cssi/SciSciGPT-SciSciNet huggingface dataset:
Brain-Tumor-Related Epilepsy in Children

Biology, epidemiology, presentation, optimal management, and outcomes of brain tumors change throughout the lifespan. The most rapid changes occur in the first two decades of life. Brain tumors have a lower incidence in children than adults, but represent a higher overall proportion of childhood cancer. Despite a relatively low incidence of high-grade primary tumors and metastases, brain and other central nervous system tumors account for a substantial burden of childhood cancer morbidity and mortality. Seizures are an equally common manifestation of supratentorial tumors in children and adults, but tumors are a less common cause of seizures and epilepsy in childhood. Initial presentation with seizures portends a longer survival. Thus, seizures are often among the primary considerations for management. Optimal management strategies that account for the unique challenges of these combined diagnoses in the pediatric patient are evolving.
Discovery and Access Systems: Discussion of Value Added Dimensions Using Twitter

The use of hashtags in Twitter closely resembles the use of controlled vocabulary in online library catalogs. This natural link between this micro-blogging tool and library catalogs offers an opportunity to consider how Twitter and its accompanying hashtags can contribute to innovations in the 21st century library catalog. One of the most important aspects of libraries as physical places is their role as social spaces, a role they have yet to successfully fulfill in their online presence. Incorporating social media tools such as Twitter into library catalogs offers a venue for conversation and interaction to simulate the experience of users present in physical library spaces. Twitter’s hashtags offer a means of aggregating conversations and information on topics from the catalog, librarians and users and facilitating the growth of online communities. The benefits of integrating Twitter into the online library catalog can be viewed from the framework of the Eisenberg-Dirk modification of Taylor’s value-added model, which acknowledges the developing interactivity of information systems. Additional insight is possible by using the Chang Iyer morphological box of Twitter application, which is based on Ames and Newman’s taxonomy of tagging motivations, to analyze possible value-added attributes of each interface feature.
Surgical Findings and Outcomes in Premenopausal Breast Cancer Patients Undergoing Oophorectomy: A Multicenter Review From the Society of Gynecologic Surgeons Fellows Pelvic Research Network.

Abstract Study Objective To describe the procedures performed, intra-abdominal findings, and surgical pathology in a cohort of women with premenopausal breast cancer who underwent oopherectomy. Design Multicenter retrospective chart review (Canadian Task Force classification II-3). Setting Nine US academic medical centers participating in the Fellows' Pelvic Research Network (FPRN). Patients One hundred twenty-seven women with premenopausal breast cancer undergoing oophorectomy between January 2013 and March 2016. Intervention Surgical castration. Measurements and Main Results The mean patient age was 45.8 years. Fourteen patients (11%) carried a BRCA mutations, and 22 (17%) carried another germline or acquired mutation, including multiple variants of uncertain significance. There was wide variation in surgical approach. Sixty-five patients (51%) underwent pelvic washings, and 43 (35%) underwent concurrent hysterectomy. Other concomitant procedures included midurethral sling placement, appendectomy, and hysteroscopy. Three patients experienced complications (transfusion, wound cellulitis, and vaginal cuff dehiscence). Thirteen patients (10%) had ovarian pathology detected on analysis of the surgical specimen, including metastatic tumor, serous cystadenomas, endometriomas, and Brenner tumor. Eight patients (6%) had Fallopian tube pathology, including 3 serous tubal intraepithelial cancers. Among the 44 uterine specimens, 1 endometrial adenocarcinoma and 1 multifocal endometrial intraepithelial neoplasia were noted. Regarding the entire study population, the number of patients meeting our study criteria and seen by gynecologic surgeons in the FPRN for oophorectomy increased by nearly 400% from 2013 to 2015. Conclusion Since publication of the Suppression of Ovarian Function Trial data, bilateral oophorectomy has been recommended for some women with premenopausal breast cancer to facilitate breast cancer treatment with aromatase inhibitors. These women may be at elevated risk for occult abdominal pathology compared with the general population. Gynecologic surgeons often perform castration oophorectomy in patients with breast cancer as an increasing number of oncologists are using aromatase inhibitors to treat premenopausal breast cancer. Our data suggest that other abdominal/pelvic cancers, precancerous conditions, and previously unrecognized metastatic disease are not uncommon findings in this patient population. Gynecologists serving this patient population may consider a careful abdominal survey, pelvic washings, endometrial sampling, and serial sectioning of fallopian tube specimens for a thorough evaluation.
A Content Analysis of Military Psychology: 2002–2014.

Content analysis of articles published in professional journals is a viable method to assess the trends and topics a profession deems to be important. Military psychology does not involve only 1 su...
Update on cellular encapsulation

There is currently a significant disparity between the number of patients who need lifesaving transplants and the number of donated human organs. Xenotransplantation is a way to address this disparity and attempts to enable the use of xenogeneic tissues have persisted for centuries. While immunologic incompatibilities have presented a persistent impediment to their use, encapsulation may represent a way forward for the use of cell-based xenogeneic therapeutics without the need for immunosuppression. In conjunction with modern innovations such as the use of bioprinting, incorporation of immune modulating molecules into capsule membranes, and genetic engineering, the application of xenogeneic cells to treat disorders ranging from pain to liver failure is becoming increasingly realistic. The present review discusses encapsulation in the context of xenotransplantation, focusing on the current status of clinical trials, persistent issues such as antigen shedding, oxygen availability, and donor selection, and recent developments that may address these limitations.
Effects of integrating care for Medicare-Medicaid dually eligible seniors in Minnesota

Individuals dually eligible for Medicare and Medicaid often receive fragmented and inefficient care. Using Minnesota fee-for-service claims, managed care encounters, and enrollment data for 2010-2012, we estimated the likely impact of Minnesota Senior Health Option (MSHO)-seen as the first statewide fully integrated Medicare-Medicaid model-on health care and long-term services and supports use, relative to Minnesota Senior Care Plus (MSC+), a Medicaid-only managed care plan with Medicare fee for service. Estimates suggest that MSHO enrollees had significantly higher use of primary care and, potentially, of community-based services, combined with lower use of hospital-based care than similar MSC+ enrollees. Adopting fully integrated care models like MSHO may have merit in other states.
High-resolution 3D shape deformation, displacement, and strain measurement for robotic flapping wings

3D displacement and strain measurement for the fast flapping wings is of crucial importance to micro air vehicle design. This research introduces a high-resolution photomechanics testing method for robotic flapping wings. First, the dynamic 3D shape of a fast flapping flight process is reconstructed by the high-speed structured light technique with defocused binary stripe illumination. Then, the 3D displacement map is extracted through geodesic analysis. Finally, the Green- Lagrange strain tensor is computed by Kirchhoff-Love shell theory. Experiments will demonstrate the success of the method by testing a robotic bird with a wings’ flapping frequency over 20 cycles/second.
Thoracoscopic Aortopexy for Severe Tracheomalacia

Abstract Introduction: Aortopexy is a well-established technique for the treatment of severe tracheomalacia that occurs most commonly in the setting of children with esophageal atresia and tracheoe...
Fiber Optic Diagnostics for Scaled Explosion Experiments

Measurements taken with new fiber optic shock wave diagnostics are used to identify plastic and elastic deformation of material under shock compression. This deformation is caused by a point like explosion in a spherical cavity within a containment material and is observed by monitoring cavity wall motion using a fiber tip sensor. Additionally, a new fiber optic loop diagnostic analogous to a Dremin loop is also demonstrated for the first time and the benefits are discussed.
The domain switching and structural characteristics of PLZT bulk ceramics and thin films chemically prepared from the same acetate precursor solutions

Lead lanthanum zirconate titanate (PLZT) ferroelectrics were produced in bulk ceramic and thin-film form from the same acetate precursor solutions in order to compare their electrical and physical properties. Bulk ceramics were hot pressed from chemically coprecipitated powders, and thin films were fabricated by spin coating on silver foil and platinum-coated silicon wafer substrates. A number of PLZT compositions were investigated, including ferroelectric memory materials near the morphotropic phase boundary with 2% La, memory and slim-loop ferroelectric x/65/35 (La/Zr/Ti) compositions with up to 12% La, as well as some antiferroelectric thin-film materials. Internal film stress from thermal expansion mismatch between films and substrates was found to contribute to differences in electrical properties and Curie temperatures between the thin film and bulk materials, as were interface layers between the films and substrates, mechanical clamping from the substrates and grain size.
The Process of Integrating an Evidence-Based Intervention into a Public Health Department to Improve Nutrition and Physical Activity Behaviors in Parents and Children

The purpose of this manuscript is to describe a mutually beneficial collaboration with a Public Health Department and a University to implement an evidence-based program to teach nutrition and physical activity to improve adult and child outcomes. We first assessed the needs of the Public Health Department to build sustainable capacity. Next, all collaborators were invited to work together to focus on success. We invested in the leadership structure and strategically planned together. Finally, all of the collaborators worked together to practice cultural awareness. The process of implementing evidence-based programs allows all collaborators to emerge from the interaction stronger as a result of respectful dialogue and team building.
Local and Landscape Effects to Biological Controls in Urban Agriculture-A Review.

Urban agriculture is widely practiced throughout the world. Urban agriculture practitioners have diverse motivations and circumstances, but one problem is ubiquitous across all regions: insect pests. Many urban farmers and gardeners either choose to, or are required to forego, the use of chemical controls for pest outbreaks because of costs, overspray in populated areas, public health, and environmental concerns. An alternative form of pest control is conservation biological control (CBC)—a form of ecological pest management—that can reduce the severity of pest outbreaks and crop damage. Urban farmers relying on CBC often assume that diversification practices similar to those used in rural farms may reduce insect pest populations and increase populations of beneficial insects, yet these management practices may be inappropriate for applications in fragmented urban environments. In this review, we assess urban CBC research and provide a synthesis for urban agriculture practitioners. Our findings indicate that local and landscape factors differentially affect insect pests and beneficial arthropods across the reviewed studies, and we identify several on-farm practices that can be implemented to increase biological control in urban agriculture.
Facebooking Alone? Millennials’ Use of Social Network Sites and Volunteering:

The younger generation’s widespread use of online social network sites has raised concerns and debates about social network sites’ influence on this generation’s civic engagement, whether these sit...
Ultraviolet light (365 nm) transmission properties of articular cartilage as a function of depth, extracellular matrix, and swelling.

Current tissue engineering approaches for treatment of injured or diseased articular cartilage use ultraviolet light (UV) for in situ photopolymerization of biomaterials to fill chondral and osteochondral defects as well as resurfacing, stiffening and bonding the extracellular matrix and tissue interfaces. The most commonly used UV light wavelength is UVA 365 nm, the least cytotoxic and deepest penetrating. However, little information is available on the transmission of UVA 365 nm light through the cartilage matrix. In the present study, 365 nm UV light transmission was measured as a function of depth through 100 μm thick slices of healthy articular cartilage removed from mature bovine knees. Transmission properties were measured in normal (Native) cartilage and after swelling equilibration in phosphate-buffered saline (Swollen). Single-factor and multiple linear regression analyses were performed to determine depth-dependencies between the effective attenuation coefficients and proteoglycan, collagen and water contents. For both cartilages, a significant depth-dependency was found for the effective attenuation coefficients, being highest at the articular surface (superficial zone) and decreasing with depth. The effective attenuation coefficients for full-thickness cartilages were approximately a third lower than the total attenuation coefficients calculated from the individual slices. Analysis of absorption and scattering effects due to the ECM and chondrocytes found that UV light scatter coefficients were ∼10 times greater than absorption coefficients. The greater transmittance of UV light through the thicker cartilage was attributed to the collagen within the ECM causing significant backscatter forward reflectance.
Imagining stories: attitudes and operators

This essay argues that there are theoretical benefits to keeping distinct—more pervasively than the literature has done so far—the psychological states of imagining that p versus believing that in-the-story p, when it comes to cognition of fiction and other forms of narrative. Positing both in the minds of a story’s audience helps explain the full range of reactions characteristic of story consumption. This distinction also has interesting conceptual and explanatory dimensions that haven’t been carefully observed, and the two mental state types make distinct contributions to generating emotional responses to stories. Finally, the differences between the mental states illuminate how a given story can be both shared with others and at the same time experienced as personal.
Covid-19, gender inequality, and the responsibility of the state

Previous research has shown that women are disproportionately negatively affected by a variety of socio-economic hardships, many of which COVID-19 is making worse In particular, because of gender roles, and because women’s jobs tend to be given lower priority than men’s (since they are more likely to be part-time, lower-income, and less secure), women assume the obligations of increased caregiving needs at a much higher rate This unfairly renders women especially susceptible to short-and long-term economic insecurity and decreases in wellbeing Single-parent households, the majority of which are headed by single mothers, face even greater risks These vulnerabilities are further compounded along the dimensions of race, ethnicity, class, and geography Drawing upon the philosophical literature on political responsibility and structural injustice (specifically, the work of Iris Marion Young), I argue that while the state may not have had either foresight into, or control over, the disproportionate effect the pandemic would have on women, it can nonetheless be held responsible for mitigating these effects In order to do so, it must first recognize the ways in which women have been affected by the outbreak Specifically, policies must take into account the unpaid labor of care that falls on women Moreover, given that this labor is particularly vital during a global health pandemic, the state ought to immediately prioritize the value of this work by providing financial stimuli directly to families, requiring employers to provide both sick leave and parental leave for at least as long as schools and daycares are inoperational, and providing subsidized emergency childcare © 2020, International Journal of Wellbeing Charitable Trust All rights reserved
Resilience and burnout in healthcare students and inpatient psychiatric nurses: A between-groups study of two populations

Abstract Background Stressful environments can have significant effects on an individual and lead to burnout. Psychological consequences of burnout include trauma reactions, depression, anxiety and substance use disorders. Resilience, a protective mechanism can mitigate the negative impact of burnout. Method This study utilizes an exploratory correlational design to determine whether or not there is 1) a similar correlation between resilience and burnout between psychiatric nurses working in a high stress environment and students who are naive to the high stress academic environment and 2) a higher level of resilience in the psychiatric nurses compared to the healthcare students. Results A significant inverse relationship was observed with respect to resilience and burnout in both the professional nurse and student groups. However, the inpatient psychiatric nurse group was not found to have a higher level of resilience than the student group, when controlling for age. Conclusion: This suggests that resilience to burnout is not related to the work environment but life experience (age) was found to be a factor related resilience in this sample.
Contour Exploration with Potentiostatic Kinematics

We introduce a method of exploring potential energy contours in complex dynamical systems based on potentiostatic kinematics wherein the systems are evolved with minimal changes to their potential energy. We construct a simple iterative algorithm for performing potentiostatic kinematics, which uses an estimate curvature to predict new configurations space coordinates on the potential energy contour and a potentiostat term component to correct for errors in prediction. Our methods are then applied to atomic structure models using an interatomic potential for energy and force evaluations as would commonly be invoked in a molecular dynamics simulation. Using several model systems, we assess the stability and accuracy of the method on different hyperparameters in the implementation of the potentiostatic kinematics. Our implementation is open source and available within the Atomic Simulation Environment (ASE) package for atomic simulation.
Returns to Networking in Academia

This paper examines effects of academic networks in a Stackelberg differential game between journal editors and authors. Authors choose research papers to maximize satisfaction, while editors determine research quality to maximize journal reputation. Verifying the system for stability, results show that academic networks neither affect the number of publications nor the quality of an author’s papers. Networks only affect the number of an author’s citations. Editors’ preferences for publishing an author because of her network membership seem irrelevant. This happens because editors compete to increase their journal’s reputation by publishing high quality papers. Consequently, there is little room for editorial bias. Further, increased journal competition has the potential to erode the citation gains. The equilibrium research quality is below the maximum possible quality. Increases in publication benefits are shown to leave citations unaffected, increase the number of publications, and decrease research quality. The results generally carry through when publishing markets tend to a monopoly.
Massive transfusions and severe hypocalcemia: An opportunity for monitoring and supplementation guidelines.

Background Massive transfusion protocols (MTPs) are associated with severe hypocalcemia, contributing to coagulopathy and mortality in severely injured patients. Severity of hypocalcemia following massive transfusion activation and appropriate treatment strategies remain undefined. Study design and methods This was a retrospective study of all MTP activations in adult trauma patients at a Level 1 trauma center between August 2016 and September 2017. Units of blood products transfused, ionized calcium levels, and amount of calcium supplementation administered were recorded. Primary outcomes were ionized calcium levels and the incidence of severe ionized hypocalcemia (iCa ≤1.0 mmol/L) in relation to the volume of blood products transfused. Results Seventy-one patients had an MTP activated during the study period. The median amount of packed red blood cells (PRBCs) transfused was 10 units (range 1-52). A total of 42 (59.1%) patients had periods of severe hypocalcemia. Patients receiving 13 or more units of PRBC had a greater prevalence of hypocalcemia with 83.3% having at least one measured ionized calcium ≤1.0 mmoL/L (p = .001). The number of ionized calcium levels checked and the amount of supplemental calcium given in patients who experienced hypocalcemia varied considerably. Discussion Severe hypocalcemia commonly occurs during MTP activations and correlates with the number of packed red blood cells transfused. Monitoring of ionized calcium and amount of calcium supplementation administered is widely variable. Standardized protocols for recognition and management of severe hypocalcemia during massive transfusions may improve outcomes.
Salvage of the injured upper extremity.

A 48-year-old man playing cards was accused of cheating. An assailant with a shotgun wounded the victim in the area of the right biceps muscle. When personnel from emergency medical services arrived, they applied a pressure dressing to the right arm to control profuse hemorrhage. The patient was awake and alert with a heart rate of 130 beats per minute and a systolic blood pressure of 110 mm Hg. The pressure dressing over the right arm was saturated with blood and was removed. Findings on examination included the following: a 20×12 cm cavity in the anterior right arm; absence of much of the right biceps muscle; absence of the brachial artery and venae comitantes; an intact median nerve; limited function of the right elbow; intact function of the right wrist and fingers; and absent right radial and ulnar pulses at the wrist. A pressure dressing was reapplied to the open wound in the right arm. As a blood specimen was drawn for type and cross-match, resuscitation with a crystalloid solution was initiated. An X-ray of the right arm documented that the shotgun pellets were all in the area of the right biceps muscle (figure 1). After administration of a cephalosporin antibiotic, the patient was moved to the operating room. Figure 1 X-ray of the right humerus documents no fracture and limited distribution of pellets. Skin preparation and draping included the chest and the entire right upper extremity from the left nipple to the right fingernails and from below the umbilicus to the toenails bilaterally. After the pressure dressing was removed, there was profuse venous hemorrhage from the open wound in the anterior right arm. Attempts at suture and metal clip control of multiple open veins had an only modest effect on controlling the hemorrhage. Based on the injuries described, your choice …
Using Dissipative Particle Dynamics to Model Effects of Chemical Reactions Occurring within Hydrogels

Computational models that reveal the structural response of polymer gels to changing, dissolved reactive chemical species would provide useful information about dynamically evolving environments. However, it remains challenging to devise one computational approach that can capture all the interconnected chemical events and responsive structural changes involved in this multi-stage, multi-component process. Here, we augment the dissipative particle dynamics (DPD) method to simulate the reaction of a gel with diffusing, dissolved chemicals to form kinetically stable complexes, which in turn cause concentration-dependent deformation of the gel. Using this model, we also examine how the addition of new chemical stimuli and subsequent reactions cause the gel to exhibit additional concentration-dependent structural changes. Through these DPD simulations, we show that the gel forms multiple latent states (not just the “on/off”) that indicate changes in the chemical composition of the fluidic environment. Hence, the gel can actuate a range of motion within the system, not just movements corresponding to the equilibrated swollen or collapsed states. Moreover, the system can be used as a sensor, since the structure of the layer effectively indicates the presence of chemical stimuli.
Iterative Linear Regresssion by Sector

Two-color DNA microarray data has proven valuable in high-throughput expression profiling. However microarray expression ratios (logbase2ratios) are subject to measurement error from multiple causes. Transcript abundance is expected to be a linear function of signal intensity (y = x) where the typical gene is non-responsive. Once linearity is confirmed, applying the model by fitting log-scale data with simple linear regression reduces the standard deviation of the logbase2ratios, after which fewer genes are selected by filtering methods. Comparing the residuals of regression to leverage measures can identify the best candidate genes. Spatial bias in logbase2ratio, defined by printing pin and detected by ANOVA, can be another source of measurement error. Independently applying the linear normalization method to the data from each pin can easily eliminate this error. Less easily addressed is the problem of cross-homology which is expected to correlate to cross-hybridization. Pair-wise comparison of genes demonstrate that genes with similar sequences are measured as having similar expression. While this bias cannot be easily eliminated, the effect of this probable cross-hybridization can be minimised in clustering by weighting methods introduced here.
Distal baclofen pump catheter migration associated with far-lateral paraspinal surgical placement.

Objectives. The increased rigidity and spasms implicit to patients being treated with baclofen provide a potential source of drug delivery system–related complications. Placement of the intrathecal catheter from the far-lateral paraspinal approach has been advocated to avoid catheter fracture as previously reported with a midline approach. A thin fascial layer and increased muscle bulk laterally could increase motion of catheters placed in this position. The authors report on a series of patients found to have spinal catheter migration out from the thecal sac following a far-lateral paraspinal surgical approach. Materials and Methods. The medical records of six consecutive patients who required revision of an intrathecal baclofen infusion system secondary to spinal catheter migration were included in this retrospective review. Each patient failed to respond to oral antispasmodic therapy and showed a positive response to a trial of intrathecal baclofen before initial pump implantation. Clinical notes and operative reports were reviewed. Results. All patients had a baclofen pump inserted with the intrathecal catheter placed through the far-lateral portion of the paraspinal musculature entering above the lumbar vertebral pedicle. In all cases, the spinal catheter migrated and was found coiled outside of the thecal sac. In two patients, this occurred on two separate occasions. Mean time to catheter revision following implantation was 7 ± 2 months. Conclusions. Spinal catheter migration from the subarachnoid space can occur with intrathecal baclofen infusion systems. Alternative methods for spinal catheter placement warrant further study.
Bootstrapping in Gnutella: A measurement study

To join an unstructured peer-to-peer network like Gnutella, peers have to execute a bootstrapping function in which they discover other on-line peers and connect to them. Until this bootstrapping step is complete, a peer cannot participate in file sharing activities. Once completed, a peer’s search and download experience is strongly influenced by the choice of neighbor peers resulting from the bootstrapping step. Despite its importance, there has been very little attention devoted to understanding the behavior of this bootstrapping function. In this paper, we study the bootstrapping process of a peer in the Gnutella network. We find that (1) there is considerable variation among various servent implementations, and hence in their bootstrapping performance. (2) The neighbors of a peer, which are the outcome of the bootstrapping process, play a very important role in the peer’s search and download performance. (3) Even though the GWebCache system for locating peers is designed to operate as a truly distributed caching system, it actually operates more like a centralized infrastructure function, with significant load imbalance. (4) The GWebCache system is subject to significant misreporting of peer and GWebCache availability, due to stale data and absence of validity checks.
Conversion Infrastructure for Maintaining High Availability of Web Services Using Multiple Service Providers

Web Services allow an enterprise to focus on its own business expertise and to employ information technology services offered by others, however, doing so exposes the enterprise to the risk of loss of service or data, if the service provider fails. The use of multiple service providers reduces the risk of failure, but it introduces the complication of incompatible service interfaces, data formats, and stored data. In this paper, we propose a conversion infrastructure that facilitates the use of multiple alternative Web Services at different service providers, to achieve high availability, even in the event of a failure or a catastrophe.
Unsupervised learning of functional categories in video scenes

Existing methods for video scene analysis are primarily concerned with learning motion patterns or models for anomaly detection. We present a novel form of video scene analysis where scene element categories such as roads, parking areas, sidewalks and entrances, can be segmented and categorized based on the behaviors of moving objects in and around them. We view the problem from the perspective of categorical object recognition, and present an approach for unsupervised learning of functional scene element categories. Our approach identifies functional regions with similar behaviors in the same scene and/or across scenes, by clustering histograms based on a trajectory-level, behavioral codebook. Experiments are conducted on two outdoor webcam video scenes with low frame rates and poor quality. Unsupervised classification results are presented for each scene independently, and also jointly where models learned on one scene are applied to the other.
Sensitive information: A review and research agenda

A basic challenge for intelligence and security informatics is exploring the ways in which humans categorize or classify “sensitive” information. Research and practice support the critical nature of categorization frameworks, yet there are a number of different ways humans conceptualize sensitive information. In this paper we review some of the dilemmas associated with classification of sensitive information, present different classification approaches, and then identify alternative propositions related to factors that influence judgments about degree of sensitivity. We conclude with directions for future research.
Guest Editorial Special Section on 2012 Workshop on the Algorithmic Foundations of Robotics (WAFR)

THe five papers in this special section are revised and extended versions of papers representing the best of WFAR 2012.
Bin packing: on optimizing the number of pieces packed

We consider bin-packing variations related to the well-studied problem of maximizing the total number of pieces packed into a fixed set of bins. We show that, when the objective is to minimize the total number of pieces packed subject to the constraint that no unpacked piece will fit, no polynomial-time relative approximation algorithm exists (unless, of course,P=NP). That is, we prove that it isNP-hard to guarantee packing no more than a constant multiple of the optimal number of pieces, for any constant. This appears to be the first bin-packing problem for which this property has been demonstrated. Furthermore, this result also holds for the allied packing variant which seeks to minimize the maximum number of pieces packed in any single bin. We find the situation to be markedly better for the problem of maximizing the minimum number of pieces in any bin. If all bins possess the same capacity, we prove that the familiar SPF rule is an absolute approximation algorithm with additive constant 1, and can therefore be regarded as a best possible heuristic. For the more general and difficult case in which bin capacities may differ, it turns out that SPF fails to qualify as even a relative approximation algorithm. However, we devise an implementation of the well-known FFD heuristic, which we show to be a relative approximation algorithm, yielding a worst-case performance ratio of 1/2 with additive constant 0. Moreover, we prove that (unlessP=NP) no polynomial-time algorithm can guarantee a higher ratio without sacrificing the additive constant.
Parental Divorce and Young Adults' Beliefs About Love

Abstract The purpose of this study was to compare collegc students from intact vs. divorced families on bcliefs and attitudes about love and romantic relationships. We examincd, with a sample of over 1,000 college students (389 males and 634 females), how thc two groups differed on attachment types (e.g., Hazan & Shaver, 1987), love styles (e.g., Hendrick & Hendrick, 1986), romantic beliefs (e.g., Sprcchcr & Metts, 1989), and the belief that love should be the basis for marriage (e.g., Kcphart, 1967). Women with divorced parents, relative to women with nondivorced parents, werc less likely to have a secure attachment style but morc likely to have an avoidant attachment style; were less pragmatic, manic and agamic in their love styles; and were less idealistic in their romantic beliefs. Only one difference was found bctwccn thc two groups for men: Men from divorced families were more erotic than men from intact families. However, follow-up analyses which included a comparison of three groups formed based o...
Monolayer coupling in phosphatidylserine bilayers: distinct phase transitions induced by magnesium interacting with one or both monolayers.

Abstract We have investigated the thermotropic behavior of phosphatidylserine bilayers interacting with Mg2+ either on one side or both sides, using differential scanning calorimetry. Large unilamellar vesicles (LUV) of phosphatidylserine exposed to Mg2+ on the external side only displayed an upward shift of the gel-liquid transition temperature (Tm) of about 6–8 C° relative to the Tm of LUV in Na+. Mg2+ was shown not to enter the vesicle interior, by means of fluorescence measurements on encapsulated 8-hydroxyquinoline-5-sulfonate. Multilamellar vesicles prepared in the presence of Mg2+, or vesicles prepared by Mg2+-induced fusion of small unilamellar vesicles, had Tm values that were shifted upward by about 16–17 C°. When the latter preparation was treated with EDTA to produce vesicles with Mg2+ inside and Na+ outside, the Tm was found to be shifted again by only 6–8 C°. These observations indicate that the monolayer interacting with Na+ fluidizes the monolayer interacting with Mg2+, and thet the latter tends to solidify the former. The two monolayers thus appear to be coupled, possibly by hydrocarbon chain interdigitation.
Performance of Cognitive Radios in Dynamic Fading Channels Under Primary Outage Constraint

This article investigates the performance of a cognitive user in a dynamic fading environment. The cognitive user communicates, using a spectrum-sharing technology, over a channel reserved to a primary user (PU). The transmit power of the cognitive user satisfies the outage probability constraint of the PU. The channels of the primary and cognitive users experience independent and non-identically distributed fading models. Nakagami- $$m$$ m and hyper-Nakagami- $$m$$ m channel fading models are specifically considered. The cognitive user's mean transmit power, channel capacity, and bit error rate are derived for this setup. In addition, numerical results are presented to verify the theoretical analysis and investigate the effects of the parameters of the communication environment on the performance measures of the cognitive user.
Clutch characteristics of two populations of nine-spined stickleback from south-central Alaska

Clutch size of nine-spined stickleback Pungitius pungitius from Airolo and Dog Bone Lakes, Alaska, showed small but significant differences between lakes and across 2 years. The variation in clutch size was independent of variation in egg mass, which did not differ appreciably between lakes or across years.
Selective effects of mitogens on subpopulations of mouse lymphoid cells

Abstract The mitogenic effects of phytohemagglutinin (PHA), pokeweed mitogen (PWM), staphylococcal enterotoxin B (SEB) and endotoxins upon mouse spleen cells and various subpopulations were examined. The differential responses to these mitogens by cells of varying density indicate that LPS stimulates a different subpopulation from that of PHA and SEB. The subpopulation containing cells responsive to PWM seemed to differ from both of these patterns. In contrast to the effect of PHA, PWM, and SEB, thymus cells were not stimulated by LPS. LPS- and PWM-stimulated cells taken from both neonatally thymectomized and adult-thymectomized, irradiated, and bone-marrow-reconstituted animals: SEB and PHA failed to do this. It is concluded that the subpopulation responding to SEB, like that to PHA, is thymus dependent but that the two are probably not completely overlapping. That containing PWM responsive cells involves both thymus-independent and thymus-dependent cell components. The subpopulation stimulated by LPS is contained in a low density sub-population, which appears to be completely T independent.
Persistent changes in corticotropin-releasing factor neuronal systems induced by maternal deprivation

There is considerable evidence that CRF-containing neurons integrate the endocrine, autonomic, immune, and behavioral responses to stress. In this study we examined long term effects of early stress on developing hypothalamic and extrahypothalamic CRF neural systems in the rat brain and subsequent responses to stress in the adult. Specifically, we sought to determine whether adult male rats previously isolated for 6 h daily during postnatal days 2-20 react in a biochemically distinct manner to a mild foot shock stress compared to controls. Four treatment groups were examined: nondeprived (NDEP)/no shock, NDEP/shock, deprived (DEP)/no shock, and DEP/shock. Compared to the NDEP group, DEP rats exhibited an increase in both basal and stress-induced ACTH concentrations. Moreover, DEP rats exhibited a 125% increase in immunoreactive CRF concentrations in the median eminence and a reduction in the density of CRF receptor binding in the anterior pituitary compared to those in all NDEP rats. Alterations in extrahypothalamic CRF systems were also apparent in DEP vs. NDEP animals, with an observed 59% increase in the number of CRF receptor-binding sites in the raphe nucleus and an 86% increase in immunoreactive CRF concentrations in the parabrachial nucleus. These results indicate that maternal deprivation before weaning in male rats produces effects on CRF neural systems in both the central nervous system and pituitary that are apparent several months later and are probably associated with persistent alterations in behavioral response in adult rats.
Pathways for mercury uptake by fish from bed sediments

Abstract Mercury transfer from bed sediments to freshwater fish was observed 20 days in the laboratory. Organic-rich sediments from the Ottawa River were contaminated with mercuric chloride to produce a total mercury concentration of 1·023 ppm. Two possible mercury routes from bed sediments to fish were quantitatively evaluated. The concentration of mercury accumulated in fish from bed sediments was nine times higher than that accumulated from water in which mercury had come from bed sediments. The mercury concentration in individual fish varied considerably.
Peak volitional torques for wrenches and screwdrivers

Abstract Effects of grip shape (regular, circular, square, and triangular), wrist orientation (3 for screwdrivers and 7 for wrenches) and duration of repeated exertions on the maximum torque males and females could exert in different postures with 4 wrenches and 4 screwdrivers were investigated experimentally. Quantitative data were collected by conducting two independent sequential experiments. Circular grips for wrenches and triangular grips for screwdrivers maximized torque exertion capability. The peak torque declined with the duration of repeated exertions but stabilized after 180 s. Wrist orientation also had a significant influence on how much torque individuals could exert. A third experiment generated torque data for two additional body postures that were not included in previous works. From this investigation, correction factors were developed to generate peak torque exertion capability data of individuals with wrenches and screwdrivers for a variety of conditions dictated by body posture, wrist orientation, duration of repeated exertions, and grip shape. The paper includes the basic torque exertion capability design data tables and the correction factors.
Comparison of rat hepatic and pulmonary microsomal metabolism of benzene and the lack of benzene-induced pneumotoxicity and hepatotoxicity

Since little is known about the toxicity of benzene in the lung or if the lung is capable of metabolizing benzene, the ability of the lung to bioactivate or detoxify benzene and the pneumotoxicity of benzene were determined. While overall metabolism was lower, pulmonary microsomes converted benzene (17.5 microM) to hydroquinone, considered to be a marker for benzene toxicity, in proportionately greater amounts than did hepatic microsomes. Treatment of rats with pyridine, an inducer of CYP2E1, enhanced hepatic microsomal metabolism of benzene, although benzene, which is also considered to be an inducer of CYP2E1, did not. Neither pyridine nor benzene treatment induced the pulmonary microsomal metabolism of benzene. When hepatic and pulmonary microsomes from control and pyridine-treated rats were incubated with benzene (17.5 microM) and the CYP2E1 inhibitor, diethyldithiocarbamate, benzene metabolism was significantly inhibited, indicating that CYP2E1 is the predominant cytochrome P-450 isozyme involved in hepatic and pulmonary metabolism in microsomes from control and pyridine-treated rats. Benzene (600 mg/kg body weight, i.p.) did not cause significant lung cell damage as determined by measurement of gamma-glutamyltransferase and lactate dehydrogenase in bronchoalveolar lavage fluid. Induction of CYP2E1 and CYP2B1/2 with pyridine and phenobarbital, respectively, did not alter this lack of effect. Thus, the primary concern about benzene and the lung should focus on benzene metabolism as opposed to acute toxicity.
Semantic predicates in parser generations

Abstract Parser-based pattern matching proves to be attractive to compiler implementors because of its use in compiler-compilers. Semantic predicates can be added to parsers to augment the decision making power provided by syntactic analysis. This paper presents a practical technique to incorporate them within the framework of existing parser generators. A nearly vanilla parser can be used in this manner provided that epsilon productions are added to the grammar. Reduction by epsilon productions triggers the predicates, which as a side effect modify the lookahead symbol(s), thus influencing the progress of the parser at the last possible minute.
Localized perturbations in CheY structure monitored by NMR identify a CheA binding interface

Phosphotransfer between the autophosphorylating histidine kinase CheA and the response regulator CheY represents a crucial step in the bacterial chemotaxis signal transduction pathway. The ^(15)N−^1H correlation spectrum of CheY complexed with an amino-terminal fragment of CheA exhibits specific localized differences in chemical shifts when compared to the spectrum of uncompiexed CheY. When mapped onto the three-dimensional structure of CheY, these changes define a region distinct from the active site. A single amino-acid substitution within this binding region on CheY, alanine to valine at position 103, significantly decreases the affinity of CheY for CheA. The binding face described by these changes partially overlaps a flagellar switch binding surface previously defined by mutagenesis.
Diagnostic accuracy of ultrasound above and below the beta-hCG discriminatory zone.

Objective: To evaluate clinical use and accuracy of transvaginal ultrasound for diagnosing intrauterine pregnancies, spontaneous miscarriages, and ectopic pregnancies in women who present with β-hCG concentrations above or below an established discriminatory zone. Methods: Ultrasound diagnosis at presentation was compared with final clinical diagnosis in 333 consecutive pregnant women who presented to an emergency department with vaginal bleeding or abdominal pain. The sensitivity, specificity, predictive value, and overall diagnostic accuracy of ultrasound were calculated. Results: Transvaginal ultrasound was nondiagnostic in 59 (17.7%) of 333 subjects and 43 (67.2%) of 64 subjects with β-hCG levels below 1500 mIU/mL at presentation. Preliminary ultrasound diagnoses were reported significantly more frequently when presenting β-hCG levels were above 1500 mIU/mL (253 [94.1%] of 269 subjects) compared with levels below 1500 mIU/mL (21 [32.8%] of 64 subjects: P < .001; relative risk (RR) 3.4 [95% confidence interval (CI) 2.23, 5.18]). The proportion of accurate preliminary ultrasound diagnoses was significantly higher in subjects who presented with β-hCG levels above 1500 mIU/mL (227 [91.5%] of 248 subjects) compared with levels below 1500 mIU/mL (18 [28.6%] of 63 subjects: P < .001; RR 2.9 [95% CI 2.04, 4.15]). Sensitivity of transvaginal ultrasound diagnosis of intrauterine pregnancy, spontaneous miscarriage, and ectopic pregnancy in women who presented with β-hCG levels below 1500 mIU/mL was 33.3%, 28.2%, and 25.0%, respectively. Conclusion: The sensitivity, predictive value, and accuracy of transvaginal ultrasound for diagnosing complications of early pregnancy were poor when β-hCG levels were below the discriminatory zone at presentation. Ultrasound impressions should be correlated with β-hCG concentrations.