cssi/SciSciGPT-SciSciNet huggingface dataset:
Structural Basis of Response Regulator Inhibition by a Bacterial Anti-Activator Protein

The complex interplay between the response regulator ComA, the anti-activator RapF, and the signaling peptide PhrF controls competence development in Bacillus subtilis. More specifically, ComA drives the expression of genetic competence genes, while RapF inhibits the interaction of ComA with its target promoters. The signaling peptide PhrF accumulates at high cell density and upregulates genetic competence by antagonizing the interaction of RapF and ComA. How RapF functions mechanistically to inhibit ComA activity and how PhrF in turn antagonizes the RapF-ComA interaction were unknown. Here we present the X-ray crystal structure of RapF in complex with the ComA DNA binding domain. Along with biochemical and genetic studies, the X-ray crystal structure reveals how RapF mechanistically regulates ComA function. Interestingly, we found that a RapF surface mimics DNA to block ComA binding to its target promoters. Furthermore, RapF is a monomer either alone or in complex with PhrF, and it undergoes a conformational change upon binding to PhrF, which likely causes the dissociation of ComA from the RapF-ComA complex. Finally, we compare the structure of RapF complexed with the ComA DNA binding domain and the structure of RapH complexed with Spo0F. This comparison reveals that RapF and RapH have strikingly similar overall structures, and that they have evolved different, non-overlapping surfaces to interact with diverse cellular targets. To our knowledge, the data presented here reveal the first atomic level insight into the inhibition of response regulator DNA binding by an anti-activator. Compounds that affect the interaction of Rap and Rap-like proteins with their target domains could serve to regulate medically and commercially important phenotypes in numerous Bacillus species, such as sporulation in B. anthracis and sporulation and the production of Cry protein endotoxin in B. thuringiensis.
Solutions to Environmental and Economic Problems (STEEP).

This article describes one model for organizing and mobilizing scientific resources to address the highly complex and costly problem of soil erosion in the Pacific Northwest. With a U.S. Department of Agriculture grant to the agricultural experiment stations in Washington, Oregon, and Idaho, as well as supplementary state and federal funds, STEEP awards intermediate-term (15 year) grants for research in five areas: tillage and plant management, plant design, erosion and runoff predictions, pest management, and socioeconomics of erosion control. Most of the research projects require collaboration across disciplines and, in some instances, across state boundaries. After 6 years of effort the results obtained with STEEP indicate that the model might be applicable to other regions and problems.
Generalized Susceptibility Theory I. Theories of Hypochromism

A general theory is developed for the linear response of an interacting molecular system to an external field. The exact ground state of the system is expressed in terms of the uncoupled molecule (zeroth-order) state by means of adiabatic time-dependent perturbation theory. Including the external field to first order in the time-development operator leads to an infinite-order expansion of the linear response function for physical quantities such as current-charge density and electric-dipole polarization. Two basic approximations involving partial decorrelation of charge motion and spatial separability of the molecules allow the response function to be determined by a simplified Dyson-type equation, which can be put into closed form by further approximations. The approximate linear response function (susceptibility) so obtained is given in terms of the isolated molecule susceptibility and corresponds exactly to the results of classical, local field theory. Emphasis throughout is placed on the effect of molecular interaction on absorption spectra. Comparisons among theories of hypochromism show clearly that all previously reported theories are mutually compatible and are either equivalent to, or are contained in, the theory developed here. The relation of the present theory to a coupled equivalent oscillator model is discussed and the results are applied to a simple physical model.
Aneurysmal bone cyst of the atlas: successful treatment through selective arterial embolization: case report.

OBJECTIVE AND IMPORTANCE: Aneurysmal bone cysts (ABCs) are benign and expanisle osteolytic lesions that can occur in any location in the spine, including the craniovertebral junction. Aggressive resection followed by bone grafting has been the mainstay of treatment, with selective arterial embolization as a presurgical adjunct. Complete excision of these lesions at the craniovertebral junction is associated with high surgical morbidity. We report a case of successful treatment of an ABC of the atlas in a child with selective arteria embolization alone. CLINICAL PRESENTATION: A 10-year-old girl presented with presistent neck pain after a snowboarding accident. Computed tomography and magnetic resonance imaging of the cervical spine revealed an expansile cystic mass involving the right lateral mass of C1. Digital subtraction angiography revealed a tumor blush, which, along with the cystic appearance of the lesion, was consistent with an ABC. INTERVENTION: The arterial feeders to the lesion were selectively embolized with polyvinyl alcohol particles. Three sessions of embolization were required to eradicate the blood supply to the lesion completely. CONCLUSION: Complete surgical resection of ABCs at the craniovertebral junction can be associated with high morbidity secondary to the highly vascular and destructive nature of these lesions. The case discussed here demonstrates the viability of selective arterial embolization as a primary and stand alone modability of treatment.
On the Formation of Whitecaps by a Threshold Mechanism. Part III: Field Experiment and Comparison with Theory

Abstract This paper is the third in a series of papers which seek to evaluate the hypothesis that deep water whitecapping is predictable in terms of a threshold mechanism involving the vertical acceleration. Parts I and II of the series have developed the descriptive framework for the investigation and examined several geometro-statistical predictions of the threshold model, the first by direct integration of the joint probability densities for the vertical acceleration, the second by Monte Carlo simulation of the vertical acceleration field. In Part III we describe a field experiment designed to study the statistical geometry of the whitecap field and to test the theoretical predictions of Parts I and II. This experiment, conducted at an experimental site in the Bight of Abaco, Bahamas, combines a series of photographs of whitecap events with simultaneous array measurements of waves. The photographs were taken from above the water surface and cover an area nominally 10 m on a side. A total of 2292 whitec...
Enhancing Photochemical Activity of Semiconductor Nanoparticles with Optically Active Ag Nanostructures: Photochemistry Mediated by Ag Surface Plasmons

Composite materials composed of optically active Ag nanostructures and TiO2 photocatalysts show enhanced photoactivity compared to the pure TiO2 in the decomposition of methylene blue. The enhanced photochemical activity is attributed to radiative transfer of energy, mediated by surface plasmons, from Ag particles to the semiconductor leading to higher concentrations of charge carriers (e−/h+ pairs) in the semiconductor and therefore to higher photochemical activity. We demonstrate that the performance of the composite photocatalysts is a strong function of the size and shape of Ag nanostructures. This can be explained by the size- and shape-specific optical activity of Ag nanostructures. We show that by rationally changing the size and shape of Ag nanostructures it is possible to maximize photochemical activity of a semiconductor at a given excitation wavelength.
Effect of Preparation and Electrode Placement on the Frog ERG

Diffuse illumination was used to stimulate the in-place frog eye. The intact, essentially intact, and opened-eye preparations were used. With the intact eye, the ERG was detected by a ventrodorsal, craniodorsal, or caudodorsal electrode placement on the skin around the eye, but not by a craniocaudal, ventrocranial, or caudoventral placement. An asymmetrical electrode placement on the cornea, or placement of the reference on the cornea and probe on the skin or on an injured corneal section, also detected the ERG. In the opened eye, only the ERG was detected with reference on the retina’s vitreous side. With the reference on the cornea, the EIRG was seen. In the essentially intact eye, with the probe entering from the choroidal side, only the ERG was observed with either a corneal or a choroidal reference. Two hypotheses were advanced. The first was the presence of an insulating layer, probably Bruch’s membrane, in most of the eye except for the cornea which is insulated by Bowman’s membrane. The second was that the EIRG is a complex waveform resulting from the ERG’s entering both the probe and reference electrodes and summing algebraically if the insulating layer just mentioned were sufficiently disturbed.
Trends in survival of hospitalized myocardial infarction patients between 1970 and 1985. The Minnesota Heart Survey.

BACKGROUNDThe Minnesota Heart Survey is a population-based study designed to monitor and explain trends in cardiovascular mortality, morbidity, and risk factors. As part of this effort, a 50% sample of patients hospitalized for myocardial infarction (MI) in the seven-county Twin Cities (Minneapolis and St. Paul) metropolitan area was reviewed in 1970, 1980, and 1985. Those with a validated definite MI were followed for 4-year mortality. The purpose was to determine whether the improved survival observed between 1970 and 1980 was extended to the 1980-1985 period.METHODS AND RESULTSCrude 28-day mortality in men changed from 18% in 1970 to 12% in 1980 to 13% in 1985; in women it changed from 27% in 1970 to 22% in 1980 to 18% in 1985. After adjustment for severity factors (e.g., age, previous MI, and admission heart rate and systolic blood pressure), 28-day mortality was significantly lower in 1980 than in 1970 in men (RR, 0.66; 95% CI, 0.47, 0.92) and in women (RR, 0.69; 95% CI, 0.46, 1.04), but no change oc...
New Test method for determining energy absorption mechanisms in polymer composite plates

In passenger vehicles the ability to absorb energy due to impact and be survivable to the occupant is called the “crashworthiness” of the structure. To identify and quantify the energy absorbing mechanisms in candidate automotive composite materials, test methodologies were developed for conducting progressive crush tests on composite plate specimens. The test method development and experimental setup focused on isolating the damage modes associated with frond formation that occurs in dynamic testing of composite tubes. A new test fixture was designed to progressively crush composite plate specimens under quasi-static test conditions. Features incorporated into the design include an observable crush zone, long crush length, interchangeable contact profile, frictionless roller for contact constraint, and out of plane roller supports to prevent buckling. Preliminary results are presented under a sufficient set of test conditions to validate the operations of the test fixture. The activation of different damage mechanisms was demonstrated by the validation tests on the representative composite material systems. The experimental data, in conjunction with test observations will be used in future work to identify the characteristic damage and failure modes, and determine the energy absorption capability of candidate automotive composite material systems.
High temperature sulfidation behavior of low Al iron-aluminum compositions

Iron-aluminum weld overlay coatings are currently being considered for enhanced sulfidation resistance. The performance of these alloys in reducing atmospheres far exceeds other conventional materials presently used. However, the application of iron-aluminum alloys is currently limited due to hydrogen cracking susceptibility subsequent to welding. A direct correlation between the severity of embrittlement and the amount of aluminum in the alloy has been observed, specifically when the composition resides in the ordered region of the Fe-Al phase diagram (above 10 wt% Al). Higher Al overlays have been deposited, but only with extensive pre-heat and post-weld heat treatments which are not always feasible. In addition to the welding problem, detailed corrosion studies indicating the sulfidation behavior of these binary alloys has not been fully conducted. Previous research has utilized gas compositions and temperatures which would be considered very aggressive (temperatures above 700 C and P{sub S2} {ge} 10{sup {minus}7} atm), especially when compared to industrial boiler environments. Less assaulting conditions could not be found in the open literature. Therefore, research has been initiated to evaluate the sulfidation behavior of weldable iron-aluminum compositions, in the range of 5--10 wt% Al, in moderately reducing environments.
Quantum size effects on the (0001) surface of double hexagonal close packed americium

Electronic structures of double hexagonal close-packed americium and the (0001) surface have been studied via full-potential all-electron density-functional calculations with a mixed APW+lo/LAPW basis. The electronic and geometric properties of bulk dhcp Am as well as quantum size effects in the surface energies and the work functions of the dhcp Am (0001) ultra thin films up to seven layers have been examined at nonmagnetic, ferromagnetic, and antiferromagnetic configurations with and without spin orbit coupling. The anti-ferromagnetic state including spin-orbit coupling is found to be the ground state of dhcp Am with the 5f electrons primarily localized. Our results show that both magnetic configurations and spin-orbit coupling play important roles in determining the equilibrium lattice constant, the bulk modulus as well as the localized feature of 5f electrons for dhcp Am. Our calculated equilibrium lattice constant and bulk modulus at the ground state are in good agreement with the experimental values respectively. The work function of dhcp Am (0001) 7-layer surface at the ground state is predicted to be 2.90 eV. The surface energy for dhcp Am (0001) semi-infinite surface energy at the ground state is predicted to be 0.84 J/m2. Quantum size effects are found to be more pronounced in work functions than in surface energies.
Braitenbergian experiments with simple aquatic robots

This paper describes the development of a short introductory underwater robotics course, aimed at college freshman and high school and middle school students. During these courses, students work in teams to build and program underwater robots using a combination of LEGO and other simple materials. As an introduction to ideas of artificial intelligence and robot programming, students undertook a practical exploration of the concepts developed by cybernetician Valentino Braitenberg in his famous book "Vehicles: Experiments in Synthetic Psychology". Over five laboratory sessions, students gradually evolved their own designs for waterborne "robotic amoebas" through a series of progressively more complex design challenges. These courses build on our previously reported work in which students have built underwater Remotely Operated Vehicles using similar materials and educational strategies. This work is now being adapted for dissemination to large numbers of middle and high schools across New Jersey through a grant from the National Science Foundation.
Genetics and Alcoholism Simulacra

The author explores the role of genetic techniques in developing simulacra for eventual use as models in alcoholism research.
Influences of spherical tip radius, contact depth, and contact area on nanoindentation properties of bone

Nanoindentation has been widely used as a means to measure the micro-mechanical properties of bone and to predict the macroscopic properties. The role of indent depth and indenter tip geometry in measuring the hierarchical properties of bone tissue was explored experimentally using a range of spherical indenter tips of R=5, 25, 65, and 200 μm. Nanoindentation arrays, not targeted to fall on specific structures or locations, enabled statistical sampling of osteons within PMMA-embedded, bovine, cortical bone on a single sample to a range of maximum displacements (minimum of 100 nm and maximum of 2000 nm). Elastic finite element models were then utilized to isolate the contributions of indenter tip radius, contact area, and position within the lamellar structure in comparison to the experimental results. For a small, R=5 μm indenter tip, indentation modulus consistently increased with contact depth and increased plastic deformation, resulting in an artificial increase in elastic properties. While larger radius tips (R=25, 65, and 200 μm) did not enable evaluation of a high spatial resolution on the surface, they produced data that was representative of the lower load and contact depth measurements with the smaller tip. However the sensitivity to mechanical property variations across the 2-D surface of the material was lost with increase in indenter tip size. Correspondingly, measurement variance was also decreased as the volume contributing to the indent response represented an average of surface roughness, varying mineral content, defects, and underlying tissue type and structure.
Interventions for Heart Failure Readmissions: Successes and Failures

Heart failure readmissions result in significant costs to the health care system and to patients’ quality of life, but programs to reduce readmissions have met with mixed success. Successful strategies have included multidisciplinary hospital-based quality initiatives, disease management programs, and care transition interventions. Devices like telemonitors and indwelling catheters, however, have met with mixed success. Research is still needed to elucidate the most effective interventions for readmission reduction in the HF population.
Renal allograft biopsies in the era of C4d staining: the need for change in the Banff classification system

C4d immunostaining in the peritubular capillaries (PTC) is a marker of antibody-mediated rejection (AMR). We evaluated the histopathologic diagnoses of 388 renal transplant biopsies since the implementation of routine C4d immunostaining at our center. Of these, 155 (40%) biopsies had evidence of acute cellular rejection (ACR), out of which 119 (77%) had pure ACR, 31 (20%) had ACR with concomitant features of AMR, and five (3%) had ACR with focal C4d staining. Sixty-four (16%) biopsies exhibited features of AMR [33 (52%) pure AMR, and 31(48%) concomitant AMR and ACR]. One hundred and fifty-five (40%) biopsies had features of interstitial fibrosis and tubular atrophy (IFTA). Of these, 20 (13%) had concomitant AMR [13 (8.5%) had pure AMR and seven (4.5%) had concomitant ACR and AMR]. Creatinine at the time of biopsy was higher in patients with mixed ACR and AMR and the clinical behavior of mixed lesions is more aggressive over time. Despite having a lower serum creatinine at the time of biopsy, patients with IFTA experienced gradual decline in graft function over time. The pathologic findings in renal allograft biopsies are often mixed and mixed lesions appear to have more aggressive clinical behavior. These findings suggest the need for change in the Banff classification system to better capture the complexity of renal allograft pathologies.
Procedures to Follow if a Law Enforcement Official Asks for Patron Information: A Checklist for Access Services Student Employees

ABSTRACT Since the U.S.A. PATRIOT Act was signed into law in October, 2001, library administrators have become increasingly concerned that staff–especially student employees–continue to protect the confidentiality of patron records. Administrators have also become increasingly concerned that when law enforcement officials provide paperwork giving them legal access to patron records, staff take steps both to divulge no more information than is necessary and to protect the institution from liability. In response to these concerns, the University of Colorado, Boulder, created an easy-to-understand and easy-to-use document for its public services student employees. This article describes the process by which that document was created, how it was introduced to staff and student employees, and what additional steps are planned for the future. Finally, the document itself is included as a possible model for other institutions that may wish to create procedural guidelines for student employees.
Dynamic Testing Of Optical Disk Profile

AbstractIt is shown that focus error signal spectrum, measured while disk is spinning, represents Fourier transform of the disk profile modified by the loop gain.IntroductionMinimum laser spot diameter and its variations due to defocusing set the limit to data densities on optical disk. In closed loop feedback systems, the amount of deviation from the "best focus" position (focus error signal) is determined by the disk displacement (disk profile and spindle run-out) and servo loop properties (gain and frequency response). Put another way, disk deformation and vibrations determine the maximum disk RPM's while main­ taining focus within specified limits. Therefore, it is imperative to manufacture disks to specified flatness and control manufacturing process by measuring disk profile using a quick, reliable noncontact method. This paper describes one such method.Disk profile Along a given circumference, the disk has a certain profile P(X) as shown in Figure 1.P(X)» X .Figure 1One can consider P(X) to be a combination of sinusoidal variations such that P(X) = ZAU)COS(2IUX+0(£)) . .... (1)Where £ is the spatial frequency of deviation, and A (5) is the amplitude of that compo­ nent. As the disk revolves, focus servo must follow amplitude variation A (c) at a fre­ quency given byf = CV. . . . . (2) Where V is the linear velocity of the media at radius r and is given byV = 2rTIRPS. . . (3) Where RPS is the number of disk revolutions per second and r is the radius of interest.As the disk revolves, its profile as a function of time P(t) will be similar to the curve shown in Figure 1 within one revolution, and then repeates itself with each full revolution.236
Searching for the Real Florida in the Land of Make Believe: Historical Archaeology as Public Archaeology, Orange County, Florida

Orange County encompasses the city of Orlando and is home to over one million residents and attracts millions of tourists annually. Starting in the twentieth century, areas in the county sustained intensive agricultural use and later massive residential and commercial development. As a result of these activities, natural and historic areas were spoiled while others vanished completely. Prior to the 1970s and the establishment of Walt Disney World, the area’s tourism industry revolved primarily around its natural amenities, only to be supplanted by a form that was thematic and “make believe”. In 2006, an archaeology program was initiated to unearth the county’s early history as a way of searching for the “real Florida.” This paper will discuss how public archaeology has the potential for addressing problems that affect cultural and natural resources as history is unearthed at the neighborhood level.
Theory and measures of individual differences in studies of trait by treatment interaction. 1

Abstract Studies based on the methodology of Trait by Treatment Interaction (TTI) have tended to emphasize input‐output relations as they interact with individual differences. Consideration of intervening processes employed by learners has been neglected to the possible detriment of empirical and theoretical contributions. The development of taxonomies of how situations are coded and of the kinds of processes used by learners with different characteristics appears to be essential. Furthermore, assessment of individual differences must correspond to the theoretical demands of a given study. The attainment of these objectives requires renewed attention to carefully derived “theoretical”; statements of interlocking and dynamic relations among situations, traits, processes, and outcomes.
Scope and heterogeneous nature of MODY.

This review summarizes aspects of the phenotypic expression, natural history, recognition, pathogenesis, and heterogeneous nature of maturity-onset diabetes of the young (MODY), which is inherited in an autosomal-dominant pattern. There are differences in metabolic, hormonal, and vascular abnormalities in different ethnic groups and even among White pedigrees. In MODY patients with low insulin responses, there are delayed and decreased insulin and C-peptide secretory responses to glucose from childhood or adolescence even before glucose intolerance appears, which may represent the basic genetic defect. When followed for decades, nondiabetic siblings have normal insulin responses. The fasting hyperglycemia of some MODY patients has been treated successfully with sulfonylureas for up to 30 yr. In a few patients, after years or decades of diabetes, the insulin and C-peptide responses to glucose are so low that they resemble those of early insulin-dependent diabetes mellitus. The progression of the insulin secretory defect over time distinguishes between these two types of diabetes. In contrast are patients from families who have very high insulin responses to glucose, despite glucose intolerance and fasting hyperglycemia similar to that seen in patients with low insulin responses. In many of these patients, there is in vivo and in vitro evidence of insulin resistance. Whatever its mechanism, the compensatory insulin responses to nutrients must be insufficient to maintain normal carbohydrate tolerance. This suggests that diabetes occurs only in those patients who have an additional islet cell defect, i.e., insufficient beta-cell reserve and secretory capacity. In a few MODY pedigrees with high insulin responses to glucose and lack of evidence of insulin resistance, a structurally abnormal mutant insulin molecule that is biologically ineffective is secreted. No associations have been found between specific HLA antigens and MODY in White, Black, and Asian pedigrees. Linkage studies of the insulin gene, insulin-receptor gene, erythrocyte/HepG2 glucose-transporter locus, and apolipoprotein B locus have shown no association with MODY. Vascular disease may be as prevalent as in conventional non-insulin-dependent diabetes mellitus. Because of autosomal-dominant transmission and penetrance at a young age, MODY is a good model for further investigations of etiologic and pathogenetic factors in non-insulin-dependent diabetes mellitus, including the use of genetic linkage strategies to identify diabetogenic genes.
Fano resonance membrane reflectors from mid-infrared to far-infrared

Compact broadband reflectors (BBRs) are of great importance for optoelectronic devices and photonic integrated circuits like lasers, photodetectors, solar cells, and sensors, etc. Traditionally, they can be realized by using metal films or stacked dielectric thin films. Metal films can offer larger reflection bandwidth but are limited by their intrinsic absorption losses. Stacked dielectric thin films can achieve very low losses. But they typically require many individual layers with stringent refractive index and thickness tolerances for each layer. It becomes more of an engineering challenge to realize extremely high reflection DBRs at longer wavelengths, including mid-IR, far-IR, and THz frequencies, due to the scaling of quarter-wavelength stack dielectrics.
Venezuelan encephalitis antibody studies in certain Florida wildlife.

Between November, 1966 and November, 1968 serum samples from 725 wild vertebrates from south Florida were examined for antibody to Venezuelan encephalitis virus by the hemagglutination-inhibition test. Antibodies to Venezuelan encephalitis were found in 29 sera from the cotton mouse, Peromyscus gossypinus, the cotton rat, Sigmodon hispidus, the rice rat, Oryzomys palustris, the black rat, Rattus rattus, and the white-tailed deer, Odocoileus virginianus. Recent circulation of Venezuelan encephalitis virus in habitats other than documented enzootic foci warrants extensive ecological studies in areas adjacent to the Everglades National Park.
Mechanisms of sepsis and insights from clinical trials.

Multiple clinical trials of adjunctive therapy for sepsis and septic shock have been conducted to neutralize bacterial components or to modulate host inflammatory responses to infection but with limited success. Many therapies are beneficial only in patients with a high severity of illness and have minimal or harmful effects in patients that are less severely ill. Improved measures of severity of illness and discovery of biomarkers to help identify these high-risk patients are needed.
Chandler Wobble, earthquakes, rotation, and geomagnetic changes

A pattern recognition algorithm can be applied to the seismicity of major earthquake belts, to the amplitudes of Chandler Wobble, to changes in the rotational velocity of the Earth, and to the drift of the eccentric geomagnetic dipole for the years 1901–64. The patterns which emerged suggest that all of these diverse phenomena are related.
Identifying and Measuring Racial Profiling by the Police

Over the past decade, public concern about racial profiling and racially disparate treatment of drivers during routine traffic stops has become a critical issue facing law enforcement. Racial disparities in traffic stops, citations and searches impose serious costs on minority citizens and can strain relationships between community members and the police. Over the past decade, researchers, police administrators and legal advocates have employed various methodologies to measure whether or not, and under what conditions, racial profiling exists. Despite a proliferation of research on the subject, many questions about how to best measure racial profiling remain unanswered. This study provides an overview of the problem of racial profiling and discusses the strengths and limitations of the most common research strategies that have been used to identify and measure the prevalence of the problem.
New Identities for Critical-Point Constraints with Application to Cubic Equations of State

This work presents a new mathematical condition and procedure for application of the classical critical-point constraints for pure components. Although the condition applies to any EoS, the applications in this work are to cubic EoS. Using the generalized cubic EoS, we have developed algebraic equations that relate the critical Z-factor, Z C , to the parameters in the particular cubic EoS. We then proceeded to examine particular equations with two to five parameters.
Isolation of anaerobic oxalate-degrading bacteria from freshwater lake sediments

Enrichment cultures that anaerobically degraded oxalate were obtained from lake sediment inocula. From these, 5 pure cultures of anaerobic oxalate-degrading bacteria were isolated and partially characterized. The isolates were Gram-negative, non-sporeforming, non-motile, obligate anaerobes. Oxalate was required for growth and was stoichiometrically converted to formate; 14CO2 was also recovered when 14C-oxalate was added. Maximal growth occurred when the oxalate concentration was 50 mM. Acetate stimulated growth in the presence of oxalate, however, 14C-experiments indicated that acetate was only utilized for cell carbon. The isolates were either spiral-shaped or rod-shaped organisms. The first morphotype grew much more slowly than the second and exhibited 13-fold lower cell yields. These isolates represent a new strain of oxalate-degrading bacteria. The second morphotype was similar to the anaerobic oxalate-degrading bacteria previously found in rumen. This report extends the known habitats in which anaerobic oxalate-degrading organisms have been found to include aquatic sediments.
On the tractability of linear tensor product problems in the worst case

It has been an open problem to derive a necessary and sufficient condition for a linear tensor product problem to be weakly tractable in the worst case. The complexity of linear tensor product problems in the worst case depends on the eigenvalues {@l"i}"i"@?"N of a certain operator. It is known that if @l"1=1 and @l"[email protected]?(0,1) then @l"n=o((lnn)^-^2), as n->~, is a necessary condition for a problem to be weakly tractable. We show that this is a sufficient condition as well.
Energy-aware QoS for application sessions across multiple protocol domains in mobile computing

The proliferation of heterogeneous devices and diverse networking technologies demands flexible models to guarantee the quality-of-service (QoS) at the application session level, which is a common behavior of many network-centric applications, e.g., Web browsing and Instant messaging. Several QoS models have been proposed for heterogeneous wired/wireless environments. However, we envision that the missing part, which is also a big challenge, is taking energy, a scarce resource for mobile and energy-constrained devices, into consideration. In this paper we propose a novel energy-aware QoS model, e-QoS, for application sessions that might across multiple protocol domains, which will be common in the future Internet, rather than an exception. The model provides QoS guarantee by dynamically selecting and adapting application protocols. To the best of our knowledge, our model is the first attempt to address QoS adaptation at the application session level by introducing a new QoS metric called session lifetime. To show the effectiveness of the proposed scheme, we have implemented two case studies: Web browsing from a Pocket PC to a regular Web server, and an instant messaging application between two Pocket PCs. In the former case study, our approach outperforms the conventional approach without energy-aware QoS by more than 30% in terms of the session lifetime. In the second case study, we also successfully extend the session lifetime to the value negotiated by two Pocket PCs with very diverse battery capacities.
Distinct phosphorylation signals converge at the catalytic center in glycogen phosphorylases

Abstract Background: Glycogen phosphorylases (GPs) catalyze the conversion of the storage form of carbohydrate (glycogen) to the readily usable form (glucose-1-phosphate) to provide cellular energy. Members of this enzyme family have evolved diverse regulatory mechanisms that control a conserved catalytic function. The mammalian and yeast GPs are expressed as inactive forms requiring phosphorylation for activation. Phosphorylation of yeast GP occurs at a distinct site from that of mammalian GP. This work addresses the structural basis by which distinct activation signals relay to the conserved catalytic site in yeast and mammalian GPs. Such knowledge may help understand the principles by which diverse biological regulation evolves. Results: We have compared the crystal structures of the unphosphorylated and phosphorylated forms of yeast GP and propose a relay which links phosphorylation to enzyme activation. Structural components along the activation relay becomes more conserved within the GP family downstream along the relay, towards the catalytic center. Despite distinct upstream activation signals, a response element downstream of the relay leading to the catalytic center is conserved in all GPs. The response element consists of ten hydrophobic residues dispersed over two subunits of the homodimer. Phosphorylation induces hydrophobic condensation of these residues via structural rearrangement, which triggers conformation change of the active site GATE loop, leading to enzyme activation. Conclusions: Members of the GP family with diverse activation mechanisms have evolved from a constitutively active ancestral enzyme which has the TOWER hydrophobic response element in the active position. Diverse regulation evolved as a result of evolutionary constraint on the downstream response element in the active state, coupled with flexibility and variability in elements of the upstream relays.
Circadian variation of RNA in human leucocytes.

DIURNAL changes in RNA content have been described for animal cell lines such as liver1 and epithelium2, and so it would seem logical that similar periodic changes in RNA would occur in vivo in other eukaryotic cells.
Neck Cannulation for the Repair of Thoracic Artery Aneurysms in the Infant

Thoracic aneurysms are relatively rare in infancy. We report our experience with two such patients, one with a false aneurysm of the ascending aorta and the other with a mycotic aneurysm of the main pulmonary artery. Neck cannulation prior to sternotomy, using cannulae designed for extracorporeal membrane oxygenation, allowed entry into the mediastinum under controlled circumstances and permitted the successful repair of the aneurysms.
Tracer diffusion of crown ethers in chlorobenzene from 301 to 373 K

Abstract Tracer diffusivities are reported for s-trioxane, 12-crown-4, 15-crown-5, and 18-crown-6 in chlorobenzene from 301 to 373 K. The results are discussed in terms of Arrhenius equation for diffusion, Stokes' law, and Hildebrand's free-volume model. An extension of Dymond's hard sphere self-diffusion equation to tracer diffusion has been found to successfully correlate the data reported here.
Lymphangiographic patterns in filarial oedema of lower limbs.

The authors have studied forty cases of lymphoedema due to Wuchereria bancrofti by means of lymphangiography. They were able to classify the cases according to clinical severity into those without oedema following acute lymphangitic episodes; those showing oedema only after exercise; a further group with permanent oedema; and finally a group with solid oedema and often with skin changes. These clinical groups correlated accurately with increasing abnormalities of the leg lymphatics. The mechanism of oedema is discussed and it is suggested that it is due to widespread perilymphatic fibrosis set up by dead worms. The clinical implications of the lymphographic findings are pointed out.
Reactivation of Kaposi's Sarcoma-Associated Herpesvirus Infection from Latency by Expression of the ORF 50 Transactivator, a Homolog of the EBV R Protein☆

Kaposi's sarcoma (KS)-associated herpesvirus (KSHV), or human herpesvirus 8, is a lymphotropic virus strongly linked to several AIDS-related neoplasms. The primary reservoir of infection consists of latently infected B lymphocytes and possibly other mononuclear cells. Viral reactivation from latency and spread from this lymphoid reservoir is presumably required for development of nonlymphoid tumors like KS. Here we show that deregulated expression of a single viral gene, ORF 50, which encodes a transactivator able to selectively upregulate delayed-early viral genes, suffices to disrupt latency and induce the lytic gene cascade in latently infected B cells. The identification of this gene opens the way to studies of the physiologic mechanisms controlling reactvation of KSHV from latency.
The Effect of Host Development on Parasitism and Mortality of Two Pests Attacked by Trichogramma evanescens (Hymenoptera: Trichogrammatidae)

In laboratory experiments host development had a significant effect on the parasitism and mortality of Pieris rapae (L.) and Trichoplusia ni (Hubner) eggs attacked by Trichogramma evanescens Westwood. Parasitism of P. rapae (mean, 74.0%) was lower at the beginning and end of host embryonic development than in the intermediate stages, but there was no significant difference in mortality (mean, 95.0%) through this period. Parasitism of T. ni (mean, 59.6%) declined linearly with increasing host development. Mortality (mean, 88.8%) was higher in the early and late stages of host development than during the intermediate stages. The data indicate that host development may be a critical factor in selecting candidate parasites to be used in biological control programs.
An Induction Motor with Paralleled Rotor and Stator

A wound rotor induction motor may be operated with the stator and the rotor independently magnetized, (neither supply frequency corresponding to the slip frequency). If the stator and rotor are paralleled the pull-out torque as a motor is approximately doubled and the continuous horsepower output may be increased, and as an induction generator, the maximum kva. output is increased. It may be operated simultaneously as a motor and as a generator. This method of operation was new to the authors and to several eminent induction motor designers and as no reference has been found to others employing this principle, the theory has been developed and is presented with the experimental results of tests.
Forces across the middle of the intact clavicle during shoulder motion.

Hypothesis The optimal management of displaced middle third clavicle fractures is currently under investigation. Advances in fracture fixation technology have expanded the indications for operative fracture management. Data are currently unavailable regarding the normal forces and moments that occur in the middle clavicle with motion of the glenohumeral joint. This study tested our null hypothesis that active range of motion in internal rotation, external rotation, and abduction would produce a similar magnitude of force across the middle clavicle. Materials and methods Clavicle forces were measured in 6 whole fresh frozen cadavers using a 6 degree-of-freedom load cell mounted to the middle third of the clavicle. The rotator cuff tendons were isolated, divided, and connected to a system of weights. The forces across the clavicle in 3 orthogonal directions were quantified during simulated active abduction, internal rotation, and external rotation. Results There were statistically greater axial compressive force and torque in the clavicle during humeral abduction compared with internal or external rotation. During external rotation, there were statistically greater tensile forces compared with abduction or internal rotation. There were no statistical differences in the superior-inferior or anterior-posterior forces with the 3 motions studied. Discussion Overall, active abduction caused the greatest increase in middle clavicle forces and torque. Abduction resulted in the most significant axial compressive force, whereas active external rotation caused the greatest tensile force across the intact middle clavicle. Conclusions To our knowledge, these findings represent the first results describing the forces across the intact clavicle during glenohumeral motion. These data can be used to aid clinicians in treating these fractures, guide the design of future biomechanical studies, and develop rehabilitation protocols.
Chasing Rainbows: A Comment on School Choice and the National Football League

We are pleased to see our article, “Rethinking the Market Metaphor: School Choice, the Common Good, and the National Football League,” appear in the Journal of School Choice (Beal & Olson Beal, thi...
Supervision: The New Clinical Supervisor: Tools for the Medical Setting

Placement of graduate student clinicians in medical environments continues to serve as an ongoing challenge for many universities. This article addresses five questions, proposed by clinical superv...
Attempts to Improve English L2 Pronunciation: The Variable Effects of Different Types of Instruction

This study compared the pronunciation of targeted vocabulary items in spontaneous speech by 23 adult Chinese L1 learners of L2 English grouped into four different conditions reflecting current pedagogical practices: (a) traditional drilling activities, (b) self-study with tape recordings, (c) interactive activities, and (d) a no-intervention control condition. One hundred and twenty native-speaking listeners judged whether there was improvement or deterioration in pronunciation before and at two separate times subsequent to each of the four conditions. Because none of the results appeared to overwhelmingly favor one teaching technique, we included a discussion of the range of patterns of change brought about by the four input types. We also present arguments for a more serious consideration of the complex effects potentially involved when setting out to modify a learner's L2 pronunciation.
pH-Controlled Assembly and Disassembly of Electrostatically Linked CdSe−SiO2 and Au−SiO2 Nanoparticle Clusters

The effect of pH on the self-assembly and disassembly of nanoparticle aggregates (clusters) of amine modified silica spheres (50 nm) and carboxylic acid modified gold (7 nm) or cadmium selenide (6 nm) spheres was investigated using electron microscopy and infrared and electronic spectroscopy. 4-Mercaptobenzoic acid (MBA) ligated cadmium selenide nanoparticles were synthesized by ligand exchange on 6 nm trioctylphosphine oxide ligated CdSe nanoparticles in basic methanol solution at room temperature. Reaction of CdSe(MBA) and 11-mercaptoundecanoic acid (MUA) ligated gold nanoparticles with tetramethylammonium hydroxide in methanol or THF produced CdSe(MBA)-[N(CH3)4+] and Au(MUA)-[N(CH3)4+] as black solids. On the basis of signal integration in the 1H NMR spectra, organic groups occupy areas of 0.44 nm2 (MBA), 0.22 nm2 (MUA), and 0.69 nm2 (APS) on the nanoparticle surfaces. Combination of these modified colloids with solutions of 3-aminopropylsiloxane ligated colloidal silica in aqueous solution at various ...
The effect of hydrological patterns and breeding-season flooding on the numbers and distribution of wading birds in Everglades National Park

Field ecologists in Everglades National Park know that the dynamics of water flow affect the breeding success of wading birds. A number of recent studies have suggested foraging success as the primary causal link. Data on the number and location of foraging birds are available from the Systematic Reconnaissance Flights, monthly aerial surveys of wading birds and surface water condition. A set of regression models were developed that predict the number of foraging birds observed in the Park at the beginning of May, a crucial period in the breeding season of almost all wading birds in this area. Predictor variables were obtained by converting the observations of surface water condition into three indexes that describe (1) the amount of surface water in the Park in January (near the beginning of the ‘dry’ season), (2) the rate at which it dries over the subsequent months, and (3) the amount of disruption to that drying process. An information-theoretic measure, ICOMP(IFIM), was used to choose on the basis of parsimony between the large set of possible models that incorporate these predictors. Most species were best predicted by the same few models, and the fitted model parameters were also similar, indicating that the same pattern of surface water dynamics was optimal for most species. The optimal pattern was: intermediate water levels at the beginning of the dry season, a rapid rate of drying, and no disruption in the drying process. A number of disruptions in drying since 1985 have been the result of releases of water from the flow-control structures at the northern boundary of Everglades National Park. Reducing or eliminating these unnatural hydrological events should help wading bird populations to increase.