cssi/SciSciGPT-SciSciNet huggingface dataset:
Zika virus causes testicular atrophy.

Zika virus (ZIKV) is an emerging mosquito-borne flavivirus that has recently been found to cause fetal infection and neonatal abnormalities, including microcephaly and neurological dysfunction. ZIKV persists in the semen months after the acute viremic phase in humans. To further understand the consequences of ZIKV persistence in males, we infected Ifnar1 −/− mice via subcutaneous injection of a pathogenic but nonlethal ZIKV strain. ZIKV replication persists within the testes even after clearance from the blood, with interstitial, testosterone-producing Leydig cells supporting virus replication. We found high levels of viral RNA and antigen within the epididymal lumen, where sperm is stored, and within surrounding epithelial cells. Unexpectedly, at 21 days post-infection, the testes of the ZIKV-infected mice were significantly smaller compared to those of mock-infected mice, indicating progressive testicular atrophy. ZIKV infection caused a reduction in serum testosterone, suggesting that male fertility can be affected. Our findings have important implications for nonvector-borne vertical transmission, as well as long-term potential reproductive deficiencies, in ZIKV-infected males.
Prediction of Suicide Ideation and Attempt Among Substance-Using Patients in Primary Care

Background Suicide is a major public health concern, particularly among people who use illicit substances and/or non-prescribed medications. Methods The present study prospectively assessed the incidence and predictors of suicidal ideation (SI) and suicide attempt (SA) among 868 substance-using patients over 12 months after receiving primary care within seven public primary care clinics. Results Participants reported a high incidence of SI (25.9%) and SA (7.1%) over the year following primary care visits. Suicidality was elevated in patients who were female; lacked a high school diploma; were unemployed; reported depression, anxiety, hallucinations, concentration difficulty, or violent behavior; used nicotine or stimulants; used the emergency department or mental health services in the past 90 days; reported current quality-of-life impairment in mobility or usual activities; or reported recent SI or lifetime SA at baseline. In multiple regression analyses, only past 30-day SI, any lifetime SA, past 90-day violent behavior, and current impairment due to anxiety or depression at baseline uniquely predicted SI or SA beyond other variables. Conclusions Results support the need for screening for suicidality among primary care patients who use illicit substances and identify key of these patients who are at particularly elevated risk for suicidality.
Transcatheter Aortic Valve Replacement With Different Valve Types in Elliptic Aortic Annuli.

BACKGROUND The aim of this study was to determine the influence of an elliptic annulus on acute device success rates following self-expanding (SE) transcatheter aortic valve replacement (TAVR) vs. balloon-expandable (BE) TAVR.Methods and Results:Outcomes were assessed using Valve Academic Research Consortium-2 definitions. Aortic annulus ratio (AAR) was measured as short axis diameter/long axis diameter. Mean AAR was 0.81±0.06. Patients were therefore divided into 2 groups: AAR <0.82 and AAR ≥0.82. For circular annuli (AAR ≥0.82; 363 patients), high device success rates were achieved in both valve groups (SE valve, 90.5% vs. BE valve, 95.0%, P=0.14). Conversely, for AAR <0.82 (374 patients), SE valves had lower device success rates than BE valves (82.5% vs. 95.3%, P=0.002). For elliptic annuli, SE-TAVR was an independent predictor of unsuccessful device implantation (OR, 6.34, P<0.001). Nonetheless, increased oversizing of SE valves for elliptic annuli was associated with an exponential rise in device success (threshold ≥17.5%; area under the curve, 0.83) but not for BE-TAVR. Furthermore, optimally oversized SE valves and BE valves had a similarly high device success for elliptic annuli (SE valve, 96.2% vs. BE valve, 95.3%). CONCLUSIONS For circular annuli, similarly high device success was achieved for the 2 valve types. Conversely, for elliptic annuli, SE valves had a lower device success than BE valves. Device success following optimal oversizing of SE valves, however, was similar to that for BE valves.
Calcium Oscillation Frequency-Sensitive Gene Regulation and Homeostatic Compensation in Pancreatic β-Cells.

Pancreatic islet $$\upbeta $$ -cells are electrically excitable cells that secrete insulin in an oscillatory fashion when the blood glucose concentration is at a stimulatory level. Insulin oscillations are the result of cytosolic $$\hbox {Ca}^{2+}$$ oscillations that accompany bursting electrical activity of $$\upbeta $$ -cells and are physiologically important. ATP-sensitive $$\hbox {K}^{+}$$ channels (K(ATP) channels) play the key role in setting the overall activity of the cell and in driving bursting, by coupling cell metabolism to the membrane potential. In humans, when there is a defect in K(ATP) channel function, $$\upbeta $$ -cells fail to respond appropriately to changes in the blood glucose level, and electrical and $$\hbox {Ca}^{2+}$$ oscillations are lost. However, mice compensate for K(ATP) channel defects in islet $$\upbeta $$ -cells by employing alternative mechanisms to maintain electrical and $$\hbox {Ca}^{2+}$$ oscillations. In a recent study, we showed that in mice islets in which K(ATP) channels are genetically knocked out another $$\hbox {K}^{+}$$ current, provided by inward-rectifying $$\hbox {K}^{+}$$ channels, is increased. With mathematical modeling, we demonstrated that a sufficient upregulation in these channels can account for the paradoxical electrical bursting and $$\hbox {Ca}^{2+}$$ oscillations observed in these $$\upbeta $$ -cells. However, the question of determining the correct level of upregulation that is necessary for this compensation remained unanswered, and this question motivates the current study. $$\hbox {Ca}^{2+}$$ is a well-known regulator of gene expression, and several examples have been shown of genes that are sensitive to the frequency of the $$\hbox {Ca}^{2+}$$ signal. In this mathematical modeling study, we demonstrate that a $$\hbox {Ca}^{2+}$$ oscillation frequency-sensitive gene transcription network can adjust the gene expression level of a compensating $$\hbox {K}^{+}$$ channel so as to rescue electrical bursting and $$\hbox {Ca}^{2+}$$ oscillations in a model $$\upbeta $$ -cell in which the key K(ATP) current is removed. This is done without the prescription of a target $$\hbox {Ca}^{2+}$$ level, but evolves naturally as a consequence of the feedback between the $$\hbox {Ca}^{2+}$$ -dependent enzymes and the cell’s electrical activity. More generally, the study indicates how $$\hbox {Ca}^{2+}$$ can provide the link between gene expression and cellular electrical activity that promotes wild-type behavior in a cell following gene knockout.
Connecting External Deduction Tools with ACL2

We present an interface connecting the ACL2 theorem prover with external deduction tools. The structuring mechanisms of ACL2 make the design of the interface challenging. We discuss some of the challenges and develop a precise specification of the requirements on the external tools for a sound connection with ACL2.
Expression cloning of a zinc-finger cyclic AMP-response-element-binding protein

In response to specific extracellular signals, intracellular cyclic AMP levels increase, leading to a variety of responses including the alteration of transcription of many eukaryotic genes. This transcriptional effect is frequently mediated through the cyclic AMP-response element (CRE) motif T(T/G)ACGTCA. Using an expression screening approach we have cloned a yeast gene, MSN2, that encodes a 78 kDa protein that recognizes this consensus CRE motif. Phosphorylation of the MSN2 protein by the catalytic subunit of protein kinase A stimulates DNA binding in vitro. Two putative Cys2His2-type zinc fingers present in the C-terminal 79 amino acids of the MSN2 protein are sufficient to confer CRE-binding specificity. Therefore, MSN2 represents a novel CRE-binding protein distinct from the multiple previously characterized basic region-leucine zipper repeat CRE-binding proteins.
The Field Theory: Martial Law, the Suspension Power, and the Insurrection Act

In Ex parte Merryman, Chief Justice Taney famously rejected President Lincoln's power to unilaterally suspend the writ of habeas corpus in and around Baltimore at the outset of the U.S. Civil War. According to Taney, only Congress can provide for suspension of the writ, and Congress had not so provided. Just one year later, though, the Vermont federal circuit court held, in Ex parte Field, that the suspension of habeas corpus is necessarily coincident to the imposition of martial law. Because President Lincoln had the statutory authority to impose martial law by virtue of the so-called Militia Acts, Field concluded, Congress had effectively, if not explicitly, given sanction to Lincoln's suspension of habeas in those areas where martial law was validly in force. This Article attempts a thorough reconstruction of the Field theory, beginning with the facts of Merryman itself before moving to the pre-Civil War precedents on which the decision in Field relied. As it concludes, the President's authority to impose martial law in crisis situations does in fact derive from the Militia Acts, and there is at least a colorable argument that Baltimore was under martial law at the time Merryman was decided. More importantly for present purposes, though, the Article analyzes the deep and profound questions as to the substantive preconditions for the imposition of martial law through the lens of the modern-day Insurrection Act, concluding that the statutory framework, in current form, does not adequately demarcate the point past which martial law is appropriate. Because Congress has the power to provide for the calling forth of the military to respond to domestic crises, Congress can provide for greater accountability - especially at the end of the next emergency - and, the Article concludes, Congress should do so.
Venous thromboembolism is associated with advanced cancer stage, hypertension and cardiovascular disease regardless of latency from surgery in patients with uterine serous carcinoma.

e17568Background: Although gynecologic cancer patients are known to be at increased risk of venous thromboembolism (VTE) after surgical staging, it remains unclear how long that risk persists. This...
Prevention Is the Best Treatment: The Case for Understanding the Transition from Monoclonal Gammopathy of Undetermined Significance to Myeloma

Multiple myeloma is an invariably fatal cancer of plasma cells. Despite tremendous advances in treatment, this malignancy remains incurable in most individuals. We postulate that strategies aimed at prevention have the potential to be more effective in preventing myeloma-related death than additional pharmaceutical strategies aimed at treating advanced disease. Here, we present a rationale for the development of prevention therapy and highlight potential target areas of study.
Evaluation of Above Study Region Sites for Future Calibration and Validation of Nisar Science Requirements

The ecosystem science requirements for the NASA ISRO Synthetic Aperture Radar (NISAR) will need to be validated after its launch in 2021 [1]. NASA has also been conducting a major field campaign in the boreal region of North America called the Arctic Boreal Vulnerability Experiment (ABoVE) [2]. ABoVE presents an opportunity to establish critical Cal/Val sites for the NISAR mission, as requirements for estimating biomass under 100 t/ha, detecting disturbance in forested areas, delineation of wetland inundation, and measuring permafrost deformation must be validated in the boreal region. Here, we describe preliminary analysis of field measurements collected as part of ABoVE against a time series of C-band SAR data from the ESA Sentinel-1 satellites.
Perceptual span in individuals with aphasia.

Background: Perceptual span refers to the field of effective vision during reading comprehension. It is determined by many factors, including reading proficiency. No studies have investigated the p...
Ritonavir and cobicistat as pharmacokinetic enhancers in pregnant women.

Ritonavir and cobicistat are commonly used as pharmacokinetic enhancers to boost plasma concentrations of antiretrovirals used to treat HIV infection, including the protease inhibitors atazanavir, ...
Selective use of Molecular Testing Based on Sonographic Features of Cytologically Indeterminate Thyroid Nodules: A Decision Analysis

Molecular diagnostics can allow some patients with indeterminate thyroid nodule cytopathology to avoid diagnostic hemithyroidectomy; however, the testing is costly. We hypothesized that molecular testing with the intention of preventing unnecessary diagnostic hemithyroidectomy would be cost-effective if this test was applied selectively based on sonographic risk of malignancy. A Markov model was constructed depicting a 40-year-old patient with a cytologically indeterminate thyroid nodule. Molecular testing of fine needle aspiration material was compared to a strategy of immediate diagnostic hemithyroidectomy. Data from a single tertiary-referral health system were reviewed to estimate the outcomes of molecular testing of indeterminate nodules stratified by the American Thyroid Association sonographic classification system. Other outcome probabilities and their utilities were derived from literature review. Costs were estimated with Medicare reimbursement data. A $100,000/QALY threshold for cost-effectiveness was applied. Sensitivity analysis was employed to examine uncertainty in the model’s assumptions. Of 123 patients who underwent molecular testing for indeterminate cytology, 12 (9.8%) were classified as high sonographic suspicion, 49 (40%) were intermediate suspicion, and 62 (50%) were low or very low suspicion. Molecular testing was only cost-effective when the pretest probability of a negative test was greater than 31%. The model was most sensitive to the cost of molecular testing and the quality adjustment factor for hypothyroidism. In hypothetical modeling, molecular testing is only cost-effective for cytologically indeterminate thyroid nodules with sonographic features that are intermediate or low suspicion for malignancy. In nodules with high sonographic suspicion, molecular testing is rarely negative and appears to add minimal value.
Low-power analog-to-digital converter

This paper describes the design and testing of a low power Analog to Digital converter. In the design of Z-Plane focal plane array technology the consumption of power by circuitry in the signal processing electronics, that are part of the Z-Plane, is a primary limiting factor in the overall Z-Plane system signal processing architecture. The Analog to Digital converter was designed by applying charge-coupled device (CCD) technology to the binary weighing problem. The Analog to Digital converter is, with the exception of the comparator, an all digital CMOS design. The design concepts are discussed along with preliminary test results.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Endoscopic removal of eroded laparoscopic adjustable gastric bands: a preferred approach

Abstract Background Complications related to laparoscopic adjustable gastric banding (LAGB) have led to an increased number of removals. An uncommon but potentially devastating complication is gastric band erosion into the gastric lumen, which can be managed by open surgical, laparoscopic, and endoscopic approaches. Objective A wide array of management techniques has been reported for removal of LAGB that have eroded into the stomach. We describe the preferred method for successful endoscopic band removal at our institution. Setting Community tertiary-care referral hospital accredited by the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program. Methods A single-center, retrospective review of a prospectively maintained database was used to identify patients who underwent LAGB removal from 2009 to 2019. We identified the subset of patients with band erosion. We analyzed patient characteristics, presenting symptoms, diagnostic modalities, and method of band extraction. Results A total of 132 patients underwent LAGB removal, among whom 22 (16.7%) patients were diagnosed with erosion. Seven (32%) patients underwent laparoscopic removal, 14 (64%) patients underwent endoscopic removal, and 1 patient (4%) underwent combined laparoscopic and endoscopic approach. These latter patients had variable amounts of erosion and buckle visibility, but all underwent endoscopic retrieval. We found that using an endoscopic retrograde cholangiopancreatography guidewire with an endoscopic retrograde cholangiopancreatography mechanical lithotriptor for band transection and snare for retrieval have been effective. Conclusions A standardized, multidisciplinary, and minimally invasive endoscopic approach for LAGB erosion has been found to be successful without the need for further surgical intervention and may be offered to patients upon discovery of erosion.
Handyfuge-LAMP: low-cost and electricity-free centrifugation forisothermal SARS-CoV-2 detection in saliva.

Point of care diagnostics for COVID-19 detection are vital to assess infection quickly and at the source so appropriate measures can be taken. The loop-mediated isothermal amplification (LAMP) assay has proven to be a reliable and simple protocol that can detect small amounts of viral RNA in patient samples (<10 genomes per μL) (Nagamine, Hase, and Notomi 2002) Recently, Rabe and Cepko at Harvard published a sensitive and simple protocol for COVID-19 RNA detection in saliva using an optimized LAMP assay (Rabe and Cepko, 2020). This LAMP protocol has the benefits of being simple, requiring no specialized equipment; rapid, requiring less than an hour from sample collection to readout; and cheap, costing around $1 per reaction using commercial reagents. The pH based colorimetric readout also leaves little ambiguity and is intuitive. However, a shortfall in many nucleic acid-based methods for detection in saliva samples has been the variability in output due to the presence of inhibitory substances in saliva. Centrifugation to separate the reaction inhibitors from inactivated sample was shown to be an effective way to ensure reliable LAMP amplification. However, a centrifuge capable of safely achieving the necessary speeds of 2000 RPM for several minutes often costs hundreds of dollars and requires a power supply. We present here an open hardware solution- Handyfuge - that can be assembled with readily available components for the cost of <5 dollars a unit and could be used together with the LAMP assay for point of care detection of COVID-19 RNA from saliva. The device is then validated using the LAMP protocol from Rabe and Cepko. With the use of insulated coolers for reagent supply chain and delivery, the assay presented can be completed without the need for electricity or any laboratory scale infrastructure.
Interdisciplinary Care and a Focus on Fertility Preservation When Multi-cystic Ovaries Cause Ovarian Torsion: A Case of a 9-year-old Girl with Severe, Undiagnosed Hypothyroidism.

Abstract Background Ovarian torsion can occur in Van Wyk Grumbach syndrome, a disorder characterized by severe primary hypothyroidism and ovarian enlargement. To date, all documented cases of torsion in this setting describe oophorectomy, which has significant hormonal and fertility implications. Case A 9-year-old pubertal girl presented to the emergency room with abdominal pain. Magnetic resonance imaging demonstrated bilateral, multi-cystic ovaries. Operative laparoscopy confirmed unilateral adnexal torsion, and detorsion without oophorectomy was accomplished. Postoperative laboratory tests revealed severe primary hypothyroidism. Ovarian size was reduced with hormone replacement therapy. Summary and Conclusion This case demonstrates that prompt interdisciplinary intervention and awareness of severe hypothyroidism as a cause of ovarian torsion related to enlarged, multi-cystic ovaries may reduce the rate of oophorectomy, allowing preservation of pediatric patients’ future fertility, and reducing morbidity postoperatively through prompt, long-term thyroid supplementation.
Pandemics Past and Present: A Guided Inquiry Approach.

Background:COVID-19 exposed undergraduate medical education curricular gaps in exploring historical pandemics, how to critically consume scientific literature and square it with the lay press, and ...
Sub-2 mm Depth of Interaction Localization in PET Detectors with Prismatoid Light Guide Arrays and Single-Ended Readout using Convolutional Neural Networks.

Purpose Depth of interaction (DOI) readout in PET imaging has been researched in efforts to mitigate parallax error, which would enable the development of small diameter, high-resolution PET scanners. However, DOI PET has not yet been commercialized due to the lack of practical, cost-effective, and data efficient DOI readout methods. The rationale for this study was to develop a supervised machine learning algorithm for DOI estimation in PET that can be trained and deployed on unique sets of crystals. Methods Depth collimated flood data was experimentally acquired using a Na-22 source with a depth-encoding single-ended readout Prism-PET module consisting of lutetium yttrium orthosilicate (LYSO) crystals coupled 4-to-1 to 3×3 mm 2 silicon photomultiplier (SiPM) pixels on one end and a segmented prismatoid light guide array on the other end. A convolutional neural network (CNN) was trained to perform DOI estimation on data from center, edge and corner crystals in the Prism-PET module using (a) all non-zero readout pixels and (b) only the 4 highest readout signals per event. CNN testing was performed on data from crystals not included in CNN training. Results An average DOI resolution of 1.84 mm full width at half maximum (FWHM) across all crystals was achieved when using all readout signals per event with the CNN compared to 3.04 mm FWHM DOI resolution using classical estimation. When using only the 4 highest signals per event, an average DOI resolution of 1.92 mm FWHM was achieved, representing only a 4% dropoff in CNN performance compared to using all non-zero pixels per event. Conclusions Our CNN-based DOI estimation algorithm provides the best reported DOI resolution in a single-ended readout module and can be readily deployed on crystals not used for model training.
Integrating qualitative and quantitative methods to develop a comprehensive coding manual: Measuring attention to mathematics in play contexts

Abstract This coding manual was created to quantify and characterize the ways in which parents and their preschool children attend to mathematical features during play. We operationalized attention to mathematical features as instances during which parents or children made verbal references to quantitative (i.e., number, quantity, part-whole relations) or spatial (e.g., size, shape, spatial location, positional orientation) features. Through analysis of videotapes and transcripts of parent-child play sessions, we coded these verbal communications as questions, responses, mentions, or repetitions; and coded corresponding nonverbal support as either explicit, implicit, or irrelevant to the mathematical features coded. Analyses of independent coding by two coders indicated that we reliably coded instances of attending to mathematical features and the ways in which dyads talked about these features. Codes for nonverbal behaviors were less reliable and may require further development to improve reliability. The reliability analyses on verbal communication also illustrated the Kappa paradox—in our case, the high proportion of feature mentions led to a low value of Cohen's Kappa even when the percent agreement and Gwet's Agreement Coefficient 1 were high. The coding scheme served as a framework for our recent report on the frequency of parents' and children's attention to mathematical features and the association between parents' and children's attention to these features (Chan et al., 2020). This coding manual leverages the benefits of a mixed-methods approach by coding qualitative observations for quantitative analysis, and may provide other researchers with a framework for coding attention to mathematical features in a play context and developing manuals for analyzing other aspects of parent-child interaction.
Wind Vector and Wave Height Retrieval in Inland Waters Using CYGNSS

Spaceborne GNSS Reflectometry (GNSS-R) measurements over inland waters have exhibited strong coherent scattering. The strong reflected signal from a relatively small spatial extent (several km) is highly sensitive to surface waves. This sensitivity can be leveraged to estimate wave height profiles across inland waters. Coupled with a wind wave model, retrievals of wind vector can be performed using a forward model approach. The surface waves play a significant role in nearshore ecosystems, affecting sediment resuspension, biomass production, and fish habitat, among others. This paper details a novel approach to estimating surface wave profiles and wind vectors using the passive, bistatic radar receiver aboard CYGNSS. The first ever retrieval of wind vector and wave height of an inland water body using spaceborne GNSS-R will be shown using raw signals recorded onboard CYGNSS.
Re: Docket No. CFPB-2021-0004, Request for Information and Comment on Financial Institutions’ Use of Artificial Intelligence, including Machine Learning, Questions 17, 8, 10, and 12

These Comments, submitted in response to the Consumer Financial Protection Bureau's Request for Information: Financial Institutions' Use of Artificial Intelligence, including Machine Learning, explain: (1) how and why financial institutions' use of Artificial Intelligence/Machine Learning (AI/ML) systems to produce and micro-target digital marketing and online sales processes will lead to deception, unfair treatment, and abuse of consumers, (2) why current approaches to financial institution supervision and enforcement can be stymied by these uses of AI/ML systems, (3) the risks to financial institutions of relying on AI/ML systems produced by third parties to design and micro-target digital marketing and online sales processes, (4) the risk that financial institutions' AI/ML digital marketing and online sales systems will target protected classes of consumers for deception, unfair treatment, and abuse, and (5) some suggestions for addressing these problems.
Artificial Intelligence and the Carousel of Soft Law

The impulse of so many organizations across nearly every sector of society to promulgate principles in response to the ascendance of artificial intelligence is understandable and predictable. There is some utility in public commitments to universal values in the context of AI, and common principles can lay a foundation for societal change. But ultimately what is missing is not knowledge about the content of ethics as much as political will. If, as both detractors and proponents claim, AI constitutes the transformative technology of our time, then one of the aspects of society that must transform is the law and legal institutions.
A chemocentric view of the natural product inventory

As the identification of previously undetected microbial biosynthetic pathways burgeons, there arises the question of how much new chemistry is yet to be found. This, in turn, devolves to: what kinds of biosynthetic enzymatic transformations are yet to be characterized?
Creolizing Contradance in the Caribbean

Reviewed Medium: book Year: 2009 Pages: 288 Details: includes CD Publisher: Temple University Press ISBN: 1-59213-734-2 (hard cover). Prices: $69.50 USD(hard cover).
Trading Off Parallelism and Numerical Stability

The fastest parallel algorithm for a problem may be significantly less stable numerically than the fastest serial algorithm. We illustrate this phenomenon by a series of examples drawn from numerical linear algebra. We also show how some of these instabilities may be mitigated by better floating point arithmetic.
Topological foundations of design and control of multidimensional discrete systems

Local and global connectedness, arcwise connectedness, path connectedness, and order relation are among the main structural components of complicated neural networks, communications networks, and other multidimensional discrete systems. All such systems are finitely connected. They can be considered as subspaces of some integer product spaces, Alexandroff spaces, primitively derived spaces, or other subclass of primitively path connected spaces. Connectivity, local connectivity, and order relation in such spaces are examined here. Finite connectedness and lexicographic union of ordered topological spaces are especially important because of their widespread applications. >
The arrangement of DNA in lambda phage heads. II. lambda DNA after exposure to micrococcal nuclease at the site of head-tail joining.

Abstract DNA in lambda phage heads (lacking tails) is damaged by treatment with micrococcal nuclease. Alkaline sucrose gradient sedimentation of the DNA extracted from nuclease-treated and untreated heads reveals no hydrolysis of internal phosphodiester bonds. Transformation of helper-infected cells by whole or half molecules of treated DNA is as efficient as by control DNA. Thus, the site of nuclease damage must be near the ends and very limited. Below 20 °C, DNA from nuclease-treated heads forms circles in vitro more rapidly than control DNA, presumably by hydrogen bonding at the single-stranded ends. In the control DNA, these bonds melt at 61°C, but in the treated DNA they melt at 36 °C. The data suggest that λ DNA molecules are positioned in phage heads so that a few terminal bases of the single-stranded 5′ ends are exposed to micrococcal nuclease when it attacks at the site for tail attachment.
Source of the Oxygen in the C-O-P Linkage of the Acyl Phosphate in Transport Adenosine Triphosphatases

The source of the oxygen in the C-O-P linkage of the acyl phosphate in the Na+, K+-ATPase of porcine kidney and the Ca2+, Mg2+-ATPase of rabbit muscle sarcoplasmic reticulum has been assessed. Formation of the Na+, K+-ATPase acyl phosphate in presence of ouabain and [18O]Pi results in the C-O-P bridge oxygen remaining nonisotopic. Thus, the mode of entry of Pi into the acyl phosphate is by attack of a carboxylate oxygen on the phosphorus atom and displacement of a hydroxyl group. When the acyl phosphate of the Ca2+, Mg2+-ATPase or the Na+, K+-ATPase is formed in the presence of H18OH, the C-O-P bridge oxygen also remains nonisotopic. These results show that the acyl phosphate is cleaved by water oxygen attack on the phosphorus atom and rules out any acyl transfer to an enzyme group and subsequent hydrolysis by attack of water oxygen on the acyl carbon atom. The phosphoryl oxygens of the Na+,K+-ATPase phosphoenzyme at 15° derived either from [18O]Pi in the presence of ouabain or from ATP in the presence of H18OH were observed to undergo exchange with medium water, not accounted for by exchange of Pi oxygens with HOH and incorporation of the Pi into the protein-bound acyl phosphate.
A thresholding technique for differentiation of materials used in remote sensing

This paper introduces a new remote sensing technique based on polarimetric detection principles, aimed at enhancing the discrimination of unresolved materials, Amorphous Silicon and Polysilicon. Some of the polarimetric measurements performed at different angles of incidence (angular rotations) of these materials are presented using backscattered polarimetric signals obtained with a polarimetric system (test bed). A new discrimination technique of these materials based on their angle of rotation has been presented. This technique calculates the rotation angle at which maximum discrimination between these materials is possible using a thresholding method. Based on the initial results, it can be said that maximum discrimination between the materials is possible more at off-axis angles than at the angle of incidence.
Time-step targeting methods for real-time dynamics using the density matrix renormalization group

We present a time-step targeting scheme to simulate real-time dynamics efficiently using the density matrix renormalization group. The algorithm works on ladders and systems with interactions beyond nearest neighbors, in contrast to existing Suzuki-Trotter-based approaches.
Evidence for central venous pressure resetting during initial exposure to microgravity

We measured central venous pressure (CVP); plasma volume (PV); urine volume rate (UVR); renal excretion of sodium (UNa); and renal clearances of creatinine, sodium, and osmolality before and after acute volume infusion to test the hypothesis that exposure to microgravity causes resetting of the CVP operating point. Six rhesus monkeys underwent two experimental conditions in a crossover counterbalance design: 1) continuous exposure to 10 degrees head-down tilt (HDT) and 2) a control, defined as 16 h/day of 80 degrees head-up tilt and 8 h prone. After 48 h of exposure to either test condition, a 120-min course of continuous infusion of isotonic saline (0.4 ml. kg(-1). min(-1) iv) was administered. Baseline CVP was lower (P = 0.011) in HDT (2.3 +/- 0.3 mmHg) compared with the control (4.5 +/- 1.4 mmHg) condition. After 2 h of saline infusion, CVP was elevated (P = 0.002) to a similar magnitude (P = 0.485) in HDT (DeltaCVP = 2.7 +/- 0.8 mmHg) and control (DeltaCVP = 2.3 +/- 0.8 mmHg) conditions and returned to preinfusion levels 18 h postinfusion in both treatments. PV followed the same pattern as CVP. The response relationships between CVP and UVR and between CVP and UNa shifted to the left with HDT. The restoration of CVP and PV to lower preinfusion levels after volume loading in HDT compared with control supports the notion that lower CVP during HDT may reflect a new operating point about which vascular volume is regulated. These results may explain the ineffective fluid intake procedures currently employed to treat patients and astronauts.
Variations in Use of Dental Care Facilities by Low-Income White and Black Urban Populations

Since Massachusetts instituted its Medicaid Program, there has been a steady increase in use of dental service. A comparison of data from this 1968 study with data obtained in 1967 shows changing patterns of dental care. More low-income families, both black and white, are now receiving regular dental care and are going to private practitioners. However, maldistribution of dentists in urban areas imposes a greater hardship on black families who must travel farther and spend more money on transportation.
The development of membrane protein crystallization screens based upon detergent solution properties

Abstract A principal hypothesis of our research is that the properties of detergent and protein/detergent solutions, such as their phase behavior and critical phenomena, play a significant role during membrane protein crystallization. Therefore, the characterization of these properties, and the subsequent incorporation of this information into crystallization experiments, will enable the more successful formation of well-ordered membrane protein crystals for structure determination. We are utilizing a variety of techniques for the development and implementation of detergent-specific membrane protein crystallization screens. Observation of dye partitioning in detergent/solute mixtures enables the relatively rapid determination of phase boundaries, and this information is utilized in the design of crystallization screens that are currently being tested. A commercial crystallization robot has been modified for use in the in situ setup of crystallization screens. Lastly, the characterization of critical phenomena in detergent solutions has been initiated.
The isomeric composition of lactated Ringer’s has no differential effect on gastric dysfunction after mesenteric ischemia/reperfusion

Abstract Lactated Ringer’s is the standard of care trauma resuscitation, but the D-isomer of lactate has been shown to activate proinflammation. We have shown that superior mesenteric artery occlusion (SMAO) without resuscitation causes gastric dysfunction characterized by luminal fluid accumulation and alkalization. In the same model, LR resuscitation protected the ileum, but the presence of the D-isomer abrogated this effect. We, therefore, hypothesized that the isomeric composition of LR resuscitation would have a differential effect on gastric dysfunction and inflammation in this model. Rats underwent sham or SMAO for 60 min. Five minutes prior to clamp removal, SMAO animals received no resuscitation, 20 ml/kg IV (our standard) of either LL or LD isomer LR, or 17 ml/kg IV normal saline (NS) as equal salt load control. Animals were sacrificed at 6 h of reperfusion and gastric mucosa was harvested for analysis. Gastric dysfunction was quantitated by gastric volume and luminal pH. Heme-Oxygenase-1 (HO-1; index of anti-inflammation) and inducible Nitric Oxide Synthase (iNOS; index of proinflammation) protein expression were analyzed by Western immunoblot. Data are reported as mean ± SEM ( n > 6/group; ANOVA). Means with different letters are significantly different. SMAO (no resuscitation) increased gastric volume and pH. All three resuscitative regimens decreased gastric volume, had no effect on pH, and equally induced HO-1 and iNOS. In conclusion, isomeric composition of LR had no differential effect on gastric dysfunction and inflammation after SMAO in contradistinction to its previously observed effects in the ileum. The isomeric immunomodulatory effects of LR appear to be organ specific. TABLE—ABSTRACT P87 . Model Volume (ml) pH (pH) HO-1 (AU) iNOS (AU) Sham 0.30 ± 0.05 a 1.67 ± 0.16 a 0.36 ± 0.02 a 0.28 ± 0.03 a SMAO 2.22 ± 0.57 b 6.58 ± 0.20 b 0.43 ± 0.05 a 0.29 ± 0.07 a SMAO/LL 1.28 ± 0.31 c 5.58 ± 0.62 b 0.56 ± 0.04 b 0.50 ± 0.06 b SMAO/LD 0.80 ± 0.23 c 6.38 ± 0.38 b 0.57 ± 0.04 b 0.44 ± 0.03 b SMAO/NS 1.03 ± 0.12 c 5.83 ± 0.60 b 0.59 ± 0.05 b 0.49 ± 0.10 b
Attenuation of luteinizing hormone secretory burst amplitude as a proximate basis for the hypoandrogenism of healthy aging in men.

To evaluate the impact of healthy aging on specific features of endogeneous LH secretion and clearance, we applied deconvolution analysis to 24-h serum immunoradiometric LH concentration series obtained in normal men whose ages ranged from 21-73 yr. Deconvolution analysis was employed to quantitate the number, amplitude, duration, and mass of individual LH secretory bursts underlying the serum LH concentration profiles, and simultaneously estimate the half-life of LH in individual men. Plasma total and free testosterone and estradiol concentrations and body mass index (a measure of relative adiposity) were studied as possible significant covariates of age and LH secretion. We found that age was a negative determinant of LH secretory burst amplitude (r = -0.519, P = 0.013), and a positive predictor of LH secretory burst frequency (r = +0.435, P = 0.043) and basal LH secretory rates (r = +0.486, P = 0.029). Increasing age also correlated positively with LH secretory burst half-duration (duration of the secr...
Effects of sedimentation on the behavior and distribution of riffle insects in a laboratory stream 1

Abstract Studies were conducted to determine the effects of 3 levels of sedimentation on the behavior and distribution of selected mayflies, stoneflies and caddisflies in artificial laboratory streams. Most species responded negatively to increased levels of sedimentation; all preferred unsedimented over heavily sedimented substrate. Sensitivity to sedimentation differed among species with size, morphology, and behavior accounting for much of the variation. As sediment levels increased, more of the test substrate became uninhabited. Density per cobble increased only slightly with greater quantities of fine sediment. Nonburrowing species were unsuccessful in gaining access beneath cobbles when the undersurfaces and sides were sealed in fine sediments.
Preparation of Oxygen Ion Conducting Ceramic Hollow-Fiber Membranes

Hollow-fiber membranes of mixed conducting perovskite Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ) were prepared using a sequence of extrusion, gelation, and sintering steps. For this purpose, a finely divided mixture of the component oxides was prepared by the modified Pechini technique and suspended in a polymer solution. The suspension was extruded through a spinneret and gelled in water. The resulting fiber was first heated at 800 °C to remove the polymer and then at 1100 °C to form the perovskite and simultaneously sinter the particles to a gastight membrane. The fibers were characterized by scanning electron microscopy and tested for air separation at ambient pressure and temperature between 700 and 950 °C. The maximum oxygen flux measured was 3.9 mL/min/cm^2 at 950 °C and 0.022 atm of average permeate oxygen partial pressure.
What do surgery residents do on their call nights

Abstract Background Surgical resident education is entering a critical era of achieving core competencies despite work hour restrictions. An assessment of on-call activity is needed to maximize educational merit. Methods A time-motion study of resident on-call activity was performed at a university medical center and an urban affiliate hospital. Residents were followed by “shadow” residents who concurrently recorded resident activity. Results Activities of daily living and patient evaluation comprised the majority of on-call activity. Residents slept a median of 200 minutes per night. Cross-coverage activities accounted for 41% of pages and 19% of patient evaluation. Direct patient contact comprised only 7% of call night duties. Communication activity occupied 15% of total minutes, and a mean of 16 pages were received nightly. Significant differences in activities existed between resident levels and hospitals. Conclusions Call activity consists primarily of activities of daily living, patient evaluation, and communication. Sleep accounts for nearly one third of all on-call activity. These data may be useful in improving both patient care and resident call experience.
Fluorogenic substrate assay of antithrombin III: a clinical study

Abstract The fluorogenic substrate assay of antithrombin III (AT III) was compared with a thrombin inhibition (two-stage) clotting test and a radial immunodiffusion assay. Normal ranges based on a population of 25 individuals were 88–121% (fluorogenic substrate), 72–111% (clotting) and 22.5–35.3 mg/dl (RID). A clinical comparison of the methods showed a linear relationship between the fluorogenic substrate and immunologic methods (r = 0.69, p
Comments on two methods for designing a digital equivalent to a continuous control system

Rattan (1984, 1989) suggests two methods for designing a digital control system to match the performance of a given continuous control system as closely as possible. In this note, two main points are made. First, there are a number of errors in the paper by Rattan (1989) that significantly affect its conclusions. Second, neither of the methods is guaranteed to produce a stable closed-Loop system, even if the original closed-loop system is stable. In fact, the two methods will generally lead to unstable closed-loop systems when the number of free parameters in the compensator design process is large. >
Continuous estimation of viscosity, fluid density, surface tension, and heat output during fermentations

Currently, sensors for measuring fluid density, surface tension, viscosity, and heat output are rarely if ever used in estimating conditions continuously in microbial cultures. Measurement of fluid density and surface tension can be accomplished with differential air pressure-based sensors. Fluid viscosity can be estimated by measuring differential fluid pressures. These three sensors, as tested with cultures, were comprised of glass and rubber tubing, a gas supply for density and surface tension and a peristaltic pump for viscosity. The heat output was estimated with an infrared detector spaced two inches from the bottom surface of a solid-state culture flask.
Water mediated proton transfer in a mesostructured aluminosilicate framework: an ab initio molecular dynamics study.

The proton transfer process mediated by water molecules adsorbed in an aluminosilicate framework has been studied using ab initio molecular dynamics simulations. This investigation has been carried out using a quasi-one-dimensional model simulating the mesoporous aluminosilicate channel structures. The effects of both the water loading and temperature of the system have been considered. At low coverage (one water molecule per acid site), the hydroxonium ion (H3O)+ is found to be a transition state, in agreement with earlier studies on zeolites. At a higher water coverage (two water molecules per acid site), the (H5O2)+ species and the hydrogen bonded “neutral complex” structure are both found to be stable complexes at finite temperatures. The vibrational frequency spectrum is simulated by performing a Fourier transform of the velocity autocorrelation function (VAF), and the peak positions in the VAF are compared with IR measurements and zero-temperature calculations.
Origins of maternal role satisfaction and its influences upon maternal interactive behavior and infant-mother attachment☆

Abstract This longitudinal study sought to examine the origins of maternal role satisfaction, and the influence of mothers' perceptions of their various roles upon subsequent interactions with their infants and the quality of infants' 1-year attachment to mother. Interviews and questionnaires provided assessments of first-time mothers' (N = 32) prenatal marital satisfaction and social support as well as 4-month perceptions of their various life roles (self, wife, homemaker, employee); observations were employed to assess mothers' 9-month interactive behaviors and the quality of infant-mother attachment at 1 year. Path analysis revealed that mothers reporting high levels of satisfaction with their marriages and high levels of family support during the prenatal period were most likely to report a higher degree of role satisfaction at 4 months. High levels of role satisfaction were in turn predictive of optimal (i.e., sensitive) interactions with infants at 9 months, and these sensitive interactions contributed to development of secure infant-mother attachments by 1 year. These findings demonstrate the importance of mothers' social contexts in shaping their perceptions of themselves and the importance of these perceptions in guiding mothers' interactions and relationships with their infants.
Gender differences in tobacco use in Africa, Asia, the Pacific, and Latin America

This paper reviews historical, anthropological and contemporary survey data concerning gender differences in tobacco use in Africa, Asia, the Pacific, and Latin America. In many cultural groups in these regions, tobacco use has been substantially more common among men than among women. In some groups, tobacco use has been about equally common for both sexes. No evidence was found of any group in which tobacco use has been substantially more common among women. The widespread pattern of greater tobacco use by men appears to be linked to general features of sex roles. For example, men have often had greater social power than women, and this has been expressed in greater restrictions on women's behavior, including social prohibitions against women's smoking. These social prohibitions against women's smoking have strongly inhibited women's tobacco use and thus have been a major cause of gender differences in tobacco use. Gender differences in tobacco use have varied in magnitude, depending on the type of tobacco use and the particular cultural group, age group and historical period considered. Causes of the variation in gender differences in tobacco use include variation in women's status and variation in the social significance and benefits attributed to particular types of tobacco use in different cultures. Contact with Western cultures appears to have increased or decreased gender differences in smoking, depending on the specific circumstances. The patterns of gender differences in tobacco use in non-Western societies are similar in many ways to the patterns observed in Western societies, but there are several important differences.(ABSTRACT TRUNCATED AT 250 WORDS)