cssi/SciSciGPT-SciSciNet huggingface dataset:
Taking a Break, or Taking a Class? Examining the Effects of Incentivized Summer Enrollment on Student Persistence

This study examines the effects of an incentivized summer enrollment initiative on student persistence. In particular, we analyze how participation in summer classes (at least 3 credit hours) affect students’ likelihood to reenroll in the fall semester at a two-year, private, technical college in Boston. The novel initiative, which provides eligible students with a free summer class of up to four credits, was launched in academic year 2010–2011. We obtained data for five consecutive cohorts since implementation at the Benjamin Franklin Institute of Technology. To study its effects, we build on the framework of academic momentum, human capital theory, and draw from the behavioral economics literature. To better account for potential selection bias in the estimation, this study employs two propensity score matching techniques, including a doubly robust design. We find that attending summer classes is associated with significant increases in students’ chances to persist and reenroll in the fall semester. More specifically, we estimate the average treatment effect (ATE) and average treatment effect on the treated (ATET) to be between 30 and 32%. Results also show a higher percentage of students enrolling in summer classes at this institution (35%) when compared to national rates. Based on our results and previous findings in the literature, we argue there is mounting evidence that attending summer session increases student persistence and degree completion, and that the combination of summer enrollment with well-designed incentive structures can enhance positive effects further. Implications for policy and educational practice are discussed.
Energy-aware leader-follower tracking control for electric-powered multi-agent systems

Abstract This paper aims to extend the operation time/range of an electric-powered multi-agent system (MAS) in leader-followertracking tasks, through integrating battery-based energy awareness with distributed tracking control synthesis. While MASs have gained much popularity nowadays, their use and deployment are often restricted by the operation time/range, due to the limited battery capacity. In an effort to overcome such a barrier, this work proposes to leverage a battery’s rate capacity effect to extend its runtime, which states that more energy can be drawn from the battery on less aggressive discharging rates. The battery-aware leader-follower tracking control design is then established in a model predictive control (MPC) framework, which strikes a tradeoff between tracking performance and energy consumption rates, accounts for the battery’s rate capacity dynamics, and incorporates the energy and power constraints. A distributed optimization method is used to distribute the MPC across the agents of the MAS. leader-follower tracking based on the proposed distributed MPC algorithm is then evaluated through a case study and compared with an existing algorithm in the literature. The simulation results show its effectiveness in extending the operation.
A Command-by-Intent Architecture for Battlefield Information Acquisition Systems

In military operations, Commander's Intent describes the desired end state and purpose of the operation, expressed in a concise and clear manner. Command by intent is a paradigm that empowers subordinate units to exercise measured initiative to meet mission goals and accept prudent risk within commander's intent. It improves agility of military operations by allowing exploitation of local opportunities without an explicit directive from the commander to do so. This paper discusses what the paradigm entails in terms of architectural decisions for data fusion systems tasked with real-time information collection to satisfy operational mission goals. In our system, information needs of decisions are expressed at a high level, and shared among relevant nodes. The selected nodes, then, jointly operate to meet mission information needs by forwarding and caching relevant data without explicit directives regarding the objects to fetch and sources to contact. A preliminary evaluation of the system is presented using a target tracking application, set in the context of a NATO-based mission scenario, called Anglova. Evaluation results show that delegating some decision authority to the data fusion system (in terms of objects to fetch and sources to contact) allows it to save more network resources, while also increasing mission success rate. The system is therefore particularly well-suited to operation in partially denied or contested environments, where resource bottlenecks caused by adversarial activity impair one's ability to collect real-time information for mission-critical decision making.
Chronic low level oxidative stress in primary hyperoxaluria type 1

The Primary Hyperoxalurias (PH’s) are a family of inborn errors of glyoxylate metabolism resulting in excessive production of endogenous oxalate and PH1 is the most severe form of this disorder. There is no cure and treatment options are limited due to a poor understanding of the underlying pathology. Based on previously published reports we hypothesize that oxidative stress may play a unique role in PH1. In the absence of alanine-glyoxylate aminotransferase (AGT), the liver specific enzyme deficient in PH1, a futile redox cycle can occur between glycolate oxidase (GO) and glyoxylate reductase (GR). GO produces hydrogen peroxide and GR consumes NADPH. This mechanism points to a potential alteration in redox environment that has not yet been studied. Therefore, we performed a comprehensive global proteomics study comparing livers of PH1 mice to WT mice. In this study we found 155 significantly altered proteins, including 36 redox related proteins. PH1 model mice at experimental age show no phenotypic difference except for increased oxalate excretion. This data, combined with the use of Systems/ Pathway analysis, strongly suggests that PH1 mice are experiencing oxidative stress. Interestingly, functional data did not fully reflect these findings. mtDNA damage was not significantly changed in PH1 vs. WT using an XLPCR technique, nor was urinary 8-oxodG using an ELISA kit. However, GSH levels were significantly lower in PH1 mice measured by HPLC-ECD. All together this evidence suggests that the PH1 mouse is experiencing chronic low levels of oxidative stress that the mouse is compensating for at the proteomic level. Therefore, we have concluded that the redox related proteins have been modified in order to cope with an otherwise undetectable change in oxidative stress. We believe this is a highly unusual multi-tool approach and finding that the standard oxidative stress related tools would have missed if carried out alone.
Role of Bile Acids and GLP-1 in Mediating the Metabolic Improvements of Bariatric Surgery.

Background & aims Bile diversion to the ileum (GB-IL) has strikingly similar metabolic and satiating effects to Roux-en-Y gastric bypass (RYGB) in rodent obesity models. The metabolic benefits of these procedures are thought to be mediated by increased bile acids, although parallel changes in body weight and other confounding variables limit this interpretation. Methods Global G protein–coupled bile acid receptor-1 null (Tgr5−/−) and intestinal-specific farnesoid X receptor null (FxrΔ/E) mice on high-fat diet as well as wild-type C57BL/6 and glucagon-like polypeptide 1 receptor deficient (Glp-1r−/−) mice on chow diet were characterized following GB-IL. Results GB-IL induced weight loss and improved oral glucose tolerance in Tgr5−/−, but not FxrΔ/E mice fed a high-fat diet, suggesting a role for intestinal Fxr. GB-IL in wild-type, chow-fed mice prompted weight-independent improvements in glycemia and glucose tolerance secondary to augmented insulin responsiveness. Improvements were concomitant with increased levels of lymphatic GLP-1 in the fasted state and increased levels of intestinal Akkermansia muciniphila. Improvements in fasting glycemia after GB-IL were mitigated with exendin-9, a GLP-1 receptor antagonist, or cholestyramine, a bile acid sequestrant. The glucoregulatory effects of GB-IL were lost in whole-body Glp-1r−/− mice. Conclusions Bile diversion to the ileum improves glucose homeostasis via an intestinal Fxr-Glp-1 axis. Altered intestinal bile acid availability, independent of weight loss, and intestinal Akkermansia muciniphila appear to mediate the metabolic changes observed after bariatric surgery and might be manipulated for treatment of obesity and diabetes.
Instructed-assembly of small peptides inhibits drug-resistant prostate cancer cells

Despite multiple new-drug approvals in recent years, prostate cancer remains a global health challenge because of the prostate cancers are resistant to androgen deprivation therapy. Here we show that a small D-phosphopeptide undergoes prostatic acid phosphatase (PAP)-instructed self-assembly for inhibiting castration-resistant prostate cancer (CRPC) cells. Specifically, the installation of phosphate at the C-terminal of a D-tripeptide results in the D-phosphopeptide. Dephosphorylating the D-phosphopeptide by PAP forms uniform nanofibers that inhibit VCaP, a castration-resistant prostate cancer cell. A non-hydrolyzable phosphate analogue of the D-phosphopeptide, which shares similar self-assembling properties with the D-phosphopeptide, confirms that PAP-instructed assembly is critical for the inhibition of VCaP. This work, for the first time, demonstrates PAP-instructed self-assembly of peptides for selective inhibiting castration-resistant prostate cancer (CRPC) cells.
Mechanical Thrombectomy in Distal Vessels: Revascularization Rates, Complications, and Functional Outcome.

Introduction Pivotal trials have shown the tremendous efficacy of mechanical thrombectomy in proximal occlusions. However distal occlusions involving second-order branches of the middle cerebral artery and beyond, anterior cerebral and posterior cerebral arteries were not represented. In this study, we investigated the feasibility and safety of distal circulation mechanical thrombectomy. Methods A retrospective review of patients presenting with distal circulation acute ischemic stroke who underwent mechanical thrombectomy 2010 and 2018. Results Of 453 patients who underwent mechanical thrombectomy for acute ischemic stroke, 76 had a distal occlusion. The mean National Institute Health Stroke Scale on admission was 12. Vessels involved included second-order branches of the middle cerebral artery (89%), third- and fourth-order branches of the middle cerebral artery (5%), second-order branch of the anterior cerebral artery (3%), and posterior cerebral artery (3%). Most procedures required 1 pass to recanalize the vessel (55%, n = 42). Thrombolysis in Cerebral Infarction score ≥IIb was achieved in 89% of subjects. Mortality rate was 8% and independent functional outcome of m Rankin score ≤2 at 3 months was seen in 64.7% with clinical follow-up. On multivariate analysis, distal circulation had a significantly shorter length of stay by about 2 days, compared with proximal circulation. Subjects with proximal occlusion were more than 5 times more likely to have a good Thrombolysis in Cerebral Infarction score compared with the distal group. There was no significant difference in periprocedural and postprocedural complications, good functional outcome at 3 months, and mortality between both groups. Conclusions Mechanical thrombectomy procedure for distal circulation strokes is as effective and safe as a proximal group. Though distal vessels supply smaller brain area; however, when symptoms are pronounced, the benefit of the procedure outweighs the risks.
Redox-Active Heteroacene Chromophores Derived from a Nonlinear Aromatic Diimide.

This work describes a three-step chromatography-free protocol for the synthesis of a novel organic materials building block, dichlorinated mellophanic diimide (MDI), that is shown to undergo nucleo...
Gut microbiome, antibiotic use, and immunotherapy responsiveness in cancer.

Immune checkpoint inhibitors (ICIs) have transformed the treatment of solid malignancies, but responses are heterogeneous with benefit generally limited to only a fraction of patients.
Recapturing Control: Robotics and the Shift from Medicalized to Biomedicalized Surgery

Biomedicalization theory has proven itself a generative theoretical lens for examining the commodification of health and the associated constitution of new medical practices. A shift from the contr...
Chapter 14 – Neurodegenerative disorders

Publisher Summary Neurodegenerative disorders are a heterogeneous collection of well-recognized conditions of unknown etiology having in common a clinical history of a set of characteristic neurologic deficits with pathoanatomic correlation. Recent classifications emphasize clinical presentations, such as dementing, movement, and neuromuscular disorders. Others may be identified only by extensive and expensive immuno cytochemical and biochemical studies. In this chapter, the most common disorder encountered is Alzheimer's disease (AD). Some cases with these chronic conditions are seen by the medical examiner because of an unexpectedly sudden death. As exemplified, asphyxia may result from aspiration of food or foreign objects in persons with dementia and/or neuromuscular disorders. More usual circumstances include death at home with evidence of neglect by a caretaker, the possibility of elder abuse of the demented, and those killed by auto and other accidents while wandering. Decedents with nondementing disorders under medical management, such as those with Parkinson's disease, are seen much less frequently. The gross anatomic features of the brain of a case of AD, even those submitted with a history of dementia, may show surprisingly minor deviations from the norm.
Correction to: An innovative approach to integrate unequal protection-based steganography and progressive transmission of physiological data

There was an error in Eq. 15 in the original publication. The term |C (k)| should have been in the denominator.
DC-link Capacitor Voltage Balancing Control for Series Half Bridge LLC Resonant Converter

This paper presents control methods that achieve DC-link capacitor voltage balance of a series half bridge (SHB) LLC resonant converter operating at different modulation schemes. The principle of the proposed balancing control method is analyzed and studied based on six normally used operation modes of the SHB LLC converter. DC-link capacitor voltage balancing strategies are developed separately for two common modulation schemes in SHB topology. The performance of the proposed voltage balancing control method is experimentally verified on a 7.5-kW SHB LLC DC/DC converter prototype under different operating conditions.
Synergistic effect of high-light and low temperature on cell growth of the Δ12 fatty acid desaturase mutant in Synechococcus sp. PCC 7002

The effect of polyunsaturated fatty acids on photosynthesis and the growth of the marine cyanobacterium Synechococcus sp. PCC 7002 was examined using wild-type and Δ12 fatty acid desaturase mutant strains. Under a light intensity of 250 μmol m−2 s−1, wild-type cells could grow exponentially in a temperature range of 20–38 °C, but growth was non-exponential below 20 °C and ceased at 12 °C. The Δ12 desaturase mutant cells lacking polyunsaturated fatty acids had the same growth rate as wild-type cells in a temperature range of 25–38 °C but grew slowly at 22 °C, and no cell growth took place below 18 °C. Under a very high-light intensity of 2.5 mmol m−2 s−1, wild-type cells could grow exponentially in a temperature range of 30–38 °C, although the high-light grown cells became chlorotic because of nitrogen limitation. The temperature sensitive phenotype in the Δ12 desaturase mutant was enhanced in cells grown under high-light illumination; the mutant cells could grow at 38 °C, but were killed at 30 °C. The decrease of oxygen evolution and nitrate consumption by whole cells as a function of temperature was similar in both wild type and the Δ12 desaturase mutant. No differences were observed in either light-induced damage of oxygen evolution or recovery from this damage. No inactivation of oxygen evolution took place at 22 °C under the normal light intensity of 250 μmol m−2 s−1. These results suggest that growth of the Δ12 desaturase mutant at low temperature is not directly limited by the inactivation of photosynthesis, and raise new questions about the functions of polyunsaturated membrane lipids on low temperature acclimation in cyanobacteria.
Adhesion molecule L1 inhibition increases infarct size in cerebral ischemia-reperfusion without change in blood-brain barrier disruption.

Objective Neural cell adhesion molecule L1CAM (L1) is involved in neuroprotection. To investigate a possible neuroprotective effect of L1 during ischemia, we determined whether blocking L1 with an antagonistic antibody would worsen the outcome of focal cerebral ischemia-reperfusion and increase blood-brain barrier (BBB) disruption. Methods Transient middle cerebral artery occlusion (MCAO) was performed in anesthetized rats. Five µg of antagonistic mouse IgG monoclonal L1 antibody 324 or non-immune control mouse IgG was applied on the ischemic-reperfused cortex during one hour of MCAO and two hours of reperfusion. At two hours of reperfusion, BBB permeability, size of infarct using tetrazolium staining, number of TUNEL-labeled apoptotic cells, and immunohistochemistry for expression of PTEN and p53 were studied. Results The antagonistic L1 antibody 324 increased the percentage of cortical infarct area (+36%), but did not affect BBB permeability in the ischemic-reperfused cortex. The antagonistic L1 antibody increased number of apoptotic neurons and p53 expression, but decreased PTEN expression. Conclusion Functional antagonism of L1 increases infarct size by increasing numbers of apoptotic neurons without affecting BBB permeability during the early stage of cerebral ischemia-reperfusion. Our data suggest that L1 affects primarily the brain parenchyma rather than BBB during early stages of cerebral ischemia-reperfusion and that endogenous brain L1 may be neuroprotective.
Leader Power and Agency-Communion Orientations as Moderators of the Effects of Organizational Characteristics on Workplace Bullying

This conceptual paper suggests that the distinction between an autocratic and democratic leadership orientation may serve as an important moderator of the relationship between key organizational characteristics and workplace bullying. More specifically, we explore leader autocratic vs. democratic power orientations and leader agentic vs. communal orientations as the theoretical bases for developing a new model of perceived leadership orientation as a moderator of the relationships between certain key organizational characteristics and perceptions of workplace bullying behavior. Our model proposes differential moderating effects for both leader autocratic-democratic power orientation and leader agentic-communal orientation. Particularly, we contend that democratic and communal leadership orientations may lead to fewer perceptions of bullying in the workplace. We conclude with a discussion of our model’s practical implications and suggestions for future research on this subject.
Types of information that patients with lung cancer with targetable driver mutations and their caregivers learn from online forums: Results of a qualitative study.

161Background: Patients and caregivers seek information about cancer from a variety of sources in addition to their medical team. In recent years, patients with specific lung cancer subtypes have c...
Application of Dynamic Mode Decomposition to Study Temporal Flow Behavior in a Saccular Aneurysm.

Aneurysms are abnormal expansion of weakened blood vessels which can cause mortality or long-term disability upon rupture. Several studies have shown that inflow conditions spatially and temporally influence aneurysm flow behavior. The objective of this investigation is to identify impact of inflow conditions on spatio-temporal flow behavior in an aneurysm using Dynamic Mode Decomposition (DMD). For this purpose, low-frame rate velocity field measurements are performed in an idealized aneurysm model using Particle Image Velocimetry (PIV). The inflow conditions are precisely controlled using a ViVitro SuperPump system where non-dimensional fluid parameters such as peak Reynolds number (Rep) and Womersely number (α) are varied from 50-270 and 2-5, respectively. The results show the ability of DMD to identify the spatial flow structures and their frequency content. Furthermore, DMD captured the impact of inflow conditions, and change in mode shapes, amplitudes, frequency, and growth rate information is observed. The DMD low-order flow reconstruction also showed the complex interplay of flow features for each inflow scenario. Furthermore, the low-order reconstruction results provided a mathematical description of the flow behavior in the aneurysm which captured the vortex formation, evolution, and convection in detail. These results indicated that the vortical structure behavior varied with the change in α while its strength and presence of secondary structures is influenced by the change in Rep.
The representation of coordinator meanings

This chapter provides the analysis of coordination introduced in terms of abstract logical operators. It shows several advantages of the correlational approach and provides a common semantics for the coordination of both phrases and clauses, as well as for the discourse coherence of the juxtaposed sentences. The coordination of every major category is possible, which produces some possibilities such as: nominal phrases, common noun phrases and determined noun phrases, and clauses known as the complementizer phrases. In addition, it is argued that all coordination can be understood as expressing a degree of correlation between (at least) two vectors. For the coordination of phrases, one vector is the denotation of the coordinated linguistic category and the other is the vector denoting the linguistic category which the coordinated category applies, which is given by the grammar. For the coordination of clauses, the vectors are those denoted by the two (or more) coordinated clauses. The choice of correlation is mandated by the hypothesis that it is implemented neurologically by Hebbian learning and perhaps by synchronization of oscillating cells or cell assemblies.
DSC studies of new energy storage materials

Abstract Energy storage materials (ESMs) have shown some utility in passive supplemental heating applications. This investigation was undertaken to ascertain the value in passive cooling applications of some known and some new ESMs using differential scanning calorimetry. The method works extremely well in all cases tested, both for single heating and cooling runs and for continuous heating and cooling cycles. The scale-up full-room tests give the same results as DSC further validating this method. Though the materials studied all have some desirable properties, none was deemed of general use. From this investigation, the necessary parameters for the discovery of new ESMs have become clear, and study of this is underway.
EAAC1 is expressed in rat and human prostate epithelial cells; functions as a high-affinity L-aspartate transporter; and is regulated by prolactin and testosterone

Prostate epithelial cells accumulate a high level of aspartate that is utilized as a substrate for their unique function of production and secretion of enormously high levels of citrate. In most mammalian cells aspartate is synthesized; and, therefore is a non-essential amino acid. In contrast, in citrate-producing prostate cells, aspartate is an essential amino acid that must be derived from circulation. The prostate intracellular/extracellular conditions present a 40:1 concentration gradient. Therefore, these cells must possess a plasma membrane-associated aspartate uptake transport process to achieve their functional activity. In earlier kinetic studies we identified the existence of a unique Na+-dependent high-affinity L-aspartate transport process in rat prostate secretory epithelial cells. The present report is concerned with the identification of this putative L-aspartate transporter in rat and human prostate cells. The studies show for the first time that EAAC1 is expressed in normal rat prostate epithelial cells, in normal and hyperplastic human prostate glands, and in human malignant prostate cell lines. EAAC1 expression and high-affinity L-aspartate transport are correspondingly down-regulated by EAAC1 siRNA knock down. Exposure of prostate cells to physiological levels of prolactin or testosterone results in an up-regulation of EAAC1 expression and a corresponding increase in the high-affinity transport of L-aspartate into the cells. This study shows that EAAC1 functions as the high-affinity L-aspartate transporter that is responsible for the uptake and accumulation of aspartate in prostate cells. In other cells (predominantly excitable tissue cells), EAAC1 has been reported to function as a glutamate transporter rather than as an aspartate transporter. The regulation of EAAC1 expression and L-aspartate transport by testosterone and prolactin is consistent with their regulation of citrate production in prostate cells. The identification of EAAC1 as the high-affinity L-aspartate transporter now permits studies to elucidate the mechanism of hormonal regulation of EAAC1 gene expression, and to investigate the mechanism by which the cellular environment effects the functioning of EAAC1 as an aspartate transporter or as a glutamate transporter.
Bankruptcy Boundary Games

For the past several decades, Congress has steadily expanded the exclusion of securities market operations from core bankruptcy protections. This Article focuses on three of the most important of these issues: the exclusion of brokerage firms from Chapter 11; the protection of settlement payments from avoidance as preferences or fraudulent conveyances; and the exemption of derivatives from the automatic stay and other basic bankruptcy provisions. In Parts I, II and III of the Article, I consider each of the issues in turn, showing that each has had serious unintended consequences. Both Drexel Burnham and Lehman Brothers evaded the brokerage exclusion, for instance; and the settlement provision has been invoked in several high profile contexts that do not fit neatly within the core cases for which it was designed. The application of the special derivatives provisions has also raised even more questions, once again most prominently in the Lehman bankruptcy. In the final part of the Article and in a brief conclusion, I explore the implications of the awkward interaction between bankruptcy and securities law. I begin by speculating about how bankruptcy courts will handle each of these issues if Congress does not alter the current rules. I then consider how Congress might intervene in these areas to address some of the problems that have arisen. I focus most extensively on the most complex of the issues, bankruptcy’s special protections for derivatives and other financial contracts. After surveying possible alternatives to the existing framework, I propose and defend two strategies for reform: under the first and more novel, the stay would apply in cases involving systemically important firms but not in other cases; and the second would simply remove the existing exemptions, imposing the stay in all cases. I argue that the choice between the two approaches depends on the overall structure of financial services regulation.
Pairwise symmetry decomposition method for generalized covariance analysis

We propose a new theoretical framework for generalizing the traditional notion of covariance. First, we discuss the role of pairwise cross-cumulants by introducing a cluster expansion technique for the cumulant generating function. Next, we introduce a novel concept of symmetry decomposition of probability density functions according to the C/sub 4V/ group. By utilizing the irreducible representations, generalized covariances are explicitly defined, and their utility is demonstrated using an analytically solvable model.
From Rags to “Rich as Rockefeller”: Portrayals of Class Mobility in Newbery Titles

AbstractSeveral scholars have noted the prevalence of the discourse of upward class mobility in the United States, particularly within K–12 education settings. “Rags‐to‐riches” stories, an extreme form of upward mobility discourse, have been embedded in American culture for generations. However, the prevalence of upward mobility discourse in recently published books for children has not been widely studied. Children’s literature merits scholarly attention because it has the potential to influence the perceptions and worldviews of young people, and books for youth reflect the values that adults in a society want to pass on to young people. This qualitative content analysis, grounded in assumptions of the sociology of school knowledge and critical literacy, investigates representations of upward class mobility in 22 titles given the Newbery Medal or Honor between 2009 and 2013. The findings indicate 7 out of 22 books include poor and working‐class characters experiencing class ascendency. Characters became ...
Romancing the Real: Folklore and Ethnographic Representation in North Africa

Romancing the Real: Folklore and Ethnographic Representation in North Africa. Sabra J. Webber. Publications of the American Folklore Society, New Series. Philadelphia: University of Pennsylvania Press, 1991. 293 pp.
Specificity of an Isolated Salivary Factor Material to Cystic Fibrosis

An oyster gill ciliostatic factor material has been isolated from the saliva of patients with cystic fibrosis (CF) by utilizing its ability to bind to alpha-amylase. It was quantitatively assayed by its ability to reversibly inhibit rabbit muscle glycogen debranching enzyme. The specificity of this CF factor material was investigated by comparing activities from the saliva of CF homozygotes (patients) varying in age, sex, and the severity of the disease; CF obligate heterozygotes (carriers); normal control subjects who had no family history of CF; non-CF asthmatic and allergic bronchitis patients; non-CF immunologically deficient patients with chronic respiratory problems; non-CF juvenile diabetic patients; non-CF pancreatic insufficiency patients; non-CF patients with obstructive liver cirrhosis; and non-CF patients with ectodermal dysplasia. The results show that the CF factor material isolated from CF saliva is specific to subjects with cystic fibrosis and is not associated with similar non-CE chronic disease states, nor is it produced as a result of an organ pathology associated with CF. There was no correlation between the amount of factor present in an individual CF homozygote sample and the severity of the disease. In the case of both the CF homozygote and heterozygote samples, there was also no correlation in either age or sex and the amount of factor present. The degree of inhibition produced by CF homozygotes compared to CF heterozygotes is characteristic of the autosomal recessive mode of inheritance of CF. This finding appears to associate the isolated CF factor material with the affected CF gene and suggests that the factor material is related in some way to the genetic lesion in CF.
The future of coral reefs

Coral reefs have been degrading faster than they have been recovering (Done 1992; Ginsburg 1994; Hughes 1994; Grigg and Birkeland 1997; McManus and Vergara 1998; Wilkinson 1993, 1998) and they have been accruing in their degraded states because they achieve alternate stable states of algae instead of corals (Knowlton et al. 1981; Knowlton 1992; Done 1992; Hughes 1994), and because rates of damage are much greater than rates of recovery (Muzik 1985; Birkeland 1997a). With the accumulation of reefs in alternative stable states, the total area of some reefs previously dominated by coral is decreasing over time (Muzik 1985; Knowlton et al. 1981, 1990; Wilkinson 1993), and the balance has been continuously in the negative for corals over the past few decades (LaPointe 1989; Hallock et al. 1993; Birkeland 1997a). Furthermore, human activities are now bringing about environmental changes on a global scale (Smith and Buddemeier 1992; Hoegh-Guldberg 1999; Tsuchiya 1999; Wilkinson et al. 1999) which alter the basic conditions and nature of environmental processes in the domain.
Fundamentals of integrated dictionary/ directory systems

Abstract One of the most potent tools available to support achievement of control over an organization's information resource is the Integrated Dictionary/Directory (D/D) System. Use of a D/D System can assist in data inventory management, cost control and improving resiliency to changing requirements. A D/D System is composed of a database (describing the information resource), retrieval and analysis capabilities, interfaces (enabling other software to access the D/D) and data management tools. Some D/D Systems are independent from other software packages; some either are dependent on or are actually embedded in other data management systems. D/D Systems provide functions to assist in interfacing the D/D to other software and loading the D/D with meta-data from other software. Use of a D/D System is a first step toward achieving control of the data resource.
Reaction Time and Anticipation Time: Effects of Development

Abstract The developmental nature of reaction time (RT) and anticipation timing (AT) performance, as well as the relationship between them, was investigated using 15 male and 15 female subjects at each of five age levels—7, 9, 11, 13, and 20 yrs. Each subject was given 40 trials for both RT and AT performance with task order counterbalanced. Results indicated that as age increased RT decreased, with males having more rapid RT than females. The two younger age groups differed from the three older groups on AT performance. RT was significantly correlated with AT (|CE| measure) for the 7, 9, and 11 yr old males but not in any other age by gender condition. Apparently neither young males nor young females have a good motor plan in memory to control AT performance. However, the more rapid RT (and thus better response initiation) of the males allows better AT performance at the younger ages. Beginning about 10–11 yrs of age, better motor plans are developed in children's memory system, leading to less reliance ...
Thermal Contact Conductance of a Bone-Dry Paper Handsheet/Metal Interface

An apparatus was constructed for determination of the thermal contact conductance for a paper handsheet/metal interface and for measurement of the effective thermal conductivity of handsheet samples. Bone-dry Bleached Southern Mixed Kraft handsheets with a water retention value of 1.832 were used to study the effect of pressure on thermal contact conductance and to measure the effective thermal conductivity of samples at various sheet density levels. A regression model describing the interface thermal contact conductance as a function of pressure and basis weight was derived. The contact conductance increases with increasing pressure or with decreasing basis weight. At a pressure of 2.3 kPa, the value of the interface contact conductance for the bone-dry samples considered ranges from approximately 97 W/m{sup 2}K for a sheet of 348.7 g/m{sup 2} basis weight to 200 W/m{sup 2}K for a sheet of 68.0 g/m{sup 2} basis weight. For pressures near 300 kPa, these values increase to 146 and 452 W/m{sup 2}K, respectively. The effective thermal conductivity of the handsheet samples was derived from measured values of overall joint conductance and interface contact conductance. The results indicate that the thermal conductivity of the bone-dry samples increases with increasing sheet density, ranging from 0.14 W/mK tomore » 0.70 W/mK for sheet densities of 90 kg/m{sup 3} to 500 kg/m{sup 3}, respectively, for the samples considered.« less
Training procedures for acquisition and retention of reading in retarded youth

Abstract The effectiveness of trial-and-error, fading, and delay procedures for teaching oral reading responses to four mentally retarded males was evaluated. Trial-and-error training involved pictorial feedback and differential reinforcement of responses to printed stimuli. Both fading and delay procedures consisted of gradual transfer of stimulus control from pictorial representations of the words to the printed stimuli alone. Fading was accomplished via decreasing picture intensities, while delay involved increasing time intervals between word and picture presentations. A multiple baseline design across six sets of three words each was employed. Subjects were given probe sessions consisting of three random presentations of 18 words. Training with one of the three procedures was conducted on one set of three words until a criterion of three consecutive correct trials was met. Dependent measures were correct reading responses, errors of commission, errors of omission during probes, and trials to criterion during training. Significant differences between procedures were demonstrated, with fading and/or delay procedures producing greater acquisition and retention than trial-and-error techniques.
Partial volume estimation: an improvement for eigenimage method

This paper presents a sub-voxel analysis method for multi- parameter volumetric images such as MRI to provide partial volume estimation. The proposed method finds a continuous function for a neighboring structure of each voxel. The estimation function and neighboring structure are chosen from the quadratic/cubic polynomials and a set of 2D/3D symmetric neighborhood architectures, respectively. Then, a new form of the eigenimage method, based on Gram-Schmidt orthogonalization, is derived for each choice of estimation function and neighboring structure. Finally, the above estimators are applied to a simulation model consisting of materials similar to CSF, WM, and GM of the human brain in T1- , T2-, and PD-weighted MRI. In the presence of noise, the examined continuous estimators show a smaller standard deviation (up to 40%) than the standard eigenimage method. Also the chosen estimators have analytical solution for their Gram-Schmidt filters, so their execution times are comparable with that of the standard eigenimage method. In addition, the proposed approach can determine the 3D distribution of each material and extract the connecting surfaces of the materials within each voxel.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Classes of primary abelian groups determined by valuated subgroups

Abstract If j and k are non-negative integers, a large class of abelian p -groups is defined, containing both the p ω + j -projectives and the p ω + k -injectives, which is closed with respect to the usual categorical operations. These groups are determined using isometries of their p j + k +1 -socles.
Radiation, evaporation and the maintenance of turbulence under stable conditions in the lower atmosphere

An expression is derived relating the critical flux Richardson number with the critical (gradient) Richardson number. In contrast to an earlier analysis by Townsend (1958), which is restricted to the atmosphere well outside the earth's boundary layer, the present treatment is intended specifically for turbulent flow in the lower atmosphere and it takes account of the effect of evaporation on the stability. The effect of radiation on the rate of destruction of the mean square of the temperature fluctuations is obtained by considering the radiative flux divergence in a stratified atmosphere and by using a simple functional relationship to represent empirical emissivity data.
Agro-Industrial Processing and Agricultural Pricing Under Uncertainty

Processing domestically available materials for export has intuitive appeal, e.g. if transport costs are reduced. Uncertainty in the supply of the raw material can be a crucial factor. The theoretical model of this paper shows how to choose the optimal processing capacity and, relatedly, the optimal price to pay producers of the input. Issues include: decision makers' preferences; sources and nature of uncertainty; availability of inputs to produce the raw material; and technology and costs of processing. Econometric estimates of the climate-yield relation are used to simulate these decisions for the case of Senegalese groundnut processing. There is an intuitive appeal to industrial strategies based on processing domestically available raw materials for export. For instance, relative to export of the raw material for processing abroad, domestic processing often achieves cost savings based on certain locational advantages, such as the opportunity to decrease the product's weight prior to transport.' In this paper, I analyse the costs and benefits of investing in processing capacity under particular conditions, and the related question of the appropriate domestic pricing of the raw material. The second part of the paper presents an application of the theory to Senegalese groundnut culture and processing. Especially for agricultural inputs, the domestic supply of the raw material is likely to be uncertain. This uncertainty interacts with locational advantages in important ways affecting both the optimal choice of agro-industrial processing capacity and the optimal choice of the price to be offered agricultural producers of the input. From the viewpoint of the processing mills, the locational advantage means that stochastically low availability of the raw material cannot be (fully) compensated by imports. Thus, the problem of idle processing capacity arises. Similarly, harvests of the input above the level that can be processed imply some loss of the locational advantages, assuming that the input cannot be stored costlessly. To illustrate these basic notions, consider the simplest case of a single input with a given world price, pj, transformed at a constant unit cost, r, into an output with a given world price, p. Let the size of the crop also be certain, say of magnitude m. So long as (p -pI) _ r, optimal processing capacity is m. Now consider a situation of uncertainty with two equiprobable states of nature faced
Correlates of Attachment Perceptions in Parents of Children with Autism Spectrum Disorders

This study explored the relationship between parents’ perceptions of their child’s attachment to them and parents’ own affective attachment to their child, as well the relationship of these constructs to parenting stress, parent-rated child functional impairment, and parenting sense of competence. Mothers (n = 76) and fathers (n = 30) of children ages 2–10 with autism spectrum disorders participated. Overall, parents’ affective attachment to their child was more consistently related to other aspects of their parenting experiences than were their perceptions of their child’s attachment to them. Also, perceptions of child-to-parent attachment were related to other aspects of parenting for fathers more than for mothers. Implications for parenting interventions and future research, such as longitudinal investigations, are discussed.
Silver palladium core–shell electrocatalyst supported on MWNTs for ORR in alkaline media

Abstract We show that silver palladium core-shell catalysts supported on multiwalled carbon nanotubes (Ag@Pd/MWNTs) are highly active and alcohol tolerant for oxygen reduction reactions (ORR) in alkaline media. These electrocatalysts were synthesized by galvanic displacement of Pd on Ag nanoparticles deposited on MWNTs. The Ag@Pd/MWNTs are shown to be tolerant of the presence of methanol and ethanol in the electrolyte. In the presence of methanol, the Ag@Pd/MWNTs current density decreased by 0.18 mA/cm2, compared to Pt/C (0.97 mA/cm2) and Pd/C (1.09 mA/cm2). In the presence of ethanol, the Ag@Pd/MWNTs current density decreased by 0.12 mA/cm2, compared to Pt/C (0.87 mA/cm2) and Pd/C (2.13 mA/cm2). The Ag@Pd/MWNTs also show improved durability with an increased mass activity of ~3.5 times that of standard Pd/C, after durability testing in ethanol. The Ag@Pd/MWNTs are promising platinum free direct alcohol fuel cell cathode catalysts due to their high activities and durability, as well as their improved tolerance to methanol and ethanol from possible fuel crossover.
TH‐C‐J‐6B‐08: A New Cone‐Beam CT Repositioning Technique Through Deformable Registration

Purpose: To develop a novel technique to fully utilize the 3D anatomic information provided by cone‐beam CT(CBCT) on‐board imager for automated patient repositioning and quantitatively evaluate its performance by comparing with the existing CBCT‐guided positioning techniques. Method and Materials: A pelvis phantom consisting of bladder, prostate, rectum, and bony structures, was constructed and scanned using a GE Discovery‐ST CT for treatment planning. After applying a deformation, it was scanned again with both Varian Trilogy on‐board CBCT and the regular GECT. The internal movement of the prostate was studied by using a BSpline deformable model. With the deformable registration, the displacement of each point in the prostate‐target was obtained, and the repositioning parameters were subsequently calculated by minimizing the least‐square distance of all the target points between the two setups. The method was compared with the currently used positioning methods including bony anatomy alignment and minimizing CT‐number difference (MCD) via rigid transformation. Results: Both the proposed and the MCD method showed differences from bony anatomy alignment, reflecting the fact of independent internal organ motion. Discrepancy between the proposed and the MCD method was also observed: 12mm in x‐, 9mm in y‐, and 5mm in z‐axis, respectively. The proposed method presented a better overall accuracy for the target localization as judged by the least‐square distance. When regular CT was used instead of CBCT for positioning, consistent result was obtained by the proposed method, while the MCD method generated different positioning parameters. Conclusion: With the proposed CBCT‐guided repositioning technique, the uncertainty of soft‐tissue target localization could be greatly reduced, ensuring conformal dose distribution to be precisely delivered as planned. This also allows implementation of conformal radiotherapy with smaller margins than currently applied, leading to less complications and improved outcome of the treatment.
Spectroscopic properties of CuO, SnO, and Dy2O3 co-doped phosphate glass: from luminescent material to plasmonic nanocomposite

Prospective applications of noble metal and rare-earth co-doped dielectrics in optical devices demand for a comprehensive understanding of the influence of material composition and processing on resulting properties. In this study, we report on the spectroscopic properties of a 50P2O5:50BaO glass matrix containing copper, tin, and dysprosium prepared by melting and subsequently subjected to heat treatment (HT). An achievement in terms of material preparation is that addition of stoichiometric amounts of CuO and SnO dopants along with the source of Dy3+ ions (Dy2O3) is shown effective for the precipitation of Cu nanoparticles (NPs) during HT. Optical absorption and photoluminescence (PL) spectroscopy including emission decay dynamics are employed in the characterization of the co-doped material as prepared, and as a function of HT. The basic structure of the phosphate host is assessed by 31P nuclear magnetic resonance spectroscopy. The optical data suggests the presence of both Cu2+ and Cu+ ions in the melt-quenched co-doped glass together with the Dy3+ ions. Thermal processing is indicated to result in the chemical reduction of ionic copper species via Sn2+ and ultimately produces the non-luminescent plasmonic Cu particles. The presence of such NPs is also observed to produce a quenching effect on Dy3+ PL, interpreted in terms of an ion-to-particle excitation energy transfer operating via interband transitions in the nanoscale metal. Thus, the glass may act as either a luminescent material or a plasmonic nanocomposite desirable for nonlinear optics dependent upon its thermal history.