cssi/SciSciGPT-SciSciNet huggingface dataset:
First-principles calculations on LixNiO2: phase stability and monoclinic distortion

The phase diagram of Li x NiO 2 (0< x < 1) and the evolution of the monoclinic distortion as a function of the lithium content are calculated using a combination of first-principles energy methods and statistical-mechanics techniques. As a function of the temperature different ordered Li x NiO 2 structures appear in the phase diagram at x= 0.25, 0.33, 0.4, 0.5 and 0.75. Noteworthy, a new and unsuspected phase, Li 0.4 NiO 2 , dominates the low-lithium region of the phase diagram. In agreement with experimental results, maxima in monoclinicity (a m /b m ) are predicted to occur near Li 0.75 NiO 2 and Li 0 4 NiO 2 , The coupling between the Li-vacancy ordering and the Jahn-Teller activity of Ni 3+ ions plays a crucial role in the stability of ordered Li x NiO 2 structures and is at the origin of the monoclinic distortion. As a result, the different electrochemical behavior of Li x NiO 2 versus Li x CoO 2 lies in the electronic nature of the involved transition metal cation.
A novel implementation of a chirp Z-transform using a CORDIC processor

An efficient implementation of the chirp Z transform (CZT) using a CORDIC (coordinate rotation digital computer) processor is presented. In particular, it is shown that a scaling operation in the CZT algorithm can be conveniently implemented with a norm correction (normalization) computation, which is often considered as an overhead in the CORDIC algorithm. Furthermore, since the desired frequencies of CZT are specified before computation, it is possible to reduce the total number of CORDIC iterations by finding a most economical representation of the angle in terms of the elementary CORDIC rotation angles. A simple suboptimal solution is proposed to solve this difficult optimization problem. This implementation is most effective when very few complex frequencies on the Z plane are to be evaluated via CZT. >
Advantages and limitations of cytogenetic, molecular cytogenetic, and molecular diagnostic testing in mesenchymal neoplasms.

Elucidation of the pathogenesis of bone and soft tissue tumors has been challenging because the genetic events are unique for the different mesenchymal tumor subtypes. However, enormous progress has been achieved with the advancement of cytogenetic and molecular genetic techniques. As a result, relevant oncogenes and tumor suppressor genes have been identified and localized, and new gene constructs and their protein products that result from translocations during sarcoma genesis have been determined. The identification of tumor-specific genetic markers for bone and soft tissue tumors, such as Ewing’s sarcoma, has added a new dimension to the formulation of a diagnosis and the resolution of cellular origin. Many of the genetic markers appear to have prognostic value, and studies to determine their potential applications as specific therapeutic targets are in progress. Three common genetic approaches used to identify mesenchymal tumorspecific abnormalities are conventional cytogenetic, molecular cytogenetic (fluorescence in situ hybridization, or FISH) and reverse transcription-polymerase chain reaction (RT-PCR) analyses. In this instructional lecture, emphasis is placed on the practical applications of each of these techniques, including their advantages and limitations. Certain case presentations are included to illustrate the integration of traditional histopathological and genetic approaches and serve as useful paradigms.
Trichothiodystrophy: clinical spectrum, central nervous system imaging, and biochemical characterization of two siblings.

Trichothiodystrophy (TTD), an autosomal recessive disorder characterized by sulfur-deficient brittle hair, identifies a group of genetic disorders with an altered synthesis of high-sulfur matrix proteins and a defect in excision repair of ultraviolet damage in fibroblasts of most TTD patients. In contrast to patients with xeroderma pigmentosum (XP), TTD patients do not have an increased frequency of skin cancers. TTD patients may be grouped into four categories: 1) those without photosensitivity and without a defect in excision repair of UV damage; 2) those without photosensitivity and with an excision-repair defect in the same gene as in XP-D (complementation group D); 3) those with photosensitivity and with the XP-D repair defect; 4) those with photosensitivity and with a repair defect distinct from that in XP-D. We present a brother and sister in the third category of TTD. Clinically, the patients have brittle hair, short stature, ichthyosis, photosensitivity, nail and dental dysplasias, cataracts, mental retardation, and pyramidal tract abnormalities. Diagnosis was made by hair mount, which shows the characteristic banding pattern with polarizing microscopy, and by hair amino acid analysis, which demonstrated decreased high-sulfur matrix proteins. Fibroblasts cultured from skin biopsies had a marked DNA excision repair defect similar to the repair defect seen in XP-D. We have documented a unique dysmyelinating disorder on magnetic resonance imaging of the brain that might explain their mental retardation, marked hyperactivity, and neurologic deficits. Following the discovery that the human excision repair cross complementing rodent ultraviolet group 2 (ERCC2) gene is able to correct the ultraviolet sensitivity of XP-D cell strains, the ERCC2 cDNA from previous TTD patients was sequenced and shows frameshifts, deletions and point mutations in the ERCC2 gene. Molecular analysis of our patients is in progress. Molecular analysis of the defects in ERCC2 in clinically distinct patients with XP, XP/Cockayne's syndrome, and TTD may provide insight into the molecular mechanisms of these genetically related but clinically distinct disorders. J Invest Dermatol 103:154S-158S, 1994
Concentrations of carbachol stimulating phosphoinositide hydrolysis cause a sustained decrease in membrane potential and firing rate: role of inositol and inositol polyphosphate second messengers

Abstract We have investigated the relationship between muscarinic agonist-stimulated phosphoinositide (PI) hydrolysis and electrophysiological responses in rat hippocampal slice preparations. In a previous extracellular study37, we found that muscarinic agonists at concentrations that stimulate PI hydrolysis result in a biphasic firing response; an initial increase in firing followed by loss of firing at higher concentrations. To test the hypothesis that variability in obtaining consistent loss of firing is related to depletion of intracellular inositol, we investigated the effects of adding exogenous inositol to the buffer. We now report that concentrations of inositol similar to those in cerebral spinal fluid (30–100 μM) augment carbamylcholine (carbachol, CCh) mediated loss of firing and [3H]inositol-1,3,4,5-tetrakisphosphate ([3H]Ins(1,3,4,5)P4) formation. Inhibition of firing produced by 30 μM CCh in the presence of inositol was associated with a sustained depolarization of 20–25 mV, an increased slope resistance in the depolarized range(−60 to −40 mV), and a parallel shift in the hyperpolarized (−100 to −70 mV) range of the voltage-current curve and increased frequency of spontaneous IPSPs. Under voltage-clamp, measurements of the M-current (IM) showed sustained inactivation by CCh with reversal after washout of CCh. Manual depolarization of cells by current injection to the same level of depolarization as attained with CCh did not usually lead to the same loss of firing. These findings suggest that IM, and possibly other voltage-independent currents or ion pumps, may cause loss of firing only in part through a depolarization blockade of firing and not through desensitization. Furthermore, CCh treatment without inositol did not depolarize neurons as much as CCh with inositol, and usually did not cause a delayed loss of firing. Brain slice preparations may thus require physiological concentrations of inositol to show consistent or maximum phosphoinositide-mediated electrophysiological responses.
Kir2.3 Isoform Confers pH Sensitivity to Heteromeric Kir2.1/Kir2.3 Channels in HEK293 Cells

Background Data on pH regulation of the cardiac potassium current I K1 suggest species-dependent differences in the molecular composition of the underlying Kir2 channel proteins. Objective The purpose of this study was to test the hypothesis that the presence of the Kir2.3 isoform in heterotetrameric channels modifies channel sensitivity to pH. Methods Voltage clamp was performed on HEK293 cells stably expressing guinea pig Kir2.1 and/or Kir2.3 isoforms and on sheep cardiac ventricular myocytes at varying extracellular pH (pH o ) and in the presence of CO 2 to determine the sensitivity of macroscopic currents to pH. Single-channel activity was recorded from the HEK293 stables to determine the mechanisms of the changes in whole cell current. Results Biophysical characteristics of whole-cell and single-channel currents in Kir2.1/Kir2.3 double stables displayed properties attributable to isoform heteromerization. Whole-cell Kir2.1/Kir2.3 currents rectified in a manner reminiscent of Kir2.1 but were significantly inhibited by extracellular acidification in the physiologic range (p K a ∼ 7.4). Whole-cell currents were more sensitive to a combined extracellular and intracellular acidification produced by CO 2 . At pH o = 6.0, unitary conductances of heteromeric channels were reduced. Ovine cardiac ventricular cell I K1 was pH o and CO 2 sensitive, consistent with the expression of Kir2.1 and Kir2.3 in this species. Conclusion Kir2.1 and Kir2.3 isoforms form heteromeric channels in HEK293. The presence of Kir2.3 subunit(s) in heteromeric channels confers pH sensitivity to the channels. The single and double stable cells presented in this study are useful models for studying physiologic regulation of heteromeric Kir2 channels in mammalian cells.
Visible light interferometer for EUVL system alignment

A visible wavelength interferometer has been developed for the alignment of an extreme ultraviolet lithography (EUVL) camera. Although the EUVL camera will operate at 13.4 nm, the alignment is far more conveniently done at visible wavelengths, at ambient pressure. Traditional visible interferometers are not capable of reaching the better than 1 nm accuracy required for EUVL camera alignment; so a phase shifting diffraction-limited interferometer was constructed and used to align and quantify the EUVL wavefront to an accuracy better than (lambda) visible/2000. The interferometer and alignment process are described, and camera wavefront measurements presented.
Pyruvate: metabolic protector of cardiac performance

Pyruvate, a metabolic product of glycolysis and an oxidizable fuel in myocardium, increases cardiac mechanical performance and energy reserves, especially when supplied at supraphysiological concentrations. The inotropic effects of pyruvate are most impressive in hearts that have been reversibly injured (stunned) by ischemia/reperfusion stress. Glucose appears to be an essential co-substrate for pyruvate's salutary effects in stunned hearts, but other fuels including lactate, acetate, fatty acids, and ketone bodies produce little or no improvement in postischemic function over glucose alone. In contrast to pharmacological inotropism by catecholamines, metabolic inotropism by pyruvate increases cardiac energy reserves and bolsters the endogenous glutathione antioxidant system. Pyruvate enhancement of cardiac function may result from one or more of the following mechanisms: increased cytosolic ATP phosphorylation potential and Gibbs free energy of ATP hydrolysis, enhanced sarcoplasmic reticular calcium ion uptake and release, decreased cytosolic inorganic phosphate concentration, oxyradical scavenging via direct neutralization of peroxides and/or enhancement of the intracellular glutathione/NADPH antioxidant system, and/or closure of mitochondrial permeability transition pores. This review aims to summarize evidence for each of these mechanisms and to consider the potential utility of pyruvate as a therapeutic intervention for clinical management of cardiac insufficiency.
When morality meets politics in development

This paper advances the thesis that there is an important role for political engagement in the development of moral identity. When young people take their moral interests into the realm of political action, moral identity is annealed and a lasting new level of maturity is reached. Political participation is not the only path to a mature identity, but it is effective and supported by empirical findings and theory. This thesis contrasts with positions that follow from more familiar theories of moral development which emphasise reasoning over identity, pit the individual against institutional moral traditions and view moral identity as a private possession rather than a shared and public relationship. Attentiveness to political engagement puts focus on developmental processes of dealing with competing interests and on institutions that serve as repositories of moral traditions, thus linking youth to moral communities. As a result, individuals are able to form identities in relationship to established traditi...
A new approach to treating acute otitis media.

BACKGROUND Acute otitis media (AOM) is one of the most frequently diagnosed pediatric conditions, accounting for one in three office visits; AOM is second only to an upper respiratory tract infection (URI) in frequency. Otitis media is defined as an inflammation of the middle ear resulting from various etiologies, generally a viral or bacterial infection. By the age three years, approximately 85% of children will have experienced at least one episode of AOM that required treatment with antibiotics. The incidence of AOM is greater in the winter season, in males, and in Caucasian and Native American children. Despite research showing that approximately 78% of uncomplicated AOM spontaneously resolves without any treatment, the cost to society for this condition remains enormous. In children younger than 13 years of age, $5.3 billion of direct and indirect costs is attributed to the identification and treatment of otitis media. Clinical evidence suggests that the treatment of a child who does not appear ill but has signs of AOM can be conservative and should be directed towards relieving symptoms, restoring normal activities, avoiding serious sequelae, keeping costs low, and reducing antibiotic resistance. Determining when antibiotics are needed, which antibiotic should be utilized, and at what dosage antibiotics are to be prescribed is often a challenge in primary care. In 2004 the American Academy of Pediatrics and the American Academy of Family Physicians examined available evidence-based clinical studies and formulated new guidelines for the identification and management of AOM in children. This practice guideline will review some of these new recommendations.
Performance characteristics in the determination of soil‐water pH and soil‐SMP buffer pH using a flow‐through junction combination electrode

Abstract A laboratory robot has been used to assess the performance of a commercially available flow‐through junction pH electrode. The electrode was tested for accuracy and precision in the determination of soil‐water pH (pHw) and the Shoemaker, McLean, and Pratt buffer solution pH (pHSMP). The significance of the pHSMP determination lies in subsequent calculations of soil lime requirement (LR). Response times and hysteresis effects were compared under different operating conditions.
Ultrastructure of the peduncular aesthetascs of Speleonectes tanumekes (Crustacea, Remipedia) in comparison with crustaceans from stressful environments

Abstract. Osmotic stress associated with the freshwater environment and desiccation stress associated with the terrestrial environment may have a shortening effect on the length of the innervation of crustacean aesthetascs. Physical stress of the littoral environment may have a similar effect on the length of the cuticular portion of aesthetascs. The aesthetascs of crustaceans that inhabit these environments share a similar ultrastructural feature, which may help animals cope with these environmental stresses. This ultrastructural feature, the position of the basal bodies proximal to the lumen of the aesthetasc, is absent from the aesthetascs of crustaceans that occur in the typical marine environment. Interestingly, the ultrastructural feature associated with these stressful habitats is present in the peduncular aesthetascs of the remipede Speleonectes tanumekes, even though the environmental stresses that may invoke the reduction of aesthetascs are absent in the marine-cave environment where this animal occurs. The importance of the sensitivity of aesthetascs for survival in this lightless environment may result in a selective pressure that favors basal bodies to be positioned proximal to the lumen of the aesthetasc.
Stimuli-responsive reagent system for enabling microfluidic immunoassays with biomarker purification and enrichment.

Immunoassays have been translated into microfluidic device formats, but significant challenges relating to upstream sample processing still limit their applications. Here, stimuli-responsive polymer–antibody conjugates are utilized in a microfluidic immunoassay to enable rapid biomarker purification and enrichment as well as sensitive detection. The conjugates were constructed by covalently grafting poly(N-isopropylacrylamide) (PNIPAAm), a thermally responsive polymer, to the lysine residues of anti-prostate specific antigen (PSA) Immunoglobulin G (IgG) using carbodiimide chemistry via the polymer end-carboxylate. The antibody-PNIPAAm (capture) conjugates and antibody-alkaline phosphatase (detection) conjugates formed sandwich immunocomplexes via PSA binding in 50% human plasma. The complexes were loaded into a recirculating poly(dimethylsiloxane) microreactor, equipped with micropumps and transverse flow features, for subsequent separation, enrichment, and quantification. The immunocomplexes were capture...
Surface Fractal Parallel Plate Models for Micropore Structures of Active Carbon

Abstract In order to analyze the micropore structures of active carbon, two types of surface fractal parallel plate models are calculated. It is shown that the disordered model, in which fractal surfaces are less restrictively piled up in the horizontal direction compared with the ordered one, can simulate the micropore size distribution of active carbon. The average micropore width L av can be expressed by L av = f (−Δ W / W ) = g ( n , D S ), where −Δ W / W is the percentage burnoff based on the ideally layered graphite model with the surface fractal dimension D S = 2, and n is the number of the contraction mapping.
Pathologic Findings Associated with Delayed Death in Nonhuman Primates Experimentally Infected with Zaire Ebola Virus

Zaire Ebola virus infection in macaques causes a fatal disease with a pathogenesis similar to that in humans. During several independent therapy studies, we noted altered tissue tropism in 6 rhesus macaques that survived longer than those with a typical disease course. The mean time to death for these 6 macaques was 21.7 days, which is significantly longer than the average mean time to death of 8.3 days for 20 untreated historical control animals. In addition to living significantly longer, these 6 animals exhibited a variety of deteriorating clinical signs with pathologic findings that were not seen in the untreated control animals, as well as the presence of viral antigen in the brain, eye, pancreas, thyroid, and lung. We suggest that treatment extended the time course of the disease and permitted the virus to infect tissues not usually affected in the typical model.
Single-Molecule Studies of the Bacteriophage T4 DNA Packaging Motor

Viruses employ many different mechanisms to complete their replication cycle in an optimal manner. Tailed, double-stranded DNA (dsDNA) bacteriophages rely on extreme internal pressures within their capsids to eject their genomes when infecting a host cell. A subset of DNA translocating molecular motors have evolved to package their genomes into preassembled viral capsids. The Bacteriophage T4 packaging motor generates high forces >60 pN and translocates DNA at rates exceeding 2000 bp/s, although it exhibits an unusually wide variability in rates. Recently, Rao, Rossmann and coworkers obtained X-ray and cryo-electron microscopy structures of the ATPase responsible for DNA translocation, gp17, and have proposed a model for motor function based on interesting differences in the two structures. Key regions in this model include an interface between two globular subdomains with ion pairs proposed to help generate motor forces, and a hinge region that allows the subdomains to move together and apart as a ratchet. We have succeeded in carrying out single molecule measurements of packaging dynamics with several mutant gp17 complexes with residues altered in these regions and have observed alterations in motor velocity and force. Efforts to fill in more details of the catalytic cycle and extend this model by comparing simulated predictions with experimental results will be discussed.
Characteristic patterns of shelf circulation at the boundary between central and southern California

[1] The coastal circulation in the Santa Barbara Channel (SBC) and the southern central California shelf is described in terms of three characteristic flow patterns. The upwelling pattern consists of a prevailing equatorward flow at the surface and at 45 m depth, except in the area immediately adjacent to the mainland coast in the SBC where the prevailing cyclonic circulation is strong enough to reverse the equatorward tendency and the flow is toward the west. In the surface convergent pattern, north of Point Conception, the surface flow is equatorward while the flow at 45 m depth is poleward. East of Point Conception, along the mainland coast, the flow is westward at all depths and there results a convergence at the surface between Point Conception and Point Arguello, with offshore transport over a distance on the order of 100 km. Beneath the surface layer the direction of the flow is consistently poleward. The relaxation pattern is almost the reverse of the upwelling pattern, with the exception that in the SBC the cyclonic circulation is such that the flow north of the Channel Islands remains eastward, although weak. The upwelling pattern is more likely to occur in March and April, after the spring transition, when the winds first become upwelling favorable and while the surface pressure is uniform. The surface convergent pattern tends to occur in summer, when the wind is still strong and persistently upwelling favorable, and the alongshore variable upwelling has build up alongshore surface pressure gradients. The relaxation pattern occurs in late fall and early winter, after the end of the period of persistent upwelling favorable winds.
Characterizing classes of antiretroviral drugs by genotype.

This paper develops methods for using HIV-1 genotypic information to group patients who are expected to have similar patterns of sensitivity or resistance to two or more drugs. The methods presented are an extension of prediction based classification to handle multiple drug responses. Here, the goal is to determine the probability that one antiretroviral therapy will be more favourable than another for an individual given the specific genotypic or other characteristics of the infecting viral population. This approach requires a model relating genotype to a vector of drug specific phenotypic responses. A comparison of Nelfinavir and Indinavir is provided using 2746 protease sequences and corresponding in vitro sensitivity assays provided to us by the Virco Group.
Heterojunction bipolar transistors using Si-Ge alloys

Advanced epitaxial growth techniques permit the use of pseudomorphic Si/sub 1-x/Ge/sub x/ alloys in silicon technology. The smaller bandgap of these alloys allows for a variety of novel band-engineered structures that promise to enhance silicon-based technology significantly. The authors discuss the growth and properties of pseudomorphic Si/sub 1-x/Ge/sub x/ structures and then focus on their applications, especially the Si/sub 1-x/Ge/sub x/-base heterojunction bipolar transistor (HBT). They show that HBTs in the Si/sub 1-x/Ge/sub x/ system allow for the decoupling of current gain and intrinsic base resistance. Such devices can be made by using a variety of techniques, including molecular-beam epitaxy and chemical vapor deposition. The authors describe the evolution of fabrication schemes for such HBTs and describe the DC and AC results obtained. They show that optimally designed HBTs coupled with advanced bipolar structures can provide performance leverage. >
Reflection on a Rough Surface from an Acoustic Point Source

A simple solution is developed for the reflected waves on a rough surface from a simple harmonic point source. It is assumed that the roughness is represented by a distribution of hemispherical bosses whose size and mutual distance are small relative to the wavelength. It is shown that under these conditions the effect of the roughness is equivalent to a boundary condition for the wave equation. This boundary condition embodies the surface polarization and the mutual interaction of the bosses. If the generating source lies above the reflecting surface the reflected wave is found to be equivalent to that originating from concentrated and distributed image sources on a line situated below the specular image with a magnitude decreasing exponentially with depth. The case of vanishingly small roughness is discussed along with the field intensity at large distance and grazing incidence. The effect of fluid viscosity is also evaluated.
Mapping the magnetic phase diagram of metastable fct Fe/Cu(100) using Co atoms

In ultrathin Fe films grown at room temperature on Cu(100), observed thickness and temperature-dependent spin reorientations are preceded by structural transformations. We use a method involving Co capping atoms to generate a magnetic phase diagram for this system in the absence of these structural changes. The phase diagram shows that the recently observed stripe-phase melting in the Fe/Cu(100) system is related to the onset of a spin reorientation, rather than to a ferromagnetic-to-paramagnetic transition. In addition, the phase diagram allows us to determine the temperature-dependent anisotropy constants for Fe/Cu(100) films.
Non-Antibiotic-Associated Pseudomembranous Colitis Due to Toxin-Producing Clostridia

Abstract A substance producing cytotoxicity in tissue culture was detected in stool specimens from all of four patients with pseudomembranous colitis due to antibiotics and in one of 54 with antibiotic-associated diarrhea. These stools also caused enterocolitis when injected intracecally into hamsters. On each occasion, cytotoxicity in tissue culture and enterocolitis in hamsters were neutralized by pretreatment with gas-gangrene antitoxin. The toxicity in both tissue cultures and hamsters could be reproduced with broth cultures of clostridia strains isolated from four of the five stools. These results suggest that toxin-producing clostridia are responsible for antibiotic-associated pseudomembranous colitis. (N Engl J Med 298:531–534, 1978)
A ROSAT observation of the nearby spiral galaxy NGC 6946

I present the ROSAT Position-Sensitive Proportional Counter (PSPC) image of the nearby, nearly face-on, spiral galaxy NGC 6946. The galaxy was observed with Einstein in 1980, uncovering a nuclear source, a source on or near the northern spiral arm, SN 1980K, and evidence for non-point-source (i.e., diffuse) emission. The ROSAT image resolves the nuclear region into approximately three sources, yields an accurate position for the north arm source, and reveals diffuse extended emission across the galaxy face, tracing at least the bright northern spiral arm of the galaxy. The diffuse emission is almost certainly the very hot component of the galaxy's interstellar medium and is probably similar to that found in the Milky Way and the Large Magellanic Cloud.
Best unbiased estimation of fixed effects in mixed ANOVA models

Abstract In a linear model with an arbitrary variance–covariance matrix, Zyskind (Ann. Math. Statist. 38 (1967) 1092) provided necessary and sufficient conditions for when a given linear function of the fixed-effect parameters has a best linear unbiased estimator (BLUE). If these conditions hold uniformly for all possible variance–covariance parameters (i.e., there is a UBLUE) and if the data are assumed to be normally distributed, these conditions are also necessary and sufficient for the parametric function to have a uniformly minimum variance unbiased estimator (UMVUE). For mixed-effects ANOVA models, we show how these conditions can be translated in terms of the incidence array, which facilitates verification of the UBLUE and UMVUE properties and facilitates construction of designs having such properties.
The sterling trap: foreign reserves management at the Bank of France, 1928–1936

French reserves policy during the interwar years has been heavily criticised because of its consequences for other countries. This article presents new monthly data on the Bank of France's foreign reserves currency composition between 1928 and 1936, and identifies the motivations behind reserves policy. The Bank of France's aim was to limit the risk of capital loss on its foreign portfolio. The determining factor in its portfolio allocation decisions was the credibility of reserves currencies on the exchange market. Credibility issues explain both the sale of pounds against dollars during 1929 and 1930 and the massive conversion of foreign holdings into gold from 1931 on. However, due to the huge volume of its reserves, the Bank also had to consider the effects of its own actions on the market. Its cooperative attitude towards sterling in the months before British devaluation can be explained through its market position. The Bank of France's portfolio choice was that of a large player in a low-credibility international monetary system.
Human Immunodeficiency Virus Type 1 Virion Density Is Not Determined by Nucleocapsid Basic Residues

The human immunodeficiency virus type 1 (HIV-1) Gag polyprotein is sufficient for assembly and release of virion-like particles from the plasma membrane. To promote assembly, the Gag polyprotein must polymerize to form a shell that lines the inner membrane of nascent virions. Several techniques have been used to functionally map the domain required for Gag polymerization (the I domain). Among these methods, isopycnic centrifugation has been used under the assumption that changes in virion density reflect impairment in Gag-Gag interaction. If virion density is determined by efficient Gag-Gag interaction, then mutation of basic residues in the nucleocapsid (NC) domain should disrupt virion density, since these residues constitute the I domain. However, we have previously shown that simultaneous disruption of up to 10 HIV-1 NC basic residues has no obvious effect on virion density. To rule out the possibility that HIV-1 NC basic residues other than those previously mutated might be important for virion density, mutations were introduced at the remaining sites and the ability of these mutations to affect Gag-Gag interaction and virion density was analyzed. Included in our analysis is a mutant in which all NC basic residues are replaced with alanine. Our results show that disruption of HIV-1 NC basic residues has an enormous effect on Gag-Gag interaction but only a minimal effect on the density of those virions that are still produced. Therefore, the determinants of the I domain and of virion density are genetically distinguishable.
Conservative management of giant symptomatic angiomyolipomas in patients with the tuberous sclerosis complex.

OBJECTIVE To present two patients with the tuberous sclerosis complex in whom giant angiomyolipomas (AMLs) were managed conservatively for >20 years, as large (>4 cm) symptomatic AMLs are generally treated with embolization or nephrectomy because of the risks of haemorrhage. PATIENTS AND METHODS The first patient initially presented with bilateral renal AMLs replacing >70% of his parenchymal volume, and a large left renal cyst. Since presentation he was hospitalized three times, but has had no transfusions or procedures to treat his AMLs. His renal function has remained stable during this 21-year interval. The second patient initially presented with bilateral renal AMLs that were not amenable to nephron-sparing surgery. After removing her nonfunctioning left kidney, the 24-cm AML in her right kidney was managed conservatively for >20 years, during which she had 44 transfusions and 11 hospitalizations before uncomplicated right nephrectomy and subsequent need for haemodialysis. CONCLUSION Conservative management of AMLs can preserve renal function for >20 years in patients with tuberous sclerosis at high risk of end-stage renal disease.
Enzymatic cleavage and synthesis of L-threo-beta-phenylserine and L-erythro-beta-Phenyldrine.

As has been demonstrated in earlier communications, D,L-threo-β-phenylserine-3-14C and D,L-phenylalanine-3-14C are incorporated into the benzoyl moiety of urinary hippuric acid1,2. These results led to the assumption of an enzymatic, in vivo splitting between C2 and C3 of the side-chain, as has been found to occur in vitro for L-phenylserines3,4.
Affinity capture and recovery of DNA at femtomolar concentrations with peptide nucleic acid probes.

Abstract The efficacy of PNA vs DNA oligomers for the recovery of femtomolar concentrations of 16S rDNA targets was determined with solution- and mixed-phase hybridization formats and limiting dilution quantitative PCR. Several results contradict existing perceptions of expected PNA behavior deduced from hybridization studies with oligonucleotide targets at high concentration. For example, DNA probes in the solution hybridization format performed as well as or better than PNA probes under high- or low-salt conditions, regardless of hybridization time or target size. In the mixed-phase hybridization format, however, PNA probes showed certain advantages, with more rapid and efficient binding/recovery of target nucleic acids regardless of target size. Recovery of target DNA with PNA probes was always more efficient in low-salt (20 mM in Na+) than high-salt (400 mM in Na+−) phosphate buffer. Recovery of target DNA by PNA probes was enhanced in the presence of excess, nontarget DNA, and differences in PNA efficacy under low- or high-salt conditions vanquished. In contrast, DNA probe performance was unaffected by the presence or absence of exogenous DNA in both solution- and mixed-phase hybridization formats. The absolute recovery and detection limit of the affinity purification method with either DNA or PNA probes was approximately 102 input target molecules at zeptamolar concentrations.
MILL ON VOLUNTARY SELF-ENSLAVEMENT

(1988). MILL ON VOLUNTARY SELF-ENSLAVEMENT. Philosophical Papers: Vol. 17, No. 3, pp. 171-183.
Attribute correlations between haptic and auditory modalities

Correlations between attributes in the haptic domain and those in the auditory will assist in multimodal applications. This paper looks at the auditory attributes of pitch and reverberation and the haptic attributes of vibration, size and viscosity and seeks to correlate changes in one of the modalities with changes in the other. A total of 4 pairs of experiments were performed. The results indicate significant correlations in 3 of the pairs: pitch/vibration, pitch/viscosity, reverberation/size. There was no significant correlation found between reverberation and viscosity. These results have significance for designers of multimodal interfaces in virtual environments.
The LOV2 domain of phototropin: A reversible photochromic switch

Light, oxygen, or voltage (LOV) domains constitute a new class of photoreceptor proteins that are sensitive to blue light through a noncovalently bound flavin chromophore. Blue-light absorption by the LOV2 domain initiates a photochemical reaction that results in formation of a long-lived covalent adduct between a cysteine and the flavin cofactor. We have applied ultrafast spectroscopy on the photoaccumulated covalent adduct state of LOV2 and find that, upon absorption of a near-UV photon by the adduct state, the covalent bond between the flavin and the cysteine is broken and the blue-light-sensitive ground state is regained on an ultrafast time scale of 100 ps. We thus demonstrate that the LOV2 domain is a reversible photochromic switch, which can be activated by blue light and deactivated by near-UV light.
The Interdependence of Social Awareness and Literacy Instruction

It is essential to help foster students' social awareness in addition to their academic skills. Through discussions of stories that emphasize social issues such as racism and prejudice, students have the opportunity to develop and explore their own beliefs. But what do they really learn, and how? In this article, the authors document their efforts to understand children's comprehension, both of socially themed books and of the belief systems they represent. They also describe the supports that must be provided to ensure that students comprehend the plot of a story and the underlying messages. Finally, the authors offer suggestions for supporting children at different levels within the classroom, as well as appropriate books for children of different ages.
Irreversible Electroporation in Eradication of Rabbit VX2 Liver Tumor

Abstract Purpose To show the effectiveness and safety of irreversible electroporation (IRE) in treating large tumor models. Materials and Methods VX2 liver tumor implantation was performed in 35 New Zealand White Rabbits. The rabbits were divided into three groups 1 week after implantation. The control group included 15 rabbits; the remaining 20 rabbits were divided into two IRE treatment groups. For the treatment groups, 10 rabbits underwent ablation with a single IRE application (IRE-S group), and 10 rabbits underwent ablation with multiple IRE applications (IRE-M group). Treatments and outcomes were analyzed using ultrasound, contrast-enhanced computed tomography (CT), and immunohistologic staining (hematoxylin and eosin [HE complete ablation of the tumor was seen in the IRE-M group. These findings successfully show the beneficial effects and safety of IRE in the treatment of tumors and validate its potential as a clinically translatable treatment.
Real-time video compression using differential vector quantization

This paper describes hardware that has been built to compress video in real time using full-search vector quantization (VQ). This architecture implements a differential-vector-quantization (DVQ) algorithm and features a special-purpose digital associative memory, the VAMPIRE chip, which has been fabricated in 2 /spl mu/m CMOS. We describe the DVQ algorithm, its adaptations for sampled NTSC composite-color video, and details of its hardware implementation. We conclude by presenting both numerical results and images drawn from real-time operation of the DVQ hardware. >
Life cycle polyphenism as a factor affecting ecological divergence within Notophthalmus viridescens

Polyphenism, which allows a single genotype to express multiple discrete phenotypes in response to environmental cues, is an adaptive trait in heterogeneous environments. Pond hydroperiod is an important ecological parameter affecting amphibian life history, and variation in local pond hydrology has been hypothesized to play a role in species divergence via changes in polyphenism. The eastern newt (Notophthalmus viridescens) expresses life cycle polyphenism. Larvae develop along three possible pathways: metamorphosis to aquatic lunged adult via a terrestrial juvenile (eft) stage, metamorphosis directly to an aquatic lunged adult, or maturation directly to an aquatic gilled adult without metamorphosis (i.e., paedomorphosis). Subspecies of N. viridescens vary in their polyphenic patterns, suggesting possible adaptation to different environments. However, no studies have experimentally tested how genetic and environmental components contribute to the observed differences among subspecies and whether such differences may facilitate divergence. We tested whether adaptation to local pond hydrology via polyphenic changes existed among subspecies by rearing larvae of three subspecies (N. v. dorsalis, N. v. louisianensis, and N. v. viridescens) along three hydroperiod regimes (short, long, and constant) in outdoor artificial ponds. We found that larval N. v. viridescens obligately metamorphosed to efts under all hydroperiods, whereas N. v. dorsalis and N. v. louisianensis exhibited plasticity: larvae metamorphosed to efts under drying conditions but metamorphosed directly to aquatic adults or became paedomorphic in constant water. Also, N. v. viridescens metamorphosed to efts faster and at a smaller body size than the other two subspecies. These data suggest that subspecies of N. viridescens are adapted to different pond hydroperiods, supporting the potential for polyphenism to facilitate divergence. Canalizing selection for certain alternative phenotypes within a single species in which other populations remain plastic may play an important role in the initiation of ecological divergence.
Heat transfer in partially miscible ternary systems

In the study of mass transfer between partially miscible liquids, temperature perturbations have been found to have an important effect in the generation of interfacial activity. Micro- and macro-generated interfacial convection usually occurs in combination with one another even in fairly simple heat or mass transfer events. These combinations are responsible for the enhancement of mass transfer rates. In an effort to acquire a better understanding of the heat transfer effects in ternary liquid-liquid systems, temperature difference profiles were measured when contacting two partially miscible phases. A vertical and a rotational transfer cell were designed to contact the partially miscible phases without inducing external disturbances. Five thermocouples were immersed in the bottom liquid phase at predetermined positions below the interface. In order to understand the influence of the convection generated, the vertical cell was designed to hinder convection in one phase, while the rotational cell permits...
Sensitivity Analysis of Simplified Diffusion-Based Corrosion Initiation Model of Concrete Structures Exposed to Chlorides

Abstract This paper presents the results of a sensitivity analysis of the diffusion-based corrosion initiation model for reinforced concrete structures built in chloride-laden environments. Analytical differentiation techniques are used to determine the sensitivity of the time to corrosion initiation to the four governing parameters of the model, which include chloride diffusivity in concrete, chloride threshold level of steel reinforcement, concrete cover depth, and surface chloride concentration. For conventional carbon steel, the time to corrosion initiation is found to be most sensitive to concrete cover depth, followed by chloride diffusion coefficient, with normalized sensitivity coefficients of about 2 and − 1. For corrosion resistant steels, the time to corrosion initiation is most sensitive to the surface chloride concentration and chloride threshold level followed by the concrete cover depth and chloride diffusion coefficient. The results of this sensitivity analysis are discussed in detail, including the variations in predicted time to corrosion initiation induced by variations of the four model parameters and their implications for the design and maintenance of concrete structures built in corrosive environments.
Reimplantation of autogenous parathyroid tissue: an experimental study.

Four different techniques of parathyroid gland reimplantation into muscle were studied in 38 dogs following total parathyroidectomy. The types of autotransplants were whole gland, minced glandular tissue, thin slices 0.3 mm or less, and thick slices 0.4 mm to 0.5 mm. The animals were followed for four months. Parathyroid function was evaluated by serum calcium and phosphorus determinations. Graft sites were extirpated two months after re-implantation and studied histologically. The thin slice technique was found to be most successful of the four techniques studied.
Using Climate Forecasts for Water Management: Arizona and the 1997-1998 El Nino

: Unrelenting pressure on limited surface water supplies requires increasingly sophisticated water management approaches. Climate forecasts of seasonal precipitation and temperature are potentially useful, but the operational water management community currently underutilizes them. However, some agencies in Arizona took unprecedented advantage of forecasts for a potentially wet winter during the 1997–1998 El Nino event. This study investigates use of this information through a series of semi-structured in-depth interviews with key personnel from agencies responsible for emergency management and water supply; their jurisdictions ranged from urban to rural and local to regional. Interviews investigated information acquisition, interpretation, and incorporation into specific decisions and actions. While unprecedented actions were taken by some water management agencies and no agencies implemented inappropriate measures, some missed opportunities for more effective response, primarily through inaction. This study reveals a variety of technical factors and institutional characteristics affecting forecast use. Study findings emphasize the need for: (a) closer ongoing relationships between forecast producers and users, (b) increased institutional flexibility to exploit the increasing skill of seasonal climate forecasts, (c) demonstration projects of effective forecast use, and (d) a regional forum to facilitate information transfer between the hydro-climatic research community and operational water managers.
A design science research methodology and its application to accounting information systems research

Natural science research follows a stereotypical pattern and such uniformity makes it easier to recognize and evaluate the results of such research. A similar format has been lacking for design science research. This issue was addressed by Peffers et al. (2008) who defined such a template for design science research for information systems: the design science research methodology (DSRM). In this paper, we first discuss design science research and the DSRM. Then, we illustrate the application of the DSRM to AIS research through retroactive analysis. Finally, we integrate the DSRM into the operational specification of artifact networks and use the REA literature for illustration purposes.
Solubility of anthracene in binary alkane + 2-butoxyethanol solvent mixtures at 298.2 K

Article discussing the solubility of anthracene in binary alkane + 2-butoxyethanol solvent mixtures at 298.2 K.
Alkoxysilane oligomer modified epoxide primers

Abstract Telechelic resins with reactive end groups (epoxy phosphate and epoxy ester) were synthesized using bisphenol-A (BPA) epoxide. The bisphenol-A based epoxide, the epoxy phosphate, and the epoxy ester were all modified with tetraethylorthosilicate (TEOS) oligomers, which were prepared through the hydrolysis and condensation of TEOS monomer with water under acidic condition. The epoxide/polysilicate (organic/inorganic) hybrid systems were characterized systematically, using FTIR, 1 H, 13 C, 31 P, and 29 Si NMR, and MALDI-TOF. The modified epoxides were thermally cured with a melamine-formaldehyde resin, cast on steel substrates. The coating performance of the modified epoxides was evaluated by pencil hardness, crosshatch adhesion, reverse and direct impact resistance, mandrel bending, and pull-off adhesion. Viscoelastic properties of the hybrid systems were also evaluated as a function of polysilicate content. Corrosion performance was evaluated via salt spray (fog) test for 264 h. Salt spray analysis revealed that inorganically modified epoxides provided improvement over the unmodified epoxide resins with respect to both corrosion resistance and adhesion to steel substrates.