cssi/SciSciGPT-SciSciNet huggingface dataset:
Testing one premise of scientific inquiry in science classrooms: Examining students' scientific explanations and student learning

In this study, we analyzed the quality of students' written scientific explanations found in notebooks and explored the link between the quality of the explanations and students' learning. We propose an approach to systematically analyzing and scoring the quality of students' explanations based on three components: claim, evidence to support it, and a reasoning that justifies the link between the claim and the evidence. We collected students' science notebooks from eight science inquiry-based middle-school classrooms in five states. All classrooms implemented the same scientific-inquiry based curriculum. The study focuses on one of the implemented investigations and the students' explanations that resulted from it. Nine students' notebooks were selected within each classroom. Therefore, a total of 72 students' notebooks were analyzed and scored using the proposed approach. Quality of students' explanations was linked with students' performance in different types of assessments administered as the end-of-unit test: multiple-choice test, predict-observe-explain, performance assessment, and a short open-ended question. Results indicated that: (a) Students' written explanations can be reliably scored with the proposed approach. (b) Constructing explanations were not widely implemented in the classrooms studied despite its significance in the context of inquiry-based science instruction. (c) Overall, a low percentage of students (18%) provided explanations with the three expected components. The majority of the sample (40%) provided only claims without any supporting data or reasoning. And (d) the magnitude of the correlations between students' quality of explanations and their performance, were all positive but varied in magnitude according to the type of assessment. We concluded that engaging students in the construction of high quality explanations may be related to higher levels of student performance. The opportunities to construct explanations in science-inquiry based classrooms, however, seem to be limited. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 583–608, 2010
Resultants of skewly composed polynomials

This paper studies resultants of skewly composed polynomials, obtained from n homogeneous polynomials by replacing their variables with n + 1 other homogeneous polynomials, called the inner components. It is shown that the resultant of such composed polynomials is a nested resultant where the inner resultant only depends on the inner components. This work can be considered as a continuation of Jouanolou's and Cheng/McKay/Wang's works on resultants of composed polynomials, who consider non-skewly composed polynomials obtained by composing n homogeneous polynomials with n homogeneous polynomials. Interestingly, in their case the composition structure causes the resultant of composed polynomials to be a power product of resultants, whereas in the current work it is a completely different nested resultant.
An adaptive mesh-moving and refinement procedure for one-dimensional conservation laws

We examine the performance of an adaptive mesh-moving and /or local mesh refinement procedure for the finite difference solution of one-dimensional hyperbolic systems of conservation laws. Adaptive motion of a base mesh is designed to isolate spatially distinct phenomena, and recursive local refinement of the time step and cells of the stationary or moving base mesh is performed in regions where a refinement indicator exceeds a prescribed tolerance. These adaptive procedures are incorporated into a computer code that includes a MacCormack finite difference scheme wih Davis' artificial viscosity model and a discretization error estimate based on Richardson's extrapolation. Experiments are conducted on three problems in order to qualify the advantages of adaptive techniques relative to uniform mesh computations and the relative benefits of mesh moving and refinement. Key results indicate that local mesh refinement, with and without mesh moving, can provide reliable solutions at much lower computational cost than possible on uniform meshes; that mesh motion can be used to improve the results of uniform mesh solutions for a modest computational effort; that the cost of managing the tree data structure associated with refinement is small; and that a combination of mesh motion and refinement reliably produces solutions for the least cost per unit accuracy.
A combination of four cell types for rapid detection of enteroviruses in clinical specimens.

Isolation in cell culture is currently the most sensitive and reliable way to demonstrate enterovirus (EV) in clinical specimens. During July-October 1982 and 1983, we studied the impact of adding two new cell lines, Buffalo green monkey kidney (BGM) and human rhabdomyosarcoma (RD), to the more traditional cell combination used for EV isolation, human embyronic lung (HEL) and primary cynomolgus monkey kidney (CMK) cells; 2,558 specimens were studied: 632 fecal, 677 respiratory, 537 CSF, and 712 blood. An EV was isolated from 417 (16%); of these, 77 (18%) were positive only in BGM or RD; 35% (146/417) of the specimens were positive in BGM, RD, or both, at least one day earlier than in the traditional cells. BGM cells were helpful in isolation of group B coxsackieviruses (CB): 99% of 121 positive specimens were detected in BGM vs 73% in CMK and 23 % in HEL; 72 % of the CB isolates were detected by day 2 in BGM vs 48% in CMK and 0% in HEL. RD cells were helpful in the isolation of echoviruses: 59% of the 189 positive specimens were detected in RD vs 67% in HEL and 58% in CMK. RD was the only positive cell type in 28/ 189 (15 %) positive specimens; 31 % of the echovirus isolates were detected by day 2 in RD, vs 20% in HEL and 19% in CMK. Using the cell types described, we provided the clinician with results in 42% of the EV-positive specimens by day 2 after inoculation and in 61 % by day 4.
An Experimental Study of Plastic Synthetics in Thoracic Surgery

Since Tuffier's original description of the extrapleural operation in 1891, the procedure has been subjected to various modifications, particularly the introduction of different plombage materials. Fat was probably the first solid plombe to be employed, but was discarded rather early because of its inherent deficiencies: lack of resistance to pressure and tendency to liquefy. Bear's introduction of the paraffin pack was a notable step forward, and indeed this method is still in use. Subsequently, in a attempt to find the ideal type of plombe, various investigators have used gauze, rubber dam, rubber balloons, muscle flaps, and oil. As in all therapeutics, the very multiplicity of the agents used attests to the universal lack of applicability of any one. However, some of the discredit which has accrued to the procedure stems not only from the individual substance themselves, but from the very nature of the operation. One of the most frequent and disastrous complications of the procedure is broncho-extrapleural fistula. This has been commonly attributed to perforation of large, peripherally placed cavities either by pressure of the plombe, or secondary to necrosis of the cavity wall following stripping of its parietal extrapleural blood supply. Although there is no universal agreement on the pathogenesis of broncho-extrapleural fistulae, there is some evidence that pressure of an extrapleural pack may play a part. Certainly, too, those series in which case selection has been carefully carried out with regard to size, type, and position of cavities have shown a notably low incidence of fistu1ae.l The inadequacy of the plombage materials devised to date has led many phthisiologists to return to extrapleural pneumothorax as a definitive procedure or as a preliminary procedure to a permanent oleothorax. This approach has been particularly popular in Scandinavia and Mexi~o,~ and workers in those countries attribute its efficacy to meticulous attention to detail in its performance. In this country, extrapleural pneumothorax has not become widely popular, chiefly because of the technical factors in the operation, ' the difficulty encountered in maintaining the space, and the need
Application of the Electromechanical Surface Damping to the Vibration Control of a Cantilever Plate

The electromechanical surface damping technique (EMSD) is applied to suppress the bending and twisting (torsional) peak vibration amplitudes of a cantilever plate. The technique is a combination of the constrained layer damping (CLD) and the shunted piezoelectric methods in which the constraining layer of the CLD is replaced by a shunted piezoelectric ceramic. The frequency responses, to a white noise random base excitation, of the EMSD-treated plate at the vicinity of the first and second bending and twisting resonant frequencies are determined and compared with the corresponding responses of the CLD treatment. It is shown that, in general, the EMSD treatment provides more suppression of the bending and twisting peak vibration amplitudes than the conventional CLD treatment. The EMSD treatment, however, is more effective at higher frequencies and lower temperatures, which suggests that the EMSD method can be applied to extend the effective range of frequencies and/ or temperatures of the conventional CLD method. The work presented is primarily analytical; however, a crude and preliminary experimental work is presented to demonstrate the feasibility of the EMSD technique.
5-HT induces duodenal mucosal bicarbonate secretion via cAMP- and Ca2+-dependent signaling pathways and 5-HT4 receptors in mice

In previous studies, we have found that 5-hydroxytryptamine (5-HT) is a potent stimulant of duodenal mucosal bicarbonate secretion (DMBS) in mice. The aim of the present study was to determine the ...
High-Resolution, Rotationally Resolved Electronic Spectroscopy of the MgNC Radical.

High-resolution, rotationally resolved, laser-induced fluorescence (LIF) spectra for the origin band, as well as several transitions involving vibrationally excited levels of the A2Pi <-- &Xtilde2Sigma+ electronic transition of the MgNC radical, have been recorded using the output of a pulse-amplified Ti:Sapphire ring laser. The MgNC radical was generated in a supersonic free jet expansion by simultaneous laser ablation of a magnesium rod and photolysis of acetonitrile (CH3CN). Rotational analysis yielded molecular constants for both the ground and excited states of the studied vibronic transitions. The molecular constants for the vibrationless state of the &Xtilde state are in excellent agreement with previous microwave studies of MgNC. Since the A electronic state of MgNC is a linear 2Pi state, the bending vibronic level structure is subject to both Renner-Teller and spin-orbit coupling. Suggested vibronic assignments of the observed transitions, made considering both these interactions and with the aid of the rotational analysis, are discussed. Copyright 1999 Academic Press.
Pemetrexed in the treatment of advanced non-small-cell lung cancer: A review of the clinical data

Pemetrexed is a novel multitargeting antimetabolite that has first-line and second-line activity against non-small cell lung cancer (NSCLC). Phase II studies have shown significant efficacy and a favorable toxicity profile of the combination of pemetrexed plus platinum as first-line therapy for NSCLC. Second-line activity against NSCLC was demonstrated in a phase III trial comparing single-agent pemetrexed with docetaxel; in that trial, survival was comparable between these agents but side effects were significantly less for patients who received pemetrexed. Pemetrexed is also an active agent against mesothelioma. A phase III trial comparing pemetrexed plus cisplatin with cisplatin alone showed for the first time a regimen that improves survival in this disease and led to FDA approval of pemetrexed in combination with cisplatin for mesothelioma. As a radiosensitizer, pemetrexed has been well-tolerated when given concurrent with chest radiation, and a phase I study is under way assessing its tolerability in combination with carboplatin in this setting. Pemetrexed is clearly a useful agent in the treatment of thoracic malignancies, and is worthy of further study in combination with other drugs having novel mechanisms of action.
Single-hole state in half-filled 2D Hubbard model

We have investigated the ground state of a single hole in the half-filled Hubbard model on a 2D square lattice using the coupled-cluster method. In particular we obtained an analytical expression of the hole energy dispersion function ɛ(k) which is consistent with earlier studies on thet-J model in the strong-coupling limit. An appreciable discrepancy on the hole energy bandwidth is, however, observed between the Hubbard model and thet-J model. We believe that this discrepancy is due to the absence of the three-site interaction term in thet-J model.
Electromechanical characterization of a active structural fiber lamina for multifunctional composites

Abstract Piezoelectric fiber composites (PFCs) are a new group of materials recently developed in order to overcome the fragile nature of monolithic piezoceramics. To resolve the inadequacies of current PFCs, a novel active structural fiber (ASF) was developed that can be embedded in a composite material to perform sensing and actuation, in addition to providing load bearing functionality. The ASF combines the advantages of the high tensile modulus and strength of the traditional composite reinforcements as well as the sensing and actuation properties of piezoceramic materials. A micromechanics model and a finite element model have been developed to study the effective piezoelectric coupling coefficient of the ASF as well as the ASF lamina. In order to evaluate the performance of the ASF when embedded in a polymer matrix and validate the model’s accuracy, single fiber lamina have been fabricated and characterized through testing with an atomic force microscope. The results of the testing demonstrate the accuracy of the model and show that ASF composites could lead to load bearing composites with electromechanical coupling greater than most pure piezoelectric materials.
Sulfonamide-reactive lymphocytes detected at very low frequency in the peripheral blood of patients with drug-induced eruptions☆☆☆★★★

Abstract Background: The role of T lymphocytes in mediating drug eruptions is uncertain. Methods: Twenty-four patients with eruptions induced by sulfonamide-related drugs were studied to detect lymphocyte reactivity to drugs. Both the lymphocyte transformation test and limiting dilution analysis were used as assays for drug-reactive lymphocytes. Peripheral blood lymphocytes were expanded in interleukin-2 and tested for reactivity to sulfamethoxazole and furosemide. Results: The lymphocyte transformation test results to sulfamethoxazole, sulfisoxazole, and furosemide were found to be generally unreliable with a high rate of false-negative and false-positive results. However, as determined by limiting dilution analysis, sulfamethoxazole-reactive lymphocytes were detected in the peripheral blood of one patient at a frequency of 1/172,000. This is within the lower range of frequencies of urushiol-reactive T cells in the peripheral blood of patients with allergic contact dermatitis to urushiol (poison ivy). Two sulfonamide-reactive lymphocyte lines were cultured from two patients. Both lines proliferated in response to sulfamethoxazole but not in response to furosemide, suggesting that furosemide does not cross-react with the sulfonamides. Conclusions: Lymphocytes reactive to sulfamethoxazole were detected at low frequencies in the peripheral blood of three patients with drug eruptions secondary to administration of sulfamethoxazole. (J ALLERGY CLIN IMMUNOL 1994;94:465-72.)
Reading list offered by Virginia Commonwealth University Medical College of Virginia School of Dentistry: an evaluation

A reading list that consists of valuable articles on dentistry is compiled quarterly to assist the practitioner in the development of an effective home-study program. One year after the initiation of the program, a questionnaire was mailed to the participants to determine the effectiveness of this endeavor. Feedback from the questionnaires indicated a favorable reaction and an enthusiastic desire for the continuation of the program. The Virginia Commonwealth University School of Dentistry compiles quarterly a reading list that is designed to keep the practitioner abreast of current developments within the profession.
Circularly Polarized Phase Shifter for Use in Phased Array Antennas

An X-band, circularly-polarized, nonreciprocal, ferrite phase shifter has been developed whose size and electrical performance are favorably suited for use in transmission or reflection-type phased arrays requiring element center-to-center spacings of about 0.5 /spl lambda/. The phase shifter has the same configuration as a Faraday rotator with a ferrite rod located at the center of a circular waveguide with an axially applied field. If a circularly polarized wave is passed through this geometry, a nonreciprocal phase-current characteristic is obtained. The array antenna is configured so that no phase-control field reversals are needed between transmit and receive modes of RADAR operation. The radiating element has been designed as an integral part of the beam steering element using waveguide array simulator techniques, this paper will discuss various design problems and performance of the beam steering element. A 1300-element phased array was constructed and tested. Its performance, as it relates to the phase-setting accuracy of 1300 phase-shifter constituents, is stated briefly.
Transboundary Forestry and Water Management in Nicaragua and Honduras: From Conflicts to Opportunities for Cooperation

In the mountainous western border region of Nicaragua and Honduras, a lack of integrated forestry, water, and land-use policies has contributed to a series of interrelated conflicts both within and across country borders. These conflicts are manifested in increases in illegal deforestation, forest fires, and deteriorating surface water resources. Although problems appear most obviously in terms of natural resource shortages, the root of the problems is often the inadequate decision-making process. In this study, we use a problem-oriented approach to describe three natural resource conflicts, analyze the decision-making and social processes contributing to these conflicts, and offer recommendations by describing how a bi-national community-based water monitoring regime could improve data collection and the inclusivity of the decision-making process.
The Ghosts of Institutionalization at Pennhurst's Haunted Asylum

In the woods of Spring City, Pennsylvania, lies Pennhurst, a school for people with developmental and physical disabilities from 1908 to 1987. Like many institutions, Pennhurst eventually became a place of abuse and neglect. Pennhurst was finally shut down, and the residents were relocated into group homes. Two years ago, a group well educated about Pennhurst's past formed the Pennhurst Memorial and Preservation Alliance, a nonprofit dedicated to making Pennhurst into a national museum. Standing in the way of PM&PA's vision was a businessman named Richard Chakejian, who purchased Pennhurst from the state for $2 million and has now converted it to a haunted house. The result is a bizarre hybrid of history and legend, and of criminality and commercialism, that simultaneously evokes and erases Pennhurst's troubled past.
Encryption and Error-Correction Coding Using D Sequences

This paper presents several new properties of D sequences that have applications to encryption and error coding. It also considers the problem of joint encryption and error-correction coding and proposes a solution using D sequences. The encryption operation considered is equivalent to exponentiation, which forms the basis of several public-key schemes. An application of D sequences to generating events with specified probabilities is also presented.
Acute pancreatitis in patients after bariatric surgery: incidence, outcomes, and risk factors.

The incidence of acute pancreatitis (AP) in bariatric surgery patients is not known. Ouraim was to determine the incidence, outcomes, and risk factors of AP in post-bariatric surgery patients. An historical cohort study was conducted of all patients who underwent Roux-en-Y gastric bypass, sleeve gastrectomy, adjustable gastric banding, and revisional procedures at our institution from January 2004 to September 2011. Patients who developed AP were identified by review of the electronic medical record. A nested case-control study using Cox regression analysis was done to identify risk factors. A total of 2695 patients underwent bariatric surgery. Twenty-eight patients (1.04 %) developed AP during a median follow-up of 3.5 years (interquartile range [IQR] 1.9–5.8). One patient had severe AP, and there was one AP-related death. In the case-control study, the only baseline variable that predicted post-operative AP was a prior history of AP. Three other variables identified after surgery were associated with AP: (1) rapid weight loss as measured by percent of excess weight loss (EWL) at the first post-operative visit, (2) abnormal findings on post-operative ultrasound (stones, sludge or ductal dilation), and (3) post-operative complications of bowel leak or anastomotic stricture. The incidence of AP in this cohort is 1.04 %, which is higher than that reported for the general population (~17/100,000, 0.017 %). Most cases were clinically mild and managed conservatively with good outcomes. Rapid post-operative weight loss and the presence of gallstones or sludge on post-operative ultrasound were significant risk factors for AP.
Stiffness Shaping for Zero Vibration Fluidic Flexible Matrix Composites

This paper studies semi-active vibration control using Fluidic Flexible Matrix Composites (F2 MC) as variable stiffness structures. The apparent stiffness of F2 MC tubes can be changed using a variable orifice valve. With fiber reinforcement, the volume inside the tube may change with external load. With an open valve, the liquid is free to move in or out of the tube, so the apparent stiffness will not changed. When the valve is closed, the high bulk modulus liquid is confined, which resists the volume change and causes the apparent stiffness of the tube to increase. The equations of motion of an F2 MC-mass system is derived using a 3D elasticity model and the energy method. A reduced order model is then developed for fully-open or fully-closed valves. A Skyhook valve that cycles the valve between open and closed, asymptotically decays the vibration. A Zero Vibration (ZV) Stiffness Shaping technique is introduced to suppress the vibration in finite time. A sensitivity analysis of the ZV Stiffness Shaper studies the robustness to parameteric uncertainties.© 2008 ASME
Vascular proliferation and vascular endothelial growth factor expression in the rhesus macaque endometrium.

The relationship between vascular endothelial growth factor (VEGF) expression and the pattern of vascular proliferation in the rhesus macaque endometrium has not been studied. In this report, we used in situ hybridization to evaluate VEGF, VEGF receptor type 1 and VEGF receptor type 2 mRNA expression during hormonally regulated menstrual cycles in ovariectomized macaques. Proliferating endothelial cells were identified by a double immunocytochemistry procedure that detected Ki-67 antigen and von Willebrand factor in the same endothelial cells. One and 2 d after progesterone withdrawal (premenstrual), VEGF mRNA was up-regulated in the glands and stroma of the superficial endometrial zones, a finding that supports our previous suggestion that VEGF may play a role in the menstrual induction cascade. During the postmenstrual repair phase, the healing surface epithelium showed a further, dramatic increase in expression of VEGF mRNA, accompanied by strong increases in signals for VEGF receptor types 1 and 2 in ...
Meal-Feeding Rodents and Toxicology Research

Most laboratory rodents used for toxicology studies are fed ad libitum, with unlimited access to food. As a result, ad libitum-fed rodents tend to overeat. Research demonstrates that ad libitum-fed rodents are physiologically and metabolically different from rodents fed controlled amounts of food at scheduled times (meal-fed). Ad libitum-fed rodents can develop hypertriglyceridemia, hypercholesterolemia, diet-induced obesity, nephropathy, cardiomyopathy, and pituitary, pancreatic, adrenal, and thyroid tumors, conditions likely to affect the results of toxicology research studies. In contrast, meal-feeding synchronizes biological rhythms and leads to a longer life span, lower body weight, lower body temperature, hypertrophy of the small intestine, and synchronization of hepatic and digestive enzymes. The circadian rhythms present in nearly all living organisms are entrained by light intensity and food intake, and peripheral clocks in all organs of the body, especially the GI tract and liver, are particularly sensitive to food intake. Feeding schedule has been demonstrated to alter the toxicity and metabolism of drugs including sodium valproate, chloral hydrate, acetaminophen, gentamicin, and methotrexate. Feeding schedule alters the expression of genes that code for Phase I, II, and III proteins, thereby altering the rate and amplitude of drug disposition. Rhythms of plasma insulin and glucagon that fluctuate with food ingestion are also altered by feeding schedule; ad libitum feeding promotes hyperinsulinemia which is a precursor for developing diabetes. The emerging field of chronopharmacology, the interaction of biological rhythms and drugs, will lead to optimizing the design and delivery of drugs in a manner that matches biological rhythms, but it is wise for toxicology researchers to consider feeding schedule when designing these experiments. It has been 10 years since the Society for Toxicologic Pathology voiced its position that feeding schedule is an important variable that should be controlled in toxicology experiments, and research continues to underscore this position.
A mixed-mode FPAA SoC for analog-enhanced signal processing

We present the RASP 2.9v, an FPAA for mixed-signal computation with an emphasis on enhanced digital support. This 25mm2, 350nm CMOS chip includes on-chip compilable DACs, dynamic reconfigurability and digital storage, and 76,000 programmable elements. We demonstrate an analog image-transform processor, an arbitrary waveform generator, and a mixed-mode FIR filter.
White light Sagnac interferometer for snapshot linear polarimetric imaging.

The theoretical and experimental demonstration of a dispersion-compensated polarization Sagnac interferometer (DCPSI) is presented. An application of the system is demonstrated by substituting the uniaxial crystal-based Savart plate (SP) in K. Oka’s original snapshot polarimeter implementation with a DCPSI. The DCPSI enables the generation of an achromatic fringe field in white-light, yielding significantly more radiative throughput than the original quasi-monochromatic SP polarimeter. Additionally, this interferometric approach offers an alternative to the crystal SP, enabling the use of standard reflective or transmissive materials. Advantages are anticipated to be greatest in the thermal infrared, where uniaxial crystals are rare and the at-sensor radiance is often low when compared to the visible spectrum. First, the theoretical operating principles of the Savart plate polarimeter and a standard polarization Sagnac interferometer polarimeter are provided. This is followed by the theoretical and experimental development of the DCPSI, created through the use of two blazed diffraction gratings. Outdoor testing of the DCPSI is also performed, demonstrating the ability to detect either the S2 and S3, or the S1 and S2 Stokes parameters in white-light.
Who joins a preventive intervention? How risk status predicts enrollment

The objective of this study was to identify social, psychological, and health-related variables that predict mothers' refusals to join a prevention program for families of children with chronic illnesses. A two-step recruitment process was used with 193 families of children with chronic illnesses. First, families were recruited for a longitudinal research survey. Then, mothers were given the opportunity to randomly receive one of two programs. Mothers who refused the opportunity to participate in either program continued in the research project. Data were collected through structured interviews at baseline and 12 months later. Compared to mothers who agreed to participate in one of the programs, those who refused reported more confidence, more support, and less depression and higher functional status and better adjustment in their child. Mothers who agree to participate in a longitudinal research effort but refuse to participate in an intervention program are likely to be functioning well, and may perceive no need for a program designed to prevent mental health problems. © 2001 John Wiley & Sons, Inc.
A New, Non-Destructive Method for Sampling Burrowing Crayfish

Abstract Burrowing crayfish are typically sampled by excavation, which results in habitat destruction. Several less destructive trapping methods have been devised, though their results have been inconsistent in our experience. To conduct studies of growth and longevity, a more efficient method was needed to sample burrowing crayfish while leaving their burrows intact. We describe a new trap design based on a reversed pitfall trap. This trap was tested using a population of burrowing crayfish, Cambarus Lacunicambarus diogenes (Devil Crayfish), in Alabama. The weekly trapping success rate (n = 18 traps) over a 4-week period ranged from 6% to 33%, with an average success rate of 17%. We feel that the implementation of our design will enhance studies requiring nondestructive sampling.
Active isolation devices

This paper examines the design of a linear motor combining piezoceramic actuation with viscoelastic damping. The actuator consists of aluminum discs alternately treated with piezoceramics and viscoelastic material. The discs are joined together by a rod through their center and cantilevered inside a cylinder to form a linear motor. This configuration offers increased design flexibility. The issues of a combined passive/active actuator design are discussed in terms of vibration isolation.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Reversal of the antiproliferative effect of the antiestrogen tamoxifen by polyamines in breast cancer cells.

Numerous studies suggest a relationship between the action of hormones on their target tissues and the synthesis of polyamines. To evaluate the role of polyamines in the mediation of the effect of estrogen on the growth of experimental hormone-responsive mammary cancer, we investigated whether the cytotoxic effect of the antiestrogen tamoxifen could be rescued by exogenous administration of polyamines. When added to N-nitrosomethylurea-induced mammary tumors grown in soft agar in the presence of tamoxifen, putrescine, spermidine, and spermine were able to reverse the inhibitory effect of antiestrogens on colony formation in a dose-dependent fashion. In contrast, no effect on colony number was observed when polyamines were added in the absence of tamoxifen. These results indicate that in this system, the antitumor effect of tamoxifen is mediated through induction of polyamine depletion. Consequently, the data suggest that estrogens may stimulate mitogenesis of the N-nitrosomethylurea-induced mammary tumor ...
Mitosis: Aurora Gives Chromosomes a Healthy Stretch

Abstract Attachment of sister chromatids to microtubules from opposite spindle poles — bi-orientation — generates tension at the kinetochores. The Ipl1/Aurora B kinase responds to the absence of tension at mono-oriented chromosomes and promotes microtubule turnover and spindle checkpoint activation until a stable bi-oriented attachment is achieved.
Timing in the evolution of derived floral characters: upper cretaceous (turonian) taxa with tricolpate and tricolpate-derived pollen

Abstract Various hypotheses that seek to explain the rich species diversity of angiosperms relative to other seed plants are briefly mentioned or reviewed. Of these, the subset that relates angiosperm diversity in some way to the relationship between angiosperms and insects, particularly anthophilous insects, is here the object of attention. Specifically, I address and reject the possibility that the relationship between angiosperm diversification and insects, particularly those demonstrating a preference for flowers with derived floral characteristics associated with insect pollination, may be ruled out because of asynchronous patterns of diversification in the fossil record. New data on floral structure from the Turonian of the Atlantic Coastal Plain reveal a surprising diversity of floral characters in taxa bearing tricolpate and tricolporate-derived pollen. The characters and taxa that appear in these Turonian sediments suggest that rather specific modes of insect pollination, perhaps involving highly derived insect pollinators, already existed at 90 Ma. Given the observed rate of diversification of angiosperms during that time and the pattern of evolution in insects, including what can be inferred about the history of the Apidae, these new floral data suggest that hypotheses relating angiosperm diversity to highly specific pollinators are still valid in the context of fossil evidence. Even so, consistency with fossil evidence is not necessarily proof of these relationships. In any case, there may well be multiple causes of relatively high angiosperm species diversity and understanding the relative importance of each of these requires neontological as well as paleontological investigations. One promising approach is to work within the context of phylogenetic patterns with more fossil data.
Glutamate-459 Is Important for Escherichia coli Branching Enzyme Activity†

The branching enzyme belongs to the amylolytic family, a group of enzymes that cleave and/or transfer chains of glucan. The amylolytic enzymes are homologous and all contain four conserved regions, proposed to contain the active site. By primary structure analysis, a conserved position unique to branching enzymes has been identified. This residue, which is either Asp or Glu, depending on the species, is located immediately after the putative catalytic Glu-458 (Escherichia coli numbering). Branching enzymes differ from other amylolytic enzymes in having this acid pair, and we asked if this motif could be essential for branching enzyme action. We used site-directed mutagenesis of the Glu-459 residue in the E. coli branching enzyme in order to determine the significance of the conserved Asp/Glu in branching enzymes. A substitution of Glu-459 to Asp resulted in increased specific activity compared to wild-type, suggesting that the mutation had created a more efficient enzyme. Changing Glu-459 to Ala, Lys, or Gln lowered the specific activities and altered the preferred substrate from amylose to amylopectin.
Solar Cycle Forecasting

Predicting the behavior of a solar cycle after it is well underway (2–3 years after minimum) can be done with a fair degree of skill using auto-regression and curve fitting techniques that don’t require any knowledge of the physics involved. Predicting the amplitude of a solar cycle near, or before, the time of solar cycle minimum can be done using precursors such as geomagnetic activity and polar fields that do have some connection to the physics but the connections are uncertain and the precursors provide less reliable forecasts. Predictions for the amplitude of cycle 24 using these precursor techniques give drastically different values. Recently, dynamo models have been used directly with assimilated data to predict the amplitude of sunspot cycle 24 but have also given significantly different predictions. While others have questioned both the predictability of the solar cycle and the ability of current dynamo models to provide predictions, it is clear that cycle 24 will help to discriminate between some opposing dynamo models.
Planting Date and Glyphosate Timing on Soybean

Planting date of soybean may be one factor that affects the crop's ability to compete with weeds. Field experiments were conducted over 3 yr at two locations in Illinois to determine whether planting date affects optimal weed management strategies and the critical time of weed removal (CTWR) in glyphosate-resistant soybean. Across planting dates, a PRE application of metolachlor plus metribuzin followed by a single glyphosate application at a 10- or 20-cm weed height at Monmouth or at a 20-cm weed height at Urbana was effective at protecting yield. At Monmouth, higher yields occurred with sequential glyphosate applications than with a single application in the early planting in 2 yr when weeds were removed at a height of 10 cm. Across planting dates, highest yields at Monmouth occurred with a single glyphosate application when weeds were 20 to 30 cm tall. At Urbana, the CTWR was not affected by planting date and occurred between 176 and 290 growing-degree days (GDD) after planting, corresponding to the V1...
Determination of Iron Toxicity in Mice

Studies indicated that mice fasted 22 ± 2 hr. prior to treatment were consistent in the way they reacted to oral administration of iron. The maintenance of a uniformly empty intestinal tract prior to oral administration of iron made possible a linear relationship between log-dose and death. Commercial iron preparations were employed to demonstrate different toxicities due to different availabilities of iron, and LD 50 's were estimated where possible. The oral LD 50 of FeSO 4 .7H 2 O containing 0.201 mg. of Fe/mg. was found to be 160 ± 3 mcg./Gm. (32 ± 0.6 mcg. of Fe/Gm.), using death within 24 hr. as the end point following a prior defined stated fasting period; the LD 50 after 1.5 hr. was determined also. The symptoms of toxicity and the time and pattern of death were found similar to the form iron toxicity takes in humans. A ferrous sulfate solution was found to be a satisfactory standard iron preparation, and oral LD 50 estimates were made in male and female Fairfield Webster and B 4 BC strains of fasted mice. The B 4 BC strain in both sexes was found to be more susceptible to iron toxicity than the Fairfield Webster strain. The males of the Fairfield Webster strain were found more sensitive to iron toxicity than the females. Mice exposed to feces and sawdust during the prior fasting period were found less susceptible to iron toxicity than those animals isolated from these elements during this fasting period.
Finite element analysis of an accordion-like honeycomb scaffold for cardiac tissue engineering

Optimizing the function of tissue engineered cardiac muscle is becoming more feasible with the development of microfabricated scaffolds amenable to mathematical modeling. In the current study, the elastic behavior of a recently developed poly(glycerol sebacate) (PGS) accordion-like honeycomb (ALH) scaffold [Engelmayr et al., 2008. Nature Materials 7 (12), 1003-1010] was analyzed. Specifically, 2D finite element (FE) models of the ALH unit cell (periodic boundary conditions) and tessellations (kinematic uniform boundary conditions) were utilized to determine a representative volume element (RVE) and to retrospectively predict the elastic effective stiffnesses. An RVE of 90 ALH unit cells (≃3.18×4.03mm) was found, indicating that previous experimental uni-axial test samples were mechanically representative. For ALH scaffolds microfabricated from PGS cured 7.5h at 160°C, FE predicted effective stiffnesses in the two orthogonal material directions (0.081±0.012 and 0.033±0.005MPa) matched published experimental data (0.083±0.004 and 0.031±0.002MPa) within 2.4% and 6.4%. Of potential use as a design criterion, model predicted global strain amplifications were lower in ALH (0.54 and 0.34) versus rectangular honeycomb (1.19 and 0.74) scaffolds, appearing to be inversely correlated with previously measured strains-to-failure. Important in matching the anisotropic mechanical properties of native cardiac muscle, FE predicted ALH scaffolds with 50μm wide PGS struts to be maximally anisotropic. The FE model will thus be useful in designing future variants of the ALH pore geometry that simultaneously provide proper cardiac anisotropy and reduced stiffness to enhance heart cell-mediated contractility.
Impact of size of region-of-interest on differentiation of renal cell carcinoma and renal cysts on multi-phase CT: Preliminary findings

Abstract Introduction To assess impact of size of regions-of-interest (ROI) on differentiation of RCC and renal cysts using multi-phase CT, with focus on differentiating papillary RCC (pRCC) and cysts given known hypovascularity of pRCC. Methods 99 renal lesions (23 pRCC, 47 clear-cell RCC, 7 chromophobe RCC, 22 cysts) underwent multi-phase CT. Subjective presence of visual enhancement was recorded for each lesion. Whole-lesion (WL) ROIs, and small (≤5 mm2), medium (average size of small and large ROIs), and large (half of lesion diameter) peripherally located partial-lesion (PL) ROIs, were placed on non-contrast and nephrographic phases. Impact of ROI size in separating cysts from all RCC and from pRCC based on increased attenuation between phases was assessed using ROC analysis. Results Visual enhancement was perceived in 96% of ccRCC, 61% of pRCC, and 9% of cysts. AUCs for separating all RCC and cysts for WL-ROI and small, medium, and large PL-ROIs were 91%, 96%, 91% and 93%, and among lesions without visible enhancement were 60%, 79%, 67% and 67%. AUCs for separating pRCC and cysts for WL-ROI and small, medium, and large PL-ROIs were 78%, 92%, 82% and 84%, and among lesions without visible enhancement were 64%, 88%, 69% and 69%. Conclusion Small PL-ROIs had higher accuracy than WL-ROI or other PL-ROIs in separating RCC from cysts, with greater impact in differentiating pRCC from cysts and differentiating lesions without visible enhancement. Thus, when evaluating renal lesions using multi-phase CT, we suggest placing small peripheral ROIs for highest accuracy in distinguishing renal malignancy and benign cysts.
Roles apparent resistivity amplitude and phase play in an aquifer's electrical‐hydraulic conductivity correlation

[1] This paper argues how the spectral characteristics of two borehole apparent resistivity traces further corroborate two statistically significant electrical-hydraulic (eh) conductivity correlations previously reported in Nevada's fractured welded tuffs. Even though the eh conductivity correlation is positive in one borehole and negative in the other, as explained by low pore water electrical conductivity and the absence or presence of alteration minerals, both apparent resistivity amplitude spectra are identically power-law structured. This is interpreted to mean that eh flow is occurring along rock fractures of a common regional fractal dimension. Furthermore, both apparent resistivity phase spectra are strikingly linear, as mandated by the condition of incompressible fluids. Linear phase implies a groundwater flow that is geostatistically nonstationary in the wide sense, a complication normally not considered by hydrogeologists.
The Incredible Years: Parents, Teachers, and Children Training Series

SUMMARY This article summarizes the Incredible Years Training Series which consists of three empirically validated and integrated programs for parents, teachers and children that are designed to promote social competence and prevent, reduce and treat conduct problems in young children ages 3 to 8 years. This summary explains the risk and protective factors related to the early development of conduct problems and describes how these interventions address those risk factors which are malleable. The training methods, content, and processes are explained. Finally, the highlights of selected studies of each of these programs is presented.
Millennial musings on molecular motors

In a universe that is dominated by increasing entropy, living organisms are a curious anomaly. The organization that distinguishes living organisms from their inanimate surroundings relies upon their ability to execute vectorial processes, such as directed movements and the assembly of macromolecules and organelle systems. Many of these phenomena are executed by molecular motors that harness chemical potential energy to perform mechanical work and unidirectional motion. This article explores how these remarkable protein machines might have evolved and what roles they could play in biological and medical research in the coming decades.
Imagery Scripts and a Computerized Subtraction Stress Task Both Induce Stress in Methamphetamine Users: A Controlled Laboratory Study

Patients treated for methamphetamine (MA) dependence have a high rate of relapse, and stress is thought to play a key role. We sought to develop a computerized procedure for experimentally inducing stress in MA users. In a within-subjects design, we compared a computerized subtraction stress task (SST) to personalized stress-imagery scripts and a control condition (neutral imagery) in 9 former MA users, recruited in San Francisco in 2006–2007. We assessed blood hormone levels, anxiety and craving for MA on visual analog scales, and the Positive and Negative Affect Schedule and made linear mixed-effects models to analyze the results. Both the SST and stress scripts were effective in inducing self-report markers of stress in MA users. Because the SST is easily reproducible and requires less time of staff and participants, it may be a useful alternative for measuring stress reactivity in drug users.
Flower development: Repressing reproduction

The homeotic genes that determine floral organ identity in plants turn out to be regulated by trans-acting factors related to the Polycomb-group proteins that have long been known as regulators of homeotic gene expression in Drosophila.
St John's wort and imipramine-induced gene expression profiles identify cellular functions relevant to antidepressant action and novel pharmacogenetic candidates for the phenotype of antidepressant treatment response

Both the prototypic tricyclic antidepressant imipramine (IMI) and the herbal product St John's wort (SJW) can be effective in the treatment of major depressive disorder. We studied hypothalamic gene expression in rats treated with SJW or IMI to test the hypothesis that chronic antidepressant treatment by various classes of drugs results in shared patterns of gene expression that may underlie their therapeutic effects. Individual hypothalami were hybridized to individual Affymetrix chips; we studied three arrays per group treatment. We constructed 95% confidence intervals for expression fold change for genes present in at least one treatment condition and we considered genes to be differentially expressed if they had a confidence interval excluding 1 (or -1) and had absolute difference in expression value of 10 or greater. SJW treatment differentially regulated 66 genes and expression sequence tags (ESTs) and IMI treatment differentially regulated 74 genes and ESTs. We found six common transcripts in response to both treatments. The likelihood of this occurring by chance is 1.14 x 10(-23). These transcripts are relevant to two molecular machines, namely the ribosomes and microtubules, and one cellular organelle, the mitochondria. Both treatments also affected different genes that are part of the same cell function processes, such as glycolytic pathways and synaptic function. We identified single-nucleotide polymorphisms in the human orthologs of genes regulated both treatments, as those genes may be novel candidates for pharmacogenetic studies. Our data support the hypothesis that chronic antidepressant treatment by drugs of various classes may result in a common, final pathway of changes in gene expression in a discrete brain region.
Dexamethasone blocks the systemic inflammation of alveolar hypoxia at several sites in the inflammatory cascade.

Alveolar hypoxia produces a rapid and widespread systemic inflammation in rats. The inflammation is initiated by the release into the circulation of monocyte chemoattractant protein-1 (MCP-1) from ...