cssi/SciSciGPT-SciSciNet huggingface dataset:
Dynamics of host plant selection and host-switching by silver-spotted skipper caterpillars

Investigations of host plant selection in herbivorous arthropods have emphasized the importance of oviposition site selection by adults; however, a more complete picture of this process requires additional consideration of the factors influencing host plant choice during the immature feeding stages. We conducted a series of larval choice experiments to examine both the innate and induced preferences of larvae of the Silver-spotted skipper (Epargyreus clarus L.) on three commonly used hosts (Wisteria, Robinia, and Pueraria). Late instar E. clarus larvae reared on each of the three host plants displayed an overall pattern of innate preferences that correlated well with larval performance measures and reflected differences in foliar nutrient concentrations. Larval preferences were also influenced by rearing host species, indicating a role for feeding-induced preferences. When larvae reared on low-quality Wisteria for the first four instars were switched to higher quality Pueraria for the final instar, they developed more quickly and attained significantly higher pupal mass than larvae maintained on Wisteria throughout development. Similarly, larvae switched from Pueraria to Wisteria for the final instar suffered increased development time and produced significantly smaller pupae than those maintained on Pueraria throughout. Thus host-switching, particularly during the more mobile final instars, appears to offer larvae an opportunity to recoup fitness losses associated with early development on a low-quality host. For an equal amount of consumption, larvae feeding on Pueraria gained 50% more mass than those feeding on Wisteria, reflecting measured differences in foliar nitrogen concentration; despite these overall differences in quality, larval growth efficiency was similar among hosts. Especially in the age of common exotic plant introductions, a full understanding of the behavioral component of host selection by herbivorous insects requires appreciation of the dynamic role that immatures can play in host selection and use.
Adaptive MIMO OFDM receivers: Implementation impairments and complexity issues*

Abstract MIMO OFDM communications is a promising choice for future high data rate wireless systems. However, the commercial deployment of MIMO OFDM systems faces some challenges, including those arising from front-end analog implementation impairments and complex receiver structures. The impairments are caused by the analog processing of the received radio frequency (RF) signal and they cannot be e±ciently nor entirely eliminated in the analog domain. This paper illustrates the e®ect of In-phase and Quadrature-phase (IQ) imbalances on system performance. Receiver algorithms are described that compensate for IQ imbalances. The structure of space-time block codes, along with the assumed structure of the distortion models, are exploited to design reduced-complexity adaptive receivers that are robust to IQ imbalances.
Cytotoxicological pathways induced after nanoparticle exposure: studies of oxidative stress at the 'nano-bio' interface.

Nanotechnology is advancing rapidly; many industries are utilizing nanomaterials because of their remarkable properties. As of 2017, over 1800 “nano-enabled products” (i.e. products that incorporate a nanomaterial feature and alter the product's performance) have been used to revolutionize pharmaceutical, transportation, and agriculture industries, just to name a few. As the number of nano-enabled products continues to increase, the risk of nanoparticle exposure to humans and the surrounding environment also increases. These exposures are usually classified as either intentional or unintentional. The increased rate of potential nanoparticle exposure to humans has required the field of ‘nanotoxicology’ to rapidly screen for key biological, biochemical, chemical, or physical signals, signatures, or markers associated with specific toxicological pathways of injury within in vivo, in vitro, and ex vivo models. One of the common goals of nanotoxicology research is to identify critical perturbed biological pathways that can lead to an adverse outcome. This review focuses on the most common toxicological pathways induced by nanoparticle exposure and provides insights into how these perturbations could aid in the development of nanomaterial specific adverse outcomes, inform nano-enabled product development, ensure safe manufacturing practices, promote intentional product use, and avoid environmental health hazards.
Conceptos fundamentales para un estudio prospectivo sobre tecnología y educación en las escuelas chilenas

El presente articulo indaga en conceptos generales del enfoque prospectivo como punto de partida para analizar la evidencia existente acerca de las tendencias actuales de las TIC en el sistema escolar chileno, para anticipar mas adelante futuros escenarios acerca de la evolucion y rutas probables para los proximos anos tomando en cuenta la actual incorporacion, uso y aplicacion de las mencionadas tecnologias. Se aborda en una primera mirada el futuro de la sociedad y la tecnologia como detonante de cambios que ocurren a gran velocidad y que bosquejan nuevas relaciones sociales y economicas. Se hace referencia y se analiza las areas de investigacion tecnologica mas adelantadas asi como sus tendencias y principales paradojas en un enfoque que sugiere anticiparnos al devenir. La introduccion de las TIC en educacion en los paises desarrollados comenzo hace mas de tres decadas y ellos han tenido especial preocupacion por la investigacion de los efectos futuros a fin de ajustar, adaptar y anticipar el futuro de la sociedad. En Chile no hemos evaluado su impacto sistemico, en otras palabras cuales son los aspectos positivos y negativos asociados a las TIC en la ensenanza, aprendizaje o en los procesos de gestion de las escuelas por lo que hay amplias brechas de incertidumbre acerca de los escenarios futuros probables. Por esta razon tambien se pretende alentar a mas investigadores a pensar nuevos estudios desde el enfoque prospectivo los cuales tambien consideren esos futuros probables a fin de alcanzar el mas deseable y beneficioso
Activation of anti-oxidant Nrf2 signaling by enone analogues of curcumin.

Abstract Inflammation and oxidative stress are common in many chronic diseases. Targeting signaling pathways that contribute to these conditions may have therapeutic potential. The transcription factor Nrf2 is a major regulator of phase II detoxification and anti-oxidant genes as well as anti-inflammatory and neuroprotective genes. Nrf2 is widespread in the CNS and is recognized as an important regulator of brain inflammation. The natural product curcumin exhibits numerous biological activities including ability to induce the expression of Nrf2-dependent phase II and anti-oxidant enzymes. Curcumin has been examined in a number of clinical studies with limited success, mainly owing to limited bioavailability and rapid metabolism. Enone analogues of curcumin were examined with an Nrf2 reporter assay to identify Nrf2 activators. Analogues were separated into groups with a 7-carbon dienone spacer, as found in curcumin; a 5-carbon enone spacer with and without a ring; and a 3-carbon enone spacer. Activators of Nrf2 were found in all three groups, many of which were more active than curcumin. Dose-response studies demonstrated that a range of substituents on the aromatic rings of these enones influenced not only the sensitivity to activation, reflected in EC50 values, but also the extent of activation, which suggests that multiple mechanisms are involved in the activation of Nrf2 by these analogues.
Efficient In-Memory, List-Based Text Inversion

When building a large inverted file index on a system with effectively unlimited memory, performance may be constrained by RAM latency. To optimise speed requires an understanding of the non-uniform memory access characteristics of modern systems. We address three main techniques for improving the performance of an in-memory, list-based inverted file indexer: List chunking, in-chunk postings compression, and use of virtual memory "Large Pages". We compare performance of dynamic chunking schemes capable of adapting to the Zipf-like distribution of term frequencies. Using a data set with 8.5 billion word occurrences, we find that the techniques are cumulative. Chunking almost halves the memory required for linked lists, while dramatically reducing the number of cache-line reads required to traverse the lists; In-chunk compression further halves the memory footprint, though it does not make much difference to speed; Large pages reduce the inefficiency of page table walks and speed up both phases of index building.
Lithium-Induced Nephropathy

Lithium-Induced Nephropathy A 59-year-old man with a history of bipolar disorder was admitted to the hospital after a fall and was incidentally found to have numerous small renal cysts, a finding consistent with previous lithium treatment.
Improvement of an Exponential Cohesive Zone Model for Fatigue Analysis

Cohesive zone model is an important tool for fatigue analysis, especially for fatigue crack growth along with an interface. A pioneering model is the one of Roe and Siegmund (Eng Fract Mech 70:209–232, 2003), in which the damage accumulation is calculated using an irreversible exponential cohesive law. However, it is found in our recent research that the constant unloading and reloading slope in Roe’s damage evolution law could cause a discontinuity in the traction–separation curve when the mixed mode ratio changes. This limits its application to single mode cyclic loading or scenarios where the mixed mode ratio is constant. In this paper, the cause of such discontinuity is analyzed, and a robust cyclic loading formulation is proposed, which will help the exponential cohesive law remain continuous under arbitrary mixed mode cyclic loading. Moreover, it is found in this paper that by adding a scale factor to the Roe’s damage law, the fatigue failure time can be approximated with less computational cost. The relationship between fatigue failure time and the scale factor is shown to be inversely proportional.
Congenital and Acquired Disorders of the Vocal Folds

Congenital and acquired pediatric vocal fold disorders are remarkably different than in adults. The histopathologic structure and continuing maturation of a child’s larynx limit our current understanding of the principles and techniques of management of pediatric dysphonia. Commonly, interventions in neonates with disorders affecting the vocal folds are often deferred until later in life, unless presenting with critical airway obstruction.
What Is the Outcome and Fate of Frozen Supernumerary Embryos Resulting from Egg Donation

Cryopreservation of supernumerary embryos affords patients the potential opportunity to achieve multiple pregnancies from a single fresh IVF cycle or to at least have a second chance at success if the first attempt failed. In addition, the availability of frozen embryos reduces overall patient cost and increases the cumulative odds of pregnancy per case. Embryo cryopreservation is of particular importance in oocyte donation cycles because the number of embryos available frequently exceeds that which is acceptable (or desirable) for embryo transfer. Furthermore, limited resources specific to oocyte donation, including donor availability and cost, augment the appeal of cryopreservation. Despite the desire to cryopreserve supernumerary embryos at the time of the fresh donor oocyte transfer, more often than not, patients do not return to use their surplus embryos. Analysts estimate that as of 2003, over 400,000 embryos from all sources remained in storage facilities in the United States. As the number of IVF procedures has only grown over the past decade, we speculate that this number has nearly doubled.
Modeling of Non-ideal Variable Pitch Valve Springs for Use in Automotive Cam Optimization

Optimal control theory has been studied for use in developing valve trains in engines to minimize vibration and wear. Previous works have concentrated on the optimization of the cam lobe profile using an ideal linear spring model for the valve spring. The ideal linear spring model cannot capture the variations in spring stiffness that occur at high speeds due to the internal spring dynamics. By using a multiple-mass lumped-parameter spring, greater accuracy may be obtained in simulation. In addition, such a model allows for the introduction of spring pitch to be included as an additional optimization parameter. In this paper, a simple multi-mass variable pitch spring model is developed to be used in valve pitch optimization as well as cam profile optimization.
Strategies to Improve Direct EM Patlak Reconstructions

Direct Expectation-Maximization (EM) reconstruction of parametric images from PET data has been proposed, to take advantage of the known Poisson character of raw PET data. However, direct reconstruction algorithms are then dependent on the properties of the kinetic model and of the radiotracer used. Moreover, the first direct EM reconstruction algorithm proposed, the Parametric Iterative Reconstruction (PIR) algorithm, based on the Patlak plot, converges slowly when applied to [$^{18\mathrm{F}}$]FDG data. Thus, alternative algorithms have been proposed to accelerate convergence. In this study, we propose additional strategies to improve the PIR algorithm. One strategy is to use a line search procedure to increase the size of steps taken at each iteration (PIR-LS). Another group of strategies is to apply physiological constraints (PIR-PC) on the intercept parameter of the Patlak plot, since this parameter has a small dynamic range and is more stable across subjects and across physiological and disease states. The third strategy is to apply a linear transform to the independent variables of the Patlak model (PIR-LTIV) to obtain new independent variables more favorable for convergence. PIR-LS, PIR-PC and PIR-LTIV were first compared to PIR and the Nested EM algorithm on simulated 2D data. Results showed that all new methods could increase the convergence speed of PIR, with PIR-LTIV having the fastest convergence among the new methods, and similar to that of the Nested EM algorithm. Then, PIR and PIR-LS were compared using a simulated dynamic brain dataset, PIR andPIR-PC were compared on a real lung tumor data set, and PIR-LTIV was tested on simulated brain data, real brain data, and the real lung tumor dataset. These data confirmed that all new methodscould increase PIR convergence, with PIR-LTIV being the most promising since convergence speed was visually similar to that of indirect reconstructions, with lower image noise.
Designing Photolabile Ruthenium Polypyridyl Crosslinkers for Hydrogel Formation and Multiplexed, Visible-light Degradation

Photoresponsive materials afford spatiotemporal control over desirable physical, chemical and biological properties. For advanced applications, there is need for molecular phototriggers that are readily incorporated within larger structures, and spatially-sequentially addressable with different wavelengths of visble light, enabling multiplexing. Here we describe spectrally tunable (λmax = 420-530 nm) ruthenium polypyridyl complexes functionalized with two photolabile nitrile ligands that present terminal alkynes for subsequent crosslinking reactions, including hydrogel formation. Two Ru crosslinkers were incorporated within a PEG-hydrogel matrix, and sequentially degraded by irradiation with 592 nm and 410 nm light.
Dead space fractions in neonates following first-stage palliation for hypoplastic left heart syndrome.

Purpose (1) To characterise changes in dead space fraction during the first 120 post-operative hours in neonates undergoing stage 1 palliation for hypoplastic left heart syndrome, including hybrid procedure; (2) to document whether dead space fraction varied by shunt type (Blalock-Taussig shunt and Sano) and hybrid procedure; and (3) to determine the association between dead space fraction and outcomes. Methods Retrospective chart review in neonates undergoing stage 1 palliation for hypoplastic left heart syndrome in a cardiac intensive care unit over a consecutive 30-month period. A linear mixed model was used to determine the differences in dead space over time. Multivariable linear regression and a multivariable linear mixed model were used to assess the association between dead space and outcomes at different time points and over time, respectively. Results Thirty-four neonates received either a Blalock-Taussig shunt (20.5%), Sano shunt (59%), or hybrid procedure (20.5%). Hospital mortality was 8.8%. Dead space fractions in patients undergoing the hybrid procedure were significantly lower on day 1 (p = 0.01) and day 2 (p = 0.02) and increased over time. A dead space fraction g0.6 on post-operative days 3-5 was significantly associated with decreased duration of mechanical ventilation in all surgical groups (p 0.6 on post-operative days 3-5 was associated with lower duration of mechanical ventilation in all surgical groups. A more comprehensive, prospective assessment of dead space in this delicate patient population would likely be beneficial in improving outcomes.
You can do it! An experimental evaluation of an encouragement intervention for female students

Although encouragement is a prevalent means of social support in everyday life, the empirical study of encouragement interventions has been sparse. Therefore, in this study, the authors evaluated a...
Transfusion of Storage-Damaged Red Blood Cells Induces Ferroptosis in Splenic Macrophages

Abstract Red blood cell (RBC) transfusions are a common therapeutic, used in a wide range of settings (e.g., trauma). Therefore, potential outcomes, positive or negative, have special clinical relevance. Preparation of RBC units for transfusion involves refrigerated storage for an extended period of time, during which RBCs undergo multiple metabolic and physical changes, collectively known as the “storage lesion.” As a result, a proportion of the stored RBCs are rapidly cleared from the circulation post-transfusion by macrophages in the liver and spleen. However, the subsequent effects on macrophages of an acute, robust erythrophagocytosis event are still unclear, especially given the substantial amount of iron that is introduced into the cell in a short amount of time. Therefore, we sought to study the effects of substantial erythrophagocytosis on splenic macrophages, which normally play a key role in RBC-derived iron recycling. One possible outcome is macrophage cell death due to ferroptosis, an iron-dependent form of non-apoptotic cell death originally identified in cancer cells, but not yet demonstrated in macrophages. Using a mouse model of storage-damaged RBC transfusion and clearance, wild-type C57BL/6 mice were transfused with fresh (i.e., Further studies into the mechanism of RPM cell death uncovered ferroptosis-specific characteristics. Thus, by 2 hours after transfusion of old RBCs, increased levels of DCF fluorescence, indicative of reactive oxygen species (16.1% to 24.1%; p In conclusion, substantial erythrophagocytosis after transfusion of storage-damaged RBCs induces ferroptosis in splenic RPMs. To date, ferroptosis has been described in cancer cells, kidney tubule cells, fibroblasts, neurons, and T cells. However, to our knowledge, this is the first report in macrophages, which play important roles in RBC clearance and iron recycling. This finding sheds light on potential adverse effects on macrophage populations from transfusions of “old” RBCs and also highlights a potential clinical use for ferroptosis inhibitors for preventing substantial losses in an important phagocyte population. Download : Download high-res image (225KB) Download : Download full-size image Figure . Disclosures Spitalnik: New Health Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees.
Towards a Scalable, Self-Reconfigurable Robot with Compliant Modules

We present a planar, self-reconfigurable modular robot with onboard processing, sensing, communication, and passive components for actuation. Modules consist primarily of a flexible printed circuit board rolled in a loop that is populated with all electronic components and 12 simplified electro-permanent magnets for mobility and communication. The flexible PCB eases assembly and introduces compliance for safe interaction with external objects and other modules, as well as configuration of large scale lattice configurations beyond what the manufacturing tolerances allow. This thrust towards scalable robots composed of passively compliant modules is an important step in addressing the grand challenges of mechanical wear and error tolerance in large-scale collectives.
RESCUE transesophageal echocardiography for monitoring of mechanical chest compressions and guidance for extracorporeal cardiopulmonary resuscitation cannulation in refractory cardiac arrest

There is a growing interest in using point-of-care transesophageal echocardiography (TEE) during cardiac arrest. TEE is effective at identifying the etiology of sudden cardiovascular collapse and guiding management during the resuscitation. In selected patients with refractory cardiac arrest, extracorporeal cardiopulmonary resuscitation (ECPR) can be considered. ECPR requires percutaneous vascular access for the implantation of veno-arterial extracorporeal membrane oxygenation circuit. We present a case of prolonged cardiac arrest in which rescue TEE was pivotal in narrowing the differential diagnosis, monitoring of mechanical chest compression performance, and guiding cannulation for ECPR.
R-loops promote trinucleotide repeat deletion through DNA base excision repair enzymatic activities

Trinucleotide repeat (TNR) expansion and deletion are responsible for over 40 neurodegenerative diseases and associated with cancer. TNRs can undergo somatic instability that is mediated by DNA damage and repair and gene transcription. Recent studies have pointed toward a role for R-loops in causing TNR expansion and deletion, and it has been shown that base excision repair (BER) can result in CAG repeat deletion from R-loops in yeast. However, it remains unknown how BER in R-loops can mediate TNR instability. In this study, using biochemical approaches, we examined BER enzymatic activities and their influence on TNR R-loops. We found that AP endonuclease 1 incised an abasic site on the nontemplate strand of a TNR R-loop, creating a double-flap intermediate containing an RNA:DNA hybrid that subsequently inhibited polymerase β (pol β) synthesis of TNRs. This stimulated flap endonuclease 1 (FEN1) cleavage of TNRs engaged in an R-loop. Moreover, we showed that FEN1 also efficiently cleaved the RNA strand, facilitating pol β loop/hairpin bypass synthesis and the resolution of TNR R-loops through BER. Consequently, this resulted in fewer TNRs synthesized by pol β than those removed by FEN1, thereby leading to repeat deletion. Our results indicate that TNR R-loops preferentially lead to repeat deletion during BER by disrupting the balance between the addition and removal of TNRs. Our discoveries open a new avenue for the treatment and prevention of repeat expansion diseases and cancer.
Characteristics of secondhand cannabis smoke from common smoking methods: Calibration factor, emission rate, and particle removal rate

Abstract The widespread legalization of recreational cannabis use raises growing concerns about exposure to secondhand cannabis smoke (SCS). However, few studies are characterizing fine particulate matter (PM2.5) exposure from SCS. Here, we determined PM2.5 calibration factors (CFs) for SCS from four common cannabis consuming methods—glass pipe smoking, joint smoking, bong smoking, and cannabis pen vaping—for widely used optical monitors (SidePak™ AM510, TSI Inc., Shoreview, MN) by comparing the monitors with gravimetric mass measurements. We furthermore investigated the emission rate, particle size distribution, and particle removal rate of SCS. The CFs of SidePak PM2.5 monitors measuring the four types of SCS were 0.31 (SE = 0.02), 0.39 (SE = 0.02), 0.40 (SE = 0.01), and 0.44 (SE = 0.03), respectively. The arithmetic mean emission rates of the four SCS sources were ~2–6 times that of secondhand tobacco smoke (STS) on a per-puff basis. The fresh SCS (1-min after smoking) showed a bimodal size distribution—one mode located at ~380–420 nm and another at ~800–840 nm. Under low-ventilation conditions, the indoor removal rates of SCS from cannabis vaping were slightly higher (i.e., 0.61–0.77/h) than those for the other three sources (i.e., 0.35–0.53/h).
ACTIVITY OF TiO_2 IN MOLTEN BLAST FURNACE SLAG CONTAINING TITANIUM OXIDE

Activity of TiO_2 in the molten blast furnaee slag containing titanium oxide has been examined at 1500℃ by means of "molten slag-Sn" chemical equilibrium method, using metallic Sn as flux and graphite as deoxidizer, together with phase diagram calculation. In the pentary slag sys-tem CaO--MgO--SiO_2--TiO_2--Al_2O_3, a_(TiO_2)=0.01--0.05 or 0.02--0.10 with pure liquid or solid TiO_2 as normal state, respectively. The activity and activity coefficient of TiO_2 in relation to concen-tration of titanium oxide have been discussed.
Early immersion in a dedicated one-month Anesthesiology Professional Practice rotation for Post-Graduate Year-1 interns is associated with an increase in scholarly activity during residency.

Abstract Study objective Despite the Accreditation Council for Graduate Medical Education scholarly activity requirement, incorporating education on scholarly fundamentals into residency is challenging. We designed and implemented an academic non-clinical rotation for Post Graduate Year-1 (PGY-1) interns and its association with subsequent resident scholarly productivity was determined. We hypothesized that early immersion in such a rotation would be associated with increased scholarly activity during residency. Design Retrospective educational comparative study, of two cohorts of anesthesiology residents in the graduating classes of 2015–2020. Setting Large anesthesiology residency program at a U.S. academic medical center. Intervention A one-month academic rotation titled Anesthesia Professional Practice for PGY-1 interns has been implemented since 2014. The rotation curriculum broadly covers important topics for scholarly projects and provides introductions to academic faculty and institutional resources. Measurements The scholarly products (abstracts, publications, book chapters, research protocols, and grant applications) were quantified using Scholarly Activity Points, a previously described metric that accounts for significance and the resident's contribution. Total Scholarly Activity Points for each resident and number of publications prior to residency were determined for both cohorts. Segmented regression was employed with Scholarly Activity Points as the outcome; participation in the early immersion rotation and prior publications were used as input variables. Main results Resident participation in the early immersion rotation was significantly associated with higher Scholarly Activity Points. The confounding variable of pre-residency publication count was not significantly correlated to this increase. Conclusions Immersion in a one-month academic program during PGY-1 internship may contribute to increased scholarly productivity during residency.
Snap-Buckling of Shallow Prestressed Arches

An analysis is presented of the effect of an initial horizontal thrust on the buckling and post-buckling behavior of a shallow, circular, elastic arch with fixed ends. Loading by a uniform pressure and by a concentrated central force are considered. Dimensionless load-deflection curves are obtained for various values of a geometric parameter and a dimensionless prestress parameter. In comparing arches with the same initial shape, but different initial thrusts, the load corresponding to any value of the central deflection is observed to decrease with increasing precompression and increase with increasing pretension. The susceptibility of a given arch shape to snap-buckling is increased by increasing precompression and decreased by increasing pretension. Also, buckling in an asymmetric mode occurs for shallower and shallower arches with increasing compressive prestress; buckling in a symmetric mode occurs for deeper and deeper arches with increasing tensile prestress. The reduction (increase) in the load minimum with increasing compressive (tensile) prestress is more pronounced than is the reduction (increase) in the load maximum.
Synthesis of galactosylceramide and glucosylceramide by mouse kidney preparations.

A particulate fraction was prepared from kidneys, lyophilized, and coated with ceramide. After incubation with UDP-[14C]Gal and appropriate cofactors, the major radioactive component in the lipid fraction was galactosylceramide (Gal-Cer). If UDP-Glc was substituted for UDP-Gal, the product was glucosylceramide (Glc-Cer). Specific activity for Gal-Cer synthesis was present at comparable levels in kidney preparations from males or females at early ages. However, between 20 and 30 days of age there was a 5-fold increase in activity in preparations from male kidney, followed by a slight decline. In contrast, Gal-Cer synthesis in kidney preparations from female mice decreased slowly from 10 to 70 days of age. Despite the low levels of Gal-Cer in kidney, enzymatic activity for its synthesis was high, 0.8 nmole per mg of protein per hour in 30-day-old males. This was 40% of the specific activity for Gal-Cer synthesis in brains of the same animals. Glc-Cer synthesis by kidney followed a developmental pattern markedly different from that for Gal-Cer formation. There was an increase in activity throughout the time period studied (10 to 64 days of age), but activity was most rapid between 30 and 40 days of age. Activity in preparations of female kidney followed a similar pattern but was lower than that of preparations from males at 10 days of age and increased less rapidly. In kidneys of mature male animals, the specific activity for Glc-Cer synthesis was twice that of the females.
Mycobacteriophages and Tuberculosis

This chapter focuses on a discussion of recent developments in mycobacteriophage research with an emphasis on how these have advanced one’s understanding of tuberculosis. Mycobacteriophages have been isolated from rather exotic locations, such as the zebra pits at the Bronx zoo and the grounds of the tuberculosis hospital in Chennai, but they can be isolated from most soil and compost samples. The overall diversity of the mycobacteriophage population can also be examined by assessing the proportion of gene products that are unique and do not match any other mycobacteriophage genes. It is sometimes stated that the average genome size for double-stranded DNA (dsDNA) tailed phages is about 50 kbp, perhaps based largely on the well characterized and much utilized phage lambda. One of the most evident features of the mycobacteriophage genomes is their pervasive mosaicism, a common feature of phage genomes. This mosaicism is found in other phage genomes but is particularly pervasive in the mycobacteriophages; it is notable in that the mosaic elements are frequently single genes rather than large sets of genes. Examination of mycobacteriophage tape measure protein (Tmp) reveals the presence of small sequence motifs that are related to Mycobacterium tuberculosis proteins. Investigators may be discouraged from using phage-based delivery tools for mycobacterial genetics due to the perceived complexity of constructing the necessary recombinant phages.
Reactive Glia Express Cytosolic Phospholipase A2 After Transient Global Forebrain Ischemia in the Rat

Background and Purpose Phospholipid breakdown has been reported to be an early event in the brain after global cerebral ischemia. Our earlier observations showing the localization of cytosolic phospholipase A2 (cPLA2) to astrocytes in aged human brains and the intense glial activation observed after global forebrain ischemia prompted us to investigate the cellular localization of cPLA2 in the rat brain subjected to global ischemia. Methods Immunohistochemistry was performed in sections through the dorsal hippocampus in rats subjected to 30 minutes of four-vessel occlusion. PLA2 was localized with the use of a highly selective antiserum. Double immunofluorescent localization was performed to colocalize cPLA2 with various glial cell types. cPLA2 levels were also measured by enzymatic assay and Western blot analysis. Results A marked induction of cPLA2 was observed in activated microglia and astrocytes in the CA1 hippocampal region at 72 hours after ischemia. Only a subset of astrocytes and microglia were immunoreactive for cPLA2. Twenty-four hours after ischemia, numerous cPLA2 immunoreactive astrocytes were observed. Western blot analysis of hippocampal homogenates at 72 hours after ischemia showed induction of a 100-kD band that comigrated with purified human cPLA2, and a threefold induction in cPLA2 activity was demonstrated by enzymatic assay. Conclusions These results indicate that both reactive astrocytes and microglia contain elevated levels of cPLA2. Induction of cPLA2 was confined to areas of neurodegeneration and likely precedes its onset. The results suggest that reactive glia may play a role in the pathophysiology of delayed neuronal death after transient global forebrain ischemia.
The Determination of Fat in the Presence of Free Fatty Acids. II. Differences in the Behavior of Individual Acids in the Mojoinnier Test

Summary The Mojonnier test does not recover equal percentages of the various free acids which may be present in the butterfat. This is due, in part at least, to variations in the amount of different acids volatilized when the sample is heated to remove the ether. It seems probable that the recovery of free acids by the Mojonnier method can be traced to hydrolysis of the ammonium soaps with the subsequent extraction of the liberated acid. The degree of hydrolysis would depend upon the nature of the acid, but it might be reduced in all cases by the substitution of a stronger base for the ammonia. Lithium hydroxide offers some promise, but its saponifying action must be studied more carefully before it can be recommended.
Epifluorescence microscopy, a technique for the study of feeding in Crassostrea virginica veliger larvae

Epifluorescence microscopy was applied as a new technique to observe the response of Crassostrea virginica veliger larvae to the algal foods Monochrysis lutheri or Chlorella autotrophica. Uptake, lysis, and digestion or rejection of these algae by oyster larvae were observed microscopically through the autofluorescence of chlorophyll a and its derivatives. Both species of algae were taken up by large numbers of larvae within 5 min after being added to larval cultures. The good growth of larvae obtained with M. lutheri as a food source was related to rapid uptake, lysis, and digestion of this alga. Larvae fed with C. autotrophica did not grow. Althogh C. autotrophica was also taken up rapidly by the larvae, there was no lysis or digestion of these algae and cells were eventually voided.
Biosynthesis of glucagon in isolated pigeon islets.

Abstract Biosynthesis of glucagon was studied using isolated pigeon islets of Langerhans. H3-leucine and H3-tryptophan were found to be actively incorporated into glucagon and a large molecular weight glucagon-related component. Incorporation into both components was inhibited by cycloheximide and significantly reduced by glucose. The possibility of a precursor molecule for the biosynthesis of glucagon was suggested.
Influence of Nitroprusside on Cerebral Pressure Autoregulation

The authors studied 10 cats to assess the question of abolition of cerebral autoregulation attendant on the use of nitroprusside for hypotensive anesthesia. After the establishment of stable base line parameters, a continuous infusion of sodium nitroprusside was begun in a dose sufficient to maintain a mean systemic arterial pressure of 65 mm Hg. Infusion was continued for incremental periods of 30 seconds to 10 minutes, increasing the time of infusion by 30 seconds after each subsequent trial. At 10 seconds after the cessation of nitroprusside administration, intravenous dopamine was infused to raise the systemic arterial pressure to a mean of 100 mm Hg, and the subsequent response in intracranial pressure was recorded in each instance. In no animal was a loss of cerebral autoregulation noted when the nitroprusside infusion was maintained for 3 minute or less. When the infusion was maintained for 4 minutes or longer, cerebral autoregulation was lost in each animal, and the length of time to return of cerebral autoregulation correlated with the duration of nitroprusside infusion. Sodium nitroprusside disturbs the integrity of cerebral pressure autoregulation, and the onset and extent of this disturbance is a dose-dependent phenomenon.
Improved outcomes in patients with acute allergic syndromes who are treated with combined H1 and H2 antagonists

Abstract Study Objective: Although the addition of H 2 blockers to H 1 antagonists has been promoted for use in anaphylaxis, there have been no large studies establishing the advantage of this approach in treating acute allergic syndromes. In this study we tested the hypothesis that combined H 1 and H 2 blockage results in improved outcomes in patients treated for acute allergic syndromes compared with treatment with H 1 blockade alone. Methods: In a randomized, double-blind, placebo-controlled trial, 91 adult patients with acute allergic syndromes were treated with either 50 mg of diphenhydramine and saline solution (control group) or with 50 mg of diphenhydramine and 50 mg of ranitidine (active group). These patients were treated with parenteral administration. Patients were recruited from an emergency department at an urban academic medical center. The primary endpoints were resolution of urticaria, angioedema, or erythema at 2 hours after protocol treatment. Areas of cutaneous involvement, heart rates, blood pressures, respiratory findings, and symptom scores were also assessed at baseline, 1 hour, and 2 hours. Results: There were significantly more patients without urticaria at 2 hours among the patients in the active group compared with those in the control group. Both groups had similar proportions of urticaria at baseline. Logistic regression models to predict resolution of urticaria, which accounted for baseline urticarial involvement, showed odds ratios in favor of the active group treatment. Similar findings were observed when the absence of both urticaria and angioedema was considered as the dependent variable. There was not a significant difference between the 2 groups with regard to the absence of erythema or angioedema (irrespective of the presence of urticaria) at 2 hours. Blood pressure and symptoms did not show differences between the 2 groups over time. Lower heart rates were observed 1 hour after treatment in the active treatment group (mean reduction 10 beats/min) compared with those found in the placebo group (mean reduction 6 beats/min). Conclusion: These data show that adding H 2 blockers to H 1 antagonists results in additional improvement of certain cutaneous outcomes for patients presenting with acute allergic syndromes. These findings favor the recommendation for using combined H 1 and H 2 antihistamines in acute allergic syndromes. [Lin RY, Curry A, Pesola GR, Knight RJ, Lee H-S, Bakalchuk L, Tenenbaum C, Westfal RE. Improved outcomes in patients with acute allergic syndromes who are treated with combined H 1 and H 2 antagonists. Ann Emerg Med. November 2000;36:462-468.]
The Sikhs: History, Religion, and Society

The Sikhs, a colorful and controversial people about whom little is generally known, have been the subject of much hypothetical speculation. Their non-conformist behavior, except to their own traditions, and their fierce independence, even to demanding autonomy, have recently attracted world-wide attention. Hew McLeod, internationally known scholar of Sikh studies, provides a just and accurate description in his introduction to this religious community from northern India now numbering about sixteen million people, exploring their history, doctrine, and literature. The Sikhs begins by giving an overview of the people's history, then covers the origins of the Sikh tradition, dwelling on controversies surrounding the life and doctrine of the first Master, Guru Nanak (1469-1539). The book surveys the subsequent life of the community with emphasis on the founding of the Khalsa, the order that gives to Sikhs the insignia by which they are best known. The remaining sections concern Sikh doctrine, the problem of who should be regarded as a Sikh, and a survey of Sikh literature. Finally, the book considers the present life of the community-its dispersion around the world to Asia, Australasia, North America, Africa, and Europe, and its involvement in the current trials of the Punjab. Sikh culture is believed to have been settled and unchanging from the time of the Gurus onwards.The Sikhs, a major new work by a leading authority, reveals that this is a very misleading view. McLeod treats a variety of questions sympathetically and in so doing he establishes a new understanding for students of religion and for all those interested in current events in India.
Prostaglandin-Mediated Effects on Growth and Markers of Biochemical Development in the Rat

Summary: Several markers of growth and biochemical development in the rat were studied after administration of prostacyclin (PGI2) and 16, 16-dimethyl prostaglandin E2 (16, 16DM PGE2). Intermittent administration of PGI2 for 3 days to 10− and 19-day-old animals, with subsequent sacrifice at 14 and 23 days, resulted in significant dose related decreases in growth at 23 days. Total sucrase and maltase (glucoamylase) activities were elevated compared to controls at 14 days. Total activities of these enzymes were decreased in postweaned 23-day-old animals, but specific activities per mg intestinal protein were not significantly different. 16,16DM PGE2 administered continuously between day 10–16 of life caused alterations in growth as well as increases in sucrase and maltase (glucoamylase) activities. Exogenously administered prostaglandins, therefore, are associated with altered growth and markers of biochemical development in the rat.
Evidence-based treatment of stuttering: I. Definition and application.

Abstract The philosophy guiding evidence-based treatment and its application to decision-making in stuttering treatment is described. Limitations to the use of evidence-based treatment principles to guide stuttering treatment, namely the lack of a substantial treatment research literature that can serve as the basis for meta-analyses and systematic reviews of effective treatment studies, are bemoaned. Guidelines are provided to aid clinicians in their own conduct of critical evaluations of treatment research. Educational objectives: The reader will learn about and be able to (1) describe the four steps that characterize evidence-based practice, (2) evaluate previous efforts to develop practice guidelines for stuttering, (3) assess the importance of an evidence-based approach to stuttering treatment, and (4) discuss the need for more research that will contribute to the evidence base.
Safety and antibody persistence following Haemophilus influenzae type b conjugate or pneumococcal polysaccharide vaccines given before pregnancy in women of childbearing age and their infants.

Background. Immunization of healthy women before pregnancy is a potential approach to providing increased levels of maternal antibody to newborns to protect them from infections occurring during the perinatal period and first months of life. Methods. Healthy nonpregnant Pima Indian women of childbearing age were randomized to receive one of two Haemophilus influenzae type b (Hib) conjugate vaccines [HbOC or Hib-meningococcal outer membrane protein complex (OMP)] or a 23-valent pneumococcal polysaccharide vaccine (PnPs). Infants received Hib-OMP vaccine at 2, 4 and 12 months of age. Vaccine safety and immunogenicity was evaluated in the women and their infants. Results. Anti-polyribose ribitol phosphate antibody titers were significantly higher in women in both Hib conjugate vaccine groups than in the pneumococcal vaccine group throughout the 37-month observation period. Antibody responses to HbOC vaccine were significantly higher than those to Hib-OMP. A subsequent booster dose of each Hib conjugate vaccine induced reactions and antibody responses similar to those of the first dose. Infants born to mothers immunized with Hib vaccines compared with PnPs had significantly higher polyribose ribitol phosphate-specific IgG antibody titers at birth and 2 months of age but lower antibody responses to Hib-OMP at 6 months and similar titers before and after boosting with Hib-OMP at 1 year of age. By contrast women immunized with PnPs did not have significantly elevated concentrations of pneumococcal-specific antibody at delivery, and their infants had pneumococcal antibody titers similar to those of infants born to mothers who did not receive pneumococcal vaccine before pregnancy. Conclusion. Hib conjugate vaccine given to women before pregnancy significantly increased the proportion of infants who had protective Hib antibody levels at birth and 2 months of age.
Binding of histamine by glass surfaces

Tritiated histamine (Hm) is significantly bound by glass surfaces. Many of the characteristics of the Hm binding suggest a specific process. Binding reaches equilibrium in 40 minutes and can be prevented by unlabeled Hm. Scatchard analysis reveals two Hm binding sites with dissociation constants of 0.051 μM and 14.4 μM. Histamine is 78.9% bound to the glass surface after 40 minutes when the concentration of Hm is 4ng/ml. Hm binding to glass can be prevented by potassium phosphate buffers, EDTA, and 0.1M HCl and reduced by albumin, formic acid, and ethanol. Binding does not occur with quartz and is minimal with polystyrene tubes.
The role of enzymatic processing in the biological actions of substance P

Abstract There is considerable evidence that substance P (SP) is a neurotransmitter in the CNS. Current findings suggest that the effects of synaptically released SP are terminated by enzymatic breakdown, primarily by endopeptidase 3.4.24.11 (endo 24.11). The products of cleavage by endo 24.11 include the amino-terminal fragment SP(1–7). Evidence suggests that SP is involved in mediating baroreceptor reflex activity in the nucleus of the solitary tract (NTS). Microinjection of SP into the NTS lowered blood pressure and heart rate. Microinjection of SP(1–7) into the NTS reproduced the effects of SP on both heart rate and blood pressure. Intra-NTS injection of phosphoramidon, an inhibitor of endo 24.11 activity, completely blocked the effects of a subsequent injection of SP. This blocking effect of phosphoramidon was unaltered by pretreatment with the opiate inhibitor naloxone. In contrast, phosphoramidon failed to block the depressor and bradycardic effects of SP(1–7). The implications of these findings regarding the role of endo 24.11 in the metabolism of SP are discussed.
PCBs and DDT in Saginaw Bay white suckers

Abstract Fillets from 25 white suckers ( Catostomus commersoni ) obtained from the Saginaw Bay, Lake Huron commercial fishery were analyzed for PCBs and ∑DDT (DDE-DDD-DDT). PCB levels ranged from 0.01 – 0.18 ppm while ∑DDT levels ranged from
Assessment of Microburst Models for Downdraft Estimation

The effectiveness of three microburst models in estimating the downdraft from horizontal velocity measurements is assessed. The development of the models and their characteristics are discussed. The simplest model, a linear one, works well for altitudes below 200 m and near the microburst core. A ring-vortex model and an empirical model give the best overall results. The former is the most complex, requiring four variables to define it. The empirical model uses three variables.
Synapses: Glia help synapses form and function

A sophisticated new cell-culture system has shown that glial cells can promote synaptogenesis and enhance the efficacy of synaptic transmission. These effects are not secondary to increased neuronal survival but probably involve changes in neuronal activity levels and a secreted glial factor.