cssi/SciSciGPT-SciSciNet huggingface dataset:
A Concurrent Product-Development Approach for Friction-Stir Welded Vehicle-Underbody Structures

High-strength aluminum and titanium alloys with superior blast/ballistic resistance against armor piercing (AP) threats and with high vehicle light-weighing potential are being increasingly used as military-vehicle armor. Due to the complex structure of these vehicles, they are commonly constructed through joining (mainly welding) of the individual components. Unfortunately, these alloys are not very amenable to conventional fusion-based welding technologies [e.g., gas metal arc welding (GMAW)] and to obtain high-quality welds, solid-state joining technologies such as friction-stir welding (FSW) have to be employed. However, since FSW is a relatively new and fairly complex joining technology, its introduction into advanced military-vehicle-underbody structures is not straight forward and entails a comprehensive multi-prong approach which addresses concurrently and interactively all the aspects associated with the components/vehicle-underbody design, fabrication, and testing. One such approach is developed and applied in this study. The approach consists of a number of well-defined steps taking place concurrently and relies on two-way interactions between various steps. The approach is critically assessed using a strengths, weaknesses, opportunities, and threats (SWOT) analysis.
A direct comparison of two nonviral gene therapy vectors for somatic integration: in vivo evaluation of the bacteriophage integrase ϕC31 and the Sleeping Beauty transposase

In this study we performed a head-to-head comparison of the integrase phiC31 derived from a Streptomyces phage and the Sleeping Beauty (SB) transposase, a member of the TC1/mariner superfamily of transposable elements. Mouse liver was cotransfused with a vector containing our most robust human coagulation factor IX expression cassette and the appropriate recombinase recognition site and either a phiC31- or a SB transposase-expressing vector. To analyze transgene persistence and to prove somatic integration in vivo we induced cell cycling of mouse hepatocytes and found that the transgene expression levels dropped by only 16 to 21% and 56 to 66% in mice that received phiC31 and SB, respectively. Notably, no difference in the toxicity profile was detected in mice treated with either recombinase. Moreover we observed that with the integrase-mediated gene transfer, transgene expression levels were dependent on the remaining noncoding vector sequences, which also integrate into the host genome. Further analyses of a hot spot of integration after phiC31-mediated integration revealed small chromosomal deletions at the target site and that the recombination process was not dependent on the orientation in which the phiC31 recognition site attached to the pseudo-recognition sites in the host genome. Coupled together with ongoing improvements in both systems this study suggests that both nonviral vector systems will have important roles in achieving stable gene transfer in vivo.
Moisture pulses, trace gas emissions and soil C and N in cheatgrass and native grass-dominated sagebrush-steppe in Wyoming, USA

Abstract Effects of large-scale weed invasion on the nature and magnitude of moisture-pulse-driven soil processes in semiarid ecosystems are not clearly understood. The objective of this study was to monitor carbon dioxide (CO2) and nitrous oxide (N2O) emissions and changes in soil carbon (C) and nitrogen (N) following the application of a water pulse in Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) communities dominated by the exotic annual grass cheatgrass (Bromus tectorum) and by the native perennial grass western wheatgrass (Pascopyrum smithii). Sampling locations were established in shrub interspaces dominated by B. tectorum and P. smithi and beneath shrub canopies adjacent to interspaces dominated by B. tectorum and P. smithi, where no grass was present. Soils were classified as fine-loamy, mixed, Borollic Haplargids. Soil samples (0–10 cm) and air samples were collected at 0, 4, 8, 24, 49, 72, and 216 h following additions of 25.4 mm of water. Soil samples were analyzed for dissolved organic carbon (DOC), microbial biomass carbon (MBC), extractable ammonia (NH4+), extractable nitrate (NO3−), and dissolved organic nitrogen (DON). Grass species induced differences in soil nitrification, N2O and CO2 emissions, and the quantity and timing of labile C available to microbial populations responding to increased moisture availability. In the first 8-h phase after wetting P. smithii soils had the greatest CO2 emissions compared to other soils but B. tectorum soils had the greatest N2O emissions and the greatest increases in CO2 emissions relative to before wetting. Microbial biomass C in B. tectorum interspace soils increased rapidly but the response was short-lived despite sufficient water availability. After the first 8 h of soil response to wetting, the observed MBC declines in B. tectorum interspace coincided with disproportional DOC and DON concentration increases. Similar DOC and DON increases were also observed in B. tectorum soils beneath shrub canopy. In contrast, DOC and DON concentrations in P. smithii soils remained unaffected by soil wetting and small MBC increases observed during the first 8-h phase did not decline as rapidly as in B. tectorum interspace soils. In conclusion, summer drying-wetting cycles that occur frequently in areas invaded by B. tectorum can accelerate rates of nitrification and C mineralization, and contribute significantly to trace gas emissions from sagebrush-steppe grasslands. With frequent summer rainfall events, the negative consequences B. tectorum presence in the ecosystem can be significant.
Complement factors and their receptors

In summary, recent advances in molecular cloning of anaphylatoxins and the anaphylatoxin receptors add new dimensions to our investigations and understanding of the molecular mechanisms involved in anaphylatoxin action. Combining knowledge accumulated from peptide modeling of the ligands with mutagenesis studies of these ligands and their receptors makes it possible to more accurately model interactive sites and understand the sequence of molecular interactions required for cellular activation. In addition, these new developments provide valuable tools for investigating, yet unknown, activities and cellular targets of the anaphylatoxin molecules.
Free recall of nouns presented in sentences

The results of two experiments indicated that the presence of sentences as context has a deleterious effect on the recall and clustering of related nouns, even when the method of complete presentation is used and the nouns are underlined. There was weak evidence that the sentence-context effect was due to the presence of context words and not to the ordering of the context words as sentences.
Contraception: An update for psychiatrists

Abstract Despite significant advances in the field of contraceptive technology, especially that of hormonal contraception, during the past three decades, ever increasing numbers of unplanned pregnancies continue to remain problematic. This is to a great extent because of the fact that many women are still concerned about the safety of hormonal contraception and are unaware of their noncontraceptive benefits. It therefore behooves all of us as health care providers to assure thorough and appropriate counseling of the reproductive aged woman regarding the availability of these methods and to emphasize their contraceptive as well as their noncontraceptive health benefits.
A novel network for nonlinear modeling of neural systems with arbitrary point-process inputs

This paper address the issue of nonlinear model estimation for neural systems with arbitrary point-process inputs using a novel network that is composed of a pre-processing stage of a Laguerre filter bank followed by a single hidden layer with polynomial activation functions. The nonlinear modeling problem for neural systems has been attempted thus far only with Poisson point-process inputs and using cross-correlation methods to estimate low-order nonlinearities. The specific contribution of this paper is the use of the described novel network to achieve practical estimation of the requisite nonlinear model in the case of arbitrary (i.e. non-Poisson) point-process inputs and high-order nonlinearities. The success of this approach has critical implications for the study of neuronal ensembles, for which nonlinear modeling has been hindered by the requirement of Poisson process inputs and by the presence of high-order nonlinearities. The proposed methodology yields accurate models even for short input-output data records and in the presence of considerable noise. The efficacy of this approach is demonstrated with computer-simulated examples having continuous output and point-process output, and with real data from the dentate gyrus of the hippocampus.
Age-related trends in utilization and outcome of open and endovascular repair for abdominal aortic aneurysm in the United States, 2001-2006

Objective This study used a large national administrative in-hospital database to compare utilization and age-specific outcomes between open repair (OAR) and endovascular (EVAR) repair for the treatment of abdominal aortic aneurysm (AAA). Methods Discharges with the principal International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes for EVAR and OAR and principal diagnosis code of intact AAAs were selected from the 2001 to 2006 Nationwide Inpatient Sample (NIS). Weighted least-square regression was used to test the trend of utilization by age. Multiple linear and logistic regression analyses were used to assess the risk-adjusted outcomes. Results Nationally, the estimated number of elective AAAs treated with EVAR increased from 11,171 in 2001 to 21,725 in 2006 ( P = .003). The number of elective AAAs treated with OAR declined from 17,784 to 8451 during the same period ( P Conclusions As short-term surgical outcomes are consistently improving for patients undergoing AAA repair, elective EVAR has replaced OAR as the more common method of repair in the United States. The introduction of this technology has been rapidly adopted, particularly for the oldest-old surgical patients, aged ≥85 years, who previously may not have been offered surgical intervention for asymptomatic AAA. Further investigation is necessary to examine whether this trend improves the long-term survival and quality of life for this elderly population.
The Dark Side of Community: Moralistic Homicide and Strong Social Ties

Abstract Contrary to common belief, strong communities do not necessarily enjoy low rates of violence. Applying Baumgartner's (1988) thesis that confrontational forms of conflict management tend to be found where social interaction is intense, this paper argues that conflict-related or “moralistic” homicide is associated with several of the defining characteristics of community. Thus, a considerable amount of evidence, modern and pre-modern, suggests that moralistic homicide flourishes under conditions of proximity, sociability, immobility, publicity and loyalty.
Prefrontal entrainment of amygdala activity signals safety in learned fear and innate anxiety

Successfully differentiating safety from danger is an essential skill for survival. While decreased activity in the medial prefrontal cortex (mPFC) is associated with fear generalization in animals and humans, the circuit-level mechanisms used by the mPFC to discern safety are not clear. To answer this question, we recorded activity in the mPFC, basolateral amygdala (BLA) and dorsal and ventral hippocampus in mice during exposure to learned (differential fear conditioning) and innate (open field) anxiety. We found increased synchrony between the mPFC and BLA in the theta frequency range (4-12 Hz) only in animals that differentiated between averseness and safety. Moreover, during recognized safety across learned and innate protocols, BLA firing became entrained to theta input from the mPFC. These data suggest that selective tuning of BLA firing to mPFC input provides a safety-signaling mechanism whereby the mPFC taps into the microcircuitry of the amygdala to diminish fear.
Reducing benzodiazepine self-administration with contingent reinforcement.

Abstract The purpose of the present study was to determine whether drug self-administration by methadone maintenance clients can be influenced by offering methadone clinic privileges contingent upon reductions in drug use, and to compare the reinforcing efficacy in this regard of two different clinic privileges. Eight methadone maintenance clients who had histories of supplemental benzodiazepine use participated. In order to transfer illicit drug use to the treatment clinic, clients were prescribed diazepam, 20 mg/day, at the methadone clinic dispensary. Following assessment of baseline diazepam use, clients were offered, during 6-week blocks of time, either the chance to obtain a single methadone take-home dose or the chance to self-regulate their methadone dose for a single day. These privileges were contingent upon refusing prescribed diazepam at the clinic. During baseline weeks, 95.6% of available diazepam doses were requested. When take-home privileges were available, only 11.2% of diazepam doses were requested, while when dose self-control was available, 69.7% of doses were requested. The study showed that the supplemental drug use of methadone maintenance clients can be influenced by clinic privileges which are available contingent upon reductions of drug use. The medication take-home privilege was more effective as a reinforcer than was limited methadone dosage self-control. Methadone clinic privileges can be used as intervention tools to promote desirable therapeutic behavior change in drug addicts, and in particular to promote reductions in supplemental drug use.
Freezing tolerance of selected perennial ryegrass ( Lolium perenne L.) accessions and its association with field winterhardiness and turf traits

Many winter stresses affect the ability of a perennial grass to overwinter in cold, temperate climates. Freezing tolerance is one of the major component traits affecting winterhardiness. Although effective freezing tolerance assessment procedures have long been available for perennial ryegrass (Lolium perenne L.), no work has been done to characterize plant collections in the United States that may possess novel variation for freezing tolerance and winterhardiness. In this study, 21 accessions sampled from a larger set of 300 accessions with known winterhardiness and 3 check varieties were subjected to environmentally-controlled, low temperature acclimation, followed by controlled freezing using a programmable laboratory freezer. Eight freezing treatments from −2 to −16°C were used to determine survival across the known spectrum of freezing tolerance in perennial ryegrass. LT50 values were estimated based on whole plant survival, as well as tiller survival at each of the temperature treatments in the evaluation. LT50 values for the accessions and checks ranged from −10.31 to −13.95°C, with 3 accessions possessing significantly greater freezing tolerance than the most freeze-tolerant check, ‘NK200’. LT50 values were well correlated with winterhardiness in St. Paul during the winters of 2004–2005 and 2005–2006. Lower LT50 values in this experiment were associated with greater spring growth following the stressful winter of 2004–2005 and upright growth habit. The lack of negative biological association between freezing tolerance and turf quality components indicates that freezing tolerance testing could be a useful tool in breeding and selection with landrace germplasm.
Internet-based image analysis quantifies contractile behavior of individual fibroblasts inside model tissue.

In a cell-populated collagen gel, intrinsic fiber structure visible in differential interference contrast images can provide markers for an in situ strain gauge to quantify cell-gel mechanics, while optical sections of fluorescent protein distribution capture cytoskeletal kinematics. Mechanics quantification can be derived automatically from timelapse differential interference contrast images using a Deformation Quantification and Analysis software package accessible online at http://dqa.web.cmu.edu. In our studies, fibroblast contractile machinery was observed to function entirely within pseudopods, while GFP-alpha-actinin concentrated in pseudopod tips and cortex. Complex strain patterns around individual cells showed instances of both elastic and inelastic strain transmission, suggesting a role in observed long-range alignment of cells.
Renal cell carcinoma: current status and future directions

Although renal cell carcinoma accounts for only 3% of adult malignancies, it has been increasing in incidence by 2-4% per year since the 1970's. Cigarette smoking, obesity and end-stage renal disease are important risk factors. Genetic syndromes such as von Hippel-Lindau disease are also associated with an increased incidence of renal cell carcinoma. Localized disease should be treated with surgical resection. However, approximately 30% of patients present with metastatic disease. Complete resection of metastases can result in long-term survival in some individuals. Removal of the primary renal tumor in patients with unresectable disseminated disease has also been shown to improve survival in selected good performance status patients receiving systemic immunotherapy. While chemotherapy has been relatively ineffective in the treatment of renal cell carcinoma, biologic therapy with interleukin-2 or interferon does lead to responses in a minority of patients, with occasional long-term survivors. Recently, promising results have been reported with allogeneic stem cell transplantation using a non-myeloablative conditioning regimen. However, therapy for metastatic renal cell carcinoma remains inadequate. Ongoing trials with novel approaches such as anti-angiogenesis agents, cyclin-dependent kinase inhibitors, and tumor vaccines will hopefully lead to improved outcomes in this disease.
Subsidence of atlantic continental margins

Abstract The seaward subsidence recorded in the stratigraphy and structure of the rifted aseismic margins of southeastern North America and northwestern Africa involves both uplift of the continent and subsidence of the ocean basin. The opposing vertical movements can be explained alternatively by models of material transfer (rock flowage) between the continent and ocean basin and of in-situ material (rock) density changes and probably result from a combination of the two processes.
Optimal stocking policies for low usage items in multi‐echelon inventory systems

Multi-echelon logistic systems are essential parts of the service support function of high technology firms. The combination of technological developments and competitive pressures has led to the development of services systems with a unique set of characteristics. These characteristics include (1) low demand probabilities: (2) high cost items; (3) complex echelon structures; (4) existence of pooling mechanisms among stocking locations at the same echelon level; (5) high priority for service, which is often expressed in terms of response time service levels for product groups of items: (6) scrapping of failed parts; and (7) recycling of issued stock due to diagnostic use. This article develops a comprehensive model of a stochastic, multi-echelon inventory system that takes account of the above characteristics. Solutions to the constrained optimization problem are found using a branch and bound procedure. The results of applying this procedure to a spare parts inventory system for a computer manufacturer have led to a number of important policy conclusions.
A comparison of two computer-administered versions of the NIMH diagnostic interview schedule

Abstract This study compared three versions of the NIMH Diagnostic Interview Schedule (DIS): “traditional” interviewer-administered DIS; computer-administered DIS (subject interacting alone with computer); computer-prompted DIS (interviewer using computer program as a guide). Kappas for 20 diagnoses ranged from .15 to .94, and averages for the three method pairs ranged from .57 to .64, which are comparable to other DIS reliability studies. Agreement between pairs of methods were comparable. Subjects' attitudes toward the computer interview were positive. While they felt they could better describe their feelings and ideas to a human, they found the computer contact less embarrassing. Overall, subjects had no preference for one method over another. Measures of social desirability and deviant response biases were correlated with diagnostic results. Reading ability did not affect subject's ability to respond to the DIS, although subjects with lower reading levels preferred the computer interview more.
Catalytic deoxygenation of fatty acids and their derivatives to hydrocarbon fuels via decarboxylation/decarbonylation

Fatty acids and their derivatives can be converted to renewable and carbon-neutral fuel-like hydrocarbons that are entirely fungible with fossil fuels. Typically, these hydrocarbon-based biofuels are obtained through hydrotreating, a method which has the significant disadvantages of requiring problematic sulfided catalysts and high pressures of hydrogen. In recent years, decarboxylation/decarbonylation has been proposed as an alternative method, as this approach has the advantages of permitting the use of simpler catalysts and requiring less hydrogen than hydrotreating. In this contribution, the deoxygenation of fatty acids and their derivatives to fuel-like hydrocarbons via decarboxylation/decarbonylation is critically reviewed. The main aspects discussed include the influence of the feed, catalyst, reactor system and reaction conditions on the decarboxylation/decarbonylation reaction, as well as the reaction mechanism and catalyst deactivation/regeneration. Copyright © 2012 Society of Chemical Industry
A new operative technique for restorative proctocolectomy: the endorectal pull-through combined with a double-stapled ileo-anal anastomosis.

Abstract Background In children, restorative proctocolectomy is usually accomplished by a rectal mucosectomy followed by a hand-sewn ileo-anal anastomosis±ileal pouch. In certain patients, a hand-sewn anastomosis can be technically difficult. This led us to develop a new technique that combines endorectal mucosectomy with a double-stapled ileo-anal anastomosis. Methods After colectomy, an ileal J-pouch is constructed. The head of the circular stapler is placed in the apex of the pouch and secured. An endorectal mucosectomy is completed from the abdomen to approximately 1.5 cm above the dentate line. The rectal mucosal/submucosal tube is everted onto the perineum. A transverse stapler is positioned 1.5 cm above the dentate line on the perineum and fired. The circular stapler is inserted transanally and the trocar advanced through the transverse staple line until the head and anvil are mated and then fired. A loop ileostomy is constructed. Results Thirteen patients, with a mean age of 12.3 years, have undergone endorectal mucosectomy with a double-stapled anastomosis without major complication. The operative time averaged 280±70 minutes. The mean 24-hour stool frequency, with 9 months' follow-up, was 6.8±3.2, of which 1±0.7 were at night. Conclusions The combination of endorectal mucosectomy with a double-stapled anastomosis is a new approach for patients requiring restorative proctocolectomy. In our early experience, this technique was completed with a low complication rate and excellent functional results.
A consideration of the differences between a Janeway's lesion and an Osler's node in infectious endocarditis.

Janeway's lesions and Osler's nodes are regarded as excellent clues to the diagnosis of infectious endocarditis; however, very few physicians have actually witnessed these findings, and there is some confusion in distinguishing between the two. This article concerns a patient with infectious endocarditis due to Diplococcus pneumoniae , who had tender vesicular lesions thought to be Osler's nodes and a nontender erythematous nodule on the foot compatible with a Janeway's lesion. The original comments by William Osler and Edward Janeway are presented, and the literature following their descriptions is reviewed. It is concluded that the only essential diagnostic difference between the two is the tenderness that is associated with an Osler's node but not with a Janeway's lesion.
Cellular senescence in a cloned strain of bovine fetal aortic endothelial cells

The life-span in vitro and other proliferative characteristics of a strain of endothelial cells cloned from the aorta of a fetal calf were examined. Cultures of these cells had a replicative life-span of approximately 80 cumulative population doublings. Growth rates in the logarithmic phase and plateau densities decreased as the cumulative population-doubling level increased. After approximately 65 percent of the life-span of a culture was completed, the percentage of cells that incorporated [3H]thymidine during a 24-hour labeling period began to decrease rapidly. The cells expressed factor VIII antigen and their intercellular borders were stainable with silver nitrate throughout the life-span of each culture. Average cellular attachment size increased more than threefold between cumulative population-doubling levels 41 and 80. The facility with which cloned strains of endothelial cells can be isolated should encourage further exploitation of this important cell culture model.
Rethinking the smart closet as an opportunity to enhance the social currency of clothing

Here we present findings of a needs validation study of 18-25 year old women and their wardrobes. Based on their feedback, we developed a prototype system that allows for borrowing and sharing of information about clothing via Facebook. The novelty of our interface lies in its combining RFID tags and social networking. In doing so we bridge the material and virtual realms and demonstrate the importance of material culture for ubiquitous computing.
10th Anniversary Critical Review: Naturally occurring asbestos

Asbestos is a naturally occurring mineral in the Earth's crust, and it is not confined to the historic and current asbestos mining areas, but rather quite commonly encountered in certain geological environments across the world. That diseases developed as a result of high exposures suffered by miners and asbestos products workers is incontrovertible. In addition, asbestos contamination as a result of past production and use is considered a serious issue where remediation is normally required. However, the risk to health of living on soil and rock where asbestos is encountered as a result of the natural occurrence of small quantities of asbestos minerals is less obvious. The picture becomes even less clear when the minerals are subject to intensive investigation, since our generally accepted definitions of asbestos are themselves put to the test. The discovery of asbestos or related minerals has consequences beyond any immediate risks to health, including profound effects on the value of and ability to use or enjoy property. This review examines the issue of naturally occurring asbestos (NOA) as it has developed in the United States of America and elsewhere, including some superficial insights into the reactions of communities to the presence of NOA. These responses to ‘contamination’ by nature deserve further in-depth study.
The need for axillary lymph node dissection in T1/T2 breast cancer surgery--reply to counterpoint.

See Counterpoint by Sabel, [p. 7156][1] Dr. M.S. Sabel states that the low accrual and low event rate of the ACOSOG Z011 study are reasons as to why the results may not be ready to be adopted. This is not consistent with his belief that completion of axillary lymph node dissection (ALND) may be
B7-1-HSA (CD80-CD24), a recombinant hybrid costimulatory molecule retains ligand binding and costimulatory functions.

Optimal activation of naive T lymphocyte requires two signals; an antigen-specific signal initiated by engagement of TCR with the antigen-MHC complex and a costimulatory signal independent of the antigen receptor complex. Without the costimulatory signal, T cells become anergic. Various adhesion molecules, such as B7-1 (CD80) and heat stable antigen (HSA, CD24), expressed on antigen presenting cells have been demonstrated to provide costimulatory signals to T cells. It was reported that the combinations of different adhesion molecules could induce even stronger immune response. In this study, we made a hybrid costimulatory molecule, B7-1-HSA, and tested its T cell stimulatory function. Chinese hamster ovary (CHO) cells expressing this hybrid molecule bound both anti-CD80 and anti-CD24 monoclonal antibodies, and induced stronger T cell proliferation than CHO cells expressing B7-1 or HSA alone. These results suggest that the B7-1-HSA hybrid molecule can deliver two costimulatory signals simultaneously that can synergize in inducing T cell proliferation. The purified B7-1-HSA protein reacted with both anti-B7-1 and anti-HSA mAbs in Western blotting and specifically mediated adhesion of Jurkat cells. Furthermore, purified B7-1-HSA molecule spontaneously incorporated onto cell membrane through its glycolipid anchor suggesting that this hybrid costimulatory molecule can be used in protein transfer to develop effective cancer vaccines.
Inhibition of methanogenesis by DDT.

Methanobacterium strain M.o.H. is a strict, anaerobic methane-forming bacterium which obtains its energy from the oxidation of hydrogen; the electrons generated are passed to CO2 which is reduced to CH4. Inhibition of CH4 biosynthesis by alkyl halides was first documented by Bauchop1 who reported that the addition of carbon tetrachloride, chloroform or methylene chloride to rumen fluid inhibited CH4 production and increased H2 production. Rufener and Wolin2 reported similar findings in an artificial rumen system. Van Nevel3 described the inhibitory effects of chloral hydrate on CH4 formation in sheep rumen fluid incubated in vitro and in vivo. These observations were extended by Wood4 who described the inhibitory effects of chloroform, dichloromethane, methylene chloride and propyl iodide on CH4 formation in cell extracts of Methanobacterium omelianskii. Photolysis was observed to reverse inhibition. The site of action of these compounds has not been identified, but the reversal of inhibition by light was taken as evidence that the site is a B12 complex involved in the final transmethylation reactions which lead to CH4 synthesis4. The similarity between chloroform and the active centre of 1,1,1,trichloro-2,2 bis p-chlorophenyl ethane (DDT) raised the possibility that this pesticide might also inhibit methane biosynthesis.
Mechanism for intein C-terminal cleavage: a proposal from quantum mechanical calculations.

Inteins are autocatalytic protein cleavage and splicing elements. A cysteine to alanine mutation at the N-terminal of inteins inhibits splicing and isolates the C-terminal cleavage reaction. Experiments indicate an enhanced C-terminal cleavage reaction rate upon decreasing the solution pH for the cleavage mutant, which cannot be explained by the existing mechanistic framework. We use intein crystal structure data and the information about conserved amino acids to perform semiempirical PM3 calculations followed by high-level density functional theory calculations in both gas phase and implicit solvent environments. Based on these calculations, we propose a detailed “low pH” mechanism for intein C-terminal cleavage. Water plays an important role in the proposed reaction mechanism, acting as an acid as well as a base. The protonation of the scissile peptide bond nitrogen by a hydronium ion is an important first step in the reaction. That step is followed by the attack of the C-terminal asparagine side chain on its carbonyl carbon, causing succinimide formation and simultaneous peptide bond cleavage. The computed reaction energy barrier in the gas phase is ∼33 kcal/mol and reduces to ∼25 kcal/mol in solution, close to the 21 kcal/mol experimentally observed at pH 6.0. This mechanism is consistent with the observed increase in C-terminal cleavage activity at low pH for the cleavage mutant of the Mycobacterium tuberculosis RecA mini-intein.
Optically addressed ferroelectric memory with nondestructive readout.

This paper describes a new two-capacitor memory cell configuration that provides an enhanced bipolar optoelectric response from the edges of the capacitor at incident power as low as ~ 2mW/micrometer squared.
Global Imbalances: Globalization, Demography, and Sustainability

if you sum up the current account deficits of all nations that are running deficits in the world economy, the U.S. deficit accounts for about 70 percent of the total. In any country's national accounts, it will hold true as an identity that the current account deficit?the excess of payments (M) to the rest of the world for goods, services, investment income, and unilateral transfers over receipts (X) from the rest of the world for similar items?exactly equals (apart from measurement errors, which may be substantial) the excess of aggregate expenditure (E) for goods and services over national output (Y), which in turn equals the excess of investment (I) over savings, both public (T - G) and private (S). In symbols:
On vibrational relaxation in liquid and solid AsD3

Abstract We have studied some vibrational-relaxation effects in liquid and solid AsD 3 . Experimentally, we measured the Raman ν 1 (symmetry species A 1 ) band at 160 K and 54 K. Our theoretical approach in analyzing the data makes use of the memory-functions technique to result in a clear physical description of the behaviour in the system. We regard the agreement between experiment and theory as more than satisfactory.
Metabolic requirements for melanophore-stimulating hormone (MSH) secretion.

Abstract Melanophore-stimulating hormone (MSH) secretion is regulated by an active transport (Na+−K+ pump) system. Release of MSH in vitro from the frog or rat pars intermedia is acutely sensitive to any physiological changes affecting the substrates for active transport. Addition of glucose to the incubation medium, for example, reversibly enhances MSH secretion over that of medium lacking the sugar. Dinitrophenol, cyanide, oligomycin, deoxyglucose, and iodoacetic acid reversibly inhibit MSH secretion, suggesting citric acid cycle and glycolytic pathway contributions to MSH secretion. Oligomycin is the most potent inhibitor of MSH release suggesting that high-energy intermediates may be final important factors in MSH release. The effects of these metabolic inhibitors are antagonized by the presence of glucose in the incubation medium. Cytochalasin B is inhibitory to MSH secretion and its effect is antagonized in medium containing glucose, suggesting that its mechanism of action also may relate to effects on active transport. Cold temperature is reversibly inhibitory to MSH release. The unique feature of the pars intermedia cell in vitro is its acute energy requirement needed to maintain continuous active transport function for the secretion of MSH.
Elliptical versus circular erythrocyte marginal bands: isolation, shape conversion, and mechanical properties.

Differentiation of nucleated erythrocytes involves transformation from spheroids to flattened discoids to mature flattened ellipsoids. The marginal band (MB) of microtubules is required for this process and continues to play a role in maintaining mature ellipsoidal cell shape. One hypothesis for MB function is that cell ellipticity is generated and maintained by asymmetric application of force across a flexible, circular MB frame by the membrane skeleton or other transverse elements. This is based on an earlier finding that isolated erythrocyte MBs are much more circular than MBs in situ. However, our present studies of salamander erythrocyte MBs isolated by a detergent-based method challenge this hypothesis. Most of these isolated MBs are initially elliptical, even though they lack transverse material (= E-MBs). They can be stabilized in that form for long periods and can be converted experimentally into the circular form (= C-MBs) by extended incubation in isolation medium or by treatment with elastase or subtilisin. We have tested an alternative hypothesis for generation and maintenance of ellipsoidal MBs, one based on intrinsic differential bending resistance and supported by construction of models. Using laser microsurgical transection to compare mechanical responses of isolated E-MBs and C-MBs, we have found their behavior to be quite different. Whereas C-MBs linearize, most E-MBs do not, instead retaining considerable curvature. These results are incompatible with the differential bending resistance hypothesis, which predicts both C-MB and E-MB linearization. However, they are consistent with a third model, in which material bound to the MB stabilizes it in the mature ellipsoidal form, and indicate that the mechanism for maintenance of MB ellipticity differs from that involved in its generation. Cell Motil. Cytoskeleton 40:238–248, 1998. © 1998 Wiley-Liss, Inc.
Mouse Huntington's disease gene homolog ( Hdh )

The incurable neurodegenerative disorder, Huntington's disease (HD), is caused by an expanded, unstable CAG repeat encoding a stretch of polyglutamine in a 4p16.3 gene (HD) of unknown function. Near the CAG repeat is a polyproline-encoding CCG repeat that shows more limited allelic variation. The mouse homologue,Hdh, has been mapped to chromosome 5, in a region devoid of mutations causing any comparable phenotype. We have isolated overlapping cDNAs from theHdh gene and compared their sequences with the human transcript. The consensus mouse coding sequence is 86% identical to the human at the DNA level and 91% identical at the protein level. Despite the overall high level of conservation,Hdh possesses an imperfect CAG repeat encoding only seven consecutive glutamines, compared to the 13–36 residues that are normal in man. Although no evidence for polymorphic variation of the CAG repeat was seen, a nearby CCG repeat differed in length by one unit between several strains of laboratory mouse andMus spretus. The absence of a long CAG repeat in the mouse is consistent with the lack of a spontaneous mouse model of HD. The information presented concerning the sequence of the mouse gene should facilitate attempts to create such a model.
Stellar Photometry In Crowded Fields

Software available at KPNO for performing stellar photometry on digital images is summarized. Aperture sum and two dimensional fitting techniques are described and compared in terms of accuracy, versatility, and computational efficiency. Algorithms are presented for deriving the point spread function (PSF) from intensity data, and fitting it via chisquare minimization techniques to either single or multiple stellar images. The results of tests performed on artificial starfields are summarized and evaluated. Two dimensional psf fitting techniques are seen to be a versatile and accurate tool even in fairly crowded fields, though computationally quite expensive compared to aperture sum techniques.
PFIT and PFRIT: bioinformatic algorithms for detecting glycosidase function from structure and sequence

The identification of the enzymes involved in the metabolism of simple and complex carbohydrates presents one bioinformatic challenge in the post-genomic era. Here, we present the PFIT and PFRIT algorithms for identifying those proteins adopting the α/β barrel fold that function as glycosidases. These algorithms are based on the observation that proteins adopting the α/β barrel fold share positions in their tertiary structures having equivalent sets of atomic interactions. These are conserved tertiary interaction positions, which have been implicated in both structure and function. Glycosidases adopting the α/β barrel fold share more conserved tertiary interactions than α/β barrel proteins having other functions. The enrichment pattern of conserved tertiary interactions in the glycosidases is the information that PFIT and PFRIT use to predict whether any given α/β barrel will function as a glycosidase or not. Using as a test set a database of 19 glycosidase and 45 nonglycosidase α/β barrel proteins with low sequence similarity, PFIT and PFRIT can correctly predict glycosidase function for 84% of the proteins known to function as glycosidases. PFIT and PFRIT incorrectly predict glycosidase function for 25% of the nonglycosidases. The program PSI-BLAST can also correctly identify 84% of the 19 glycosidases, however, it incorrectly predicts glycosidase function for 50% of the nonglycosidases (twofold greater than PFIT and PFRIT). Overall, we demonstrate that the structure-based PFIT and PFRIT algorithms are both more selective and sensitive for predicting glycosidase function than the sequence-based PSI-BLAST algorithm.
Isolation and amino acid sequence of bovine platelet factor 4.

Abstract Bovine platelet factor 4 was isolated by affinity chromatography using dextran sulfate Sepharose and purified by subsequent gel filtration. The complete amino acid sequence of this 88-residue, 9505-Da protein was determined by isolation and analysis of the overlapping peptides from tryptic and Staphylococcus aureus hydrolysates of reduced, carboxymethylated, and reductive methylated protein. Primary structure comparison was made between bovine platelet factor 4, human platelet factor 4, and human β-thromboglobulin. The bovine platelet factor 4 amino-terminal region, which contains two unique phenylalanine residues, is extended by 15 residues relative to human platelet factor 4. The bovine carboxy-terminal region is extended by three residues relative to human platelet factor 4 and differed from β-thromboglobulin in the absence of two additional terminal residues. Bovine platelet factor 4 shares sequence similarities proportionately with both human platelet factor 4 and β-thromboglobulin. The sequences of the lysine-rich carboxy-terminal putative heparin binding domains are essentially identical for all three proteins. The heparin neutralizing potencies of bovine and human platelet factor 4 are similar: 40 USP units of heparin neutralized per milligram protein, as measured by a modified chromogenic substrate assay. Heparin neutralization was lost by reduction of the disulfide bonds, but only attenuated by tryptic digestion of the intact protein.
An oculocerebral syndrome with aminoaciduria and keratosis follicularis.

A 4-year-old Negro boy was studied in whom there were keratotic follicular skin lesions, corneal clouding, sparseness of the eye lashes, and absence of the lateral portions of the eyebrows. These are the features of keratosis follicularis spinulosa decalvans. In addition, he had congenital glaucoma, a lenticular cataract, mental retardation, arachnodactyly, and aminoaciduria. This association has not previously been reported.
Patterns of growth and sexual size dimorphism in two species of box turtles with environmental sex determination.

An adaptive explanation for environmental sex determination is that it promotes sexual size dimorphism when larger size benefits one sex more than the other. That is, if growth rates are determined by environment during development, then it is beneficial to match developmental environment to the sex that benefits more from larger size. However, larger size may also be a consequence of larger size at hatching or growing for a longer time, i.e., delayed age at first reproduction. Therefore, the adaptive significance of sexual size dimorphism and environmental sex determination can only be interpreted within the context of both growth and maturation. In addition, in those animals that continue to grow after maturation, sexual size dimorphism at age of first reproduction could differ from sexual size dimorphism at later ages as growth competes for energy with reproduction and maintenance. I compared growth using annuli on carapace scales in two species of box turtles (Terrapene carolina and T. ornata) that have similar patterns of environmental sex determination but, reportedly, have different patterns of sexual size dimorphism. In the populations I studied, sexual size dimorphism was in the same direction in both species; adult females were, on average, larger than adult males. This was due in part to males maturing earlier and therefore at smaller sizes than females. In spite of similar patterns of environmental sex determination, patterns of growth differed between the species. In T. carolina, males grew faster than females as juveniles but females had the larger asymptotic size. In T. ornata, males and females grew at similar rates and had similar asymptotic sizes. Sexual size dimorphism was greatest at maturation because, although males matured younger and smaller, they grew more as adults. There was, therefore, no consistent pattern of faster growth for females that may be ascribed to developmental temperature.
A New Ichnospecies of Arthrophycus from the Late Carboniferous (Pennsylvanian) of Michigan, USA

A unique ichnofossil assemblage from Pennsylvanian-age sandstones near Eaton Rapids, Michigan, USA, comprises straight-to-curved traces preserved in convex hyporelief, with the transverse ridges and median grove associated with the ichnogenus Arthrophycus. The Michigan traces show some branching or pseudo-branching (also known from other Arthrophycus specimens) and are among the smallest structures (millimeters in diameter) attributed to this ichnogenus. The orientation of the Michigan Arthrophycus burrows is distinct from other ichnospecies of this taxon in the pronounced co-planar alignment of the burrows, as opposed to the multiplanar, interweaving, “bundled” nature typical of the ichnogenus. On this basis we assign the Michigan specimens to a new ichnospecies of Arthrophycus. The “paralleling behavior” of the new taxon may reflect a strategy of the tracemaker to avoid previous burrows and reflect differences in resource availability or current energy. This new taxon supports previous records of the oc...
Maternal and Newborn Care During Disasters: Thinking Outside the Hospital Paradigm

Emergencies that challenge the infrastructure of the current health care system require a shift in the standard of usual practice. Pregnant women and their newborns are intimately linked special populations that require continued care despite the community circumstances. Pre-event planning with community partners can generate a safer alternative for providing care during a public health emergency. Lessons learned from international and United States public health emergencies have resulted in a better understanding of the essentials of care and the development of resources to guide planning for these populations.
Factor C-LHIH which inhibits the luteinizing hormone from basal release and from synthetic LHRH and studies on purification of FSHRH.

Summary A new entity, factor C-LHIH, inhibits the basal release of the luteinizing hormone, and inhibits the release of LH and FSH from synthetic LHRH. Factor C-LHIH has been assayed in fractions which were and were not derived from biosynthesis. Factor C-LHIH and FSHRH (not LHRH or GnRH) initially fractionated together. The latter obscured the former, and FSH assays guided fractionation. After partition chromatography on Sephadex G-25 in two systems, factor C-LHIH and FSHRH were separated by Sephadex LH-20, purified by DEAE Sephadex and high pressure liquid chromatography to give fractions of factor C-LHIH which inhibited LH-release at 100–500 nanograms, and did not inhibit the TRH-TSH response.