bluuebunny/crossref_metadata_2025 huggingface dataset:
Ring‐opening polymerization of L‐lactide using half‐titanocene complexes of the ATiCl2Nu type: Synthesis, characterization, and thermal properties
Authors: Saridis Emmanuel , Maroulas Serafeim‐Dionysios , Pitsikalis Marinos
Published: December 2012

Various half‐titanocene complexes of the ATiCl2Nu type, where A is the pentamethylcyclopentadienyl (Cp*) or indenyl (Ind) group and Nu a nucleophile (ethoxy group or chloride), were used for the polymerization of L‐lactide, LLA. In the cases where Nu is an ethoxy group, a 5% excess of ATiCl3 was used to accelerate the polymerization reaction. These systems were proven to be very efficient initiators for the ring‐opening polymerization (ROP) of LLA in toluene at 130 °C. Kinetic studies revealed that in most cases the polymerization yield was quantitative and the molecular weight increased linearly with time, leading to well‐defined PLLA with narrow molecular weight distributions (Mw/Mn ≤ 1.1). LLA was also polymerized by the in situ formation of the initiating system after mixing IndTiCl3, benzyl alcohol, BzOH, and NEt3. The thermal properties of the produced polymers were examined by differential scanning calorimetry and thermogravimetric analysis. The activation energy of the thermal decomposition was calculated by the Ozawa–Flynn–Wall and Kissinger methods. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Synthesis of dual‐functional copolymer with orthogonally photosensitive groups
Authors: Xu Lebo , Farrell John , Karunakaran Raghuraman G. , Honglawan Apiradee , Yang Shu
Published: December 2012

A dual‐functional copolymer, poly(4‐styrenesulfonyl azide‐co‐t‐butyl‐methacrylate), with built‐in photoacid labile and photocrosslinkable components was designed and synthesized by radical copolymerization. The mixture of copolymer and photoacid generators was spin coated on aminosilane treated Si wafers and polycarbonate (PC). When exposed to 365 nm UV light, photoacids were generated, which decomposed the acid labile groups, t‐butyl‐ester, to carboxylic acid in the exposed region, leading to drastic change of wettability from hydrophobic to hydrophilic after developing the film in an aqueous base solution. The patterned polymer film could be subsequently photoimmobilized on the substrate under 254 nm deep UV exposure through CH insertion via exited azide groups. 1H‐NMR and Fourier transform infrared spectra confirmed the synthesis of the copolymer, and the photodecomposition and photografting reactions occurred orthogonally at 365 and 254 nm, respectively, without interfering each other. On the patterned surfaces, including a hexagonal dot array and a gradient line array, we demonstrated selective wetting in the 365 nm exposed regions. On the gradient line array, we showed an interesting ratchet wetting pattern. Finally, we showed that the copolymer could be used to modify the wettability of PC while maintaining its high optical quality. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Synthesis and properties of high‐performance functional polyimides containing rigid nonplanar conjugated tetraphenylethylene moieties
Authors: Liu Yiwu , Zhang Yi , Lan Qi , Qin Zexin , Liu Siwei , Zhao Cunyuan , Chi Zhenguo , Xu Jiarui
Published: December 2012

A simple diamine (TetraPEDA) containing rigid nonplanar conjugated tetraphenylethylene (TetraPE) moieties was designed and synthesized through Wittig–Horner and Suzuki coupling reactions. Four kinds of high‐performance functional polyimides (PI) were thus prepared by the polymerization of TetraPEDA and four dianhydrides, respectively. Because of the introduction of the aromatic rigid nonplanar TetraPE structure, the PI exhibited special fluorescent characteristics, as the maximum fluorescence emission of the four PI was observed at 425–505 nm in NMP solution and at 470–491 nm in film state. Also these organo‐soluble PI showed outstanding properties, such as low dielectric constant (even without fluorinated substituent), light color, high glass transition temperatures (382–443 °C) and thermal stability in air (Td5% up to 565 °C), and excellent mechanical properties. The polymer memory devices with the configuration of indium tin oxide/PI/aluminum (ITO/PI/Al) exhibited distinct volatile memory characteristics of static random access memory, with an ON/OFF current ratio of 1 × 104 to 1 × 105. These functional PI showed attractive potential applications in the field of high performance flexible polymer photoconducting devices or fluorescent polymer memory devices. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
All‐polymer solar cells utilizing low band gap polymers as donor and acceptor
Authors: Tang Yaqi , McNeill Christopher R.
Published: December 2012

All‐polymer solar cells based on blends of the low band gap polymers poly{[4,8‐bis[(2‐ethylhexyl)oxy]benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl][3‐fluoro‐2‐[(2‐ethylhexyl)carbonyl]thieno[3,4‐b]thiophenediyl]} (PTB7) and poly{[N,N‐9‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,59‐(2,29‐bithiophene)} (P(NDI2OD‐T2)) are demonstrated. The use of the donor polymer PTB7 instead of poly(3‐hexylthiophene) results in a higher open‐circuit voltage and an overall spectral response better matched to the solar spectrum. A power conversion efficiency of 1.1% is reported with a peak external quantum efficiency of 18% at a wavelength of 680 nm. The microstructure of PTB7:P(NDI2OD‐T2) blends is also investigated using a combination of grazing‐incidence wide‐angle X‐ray scattering (GIWAXS), near‐edge X‐ray fine‐structure (NEXAFS) spectroscopy, atomic force microscopy (AFM), and scanning transmission X‐ray microscopy (STXM). GIWAXS measurements show that PTB7:P(NDI2OD‐T2) blends contain P(NDI2OD‐T2) crystallites with a (100) thickness of 9.5 nm dispersed in an amorphous PTB7 matrix. STXM measurements indicate a lack of mesoscale phase separation, with AFM and NEXAFS measurements revealing a P(NDI2OD‐T2)‐rich top surface with fibrillar morphology. These results indicate that the pairing of low band gap polymers as both donor and acceptor polymers in all‐polymer solar cells may be an effective strategy for realizing high‐efficiency all‐polymer solar cells. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013
Respiratory and hemodynamic effects of a stepwise lung recruitment maneuver in pediatric ARDS: A feasibility study
Authors: Cruces Pablo , Donoso Alejandro , Valenzuela Jorge , Díaz Franco
Published: December 2012

Background

Little is known about the efficacy and safety of recruitment maneuvers (RMs) in pediatric patients with acute respiratory distress syndrome (ARDS). We therefore assessed the effects on gas exchange and lung mechanics and the possible detrimental effects of a sequential lung RMs and decremental positive end‐expiratory pressure (PEEP) titration in pediatric ARDS patients.

Methods

We enrolled patients <15 years of age with ARDS, progressive hypoxemia, <72 hr of mechanical ventilation, and hemodynamic stability. A step‐wise RM and decremental PEEP trial were performed. Safety was evaluated as the occurrence of hypotension and low pulse oxymeter oxygen saturation during the maneuver and development of airleaks after. Efficacy was evaluated as changes in lung compliance (Cdyn) and gas exchange 1, 12, and 24 hr after the RM.

Results

We included 25 patients, of median age 5 (1–16) months, median weight 7.0 (4.1–9.2) kg, median PaO2/FIO2 117 (96–139), and median Cdyn 0.48 (0.41–0.68) ml/cmH2O/kg at baseline. Thirty RM were performed, with all completed successfully. No airleaks developed. Mild hypotension was detected during four procedures. Following RM, Cdyn, and PaO2/FIO2 increased significantly (P < 0.01 each), without changes in PaCO2 (P = 0.4). A >25% improvement in lung function (Cdyn or PaO2/FIO2) was observed after 90% of the RM procedures. Gas exchange worsening over the next 24 hr resulted in HFOV use in 36% of patients, while the remaining subjects sustained improvements in oxygenation at 12 and 24 hr. The 28‐day mortality rate was 16%.

Conclusions

Sequential RMs were safe and well tolerated in hemodynamically stable children with ARDS. RMs and a decremental PEEP trial may improve lung function in pediatric patients with ARDS and severe hypoxemia. Pediatr Pulmonol. 2013; 48:1135–1143. © 2012 Wiley Periodicals, Inc.
The contribution of proteomics towards deciphering the enigma of Coxiella burnetii
Authors: Vranakis Iosif , Papadioti Anastasia , Tselentis Yannis , Psaroulaki Anna , Tsiotis Georgios
Published: December 2012

Coxiella burnetii, the causative agent of Q fever, is an intracellular bacterium and a potential weapon for bioterrorism. The widespread throughout the world, zoonosis is manifested clinically as a self‐limited febrile illness, as pneumonia (acute Q fever) or as a chronic illness with endocarditis being its major complication. The recent Netherlands Q fever outbreak has driven the bacterium from a relatively cryptic, underappreciated, “niche” microorganism on the sideline of bacteriology, to one of possibly great impact on public health. Advances in the study of this microorganism proceeded slowly, primarily due to the, until recently, obligatory intracellular nature of the pathogen that in its virulent phase I must be manipulated under biosafety level‐3 conditions. Proteomic studies, in particular, have generated a vast amount of information concerning several aspects of the bacterium such as virulence factors, detection/diagnostic and immunogenic biomarkers, inter‐/intraspecies variation, resistance to antibiotics, and secreted effector proteins with significant clinical impact. The phenomenon observed following the genomics era, that of generation and accumulation of huge amount of data that ultimately end up unexploited on several databases, begins to emerge in the proteomics field as well. This review will focus on the advances in the field of C. burnetii proteomics through MS, attempting in parallel to utilize some of the proteomics findings by suggesting future directions for the improvement of Q fever diagnosis and therapy.
Ion Chromatographic Analysis of Ammonium Dinitramide–Oxidizer for Propellant and Pyrotechnic Applications
Authors: Raghavan Rajeev , Jacob Salu
Published: December 2012

Analysis of ammonium dinitramide (ADN), the advance rocket propellant oxidizer, in pure form as well as in mixtures was carried out by ion chromatography (IC). The purity of ammonium dinitramide was directly determined by estimating the dinitramide ions and indirectly by estimating the impurities. Both methods gave results comparable with those determined by Differential Scanning Calorimetry and UV spectroscopy. The chemical composition of ADN in mixtures containing nitrate, chromate, chlorate, perchlorate, and thiocyanate ions was quantitatively estimated in the same solution without any interferences or prior separation of analyte ions. The newly developed ion chromatographic methods for the analysis of ADN are simple and fast with good accuracy and precision when compared to other analytical techniques. The IC methods are found to be highly suitable for quality control analysis of ADN containing compositions and for the online process monitoring of the formation of ADN in the reaction mixture.
The Effect of Ambient Conditions on the Burning Rate of Gel Fuel Droplets
Authors: Bar‐or Dory , Natan Benveniste
Published: December 2012

An experimental study was conducted to determine the dependence of the burning rate coefficient of gel fuel droplets on the pressure at different ambient oxygennitrogen mixtures. Experiments were conducted using a pressure chamber, in which the droplet was suspended and the combustion process was video‐photographed by a high‐speed digital video camera. The tests were conducted at pressures between 0.1–4 MPa at different ambient oxygennitrogen compositions (air, 40 % O2 – 60 % N2, and 60 % O2 – 40 % N2). The fuel was a compound of 95 % kerosene and 5 % gellant. At sub‐critical pressure conditions, the burning rate coefficient was found to increase with increasing ambient oxygen mass fraction. At supercritical conditions, no dependence of the burning rate coefficient on the ambient mixture was found. The results indicate that the burning rate coefficient depends on the oxygen partial pressure, at least at low pressures.
Induction of Pluripotent Stem Cells from Primordial Germ Cells by Single Reprogramming Factors
Authors: Nagamatsu Go , Kosaka Takeo , Saito Shigeru , Honda Hiroaki , Takubo Keiyo , Kinoshita Taisuke , Akiyama Hideo , Sudo Tetsuo , Horimoto Katsuhisa , Oya Mototsugu , Suda Toshio
Published: December 2012

Germ cells are similar to pluripotent stem cells in terms of gene expression patterns and the capacity to convert to pluripotent stem cells in culture. The factors involved in germ cell development are also able to reprogram somatic cells. This suggests that germ cells are useful tools for investigating the mechanisms responsible for somatic cell reprograming. In this study, the expression of reprograming factors in primordial germ cells (PGCs) was analyzed. PGCs expressed Oct3/4, Sox2, and c-Myc but not Klf4. However, Klf2, Klf5, Essrb, or Essrg, which were expressed in PGCs, could compensate for Klf4 during somatic cell reprograming. Furthermore, PGCs could be converted to a pluripotent state by infection with any of the known reprogramming factors (Oct3/4, Sox2, Klf4, and c-Myc). These cells were designated as multipotent PGCs (mPGCs). Contrary to differences in the origins of somatic cells in somatic cell reprogramming, we hypothesized that the gene expression levels of the reprogramming factors would vary in mPGCs. Candidate genes involved in the regulation of tumorigenicity and/or reprogramming efficiency were identified by comparing the gene expression profiles of mPGCs generated by the exogenous expression of c-Myc or L-Myc.
Activin Receptor-Like Kinase 5 Inhibition Reverses Impairment of Endothelial Cell Viability by Endogenous Islet Mesenchymal Stromal Cells
Authors: Clarkin Claire E. , King Aileen J. , Dhadda Paramjeet , Chagastelles Pedro , Nardi Nance , Wheeler-Jones Caroline P. , Jones Peter M.
Published: December 2012

Following islet transplantation, islet graft revascularization is compromised due to loss of endothelial cells (ECs) during islet culture. TGF-β signaling pathways are essential for vascular homeostasis but their importance for islet EC function is unclear. We have identified a population of multipotent mesenchymal stromal cells (MSCs) within islets and investigated how modulation of TGF-β signaling by these cells influences islet EC viability. Cultured islets exhibited reduced expression of EC markers (VEGFR2, VE-cadherin and CD31), which was associated with diminished but sustained expression of endoglin a marker of both ECs and MSCs. Double fluorescent labeling of islets in situ with the EC marker CD31 disclosed a population of CD31-negative cells which were positive for endoglin. In vitro coculture of microvascular ECs with endoglin-positive, CD31-negative islet MSCs reduced VEGFR2 protein expression, disrupted EC angiogenic behavior, and increased EC detachment. Medium conditioned by islet MSCs significantly decreased EC viability and increased EC caspase 3/7 activity. EC:MSC cocultures showed enhanced Smad2 phosphorylation consistent with altered ALK5 signaling. Pharmacological inhibition of ALK5 activity with SB431542 (SB) improved EC survival upon contact with MSCs, and SB-treated cultured islets retained EC marker expression and sensitivity to exogenous VEGF164. Thus, endoglin-expressing islet MSCs influence EC ALK5 signaling in vitro, which decreases EC viability, and changes in ALK5 activity in whole cultured islets contribute to islet EC loss. Modifying TGF-β signaling may enable maintenance of islet ECs during islet isolation and thus improve islet graft revascularization post-transplantation.
Transection of the Liver Parenchyma With an Ultrasound Dissector or a Stapler Device: Results of a Randomized Clinical Study
Authors: Savlid Mats , Strand Angelica Horna , Jansson Anders , Agustsson Thorhallur , Söderdahl Gunnar , Lundell Lars , Isaksson Bengt
Published: December 2012

Background

Perioperative hemorrhage and postoperative bile leakage are severe complications of liver surgery. They may be related to the techniques used to divide the tissue. We designed a randomized clinical trial to compare the cavitron ultrasonic surgical aspirator (CUSA) and an endoscopic stapler device applied in routine clinical hepatic surgical practice.

Methods

All consecutive patients admitted for elective hepatic resective surgery—at least bisegmentectomy of the liver—were assessed for enrollment in the study. A total of 100 patients were subsequently randomized. There was a good balance between the study groups concerning issues that may be of relevance for the perioperative and postoperative courses. The primary objective of the study was to achieve an approximately 25 % reduction in perioperative blood loss and postoperative bile leakage. Secondary outcome variables were operating time, general postoperative morbidity, length of hospital stay, and direct medical costs.

Results

The amount of perioperative or postoperative blood loss did not differ significantly between the two groups. We observed a trend toward shorter transection and operating time for patients in whom staplers were used, but the difference did not reach statistical signifcance. The postoperative courses were close to identical in the respective study arms with no difference in bile leakage rates or in the total morbidity profiles. The direct medical costs were nonsignificantly lower in the group where staplers were used for liver transection.

Conclusions

The results show that the use of endoscopic vascular staplers in liver surgery is feasible and safe. It offers an attractive alternative for division of the liver parenchyma during routine hepatic surgery, being comparable to the use of CUSA without adding extra costs.
Utilisation of a Level 1 Trauma Centre in KwaZulu‐Natal: Appropriateness of Referral Determines Trauma Patient Access
Authors: Hardcastle Timothy Craig , Reeds Matthew Giles , Muckart David James Jackson
Published: December 2012

Background

Appropriate referral of major trauma patients to an accredited Level 1 Trauma facility is associated with improved outcome. A new Level 1 Trauma Centre was opened at Inkosi Albert Luthuli Central Hospital in March 2007. This study sought to audit the referral pattern of external consults to the trauma unit and ascertain whether the unit was receiving appropriate referrals and has adequate capacity.

Methods

An audit was performed of the referral proformas used in the unit to record admission decisions and of the computerised trauma database. The audit examined referral source (scene vs. interhospital), regional distribution, and final decision regarding admission of the injured patients. The study was approved by the UKZN Ethics Committee (BE207/09 and 011/010).

Results

Of the 1,212 external consults, 540 were accepted for admission while the rest were not accepted for various reasons. These included 206 cases where no bed was available, 233 did not meet admission criteria (minor injury or futile situation), and 115 were for subspecialty management of a single‐system injury. Finally, 115 were initially refused pending stabilisation for transfer at a regional facility. Twenty‐six percent of the cases were referrals from the scene, with an acceptance rate of 96 %. Most patients (59 %) were from the local eThekwini region.

Conclusion

Major multiorgan system trauma remains a significant public health burden in KwaZulu‐Natal. A Level 1 Trauma Service is used appropriately in most circumstances. However, the additional need for more hospital facilities that provide such services across the whole province to enable effective geographical coverage for those trauma patients requiring such specialised trauma care is essential.
Management of Recurrent Inguinal Hernia at a Tertiary Care Hospital of Southern Sindh, Pakistan
Authors: Memon Ahmer A. , Siddiqui Faisal G. , Abro Arshad H. , Agha Ahmed H. , Lubna Shahzadi , Memon Abdul S.
Published: December 2012

Background

The goal of the present study was to determine the frequency, mode of presentation, and need for reoperation in the treatment of recurrent inguinal hernia at Liaquat University Hospital, Jamshoro, Sindh, Pakistan.

Methods

This descriptive, cross‐sectional study was conducted over a period of four years, from January 2007 through December 2010. A total of 916 patients with inguinal hernia underwent operation in the Department of Surgery at Liaquat University Hospital Jamshoro, Sindh, Pakistan, during the study period. Of them, 62 patients were diagnosed to have recurrent inguinal hernia and were included in the study. Female patients and patients with other types of hernia like femoral, epigastric, and paraumbilical defects were excluded.

Results

Among the 62 patients studied, the commonest age group with recurrence was 41–50 years (43.5 %). Fifty‐one (82.2 %) of the patients were ambulatory workers. In 47 cases (75.8 %) recurrence was on the right side, and in 15 (24.1 %) recurrence was on the left side. First time recurrence was seen in 54 patients (87 %) and second time recurrence was seen in 7 patients (11.2 %); third time recurrence was observed in only one patient. All of these patients had an initial open surgery without mesh, except one. Bassini’s repair was done as a primary repair in 47 (75.8 %) cases. A total of 11 patients (17.7 %) had no previous medical records. Darning repair was done in 3 patients (4.8 %), and open surgery with mesh was performed in only one patient. The highest recurrence rates were seen in patients whose hernia repairs had been done by postgraduate trainees. That is, 45 of the patients requiring reoperation (72.5 %), compared to 11 (17.7 %), and 6 (9.6 %) operations performed by registrars and consultants, respectively. All patients in our study underwent tension‐free Lichtenstein mesh repair. Postoperative complications included retention of urine (40.3 %), scrotal hematoma (6.4 %), and wound infection (3.2 %).

Conclusions

Recurrent inguinal hernia is still frequently observed today, and the Lichtenstein tension‐free repair has gained great acceptance worldwide and is currently considered the procedure of choice for primary and recurrent inguinal hernias.
How Neighborhood Structural and Institutional Features Can Shape Neighborhood Social Connectedness: A Multilevel Study of Adolescent Perceptions
Authors: Lenzi Michela , Vieno Alessio , Santinello Massimo , Perkins Douglas D.
Published: December 2012

According to the norms and collective efficacy model, the levels of social connectedness within a local community are a function of neighborhood structural characteristics, such as socioeconomic status and ethnic composition. The current work aims to determine whether neighborhood structural and institutional features (neighborhood wealth, percentage of immigrants, population density, opportunities for activities and meeting places) have an impact on different components of neighborhood social connectedness (intergenerational closure, trust and reciprocity, neighborhood‐based friendship and personal relationships with neighbors). The study involved a representative sample of 389 early and middle adolescents aged 11–15 years old, coming from 31 Italian neighborhoods. Using hierarchical linear modeling, our findings showed that high population density, ethnic diversity, and physical and social disorder might represent obstacles for the creation of social ties within the neighborhood. On the contrary, the presence of opportunities for activities and meeting places in the neighborhood was associated with higher levels of social connectedness among residents.
Dufour and Soret Effects in an Axisymmetric Stagnation Point Flow of Second Grade Fluid with Newtonian Heating
Authors: Nawaz M. , Alsaedi A. , Hayat T. , Alhothauli M. S.
Published: December 2012

The problem of magnetohydrodyanmic stagnation point flow and heat transfer of second grade fluid past a radially stretching sheet is investigated. The flow problems are examined in the presence of Newtonian heating and Soret and Dufour effects. The relevant mathematical problems are developed through equations of continuity, momentum, energy and concentration. The reduced differential equations are solved for the convergent series solutions. In order to validate the homotopy analysis method (HAM), a comparative study between the present and previous results is made. It is observed that Dufour and Soret effects on temperature and concentration distributions are different. Qualitatively, the influence of Prandtl number on temperature and Schmidt number on concentration is similar. It is further noted that the diffusion of solute in second grade fluid is increasing function of Soret number whereas it decreases when Dufour number increases.
The city as a transient home: residential patterns of Moscow workers around the turn of the twentieth century
Authors: MAZANIK ANNA
Published: December 2012

This article examines the social topography and the housing patterns of Moscow workers in the context of their social status and experience of immigration. It argues that in the early twentieth century Moscow was characterized by extremely poor housing conditions and the absence of clear residential segregation of social classes due to the lack of profound planning policy and urban reforms.
The Speaker of the House: A Study of Leadership. By Matthew N. Green
Authors: Beckmann Matthew N.
Published: December 2012

The Speaker of the House: A Study of Leadership. By Matthew N. Green. New Haven: Yale University Press, 2010. 292p. $30.00.

In his book, Matthew N. Green investigates Speakers' purposive goals, tactical options, and legislative influence. The overriding thesis: Speakers' actions do not simply reflect “the majority of the majority's” interests and preferences, but rather emerge from a more diverse set of goals. As Green argues: “Speakers may exercise legislative leadership on behalf of the preferences of others besides the majority party in Congress [including] representing his or her own district … achieving his or her own preferred policy outcome … helping the party's president, the institutional presidency, or the House as a whole” (p. 17).
Nonviolent Revolutions: Civil Resistance in the Late 20th Century. By Sharon Erickson Nepstad
Authors: Pearlman Wendy
Published: December 2012

Nonviolent Revolutions: Civil Resistance in the Late 20th Century. By Sharon Erickson Nepstad. New York: Oxford University Press, 2011. 200p. $99.00 cloth, $24.95 paper.

We live in nonviolent revolutionary times. From Egypt to Moscow, New York to Manama, 2011 saw millions of peaceful protestors take to the streets to demand change. Under what conditions do civilian-based struggles achieve their goals without resort to violence?
From Representative Democracy to Participatory Competitive Authoritarianism: Hugo Chávez and Venezuelan Politics
Authors: Mainwaring Scott
Published: December 2012

The study of Latin American politics has always generated great new research questions, and within Latin America, no country's experience has generated more interesting questions than Venezuela since the election of Hugo Chávez in 1998. Contemporary Venezuela raises fascinating questions about the collapse of a highly institutionalized party system and the erosion or breakdown of what had been the third-oldest democracy outside of the advanced industrial democracies. What accounts for these stunning developments? What can we learn from them? These issues go to the core of important developments in Latin American politics, and they are major issues for comparative political scientists beyond Latin America.
Neoliberalism, Race, and the American Welfare State
Authors: Boettke Peter J.
Published: December 2012

Disciplining the Poor: Neoliberal Paternalism and the Persistent Power of Race. By Joe Soss, Richard C. Fording, and Sanford F. Schram. Chicago: University of Chicago Press, 2011. 368p. $75.00 cloth, $25.00 paper.

It is more than 15 years since the Personal Responsibility and Work Opportunity Act was passed in 1996, famously described by then-President Bill Clinton as “the end of welfare as we know it.” In Disciplining the Poor, Joe Soss, Richard Fording, and Sanford Schram analyze recent changes in US welfare policy as reflections of broader transformations of the “governance” of poverty, arguing that these transformations represent a new form of “neoliberal paternalism” in which race continues to be an important element. In this symposium, a diverse group of political scientists working on welfare issues have been asked to critically assess the book's account and to comment more broadly on the importance of the “governance of poverty” to the future of American politics.—Jeffrey C. Isaac, Editor
Neoliberalism, Race, and the American Welfare State
Authors: Katzenstein Mary Fainsod
Published: December 2012

Disciplining the Poor: Neoliberal Paternalism and the Persistent Power of Race.By Joe Soss, Richard C. Fording, and Sanford F. Schram. Chicago: University of Chicago Press, 2011. 368p. $75.00 cloth, $25.00 paper.

It is more than 15 years since the Personal Responsibility and Work Opportunity Act was passed in 1996, famously described by then-President Bill Clinton as “the end of welfare as we know it.” InDisciplining the Poor, Joe Soss, Richard Fording, and Sanford Schram analyze recent changes in US welfare policy as reflections of broader transformations of the “governance” of poverty, arguing that these transformations represent a new form of “neoliberal paternalism” in which race continues to be an important element. In this symposium, a diverse group of political scientists working on welfare issues have been asked to critically assess the book's account and to comment more broadly on the importance of the “governance of poverty” to the future of American politics.—Jeffrey C. Isaac, Editor
Assessing Difficulties in Career Decision Making Among Swiss Adolescents with the German My Vocational Situation Scale
Authors: Hirschi Andreas , Herrmann Anne
Published: December 2012

Assessing problems in career decision making among adolescents is important for career guidance and research. The present study is the first to investigate among Swiss adolescents the factor structure and convergent validity in relation to personality of the German-language adaptation of the My Vocational Situation Scale. Two preliminary studies (N = 217) suggested that using a 5-point Likert scale response format would increase scale reliability. The confirmatory factor analyses in the main study with two cohorts (n = 341, eighth grade; n = 303, eleventh grade) confirmed that four main factors, which assess problems with identity, decision making, information, and perceived barriers, underlie the data. The barriers factor was differentiated into aspired vocation and personal situation. Construct validity was supported by significant relationships between favorable personality characteristics (emotional stability, extraversion, agreeableness, conscientiousness, generalized self-efficacy, and internal locus of control) and fewer problems. The results suggest that the vocational identity and barriers scales can be fruitfully applied to research on and the practice of career counseling with adolescents.
Perceived Familiarity with a Judgmental Situation Improves Lie Detection Ability
Authors: Reinhard Marc-André , Sporer Siegfried L. , Scharmach Martin
Published: December 2012

Lie catchers are often barely better than chance. In this experiment, we investigated the influence of manipulated perceived familiarity with a situation that measured participants’ ability to correctly classify lies and truths. As expected, participants in the high-familiarity condition showed substantially (21%) greater classification accuracy for both truths and lies than in the low-familiarity condition. Furthermore, as predicted, mediational analyses indicated that the higher classification accuracy rates in the high-familiarity conditions were due in part to a stronger reliance on content cues and less use of stereotypical nonverbal cues, compared to the low-familiarity condition. Participants in the high-familiarity condition were also more confident in their decision and better calibrated than participants who had been led to believe that they were unfamiliar with the situation. Analyses of confidence-accuracy calibration challenge previous findings of low correlations between confidence and accuracy.
Correlation of ignimbrites using characteristic remanent magnetization and anisotropy of magnetic susceptibility, Central Andes, Bolivia
Authors: Ort Michael H. , de Silva Shanaka L. , Jiménez C. Néstor , Jicha Brian R. , Singer Bradley S.
Published: December 2012

Large ignimbrite flare‐ups provide records of profound crustal modification during batholith formation at depth. The locations of source calderas and volumes and ages of the eruptions must be determined to develop models for the tectonomagmatic processes that occur during these events. Although high‐precision isotopic ages of the ignimbrites are critical, less expensive and more rapid techniques, such as paleomagnetism, can extend the temporal information from dated outcrops. Paleomagnetic and rock magnetic data, including characteristic remanent magnetization (ChRM) and anisotropy of magnetic susceptibility (AMS), from the Altiplano‐Puna Volcanic Complex of the Central Andes reliably identify calderas and eight associated Mio‐Pliocene ignimbrites.

ChRM results indicate a larger between‐site error for most ignimbrites, in comparison to within‐site scatter. Part of this dispersion may be due to tumescence/detumescence associated with the caldera‐forming eruptions, but most of the effect is probably due to the recording of paleosecular variation during cooling and vapor‐phase crystallization of the thick ignimbrites. AMS data identify the source calderas for four ignimbrites and provide limits on possible post‐emplacement rotations of the deposits. AMS data indicate significant topographic control on inferred flow directions, implying that the flows were dense and/or of low mobility.
Intraseasonal mixed‐layer heat budget in the equatorial Atlantic during the cold tongue development in 2006
Authors: Giordani Hervé , Caniaux Guy , Voldoire Aurore
Published: December 2012

Estimating the mixed‐layer heat budget is a key issue for understanding the cold tongue development in the eastern equatorial Atlantic. A high‐resolution ocean regional model is used to diagnose the mixed‐layer heat budget online during the EGEE‐3 experiment from May to August 2006. The heat budget shows the major role of the horizontal advection and turbulent mixing in the mixed‐layer temperature balance in the cold tongue. The surface net heat flux and entrainment processes play a minor role. The equatorial cooling is mainly induced by low‐frequency advection, which is balanced by high‐frequency zonal and meridional advections. The high‐frequency advections are organized in patterns along the northern edge of the cold tongue, where they are associated with strong sea surface temperature gradients and well‐developed tropical instability waves in the western Atlantic. Special attention is paid to the wind energy flux, which controls horizontal advection and turbulent mixing. We suggest that the wind energy flux drives the vertical velocity, which in turn adjusts the mixed‐layer depth, its stratification, and the vertical shear of the horizontal current. Although vertical advection is not essential in providing cold water in the Atlantic cold tongue, it is shown that the vertical velocity plays a central role in preconditioning the mixed layer and maximizes the turbulent mixing.
In Vivo Detection of Cerebral Cortical Microinfarcts with High-Resolution 7T MRI
Authors: van Veluw Susanne J , Zwanenburg Jaco JM , Engelen-Lee JooYeon , Spliet Wim GM , Hendrikse Jeroen , Luijten Peter R , Biessels Geert Jan
Published: December 2012

Cerebrovascular disease has an important role in cognitive decline and dementia. In this context, cerebral microinfarcts are attracting increasing attention, but these lesions could thus far not be detected in vivo. The aim of this study was to try to identify possible cortical microinfarcts on high-resolution 7T in vivo magnetic resonance imaging (MRI) and to perform a histopathologic validation study on similar appearing lesions on 7T ex vivo MRI of postmortem brain tissue. The study population consisted of 22 elderly subjects, who underwent 7T MRI. The fluid attenuated inversion recovery, T2, and T1 weighted scans of these subjects were examined for possible cortical microinfarcts. In the ex vivo MRI study, 15 formalin-fixed coronal brain slices of 6 subjects with Alzheimer and vascular pathology were examined and subjected to histopathologic verification. On the in vivo scans, 15 cortical lesions could be identified that were likely to be microinfarcts in 6 subjects. In the postmortem tissue, 6 similar appearing lesions were identified of which 5 were verified as cortical microinfarcts on histopathology. This study provides strong evidence that cortical microinfarcts can be detected in vivo, which will be of great value in further studies into the role of vascular disease in cognitive decline and dementia.
The membrane adaptor LAT is proteolytically cleaved following Fas engagement in a tyrosine phosphorylation-dependent fashion
Authors: García-Blesa Antonio , Klossowicz Mikolaj , López-Osuna Carmen , Martínez-Florensa Mario , Malissen Bernard , García-Cózar Francisco J. , Miazek Arkadiusz , Aguado Enrique
Published: December 2012

Engagement of the TCR (T-cell receptor) induces tyrosine phosphorylation of the LAT (linker for the activation of T-cells) adaptor, and thereby it recruits several cytosolic mediators for downstream signalling pathways. The Fas protein is essential for T-lymphocyte apoptosis, and following Fas engagement, many proteins are proteolytically cleaved, including several molecules that are important for the transduction of TCR intracellular signals. In the present study, we demonstrate that the adaptor LAT is also subject to a proteolytic cleavage in mature T-lymphocytes and thymocytes in response to Fas engagement, and also on TCR stimulation, and we identify three aspartic acid residues at which LAT is cleaved. Interestingly, these aspartic acid residues are located in proximity to several functionally important tyrosine residues of LAT, raising the possibility that their phosphorylation could modulate LAT cleavage. Consistent with that hypothesis, we show that induction of phosphorylation by pervanadate or H2O2 in Jurkat cells and thymocytes inhibits Fas-mediated cleavage of LAT. Moreover, we show that LAT proteolysis is also enhanced during anergy induction of primary human T-cells, suggesting that LAT cleavage may act as a regulator of TCR-mediated activation of T-cells and not only as a transducer of cell death promoting stimuli.
On Core XPath with Inflationary Fixed Points
Authors: Afanasiev Loredana , Cate Balder ten
Published: December 2012

We prove the undecidability of Core XPath 1.0 (CXP) [G. Gottlob and C. Koch, inProc. of 17th Ann. IEEE Symp. on Logic in Computer Science, LICS ’02 (Copenhagen, July 2002).IEEE CS Press (2002) 189–202.] extended with anInflationary Fixed Point (IFP)operator. More specifically, we prove that the satisfiability problem of this language is undecidable. In fact, the fragment of CXP+IFP containing only theselfanddescendantaxes is already undecidable.
A Rare Case of Inflammatory Pseudotumor with Both Involvement of Lung and Heart
Authors: Cagac Ozgur , Birkan Yasar , Sunbul Murat
Published: December 2012

Inflammatory pseudotumor (IPT) is a rare disorder that is benign and tumor-like reactive masses with unknown etiology. The mass usually confines to the lung but other organs involvement such as liver, stomach, lymph nodes could affect. IPT of heart is usually determined with children and young adults. Only 15 cases are detected in adults. We present here a rare case of IPT with both involvement of lung and heart.
Negative effect of crystallization on the mechanism of laser damage in a HfO2/SiO2 multilayer
Authors: Tateno Ryo , Okada Hajime , Otobe Tomohito , Kawase Keigo , Koga James K. , Kosuge Atsushi , Nagashima Keisuke , Sugiyama Akira , Kashiwagi Kunihiro
Published: December 2012

Elucidation of the mechanisms of laser damage is indispensable in realizing high resistance mirrors for the next generation of ultra-short pulse high intensity lasers. In this study, the surface and a section of the laser-damaged area of a laser mirror were observed with a laser microscope and a transmission electron microscope (cross-sectional TEM), respectively. A grain boundary of HfO2 microcrystal was observed in the damaged area. This observation and an evaluation of the mirror's damage resistance showed that the formation of crystals in the multilayer mirror is one of the major determinants of damage resistance.
Fermionic and bosonic Laughlin state on thick cylinders
Authors: Jansen Sabine
Published: December 2012

We investigate a many-body wave function for particles on a cylinder known as Laughlin's function. It is the power of a Vandermonde determinant times a Gaussian. Our main result is: in a many-particle limit, at fixed radius, all correlation functions have a unique limit, and the limit state has a non-trivial period in the axial direction. The result holds regardless how large the radius is, for fermions as well as bosons. In addition, we explain how the algebraic structure used in proofs relates to the formalism of quasi-state decompositions.
On the scaling of steady structured waves in heterogeneous materials
Authors: Vogler T. J. , Borg J. P. , Grady D. E.
Published: December 2012

Large amplitude steady waves in materials have been observed to display certain scaling relationships between the strain rate and the stress amplitude. In many homogeneous materials, strain rate scales with stress to the fourth power. However, scaling of strain rate with stress to the first, second, and fourth power has been found for different classes of heterogeneous materials. We examine wave structures for three classes of heterogeneous materials through mesoscale simulations that resolve the scale of heterogeneity explicitly. We utilize these simulations to gain insight into the scaling phenomena observed and to identify the critical non-dimensional parameters for the phenomena. These parameters are then applied to the available experimental data for the three classes. The same set of non-dimensional groups is found to be appropriate for layered and particulate composite materials, while somewhat different groups are found for granular materials. Two different types of simulations lead to different conclusions on the need for the inclusion of strength in the non-dimensionalization for granular materials. The groups formed are found to collapse the experimental data quite well when the strength parameter is not included. Finally, a simple model for granular materials demonstrates that the crucial aspect of their behavior that controls the scaling of waves is the need for mass transfer to close voids in the material.
Oscillation dynamics of embolic microspheres in flows with red blood cell suspensions
Authors: Das Tamal , Carugo Dario , Zhang Xunli , Chakraborty Suman
Published: December 2012

Dynamic nature of particle motion in blood flow is an important determinant of embolization based cancer therapy. Yet, the manner in which the presence of high volume fraction of red blood cells influences the particle dynamics remains unknown. Here, by investigating the motions of embolic microspheres in pressure-driven flows of red blood cell suspensions through capillaries, we illustrate unique oscillatory trends in particle trajectories, which are not observable in Newtonian fluid flows. Our investigation reveals that such oscillatory behavior essentially manifests when three simultaneous conditions, namely, the Reynolds number beyond a threshold limit, degree of confinement beyond a critical limit, and high hematocrit level, are fulfilled simultaneously. Given that these conditions are extremely relevant to fluid dynamics of blood or polymer flow, the observations reported here bear significant implications on embolization based cancer treatment as well as for complex multiphase fluidics involving particles.
Calculation of chemical reaction rate constants using on-the-fly high level electronic structure computations with account of multidimensional tunneling
Authors: Kryvohuz Maksym
Published: December 2012

The semiclassical instanton approach to the calculation of reaction rate constants at arbitrary temperatures in multiatomic systems is combined with high-level ab initio calculations of reactive potential energy surface (PES). The number of required ab initiocalculations weakly depends on system size and allows on-the-fly evaluations of PES with high accuracy. The approach can be efficiently parallelized and provides a practical way of calculating quantum reaction rate constants with account of nuclear quantum effects such as multidimensional tunneling and zero point energies, which are rigorously incorporated in the theory. An algorithm for the search of instanton trajectories is explained. Application of the approach is illustrated for H + H2 → H2 + H and D + D2 → D2 + D bimolecular reactions in the wide temperature range with on-the-fly evaluation of PES at the ab initio full configuration interaction (FCI), coupled-cluster single double (CCSD), and single and double excitation configuration interaction (CISD) levels.
The additive effect of harmonics on conservative and dissipative interactions
Authors: Santos Sergio , Gadelrab Karim R. , Barcons Victor , Font Josep , Stefancich Marco , Chiesa Matteo
Published: December 2012

Multifrequency atomic force microscopy holds promise as a tool for chemical and topological imaging with nanoscale resolution. Here, we solve the equation of motion exactly for the fundamental mode in terms of the cantilever mean deflection, the fundamental frequency of oscillation, and the higher harmonic amplitudes and phases. The fundamental frequency provides information about the mean force, dissipation, and variations in the magnitude of the attractive and the repulsive force components during an oscillation cycle. The contributions of the higher harmonics to the position, velocity, and acceleration can be added gradually where the details of the true instantaneous force are recovered only when tens of harmonics are included. A formalism is developed here to decouple and quantify the viscous term of the force in the short and long range. It is also shown that the viscosity independent paths on tip approach and tip retraction can also be decoupled by simply acquiring a FFT at two different cantilever separations. The two paths correspond to tip distances at which metastability is present as, for example, in the presence of capillary interactions and where there is surface energy hysteresis.
Identifying graphene layers via spin Hall effect of light
Authors: Zhou Xinxing , Ling Xiaohui , Luo Hailu , Wen Shuangchun
Published: December 2012

The spin Hall effect (SHE) of light is a useful metrological tool for characterizing the structure parameters' variations of nanostructure. In this letter, we propose using the SHE of light to identify the graphene layers. This technique is based on the mechanism that the transverse displacements in SHE of light are sensitive to the variations of graphene layer numbers.
Strain-controlled electron switch in graphene
Authors: Cao Zhen-Zhou , Cheng Yan-Fu , Li Guan-Qiang
Published: December 2012

We explore the transmission properties of electrons through an n-p-n junction and propose a design for a strain-controlled electron switch in graphene. We analyze the conductance as a function of the strain magnitude and direction, the energy gap, the width and height of the potential barrier, and the energy of the incident electrons. The switch can be turned off using strain applied only along special directions. The conductance, with gaps caused by evanescent waves, is almost unaffected by the barrier width but is affected by the height. A larger strain magnitude can restrain the conductance of higher energy electrons.