cssi/SciSciGPT-SciSciNet huggingface dataset:
Community College Student Success: What Institutional Characteristics Make a Difference?.

Abstract Most of the models developed to examine student persistence and attainment in postsecondary education largely fail to account for the influence of institutional factors, particularly when attendance is observed at multiple institutions. Multi-institutional attendance is common for students who begin at a community college, but until now an empirical framework to estimate the contribution of more than one institution's characteristics on students’ educational outcomes has been largely absent in the literature. One of the goals of this study is to determine which institutional characteristics are correlated with positive community college outcomes for students who attend one or more colleges as measured by individual student probability of completing a certificate or degree or transferring to a baccalaureate institution. Using individual-level data from the National Education Longitudinal Study of 1988 (NELS:88) and institutional-level data from the Integrated Postsecondary Education Data System (IPEDS), we find consistent results across different specifications; namely, a negative relationship between relatively large institutional size, proportion of part-time faculty and minority students on the attainment of community college students.
Connectionism and the problem of systematicity: why Smolensky's solution doesn't work.

In two recent papers, Paul Smolensky 1987, 1988b responds to a challenge Jerry Fodor and Zenon Pylyshyn (Fodor and Pylyshyn, 1988) have posed for connectionist theories of cognition: to explain the existence of systematic relations among cognitive capacities without assuming that cognitive processes are causally sensitive to the constituent structure of mental representations. This challenge implies a dilemma: if connectionism can’t account for systematicity, it thereby fails to provide an adequate basis for a theory of cognition; but if its account of systematicity requires mental processes that are sensitive to the constituent structure of mental representations, then the theory of cognition it offers will be, at best, an implementation architecture for a “classical” (language of thought) model. Smolensky thinks connectionists can steer between the horns of this dilemma if they avail themselves of certain kinds of distributed mental representation. In what follows, we will examine this proposal.
Micro-temperature manipulation in cryogenic machining of low carbon steel

Abstract This paper presents an environmentally safe approach of micro-manipulation of cutting temperatures in machining AISI/SAE 1008 low carbon steel, a material widely recognized as a difficult-to-machine material from the viewpoint of chip control. A temperature distribution in different functional cutting zones is prescribed so that the material properties in each sub-zone can be altered to meet the machinability requirements. Liquid nitrogen is selectively applied to the chip and the tool rake face in well-controlled jet. Finite element analysis shows that this cooling approach can bring the chip temperature down to the embrittlement temperature for the material, −55°C. Consequently, it expands the chip-breaking range of feed and cutting speed, with a reduced chip–tool interface temperature and increased tool life. This approach also minimizes the undesirable cooling effect to the shear zone to avoid the increase of material strength and cutting resistance.
The secreted protein acidic and rich in cysteine (SPARC) induces endoplasmic reticulum stress leading to autophagy-mediated apoptosis in neuroblastoma

Our previous studies showed that overexpression of secreted protein acidic and rich in cysteine (SPARC) induced autophagy-mediated apoptosis in PNET cells. In the present study, we attempted to elucidate the molecular mechanisms and signaling cascades associated with SPARC overexpression in combination with radiation therapy that eventually leads to autophagy-mediated apoptosis in neuroblastoma. SPARC expression in SK-N-AS and NB-1691 cells demonstrated the activation of caspase 3, cleavage of PARP and induction of apoptosis. The experiments to unravel the mechanisms associated with autophagy-apoptosis illustrated that SPARC overexpression triggered endoplasmic reticulum (ER) stress and thereby unfolded protein response (UPR). This was apparent with the activation of stress receptors, inositol-requiring enzyme (IRE 1α), RNA-dependent protein kinase (PKR)-like ER kinase (PERK) and BiP. This study further demonstrated the induction of transcription factor CHOP as a result of IRE-JNK activation in response to increased SPARC levels. Inhibition of ER stress and JNK activation led to inhibition of autophagy-mediated apoptosis. Further, the apparent expression of ER stress molecules among the orthotopic tumors treated by SPARC overexpression plasmids substantiated our in vitro observations. Taken together, these results illustrate the critical role of ER stress in regulating autophagy-mediated apoptosis in SPARC-overexpressed neuroblastoma cells and radiation treatment.
How to distinguish dislocation drag processes from thermal activation

Experiments are described which demonstrate the influence of viscosity on thermal activation. In addition experiments which delineate the magnetooscillations in the drag coefficient are detailed. The first set of experiments shows that the creep rate, after plastic deformation, exhibits a minimum and a maximum. This is explained by considering the temperature dependence of the electron drag in the superconducting state. The magnetooscillations a allow a distinction to be made between an anharmonic drag mode and a flutter mode; the experiements show that a flutter mode is preferred for temperatures below 5 K. Es werden Experimente beschrieben, in denen der Einflusder Viskositat auf die thermische Aktivierung geneigt wird und magnetische Oszillationene im Drag-Koeffizienten aufgedeckt werden. Die ersteren Experimente zeigen, dasnach plastischer Deformation die Kriechrate ein Minimum und ein Maximum aufweist, was durch die Temperaturabhangigkeit des Elektronendrags im supraleitenden Zustand crklart wird. Die magnetischen Oszillationen, erlauben, eine anharmonische Dragmode und eine Flattermode zu unterscheiden; die Experimente zeigen, das unterhalb 5 K die Flattermode vorherrscht.
Identifying Motivation and Interpersonal Performance Using Peer Evaluations

Peer evaluations have historically shown high predictive validity, but the reason for this strength has not been clear. This research used an assessment center and subsequent training program to in...
LRP6 overexpression defines a class of breast cancer subtype and is a target for therapy

The Wnt/β-catenin signaling pathway is activated in breast cancer, a leading cause of cancer mortality in women. Because mutations in the key intracellular components of this pathway are rare, identifying the molecular mechanisms of aberrant Wnt activation in breast cancer is critical for development of pathway-targeted therapy. Here, we show that expression of the Wnt signaling coreceptor LRP6 is up-regulated in a subpopulation of human breast cancers. LRP6 silencing in breast cancer cells reduces Wnt signaling, cell proliferation, and in vivo tumor growth. In vivo administration of an LRP6 antagonist, Mesd, markedly suppressed growth of MMTV-Wnt1 tumors without causing undesirable side effects. These results demonstrate that Wnt activation at the cell surface contributes to breast cancer tumorigenesis. Together, our studies highlight LRP6 as a potential therapeutic target in breast cancer, and introduce Mesd as a promising antitumor agent for treating breast cancer subtypes with Wnt activation at the cell surface.
An analysis of television series with minority‐lead characters

This paper traces the development of trends in serial programming devoted to minorities in prime‐time television. It also revisits the literature on minorities and media to see if past “media‐as‐mirror” findings can be better understood in light of interdependent economic conduct characteristic of the network oligopoly. Study results reveal that quantitative growth in minority‐lead series was greatest during the 1970s, although Asians, Hispanics, and women were underrepresented through 1990. The erratic nature of that growth suggests that it has less to do with social consciousness than with the fact that minorities have become a highly sought‐after target for advertisers.
Stable Pausing by RNA Polymerase II Provides an Opportunity to Target and Integrate Regulatory Signals

Summary Metazoan gene expression is often regulated after the recruitment of RNA polymerase II (Pol II) to promoters, through the controlled release of promoter-proximally paused Pol II into productive RNA synthesis. Despite the prevalence of paused Pol II, very little is known about the dynamics of these early elongation complexes or the fate of the short transcription start site-associated (tss) RNAs they produce. Here, we demonstrate that paused elongation complexes can be remarkably stable, with half-lives exceeding 15 min at genes with inefficient pause release. Promoter-proximal termination by Pol II is infrequent, and released tssRNAs are targeted for rapid degradation. Further, we provide evidence that the predominant tssRNA species observed are nascent RNAs held within early elongation complexes. We propose that stable pausing of polymerase provides a temporal window of opportunity for recruitment of factors to modulate gene expression and that the nascent tssRNA represents an appealing target for these interactions.
Modeling and analysis of cell differentiation using hybrid systems

The capacity of cells to differentiate into specialized types is fundamental to the development of organisms. However, the underlying cell differentiation process is not yet well understood. In this work, we consider cell differentiation resulting from interactions of the Delta and Notch proteins. We model the protein concentration dynamics using switched affine hybrid automata. Applying tools from monotone dynamical system theory, we prove steady-state properties of the model. We also find, by exploiting symmetries in the system, conditions on the model parameters to ensure that the steady-state reached is consistent with biological observations. We conclude that the piecewise affine hybrid model is a good framework for modeling the cell differentiation process because the consistency of the model with biological observations can be analyzed theoretically for cellular networks of arbitrary size.
Thinking Different about the UN Security Council

media-genic: countries debate, votes are taken, drama abounds as when Colin Powell made his case for intervention in Iraq. The Council's composition is sup posed to reflect coercive power in the world, and it is the only institution whose decisions are expected to be binding on all member states of the UN. Sometimes it does not seem to work well and reformers want to change its composition bet ter to reflect current power. The UN Security Council and the Politics of International Authority seeks to encour age us to think differently about the institution, reflecting a radically alternative way to conceptualize power in supranational institutions. It is different from the usual take on the Security Council, which can focus on process and issues dealt with, like Edward Luck's (2006) UN Security Council: Practice and Promise, or David Malone's (1998) analysis of the specific case of Haiti in his Decision-making in the UN Security Council, or Chinmaya Gharekhan's (2006) personal memoire in The Horseshoe Table: An Inside View of the UN Security Council. Bruce Cronin and Ian Hurd start the process in their introductory chapter, which sets out their focus on authority and legitimacy as key factors in the Council's effectiveness. Authority here means "a relation among actors within a hierarchy in which one group is recognized as having both the rights and the competence to make binding decisions for the rest of the community..." (p. 6). As such it is related to legitimacy, a form of very soft power. Hurd's next chapter elaborates on this and sets up tests of authority as a way of assessing the Council. This is based on Hurd's earlier work on legitimacy in After Anarchy: Legitimacy and Power in the United Nations Security Council (Hurd 2007). Eric Voeten's chapter on the nature of Security Council authority combines an institutionalist and a realist perspective on how decision making can be seen as bargaining between a public goods perspective (peace and security are good for everyone) and a private goods perspective (a given State's national interest). He shows that the decision-making process is evolving in such a way that agree ment in the Security Council is becoming increasingly important. Bruce Cronin's chapter on how international consensus has expanded the Security Council's legal authority is a central argument in the volume. It demon strates that consensus, which is the prevailing means of decision making at the international level, allows international law to develop. As he notes, "...it reflects the growth of legal norms that are derived not from individual state consent,
Molecular and symbiotic characterization of exopolysaccharide‐deficient mutants of Rhizobium tropici strain CIAT899

We studied the symbiotic behaviour of 20 independent Tn5 mutants of Rhizobium tropici strain CIAT899 that were deficient in exopolysaccharide (EPS) production. The mutants produced non-mucoid colonies, were motile, grew in broth cultures at rates similar to those of the parent, and produced significantly less EPS than did CIAT899 in broth culture. A genomic library of strain CIAT899, constructed in pLA2917, was mobilized into all of the mutants, and cosmids that restored EPS production were identified. EcoRI restriction digests of the cosmids revealed nine unique inserts. Mutant complementation and hybridization analysis showed that the mutations affecting EPS production fell into six functional and physical linkage groups. On bean, the mutants were as efficient in nodulation and as effective in acetylene reduction as strain CIAT899, induced a severe interveinal chlorosis, and all but one were less competitive than CIAT899. On siratro, CIAT899 induced nodules that were ineffective in acetylene reduction, whereas the EPS-deficient mutants induced effective nodules. Microscopic examination of thin sections showed that nodules from both siratro and bean plants inoculated with either CIAT899 or an EPS-deficient mutant contained infected cells. These data indicate that EPS is not required for normal nodulation of bean by R. tropici, that it may contribute to competitiveness of R. tropici on bean, and that the loss of EPS production is accompanied by acquisition of the ability to reduce acetylene on siratro.
THE EFFECT OF REINFORCEMENT OF STATEMENTS OF PUPIL–TEACHER RELATIONSHIPS IN A FREE RESPONSE SITUATION ON MINNESOTA TEACHER ATTITUDE INVENTORY SCORES1,2

This study was designed to apply reinforcement theory to changing attitudes as measured by the MTAI of teacher education students. Subjects consisted of 93 educational psychology students who were randomly assigned to one of the three groups (Treatment, Hawthorne, and Control), The experimental treatment consisted of inviting students in for five brief “get-acquainted” interviews in which any statement expressing positive attitudes toward teacher-pupil relationships was reinforced. Two control groups were used; one received no special treatment, while the other was invited in for five “get-acquainted” interviews, but was not reinforced for expressing favorable attitudes toward pupil-teacher relationships. Results indicated no significant differences among the three groups. This study indicates that for students enrolled in an educational psychology course those who receive reinforcement outside of class for verbalizing appropriate attitudes of teacher-pupil relationships do not show significant gain in MTAI scores over those students in the course who do not receive such reinforcement outside of class.
A high repetition rate TEA CO2 laser operating at λ=9.3-μm for the rapid and conservative ablation and modification of dental hard tissues

TEA CO2 lasers tuned to the strong mineral absorption of hydroxyapatite near λ=9-μm are ideally suited for the efficient ablation of dental hard tissues if the laser-pulse is stretched to greater than 5-10-μs to avoid plasma shielding phenomena. Such CO2 lasers are capable of operating at high repetition rates for the rapid removal of dental hard tissues. An Impact 2500 TEA CO2 laser system from GSI Lumonics (Rugby, UK) custom modified by LightMachinery (Ottawa, Canada) with a repetition rate of 0-500 Hz was used for rapid tissue removal. The single pulse ablation rates through enamel were determined for incident fluence ranging from (1-160 J/cm2). Lateral incisions using a computer controlled scanning stage and water spray were produced and the crater morphology and chemical composition were measured using optical microscopy and high-resolution synchrotron radiation infrared spectromicroscopy. The transmission through 2-meter length 300, 500, 750 and 1000-μm silica hollow waveguides was measured and 80% transmission was achieved with 40-mJ per pulse. The λ=9.3-μm laser pulses efficiently removed dental enamel at rates exceeding 15-μm per pulses with minimal heat accumulation. The residual energy remaining in tooth samples was measured to be 30-40% without water cooling, significantly lower than for longer CO2 laser pulses. These results suggest that high repetition rate TEA CO2 laser systems operating at λ=9.3-μm with pulse durations of 10-20-μs are ideally suited for dental application.© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Reactions of the Dirhenium(II) Complexes Re(2)X(4)(m-dppm)(2) (X = Cl, Br; dppm = Ph(2)PCH(2)PPh(2)) with Isocyanides. 11.(1) A Triply Bonded Dirhenium Complex Containing a Labile Acetonitrile Ligand. Synthesis, Structural Characterization, and Reactivity of [(XylNC)(CH(3)CN)ClRe(m-dppm)(2)ReCl(2)(CO)]O(3)SCF(3).

The reaction of the open bioctahedral form of Re(2)Cl(4)(m-dppm)(2)(CO)(CNXyl) (1), where XylNC = 2,6-dimethylphenyl isocyanide, with TlO(3)SCF(3) in the presence of acetonitrile proceeds with retention of stereochemistry at the dirhenium unit to afford the complex [Re(2)Cl(3)(m-dppm)(2)(CO)(CNXyl)(NCCH(3))]O(3)SCF(3) (3). The single-crystal X-ray structure determination of 3 shows that a RetRe bond is retained (the Re-Re distance is 2.378(3) A) and that it is the chloride ligand trans to the XylNC ligand of 1 which is labilized. Complex 1 reacts with TlO(3)SCF(3) in a noncoordinating solvent to produce the unsymmetrical complex [Re(2)Cl(3)(m-dppm)(2)(CO)(CNXyl)]O(3)SCF(3) (2), through loss of this same chloride ligand of 1 and CO transfer from the adjacent Re center. The acetonitrile ligand of 3 is very labile and is readily displaced by XylNC and t-BuNC, with retention of stereochemistry, to produce complexes of stoichiometry [Re(2)Cl(3)(m-dppm)(2)(CO)(CNXyl)(CNR)]O(3)SCF(3) (R = Xyl, 4a; R = t-Bu, 4b). In a noncoordinating solvent, the nitrile ligand of 3 is lost and 2 is formed following CO transfer; this conversion is reversed upon the reaction of 2 with acetonitrile. When 3 is treated with CO, the acetonitrile ligand is again displaced, but in this instance the reaction is accompanied by a structure change to produce an edge-sharing bioctahedral complex of the type [Re(2)(m-CO)(m-Cl)(m-dppm)(2)Cl(2)(CO)(CNXyl)]O(3)SCF(3) (5).
The Best and Worst of Currencies: Seigniorage and Currency Policy in Spain, 1597-1650

The Spanish Monarchy pursued a rational policy of price discrimination among its Castilian currencies while financing its early-seventeenth-century wars. Largedenomination gold and silver coins circulated internationally, forcing the Monarchy to act more competitively and not seek additional short-run revenue. In contrast, petty coinage was a local monopoly. The Monarchy raised seigniorage rates and issued large quantities, generating large revenues. The nominal petty money stock grew rapidly, then fluctuated. The real petty money stock grew, then varied little as petty currency depreciation dampened nominal changes. In 1642, King Philip IV made plans to visit his Iberian provinces of Valencia and Aragon to raise the morale of his subjects and troops in Spain's war against France. Unfortunately, Philip and his party had to delay their departure from his home province of Castile because his Castilian petty copper coins were not accepted in his other provinces.1 Meanwhile, Castile's large-denomination silver and gold coins circulated around the globe. One might say that Castile's large-denomination and petty moneys were the best and worst of early modern currencies. How do we explain this development? The contrasting respect for Castile's currencies was caused by differing sovereign currency policies. Those differences arose as the Habsburg Spanish Monarchy financed intermittent wars that began in the 1520s and lasted for more than a century. It issued large, discrete bursts of copper petty coinage that generated significant seigniorage and caused petty currency depreciation. Meanwhile, silver currency did not depreciate. The Monarchy twice devalued the currency in terms of gold, but gold coins circulated widely at the new face values.
Thermodynamic characterization of tandem mismatches found in naturally occurring RNA

Although all sequence symmetric tandem mismatches and some sequence asymmetric tandem mismatches have been thermodynamically characterized and a model has been proposed to predict the stability of previously unmeasured sequence asymmetric tandem mismatches [Christiansen,M.E. and Znosko,B.M. (2008) Biochemistry, 47, 4329-4336], experimental thermodynamic data for frequently occurring tandem mismatches is lacking. Since experimental data is preferred over a predictive model, the thermodynamic parameters for 25 frequently occurring tandem mismatches were determined. These new experimental values, on average, are 1.0 kcal/mol different from the values predicted for these mismatches using the previous model. The data for the sequence asymmetric tandem mismatches reported here were then combined with the data for 72 sequence asymmetric tandem mismatches that were published previously, and the parameters used to predict the thermodynamics of previously unmeasured sequence asymmetric tandem mismatches were updated. The average absolute difference between the measured values and the values predicted using these updated parameters is 0.5 kcal/mol. This updated model improves the prediction for tandem mismatches that were predicted rather poorly by the previous model. This new experimental data and updated predictive model allow for more accurate calculations of the free energy of RNA duplexes containing tandem mismatches, and, furthermore, should allow for improved prediction of secondary structure from sequence.
Effectiveness of multidimensional family therapy with higher severity substance-abusing adolescents: Report from two randomized controlled trials

Objective: We used growth mixture modeling to examine heterogeneity in treatment response in a secondary analysis of 2 randomized controlled trials testing multidimensional family therapy (MDFT), an established evidence-based therapy for adolescent drug abuse and delinquency. Method: The first study compared 2 evidence-based adolescent substance abuse treatments: individually focused cognitive–behavioral therapy and MDFT in a sample of 224 urban, low-income, ethnic minority youths (average age 15 years, 81% male, 72% African American). The second compared a cross-systems version of MDFT (MDFT—detention to community) with enhanced services as usual for 154 youths, also primarily urban and ethnic minority (average age 15 years, 83% male, 61% African American, 22% Latino), who were incarcerated in detention facilities. Results: In both studies, the analyses supported the distinctiveness of 2 classes of substance use severity, characterized primarily by adolescents with higher and lower initial severity; the higher severity class also had greater psychiatric comorbidity. In each study, the 2 treatments showed similar effects in the classes with lower severity/frequency of substance use and fewer comorbid diagnoses. Further, in both studies, MDFT was more effective for the classes with greater overall substance use severity and frequency and more comorbid diagnoses. Conclusions: Results indicate that for youths with more severe drug use and greater psychiatric comorbidity, MDFT produced superior treatment outcomes.
Novel soybean oils with different fatty acid profiles alter cardiovascular disease risk factors in moderately hyperlipidemic subjects

BACKGROUND A variety of soybean oils were developed with improved oxidative stability and functional characteristics for use as alternatives to partially hydrogenated fat. OBJECTIVE The objective was to assess the effect of selectively bred and genetically modified soybean oils with altered fatty acid profiles, relative to common soybean and partially hydrogenated soybean oils, on cardiovascular disease risk factors. DESIGN Thirty subjects (16 women and 14 men) aged >50 y with LDL-cholesterol concentrations >130 mg/dL at screening consumed 5 experimental diets in random order for 35 d each. Diets contained the same foods and provided 30% of energy as fat, of which two-thirds was either soybean oil (SO), low-saturated fatty acid soybean oil (LoSFA-SO), high-oleic acid soybean oil (HiOleic-SO), low-alpha-linolenic acid soybean oil (LoALA-SO), or partially hydrogenated soybean oil (Hydrog-SO). RESULTS Plasma phospholipid patterns reflected the predominant fat in the diet. LDL-cholesterol concentrations were 3.66 +/- 0.67(b), 3.53 +/- 0.77(b), 3.70 +/- 0.66(b), 3.71 +/- 0.64(a,b), and 3.92 +/- 0.70(a) mol/L; HDL-cholesterol concentrations were 1.32 +/- 0.32(a,b), 1.32 +/- 0.35(b), 1.36 +/- 0.33(a), 1.32 +/- 0.33(b), and 1.32 +/- 0.32(a,b) mol/L for the SO, LoSFA-SO, HiOleic-SO, LoALA-SO, and Hydrog-SO diets, respectively (values with different superscript letters are significantly different, P < 0.05). No significant effects were observed on VLDL-cholesterol, triacylglycerol, lipoprotein(a), and C-reactive protein concentrations or on ratios of LDL cholesterol to apolipoprotein B (apo B) and HDL cholesterol to apo A-I. Total cholesterol:HDL cholesterol was lower after subjects consumed the unhydrogenated soybean oils than after they consumed the Hydrog-SO diet. CONCLUSIONS All varieties of soybean oils resulted in more favorable lipoprotein profiles than did the partially hydrogenated form. These soybean oils may provide a viable option for reformulation of products to reduce the content of trans fatty acids.
Cache Optimization For Embedded Processor Cores: An Analytical Approach

Embedded microprocessor cores are increasingly being used in embedded and mobile devices. The software running on these embedded microprocessor cores is often a priori known, thus, there is an opportunity for customizing the cache subsystem for improved performance. In this work, we propose an efficient algorithm to directly compute cache parameters satisfying desired performance criteria. Our approach avoids simulation and exhaustive exploration, and, instead, relies on an exact algorithmic approach. We demonstrate the feasibility of our algorithm by applying it to a large number of embedded system benchmarks.
COVARIANCE ANALYSIS SCALE TRANSFORMATION IN STATISTICAL TREATMENT OF NON-ADDITIVE UNITS.

Summary.-Previously stated necessity for scale transformation of data in which prestimulus and change magnirudes are significantly related can be seen to derive from the use of an inappropriate expression of variability. An example employing covariance analysis lends support to this conclusion. It also makes salient the problem of satisfactory treaunent of significant slope differences among samples in the evaluarion of elevation differences. Two measurements of a given funccion are usually available for the statistical evaluation of response to stimulation: the prestirnulus level and the level reached upon stimulation (stimulus level). It is a common practice then to calculate a third value, the difference (A) between che measures, and to utilize it as che response measure in subsequent scatiscical cescs. However, an apparent problem, particularly associated with physiological measurements but with more general implications, is the common observation that the magnicude of A is systematically related to the magnitude of prescimulus values, i.e., A unics obtained at different prestimulus levels are non-additive.' The marked frequency of such observations among che responses of a wide variety of organs has even led to formal statemenc of the relationship in Wilder's "Law of Initial Values" ( 1957). Darrow (1937, p. 289) has written concerning this phenomenon that ". . . resistance or resistance change is a very unsatisfactory measure of conditions in the organism because small resistance changes at low resistance may indicate very large changes in physiological activity and large changes in resistance at high resistance may indicate very small changes in physiological activity." This justifiable early concern with the correspondence between physiological processes and their measurement was later followed by a concern wich the requirements for valid scatiscical evaluation of data. Most authors have been aware of requirements such as normality and hornoscedascicity, but nevertheless have attributed great importance to the existence of a relationship between prestimulus and change values. Haggard (1949a, p. 380) has stated that ". . . nonadditivity makes the error variance larger and more heterogeneous, with a consequent loss or distortion of information." Lacey and Siege1 ( 1949, p. 123) have 'This paper was prepared during the tenure of a Research Career Development Award (K3-4907) of the National Institute of Mental Health. The author wishes to acknowledge his indebtedness to Dr. George W. Snedecor for his constructive comments on the substance of this paper, and Dr. Josiah Macy, Jr., for the generous use of his computer facilities at Albert Einstein College of Medicine. This may apply equally well to stimulus level units. It has been pointed out (Block & Bridget, 1962) that as a consequence of the relationship: b,. , - b,-,. , = 1.0, the re
Investigation of the mechanism of iron acquisition by the marine bacterium Alteromonas luteoviolaceus: Characterization of siderophore production

Iron availability in the ocean ranges from one to four orders of magnitude below typical growth requirements of bacteria. The discrepancy between Fe availability and requirements raises questions about the mechanisms that marine bacteria use to sequester Fe{sup 3+}. Surprisingly little is known about the siderophores produced by marine bacteria. Growth conditions of an open-ocean bacterial isolate, Alteromonas luteoviolaceus, were investigated to determine the conditions which enhance siderophore production. Methods to isolate and purify the siderophores were determined. The siderophores produced by A. luteoviolaceus were partially characterized by mass spectral analysis, amino acid analysis, qualitative analytical tests, chemical degradation, and nuclear magnetic resonance. A new set of outer membrane proteins was also produced when the bacterium was grown under Fe-limited conditions.
Endoscopic Ultrasound-Guided Management of Pancreatic Pseudocysts and Walled-Off Necrosis

The outcome of endoscopic management of pancreatic fluid collections is dependent on the type of collection being treated. While pseudocysts have an excellent treatment response, the outcomes are modest for walled-off pancreatic necrosis. Recent advances in cross-sectional body imaging have enabled a more accurate distinction of pancreatic fluid collections, which, in turn, facilitates the correct triage of patients to receive the appropriate treatment. Newly described endoscopic techniques and the development of dedicated accessories have improved the clinical outcomes in walled-off pancreatic necrosis, with treatment success rates comparable to that of minimally invasive surgery. This review summarizes the key concepts and provides a concise update on the endoscopic management of pancreatic fluid collections.
THE SOCIAL ORGANIZATION OF DRUG USE AND DRUG DEALING AMONG URBAN GANGS

Youth gangs are a major part of the urban landscape. Gang members always have been involved in collective and individual violence and, in recent years, in drug use and drug dealing. Involvement in drug dealing recently has been associated with increased violence among gangs. However, variation in organizational and social processes within gangs suggests that there also will be variation in drug-crime relationships among gang members. Analyses of the drug-crime relationships were conducted from interviews with 151 gang members in three cities. Four types of gangs were identified, and similar gang types were observed in the three cities. All gang types had high involvement in drug use, but drug dealing varied. The severity of collective gang crime was associated with the prevalence of drug use within a gang. Drug dealing occurred among gangs with both high and low involvement in violence and other crimes. Involvement in cocaine, opiates, and PCP occurred among both violent and nonviolent gangs, as well as among gangs with different involvement in drug dealing. The results suggest that the drug-crime relationship is skewed and spurious for gang members, similar to relationships among nongang inner-city adolescents. Members of violent gangs more often reported the existence of several features of social organization and cohesion in their gangs, independent of gang involvement in drug use and dealing. Similar to other urban adolescents, for gang members violence is not an inevitable consequence of involvement in drug use or dealing.
The effect of Hf and Ti additions on microstructure and properties of Cr2Nb–Nb in situ composites

The present paper describes the effect of Hf and Ti additions on the microstructures and mechanical properties of two-phase composites based on the Cr2Nb–Nb eutectic. The microstructures of directionally solidified in situ composites containing 50–70% by volume of the Laves phase Cr2Nb which was modified with Hf (7.5–9.2%) and Ti (16.5–26%) are described. Partitioning of Hf and Ti between the two phases is discussed using microprobe and EDS results. The tensile properties at 1100 and 1200 °C are described and compared with those of an analogous niobium silicide-based composite. The Cr2(Nb)–(Nb) composite tensile yield strengths at 1200 °C were increased over that of monolithic Cr2Nb to ∼130 MPa. However, at 1200 °C the yield strengths of the silicide-based composites were approximately twice those of the Cr2(Nb)–(Nb) composites.
On composability of localization protocols for wireless sensor networks

Realistic, complex outdoor environments pose significant challenges for node localization in wireless sensor networks. In spite of the fact that many elegant and clever solutions have been proposed, no robust localization system has emerged. This status quo is because existing solutions work well for single sets of assumptions that, however, do not always hold in complex environments. In this article we review the state of the art for node localization in wireless sensor networks and show how localization protocol composability has the potential to provide the robust solution that is needed. By composing localization protocols in a hierarchy and allowing the execution of multiple localization schemes, robust solutions against any single protocol failure can be built.
Large scale generation of genetically modified T-cells using micro-electroporators for cancer treatments

To address B-lineage acute lymphoblastic leukemia (B-ALL), we use a bioengineering approach to achieve high-efficient non-viral gene transfer of tumor-specific CAR+ T cells for on-demand use. Specifically, we have developed CD19-specific chimeric antigen receptors (CARs) to redirect the specificity of T cells for B-cell malignancies. We introduce CARs via a non-viral gene transfer: electroporation. We have fabricated and tested a series of high throughput micro-electroporation devices (HitMeDs) with the end result that a HitMeD can electroporate a large number (≫109) human T cells within short time period (≪4 hours). We connect the HitMeDs to a BTX pulse generator and a monitoring system. We have adapted HitMeDs to the electro-transfer of CAR mRNA which avoids the potential genotoxicity associated with vector integration. After electroporation, 70% to 80% of the T cells express CD19 -specific CAR.
Microscopic single-crystal refractometry as a function of wavelength

The refractive indices of crystal fragments 50–200 μm in size can be measured for light wavelengths between 365 and 1100 nm with a spindle-stage refractometer. Established methods from optical crystallograpy are used to orient a crystal on the microscope spindle stage and then to match its refractive index to an immersion fluid. The refractive index of the fluid for the wavelength of light and matching temperature is determined by comparison of a reference crystal on a second spindle axis with the fluid under the match conditions. Investigations of new nonlinear-optical crystals admirably demonstrate the advantages of measuring the refractive index to ±0.0004 in small single crystals.
Laboratory Detection of FeCO + (X 4 Σ - ) by Millimeter/Submillimeter Velocity Modulation Spectroscopy

The millimeter/submillimeter spectrum of the molecular ion FeCO (X 4 S) has been recorded using velocity modulation spectroscopy. The molecular ion was created in an AC discharge of Fe(CO)5 and argon. Twentyseven rotational transitions, each consisting of four fine-structure components, were measured in the range 198– 418 GHz. The data were fit with a case b Hamiltonian, and rotational, spin-rotation, and spin-spin constants were determined. Because of the presence of higher order spin-orbit interactions, probably caused in part by a nearby 4 P excited state, numerous centrifugal distortion terms were needed for the spectral analysis. The value of g s, the third-order spin-rotation constant, was also remarkably large at 72.4 MHz. Rest frequencies for FeCO are now available for interstellar and circumstellar searches. This species may be present in molecular clouds, where CO is abundant and gas-phase iron should be in the form of Fe. Molecular ions such as FeCO could be the hidden carriers of metallic elements in such clouds. Subject headings: astrochemistry — ISM: molecules — line: identification — methods: laboratory — molecular data — stars: AGB and post-AGB
Management of Colonoscopic Perforations

Objective: To document our evolving surgical management of colonoscopic perforation and examine factors crucial to the improvement of patient care. Design: We conducted a computer-based retrospective analysis of medical records (1980 through 1995). Material and Methods: Among 57,028 colonoscopic procedures performed, 43 patients (0.075%, or 1 perforation in 1,333 procedures) had a colonic perforation. Two additional patients were treated after colonoscopy performed elsewhere. The outcomes analyzed included surgical morbidity and mortality. Results: Twenty-six women and 19 men who ranged in age from 28 to 85 years (median, 69) were treated for colonic perforation. More than 80% of perforations occurred during the latter half of the study period because of the increased volume of colonoscopic procedures (8 perforations among 12,581 examinations from 1980 through 1987 versus 35 perforations among 44,447 colonoscopies from 1988 through 1995). Emergency laparotomy was performed in 42 patients (93%). Perforations occurred throughout the colon: right side=10; transverse=9; and left side=23. Three patients without evidence of peritoneal irritation fared well with nonoperative management. Most patients underwent primary repair or limited resection in conjunction with end-to-end anastomosis. In 14 patients (33%), an ostomy was created. One patient underwent laparotomy without further treatment. Intra-abdominal contamination ranged from none (31%) to local soiling (48%) to diffusely feculent (21%). Postoperative complications occurred in 12 patients and were associated with older age ( P = 0.01), large perforations ( P = 0.03), and prior hospitalization ( P = 0.04). No postoperative deaths occurred. Conclusion: Despite a consistently low risk of colonic perforation, the increasing use of colonoscopy in our practice has resulted in an increased number of iatrogenic colonic perforations. In order to minimize morbidity and mortality, prompt operative intervention is the best strategy in most patients. Non-operative management is warranted in carefully selected patients without peritoneal irritation.
Identification of Legionella pneumophila rcp, a pagP-like gene that confers resistance to cationic antimicrobial peptides and promotes intracellular infection

In the course of characterizing a locus involved in heme utilization, we identified a Legionella pneumophila gene predicted to encode a protein with homology to the product of the Salmonella enterica serovar Typhimurium pagP gene. In Salmonella, pagP increases resistance to the bactericidal effects of cationic antimicrobial peptides (CAMPs). Mutants with insertions in the L. pneumophila pagP-like gene were generated and showed decreased resistance to different structural classes of CAMPs compared to the wild type; hence, this gene was designated rcp for resistance to cationic antimicrobial peptides. Furthermore, Legionella CAMP resistance was induced by growth in low-magnesium medium. To determine whether rcp had any role in intracellular survival, mutants were tested in the two most relevant host cells for Legionnaires' disease, i.e., amoebae and macrophages. These mutants exhibited a 1,000-fold-decreased recovery during a Hartmannella vermiformis coculture. Complementation of the infectivity defect could be achieved by introduction of a plasmid containing the intact rcp gene. Mutations in rcp consistently reduced both the numbers of bacteria recovered during intracellular infection and their cytopathic capacity for U937 macrophages. The rcp mutant was also more defective for lung colonization of A/J mice. Growth of rcp mutants in buffered yeast extract broth was identical to that of the wild type, indicating that the observed differences in numbers of bacteria recovered from host cells were not due to a generalized growth defect. However, in low-Mg(2+) medium, the rcp mutant was impaired in stationary-phase survival. This is the first demonstration of a pagP-like gene, involved in resistance to CAMPs, being required for intracellular infection and virulence.
The thin-film deposition of conjugated molecules for organic electronics

Device-quality conjugated organic thin films are now routinely prepared in many different ways to fabricate light-emitting diodes, thin-film transistors, and photovoltaic devices. Understanding how to design molecules through versatile synthetic chemistry and the mechanisms of phase transformation and chemical reaction that occur during the thin-film deposition process becomes especially vital for the performance of the applications. This article reviews the current understanding of various thin-film deposition technologies for the conjugated organic molecules primarily used in optoelectronics, particularly in photovoltaic applications.
Vitamin D Deficiency Enhances the Growth of MC-26 Colon Cancer Xenografts in Balb/c Mice

Vitamin D deficiency has been associated with increased risk of colon cancer in epidemiologic and prospective clinical studies. In vitro and in vivo studies demonstrated that 1,25-dihydroxycholecalciferol [1,25(OH)2D3] and its analogs inhibit colon cancer cell proliferation. Few studies have evaluated the effect of vitamin D deficiency on the development and growth of colon cancer. To assess the antiproliferative effects of 25-hydroxyvitamin D [25(OH)D] and 1,25(OH)2D3 in vitro, we cultured MC-26 (a colon cancer cell line) in the presence of 25(OH)D3 and 1,25(OH)2D3 and performed [3H]thymidine incorporation. The proliferation of MC-26 was significantly inhibited by both 25(OH)D3 and 1,25(OH)2D3. To determine the effect of vitamin D deficiency on colon cancer proliferation, Balb/c mice were rendered vitamin D deficient by feeding them a vitamin D-deficient diet for 3 mo. A group of vitamin D-sufficient mice was given the same diet with supplemental vitamin D. The mice were injected with MC-26 colon cancer cells and the tumors were measured daily for 20 d. Vitamin D-sufficient mice had 40% smaller tumors than vitamin D-deficient mice. The tumors were evaluated for mRNA expression of the vitamin D receptor (VDR) and 25-hydroxvitamin D-1alpha-hydroxylase (1alpha-OHase) by quantitative RT-PCR. The expression of the mRNA for the VDR and the 1alpha-OHase was 37- and 6-fold higher, respectively, in the vitamin D-sufficient mice compared with the vitamin D-deficient mice. We conclude that vitamin D deficiency enhances the growth of colon cancer in mice. The tumor expression of VDR and 1alpha-OHase indicates possible autocrine/paracrine cell growth regulation by vitamin D.
CALCULATION OF INTER-BRANE POTENTIAL IN COMPACT SPACE

The potential between branes in a compact space obeys a modified Poisson equation. Although the Green's functions for simple spaces such as the torus are known, we illustrate the use of a well-established method from solid state physics that may be used to find the potential on a general compact space. This potential is relevant for inflationary scenarios, and in particular helps determine whether a given model satisfies the slow-roll conditions. We show that models with branes at small angles generally give enough inflation.
Growth Path for Computers in Automated Analysis

We are always interested in finding ways to increase our effectiveness as scientists. One way to do this is to see if there are better tools to help us in the jobs we face, or more effective ways of using the tools that we have. Attaching a computer to an instrument makes a powerful new instrument; any instrument, and almost any computer. A computer in itself is not an instrument, but when attached to any instrument it is. Thus, this is a possible technique for increasing our effectiveness which may apply to many disciplines. Rather than describe a specific instance, although I will give examples, I will try instead to give an overview of this type of growing activity, and try to state where I think it is heading. In this sense, this is somewhat of a selected version of what is going on in “Lab Automation”.