cssi/SciSciGPT-SciSciNet huggingface dataset:
Polybrominated diphenyl ethers and gut microbiome modulate metabolic syndrome-related aqueous metabolites in mice

Polybrominated diphenyl ethers (PBDEs) are persistent environmental toxicants associated with increased risk for metabolic syndrome. Intermediary metabolism is influenced by the intestinal microbiome. To test the hypothesis that PBDEs reduce host-beneficial intermediary metabolites in an intestinal microbiome-dependent manner, 9-week old male conventional (CV) and germ-free (GF) C57BL/6 mice were orally gavaged once daily with vehicle, BDE-47, or BDE-99 (100 μmol/kg) for 4 days. Intestinal microbiome (16S rDNA sequencing), liver transcriptome (RNA-Seq), and intermediary metabolites in serum, liver, as well as small and large intestinal contents (SIC and LIC; LC-MS) were examined. Changes in intermediary metabolite abundances in serum, liver, and SIC, were observed under basal conditions (CV vs. GF mice) and by PBDE exposure. PBDEs altered the largest number of metabolites in the LIC; most were regulated by PBDEs in GF conditions. Importantly, intestinal microbiome was necessary for PBDE-mediated decreases in branched-chain and aromatic amino acid metabolites, including 3-indolepropionic acid, a tryptophan metabolite recently shown to be protective against inflammation and diabetes. Gene-metabolite networks revealed a positive association between the hepatic glycan synthesis gene α-1,6-mannosyltransferase (Alg12) mRNA and mannose, which are important for protein glycosylation. Glycome changes have been observed in patients with metabolic syndrome. In LIC of CV mice, 23 bacterial taxa were regulated by PBDEs. Correlations of certain taxa with distinct serum metabolites further highlight a modulatory role of the microbiome in mediating PBDE effects. In summary, PBDEs impact intermediary metabolism in an intestinal microbiome-dependent manner, suggesting that dysbiosis may contribute to PBDE-mediated toxicities that include metabolic syndrome.
2-D Magnetoresistive Point Field Detector-based Current Sensing for High-Density Power Modules

Giant Magnetoresistive (GMR) point field detector (PFD) based current sensing, previously integrated in 2-in-1 power modules provided galvanic isolation and increased power density by sensing 1-D magnetic fields near the leadframes. In this work, 2-D Magnetoresistive (MR) PFDs are utilized to sense 2-D fields to compensate for the inherently weak 1-D fields in commercial 6-in-1 IGBT power modules. This paper leverages 2-D field metrics established previously for busbar current sensing, to analyze the power module’s field shape and to optimally position the 2-D MR PFDs in the module. This work also develops a methodology to decouple cross-coupled, planar vector fields. This decoupling methodology is critical to sense the phase currents which have superimposed fields inside the three-phase power modules. This new concept of using 2-D MR PFDs to provide integrated current sensing in high-density 6-in-1 power modules is demonstrated via experiments in an induction machine dynamometer test setup.
von Uexküll’s Theory of Meaning and Gibson’s Organism–Environment Reciprocity

Jakob von Uexkull is mostly known for his concept of Umwelt—the meaningful surrounding of animals. von Uexkull insisted vehemently on the fact that Umwelt vindicated Kant’s subjectivist epistemolog...
Ethnic and Gender Disparities in the Uptake of Transcatheter Aortic Valve Replacement in the United States.

Little is known about ethnic and gender disparities for transcatheter aortic valve replacement (TAVR) procedures in the United States. We queried the Nationwide Inpatient Sample (NIS) database (2011–2014) to identify patients who underwent TAVR. We described the temporal trends in the uptake of TAVR procedures among various ethnicities and genders. Our analysis identified 39,253 records; 20,497 (52.2%) were men and 18,756 (47.8%) were women. Among all TAVRs, 87.2% were Caucasians, 3.9% were African Americans (AA), 3.7% were Hispanics, and 5.2% were of other ethnicities. We found a significant rise in the trend of TAVRs in all groups: in Caucasian men (coefficient = 0.946, p < 0.001), Caucasian women (coefficient = 0.985, p < 0.001), AA men (coefficient = 0.940, p < 0.001), AA women (coefficient = 0.864, p < 0.001), Hispanic men (coefficient = 0.812, p = 0.001), Hispanic women (coefficient = 0.845, p < 0.001). Hence, the uptrend was most significant among Caucasian women, and relatively least significant among Hispanic men. Multivariate regression analysis was conducted to evaluate in-hospital mortality among different groups after adjusting for demographics and baseline characteristics. After multivariable regression for baseline characteristics overall, the in-hospital mortality per 100 TAVRs was highest among Hispanic men 5.5%, followed by Caucasian women 5.0%, Hispanic women 4.6%, AA women 3.7%, AA men 3.4%, and Caucasian men 3.38% (adjusted p value = 0.004). In this observational study, we demonstrated that there is evidence of ethnic and gender differences in the overall uptake and adjusted mortality of TAVRs in the United States.
HERPETOLOGICAL INVENTORY OF THE STIKINE RIVER REGION, ALASKA, 2010–2018

We conducted 7 y of herpetological inventories in the Stikine River Region of Southeast Alaska between 2010 and 2018. We observed a total of 2555 individuals representing 6 amphibian species in 5 families at more than 30 sites. This study did not document any reptiles. Among sampled sites, Shakes Hot Springs and Twin Lakes Warm Springs exhibited the greatest density of amphibians across all study years, and both served as breeding habitat for 1 or more species. The Twin Lakes, Shakes Hot Springs, and Paradise Slough sites exhibited the greatest species diversity, with 4 amphibian species recorded at each site. We also compared occurrence and breeding activity to historical data to elucidate possible changes in site-specific assemblages over time. We report new distribution records for the Long-toed Salamander (Ambystoma macrodactylum), and confirmed recent presence of this species at Twin Lakes, where it was thought to have been extirpated. We also confirm the presence of Columbia Spotted Frogs (Rana luteiventris) on Wrangell Island. We were unable to verify the presence of the Northwestern Salamander (Ambystoma gracile) or the Common Gartersnake (Thamnophis sirtalis) in this region. The observations reported here provide baseline amphibian population data for comparison with future surveys.
Finding the neural correlates of collaboration using a three-person fMRI hyperscanning paradigm

Abstract Humans have an extraordinary ability to interact and cooperate with others, which plays a pivotal role in societies at large. Despite its potential social and evolutionary significance, research on finding the neural correlates of collaboration has been limited partly due to restrictions on simultaneous neuroimaging of more than one participant (a.k.a. hyperscanning). A series of works now exists that used dyadic fMRI hyperscanning to examine the interaction between two participants. However, to our knowledge, no study to date has aimed at revealing the neural correlates of social interactions using a 3-person (or triadic) fMRI hyperscanning paradigm. Here, for the first time, we simultaneously measured the blood-oxygenation-level-dependent (BOLD) signal of triads (m=12 triads; n=36 participants), while they engaged in a joint drawing task based on the social game of Pictionary®. General linear model (GLM) analysis revealed increased activation in the brain regions previously linked with the theory of mind (ToM) during the collaborative phase compared to the independent phase of the task. Furthermore, using intersubject brain synchronization (IBS) analysis, we revealed increased synchrony of the right temporo-parietal junction (R TPJ) during the collaborative phase. The increased synchrony in the R TPJ was observed to be positively associated with the overall team performance on the task. In sum, our novel paradigm revealed a vital role of the R TPJ among other ToM regions during a triadic collaborative drawing task.
Patient-Reported Quality of Hospital Discharge Transitions: Results from the SILVER-AMI Study.

Transitions from hospital to home in older patients are a high-risk period for adverse outcomes in a population that may have more challenges navigating the healthcare system. There is little information about the association of patient-reported quality of hospital discharge processes with clinical outcomes. We evaluated whether patient-reported quality of hospital discharge processes was associated with emergency department utilization and rehospitalization within 30 days of discharge after hospitalization for acute myocardial infarction (AMI) in older adults. Multi-center, prospective cohort study. The ComprehenSIVe Evaluation of Risk Factors in Older Patients with Acute Myocardial Infarction (SILVER-AMI) study was a longitudinal study of 3006 adults age 75 and older hospitalized with AMI recruited from 94 academic and community hospitals from across the USA. N/A Patients answered a subset of questions from the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey. Readmissions and emergency department utilization within 30 days of discharge were ascertained through medical record review. A total of 2132 patients were included in the study. Patients’ median age was 81 years and the response rate to the survey of discharge quality was 87%. Patients who reported being asked about having the help they needed at home were significantly less likely to have emergency room utilization within 30 days of discharge in both the unadjusted (0.65, 95% CI 0.43–0.99) and adjusted (0.65, 95% CI 0.42–0.997) models, though there was no significant association with readmission. Report of an assessment of help needed at home during hospitalization was associated with lower post-discharge emergency department utilization. Efforts to improve outcomes after hospital discharge in older patients may benefit from greater focus on assessing need of help at home.
The Impact of Human Mobility on Regional and Global Efforts to Control HIV Transmission

HIV prevention and control methods are implemented on different scales to reduce the spread of the virus amongst populations. However, despite such efforts, HIV continues to persist in populations with a global incidence rate of 1.8 million in 2017 alone. The introduction of new infections into susceptible regional populations promotes the spread of HIV, indicating a crucial need to study the impact of migration and mobility on regional and global efforts to prevent HIV transmission. Here we reviewed studies that assess the impact of human mobility on HIV transmission and spread. We found an important role for both travel and migration in driving the spread of HIV across regional and national borders. Combined, our results indicate that even in the presence of control and preventive efforts, if migration and travel are occurring, public health efforts will need to remain persistent to ensure that new infections do not grow into outbreaks.
Capon–Bartlett cross-spectrum and a perspective on robust adaptive filtering

Abstract Adaptive filtering / beamforming (ABF) optimized for maximum signal-to-interference-plus-noise ratio (SINR) results in filter weights that depend on the data covariance and the signal array response vector. The effectiveness of practical application of such solutions, however, is limited by (i) extent of data stationarity and (ii) imperfect knowledge of the true signal array response vector. Robust ABF methods attempt to address these two critical issues via a slight reformulation of the ABF problem statement. Many robust ABF solutions result in some form of diagonal loading of the data covariance, and can be interpreted as a hybrid beamformer that engages the tradespace between data adaptive beamforming and conventional beamforming (CBF). In view of this interpretation, an exact joint probability distribution is derived for 1) the data adaptive Capon minimum variance distortionless response (MVDR) spectral estimator, and 2) the conventional Bartlett spectral estimator (a.k.a. the smoothed periodogram) when based on the same data covariance estimate. The resulting joint distribution motivates (i) proposal of a robust adaptive filtering design that constrains filter weight cross coherence (a metric quantifying the statistical coupling between the Capon and Bartlett spectral statistics), and (ii) introduction of a coherence estimate called the Capon–Bartlett cross spectrum.
Navigating over 3D environments while minimizing cumulative exposure to hazardous fields

Abstract This note revisits the navigation problem for a mobile agent in 3D environments and incorporates the accumulated effects of a hazardous spatial field on the mobile agent motion. Such effects are encountered by human evacuation of indoor environments with carbon monoxide as the hazardous field. The accumulated amount of carbon monoxide inhaled during the flight to escape plays a detrimental role in the ability of an evacuee to escape; if this accumulated amount inhaled exceeds a threshold value the evacuee is incapacitated. Using the accumulated amount, represented by the line integral of the spatial field along the chosen escape trajectory, as an augmented state, the navigation problem is cast as an optimal control problem. The solution to the 3D navigation over hazardous fields, which is applicable to both human evacuees in indoor environments and mobile robots traversing over hazardous environments, is presented and a related problem of minimizing the accumulated amount is also formulated and solved. Simulation results are presented to demonstrate the proposed results.
Regulations and Guidelines for Chemigation

Chemigation is a process where an irrigation system is used for transport and delivery of agrochemicals, generally fertilizers and pesticides, to a crop (Haman and Zazueta, 2017). Drip or micro-sprinkler irrigation systems are often used in chemigation. If the irrigation is properly plumed and chemigation properly implemented, chemigation can help growers reduce chemical usage and costs as it is applied using existing irrigation distribution infrastructure. However, the irrigation system must first be outfitted with properly designed injection and safety equipment. In addition, it is important that the irrigation system is built to allow the injection of chemicals or fertilizers at a known rate and that ensures application uniformity. Knowing the correct concentration of chemicals during chemigation is critical as some chemicals could potentially damage plants. Chemigation of chemicals/fertilizers at higher concentrations could also lead to leaching and contamination of freshwater bodies. The purpose of this document is to provide a brief overview of the regulations and some helpful tips for growers interested in chemigation.
Phase diagram of four-dimensional dynamical triangulations with a boundary

We report on simulations of DT simplicial gravity for manifolds with the topology of the 4-disk. We find evidence for four phases in a two-dimensional parameter space. In two of these the boundary plays no dynamical role and the geometries are equivalent to those observed earlier for the sphere $S^4$. In another phase the boundary is maximal and the quantum geometry degenerates to a one dimensional branched polymer. In contrast we provide evidence that the fourth phase is effectively three-dimensional. We find discontinuous phase transitions at all the phase boundaries.
A matter of size? Material, structural and mechanical strategies for size adaptation in the elytra of Cetoniinae beetles

Abstract Nature's masterfully synthesized biological materials take on greater relevance when viewed through the perspective of evolutionary abundance. The fact that beetles (order Coleoptera) account for a quarter of all extant lifeforms on Earth, makes them prime exponents of evolutionary success. In fact, their forewings are acknowledged as key traits to their radiative-adaptive success, which makes the beetle elytra a model structure for next-generation bioinspired synthetic materials. In this work, the multiscale morphological and mechanical characteristics of a variety of beetle species from the Cetoniinae subfamily are investigated with the aim of unraveling the underlying principles behind Nature's adaptation of the elytral bauplan to differences in body weight spanning three orders of magnitude. Commensurate with the integral implications of size variation in organisms, a combined material, morphological, and mechanical characterization framework, across spatial scales, was pursued. The investigation revealed the simultaneous presence of size-invariant strategies (chemical compositions, layered-fibrous architectures, graded motifs) as well as size-dependent features (scaling of elytral layers and characteristic dimensions of building blocks), synergistically combined to achieve similar levels of biomechanical functionality (stiffness, energy absorption, strength, deformation and toughening mechanisms) in response to developmental and selection constraints. The integral approach here presented seeks to shed light on Nature's solution to the problem of size variation, which underpins the diversity of beetles and the living world.
Dimensionality-Reduced Fermi Level Pinning in Coplanar 2D Heterojunctions.

Electronic transport through a metal|semiconductor (M|S) heterojunction is largely determined by its Schottky barrier. In 3D M|S junctions, the barrier height determines the turn-on voltage and is often pinned by the interface states, causing Fermi level pinning (FLP). The pinning strength in 3D depends on the ratio Ci/CM between the interface quantum capacitance Ci and the metal surface capacitance CM. In 2D, the interface dipole does not influence the band alignment, but still affects the Schottky barrier and transport. In light of the general interest in building 2D electronics, in this work we discover the relevant material parameters which dictate the behavior and strength of FLP in 2D M|S contacts. Using a multiscale model combining first-principles, continuum electrostatics, and transport calculations, we study a realistic Gr|MoS2 interface as an example with high interface state density (Ci/CM ≫ 1). Transport calculations show partial pinning with a strength P ∼ 0.6, while a 3D junction with similar heterogeneity gives full pinning with P = 1 as expected. We further show that in 2D M|S contacts the turn-on voltage and pinning strength are affected by a physical parameter l/λD, the ratio between the interface width l, and the thermal de Broglie wavelength λD. Pinning is absent for ideal line-contacts (l/λD = 0), but increases for realistic l/λD values.
Sleep apnea, coronary artery calcium density, and cardiovascular events: results from the Multi-Ethnic Study of Atherosclerosis

Study Objectives: Evaluate the association between obstructive sleep apnea (OSA), coronary artery calcium (CAC) density, and cardiovascular events in the Multi-Ethnic Study of Atherosclerosis (MESA...
First Bank (Nigeria) Limited: Reframing of Core Business Philosophy

Essence of the lemons problem of Akerlof (1970) is not easy to communicate to practitioners, particularly practitioners in realm of commercial banking. Commercial bankers, particularly those located in developing or emerging countries typically find it difficult to understand how in face of increase in deposit costs, a decrease in lending rates can generate more shareholder value than an increase in lending rates. This case utilizes financial statements of one of the leading and largest commercial banks in Nigeria (ranked top five in size) to provide real life illustration of emergence and correction of a lemons problem within context of commercial banking. The link between the lemons problem and share valuations is explicitly explored. Teaching Notes are available to instructors upon request from the case study author.
Reconstructing the evolutionary history of the oxytocin and vasotocin receptor gene family: Insights on whole genome duplication scenarios

Abstract Vertebrate genome evolution remains a hotly debated topic, specifically as regards the number and the timing of putative rounds of whole genome duplication events. In this study, I sought to shed light to this conundrum through assessing the evolutionary history of the oxytocin/vasotocin receptor family. I performed ancestral analyses of the genomic segments containing oxytocin and vasotocin receptors (OTR-VTRs) by mapping them back to the reconstructed ancestral vertebrate/chordate karyotypes reported in five independent studies (Nakatani et al., 2007; Putnam et al., 2008; Smith and Keinath, 2015; Smith et al., 2018; Simakov et al., 2020) and found that two alternative scenarios can account for their evolution: one consistent with one round of whole genome duplication in the common ancestor of lampreys and gnathostomes, followed by segmental duplications in both lineages, and another consistent with two rounds of whole genome duplication, with the first occurring in the gnathostome-lamprey ancestor and the second in the jawed vertebrate ancestor. Combining the data reported here with synteny and phylogeny data reported in our previous study (Theofanopoulou et al., 2021), I put forward that a single round of whole genome duplication scenario is more consistent with the synteny and evolution of chromosomes where OTR-VTRs are encountered, without excluding the possibility of a scenario including two rounds of whole genome duplication. Although the analysis of one gene family is not able to capture the full complexity of vertebrate genome evolution, this study can provide solid insight, since the gene family used here has been meticulously analyzed for its genes’ orthologous and paralogous relationships across species using high quality genomes.
The association of the sebum excretion rate with melasma, erythematotelangiectatic rosacea, and rhytides.

Author(s): Foolad, Negar; Shi, Vivian Y; Prakash, Neha; Kamangar, Faranak; Sivamani, Raja K | Abstract: Background: Rosacea and melasma are two common skin conditions in dermatology. Both conditions have a predilection for the centrofacial region where the sebaceous gland density is the highest. However it is not known if sebaceous function has an association with these conditions.Aims and Objectives: We aimed to assess the relationship between facial glabellar wrinkle severity and facial sebum excretion rate for individuals with rosacea, melasma, both conditions, and in those with rhytides. Secondly, the purpose of this study was to utilize high resolution 3D facial modeling and measurement technology to obtain information regarding glabellar rhytid count and severity.Materials and Methods: A total of 21 subjects participated in the study. Subjects were divided into four groups based on facial features: rosacea-only, melasma-only, rosacea and melasma, rhytides-only. A high resolution facial photograph was taken followed by measurement of facial sebum excretion rate (SER).Results: The SER was found to decline with age and with the presence of melasma. The SER negatively correlated with increasing Wrinkle Severity Rating Scale. Through the use of 3D facial modeling and skin analysis technology, we found a positive correlation between clinically based grading scores and computer generated glabellar rhytid count and severity.Conclusion: Continuing research with facial modeling and measurement systems will allow for development of more objective facial assessments. Future studies need to assess the role of technology in stratifying the severity and subtypes of rosacea and melasma. Furthermore, the role of sebaceous regulation may have important implications in photoaging.
Bioavailability and Toxicity of a Mixture of Sediment-Associated Chlorinated Hydrocarbons to the Amphipod Pontoporeia hoyi

The toxicity and bioavailability of a mixture of 13 sediment-associated chlorinated hydrocarbons were determined for the amphipod Pontoporeia hoyi. The processes were traced with two radiolabeled compounds, '4C-2,2',4,4'-tetrachlorobiphenyl (2244TCB) and 3H-ben- zo(a)pyrene (BaP). The toxicity of the chlorinated hydrocarbon mixture resulted primarily from the lindane and dieldrin components. The 72-h LCM was 14.5 nmol g-I as the sum of the added chlorinated hydrocarbons and 4.7 nmol g-I as the sum of the lindane and dieldrin. At 144 h the LCws had dropped to 1.51 and 0.53 nmol g-I, respectively. At the lowest dose, 2.4 nmol g-' sediment, the time to yield 50% mortality (LTSo) was 119 h. The toxicokinetics for the radiolabeled compounds yielded sediment uptake clearance constants of 0.0018 and 0.018 g dry sediment g-I animal h-I for BaP and 2244TCB in the absence of added chlorinated hydrocarbons. At the lowest chlorinated hydrocarbons dose, the clearance constants of both BaP and 2244TCB were approxi- mately doubled. The clearance constants were not proportional to the freely dissolved concentra- tion of the radiolabeled compounds in the interstitial water but were presumed to be proportional to the compound desorption rates. For the chlorinated hydrocarbons, the uptake clearances were inversely proportional to the log of the octanol-water partition coefficient. The bioaccumulation factor (BAF, concentration in the organism divided by the concentration in the sediment) ap- peared to peak at about a log octanol-water partition coefficient of 6. However, the BAF ranged from less than 1 to greater than 30 for compounds with a log KO, near 6.
The mathematics of programming and why we should teach it

Much of the work on program correctness and how it could influence programming was developed in the 1970's. Nevertheless, first-semester texts and even second-semester texts on programming don't touch the topic, or pay only lip service to it. The students, the CS curriculum, and the field lose out because of this. We produce inefficient hackers, who can't see the beauty in well-done, disciplined programming. CS already has its field of Computational Complexity; we should be teaching Computational Simplicity. In this lecture, we will try to show how correctness concerns can be integrated into our courses and the effect that the integration has.
Programming with tabling in XSB

I describe how XSB, a tabling Prolog system, can be used effectively to program useful tasks in a variety of domains. The presentation is through the use of examples, with examples being taken from some of the following areas: traditional dynamic programming problems, finite state automata theory, context-free language recognition, parsing and analysis, recursive aggregation, meta-interpreters, program analysis and abstract interpretation, model checking, and abduction.
Learning Multi-target Tracking with Quadratic Object Interactions.

We describe a model for multi-target tracking based on associating collections of candidate detections across frames of a video. In order to model pairwise interactions between different tracks, such as suppression of overlapping tracks and contextual cues about co-occurence of different objects, we augment a standard min-cost flow objective with quadratic terms between detection variables. We learn the parameters of this model using structured prediction and a loss function which approximates the multi-target tracking accuracy. We evaluate two different approaches to finding an optimal set of tracks under model objective based on an LP relaxation and a novel greedy extension to dynamic programming that handles pairwise interactions. We find the greedy algorithm achieves equivalent performance to the LP relaxation while being 2-7x faster than a commercial solver. The resulting model with learned parameters outperforms existing methods across several categories on the KITTI tracking benchmark.
System Identification: Impulse Response Functions

An approach is presented for estimating the impulse response function of a multidegree-of-freedom structural system. The approach discretizes the time axis into contiguous time segments and estimates the structure's impulse response function for each time segment. The identification problem is formulated in the time domain and in matrix form which is solvable using math programming techniques. The solution is a global optimum because the problem is a convex programming problem.
An analysis of the 2004 supply chain management trading agent competition

We present results from the supply chain management scenario in the 2004 Trading Agent Competition. We discuss behavioral differences between the agents that were important factors in determining how the agents finished in the competition. Strategic interactions played an important role in the supplier market, where one agent employed a strategy designed to block other agents' access to suppliers at a key point in the game. This strategy and the different ways that agents responded had an important impact on the outcome of the game. In the customer sales market, the economic forces of supply and demand played an important role in shaping market behavior. However, agents showed very different abilities to effectively find and exploit good market conditions.
Web GIS as a useful tool for the health and social service sector

Web geographic information systems (GIS) can be used to support the efforts of service providers in health and social service setting. This article examines the potential of Web GIS to help health and social service providers understand the distribution of their services and their target populations in San Diego County. Agencies completed a user needs questionnaire and participated in user-testing meetings to guide the development of the Web GIS. The result was a two-part Web GIS which allows agencies to: 1) define and update their service locations and boundaries in a password-protected Web GIS Editor; 2) view and analyse health and social services, older population demographics, healthcare clinics, affordable housing, and public transportation in a publicly-accessible Web GIS Viewer. Surveys and interviews conducted with agencies showed satisfaction with the implementation of the system, and the potential of Web GIS in supporting service delivery and outreach.
Diffusion and dissociation of neutral divacancies in crystalline silicon

Based on ab initio calculations with a 216-atom supercell, we find mechanisms for the diffusion and dissociation of the neutral-state divacancy ${(V}_{2}^{0}).$ Contrary to the popular belief that diffusion is via successive detachment and recombination (a two-step process), we find that ${V}_{2}^{0}$ diffusion follows predominantly a one-step hopping mechanism; that is, two adjacent vacancies move together. The calculated activation energy of 1.35 eV is in excellent agreement with experiment (\ensuremath{\approx}1.3 eV). This work suggests that to dissociate the $V\ensuremath{-}V$ pair the neighboring Si atoms on each side of the ${V}_{2}^{0}$ must move inward simultaneously to form the stable $V\ensuremath{-}\mathrm{S}\mathrm{i}\ensuremath{-}\mathrm{S}\mathrm{i}\ensuremath{-}V$ configuration, and then a third neighboring Si atom hops inward to leads to the $V\ensuremath{-}\mathrm{S}\mathrm{i}\ensuremath{-}\mathrm{S}\mathrm{i}\ensuremath{-}\mathrm{S}\mathrm{i}\ensuremath{-}V$ state whose energy is almost equivalent to that of two separated monovacancies ${(2V}_{1}^{0})$ of 6.96 eV. We also present the formation energy of the vacancy-vacancy complex for different relative positions, providing insight into the vacancy-vacancy interaction.
Evidence of Proteolytic Activity and Its Effect on Gelation of Myofibrillar Protein Concentrate from Bovine Cardiac Muscle

To explore the impact of endogenous proteases on the gelation properties of beef heart surimi, the surimi samples were incubated at different temperatures. Maximum (4.8 N) and minimum (3.3 N) gel strengths were produced by surimi sols preincubated at 60 and 50 °C, respectively. Preincubation at 60 °C as well as slow linear heating also produced gels with the highest storage modulus and water-holding capacity. Proteolytic activity with an optimum pH of 5.0 and temperature close to 50 °C was discovered. Addition of protease inhibitors, particularly bovine plasma powder, reduced the extent of gel weakening caused by the proteases and, concomitantly, enhanced the water-holding capacity of the surimi gel. SDS−PAGE showed that in the absence of protease inhibitors, myosin was partially hydrolyzed and a 130 kDa polypeptide formed during preincubation at 50 °C. Bovine plasma powder and egg white inhibited the formation of the new polypeptide. Keywords: Beef heart; myofibrillar protein; proteolysis; protease inhib...
Electron dynamics in a crystal.

We derive the semiclassical equation of motion for an electron in a periodic crystal in the presence of external electromagnetic fields.
Expansion, Maintenance, and Memory in NK and T Cells during Viral Infections: Responding to Pressures for Defense and Regulation

Immune responses are critical for defense. During primary infections, the antigen-specific CD8 T cells of the adaptive immune system are expanded from extremely low frequencies of cells and develop ‘‘memory’’ for heightened secondary responses. Innate natural killer (NK) cells, present at much higher frequencies, can also be expanded and develop memory. Subset NK and T cell proliferative responses are induced as a result of engagement of activator receptors for ligands expressed during particular viral infections, and the conditions are accompanied by stimulation of their antimicrobial functions. Increases in CD8 T cell numbers help optimize defense, but because of their higher basal frequencies, the need for increases in NK cell numbers is difficult to understand. The systems must have evolved under concurrent pressures for balance to limit damage from the immune responses themselves as well as to mediate defense against infection, however, as expanded NK and T cells present a threat for collateral damage. A recently defined function for an activating receptor in sustaining NK cells to produce interleukin (IL)-10 and regulate CD8 T cells is reviewed here in the context of T cell responses and memory. A rationale emerges for the role of proliferation in maintenance and regulation. The observations suggest that the immune system uses cell expansion to effectively deliver self-control as well as defense.
A role for the subthalamic nucleus in 5-HT2C-induced oral dyskinesia

Abstract The 5-hydroxytryptamine 2c serotonin receptor is broadly distributed in brain, however its functional role is unknown. Peripheral administration of drugs acting at the 5-hydroxytryptamine 2c receptor induces abnormal oral dyskinesias, hyperkinetic motor disorders that often result from dysfunction of the basal ganglia. The subthalamic nucleus, a brain region anatomically and functionally related to the basal ganglia, has been implicated in oral dyskinesia. The subthalamic nucleus contains messenger RNA encoding 5-hydroxytryptamine 2c receptors, suggesting its potential role in 5-hydroxytryptamine 2C -mediated oral dyskinesia. Both systemic administration and local unilateral infusion of the 5-hydroxytryptamine 2C/1B agonist, 1-( m -chlorophenyl)piperazine into the subthalamic nucleus increased orofacial movements. Oral movements following subthalamic infusion of 1-( m -chlorophenyl)piperazine were blocked by systemic administration of the 5-hydroxytryptamine 2C/2A antagonists mianserin, ketanserin and mesulergine but were not altered by systemic pretreatment with either the 5-hydroxytryptamine 1A/2A and dopamine antagonist spiperone or the 5-hydroxytryptamine 1A/1B antagonist pindolol. Co-infusion of mesulergine with 1-( m -chlorophenyl)piperazine into the subthalamic nucleus blocked 1-( m -chlorophenyl)piperazine-stimulated oral movements. Oral bouts following systemically administered 1-( m -chlorophenyl)piperazine were markedly reduced following bilateral subthalamic infusion of either mesulergine or the selective 5-hydroxytryptamine 2c antagonist SDZ SER 082. The findings indicate that stimulating 5-hydroxytryptamine 2c receptors in the subthalamic nucleus elicits orofacial dyskinesia in the rat. These data are novel in providing a behavioral model for central 5-hydroxytryptamine 2c receptor stimulation attributed to a specific anatomical location, and suggest that antagonists at the 5-hydroxytryptamine 2C receptor could be useful in treating hyperkinetic motor disorders.
Preclinical evaluation and intraoperative human retinal imaging with a high-resolution microscope-integrated spectral domain optical coherence tomography device.

Purpose The authors have recently developed a high-resolution microscope-integrated spectral domain optical coherence tomography (MIOCT) device designed to enable OCT acquisition simultaneous with surgical maneuvers. The purpose of this report is to describe translation of this device from preclinical testing into human intraoperative imaging. Methods Before human imaging, surgical conditions were fully simulated for extensive preclinical MIOCT evaluation in a custom model eye system. Microscope-integrated spectral domain OCT images were then acquired in normal human volunteers and during vitreoretinal surgery in patients who consented to participate in a prospective institutional review board-approved study. Microscope-integrated spectral domain OCT images were obtained before and at pauses in surgical maneuvers and were compared based on predetermined diagnostic criteria to images obtained with a high-resolution spectral domain research handheld OCT system (HHOCT; Bioptigen, Inc) at the same time point. Cohorts of five consecutive patients were imaged. Successful end points were predefined, including ≥80% correlation in identification of pathology between MIOCT and HHOCT in ≥80% of the patients. Results Microscope-integrated spectral domain OCT was favorably evaluated by study surgeons and scrub nurses, all of whom responded that they would consider participating in human intraoperative imaging trials. The preclinical evaluation identified significant improvements that were made before MIOCT use during human surgery. The MIOCT transition into clinical human research was smooth. Microscope-integrated spectral domain OCT imaging in normal human volunteers demonstrated high resolution comparable to tabletop scanners. In the operating room, after an initial learning curve, surgeons successfully acquired human macular MIOCT images before and after surgical maneuvers. Microscope-integrated spectral domain OCT imaging confirmed preoperative diagnoses, such as full-thickness macular hole and vitreomacular traction, and demonstrated postsurgical changes in retinal morphology. Two cohorts of five patients were imaged. In the second cohort, the predefined end points were exceeded with ≥80% correlation between microscope-mounted OCT and HHOCT imaging in 100% of the patients. Conclusion This report describes high-resolution MIOCT imaging using the prototype device in human eyes during vitreoretinal surgery, with successful achievement of predefined end points for imaging. Further refinements and investigations will be directed toward fully integrating MIOCT with vitreoretinal and other ocular surgery to image surgical maneuvers in real time.
Phase strength effects on chemical mixing in extensively deformed alloys

Abstract Forced chemical mixing during extensive straining requires that the constituent phases co-deform, and is therefore a sensitive function of their mechanical properties, particularly strength. To develop a quantitative understanding of such phase strength effects on co-deformation and steady-state chemical mixity during severe deformation processing, we studied several tungsten–transition metal couples with a range of differences in strength during a process of mechanical alloying in a high-energy ball mill. Changes in the powders’ microstructures, mechanical properties and chemical mixing revealed two distinct behaviors: alloys either chemically homogenized or remained dual phase, depending on the relative strengths of the base alloying elements. A kinetic Monte Carlo simulation of mechanical alloying that accounts for a phase strength mismatch reproduced the experimentally observed behaviors, and provides quantitative insight into the combination of material and processing parameters that control mechanical mixing.
FLOW-RATES AND ELECTROLYTES IN MINOR-SALIVARY-GLAND SALIVA IN NORMAL SUBJECTS AND PATIENTS WITH CYSTIC FIBROSIS

Abstract A new method for collecting the saliva secreted by small salivary glands from the inner aspect of the upper lip allows sodium, potassium, calcium, and magnesium to be determined as well as flow-rates. Sodium levels were markedly raised and flow-rates moderately decreased in patients with cystic fibrosis (C.F.), whereas the levels of the other ions determined were equal to those of normal subjects. In both groups sodium increased with increasing flow-rates, but potassium, magnesium, and calcium levels decreased inversely with the rates of flow. The small salivary glands are the only exocrine glands (apart from the sweat-glands) which consistently exhibit the sodium abnormality in C.F. In C.F. patients, although the levels of sodium are normal in submaxillary and parotid saliva, the mixed saliva contains a variable and slight but definite increase in sodium concentration because of the variable admixture of small-salivary-gland saliva.
Paenibacillus larvae 16S-23S rDNA intergenic transcribed spacer (ITS) regions: DNA fingerprinting and characterization.

Abstract Paenibacillus larvae is the causative agent of American foulbrood in honey bee ( Apis mellifera ) larvae. PCR amplification of the 16S–23S ribosomal DNA (rDNA) intergenic transcribed spacer (ITS) regions, and agarose gel electrophoresis of the amplified DNA, was performed using genomic DNA collected from 134 P . larvae strains isolated in Connecticut, six Northern Regional Research Laboratory stock strains, four strains isolated in Argentina, and one strain isolated in Chile. Following electrophoresis of amplified DNA, all isolates exhibited a common migratory profile (i.e., ITS-PCR fingerprint pattern) of six DNA bands. This profile represented a unique ITS-PCR DNA fingerprint that was useful as a fast, simple, and accurate procedure for identification of P . larvae . Digestion of ITS-PCR amplified DNA, using mung bean nuclease prior to electrophoresis, characterized only three of the six electrophoresis bands as homoduplex DNA and indicating three true ITS regions. These three ITS regions, DNA migratory band sizes of 915, 1010, and 1474 bp, signify a minimum of three types of rrn operons within P . larvae . DNA sequence analysis of ITS region DNA, using P . larvae NRRL B-3553, identified the 3′ terminal nucleotides of the 16S rRNA gene, 5′ terminal nucleotides of the 23S rRNA gene, and the complete DNA sequences of the 5S rRNA, tRNA ala , and tRNA ile genes. Gene organization within the three rrn operon types was 16S–23S, 16S–tRNA ala –23S, and l6S–5S–tRNA ile –tRNA ala –23S and these operons were named rrn A, rrn F, and rrn G, respectively. The 23S rRNA gene was shown by I- Ceu I digestion and pulsed-field gel electrophoresis of genomic DNA to be present as seven copies. This was suggestive of seven rrn operon copies within the P . larvae genome. Investigation of the 16S–23S rDNA regions of this bacterium has aided the development of a diagnostic procedure and has helped genomic mapping investigations via characterization of the ITS regions.
A highly membrane-active peptide in Flock House virus: implications for the mechanism of nodavirus infection.

Background Nodaviruses are among the simplest animal viruses, and are therefore attractive systems for deconvoluting core viral processes such as assembly, infection and uncoating. Membrane translocation of the single-stranded RNA genome of nodaviruses has been proposed to be mediated by direct lipid-protein interactions between a post-assembly autocatalytic cleavage product from the capsomere and the target membrane. To probe the validity of this hypothesis, we have synthesized a 21-residue Met→Nle (norleucine) variant of the amino-terminal helical domain (denoted here as γ 1 ) of the cleavage peptide in Rock House nodavirus (FHV) and studied its ability to alter membrane structure and function. Results The synthetic peptide γ 1 increases membrane permeability to hydrophilic solutes, as judged by fluorescence experiments with liposomeencapsulated dyes and ion-conductance measurements. Furthermore, peptide orientation and location within lipid bilayers was determined using tryptophan-fluorescence-quenching experiments and attenuated total reflectance infrared spectroscopy. Conclusions The helical domain of the FHV cleavage product partitions spontaneously into lipid bilayers and increases membrane permeability, consistent with the postulated mechanism for viral genome translocation. The existence of a membrane-binding domain in the FHV cleavage sequence suggests peptide-triggered disruption of the endosomal membrane as a prelude to viral uncoating in the host cytoplasm. A model for this interaction is proposed.
Tubeless percutaneous renal surgery: review of first 112 patients.

Abstract Objectives. To assess the outcome and safety of the first 112 patients undergoing tubeless percutaneous renal surgery. Methods. A total of 116 renal units in 112 patients underwent tubeless percutaneous renal surgery from December 1995 to November 2000 performed by a single urologist. The “tubeless” procedures consisted of nephrolithotripsy or endopyelotomy. An antegrade internal ureteral stent was placed during surgery, as was a Foley catheter for bladder drainage, in all patients. Nephrostomy tubes were not used in any patient. The incidence of complications, length of hospitalization, outcomes, transfusion requirements, stone burden, and stone-free rates were obtained by chart review. Results. Of the 112 patients, 86 patients underwent percutaneous stone extraction and 26 patients underwent percutaneous antegrade endopyelotomy. In the group of patients undergoing percutaneous stone extraction, the mean stone burden was 3.30 cm2. Patients stayed in the hospital an average of 1.25 days. A total of 5 patients required postoperative transfusions. One patient was found on readmission to have a pseudoaneurysm. A 93.0% stone-free rate was achieved. The correlations between transfusion rates, days of hospitalization, and outcome with stone burden were not statistically significant (P = 0.56, 0.78, and 0.18, respectively). For the endopyelotomy group, the mean length of hospitalization was 1.56 days. Only 1 patient required a transfusion, and 3 patients had postoperative complications. Of the 26 patients, 88.5% had a successful outcome from their endopyelotomy. Conclusions. Tubeless percutaneous renal surgery is a safe and effective procedure and can be performed in patients even with a moderate stone burden.
Proteolytic processing is necessary to separate and ensure proper cell growth and cytokinesis functions of HCF-1

HCF-1 is a highly conserved and abundant chromatin-associated host cell factor required for transcriptional activation of herpes simplex virus immediate-early genes by the virion protein VP16. HCF-1 exists as a heterodimeric complex of associated N- (HCF-1N) and C- (HCF-1C) terminal subunits that result from proteolytic processing of a precursor protein. We have used small-interfering RNA (siRNA) to inactivate HCF-1 in an array of normal and transformed mammalian cells to identify its cellular functions. Our results show that HCF-1 is a broadly acting regulator of two stages of the cell cycle: exit from mitosis, where it ensures proper cytokinesis, and passage through the G1 phase, where it promotes cell cycle progression. Proteolytic processing is necessary to separate and ensure these two HCF-1 activities, which are performed by separate HCF-1 subunits: the HCF-1N subunit promotes passage through the G1 phase whereas the HCF-1C subunit is involved in proper exit from mitosis. These results suggest that HCF-1 links the regulation of exit from mitosis and the G1 phase of cell growth, possibly to coordinate the reactivation of gene expression after mitosis.