cssi/SciSciGPT-SciSciNet huggingface dataset:
Reliability and Validity of Play‐based Observations: relationship between the PLAY behaviour observation system and standardised measures of cognitive and social skills

Abstract Little, if any, examination of the reliability and validity of play‐based assessment exists in the current literature. Thus, the present study specifically examined the relationship between scores obtained on a classroom‐based play observation system and standardised measures of cognitive and social competence with preschool children. High reliability between observers was established for the play‐based assessment measure. In addition, concurrent validity was assessed by comparing scores on the PLA Y assessment measure with scores the children obtained on the Battelle Developmental Inventory (BDI) and Social Skills Rating Scale (SSRS‐T). Significant positive correlations in the predicted directions were obtained: Children rated as more cognitively and socially competent were found to engage in higher levels of play behaviours (e.g. associative‐constructive and co‐operative‐dramatic), while children identified as less cognitively and socially competent engaged in lower levels of play behaviours (e...
David T. Gibson: from biodegradation to biocatalysis.

Some bacteria have the remarkable ability to grow on aromatic hydrocarbons such as benzene, toluene, and naphthalene. This is remarkable because the resonance energy of benzanoid rings renders these compounds extraordinarily stable to biodegradation. It turns out bacterial dioxygenases can relieve ring resonance by a unique reaction involving molecular oxygen as a substrate. No person contributed more to our knowledge of bacterial dioxygenases than David T. Gibson, who died on July 24, 2014, of unknown causes, likely related to paralysis that he suffered in 1983 from an unidentified illness. He was 76 years old.
Lysosomal behavior during lateral motor column neurogenesis

Abstract Modulations in the total and free activities of acid phosphatase, acid protease, aryl sulfatase, and β-glucuronidase reveal that maximum lysosomal activity accompanies histogenetic cell death within the lateral motor column (LMC) of Rana pipiens larvae. LMC neurogenesis is separable into three distinct periods. In the first, hydrolytic activity remains low through the initial half of the period only to exhibit an exponential rise in the latter half. This increase in acid hydrolase activity continues well into the period of histogenetic cell death (Period 2). At this juncture, lysosomal activity (total and free) reaches a maximum. Subsequently, hydrolytic activity declines with the cessation of neuronal death (Period 3). Activation experiments indicate that lysosomal granules isolated during the cell death period are extremely sensitive to a variety of procedures which disrupt membranes, whereas preparations from younger or older larvae are more stable. Alterations in lysosomal properties are discussed in terms of our present knowledge on lysosomal packaging, activation, and heterogeneity during the course of neural maturation.
Color-based hybrid reconstruction for endoscopy

Three-dimensional (3D) reconstruction of images acquired during endoscopy presents an enormous opportunity for computer vision, however reconstructing geometry from such images is challenging due to lack of features. Shape From Shading (SFS) is an approach to obtain the shape of an object from a single image, but most current methods that are applicable to endoscopy are susceptible to errors caused by surfaces with differing reflectance characteristics. Another weakness of SFS is that while it has high frequency detail information, its shape is inaccurate in the low frequency sense, which makes it difficult to compare to ground truth. Multiview reconstruction (MR), on the other hand, yields reliable shape but lacks details. In this paper, we propose a novel method to perform SFS using a color projection that minimizes intensity variance caused by differing surface characteristics. We then combine the resulting reconstruction with a multiview reconstruction obtained from bundle adjustment, and combine the two reconstructions using an approach inspired by Laplacian surface editing to get a reconstruction that is accurate both in details and overall shape. We compare our results to ground truth to show improvement over existing approaches.
Efficient construction of diketopiperazine macroarrays through a cyclative-cleavage strategy and their evaluation as luminescence inhibitors in the bacterial symbiont Vibrio fischeri.

Diketopiperazines (DKPs) are a well-known class of heterocycles that have emerged as promising biologically active scaffolds. Solid-phase organic synthesis has become an important tool in the combinatorial exploration of these privileged structures, expediting the synthesis and, often, the discovery of active compounds. We recently identified several DKPs that are capable of inhibiting the luminescence response of the bacterial symbiont Vibrio fischeri, and we sought to further test the scope of this biological activity. Herein, we report the synthesis of DKP macroarrays using a SPOT-synthesis approach based on an Ugi/DeBoc/Cyclize strategy. Neither a spacer nor a linker was required for macroarray construction on cellulose support, and the cyclative cleavage produced high purity DKPs in good yields. Using this protocol, we prepared a library of 400 DKPs on cellulose support and evaluated its members as luminescence inhibitors in V. fischeri. We found six DKPs capable of inhibiting luminescence by at leas...
Field evidence that shrimp predation regulates meiofauna.

The grass shrimp Palaemonetes pugio, a suspected predator/disturber on meiofauna, and other large natant forms (>2 mm) were selectively excluded from microecosystem tanks for nine months during which time replicability between the tanks was established. Subsequently, shrimp were reintroduced into one of the four tanks via an aquarium and the meiofauna populations monitored in the “shrimp” and control tanks. In the presence of the predator/disturber, total meiofauna, nematode, oligochaete, and polychaete densities were significantly lower than in control tanks. In the presence of the predator/disturber, total meiofauna, nematode, oligochaete, and polychaete densities were significantly lower than in control tanks. Shrimp predation/disturbance significantly reduced meiofauna abundance in this salt marsh habitat but it did not alter the species diversity of the dominant taxon. The meiobenthos displayed characteristics common to other biologically regulated assemblages and our data provide the first field evidence of macrofaunal control of meiofauna community structure.
Cyanide ion-selective electrode measurements in the presence of copper

The response of a cyanide ion-selective electrode (ISE) in the presence of copper has been investigated. The interferences of metal ions, like copper, on the response of the cyanide ISE prevents its use for routine direct analysis of metal cyanide containing waste water. In this work an improved understanding of the chemistry at the electrode, and the effects of different cyanide and copper concentrations and matrix pH values on the electrode response, has been developed. Based on this insight, a semi-empirical approach is described to allow calibration of the ISE enabling the estimation of total cyanide. While not as robust as, for example, total cyanide distillation, it provides an inexpensive, rapid and convenient approach for more frequent and widespread screening of industrial waste waters.
The evaluation of unilateral vocal fold immobility:Is chest x-ray enough?

Summary Unilateral vocal fold immobility (UVFI) is a sign of underlying disease. No consensus exists regarding the appropriate evaluation. This study was performed to determine the ability of a chest radiograph (CXR) to limit further costly testing. The charts of 169 patients with previously undiagnosed UVFI were reviewed. In 113 patients the etiology was identified during the history and physical examination (H&P), or the H&P led to a directed evaluation. There were nine patients in whom the evaluation was incomplete. There were 47 patients in whom the etiology was not identified during the H%P. In 28 patients, the CXR identified the etiology, and in 16 cases the CXR ruled out an intrathoracic cause. There were three patients whose H&P and CXR did not identify their cervical etiology. No patients had a thoracic etiology that was not identified by CXR. An algorithm was developed: If H&P fail to determine the etiology or to direct the evaluation, CXR is performed and followed by appropriate evaluation if positive. A negative CXR is followed with computed tomography (CT) of the neck from the skull base to thoracic inlet for right-sided UVFI and to the aortic triangle for left-sided UVFI. Other diagnostic studies are directed by signs and symptoms. A chest CT is not recommended unless there is clinical suspicion of a pulmonary or thoracic process. Key Words: Evaluation-Vocal fold immobility-Vocal cord paralysis.
Peace Activists: Maintaining Morale

Peace activism has had little attention from scholars and researchers, despite evidence of its relative effectiveness in avoiding and halting wars. This article examines the characteristics of peace and other social activists, revealing the strengths of their attributes as well as their vulnerability to morale problems. It then proposes three sets of actions to maintain morale and counteract the threats. Finally, this article proposes four potential directions for research and concludes with a summary.
Coupled LO phonon-plasmon modes in a magnetized semiconductor

Abstract The longitudinal optic (LO) phonon susceptibility is evaluated for a semiconductor subjected to a steady magnetic field. Coupling of the lattice vibrations and free electrons is described by a Frohlich interaction, and electron correlation effects are treated within the random phase approximation (RPA). The susceptibility displays resonances, as a function of frequency for a fixed wavevector perpendicular to the applied field, at frequencies that correspond to excitation of coupled LO phonon-plasmon–cyclotron modes. The spectrum and corresponding spectral weights for inelastic neutron scattering are evaluated for a model of n-type GaAs.
Prophylactic methylprednisolone to reduce inflammation and improve outcomes from one lung ventilation in children: a randomized clinical trial

Background One lung ventilation (OLV) results in inflammatory and mechanical injury, leading to intraoperative and postoperative complications in children. No interventions have been studied in children to minimize such injury. Objective We hypothesized that a single 2-mg·kg−1 dose of methylprednisolone given 45–60 min prior to lung collapse would minimize injury from OLV and improve physiological stability. Methods Twenty-eight children scheduled to undergo OLV were randomly assigned to receive 2 mg·kg−1 methylprednisolone (MP) or normal saline (placebo group) prior to OLV. Anesthetic management was standardized, and data were collected for physiological stability (bronchospasm, respiratory resistance, and compliance). Plasma was assayed for inflammatory markers related to lung injury at timed intervals related to administration of methylprednisolone. Results Three children in the placebo group experienced clinically significant intraoperative and postoperative respiratory complications. Respiratory resistance was lower (P = 0.04) in the methylprednisolone group. Pro-inflammatory cytokine IL-6 was lower (P = 0.01), and anti-inflammatory cytokine IL-10 was higher (P = 0.001) in the methylprednisolone group. Tryptase, measured before and after OLV, was lower (P = 0.03) in the methylprednisolone group while increased levels of tryptase were seen in placebo group after OLV (did not achieve significance). There were no side effects observed that could be attributed to methylprednisolone in this study. Conclusions Methylprednisolone at 2 mg·kg−1 given as a single dose prior to OLV provides physiological stability to children undergoing OLV. In addition, methylprednisolone results in lower pro-inflammatory markers and higher anti-inflammatory markers in the children's plasma.
Finding transatlantic common ground on climate change

Global climate change has emerged as a key issue straining relations between the European Union and the United States. Last fall in The Hague, US and EU negotiators failed to agree on rules for implementing the Kyoto Protocol, the centerpiece of international attempts to control emissions of climate-altering greenhouse gases. This spring, the incoming Bush administration announced it would oppose US participation in the Kyoto accord, launching a flurry of criticism in Europe. It is not surprising that climate change has become so contentious. In recent decades, nations have negotiated a wide variety of environmental agreements on issues ranging from solid waste to ozone-depleting CFCs. But climate change is perhaps the most vexing challenge. Since almost every sector of each nation’s economy emits greenhouse gases, few human activities would remain untouched by attempts to control them. The problem is global and long-term – emissions from any spot on Earth can affect the climate worldwide for centuries, though with potentially very different consequences in different places. Climate change is also fraught with uncertainty. Current scientific understanding supports a range of views, from those who see the problem as a potential environmental catastrophe to those who argue its effects will be hard to notice among the other changes of the 21st century. Over the last decade, important progress has been made towards addressing the climate change challenge. In the 1992 Framework Convention on Climate Change, most national governments agreed to a common, though ambiguous, long-term goal of stabilising atmospheric concentrations of greenhouse gases at a safe level. In the Framework’s 1997 Kyoto Protocol, nations agreed to the key
Professionalism among Engineers and Engineering Managers

ABSTRACTThis study applies Hall's “Modified Professional Inventory Scale” to measure the degree of professionalism among engineers and engineering managers. Among the professional characteristics evaluated were 1) sense of service or mission, 2) degree of self-direction and regulation, 3) sense of calling, 4) professional affiliation, and 5) degree of autonomy. The results clearly indicate that both engineers and engineering managers exhibit a greater openness and other directed orientation than is normally found in the more traditional professional models. Somewhat surprisingly, we found that engineering managers exhibited a higher degree of professionalism and greater sense of relatedness within the profession than engineers.
Differences Between Local and Orbital Dynamic Stability During Human Walking

Currently there is no commonly accepted way to define, much less quantify, locomotor stability. In engineering, "orbital stability" is defined using Floquet multipliers that quantify how purely periodic systems respond to perturbations discretely from one cycle to the next. For aperiodic systems, "local stability" is defined by local divergence exponents that quantify how the system responds to very small perturbations continuously in real time. Triaxial trunk accelerations and lower extremity sagittal plane joint angles were recorded from ten young healthy subjects as they walked for 10 min over level ground and on a motorized treadmill at the same speed. Maximum Floquet multipliers (Max FM) were computed at each percent of the gait cycle (from 0% to 100%) for each time series to quantify the orbital stability of these movements. Analyses of variance comparing Max FM values between walking conditions and correlations between Max FM values and previously published local divergence exponent results were computed. All subjects exhibited orbitally stable walking kinematics (i.e., magnitudes of Max FM or = 0.049). Thus, the variability inherent in human walking, which manifests itself as local instability, does not substantially adversely affect the orbital stability of walking. The results of this study will allow future efforts to gain a better understanding of where the boundaries lie between locally unstable movements that remain orbitally stable and those that lead to global instability (i.e., falling).
Environmental agency in read-alouds

Despite growing interest in helping students become agents of environmental change who can, through informed decision-making and action-taking, transform environmentally detrimental forms of human activity, science educators have reduced agency to rationality by overlooking sociocultural influences such as norms and values. We tackle this issue by examining how elementary teachers and students negotiate and attribute responsibility, credit, or blame for environmental events during three environmental read-alouds. Our verbal analysis and visual representation of meta-agentive discourse revealed varied patterns of agential attribution. First, humans were simultaneously attributed negative agentive roles (agents of endangerment and imbalance) and positive agentive roles (agents of prevention, mitigation, and balance). Second, while wolves at Yellowstone were constructed as intentional (human-like) agents when they crossed over into the human world to kill livestock in nearby farms, polar bears in the Arctic were denied any form of agential responsibility when they approached people’s homes. Third, anthropogenic causation of global warming was constructed as distal and indirect chains of cause and effect (i.e., sophisticated sequences of ripple effects), whereas its mitigation and prevention assumed the form of simple and unidirectional causative links (direct and proximal causality). Fourth, the notion of balance of nature was repeatedly used as a justification for environmental conservation but its cause and dynamic nature remained unclear. And, fifth, while one teacher promoted environmental agency by encouraging students to experience positive emotions such as love of nature, freedom, and oneness with nature, the other teachers encouraged students to experience negative emotions such as self-blame and guilt. This study’s main significance is that it highlights the need for environmental educators who set out to promote environmental agency to expand the focus of their instructional efforts beyond rational argumentation and reasoning. It also underscores the importance of increasing school teachers’ awareness of implicit discursive messages in particular patterns of environmental agency attribution when discussing environmental issues with students and implementing pedagogical strategies centered on oral deliberation such as read-alouds.
The common mucosal immune system and current strategies for induction of immune responses in external secretions

The selective induction of antibodies in external secretions is desirable for the prevention of various systemic as well as predominantly mucosa-restricted infections. An enormous surface area of mucosal membranes is protected primarily by antibodies that belong, in many species, to the IgA isotype. Such antibodies are produced locally by large numbers of IgA-containing plasma cells distributed in subepithelial spaces of mucosal membranes and in the stroma of secretory glands. In humans and in some animal species, plasma-derived IgA antibodies do not enter external secretions in significant quantities and systemically administered preformed IgA antibodies would be of little use for passive immunization. Systemic administration of microbial antigens may boost an effective S-IgA immune response only in a situation whereby an immunized individual had previously encountered the same antigen by the mucosal route. Local injection of antigen in the vicinity of secretory glands is usually accompanied by an undesirable concomitant systemic response and frequently requires the addition of adjuvants that are unacceptable for administration in humans. Immunization routes that involve ingestion or possibly inhalation of antigens lead to the induction of not only local but also generalized immune responses manifested by the parallel appearance of S-Iga antibodies to ingested or inhaled antigens in secretions of glands distant from the site of immunization. Based on extensive studies in animal models as well as in humans, convincing evidence is available that antigen-sensitized and IgA-committed precursors of plasma cells from GALT are disseminated to the gut, other mucosa-associated tissues, and exocrine glands. However, due to the limited absorption of desired antigens from the gut lumen of orally immunized individuals, repeated large doses of antigens are required for an effective S-IgA response. Novel antigen delivery systems for the stimulation of such responses are currently being examined in several laboratories. Live attenuated or genetically manipulated bacteria expressing other microbial antigens have also been used for selective colonization of gut-associated lymphoid tissues. Unique antigen packaging and the use of adjuvants suitable for oral administration hold promise for an efficient antigen delivery to critical tissues in the intestine and deserve extensive exploration. The oral immunization route appears to have many advantages over systemic immunization.(ABSTRACT TRUNCATED AT 400 WORDS)
Pasteurized and sterilized maple sap as functional beverages: Chemical composition and antioxidant activities

Abstract Maple sap has been consumed for centuries as a tonic by the indigenous peoples of eastern North America but is primarily utilized in this region to produce maple syrup. The natural watery form of maple sap makes its application as a functional beverage appealing but due to microbial growth, sterilization or pasteurization would be necessary before sap could be consumed. This study was designed to investigate the chemical composition (sugars, amino acids, organic acids, minerals, and phenolics) and antioxidant effects of maple sap after undergoing pasteurization and sterilization. After both processes, sugars, amino acids, organic acids, and minerals were preserved in the sap samples and they had similar phenolic contents (0.25–0.27 mg/100 g gallic acid equivalents) and antioxidant activities (IC50 ca. 550 μg/mL by DPPH assay). HPLC-DAD analyses revealed over 25 constituents in the sap samples of which 15 were identified using phenolic standards. In addition, one compound, 3′,5′-dimethoxy-4′-hydroxy-(2-hydroxy)acetophenone, not previously reported from maple syrup, was isolated and identified (by NMR) for the first time from maple sap. Therefore, the preservation of chemical constituents and antioxidant activity in maple sap after pasteurization and sterilization warrants its application as a functional beverage beyond its primary use for maple syrup production alone.
Thermally stable, highly fluorinated stationary phases for gas chromatography

Abstract The chromatographic properties of three highly fluorinated stationary phases namely Fomblin YR [a poly(perfluoroalkyl) ether], PPF-20 [a poly(perfluorphenylene) ether], and Fluorad FC-430 [a fluoroalkyl ester], are compared with those of conventional phases. The importance of phase structure, coating solvent, and surface chemistry of the support for the preparation of efficient and stable column packings is outlined. The retention of solutes of different structures is shown to occur by a combination of gas—liquid partitioning and interfacial adsorption. The relative importance of partitioning compared to adsorption is influence by the degree of fluorination and the measurement temperature. From accurately determined gas—liquid partition coefficients, corrected McReynolds phase constants and partial molar free energies of solution for a methylene group (Δ G ) were determined for the highly fluorinated phases. In the case of Fomblin YR, the very low value for Δ G (CH 2 ) compared to conventional phases provides a quantitative indication of the weak intermolecular forces operating in the chromatographic system. Higher values for PPF-20 indicate stronger dispersive interactions for the perfluroaromatic phase compared to the perfluoroalkyl phases.
Dysphagia in psychiatric patients: Clinical and videofluoroscopic study

Deaths due to airway obstruction are more common in psychiatric inpatients than in the normal population. A dysphagia program was started in a 400 bed Massachusetts psychiatric hospital after 4 patients in 1 year died from asphyxia. In the year after the program was started, there were no deaths; however, 28 patients experienced 32 choking incidents. The 28 patients received clinical evaluations by speech pathologists, neurologists, psychiatrists, and internists. Of the incidents, 55% required use of the Heimlich maneuver to open the airway. Choking incidents could be classified into five types based on results of clinical examination: bradykinetic, dyskinetic, fast eating syndrome, paralytic, and medical. Twenty-one of the 28 patients were studied by videofluoroscopy and 86% of the videos were abnormal, showing aspiration in eight, webs in five, and delay in the oral phase in five. Patients with bradykinetic dysphagia (secondary to neuroleptic-induced extra-pyramidal syndrome [EPS]) and paralytic dysphagia appeared to experience a more severe from of choking.
Metamorphosis Hurts: Resistant Students and Myths of Transformation

In labeling students who seem unengaged or defiant in class as “resistant,” teachers may not always be imaginative or thorough enough in thinking about the reasons for this student stance. Though resistance may be a useful concept for such students because teachers see it as something that can be both active and passive, one problem with the label of “resistant student” is that it often implies a binary relationship with the teacher. Yet the roots of student resistance may not be in the teacher but in anxieties and fears that are often inherent in the literacy classroom. If teachers cannot envision what students may be resisting and why, it is impossible to move beyond a classroom tug-of-war to actually engage such students in learning.
Bleeding patterns of the hormone replacement therapies in the postmenopausal estrogen and progestin interventions trial.

Abstract OBJECTIVE: To explore whether significant differences exist between bleeding patterns with common regimens of hormone replacement therapy using two different progestogens. METHODS: A total of 875 women in the Postmenopausal Estrogen and Progestin Interventions Trial took either placebo, conjugated equine estrogen 0.625 mg, conjugated equine estrogen 0.625 mg plus medroxyprogesterone acetate 2.5 mg in a continuous fashion, or conjugated equine estrogen 0.625 mg daily plus either cyclical medroxyprogesterone acetate 10 mg or cyclical micronized progesterone 200 mg/day for 12 days per month. Bleeding days, amounts, and episodes were recorded in diaries and aggregated by 6-month intervals for 3 years for the 596 participants with a uterus. Any bleeding for women on continuous regimens, or more than 6 episodes of bleeding per 6-month period for cyclical regimens, was considered excess. RESULTS: Conjugated equine estrogen plus micronized progesterone cyclical was associated with fewer excess episodes of bleeding than conjugated equine estrogen plus medroxyprogesterone acetate continuous in the first 6 months. Quantities of bleeding for conjugated equine estrogen plus micronized progesterone cyclical were less than for conjugated equine estrogen plus medroxyprogesterone acetate cyclical through 30 months and for the number of bleeding days through study end. The 3-year cumulative quantities, days, and episodes of bleeding were significantly lower for conjugated equine estrogen plus micronized progesterone cyclical than for conjugated equine estrogen plus medroxyprogesterone acetate cyclical. Placebo treated women had scant bleeding and conjugated equine estrogen had modest amounts relative to the combination therapies. CONCLUSION: The bleeding measures for conjugated equine estrogen plus micronized progesterone cyclical showed consistent advantages over those for cyclical conjugated equine estrogen plus medroxyprogesterone acetate in terms of quantity, length, and episodes of bleeding. In the first 6 months, conjugated equine estrogen plus micronized progesterone cyclical had fewer excess bleeding episodes than continuous conjugated equine estrogen plus medroxyprogesterone acetate.
Seasonal variation in the effects of food availability on gametogenesis in the purple urchin (Strongylocentrotus purpuratus)

The amount of food and when it is available affect both the timing of reproduction and the number of gametes produced by purple sea urchins, Strongylocentrotus purpuratus. To investigate this further, the effects of food availability on feeding rates, gonad growth, and gamete development were examined in S. purpuratus collected from the Point Loma kelp forest near San Diego, California, USA (32.69° N, 117.26° W) in September (Fall) 2007, and February (Spring) and July (Summer) 2008, using laboratory mesocosms. Each seasonal laboratory feeding experiment lasted 3 months, and different levels of food availability were established with different feeding frequencies (from 1 to 7 days week−1). Gonad tissues of male and female urchins were staged at the end of each experiment using histological analyses. Reduced food availability resulted in increased daily consumption rates, especially in the Fall when gamete development began. Food limitation at this time resulted in failure to produce viable gametes, suggesting there is a critical period early in gonad development when food limitation affects reproductive competency. Food limitation later in gonad development did not stop viable gamete production, although it did reduce gamete output.
Environment and developmental risk in children with sex chromosome abnormalities.

Abstract Forty-six children with sex chromosome abnormalities (SCA), identified in the chromosome screening of 40,000 consecutive newborns between 1964 and 1974, have been studied longitudinally. Language, motor, psychosocial, and school impairment occurred more frequently in the 38 nonmosaic propositi but not in the 8 mosaic propositi, relative to the group of 32 control siblings. Incidences of motor, school, and psychosocial impairment increased dramatically when the SCA children came from dysfunctional families, as rated by the Family Dysfunction Index, but not in control subjects. Biological factors that influence environmental risk are discussed, and the importance of understanding “protective factors” in unaffected SCA children noted.
In Vitro Evaluation of Ferrihydrite as an Enterosorbent for Arsenic from Contaminated Drinking Water

Arsenic (As) is a toxic trace element found in groundwater due to natural and industrial processes. Exposure has been linked to cancers of the bladder, lungs, skin, kidneys, nasal passages, liver, and the prostate. Arsenic in drinking water is a problem in many countries, notably Bangladesh and Taiwan. The purpose of this research was to utilize binding isotherms, a simulated gastrointestinal (GI) model, and the adult Hydra bioassay to evaluate ferrihydrite's potential to bind As and serve as a potential enterosorbent for As found in drinking water. A variety of clay minerals and synthesized iron oxides including ferrihydrite were screened for their ability to bind As(III), as sodium arsenite, and As(V), as sodium arsenate. After ferrihydrite was demonstrated to be the most effective sorbent for both As species, adsorption isotherms were performed. All isotherm data were fit to the Langmuir equation to determine adsorption capacity (Qmax). Ferrihydrite bound 96% of As(III) and 97% of As(V) in the screening studies and had a Qmax of 1.288 mol/kg for As(III) and 0.744 mol/kg for As(V). Using a simulated GI model, ferrihydrite was found to effectively adsorb As(V) and As(III) in the stomach and intestine. Ferrihydrite (0.25% w/w) protected adult Hydra at levels up to 200 times the minimal effective concentration (MEC) for As(III) and up to 2.5 times the MEC for As(V). These experiments confirm that ferrihydrite is a high capacity sorbent of As and that it is effective at removing As in a simulated GI model. These results suggest that ferrihydrite could be used as a potential enterosorbent for As found in drinking water. Future work will focus on verifying ferrihydrite's safety and efficacy in vivo.
Effects of chronic exposure to hydrogen sulphide on newly hatched brown trout Salmo trutta L.

Abstract The effects of hydrogen sulphide on newly hatched brown trout, Salmo trutta , were examined. Fry were exposed to H 2 S concentrations of between 2 and 13 μg/litre for 8 and 22 days. The 96-h LC 50 was 7 μg/litre. At 2–5 μg/litre H 2 S, survival was 8 to 15% above that of control fish over exposure periods of 8 and 22 days. Fish exposed to these low concentrations of hydrogen sulphide reached total lengths 50 to 200% greater than those of control fish. Examination of gill lamellae of fish exposed to the low, chronic concentrations revealed shorter, thicker lamellae with bulbous tips compared with controls. The ratio of lamella length to diameter was 3·02 for exposed fish compared with 4·53 for control fish. The behaviour of the exposed fish suggested that they were experiencing respiratory stress.
Modification of structure and synaptic physiology in transformed Shrimp muscle

1. The gross anatomy of the nerves and muscles in the pincer and snapper claws ofAlpheus armillatus is described. In both claws there are three muscles: the opener muscle, the main closer muscle, Cl1, and the small closer muscle, Cl2. 2. The number of fibers in each of the two closer muscles is similar for a pair of claws removed from the same animal. However, the size of individual closer muscle fibers in the snapper is about two times greater, both in length and diameter, than in the pincer. 3. Sarcomeres in fibers of the opener muscle and the small closer muscle are similar in length for the pincer and the snapper. In contrast, sarcomeres in the main closer muscle of the pincer are shorter than those in the snapper Cl2 muscle. 4. Excitatory junctional potentials (ejp's) recorded from single pincer Clx muscle fibers at 1 Hz were always small in amplitude (≦12 mV) and facilitated poorly at 10 Hz. Snapper Cl1 ejp's ranged up to about. 30 mV in amplitude and displayed a large degree of facilitation at 10 Hz. 5. During the process of pincer transformation into a snapper claw, parallel changes occur in both the sarcomere length of Cl1 muscle fibers and the degree of ejp facilitation.
Density-Dependent Parasitism and the Evolution of Aggregated Nesting in the Solitary Hymenoptera

Aggregated nesting is widespread among the solitary Hymenoptera and may represent an important step toward the evolution of eusociality via the semisocial pathway. Five hypotheses have been proposed to explain the evolution of nesting aggregations: first, aggregation may occur in response to a restricted distribution of some key resource; second, aggregation may increase foraging efficiency; third, aggregation may confer improved protection from natural enemies; fourth, aggregation may decrease the cost of nest site search; and fifth, aggregation may increase opportunities to reuse old nests. Proximate explanations for the formation of nesting aggregations, including the philopatry hypothesis, do not compete with these ultimate explanations but, rather, complement them. The role of parasite pressure in favoring or disfavoring aggregated nesting has become an area of active research and debate. This paper reviews field studies of density-dependent foraging by nest parasites and resulting patterns of nest exploitation to test generalizations concerning the effects of parasites. Nest parasites foraged either independently of host nest density ( n = 2) or they concentrated in areas of high nest density ( n = 4). Nest parasitism was directly density dependent ( n = 8), density independent ( n = 4), or inversely density dependent ( n = 2). Thus, parasite pressure may favor either aggregated or dispersed nesting. Diversity in patterns of density dependence appears to result from the interaction of variable parasite foraging strategies and host defensive strategies. Inversely density-dependent parasitism may result from parasites being limited by egg supply or handling time, or from improved defense capabilities of grouped hosts. Improved defense may be a product of increased parasite confusion, active group defense, selfish herding, or improved parasite detection. Data supporting these hypotheses are critically reviewed and further research needs are identified.
Mars Odyssey navigation experience

The 2001 Mars Odyssey Mission has returned an orbiter to Mars to map the planet and search for water. The success of this mission has reestablished confidence in Mars exploration that will pave the way for future orbiters, landers, and rovers. The spacecraft has completed its journey and is now in the science gathering phase of the mission. The orbital mission began in February 2002 and will continue through at least 2006. We present an overview of the navigation performance, with a comparison of the prelaunch requirements and expected performance to the in-flight experience.
Non-weak inhibition and phase resetting at negative values of phase in cells with fast-slow dynamics at hyperpolarized potentials

Phase response is a powerful concept in the analysis of both weakly and non-weakly perturbed oscillators such as regularly spiking neurons, and is applicable if the oscillator returns to its limit cycle trajectory between successive perturbations. When the latter condition is violated, a formal application of the phase return map may yield phase values outside of its definition domain; in particular, strong synaptic inhibition may result in negative values of phase. The effect of a second perturbation arriving close to the first one is undetermined in this case. However, here we show that for a Morris---Lecar model of a spiking cell with strong time scale separation, extending the phase response function definition domain to an additional negative value branch allows to retain the accuracy of the phase response approach in the face of such strong inhibitory coupling. We use the resulting extended phase response function to accurately describe the response of a Morris---Lecar oscillator to consecutive non-weak synaptic inputs. This method is particularly useful when analyzing the dynamics of three or more non-weakly coupled cells, whereby more than one synaptic perturbation arrives per oscillation cycle into each cell. The method of perturbation prediction based on the negative-phase extension of the phase response function may be applicable to other excitable cell models characterized by slow voltage dynamics at hyperpolarized potentials.
Phase-locking of an overdamped pendulum

Abstract We analyze phase-locking of an overdamped pendulum in the general case of all harmonics of the driving field and all frequencies. The results show that to first order in the ac amplitude, no harmonic phase-locking exists. The range of phase-locking for fundamental phase-locking is calculated and comparisons to numerical experiments show excellent agreement for all frequencies.
Emotional Aspects of Language Brokering among Mexican American Adults

Children of immigrant parents often are asked to language broker, translating documents and face-to-face interactions, for their parents and other adults. Many individuals continue to language broker as adults for their parents and other relatives, despite their adult status and living away from home. Twenty Mexican American college students (female = 17, male = 3) who currently language broker answered a questionnaire about their experiences language brokering, frequency of brokering, type of items and situations translated, emotions when language brokering, self esteem and level of acculturation. Participants translated most often for parents, on the phone, and for grandparents and other relatives. Overall, participants reported feeling positively about their language brokering experiences. More frequent language brokering was associated with higher self-esteem. Participants rated feeling helpful, proud and useful when language brokering as the highest three emotions among a list of emotions. Feeling an...
Effects of mammalian gonadotropins (ovine FSH and LH) in female lizards.

The effects of ovine follicle stimulating hormone (FSH) and luteinizing hormone (LH) were studied in females of three lizard species—Anolis carolinensis, Uta stansburiana, and Sceloporus occidentalis. In intact Anolis, that were physiologically hypophysectomized with respect to gonadotropins, doses of 10 μg FSH (12 mU) every other day produced normally enlarged ovaries, some ovulation and hypertrophy of the oviducts within two weeks. Combinations of 1 or 10 μg LH with this dose had no additional effect. A higher dose of FSH (50 μg) given alone or in combination with 50 μg LH for 13 or 29 days, caused an abnormal enlargement of the ovaries but seemed to block ovulation; oviducts were maximally enlarged in 13 days. LH alone (50 μg, 40 mU) for 13 or 29 days produced only slight ovarian and oviducal development, less than did 10 μg FSH for 14 days. The relative actions of FSH and LH in hypophysectomized Anolis, were similar to those described above. Also, a very low dose (0.1 μg) of a purified FSH from Papkoff was found to promote ovarian development, oviducal enlargement, and ovulation in the hypophysectomized lizard. In hypophysectomized Uta and Sceloporus, 0.5 – 2 μg of the highly purified Papkoff FSH preparation caused ovulation in enlarged ovaries. The addition of 0.5 mU LH to these low doses of FSH had no effect, and LH alone was ineffective in producing ovulation. FSH also caused enlargement of the oviducts.
In-vitro cultivation of human oral keratinocytes.

Abstract The technique of Rheinwald and Green (1975b) for the serial cultivation of foreskin keratinocytes was modified to facilitate the cultivation of gingival and buccal keratinocytes. We used 7–10-day epithelial outgrowths from excised tissue fragments as a source of keratinocytes, whereas Rheinwald and Green used enzymically-dissociated keratinocytes from freshly obtained foreskin. Mitomycin-C treatment as opposed to gamma irradiation was used to suppress the growth of fibroblast feeder layers. Single oral keratinocytes proliferated to form colonies resembling a stratified squamous epithelium. Light and electron microscopy revealed structures usually associated with epithelia, i.e. desmosomes, tonofilaments, tonofibrils, thickened cell membranes and a glycocalyx on the free surface of the epithelium. Oral keratinocytes underwent 20–40 doublings before senescence.
The Treatment of Serous Macular Detachment Secondary Choroidal Melanomas and Nevi

The authors successfully treated with laser photocoagulation five patients who had a serous macular detachment secondary to leakage from a pigmented choroidal tumor. Three patients had dye leakage on fluorescein angiography from a choroidal neovascular membrane. The subretinal fluid resolved in all three patients after the neovascular membrane was obliterated by either krypton red (2 patients) or argon green (1 patient) laser photocoagulation. The other two patients had prominent leakage from a localized choroidal neovascular membrane as well as mild diffuse leakage over the entire tumor. Focal argon laser treatment to the neovascular membrane alone did not cause permanent resolution of the subretinal fluid. The fluid did resolve, however, after the entire area of diffuse leakage was retreated with photocoagulation. In one of the patients who received both focal and confluent laser treatment, the choroidal tumor grew in a collar-button fashion through Bruch's membrane at the original site of focal treatment. This eye was enucleated, and results of histopathologic examination showed a choroidal melanoma.
Weighted Parzen windows for pattern classification

This paper introduces the weighted-Parzen-window classifier. The proposed technique uses a clustering procedure to find a set of reference vectors and weights which are used to approximate the Parzen-window (kernel-estimator) classifier. The weighted-Parzen-window classifier requires less computation and storage than the full Parzen-window classifier. Experimental results showed that significant savings could be achieved with only minimal, if any, error rate degradation for synthetic and real data sets.
Seed-coat thickness data clarify seed size–seed-bank persistence trade-offs in Abutilon theophrasti (Malvaceae)

Theoretical models predict that seed size and seed-bank persistence evolve interdependently, such that strong selection for one trait corresponds with weak selection for the other. This framework has been supported and rejected by empirical data, and thus, conclusive evidence is lacking. We expanded the seed size–persistence framework to include seed-coat thickness, a defence trait previously correlated with seed survival in soil. To do this, we used Abutilon theophrasti accessions with varied evolutionary histories and we quantified associations among seed traits including morphology, size, coat thickness, dormancy (percentage of viable seeds that fail to germinate under optimum conditions) and seed-bank persistence (percentage of viable seeds remaining after 1 year of burial). Statistical models were developed to test the hypothesis that combined measurements of seed-coat thickness and seed size better explain variability in seed-bank persistence than seed-size data alone. Results indicated that measurements of seed size (length, width, mass) were negatively correlated with coat:width ratio (coat thickness relative to seed width) and coat:mass ratio (coat thickness relative to seed mass). Accessions characterized by smaller seeds with proportionally thicker seed coats were more dormant and more persistent in soil than accessions characterized by larger seeds with proportionally thinner seed coats. Seed-coat thickness data improved the explanatory power of logistic regression models for seed-size effects on both seed-bank persistence and dormancy. These results indicate that supplementing seed-size data with seed-defence data may clarify previously reported contradictory results regarding trade-offs between seed size and seed-bank persistence.
The Use of Abdominal Free Fat for Volumetric Augmentation and Primary Dural Closure in Supratentorial Skull Base Surgery: Managing the Stigma of a Temporal Defect

The most prominent stigma of supratentorial skull base surgery is the defect caused by wasting of the temporalis muscle by denervation, devascularization, or rotation of the muscle. Any of the above may lead to a unilateral temporal deformity informally referred to patients as “the divot in my head.” Abdominal free fat grafting has been used by surgeons for years to close posterior fossa defects with excellent results. We present our experience using abdominal free fat grafts to improve cosmetic results and to prevent cerebrospinal fluid leaks in supratentorial skull base surgery. The basic technique and its benefits are described.
Tales from the dark side: a phenomenography of adult critical reflection

Encouraging adults to undertake critical reflection is one of the most frequently espoused aims of graduate programmes of adult education. A considerable body of adult educational literature has be...
Hydrogen exchange in the lipid bilayer-bound gramicidin channel

Hydrogen exchange experiments for a membrane-bound polypeptide could lead to interesting functional and structural insights. Here, hydrogen/deuterium exchange, saturation transfer and differential relaxation experiments have been performed on oriented lipid bilayer-bound polypeptide samples to measure the exchange lifetimes. The polypeptide, gramicidin A, forms a monovalent cation selective channel across membranes. The pH dependent results suggest that the indole Ne1-H groups show base catalyzed hydrogen exchange, but that the backbone amide sites are not base catalyzed, consistent with the exclusion of anions from this channel. Furthermore, the recently described [1] orientational distribution of the individual peptide carbonyls (i.e. carbonyls either tipped slightly in toward or away from the channel axis) is consistent with the observed difference in odd- and even-numbered amide residue exchange lifetimes.