cssi/SciSciGPT-SciSciNet huggingface dataset:
DETERMINACION AMPEROMETRICA INDIRECTA DE Se(IV) CON PRECONCENTRACIONEN LINEA POR ANALISIS DE INYECCION EN FLUJO

Se han optimizado las condiciones experimentales para la deteccion amperometrica indirecta de Se(IV) por analisis de inyeccionen flujo (FIA). El metodo se basa en la reduccion de Se(IV)a Se(0), en medio acido y en presencia de un exceso de yoduro, generandose yotrion, especie que es electroactiva y es detectada amperometricamenteen una celda de flujo con un electrodo de carbono vitreo como electrodo de trabajo. La senal generada depende de la cantidad de Se(IV) en las muestras. En condiciones optimizadas se procedio a evaluar las caracteristicas analiticas del metodo. Los limites de deteccion y de cuantificacion fueron de 4,8 mg l-1y 15,9 mg l-1 respectivamente. Debido a que el metodo propuesto esta destinado a su aplicacion a la determinacion de Se(IV) en muestras de aguas naturales, se hizo necesario aumentar la sensibilidad de la deteccion, por lo que se acoplo al sistema una etapa de preconcentracion en linea, la que se lleva acabo en una microcolumna rellena con resina de intercambio ionico Dowex 1-X8. En estas condiciones el limite de deteccion fuede 0,06 mg l-1 y el de cuantificacion de 0,2 mgl-1. La etapa de preconcentracion en linea aumentala sensibilidad de la deteccion amperometrica lo que permitela determinacion de concentraciones de Se(IV), del orden del mgl-1
Neuroscience: The connected self

Christof Koch tours the idea that the essence of the mind lies in the links between neurons.
The acoustical characteristics of the normal and abnormal temporomandibular joint.

Abstract This paper describes the results of a clinical study that recorded and analyzed sounds emitted from the temporomandibular joint (TMJ) during simple function as a means for differentially diagnosing disorders of the joint. The technique is based on the principle that each different disorder of the TMJ produces a different effect on the mechanical relationship between the articulating surfaces of the joint, and that these mechanical effects can be determined by analyzing joint sounds in relation to joint movement. A total of 79 patients (101 joints) were studied; 32 (46 joints) were diagnosed as having extracapsular disorders, (primarily MPD), 27 (32 joints) were diagnosed as having a displaced disc with reduction, nine (10 joints) were diagnosed as having a displaced disc without reduction, and 11 (13 joints) were diagnosed as degenerative disease (osteoarthritis/arthrosis). In addition, 25 adults (50 joints) with normal TMJs were included as controls. The results of this study demonstrated that each specific disease of the TMJ is characterized by a unique relationship between the sounds propagated by the joint and the movement of the joint. Essentially, an extracapsular disease was characterized by acoustic quiescence during natural (as opposed to maximal) jaw movement, an internal derangement by a usually symmetrical short duration click/reciprocal click, or random click complex, depending on the subcategory of the disorder, and a degenerative disease by a long duration noise during either or both jaw opening and closing. The data further suggest that the technique serves to reflect the mechanical events (and abnormalities) that are involved in function of the diseased joint and has potential for use as a clinical diagnositic tool.
Improved Homogenization of Recombinant Escherichia coli following Pretreatment with Guanidine Hydrochloride

Pretreatment of recombinant Escherichia coli, expressing human growth hormone inclusion bodies, with guanidine hydrochloride and Triton X-100 prior to high-pressure homogenization has been investigated. Homogenates were analyzed for protein release, viscosity, and particle size. We were able to reduce the number of passes required for cell disruption and the number of downstream processing steps required for the recovery of protein from inclusion bodies by pretreating cells with guanidine HCl and Triton X-100. Pretreatment of exponential growth phase cells with 1.5 M guanidine HCl and 1.5% Triton X-100 gave adequate disruption after one pass at 41 MPa with a particle size distribution similar to that for untreated cells disrupted after one pass at 62 MPa. This combination of guanidine HCl and Triton X-100 was also selected so as to wash the inclusion bodies without solubilization of the human growth hormone. Pretreatment of cells with 4 M guanidine HCl produced cell debris that was substantially smaller than the debris from untreated cells and partially solubilized the inclusion bodies. Cells harvested in the stationary growth phase were more resistant to high-pressure homogenization and pretreatment.
Sheep platelets as a model for human platelets: Evidence for specific paf (platelet activating factor) receptors

In a number of animals, the platelet response to Platelet Activating Factor (PAF) has been shown to differ considerably from that in humans. However, aggregation, release and particularly shape change were quite similar for human and sheep platelets. In this study, aggregation and shape change analysis were used to measure the response of sheep platelets to various synthetic analogs of PAF. Response is greatly reduced with no alkyl group in position 2 of PAF and decreases progressively as the number of carbons of the alkyl gets larger than three. A reduction of activity is also seen as the ether linkage at position 1 of PAF is replaced by an ester linkage. These changes are indicative of a specific membrane receptor for PAF in sheep platelets and confirm the usefulness of sheep platelets as a model for PAF-platelet interaction in humans.
The Alyavdin-Weibull plot of grinding data and the order of kinetics

Abstract The hypothesis ascribed by Austin and Luckie to Harris, that “…a Weibull plot of grinding data should give a straight line of slope one if grinding is first order”, does not properly express Harris” views. At least their statement should have been preceded by “If the restrictive interrelationship between the breakage and selection functions is valid and independent of time”. Other aspects of the hypothesis are discussed. Titus, if the interrelationship is valid and dependent upon time the slope in the t small region is related to the extent of time dependence rather than order. If the interrelationship is invalid the hypothesis is inapplicable. With real data, the hypothesis can be useful in the region where particle size, weight percent under-size and time of grinding (x, Y, t) are small; it is in agreement with data presented by Austin and Luckie. The principal use of the Alyavdin-Weibull chart is as an aid in the analysis of kinetic data, rather than as a procedure in its own right.
Immunological Maturation in the Tunicate Ciona intestinalis

The least explored areas in the phylogenetic development of immunity are the primitive chordate subphyla. The limited studies on tunicate internal defense mechanisms are presented and discussed. Primary and secondary immune responses and immunological maturation to vertebrate erythrocytes in Ciona intestinalis suggest that its internal defense mechanisms may be closely allied to both the invertebrates and vertebrates.
Copper homeostasis in Mycobacterium tuberculosis

Copper (Cu) is a trace element essential for the growth and development of almost all organisms, including bacteria. However, Cu overload in most systems is toxic. Studies show Cu accumulates in macrophage phagosomes infected with bacteria, suggesting Cu provides an innate immune mechanism to combat invading pathogens. To counteract the host-supplied Cu, increasing evidence suggests that bacteria have evolved Cu resistance mechanisms to facilitate their pathogenesis. In particular, Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, has evolved multiple pathways to respond to Cu. Here, we summarize what is currently known about Cu homeostasis in Mtb and discuss potential sources of Cu encountered by this and other pathogens in a mammalian host.
988-7 Endothelin ETA/B Receptor Antagonist Reduces Infarct Size: A Novel Therapy for Acute Myocardial Infarction

We have previously shown that regional myocardial ischemia foliDwed by reperfusion (rep) significantly enhances cardiac release of the potent vasoconstrictor endothelin (ET). We now examine the association of ET production and myocardial blood flow IMBF) in rabbits (n = 14) undergoing 30 min Df circumflex occlusion and 3 hrs of rep. MBF was measured with radioactive microspheres at baseline, 15 min into occlusion, 1 min, 1 and 3 hrs into rep. Utilizing molecular biology techniques, ET1 mRNA was measured at 3 hrs and found to be elevated in the central ischemic zone (CIZ) compared to the non ischemic zone INIZ). In a second study we investigated the effects of exogenous ETl and PD145065 (an ETA/B receptor antagonist) on infarct size of rabbits undergoing 30 min of circumflex occlusion and 48 hrs of rep. Download : Download high-res image (54KB) Download : Download full-size image Drug infusion started with an initial bolus (PD145065 3 mg/kg; n = 10 or ETl 10-10 m/kg; n = 9) 10 min before occlusion followed by 10-11 m/kg/min of ET1 or 0.6 mg/kg/min of PD145065 for 2 hrs and 40 minutes. Control animals (n = 10) received the same volumes in saline. Infarct size (AN) was measured histologically and expressed as percentage of area at risk (AR).Results as Mean ± SEM. Conclusions 1. Myocardial rep after ischemia is associated with marked reactive hyperemia. This flow decreases significantly in the CIZ at 3 hrs into rep demonstrating for the first time that the “no-reflow phenomenon” exists in the rabbit model. 2. ET1 mRNA was elevated in the CIZ at 3 hrs, suggesting a cause-effect relationship between ET1 production and the “no-reflow phenomenon”. 3. Exogenous infusion of ET1 fails to alter infarct size but antagonism of the ETA/B receptors significantly reduces infarct size in rabbits and this might represent a novel therapy for acute myocardial infarction in man.
High-density lipoprotein metabolism in human apolipoprotein B(100) transgenic/brown adipose tissue deficient mice: a model of obesity-induced hyperinsulinemia.

Obese and diabetic humans display decreased plasma high-density lipoprotein cholesterol (HDL-C) concentrations and an increased risk for coronary heart disease. However, investigation on HDL metabo...
Measurement of the spatial evolution of the deprotection reaction front with nanometer resolution using neutron reflectometry

The use of chemically amplified photoresists for the fabrication of sub-100 nm features will require spatial control with nanometer level resolution. To reach this goal, a detailed understanding of the complex reaction-diffusion mechanisms at these length scales is needed and will require high spatial resolution measurements. In particular, few experimental methods can directly measure the spatial evolution of the deprotection reaction front and correlate it with the developed structure. In this work, we demonstrate the complementary use of neutron (NR) and x-ray (XR) reflectometry to measure the reaction front profile with nanometer resolution. Using a bilayer geometry with a lower deuterium-substituted poly(tert-butoxycarboxystyrene) (d-PBOCSt) layer and an upper poly(hydroxystyrene) (PHOSt) layer loaded with a photoacid generator (PAG), we directly measure the spatial evolution of the reaction front. We show that the reaction front profile is broader than the initial interface after a post-exposure bake and the compositional profile changes upon development in an aqueous base solution. We also directly correlate the final developed structure with the reaction front profile. The spatial detail enabled by this general methodology can be used to differentiate between and evaluate quantitatively reaction-diffusion models.
Instruments for evaluating school psychologists' functioning and service

The evaluation of school psychological services is both a responsibility and an opportunity too long ignored. Unique problems must be overcome in evaluating school psychologists, but the task is not insurmountable. This paper describes and presents examples of five data collection devices which can be used in the evaluation effort: the vignette-based questionnaire, the role-model questionnaire, the services received questionnaire, the teacher interview, and nonobtrusive measurement.
On the reflection of elastic waves incident on the boundary of a diatomic half-space

Abstract The paper examines reflection of a plane longitudinal wave incident upon the surface of a half-infinite space the material of which is elastic, and the particles include two atoms of different thermomechanical properties. After establishing the constitutive equations of the constituents, equations of motion are solved by appeal to four quasi-potential functions. Satisfaction of the boundary conditions yields the characteristic equation of the problem which—in contrast to the conventional case, and in agreement with observations—indicates dispersion of waves. An example involving relaxed bonds between the constituents is examined and illustrated by graphs.
Second-phase optokinetic after-nystagmus and vestibular compensation.

To evaluate the direction-specific effect of optokinetic storage function on balance compensation after unilateral labyrinthectomy, squirrel monkeys (n=12) were exposed to a prolonged (30 min) daily optokinetic stimulus (horizontal, constant speed-90d`/sec) for 14 days; either in the ipsilateral direction to the slow phase of spontaneous nystagmus, or in the contralateral direction, or without any optokinetic stimulus. The effect of optokinetic stimulus in ipsilateral direction (slow phase of OKAN-I I in the opposite direction) was significantly more (p>0.001) in the vestibulo-oculomotor balance (static) regainment than the other two groups, but this group showed the severest gait deviation in the vestibulo-spinal balance function (p>0.05).
Unemployment equilibrium in a random economy

Abstract In this paper we study an economy in which prices for some commodities are linked to other flexible prices. Our model allows supply-side rationing in the form of random drawing of unemployed suppliers. The unemployment equilibrium in a random economy is achieved by the joint movement of flexible prices and unemployment probabilities. With equality price linkages we show the existence of a non-trivial unemployment equilibrium which entails a reasonable relationship between equilibrium prices and unemployment probabilities. With inequality price linkages, we prove the existence of a non-trivial unemployment equilibrium where the a priori chosen numeraire is never rationed.
Approximate polarization selection rules for the 3P0 → 3H4 transition in Pr: β" alumina single crystals

Emission spectra of the 3 P 0 → 3 H 4 transition in Pr:β″ alumina single crystals excited by both a broad-band blue source and by dye laser excitation at various wavelengths within the inhomogeneously-broadened 3 H 4 → 3 P 0 absorption line are considered. These spectra are strongly polarized, and are therefore due to Pr 3+ ions in the Beevers-Ross (BR) sites. An approximately-axial model for the crystal field at a BR site predicts crystal field splitting of the 3 H 4 level and polarization selection rules which approximately mach those we have observed
An unusual course of thioglycoside activation with bromine: synthesis and crystal structure of 4-O-acetyl-2-bromo-2,3,6-trideoxy-3-C-methyl-3-trifluroacetamido-α-l-altropyranosyl bromide

Abstract Bromine activation of phenyl 4-O-acetyl-2,3,6-trideoxy-3-C-methyl-3-trifluoroacetamido-1-thio-α,β- l -ribo-hexopyranoside and attempted coupling with an acceptor in the presence of silver silicate gave an unusual bicyclic product, 2-trifluoromethyl-(4-O-acetyl-2-bromo-2,3,6-trideoxy-3-C-methyl-α- l -altrohexopyrano)-[3,2,1-d,e]-2-oxazine, instead of the expected disaccharide. Detailed investigation supported by X-ray crystallographic analysis showed that a trans dibromide is an intermediate in this reaction and that the dibromide is likely formed from a glycal that is generated by elimination during the coupling step.
Letter Regarding Article by Leeper et al, “Statin Use in Patients With Extremely Low Low-Density Lipoprotein Levels Is Associated With Improved Survival”

To the Editor: In the August 7, 2007, issue of Circulation , Leeper and colleagues1 report that statin therapy is associated with 35% improved survival in patients with low-density lipoprotein (LDL) values <60 mg/dL. The authors suggest that benefits are derived from the pleiotropic effects of statins, such as a reduction in inflammation, restoration of endothelial function, and …
Guidelines for preparing software user documentation

Clear, easy-to-use software user's manuals make strong demands on special technical communication techniques. Principles and guidelines are given for analyzing the audience and dealing with wide-ranging backgrounds of potential users. Types of information to be included in a complete manual are suggested, with a technique for creating a user-oriented rather than process-oriented organization. Accuracy verification is emphasized. Simple tips are gievn for formatting for quick comprehension and reference, for deciding on packaging, for creating helpful illustrations and examples, and for setting up clear and consistent conventions. Simple guidelines are offered for writing clearly and concisely and for editing.
An object-oriented knowledge-based system for manufacturability of printed wiring boards

Abstract Design for manufacturability has been proved to be a solution that avoids the problems created by design not amenable to manufacturing. The designer should be aware of the manufacturing constraints to achieve the design for manufacturability. The rapid change in printed circuit board aanufacturing with the induction of surface mounted components and robotic assembly has changed the scenario of the design. The high-density packaging capability of surface mounted technology has contributed enormously to the development of new trends in printed wiring board manufacturing. Pwbma , Printer Wiring Board Manufacturability Advisor (printed wiring board is another name for printed circuit board), a knowledge-based system, is developed to capture this new technology and its interaction with the existing through-hole mounting technology. Rules and guidelines pertaining to manufacturability of the board are formulated and incorporated into the knowledge base in building the system, which is built on an object-oriented paradigm. The importance of the object-oriented approach, the implementation of the object-oriented paradigm, object-oriented programming using Smalltalk-80, and the hierarchical rule structure paradigm are discussed. The implementation of meta-level to increase the efficiency of the system is also presented. Furthermore a rating system is introduced to rank various designs. Pwbma is capable of suggesting design modifications at the early stage of design to eliminate the manufacturing problems in the later phase of board production. The system is very easy to use with a broad user interface.
Investigating the impact of a community-based geriatric dentistry rotation on oral health literacy and oral hygiene of older adults.

Objective This study investigated the impact of a community-based geriatric dentistry rotation on older adults' oral health literacy and oral hygiene. Materials and methods A pre–post study design was used to assess the impact of the educational intervention. The study sample consisted of 67 older adults, who resided in independent or assisted living apartments (age: M = 84, SD = 7.3). Over the course of the programme, participants received patient education pertaining to oral health and oral hygiene. Oral health literacy was assessed using the Rapid Estimation of Adult Literacy in Dentistry (REALD–30) test at baseline and on the final visit. Oral hygiene was measured on four visits using the O'Leary, Drake and Naylor Plaque Control Record (PI). Results REALD-30 scores significantly increased, and PI scores significantly decreased for all subjects following participation in the programme (p < 0.001, and p < 0.01, respectively). Hierarchical multiple regression demonstrated that neither study subjects' individual characteristics nor their health literacy significantly predicted the change in oral hygiene. Conclusion This study demonstrated that a community-based geriatric dentistry rotation involving multiple interactions with dental students can in the short term significantly and positively impact older adults' oral health literacy and oral hygiene status.
A mixture model approach to detecting differentially expressed genes with microarray data

An exciting biological advancement over the past few years is the use of microarray technologies to measure simultaneously the expression levels of thousands of genes. The bottleneck now is how to extract useful information from the resulting large amounts of data. An important and common task in analyzing microarray data is to identify genes with altered expression under two experimental conditions. We propose a nonparametric statistical approach, called the mixture model method (MMM), to handle the problem when there are a small number of replicates under each experimental condition. Specifically, we propose estimating the distributions of a t -type test statistic and its null statistic using finite normal mixture models. A comparison of these two distributions by means of a likelihood ratio test, or simply using the tail distribution of the null statistic, can identify genes with significantly changed expression. Several methods are proposed to effectively control the false positives. The methodology is applied to a data set containing expression levels of 1,176 genes of rats with and without pneumococcal middle ear infection.
Feast or Famine: The Sympathetic Nervous System Response to Nutrient Intake

: 1. The use of tritiated norepinephrine (NE) to measure the turnover rate of NE in sympathetically innervated organs was pioneered in the laboratory of Julius Axelrod. This technique provides an organ specific assessment of sympathetic activity, integrated over a 24 h period, in free living laboratory animals. As such it has proved useful in estimating changes in sympathetic outflow in different physiologic and patho-physiologic states. 2. Studies employing NE turnover techniques in laboratory rodents have demonstrated conclusively that fasting suppresses and overfeeding stimulates the sympathetic nervous system (SNS). These changes in sympathetic activity also occur in humans. 3. Diet-induced changes in SNS activity are regulated by insulin-mediated glucose uptake and metabolism in central neurons sensitive to insulin and located anatomically in the ventro-medial hypothalamus. The regulation is imposed by descending inhibition of tonically active sympathetic brainstem centers. 4. Diet-induced changes in SNS activity mediate changes in energy production known as dietary thermogenesis. The capacity for dietary thermogenesis serves as a potential buffer against weight gain.5. Insulin stimulated SNS activity contributes to obesity-related hypertension. The insulin resistance of obesity, and consequent hyperinsulinemia, drives sympathetically mediated thermogenesis, restoring energy balance at the expense of SNS over activity. The association of obesity and hypertension, therefore, may be the unintended consequence of mechanisms recruited in the obese to limit further weight gain.
Wilm’s Tumor: Ten Year Experience at Kanti Children’s Hospital

Introduction: Wilm's tumor is the second most common abdominal tumor in children. It arises from the kidney. The survival of children with Wilm's tumor has improved over the past 25 years. Objectives: To study the clinical presentation of Wilm’s tumor and evaluate the ten year survival. Materials and Methods: A retrospective hospital based study was conducted at Kanti Children's Hospital from March 1998 to February 2008. A total of 60 histopathologically diagnosed children below 14 yr of age were included in the study. Results: About 2/3rd (66.5%) presented with abdominal swelling followed by abdominal pain (16.5%) and fever (13.5%). A few children manifested with red colored urine (3.5%). The age of children ranged from one month to 13 years with the mean age of 36 months. Males were affected more than the females (M:F=3:1). Most affected age group was 2 to 5 yrs (41.5%) followed by 1 to 2 yrs (25.0%). Most of the cases were in stage III (36.5%) followed by stage II (33.5%). SIOP protocol was used to treat these children and overall 10 year survival rate was 50.0%. One fifth (20%) of the cases died, 16.5% relapsed and 13.5% lost to follow up. Conclusion: Despite severe resource limitations, paediatric oncology unit at Kanti Children’s Hospital has been successfully treating Wilm's tumor with the success rate of 50.0%. Key words: Chemotherapy; Outcome; Remission; Wilm’s tumor; SIOP. DOI: 10.3126/jnps.v30i2.3449 J. Nepal Paediatr. Soc. May-August, 2010 Vol 30(2) 85-89
Coexpression of Mammalian Cytochrome P450 and Reductase inEscherichia coli

Abstract cDNAs for human cytochrome P450 2E1 and rat NADPH–cytochrome-P450 reductase were cloned separately and in tandem into bacterial expression vectors, and expression of the two proteins in Escherichia coli was monitored by immunoblotting, spectroscopy, and catalytic assays. The cDNAs were separated on the coexpression plasmid by 22 nucleotides, with the P450 cDNA preceding the reductase cDNA. P450 content in solubilized cell membranes, whether expressed alone or coexpressed with P450 reductase, was approximately 0.11 nmol/mg of protein, and approximately 0.8 nmol could be obtained per liter of culture. Reductase content was five- to sixfold greater than P450 content when coexpressed, but severalfold less than that obtained when expressed without the upstream P450 cDNA, indicating differences in both stability and translatability between the two proteins. Solubilized membranes from cells expressing both proteins catalyzed aniline hydroxylation, p -nitrophenol hydroxylation, and N -nitrosodimethylamine demethylation at rates equivalent to those obtained by combining P450 and reductase preparations; addition of purified reductase to these membranes did not augment the activity. However, in contrast to results obtained with P450 2E1 expressed in other heterologous systems, addition of rabbit liver cytochrome b 5 to preparations catalyzing p -nitrophenol or N -nitrosodimethylamine oxidation did not increase turnover, and, although activity could be shown with unsolubilized membranes, oxidation of these substrates in vivo could not be demonstrated. Nonetheless, the ability to coexpress P450 and reductase in E. coli so as to generate a functional monooxygenase system in vitro enhances the utility of this organism for the expression and characterization of cloned P450 isoforms.
Pulsed brachytherapy as a substitute for continuous low dose rate: an in vitro study with human carcinoma cells.

Abstract Purpose: Pulsed dose rate (PDR) brachytherapy as a substitute for continuous low dose rate (CLDR) has the potential to be a useful option in brachytherapy. However, the frequency and duration of pulses that will produce results practically equivalent to CLDR is still an open and important question. This study was designed to compare the survival of human tumor cells, cultured in vitro , and exposed to continuous or pulsed irradiation where the pulse frequency was varied. Methods and Materials: Three different human carcinoma cells, derived from cervical and breast cancers, were exposed to CLDR gamma rays, or to pulsed irradiations with the same overall dose rate. Pulsed regimens used were 3.8 min every hour, 7.6 min every 2 h, 11.4 min every 3 h, 15.2 min every 4 h, 22.8 min every 6 h, and 45.6 min every 12 h. For each comparison between CLDR and PDR, the overall dose and the overall time were the same. Experimental design was such that significant differences in biological effectiveness, if present, would be detected. Results: For the cell lines investigated, hourly pulses resulted in cell survival indistinguishable from CLDR. However, as the pulse interval was increased, cell survival progressively decreased compared with CLDR, and the pulsed regimes were no longer equivalent to continuous low dose rate. Conclusion: This study provides some evidence to support the suggestion that a 10-min pulse, repeated every 1 to 2 h, would be functionally equivalent to a continuous low dose rate irradiation, at least in terms of early responding endpoints. Longer intervals between pulses might result in loss of equivalence in some cases.
Conversion of diatoms to clays during early diagenesis in tropical, continental shelf muds

In coastal muds downdrift from the Amazon River mouth, marine diatom frustules are rapidly converted to various forms of authigenic aluminosilicate phases during burial. The dominant neoformed crystalline phases have a composition similar to K-smectite, yield electron diffraction patterns characteristic of clay minerals, and exhibit a range of crystal sizes and morphologies, including euhedral pseudohexagonal crystals and anhedral flakes replacing biogenic silica. A poorly crystalline or microcrystalline K-rich and Fe-rich aluminosilicate material also replaces the siliceous frustules. The conversion process is not always complete, leaving relics of the original frustule in the resulting authigenic aluminosilicate phases. Laboratory incubation experiments with cultured diatoms demonstrate that the conversion process occurs in 20–23 months. The conversion of biogenic silica to authigenic clays occurs throughout the Amazon deltaic deposits and presumably takes place in other comparable depositional settings. Biogenic silica alteration provides proof for a direct link between the biogeochemical cycle of silica in nearshore environments and the neoformation of cation-rich aluminosilicate phases, and it may prove to be important for oceanic geochemical cycles as a sink for Si, K, and other elements incorporated in the authigenic aluminosilicates. Rapid formation of authigenic K-smectite may also represent a reaction stage leading to eventual formation of illitic clays during later diagenesis.
Changing temperatures influence suitability for modeled mountain pine beetle (Dendroctonus ponderosae) outbreaks in the western United States

[1] Insect outbreaks are significant disturbances in forests of the western United States, with infestation comparable in area to fire. Outbreaks of mountain pine beetle (Dendroctonus ponderosae Hopkins) require life cycles of one year with synchronous emergence of adults from host trees at an appropriate time of year (termed "adaptive seasonality") to overwhelm tree defenses. The annual course of temperature plays a major role in governing life stage development and imposing synchrony on mountain pine beetle populations. Here we apply a process-based model of adaptive seasonality across the western United States using gridded daily temperatures from the Vegetation/Ecosystem Modeling and Analysis Project (VEMAP) over the period 1895-2100. Historical locations of modeled adaptive seasonality overlay much of the distribution of lodgepole pine (Pinus contorta Douglas), a favored host, indicating that suitable temperatures for outbreak occurred in areas of host availability. A range of suitable temperatures, both in the mean and over an annual cycle, resulted in adaptive seasonality. Adaptive seasonality typically occurred when mean annual temperatures were 3°-6°C, but also included locations where mean temperatures were as low as 1°C or as high as 11°C, primarily as a result of variability in winter temperatures. For most locations, years of adaptive seasonality were uncommon during 1895-1993. We analyzed historical temperatures and adaptive seasonality in more detail in three northern forest ecoprovinces. In the Northern and Middle Rockies, areas of adaptive seasonality decreased at lower elevations and increased at higher elevations during warmer periods, resulting in a movement upward in elevation of adaptive seasonality. In contrast, the Cascade Mountains exhibited overall declines in adaptive seasonality with higher temperatures regardless of elevation. Projections of future warming (5°C in the western United States) resulted in substantial reductions in the overall area of adaptive seasonality. At the highest elevations, predicted warmer conditions will result in increases in the area of adaptive seasonality. Our findings suggest that future climate change may alter forest ecosystems indirectly through alteration of these important disturbances.
Health care services for HIV-positive substance abusers in a rural setting: an innovative program.

ABSTRACT Agencies that deliver health care services to HIV-positive substance abusers living in rural areas of the United States face particular treatment challenges and barriers to care. Rural consumers of HIV/AIDS health care–related services identified long travel distances to medical facilities, lack of transportation, lack of availability of HIV-specific medical personnel, a shortage of mental health and substance abuse services, community stigma, and financial problems as leading barriers to access to care. This article discusses barriers to care for rural HIV-positive substance abusers, and challenges for rural health care providers. In addition, it presents a case study of Health Services Center, a model program that has devised innovative practices in the delivery of health care services to HIV-positive substance abusers in rural northeastern Alabama.
Predictors of early quality-of-life improvement after laparoscopic gastric bypass surgery.

Abstract Background Quality of life is getting more attention in the medical literature. Treatment outcomes are now gauged by their effect on quality of life (QOL), along with their direct effect on diseases they are targeting. Similarly, in obesity, consensus has been reached on the importance of QOL as an independent outcome measure for obesity surgery along with weight loss and comorbidity. Therefore, the aim of this study was to assess the impact of patient demographics and comorbidities on short-term QOL improvement after laparoscopic gastric bypass (LGB) surgery. Methods The change in QOL after LGB was assessed in 171 patients (147 women, 24 men; mean age, 43.1 y) using the Short-Form-36 (SF-36) questionnaire. Multivariate logistic regression analysis was used to identify patients' demographics and comorbidities predictive of major QOL improvement. Results Body mass index decreased significantly at 3 months (48.5 ± 5.8 to 38.4 ± 5.4 kg/m 2 ; P P r = .29, P = .001; R = .22, P = .005; respectively), but the magnitude of QOL change did not correlate with the number of comorbidities ( P = .5). When the entire cohort of patients was dichotomized according to their magnitude of change in SF-36 scores, the univariate analysis showed that the group of patients with no improvement or minor improvement in their SF-36 was characterized by a higher percentage of male sex and a lower prevalence of diabetes. These 2 preoperative factors remained statistically significant in the multivariate analysis. Preoperative diagnosis of type 2 diabetes increased the likelihood of major improvement in QOL after LGB by 6.2 times, whereas being a woman increased this likelihood by 16.1 times. Conclusions Significant weight loss was achieved as early as 3 months after LGB, causing substantial improvement in QOL in more than 95% of patients. Women with type 2 diabetes have the highest odds to achieve a major QOL improvement after LGB and therefore they should represent the ideal target population for surgical weight loss programs.
Diurnal and Tidal Variability in the Photobiology of the Seagrass Halophila johnsonii in a Riverine Versus Marine Habitat

The threatened seagrass Halophila johnsonii grows intertidally to 3 m deep in river-influenced and marine-influenced habitats. In this study, environmental parameters and photosynthetic characteristics of H. johnsonii were measured hourly for populations from adjacent riverine and marine habitats under opposite tidal regimes (high tide at midday, low tide at midday). The two populations exhibited habitat-specific diurnal responses, which indicate long-term acclimatization to their different environments. During periods with similar bottom irradiances, effective photochemical efficiencies and chlorophyll concentrations were comparatively greater in the riverine population, indicative of low-light acclimation. In addition, ultraviolet pigment absorbance (340–345 nm) was generally greater in the riverine plants and it generally increased following ebb tides and decreasing salinity, suggesting a stress response. Multivariate analyses indicated that photosynthetic characteristics were most dissimilar when environmental conditions were most dissimilar, i.e., riverine plants when low tide occurred at midday compared to marine plants when high tide occurred at midday. Salinity, photosynthetically active radiation, and optical water quality (K 0PAR, S CDOM, and a 412) were most correlated with variability in photosynthetic characteristics. As there is no significant genetic variation among populations of H. johnsonii, the photosynthetic characteristics of the riverine and marine populations we examined reflect acclimation to their respective habitats through a highly phenoplastic physiology.
The Power of Jonckheere's Test

Abstract This paper discusses the power of Jonckheere's test under the ordered alternative hypothesis. It is shown that the power of the test is bounded significantly away from one under certain shift alternatives and sample sizes.
High initial frequency of TCR-transgenic CD8 T cells alters inflammation and pathogen clearance without affecting memory T cell function.

In adoptive transfer experiments, the initial frequency of naive TCR-transgenic T cells impacts CD8 T cell phenotype after acute infections. The exact reasons for the observed changes, however, are unclear and it is unknown whether alterations in phenotype translate into impaired memory T cell function as well. Here we perform in vivo comparisons of effector and memory CD8 T cells generated from high or low numbers of naive precursors. We show that high numbers of adoptively transferred T cells exhibit effector functions that alter systemic inflammation and pathogen abundance in the initial days after infection. While these altered environmental conditions resulted in profound changes in primary effector and memory CD8 T cell phenotype, memory T cells derived from both high and low numbers of naive precursors protected equally well against re-infection and generated secondary effector and memory T cells that were similar in numbers and phenotype. Our results confirm the necessity to use low numbers of naive precursors to mimic endogenous immune responses but show at the same time that memory CD8 T cell function in adoptive transfers is independent of input numbers.
Sampling With Synthesis: A New Approach for Releasing Public Use Census Microdata

Many statistical agencies disseminate samples of census microdata, that is, data on individual records, to the public. Before releasing the microdata, agencies typically alter identifying or sensitive values to protect data subjects’ confidentiality, for example by coarsening, perturbing, or swapping data. These standard disclosure limitation techniques distort relationships and distributional features in the original data, especially when applied with high intensity. Furthermore, it can be difficult for analysts of the masked public use data to adjust inferences for the effects of the disclosure limitation. Motivated by these shortcomings, we propose an approach to census microdata dissemination called sampling with synthesis. The basic idea is to replace the identifying or sensitive values in the census with multiple imputations, and release samples from these multiply-imputed populations. We demonstrate that sampling with synthesis can improve the quality of public use data relative to sampling followe...
Oral squamous cell carcinoma positive for p16/human papilloma virus in post allogeneic stem cell transplantation: 2 cases and review of the literature

Complications of allogeneic hematopoietic stem cell transplantation (allo-HSCT) includes the risk of secondary malignancies. This may be related to mechanisms including radiation and chemotherapy regimens, chronic graft-versus-host disease, inflammation, and prolonged imunosuppression. Oral squamous cell carcinoma (OSCC) is a complication associated with chronic graft-versus-host disease after allo-HSCT. Although human papillomavirus (HPV) is known to be associated with OSCC, the role of HPV in development of OSCC in post-HSCT patients has not been studied. We identified 2 cases of OSCC in allo-HSCT recipients. Both biopsy specimens tested positive for p16(INK4A), a surrogate marker for HPV. We propose that the association of OSCC and HPV in patients after allo-HSCT may not be incidental. Clinical implications of these cases may imply the need for a HPV screening, early intervention, and consideration of anti-HPV vaccination in this population. The effectiveness of such interventions could be validated in a prospective clinical study.
The effect of pH and natural microbial phosphatase activity on the speciation of uranium in subsurface soils

Abstract The biomineralization of U(VI) phosphate as a result of microbial phosphatase activity is a promising new bioremediation approach to immobilize uranium in both aerobic and anaerobic conditions. In contrast to reduced uranium minerals such as uraninite, uranium phosphate precipitates are not susceptible to changes in oxidation conditions and may represent a long-term sink for uranium in contaminated environments. So far, the biomineralization of U(VI) phosphate has been demonstrated with pure cultures only. In this study, two uranium contaminated soils from the Department of Energy Oak Ridge Field Research Center (ORFRC) were amended with glycerol phosphate as model organophosphate source in small flow-through columns under aerobic conditions to determine whether natural phosphatase activity of indigenous soil bacteria was able to promote the precipitation of uranium(VI) at pH 5.5 and 7.0. High concentrations of phosphate (1–3 mM) were detected in the effluent of these columns at both pH compared to control columns amended with U(VI) only, suggesting that phosphatase-liberating microorganisms were readily stimulated by the organophosphate substrate. Net phosphate production rates were higher in the low pH soil (0.73 ± 0.17 mM d−1) compared to the circumneutral pH soil (0.43 ± 0.31 mM d−1), suggesting that non-specific acid phosphatase activity was expressed constitutively in these soils. A sequential solid-phase extraction scheme and X-ray absorption spectroscopy measurements were combined to demonstrate that U(VI) was primarily precipitated as uranyl phosphate minerals at low pH, whereas it was mainly adsorbed to iron oxides and partially precipitated as uranyl phosphate at circumneutral pH. These findings suggest that, in the presence of organophosphates, microbial phosphatase activity can contribute to uranium immobilization in both low and circumneutral pH soils through the formation of stable uranyl phosphate minerals.
Intracellular location and number of replicating parental DNA molecules of bacteriophages lambda and phi-X174.

Abstract The parental DNA of bacteriophages λ and φX174 becomes associated with a host cell component after infection. This host cell component has the properties of a lipoprotein and is probably the cell membrane. There is a minimum of 60 to 80 sites on the membrane for attachment of parental λ and φX DNA, but the sites are not homologous for the two phages. Replication of parental λ and φX DNA occurs on the membrane, but, at high multiplicity, parental DNA of each is released into the cytoplasm. The semiconservative replication of φX parental replicative form DNA is limited to one or a few genomes per cell, whereas more than 60 parental λ genomes per cell can be replicated during the infective process.
The asymptotics of the least trimmed absolute deviations (LTAD) estimator

Abstract The method of least trimmed absolute deviations (LTAD) is formally treated. This method, like the LMS and LTS methods of Rousseeuw (1987), uses a criterion function that is calculated over half-samples. A population analogue is defined and its properties are discussed. The asymptotic properties of the LTAD estimator are derived. It is shown to be consistent and asymtotically normal. It is also shown to be, with asymptotic certainty, the midpoint of the interval spanned by the selected half-sample. Further, it is shown how to construct a distribution-free tolerance interval for predicting the next observation. Finally, comparisons of the asymtotic variances for the LTS and LTAD are made and recommendations are given.
Predicting the Hermeticity of Compression Seals in Microchannel Hemodialysers

Most end stage renal disease patients receive kidney hemodialysis three to four times per week at central medical facilities. At-home kidney dialysis increases the convenience and frequency of hemodialysis treatments which has been shown to produce better patient outcomes. One limiting factor in realizing home hemodialysis treatments is the cost of the hemodialyser. Microchannel hemodialysers produced using compression sealing techniques show promise for reducing the size and cost of hemodialysers. Challenges include the use of a 25 μm thick elastoviscoplastic mass transfer membrane for gasketing. This paper provides a framework for predicting the hermeticity of these compression seals. The mechanical properties of a Gambro AN69ST membrane are determined and used to establish limits on the dimensional tolerances of the polycarbonate laminae containing sealing boss used to seal the hemodialyser. The resulting methods are applied to the fabrication of a hemodialysis device showing constraints on the scaling of this method to larger device sizes. The resulting hemodialysis device is used to perform urea mass transfer experiments without leakage.Copyright © 2014 by ASME
The effect of aldosterone on the energetics of sodium transport in the frog skin

Abstract Uncertainty persists as to whether the stimulation of active sodium transport by aldosterone is attributable to effects on permeability or energetic factors. This question has been examined with the aid of a thermodynamic formulation in which the rate of both active sodium transport JNa and O2 consumption Jr are assumed to be linear functions of the electrical potential difference Δψ and the affinity A (negative free energy) of metabolic reaction. Previous studies have indicated constancy of a characteristic affinity on perturbation of Δψ, suggesting the possibility of its evaluation. In studies of paired frog skins the admnistration of aldosterone led to a significant increase in the short-circuit current I0, a suggestive increase in the associated rate of O2 consumption Jro, and a significant increase in the ratio −I 0 { d J r / d (Δψ)} dJ r d(δψ) . If linearity obtains this ratio is equal to A. Depression of active sodium transport and the associated metabolism with amiloride, which depresses permeability, also results in an increase in the apparent affinity −I 0 { d J r / d (Δψ)} dJ r d(δψ) . The results indicate that aldosterone does not act simply by increasing the permeability or the number of transport units operating in parallel, but suggests that energetic factors are implicated as well.
Outcome of pediatric resuscitation

A one-year prospective study of 105 resuscitations in 74 children was done at Milwaukee Children's Hospital. Resuscitation outcome was correlated to location of arrest, level of monitoring at time of arrest, and type of arrest. Type of arrest was the only analyzed variable that influenced outcome. This study indicates that outcome for children requiring resuscitation for respiratory arrest without cardiac arrest is reasonably good (25% mortality). However, the outcome for children requiring resuscitation for cardiac or cardiorespiratory arrest is poor (87% to 89% mortality or severe morbidity). Children who suffered a respiratory arrest without cardiac arrest had a better outcome than did adults. However, children who had a cardiac or cardiopulmonary arrest had the same poor outcome as did adults.