cssi/SciSciGPT-SciSciNet huggingface dataset:
The role of luminance and chromatic cues in emmetropisation.

Purpose At birth most, but not all eyes, are hyperopic. Over the course of the first few years of life the refraction gradually becomes close to zero through a process called emmetropisation. This process is not thought to require accommodation, though a lag of accommodation has been implicated in myopia development, suggesting that the accuracy of accommodation is an important factor. This review will cover research on accommodation and emmetropisation that relates to the ability of the eye to use colour and luminance cues to guide the responses. Recent Findings There are three ways in which changes in luminance and colour contrast could provide cues: (1) The eye could maximize luminance contrast. Monochromatic light experiments have shown that the human eye can accommodate and animal eyes can emmetropise using changes in luminance contrast alone. However, by reducing the effectiveness of luminance cues in monochromatic and white light by introducing astigmatism, or by reducing light intensity, investigators have revealed that the eye also uses colour cues in emmetropisation. (2) The eye could compare relative cone contrast to derive the sign of defocus information from colour cues. Experiments involving simulations of the retinal image with defocus have shown that relative cone contrast can provide colour cues for defocus in accommodation and emmetropisation. In the myopic simulation the contrast of the red component of a sinusoidal grating was higher than that of the green and blue component and this caused relaxation of accommodation and reduced eye growth. In the hyperopic simulation the contrast of the blue component was higher than that of the green and red components and this caused increased accommodation and increased eye growth. (3) The eye could compare the change in luminance and colour contrast as the eye changes focus. An experiment has shown that changes in colour or luminance contrast can provide cues for defocus in emmetropisation. When the eye is exposed to colour flicker the eye grows almost twice as much, and becomes more myopic, compared to when the eye is exposed to luminance flicker. Summary Neural responses of the luminance and colour mechanisms direct accommodation and emmetropisation mechanisms to different focal planes. Therefore, it is likely that the set point of refraction and accommodation is dependent on the sensitivity of the eye to changes in spatial and temporal, colour and luminance contrast.
Why Dominicans Migrate: The Complex of Factors Conducive to Undocumented Maritime Migration

This interpretive ethnography draws on interviews with migrants, smugglers, and border-enforcement personnel to provide a condensed overview of the multiple factors conducive to undocumented maritime migration from the Dominican Republic to Puerto Rico. The article explores the dynamic interactions of these economic, social, cultural, historical, political, military, religious, family, and personal factors as components of a causal composite. It also provides significant new ethnographic information that updates and expands current knowledge on Dominican migration.
Homeless children and education: an evaluation of the Stewart B. McKinney homeless assistance act

Abstract Children are the poorest group of Americans, and among those most devastated by poverty are homeless children. Numerous problems associate with homelessness for children, including academic problems: Homeless children tend to perform more poorly in school, repeat grades more often, and drop out of school more often than do other children. Risks at each stage of a homeless child's development contribute to this poor academic performance, which engenders tremendous costs for homeless children and for society. This paper explains the provisions and evaluates the worth of the Stewart B. McKinney Homeless Assistance Act of 1987 in relation to the education of homeless children. The act upholds lofty principles, but there are crucial flaws in the act itself and in the enforcement of the act that critically undermine its worth. Based on this evaluation, recommendations for policymakers are offered.
Dopamine transporter endocytic determinants: Carboxy terminal residues critical for basal and PKC-stimulated internalization

Dopamine (DA) reuptake terminates dopaminergic neurotransmission and is mediated by DA transporters (DATs). Acute protein kinase C (PKC) activation accelerates DAT internalization rates, thereby reducing DAT surface expression. Basal DAT endocytosis and PKC-stimulated DAT functional downregulation rely on residues within the 587-596 region, although whether PKC-induced DAT downregulation reflects transporter endocytosis mechanisms linked to those controlling basal endocytosis rates is unknown. Here, we define residues governing basal and PKC-stimulated DAT endocytosis. Alanine substituting DAT residues 587-590 1) abolished PKC stimulation of DAT endocytosis, and 2) markedly accelerated basal DAT internalization, comparable to that of wildtype DAT during PKC activation. Accelerated basal DAT internalization relied specifically on residues 588-590, which are highly conserved among SLC6 neurotransmitter transporters. Our results support a model whereby residues within the 587-590 stretch may serve as a locus for a PKC-sensitive braking mechanism that tempers basal DAT internalization rates.
Environmental and Resource Sociology: Theoretical Issues and Opportunities for Synthesis1

Rural sociologists have been disproportionately represented among the major contributors to environmental sociology. In part, this is because several areas of longstanding rural sociological interest (e.g., sociology of resource management and outdoor recreation, studies of resource-dependent communities) essentially came to be redefined as environmental sociology during the 1970s. The most significant role of rural sociologists in building environmental sociology, however, has perhaps been the fact that the material and biophysical nature of the phenomena they have traditionally studied contributed to a general predisposition to recognize the “materiality” of social structure and social life. I assess the major strategies that have been developed for theorizing this materiality, and then indicate some of the most critical lines of debate and dissension. I argue that if these debates are examined in their specifics—rather than as incompatible perspectives or “paradigms”—some opportunities for synthesis become apparent. Some suggested avenues of synthesis are set forth.
Work in progress — 2D paper trusses as a mechanism for teaching K12 fundamental STEM topics

Louisiana Tech University in partnership with three local high schools has recently developed NASA-Threads, a high school curriculum that integrates engineering, mathematics, and physics. The curriculum uses hands-on projects that develop student ability to solve realistic multiple-step problems and bring excitement into the classroom. One of the projects implemented in the “Work and Mechanics” portion of the curriculum involves the design, fabrication and testing of a two dimensional (2D) paper truss. Tensile truss members are made of dogbone-shaped manila folder strips, compressive specimens are made from paper mat board, and joints are held together with aluminum screw posts. The truss geometry and testing configuration ensure that the truss will fail when the most heavily loaded tensile member reaches its breaking strength. Tensile testing of individual members prior to the design process provides the data needed for students to design a truss whose load carrying capacity can be accurately estimated. The 2D paper trusses are easy to fabricate when compared to other paper or wooden trusses and provide an excellent way to introduce high school students to structural mechanics.
Dynamic economic equilibrium under redistribution

We characterize the equilibrium of simple dynamic economy with linear production and redistribution, where agents face arbitrary sequences of after tax returns on wealth. This allows us to study the dynamics of the distribution of wealth. We apply our analytical method to illustrate that for an agent with wealth less than or equal to the median, there may be no tradeoff between growth and equality, while there could be a tradeoff between growth and welfare.
Infusion of fluorinated pyrimidines into hepatic artery for treatment of metastatic carcinoma of liver.

Hepatic artery infusion of 5-fluorouracil via transbrachial artery catheter by repeated acute monthly courses has been used in 101 patients. Objective regressions were seen in 39 of 68 patients (59%) with gastrointestinal malignancies; however, only rare regressions were observed in 41 neoplasms of other primary sites. Twenty patients were treated adequately by prolonged continuous infusion of 5-fluoro-2′-deoxyuridine. Five of these patients obtained objective regressions. This was not a randomized comparative study of the two methods but comprised two separate studies. The acute intermittent program appeared superior to prolonged chronic infusion; however, with the latter method, he-matopoietic toxicity was less severe. The use of hepatic artery catheters positioned via the brachial artery has been a practical and effective method of pursuing this form of therapy with the major significant complication, irreversible ischemic changes of the fingers and hand, occurring in only two patients.
Does Chemistry Really Matter in the Chemical Vapor Deposition of Titanium Dioxide? Precursor and Kinetic Effects on the Microstructure of Polycrystalline Films

A side-by-side comparison of the TiO2 deposition kinetics and the corresponding microstructures was studied. The two precursors were titanium(IV) isopropoxide and anhydrous titanium(IV) nitrate, and all depositions were conducted at low pressures (<10-4 Torr) in an ultrahigh vacuum chemical vapor deposition reactor. For both precursors deposition kinetics were qualitatively similar and exhibited three distinct regimes as a function of temperature. At the lowest temperatures, growth was limited by the rate of precursor reaction on the substrate surface. At intermediate temperatures flux-limited growth was obtained, and at the highest temperatures the growth rates decreased with increasing temperatures. The overall behavior was modeled quantitatively for each precursor using a two-step mechanism involving reversible adsorption followed by irreversible reaction. Titanium(IV) nitrate exhibited a lower activation energy of reaction (Er = 98 kJ/mol) which allowed deposition at lower temperatures compared to tit...
Precursors to pulmonary neoplasia

Squamous dysplasia in the bronchi has been long recognized as a precursor of lung carcinoma, particularly squamous carcinoma. Atypical adenomatous hyperplasia (AAH) has been recently implicated as a precursor to adenocarcinoma. Bronchiolar neuroendocrine cell hyperplasia has also been suggested as a precursor to some pulmonary carcinoid tumors. The atypical adenomatous hyperplasia-adenocarcinoma sequence has been likened to the adenoma-carcinoma sequence in the large intestine. AAH is commonly multifocal, and may explain multicentricity that is observed with some adenocarcinomas. AAH has been shown to have immunohistochemical, morphometric, flow cytometric and genetic abnormalities overlapping with adenocarcinoma. Bronchiolar neuroendocrine cell hyperplasia (carcinoid tumorlets) is classically associated with inflammatory lesions in the airways, but may also be multifocal and bilateral. In the latter setting, lesions may attain a size greater than 0.5 cm and be (arbitrarily) classified as carcinoid tumors.
Effects of defoliation on seed protein concentration in normal and high protein lines of soybean

Two high (NC106, NC111) and two normal (NC103, NC107) seed protein concentration lines, derived from two different recurrent selection populations of soybean (Glycine max L. Merr.) were subjected to partial defoliation at beginning seed fill (R5) under outdoor pot culture and field conditions. The aim of this study was to test the hypothesis that capacity to store N in vegetative organs and/or to mobilize that N to reproductive organs is associated with the high seed protein concentration trait. Symbiotic N2 fixation was the sole source of N in the pot experiment and the major source of N (met > 50% of the N requirement) in the low N soil used in the field experiment. Seed protein concentration and seed yield at maturity in both experiments and N accumulation and mobilization between R5 and maturity in the pot experiment were measured. The four genotypes did not differ significantly with respect to the amount of N accumulated before beginning seed fill (R5). Removal of up to two leaflets per trifoliolate leaf at R5 significantly decreased the seed protein concentration of NC107/111 but had no effect on this trait in NC103/106. Defoliation treatments significantly decreased seed yield, whole plant N accumulation (N2-fixation) during reproductive growth and vegetative N mobilization of all genotypes. Differences in harvest indices between the high and low protein lines accounted for approximately 35% of the differences in protein concentration. The two normal protein lines mobilized more vegetative N to the seed (average. 5.26 g plant−1) than the two high protein lines (average. 4.28 g plant−1). The two high seed protein lines (NC106, NC111) exhibited significantly different relative dependencies of reproductive N accumulation on vegetative N mobilization, 45% vs. 29%, in the control treatment. Whereas, NC103 with normal and NC106 with high seed protein concentration exhibited similar relative dependencies of reproductive N accumulation on vegetative N mobilization, (47% vs. 45%). Collectively, these results indicate that N stored in shoot organs before R5 and greater absolute and relative contribution of vegetative N mobilization to the reproductive N requirement are not responsible for the high seed protein concentration trait.
Distinct interactions between Ca2+/calmodulin and neurotransmitter stimulation of adenylate cyclase in striatum and hippocampus.

1. Ca2+ and cAMP both act as intracellular second messengers of receptor activation. In neuronal tissue, Ca2+ acting via calmodulin can elevate cAMP levels. This regulation by Ca2+ provides a means whereby the elevation of intracellular [Ca2+] might modulate cAMP generation. 2. In the present studies, the impact of the Ca2+/calmodulin regulation on receptor-mediated stimulation of activity is compared in striatum and hippocampus—regions of differing sensitivity to Ca2+/camodulin. Ca2+/calmodulin stimulated striatal and hippocampal adenylate cyclase activity by 1.4-and 2.7-fold respectively, while dopamine and vasoactive intestinal peptide (VIP) stimulated the enzyme activity of these respective regions by 1.3- and 2-fold. 3. In the presence of Ca2+/calmodulin, the dopamine dose-response curve in the striatum was shifted upward, without alteration of the slope of the curve or of the maximal stimulation of activity elicited by dopamine. In the hippocampus, the ability of VIP to stimulate adenylate cyclase activity was reduced by the presence of calmodulin. 4. The dose dependence of these actions of calmodulin was examined. In the striatum, the stimulation of adenylate cyclase activity by 0.1 to 0.3µM calmodulin obscured dopamine stimulation, while 1 to 10µM was additive with the dopamine stimulation. In the hippocampus, all concentrations of calmodulin (0.1 to 10µM) reduced VIP-mediated stimulation of enzyme activity. 5. These data suggest that the ratio of calmodulin-sensitive to calmodulin-insensitive adenylate cyclase activity varies in different rat brain regions and that, in those regions in which this ratio is low (e.g., rat striatum and most peripheral systems), calmodulin- and receptor-mediated activation of adenylate cyclase activity will be additive, while in those systems in which this ratio is high (e.g., most of the central nervous system), calmodulin will reduce receptor-mediated stimulation of enzyme activity.
Finite-Size Scaling at Critical Points with Spatial Anisotropies

We report some selected recent developments in the finite-size scaling theory of critical phenomena occurring in systems with strong spatial anisotropies. Such systems are characterized by correlation lengths divergent with different exponents (ν⊥, ν||) along different directions. Attention is focused on the driven diffusive lattice gas that exhibits a second order nonequilibrium phase transition. We present in detail the phenomenology and its comparison with computer simulation. Novel features of finite-size effects in anisotropic nonequilibrium systems are emphasized.
Isolation, Purification, and Partial Characterization of an Autocrine Periodontal Ligament Cell Chemotactic Factor

Periodontal ligament (PDL) cells are believed to play a critically important role in the regeneration of the periodontium. We have suggested that polypeptide growth factors can enhance periodontal regeneration by stimulating PDL cell chemotaxis and mitogenesis. This manuscript describes the identification of a novel chemotactic factor isolated from human PDL cells which we named PDL-CTX. PDL-CTX induces the directed migration of human PDL cells in vitro and was found to be a more potent chemotactic agent than other known growth factors. Additionally, PDL-CTX has no chemotactic effect on gingival fibroblasts or gingival epithelial cells. Both tryptic digestion and boiling abolished PDL-CTX's biological activity. The designed purification method included Mono-S cation exchange, heparin-sepharose affinity, and microbore reverse-phase HPLC. The purified factor has a relative molecular weight of approximately 7000 daltons based on sodium dodecyl sulfate (SDS) gel analysis. The amino acid composition and partia...
Mechanisms of Microstructure Evolution in an Austenitic Stainless Steel Bond Generated Using a Quaternary Braze Alloy

In typical braze joints, melting point depressants degrade the structural robustness by concentrating as brittle phases into continuous seams along the centerline. The objective of the present article is to sufficiently understand the mechanisms governing the microstructure of a typical braze so that approaches for modifying the fabrication to eliminate brittleness can be identified. A characterization conducted for a quaternary braze used for stainless steel bonds, containing P and Si melting point depressants, reveals that the thermochemical interactions governing the microstructure include solution/reprecipitation, solid-state diffusion, and solidification. It is shown that the Si can be incorporated into a solid solution γ-Ni(Fe, Si) phase that forms by reprecipitation. Moreover, this interaction can suppress the formation of silicides within a permissible braze cycle. However, the P is only diluted through solid-state diffusion into the parent alloy. This happens slowly because of its low solubility rendering it impractical to eliminate the phosphide intermetallic. Approaches that obviate this impediment to joint robustness are described. They involve the spatial disruption of the continuous phosphide-containing eutectic with a ductile γ-Ni(Fe, Si) phase.
Deformation Criterion of Stability for Dumps Located on a Glacier (by an Example of the Kumtor Deposit)

The deformation criterion of stability is proposed to calculate the “glacier — overburden rock” system stability based on the use of the ultimate vertical deformation of glacier. The dependences of the simultaneous change in vertical displacement and total stain rate on seasonal temperature variations are established.
Comparison of admission control schemes in ATM networks

Asynchronous transfer mode (ATM) offers an efficient means of carrying a wide spectrum of BISDN traffic provided that network congestion is prevented. Unfortunately, efficient congestion control is difficult to achieve in integrated broadband networks, owing to the wide range of traffic characteristics and quality of service (QOS) requirements. We have implemented a network simulator that allows us to evaluate many proposed admission control schemes using many different traffic models. We present the results of several simulation studies, including one study of the performance of the admission control schemes in the presence of traffic sources that exhibit long-term dependence.
Distributed iterative regularization algorithms for monotone Nash games

In this paper, we consider the development of single-timescale schemes for the distributed computation of Nash equilibria. In general, equilibria associated with convex Nash games over continuous strategy sets are wholly captured by the solution set of a variational inequality. Our focus is on Nash games whose equilibrium conditions are given by monotone variational inequalities, a class referred to as monotone Nash games. Unless suitably strong assumptions (such as strong monotonicity) are imposed on the mapping corresponding to the variational inequality, distributed schemes for computing equilibria often require the solution of a sequence of regularized problems, each of which has a unique solution. Such schemes operate on two timescales and are generally harder to implement in online settings. Motivated by this shortcoming, this work focuses on the development of three single timescale iterative regularization schemes that require precisely one projection step at every iteration. The first is an iterative Tikhonov regularization scheme while the second is an analogously constructed iterative proximal-point method. Both schemes are characterized by the property that the regularization/centering parameter are updated after every iteration, rather than when one has an approximate solution to the regularized problem. Finally, a modified form of the proximal-point scheme is also presented where the weight on the proximal term is updated as well.
Survivorship issues in hematopoietic stem cell transplantation.

Objectives To review recent research of long-term complications and prevention techniques in hematopoietic stem cell transplantation (HSCT). Data Sources Peer review journals, books, and research studies. Conclusion Increasing numbers of HSCTs are performed worldwide, leading to an escalating increase in the number of survivors. Only by increased awareness in prevention, diagnosis, and lifelong surveillance can multiorgan toxicities be decreased. Implications for Nursing Practice Community nurses as well as oncology nurses practicing in research and clinical settings have unique access to patients before and after HSCT. Educating and caring for survivors throughout the entire trajectory of stem cell transplantation can assist in establishing best practice techniques to diminish these complications.
Deployment-related TBI, persistent postconcussive symptoms, PTSD, and depression in OEF/OIF veterans.

Objective: A substantial proportion of the more than 2 million service members who have served in Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) have experienced a traumatic brain injury (TBI). Understanding the long-term impact of TBI is complicated by the nonspecific nature of postconcussive symptoms (PCSs) and the high rates of co-occurrence among TBI, posttraumatic stress disorder (PTSD), and depression. The goal of the present research was to examine the relations among TBI, persistent PCSs, and symptoms of PTSD and depression among returning OEF/OIF veterans. Method: 213 OEF/OIF veterans (87% male) completed a semistructured screening interview assessing deployment-related TBI and current, persistent PCSs. Participants also completed self-report measures of combat exposure and current symptoms of PTSD and depression. Results: Nearly half (46%) of sampled veterans screened positive for TBI, the majority of whom (85%) reported at least one persistent PCS after removing PCSs that overlapped with PTSD and depression. Veterans with deployment-related TBI reported higher levels of combat exposure and symptoms of PTSD and depression. Structural equation modeling was used to assess the fit of 3 models of the relationships among TBI, combat exposure, persistent PCSs, PTSD, and depression. Consistent with hypotheses, the best-fitting model was one in which the effects of TBI on both PTSD and depression were fully mediated by nonoverlapping persistent PCSs. Conclusions: These findings highlight the importance of addressing persistent PCSs in order to facilitate the functional recovery of returning war veterans.
EPR Detects Changes in the Transmembrane Region of the SERCA-Phospholamban Complex upon Ser16 Phosphorylation

We have used site-directed spin labeling and electron paramagnetic resonance (EPR) spectroscopy to investigate the effects of Ser16 phosphorylation on phospholamban's interaction with the sarcoplasmic reticulum Ca-ATPase (SERCA). Muscle contraction is signaled by the release of Ca from the sarcoplasmic reticulum (SR), while SERCA mediates muscle relaxation by actively pumping Ca back into the SR lumen. Cardiac SERCA is regulated by phospholamban (PLB), a single-pass transmembrane protein that inhibits the Ca pump unless phosphorylated at Ser16.We have shown that Ser16 phosphorylation does not dissociate PLB from SERCA to relieve inhibition, but instead induces a structural change in PLB's transmembrane (TM) helix that restores SERCA Ca sensitivity. To characterize this change, we have attached spin labels along the TM helix and performed EPR accessibility measurements to determine the effects of Ser16 phosphorylation on TM helix topology within the regulatory complex. Our results show that upon phosphorylation, the TM helix undergoes a vertical shift that could break inhibitory interactions between SERCA and PLB. Complementary ongoing studies employ these spin-labeled PLB constructs to determine changes in (a) the orientation of PLB and (b) distances to probes on SERCA, with the goal of obtaining a detailed structural model for the regulatory transitions within the SERCA-PLB complex.
On the motion of a flat plate at high speed in a viscous compressible fluid. I. Impulsive motion

The effect of giving an infinite plate, immersed in a compressible fluid, an impulsive velocity U in its own plane is examined on the assumption that M = U / a 0 ≫ 1 where a 0 is the velocity of sound in the undisturbed fluid. To begin with the flow field is very complex but very soon after the motion has begun a shock wave moves at right angles to the plate gradually weakening and eventually degenerating into a sound wave. Attention is concentrated on the flow field when there is a distinct strong shock wave, it being assumed, and justified a posteriori , that the flow behind it may be divided into an inviscid region and a boundary layer region. The equation of the shock wave and a complete description of the flow behind it is found when log M , where ν 0 is the coefficient of kinematic viscosity of the undisturbed air. An approximate method is also given to enable the solution to be joined up to Van Dyke's (10) which is valid when .
Length Scale Selects Directionality of Droplets on Vibrating Pillar Ratchet

Directional control of droplet motion at room temperature is of interest for applications such as microfluidic devices, self-cleaning coatings, and directional adhesives. Here, arrays of tilted pillars ranging in height from the nanoscale to the microscale are used as structural ratchets to directionally transport water at room temperature. Water droplets deposited on vibrating chips with a nanostructured ratchet move preferentially in the direction of the feature tilt while the opposite directionality is observed in the case of microstructured ratchets. This remarkable switch in directionality is consistent with changes in the contact angle hysteresis. To glean further insights into the length scale dependent asymmetric contact angle hysteresis, the contact lines formed by a nonvolatile room temperature ionic liquid placed onto the tilted pillar arrays were visualized and analyzed in situ in a scanning electron microscope. As a result, the ability to tune droplet directionality by merely changing the length scale of surface features all etched at the same tilt angle would be a versatile tool for manipulating multiphase flows and for selecting droplet directionality in other lap-on-chip applications.
Building a legacy of volunteers through servant leadership: A cause-related sporting event

This study explores the leadership style of the founder of a cause-related sporting event and investigates the effects of this style on motivating volunteers. The National Kidney Foundation Surf Festival, established more than twenty-five years ago to benefit people with kidney disease, was selected as an extreme case because of the event's longevity and success. Data were collected through semi-structured personal interviews, document analysis, and personal observation. Results indicated that the founder is a servant leader. Three key themes of servant leadership, and its influence on volunteer motivation, emerged from the data: generating a shared vision dedicated to helping others, building a caring and loving community, and creating the freedom and resources for followers to become servants themselves. Our findings also indicated that the spiritual and moral tenets of servant leadership are applicable to secular nonprofit organizations.
An Assessment: Student Satisfaction in Noncredit Programs

(1982). An Assessment: Student Satisfaction in Noncredit Programs. The Journal of Continuing Higher Education: Vol. 30, No. 1, pp. 9-11.
It's Not Too Late: Insomnia Research and Palliative Care:

The purpose of palliative care is to alleviate noxious symptoms and promote quality of life in patients and families facing life-threatening illness. Although research in palliative care has made advances in evidenced-based practice, research into sleep disturbances in the context of advanced disease has remained very limited. This research deficit is critical given that sleep disturbance can have a significant impact on quality of life. The purpose of this article is to explore relationships between sleep disturbance and palliative care as reflected in the literature. From this perspective, the author concludes with issues of relevance to nursing care of patients with advanced disease.
Contexts of English Language Use among Immigrants to the United States1

This analysis of New Immigrant Survey data indicates that the longer immigrants are in the U.S., the more likely they are to use English with friends, at work, at home, and with a spouse. The average immigrant arriving as a young adult has a predicted probability of using English with friends upon arrival of 0.44, a figure that doubles after 15 years in the U.S. The same average immigrant has a 0.40 probability of using English at home upon arrival, which rises to 0.55 after 15 years. The results suggest substantial language shift with the first generation.
Detection of unsuspected renal artery stenoses in patients with abdominal aortic aneurysms: Refined indications for preoperative aortography

Renal artery stenoses (RASs) that are unsuspected on clinical grounds are common in patients with peripheral vascular disease. These lesions may be missed in patients with abdominal aortic aneurysms (AAAs) who undergo arteriography based on selective clinical indications alone. We reviewed 98 consecutive patients with AAAs to determine how often selective arteriography would fail to diagnose unsuspected RAS. The location and degree of RASs were noted on preoperative arteriograms, which were routinely obtained in all patients considered for AAA repair during the study period. Medical records were studied to determine the presence of selective clinical indications for preoperative arteriography (moderate to severe hypertension or renal insufficiency). Twenty-four patients had a significant (≥50% diameter loss) RAS, and 10 patients had a severe (≥75% diameter loss) RAS or renal artery occlusion. Patients with significant RAS had a higher incidence of hypertension (p=0.035) and renal insufficiency (p=0.018). All 10 patients with severe RASs required at least two antihypertensive medications to control their hypertension compared with 22 of 88 patients who did not have a severe RAS (p<0.001). Forty-three patients had an indication for arteriography according to selection criteria (renal insufficiency, moderate or severe hypertension, or both). No severe RASs were found in patients who did not meet the selection criteria for arteriography. Using arteriography based on the presence of hypertension requiring two or more medications for control will detect the vast majority of severe, unsuspected RASs in AAA patients.
Lessons learned obtaining informed consent in research with vulnerable populations in community health center settings

Background: To improve equity in access to medical research, successful strategies are needed to recruit diverse populations. Here, we examine experiences of community health center (CHC) staff who guided an informed consent process to overcome recruitment barriers in a medical record review study. Methods: We conducted ten semi-structured interviews with CHC staff members. Interviews were audiotaped, transcribed, and structurally and thematically coded. We used NVivo, an ethnographic data management software program, to analyze themes related to recruitment challenges. Results: CHC interviewees reported that a key challenge to recruitment included the difficult balance between institutional review board (IRB) requirements for informed consent, and conveying an appropriate level of risk to patients. CHC staff perceived that the requirements of IRB certification itself posed a barrier to allowing diverse staff to participate in recruitment efforts. A key barrier to recruitment also included the lack of updated contact information on CHC patients. CHC interviewees reported that the successes they experienced reflected an alignment between study aims and CHC goals, and trusted relationships between CHCs and staff and the patients they recruited.
Capacity analysis of free-space optical communication channels with multiple receiver apertures

A laser beam experiences random wavefront distortion, beam wander, and beam broadening along its path through the turbulent atmosphere. These atmospheric effects cause excessive average power loss and random power fluctuation, called fading, at the receiver aperture. Using multiple receiver apertures is an effective approach to mitigate channel fading by exploring spatial diversity. This paper studies the free-space optical communication systems with single transmitter aperture and multiple receiver apertures from an information-theoretical point of view. The system is modeled as a discrete-time binary-input slowly fading Poisson channel. The maximum channel capacity and the corresponding optimal binary distribution are derived for signal dominated binary-input Poisson channels. An information-theoretical justification of using equiprobable binary distribution for the widely used OOK modulated optical system is provided. It is proved that fading always decreases average channel capacity if channel is signal dominated. However, fading-free capacity can be approached by using large number of receiver apertures. For systems employing low dark current photodetectors, multiple receiver apertures can both increase channel capacity and decrease outage probability. However, if dark current level is high, more receiver apertures may result in lower channel capacity. The connections between single and multiple receiver aperture channels are studied.
Ontogenetic development of nutrient transporters in cat intestine

The ratio of intestinal glucose (Glc) to amino acid (AA) transporter activity rises with age in animals of species in which the ratio of dietary carbohydrate to protein also rises. Does this shift function to match transporter activity to current dietary substrate levels or to the high AA requirements of young growing animals? We compared intestinal brush-border uptake of Glc and the AA proline (Pro) in adult and tadpole bullfrogs, since with age this species changes from an herbivore to a carnivore and hence its dietary carbohydrate-to-protein ratio decreases rather than increases. Like typical adult herbivores, tadpoles have a long, highly coiled, narrow-bore, thin-walled intestine with a long, heavy colon, whereas adult bullfrogs have a short, wide-bore, thick-walled intestine typical of carnivores. The ratio of Glc to Pro uptake capacity is essentially the same in adults as in larval tadpoles and is typical of carnivores but unprecedently low for herbivores. This suggests that both functions proposed for developmental shifts of Glc and AA transport in other species are significant and that their effects cancel each other in bullfrogs. Transporter kinetic constants vary predictably with developmental stage. Intestinal daily uptake capacity is comparable to actual daily intake for Glc in adults and for Pro in both tadpoles and adults but is much lower than intake for Glc in tadpoles, probably because most carbohydrate ingested by tadpoles is in the form of high molecular weight polymers that are not utilized.
Proton Magnetic Resonance Studies of Adsorption of Salts on Dextran Gels

Abstract The proton magnetic resonance spectra of various salt-gel solutions and frozen salt-gel solutions are reported for dextran gels. When compared to spectra obtained for polyacrylamide gels and ion-retardation resins, very little adsorption is noted for dextran gels. Therefore, the probable mechanism for separation of inorganic salts by dextran gels is ion exclusion.
Detailed measurements of the H beta line shape in a transient plasma using a fiber optics slit system.

Through the use of fiber optics, a series of very narrow slits have been constructed and placed at the exit plane of a spectrograph. Plasma radiation which is dispersed by the spectrograph is incident on the slits and is transmitted to separate phototubes via the quartz fibers. With this technique, time resolved measurements of the spectral shape of the hydrogen H beta line have been made and used to determine the electron density of a transient plasma. Data obtained in a shock tube indicated that the thermodynamic conditions behind the reflected shock in a mixture of 20% H2-80% He, at incident shock speeds of 12 to 14 km/sec and pressures of 66.6 to 133.3 N/sq m (0.5 to 1.0 mm Hg), correspond to theoretically predicted conditions. Immediately behind the incident shock at speeds of 17 to 24 km/sec the data indicate that the plasma reached equilibrium then demonstrated a drop in intensity which has been attributed to radiative cooling.
Metal-to-Metal Silyl Migration and Silicon−Carbon Bond Cleavage/Re-formation Processes in the Methylene/Silyl Complexes Cp*2Ru2(μ-CH2)(SiR3)(μ-Cl)

Ruthenium methylene/silyl complexes of stoichiometry Cp{sup *}{sub 2}Ru{sub 2}({mu}-CH{sub 2})(SiR{sub 3})({mu}-Cl), where SiR{sub 3} = SiMe{sub 3} (1), SiEt{sub 3} (2), SiMe{sub 2}Et (3), and SiMe{sub 2}Ph (4), are produced when [Cp{sup *}RuCl]{sub 4} is treated with the appropriate dialkylmagnesium reagent, Mg(CH{sub 2}SiR{sub 3}){sub 2}. Each complex undergoes two fluxional processes as observed by variable-temperature {sup 1}H NMR spectroscopy. The low-temperature exchange process is migration of the SiR{sub 3} unit from one Ru center to the other, whereas the high-temperature process is the reversible re-formation of the C-Si bond between the silyl group and the bridging methylene unit. The activation parameters for the low-temperature exchange process in 1--4 are sensitive to the nature of the silyl group: {Delta}H{sup {double_dagger}} becomes smaller and {Delta}S{sup {double_dagger}} becomes more negative if the SiR{sub 3} group bears nonidentical or larger, more flexible substituents. This finding suggests that the transition state for this exchange process is crowded or characterized by different amounts of solvent reorganization depending on the SiR{sub 3} group involved. In contrast, the activation parameters for the high-temperature process in 1--4 are relatively independent of the nature of the silyl ligand. The small variation in the activation parameters for reformation of the C-Simore » bond is consistent with a noncrowded transition state in which the solvent reorganization is relatively independent of the nature of the SiR{sub 3} group.« less
Finite element modeling of pulse Eddy current NDT phenomena

Transient electromagnetic fields for nondestructive testing (pulse eddy current methods) have been used experimentally for such applications as coating thickness measurements [1] and the inspection of reactor fuel tubing.[2] The lack of suitable models to facilitate understanding of the interaction of the pulsed field with the test specimen has hindered a wider acceptance of the method as a tool in NDT. Two models, based on the finite element technique, are described. A through transmission arrangement of a source and pickup coil with a conductive plate separating the two coils is modeled. The first model, used for a periodic current pulse source, makes use of the Fourier series of the source current to solve a steady-state problem for each significant harmonic. The harmonic solutions are then summed to calculate the total EMF in the pickup coil. The second model provides a transient time stepping solution for a single current pulse applied to the source coil. In both cases, axisymmetric geometries are studied using a magnetic vector potential formulation. Solutions are compared with experimental results.
Selegiline in the Treatment of Negative Symptoms of Schizophrenia

Key words: Selegiline; schizophrenia; negative symptoms; neurotherapeutics; clinical trial. Introduction and Overview One of the great successes of modern psychiatry was the introduction of antipsychotic drugs over 50 years ago (Ayd & Blackwell, 1970). The impressive effectiveness of these agents in relieving florid positive symptoms of schizophrenia has permitted a whole population of formerly institutionalized patients to live in the community. Unfortunately, this great benefit has not been matched by the effect of antipsychotic drugs on the negative symptoms of schizophrenia, which so limit the daily function of these patients, and classical neuroleptics often worsened these symptoms. More recently, atypical antipsychotics have shown improved properties in this regard, but negative symptoms remain the least medication-responsive features of chronic schizophrenia. The impoverishment of emotion and initiative that underlie negative symptoms resemble symptoms affecting patients with Parkinson's disease, as well as the pseudo-parkinsonian effects of first-generation antipsychotics, and has been hypothesized to reflect specific deficits in the functioning of dopaminergic pathways (Bermanzohn & Siris, 1992; Davis et al ., 1991). Selegiline (formerly 1-depreny1) is a dopamine enhancing antiparkinsonian drug (Knoll, 1983), which acts as a selective monoamine oxidase type B (MAO-B) inhibitor without the clinical toxicities that have limited the use of non-selective MAO inhibitors (MAOIs) in psychiatry. The potential of selegiline to alleviate some of the parkinsonian-like emotional deficits of schizo-phrenics has led to a series of investigations of its use as a specific remedy for negative symptoms over the past 15 years.
A parallel GPSS based on the ParaSol simulation system

Much of the research in parallel discrete-event simulation (PDES) has resulted in new experimental simulation languages or toolkits. Meanwhile, the simulation community continues to use existing (serial) commercial tools which are reportedly more powerful and flexible from a modeler's point of view. A possible way to increase the impact of PDES in the simulation community is to make existing simulation packages execute in parallel. Towards this end, we present a parallelization of the GPSS simulation language. We implement parallel GPSS as a GPSS-to-C++ translator and execute the transformed code with the help of the ParaSol parallel simulation system. The mapping from GPSS to ParaSol is simple because, unlike other parallel simulation systems, ParaSol is transaction oriented. On the other hand, because GPSS was not designed with parallelism in mind 'there are GPSS constructs that can behave poorly in a parallel environment. We present details on the mapping, some of the challenges we faced in this task, and key solutions that we adopted to enhance parallelism.
Cell-mediated Delivery and Targeted Erosion of Vascular Endothelial Growth Factor-Crosslinked Hydrogels.

We have previously reported a novel polymeric delivery vehicle that is assembled via interaction between heparin and the vascular endothelial growth factor (VEGF). Here, the cell-responsiveness of this hydrogel — including the delivery of VEGF in response to VEGFR-2 overexpressing PAE/KDR cells (porcine aortic endothelial cells (PAE) equipped with the transcript for the kinase insert domain receptor (KDR)), consequent erosion of the hydrogel matrix, and cellular response - are highlighted. The release of VEGF and hydrogel erosion reached 100% only in the presence of PAE/KDR. The [PEG-LMWH/VEGF] hydrogel (PEG = poly(ethylene glycol), LMWH = low molecular weight heparin) correspondingly prompted increases in VEGFR-2 phosphorylation and proliferation of PAE/KDR cells. This study proves that growth factor-crosslinked hydrogels can liberate VEGF in response to specific receptors, causing gel erosion and desired cell responses. The promise of these approaches in therapeutic applications, including targeted delivery, is suggested.
Quantifying size distributions of nanolipoprotein particles with single-particle analysis and molecular dynamic simulations

Self-assembly of purified apolipoproteins and phospholipids results in the formation of nanometer-sized lipoprotein complexes, referred to as nanolipoprotein particles (NLPs). These bilayer constructs are fully soluble in aqueous environments and hold great promise as a model system to aid in solubilizing membrane proteins. Size variability in the self-assembly process has been recognized for some time, yet limited studies have been conducted to examine this phenomenon. Understanding the source of this heterogeneity may lead to methods to mitigate heterogeneity or to control NLP size, which may be important for tailoring NLPs for specific membrane proteins. Here, we have used atomic force microscopy, ion mobility spectrometry, and transmission electron microscopy to quantify NLP size distributions on the single-particle scale, specifically focusing on assemblies with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and a recombinant apolipoprotein E variant containing the N-terminal 22 kDa fragment (E422k). Four discrete sizes of E422k/DMPC NLPs were identified by all three techniques, with diameters centered at ∼14.5, 19, 23.5, and 28 nm. Computer simulations suggest that these sizes are related to the structure and number of E422k lipoproteins surrounding the NLPs and particles with an odd number of lipoproteins are consistent with the double-belt model, in which at least one lipoprotein adopts a hairpin structure.
Negotiating Frames Through Refusal Acts: A Pragmatic Analysis of Native/ Non-native Speakers' Interactions in Problem-Solving Telephone Conversations

The purpose of this study is to investigate frame negotiation and construction through a pragmatic analysis of the speech act refusal. This act serves as a marker of conflicting frames in Problem-Solving-Service Call (PSSC) interac- tions between native speakers of English and non-native speakers of English (NNS). Sixteen authentic PSSCs were re- corded by eight NNS (Chinese) when they were talking to customer service representatives. A pragmatic analysis of mo- ment-by-moment encounters of their interactions will, first, demonstrate how refusal acts trigger conflicting frames; sec- ond, how conflicting frames are further marked by structured linguistic items to indicate individuals' presuppositions, and third how conflicting frames are redefined through a co-constructing process. Instructional implications are provided to suggest frame knowledge building in second language learning activities.