cssi/SciSciGPT-SciSciNet huggingface dataset:
Weakness in Young Chicks on a Diet Supplemented with Aluminum Hydroxide Gel

ABSTRACT IN THE course of experiments on atherosclerosis in young chicks (Rodbard et al., 1950, 1951a, 1952) we observed a syndrome of weakness which followed the ingestion of a diet to which a reactive aluminum hydroxide gel had been added. METHODS A total of 7 experiments was performed using newly hatched commercial incrossbred (Hyline) or New Hampshire chicks placed in a brooder and given a commercial starter mash 1 which has consistently been adequate for normal growth and development. The experimental animals were given the same mash mixed with a specially prepared gel containing aluminum hydroxide. 2 The resulting mash contained 25 mg. of aluminum per gram of food (experiments 1 to 7). Lower concentrations of the gel were also tested (experiments 2, 3). Fresh batches were prepared at intervals of three days. The ration tended to cake and it was necessary to break up the feed at least three times daily so . . .
Release of 3H-dopamine and analogous monoamines from rat striatal tissue

1. The release of previously accumulated 3H-dopamine (DA) from minces of striatal tissue prepared from the brains of pargyline-pretreated rats was evaluated by superfusion with a physiological buffer solution in a six-chamber apparatus with silver toroid electrodes to provide electrical field stimuli. The identity of released tritium as 3H-DA was demonstrated chromatographically and 3H-DA taken up was found in a synaptosomal subcellular fraction. 2. Release of 3H-DA previously accumulated at 0.3 microM was found to be linearly dependent on stimulus intensity between 1 and 10 V (for 60 sec); 5 V was selected as a standard stimulus. 3. Release of 3H-DA did not occur from minces of rat liver, nor was there release of previously accumulated labeled urea or leucine from striatal tissue by electrical stimulation, 50 mM KCL, or 0.1 mM (+)-amphetamine. When 3H-DA was taken up in the presence of cocaine (1 mM) or benztropine (100 microM), electrically induced release of 3H-DA was markedly reduced, while spontaneous efflux was much less altered. 4. Release of 3H-DA was also induced by depolarizing concentrations of K+, as well as by Rb+ or NH4+, and by veratridine. Electrical release and that induced by 50 mM K+ or 100 microM veratridine was blocked by the omission of Ca2+ (with EDTA added) and that induced by veratridine was blocked by tetrodotoxin (30 microM).
Enzymatic sulfation of steroids. XVII. The properties of the glucocorticoid sulfotransferase activity of guinea pig liver cytosol.

Abstract Our earlier studies showed little glucocorticoid sulfate in livers of guinea pigs given near-physiological doses of cortisol, compared to rats. This difference appeared to be related to the poor ability of guinea liver to respond to cortisol by enzyme induction. In the process of determining the basis for the paucity of cortisol sulfation in guinea pig liver, we developed a radioisotopic, pH 6.8 assay for its cytoplasmic cortisol sulfotransferase activity. In males, the maximum enzyme activity, 83.1 ± 22 nmol / h per g liver, was obtained with 375 μM cortisol and 240 μM 3′-phosphoadenosine-5′-phosphosulfate, the reaction coenzyme. The apparent K m values for cortisol and coenzyme were 150–188 and 60–87 μM, respectively. DEAE-Sephadex A-50 chromatography of cytosol from males showed it to contain five peaks of cortisol sulfotransferase activity (I–V). These comprised 13 ± 6, 24 ± 8, 33 ± 9, 18 ± 12 and 13 ± 6%, respectively, of the maximum recovered activity. Peak III and rat-liver sulfotransferase III (the glucocorticoid-preferring sulfotransferase in rats) eluted similarly from ion-exchange columns. When 40 μM cortisol was used for suboptimal enzyme assays, most guinea pig liver cortisol sulfotransferase activity was due to peak III. Male and female guinea pigs exhibited similar amounts of hepatic cortisol sulfotransferase activity, with similar properties. However, a sixth peak of cortisol sulfotransferase activity was present in some females. The pH optimum of the enzyme activity in both sexes was 6.7± 0.432 with 375 μM cortisol and 6.9 ± 0.20 with 40 μM cortisol. AMP, ADP, ATP or GTP (1.0 mM) did not effectively replace 240 μM 3′-phosphoadenosine-5′-phosphosulfate as coenzyme. The product of the enzyme reaction was cortisol-21-sulfate. The study explained why guinea pig liver sulfated near-physiological doses of cortisol poorly compared to rat liver.
Effect of testosterone on circulating eosinophils in the guinea pig.

McDERMOTT, Fry, Brobeck and Long (1) interpreted the absence in the adrenalectomized castrate male rat of the eosinopenia following epinephrine which occurred in the adrenalectomized male to indicate “a slight overlap in the effect of adrenal and gonadal steroids/7 An eosinopenic effect of male sex hormone is also suggested by 1) the lower level of circulating eosinophils in the normal male than female guinea pig (2, 3, 4), and 2) the greater increase in circulating eosinophils after hypophysectomy in the male guinea pig than in the female (4). Calculation of the number of eosinophils per mm.3 from Crafts’ data (5, 6) on the percentage eosinophils in the rat shows that in this species there is also a greater increase in the hypophysectomized male than female. Direct evidence for an eosinopenic effect of testosterone in the guinea pig is given in the following report.
X-ray absorption near edge structure in metals: Relativistic effects and core-hole screening.

A long standing theoretical problem ``the absence of a white line in the ${L}_{2}$ x-ray absorption near edge spectrum of Pt metal'' has been solved taking into account relativistic effects and the presence of a core hole. The photoabsorbing atom is treated as a single-site impurity in our theory of x-ray absorption near edge structure (XANES) based on the fully relativistic layer Korringa-Kohn-Rostoker Green-function method. Comparing the XANES of Al with those of Cu and Pt, it is found that for transition metals $d$ electrons play a dominant role in deep core-hole screening, whereas in Al $\mathrm{sp}$ electrons are important.
Outcome of arthroscopic single bundle reconstruction for complete posterior cruciate ligament tear

Abstract Purpose : To evaluate the clinical outcome and correlate the results and degenerative change of the affected knees with the duration of injury, ligament laxity and follow-up time in 30 patients with 31 knees undergoing arthroscopic single bundle reconstruction for complete posterior cruciate ligament (PCL) tear with 2–9-year follow-up. Materials and methods : This series included 22 men and 8 women with an average age of 32 years. High-energy trauma accounts for 93.5% of PCL injury, while only 6.5% are sports related. Arthroscopic single bundle PCL reconstruction was performed in all knees. The average follow-up time was 40 (range: 24–108) months. The methods of evaluation included functional assessment, ligament laxity and radiograph of the knee. Results : The overall clinical results showed 77.4% satisfactory (61.3% excellent and 16.1% good) and 22.6% unsatisfactory (16.1% fair and 6.5% poor). Complete restoration of ligament stability was noted in 52% of the knees with one third showing mild (0–5 mm) and 9.7% moderate (5–10 mm) ligament laxity. The incidence of radiographic degenerative changes was 52% (16/31), and it correlated with the duration of injury, severity of ligament laxity and length of follow-up time. Conclusion : Arthroscopic single bundle reconstruction produced 77.4% satisfactory clinical results in medium term follow-up. Despite good clinical results, complete restoration of ligament stability was achieved in only 52% of the knees. The incidence of degenerative changes of the affected knees was 52% that correlated with the duration of injury, ligament laxity and follow-up time.
Discordance between urine pH measured by dipstick and pH meter: implications for methotrexate administration protocols.

Abstract Objectives To minimize toxicity of high-dose methotrexate (MTX) therapy, urinary alkalinization with frequent monitoring of urine pH is required. Urine pH is usually assessed by fast and convenient dipstick methods. When urine color interferes with dipstick measurement, as occurs in patients receiving MTX, alternative methods such as pH meters are used. Nursing staff caring for patients on high-dose MTX reported that urine pH results from dipstick and pH analyzers were often clinically discordant. As a result urine pH by dipstick and pH meter were compared in patients on high-dose MTX therapy and patients with normal-colored urine samples. Design and methods We measured urine pH by dipstick and pH meter in 116 urine samples from 4 patients receiving high-dose MTX therapy, and in 50 normal-colored urine samples from 50 patients not on MTX therapy. Results In patients on MTX therapy the mean (± standard deviation) bias between dipstick and pH meter urine pH was 0.7 ± 0.4, compared to 0.4 ± 0.3 in patients not on MTX. For patients on MTX clinical concordance between dipstick and pH meter urine results was poor around a clinical cut-off of pH 8.0. Of the 92 samples with a meter urine pH ≤ 8.0, 72 had a discordant value by dipstick (pH > 8). Conclusions Urine pH readings by dipstick and pH meter are not equivalent, and the bias between them is exacerbated in patients on MTX. Institutions with high-dose MTX therapy protocols should not alternate between dipstick and pH meter urine pH monitoring.
Gopher: a unidirectional means of distributing spectrochemical resources

Abstract Unidirectional sharing of spectrochemical data and programs is proposed with the use of Gopher client/server software from the University of Minnesota. This software tool allows the establishment of a repository for data and programs that can be accessed by anyone connected to the Internet. Since the transfer of information is only in one direction, an administrator can maintain a current and virus-free data base for the spectrochemical community.
A CHIEFTAINCY DISPUTE AND RITUAL MURDER IN ELMINA, GHANA, 1945–6

Between 6.30 and 7.00 a.m. on Monday morning, 19 March 1945 the body of a young girl of ten was found on the beach a short distance from the town of Elmina at a popular bathing spot known as Akotobinsin. According to the coroner, she had been dead for between 24 and 48 hours. There was no water in her lungs or stomach which indicated that she had not died by drowning. Instead, her upper and lower lips, both cheeks, both eyes, her private parts and anus, and several elliptical pieces of skin from different parts of her body had been removed. Many of these wounds exposed large blood vessels and the coroner concluded that ‘death was due to shock and hemorrhage’. She was identified as Ama Krakraba who had been missing since the evening of Saturday, 17 March. Her frantic mother had immediately suspected foul play and had confronted Kweku Ewusie, the Regent of the Edina State, who was later accused of having ‘enticed’ the young girl to the third floor of Bridge House, where he lived, ‘by the ruse of sending her out on an errand to buy tobacco’. There she had been murdered so that her body parts could be used to make ‘medicine’ to help the Regent's faction win a court case that was critical for their political standing in Elmina. On the 24 March, after a preliminary investigation, the colony's attorney-general brought charges of murder against Kweku Ewusie and four others from Elmina: Joe Smith, Herbert Krakue, Nana Appram Esson, alias Joseph Bracton Johnson, and Akodei Mensah. They were tried at the Accra Criminal Assizes from 16 May to 2 June, found guilty of first degree murder and sentenced to be hanged. The West African Court of Appeal turned down their appeal on 28 June 1945 as did the Privy Council on 14 January 1946. On 1 February 1946, Kweku Ewusie, Joe Smith and Herbert Krakue were hanged at James Fort in Accra, and on 2 February, J. B. Johnson and Akodei Mensah met the same fate.
On generalizations of the deBruijn-Erdo¨s theorem

Abstract Let L = {l1, l2, …, lk} be a collection of k positive integers, let A be a family of subsets of an n-element set and let C = {Ai ∈ A : |Ai| ∈ L }. We show that if |Ai ∩ Aj| ∈ L for all Ai, Aj ∈ A and if | C | = 0 or if ∩ Ai ∈ C Ai ≠ 0 then |A| ≤ ∑ i=0 k ( n - 1 i ) . This result is used to prove that if 1 ≤ |Ai ∩ Ai| ≤2 for all Ai, Aj ϵ A then |A| ≤ ( n - 1 0 ) + ( n - 1 1 ) + ( n - 1 2 ) and this is best possible. We also prove that the following conjecture is true when n is sufficiently large. Conjecture. Let L = {l1, l2, …, lk} be a collection of k positive integers. If Ai ∩ Aj| ∈ L for all Ai, Aj ∈ A , then |A| ≤ ∑ i=0 k ( n - 1 i ) . Finally, a modular version of the above theorem is proved and is used to partially confirm a conjecture of Alon, Babai, and Suzuki. These results generalize earlier results of deBruijn and Erdos, Bose, Ryser, Frankl and Furedi, and others.
Igor Lukes, On the Edge of the Cold War: American Diplomats and Spies in Postwar Prague

Our written history is often darker than that we have really lived, for, as Hegel observed, ‘periods of happiness are blank pages in it’.1 Historians are wont to study war rather than peace, turmoi...
13C Relaxation of dichloromethane in solution

Abstract Carbon-13 spin-lattice relaxation times and nuclear Overhauser enhancements of dichloromethane were measured in “inert” solvents of varying viscosity and in various Lewis basic solvents. Derived CH rotational correlation times were observed to remain approximately constant in the non-interactive mixtures, but to increase, by as much as a factor of three, in the basic solvents. Correlation times calculated by the Hu-Zwanzig slip model were, in all cases, shorter than the measured values. The theory predicted a viscosity dependence of τc, which was not observed experimentally. Rotational times calculated with the Hynes-Kapral-Weinberg model were somewhat longer than the observed values. However, the theory did correctly predict that τc should be approximately independent of viscosity in the non-interactive mixtures. A close agreement between theory and experiment was found for dichloromethane in the basic solvents. Therefore, the increase of τc in these solutions cannot be ascribed to slowed reorientation of the associated dimer. The results suggest that the CH bond retains a degree of rotational mobility in the hydrogen bonded complex.
Experimental/ computational evaluation of flow stress at high strain rates with application to adiabatic shear banding

Abstract Experimental techniques are described and illustrated for direct measurement of temperature, strain-rate, and strain effects on the flow stress of metals over a broad range of strains and strain rates. The approach utilizes: (1) the dynamic recovery Hopkinson bar technique recently developed at UCSD (Nemat-Nasser et al., Proc. R. Soc. London A20 , 371–391), in which samples are subjected to a single predefined stress pulse and then recovered without having been subjected to any additional loads; (2) direct measurement of sample temperature by high-speed infra-red detectors; and (3) ability to change the strain rate during the course of experiment at high strain rates. In this manner, constitutive parameters of elasto-viscoplastic flow of metals and metallic alloys are established and used in constitutive models for large-scale computational simulation of high strain-rate phenomena such as adiabatic shear banding. For application to this kind of very high strain-rate events, it becomes necessary to further tune the constitutive parameters through additional coordinated experimental and computational efforts. To this end, Taylor anvil tests are performed, accompanied by high-speed photographic recording of the deformation, and the results are compared with those obtained by finite-element simulations, leading to fine tuning of parameters in the material's flow stress. This procedure is illustrated for tantalum and tantalum/tungsten alloys, as well as for VAR 4340 steel. The simulations are performed using the PRONTO-2D finite-element code, in which an explicit constitutive algorithm, recently proposed by the first two authors and co-workers, has been implemented; Nemat-Nasser (1991, Mech. Mater. 11 , 235–249), Nemat-Nasser and Chung (1992, Comput. Meth. Appl. Mech. Eng. 95, 205–219), and Nemat-Nasser and Li (1992, Comput. Struct. 44 (5), 937–963). This algorithm is always stable and incredibly accurate, independently of the time or strain increments. The constitutive model and the constitutive algorithm are used to simulate adiabatic shear bands produced in a hat-shaped specimen under controlled conditions (Beatty et al., 1991, Proc. 12th Army Symp. on Solid Mechanics , pp. 331–345), arriving at excellent correlation with experiments.
Conventional Investing in a Complex World

In the wake of market volatility, many investors may feel a desire to change their approach and be more “nimble” or “opportunistic” in their pursuit of investment goals. In this article, Robert Maynard, Chief Investment Officer for the Public Employee Retirement System of Idaho and Brandes Institute Advisory Board member, cautions investors who are thinking about abandoning traditional investment plans. He advocates policies that are simple, transparent, and focused rather than the increasingly popular “alternative” tactics, such as illiquid instruments and vehicles, leverage, and complex, opaque investment strategies.
Some evidence of Es-layer effects upon 137 MHz radio waves

Abstract The occurrence of pronounced scintillation of radio waves transmitted from synchronous satellite Early Bird (1965-28A) appears to be correlated with the growth of the Es layer frequency ƒ 0 E s . The scintillation disturbances are usually short term but occasionally exist for as much as an hour. A number of the disturbances have well defined quasi-periodic edges although they generally exhibit a noisy spectrum.
Suppression of fuel and air stream diluted methane–air partially premixed flames in normal and microgravity

Abstract The effects of fuel and air stream dilution (ASD) with carbon dioxide on the suppression of normal and microgravity laminar methane–air partially premixed coflow jet flames were experimentally and numerically investigated. Experiments were conducted both in our normal-gravity laboratory and at the NASA Glenn Research Center 2.2 s drop tower. Measurements included flame topology and liftoff heights of diluted flames, critical diluent mole fractions for flame blowout, and the radiant heat loss from flames. The flames were also simulated using an axisymmetric unsteady numerical code that utilizes detailed chemistry and transport models. In addition, counterflow flame simulation results were used to examine similitude between the counterflow and coflow flame suppression, and further characterize the effectiveness of fuel stream versus ASD on flame extinction. A smaller relative fuel stream dilution (FSD) extinguishes partially premixed flames (PPFs) with increasing premixing as compared to dilution of the air stream. Conversely, smaller ASD is required to extinguish PPFs as they become less premixed and approach nonpremixed (NP) behavior. Fuel stream diluted PPFs and air stream diluted NP flames extinguish primarily through a reactant dilution effect while fuel stream diluted NP flames and air stream diluted PPF are extinguished primarily by a thermal cooling effect. Normal gravity flames lift off and blow out with a smaller diluent mole fraction than microgravity flames. The difference between the fuel and ASD effectiveness increases as the gravitational acceleration is reduced. Radiation heat losses are observed to increase with increasing diluent mole fraction and decreasing gravity.
Plugging an Induction Motor

Plug stopping a low-inertia squirrel-cage induction motor can provide a very quick stop, but the motor draws high peak currents from the power system and delivers high transient torques to the driven machinery. This engineering phenomena is well documented, yet the potential pitfalls of plugging applications are often not appreciated. The induction motor is so widely used in industry that a review of its plugging characteristics may be useful.
Bone plating techniques in head and neck tumor surgery

Plating techniques have increased the ability of the surgical team to resect tumors while decreasing postoperative morbidity. By maintaining preoperative form, cosmetic facial contour and considerable function are also preserved. Immediate reconstruction is possible and secondary reconstruction is easier. By maintaining bone segments in the correct anatomic position, the surgeon does not have to confront scar tissue contracture to properly align the segments during the secondary reconstruction. Plates and screws may also be used to fixate bone grafts during primary and secondary reconstruction.
Perineural hematoma following lumbar transforaminal steroid injection causing acute-on-chronic lumbar radiculopathy: a case report.

Introduction Transforaminal epidural steroid injections (TFESI) are commonly performed for the treatment of lumbar herniated nucleus pulposus and lumbosacral radiculopathy. Although rare, documented complications including spinal cord infarction, paraparesis, epidural abscess, paraplegia, and epidural hematoma have been reported. Here, we present a case of perineural hematoma affecting the L4 nerve root resulting in progressive acute-on-chronic lumbar radiculopathy following TFESI. Case Report A 72-year-old female presented with 3 months of low back and right anterior thigh pain. She subsequently underwent right L3 and L4 TFESI for physical examination findings concordant with radiographic right foraminal stenosis at L3-4 and L4-5 with L3-4 spondylolisthesis. Over the following week, the patient reported progressive right lower extremity weakness, worsening sensory loss, and ambulatory dysfunction. Examination revealed mild L3/4 myotomal weakness, sensory changes, and areflexia at the right patella. A gadolinium-enhanced MRI was ordered, which showed focal abnormal signal with involvement of the right L4-L5 neuroforamina and extending slightly far laterally, consistent with a small hematoma, affecting the L4 nerve root. Within 2 months, her strength and reflexes normalized and sensory loss diminished following medical management. Discussion Although extremely rare, perineural or foraminal hematomas may occur as a serious complication of TFESI, even in the setting of a standardized procedure. Hematoma may cause worsening of symptoms in the acute and subacute phase following TFESI. Further investigation into the etiologies of such injuries is warranted and must be added to the considerations of pain physicians performing these procedures.
The effects of volcanic ash disturbances on a peat-forming environment; environmental disruption and taphonomic consequences

The maceral and palynological composition of the C coal bed (Upper Cretaceous), central Utah, was significantly affected by the periodic deposition of volcanic ash in the precursor peat mire. The coal bed contains four altered volcanic ash partings (tonsteins). Sixty-seven coal and rock samples from 10 cores of the coal bed were examined for maceral composition, and 163 coal and rock samples from 10 cores were analysed for palynological composition. Abundant semifusinite (an inertinite maceral with a poorly preserved cell structure and a hight gray reflectance) is found in coal samples directly below the upper tonstein, the thickest (30-40 cm thick) of the tonstein partings
Risk factors for surgical site infection in pediatric cardiac surgery patients undergoing delayed sternal closure

Objectives To determine the incidence of surgical site infections (SSIs) in congenital heart surgery (CHS) patients undergoing delayed sternal closure (DSC) and to evaluate risk factors for SSI. Methods A nested case–control study was performed within a cohort of CHS patients undergoing DSC at our institution between 2005 and 2009. Cases met 2008 Centers for Disease Control and Prevention criteria for SSI; control subjects were matched based on year of surgery. Uni- and multivariate logistic regressions were performed to identify SSI risk factors. Results Of 375 patients who underwent DSC, 43 (11%) developed an SSI. The analysis included 172 patients (43 cases, 129 controls); 118 (69%) were neonates, 80 (47%) had undergone Norwood procedure, and 150 (87%) had DSC initiated in the operating room. Case and control subjects were similar based on pre- and intraoperative characteristics. Duration of mechanical ventilation, intensive care unit and hospital length of stay, and mortality were significantly greater in patients with an SSI. Multiple periods of DSC, longer duration of DSC, greater dependence on parenteral nutrition, and extracorporeal membrane oxygenation were significantly associated with SSI in univariate analyses. Multivariate analysis demonstrated that multiple periods of DSC (adjusted odds ratio, 5.9; 95% confidence interval, 1.7-20.1) and extracorporeal membrane oxygenation (adjusted odds ratio, 2.9; 95% confidence interval, 1.1-7.6) remained independent risk factors for SSI. Conclusions For CHS patients undergoing DSC, extracorporeal membrane oxygenation and multiple periods of DSC are independent risk factors for SSI. New strategies for prevention and prophylaxis of SSI may be indicated for these high-risk patients who have worse outcomes and greater health care resource utilization.
Association of Depression and Urolithiasis

Objectives To study the hypothesis that patients with urolithiasis would have a higher prevalence of depression compared to the general population. Urolithiasis is associated with frequent recurrences. Patients with urolithiasis may develop a chronic condition associated with poor quality of life and depression. The frequency and severity of stones episodes would relate to depression. Methods In an institutional review board–approved study; we prospectively recruited 115 patients who were evaluated for urolithiasis. Patients completed an Emory stone questionnaire covering demographics and a validated CES-D depression questionnaire. Depression scores were compared with U.S. norms. Demographics and clinical variables were analyzed. Results On the CES-D depression questionnaire 30.4% of patients scored ≥16, a “significant level of physiological distress.” The U.S. lifetime prevalence of depression was 16.5%. Determinants of depression included the following: family history of urolithiasis (OR = 3.49, CI = 1.51; 8.07), stone episode within the last 12 months (OR = 2.77, CI = 1.18; 6.53), and >1 emergency room visits for stone disease (OR = 2.61, CI = 1.14; 5.99). Patients with Charlson comorbidity indexes of ≤ 1 were more likely to be depressed than those scoring >1 (OR 2.89, CI = 1.20; 6.95). There were no significant associations with age at first stone, number of lifetime stones, number of surgeries, number of workdays missed, and need for dietary modifications or medications for stone prevention. Conclusions The prevalence of depression in our patient cohort with urolithiasis was substantially greater than societal norms. Multiple stone-related factors were associated with significant psychological distress. Appreciation of this issue may allow better patient care.
A threshold model for vocalization to handling in Mus domesticus.

Rates of vocalization in response to experimenter handling were assessed in eight inbred parent strains and their F1 crosses. Use of a stimulation level greater than that previously used by Whitney and a normalizing transformation of response rates provided evidence for a threshold-of-response model for vocalization. The diallel analysis indicated that a simple additive-dominance model fit the normalized data well. Substantial additive genetic variance and incomplete dominance favoring vocalization to handling were observed. Vocalization rates of recently domesticated wild-trapped mice did not differ from the diallel average, nor was there a strong relationship between vocalization rates of the strains tested and other assessments of wildness or temperament reported for these strains. Taken together, Whitney's work and the present data provide an extended testing environment for the vocalization response, producing a more comprehensive picture of the genetic architecture of the response than is possible from either study alone.
Single potassium ion seeks open channel for transmembrane travels: tales from the KcsA structure

Potassium channels selectively catalyze potassium transport across cell membranes. Over the past five decades, a multitude of potassium channel models have been proposed. The recent crystal structure determination of the KcsA potassium channel confirms, corrects and expands our understanding of a fundamental biological catalyst, revealing the basis of exquisite selectivity and near diffusion-limited throughput.
r dr r: ENGAGING STUDENTS WITH SIGNIFICANT MATHEMATICAL CONTENT FROM THE SIMPSONS

ABSTRACT The Simpsons is an ideal source of fun ways to introduce important mathematical concepts, motivate students, and reduce math anxiety. We discuss examples from The Simpsons related to calculus, geometry, and number theory that we have incorporated into the classroom. We explore student reactions and educational benefits and difficulties encountered.
New evidence on the small properties of estimators of sur models with autocorrelated disturbances

Abstract This study analytically examines the effect of trends in exogenous variables on the small-sample relative performance of alternative estimators of a SUR model with positively autocorrelated AR(1) disturbances. It is disclosed that when exogenous variables are trended: (1) an estimator that makes both autocorrelation and cross-correlation adjustments of the disturbances but drops the first observations in the process of autocorrelation adjustment frequently performs worse than OLS; (2) an estimator that makes cross-correlation adjustment ignoring the autocorrelation of the disturbances can occasionally be less efficient than OLS. The implied prescription for a practicing econometrician is, then, that he should use an estimator that makes a complete adjustment of both correlations, i.e., a GLS version.
Effects of management regime on the abundance and nest survival of shrubland birds in wildlife openings in northern New England, USA

Abstract Many shrubland bird species are declining in eastern North America and as a result forest managers have used a variety of techniques to provide breeding habitat for these species. The maintenance of permanent “wildlife openings” using prescribed burns or mechanical treatments is a widely used approach for providing habitat for these species, but there have been no studies of the effects of treatment regime on bird abundance and nest survival in managed wildlife openings. We studied shrubland birds in wildlife openings on the White Mountain National Forest (WMNF) in New Hampshire and Maine, USA, during 2003 and 2004. We analyzed bird abundance and nest survival in relation to treatment type (burned versus mowed), treatment frequency, time since treatment, and patch area. We found that wildlife openings provided habitat for shrubland birds that are not present in mature forest. There was relatively modest support for models of focal bird species abundance as a function of treatment regime variables, despite pronounced effects of treatment on habitat conditions. This probably was attributable to the combined effects of complex site histories and bird site fidelity. Overall nest success (52%) was comparable to other types of early-successional habitats in the region, but there were few supported relationships between nest survival and treatment variables. We conclude that wildlife openings provide quality habitat for shrubland birds of high conservation interest as long as managers ensure treatment intervals are long enough to permit the development of woody vegetation characteristic of the later stages of this sere. Also, wildlife openings should be large enough to accommodate the territory sizes of all target species, which was ≥1.2 ha in this study.
Dietary copper enhances the hepatotoxicity of Senecio jacobaea in rats.

To determine the effects of dietary copper on the toxicity of Senecio jacobaea (tansy ragwort), a plant that contains the hepatotoxic pyrrolizidine alkaloids (PAs), young male rats were fed diets containing 0 or 5% dried tansy ragwort tops and 0 or 5% μg/g copper (as copper sulfate) for 5 weeks. Hepatotoxicity was measured by the activities of plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). Comsumption of diets containing 5% tansy ragwort alone produced a significant reduction in weight gain accompanied by a 122% increase in plasma AST activity, a 106% increase in ALP activity, and a 152% increase in ALT activity, compared to pair-fed controls. When copper was added to the tansy ragwort diet, the activities of both plasma AST and ALT were increased by more than 350%. Plasma ALP activity was also further enhanced by dietary copper in the tansy ragwort-fed animals but to a lower extent. Supplementary copper alone or a reduction in food intake had no significant effect on any of the enzyme activities. The results suggest that copper potentiates the hepatotoxic effects of tansy ragwort in rats.
Gene transfer in vivo with DNA-liposome complexes: lack of autoimmunity and gonadal localization.

ABSTRACT Direct gene transfer into localized arterial segments can be performed in vivo by transfection with DNA–liposome complexes. This technique holds promise for the treatment of human diseases...
Estimating the changes in the distribution of energy efficiency in the U.S. automobile assembly industry

Abstract This paper describes the EPA's voluntary ENERGY STAR program and the results of the automobile manufacturing industry's efforts to advance energy management as measured by the updated ENERGY STAR Energy Performance Indicator (EPI). A stochastic single-factor input frontier estimation using the gamma error distribution is applied to separately estimate the distribution of the electricity and fossil fuel efficiency of assembly plants using data from 2003 to 2005 and then compared to model results from a prior analysis conducted for the 1997–2000 time period. This comparison provides an assessment of how the industry has changed over time. The frontier analysis shows a modest improvement (reduction) in “best practice” for electricity use and a larger one for fossil fuels. This is accompanied by a large reduction in the variance of fossil fuel efficiency distribution. The results provide evidence of a shift in the frontier, in addition to some “catching up” of poor performing plants over time.
Effects of Colupulone, a Component of Hops and Brewers Yeast, and Chromium on Glucose Tolerance and Hepatic Cytochrome P450 in Nondiabetic and Spontaneously Diabetic Mice

Abstract Brewers yeast contains factors that increase and decrease glucose tolerance. Hop components (lupulones) that adhere to yeast during the brewing process elicit a variety of biological effects including the induction of hepatic cytochrome P4503A. Colupulone was tested for its effects on glucose tolerance and cytochrome P450. Serum glucose levels 30 min after the injection of glucose were lowered by colupulone in nondiabetic Swiss-Webster mice, elevated in diabetic C57Bl/KSJ-db/db mice, and unaffected in nondiabetic C57Bl/KSJ+m/+m mice. Colupulone lowered hemoglobin glycation slightly in +m/+m mice but not in db/db mice. The cytochrome P450 system was highly induced by colupulone in both db/db and +m/+m mice. Chromium, which acts in concert with the factor in yeast that enhances glucose tolerance, had little or no effect on the plasma glucose level or the cytochrome P450 system in either +m/+m or db/db mice.
Case---KEY Electronics---Sourcing and Warehouse Analysis

This case is based on a real-life scenario. Names, dates, and company information have been disguised to protect the identity of the company.
Phonemes, intensity and attention: differential effects on the mismatch negativity (MMN).

Auditory event-related potentials (ERPs) to speech sounds were recorded in a demanding selective attention task to measure how the mismatch negativity (MMN) was affected by attention, deviant feature, and task relevance, i.e., whether the feature was target or nontarget type. With vowel-consonant-vowel (VCV) disyllables randomly presented to the right and left ears, subjects attended to the VCVs in one ear. In different conditions, the subjects responded to either intensity or phoneme deviance in the consonant. The position of the deviance within the VCV also varied, being in the first (VC), second (CV), or both (VC and CV) formant-transition regions. The MMN amplitudes were larger for deviants in the attended ear. Task relevance affected the MMNs to intensity and phoneme deviants differently. Target-type intensity deviants yielded larger MMNs than nontarget types. For phoneme deviants there was no main effect of task relevance, but there was a critical interaction with deviance position. The both position gave the largest MMN amplitudes for target-type phoneme deviants, as it did for target- and nontarget-type intensity deviants. The MMN for nontarget-type phoneme deviants, however, showed an inverse pattern such that the MMN for the both position had the smallest amplitude despite its greater spectro-temporal deviance and its greater detectability when it was the target. These data indicate that the MMN reflects differences in phonetic structure as well as differences in acoustic spectral-energy structure of the deviant stimuli. Furthermore, the task relevance effects demonstrate that top-down controls not only affect the amplitude of the MMN, but can reverse the pattern of MMN amplitudes among different stimuli.
Atomic physics: cold meeting at a junction.

The Josephson effect is a macroscopic manifestation of quantum mechanics usually seen in superconductors. Observation of this effect in a gas of ultracold atoms demonstrates the underlying unity of solid and gaseous systems.
Applications of clifford analysis to axially symmetric partial differential equations

The spherical decomposition of harmonic polynomials into solutions of Dirac's equation in R n is used to examine solutions to differential equations defined over axially symmetric domains in R n+1.To some of these cquations we arc ahle to associate systems of Hermite polynomials. We are also ahle to apply analytic continuation techniques to describe certain potentials associated to higher order Dirac operators.
Groundwater flow, velocity, and age in a thick, fine-grained till unit in southeastern Wisconsin

Abstract Piezometer nests were installed at study sites in each of five north-south-trending end moraines of the late Pleistocene Oak Creek Formation in southeastern Wisconsin. The formation is composed primarily of a fine-grained glacial diamicton (till) and laterally continuous and discontinuous, coarse-grained lake and meltwater stream sediment. It overlies the Silurian dolomite aquifer, which is a source of drinking water to rural areas. The average vertical linear velocity and age of ground water in the Oak Creek Formation were estimated by three methods: Darcy's Law, environmental isotopes including 3 H, δ 2 H, δ 18 O, and 14 C (dissolved inorganic carbon), and solute transport modeling of 18 O. The F-1 and Metro sites in the Tinley moraine showed excellent agreement among the three estimates of vertical velocity and showed the lowest velocity values (0.3–0.5 cm year −1 downward), which suggests that diffusion controls vertical mass transport at these sites. Although the extrapolated maximum age of ground water is 35 000 years, ground water below 75 m at these sites is probably not older than 15 000 years, which is the maximum age of the formation. Estimates of velocity showed less agreement at study sites in the Lake Border moraine system to the east and ranged from about 0.2 to 20.7 cm year −1 ; maximum groundwater age could range from 213 to 6000 years. Higher and more variable velocities, perhaps owing to thinner and more heterogeneous sediment in these areas, suggest that diffusion may not dominate vertical mass transport. Heterogeneity and fractures may also promote the development of groundwater flow systems dominated by lateral flow. Because of the uncertainty about the nature of groundwater flow, velocity, and age in the formation east of the Tinley moraine, future waste-disposal activity in southeastern Wisconsin should be confined to the thickest parts of the Tinley moraine near the present F-1 and Metro sites.
Bronchoscopic removal of aspirated foreign bodies in children

Foreign body aspiration is the cause of death for more than 300 children each year in the United States. Tracheobronchial inhalation of foreign bodies may result in acute respiratory distress, atelectasis, chronic pulmonary infections, or death. A review of the records of 548 children (aged 4 months to 18 years) was undertaken to identify factors important in diagnosis, to illustrate the effectiveness of current endoscopic techniques and equipment, and to evaluate the results and complications of management. Coughing, choking, and wheezing were the presenting symptoms seen for 95% of the patients. Results of inspiratory and expiratory chest radiographs were positive in 83% of the 440 children who had foreign bodies removed. Fluoroscopy findings were positive for 67 patients, 90% of whom had foreign bodies removed. Foreign bodies were successfully identified and removed in 440 patients (80%). A wide variety of objects was recovered, the most common being peanuts, organic material, other nuts, popcorn, seeds, plastic objects, and pins. The foreign bodies were in the right bronchus in 49%, the left in 44%, and the trachea and hypopharynx in 4%. Two thirds of the objects were lodged in the mainstem bronchi, on either side, and the remainder were in the distal bronchi. Bronchoscopy is required for treatment, and with experience this procedure can be simple and safe. Ninety-nine percent of the foreign bodies identified during bronchoscopy were removed successfully. Minor complications occurred in 5%, and there were no deaths.
Mitochondrial dysfunction in liver disease and organ transplantation

The mitochondria play a crucial role in maintaining hepatocyte integrity and functions. Mitochondrial defects are either inherited or acquired. Mitochondria dysfunction occurs when the hepatocyte experience excessive physiologic stress. Its clinical presentation depends on the severity of the stress. It varies from mild abnormalities in liver biochemical tests to manifestations of acute or chronic liver failure. Mitochondria dysfunction is implicated in most liver disease and in early graft dysfunction after liver transplantation. This review will address the role of mitochondria in liver disease.
Unconventional therapies for cancer and cancer-related symptoms

Summary A significant proportion of cancer patients try unconventional therapies and many use ‘complementary' therapies, as adjuncts to mainstream care, for management of symptoms and to improve quality of life. A smaller proportion use ‘alternative' therapies, which are typically invasive, biologically active, and commonly promoted as replacements for, rather than adjuncts to, mainstream therapy. Many alternative therapies, including high-dose vitamin C, the Di Bella regimen, and laetrile have been shown not to be effective. For others, such as metabolic therapy, evidence is extremely limited. Conversely, most complementary therapies are well studied and of proven benefit. There is evidence from randomised trials supporting the value of hypnosis for cancer pain and nausea; relaxation therapy, music therapy, and massage for anxiety; and acupuncture for nausea. Such complementary therapies are increasingly provided at mainstream cancer centres.
Conjugate-Gradient Methods for Large-Scale Minimization in Meteorology

Abstract During the last few years new meteorological variational analysis methods have evolved, requiring large-scale minimization of a nonlinear objective function described in terms of discrete variables. The conjugate-gradient method was found to represent a good compromise in convergence rates and computer memory requirements between simpler and more complex methods of nonlinear optimization. In this study different available conjugate-gradient algorithms are presented with the aim of assessing their use in large-scale typical minimization problems in meteorology. Computational efficiency and accuracy are our principal criteria. Four different conjugate-gradient methods, representative of up-to-date available scientific software, were compared by applying them to two different meteorological problems of interest using criteria of computational economy and accuracy. Conclusions are presented as to the adequacy of the different conjugate algorithms for large-scale minimization problems in different met...
Coulomb interactions at quantum Hall critical points of systems in a periodic potential

We study the consequences of long-range Coulomb interactions at the critical points between integer/fractional quantum Hall states and an insulator. We use low energy theories for such transitions in anyon gases in the presence of an external periodic potential. We nd that Coulomb interactions are marginally irrelevant for the integer quantum Hall case. For the fractional case, depending upon the anyon statistics parameter, we nd behavior similar to the integer case, or ow to a novel line of xed points with exponents z =1 , >1 stable against weak disorder in the position of the critical point, or runaway ow to strong coupling.
Regulation of coronary blood flow

A very schematic summary of possible factors that affect coronary vascular resistance is illustrated in Fig. 11. These factors are mechanical, myogenic, metabolic, and neural. Mechanical influence is passive and is essentially determined by the extravascular compression which is important only during systole and particularly in the subendocardial layers of the left ventricular myocardium. With respect to the myogenic factor it is controversial whether it plays a role in adjustments of coronary vascular tone. Metabolic processes are possibly integrated at the level of the myocardial cell PO2 which is the resultant of oxygen supply and need, which in turn depend on the myocardial contractile activity as well as other biochemical processes. A decrease in myocardial PO2 gives rise to the release of the vasodilator metabolite adenosine. Nevertheless, other chemical factors (H+, K+, osmolarity) known to be released by the heart (which by themselves are poor and transient coronary vasodilators and whose release does not correspond with changes in coronary resistance) may play a role by modulating the coronary sensitivity to adenosine and other factors.
Isotopic breaking of gauge symmetry

By using the integrability conditions for the existence of a Lagrangian, a classical gauge symmetry-breaking mechanism is introduced whereby (a) the original gauge Lagrangian is replaced by an equivalent chiral Lagrangian without changing the local variables and conserved currents, (b) the original gauge symmetry is broken by the equivalent Lagrangian and is replaced by a different symmetry which leads to the conservation of the original charge current, and (c) this different symmetry generally results to be a mixture of space-time and internal transformations.