cssi/SciSciGPT-SciSciNet huggingface dataset:
Targeted cloning of fungal telomeres.

Telomeres are the sequences that form the ends of eukaryotic chromosomes and are essential structures that confer genome stability and guide chromosome behavior. In addition, the terminal regions of the chromosomes tend to house genes with predicted roles in ecological adaptation. Unfortunately, however, most fungal genome assemblies contain very few telomeres and, therefore, the identities of genes residing near the chromosome ends are often unknown. In an effort to develop a complete understanding of the organization and gene content of chromosome ends in a number of fungi, we developed efficient methods for the identification and targeted cloning of telomeres. This chapter describes the basic steps and shows exemplary results from the targeted cloning of Epichloe festucae telomeres.
Discrepancy between mother and child perceptions of their relationship : II. Consequences for children considered within the context of maternal physical illness

Discrepancies between parent and child perceptions of parenting have been well established. The current study addressed whether discrepancies in one dimension of parenting, the parent-child relationship, are associated with child adjustment difficulties concurrently and longitudinally. In particular, it was hypothesized that greater discrepancies in mother and child perceptions of parenting would be associated with child adjustment difficulties. Furthermore, it was hypothesized that families experiencing a stressor—in this case, maternal infection with the human immunodeficiency virus (HIV)—would experience larger discrepancies than families in which the mother is noninfected and that maternal HIV infection would moderate the association between discrepant views and child adjustment. Participants were 183 African-American women (61 HIV infected; 122 noninfected) and one of their noninfected children. All participants were from the inner-city area of New Orleans. Results indicated that discrepancies in mother and child perceptions of their relationship was associated with mother and child reports of externalizing behavior problems concurrently and longitudinally. In addition, discrepancies were significantly higher in families experiencing maternal HIV infection than in the noninfected group. However, with one exception, maternal HIV status failed to moderate the relationship between discrepancies in perception and child adjustment, indicating that discrepancies play a similar role in both types of families. Clinical implications of the present results are discussed.
Correlation Between Ankle Impedance and EMG Signals

The correlation of the lower-leg muscle contraction to the ankle impedance of unimpaired subjects is studied. Each subject participated in 5 experimental trials, each with a different co-contraction level: 0%, 10%, 20%, 30%, and 40% of their maximum voluntary contraction (MVC). A linear model is developed to relate the muscle contraction and the ankle impedance. Next, an ANOVA test is used to verify the significance of the parameters. Low correlation is found on the inversion-eversion degree-of-freedom of the ankle, suggesting non-linear models might be more effective in describing this relationship.
QueCC: A Queue-oriented, Control-free Concurrency Architecture

We investigate a coordination-free approach to transaction processing on emerging multi-sockets, many-core, shared-memory architecture to harness its unprecedented available parallelism. We propose a queue-oriented, control-free concurrency architecture, referred to as QueCC, that exhibits minimal contention among concurrent threads by eliminating the overhead of concurrency control from the critical path of the transaction. QueCC operates on batches of transactions in two deterministic phases of priority-based planning followed by control-free execution. We extensively evaluate our transaction execution architecture and compare its performance against seven state-of-the-art concurrency control protocols designed for in-memory stores. We demonstrate that QueCC can significantly outperform state-of-the-art concurrency control protocols under high-contention by up to 6.3x. Moreover, our results show that QueCC can process nearly 40 million YCSB transactional operations per second while maintaining serializability guarantees with write-intensive workloads. Remarkably, QueCC out-performs H-Store by up to two orders of magnitude.
Side-by-Side Human–Computer Design Using a Tangible User Interface

We present a digital–physical system to support human–computer collaborative design. The system consists of a sensor-instrumented “sand table” functioning as a tangible space for exploring early-stage design decisions.
Cyberattacks on Primary Frequency Response Mechanisms in Power Grids

Primary frequency response (PFR) is an important mechanism for making power grids resilient to faults that could lead to outages. We present the first study of cyberattacks that could cause power outages by infiltrating operational technology networks in generation control systems to inhibit the PFR.
Using gamma ray monitoring to avoid missing the next Milky Way Type Ia supernova

A Milky-Way Type Ia Supernova (SNIa) could be unidentified or even initially unnoticed, being dim in radio, X-rays, and neutrinos, and suffering large optical/IR extinction in the Galactic plane. But SNIa emit nuclear gamma-ray lines from $^{56}{\rm Ni}\to ^{56}{\rm Co}\to ^{56}{\rm Fe}$ radioactive decays. These lines fall within the Fermi/GBM energy range, and the $^{56}{\rm Ni}$ 158 keV line is detectable by Swift/BAT. Both instruments frequently monitor the Galactic plane, which is transparent to gamma rays. Thus GBM and BAT are ideal Galactic SNIa early warning systems. We simulate SNIa MeV light curves and spectra to show that GBM and BAT could confirm a Galactic SNIa explosion, followed by Swift localization and observation in X-rays and UVOIR band. The time of detection depends sensitively on the $^{56}{\rm Ni}$ distribution, and can be as early as a few days if $\gtrsim$ 10% of the $^{56}{\rm Ni}$ is present in the surface as suggested by SN2014J gamma data.
Diagnosed Sleep Apnea and Cardiovascular Disease in Atrial Fibrillation Patients: The Role of Measurement Error from Administrative Data.

Background Atrial fibrillation and obstructive sleep apnea are common conditions, but little is known about obstructive sleep apnea and cardiovascular risk among atrial fibrillation patients. Methods Using the Truven Health MarketScan databases, we constructed a prospective cohort of atrial fibrillation patients from 2007 to 2014. Atrial fibrillation, obstructive sleep apnea, stroke, myocardial infarction, and confounders were defined using the International Classification of Disease-9-CM codes. We matched individuals with an obstructive sleep apnea diagnosis with up to five individuals without a diagnosis by age, sex, and enrollment date. Cox proportional hazards models adjusted for confounders and high-dimensional propensity scores. We included migraines as a control outcome. Bias analysis used published sensitivities and specificities to generate rate ratios adjusted for obstructive sleep apnea misclassification. Results We matched 56,969 individuals with an obstructive sleep apnea diagnosis to 323,246 without. During a mean follow-up of 16 months, 3234 incident strokes and 4639 incident myocardial infarctions occurred. After adjustment, obstructive sleep apnea diagnosis was strongly associated with reduced risk of incident stroke (hazard ratio = 0.48, 95% confidence interval = 0.43, 0.53) and myocardial infarction (0.40, [0.37, 0.44]) and a smaller reduced risk of migraines (0.82, [0.68, 0.99]). Bias analysis produced wide-ranging or inestimable rate ratios adjusted for misclassification of obstructive sleep apnea. Conclusions Obstructive sleep apnea diagnosis in atrial fibrillation patients was strongly associated with reduced risk of incident cardiovascular disease. We discuss misclassification, selection bias, and residual confounding as potential explanations.
Get off my back! Inferior vena cava filter erosion into the lumbar spine.

We present the case of an 84-year-old woman with a medical history of both provoked and unprovoked deep venous thromboembolisms and heterozygosity for Factor V Leiden, on chronic rivaroxaban 20 mg/day, who was seen at our institution with increasing left leg swelling and discomfort. On examination
Podcasting, the intimate self, and the public sphere

Podcasts often take the form of traditional public affairs and public service media in a hyper-competitive, neoliberalized space that prizes above all the attention given by individualized listener...
Toward a metabolic theory of life history

The life histories of animals reflect the allocation of metabolic energy to traits that determine fitness and the pace of living. Here, we extend metabolic theories to address how demography and mass–energy balance constrain allocation of biomass to survival, growth, and reproduction over a life cycle of one generation. We first present data for diverse kinds of animals showing empirical patterns of variation in life-history traits. These patterns are predicted by theory that highlights the effects of 2 fundamental biophysical constraints: demography on number and mortality of offspring; and mass–energy balance on allocation of energy to growth and reproduction. These constraints impose 2 fundamental trade-offs on allocation of assimilated biomass energy to production: between number and size of offspring, and between parental investment and offspring growth. Evolution has generated enormous diversity of body sizes, morphologies, physiologies, ecologies, and life histories across the millions of animal, plant, and microbe species, yet simple rules specified by general equations highlight the underlying unity of life.
Thromboembolic Outcomes of Different Anticoagulation Strategies for Patients with Atrial Fibrillation in the Setting of Hypertrophic Cardiomyopathy: A Systematic Review.

Objective Limited data is available assessing the efficacy and safety of different anticoagulation (AC) strategies for prevention of thromboembolic events, major bleeding, and all-cause mortality in patients with hypertrophic cardiomyopathy (HCM) and atrial fibrillation (AF). In this systematic review, we conducted a literature search to examine the possible association between different AC strategies and prevention of these adverse outcomes. Methods Scientific databases (PubMed, EMBASE, and Scopus) were searched using relevant medical subject headings and keywords to retrieve studies published through September of 2019. Studies assessing the outcomes of interest in patients with HCM and AF receiving AC, no AC as well as direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) were selected. Results This review identified 14 observational studies evaluating thromboembolic events by AC strategies in 8,479 participants with concomitant HCM and AF. The use of AC was associated with a lower pooled incidence rate of total thromboembolic events at 9.5% (112 events in 1,175 patients) compared to 22.1% with no AC (108 events in 489 patients). In addition, the use of DOACs was associated with a lower pooled incidence rate of thromboembolic events at 4.7% (169 events in 3,576 patients) compared to 8.7% with VKAs (281 events in 3,239 patients). Furthermore, the use of DOACs compared to VKAs was associated with a lower pooled incidence rate of major bleeding and all-cause mortality at 3.8% (136 events in 3,576 patients) versus 6.8% (220 events in 3,239 patients) and 4.1% (124 events in 3,008 patients) versus 16.1% (384 events in 2,380 patients), respectively. Conclusions AC of patients with concomitant HCM and AF was associated with a lower incidence of thromboembolic events when compared to antiplatelet therapy or no treatment. Treatment with DOACs was also associated with a lower incidence of thromboembolic events, major bleeding, and all-cause mortality when compared to VKAs.
Gating and selectivity mechanisms for the lysosomal K+channel TMEM175

Transmembrane protein 175 (TMEM175) is a K+-selective ion channel expressed in lysosomal membranes, where it establishes a membrane potential essential for lysosomal function and its dysregulation is associated with the development of Parkinson's Disease. TMEM175 is evolutionarily distinct from all known channels, predicting novel ion-selectivity and gating mechanisms. Here we present cryo-EM structures of human TMEM175 in open and closed conformations, enabled by resolutions up to 2.6 A. Human TMEM175 adopts a homodimeric architecture with a central ion-conduction pore lined by the side chains of the pore-lining helices. Conserved isoleucine residues in the center of the pore serve as the gate in the closed conformation. In the widened channel in the open conformation, these same residues establish a constriction essential for K+ selectivity. These studies reveal the mechanisms of permeation, selectivity and gating and lay the groundwork for understanding the role of TMEM175 in lysosomal function.
Emerging views of genome organization in Archaea

Over the past decade, advances in methodologies for the determination of chromosome conformation have provided remarkable insight into the local and higher-order organization of bacterial and eukaryotic chromosomes. Locally folded domains are found in both bacterial and eukaryotic genomes, although they vary in size. Importantly, genomes of metazoans also possess higher-order organization into A- and B-type compartments, regions of transcriptionally active and inactive chromatin, respectively. Until recently, nothing was known about the organization of genomes of organisms in the third domain of life - the archaea. However, despite archaea possessing simple circular genomes that are morphologically reminiscent of those seen in many bacteria, a recent study of archaea of the genus Sulfolobus has revealed that it organizes its genome into large-scale domains. These domains further interact to form defined A- and B-type compartments. The interplay of transcription and localization of a novel structural maintenance of chromosomes (SMC) superfamily protein, termed coalescin, defines compartment identity. In this Review, we discuss the mechanistic and evolutionary implications of these findings.
FDA analysis of ECOG performance status and safety outcomes.

12024Background: Patients with poor performance status are often excluded from clinical trials. The FDA has published several guidances on modernizing oncology clinical trial eligibility criteria t...
Chronic Wasting Disease Diagnostic Discrepancies: The Importance of Testing Both Medial Retropharyngeal Lymph Nodes

Chronic wasting disease (CWD) of white-tailed deer (Odocoileus virginianus) is a fatal neurologic disease that is spreading across North America. A common surveillance protocol for CWD currently involves screening with an enzyme-linked immunosorbent assay (ELISA) followed by confirmatory testing with immunohistochemistry (IHC). Medial retropharyngeal lymph nodes (MRPLN) are the tissue of choice to diagnose CWD in free-ranging white-tailed deer. We examined left and right MRPLN from 101 ELISA-positive deer harvested from 2015 to 2019 to determine the prevalence of cases in which prion protein was not detected by IHC as well as differences in IHC labeling between contralateral lymph nodes. Prion protein was not detected using IHC in either MRPLN in 5.9% (6/101) of cases. There was a significant but weak positive relationship between the number of IHC-positive follicles and ELISA optical density values (R2=0.08, P=0.039). Mean optical density values in IHC-positive MRPLN were higher than in IHC-negative MRPLN; however, this was not statistically significant (P=0.260). Failure to confirm ELISA diagnoses with IHC may have been because the methods tested different areas of MRPLN, or that there were differences in test sensitivity or antibody affinity. An additional 5.9% (6/101) of cases had one IHC-positive MRPLN, whereas the contralateral MRPLN was IHC negative. Therefore, testing a single MRPLN for CWD may lead to false-negative results, regardless of methodology, which highlights the importance of collecting and testing both MRPLN.
Cardiovascular health in early adulthood predicts the development of coronary heart disease in individuals with type 1 diabetes: 25 year follow-up from the Pittsburgh Epidemiology of Diabetes Complications study

Type 1 diabetes increases CHD risk. We examined the use of the American Heart Association’s cardiovascular health metrics (blood pressure, total cholesterol, glucose/HbA1c, BMI, physical activity, diet, smoking) to predict incidence of CHD among individuals with type 1 diabetes, with the hypothesis that a better American Heart Association health metric profile would be associated with lower incident CHD. Prevalence of the seven cardiovascular health metrics was determined using first and second visits from adult participants (mean age 28.6 years) in the Epidemiology of Diabetes Complications prospective cohort study of childhood-onset type 1 diabetes. An ideal metric score (0–7) was defined as the sum of all metrics within the ideal range, and a total metric score (0–14) was calculated based on poor, intermediate and ideal categories for each metric. Incident CHD development (medical record-confirmed CHD death, myocardial infarction, revascularisation, ischaemic electrocardiogram changes or Epidemiology of Diabetes Complications physician-determined angina) over 25 years of follow-up was examined by metric scores. Among 435 participants, BMI, blood pressure, total cholesterol and smoking demonstrated the highest prevalence within the ideal range, while diet and HbA1c demonstrated the lowest. During 25 years of follow-up, 177 participants developed CHD. In Cox models, each additional metric within the ideal range was associated with a 19% lower risk (p = 0.01), and each unit increase in total metric score was associated with a 17% lower risk (p < 0.01) of CHD, adjusting for diabetes duration, estimated glomerular filtration rate, albumin excretion rate, triacylglycerols, depression and white blood cell count. Among individuals with type 1 diabetes, higher cardiovascular health metric scores were associated with lower risk of incident CHD. The American Heart Association-defined cardiovascular health metrics provide straightforward goals for health promotion that may reduce CHD risk in the type 1 diabetes population.
Word Recognition Clinical Testing of Personalized Deep Reinforcement Learning Compression

Current hearing aid fittings are carried out using prescriptive compression settings. These settings are derived from group averages but do not account for individual differences or preferences. In a previous work, we developed a human-in-the-loop deep reinforcement learning compression approach to set the compression ratios across a number of frequency bands. These compression ratios were compared to those of the widely used and accepted DSL-v5 hearing aid prescription to determine if incorporating user preference impacted word recognition performance. A pilot clinical study of this comparison for four participants is reported in this paper. The clinical testing results obtained strongly support the hypothesis that the personalized compression settings do not negatively impact word recognition or audibility compared to the prescriptive compression settings. The ability to provide a personalized amplification strategy with no degradation in hearing performance would be of benefit in hearing aids or other assistive listening technologies.
Managing Corporate Mobile Voice Expenses: Plan Choice, Pooling Optimization, and Chargeback

Mobility communication management spans the spectrum of user choice, device procurement/inventory/replacement, IT security, corporate policy compliance, expense optimization, and billing. Today, there are many vendors providing a subset or a full spectrum of such mobility communication management services to corporate customers, a service collectively (perhaps not quite accurately) known as TEM, telecom expense management. The focus of this article is on mobile voice expense optimization. A mobile voice subscription plan can generally be characterized by three parameters: a monthly fixed charge, a peak minute allowance, and an overage rate when usage exceeds a plan's minute allowance. An (stand-alone) individual user has to decide which plan to choose: too large a base plan will result in unused wasted minutes, while too small a plan will incur expensive overage charges. Similar to family plans, a corporation has different pooling options. A pooling plan allows subscribers in the same pool to share a common pool of minutes. An overage results when the collective usage exceeds the common pool of minutes. We examine the mathematics behind pooling and how to create the best pooling arrangement minimizing mobile voice expenses. The contribution of this paper first lies in the formulation of the problem, making it tractable. This formulation allows an efficient and effective solution to such a complex combinatory pooling optimization problem, using a column generation technique. We provide case studies to illustrate the potential (and actual savings) for the stand-alone plan choice decision as well as the collective pooling optimization; typically resulting in 20–30% of annual savings, which translate into tens of millions of dollars for large corporations. A very important, often a stumbling block to implement a pooling solution, aspect of pooling is chargeback—how to allocate monthly pooled expenses to individual accounts (which often belong to different units in an organization). We share with you a simple and equitable chargeback scheme, which is well received and readily implemented by corporate clients. An actual case study will be presented as well as some concluding remarks. Keywords: mobile voice expense optimization; pooling optimization; column generation; Dantzig–Wolfe decomposition; restricted master problem; chargeback; allocation of shared cost
Opsin pigments formed with acyclic retinal analogues: Minimum ‘ring portion’ requirements for opsin pigment formation

Three acyclic derivatives (3,7-dimethyl-10-ethyl-2,4,6,8-dodecatetraenal, 3,7,10-trimethyl-2,4,6,8-dodecatetraenal, and 3,7,10-trimethyl-2,4,6,8-undecatetraenal) have been synthesized and the 2-cis, 6-cis, 2,6-dicis and all-trans isomers of each isolated. Unlike the undecatetraenal compound, the dodecatetraenal derivatives, have methyl groups which can mimic the C-1 and/or C-5 methyl group of retinal. The 6-cis and 2,6-dicis isomers of the dodecatetraenal compounds form photosensitive pigments with bovine opsin. No pigment is obtained with the undecatetraenal derivative. Therefore, although the retinal cyclohexyl ring is not essential for pigment formation, at least one methyl group corresponding to the C-1 or C-5 retinal methyl may be required for obtaining stable opsin pigments.
Energy transfer pathways in Photosystem I studied by one and two color photon echo spectroscopy

One and two color three pulse photon echo spectroscopy is used to probe ultrafast energy transfer, energetic disorder and correlation between the 96 non-equivalent chlorophylls in the photosynthetic light-harvesting complex Photosystem I.
Outcome of postoperative critically ill patients with heparin-induced thrombocytopenia: an observational retrospective case-control study

Heparin-induced thrombocytopenia (HIT) is described as a decrease in platelet count associated with heparin administration and is an immune-mediated adverse drug reaction that can cause both arterial and venous thromboses. It can be a life-threatening complication of heparin exposure. Little data concerning incidence, predisposing factors, or outcome in critically ill surgical patients are available. All critically ill, postoperative patients admitted between January 1, 2000, and December 31, 2001, to a surgical intensive care unit (SICU) who tested positive by an enzyme-linked immunosorbent assay for the HIT antibody (HPIA; Diagnostica Stago, Inc., Parsippany, NJ, USA) were identified. Patient risk factors and outcomes were abstracted retrospectively from the medical record and compared with those from control patients matched for age, gender, diagnosis, severity of illness, and date of SICU admission. Two hundred and ten patients out of 2,046 patients (10%) admitted to the SICU had HIT assays performed. Nineteen patients (0.9% of admissions; 9% of tested individuals) had positive tests. HIT-antibody-positive patients, compared with 19 matched controls, had an increased risk of death or major thrombotic complications (37% versus 10%; P < 0.05) and prolonged length of intensive care unit (ICU) stay (20 days versus 10 days; P < 0.05). Exposure to heparin via intravascular flushes alone was sufficient to generate HIT antibodies in 12 of 19 (63%) patients. Five patients received platelet transfusions after the diagnosis of HIT was known; four of these patients died. Heparin flushes were the most common cause of HIT in this study. HIT-antibody-positive patients had an increased risk of death or major complications and a prolonged length of ICU stay. Platelet transfusions often were administered despite a positive HIT test result and were associated with a high mortality rate. Treatment algorithms that minimize exposure to heparin and contraindicate platelet transfusions merit further study.
“Nonalcoholic” Chronic Hepatitis in the Alcoholic

Ten alcoholic patients with biopsy proved chronic active or chronic persistent hepatitis were observed. In each patient, the responsible etiological agent appeared to be ethanol. Laboratory abnormalities could be distinguished statistically from those in a group of 121 patients with alcoholic hepatitis by their higher SGPT (262 ± 139 versus 62 ± 7 U per ml, P
CT appearance of angiosarcoma associated with chronic lymphedema.

Angiosarcoma is an uncommon, rapidly progressive neoplasm of the vascular endothelium that may be associated with chronic lymphostatic lymphedema of the extremities. Although it is seen more frequently in lymphedema of the upper extremities after mastectomy for breast carcinoma, it is also associated with idiopathic or congenital Iymphedema. This case illustrates the classic clinical course of angiosarcoma associated with idiopathic lymphedema and the previously undescribed CT appearance of lymphedema complicated by diffuse infiltrating angiosarcoma involving the entire right lower extremity. The extreme skin thickening, frequently nodular, with marked fibrous septal thickening and lakes of encapsulated fluid surrounding and directly involving muscle groups differs from the less marked honeycomb pattern typical of lymphedema on CT.
Angle-resolved photoelectron spectra of ethylene as a function of photon energy using synchrotron radiation

Abstract As a test of the applicability of multiple-scattering theory to an unsaturated organic system, angle-resolved photoelectron spectra of the first four bands of ethylene have been measured from 1.5 eV above threshold to a photon energy of 28 eV. The results are compared to the multiple-scattering theory calculations of Grimm. The comparisons are excellent except for the 1 b3u orbital below 14 eV, and the disagreement is attributed to the occurrence of autoionization. It is found that the π orbital has a much higher β value than the σ orbitals, but the β value for the π orbital varies more rapidly than that for the σ orbitals from threshold to ∼0.5 Rydberg (∼7 eV).
Crystallization of saturated water-alcohol solutions by spontaneous evaporation. Asparagin

Saturated alcohol-water solutions of asparagin and substances like it with respect to solubilities are allowed to evaporate spontaneously in the presence of “seed” crystals under prescribed conditions.
The effect of contactor area on vibrotactile magnitude function exponents for the tongue and hand

The method of magnitude production was used to investigate subjective vibratory magnitude functions for the hand and tongue. Three different contactor areas were employed. The subjects were 10 normal young adults. The results indicated that magnitude slope functions were inversely related to contactor area for both structures tested. The results suggest that the number of sensory units activated by a stimulus may be an important variable in establishing vibratory sensation magnitude functions.
Strength Degradation of Oxide/Oxide and SiC/SiC Ceramic Matrix Composites in CMAS and CMAS/Salt Exposures

CMAS (Calcium-Magnesium-Aluminosilicate) has shown to induce some deleterious effects on yittria-stabilized-zirconia (YSZ) based thermal barrier coatings (TBCs) of hot section components of aeroengines. The effects were shown to be dependent on the types and operating conditions of engines/components. The work presented here explored how CMAS would affect ceramic matrix composites (CMCs) in terms of strength degradation. Four different, gas-turbine grade CMCs were utilized including two types of MI SiC/SiCs and other two types of oxides/oxides (N720/aluminisilicate and N720/alumina). Test specimens in a simple flexure configuration were CMAS-treated at 1200 °C in air under either isothermal or thermal cycling condition. The effects of CMAS were quantified via residual strengths of treated test specimens. Strength degradation with respect to as-received strengths ranged from 10 to 20% depending on the types of CMCs. It was further observed that significant degradation of strength up to 90% occurred in an oxide/oxide CMC when sodium sulfate was added to CMAS.
Production of hybrid glycopeptide antibiotics in vitro and in Streptomyces toyocaensis

Abstract Background: The glycopeptide antibiotics vancomycin and teicoplanin are currently the last line of defence against some microorganisms that are resistant to many drugs. The emergence of vancomycin-resistant and teicoplanin-resistant enterococci underscores the need for more potent antibiotics. The glycosylation patterns of glycopeptides and chemical modifications of the glycosyl moieties have been shown to greatly influence their antibiotic activity, and certain combinations have resulted in highly active new compounds. To explore further the production of more potent glycopeptide antibiotics, we assessed whether glycosyltransferases could be used to produce hybrid compounds that contain various combinations of sugars and peptide cores. Results: We cloned five glycosyltransferase genes from Amycolatopsis orientalis strains that produce vancomycin or a related glycopeptide, A82846. The gtfB and gtfE′ genes from A. orientalis strains expressed in Escherichia coli produced glucosyltransferase activities that added glucose or xylose to the vancomycin heptapeptide. The GtfE′ protein added glucose efficiently to two other heptapeptides related to teicoplanin to produce hybrid glycopeptide antibiotics. The cloned gtfE′ gene, driven by the strong constitutive promoter ermEp ∗, was introduced into Streptomyces toyocaensis , which produces the antibiotic A47934, a heptapeptide related to teicoplanin; recombinant organisms produced glucosyl A47934, a hybrid glycopeptide antibiotic. Conclusions: Cloned glycosyltransferases from glycopeptide antibiotic producers can be used to produce novel hybrid antibiotics, both in vitro and in vivo , Because similar enzymes have differing degrees of substrate specificity, it is advantageous to characterize the substrate specificity with enzymes expressed in E. coli prior to constructing recombinant actinomycetes for production.
Molecular clock rates at loci under stabilizing selection

Abstract Under stabilizing selection in a finite population, lambda, the rate of allelic substitutions at a locus is approximately lambda approximately mu(1 + S)-1/2, where mu is the mutation rate. S, the stringency of selection upon new mutants, is defined by S = NVm/Vs, where N is the population size and Vm/Vs is a measure of the average fitness decrease experienced by new mutants. The approximation holds both for a "lonely" locus, which is the sole provider of genetic variation for the character under selection, and for an "embedded" locus, which is not. In both cases I use the Crow and Kimura model of a continuum of alleles with Gaussian selection and mutation. Monte Carlo simulations corroborate the substitution rate formula. Some molecular evolution data suggest the potential utility and limitations of the formula for estimating population size, mutation, and selection parameters. This work agrees with the rest of nearly neutral theory in emphasizing the important role of population size for substitution rates.
Varignon's Theorem for Octahedra and Cross-Polytopes

Varignon's theorem states that the midpoints of a quadrilateral form the vertices of a parallelogram (figure 1). From a historical point of view this simple theorem is noteworthy in that no one seemed to have been aware of it until Varignon discovered it in the 1700s [7]. It occurred to us that since an octahedron can be considered to be a 3-dimensional generalization of a quadrilateral and that since a midpoint can be considered as the centroid of the endpoints of a segment, it might be that the centroids of the faces of an octahedron form the vertices of a parallelepiped (figure 4). In this note, we show this and extend the result to cross-poly topes of all dimensions. We also observe that the results remain true if weights are attached to the vertices (Figure 5). At the time this article was submitted, we were not able to find the 3-dimensional
Interstitial flux phases in a superconducting niobium film with a square lattice of artificial pinning centers

We demonstrate that a square lattice of artificial pinning centers in a superconducting Nb film induces the formation of highly ordered interstitial vortex phases with different symmetries for external magnetic fields as high as the eighth matching field. These {open_quotes}supermatching{close_quotes} phases are identified by distinct differences in the behavior of their critical currents, magnetoresistivity, and magnetization. Our results are consistent with predictions of supermatching lattice symmetries by recent numerical simulations. {copyright} {ital 1999} {ital The American Physical Society}
A random-effects logit model of work-welfare transitions

Abstract This paper models the transitions between states defined in terms of work and welfare status as a discrete-time competing-risk model with unobserved heterogeneity. A random-effects logit model is estimated with a panel drawn from Wisconsin administrative records. Unobservables are assumed to follow a discrete distribution. The most striking result is that welfare recipients were substantially less likely to start working while remaining on welfare afterthe 1981 changes in program rules.
Thermal conductivity of gelatinized starches

The thermal conductivity (k) of gelatinized high-amylose and high-amylopectin starches was determined, using the heated probe method. The granular starches, mixed with distilled water at 1 to 4 kg water/ kg dry solids, were gelatinized at 120°C. Similar k values which varied from 0.434 to 0.548 W/mK in the temperature range 30 to 70°C were obtained for both starch gels. Experimental data were fitted to six structural models, representing various geometries for mixtures of water and dry starch. The perpendicular model, based on heat conduction in series through layers of dry starch and water, yielded best correlations. The predicted thermal conductivity of dry gelatinized starch (ks) increased linearly with temperature T (K) according to the equation:
Stopped-flow studies of 2'-deoxynucleotide binding to thymidylate synthase.

Abstract The mechanism of 2′-deoxynucleotide binding to Lactobacillus casei thymidylate synthase was studied using stopped-flow kinetic techniques to monitor the decrease in intrinsic protein fluorescence upon complex formation. The data were consistent with a two-step mechanism involving a rapid preequilibrium step to form the enzyme-2′-deoxynucleotide complex followed by a slow isomerization step. Rate and equilibrium constants were determined for the three 2′-deoxynucleotides (2′-deoxyuridylate, 2′-deoxythymidylate, and 5-fluoro-2′-deoxyuridylate) as a function of temperature. Similar free energy changes were found for all 2′-deoxynucleotides; however, the enthalpy and entropy changes for each step of the reaction differed for each 2′-deoxynucleotide. The thermodynamic profiles indicated that the isomerization step stabilized the enzyme-2′-deoxynucleotide complex by an additional 1500 cal/mol.
Irradiance and temperature effects on photosynthesis of tussock tundra Sphagnum mosses from the foothills of the Philip Smith Mountains, Alaska.

Photosynthetic characteristics of three species of Sphagnum common in the foothills of the Brooks Range on the North Slope of Alaska were investigated. Generally, light-saturated rates of net photosynthesis decreased in the order S. squarrosum, S. angustifolium, and S. warnstorfii when plants were grown under common growth chamber conditions. For field-grown S. angustifolium, average light compensation point at 10°C was 37 μmol m-2s-1 photosynthetic photon flux density (PPFD), and light saturation occurred between 250 and 500 μmol m-2 s-1. At 20°C, compensation point increased to 127 μmol m-2s-1 and the PPFD required for light saturation increased to approximately 500 μmol m-2s-1, while maximum rates of CO2 uptake increased only slightly. Light response curves of chamber-grown plants exhibited substantially lower compensation points and higher light-saturated rates of CO2 assimilation than field-grown material, due perhaps to a higher percentage of green, photosynthetically competent tissue. All three species exhibited broad responses to temperature, with optima near 20°C, and maintained at least 75% of maximum assimilation between approx. 13° and 30°C. Rates at 5°C were approx. 50% of maximum. Studies of the microclimate of Sphagnum at the field research site suggest that CO2 uptake should occur at near light-saturated rates during the day in open tussock tundra but that PPFD may often be limiting under Salix and Betula canopies in a water track drainage. Simulations using a simple model provided a seasonal estimate of 0.78 g dry weight (DW) of S. angustifolium produced from each initial g of photosynthetic tissue under willow canopies, assuming no water limitations. Although the simulation model suggests that production would be 66% higher in open tussock tundra, S. angustifolium is rarely found in this potentially more stressful habitat. To explain the relative abundance of Sphagnum in shaded water track areas as compared to open tussock tundra, we postulate that the vascular plant canopies provide protection from adverse effects of high temperatures, excess irradiance and reduced water availability. Under conditions of normal water availability, removal of the vascular plant cover did not affect the tissue water content of S. squarrosum, but resulted in a strong decrease in photosynthetic capacity, accompanied by chlorophyll bleaching. These results suggest that photoinhibition may limit production under certain conditions.
Determination of excess carrier lifetime of p-i-n diodes from the r.f. resistance at microwave frequencies

A steady-state method for determining the excess carrier lifetime using p-i-n diodes is presented. The carrier lifetime is obtained from the r.f. resistance of a forward-biased p-i-n diode measured at microwave frequencies. The carrier lifetime obtained with this method in diffused silicon p-i-n doides is compared with the carrier lifetime obtained from other usual methods of measurement.
Critical rhetoric: Theory and praxis

This essay sets forth a theoretical rationale for a critical rhetoric and presents eight “principles”; which, taken together, orient the critic toward the act of criticism. The theoretical rationale encompasses two forms of critique, styled as a critique of domination and as a critique of freedom. Both have in common an analysis of the discourse of power as it serves in the first case to maintain the privilege of the elite and, in the second, to maintain social relations across a broad spectrum of human activities. The principles articulate an orientation that sees critique as a transformative practice rather than as a method, recognizes the materiality of discourse, reconceptualizes rhetoric as doxastic as contrasted to epistemic, and as nominalistic as contrasted to universalistic, captures rhetoric as “influential"as contrasted to “causal,”; recognizes the importance of absence as well as presence, perceives the potential for polysemic as opposed to monosemic interpretation, and as an activity that is ...
Some Applications of Watson's Perturbation Approach to Random Matrices

In this note we draw attention to Watson's (1983) perturbation approach to random matrices, by which the asymptotic distribution of eigenvalues and eigenvectors can be derived in a very elegant way. We extend his result to functions of matrices and give some applications in principal component analysis, multivariate analysis, and canonical correlations.
Missing Household Saving and Valuation of Corporations: Inquiry into Japanese National Accounts I

The Japanese household sector has suffered a capital loss of some 400 trillion yen (in 1990 consumption prices) since 1970. This is a large enough loss to explain the Japanese recession of the 1990s. We can trace some three fourths of this capital loss to the loss in the market value of Japanese corporations relative to their accounting value (at reproduction cost). The behavior of the corporate sector leading to this loss is obscured because, in the Japanese National Accounts, the corporate sector contains both private and public enterprises, and information presented for this sector is seriously incomplete. Nevertheless, data suggest that corporations have attempted to maximize their productive capacity rather than their market value and overinvested in plant and equipment since at least 1970. An unusual corporate governance structure in Japan may have permitted and even induced corporate management to follow such a strategy. The paper concludes with a set of recommendations to improve the presentation of these issues in the National Accounts. J. Japan. Int. Econ., June 2002, 16(2) pp. 147–176. University of Pennsylvania, Philadelphia, Pennsylvania 19104 and NBER. © 2002 Elsevier Science (USA). Journal of Economic Literature Classification Numbers: C82, E21, E22, G30.
Programmable deflector and scanner using a liquid crystal television (LCTV)

In this paper, deflection and scanning of a HeNe beam by a programmable phase Fresnel lens written on a LCTV has been demonstrated. Translation and tilt aberration respectively produces coarse and fine deflection of the beam. The rapid translation of the lens function, time dependent variation of the magnitude of the tilt aberration, and a combination of these two methods are used to demonstrate laser beam scanning. In our experiments, using the wavefront tilt aberration a measurable scan deflection accuracy of less than 8 (mu) rad is achieved. Using the lens translation scheme the beam is scanned over a 0.8 cm X 0.8 cm area at a distance of 50 cm. The scan time of the current system is limited by the standard video frame rate of the existing LCTV drive electronics. The performance limits of the LCTV-based deflection and scanning system are compared with those of acousto-optic deflectors and scanners.
A Calculation of the Changes in the Conductivity of Metals Produced by Cold-Work

The increase in the electrical resistance of severely cold-worked metals has been calculated by assuming that the important change which occurs during cold-work is the introduction of large numbers of Taylor dislocations. The results obtained are as follows: The calculated increase in the electrical resistance of polycrystalline copper is in good agreement with the measured value. In case single crystals are considered, the calculations show that there is a decided dependence of the dislocation resistance on the orientation of the electric field relative to the crystallographic axes. In copper the ratio of the largest dislocation resistance to the smallest is 8. This ratio is large for materials having a small Poisson's ratio. It is found that if the dislocations are not too closely clustered no interference effects will occur. The detailed calculations for copper assume that clustering is unimportant. Measurements on single crystals are in progress.
Alternative 5C actin transcripts are localized in different patterns during Drosophila embryogenesis

The Drosophila actin gene located at cytogenetic position 5C forms at least 9 and perhaps as many as 15 different transcripts with the use of alternative transcriptional start points, differential splicing, and different regions of cleavage/polyadenylation. Each transcript contains one of two alternative 5′ exons. We have subcloned unique recombinant DNA probes specific for each separate 5′ exon and for three polyadenylation regions in to vectors containing T3 and T7 promoters. Single stranded, tritium-labeled RNA probes were generated in vitro from these constructs. These probes have been hybridized in situ to RNA transcripts present in tissue sections from Drosophila embryos. The results of these experiments indicate that transcripts homologous to the two separate 5′ exon-specific probes accumulate in strikingly different patterns during Drosophila development. Thus the incorporation of a particular 5′ exon into a transcript is correlated with tissue-specific localization of that transcript. In contrast, probes for each of the three polyadenylation regions do not detect any tissue-specific localization of transcripts.
Smart Polymeric Coatings for Surface Decontamination

Polymeric “smart” coatings have been developed that are capable of both detecting and removing hazardous nuclear and heavy metal contaminants from contaminated surfaces. These coatings consist of strippable polymeric compositions containing blends of polymers, copolymers and additives that can be brushed or sprayed onto a surface as a solution or dispersion in aqueous media. Upon drying, these coatings form strong films that can easily be peeled or stripped from the surface. When applied to a contaminated surface, these coatings display responsive behavior. Areas of contamination are indicated by a color change. As the coatings dry, the contaminants are drawn into and fixed in the polymer matrix. Subsequent removal of the coating with entrapped contaminants results in some degree of surface decontamination. Here we report the development and investigation of a smart, decontaminating coating developed for uranium and plutonium.
Teacher decision making within a basal reading program

Is teacher decision making within a reading program possible only in the most innovative and individualized models? Do basal programs bear the blame for teachers feeling restricted in decision making? Teachers using basal programs have had a history of being decision makers. The causes for resisting decision making at the present time are (1) overreliance on assessment, (2) narrowly interpreted teacher accountability, and (3) erosion of community support for teachers. Critical changes are needed in in-service programs, testing, and curriculum to foster teachers' opportunities and confidence in decision making; teachers and publishers must work for such changes.
The Role of Secondary Interactions in Selective Electrostatic Multilayer Deposition

Electrostatic layer-by-layer thin films may be directed to specific regions of a surface based on electrostatics, secondary interactions, and steric repulsion. In this study, a series of polyamines ranging from hydrophobic polyallylammonium hydrochloride (PAH) to hydrophilic linear polyethyleneimine (LPEI) were coadsorbed with poly(acrylic acid) (PAA) onto patterned self-assembled monolayer (SAM) surfaces. When an acid (COOH) and oligoethylene glycol (EG) SAMs are used as the surface template, it was found that the region of preferred deposition for the more hydrophobic polyamine species was generally the EG region at pH 4.8, rather than the partially charged COOH region. The more hydrophilic LPEI species preferred adsorption on the COOH surface. It is proposed that PAH undergoes complexation with the EG surface based on hydrophobic and hydrogen bonding interactions at moderate pH. On the other hand, the LPEI backbone is hydrated and is thought to undergo large steric repulsion with the EG surface, thus r...