cssi/SciSciGPT-SciSciNet huggingface dataset:
New approaches to the study of the mechanism of fast axonal transport

Fast axonal transport carries a constant stream of organelles through the axoplasm at velocities of up to 400 mm day −1 . Ever since the discovery of fast axonal transport, there has been speculation about the molecular mechanisms that move materials within the axon. However, experimental data about the mechanisms was limited. Recently, information about the properties of the fast transport system has been obtained using techniques such as microinjection, cell permeabilization, video microscopy and new ultrastructural methods. Although the mechanism of transport has not yet been identified, an understanding of the mechanism appears to be dose at hand.
Thermal chemistry of diiodomethane on Ni(1 1 0) surfaces II. Effect of coadsorbed oxygen

Abstract The effect of coadsorbed oxygen on the thermal chemistry of diiodomethane on Ni(1 1 0) single-crystal surfaces was studied by temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). I 3d and C 1s XPS data indicated that adsorbed diiodomethane undergoes two sequential C–I bond scission steps to ultimately produce methylene surface species, the same as on clean Ni(1 1 0). Moreover, significant amounts of methane and other heavier hydrocarbons are produced after further thermal activation of those chemisorbed methylene groups. The production of alkanes and alkenes, which is accounted for by a chain growth mechanism where the initial hydrogenation of some adsorbed methylene to methyl moieties is followed by a rate-limiting methylene insertion step to yield ethyl intermediates, is inhibited but not fully blocked by the coadsorbed oxygen. New reaction pathways are also opened up by the presence of oxygen in this system, including a direct coupling of two methylene groups to ethene, the insertion of an oxygen atom into a nickel–methylene group to produce formaldehyde, and a parallel methylene insertion chain growth sequence starting from a CH 2 I ads intermediate to ultimately yield C 3 H 5 and C 4 H 7 unsaturated gas-phase radicals.
Significance of phenotypic and chromosomal abnormalities in X‐linked mental retardation (Martin‐Bell or Renpenning syndrome)

With the exception of macro-orchidism, three families with X-linked mental retardation showed diagnostic concordance of clinical features among the affected males. Since macro-orchidism was a variable feature among the otherwise identically affected males in one family, we question the existence of a separate entity of X-linked mental retardation characterized only be testicular enlargement. The X chromosome marker of Lubs was expressed, under the culture conditions of Sutherland, in lymphocytes of the affected males of two families, one with and the other without megalotestes. Two affected members of the third family, with megalotestes, did not show the marker. Telomeric structural changes similar to the mar(X) (qter) formation were found on certain autosomes, notably, chromosome 6 in some of the affected males, potential and obligate carrier females, and in both related and unrelated normal males. These autosomal markers appear to represent a nonspecific response to either in vivo or in vitro folate deficiency. Caution against premature introduction of this test for prenatal diagnosis, in the face of current ignorance regarding diagnostic specificity, is urged.
Using Performance Feedback To Decrease Classroom Transition Time And Examine Collateral Effects On Academic Engagement

Performance feedback has been described as a necessary component of consultation. Although feedback has been used to improve academic performance of individual students, less research has examined the effects on classroom academic engagement when implementation of classroom management variables is the source of feedback. Using a multiple-baseline design, the effects of performance feedback with goal setting was examined across three high school biology teachers who were first provided with feedback on the number of seconds devoted to transitions and then successful implementation of classroom time management strategies. Feedback on the number of transition minutes alone led to decreases in transition time and corresponding increases in student academic engagement for all teachers. One teacher benefited from additional feedback on classroom time management strategies. For all teachers, low rates of transition time and high rates of academic engagement were maintained when the intervention was faded and aft...
Strata/ICC: physical models as computational interfaces

We present Strata/ICC: a computationally-augmented physical model of a 54-story skyscraper that serves as an interactive display of electricity consumption, water consumption, network utilization, and other kinds of infrastructure. Our approach pushes information visualizations into the physical world, with a vision of transforming large-scale physical models into new kinds of interaction workspaces.
Effect of concordance between sites of left ventricular pacing and dyssynchrony on acute electrocardiographic and echocardiographic parameters in patients with heart failure undergoing cardiac resynchronization therapy.

Background: Wide QRS complexes are associated with left ventricular (LV) dyssynchrony, but an optimal site of LV pacing has not been established. Hypothesis: We hypothesized that concordance between the sites of LV pacing and of latest LV mechanical activation during cardiac resynchronization therapy (CRT) is associated with more favorable acute echocardiographic changes. Methods: An analysis of 28 consecutive patients (64 ± 15 years, 46% male, 52% ischemic heart disease, LV ejection fraction 0.24 ± 0.07, QRS 163 ± 22 ms, New York Heart Association > 3 93%) implanted with biventricular (BIV) defibrillators was performed. Sites of latest LV activation were determined by tissue Doppler imaging (TDI) and speckle tracking (ST). The site of LV pacing was determined by fluoroscopy in two views. A concordance score (0-5) was created to describe the proximity of the pacing site to the site of the latest mechanical activation. Results: Compared with the worst concordance score, a perfect score was associated with shorter QRS width with LV (187 ± 40 vs. 246 ± 8 ms, p = 0.048) and BIV (134 ± 19 ms vs. 179 ± 39 ms, p = 0.05) but not with right ventricular pacing. A perfect concordance score was also associated with a greater acute reduction in LV volumes in systole (42 ± 36 ms 16 ± 22 ms, p = 0.068) and diastole (47 ± 37 vs. 8 ± 31 ml, p = 0.043) 24 h after CRT device implantation. Conclusions: A high concordance is associated with shorter QRS width with LV and BIV pacing and greater acute reduction in LV volumes. The effect of concordance on the intermediate and long-term response to BIV pacing deserves further evaluation.
Comparison of Transition Metal-Mediated Oxidation Reactions of Guanine in Nucleoside and Single-Stranded Oligodeoxynucleotide Contexts.

Abstract As the most readily oxidized of DNA’s four natural bases, guanine is a prime target for attack by reactive oxygen species (ROS) and transition metal-mediated oxidants. The oxidation products of a modified guanosine nucleoside and of a single-stranded oligodeoxynucleotide, 5′-d(TTTTTTTGTTTTTTT)-3′ have been studied using oxidants that include Co II , Ni II , and Ir IV compounds as well as photochemically generated oxidants such as sulfate radical, electron-transfer agents and singlet oxygen. The oxidized lesions formed include spiroiminodihydantoin (Sp), guanidinohydantoin (Gh), imidazolone (Iz), oxazolone (Z) and 5-carboxamido-5-formamido-2-iminohydantion (2-Ih) nucleosides with a high degree of dependence on the exact oxidation system employed. Interestingly, a nickel(II) macrocyclic complex in conjunction with KHSO 5 leads to the recently reported 2-Ih heterocycle as the major product in both the nucleoside and oligonucleotide contexts.
Perceived Discrimination and Linguistic Adaptation of Adolescent Children of Immigrants

This study examines the relationship between perceived discrimination and self-reported proficiency in English and non-English languages among adolescent children of immigrants. Data from the Children of Immigrants Longitudinal Study was used. The average age of participants was 17.2 years; 1,494 were females and 1,332 were males. Among 2,826 participants, 61% reported Latin American and Caribbean national origin and 39% reported Asian national origin. Findings from probit regression analysis showed that adolescents who felt discriminated against by school peers were more likely to report speaking and reading English less than "very well". On the other hand, adolescents who felt discriminated against by teachers and counselors at school or reported perceived societal discrimination were more likely to report speaking and reading English "very well." The results suggest youth's English, as opposed to non-English language, as the primary venue in which perceived discrimination influences youth's linguistic adaptation. The findings further indicate that the direction and possible mechanisms of this influence vary depending on the source of perceived discrimination.
RADIA: RNA and DNA integrated analysis for somatic mutation detection.

The detection of somatic single nucleotide variants is a crucial component to the characterization of the cancer genome. Mutation calling algorithms thus far have focused on comparing the normal and tumor genomes from the same individual. In recent years, it has become routine for projects like The Cancer Genome Atlas (TCGA) to also sequence the tumor RNA. Here we present RADIA (RNA and DNA Integrated Analysis), a novel computational method combining the patient-matched normal and tumor DNA with the tumor RNA to detect somatic mutations. The inclusion of the RNA increases the power to detect somatic mutations, especially at low DNA allelic frequencies. By integrating an individual’s DNA and RNA, we are able to detect mutations that would otherwise be missed by traditional algorithms that examine only the DNA. We demonstrate high sensitivity (84%) and very high precision (98% and 99%) for RADIA in patient data from endometrial carcinoma and lung adenocarcinoma from TCGA. Mutations with both high DNA and RNA read support have the highest validation rate of over 99%. We also introduce a simulation package that spikes in artificial mutations to patient data, rather than simulating sequencing data from a reference genome. We evaluate sensitivity on the simulation data and demonstrate our ability to rescue back mutations at low DNA allelic frequencies by including the RNA. Finally, we highlight mutations in important cancer genes that were rescued due to the incorporation of the RNA.
Synthesis and lithium conductivities of Li2SiS3 and Li4SiS4

Abstract The compositions in the LiSiS system were synthesized by using pyrolitic graphite-coated silica ampoules. Two ternary compounds, Li 2 SiS 3 and Li 4 SiS 4 , were identified and their powder x-ray diffraction data were reported for the first time. Li 2 SiS 3 had a = 6.735 A , b = 11.664 A , and c = 5.926 A , with a space group Cmc2 1 , while Li 4 SiS 4 had a = 13.735 A , b = 7.769 A , and c = 6.147 A , with a space group Pnma. The lithium conductivities of Li 2 SiS 3 and Li 4 SiS 4 at room temperature were 2 ×10 −6 and 5 ×10 −8 (Ω. cm ) −1 , respectively. Their ionic conduction behaviors were discussed based on their crystal structures deduced here.
The Role of Market Embeddedness in Market Scanning and Marketing Competence

Abstract This study uses the social network paradigm to examine how small business network relationships influence the flow of local business information, and whether the ability to obtain relevant, timely and accurate information leads to increased levels of marketing competence. One hundred nineteen retail store owners were surveyed to look at the role of network relationships in market scanning. The study found that retailers who had strong network relationships characterized by high levels of social capital perceived information from these networks to be more relevant, accurate and timely. Although marketing competence was related to performance, obtaining quality information about the market did not lead to the development of distinctive capabilities. More attention to networking and market research skills may help small retailers create and sustain a competitive advantage.
An estimate of the natural heat resources in a thermal area in Iceland

Abstract Various geological and geophysical principles involved in the exploitation of geothermal areas are summarized with special reference to the Hengill high-temperature thermal area located 30 to 40 km east of the city of Reykjavik, Iceland. A reservoir model, which applies to this area, is discussed quantitatively, and it is shown that the heat stored in the reservoir rock beneath the thermal area is the main source of geothermal energy. The rate at which this stored heat can be tapped depends on the availability of water. An estimate of the order of magnitude of the total recoverable heat resources in the Hengill area, based on the reservoir model presented, indicates that a total of the order of 10 10 tons (1) of water at 220 to 230 °C could be produced in this area during a period of 100 years. This water is flashed in the boreholes and will yield a total of 2.5 × 10 9 tons of dry saturated steam with a pressure ranging from 10 ata to 2 ata. The estimated production rate of steam is of the order of 3000 tons/hour, or comparable to the production which has already been obtained in the geothermal area at Larderello in Tuscany, Italy. The production costs, based on the rate of 300 tons/hour of steam, have been estimated at $ 0.16/ton steam, and the investment necessary is estimated at $ 5000/ton steam/hour. Corresponding figures for larger installations would probably be somewhat lower.
Predictors of cancellation in an oregon involuntary commitment program

The problem of attrition from mental health care programs before such services begin is poorly understood. The present research has identified several variables which predict first appointment cancellations for Oregon involuntary committment petitioners in behalf of potential clients. The value of such variables is discussed in terms of petitioner attrition from involuntary commitment programs, mental health needs of those petitioning for the involuntary commitment of “allegedly mentally ill” persons, increased mental health program efficiency, and economic benefits for underbudgeted and understaffed mental health care programs. Recommendations to improve community mental health programs in general, and involuntary commitment programs in particular are presented.
Palaeontology: Jurassic fossils and mammalian antiquity.

Two new Jurassic fossils yield conflicting reconstructions of the mammalian tree. These divergent genealogies have profoundly different implications for the origin and early diversification of mammals. See Article p.163 & Letter p.199 Independent reports of two newly discovered fossils from the Jurassic of China (around 160–165 million years old) produce conflicting reconstructions of the origins of mammals. Haramiyids were Mesozoic mammals with strange, highly derived rodent-like teeth. Because of this they have been allied with multituberculates, a larger and highly successful group of rodent-like mammals that lived until the Eocene. The problem with haramiyids is that they were until recently known only from teeth. A report by Jin Meng and colleagues reveals a much more complete creature whose features ally it with multituberculates, confirming earlier views — but also implying that the roots of extant mammals lie well back in the Triassic. By contrast, the haramiyid described by Zhe-Xi Luo and colleagues is startlingly primitive in many features of the jaw and ankle, implying that the haramiyids go way back in the mammalian scheme of things and are not related to multituberculates at all. This dichotomy is a reminder of just how little we know about fossils whose interpretation is crucial to the early evolution of mammals.
Therapeutic Storytelling for Adolescents and Young Adults

Dr Lee Slivinske, a Professor Emeritus in the Department of Social Work at Youngstown State University, and his wife, therapist and adjunct professor Johanna Slivinske, have collaborated on Therape...
Configuration of a Towline Attached to a Vehicle Moving in a Circular Path

The problem of predicting the steady-state performance of a cable-body system towed in a circular path is studied analytically. Equations governing the steady-state configuration of the towline, distribution of the tension along the towline, and the location of the towed body are derived. Hydrodynamic forces accounted for in the analysis are the buoyancy, the side force, the added-mass effect as well as the dominant fluid resistance. The present model can be applied to both aerial and underwater towed systems. The analytical model is evaluated by comparison of its predictions with limited data of laboratory tests. Numerical solutions are obtained for the case of underwater towing of sperical bodies. Based on these results, some remarks on the operational aspects of the underwater towing are presented.
Diagnosis and management of Takayasu arteritis

Summary Takayasu arteritis is a panaortitis, more frequent in Japan, South-East Asia India and Mexico, that presents in the 2nd or 3rd decade of life with a non-specific inflammatory phase, then vascular stenosis with ‘pulselessness’ with collateral development. Clinical features include reduced/absent pulses, bruits, hypertension, aortic regurgitation, neurological symptoms from ischemia. While the gold standard for diagnosis is arteriography, magnetic resonance angiography and ultrasonography are now widely used due to their non-invasive nature. Steroids are the cornerstone of medical therapy; cytotoxics may be used for failures. Surgery or angioplasty may be needed for severe vascular stenosis.
Failure loads of spot welds under combined opening and shear static loading conditions

Failure loads of spot welds are investigated under combined opening and shear static loading conditions. Square-cup specimens were used to obtain the failure loads of mild steel spot welds under a range of combined opening and shear loads. Optical micrographs of the cross-sections of spot welds before and after failure were examined to understand the failure processes under different combinations of loads. The experimental results indicate that under nearly pure opening loads, shear failure occurs in the heat affected zone along the nugget circumferential boundary. Under combined opening and shear loading conditions, necking/shear failure starts near the nugget in the stretching side of the base metal sheet. According to the experimental observations, a simple lower bound limit load analysis is conducted. The results of the lower bound limit load analysis quantitatively agree with those of the experiments. A simple closed-form equation is proposed to characterize the failure loads of spot welds under combined opening and shear static loading conditions. The failure load is expressed as a function of the tensile strength of the base metal, the nugget size, the sheet thickness, the loading angle for characterization of combined loads, and an empirical coefficient for the given welding schedule.
Serendipitous discovery of α-hydroxyalkyl esters as β-lactamase substrates.

O-(1-Carboxy-1-alkyloxycarbonyl) hydroxamates were found to spontaneously decarboxylate in aqueous neutral buffer to form O-(2-hydroxyalkylcarbonyl) hydroxamates. While the former molecules do not react rapidly with serine β-lactamases, the latter are quite good substrates of representative class A and C, but not D, enzymes, and particularly of a class C enzyme. The enzymes catalyze hydrolysis of these compounds to a mixture of the α-hydroxy acid and hydroxamate. Analogous compounds containing aryloxy leaving groups rather that hydroxamates are also substrates. Structure−activity experiments showed that the α-hydroxyl group was required for any substantial substrate activity. Although both d- and l-α-hydroxy acid derivatives were substrates, the former were preferred. The response of the class C activity to pH and to alternative nucleophiles (methanol and d-phenylalanine) suggested that the same active site functional groups participated in catalysis as for classical substrates. Molecular modeling was emp...
Congenital pulmonary venous stenosis presenting as persistent pulmonary hypertension of the newborn.

Congenital pulmonary venous stenosis (CPVS) has been previously described in older infants and children, typically manifesting as failure to thrive with congestive heart failure and subsequent respiratory deterioration. We report on 2 cases of CPVS which presented during the immediate newborn period as severe persistent pulmonary hypertension of the newborn. Pediatr Pulmonol. 1999; 28:301–306. © 1999 Wiley-Liss, Inc.
Therapeutic options for gastrointestinal carcinoids.

Although wide surgical resection is the optimal curative therapy for carcinoid tumors, in most patients the presence of metastatic disease at diagnosis usually renders excision a palliative procedure. This nevertheless decreases tumor burden, facilitates symptom control, and prevents complications caused by bleeding, perforation, or bowel obstruction resulting from fibrosis. In the stomach (types I and II) and rectum endoscopic excision may be adequate provided the lesion(s) are local. Long-term therapy is focused on symptom alleviation and improvement of quality of life using somatostatin analogues, particularly in a subcutaneous depot formulation. In some instances interferons may have a role but their usage often is associated with substantial adverse events. Conventional chemotherapy and external radiotherapy either alone or in a variety of permutations are of minimal efficacy and should be balanced against the decrease in quality of life often engendered by such agents. Hepatic metastases may be amenable to surgery, radiofrequency ablation, or embolization either alone or in combination with chemotherapeutic agents or isotopically loaded microspheres. Rarely hepatic transplantation may be of benefit although controversy exists as to its actual use. Peptide-receptor–targeted radiotherapy for advanced disease using radiolabeled octapeptide analogs ( 111 In/ 90 Yt/ 177 Lu-octreotide) appear promising but data are limited and its status remains investigational. A variety of antiangiogenesis and growth factor–targeted agents have been evaluated, but as yet have shown little promise. The keystone of current therapy remains the long-acting somatostatin analogues that alleviate symptomatology and substantially improve quality of life with minimal adverse effects.
Hybrid spectral/finite element analysis of dynamic delamination of patterned thin films

A combined spectral and finite element analysis is performed to investigate the dynamic edge delamination of patterned thin films from a substrate. The analysis is motivated by an emerging experimental technique in which high-amplitude laser-induced stress waves initiate progressive interfacial debonding of thin film interfaces. The numerical method relies on the spectral representation of the elastodynamic solutions for the substrate and the finite element model for the thin film. A cohesive model is introduced along the interface of the bimaterial system to capture the decohesion process. The important role of the film inertia on the crack extension and the appearance of the mixed-mode failure are demonstrated by observing the traction stress evolution at various points along the bond line. Parametric studies on the effect of film thickness, interface fracture toughness, loading pulse shape and amplitude on the debonding process are performed. A semi-analytical investigation on the inertial effect is carried out to predict the final crack length as a function of the film thickness and pulse amplitude.
Economic-demographic modeling with endogenously determined birth and migration rates: theory and prospects.

The standard demographic approach to population forecasting consists of extrapolating into the future carefully measured birth, death, and migration rates. An alternative is to forecast changes in those rates on the basis of social science theories. In this paper the prospects for incorporating those theories into forecasting models are assessed. The paper has two parts, the first devoted to fertility and the second to migration. Each contains a description of the demographic methods currently used by the US Bureau of the Census followed by a comprehensive review of the theoretical foundations for forecasting and an assessment of the prospects for doing so.
Gynecologic concerns in patients with anorectal malformations

Children with anorectal malformations (ARMs) constitute a significant group within a pediatric surgery practice. In females, the most common ARM is an imperforate anus with a rectovestibular fistula, followed by an imperforate anus with a rectoperineal fistula and then cloacal anomalies. Some malformations, such as an imperforate anus with a rectovestibular fistula, may seem straightforward, treated with a posterior sagittal anorectoplasty; however, it is vital to recognize the association with gynecologic anomalies. Girls with the most complex anorectal defect, cloacal malformation, have significant associated urological and gynecologic anomalies, which should be recognized and treated. An opportunity to diagnose and treat such anomalies may be missed in the newborn period or at the definitive surgery, unless the pediatric surgeon is aware of this association. With the knowledge of the associated anomalies and long-term sequelae, surgeons can provide better care for girls and important counseling for parents. Important gynecologic issues to consider may be divided into several categories, such as infancy, puberty, sexual intimacy, and obstetrical concerns. Knowledge of reproductive-related issues in females with ARMs allows the pediatric surgeon and their gynecology colleagues to provide optimal surgical management throughout infancy, childhood, and into young adulthood. Appropriate counseling for patients and families about potential reproductive concerns that may develop many years after the definitive surgical repair allows preparation and planning to preserve future fertility.
Second-Order Relative Motion Equations

An approximate solution of second-order relative motion equations is presented. The equations of motion for a Keplerian orbit in spherical coordinates are expanded in Taylor series form using reference conditions consistent with that of a circular orbit. Only terms that are linear or quadratic in state variables are kept in the expansion. The method of multiple scales is employed to obtain an approximate solution of the resulting nonlinear differential equations, which are free of false secular terms. This new solution is compared with the previously known solution of the linear case to show improvement and with numerical integration of the quadratic differential equation to understand the error incurred by the approximation. In all cases, the comparison is made by computing the difference of the approximate state (analytical or numerical) from numerical integration of the full nonlinear Keplerian equations of motion. The results of two test cases show two orders of magnitude improvement in the second-order analytical solution compared with the previous linear solution over one period of the reference orbit.
Toxicity of Epoxy Fatty Acids and Related Compounds to Cells Expressing Human Soluble Epoxide Hydrolase

Soluble epoxide hydrolase (sEH) is suggested to alter the mode of action and increase the toxic potency of fatty acid epoxides. To characterize the structural features necessary for sEH-dependent epoxy fatty acid toxicity, 75 aliphatic compounds were assayed for cytotoxicity in the presence and absence of sEH. Three groups of aliphatic epoxide−diol pairs were described by their observed differential toxicity. Group I compounds were typified by terminal epoxides whose toxicity was reduced in the presence of sEH. Group II compounds were toxic in either their epoxide or diol form, but toxicity was unaffected by sEH. Group III compounds exhibited sEH-dependent toxicity and were therefore used to investigate the structural elements required for cytotoxicity in this study. The optimal structure for group III compounds appeared to be a fatty acid 18−20 atoms long (e.g., a carbon backbone plus a terminal heteroatom) with an epoxide positioned between C-7 and C-12. In the absence of sEH, replacement of epoxides wi...
Recent advancements in corpus luteum development, function, maintenance and regression: Forum introduction

The corpus luteum is a dynamic tissue whose cellular composition is traced to the remnants of the ovarian follicle, neovascularization and infiltration of immune cells. The corpus luteum undergoes dramatic morphological and functional changes throughout its lifespan. Functionally the corpus luteum is responsible for the provision of progesterone in support of pregnancy. Depending on the species and the physiological state, the corpus luteum lifespan can last from less than a day to almost a year. During this time, whether it is during the development, maintenance, or regression stage the corpus luteum function is mediated by a number of influences including steroids, growth factors, gonadotropins, prostaglandins, cytokines, and peptide hormones. The variable expression of theses factors and their receptors control the fate of the corpus luteum.
Base excision repair of ionizing radiation-induced DNA damage in G1 and G2 cell cycle phases

Major genomic surveillance mechanisms regulated in response to DNA damage exist at the G1/S and G2/M checkpoints. It is presumed that these delays provide time for the repair of damaged DNA. Cells have developed multiple DNA repair pathways to protect themselves from different types of DNA damage. Oxidative DNA damage is processed by the base excision repair (BER) pathway. Little is known about the BER of ionizing radiation-induced DNA damage and putative heterogeneity of BER in the cell cycle context. We measured the activities of three BER enzymes throughout the cell cycle to investigate the cell cycle-specific repair of ionizing radiation-induced DNA damage. We further examined BER activities in G2 arrested human cells after exposure to ionizing radiation. Using an in vitro incision assay involving radiolabeled oligonucleotides with specific DNA lesions, we examined the activities of several BER enzymes in the whole cell extracts prepared from synchronized human HeLa cells irradiated in G1 and G2 phase of the cell cycle. The activities of human endonuclease III (hNTH1), a glycosylase/lyase that removes several damaged bases from DNA including dihydrouracil (DHU), 8-oxoguanine-DNA glycosylase (hOGG1) that recognizes 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxoG) lesion and apurinic/apyrimidinic endonuclease (hAPE1) that acts on abasic sites including synthetic analog furan were examined. Overall the repair activities of hNTH1 and hAPE1 were higher in the G1 compared to G2 phase of the cell cycle. The percent cleavages of oligonucleotide substrate with furan were greater than substrate with DHU in both G1 and G2 phases. The irradiation of cells enhanced the cleavage of substrates with furan and DHU only in G1 phase. The activity of hOGG1 was much lower and did not vary within the cell cycle. These results demonstrate the cell cycle phase dependence on the BER of ionizing radiation-induced DNA damage. Interestingly no evidence of enhanced BER activities was found in irradiated cells arrested in G2 phase.
Fluorescence lifetime measurements using total internal reflection fluorimetry: Evidence for a conformational change in albumin adsorbed to quartz

We have modified the total internal reflectance fluorimetry (TIRF) method to determine, indirectly, quantum fluorescence yield and thus infer structural changes of adsorbed plasma proteins. We employed a frequency multiplied Nd:YAG pulse laser to excite tryptophan residues of bovine serum albumin (BSA), measuring the resulting fluorescence lifetimes. BSA adsorbed on quartz was investigated at normal pH and under acidic (pH 3.8) conditions at which albumin shape change has been established in bulk solution. Albumin adsorbed at pH 7.2 has a slightly lower lifetime than the bulk solution value, reflecting a population of both native and isomerized forms. Gently washing the adsorbate surface significantly reduces fluorescence lifetime, suggesting retention of more tenacious, conformationally altered molecules. Vigorous washing further reduces fluorescence lifetimes to values close to those obtained in bulk under acidic conditions. Similar alterations in fluorescence lifetimes were observed for heat-denatured albumin. These results support the hypothesis that adsorbed albumin exists in the form of a two-layer deposit, each with a possibly different structure. A loosely held layer, consisting of BSA microaggregates and including partially unfolded molecules, exists on the undisturbed surface and is partially removed by gentle washing. Vigorous washing removes all but the most tightly held protein, which exists in a possibly further unfolded configuration. The decrease in fluorescence lifetime of adsorbed BSA implies a corresponding change in quantum yield. A change in quantum yield of BSA tryptophan fluorophors implies that measuring adsorbed protein concentration by intrinsic fluorescence is unreliable.
Gnat robots: a low-intelligence low-cost approach

Suggestions are given to cut the cost of mobile robots with acceptable limitations on intelligence. By shrinking motors and power supplies to the same scale as the sensors and control systems to create gnat-sized autonomous robots, it is possible not only to reduce the size and cost of robots, but also to open up new application areas. Now that actuators can be etched on chips, it is possible to integrate all components of a robotic system into silicon: sensors, electronics, actuators, and power sources. The author suggests that shrinking to this scale, it is possible to take advantage of VLSI manufacturing technology to enable mass production. >
Perceptions About Community Applications of RE-AIM in the Promotion of Evidence-Based Programs for Older Adults

Despite the growing literature about the RE-AIM framework as a planning, implementation, and evaluation tool, little is known about practitioners' adoption of the framework, confidence to utilize framework elements, or perceptions of its usefulness. To assess how RE-AIM was implemented by state aging service providers and public health partners, data were collected using an Internet-delivered, cross-sectional survey from 40 stakeholders in 27 funded states in an evidence-based disease prevention initiative for older adults. Most participants agreed the framework was useful for planning, implementation, and evaluation and relevant for evaluators, providers, community leaders, and policy makers. Yet nearly half felt monitoring RE-AIM requirements requires special expertise, and one third felt the different RE-AIM elements were difficult to measure. Findings indicate the RE-AIM's appropriateness and utility for planning and evaluating the dissemination of evidence-based programs to older adults; however, additional trainings, resources, and technical assistance are warranted to enhance uptake in community-wide intervention efforts.
Memory search for the first target modulates the magnitude of the attentional blink

The resolution of temporal attention is limited in a manner that makes it difficult to identify two targets in short succession. This limitation produces the phenomenon known as the attentional blink (AB), in which processing of a first target (T1) impairs identification of a second target (T2). In the AB literature, there is broad agreement that increasing the time it takes to process T1 leads to a larger AB. One might, therefore, predict that increasing the number of possible T1 identities, or target set, from 1 to 16 would lead to a larger AB. We were surprised to find that this manipulation of T1 difficulty had no influence on AB magnitude. In subsequent experiments, we found that AB magnitude interacts with T1 processing time only under certain circumstances. Specifically, when the T1 task was either well masked or had to be completed online, we found a reliable interaction between AB magnitude and the target set size. When neither of these conditions was fulfilled, there was no interaction between target set size and the AB. Previous research found that when the target set changes from trial to trial, trials with more possible targets elicited a larger AB. In the present study, the target set is held constant, reducing the demands on working memory. Nevertheless, AB magnitude still interacts with target set size, as long as the T1 task cannot be processed offline. Thus, the act of searching memory delays subsequent processing, even when the role of working memory has been minimized.
AMERICA'S CHANGING COLOR LINES: Immigration, Race/Ethnicity, and Multiracial Identification

Over the past four decades, immigration has increased the racial and ethnic diversity in the United States. Once a mainly biracial society with a large white majority and relatively small black minority—and an impenetrable color line dividing these groups—the United States is now a society composed of multiple racial and ethnic groups. Along with increased immigration are rises in the rates of racial/ethnic intermarriage, which in turn have led to a sizeable and growing multiracial population. Currently, 1 in 40 persons identifies himself or herself as multiracial, and this figure could soar to 1 in 5 by the year 2050. Increased racial and ethnic diversity brought about by the new immigration, rising intermarriage, and patterns of multiracial identification may be moving the nation far beyond the traditional and relatively persistent black/white color line. In this chapter, we review the extant theories and recent findings concerning immigration, intermarriage, and multiracial identification, and consider...
Terpenes and the thermotolerance of photosynthesis

A walk through the forest is a good way to become aquainted with the variety of terpenes emitted by plants. The most fragrant of these are the monoterpenes, which lend a distinctive smell to trees (e.g. α- and β-pinene from pines), mints (e.g. menthol from peppermint), fruits (e.g. limonene from citrus) and flowers (e.g. geraniol from roses). In addition to adding fragrance, phytogenic hydrocarbons play an important role in atmospheric chemistry. This was recognized as early as 1960 by Fritz Went who noted that blue hazes often formed above forested areas (Went, 1960). This idea was picked up by US President Ronald Reagan who accused trees of polluting the atmosphere, although in truth phytogenic hydrocarbons only contribute to pollution in air that is already contaminated by industry or automobile exhaust (Feshenfeld et al., 1992). Terpenes serve a variety of functions in plants including deterring herbivores and attracting pollinators. Until recently, the function of terpene emission from some groups of plants, which do not store the terpenes in their tissues, has been a mystery. Following the discovery that isoprene, a hemiterpene, increases the thermotolerance of photosynthesis in some species (Sharkey & Singsaas, 1995; Singsaas et al., 1997), Loreto et al. (1998) discovered that thermotolerance of the monoterpene-emitting oak, Quercus ilex, increases when leaves are fumigated with monoterpenes. Now, a report by Delfine et al. in this issue (pp. 27–36) provides further support for the hypothesis that terpenes play a role in thermotolerance of leaves and suggests, intriguingly, that the mechanism by which this occurs is not limited to plants that make these compounds.
Conditional deletion of MSX homeobox genes in the uterus inhibits blastocyst implantation by altering uterine receptivity

An effective bidirectional communication between an implantation-competent blastocyst and the receptive uterus is a prerequisite for mammalian reproduction. The blastocyst will implant only when this molecular cross-talk is established. Here we show that the muscle segment homeobox gene (Msh) family members Msx1 and Msx2, which are two highly conserved genes critical for epithelial-mesenchymal interactions during development, also play crucial roles in embryo implantation. Loss of Msx1/Msx2 expression correlates with altered uterine luminal epithelial cell polarity and affects E-cadherin/β-catenin complex formation through the control of Wnt5a expression. Application of Wnt5a in vitro compromised blastocyst invasion and trophoblast outgrowth on cultured uterine epithelial cells. The finding that Msx1/Msx2 genes are critical for conferring uterine receptivity and readiness to implantation could have clinical significance, because compromised uterine receptivity is a major cause of pregnancy failure in IVF programs.
Instabilities of one-dimensional trivial-phase solutions of the two-dimensional cubic nonlinear Schrodinger equation

Abstract The two-dimensional cubic nonlinear Schrodinger equation (NLS) is used as a model of a wide variety of physical phenomena. In this paper, we study the stability of a class of its one-dimensional, periodic, traveling-wave solutions. First, we establish that all such solutions are unstable with respect to two-dimensional perturbations with long wavelengths in the transverse dimension. Second, we establish that all such solutions are unstable with respect to two-dimensional perturbations with arbitrarily short wavelengths if the coefficients of the linear dispersion terms in the NLS have opposite signs. Both arguments rely on formal perturbation methods. Third, we use the Fourier–Floquet–Hill numerical method to examine the spectral stability problem. We present detailed spectra for twelve different solutions and demonstrate strong agreement between the numerical and asymptotic results.
Learning to Read Words: Effects of Overlearning and Similarity on Stimulus Selection.

Kindergarten children needed more trials to learn a list of similar than dissimilar words but made fewer over-generalization errors on subsequent transfer tasks. A third group of children, trained on the dissimilar list, was given overlearning trials to make up for the additional training trials needed by the similar group. While the overlearning and similar groups did not differ on over-generalization errors, both made fewer errors than were made by the dissimilar group. The authors conclude that over-generalization errors fade with over-learning and should not unduly alarm teachers. Over-generalization errors under whole-word reading instruction have been studied by McCutcheon and McDowell (1969), Otto and Pizillo (1970). and Samuels and Jeffrey (1966). These investigators found that children needed more trials to learn lists of similar than dissimilar words, but make fewer over-generalization errors on subsequent transfer tasks. These studies indicate that paired-associate training which forces children to attend to each letter in a word is less likely to lead to subse- quent over-generalization errors than training which permits children to discriminate words on the basis of fractional cues (stimulus selection). It is known, however, that adult learners engage in stimulus selection until a list is learned. Then during further overlearning trials, stimulus selection may be relaxed and additional parts of stimuli may be learned (James & Greeno, 1967). It is possible that giving overlearning trials on dissimilar lists to equal the additional trials required to learn similar lists would produce comparable over-generalization errors on transfer tasks. This hypothesis was tested with children by Gilbert, Spring, and Sassenrath (1977), with equivocal results. The investigators noted that their training procedure, patterned on previous studies, inadvertently resulted in their similar group receiving overlearning trials. This was because subjects received twelve preliminary fixed- order trials before scoring was commenced on random-order trials and some subjects in the similar group mastered the task before completing preliminary trials. In the present study, therefore, preliminary trials were reduced.
The Longer You Stay, the Worse Your Health? A Critical Review of the Negative Acculturation Theory among Asian Immigrants

Researchers have become increasingly interested in the health patterns of immigrants with longer residence in the United States, as this reveals the health consequences of integration processes. The negative acculturation effect has been the dominant interpretation of duration patterns, despite empirical and theoretical uncertainties about this assumption. This theory assumes that immigrant health declines with longer residence in the United States because of poorer health behaviors and health risks that reflect Americanized lifestyles. This paper reviews the empirical support for the negative acculturation theory among Asian immigrants to determine if and when it is an appropriate interpretation for duration patterns. I conclude that empirical inconsistencies and methodological issues limit the negative acculturation theory as the primary interpretation for duration patterns. First, there is no consistent evidence that health behaviors decline with time. There is also substantial group heterogeneity in duration patterns as well as heterogeneity across health outcomes. The literature has not adequately addressed methodological shortcomings, such as confounding by cohort effects or non-linear duration patterns. Length of residence in the United States is still an important aspect of Asian immigrant health, but the mechanisms of this relationship are still understudied. I propose alternative frameworks between duration and health that consider environmental influences and end with future research directions to explore research gaps.
Equitable Energy Consumption during Repeated Transmissions in a Multihop Wireless Network

This paper addresses the issue of network life during repeated broadcasts originating from the same source in large, strip-shaped wireless sensor networks. The proposed technique would also apply to a unicast over a strip-shaped cooperative route within a network. The proposed medium access control (MAC)-free "alternating sets" transmission strategy is based on a very low- overhead form of cooperative diversity called the opportunistic large array (OLA). The proposed alternating OLA with transmission threshold (A-OLA-T) uses a received power-based threshold to define mutually exclusive sets of nodes, such that the union of the sets includes all the nodes in the network or cooperative route during the initial broadcast. A-OLA-T alternates the set of cooperators (or OLAs) during successive transmissions to reduce the energy consumption and the duty cycles of nodes (measured in terms of the percentage time a node is on and transmitting), thereby avoiding the formation of "hot spots" (regions of overuse, high energy consumption, and traffic) in the network. Under the continuum assumption (very high node density) for two-dimensional strip networks (or routes), we obtain lower bounds (as a function of the number of alternating sets, m) on the node degree for achieving optimal load balancing in the network, and, consequently, prolonging the network life.
Demonstration of Ultralow Bit Error Rates for Spin-Torque Magnetic Random-Access Memory With Perpendicular Magnetic Anisotropy

Bit error rates below 10-11 are reported for a 4-kb magnetic random access memory chip, which utilizes spin transfer torque writing on magnetic tunnel junctions with perpendicular magnetic anisotropy. Tests were performed at wafer level, and error-free operation was achieved with 10 ns write pulses for all nondefective bits during a 66-h test. Yield in the 4-kb array was limited to 99% by the presence of defective cells. Test results for both a 4-kb array and individual devices are consistent and predict practically error-free operation at room temperature.