraepithelial lesions of the cervix in women with the human immunodeficiency virus can be predicted reliably by standard cytologic testing. Study Design: As part of a previously reported trial, 288 biopsy specimens were collected from 117 women with the human immunodeficiency virus. These specimens underwent central and local interpretation, which were compared and correlated with cytologic results. Ninety-two subjects had matched cytologic/histologic pairs at study termination, which were compared to determine whether cytologic testing was predictive of progression. Results: Of the central histologic interpretations, 26 of 288 interpretations (9%) differed from local results, 97 of 246 cytologic/histologic pairs (39%) were discordant, and 21 subjects had progression to high-grade squamous intraepithelial lesions by histologic evidence. Cytologic testing showed high-grade squamous intraepithelial lesions in 4 of 21 specimens (sensitivity, 19%). The remaining cytologic specimens were either low-grade squamous intraepithelial lesions or were normal. Conclusion: This substudy of pathologic results from a randomized clinical trial suggests that, although the risk of progression of low-grade squamous intraepithelial lesions is low, follow-up cytologic testing is unreliable. Colposcopic evaluation with directed biopsies should be continued.
Differentiation of bergmann glia cells in the cerebellum: a golgi study

The migration of Bergmann glia cells from the external granular layer to the Purkinje cell layer and the differentiation of their processes were analyzed in Golgi-Cox preparations of the cerebellum of the rat. During their migration they showed numerous cytoplasmic excrescences and long thick processes, which suggested that they may follow ameboid form of movement for their migration. The differentiation of their processes was observed to involve a series of complex events related to retraction of the thick apical processes from the tips of which sheaves of filiform processes emerged, growth in the number and the thickness of the filiform processes, resorption of some of these filiform processes, cyclic changes in the appearance, resorption and reappearance of excrescences on the filiform processes, and changes in size and shape of the growth cones. These findings are discussed in the context of the role played by the Bergmann glia cells in the postnatal developmental events in the cerebellum, and the dynamic nature of differentiation of their processes.
Competition for cellular factors that activate metallothionein gene transcription

Metallothioneins (MTs), small cysteine-rich proteins, bind to and are inducible by heavy metals such as zinc, cadmium and copper. Recent gene-transfer and mutagenesis experiments have elucidated cis-acting DNA sequences involved in this form of regulation1,2, but nothing is known about the trans-acting factors that interact with the control sequences or how such interactions influence the rate of transcription. We report here the detection of cellular factors involved in the cadmium induction of the mouse MT-I gene by an in vivo competition assay. We show that at least one class of these cellular factors acts by a positive regulatory mechanism depending on the same region of the 5′ flanking DNArequired for maximal transcription.
The flow stress of Cu3Au

Abstract Precision compression flow stress measurements were made on single crystals of Cu3Au over the temperature range 77°k to 695°k. The temperature dependence of the flow stress from 77°K to about 200°K is similar to that observed in pure f.c.c. metals. The flow stress at elevated temperatures increases markedly, as has been previously observed. A new theory is presented here in which this increase in flow stress at elevated temperatures is interpreted in terms of a modulus interaction between moving dislocations and local regions of disorder within the ordered matrix. As the temperature is raised these regions become more numerous as the long-range order parameter decreases and the flow stress rises. Very satisfactory correlations can be made between the theory and the flow stresses reported here.
Eddy-driven subduction exports particulate organic carbon from the spring bloom

The export of particulate organic carbon (POC) from the surface ocean to depth is traditionally ascribed to sinking. Here, we show that a dynamic eddying flow field subducts surface water with high concentrations of nonsinking POC. Autonomous observations made by gliders during the North Atlantic spring bloom reveal anomalous features at depths of 100 to 350 meters with elevated POC, chlorophyll, oxygen, and temperature-salinity characteristics of surface water. High-resolution modeling reveals that during the spring transition, intrusions of POC-rich surface water descend as coherent, 1- to 10-kilometer–scale filamentous features, often along the perimeter of eddies. Such a submesoscale eddy-driven flux of POC is unresolved in global carbon cycle models but can contribute as much as half of the total springtime export of POC from the highly productive subpolar oceans.
Activation of yeast hexokinase by chelators and the enzymic slow transition due to metal-nucleotide interactions.

Abstract The unusual kinetics of yeast hexokinase PII have been reinvestigated with respect to the reported Al 3+ contamination in commercial ATP preparations ( F. C. Womack and S. P. Colowick, 1979, Proc. Nat. Acad. Sci. USA 76 , 5080 ) and the effects of a series of chelator/activators under a variety of conditions. Citrate, catechol, malate, and 8-hydroxyquinoline have been found to activate the enzyme to the same level (measured by V , K glu , K MgATP , and Hill coefficient) and to act in a mutually exclusive fashion, consistent with activation by chelation of Al 3+ from contaminated ATP solutions. The experimentally determined activation constants for the series of chelators corresponded reasonably well to calculated activation constants when all metal-ligand equilibria were considered; certain discrepancies were explained as a reflection of the kinetic ability of various chelators to remove Al 3+ from ATP as well as their thermodynamic affinity for metal ions. The slow transition is interpreted as occurring in the Al-ATP-hexokinase-glucose complex with an analogous slow relaxation back to the active form when Al 3+ is removed by chelation. GTP is not affected by Al 3+ addition and has the same pH dependency as Al-free ATP (citrate treated); therefore the tightening seen with Al 3+ is specific for adenine nucleotides as well as for certain sugar substrates ( R. E. Viola, J. F. Morrison, and W. W. Cleland, 1980, Biochemistry 19 , 3131–3137 ). Al 3+ -free ATP is difficult to prepare and it is concluded that the surest way to eliminate effects of the contamination is to utilize citrate in the assays. A comprehensive mechanism is proposed in which Al-ATP binds to the hexokinase-glucose complex (but not to free enzyme), induces a slow conformational change to a form which binds Mg-ATP or Cr-ATP more poorly, and produces apparent negative cooperativity because of selective inhibition of one pathway of a partially random mechanism. Numerous other kinetic, physicochemical, and modification experiments are reinterpreted in view of the current awareness of Al-ATP inhibition of yeast hexokinase.
Outlook for medical lasers: a market update

Much has happened since lasers were introduced into medicine in the early 1960s. In this presentation we will provide a look at the current market situation and take a look ahead. We will describe the lasers and applications that hold the most promise for the future, listing the major participants and the laser types they supply in each of these application areas. If time permits, we will also present our selections for the most significant new products introduced in 1992.
A quantitative analysis of computed hypervelocity debris clouds

Abstract This paper presents quantitative analyses of computed hypervelocity debris clouds due to aluminum spheres, rods and disks impacting aluminum bumper plates. The computations were performed using an algorithm to convert distorted Lagrangian finite elements to meshfree particles. The analyses were performed using a new postprocessing algorithm. The combination of this computational approach and this postprocessing algorithm is also used to characterize behind-armor debris due to tungsten rods impacting steel plates at ballistic velocities, and the results are compared to test data. The quantitative analyses are an extension of previous qualitative comparisons to radiographs of hypervelocity debris clouds.
A Weakly Singular Formulation of Boundary Integral Equations and Field Computation near Boundaries

Applications of the boundary integral equation method to real world problems often require that field values should be obtained near boundary surfaces. A numerical difficulty is known to arise in this situation if one attempts to evaluate near-boundary fields via the conventional Green's formula. The present work addresses this particular issue. Namely, a stable computational scheme for both fields and gradients in the near-boundary region has been formulated. This approach starts with the conventional Green and Maue representations of fields and gradients written inside and outside of the defining volume. Then, a new set of integral representations that have weaker kernel singularities is derived by canceling the most singular terms between the conventional formulas of the two sides. The principal contribution of this work is the explicit construction of the improved representations for the fields and gradients. Also presented are several numerical results that demonstrate the superiority of the new representations over the conventional ones.
The Changes in Cardiac Output with Reversion of Atrial Fibrillation to Sinus Rhythm

Twelve patients were reverted from atrial fibrillation to sinus rhythm by the technic of "cardioversion." Brief, light anesthesia was the only drug employed. Under conditions of comparable oxygen consumption cardiac output was measured first in atrial fibrillation and then in sinus rhythm. Eleven patients were studied at rest and five during exercise. Ten of the 11 patients studied at rest showed a reduced arteriovenous oxygen difference with sinus rhythm and seven of the 11 increased cardiac output 0.6 L./min. or greater, an average increase of 34 per cent. All five patients studied at exercise decreased the arteriovenous oxygen difference with sinus rhythm and cardiac output rose 1.1 L./min. or greater in all, an average increase of 17 per cent.
Flux synthesis, structure and physical properties of new pseudo-binary REAl3−xGex compounds

Abstract New compounds in the system RE-Al-Ge (RE=Tb, Gd, Ho) were prepared in molten aluminum. Large, (up to 5 mm) single crystals of new pseudo-binary phases GdAl3−xGex, (x=0.1), TbAl3−xGex, (x=0.3), and HoAl3−xGex, (x=0.2) were recovered in high yield. The crystal structures were refined by single crystal X-ray diffraction techniques, and found to vary as a function of rare-earth element. Thus, GdAl3−xGex crystallizes in the Ni3Sn structure type (P63/mmc) of GdAl3. For the TbAl3−xGex the BaPb3 structure type (R-3m) is adopted, as it is for TbAl3. In the case of HoAl3−xGex, the structure type of HoAl3 is not stabilized, and the compound crystallizes in the BaPb3 structure (R-3m). Crystal data: GdAl3−xGex a=6.3115(4) A, c=4.6052(4) A, V=158.87(2) A3, P63/mmc (No. 194, Z=2); TbAl3−xGex a=6.1956(9) A, c=21.025(4) A, V=698.9(2) A3, R-3m (No. 166, Z=9); HoAl3−xGex a=6.1579(10) A, c=21.062(5) A, V=691.7(2) A3, R-3m (No. 166, Z=9). Charge transport properties indicate that these materials are good metallic conductors. At low temperatures they order antiferromagnetically, whereas above ∼50 K they are Curie–Weiss paramagnets. The temperature of maximum magnetic susceptibility (Tmax) is 5.93 K, 18.8 K, and 24.0 K for HoAl2.8Ge0.2, TbAl2.7Ge0.3, and GdAl2.9Ge0.1 respectively.
The structure of a segments from glycerinated skeletal muscle

The A band of skeletal muscle consists of an array of thick myosin-containing filaments along with non-myosin proteins such as C protein and M line protein. In order to study the arrangement of the myosin and non-myosin components, A segments which are aggregations of thick filaments held together at the M line were prepared from glycerinated chicken pectoral and rabbit psoas muscles and examined by electron microscopy. Details of the preparative technique and comparison of the morphologies of A segments and I segments are provided. The A segments from chicken pectoral muscle exhibited 11 to 12 stripes in each half lateral to the bare zone. Several less distinct bands as well as subdivisions of the individual stripes were also observed. The periodicity of the major stripes in the A segments was 424 +/- 10 A. The A segments prepared from rabbit psoas muscle had a periodicity of 432 +/- 13 A, but in contrast with chicken A segments, fewer rabbit A segments showed this periodicity. We conclude that A segments can be separated from glycerinated chicken and rabbit skeletal muscles and compare our results with those of others who prepared A segments from frog and rabbit skeletal muscles in the absence of glycerol.
Dual Systems in Rwanda Have they ever really existed

The Rwandan social system has habitually been depicted as something of a ‘dual system’ in which Tutsi are opposed to Hutu. Forgotten in this description are the country’s least numerous group, the Twa. Although Twa constitute less than 1 per cent of Rwanda’s total population and thus appear to be politically negligible, this article maintains that they were historically more important in the symbolic construction of ethnic difference than the present literature would indicate. The Twa was the first of Rwanda’s three groups to suffer practices of social exclusion, practices called kuneena batwa which continue to this day. Associated with the forest, Twa were ascribed the negativity of ‘nature’, and perceived as not fully human by other Rwandans. Later, but before the arrival of Europeans, Hutu ethnicity began to crystallize and to be negatively compared to Tutsi. European notions of biological determinism worsened these ethnogenetic processes, but it did not invent them.
Membrane fusion: a structural perspective on the interplay of lipids and proteins

The fusion of biological membranes is governed by the carefully orchestrated interplay of membrane proteins and lipids. Recently determined structures of fusion proteins, individual domains of fusion proteins and their complexes with regulatory proteins and membrane lipids have yielded much suggestive insight into how viral and intracellular membrane fusion might proceed. These structures may be combined with new knowledge on the fusion of pure lipid bilayer membranes in an attempt to begin to piece together the complex puzzle of how biological membrane fusion machines operate on membranes.
THE PATHOLOGY OF Filaria taxideae (FILARIOIDEA: FILARIIDAE) INFECTION IN THE BADGER*

A description is given of the cutaneous lesions associated with Filaria taxideae Keppner, 1970 infections in badgers, Taxidea taxus (Schreber, 1778), from Wyoming. Female F. taxideae migrated into the dermis of the host and deposited their ova beneath the epidermis. Lesions developed gradually around the groups of ova, and no haemorrhagic lesions were observed on gross examination. First-stage larvae were observed at the periphery of developing and healed lesions along with embryonated ova. A comparison is made with the formation of the cutaneous lesions associated with the closely related Parafilaria Yorke and Maplestone, 1926.
Control of a unicellular blue-green alga, Synechocystis sp., in mass algal culture

Abstract Algal species succession in high-rate pond cultures receiving swine waste was studied for a period of 6 years. Seasonal patterns of succession were consistent on a yearly basis and were not strongly affected by waste loading or pre-treatment. The unicellular, blue-green alga, Synechocystis sp., was found to have a competitive advantage over other algal species during summer and fall seasons under unmixed or intermittently mixed conditions. Continuous flow-mixing at 20–30 cm/s was effective in suppressing this alga. The removal mechanism was bioflocculation and eventual sedimentation.
Differential inhibition by nedocromil sodium of superoxide generation elicited by platelet activating factor in human neutrophils.

Nedocromil sodium (10−10–10−9M) produced a dose-related inhibition of superoxide anion generation induced by platelet activating factor (PAF) in human polymorphonuclear leukocytes (PMNs). At a higher concentration (3×10−7M), nedocromil sodium significantly inhibited superoxide generation elicited by N-formyl-methionyl-leucylphenylalanine, but was unable to block the response to phorbol dibutyrate. Nedocromil sodium (10−11–10−5M) enhanced PAF-stimulated lysozyme release in a non-concentration-dependent manner, and was completely ineffective in depressing PAF-induced release of [3H]arachidonic acid and the rise in cytosolic Ca2+. The preferential inhibitory effects of nedocromil sodium on PAF-induced activation of superoxide generation may provide insight into the therapeutic action of this drug as an anti-asthmatic agent.
Predicting institutional adjustment with the Psychological Inventory of Criminal Thinking Styles composite scales: Replication and extension

Purpose. The principal aim of this study is to determine whether the Proactive (P) and Reactive (R) composite scales of the Psychological Inventory of Criminal Thinking Styles (PICTS) are capable of predicting institutional adjustment in a group of medium security prison inmates. Method. The P and R composite scales were correlated with dichotomized and count measures of total, non-aggressive and aggressive incident reports (IRs) received during a 2-year period in a group of 219 male medium security US federal prisoners. Results. The R scale predicted dichotomized total, non-aggressive, and aggressive IRs (point biserial correlations, receiver operating characteristic (ROC) analysis, classification analyses) and all three classes of count IRs (negative binomial regression) when age, education, race, marital status, confining offence, prior disciplinary record, program completion and time in the institution were controlled. The P scale, on the other hand, predicted dichotomized total (point biserial correlation, classification analysis) and non-aggressive (point biserial correlation, ROC) IRs and the total disciplinary count when age, education, race, marital status, confining offence, prior disciplinary record, program completion and time in institution were accounted for in a negative binomial regression. Conclusion. The modest but consistent relationship observed between the R scale and subsequent disciplinary infractions suggests that R may well serve as one component of a larger assessment battery for identifying inmate's at risk for future disciplinary problems.
A new concept for a compact tape transport system

Abstract A new concept in tape transport systems for the collection and counting of radioactive samples from an on-line isotope separator has been developed. This new compact design was motivated by space limitations but important additional improvements over previous designs were made in cost, simplicity and vacuum quality. The system is based on a continuous loop of 6.5 mm wide recording tape 116 m long with a conducting coating on one side for beam current monitoring. One small stepping motor is required for operation.
MECHANICAL FORCE FIELDS IN A CLAY MINERAL PARTICLE SYSTEM

ELECTRICAL DOUBLE LAYER THEORY IS USED TO ANALYZE AN IDEALIZED MODEL UNIT OF A CLAY PARTICLE SYSTEM WITH THE PURPOSE OF DESCRIBING THE MECHANICAL STABILITY IN TERMS OF AN EQUILIBRIUM OF ATTRACTIVE AND REPULSIVE FORCES. RESTRICTING THE ANALYSIS TO TWO DIMENSIONS, A SYMMETRICAL PARALLELOGRAM FORMED BY FOUR TYPICAL CLAY MINERAL PARTICLES IS TAKEN AS A REPRESENTATIVE UNIT OF FLOCCULATED CLAY AND THE INTERACTION OF MINERAL FACES AND ASSOCIATED ELECTROLYTE IS INVESTIGATED. THE DISTORTION ENERGY OF THE SYSTEM THUS FOUND IS THEN DIRECTLY RELATED TO THE MECHANICAL STABILITY OF THE MODEL UNITS STRUCTURE AS IT VARIES FROM PARALLEL TO PERPENDICULAR ORIENTATION. THE GENERAL PATTERN OF BEHAVIOUR OF THE MODEL UNIT WILL BE SHOWN TO BE COMPATIBLE WITH THE MECHANICAL BEHAVIOR OF THE CLAY MASS. /AUTHOR/
Bifurcation and Deviation of Cleavage Paths at Through-Thickness Grain Boundaries

The behavior of cleavage crack fronts at grain boundaries in free-standing silicon thin films is investigated through a microtensile experiment. In addition to the crystallographic orientation, the orientation of grain boundary plane also plays a critical role. With respect to the initial crack surface, if the inclination angle is relatively small, the crack tends to penetrate across the boundary; if the angle is large, the crack may either bifurcate along the boundary or turn back on another crystallographic plane. The former is triggered by crack front transmission, and the latter may result in a higher critical crack growth driving force.