cssi/SciSciGPT-SciSciNet huggingface dataset:
Emotional Experiences and Coping Strategies of Family Members of Critically Ill Patients.

Background Two out of three family members experience symptoms of posttraumatic stress, depression, or anxiety lasting for months after the ICU stay. Interventions aimed at mitigating these symptoms have been unsuccessful. Research Question To understand the emotional experiences of family members of critically ill patients and to identify coping strategies used by family members during the ICU stay. Study Design and Methods: As part of a mixed methods study to understand sources of distress among ICU family members, semistructured interviews were conducted with ICU family members. Family members completed surveys at the time of interview and at 90 days to assess for symptoms of depression, anxiety, and posttraumatic stress. Results Semistructured interviews and baseline surveys were conducted with 40 ICU family members; 78% of participants (n = 31) completed follow-up surveys at 90 days. At the time of interview, 65% of family members had symptoms of depression, anxiety, or posttraumatic stress. At 90 days, 48% of surveyed family members had symptoms of psychological distress. Three primary emotions were identified among ICU family members: sadness, anger, and fear. A diverse array of coping strategies was used by family members, including problem-solving, information seeking, avoidance/escape, self-reliance, support seeking, and accommodation. Interpretation This study emphasizes similarities in emotions but diversity in coping strategies used by family members in the ICU. Understanding the relationship between ICU experiences, emotional responses, and long-term psychological outcomes may guide targeted interventions to improve mental health outcomes of ICU family members.
A Coordinated Preventive Control Optimization Method of Small Signal and Transient Stability Based on Sensitivity Analysis

In this paper, a coordinated preventive control optimization method based on sensitivity analysis is proposed to improve both small signal and transient stability. The mathematical model based on sensitivity analysis is presented for the coordinated preventive control optimization problem of small signal and transient stability. The nonlinear optimization model is transformed into a quadratic programming model by linearization the constraints through sensitivity analysis, so as to be solved by the ordinary quadratic programming method. In this paper, the computing flow of the coordinated preventive control is presented as well as the selection principle of control generators. A State Grid Cooperation of China (SGCC) 9177-bus system is utilized to validate the proposed method. The results verify the effectiveness of the coordinated preventive control optimization strategies for both small signal and transient stability. After the control strategies are implemented, the system can meet the requirements of both small signal and transient stability.
Decreased bioavailability of aminomethylphosphonic acid (AMPA) in genetically modified corn with activated carbon or calcium montmorillonite clay inclusion in soil

Abstract The widespread use of pesticides has resulted in detectable residues throughout the environment, sometimes at concentrations well above regulatory limits. Therefore, the development of safe, effective, field-practical, and economically feasible strategies to mitigate the effects of pesticides is warranted. Glyphosate is an organophosphorus herbicide that is degraded to aminomethylphosphonic acid (AMPA), a toxic and persistent metabolite that can accumulate in soil and sediment and translocate to plants. In this study, we investigated the binding efficacy of activated carbon (AC) and calcium montmorillonite (CM) clay to decrease AMPA bioavailability from soil and AMPA translocation to plants. Adsorption isotherms and thermodynamic studies on AC and CM were conducted and showed tight binding (enthalpy values >-20 kJ/mol) for AMPA with high capacities (0.25 mol/kg and 0.38 mol/kg, respectively), based on derivations from the Langmuir model. A hydra assay was utilized to indicate toxicity of AMPA and the inclusion of 1% AC and CM both resulted in 90% protection of the hydra (**p ≤ 0.01). Further studies in glyphosate-contaminated soil showed that AC and CM significantly reduced AMPA bioavailability by 53% and 44%, respectively. Results in genetically modified (GM) corn showed a conversion of glyphosate to AMPA in roots and sprouts over a 10-day exposure duration. Inclusion of AC and CM reduced AMPA residues in roots and sprouts by 47%–61%. These studies collectively indicate that AC and CM are effective sorbents for AMPA and could be used to reduce AMPA bioavailability from soil and AMPA residues in GM corn plants.
Modern Management of Perianal Crohn’s Disease: A Review:

Perianal Crohn's disease (CD) is a complex manifestation of CD that affects approximately 10% of patients. The spectrum of disease is quite variable, ranging from relatively mild disease to severe, aggressive manifestations that result in frequent hospitalizations, multiple surgeries, and poor quality of life. Despite significant recent advances in surgical and medical management, treatment remains challenging and frequently requires a multidisciplinary medical-surgical approach. The goal of this article is to review the current literature regarding the work-up, treatment, and future directions of therapy. Crucial features of effective management include the precise identification of manifestations, control of sepsis, limiting rectal inflammation, frequently with use of antitumor necrosis factor agents, and avoidance of extensive surgery.
The effects of firm size, corporate governance quality, and bad news on disclosure compliance

Motivated by calls for increased compliance, size-based regulation, and continued exemption of small firms from internal control reporting requirements, we assess the incremental effects of firm size, corporate governance quality, and bad news on disclosure compliance. We examine compliance with the disclosure requirements of an SEC-mandated filing that requires no computations or complex judgments but is nonroutine and may reveal value-decreasing information (bad news) that otherwise would not become public. The disclosures studied are those that firms provide in Form 8-K Item 4 when changing external auditors. We find that noncompliant firms have lower quality corporate governance and less need for external financing but are not smaller than compliant control firms. Additional analyses indicate that compliance is negatively associated with bad news.
Book Review: The Mentally Disordered Inmate and the Law

Criminal offenders with serious mental health disorders are inundating the correctional system at an alarming rate, and the scope and complexity of legal issues that affect prison inmates with serious mental health disorders have increased considerably in recent years. As such, there is a palpable need for a comprehensive yet accessible explanation of the legal issues that are directly relevant to the sizeable portion of prison inmates with serious mental health disorders. The second edition of Fred Cohen's The Mentally Disordered Inmate and the Law (2008), published by Civic Research Institute, effectively fills this need. This two-volume set, which is a revised and expanded version of the first edition,published in 1998, provides comprehensive coverage of the rights of prison inmates with mental disorders and the legal issues that most directly affect these inmates. And it does so in a straightforward, accessible, and practical manner. In the 10 years between the publication of the first and second editions of this book, the laws affecting prison inmates with mental disorders have changed considerably, and it should be no surprise to anyone familiar with Cohen's substantial body of impressive scholarship that he does a masterful job in the second edition of keeping pace with the rapidly changing legal landscape.
Macroeconomic Analysis of Policies Addressing Coronavirus Pandemic.

During last two quarters, active macroeconomic policies have been a significant component of the overall response of the U.S. government to the coronavirus pandemic. An analysis of current government policies addressing this short-term shock and the resulting economic impact would be helpful in developing future policies, should similar circumstances arise down the road. We conjecture that the combination of expansionary macroeconomic policies preceding the coronavirus pandemic likely shifted the level of U.S. aggregate economic output beyond the point of macroeconomic equilibrium with full employment. In other words, the start of the Coronavirus pandemic coincided with the macroeconomic phenomenon known as demand-pull inflation. In such economic conditions the level of aggregate output is much higher than the economy can sustain in the long run, but the overheated economy enjoys all the benefits of higher than natural level of national production and low unemployment in the short term. The following economic shutdown driven by growing worries over the limited hospital capacity, which would have become unable to meet the growing needs of hospitalization by Coronavirus patients, caused a severe shift in the demand for economic output, along with sharp declines in personal consumption, business investments, and exports of goods and service. The $2 trillion economic relief package known as the CARES Act of March 2020 softened the adverse economic impact of this shock to some extent. The observation in this brief suggests that the overheated economy absorbed some of the shock produced by the economic shutdown, therefore limiting the devastating impact of the sharp economic contraction.
Adjuvant radiation and cetuximab improves local control in head and neck cutaneous squamous cell carcinoma: A phase II study

Background Cutaneous squamous cell carcinoma of the head/neck (CSCCHN) is common due to chronic sun exposure. As CSCCHN highly expresses EGFR, we prospectively studied postoperative concurrent cetuximab with radiotherapy for locally advanced CSCCHN (LA-CSCCHN). Materials and methods Single-institutional phase II trial of LA-CSCCHN (NCT XXXX). Adjuvant radiation was given with concurrent cetuximab. Primary endpoint of 2-year LRC and secondary objectives of 2-year disease-free survival (DFS) and 2-year OS were assessed by Kaplan-Meier analysis. Results Twenty-four patients ages 47-88 (median 71 years) were treated from 2014 to 2017. Fourteen patients had T3/4 disease, 5 had N1 disease, and 7 were N2/3. At median follow-up of 42 months, median OS and DFS was not reached and 64 months. Two-year OS was 75%, 2-year DFS was 70.8%. LRC was 91.1% at 2 years. All grade 3 adverse events were related to skin toxicity (12.5% radiation-related dermatitis, 16.7% cetuximab-related rash). Conclusions LRC compares favorably to historical data examining postoperative radiation alone but requires further investigation.
Electrochemical deposition of amorphous aluminum oxides on lead pipes to prevent lead leaching into the drinking water.

Over 5000 public drinking water systems in the US are out of compliance with the Lead and Copper Rule. Lead leaching from lead pipes is limited by the solubility of a naturally occurring scale. Changes in water quality may cause this scale to become more soluble, releasing lead into the drinking water. We propose a novel electrochemical method to prevent lead leaching from lead pipes. In this method, an aluminum wire and an alkaline phosphate electrolyte are inserted into the pipes. The pipes are then anodized for 2 h by using an external power supply, resulting in the electrodeposition of an insoluble aluminum oxide layer on top of the preexisting scale. This technology was tested on lead pipes from the EBMUD water distribution systems located in Berkeley, CA, using recirculating synthetic and actual tap water for 120 days. The untreated pipes leached an average of 23 ppb and 38 ppb of lead respectively, when using free chlorine and monochloramine as disinfection residuals. In contrast, the treated pipes leached 3 ppb and 5 ppb respectively. These results suggest that the proposed treatment has the potential to prevent lead leaching regardless of the disinfection residual and thus should be further explored in a field trial.
SP/A-Based Behavioral Portfolio Theory

This chapter develops the implications of SP/A preferences for portfolio selection. The most important trait described here is the tendency to combine very safe securities with very risky securities, with the overall portfolio failing to be well diversified. Empirical tests of the hypotheses associated with behavioral portfolio theory have found strong support for its general features. SP/A theory provides a parsimonious behaviorally based framework for portfolio selection. Notably, this theory is especially well suited to the asset pricing approach developed in this book. In particular, it lends itself easily to an asset pricing framework which combines behavioral beliefs and behavioral preferences. SP/A theory builds on the work of Friedman and Savage (1948), which analyzed the tendency for people to act as if they are risk averse in some of their choices and risk-seeking in their other choices. A key feature of SP/A-based behavioral portfolio theory is bipolarity, in that investors form portfolios which combine very safe securities with very risky securities. The last section of this chapter presents empirical evidence supporting the bipolarity property.
Measurements of Landau-level crossings and extended states in magnetic two-dimensional electron gases

We present longitudinal and Hall magnetoresistance measurements of a ``magnetic'' two-dimensional electron gas formed in modulation-doped ${\mathrm{Zn}}_{1\ensuremath{-}x\ensuremath{-}y}{\mathrm{Cd}}_{x}{\mathrm{Mn}}_{y}\mathrm{Se}$ quantum wells. The electron spin splitting is temperature and magnetic field dependent, resulting in striking features as Landau levels of opposite spin cross near the Fermi level. Magnetization measurements on the same sample probe the total density of states and Fermi energy, allowing us to fit the transport data using a model involving extended states centered at each Landau level and two-channel conduction for spin-up and spin-down electrons. A mapping of the extended states over the whole quantum Hall effect regime shows no floating of extended states within experimental resolution as Landau levels cross near the Fermi level.
Mild elevations of international normalized ratio at hospital Day 1 and risk of expansion in warfarin-associated subdural hematomas.

Object A primary goal in the treatment of patients with warfarin-associated subdural hematoma (SDH) is reversal of coagulopathy with fresh-frozen plasma. Achieving the traditional target international normalized ratio (INR) of 1.3 is often difficult and may expose patients to risks of volume overload and of thromboembolic complications. This retrospective study evaluates the risk of mild elevations of INR from 1.31 to 1.69 at 24 hours after admission in patients presenting with warfarin-associated SDH. Methods Sixty-nine patients with warfarin-associated SDH and 197 patients with non–warfarin-associated SDH treated at a single institution between January 2005 and January 2012 were retrospectively identified. Charts were reviewed for patient age, history of trauma, associated injuries, neurological status at presentation, size and chronicity of SDH, associated midline shift, INR at admission and at hospital Day 1 (HD1), concomitant aspirin or Plavix use, platelet count, and medical comorbidities. Patients ...
Design of a Procedure Analysis Tool (PAT) for affordable aviation device human factors certification

Equipment on airliners must be certified by the FAA to ensure compliance with safety standards that are designed to minimize design-related flight crew errors. This process is currently accomplished by both Inspection and Human-In-The-Loop (HitL) testing – a time-consuming and costly process. A recent Federal Aviation Regulation (FAR) 25.1302 newly requires the analysis of all tasks increasing certification costs beyond current staffing, budget and timelines. The Procedure Analysis Tool (PAT) described in this paper is a decision support tool designed for use by inspectors performing the certification test to meet the FAR25.1302 requirements. The PAT simulates the performance of human operators performing a task on the device under evaluation and may be used as a screening tool to identify tasks that warrant HitL testing, allowing for evaluation within reasonable time and budget. The PAT calculates the percentage of pilots that perform the procedure in excess of an allowed threshold representing the Probability of Failure to Complete PFtoC the procedure. Procedures with long right tails are flagged for full HitL testing. PAT was demonstrated on 15 Swiss European airlines Standard Operating Procedures (SOP) to evaluate the Multifunction Control Display Unit (MCDU). Three procedures resulted in a PFtoC above the threshold, and were therefore flagged for HitL testing. This preliminary analysis highlights the importance of semantic cues when recognizing the emerging mission situations which has the greatest effect on the final time distribution. Entering the 15 procedures into the tool took 5.1 hours and 11.56 seconds average runtime. Analysis of the human factors certification process shows that the PAT reduces the evaluation time by 70% per function.
Microwave Background Radiation Observations at the Owens Valley Radio Observatory

For the last four years we have been engaged in an intensive program to look for intrinsic variations in the Microwave Background Radiation (MBR) at the Owens valley Radio Observatory (OVRO). We have not yet detected any variations but we have derived a very stringent upper limit. We believe that our limit is robust because different statistical tests give very similar results and because our data are consistent with gaussian statistics.
Human ACAP2 is a homolog of C. elegans CNT-1 that promotes apoptosis in cancer cells

Activation of caspases is an integral part of the apoptotic cell death program. Collectively, these proteases target hundreds of substrates, leading to the hypothesis that apoptosis is “death by a thousand cuts”. Recent work, however, has demonstrated that caspase cleavage of only a subset of these substrates directs apoptosis in the cell. One such example is C. elegans CNT-1, which is cleaved by CED-3 to generate a truncated form, tCNT-1, that acquires a potent phosphoinositide-binding activity and translocates to the plasma membrane where it inactivates AKT survival signaling. We report here that ACAP2, a homolog of C. elegans CNT-1, has a pro-apoptotic function and an identical phosphoinositide-binding pattern to that of tCNT-1, despite not being an apparent target of caspase cleavage. We show that knockdown of ACAP2 blocks apoptosis in cancer cells in response to the chemotherapeutic antimetabolite 5-fluorouracil and that ACAP2 expression is down-regulated in some esophageal cancers, leukemias and lym...
Sparse network array processing employing prior covariance knowledge

The paper examines an alternative multidimensional adaptive array processing architecture which provides a unique highly-parallelizable algorithm suitable for distributed processing. The principle is to perform interference cancellation on each element using a different sparse sampling of the remaining elements auxiliary inputs. By doing so, special correlations in the data can be exploited to significantly reduce the degrees of freedom required in each adaptive process. This reduces both the computation count and the number of samples required for adaptivity. An example space-time adaptive nulling application of airborne clutter shows near optimal performance with a factor of four computational savings over equivalent space-time techniques.
A software-based communication security facility for RHODOS and the study of the cost of providing secure communications

This paper describes the design and implementation details of the RHODOS communication security facility which provides encryption and decryption of messages. A software-based approach is taken and both the DES and LOKI cryptosystems are supported. The communication security facility is positioned at the level of the transport protocol. The study of the cost of providing secure communication is also presented.
Whole-brain three-dimensional T2-weighted BOLD functional magnetic resonance imaging at 7 Tesla

Purpose A new acquisition scheme for T2-weighted spin-echo BOLD fMRI is introduced. Methods It uses a T2-preparation module to induce blood-oxygenation-level-dependent (BOLD) contrast, followed by a single-shot three-dimensional (3D) fast gradient-echo readout with short echo time (TE). It differs from most spin-echo BOLD sequences in that BOLD contrast is generated before the readout, which eliminates the “dead time” due to long TE required for T2 contrast, and substantially improves acquisition efficiency. This approach, termed “3D T2prep-GRE,” was implemented at 7 Tesla (T) with a typical spatial (2.5 × 2.5 × 2.5 mm3) and temporal (TR = 2.3 s) resolution for functional MRI (fMRI) and whole-brain coverage (55 slices), and compared with the widely used 2D spin-echo EPI sequence. Results In fMRI experiments of simultaneous visual/motor activities, 3D T2prep-GRE showed minimal distortion and little signal dropout across the whole brain. Its lower power deposition allowed greater spatial coverage (55 versus 17 slices with identical TR, resolution and power level), temporal SNR (60% higher) and CNR (35% higher) efficiency than 2D spin-echo EPI. It also showed smaller T2* contamination. Conclusion This approach is expected to be useful for ultra-high field fMRI, especially for regions near air cavities. The concept of using T2-preparation to generate BOLD contrast can be combined with many other sequences at any field strength. Magn Reson Med 72:1530–1540, 2014. © 2013 Wiley Periodicals, Inc.
Ocean fronts drive marine fishery production and biogeochemical cycling

Long-term changes in nutrient supply and primary production reportedly foreshadow substantial declines in global marine fishery production. These declines combined with current overfishing, habitat degradation, and pollution paint a grim picture for the future of marine fisheries and ecosystems. However, current models forecasting such declines do not account for the effects of ocean fronts as biogeochemical hotspots. Here we apply a fundamental technique from fluid dynamics to an ecosystem model to show how fronts increase total ecosystem biomass, explain fishery production, cause regime shifts, and contribute significantly to global biogeochemical budgets by channeling nutrients through alternate trophic pathways. We then illustrate how ocean fronts affect fishery abundance and yield, using long-term records of anchovy–sardine regimes and salmon abundances in the California Current. These results elucidate the fundamental importance of biophysical coupling as a driver of bottom–up vs. top–down regulation and high productivity in marine ecosystems.
The Economic Impact of Sports Stadiums: Recasting the Analysis in Context

Independent empirical analyses are often used to refute assertions that sports stadiums can serve as economic catalysts. Criticisms of recent stadium investments, however, are commonly based on stu...
A multitemporal remote sensing approach to parsimonious streamflow modeling in a southcentral Texas watershed, USA

Abstract. Soil moisture condition plays a vital role in a watershed's hydrologic response to a precipitation event and is thus parameterized in most, if not all, rainfall-runoff models. Yet the soil moisture condition antecedent to an event has proven difficult to quantify both spatially and temporally. This study assesses the potential to parameterize a parsimonious streamflow prediction model solely utilizing precipitation records and multi-temporal remotely sensed biophysical variables (i.e.~from Moderate Resolution Imaging Spectroradiometer (MODIS)/Terra satellite). This study is conducted on a 1420 km2 rural watershed in the Guadalupe River basin of southcentral Texas, a basin prone to catastrophic flooding from convective precipitation events. A multiple regression model, accounting for 78% of the variance of observed streamflow for calendar year 2004, was developed based on gauged precipitation, land surface temperature, and enhanced vegetation Index (EVI), on an 8-day interval. These results compared favorably with streamflow estimations utilizing the Natural Resources Conservation Service (NRCS) curve number method and the 5-day antecedent moisture model. This approach has great potential for developing near real-time predictive models for flood forecasting and can be used as a tool for flood management in any region for which similar remotely sensed data are available.
The quantitative analysis of indole glucosinolates by gas chromatography — the importance of the derivatisation conditions

The effect of derivatisation conditions on the quantitative analysis of indole glucosinolates as the desulphated trimethylsilyl derivatives using gas chromatography is examined. Structures for the trimethylsilyl derivatives of glucobrassicin and neoglucobrassicin are suggested from an analysis of their ammonia chemical ionisation mass spectra. Caution is urged in the analysis of these compounds without prior optimisation of the conditions of derivatisation.
Asymptotic distribution theory of statistical functionals: The compact derivative approach for robust estimators

Derivatives of statistical functionals have been used to derive the asymptotic distributions ofL-,M- andR-estimators. This approach is often heuristic because the types of derivatives chosen have serious limitations. The Gâteaux derivative is too weak and the Frechet derivative is too strong. In between lies the compact derivative. This paper obtains strong results in a rigorous manner using the compact derivative onC0(R). This choice of space allows results for a broader class of functionals than previous choices, and the fact that\(\left\{ {\sqrt n \left( {\tilde F_n - F} \right)} \right\}\) is often tight provides the compact set required. A major result is the derivation of the compact derivative of the inverse c.d.f. when the range space is endowed with the uniform norm. It has applications to the asymptotic theory ofL-,M- andR-estimators. We illustrate the power of this result by applications toL-estimators in settings including the one sample problem, data grouped by quantiles, and censored survival time data.
Effect of Strychnine on Dorsal Root Potentials and Amino Acid Responses in Frog Spinal Cord

STRYCHNINE blocks both the postsynaptic inhibition of spinal motoneurones and interneurones and the inhibitory action of glycine-like amino acids (such as glycine, taurine and β-alanine (BALA)) on these neurones in the cat1, 2. These observations provide strong evidence that glycine or a closely related compound mediates spinal postsynaptic inhibition1–3 . Recently, several amino acids with postsynaptic inhibitory effects (such as γ-aminobutyric acid (GABA), BALA and glycine) have been shown to depolarise the primary afferent terminals in an isolated frog spinal cord4–6 and GABA has been proposed as a possible synaptic transmitter mediating primary afferent depolarisation5, 6. However, the fact that the glycine-like amino acids also depolarise the primary afferents in addition to GABA has prompted this study on the action of strychnine in this system.
Observation of small doubly charged niobium clusters

Abstract Small doubly charged niobium clusters are observed in a molecular beam emerging from a laser vaporization/supersonic expansion source if electron impact ionization is utilized in the expansion region. Doubly charged clusters from n = 2 to n = 15 are readily detected. The doubly charged dimer cation has the same charge to mass ratio as the very abundant singly charged monomer. However, the doubly charged dimer can be detected with collision-induced charge exchange reactions and collision-induced dissociation. The kinetic energy released into the fragment ions of the cluster decay process allows us to estimate the charge separation in the parent (4.3 A for the dimer and 5.7 A for the trimer). The results strongly imply that predictions of the stability of doubly charged clusters on the basis of binding energy of the neutral and Coulomb repulsion energy alone do not suffice and that particularly bonding conditions can yield metastable states with substantial lifetimes.
Use of artificial holes in studying community development in cryptic marine habitats in a tropical rocky intertidal region

Previous studies on the rocky intertidal shores of the Bay of Panama indicate that for many sessile and mobile organisms holes and crevices are important refuges from consumers. To study the dynamics of these hole-dwelling species assemblages, we devised a method allowing repetitive, non-destructive sampling and species manipulations in artificial holes. These are fiberglass sleeves with flanges at the outer edge that are inserted into receptacles made of quick-setting concrete. Predator and herbivore manipulations include: fences excluding slow-moving benthic consumers, bars across hole mouths restricting entry of large fishes and homogeneous (shelterless) surfaces created around a treatment decreasing abundance of small crabs. This design has withstood the rigors of two wet seasons in Panama. Results from two sites in Panama indicate that colonization occurs rapidly (6–7 months) in holes established in mid dry season. Encrusting fleshy algae (Ralfsia sp.) and ephemeral green algae (Cladophora spp.) colonize first and are succeeded by encrusting species of coralline algae, bryozoans and colonial tunicates and by erect fleshy red algae. Where consumers are present, encrusting corallines predominate; without consumers, bryozoans, tunicates and erect algae are more abundant. Zonation patterns develop within the holes, with the desiccation/heattolerant Ralfsia sp. dominating at the outer edges. With increasing deph, encrusting coralline algae, bryozoans and colonial tunicates reach their respective peak abundances. In contrast to the high variability observed among naturally occurring holes, replicates of each treatment tend to be similar. Between-treatment and between-site comparisons are less so. The naturally-occurring high level of small-scale patchiness is thus presumably due to variation in recruitment and in the local (microspatial) consumer regime. Substratum heterogeneity is therefore directly and indirectly important in maintaining a high local diversity in this community. As in other studies, consumers or disturbances are key factors in regulating patterns of community structure. More experiments of longer duration are necessary to ascertain the relative importances of consumers/disturbance and competition in controlling such assemblages.
Plasmodium protease ROM1 is important for proper formation of the parasitophorous vacuole.

Apicomplexans are obligate intracellular parasites that invade host cells by an active process leading to the formation of a non-fusogenic parasitophorous vacuole (PV) where the parasite replicates within the host cell. The rhomboid family of proteases cleaves substrates within their transmembrane domains and has been implicated in the invasion process. Although its exact function is unknown, Plasmodium ROM1 is hypothesized to play a role during invasion based on its microneme localization and its ability to cleave essential invasion adhesins. Using the rodent malaria model, Plasmodium yoelii, we carried out detailed quantitative analysis of pyrom1 deficient parasites during the Plasmodium lifecycle. Pyrom1(-) parasites are attenuated during erythrocytic and hepatic stages but progress normally through the mosquito vector with normal counts of oocyst and salivary gland sporozoites. Pyrom1 steady state mRNA levels are upregulated 20-fold in salivary gland sporozoites compared to blood stages. We show that pyrom1(-) sporozoites are capable of gliding motility and traversing host cells normally. Wildtype and pyrom1(-) sporozoites do not differ in the rate of entry into Hepa1–6 hepatocytes. Within the first twelve hours of hepatic development, however, only 50% pyrom1(-) parasites have developed into exoerythrocytic forms. Immunofluorescence microscopy using the PVM marker UIS4 and transmission electron microscopy reveal that the PV of a significant fraction of pyrom1(-) parasites are morphologically aberrant shortly after invasion. We propose a novel function for PyROM1 as a protease that promotes proper PV modification to allow parasite development and replication in a suitable environment within the mammalian host.
Potomacus pottsi n. g., n. sp., a Hymenostome Ciliate from the Potomac River*

SYNOPSIS. Potomacus pottsi n. g., n. sp., a brackish water hymenostome ciliate, is described from the Potomac River. Morphologic studies were made on specimens treated with the Chatton-Lwoff silver impregnation technic. Polymorphism, with the formation of large macrostome forms, was noted. Particular attention is given to the buccal ciliature and its importance to generic assignment in the order Hymenostomatida.
Acetylcholine receptor channel structure probed in cysteine-substitution mutants

In order to understand the structural bases of ion conduction, ion selectivity, and gating in the nicotinic acetylcholine receptor, mutagenesis and covalent modification were combined to identify the amino acid residues that line the channel. The side chains of alternate residues--Ser248, Leu250, Ser252, and Thr254--in M2, a membrane-spanning segment of the alpha subunit, are exposed in the closed channel. Thus alpha 248-254 probably forms a beta strand, and the gate is closer to the cytoplasmic end of the channel than any of these residues. On channel opening, Leu251 is also exposed. These results lead to a revised view of the closed and open channel structures.
Katalytische enantioselektive Diels-Alder-Reaktionen: Methoden, mechanistische Grundlagen, Reaktionswege und Anwendungen

Einhundert Jahre nach der Geburt von Kurt Alder und funfundsiebzig Jahre nach der Entdeckung seiner beruhmten Reaktion, einer der bedeutendsten und faszinierendsten Umwandlungen in der Chemie, ist die Forschung auf diesem Gebiet fur Chemiker in der ganzen Welt noch immer uberraschend, spannend, begeisternd und informativ. Dieser Aufsatz beruht auf Vortragen, die an der Universitat zu Koln (Kurt-Alder-Vortrag, 1992), beim Roger-Adams-Award-Symposium 1993 und anlasslich der Burgenstock-Konferenz 2001 gehalten wurden. Er beschreibt die Forschung unserer Arbeitsgruppe in Harvard uber die Entwicklung und das Verstandnis enantioselektiver Varianten von Diels-Alder-Reaktionen und umfasst 1) die Entwicklung neuer chiraler Lewis-Saure-Katalysatoren fur hoch enantioselektive (>25:1 Enantioselektivitat) [4+2]-Cycloadditionen, 2) mechanistische Einzelheiten und Anordnungen in fruhen Ubergangszustanden dieser Reaktionen, 3) den fundamentalen Einblick in die katalytische Aktivitat und Enantioselektion bei hoch enantioselektiven Diels-Alder-Reaktionen und 4) Anwendungen fur die Synthese komplexer Molekule. Der Anwendungsbereich und die Leistungsfahigkeit der Diels-Alder-Reaktion haben uber sieben Jahrzehnte stetig zugenommen, und ein Ende dieser bemerkenswerten Entwicklung ist nicht in Sicht – eine hohe Anerkennung fur dieses Gebiet der Wissenschaft und ihren grosen Erfinder.
Ambiguous Heritage: Classical Myths in the Works of Nineteenth-Century American Writers

American writers of the nineteenth century display deeply ambiguous attitudes towards classical culture, regarded both as the fountainhead of the American republic and as an outdated, elitist, and alien mode. Nathaniel Hawthorne, Herman Melville, Elizabeth Stoddard, Harold Frederic, Henry James, and Sarah Orne Jewett are among the authors to use significant allusions to classical myths, thus placing American self-identity within the context of a long and idealized cultural tradition. The ancient myths, through their disruptive grappling with the dark side of the human psyche and sexuality, also provided writers with a coded medium through which to question nineteenth-century American values. Hence the ambivalent and even unstable treatment of classical myths in the works of these authors, echoing a more general unease about the role of the Old World in the making of America.
Regulation of Rod Photoreceptor Differentiation by STAT3 Is Controlled by a Tyrosine Phosphatase

Signal pathways that reduce the levels of tyrosine-phosphorylated STAT3 (pSTAT3) allow late retinal progenitors to exit the cell cycle and enter a terminal differentiation pathway into rod photoreceptors. In the mouse retina, we previously identified PKC-β1 and PKC-γ isoforms as essential components of a key signal pathway and IGF-1 as a major extrinsic factor regulating rod formation. In this manuscript, we demonstrate that PKC decreases phosphotyrosine but not phosphoserine on STAT3 in neonatal mouse retinas. Neither IGF-1 nor PMA induced a significant change in the levels of STAT3 or in the levels of the key proteins regulating STAT3 degradation, SOCS3, and PIAS3. Treatment of neonatal mouse retinal explants with sodium orthovanadate inhibited the PKC-mediated reduction in pSTAT3, indicating a role for a phosphatase. Addition of the PTEN inhibitor bpV(phen) to explant cultures treated with IGF-1 or PMA had no effect on the reduction in pSTAT3 levels, but the effect of both IGF-1 and PMA was blocked by a concentration of the inhibitor NSC87877 that is selective for the phosphatases Shp1 and Shp2. Inhibition of Shp1/2 phosphatases was also sufficient to abolish the IGF1-mediated induction of rod photoreceptor differentiation in the retina explant cultures. We conclude that one or both of these phosphatases are key components regulating the formation of rod photoreceptors in mouse retina.
FTIR studies of calcium and sodium ionomers derived from an ethylene–methacrylic acid copolymer

A systematic study of the sodium and calcium salts of an ethylene–methacrylic acid copolymer is reported. Fourier-transform infrared spectroscopy (in the midinfrared region) is applied to the characterization of structural changes as a function of temperature and time of annealing. In the spectra of calcium ionomers, bands associated with carboxylate dimers are identified and assignments of specific spectral features to multiplets and clusters are discussed. The spectroscopic changes observed in the spectra of sodium ionomers differ somewhat from their calcium counterparts in that a single infrared band attributed to isolated carboxylate groups is observed. Assignments of specific bands to multiplets and clusters can, however, be made in a manner consistent with the interpretation of the spectra of calcium ionomers.
Pediatric Oncology Nursing: Providing Care through Decades of Change:

Pediatric oncology nursing practice has evolved over the years as new technology and trends in health care have precipitated change. Three pediatric oncology nursing leaders share their perspectives on nursing practice as it relates to treatment of a child with leukemia during four different points in time. Their comments illustrate the challenges, resources, and rewards. Their reflections, combined with a survey of the literature over the past half a century, show the dramatic impact of advances in supportive care on the practice of caring for a child with cancer. It is also evident that as the cure rate has increased, so have the efforts to improve quality of life. What has transcended time is the delivery of consistent and compassionate care, the education of patients and families, and the dedication to advocacy and support.
Economic development, population and primacy.

RICHARDSON H. W. and SCHWARTZ G. (1988) Economic development, population and primacy, Reg. Studies 22, 467–475. This paper investigates the relationship between economic development and primacy advanced by El-Shakhs, Mera and others, and finds no statistically significant link when obvious demographic influences are taken into account. Three variables (national population, the urban population share, and a Latin American dummy) explain 40% of the variation in primacy in a sample of 116 countries (including 82 developing countries). Economic factors do not appear to be important. Demography may be more influential than economics in attempts to explain primacy. RICHARDSON H. W. et SCHWARTZ G. (1988) Developpement economique, population et primaute, Reg. Studies 22, 467–475. Cet article approfondit le rapport entre le developpement economique et la primaute d'apres El-Shakhs, Mera et al. Il s'avere qu'il n'y a pas de rapport etroit statistique lorsqu'on met en consideration l'impact de l'evolution demographi...
Cell surface glycosphingolipids of normal and leukemic human lymphocytes

We performed an immunofluorescence study of the reactions of purified antibodies to six glycosphingolipids with peripheral blood lymphocytes from normal individuals and patients with chronic lymphatic leukemia. Approximately 50–60% of normal B cells reacted with antibodies to globoside, paragloboside, ganglioside GMl, and asialo GMl, 70–80% reacted with antibodies to lactosyl ceramide and trihexosyl ceramide, and 20–25% was unreactive with all six antibodies. The B lymphocytes of 78 untreated patients with chronic lymphatic leukemia were unreactive with all six antibodies, and those of the eighth patient exhibited decreased staining with all antibodies. Approximately 6–10% of normal T lymphocytes reacted with antibodies to globoside, paragloboside, GMl, and asialo GMl, and 90% of T cells exhibited no immunofluorescent reactions with the six antibodies. These antibodies directed against defined carbohydrate determinants may be useful for identification of subclasses of normal lymphocytes and in analysis of lymphoproliferative disorders.
Light scattering changes correlated with photosynthetic phosphorylation in chloroplast fragments.

Abstract It was postulated and confirmed here that light scattering changes in chloroplast membranes are manifest during photosynthetic phosphorylation. The correlation of the light scattering with photophosphorylation was demonstrated by both processes having the same requirements (phosphate, ADP, and Mg ++ ) and by their inhibition in the presence of NH 4 + ions, under conditions where photosynthetic electron transport proceeds in the presence or absence of these factors. The precise interpretation of the nature of the structural changes in chloroplast fragment systems as indicated by scattering changes is still undefined, but it may be of considerable importance that the energy transfer systems both of mitochondria and chloroplasts are capable of bringing about structural changes in their membranes by the action of the phosphorylation reactions in a predictable manner.
Toward an Augmentative and Alternative Communication symbol taxonomy: A proposed superordinate classification

As the first step in developing a symbol taxonomy, the major augmentative and alternative communication symbol classifications reported in the literature over the past decade are reviewed. The terms used to classify symbols are critically evaluated according to their internal logic, their sociolinguistic implications, and their compatibility with common definitions and usage. The clinical and educational relevance of the classification approach in question, and the reduction of dualclassification ambiguity that a given dichotomy may provide are also evaluated. The aided/unaided classification is based on production of the symbol by the user, while the static/dynamic classification is based upon the nature of the symbol's signal. Although both of these dichotomies have clinical/educational and theoretical/research implications, the aided/unaided dichotomy is proposed as the less ambiguous and the more practical classification for the superordinate level of a taxonomy. A major purpose of this paper is to st...
Thermoluminescence dating of sediments older than ≈100 ka

Abstract For several years attempts have been made to establish reliable procedures for thermoluminescence (TL) dating of sediments older than ≈100 ka. Disagreement persists among TL workers about which procedures are reliable for which sediments. Two recent reports have demonstrated that TL ages up to ≈800 ka for polymineral, fine-silt loess and up to ≈600 ka for quartz from beach-dune sands agree well with expected ages. Several factors that apparently have influeneed negatively the accuracy of other results are: use of ultraviolet TL emissions; use of the regeneration TL procedures for feldspar-bearing samples: use of a single preheating procedure; and use of a peak-integration procedure rather than an equivalent-dose plateau test. Consideration of published data suggests that more attention should be paid to the variable emissions (intensity, glow curve shapes, signal lifetimes) from discrete grains within subsamples. The effects of such variability would probably account for the failure of peak-integration and single-preheating procedures to yield expected equivalent dose values. Single-grain (or micro-TL ) studies of feldspar (and quartz) TL. both spectral emission and glow curve measurements, are recommended as aids to further understanding of current TL sediment dating practices.
Proteoglycans and hypertension. I. A biochemical and ultrastructural study of aorta glycosaminoglycans in spontaneously hypertensive rats.

Abstract The extracellular matrix of blood vessel walls contains elastin, collagen, and proteoglycans, all of which can affect vascular resistance and, hence, blood pressure by virtue of their biomechanical properties.In the present study, we have begun to explore the possibility that proteoglycans may play a role in the pathophysiology of hypertension by analyzing, qualitatively and quantitatively, the polysaccharide components of proteoglycans from aorta of two normotensive rat strains, Wistar Kyoto (WKY) and Wistar rats, and from spontaneously hypertensive (SH) rats of the Okamoto strain.The total concentration of aorta glycosaminoglycans in the SH rat was 33% higher than in the WKY rat, due to a 164% increase in chondroitin 4- and 6-sulfate.The content of dermatan sulfate (DS), hyaluronic acid (HA), and heparan sulfate (HS) was similar in the two strains.The 4-wk-old SH rat also had an increase in chondroitin sulfate (CS) compared to the 4-wk-old WKY rat, without any change in DS, HA, or HS.The Wistar rat had approximately the same concentration of CS and DS in the aorta as the WKY rat, but HS and HA were reduced by 62 and 37%, respectively.The galactosaminoglycans (CS and DS) were heterogeneous on cellulose acetate electrophoresis and exhibited a different pattern for each of the three strains.Undersulfated CS accounted for 15 % of the total CS in WKY aorta but was present in only trace amounts in the SH aorta; 2% of the CS from the Wistar aorta was undersulfated.In all three strains, DS was exclusively 4-sulfated, and the CS contained approximately equal amounts of 4- and 6-sulfated galactosamine residues.Ultrastructural studies demonstrated that the HS was localized in the subendothelial matrix and the pericellular region surrounding the medial smooth muscle cells.CS and DS were primarily associated with collagen in the media.In the SH rat aorta the subendothelial matrix was thicker, and there was a relative increase in the CS/DS in the smooth muscle cell pericellular matrix.We suggest that, if similar alterations in CS proteoglycans are present in the resistance vessels, these changes may contribute to the increased peripheral vascular resistance in the hypertensive animal.
Cretaceous Fossils Collected at Johnson Nunatak, Antarctica

Sandstone samples collected at 74 degrees 52'S, 74 degrees 02'W have been assigned a Cretaceous age on the basis of a faunal assemblage including Rotularia callosa ( Stoliczka).
Ready or not? Preparing future educators for school, family, and community partnerships

Everyone knows that family and community involvement is important for student success in school. There is a big gap, however, between knowing and doing. The challenge for schools, colleges, and dep...