cssi/SciSciGPT-SciSciNet huggingface dataset:
Influence of Complex Formation on Drug Transport

Abstract A method of a priori prediction of whether complex formation will lead to enhancement or reduction of the transport rate of a drug across biological membranes is presented. It is shown that compounding a drug with substances of lower diffusion coefficients, with which the drug will form a complex, leads to enhancement of the flux of the drug; compounding with substances with similar diffusion coefficients results in a reduction of the transport rate of unassociated drug (flux), provided the rate constants for association‐dissociation reactions are of similar magnitude. Detailed methods of computation of fluxes and concentration profiles are included.
Experimentalists and modelers: can we all just get along?

How can the interaction between theoretical neuro-scientists and their experimental counterparts be improved? This article discusses a number of suggestions relating to the presentation of data in experimental studies. In particular, published data should account for the diversity of response properties encountered, rather than concentrating on the ‘representative’ response, as well as emphasizing the stochastic nature of neurons by routinely including raw, unprocessed data from individual trials, which show the degree of variability prior to averaging.
Brain interactions in chronic schizophrenics under resting and activation conditions

The metabolic patterns of correlation among brain images obtained during resting conditions and during an eye tracking task were investigated in 12 controls and 18 chronic schizophrenics using positron emission tomography (PET) and deoxy[11C]glucose. Analyses of the interaction between brain regions revealed highly significant differences between groups under both test conditions. Schizophrenics showed lower correlations between anterior and posterior areas and between thalamus and cortical areas than the normals and less change between the baseline and the task than the normals. The schizophrenic subjects showed derangements in the pattern of interactions among brain areas, both under baseline and under activation as compared to the control group.
Thermal behavior of poly(1,8‐nonadiyne) and its cross‐polymerized product

The diacetylene macromonomer poly(1,8-nonadiyne) was investigated using differential scanning calorimetry in an effort to characterize the solid-state cross-polymerization reaction which occurs when this material is exposed to high-energy radiation. Specifically, DSC was used as a means to monitor the degree of conversion in the crystalline regions of partially cross-polymerized samples. Results from the thermal analysis of the virgin macromonomer indicate that little, if any, thermally induced reaction occurs during the DSC heating scans. Heat of fusion data were used to estimate the degree of conversion in partially cross-polymerized samples. The apparent maximum degree of conversion in the crystalline regions of this macromonomer system was found to be 78% using this method. The actual maximum conversion for the system is probably somewhat lower.
Polymorph stabilization in processed acetaminophen powders

Abstract A novel approach has been developed to stabilize the metastable form II of acetaminophen (APAP) prepared from the melt of micronized and nano-silica coated APAP I. It is suggested that stabilization of form II APAP occurs by pinning via van der Waals-type interactions on low energy defects created by micronization and impinging particles during dry coating in form I APAP, heating to the melt phase, and cooling. The defects are likely to persist into the near-molten isotropic phase due to a permanent memory effect similar to that previously observed in silica-liquid crystal composites and re-crystallize together with form II APAP. Raman spectroscopy, scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and conventional as well as intrinsic dissolution have been used to characterize the stabilized APAP II obtained. Raman measurements up to 18 months and PXRD data for micronized form II APAP show no indication of APAP I formation. Aged samples of dry-coated APAP II however display Raman features indicative of APAP I within 5 months. PXRD and SEM techniques also detected small fractions of APAP I in dry-coated APAP II. Both micronized APAP II and dry-coated APAP II give rise to a time-dependent background scattering superimposed on the Raman spectra which increases in integrated intensity with time, saturates at 180 and 90 days, respectively, and then decreases in intensity with further aging. The time-dependent scattering background occurs in the stabilized form II APAP samples only after cooling from the melt and is more intense in micronized APAP II compared to dry-coated APAP II. It is assigned to disorder associated with slowly diffusing defects created by micronization and dry coating with impinging nano-silica particles in form I APAP. Intrinsic dissolution profiles for the stabilized APAP II samples showed measureable increases, particularly for micronized APAP II.
Crack extension from flaws in a brittle material subjected to compression

The mechanisms by which cracks extend from flaws in brittle materials subjected to compressive loads are presented. Although it is recognized that most geological materials are neither dense nor single-phase, this experimental study and analysis are restricted to single-phase, dense materials in order to provide a model amenable to analysis and experimental confirmation. The flaws which occur in dense, single-phase materials are divided into three types, each type having different characteristics of crack extension. Experimental studies of crack extension from flaws introduced into blocks of polymethylmethacrylate plastic are described. The studies show that crack extension from three dimensional flaws is more complex than two-dimensional theories predict. The extension of secondary cracks may result in more damage than that which would be predicted by considering only the primary crack extension treated by current theories. The importance of the dynamic behavior of flaws which stick and then suddenly slip is shown.
A major mistake that managers make

Purpose – One does not learn from doing something right; one already knows how to do it. By doing something right one gets confirmation of what one already knows but no new knowledge. The fact that schools are more interested in teaching than in learning is apparent from their failure to determine if students learn from their mistakes. This is a critical problem in business schools and in practice in the business world.Design/methodology/approach – Errors of omission, lost opportunities, are generally more critical than errors of commission. Organizations fail or decline more frequently because of what they did not do than because of what they did.Originality/value – Many companies remain paralyzed and do not reach their potential. In such companies, no one in senior management is willing to do something that might turn out to be wrong. Every one of them wants someone else to assume responsibility for whatever they try. As a result, significant changes are seldom made.
Dimension Consistency as an Individual Difference: A New (Old) Perspective on the Assessment Center Construct Validity Debate

This article presents a historical review of how inconsistency in assessment center ratings has been regarded among AC researchers and practitioners, then compares these perspectives to views of inconsistency found in personality psychology. Based on this review, the authors argue for a return to the study of consistency as an individual difference, rather than as simple measurement error. They offer four propositions regarding the inconsistency observed in AC performance, arguing that such inconsistency presents a unique opportunity to identify individuals’ patterns of skill proficiency. Finally, they discuss ways in which differences in consistency are likely to relate to organizational interests, including implications for selection and development.
The Temporary Staffing Industry: Growth Imperatives and Limits to Contingency*

: The temporary staffing industry (TSI) in the United States has enjoyed explosive growth since the 1970s, during which time the market for temporary labor has become increasingly complex and diverse. Rather than focus, as has typically been done, on the wider labor market effects of this sustained expansion in temporary employment, this article explores patterns and processes of industrial restructuring in the TSI itself. The analysis reveals a powerfully recursive relationship among evolving TSI business practices, the industry's strategies for building and extending the market, and urban labor market outcomes as the sector has grown through a series of qualitatively differentiated phases of development or “modes of growth.” Moreover, the distinctive character of the TSI's geographic rollout raises a new set of questions concerning, inter alia, the links between temping and labor market deregulation, the nature of local competition, the scope for and limits of value-adding strategies, and the emerging global structure of the temp market. This idiosyncratic industry—which has been a conspicuous beneficiary of growing economic instability—has, throughout the past three decades, restructured continuously through a period of sustained but highly uneven growth. In so doing, it has proved to be remarkably inventive in extending the market for contingent labor, but has encountered a series of (possibly structural) obstacles to further expansion in its domestic market. These obstacles, in turn, have triggered an unprecedented phase of international integration in the TSI, along with a new mode of development—global growth.
Virtual Reality Environment for Creation of Freeform Models

A novel method has been developed using a virtual reality (VR) environment to create solid models with freeform surfaces. The VR environment emulates the physical environment for creating freeform objects, i.e. the freeform model is created in a virtual environment by shaping a virtual workpiece with a variety of virtual tools. The trajectories of the virtual tools are generated by the designer’s hand movements and they are obtained by recording the position and orientation of the motion tracker mounted on a device held by the hand. In the mathematical algorithm, the swept volumes of the design tools are computed from the tools’ geometric data and trajectories. Boolean operations are then performed on the swept volumes of the virtual tools and the virtual workpiece to create the design model.Copyright © 2002 by ASME
Tariff Policy and the Foreign Entry Decision in the Presence of a Cost-Based Informational Asymmetry

The paper demonstrates that the standard prediction on the relation between tariff rates and the mode of foreign entry—exports or direct investment—may not hold in the presence of incomplete information. A foreign firm lacks full information on the cost structure of an informed incumbent firm located in the domestic (potential) host country. Within a two-period model, the local incumbent may behave in a manner which keeps the potential foreign entrant uninformed of its cost structure. In such a pooling equilibrium, the uninformed foreign firm either refrains from entering altogether or serves the host country via exports at tariff rates which would, otherwise under complete information, induce entry via direct investment. When entry mode is altered, other standard full-information effects of trade policy may also no longer hold.
Balancing the ledger : an application of nagy's theories to the study of continuity and change among generations

This study uses an interpretive interview method to examine the micro-processes of generational continuity and change among a group of social activists. Boszormenyi-Nagy's theory of responsibility between generations, alternative models outside the family, and choice are used to explain the instances of change. Implications for research and practice are addressed.
Caffeine in Boston Harbor seawater

Caffeine has been detected in Boston Harbor seawater with concentrations ranging from 140 to 1600 ng l(-1), and in Massachusetts Bay seawater at concentrations from 5.2 to 71 ng l(-1). Sources of caffeine appear to be anthropogenic with higher concentrations in the seawater of Boston's inner harbor and in freshwater sources to the harbor. Charles River water and Deer Island sewage treatment plant effluent, the two major sources of freshwater to the harbor, contained 370 and 6700 ng l(-1) of caffeine, respectively, in 1998. Sewage influent and effluent concentrations appear to be consistent with consumption estimates of caffeinated beverages for the Boston area and total organic carbon removal targets for treated sewage. Caffeine was inversely correlated to salinity in a transect from the mouth of Boston Harbor to Stellwagen Basin, indicating it may be a useful chemical tracer of anthropogenic inputs to marine systems.
Raman scattering characterization of bismuth based mixed oxides with Bi2O3 related structures

Abstract Orthorhombic Bi 17 Ln 7 O 36 (=Bi 0.708 Ln 0.292 O 1.5 ) and triclinic BiLnO 3 (=Bi 0.5 Ln 0.5 O 1.5 ) with Ln = Tm, Yb and Lu, as well as a cubic δ-type Bi 0.7 Yb 0.3 O 1.5 , have been characterized at room temperature by Raman scattering spectrometry. The Raman spectrum deconvolution of the δ-Bi 2 O 3 type cubic form allowed us to establish a correlation between the different phases of these mixed metallic oxides for the lattice modes as well as for the internal species. Using the empirical relation from Hardcastle, the Bi O bond lengths have been estimated from the stretching frequency value observed at 635, 597 or 639 cm −1 for cubic, orthorhombic or triclinic forms, respectively. A comparison with the X-ray results is discussed. The peritectoidic transformation BiTmO 3 → δ + Tm 2 O 3 has also been characterized by Raman spectroscopy.
Diffractive optical elements for the production of synthetic spectra

We demonstrate that computer-generated diffractive optical elements can be used to synthesize the infrared spectra of real compounds. In particular, we describe a modified phase-retrieval algorithm that we have used to design diffractive elements of this type and we present experimental results for a diffractive optic which is capable of synthesizing the infrared spectrum of HF between 3600 cm{sup -1} and 4300 cm{sup -1}. The reflection-mode diffractive optic consists of 4096 lines, each 4.5 {mu}m wide, at 16 discrete depths relative to the substrate (from 0 to 1.2 {mu}m), and was fabricated on a silicon wafer using anisotropic reactive ion-beam etching in a four-mask-level process. We propose the use of such elements to replace reference cells in a new type of correlation spectroscopy that we call {open_quotes}holographic correlation spectroscopy.{close_quotes} Storage of a large number of diffractive elements, each producing a synthetic spectrum corresponding to a different target compound, in compact disk-like format, will allow a spectrometer of this type to rapidly determine the composition of unknown samples. Further, this approach can be used to perform correlation-based measurements of hazardous or transient species, for which conventional correlation spectroscopy is impractical.
The Role of Cohabitation in Asset and Debt Accumulation During Marriage

Research has found that married individuals who cohabited only once before marriage with their future spouse (i.e., “spousal cohabiters”) have a distinctive financial advantage: they accumulate more wealth over time than individuals who married without ever cohabiting (i.e., “directly married”). Using the National Longitudinal Survey of Youth 1979 and growth curve models, the present study attempts to identify the source of spousal cohabiters’ wealth advantage. We find that marriage is associated with gains for financial and nonfinancial wealth, increasing home equity, and decreasing debt over time. Spousal cohabiters begin marriage with more debt than the directly married. Conditional on education, income, and other key factors, spousal cohabiters pay down their debt faster and generate greater home equity over time thereby accumulating more wealth than the directly married. This pattern of financial behavior among spousal cohabiters explains some, but not all, of their financial advantage over married persons who never cohabited prior to marrying. Given the increasing prevalence of cohabitation among young adults, these results offer important insights into the long-term economic outcomes associated with premarital cohabitation.
Collateral damage: The effect of patient complications on the surgeon's psyche

Background The effect of patient complications on physicians is not well understood. Our objective was to determine the impact of a surgeon's complication(s) on his/her emotional state and job performance. Methods An anonymous survey was distributed to Midwest Surgical Society members and attending surgeons within the Grand Rapids, Michigan, community. Results There were 123 respondents (30.5% response rate). For the majority of participants, the first complication that had a significant emotional impact on them occurred during residency (51.2%). Most respondents reported this did not impair their professional functioning (77.2%). If a major complication was first experienced after residency, this had a greater likelihood of causing impairment (P Conclusion The majority of surgeons agreed that it was difficult to handle the emotional effects of complications throughout their careers. Efforts should be made to increase awareness of unrecognized emotional effects of patient complications and improve access to support systems for surgeons.
Hornblende, the continent maker—Evolution of H2O during circum-Pacific subduction versus continental collision

Andesitic arcs are sited over convergent lithospheric plate junctions. Aqueous fluids driven off the downgoing slab are responsible for partial fusion of the warming subducted plate and/or the overlying mantle wedge, and the ascent of calc-alkaline melts. Various hydrous minerals have been proposed to be the source of this H2O. Experimental equilibrium studies show that, under subduction-zone geothermal gradients of 5–7 °C/km, clinoamphibole constitutes a major phase in deep-seated (>75 km) metabasalts; other hydrous minerals are absent or are of very minor abundance. Clinoamphiboles dehydrate at pressures of ∼2.2–2.4 GPa under equilibrium conditions (pressure overstepping is probable), so mafic blueschists and amphibolites expel H2O at magmagenic depths. Partly serpentinized mantle beneath the oceanic crust devolatilizes at comparable to slightly higher pressures. However, micas remain stable in pelitic and granitic gneisses to pressures far exceeding 4.0 GPa, so at subduction depths >100 km, micaceous lithologies characterizing the upper and middle sialic crust fail to evolve significant H2O. Deep underflow of hydrated oceanic lithosphere thus generates most of the volatile flux along and/or above a subduction zone prior to continental collision. As large masses of quartzofeldspathic material enter a suture zone, volatile evolution at deep levels nearly ceases. While small amounts of peraluminous, S-type anatectic melts may be produced, I-type calc-alkaline arcs—and the continents—owe their formation over geologic time to the sustained underflow of oceanic lithosphere.
The Scaling of Speeds and Distances in Galileo's Two New Sciences: A Reply to Palmerino and Laird

In this reply, we respond to the comments of Palmerino and Laird on our article, "Galileo's Refutation of the Speed Distance Law of Fall Rehabilitated," published in the same issue of Centaurus.
Connecting across campus

Computer science holds a unique position to craft multidisciplinary curricula for the new generation of faculty and students across the academy who increasingly rely on computing for their scholarship. We propose that computer science programs cease curricula models that begin with a two-course sequence that emulates the natural sciences and mathematics. We report on an aggressive strategy to work with faculty from across the disciplines of arts, humanities, and the social and life sciences to help design and deliver sets of multidisciplinary, applied, and "connected" pairs of introductory courses. Preliminary results at our small liberal arts college include an increase in the percentage of women enrolling in our connected courses, more students taking an additional course in computing, a faculty energized with sharing their research early on, and new interdisciplinary research opportunities for computer science faculty and students.
Cancer: Micromanagement of metastasis

Although they were discovered only in the early 1990s, many regulatory functions of microRNAs — naturally occurring short RNA sequences — have already been reported. The latest news is that they mediate cancer spread. A microRNA that may facilitate the movement of cells from one part of the embryo to another in its normal role has been found to be highly expressed in aggressive human breast cancers and to mediate breast cancer cell migration, invasion and metastasis. MicroRNAs, naturally occurring single-stranded RNA molecules involved in gene regulation, have been implicated previously in causing cancers, but this is the first report of a link to metastasis. The functional target of the microRNA appears to be the HOXD10 gene, one of the Hox gene family involved in directing embryo development.
In Situ Carcinoma of the Breast

In situ carcinoma of the breast is a proliferation of potentially malignant cells within the lumen of the ductal-lobular system and is classified as ductal or lobular in type. It has become an increasingly frequent clinical management problem, primarily because of its enhanced detection by screening mammography. In this paper, we discuss the problems in histologic diagnosis, the natural history, presentation, and options for management of these two forms of in situ carcinoma.
Optimizing the Internet Gateway Deployment in a Wireless Mesh Network

In a wireless mesh network (WMN), mesh routers (MRs) are interconnected by wireless links and form a wireless backbone to provide ubiquitous high-speed Internet connectivity for mobile clients. The wireless backbone is tightly integrated with the Internet by nodes called as Internet gateways (IGWs). In this paper, we address the IGW deployment problem which is shown to be NP-hard. We first formulate it as a linear program (LP) issue, then develop two heuristic algorithms for the purpose of cost-efficient IGW deployment. We further compare our algorithms with a leading approach by extensive simulations. Our analysis shows the effectiveness of the proposed algorithms.
Comments on the Weather Bureau's experiment in five‐day weather‐forecasting

In the summer of 1936 the United States Department of Agriculture in cooperation with the Massachusetts Institute of Technology organized a cooperative research-project, the broad purposes of which were, first, to arrive at a clear understanding of the atmosphere as a thermodynamic circulation-engine, secondly, on the basis of such a satisfactory model for the general circulation of the atmosphere, to develop a technique far five- to ten-day forecasting of weather, with particular emphasis on the forecasting of the geographic distribution of five- and ten-day anomalies of temperature and rainfall over the United States. In the course of these investigations considerable progress was made with the description and interpretation of circulation-patterns in summer over the continent of North America. The development of isentropic analysis was the first important specific practical result of this research. Later, efforts were concentrated on the interpretation of the circulation in winter in the Northern Hemisphere. In the course of this phase of the investigation important, slow irregular changes in the cellular structure of the atmosphere were discovered and a preliminary dynamic theory for these changes was formulated, which already has proven its practical value as a tool in a five-day forecasting of weather. The picture of the general circulation of the atmosphere thus developed is now being published in a contribution from the writer to the Yearbook of the Department of Agriculture for 1941.
Morphological control in polymer solar cells using low-boiling-point solvent additives

In the global search for clean, renewable energy sources, organic photovoltaics (OPVs) have recently been given much attention. Popular modern-day OPVs are made from solution-processible, carbon-based polymers (e.g. the model poly(3-hexylthiophene) that are intimately blended with fullerene derivatives (e.g. [6,6]-phenyl-C71-butyric acid methyl ester) to form what is known as the dispersed bulk-heterojunction (BHJ). This BHJ architecture has produced some of the most efficient OPVs to date, with reports closing in on 10% power conversion efficiency. To push efficiencies further into double digits, many groups have identified the BHJ nanomorphology — that is, the phase separations and grain sizes within the polymer: fullerene composite — as a key aspect in need of control and improvement. As a result, many methods, including thermal annealing, slow-drying (solvent) annealing, vapor annealing, and solvent additives, have been developed and studied to promote BHJ self-organization. Processing organic photovoltaic (OPV) blend solutions with high-boiling-point solvent additives has recently been used for morphological control in BHJ OPV cells. Here we show that even low-boiling-point solvents can be effective additives. When P3HT:PCBM OPV cells were processed with a low-boiling-point solvent tetrahydrafuran as an additive in parent solvent o-dichlorobenzene, charge extraction increased leading to fill factors as high as 69.5%, without low work-function cathodes, electrode buffer layers or thermal treatment. This was attributed to PCBM demixing from P3HT domains and better vertical phase separation, as indicated by photoluminescence lifetimes, hole
Rectal carcinoid tumors: review of results after endoscopic and surgical therapy.

Objective To assess whether endoscopic treatment can clear local disease in patients with carcinoid tumor. Design Retrospective cohort study. Setting Tertiary care academic medical center. Patients All patients diagnosed as having a neuroendocrine tumor or carcinoid tumor of the rectum who were evaluated at our institution between January 1, 1990, and December 31, 2006. Main Outcome Measure Margin status of tumor resection. Results Eighty-five patients were identified (median age at diagnosis, 55 years). Thirty-three tumors (39%) were asymptomatic and diagnosed during screening colonoscopy. Eleven tumors (13%) were metastatic at presentation. Of the 85 tumors, 48 (56%) were smaller than 1.0 cm. Endoscopic therapy was performed in 46 patients (54%). Of these, 38 patients (83%) had tumors with positive or indeterminate margins on histologic examination; of whom 6 (16%) had residual tumor on subsequent endoscopy and 1 (3%) had recurrence as metastatic disease. One patient who had a negative margin had residual tumor on follow-up. Thirty-one patients (36%) underwent surgical resection; of these, 23 (74%) underwent transanal excision or transanal endoscopic microsurgery, 6 (19%) underwent low anterior resection, and 2 (6%) underwent abdominoperineal resection. Eight patients who did not receive local clearance of tumor had metastases on presentation, had another active malignant neoplasm, or refused further surgical treatment. Among the 85 patients, 4 metastases occurred during follow-up, including 2 from tumors smaller than 1.0 cm at presentation. Conclusions Endoscopic treatment is sufficient for tumors that are small, for tumors limited to the mucosa, and when a margin is negative for tumor. Transanal excision should be considered when margins of endoscopic resection are positive. We recommend rectal resection for tumors that are 1.0 to 1.9 cm and have high-risk features.
Challenges and coping strategies in leavening an ultra-Orthodox community:

This article reports and illustrates challenges encountered by those who were born and raised in an insular Ultra-Orthodox Jewish community and opted to transition to the modern world. Based on con...
Treatment of Unstable Distal Radial Fractures with the Volar Locking Plating System

BACKGROUND: The best treatment for an inadequately reduced fracture of the distal part of the radius is not well established. We collected prospective outcomes data for patients undergoing open reduction and internal fixation of an inadequately reduced distal radial fracture with use of the volar locking plating system. METHODS: Over a two-year period, 161 patients underwent open reduction and internal fixation of an inadequately reduced distal radial fracture with use of the volar locking plating system. Patients were enrolled in the present study three months after the fracture on the basis of strict entry criteria and were evaluated three, six, and twelve months after surgery. Outcome measures included radiographic parameters, grip strength, lateral pinch strength, the Jebsen-Taylor test, wrist range of motion, and the Michigan Hand Outcomes Questionnaire. RESULTS: Eighty-seven patients with a distal radial fracture were enrolled. The mean age at the time of enrollment was 48.9 years. Forty percent (thirty-five) of the eighty-seven fractures were classified as AO type A, 9% (eight) were classified as type B, and 51% (forty-four) were classified as type C. Radiographic assessment showed that the plating system maintained anatomic reduction at the follow-up periods. At the time of the twelve-month follow-up, the mean grip strength on the injured side was worse than that on the contralateral side (18 compared with 21 kg; p < 0.01), the mean pinch strength on the injured side was not significantly different from that on the contralateral side (8.7 compared with 8.9 kg; p = 0.27), and the mean flexion of the wrist on the injured side was 86% of that on the contralateral side. All Michigan Hand Outcomes Questionnaire domains approached normal scores at six months, with small continued improvement to one year. CONCLUSIONS: The volar locking plating system appears to provide effective fixation when used for the treatment of initially inadequately reduced distal radial fractures. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence. ORIGINAL ABSTRACT CITATION: “Treatment of Unstable Distal Radial Fractures with the Volar Locking Plating System” (2006;88:2687-94).
An apologia for papers poorly scheduled

During the program planning for my last AGU annual meeting as SPR Magnetospheric section secretary, I realized the need to apologize to the many people who were upset or disappointed by the scheduling of their talks at the annual meetings. Thus, I apologize to those who were scheduled … … on Monday or Friday (I also apologize to those who didn't want anything in the middle of the week.) … just before lunch or just after lunch … just before coffee breaks or just after coffee breaks. (I should also apologize to those whose talks were “too early in the morning” or “too late in the afternoon.”)
Models of the Structure and Voltage-Gating Mechanism of the Shaker K+ Channel

In the preceding, accompanying article, we present models of the structure and voltage-dependent gating mechanism of the KvAP bacterial K+ channel that are based on three types of evidence: crystal structures of portions of the KvAP protein, theoretical modeling criteria for membrane proteins, and biophysical studies of the properties of native and mutated voltage-gated channels. Most of the latter experiments were performed on the Shaker K+ channel. Some of these data are difficult to relate directly to models of the KvAP channel's structure due to differences in the Shaker and KvAP sequences. We have dealt with this problem by developing new models of the structure and gating mechanism of the transmembrane and extracellular portions of the Shaker channel. These models are consistent with almost all of the biophysical data. In contrast, much of the experimental data are incompatible with the "paddle" model of gating that was proposed when the KvAP crystal structures were first published. The general folding pattern and gating mechanisms of our current models are similar to some of our earlier models of the Shaker channel.
Finding similar files in large document repositories

Hewlett-Packard has many millions of technical support documents in a variety of collections. As part of content management, such collections are periodically merged and groomed. In the process, it becomes important to identify and weed out support documents that are largely duplicates of newer versions. Doing so improves the quality of the collection, eliminates chaff from search results, and improves customer satisfaction.The technical challenge is that through workflow and human processes, the knowledge of which documents are related is often lost. We required a method that could identify similar documents based on their content alone, without relying on metadata, which may be corrupt or missing.We present an approach for finding similar files that scales up to large document repositories. It is based on chunking the byte stream to find unique signatures that may be shared in multiple files. An analysis of the file-chunk graph yields clusters of related files. An optional bipartite graph partitioning algorithm can be applied to greatly increase scalability.
Communication via eye blinks - detection and duration analysis in real time

A method for a real-time vision system that automatically detects a user's eye blinks and accurately measures their durations is introduced. The system is intended to provide an alternate input modality to allow people with severe disabilities to access a computer. Voluntary long blinks trigger mouse clicks, while involuntary short blinks are ignored. The system enables communication using "blink patterns:" sequences of long and short blinks which are interpreted as semiotic messages. The location of the eyes is determined automatically through the motion of the user's initial blinks. Subsequently, the eye is tracked by correlation across time, and appearance changes are automatically analyzed in order to classify the eye as either open or closed at each frame. No manual initialization, special lighting, or prior face detection is required. The system has been tested with interactive games and a spelling program. Results demonstrate overall detection accuracy of 95.61% and an average rate of 28 frames per second.
Insights From an Evaluability Assessment of the U.S. Forest Service More Kids in the Woods Initiative

We conducted an evaluability assessment of the U.S. Forest Service's “More Kids in the Woods” internal grant initiative based on a review of 26 funded proposals, the creation of logic models, and a survey of project leaders. Evaluations of the initative are warranted because it has clear outcome objectives, is implemented as intended, and results suggest plausible benefits associated with providing underserved youth with outdoor experiences. Findings also point to the types of evaluations that will be useful and add to the limited literature on environmental grant programs as well as environmental educators’ evaluation interests, practices and perceived competencies.
Analgesic benefit, functional outcome, and patient satisfaction after partial wrist denervation

Partial wrist denervation is a useful palliative procedure for chronic wrist pain when reconstructive procedures are not feasible or desirable. We reviewed 19 patients who had 20 isolated anterior and posterior interosseous neurectomies with no previous or concurrent wrist surgery in a 5-year period at our institution. At an average of 2.5 years postoperatively, 80% of patients reported a decrease in pain, 45% reported normal or increased grip strength, and 73% of employed patients had returned to work. Three patients required additional procedures for pain relief (2 arthrodesis, 1 radial styloidectomies). Failure tended to occur in the first postoperative year. Poor preoperative range of motion and workers' compensation status were predictive of failure. Failure also occurred in the single patient with rheumatoid arthropathy. Two patients had subsequent arthrodeses. There were no complications related to the surgery. Overall, 85% of patients reported satisfaction with this procedure; 90% retrospectively would choose the same treatment for their chronic wrist pain. Partial denervation of the wrist via the anterior and posterior interosseous nerves is a technically easy procedure and may provide pain relief sufficient to markedly delay the need for more extensive salvage procedures in patients with wrist arthritis.
High-level control methods for autonomous systems

Systems that can change their behavior in response to unanticipated events during operation are called autonomous. Autonomous systems are playing an increasingly important role in both civilian and military applications. The central characteristics of autonomous systems are their abilities to sense, to learn, and to control the environment in which they operate. Based on a layered autonomy model, research on high-level control methods is conducted in this paper. At the highest level of the autonomy model, either adaptive or robust control can be used to interact with uncertain, unstructured and dynamic environments. Their possible implementations and future research directions are discussed as well.
Violence from parents in childhood and obesity in adulthood: Using food in response to stress as a mediator of risk

Guided by a life course perspective and concepts from models of stress and coping, this study tested the extent to which self-reported profiles of physical and psychological violence in childhood from parents were associated with greater odds of obesity in adulthood. This study also examined the extent to which adults' greater use of food in response to stress served as a mediator of potential associations of risk. Multivariate regression models were estimated using data from 1650 respondents in the 1995-2005 National Survey of Midlife in the U.S. (MIDUS). Results indicated that respondents who reported having experienced both psychological and physical violence from parents-with at least one type of violence having reportedly occurred frequently-were more likely to be classified as obese in contrast to respondents who reported never having experienced either type of violence from parents. Evidence from a sequence of models that tested mediation effects indicated that greater use of food in response to stress among respondents with problematic histories of violence explained, in part, their higher risk of adult obesity. Findings contribute to the growing body of evidence regarding psychosocial predictors of obesity, as well as the physical health consequences of childhood family violence. Results further suggest the importance of addressing particular aspects of life course social relationships-such as violence in childhood from parents-and their implications for psycho-behavioral uses of food within efforts to reduce rates of adult obesity.
Lower bounds for depth-three circuits with equals and mod-gates

We say an integer polynomial p, on Boolean inputs, weakly m-represents a Boolean function f if p is non-constant and is zero (mod m) whenever f is zero. In this paper we prove that if a polynomial weakly m-represents the Modq function on n inputs, where q and m are relatively prime and m is otherwise arbitrary, then the degree of the polynomial is Ω(n). This generalizes previous results of Barrington, Beigel and Rudich [BBR] and Tsai [Tsai], which held only for constant (or slowly growing) m. The proof technique given here is quite different and somewhat simpler. We use a method in which the inputs are represented as complex q th roots of unity (following Barrington and Straubing [BS]). The representation is used to take advantage of a variant of the inverse Fourier transform and elementary properties of the algebraic integers. As a corollary of the main theorem and the proof of Toda's theorem, if q, p are distinct primes, any depth-three circuit which computes the Modq function, and consists of an equals gate at the output, Modp-gates at the next level, and AND-gates of small fan-in at the inputs, must be of exponential size. In terms of Turing machine complexity classes, there is an oracle A such that \(Mod_q P^A \nsubseteq C_ = P^{Mod_p P^A }\).
Essential roles of core starvation-stress response loci in carbon-starvation-inducible cross-resistance and hydrogen peroxide-inducible adaptive resistance to oxidative challenge in Salmonella typhimurium.

The starvation-stress response (SSR) of Salmonella typhimurium encompasses the physiological changes that occur upon starvation for an essential nutrient, e.g. C-source. A subset of SSR genes, known as core SSR genes, are required for the long-term starvation survival of the bacteria. Four core SSR loci have been identified in S. typhimurium: rpoS, stiA, stiB, and stiC. Here we report that in S. typhimurium C-starvation induced a greater and more sustainable cross-resistance to oxidative challenge (15 mM hydrogen peroxide (H2O2) for 40 min) than either N- or P-starvation. Of the four core SSR loci, only rpoS and stiC mutants exhibited a defective C-starvation-inducible cross-resistance to H2O2 challenge. Interestingly, (unadapted) log-phase S. typhimurium rpoS and stiA mutants were very sensitive to oxidative challenge. Based on this, we determined if these core SSR loci were important for H2O2 resistance developed during a 60 min adaptive exposure to 60 microM H2O2 (adapted cells). Both unadapted and adapted rpoS and stiA mutants were hypersensitive to a H2O2 challenge. In addition, a stiB mutant exhibited normal adaptive resistance for the first 20 mins of H2O2 challenge but then rapidly lost viability, declining to a level of about 1.5% of the wild-type strain. The results of these experiments indicate that: (i) the rpoS and stiC loci are essential for the development of C-starvation-inducible cross-resistance to oxidative challenge, and (ii) the rpoS, stiA, and, in a delayed effect, stiB loci are needed for H2O2-inducible adaptive resistance to oxidative challenge. Moreover, we found that both stiA and stiB are induced by a 60 microM H2O2 exposure, but only stiA was regulated (repressed) by (reduced form) OxyR.
Prolonged Depletion of O6-Methylguanine DNA Methyltransferase Activity following Exposure to O6-Benzylguanine with or without Streptozotocin Enhances 1,3-Bis(2-chloroethyl)-1-nitrosourea Sensitivity in Vitro

This study was undertaken to ascertain the importance of prolonged depletion of O6-methylguanine DNA methyltransferase (MGMT) activity, following O6-benzylguanine (BG) and streptozotocin (STZ) exposure, in reversing 1,3 bis(2-chloroethyl)-1-nitrosourea (BCNU) resistance in vitro. We evaluated BCNU-induced cytotoxicity and measured the temporal recovery of MGMT activity in human colon carcinoma HT-29 cells following treatment with BG, STZ, or the combination of BG and STZ. The pretreatment regimens which provided the greatest potentiation of BCNU cytotoxicity were those exhibiting the greatest temporal inhibition of MGMT activity. The combination of BG (10 microM) and STZ (1.0 mM) produced sustained inhibition of MGMT activity through 24 h and potentiated BCNU cytotoxicity by at least one log greater than either agent alone. Similarly, BG (10-100 microM) produced marked reductions in MGMT activity and increased BCNU cytotoxicity in a dose-dependent fashion. A 100-microM dose of BG inhibited MGMT activity for 48 h and potentiated BCNU induced cell kill by 3 logs greater than BCNU alone. In addition, we observed that during the period of sustained inhibition of MGMT activity, no changes in the steady-state MGMT mRNA levels occurred. We conclude that prolonged inhibition of MGMT activity is an important determinant in reversing BCNU resistance and that chemotherapeutic regimens targeting the inactivation of MGMT activity should be optimized such that MGMT activity is depleted for at least 24 h following BCNU administration.
Expressed Needs and Behavioral Risk Factors of HIV-Positive Inmates

Considerable research has found inmates to be at high risk for HIV/AIDS. Furthermore, research has shown additional HIV/AIDS threats faced by females in the general population and especially by those incarcerated. Behavioral interventions and educational programs have been developed based on these studies. However, few empirical studies have examined the self-expressed needs of HIV-positive inmates or the degree to which inmates' needs are gender specific. This pilot study compares the needs of HIV-positive male and female jail detainees. Results illustrate surprisingly few differences between men and women and their HIV-related needs. The primary need identified for both males and females was postrelease housing. Somewhat unexpectedly, HIV treatment and care ranked low on the list of needs. The implications of these finds are discussed.
Mechanical properties of the haptic signals indicative of a breast cancer tumor

A clinical breast exam (CBE), in which a nurse or doctor palpates a patient's breast tissue searching for hard lumps, is a recommended annual breast cancer diagnostic for women over 40. Recent advances in training technology have suggested that the sensitivity of this exam can be improved and that clinicians are interested in improving training approaches. Currently researchers have an incomplete understanding of which features of the force pattern an observer must perceive in order to recognize the presence of a tumor. This limitation in our knowledge limits our ability to build more effective simulators that emphasize the specific characteristics of the signal that clinicians must perceive. Three experiments were performed using tissue analogs made from silicone rubber embedded with hard spheres. The size of the balls, their depth and the stiffness of the silicone were varied. The force exerted on a probe indented at regular intervals along the samples revealed the general force profile that a clinician may experience on his or her finger pad when searching for a tumor. Several measures of the force profiles were compared to the salience of the ball within the silicone: the ratio of the response force directly above the sphere to the force response far from the sphere, the rate of change of the force response near the sphere, and difference between the force above and to the side divided by the force to the side. These measures correlated with salience when the ball size and ball depth was varied, but not when the silicone stiffness varied. The results suggest that the relationship between the force profile and the salience of the stimulus is more complex that expected. Once this relationship is more fully understood, new training tools and procedures can be developed to trains clinicians and improve the sensitivity of clinical breast exams.