cssi/SciSciGPT-SciSciNet huggingface dataset:
Annual CO2 Flux in Dry and Moist Arctic Tundra: Field Responses to Increases in Summer Temperatures and Winter Snow Depth

We examined the annual exchange of CO2 between the atmosphere and moist tussock and dry heath tundra ecosystems (which together account for over one-third of the low arctic land area) under ambient field conditions and under increased winter snow deposition, increased summer temperatures, or both. Our results indicate that these two arctic tundra ecosystems were net annual sources of CO2 to the atmosphere from September 1994 to September 1996 under ambient weather conditions and under our three climate change scenarios. Carbon was lost from these ecosystems in both winter and summer, although the majority of CO2 evolution took place during the short summer. Our results indicate that (1) warmer summer temperatures will increase annual CO2 efflux from both moist and dry tundra ecosystems by 45–55% compared to current ambient temperatures; (2) deeper winter snow cover will increase winter CO2 efflux in both moist and dry tundra ecosystems, but will decrease net summer CO2 efflux; and (3) deeper winter snow cover coupled with warmer summer temperatures will nearly double the annual amount of CO2 emitted from moist tundra and will result in a 24% increase in the annual CO2 efflux of dry tundra. If, as predicted, climate change alters both winter snow deposition and summer temperatures, then shifts in CO2 exchange between the biosphere and atmosphere will likely not be uniform across the Arctic tundra landscape. Increased snow deposition in dry tundra is likely to have a larger effect on annual CO2 flux than warmer summer temperatures alone or warmer temperatures coupled with increased winter snow depth. The combined effects of increased summer temperatures and winter snow deposition on annual CO2 flux in moist tundra will be much larger than the effects of either climate change scenario alone.
White matter correlates of slowed information processing speed in unimpaired multiple sclerosis patients with young age onset

Slowed information processing speed is among the earliest markers of cognitive impairment in multiple sclerosis (MS) and has been associated with white matter (WM) structural integrity. Localization of WM tracts associated with slowing, but not significant impairment, on specific cognitive tasks in pediatric and young age onset MS can facilitate early and effective therapeutic intervention. Diffusion tensor imaging data were collected on 25 MS patients and 24 controls who also underwent the Symbol Digit Modalities Test (SDMT) and the computer-based Cogstate simple and choice reaction time tests. Fractional anisotropy (FA), mean (MD), radial (RD) and axial (AD) diffusivities were correlated voxel-wise with processing speed measures. All DTI metrics of several white matter tracts were significantly different between groups (p < 0.05). Notably, higher MD, RD, and AD, but not FA, in the corpus callosum correlated with lower scores on both SDMT and simple reaction time. Additionally, all diffusivity metrics in the left corticospinal tract correlated negatively with SDMT scores, whereas only MD in the right superior fronto-occipital fasciculus correlated with simple reaction time. In conclusion, subtle slowing of processing speed is correlated with WM damage in the visual-motor processing pathways in patients with young age of MS onset.
Update on the Surgical Management of Fuchs Endothelial Corneal Dystrophy

Fuchs endothelial corneal dystrophy (FECD) is the most common posterior corneal dystrophy and the leading indication for corneal transplantation in the United States. FECD is slowly progressive, and patients develop gradual corneal endothelial decompensation, eventually resulting in failure of the endothelium to maintain corneal deturgescence. Medical management consists of topical hyperosmotic agents to facilitate dehydration of the cornea, but surgical intervention is often required to regain corneal clarity. The surgical management of FECD has evolved over the past two decades as corneal transplantation techniques have allowed for more selective keratoplasty and replacement of only the diseased layers of the cornea. Prior surgical management consisted of penetrating keratoplasty (PK) that carried significant intraoperative risks associated with “open sky” as well as postoperative risks of graft rejection, wound dehiscence, postoperative astigmatism, and prolonged visual rehabilitation. In the past 15 years, endothelial keratoplasty (EK) has become the treatment of choice for endothelial disease, significantly reducing the risks associated with the surgical treatment of FECD. Here we discuss the current surgical management of FECD, including the introduction of Descemet stripping only (DSO), and highlight future investigative efforts.
Putting Parental Supervision Into Context: Taking an Assets-Based Approach in Examining the Role of Parental Supervision During Adolescence:

Studies of parental supervision often fail to consider the broader ecology in which youth are developing. In this paper, moderation and mediation analysis were utilized to examine parental supervis...
Road safety for whom?: South Carolina's proposed left lane traffic enforcement bill could perpetuate existing racial/ethnic public health disparities

Abstract Introduction Road safety is an important issue whose public health impact is further intensified by mediators of systemic racism, including biased policing. The historical precedents of Walter Scott and numerous other Black persons who have suffered violence at the hands of South Carolina (SC) police provide added impetus for explicit discussions of mechanisms to mitigate racially/ethnically biased policing in any new road safety measures. Unfortunately, these important considerations do not appear evident in H3011, a new SC enforcement bill predicated on increasing road safety by proposing stricter penalties for slow left lane drivers. Conclusions Regardless of the ultimate fate of H3011, the bill reflects a pattern of road safety enforcement legislation that seemingly fails to place racial/ethnic equity considerations at its forefront. If we, as public health researchers, truly believe that police violence is a public health crisis, we must advocate for our lawmakers to actively do more to address this issue.
Design Constraint Based Attacks

Attacks against SM which exploit information inferred from the FEOL layout combined with the knowledge of common EDA flows are termed design constraint based attacks. Examples of such information include cell types, terminal positions, distance between terminals, directions of wires, and loads offered by various cells. In this chapter, we discuss several design constraint based attacks for reverse engineering and trojan insertion. Specifically, for reverse engineering, we discuss attacks based on proximity and notions of extended proximity, the network flow model, and machine learning. For trojan insertion, we discuss attacks based on simulated annealing, proximity based mapping followed by net based pruning, and structural pattern matching.
A miniature kinematic coupling device for mouse head fixation

Head-fixation is a common technique in the preparation of subjects for neuroscience experiments. Accurate alignment, stability, and repeatability during fixation provide experimental consistency, thus enabling the subject to return to the same position over time to provide meaningful data. Head restraint systems inspired by kinematic clamps have been developed to allow micron scale repositioning across imaging epochs in rats. Here we report the development of a light-weight, implantable kinematic coupling (clamp) system that is wearable by mice, and enables repeated positioning to submicron accuracy across imaging epochs. This system uses a stainless steel headplate and a Maxwell-style three-groove kinematic mounting system with magnetic force clamping load. Spheres on the dorsal surface of the headplate provide contact points for vee-groove kinematic features machined into a tabletop mount. Evaluation of the clamp using multiphoton microscopy revealed submicron precision in registration accuracy and stability, allowing cellular resolution calcium imaging in awake, behaving mice. These results indicate that miniaturized implantable kinematic clamps for mice could be valuable for future experiments which require repositioning of subjects across time and different instruments.
Structural Studies of the Immunoglobulins IV. HEAVY AND LIGHT CHAINS OF THE γM PATHOLOGICAL MACROGLOBULINS

Abstract Six γM-globulins of antigenic Type K and one of Type L from patients with Waldenstrom's macroglobulinemia were purified, and their heavy (µ) and light κ or λ) chains were separated by reduction-alkylation and gel filtration. The purified γM-globulins and their isolated polypeptide chains were characterized by starch gel electrophoresis, immunological study, amino acid and NH2-terminal group analysis, and peptide maps. The γM-globulins were generally similar in amino acid composition but differed markedly from their constituent heavy and light chains and also from γG- and γA-globulins. The Type K (κ) light chains had NH2-terminal aspartic acid (five cases) or glutamic acid (one case), but no NH2-terminal group was detected in the Type L (λ) light chain and some of the heavy chains. For each γM-globulin the heavy and light chains were complementary in amino acid composition and peptide maps with respect to the whole protein, but differed greatly from each other. All of the heavy chains had about two-thirds of their soluble tryptic peptides in common, but differed individually with respect to the others. The κ light chains shared some peptides, all of which were identifiable with known sequence areas in Type K Bence-Jones proteins, but, like the latter proteins, they differed in other peptides representing the variable NH2-terminal half of the chain. The light chain of one γM-globulin and the Bence-Jones protein from the same patient were similar in many properties. The results support a multichain structural model of γM-globulins composed of two light chains of about 23,000 mol wt and two heavy chains. Each kind of chain appears to have a structural region subject to individual variation.
CAN READABILITY FORMULAS BE USED TO SUCCESSFULLY GAUGE DIFFICULTY OF READING MATERIALS

A grade level of reading material is commonly estimated using one or more readability formulas, which purport to measure text difficulty based on specified text characteristics. However, there is limited direction for teachers and publishers regarding which readability formulas (if any) are appropriate indicators of actual text difficulty. Because oral reading fluency (ORF) is considered one primary indicator of an elementary aged student's overall reading ability, the purpose of this study was to assess the link between leveled reading passages and students’ actual ORF rates. ORF rates of 360 elementary-aged students were used to determine whether reading passages at varying grade levels are, as would be predicted by readability levels, more or less difficult for students to read. Results showed that a small number of readability formulas were fairly good indicators of text, but this was only true at particular grade levels. Additionally, most of the readability formulas were more accurate for higher ability readers. One implication of the findings suggests that teachers should be cautious when making instructional decisions based on purported “grade-leveled” text, and educational researchers and practitioners should strive to assess difficulty of text materials beyond simply using a readability formula.
Ambient Noise Beneath the Seafloor

Simultaneous measurements of ambient noise were first made at several depths in the seafloor in August/September 1989, in a borehole off the Florida coast. Ambient noise levels decreased by a factor of three in amplitude (10 dB) between 10–100 m downhole (see figure) in the frequency range 2–50 Hz. As distance increased between the detector and the seafloor, the ambient noise levels decreased. Why do we care about ambient noise in the seafloor? One reason is that ambient noise levels limit the magnitude of earthquakes that can be detected. On land, earthquake monitoring stations are frequently placed in boreholes where better observations can be obtained. The Incorporated Research Institutions for Seismology consortium has identified the need for borehole seismic installations on the seafloor to improve the resolution of earthquake locations and of the source mechanisms of oceanic earthquakes. However, the study of ambient noise can be a fascinating subject in its own right. We do not yet completely understand how weather generates noise in the ocean, nor how the noise propagates and is distributed within the ocean and seafloor.
Induction of Apoptosis by Cell-Cycle Phase Specific Drugs

The events of apoptosis represent the outcome of processes defining a common physiological pathway of dying cells, and the inputs to this pathway are complex and highly varied1–5. It is clear that the actions of cytotoxic agents in mammalian cells frequently feed into the apoptosis pathway, and an extremely wide variety of agents/treatments have been shown to induce the events of apoptosis in cultured mammalian cells6,7. It is important to note, however, that cells vary widely in responses to specific cytotoxic agents and the induction of apoptosis by a given agent can vary between cell lines.
Multiband planar infrared metallodielectric photonic crystals designed using genetic algorithms with fabrication constraints

Planar metallodielectric photonic crystals (MDPCs) with multiple stop-bands in the far-infrared transmission spectrum have been designed using frequency selective surface (FSS) techniques at the micron-scale. A genetic algorithm (GA) has been used to optimize MDPC designs that exhibit multiple stop-bands with greater than 10 dB attenuation. It is shown that, by including design constraints in the GA to account for limitations in the fabrication process, it is still possible to synthesize a subset of MDPC structures that both meet the desired performance criteria and are capable of being accurately fabricated.
Erythrocyte Membrane Alterations Associated with the Attachment and Replication of Eperythrozoon suis: A Light and Electron Microscopic Study

Erythrocytes from pigs with experimental porcine eperythrozoonosis were examined using light microscopy and scanning and transmission electron microscopy. Three distinct forms of Eperythrozoon suis were attached to the plasma surface of erythrocyte membrane. Erythrocytes were initially parasitized by one or several immature forms. Immature forms enlarged and developed into juvenile and mature forms. The parasite replicated by budding of small immature forms from larger immature forms, juvenile forms, and mature forms. Small immature forms attached to adjacent membrane of the same erythrocyte or a nonparasitized erythrocyte. E. suis organisms were intimately associated with, but distinctly separated from erythrocyte membrane by a 30-nm electron lucent zone. Cell membrane in this area was denser than adjacent nonparasitized membrane. Early interaction between erythrocyte membrane and small immature forms resulted in no membrane deformation, but as this form enlarged, it later became embedded in a deep cup-like membrane invagination. As the immature form developed into the juvenile form a shallow, broad-based depression was observed in the membrane. A similar depression that covered a greater surface area was observed in the membrane parasitized by the mature form. The interaction between the parasitic forms and erythrocyte membrane resulted ultimately in severe membrane deformation. Parasite-membrane interactions may play an important role in the development of misdirected immune responses in experimental porcine eperythrozoonosis.
Knowing when not to stop

A recent study reveals that the eukaryotic ribosomal protein L30 binds to the selenocysteine recoding RNA element and may function to tether the recoding machinery to the translating ribosome.
Electron transfer in the dissimilatory iron-reducing bacterium Geobacter metallireducens

Abstract To investigate electron transport in the dissimilatory iron-reducing isolate Geobacter metallireducens strain GS-15, assays for redox enzymes and characterizations of cytochromes were performed. G. metallireducens produced 1.56 g dry cell weight per mol e−transferred when grown on benzoate and contained the following citric acid cycle enzymes (activities in nkat per mg cell protein); isocitrate dehydrogenase (0.84), coenzyme A-dependent 2-oxoglutarate: methyl viologen oxidoreductase (2.80), succinate dehydrogenase (0.80), and malate dehydrogenase (8.35). An oxygen-sensitive, soluble coenzyme A-dependent 2-oxoglutarate: ferredoxin oxidoreductase (0.14) with no NAD(P)-activity was observed. In cell suspensions NADPH, but not NADH, could reduce methyl viologen (2.45). Isocitrate and malate dehydrogenase activities were soluble enzymes that coupled with NADP and NAD, respectively. NADPH (0.94) and NADH (1.85) oxidation activities were observed in detergent solubilized, whole-cell suspensions using the artificial electron acceptor menadione. Menaquinone was observed at 1.2 μmol per g cell protein. The triheme c7cytochrome was purified and 37 amino acids were determined. The mass observed by mass spectroscopy was 9684±10 Da. The average mid-point potential for the three hemes was measured at −91 mV. The growth yield, redox reactions, and electron transfer components are discussed with regards to possible sites of energy conservation during growth on iron(III).
Key science legislation awaits final action

Congress is now in recess and will return to work on September 7, leaving only 4 weeks to complete action on a number of key science funding bills. Fiscal year 1994 begins on October 1. On the “must-do” list for Congress upon its return is Senate consideration and final House and Senate passage of HR2491, the VA, HUD, Independent Agencies Appropriations bill. Both the National Science Foundation and NASA are independent agencies funded under HR2491.
Electric field modulation in tissue electroporation with electrolytic and non-electrolytic additives

Electroporation, cell membrane permeabilization with short electrical field pulses, is used in tissue for in vivo gene therapy, drug therapy and minimally invasive tissue ablation. For the electroporation to be successful, the electrical field that develops during the application of the pulses needs to be precisely controlled. In this study we investigate the use of electrolytic and non-electrolytic gels to generate the precise electrical fields required for controlled electroporation, in heterogeneous and irregular tissues, in vivo. Finite element computer simulations are used to illustrate various applications, such as the treatment of irregularly shaped organs and interior cavities. The feasibility of the concept is demonstrated experimentally in vivo with a rat liver subjected to irreversible electroporation.
Clamping down on mammalian meiosis

The RAD9A-RAD1-HUS1 (9-1-1) complex is a PCNA-like heterotrimeric clamp that binds damaged DNA to promote cell cycle checkpoint signaling and DNA repair. While various 9-1-1 functions in mammalian somatic cells have been established, mounting evidence from lower eukaryotes predicts critical roles in meiotic germ cells as well. This was investigated in 2 recent studies in which the 9-1-1 complex was disrupted specifically in the mouse male germline through conditional deletion of Rad9a or Hus1. Loss of these clamp subunits led to severely impaired fertility and meiotic defects, including faulty DNA double-strand break repair. While 9-1-1 is critical for ATR kinase activation in somatic cells, these studies did not reveal major defects in ATR checkpoint pathway signaling in meiotic cells. Intriguingly, this new work identified separable roles for 9-1-1 subunits, namely RAD9A- and HUS1-independent roles for RAD1. Based on these studies and the high-level expression of the paralogous proteins RAD9B and HUS1B in testis, we propose a model in which multiple alternative 9-1-1 clamps function during mammalian meiosis to ensure genome maintenance in the germline.
Control of oxygen consumption in liver slices from normal and T4-treated rats.

Liver slices from control and T4-treated rats were incubated in medium containing glucose or succinate and oxygen consumption was measured. Control liver slices consumed 0.073 ± 0.004 µl O2/min/mg protein in medium containing glucose and 0.21 ± 0.01 µl O2/min/mg on the addition of succinate. Slices from rats given 5 daily injections of 50 µg of T4 ip consumed 0.102 ± 0.008 and 0.22 ± 0.01 µl O2/min/mg with glucose and succinate, respectively. Ouabain suppressed O2 consumption by T4-treated slices only in medium containing glucose. These data suggest that mitochondrial oxidizable substrate, and not ADP, controls the rate of oxygen consumption, and that T4 acts to increase the availability of substrate for mitochondrial oxidation. These findings are inconsistent with the theory that T4 increases tissue respiration by an effect on Na-K ATPase activity. (Endocrinology 95: 619, 1974)
Lectin detection of renal glycogen in rats with short-term streptozotocin-diabetes

Earlier histochemical findings from our laboratory have shown that a lectin (agglutinin) from Griffonia simplicifolia, which reportedly binds to terminal N-acetylglucosamine residues in glycoconjugate oligosaccharides also shows affinity for glycogen. In the present study, the lectin was conjugated to horseradish peroxidase and applied to paraffin sections of kidney from streptozotocin-diabetic rats, insulin-treated and untreated, and age-matched control rats. Griffoniasimplicifolia agglutinin II detected glycogen in cortical ascending thick limbs of untreated diabetic rat kidneys as early as 24 h following injection of streptozotocin. The number of stained cells increased steadily so that by day 14 of diabetes the lectin reacted with nearly all of the cells lining ascending thick limbs in the cortex and adjacent outer stripe of the outer medulla. Glycogen was never identified in the inner medullary stripe. Comparison of Griffonia simplicifolia agglutinin II and periodic acid-Schiff staining revealed that periodic acid-Schiff could not clearly detect glycogen until 14 days following injection of streptozotocin, which substantiated earlier claims that Griffonia simplicifolia agglutinin II might be a more sensitive indicator of glycogen than periodic acid-Schiff. The distribution of glycoconjugate containing terminal N-acetylglucosamine stainable with the lectin was unchanged in diabetic kidneys. Griffonia simplicifolia agglutinin II served in the present study to further characterise the sequence of abnormal glycogen accumulation in streptozotocin-diabetic rat kidneys. In addition, it was shown that the lectin's ability to antedate periodic acid-Schiff detection of glycogen has utility in histochemical investigations in diabetes.
Numerical and experimental characterizations of piezoresistive MEMS strain sensors

In this paper, new MEMS strain sensors are introduced. The transduction principle of the sensors is the resistance change due to piezoresistive property of polysilicon. Five different sensors are designed on the same device and tuned to resistance values of 350 Ω and 120 Ω. The sensors are aligned in horizontal, vertical and 45° directions in order to extract the principle strains. The geometry of the sensing element is a rectangular bar anchored at two ends and suspended above silicon substrate. The sensors are numerically modeled using COMSOL Multiphysics software. The model consists of all the micromachining layers, including silicon substrate, 0.7 μm thick polysilicon layer (sensing element) sandwiched between two layers of 0.35 μm thick silicon nitride layers and trenching under polysilicon layer, in order to estimate the strain that piezoresistive element is exposed to. The MEMS strain sensors are manufactured using MetalMUMPs process. The sensors are attached to aluminum and steel plates, and their gauge factors are compared with conventional foil gauges under uniaxial and biaxial loading. It is demonstrated that the MEMS strain sensors can detect both static and dynamic strains with the gauge factor reaching significantly high values. High gauge factor occurs because of unique geometry design and trenching, which amplify the strain that the polysilicon layer senses. The MEMS strain sensor can be fused with other sensing elements on the same device such as accelerometer, acoustic emission in order to have redundant measurement from a single point.
A componential model of human interaction with graphs: VI. Cognitive engineering of pie graphs.

This paper proposes and tests the following three-component model of reading a pie graph to estimate segment size: (a) selecting a mentally represented anchor segment (25%, 50%, or 75%), (b) mental...
Prostaglandin E1 induced salivary secretion.

PGE1 but not PGF2α at 500–1000 μg/kg induced a slow and sparse flow from the parotid and no flow at all from submaxillary glands. Composition of PGE1-induced parotid saliva was quite different from that evoked by any autonomic agonists. The present study suggests that PGE1 might act directly on parotid acinar cells.
Electrocardiographic effects of probucol. A controlled prospective clinical trial

Probucol is known to prolong QT intervals in some patients and to produce fatal arrhythmias in selected animal species. To assess the prevalence and clinical relevance of this effect in a controlled manner, we analyzed electrocardiograms (ECGs) and medical events in patients during a placebo-controlled crossover trial comparing single or combined administration of probucol and colestipol. Forty-two Type II hyperlipoproteinemic patients were studied for eighteen to twenty-four months. Two cardiologists independently read the tracings which were previously arranged randomly without names or dates. There were no statistical differences between the reports of the ECG parameters by the two cardiologists. The mean QTc interval of the entire patient population was lengthened after probucol administration without reaching statistical significance when compared to placebos or colestipol treatments. Forty-eight % of the patients showed lengthening of the QTc interval during probucol treatment by 11 to 70 msec increment over baseline placebo. The remaining had either no change or shortening of the interval. There were no statistically significant differences in means of R-R, PR, QRS, QTc or QoT intervals among placebo, probucol., colestipol and probucol plus colestipol treatments. It is concluded that probucol prolonged QT intervals in the electrocardiograms of about one half of patients receiving the drug with no other clinical or statistically significant evidence of cardiotoxicity or electrocardiographic effects.
Electronic Control of Frequency Converter Sets for Testing Aircraft Models

THE TESTING of airplane scale models in wind tunnels has brought about a demand for variable frequency a-c power for controlling the speed of power model motors used to drive the propellers of the plane models. To obtain aerodynamic data on the plane model which are equivalent to the expected performance of the actual plane, it is necessary to drive the model propellers at speeds greatly in excess of propeller speeds of the actual plane. During tests in the wind tunnel, it must be possible to control propeller speed and to measure accurately the speed as well as power input into the propeller.
Control of Jet Structure by Crown-Shaped Nozzles

Flow visualization and hot-wire anemometry were used to examine the effects of indeterminate-origin nozzles on flow in the near field of an otherwise axisymmetric air jet. The jet Reynolds number based on nozzle exit diameter was 19,000. Flow structure was investigated under both unforced and forced conditions where the forcing frequency corresponded to a Strouhal number based on diameter of 0.51. Time-averaged views of the unforced flow showed significant deviations of the jet from axisymmetry. Phase-averaged slices of forced flow strobed with a copper vapor laser revealed strong variations in entrainment along different azimuthal planes. Also, the phase-averaged visualizations showed repeatable coherent longitudinal vortex structures attached to the larger-scale vortex rings normally observed in round jets. When tooth length and number on the nozzle attachments were varied, the stability and propagation patterns of these longitudinal structures could be altered. Nomenclature D = jet exit diameter Euu = power spectral density function for axial velocity fluctuations / = forcing frequency ReD = Reynolds number, UD/v r = radial coordinate StD = Strouhal number, fD/U U = mean nozzle exit velocity Ux = mean axial velocity u'x = rms axial velocity x = axial coordinate /3 = azimuthal angle da = shear-layer vorticity thickness v = kinematic viscosity
Reversal of long-term LH deprivation on testosterone secretion and Leydig cell volume, number and proliferation in adult rats.

The purpose of this study was to determine whether Leydig cell volume and function could recover fully from long-term LH deprivation upon restoration of endogenous LH secretion, and whether the restoration of LH would elicit a mitogenic response, i.e. stimulate Leydig cell proliferation or affect Leydig cell number per testis. LH secretion was inhibited by treating adult rats with testosterone and oestradiol-filled (TO) silicone elastomer implants (16 weeks), and was restored by removing the implants. Changes in serum concentrations of LH and FSH, LH-stimulated testosterone secretion by testes perfused in vitro, Leydig cell volume and number per testis, average Leydig cell volume and Leydig cell [3H]thymidine incorporation were measured at weekly intervals following implant removal. The TO implants inhibited (P less than 0.01) LH secretion, but serum concentrations of FSH were not significantly different (P greater than 0.10) from control values. After implant removal, serum LH returned to control values within 1 week, whereas serum FSH increased twofold (P less than 0.01) and returned to control values at 4 weeks. LH-stimulated in-vitro testosterone secretion was inhibited by more than 99% in TO-implanted rats, but increased (P less than 0.01) to 80% of control values by 8 weeks after implant removal. The total volume of Leydig cells per testis and the volume of an average Leydig cell were 14 and 19% of control values respectively, after 16 weeks of TO implantation (P less than 0.01), but returned to 83 and 86% of controls (P greater than 0.10) respectively, by 6 weeks after implant removal. Leydig cell proliferation ([3H]thymidine labelling index) was low (less than 0.1%) in both control and TO-implanted rats, increased (P less than 0.01) fivefold from 1 to 4 weeks after implant removal and then declined to control values at 6 weeks. The increase in Leydig cell [3H]thymidine incorporation was mimicked by treating TO-implanted rats with exogenous LH, but not FSH. Leydig cells were identified in both the interstitium and the lamina propria of the seminiferous epithelium. The proportion of Leydig cell nuclei in the lamina propria was 30-fold greater (P less than 0.01) at 1 and 3 weeks after implant removal (3%) compared with that for control and TO-implanted rats (0.1%). Total Leydig cell number per testis was marginally but not significantly (P = 0.06) decreased in rats treated with TO implants for 16 weeks when compared with controls (18.4 +/- 2.2 vs 25.4 +/- 1.2 x 10(6)).(ABSTRACT TRUNCATED AT 400 WORDS)
Secondary Hyperparathyroidism and Bone Turnover in Elderly Blacks and Whites

This study was undertaken to describe the prevalence of secondary hyperparathyroidism in African-American and Caucasian participants in the Boston Low-Income Elderly Osteoporosis Study and to examine and compare associations of hyperparathyroidism with biochemical markers of bone turnover and bone density in the two racial groups. Serum osteocalcin and serum cross-linked N-telopeptides of type I collagen, and calcaneal bone mineral density were measured in February or March in 255 men and women, 64 yr of age and older. Subjects were categorized as normal or as having hyperparathyroidism, based on a serum PTH concentration below or above the top of the normal range (6.9 pmol/liter), respectively. The prevalence of hyperparathyroidism was 38% in the 144 black subjects and 20% in the 111 white subjects. Serum osteocalcin and cross-linked N-telopeptides of type I collagen were significantly higher in both black and white hyperparathyroid subjects (P < 0.05), and the hyperparathyroid-related difference in osteocalcin was greater among black than white subjects. Hyperparathyroidism was significantly associated with reduced heel bone mineral density in blacks (P = 0.008) but not in whites. This study provides evidence that secondary hyperparathyroidism is prevalent in elderly adults, both black and white, and that it should not be viewed as a benign condition in either group. Recent public health efforts to promote higher calcium and vitamin D intakes, targeted predominantly to older Caucasians, should also be directed to older African-Americans.
Influence of Rearrangement of Actin Cytoskeleton on the Overall Material Properties of ATDC5 Cells During Chondrogenesis

ATDC5 cells, a prechondrocytic cell line, were cultured in 2% agarose gel-cell constructs. A major reorientation of actin structure (stress-fiber to punctate) was observed during the chondrogenesis of these cells. 2D finite element models of cell (considered as a composite with embedded actin fibers) in a 500μ3 gel were created for days 1 (prechondrocytes), 5, 8 & 12 (chondrocytes) of culture. The response of the cells to uniaxial compression of the gel-cell construct was studied. The model predicted that, as a result of rearrangement of actin, the cells became more compliant and less anisotropic. When the gel size was reduced to 20μ3 , RUTL (Ratio of radial deformations of cell in the Transverse direction to Loaded direction) became significantly different between prechondrocytes and chondrocytes. The difference in force required to compress a 20μ3 gel-cell construct containing a prechondrocyte vs a chondrocyte to 15% deformation was 103nN (152.3 vs 48.8 nN). This information can be used to build MEMS based devices that can mechanically distinguish between the different cell types.Copyright © 2004 by ASME
Shock response of a glass-fiber-reinforced polymer composite

Abstract The present work describes the compression and release response of a glass-fiber-reinforced polyester composite (GRP) under shock loading to 20 GPa. Shock experiments in GRP were performed at Sandia National Laboratories and the US Army Research Laboratory. GRP is a heterogeneous material. The diagnostic measurements fluctuate beyond the precision of the experimental measurements but they do permit determination of an average response of the material at the end state. These experiments show that: (i) GRP deforms elastically in compression to at least 1.3 GPa; (ii) the deformation coordinates of shocked and re-shocked GRP lie on the deformation locus of initially shocked GRP to 4.3 GPa; (iii) and the release path of GRP shocked to varying magnitudes of stresses indicate that the GRP expands such that its density when stresses are released in the range of 3–5 GPa from a peak compressive stress of 9 GPa and above is lower than the initial density of GRP. Possible reasons for the observed lower density remain to be investigated.
Software basics for computational mathematics

This article discusses problems at the software design and implementation level that transcend any particular subfield of computational mathematics, but which are important to all subfields. The discussion includes desirable attributes of numerical software that are independent of the underlying algorithms, ways in which software with these attributes exploit arithmetic characteristics of the host computer, advantages to the gathering of numerical software into thematic packages and the problems involved in such work, and challenges in testing numerical software. A nontechnical overview of the subject is followed by a technical discussion which includes suggestions for research activities within DOE.
Opsoclonus-myoclonus with Beckwith-Wiedemann syndrome and hepatoblastoma

The association between Beckwith-Wiedemann syndrome and hepatoblastoma is well established and relatively commonplace. The occurrence of opsoclonus-myoclonus syndrome in individuals with occult neoplasia is also well documented. However, the development of opsoclonus-myoclonus syndrome in an infant with Beckwith-Wiedemann syndrome and hepatoblastoma has not been reported previously. The list of underlying causes of opsoclonus-myoclonus syndrome should be expanded to include hepatoblastoma, particularly in any child with features suggestive of Beckwith-Wiedemann syndrome.
Calculation of the magnetization of anisotropic superconductors with cylindrical geometry in transverse fields

Abstract Expressions for the magnetization of a monolithic superconductor with anisotropic critical currents and a cylindrical geometery have been found. A transverse field geometry, along with field independent critical currents are assumed. Additionally, we restrict ourselves to the case of full field penetration, and thus demagnetization effects are ignored. Similarly to the calculation for the slab geometry, two regimes are found; (1) sample length is greater than a certain “transfer length”, and (2) sample length is shorter than the transfer length. Analytical expressions for the magnetization in both regimes, as well as linear approximations to these expressions, are found. These results are directly compared to the equations used to describe the finite slab geometry.
Reproductive output of ponderosa pine in response to thinning and prescribed burning in western Montana

Thinning and thinning followed by prescribed fire are common management practices intended to restore historic conditions in low-elevation ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) forests of the northern Rocky Mountains. While these treatments generally ameliorate the physiology and growth of residual trees, treatment-specific effects on reproductive output are not known. We examined reproductive output of second-growth ponderosa pine in western Montana 9 years after the application of four treatments: thinning, thinning followed by spring prescribed fire, thinning followed by fall prescribed fire, and unthinned control stands. Field and greenhouse observations indicated that reproductive traits vary depending on the specific management treatment. Cone production was significantly higher in trees from all actively managed stands relative to control trees. Trees subjected to prescribed fire produced cones with higher numbers of filled seeds than trees in unburned treatments. Seed mass, perc...
Assessing Coping Strategies by Analysing Expressive Writing Samples

This study examined whether coping style can be assessed using a text analysis of expressive writing samples. Participants (n = 153) wrote about a stressful college experience and then completed a depression scale and three coping measures, including the COPE. Writing samples were analysed using Pennebaker’s Linguistic Inquiry and Word Count computer programme. Depression scores were related to the use of words denoting negative emotions but were unrelated to the use of the pronoun ‘I’. Respondents who used more words denoting negative emotions in their essays obtained lower problem-focused coping scores on the COPE. The use of insight-related words was associated with lower scores on measures of emotion-focused coping. Copyright © 2009 John Wiley & Sons, Ltd.
Management Science and Management: Implementing Management Science Via Situational Normativism

Implementation of management science via situational normativism, a descriptive-normative approach to decision making, is discussed. The situational normativism process involves a search by manager and management scientist for a synthesized situational frame of understanding involving analytic and heuristic knowledge, as discussed in the paper within which solutions to the decision situation problem can be found. Implementation constraints e.g., cognitive style constraints and political constraints are explicitly considered. A situational normativism organization development concept is suggested. Mutual understanding between scientist and manager evolves from and is fed to the situational normativism search process. Unity of science and management, implementation, and organization system development---in the sense of attaining evolved-in-the-process goals---are viewed as natural corollaries of working towards a synthesized situational frame of understanding via situational normativism. Some examples illustrating aspects of the organization development concept arising from practice are presented.
Theft and Vandalism on Construction Sites

Theft and vandalism on construction sites in the commercial construction industry is a problem that can affect productivity and drain profits. To explore the impact of theft and vandalism in the commercial construction industry, a survey was sent to commercial construction firms to gather information by which the magnitude of the problem of theft and vandalism could be estimated; and to determine what techniques have been successfully used to deter thieves and vandals. The responses were analyzed and several conclusions were developed. Firms engaging in all types of projects are susceptible to theft and vandalism. Theft is more costly to large sized firms ($100 million and over in annual volume of construction work) than smaller firms, but vandalism is more costly for smaller firms. This occurs despite the fact that larger firms use a greater number of measures to combat theft and vandalism on their construction sites. The results should be of particular interest to construction firms that want to reduce ...
Adrenergic Signaling in Human Oral Keratinocytes and Wound Repair

Catecholamines are present in saliva, but their influence on oral epithelium is not understood. Because psychological stress increases salivary catecholamines and impairs oral mucosal wound healing, we sought to determine if epithelial adrenergic signaling could link these two findings. We found that cultured human oral keratinocytes (HOK) express the α(2B)- and β(2)-adrenergic receptors (ARs). Exposure of HOK to either epinephrine or the β-AR agonist, isoproterenol, reduced migratory speed and decreased in vitro scratch wound healing. Incubation with the β-AR antagonist timolol reversed the catecholamine-induced effects, indicating that the observed response is mediated by β-AR. Epinephrine treatment decreased phosphorylation of the mitogen-activated protein kinases (MAPK) ERK1/2 and p38; these decreases were also reversed with timolol. Cultured HOK express enzymes of the epinephrine synthetic pathway, and generate epinephrine. These findings demonstrate that stress-induced elevations of salivary catecholamines signal through MAPK pathways, and result in impaired oral keratinocyte migration required for healing.
An equivalent metal ion in one- and two-metal-ion catalysis

Most known nucleotidyl-transfer enzymes use two metal ions for catalysis, but some enzymes use only one divalent cation in their active sites. A comparative analysis of previously available structural data reveals that the one-metal-ion enzymes use a similar mechanism to coordinate their single metal ion, which corresponds, functionally and structurally, to metal ion B in the two-metal-ion enzymes. Nucleotidyl-transfer enzymes, which synthesize, degrade and rearrange DNA and RNA, often depend on metal ions for catalysis. All DNA and RNA polymerases, MutH-like or RNase H–like nucleases and recombinases, and group I introns seem to require two divalent cations to form a complete active site. The two-metal-ion mechanism has been proposed to orient the substrate, facilitate acid-base catalysis and allow catalytic specificity to exceed substrate binding specificity attributable to the stringent metal-ion (Mg2+ in particular) coordination. Not all nucleotidyl-transfer enzymes use two metal ions for catalysis, however. The ββα-Me and HUH nucleases depend on a single metal ion in the active site for the catalysis. All of these one- and two metal ion–dependent enzymes generate 5′-phosphate and 3′-OH products. Structural and mechanistic comparisons show that these seemingly unrelated nucleotidyl-transferases share a functionally equivalent metal ion.
Synthesis of Trifluoromethylaryl Diazirine and Benzophenone Derivatives of Etomidate that Are Potent General Anesthetics and Effective Photolabels for Probing Sites on Ligand-Gated Ion Channels

To locate the binding sites of general anesthetics on ligand-gated ion channels, two derivatives of the intravenous general anesthetic etomidate (2-ethyl 1-(phenylethyl)-1H-imidazole-5-carboxylate), in which the 2-ethyl group has been replaced by photoactivable groups based on either aryl diazirine or benzophenone chemistry, have been synthesized and characterized pharmacologically. TDBzl-etomidate (4-[3-(trifluoromethyl)-3H-diazirin-3-yl]benzyl 1-(1-phenylethyl)-1H-imidazole-5-carboxylate) and BzBzl-etomidate (4-benzoylbenzyl-1-(1-phenylethyl)-1H-imidazole-5-carboxylate are both potent general anesthetics with half-effective anesthetic concentrations of 700 and 220 nM, respectively. Both agents resembled etomidate in enhancing currents elicited by low concentrations of GABA on heterologously expressed GABAA receptors and in shifting the GABA concentration-response curve to lower concentrations. They also allosterically enhanced the binding of flunitrazepam to mammalian brain GABAA receptors. Both agents were also effective and selective photolabels, photoincorporating into some, but not all, subunits of the Torpedo nicotinic acetylcholine receptor to a degree that was allosterically regulated by an agonist or a noncompetitive inhibitor. Thus, they have the necessary pharmacological and photochemical properties to be useful in identifying the site of etomidate-induced anesthesia.
An improved Lewis-Milne equation for the advance phase of border irrigation

The Lewis-Milne (LM) equation has been widely applied for design of border irrigation systems. This equation is based on the concept of mass conservation while the momentum balance is replaced by the assumption of a constant surface water depth. Although this constant water depth depends on the inflow rate, slope and roughness of the infiltrating surface, no explicit relation has been derived for its estimation. Assuming negligible border slope, the present study theoretically treats the constant depth in the LM equation by utilizing the simple dam-break wave solution along with boundary layer theory. The wave front is analyzed separately from the rest of the advancing water by considering both friction and infiltration effects on the momentum balance. The resulting equations in their general form are too complicated for closed-form solutions. Solutions are therefore given for specialized cases and the mean depth of flow is presented as a function of the initial water depth at the inlet, the surface roughness and the rate of infiltration. The solution is calibrated and tested using experimental data.