cssi/SciSciGPT-SciSciNet huggingface dataset:
Using transplanted oyster (Crassostrea virginica) beds to improve water quality in small tidal creeks: a pilot study

Abstract The Eastern oyster, Crassostrea virginica , may improve water quality by filtering large quantities of particulate matter (both organic and inorganic) and nutrients from the overlying water column. Additionally, oyster reefs alter hydrodynamic conditions, further increasing the removal of particulate matter from the water column. This study examined the effects of small-scale oyster additions on sediment loading, chlorophyll a , nutrient concentrations, and flow in small tidal creeks. Two reefs were established in Hewletts Creek, New Hanover County, North Carolina. Total suspended solids (TSS), chlorophyll a , and ammonium were measured upstream and downstream of each created reef and in an adjacent control channel that lacked a reef. Data were collected monthly during ebb tides over a 10-month period between September 2000 and June 2001. In the first month after initial reef placement, mean TSS concentrations downstream of reef placement were slightly lower than those upstream of the reef. Although not statistically significant, TSS concentrations downstream of the reefs were less than upstream concentrations for five out of nine and five out of seven post-reef sampling months for the upland and the lower creek sites, respectively. Chlorophyll a concentrations were not significantly affected by initial reef placement (2×3 m), but were reduced substantially after reef enlargement (3×4 m) in one of the experimental creeks. Reef placement resulted in significant increases in ammonium concentrations downstream of the transplanted-reefs. In addition, deposition of feces and pseudofeces by the oysters resulted in accumulation of finer-grained materials in the treated channel relative to the control channels. Oyster filtration was most effective three hours following high tide, when the ratio of flow discharge to reef surface area was the highest. This work demonstrates that small oyster reefs established and maintained in some small tributary channels can reduce TSS and chlorophyll a concentrations and that the magnitude of the effect may vary over the course of the tidal cycle.
Numerical simulations of unsteady, viscous, transonic flow over isolated and cascaded airfoils using a deforming grid

A compressible, unsteady, full Navier-Stokes, finite difference code was developed for modeling transonic flow through two-dimensional, oscillating cascades. The procedure introduces a deforming grid technique to capture the motion of the airfoils. Results using a deforming grid are presented for both isolated and cascaded airfoils. The load histories and unsteady pressure distributions are predicted for the NASA 64A010 isolated airfoil and compared with existing experimental data. Results show that the deforming grid technique can be used to successfully predict the unsteady flow properties around an oscillating airfoil. The deforming grid technique was extended for modeling unsteady flow in a cascade. The use of a deforming grid simplifies the specification of boundary conditions. Unsteady flow solutions similar to the isolated airfoil predictions are found for a NACA 0012 cascade with zero interblade phase angle and zero stagger. Experimental data for these cases are not available for code validation, but computational results are presented to show sample predictions from the code. Applications of the code to typical turbomachinery flow conditions will be presented in future work.
Protein Inhibitor of Mitochondrial ATP Synthase: Relationship of Inhibitor Structure to pH-Dependent Regulation

In the absence of an electrochemical proton gradient, the F1 moiety of the mitochondrial ATP synthase catalyzes the hydrolysis of ATP. This reaction is inhibited by a natural protein inhibitor, in a process characterized by an increase in ATPase inhibition as pH is decreased from 8.0 to 6.0. In order to gain greater insight into the molecular and chemical events underlying this regulatory process, the relationships among pH, helicity of the inhibitor protein, and its capacity to inhibit F1-ATPase activity were examined. First, peptides corresponding to four regions of the 82-amino-acid inhibitor protein were chemically synthesized and assessed for both retention of secondary structure, and capacity to inhibit F1-ATPase activity. These studies showed that a region of only 24-amino-acid residues, from Phe 22 through Len 45, accounts for the inhibitory capacity of the inhibitor protein, and that retention of native helical structure in this region is not essential for inhibition. Second, three mutants (33P34, 39P40, and 43P44) of the intact inhibitor protein were prepared in which a proline residue was inserted within the inhibitory region to disrupt native helical structure. The secondary structures and inhibitory capacities of these mutants were analyzed as a function of pH. These studies revealed that, despite the initial loss of helical structure within the inhibitory region due to proline insertion, a further loss of helical structure is required to modulate inhibitory activity. These results suggest that a loss of helical structure outside the inhibitory region correlates with an increase in inhibitory capacity. Finally, two separate mutants (H48A and H55A) were prepared in which a conserved histidine residue in the wild-type inhibitor protein was replaced with an alanine. The secondary structures and inhibitory capacities of these mutants were also investigated as a function of pH. Results indicated that, although histidine residues do not directly affect the inhibitory capacity of the protein, they are important for maintaining the inhibitor protein in an inactive form at high pH. Furthermore, these results show that loss in helical structure, although correlated with an increase in inhibitory capacity, is not essential for this function. These novel experiments are consistent with a model in which the inhibitor protein is envisioned as consisting of two regions, an inhibitory region and a regulatory region. It is suggested that reduction of pH allows for the protonation of a histidine residue blocking the interaction between the two regions, thus activating the inhibitory response. The pH reduction also correlates with a partial unfolding of the protein that may either cause or result from the loss of interaction between the two helices. This unfolding may be necessary for further optimization of inhibitor function.
The criteria for successful captive propagation of endangered primates

There are several criteria used for evaluating the success of captive breeding programs for endangered primates. The most stringent criterion is that animals should be maintained in captivity so that they can retain the ability to survive if they are reintroduced to the wild. Implementing the criterion means designing environments that provide analogues to the natural environment. The role of social reinforcement and observational learning in attaining behavioral competence is quite important. Thus, animals need complex social and physical environments in order to acquire the sensorimotor, social interaction, and parental care skills they need to be self-sustaining. In addition, environments should be managed to provide animals with opportunities to learn skills, foraging and predator detection skills. Research efforts must be a part of all captive breeding programs not only to improve the captive breeding environment but also to learn as much as possible about an endangered species before it becomes extinct. A variety of noninvasive research techniques are described that allow the gathering of high quality research data without compromising the breeding success of the endangered animals.
Reduction of avoidant behavior through the semantic conditioning of a self-related target stimulus

It is argued that the therapy technique of semantic desensitization is but one of several conceptually related semantic conditioning techniques that can produce therapeutic behavior change. In all of these techniques a target stimulus is paired with a series of words that differ in dictionary meaning but share a common connotation as indicated by semantic differential ratings. This study extended prior work by choosing the stimulus “myself” as a target of conditioning and by pairing it with a group of words loading at the powerful end of the Potency dimension of meaning. Subjects were 20 snake phobics who could not touch a harmless snake even when offered money. The semantic conditioning group improved substantially more on the behavioral avoidance test than did a placebo control group. Results were interpreted as indicating that the semantic conditioning techniques can be adapted to use the client's perception of himself as a target of conditioning in order to produce therapeutic change.
Ultrastructural defects in the apical neural folds in mutant embryos with spina bifida.

Ultrastructural pathology in the apical neural folds was analyzed by means of tannic acid (TA) and ruthenium red (RR) cytochemistry in abnormal (vl/vl) mutant mouse embryos ranging in age from 17–35 somites. At lumbosacral levels of the spinal cord where closure fails to occur, as well as at more cranial levels where closure occurs but results in dorsal midline abnormalities, normal deposition of TA-positive and RR-positive material occurred in the space that develops between the overlying surface ectoderm (SE) and neuroepithelium (NE). However, in lumbosacral regions, pleomorphic excrescences projected abnormally from the apices of the transitional zone cells between SE and NE cells of the open neural folds. These abnormal projections consisted of enlarged cytoplasmic blebs, as well as entire cells. The cells were not necrotic nor did they show evidence of incipient degeneration. However, it is possible that they represent aberrant putative neural crest cells, as indicated by their location in the transitional zone and by the filopodia and lamellipodia projecting from their luminal surfaces.
Absorbance Characterization of Microsphere-Based Ion-Selective Optodes

Ionophore-based microsphere sensors are characterized here in transmission mode. These sensors contain a lipophilic ionophore for the analyte cation, a chromoionophore for recognizing H+, and a lipophilic cation-exchanger. They function on the basis of an ion-exchange equilibration step where an increased concentration of analyte ion leads to increased level of extraction into the bulk of the microsphere, expelling protons in return and deprotonating the chromoionophore. Since the path length is variable across the microsphere, such bead-based sensors are normally characterized in fluorescence mode. In this paper, the response of the sensing microspheres is calculated from the ratio of transmitted light intensities at the absorbance peak maxima of the protonated and unprotonated forms of the chromoionophore. At a fixed position of the particle, the resulting responses are found to be independent of light scattering, incident light intensity and the shape or size of the microsphere. The responses of potassium-selective microspheres obtained by this method agree quantitatively with corresponding fluorescence-based data.
Examining the Specificity of Src Homology 3 Domain–Ligand Interactions with Alkaline Phosphatase Fusion Proteins

Sixteen-amino-acid-long peptides, corresponding to the optimal ligand preferences of the Src homology 3 (SH3) domains of Abl, Cortactin, Crk, p53BP2, and Src, were fused to the N-terminus of Escherichia coli alkaline phosphatase (AP). These secreted fusion proteins have been used as one-step detection probes of peptide ligand-SH3 domain interactions on microtiter plates and membranes. The binding of both the class I and II SH3 ligand-AP fusion proteins to their targets is robust and specific in comparison to chemically synthesized biotinylated peptides, used either in monovalent or tetravalent formats. p53BP2 and Cortactin SH3 ligand-AP fusions have been used to screen a mouse embryo lambda cDNA expression library and resulted in the cloning of p53BP2 and several known proteins with SH3 domains similar to that of Cortactin, respectively. In addition, the approximately 60-amino-acid-long SH3 domains of Src and Abl were fused to AP and the resulting fusion proteins were found to bind specifically to their respective peptide ligands in microtiter plates and proteins containing proline-rich regions in screens of a lambda cDNA expression library. Thus, SH3 peptide ligand- and SH3 domain-AP fusion proteins are convenient and sensitive reagents for examining the specificity of SH3 domain-ligand interactions, identifying potentially interacting proteins, and establishing high-throughput screens of combinatorial chemical libraries.
Chronic nonprogressive headaches in children and adolescents

Chronic nonprogressive headaches are common in adolescents. The features of this syndrome are distinct from those of migraine. Chronic nonprogressive headaches have received less attention and study than migraine headaches. The prevalence of this syndrome is not clear. A structured psychological interview with the patient and the parents of the patient coupled with psychological testing of the patient will usually identify factors playing a role in the continuing headache. Counseling, biofeedback, and cognitive training, combined with judicious use of medication, will frequently lead to resolution of the headache.
Meningococcal pneumonia and empyema

A case of pneumonia and empyema caused by Neisseria meningitidis is described in which the diagnosis was initially missed. Meningococcal pneumonia and empyema are rare. It is important to recognize unusual manifestations of meningococcal infection promptly because of the risk of spread to contacts including health care personnel and other patients.
Ideas on the Margins: Professional Counseling and Ideological Insularity

Efforts to professionalize counseling practice have yielded extraordinary benefits to counselors. However, professionalization has also caused counselors to adopt strict definitions of their education, practices, and ethics. In order to combat the ideological insularity brought on by professionalization, several marginalized ideas are considered. The implications of these ideas and ways to overcome ideological insularity are discussed.
Utility of computed tomographic renal angiogram in the management of childhood hypertension

The purpose of this study was to evaluate the utility of computed tomography (CT) renal angiogram (CTRA) in the management of childhood hypertension. This is a retrospective study of 24 children with clinical suspicion of renovascular disease who underwent CTRA examinations. CTRA demonstrated surgically correctable etiology of hypertension in 38% of the patients [5 with renal artery stenosis (RAS) and 4 with renal pathology]. In 5 patients, CTRA findings of RAS were confirmed by catheter angiogram. CTRA missed RAS in 1 patient in whom catheter angiogram showed beaded narrowing of the renal artery. All 6 patients with RAS had resolution of hypertension immediately after angioplasty or surgery. One patient with diffuse renal artery stenosis had an ipsilateral multicystic dysplastic kidney. In this patient hypertension resolved spontaneously as the dysplastic kidney shrunk in size. Seven patients had a renal etiology for hypertension. In 3 of these patients hypertension resolved after nephrectomy. Malignant hypertension in the 4th patient with reflux nephropathy was controlled medically after she underwent bilateral ureteral reimplantation. The remaining 3 patients with renal etiology were managed medically. We found that the etiology was central for hypertension in 4 patients with brain abnormalities, obesity in 1 overweight patient, essential hypertension in 4 patients, and thoracic aorta coarctation in 1 patient. Our study showed that in all except 1 instance CTRA could diagnose a surgically correctable cause for hypertension. CTRA provided useful information for the management of pediatric hypertension in all our patients.
Rutherford backscattering study of high temperature oxidation of melt- spun glassy fe- 22.5ai- 10zr

We have applied Rutherford backscattering spectroscopy to investigate the high temperature oxidation of melt-spun glassy Fe-22.5Al-10Zr. Oxide thicknesses and elemental depth distributions were measured at five times during oxidation at 500 °C and on both surfaces of the melt-spun ribbon. Oxidation kinetics were found to be inconsistent with oxidation by diffusion through a uniform oxide layer. The glassy metal oxidized slower on the rapidly cooled side of the ribbon. This was found to be associated with compositional differences that were present in the as-spun ribbons. The oxide that formed was composed of a thin iron-rich outer oxide beneath which was an aluminum-rich oxide that thickened with time.
Muir's identity—a supersymmetric approach

Abstract We give the extension of an identity of Muir to supersymmetric letterplace algebras, as well as a proof of both the classical and the supersymmetric case.
The rights of research assistants and the rhetoric of political suppression: Morton Grodzins and the University of California Japanese-American Evacuation and Resettlement Study.

This case study of an inter-university controversy over the publication of research from an interdisciplinary social science project on the forced migration and long-term internment of West Coast Japanese-Americans during World War II shows some of the difficulties of maintaining ownership of research materials. In this particular instance the junior employee was able to override his seniors' demand for control of the dissemination of research results by playing on the concerns about even appearing to suppress work for political reasons. The paper discusses conflicting norms of science and rhetorics of justification ranging from proprietary self-interest through "good science" to "the national interest" and onto "the needs of a free society."
Exchange in low-energy e-CO 2 collisions

The validity of three approximate treatments of the exchange interaction in low-energy $e\ensuremath{-}{\mathrm{CO}}_{2}$ scattering is assessed by comparing approximate and exact static-exchange eigenphase sums in the resonant ${\ensuremath{\Pi}}_{u}$ symmetry and the nonresonant ${\ensuremath{\Sigma}}_{g}$ and ${\ensuremath{\Sigma}}_{u}$ symmetries. Of the approximations studied\char22{}orthogonalized static, free-electron-gas model potential, and orthogonalized model potential\char22{}the latter has yielded results in best agreement with those of the exact treatment of exchange. Newly calculated static-exchange-polarization cross sections for energies from 0.1 to 2.0 eV are presented.
Fatigue damage in a unidirectional SiC/Al composite due to push-pull and zero-pull loading

Abstract Axial fatigue behaviour due to fully reversible and zero-tension cyclic loads on specimens cut from a 5 mm thick panel of a unidirectional SiC/A1 composite has been investigated at room temperature. The panel contained 40 vol.% SiC fibres (SCS-2), sandwiched between 32 layers of A1 6061 foils, which were bonded together by hot-pressing. The loading was always parallel to the fibres. Steady hysteresis loops were observed in the stress-strain plot after about 3 cycles of loading. A plot of S/N curves showed that at load ratio R = 0 the fatigue strength of the composite was about 3 times higher than that of the monolithic matrix metal. At R = −1, however, the fatigue strength of the composite was even lower than that of the matrix metal. At both R = 0 and R = −1, the composite suffered large modulus losses (about 15%) at cycles well before the final failure. At R = 0 the modulus loss involved fibre breakage and matrix cracks, which were transverse as well as parallel to the loading direction, while at R = −1 it involved delamination cracks and barrelling of outer layers. Fractography after the final failure at R = 0 showed secondary cracks and fibre pull-out.
Kinship Terminology and the American Kinship System

THE American kinship system is marked by bilateral descent, and the nuclear family and the kindred are the basic kin groups. Marriage is monogamous, residence neolocal, and inheritance by testamentary disposition. Succession is absent; a man gets no political or other office simply through kinship ties. The range of kinship is narrow, and kinship tends to be sharply divorced from other institutions such as the occupational system, the effect being to make kinship appear small beside such complex and ramifying institutions as economics and technology. The American kinship system appears to be "pushed to the wall" by other institutions, and much of its coloring derives from this.
School Nurse Case Management for Children With Chronic Illness: Health, Academic, and Quality of Life Outcomes:

More children with chronic illnesses are attending school, and some of them struggle academically because of issues related to their health. School-based case management has been suggested as one strategy to improve the academic success of these children. This study tracked the academic, health, and quality of life outcomes for 114 children with asthma, diabetes, severe allergies, seizures, or sickle-cell anemia in 5 different school districts who were provided case management by school nurses. The children ranged in age from 5 to 19 years. At the end of the school year, children experienced an improvement in quality of life and gained skills and knowledge to manage their illness more effectively. Classroom participation, grades, and participation in extracurricular activities also increased for many children. The study provides evidence of the positive impact school nurses have on children with chronic illness and suggests ways they can measure the outcomes of their interventions.
Peptide growth factors

Abstract Interaction of growth factors with target cells involves the rapid internalization of ligand: receptor complexes. The receptor possesses intrinsic tyrosyl protein kinase activity which may, in part, mediate the biological activities of the peptide factors. Sequence data indicates that growth factors and/or their receptors are related to oncogene products some of which also possess tyrosyl kinase activity.
Detection of formate, rather than carbon monoxide, as the stoichiometric coproduct in conversion of fatty aldehydes to alkanes by a cyanobacterial aldehyde decarbonylase

The second of two reactions in a recently discovered pathway through which saturated fatty acids are converted to alkanes (and unsaturated fatty acids to alkenes) in cyanobacteria entails scission of the C1−C2 bond of a fatty aldehyde intermediate by the enzyme aldehyde decarbonylase (AD), a ferritin-like protein with a dinuclear metal cofactor of unknown composition. We tested for and failed to detect carbon monoxide (CO), the proposed C1-derived coproduct of alkane synthesis, following the in vitro conversion of octadecanal (R−CHO, where R = n-C17H35) to heptadecane (R−H) by the Nostoc punctiforme AD isolated following its overproduction in Escherichia coli. Instead, we identified formate (HCO2−) as the stoichiometric coproduct of the reaction. Results of isotope-tracer experiments indicate that the aldehyde hydrogen is retained in the HCO2− and the hydrogen in the nascent methyl group of the alkane originates, at least in part, from solvent. With these characteristics, the reaction appears to be formal...
International field experiences: The impact of class, gender and race on the perceptions and experiences of preservice teachers

Abstract We explore ways class, gender and race complicate perceptions and experiences of preservice teachers during an international field experience in Honduras. Data were collected over 5 years through observations, group discussions, course assignments, and on-site focus group interviews and post-trip individual interviews. An inductive approach combined with cross-comparative analysis reveal diverse ways class, gender and race shaped and re-shaped preservice teachers' perceptions of self, peers, and host community members. We conclude with a call for international cross-cultural experiences that encourage preservice teachers to critically examine their perspectives, positions in the host community, and learning during study abroad.
Role of uniformity and geometry in IMARAD-type gamma-ray spectrometers

We show that the finite size of pixels employed in arrays of the type produced by IMARAD Imaging Systems Ltd. determines the performance of these devices in terms of energy resolution and efficiency. The geometrical considerations are similar to those discussed in the context of small pixels. Based on an understanding of this geometrical effect we show that the performance of the arrays may be optimized for particular device dimensions. In addition we also so that material grown by IMARAD Imaging Systems Ltd. by the modified horizontal Bridgman method is quite uniform and indeed well suited for the fabrication of imaging systems.
Chromaticity of the lattice and beam stability in energy-recovery linacs

Energy recovery linacs (ERLs) are an emerging generation of accelerators that promises to revolutionize the fields of high-energy physics and photon sciences. These accelerators combine the advantages of linear accelerators with that of storage rings, and augur the delivery of electron beams of unprecedented power and quality. The use of superconducting radio-frequency cavities converts ERLs into nearly perfect ``perpetuum mobile'' accelerators, wherein the beam is accelerated to the desired energy, used, and then yields the energy back to the rf field. However, one potential weakness of these devices is transverse beam breakup instability that could severely limit the available beam current. In this paper, I propose a novel method of suppressing these dangerous effects via a natural phenomenon in the accelerators, viz., the chromaticity of the transverse motion.
The structure of Ca0,3Sr0,7Cl2 and Ca0.46Sr0.54Cl2 by the X-ray Rietveld refinement procedure

The structures of tetragonal Ca/sub 0.3/Sr/sub 0.7/Cl/sub 2/ and orthorhombic Ca/sub 0.46/Sr/sub 0.54/Cl/sub 2/ were determined from X-ray powder diffraction data by the Reitveld line-profile fitting procedure. The tetragonal phase crystallizes in space group P4/n (SrBr/sub 2/-type structure) with a = 10.898(2) and c = 6.744(2) A. The cations are distributed randomly over the 8g and 2c sites. For this structure R/sub f/ = 0.095 and R/sub wp/ = 0.168. The orthorhombic phase crystallizes in space group Pbca (SrI/sub 2/-type structure) with a = 13.421(5), b = 7.053(3), and c = 6.817(2) A. The R/sub f/ and R/sup wp/ factors are 0.081 and 0.164, respectively. Interatomic distances for both phases are reported and compared with those of related structures. The CaCl/sub 2/-SrCl/sub 2/ system is found to exhibit in the 0-25 mole% region the CaCl/sub 2/..sqrt.. and ..cap alpha..-PbO/sub 2/-type structures rather than the CaCl/sub 2/- and SrI/sub 2/-type structures reported previously.
Reductions in basal limb blood flow and vascular conductance with human ageing: role for augmented α-adrenergic vasoconstriction

1. Basal whole-limb blood flow and vascular conductance decrease with age in men. We determined whether these age-associated changes in limb haemodynamics are mediated by tonically augmented sympathetic alpha-adrenergic vasoconstriction. 2. Seven young (28 +/- 2 years; mean +/- S.E.M.) and eight older (64 +/- 2 years) healthy, normotensive adult men were studied. Baseline femoral artery blood flow (Doppler ultrasound) and calculated vascular conductance were 29 and 31 % lower, respectively, and vascular resistance was 53 % higher in the older men (all P < 0.001). 3. Local (intra-femoral artery) alpha-adrenergic receptor blockade with phentolamine evoked greater increases in femoral blood flow (105 +/- 11 vs. 60 +/- 6 %) and vascular conductance (125 +/- 13 vs. 66 +/- 7 %), and reductions in vascular resistance (55 +/- 2 vs. 39 +/- 3 %) in the experimental limb of the older compared with the young men (all P < 0.001). As a result, alpha-adrenergic receptor blockade eliminated the significance of the age-associated differences in absolute levels of femoral blood flow (500 +/- 51 vs. 551 +/- 35 ml min(-1)), vascular conductance (6.02 +/- 0.73 vs. 6.33 +/- 0.26 U), and vascular resistance (0.17 +/- 0.03 vs. 0.16 +/- 0.01 U; P = 0.4-0.8, n.s.). Femoral haemodynamics in the control limb were unaffected by phentolamine administration in the contralateral (experimental) limb. Complete alpha-adrenergic receptor blockade was demonstrated by the absence of vasoconstriction in the experimental limb in response to the cold pressor test. Local propranolol was administered to control for any beta-adrenergic effects of phentolamine. Propranolol did not affect haemodynamics in the experimental or control limbs. 4. Our results indicate that the age-related reductions in basal limb blood flow and vascular conductance are mediated largely by chronically elevated sympathetic alpha-adrenergic vasoconstriction. This may have important physiological and pathophysiological implications for the ageing human.
Propellant injection for MPD thrusters

The propellant gas for a pulsed self-field MPD thruster must be supplied by a valve which will necessarily be separated from the thruster injectors by some ullage volume. A model and experimental data are presented showing the effect of the ullage volume on the propellant pulse shape, along with a discussion of the proper location for the propellant flow choke point(s). Prospective MPD pulse valves are surveyed and the performance of two solenoid valves, one with a pulse length less than 2 milliseconds, is included. Pulse shape data is presented for a thruster specially modified to reduce the ullage volume.
Longitudinal Patterns of Health System Retention Among Veterans with Schizophrenia or Bipolar Disorder

Inconsistent service use for schizophrenia and bipolar disorder is associated with poorer outcomes of care. We analyzed VHA National Psychosis Registry data for 164,150 veterans with these disorders to identify characteristics associated with 5-year patterns of survival and with retention in VHA care. Most cohort members (63%) survived the period with no break in VHA healthcare lasting over 12 months. Inconsistent utilization was associated with younger age, no service-connected disability, and less physical comorbidity, regardless of diagnosis. The influence of gender and ethnicity on attrition varied by diagnosis and gap-duration. Variation in attrition by gender and ethnicity warrants additional attention.
Sod Regrowth of St. Augustinegrass after Preemergence Herbicide Application

St. Augustinegrass [stenotaphrum secundatum (Walt.) Kuntze] sod production involves stolon regeneration from strips left from the previous harvest. Field studies were conducted to evaluate stolon regrowth and rooting following preemergence application of herbicides. Herbicides evaluated were atrazine [6-chloro-N-ethyl-N-(1-methylethyl)-1,3, 5-triazine-2,4diamine], dithiopyr [S,S-dimethyl 2-(difluoromethyl)4-(2-methylpropyl)-6-(trifluoromethyl)-3,5-pyridinecarbothioate], isoxaben [N-[3-(1-ethyl-1-methylpropyl)-5-isoxazolyl]-2,6-dimethoxybenzamide], metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], oxadiazon [3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3H}-one], pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine] and the combination of metolachlor plus atrazine. Acceptable 'Floratam' St. Augustinegrass color was noted following all treatments. Twelve to 24% of the stolons were unrooted 4 to 8 mo after application following treatment with 0.8 kg a.i. ha -1 dithiopyr. Five to 22% of the stolons were unrooted 8 mo after treatment with isoxaben at 1.1 kg ha -1 and pendimethalin at 2.2 kg ha -1 . Data collected after 8 mo showed stolon rooting to be similar to the untreated for all treatments. Turfgrass density was unaffected or slightly improved (25%) by herbicide treatment and was highest with oxadiazon, metolachlor, and metolachlor plus atrazine treatments. Neither turfgrass tensile strength nor root dry weight was reduced 14 mo after treatment with any of the herbicides evaluated. Although short-term (2 to 4 mo) negative effects followed dithiopyr, isoxaben, and pendimethalin treatments, long-term (≥8 mo) effects were transient.
The impact of social media conversations on consumer brand choices

This paper estimates the impact of social media conversations on consumer valuation of brand characteristics and demand for carbonated soft drinks (CSDs). We formulate a random coefficient, discrete choice model of consumer demand that includes social media conversations, and estimate it matching Nielsen sales data on carbonated soft drinks to social media conversations on Facebook, Twitter, and YouTube. Empirical results indicate that consumers’ conversations about brands and nutritional aspects of CSDs have a significant impact on their valuation of brand characteristics and ultimately on their choices of CSDs. These findings have important implications not only for firms using social media as a strategic tool for effective brand promotion and product design but also for public health policies aimed at reducing the consumption of sugary beverages and high-calorie foods.
Test–retest reliability of the rat N40 auditory evoked response: preliminary data

The N40 auditory evoked potential (EP) in rats has been used to develop an animal model for the study of sensory gating mechanisms. In an examination of the test-retest reliability of sensory gating indices, derived from the rat N40 EP, six rats were tested four times daily for 5 consecutive days. A paired-click paradigm (S1-S2) was used, and both the S2/S1 amplitude ratio and the S1-S2 amplitude difference measures of sensory gating capacity were calculated. Based on the means of four daily trials, reliability coefficients were as follows; r = 0.69 for S1, and r = 0.66 for S2 amplitudes. A reliability coefficient of 0.59 was found for the S1-S2 difference measure, and one of 0.47 for the S2/S1 ratio measure. These results suggest that the N40 can be used to study sensory gating, but caution has to be exercised in interpreting the data particularly in a repeated measures design.
A Genetic Algorithms Approach to Non-coding RNA Gene Searches

A genetic algorithm is proposed as an alternative to the traditional linear programming method for scoring covariance models in non-coding RNA (ncRNA) gene searches. The standard method is guaranteed to find the best score, but it is too slow for general use. The observation that most of the search space investigated by the linear programming method does not even remotely resemble any observed sequence in real sequence data can be used to motivate the use of genetic algorithms (GAs) to quickly reject regions of the search space. A search space with many local minima makes gradient decent an unattractive alternative. It is shown that a fixed-length representation for alignment of two sequences taken from the protein threading literature can be adapted for use with covariance models.
Optimal use of echocardiography in valvular heart disease evaluation

### Learning objectives Non-invasive imaging Patients with valvular heart disease (VHD) can be asymptomatic or present with a wide range of symptoms that may not correlate with the severity of valve dysfunction. Transthoracic echocardiography (TTE) and transoesophageal echocardiography (TEE) combining 2D, 3D and Doppler evaluation provide the clinician with valuable and complimentary information on heart valve structure, function and the physiological consequences of the valvular lesion. This non-invasive methodology provides crucial information during the initial clinical evaluation and at follow-up. Current guidelines recommend TTE as the initial diagnostic test to evaluate patients with known or suspected VHD.1 ,2 While 2D and M-mode TTE can assess valvular motion, morphology and pathology (when present), Doppler provides requisite information on valve haemodynamics, flow velocities across the valve, pressure gradients and calculation of valve area as well as haemodynamic data regarding pulmonary artery pressure and left ventricular (LV) filling parameters. In addition, colour flow Doppler and spectral Doppler provide critical information on valve regurgitation and stenosis severity. Exercise Doppler echocardiography is useful to assess the impact of exercise on valvular and ventricular function as well as the patient's functional capacity. The severity of a valvular lesion is determined using a multiparameter echo Doppler assessment. ### Aortic stenosis Echocardiography is the imaging modality of choice for diagnosing and estimating the severity of aortic stenosis (AS). The different echocardiographic methods used for evaluation of the aortic valve (AV) for the presence of stenosis are detailed in table 1. TTE is the most well-established imaging modality for evaluating and assessing the severity of AS.1 As shown in figure 1, valve anatomy should …
Clonal variation in above- and below-ground growth responses of Populus tremuloides Michaux: Influence of soil warming and nutrient availability

Trembling aspen (Populus tremuloides Michx.) is the most widely distributed tree species in North America making it important to terrestrial carbon and nutrient cycles. Due to anthropogenic climate change high latitude temperatures are expected to increase, making it necessary to assess the feedback between above- and below-ground carbon pools to increased temperature at sites of both high and low N-availability. We grew four clones of aspen at two levels of soil temperature and two levels of soil N-availability for 98 days and quantified photosynthesis, growth, biomass allocation, and root length production and mortality. High soil temperature increased rates of photosynthesis (65%), resulting in greater whole-plant growth (37%) through increases in roots, stems, and foliage; however these increases generally occurred only in soil of high N-availability. Root:shoot biomass allocation varied between clones but was unaffected by the soil temperature or N-availability treatments. Root length production and mortality increased at elevated soil temperature, but this response was modified by soil N-availability. At high soil temperature, soil N-availability had little effect on root dynamics, while at low soil temperature, high soil N-availability increased both the production and mortality (turnover) of roots. We conclude that trembling aspen has the potential for substantially greater growth and root turnover under conditions of warmer soil at sites of both high and low N-availability, but that allometric patterns of growth are under strong genetic, rather than environmental control.
Distributed function computation in networks: A joint delay-energy perspective

This paper considers the following network computation problem: n nodes are placed on a √n×√n grid, each node is connected to every other node within distance r(n) from itself, and is given an arbitrary input bit. Nodes communicate with each other so that finally a designated sink node can compute a target function f of the input bits. We focus on computing the identity function and the class of symmetric functions under two different communication models. We first consider a noiseless model where links are independent and noise-free, suitable for modeling wired networks. Next, we study a noisy broadcast model in which when a node transmits a bit, each of its neighbors receives a noisy copy of the bit. This is a simple model for wireless communications, originally proposed by El Gamal (1987). We use the protocol model for interference and nodes which do not share neighbors are allowed to transmit simultaneously. For every connection radius r(n), we present lower bounds on the minimum number of transmissions and the minimum number of time slots required to compute f. We then describe efficient protocols which can match both these lower bounds up to a constant factor.
Limit cycle bounds for floating point implementations of second-order recursive digital filters

It is shown that floating point realizations of linearly stable systems can exhibit four fundamental types of free responses. Sufficient conditions for the existence or nonexistence of some of these periodic response types in a given system are presented. Explicit closed form conditions on the mantissa length to guarantee certain limit cycle bounds are provided. The effect of various floating point arithmetic reformatting schemes on the convergence of recursive difference equations is also addressed. Truncation and rounding quantization schemes as well as double- and single-length product mantissa schemes are analyzed and compared. Although the method introduced is applicable to any digital filter realization implemented in floating point format, the analysis focuses on the zero-input behavior of second-order direct-form digital filters. >
Dynamics of deep‐bed filtration. Part II: Experiment

Resultats experimentaux obtenus avec des lits granulaires dont les particules ont a peu pres la meme dimension, et avec des suspensions monodispersees
Feline dermatophytosis Steps for investigation of a suspected shelter outbreak

Practical relevance:Dermatophytosis (ringworm) is the most important infectious and contagious skin disease of cats in shelters. Its importance relates to the fact that it can affect all cats, but ...
Civic Laughter Aristotle and the Political Virtue of Humor

While the loss of the second book of the Poetics has deprived us of Aristotle’s most extensive account of laughter and comedy, his discussion of eutrapelia (wittiness) as a virtue in his ethical wo...
The case for Agrarian capitalism: A response to albritton

Albritton finds Brenner's designation ‘agrarian capitalism’ inappropriate for early English agriculture, as the law of value and the commodification of labour are undeveloped. But Brenner is not theorising a ‘full‐blown’ capitalism. His theory traces a process of transition, by which new rules for social reproduction and a new capitalist logic unfolded gradually. Albritton's evidence, moreover, actually supports Brenner's thesis. Charges of class reductionism misconstrue Brenner's efforts to overcome the tendency to dichotomise society into political and economic spheres. Brenner's theory provides what the bourgeois paradigm does not: a logical explanation of how market dependency and capitalist classes emerged.
Host and bacterial factors contributing to the clearance of colonization by Streptococcus pneumoniae in a murine model

Nasopharyngeal colonization is the first step in the interaction between Streptococcus pneumoniae (the pneumococcus) and its human host. Factors that contribute to clearance of colonization are likely to affect the spread of the pneumococcus and the rate of pneumococcal disease in the population. To identify host and bacterial factors contributing to this process, we examined the time course of colonization using genetically modified mice and pneumococci. Severe combined immunodeficient mice remained persistently colonized (>6 weeks). Major histocompatibility complex II-deficient mice, but not microMT mice, were unable to clear colonization and showed a diminished T helper 1 response. Thus, CD4+ T cells, rather than the generation of specific antibody, appear to be required for effective Th1-mediated clearance. In addition, the microbial pattern recognition receptor toll-like receptor 2 (TLR2), but not TLR4, was necessary for efficient clearance of colonization. In contrast, no role of complement component 3, inducible nitric oxide synthetase, interleukin 12 (IL-12), or IL-4 could be demonstrated. Expression of the pneumococcal toxin pneumolysin enhanced acute localized inflammatory responses and promoted clearance of colonization in a TLR4-independent manner. We conclude that both innate and CD4+ T-cell-mediated immunity and proinflammatory bacterial factors, rather than a humoral adaptive immune response, are important for clearance of S. pneumoniae from the murine nasopharynx.
Studies on skeleton formation in reptiles. v. Patterns of ossification in the skeleton of Alligator mississippiensis DAUDIN (Reptilia, Crocodylia)

Abstract Patterns of ossification are described in the endo- and exoskeleton of Alligator mississippiensis . The occurrence of a dermo-supraoccipital is discussed in light of the independence of dermal and endochondral bone. The development of the bony secondary palate is discussed in light of Haeckelian recapitulation. The sequence of ossification in the limb skeleton is shown to differ from the sequence of chondrification of the cartilaginous precursors. Patterns of ossification in Alligator are compared to lepidosaurs in terms of sequence and timing. Important differences relate to ossification patterns in the limb skeleton: lepidosaurs show a dominance of digit III > IV > II > I > V, whereas Alligator shows a dominance of digits III > II > IV > I > V in the ossification process. Ontogenetic repatterning in the ossification of the axial skeleton is discussed as it bears on the serial homology of dorsal ribs, sacral ribs and caudal ribs (transverse processes).
Provably correct reactive control from natural language

This paper presents an integrated system for generating, troubleshooting, and executing correct-by-construction controllers for autonomous robots using natural language input, allowing non-expert users to command robots to perform high-level tasks. This system unites the power of formal methods with the accessibility of natural language, providing controllers for implementable high-level task specifications, easy-to-understand feedback on those that cannot be achieved, and natural language explanation of the reason for the robot's actions during execution. The natural language system uses domain-general components that can easily be adapted to cover the vocabulary of new applications. Generation of a linear temporal logic specification from the user's natural language input uses a novel data structure that allows for subsequent mapping of logical propositions back to natural language, enabling natural language feedback about problems with the specification that are only identifiable in the logical form. We demonstrate the robustness of the natural language understanding system through a user study where participants interacted with a simulated robot in a search and rescue scenario. Automated analysis and user feedback on unimplementable specifications is demonstrated using an example involving a robot assistant in a hospital.
A value theory of meta-learning algorithms

We use game theory to analyze meta-learning algorithms. The objective of meta-learning is to determine which algorithm to apply on a given task. This is an instance of a more general problem that consists of allocating knowledge consumers to learning producers. Solving this general problem in the field of meta-learning yields solutions for related fields such as information retrieval and recommender systems.
Resource Management Schemes for Multiple Traffic in Integrated Heterogeneous Wireless and Mobile Networks

In order to provide more comprehensive services, a concept of integrated heterogeneous wireless and mobile network (IHWMN) is introduced by combing different types of wireless and mobile networks (WMNs). However, it imposes great challenges such as resource management schemes to support multiple traffic in IHWMNs. In this paper, we propose two resource management schemes for IHWMNs. The first scheme is called traffic-based resource management scheme (TRMS) which allocates the resource based on traffic type, call type, bandwidth availability, and bandwidth provision. In the second scheme which is called Q-learning-based resource management scheme (QRMS), the resource management scheme is formulated as a Markov decision process (MDP) and Q-learning approach is applied to conduct the resource allocation. The system performance of both proposed schemes are evaluated and compared by using extensive simulations.