cssi/SciSciGPT-SciSciNet huggingface dataset:
Engagement and affect patterns in high school mathematics classrooms that exhibit spontaneous problem posing: an exploratory framework and study

Spontaneous problem posing (SPP) is presented as a phenomenon central to mathematical thinking, wherein learners generate problems without formal prompting, and where posed problems originate from the learner’s motivation to improve their knowledge. Because of this, they may serve as important markers of productive mathematical engagement—in particular, affective engagement—both for problem posers and their classroom communities (D’Mello & Graesser in Learning and Instruction, 22(2), 145–157, 2012). We report on a study which utilized mixed methods to examine SPP and associated affective engagement of students in four early high school mathematics classrooms in two geographic regions of the USA. For each classroom, we used observational and experience sampling methods to examine the patterns of affect problem posers and their peers experienced at individual and group levels, respectively, on a day with at least one instance of SPP observed compared with a day with no observed instances of SPP. Results show evidence of positive affect among problem posers, while their peers reported fewer negative emotions about mathematics tasks on days with SPP than on days without SPP. Moreover, a detailed analysis of two spontaneous problem posers revealed that they showed a desire to extend their own mathematical thinking, expressed dissatisfaction with their current knowledge, and directed their problems primarily towards the teacher. Results are discussed regarding the need to support students’ confidence in their original mathematical ideas in class, and for reducing negative emotional responses to mathematics tasks.
Reactive and Safe Road User Simulations using Neural Barrier Certificates.

Reactive and safe agent modelings are important for nowadays traffic simulator designs and safe planning applications. In this work, we proposed a reactive agent model which can ensure safety without comprising the original purposes, by learning only high-level decisions from expert data and a low-level decentralized controller guided by the jointly learned decentralized barrier certificates. Empirical results show that our learned road user simulation models can achieve a significant improvement in safety comparing to state-of-the-art imitation learning and pure control-based methods, while being similar to human agents by having smaller errors to the expert data. Moreover, our learned reactive agents are shown to generalize better to unseen traffic conditions, and react better to other road users and therefore can help understand challenging planning problems pragmatically.
Prognostic Utility of Pretreatment Neutrophil-Lymphocyte Ratio in Advanced Larynx Cancer.

Purpose Neutrophil-lymphocyte ratio has been explored as a prognosticator in several cancer types, but its association with larynx cancer outcomes is not well known. We aimed to identify an optimal NLR cutoff point and examine the prognostic utility of this biomarker in patients with locoregionally advanced larynx cancer treated with curative intent. Methods In the Veterans Affairs' (VA) national database, we identified patients with locoregionally advanced (T3-4N0-3M0) laryngeal squamous cell carcinoma diagnosed between 2000 and 2017 and treated with curative intent. NLR cutoff points were calculated using Contal/O'Quigley's method. Outcomes of larynx cancer-specific survival (CSS), overall survival (OS), and non-larynx cancer survival (NCS) were evaluated in multivariable Cox and Fine-Gray models. Results In 1047 patients, the optimal pretreatment NLR cutoff was identified as 4.17 - 722 patients with NLR ⩽ 4.17, 325 patients with NLR > 4.17. The elevated NLR cohort had a higher proportion of T4 disease (39.4% vs 28.4%), node positive disease (52.3% vs 43.1%), and surgical treatment (43.7% vs 35.2%). In multivariable analysis, NLR > 4.17 was independently associated with worse OS (HR 1.31, 95% CI 1.12-1.54, P = .001) and worse CSS (HR 1.46, 95% CI 1.17-1.83, P Conclusion In locoregionally advanced larynx cancer treated with curative intent, we identified elevated NLR to be associated with inferior OS and CSS. Further prospective studies are needed to investigate pretreatment NLR and our identified 4.17 cutoff as a potential larynx cancer-specific marker for this high risk population.
Generalized bilateral control of robot arms

This paper summarizes the theory of a new form of bilateral or force-reflecting manual control of remote robot (slave) arms. The mathematics of workspace representation, command structure, kinematic and dynamic control coordination required for implementing the new form of generalized bilateral control through computer programs is presented. The paper concludes with a brief description of implementation organization of the new system using a six-degree-of-freedom backdrivable hand controller, a PUMA 560 robot arm and a distributed net of microcomputers organized in two groups: one at the remote work site and one at the control station.
The human preproapolipoprotein C-II gene: complete nucleic acid sequence and genomic organization

The complete nucleic acid sequence of human preproapolipoprotein (apo) C-II has been determined from 2 apoC-II clones isolated from 2 different human genomic DNA libraries. The cloned fragments were approx. 14 and 18 kb long, and sequence analysis established that the apoC-II gene consists of 3338 nucleotides containing 3 intervening sequences of 2391, 167, and 298 bases. The first intron is located within the 5'-untranslated region of apoC-II and contains 4 Alu type sequences. The second intron interrupts the codon specifying amino acid —11 of the apoC-II signal peptide. The last intron, which contains a 38 bp sequence which is repeated 6 times, interrupts the codon specifying for amino acid +44 of the mature apolipoprotein.
Learning Rare Categories in Backpropagation

Hierarchical systems of neural networks based on the backpropagation algorithm were used to test the hypothesis that rare categories could be learned more accurately and in shorter training times than in nonhierarchical neural networks also based on the backpropagation algorithm. In two artificial data sets, the problem of learning rare categories was quantified and an existing solution was shown to be inadequate. HNNs were compared to nonhierarchical neural networks. In both artificial examples, HNNs performed better than nonhierarchical neural networks in terms of sensitivity and time to train. Specificities were not significantly different. In two real-world examples, these results were confirmed.
BEARING CAPACITY OF FOUNDATIONS ON SAND

A procedure is derived for determining the ultimate bearing capacity of sand loaded uniformly through a surface, shallow or deep strip footing. The most critical slip surface was derived mathematically and the inclination of the sides of the active wedge happened to be between o and 45 + o/2. The latter limit will be reached when D/B exceeds the ratio 3. The method proposed in this study yielded very good results without solving any transcendental equation as in the case of Meyerhof. In addition, it clarified the effect of δ on the ultimate bearing capacity. The use of the proposed method is very simple and time saving.
Ion Irradiation and Flux Pinning in Type II Superconductors

Niobium foils containing 10 and 900 wt ppm oxygen were irradiated with 3.5 MeV 58Ni +to between 50 and 100 displacements per atom. The irradiation at 900°C produced a bimodal void distribution with a large number of small voids and with large diameter voids that act as strong pinning centers for fluxoids in type II superconductors. Transverse critical current measurements showed a substantial increase in both the upper critical field Hc2 and the critical current density Jc. Jc was anisotropic and exhibited a maximum for fluxoids parallel to the irradiated surface. From the void size and number densities, determined by transmission electron microscopy, interaction forces between fluxoids and voids as well as volume pinning forces are estimated and compared with the experimental results.
Critical Issues in Urban Emergency Medical Services for Chi

In order to be effective those wishing to improve emergency care of children in an urban environment must be aware of barriers as well as resources. Urban children are at high risk for requiring emergency care as a result of both illness and injury. These children face a dangerous environment resulting from the problems of poverty, homelessness, overcrowded living conditions, drug abuse, and a shrinking tax base. They face this nation's highest rates of violent injury (intentional and unintentional), immunization delays, and preventable infectious diseases such as TB and measles. In addition, they have poor access to quality primary health care and suffer the greatest morbidity rates from chronic diseases such as asthma and diabetes. On the other hand, there is great opportunity to ensure that urban children receive quality emergency health care. The urban environment is rich in "centers of pediatric excellence," which often have paid full-time EMS systems in operation, and is the locale in which the majority of pediatric emergency medicine specialists and prehospital advanced life support providers practice. The child advocate must work to ensure that the urban child can benefit from these resources.
Biosafety Practices Associated with Potential Agents of Biocrime and Biowarfare

Conducting research in a manner that guards against theft and intentional misuse of biological materials requires a process of hazard identification and risk assessment to most effectively identify and implement a risk management plan. Procedures describing physical security, personnel reliability, and material control and accountability define a security plan for this type of research.
Towards a logic model for object-oriented systems analysis and design

We sketch a logic model for representing systems analysis diagrams. The discussion is limited to diagrams from the OMT methodology of (Rumbaugh et al., 1991) although no genuine loss of generality results. In developing our logic model, we have followed where appropriate (for state transition diagrams) the logical representation theory developed by Parsons (1990) for the semantics of VP modifiers. That semantics, as does systems analysis, views the world in terms of states and events. That the logical representation techniques used by Parsons are so useful for systems analysis strongly suggests that the confluence of terminology is more than coincidence, more than superficial. Throughout we stress the useful deductions that can be made automatically with our logic model, deductions that are not possible automatically with mere diagrams. We conclude that the program of representing systems analysis diagrams in logic holds much promise.
In vitro studies with "transfer factor". II. Transfer of the cell-migration inhibition correlate of delayed hypersensitivity in humans with nondialyzable components of leucocyte lysates from humans sensitized to histoplasmin and coccidioidin.

Abstract “Nonsensitive” cells from skin-test-negative individuals were incubated with whole cell lysates, nondialyzable and dialyzable fractions of leucocyte lysates obtained from strongly skin test sensitive histoplasmin, and/or coccidioidin sensitive donors and specific antigen. “Nonsensitive” cells incubated with whole cell lysate or nondialyzable fractions of lysate in the presence of specific antigen released a substance (MIF) which specifically inhibited the migration of guinea pig macrophages. Dialyzable fractions from active cell lysates incubated with “nonsensitive” cells and specific antigen did not liberate MIF from “nonsensitive” cells. Cell lysates, nondialyzable fractions, or dialyzable fractions alone, or in combination with nonspecific antigens in the presence of “nonsensitive” cells failed to inhibit the migration of guinea pig macrophages.
Theoretical Frames and Teaching Styles of Physical Therapy Faculty Who Lead International Service-Learning Experiences.

Purpose: International service-learning (ISL) is popular in higher education, and many physical therapy educational programs are adding ISL opportunities to their curricula because doing so aligns with student interest and the increasingly global nature of the profession. The faculty leading these experiences have not been studied. Nearly all faculty in physical therapy programs are educated as therapists and not as teachers. Most do not have any background in pedagogical practice or educational theory. The purpose of this study was to describe faculty leading ISL experiences in physical therapy educational programs and compare them to faculty who do not participate in ISL. Of specific interest were demographic variables, teaching style, and educational theoretical frames. Method: Data were collected using an online Faculty Survey. Responses from 205 physical therapy faculty subjects from across the United States were used for analysis. Forty seven (23%) of these subjects reported having participated in international service-learning. Data from faculty who participate in ISL (Y-ISL) were compared to those of faculty who do not participate in ISL (N-ISL). Analysis/Results: When comparing the Y-ISL and the N-ISL groups in terms of their demographics using descriptive statistics, t-test analysis, or chi-square analysis differences were found only in age and years of practice. In terms of teaching style type (TST) Expert/Formal Authority; Personal Model/Formal Authority/Delegator; Formal Authority/Delegator; Formal Authority/ Facilitator/Delegator; Delegator/ Facilitator, chi-square analysis results indicate that there is no significant association between TST and Y-ISL and N-ISL. When exploring the theoretical frame types (TFT); progressive, critical, and professional chi-square analysis indicated that there is a significant association between TFT and Y-ISL and N-ISL. Y-ISL faculty are more likely than N-ISL faculty to come from a critical theory frame. Regression analysis resulted in a model that is unable to predict Y-ISL or N-ISL group membership based on faculty demographics, TST, and TFT. Discussion: The relevance of the study findings in relation to institutions of higher education, the field of physical therapy in general, physical therapy educational programs both with and without ISL programs and individual faculty are addressed.
Ontogenesis and characteristics of epidermal growth factor receptors in human placenta

Abstract Epidermal growth factor promotes growth in many cell types. The role of epidermal growth factor during gestation and fetal development is unknown. This study investigates the presence and binding characteristics of epidermal growth factor receptors in placentas throughout gestation. Cell membrane preparations were obtained from first-, second-, and third-trimester placentas and hydatidiform moles. Specific epidermal growth factor receptors were observed as early as 6 weeks of gestation. Throughout gestation, Scatchard analysis of epidermal growth factor binding was curvilinear, and dissociation studies were consistent with site-to-site interaction with negative cooperativity. Affinity constants at high (K e = 9.9 ± 0.79 × 10 9 L/mol) and low (K f = 3.0 ± 0.25 × 10 9 L/mol) receptor occupancy were unchanged throughout normal gestation. However, the number of receptors per milligram of protein significantly increased with advancing normal gestation (correlation coefficient, r=0.81). In hydatidiform moles, the number of receptors was reduced when compared to that of normal tissue of similar gestational age. Our study provides a quantitative basis for further evaluation of epidermal growth factor as a possible factor in embryogenesis and fetal development.
Potential Mechanisms for Muscle-Powered Cardiac Support

Biomechanical actuation of an implanted ventricular assist device (VAD) is an attractive means of providing long-term circulatory support. Studies show that energy from electrically stimulated skeletal muscle can, in principle, be used to provide tether-free cardiac assistance without the need for percutaneous drivelines or bulky energy transmission hardware. A mechanical prosthesis designed to harness the contractile power of in situ skeletal muscle has been developed in this laboratory that collects energy from the latissimus dorsi muscle and transmits it in the form of hydraulic power. In order to use this technique to pump blood however, a practical means to deliver this energy to the bloodstream must be devised. Presented here are six prospective mechanisms designed to accomplish this task, five of which also eliminate blood contacting surfaces that often lead to thromboembolic complications in chronic VAD patients.
Implementing flexible hybrid instruction in an electrical engineering course

This study explored a modified version of hybrid instruction, referred to as the flexible hybrid format, in a lower division electrical engineering course offered at a large public university. The objective of the study is to use longitudinal data to investigate the impact of class attendance, out-of-class study time, and motivation on student exam performance. Generalized least squares and fixed effects models were used in the analyses. It was found that class attendance was indispensable; it was associated with exam performance even when all essential course material was made available online and students generally rated the online instruction component to be of higher quality. The benefit of class attendance was then explained by the ICAP hypothesis and spaced learning practice and it was suggested that online education might be more effective in teaching relatively simpler contents. Out-of-class effort significantly predicated performance in previous weeks, but not in the final period. The harmful effect of cramming was cited to explain this phenomenon. Hence, by implication, time management might be an issue in a flexible hybrid environment. Finally, motivation was found to be a robust predicator of performance and its effect was the strongest when the course was at its most challenging stage. Besides, the relationship between motivation and exam performance was likely to be bidirectional, as higher motivation resulted in better performance, which in turn further boosted motivation. Based on current findings, directions for future research were also suggested to verify our claims and improve our implementation. The study explores a hybrid format designed for more customized learning.Class attendance only predictes performance when course material is difficult.Time management is a serious issue when students are given too much liberty.Motivation predicates exam performance, especially when the content is challenging.The success of this hybrid format depends on student skills and course difficulty.
Plane wave reflection and transmission by a unidirectionally conducting screen

Plane wave reflection and transmission by a unidirectionally conducting screen is treated for the case of oblique incidence and for two polarizations. An interesting feature concerning the power relations in the reflection and transmission properties of such a screen is noted.
ALGORITHMIC RESULTS IN LIST DECODING

Error-correcting codes are used to cope with the corruption of data by noise during communication or storage. A code uses an encoding procedure that judiciously introduces redundancy into the data to produce an associated codeword. The redundancy built into the codewords enables one to decode the original data even from a somewhat distorted version of the codeword. The central trade-off in coding theory is the one between the data rate (amount of non-redundant information per bit of codeword) and the error rate (the fraction of symbols that could be corrupted while still enabling data recovery). The traditional decoding algorithms did as badly at correcting any error pattern as they would do for the worst possible error pattern. This severely limited the maximum fraction of errors those algorithms could tolerate. In turn, this was the source of a big hiatus between the error-correction performance known for probabilistic noise models (pioneered by Shannon) and what was thought to be the limit for the more powerful, worst-case noise models (suggested by Hamming). In the last decade or so, there has been much algorithmic progress in coding theory that has bridged this gap (and in fact nearly eliminated it for codes over large alphabets). These developments rely on an error-recovery model called "list decoding," wherein for the pathological error patterns, the decoder is permitted to output a small list of candidates that will include the original message. This book introduces and motivates the problem of list decoding, and discusses the central algorithmic results of the subject, culminating with the recent results on achieving "list decoding capacity."
Predicting Postcesarean Delivery Pain

Poorly treated acute pain after cesarean delivery is associated with significant short-term and long-term morbidity in young women. Due to the importance of treating perioperative pain, more emphasis has been placed on improving postoperative pain management. However, individual differences in pain perception make postoperative pain management challenging after cesarean delivery. In this review, we will identify recent studies that have utilized a variety of preoperative tests to predict acute and/or chronic postoperative pain scores after cesarean delivery.
Reducing Rollbacks Through Partitioning in PCS Parallel Simulation

Recent advances in wireless data communications tech nology have spawned an increasing demand for various types of services over wireless and wireline networks. As a result, we are witnessing an explosive growth of research and development efforts in the field of wireless and personal communication systems (PCS). Parallel simulation techniques have been investigated in studies to decrease the execution times of PCS simulations. In this paper, we present a partitioning algorithm for SWiMNet, a two-stage PCS parallel simulation testbed which makes use of a conservative scheme at Stage 1, and Time Warp at Stage 2. The partitioning algorithm focuses on statically distributing the load of the simu lation evenly in order to decrease the rollback overhead in Stage 2. The algorithm is based on an estimation of the loads involved by the model components. This paper discusses the algorithm, its implementation on a work station cluster, and the performance results of the simu lation of a real suburban area serviced ...
Toward a neuro-developmental account of the development of declarative memory.

The study of the biological bases of memory has a long history. Based on research with patients with specific lesions and disease, animal models, and neuroimaging studies, the neural substrate that supports declarative memory in adults has been relatively well articulated. By contrast, studies of the neural bases of memory in development is in its infancy. Yet joint consideration of the processes involved in building a memory trace, and of the time course of development of the neural structures involved, has contributed to the generation of specific predictions regarding the sources of age-related change. Specifically, there are suggestions that in infancy and very early childhood, encoding and consolidation processes account for substantial age-related variance in long-term declarative memory. With development, the locus of age-related variability in the vulnerability of memory traces shifts to the later-stage processes of memory storage and retrieval. These insights are afforded by consideration of multiple levels of analysis, from the biological to the behavioral. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 50: 19–31, 2008.
Practicing Peace: The Impact of a School-Based Conflict Resolution Program on Elementary Students

This study was conducted during the second year of a school-based conflict resolution program. Social-cognitive perspective taking, strategy choice, personal history with violence, and school climate were measured before and after peer mediator training and practice. A significant increase in cognitive perspective taking was revealed, indicating that both trained and untrained students became more likely to consider the perspective of others. An empathy effect, however, was not detected. Students' preference for independent conflict strategy choices increased. Patterns associated with ethnicity were also revealed, with African American students showing the greatest increase in cognitive perspective taking, and Hispanic students the greatest increase in preference for independent conflict resolution strategies. Finally, all students, regardless of their personal history with violence, appeared to benefit from this program, as compared with controls where no change was observed.
THE ROLE OF SCARF ANGLE IN THE PERFORMANCE OF ALUMINUM MATRIX COMPOSITE JOINTS

The role of geometry on the mechanical performance of scarf joints in Al-matrix composites reinforced with continuous polycrystalline alumina fibers was investigated. Model joints consisting of thin metal interlayers at varying scarf angles between composite sub-elements were designed, manufactured and tested to study the relevant deformation and failure phenomena. Specimens were produced by pressurized infiltration of molten Al-4.5%Mg into fiber preforms containing prescribed discontinuities. In this way, matrix continuity through the interlayer was ensured and defects normally introduced in actual joining operations were minimized. Reference composite specimens were produced in the same actual joining operations were minimized. Reference composite specimens were produced in the same manner and exhibited tensile strengths of the order of 700 MPa, compared with a matrix yield strength, {sigma}{sub 0}, of approximately 100 MPa. The strength of the scarf joints with aspect ratios of 17--48 and angles below 45{degree} was relatively constant, {approximately}310 {+-} 10 MPa, but increased at higher angles, reaching over 485 MPa at 75{degree}. Failure of these joints was typically by debonding at the composite-interlayer interface. A simple analytical model suggests that failure occurs when the stress normal to the interlayer reaches a critical value, although the details of the debonding mechanism aremore » still unclear. Conditions leading to a transition from debond failure to plastic collapse in joints of low aspect ratios are also discussed.« less
Anomalies associated with a prominent azygos vein on echocardiography in the pediatric population.

Background Prominent azygos veins (PAVs) have been described with interrupted inferior venae cavae (IVCs) with heterotaxy. At the authors' institution, cases of PAVs with uninterrupted IVCs have been noted. The aim of this study was to determine the occurrence rate of PAVs and associated lesions by echocardiography. Methods All patients with PAVs were collected; those with interrupted and uninterrupted IVCs were assigned to groups 1 and 2. Normal controls were assigned to group 3. Results Among 15,849 patients from January 1, 2001, to March 31, 2008, 55 (0.3%) had PAVs, 42 (76%) in group 1 and 13 (24%) in group 2. Heterotaxy was prominent in group 1, whereas patients in group 2 had no heterotaxy. Patients in group 2 had more structurally normal hearts than those in group 1 (46% vs 14%, P P = .65). Conclusions This study demonstrates that a PAV without IVC interruption is not associated with heterotaxy. Patients with PAVs should be carefully examined for partial anomalous pulmonary venous return.
X-ray storage performance of KCl:Eu2+ with high cumulated dose

The effects of high cumulative radiation dose on the luminescence properties of KCl:Eu2+ are investigated. Pellet samples of KCl:Eu2+ were given doses of up to 200 kGy at the Louisiana State University Synchrotron facility. After synchrotron irradiation, samples were optically bleached and given a clinical dose of 2 Gy from a 6 MV medical linear accelerator. Optical properties were evaluated using photostimulated luminescence (PSL), photoluminescence (PL), and temperature-dependent PSL measurements. For a cumulated dose of up to 5–10 kGy, the PSL emission intensity increased by 15% compared to the PSL signal with no radiation history. For doses higher than 10 kGy, the PSL emission intensity retained at least 70% of the original intensity. Spatial correlation of the charge storage centers increased for doses up to 5 kGy and then decreased for higher cumulative doses. Emission band at 975 nm was attributed to transitions of Eu1+. PL spectra showed an intense peak centered at 420 nm for all cumulative doses. The results of this work show that KCl:Eu2+ storage phosphors are excellent reusable materials for radiation therapy dosimetry.
Jews, Radicals and Conservatives: A Review Essay

IN A NOSTALGIC sketch, probing his embrace of the New Left politics of the mid1960s during his student days at the University of Wisconsin, Paul Breines shares a personal reflection (Breines, 1980) on the twists and pulls of two identities, one Jewish and one Leftist. At times they appear to work in tandem: at other times they pull against each other, creating internal conflict and confusion. Breines asks why, as a student, he was drawn to the history classes of George Mosse, a nonLeftist, German Jew, and not to those of William Appleton Williams, "a very American socialist historian." Breines asks himself whether he was attracted to something Jewish in Mosse, something which outweighed an affinity for socialism. The role of Breines' Jewishness troubles him, for he considers his Jewishness to be peripheral and describes himself as an "A.W.O.L. Jew." Indeed, when he and other Jewish students did discover Williams, it was not to reaffirm theirJewishness through socialism; rather it was to become American through what they perceived as an Americanized socialism. Socialism was for Breines and his peers an escape from their Jewishness, not a pursuit of it. Breines had first to be liberated from his Jewishness in order to embrace an ideology such as socialism which transcends parochialism and seeks to act on behalf of all humankind. He perceives himself as a Jew in the sense that Spinoza, Marx, Freud, or Trotsky were Jews. They were Jews who had achieved an intellectual metamorphosis of becoming non-Jews. This complex and elusive and sometimes ironic relationship between Jews and that ambiguous but widely used concept, "the politics of the Left," is the subject of this review. Although there is a substantial body of scholarly agreement about Jewish preference for the politics of the Left,'
One-dimensional ultrasound receive array using spectrally encoded optical detection

An ultrafast Ti:Sapphire laser and a Sagnac interferometer are combined for optical detection of ultrasound. Distinct spatial positions are probed simultaneously by different wavelengths within the broadband laser. Ultrasonic signals from each probe position are derived from the spectrum of the reflected light. The same single-mode fiber delivers incident and reflected light. A one-dimensional receive array is demonstrated by measuring the acoustic field of a spherically focused piezoelectric transducer. This is a promising form of parallel detection for miniaturized high-frequency ultrasonic arrays.
Fracture Mode Separation for Delamination in Platelike Composite Structures

A computationally efficient approach combining a plate crack-tip element model and a mixed-mode separation technique was developed to calculate mode mixities and stress intensity factors for delamination in platelike composite structures. The crack-tip element was based on classical plate theory, assuming the delamination surfaces to be traction free. Fracture mode separation was achieved by equating the total strain energy release rate from classical plate theory with that from the three-dimensional near-tip solution, along with two supplementary finite element analyses for special loadings. Using this approach, the separation of fracture modes under any other load combinations can easily be carried out. Numerical results showed that the present method gives good evaluations of the mixed-mode stress intensity factors.
IN VITRO BINDING ASSAYS USING 3H NISOXETINE AND 3H WIN 35,428 REVEAL SELECTIVE EFFECTS OF GONADECTOMY AND HORMONE REPLACEMENT IN ADULT MALE RATS ON NOREPINEPHRINE BUT NOT DOPAMINE TRANSPORTER SITES IN THE CEREBRAL CORTEX

The prefrontal cortices mediate cognitive functions that critically depend on local dopamine levels. In male rats, many prefrontal tasks where performance is disrupted by changes in dopamine signaling are also impaired by gonadectomy, a manipulation that increases cortical dopamine concentration, prefrontal dopamine axon density and possibly extracellular prefrontal dopamine levels as well. Because these actions could be responsible for the impairing effects of gonadectomy on prefrontal function, the question of how they might arise comes to the fore. Accordingly, the present studies asked whether dopamine levels might be increased via a hormone sensitivity of transporter-mediated dopamine uptake. Specifically, (3)H WIN 35,428 and (3)H nisoxetine, ligands selective for the dopamine (DAT)- and norepinephrine transporter (NET) respectively, were used in in vitro binding assays to ask whether gonadectomy altered transporter affinity (Kd) and/or binding site number (Bmax) in prefrontal cortex, sensorimotor cortex and/or caudate. Assays performed on tissues dissected from sham-operated, gonadectomized and gonadectomized rats supplemented with testosterone propionate or estradiol for 4 or 28 days revealed no significant group differences or obvious trends in Kd or Bmax for DAT binding or in measures of Bmax for NET binding. However, affinity constants for (3)H nisoxetine were found to be significantly higher in sensorimotor and/or prefrontal cortex of rats gonadectomized and gonadectomized and supplemented with estradiol for 4 or 28 days but similar to control in gonadectomized rats given testosterone. Because the NET contributes substantially to extracellular prefrontal dopamine clearance, these androgen-mediated effects could influence prefrontal dopamine levels and might thus be relevant for observed effects of gonadectomy on dopamine-dependent prefrontal behaviors. A hormone sensitivity of the NET could also have bearing on the prefrontal dopamine dysfunction seen in disorders like schizophrenia that disproportionately affect males, whose severity correlates with abnormal testosterone levels, and for which the NET is among suspected sites of pathology.
Captive hyaena bone choice and destruction, the Schlepp effect and olduvai archaeofaunas

Abstract Skeletal element representation at archaeological and palaeontological sites often differs from natural anatomical proportions. At archaeological sites this pattern could result from hominid behaviour, predepositional destructive or dispersive forces (such as carnivore ravaging), or post-depositional destructive forces (such as sediment compaction and leaching). Predepositional ravaging by carnivores is documented at several important Plio-Pleistocene archaeofaunal assemblages (FLK Zinjanthropus and FLKN levels 1–2). Here we present the first systematic and controlled experimental data on the effect of this process on skeletal element survival. Simulated archaeological assemblages of defleshed hammerstone-broken and unbroken bones were created within a captive spotted hyaena enclosure, and controlled numbers of hyaenas were allowed to ravage the sites. Vertebrae and pelves were nearly always chosen first for consumption by the hyaenas. Vertebrae and ribs were nearly always destroyed completely and pelves were destroyed 50% of the time. Limb-bone ends were frequently destroyed, while limb middle shaft fragments preserve nearly 100% of the original number of elements. Thus, hominid discarded bone assemblages, regardless of the original representation of elements, can come to resemble the schlepp effect simply through post-hominid hyaena scavenging. The documented pattern at FLK Zinjanthropus and FLKN1–2 of low frequencies of vertebrae, ribs and pelves and high frequencies of limbs may be due to post-hominid ravaging by hyaenas and not selective hominid transport of limb elements to the sites.
Structure determination by X-ray absorption

Abstract The present article describes the basic physics and some applications of a new technique for structure determination using X-ray absorption. The extended X-ray absorption fine structure (EXAFS) on the high energy side of absorption edges contains structure information on the local atomic environment surrounding the absorbing atom. Because EXAFS supplies the local structure about each type of atom in the sample, separately, without requiring crystallinity of the sample, it makes feasible structure measurements in many systems which have defied previous analysis by standard techniques. Some examples of diverse applications of the technique are given such as: characterizing adsorbed surface atoms; studying catalysts; measuring the environment around the metal atom in metalloproteins; determining the structure of liquids, glasses and amorphous solids; and measuring solids under high pressure. The article concludes by pointing out how the intense X-ray sources recently produced by synchrotron radiatio...
Optically Stimulated Exoelectron Emission from Potassium Chloride Single Crystals

Potassium chloride single crystals are irradiated with a 3 ke V electron beam, and the optically stimulated exoelectron spectra (OSEE) are studied as a function of dose, temperature, and energy in the range from 300 to 650 nm. Optical extinction spectra are measured simultaneously with the OSEE spectra. The exoemission spectra seem to show exoemission peaks corresponding to the F and K optical absorption bands. In addition an emission peak appears at about 400 nm within the high-energy tail of the K-band. Emission lineshapes are narrower than extinction lines and peak positions do not exactly correspond. With increasing surface damage the F-band emission diminishes. Increasing temperature produces a shift in the F-band to longer wavelengths and an increase in intensity. Kaliumchlorid-Einkristalle werden mit einem 3 ke V-Elektronenstrahl bestrahlt, und die optisch angeregten Exoelektronenspektren (OSEE) werden in Abhaangigkeit von Dosis, Temperatur und Energie im Bereich von 300 bis 650 nm untersucht. Die optischen Extinktionsspektren werden gleichzeitig mit den OSEE-Spektren gemessen. Die Exoemissionsspektren scheinen Exoemissionsmaxima entsprechend den optischen F- und K-Absorptionsbanden zu zeigen. Zusaatzlich erscheint ein Emissionsmaximum bei etwa 400 nm innerhalb des hochenergetischen Auslaaufers der K-Bande. Die Emissionslinien sind schmaler als die Extinktionslinien, und die Lagen der Maxima entsprechen sich nicht exakt. Mit zunehmendem Oberflaachendamage verschwindet die Emission der F-Bande. Das Anwachsen der Temperatur ruft eine Verschiebung der F-Bande zu laangeren Wellenlaangen und einen Anstieg der Intensitaat hervor.
Specification of Mouse Telencephalic and Mid-Hindbrain Progenitors Following Heterotopic Ultrasound-Guided Embryonic Transplantation

We have demonstrated the utility of ultrasound backscatter microscopy for targeted intraparenchymal injections into embryonic day (E) 13.5 mouse embryos. This system has been used to test the degree of commitment present in neural progenitors from the embryonic ventral telencephalon and mid-hindbrain region. Many E13.5 ventral telencephalic progenitors were observed to integrate and adopt local phenotypes following heterotopic transplantation into telencephalic or mid-hindbrain targets, whereas mid-hindbrain cells of the same stage were unable to integrate and change fate in the telencephalon. In contrast, many mid-hindbrain cells from an earlier developmental stage (E10.5) were capable of integrating and adopting a forebrain phenotype after grafting into the telencephalon, suggesting that mouse mid-hindbrain progenitors become restricted in their developmental potential between E10.5 and E13.5.
Diode-Pumped Violet Energy Upconversion in BaF(2):Er(3+).

Under 805-nm diode-laser excitation we detected intense upconversion signals at 410, 380, and 275 nm in BaF2:Er3+. Energy upconversion schemes and efficiencies are discussed in detail. Intensity parameters of Er3+ in BaF2 were derived as Ω2 = 1.048 ± 0.117 × 10-20 cm2, Ω4 = 1.478 ± 0.180 × 10-20 cm2, and Ω6 = 1.009 ± 0.127 × 10-20 cm2.
Polymorphism of turle hemoglobin and geographical differences int he frequency of variants of Chrysdemyspicta “slow” hemoglobin —an example of “temperature anti-adaptation”?

Abstract 1. 1. The hemoglobin of all turtles of the specieis Pseudemys elegans and Chrysemys picat can be separated electrophoretically into “slow” and “fast” hemoglobin components. 2. 2. The “fingerprints” of tryptic digests of “fast” and “slow” hemoglobins differ by apptroximately one-third of the peptides. 3. 3. In C. picta there is individual variation int he electrophoretic properties of “slow”, but not “fast”, hemoglobin; nearly all C. picta have one of three “slow” hemoglobin phenotypes: S, D and S-D. 4. 4. The S variants is most common in C. picta from Minnesota and Wisconsins, whereas the D variants is most common in C. picta from Arkansas and Louisiana. 5. 5. The S variant has a much higher oxygen affinity than the D variant, regardless of the conditions under which the hemoglobin is studied. This is the opposite of what would be expected ont he basis of the prevalent “reasoning” in comparative physiology and temperature adaptation. 6. 6. A possible explanation forthe higher frequency of the high oxygen affinity hemoglobin in C. picta from the colder states is based on an extreme condition, such as lenght of time under ice, rather than an average condition, such as mean temperature.
Transformation of Vibrio vulnificus by electroporation

Vibrio vulnificus is a pathogenic, estuarine bacterium associated with primary septicemia and severe wound infections. Previous studies have reported limited success in the introduction of plasmids intoV. vulnificus by conjugation, and there have been no reports of successful electroporation procedures. We report here on the introduction of recombinant plasmids into four strains ofV. vulnificus by electroporation. In contrast to the complex medium that others have used for the electroporation ofVibrio cholerae, the efficiency of transformation ofV. vulnificus was greatly improved by the use of a defined growth medium containing glucose. The addition of glycine betaine further enhanced transformant yield.
On the solutions of a general class of non-linear Schrödinger equations

Abstract A successful strategy for the analytical study of the family of non-linear Schrodinger equations i∂ψ/∂t+∂ su2ψ/∂x2+g‖ ψ ψ‖κψ=0 has been the linear delta expansion. Using this approach, the exact solution of the initial value problem ψ(x, t=0) = Cδ(x) is here obtained for the class of non-linear Schrodinger equations of the generalized form: i ∂ψ/∂t + ∂ 2 ψ/∂x 2 + (Σ j g j ‖ ψ ψ‖ κj )ψ=0 .
A Comparative Study of CdS Thin Films Grown by Chemical-Bath Deposition and Close-Spaced Sublimation

In this work we study the properties of cadmium sulfide thin films grown by chemicalbath deposition and close-spaced sublimation, on SnO2/borosilicate glass and SnO2/silicon substrates, before and after treatment in vapor CdCl2 at 400°C for 5 minutes. The as-deposited CBD CdS films had cubic structure, poor crystallinity, and high density of planar defects. After the CdCl2 treatment, these films recrystallized to the hexagonal structure, with improved crystallinity and a decrease in the density of planar defects. The as-deposited CSS films had hexagonal structure, better crystallinity, and lower density of planar defects. The main effect of the CdCl2 treatment was a decrease in the intragrain strain in the films. The CBD films had smaller grains and provided a good conformal coverage over the SnO2 films. In contrast to these films, CSS CdS did not have any oxygen or chlorine in its bulk.
Low-Temperature Properties of H, V, and F Centers in KCl and KBr

Potassium chloride and potassium bromide crystals were exposed to x rays at 10\ifmmode^\circ\else\textdegree\fi{}K. The optical absorption produced by this irradiation and the changes in optical absorption produced by subsequent annealing at higher temperatures were measured. The temperatures at which changes in optical absorption occurred were correlated with the temperatures at which free electrical charge appeared, and thermoluminescence was observed. The absorption band at 345 m\ensuremath{\mu}, in KCl, which has been named the $H$ band, is shown to result from the superposition of two or more bands, one of which is the absorption band due to self-trapped holes. In KCl, the self-trapped hole band bleaches thermally at 43\ifmmode^\circ\else\textdegree\fi{}K with a release of free electrical charge. $H$ centers disappear at 56\ifmmode^\circ\else\textdegree\fi{}K with a release of free charge. The optical absorption band of the $H$ center is shown to have its maximum at 335 m\ensuremath{\mu}. In KBr, the thermal release of free charge at 30\ifmmode^\circ\else\textdegree\fi{}K is attributed to the disappearance of $H$ centers. No charge burst was observed in KBr which may be attributed to the destruction of self-trapped holes.
Search for Improved Host Architectures: Application of de Novo Structure-Based Design and High-Throughput Screening Methods To Identify Optimal Building Blocks for Multidentate Ethers

This paper presents a computational approach to the deliberate design of improved host architectures. The approach, which involves the use of computer-aided design software, is illustrated by application to cation hosts containing multiple aliphatic ether oxygen binding sites. De novo molecule building software, HostDesigner, is interfaced with molecular mechanics software, GMMX, providing a tool for generating and screening millions of potential bidentate building block structures. Enhanced cation binding affinity can be achieved when highly organized building blocks are used to construct macrocyclic hosts.
Intercellular Signaling: An Elusive Player Steps Forth

Plasmodesmata play a central role in cell-to-cell communication in plants, allowing transport of regulatory proteins and mRNAs. A recent study has identified a specific protein that regulates the intercellular transport of macromolecules in plants, known as non-cell autonomous pathway protein 1.
Some Mathematical Notes on the Quantity Theory of Money in an Open Economy

THE RELATION between the quantity of money and the level of prices and incomes is generally treated by modern monetary theorists in terms of a "closed" economy, that is, without allowing for international trade as an integral part of the theory. In his "Monetary Analysis of Income Formation and Payments Problems,"1 J. J. Polak has shown how the existence of international trade, and the consequent possibility of balance of payments deficits, modifies in an essential way the theoretical analysis of the monetary system. The central element in his theory is that a given deficit in the balance of payments has cumulative effects on the monetary supply: it directly reduces the quantity of money until the consequent income and import changes are of sufficient size to correct the initial disequilibrium. The phenomenon is thus part of economic dynamics; that is, it relates the present state of certain economic variables to the rate of change of those and other variables. The use of mathematics seems to be unavoidable in analysis of this kind; indeed, the use of several alternative mathematical representations is occasionally of value in bringing out the specific role of the various relationships in the system. The first part of this paper reformulates Polak's system in terms of infinitesimal and continuous changes, thus replacing his difference equation by a differential equation. As a consequence, certain relations affecting liquidity that were implicit in his modelin the sense that they influenced movements within each period-have necessarily to be made explicit, so casting further light on the essential elements of the adjustment process. This generalization also allows another version of the model, of the kind used in the work of the Netherlands Bank, to be treated as a special case.