bluuebunny/crossref_metadata_2025 huggingface dataset:
Equal Opportunities for All?– A Critical Analysis of Mexico'sOportunidades
Authors: Ulrichs Martina , Roelen Keetie
Published: January 2013

In this paper we challenge the theory of change behind the Mexican Conditional Cash Transfer ProgrammeOportunidades, by questioning whether it sufficiently addresses the structural factors that prevent its poorest group of beneficiaries, indigenous people, from climbing out of poverty. Conditional cash transfer programmes likeOportunidadesmake cash transfers conditional upon school attendance and accessing health care services. The theory of change is based on the human capital theory and predicated on individualistic understandings of poverty, assuming that higher levels of education will ultimately translate into higher salaries and better jobs and thus break the intergenerational transmission of poverty.

We argue that the particular situation of indigenous people poses programme‐specific and structural constraints on the ‘one‐size‐fits‐all’ application ofOportunidadesand challenges its theory of change, thereby compromising its effectiveness in both the short‐term and long‐run. The remoteness of indigenous communities and the higher levels of marginalisation compromiseOportunidades' performance in terms of coverage, outreach and targeting for indigenous people and may exacerbate and reinforce the groups' marginalised and disadvantaged positions in comparison to the non‐indigenous population. One of the shortcomings of the programme's theory of change is an insufficient focus on constraining factors in the market, unequal access to good quality education and health care services, as well as different capital and asset levels of individuals who enter the job market. Higher levels of human capital can be an important condition to achieve higher levels of income, but unequal opportunity structures may seriously inhibit the successful progression out of poverty for different groups of poor people.

Oportunidadeshas had remarkable positive impacts, such as increasing school attendance and facilitating access to health care services for the poor. But in order to be transformative, it needs to be responsive to particular vulnerabilities and it needs to address the underlying causes of poverty.
Impact of immediate loading on early bone healing at two‐piece implants placed in fresh extraction sockets: an experimental study in the beagle dog
Authors: Blanco Juan , Mareque Santiaqo , Liñares Antonio , Pérez Javier , Muñoz Fernando , Ramos Isabel
Published: January 2013

Objective

To study early bone healing of immediately loaded implants placed in fresh extraction sockets versus immediate implants without occlusal loading in the dog.

Materials and methods

A total of 48 implants were placed in the distal sockets of Pm3 and Pm4 in the lower jaw of 12 Beagle dogs immediately after tooth extraction. In the control group, no loading was applied. In the test group, an immediate loading restoration with occlusal contacts was performed. Dogs were sacrificed at 2, 4 and 8 weeks for histological analysis.

Results

At the end of the study, there was a 100% implant and prosthesis survival. Similar results for test and control groups were observed for bone‐to‐implant contact (%) and peri‐implant bone area. Inter‐thread bone area tended to decrease in the control and increase in the test. With respect to ridge alterations, bone resorption was more pronounced on the buccal aspect and was observed in both groups.

Conclusion

Immediate loading did not impair early stages of bone healing and crestal bone modelling at two‐piece implants in fresh extraction sockets in the beagle dog; however, bone resorption occurred in all specimens in both groups.
Periodontal repair in dogs: space‐provision supports alveolar bone and cementum formation
Authors: Chiu Hsien‐Chung , Shen E‐Chin , Lin Shu‐Jiun , Susin Cristiano , Wikesjö Ulf M. E. , Fu Earl
Published: January 2013

Objective

Clinical criteria for periodontal wound healing/regeneration include wound stability, space‐provision and conditions for primary intention healing. However, wound stability/space‐provision may be difficult to obtain in non‐contained periodontal defects. The objective of this study was to; using a limited, space‐providing device as a conduit, evaluate a concept of space‐provision sans tissue occlusion for periodontal wound healing/regeneration.

Methods

Bilateral, critical‐size, supraalveolar, periodontal defects were created in eight young adult Beagle dogs. One jaw quadrant received a limited, space‐providing titanium mesh device, the contra‐lateral jaw quadrant served as sham‐surgery control followed by submerged wound closure for primary intention healing. The animals were euthanized at 8 weeks for histometric analysis of the surgical sites.

Results

Clinical healing was generally uneventful; minor late exposures observed for some defects. Experimental sites exhibited significantly enhanced mean (±SE) bone and cementum regeneration compared with control (1.10 ± 0.20 and 1.32 ± 0.10 mm versus 0.34 ± 0.18 and 0.66 ± 0.15 mm; p < 0.01). A cellular mixed (extrinsic/intrinsic) fibre cementum and functionally oriented collagen fibres were routinely observed. Wound exposures were significantly associated with reduced bone formation (p < 0.05).

Conclusions

Using a limited, space‐providing device to support periodontal wound healing/regeneration appears a promising clinical approach for non‐contained periodontal defects.
Effects of bone morphogenetic protein‐6 on periodontal wound healing/regeneration in supraalveolar periodontal defects in dogs
Authors: Chiu Hsien‐Chung , Chiang Cheng‐Yang , Tu Hsiao‐Pei , Wikesjö Ulf M.E. , Susin Cristiano , Fu Earl
Published: January 2013

Objective

Application of a synthetic BMP‐6 polypeptide in a rat periodontal fenestration defect model enhanced periodontal wound healing/regeneration including new bone and cementum formation. The purpose of this study was to translate the relevance of these initial observations into a discriminating large animal model.

Methods

Critical‐size (4–5 mm) supraalveolar periodontal defects were created at the 2nd and 3rd mandibular premolar teeth in 11 Beagle dogs. Experimental sites received BMP‐6 at 0.25, 1.0 and 2.0 mg/ml soak‐loaded onto an absorbable collagen sponge (ACS) carrier or ACS alone (control) each condition repeated in four jaw quadrants. The animals were euthanized at 8 weeks when block biopsies were collected and processed for histologic/histometric analysis.

Results

BMP‐6 at 0.25, 1.0 and 2.0 mg/ml soak‐loaded onto the ACS yielded significantly enhanced new bone (0.99 ± 0.07 versus 0.23 ± 0.13 mm/BMP‐6 at 0.25 mg/ml) and cementum (2.45 ± 0.54 versus 0.73 ± 0.15 mm/BMP‐6 at 0.25 mg/ml) formation including a functionally oriented periodontal ligament compared with control (p < 0.05). A significant inverse linear association between BMP‐6 dose and new bone (β = −0.21 ± 0.09 mm, p = 0.016) and cementum height (β = −0.34 ± 0.15 mm, p = 0.023) was observed. Minimal root resorption was observed without significant differences between groups. Ankylosis was not observed for any of the experimental groups.

Conclusions

Surgical application of BMP‐6/ACS onto critical‐size supraalveolar defects enhanced periodontal wound healing/regeneration, in particular cementogenesis including a functionally oriented periodontal ligament; the low BMP‐6 0.25 mg/ml concentration apparently providing the most effective dose.
Cadmium decontamination and reversal potential of teratological forms of the diatom Planothidium frequentissimum (Bacillariophyceae) after experimental contamination
Authors: Arini Adeline , Durant Fabien , Coste Michel , Delmas François , Feurtet‐Mazel Agnès
Published: January 2013

While the induction of teratology by cadmium (Cd) on diatoms is already known, reversal kinetics are not well documented. This study aims to understand the viability of diatoms exhibiting teratological frustules and their reproduction capacities within a Cd‐impacted population to predict their return to normal diatom forms. We worked on a frequently encountered species in French hydrosystems: Planothidium frequentissimum (Lange‐Bertalot) Round & L. Bukhtiyarova. First, a 21‐d contamination phase highlighted increasing inductionof different teratological types in response to two levels of Cd contamination: 20 and 100 μg · L−1. The deformity counting indicated that Cd firstly generated striae and mixed teratologies, then affected the central area and the valves. Second, a 28‐d decontamination phase demonstrated the Cd depuration capacity of Planothidium frequentissimum. Cd half‐lives appeared relatively low, ~6 d for the 100 μg · L−1 condition. Moreover, the decontamination phase showed a decrease in teratology abundances, but a still incomplete recovery after 28 d. Deformations of the striae appeared to be the most sustainable phenotype since they were still significantly higher than in reference cultures at the end of the decontamination phase for both Cd cultures.
The Role of Party: The Legislative Consequences of Partisan Electoral Competition
Authors: Carroll Royce , Eichorst Jason
Published: January 2013

We examine the proposition that incentives for legislative organization can be explained by the nature of electoral competition. We argue that legislators in environments where parties are competitive for majority status are most likely to have delegated power to their leadership to constrain individualistic behavior within their party, which will in turn increase the spatial predictability of individual voting patterns. Using roll‐call votes and district‐level electoral data from the U.S. state legislatures, we show empirically that increased statewide interparty competition corresponds to more predictable voting behavior overall, while legislators from competitive districts and those in the minority party have less predictable behavior.
Association of medical student burnout with residency specialty choice
Authors: Enoch Lindsey , Chibnall John T , Schindler Debra L , Slavin Stuart J
Published: January 2013

Context  Given the trend among medical students away from primary care medicine and toward specialties that allow for more controllable lifestyles, the identification of factors associated with specialty choice is important. Burnout is one such factor. The purpose of this study was to examine the associations between burnout and residency specialty choice in terms of provision for a less versus more controllable lifestyle (e.g. internal medicine versus dermatology) and a lower versus higher income (e.g. paediatrics versus anaesthesiology).

Methods  A survey was sent to 165 Year 4 medical students who had entered the residency matching system. Students answered questions about specialty choice, motivating factors (lifestyle, patient care and prestige) and perceptions of medicine as a profession. They completed the Maslach Burnout Inventory–Human Services (MBI), which defines burnout in relation to emotional exhaustion (EE), depersonalisation (DP) and personal accomplishment (PA). Burnout and other variables were tested for associations with specialty lifestyle controllability and income.

Results  A response rate of 88% (n = 145) was achieved. Experiences of MBI‐EE, MBI‐DP and MBI‐PA burnout were reported by 42 (29%), 26 (18%) and 30 (21%) students, respectively. Specialties with less controllable lifestyles were chosen by 87 (60%) students and lower‐income specialties by 81 (56%). Adjusted odds ratios (ORs) indicated that the choice of a specialty with a more controllable lifestyle was associated with higher MBI‐EE burnout (OR = 1.77, 95% confidence interval [CI] 1.06–2.96), as well as stronger lifestyle‐ and prestige‐related motivation, and weaker patient care‐related motivation. The choice of a higher‐income specialty was associated with lower MBI‐PA burnout (OR = 0.56, 95% CI 0.32–0.98), weaker lifestyle‐ and patient care‐related motivation, and stronger prestige‐related motivation.

Conclusions  Specialty choices regarding lifestyle controllability and income were associated with the amount and type of medical school burnout, as well as with lifestyle‐, prestige‐ and patient care‐related motivation. Given that burnout may influence specialty choice, particularly with regard to the primary care specialties, medical schools may consider the utility of burnout prevention strategies.
Gaze‐down endoscopic practise leads to better novice performance on gaze‐up displays
Authors: Grierson Lawrence E M , Lyons James L , Dubrowski Adam
Published: January 2013

Objectives  It is well known that precision skills are best learned when they are practised in the sensorimotor context that is present when performance is most important. However, a particular skill may vary with respect to the sensorimotor context in which it is performed. Certain sensorimotor variations can make a task more or less complex than others. Recent accounts of skill learning describe how task difficulty can be manipulated to provide optimised challenges to progress learners beyond their current level of expertise. This study tests the idea that simplified practise contexts lead novice learners to acquire skill proficiency that is more generalisable to new contexts.

Methods  We present a learning experiment in which the performances of novices who acquired a set level of proficiency in the endoscopic pots‐and‐beans task through performance‐based practise using a gaze‐up endoscopic monitor arrangement were compared against the performances of novices who acquired an equivalent level of proficiency using a simplified gaze‐down arrangement. Participants returned after 1 week for retention and transfer testing.

Results  Time and accuracy analyses revealed that participants in both training groups improved significantly over the practise protocol and maintained this performance after a period of retention. However, the comparisons of the visual display transfer performances (i.e. on the gaze‐up arrangement) of the gaze‐down trainees against the retention performances (i.e. also on the gaze‐up arrangement) of their gaze‐up counterparts and vice versa revealed that gaze‐down trainees made fewer errors in both performance contexts (F1,16 = 7.97, p = 0.01 and F1,16 = 57.05, p = 0.04, respectively).

Conclusions  These findings highlight the benefits associated with using simplified sensorimotor practise contexts for novice learners. Beginners will learn best from simplified practise because it allows them to develop good movement strategies for dealing with potential error without being overwhelmed by task complexity.
Adjusting medical school admission: assessing interpersonal skills using situational judgement tests
Authors: Lievens Filip
Published: January 2013

Context  Today’s formal medical school admission systems often include only cognitively oriented tests, although most medical school curricula emphasise both cognitive and non‐cognitive factors. Situational judgement tests (SJTs) may represent an innovative approach to the formal measurement of interpersonal skills in large groups of candidates in medical school admission processes. This study examined the validity of interpersonal video‐based SJTs in relation to a variety of outcome measures.

Methods  This study used a longitudinal and multiple‐cohort design to examine anonymised medical school admissions and medical education data. It focused on data for the Flemish medical school admission examination between 1999 and 2002. Participants were 5444 candidates taking the medical school admission examination. Outcome measures were first‐year grade point average (GPA), GPA in interpersonal communication courses, GPA in non‐interpersonal courses, Bachelor’s degree GPA, Master’s degree GPA and final‐year GPA (after 7 years). For students pursuing careers in general practice, additional outcome measures (9 years after sitting examinations) included supervisor ratings and the results of an interpersonal objective structured clinical examination (OSCE), a general practice knowledge test and a case‐based interview.

Results  Interpersonal skills assessment carried out using SJTs had significant added value over cognitive tests for predicting interpersonal GPA throughout the curriculum, doctor performance, and performance on an OSCE and in a case‐based interview. For the other outcomes, cognitive tests emerged as the better predictors. Females significantly outperformed males on the SJT (d = − 0.26). The interpersonal SJT was perceived as significantly more job‐related than the cognitive tests (d = 0.55).

Conclusions  Video‐based SJTs as measures of procedural knowledge about interpersonal behaviour show promise as complements to cognitive examination components. The interpersonal skills training received during medical education does not negate the selection of students on the basis of interpersonal skills. Future research is needed to examine the use of SJTs in other cultures and student populations.
Mutations in cell elongation genes mreB, mrdA and mrdB suppress the shape defect of RodZ‐deficient cells
Authors: Shiomi Daisuke , Toyoda Atsushi , Aizu Tomoyuki , Ejima Fumio , Fujiyama Asao , Shini Tadasu , Kohara Yuji , Niki Hironori
Published: January 2013

RodZ interacts with MreB and both factors are required to maintain the rod shape of Escherichia coli. The assembly of MreB into filaments regulates the subcellular arrangement of a group of enzymes that synthesizes the peptidoglycan (PG) layer. However, it is still unknown how polymerization of MreB determines the rod shape of bacterial cells. Regulatory factor(s) are likely to be involved in controlling the function and dynamics of MreB. We isolated suppressor mutations to partially recover the rod shape in rodZ deletion mutants and found that some of the suppressor mutations occurred in mreB. All of the mreB mutations were in or in the vicinity of domain IA of MreB. Those mreB mutations changed the property of MreB filaments in vivo. In addition, suppressor mutations were found in the periplasmic regions in PBP2 and RodA, encoded by mrdA and mrdB genes. Similar to MreB and RodZ, PBP2 and RodA are pivotal to the cell wall elongation process. Thus, we found that mutations in domain IA of MreB and in the periplasmic domain of PBP2 and RodA can restore growth and rod shape to ΔrodZ cells, possibly by changing the requirements of MreB in the process.
Suicides and Suicide Attempts in the U.S. Military, 2008–2010
Authors: Bush Nigel E. , Reger Mark A. , Luxton David D. , Skopp Nancy A. , Kinn Julie , Smolenski Derek , Gahm Gregory A.
Published: January 2013

The Department of Defense Suicide Event Report Program collects extensive information on suicides and suicide attempts from the U.S. Air Force, Army, Marine Corps, and Navy. Data are compiled on demographics, suicide event details, behavioral health treatment history, military history, and information about other potential risk factors such as psychosocial stressors that were present at the time of the event. The ultimate goal of this standardized suicide surveillance program is to assist suicide prevention in the U.S. military. Descriptive data are presented on 816 suicides and 1,514 suicide attempts reported through the program between 2008 and 2010.
On the Necessity of U‐Shaped Learning
Authors: Carlucci Lorenzo , Case John
Published: January 2013

A U‐shaped curve in a cognitive‐developmental trajectory refers to a three‐step process: good performance followed by bad performance followed by good performance once again. U‐shaped curves have been observed in a wide variety of cognitive‐developmental and learning contexts. U‐shaped learning seems to contradict the idea that learning is a monotonic, cumulative process and thus constitutes a challenge for competing theories of cognitive development and learning. U‐shaped behavior in language learning (in particular in learning English past tense) has become a central topic in the Cognitive Science debate about learning models. Antagonist models (e.g., connectionism versus nativism) are often judged on their ability of modeling or accounting for U‐shaped behavior. The prior literature is mostly occupied with explaining how U‐shaped behavior occurs. Instead, we are interested in the necessity of this kind of apparently inefficient strategy. We present and discuss a body of results in the abstract mathematical setting of (extensions of) Gold‐style computational learning theory addressing a mathematically precise version of the following question: Are there learning tasks that require U‐shaped behavior? All notions considered are learning in the limit from positive data. We present results about the necessity of U‐shaped learning in classical models of learning as well as in models with bounds on the memory of the learner. The pattern emerges that, for parameterized, cognitively relevant learning criteria, beyond very few initial parameter values, U‐shapes are necessary for full learning power! We discuss the possible relevance of the above results for the Cognitive Science debate about learning models as well as directions for future research.
Knowledge and Implicature: Modeling Language Understanding as Social Cognition
Authors: Goodman Noah D. , Stuhlmüller Andreas
Published: January 2013

Is language understanding a special case of social cognition? To help evaluate this view, we can formalize it as the rational speech‐act theory: Listeners assume that speakers choose their utterances approximately optimally, and listeners interpret an utterance by using Bayesian inference to “invert” this model of the speaker. We apply this framework to model scalar implicature (“some” implies “not all,” and “N” implies “not more than N”). This model predicts an interaction between the speaker's knowledge state and the listener's interpretation. We test these predictions in two experiments and find good fit between model predictions and human judgments.
Can older adults enhance the intelligibility of their speech?
Authors: Smiljanic Rajka
Published: January 2013

Speech understanding difficulties for older adults (OAs) are well documented. Very little is known about whether age-related changes affect their speech production as well. Intelligibility of conversational and clear speech sentences produced by five OA talkers was examined. The results of the sentence-in-noise listening tests revealed that OAs enhanced their intelligibility for young adult (YA) listeners through clear speech modifications. Importantly, though, OAs were less effective at improving their speech to benefit listeners compared to YA talkers [reported in Smiljanic and Bradlow, J. Acoust. Soc. Am. 118(3), 1677–1688 (2005)]. The results suggest that auditory and cognitive changes across lifespan can affect OA's speech patterns and intelligibility.
Metamaterial Apertures for Computational Imaging
Authors: Hunt John , Driscoll Tom , Mrozack Alex , Lipworth Guy , Reynolds Matthew , Brady David , Smith David R.
Published: January 2013

Compressed Sampling

It is often said that a picture is worth a thousand words. But images often contain a lot of redundant information—effectively creating huge data files of meaningless information. While algorithms can compress the size of a file without loss of information, such processing is done after the picture has been taken.

Hunt
et al.

(p.
310
) used a metamaterial sensor to compress the sampled scene directly, obviating the need for postprocessing. Tuning the response of the metamaterial allowed imaging of a scene with a 40:1 compression ratio, which may mean that finding that needle in a haystack may be much easier using a metamaterial camera.
Comment on "Extinction Debt and Windows of Conservation Opportunity in the Brazilian Amazon"
Authors: Halley John M. , Iwasa Yoh , Vokou Despoina
Published: January 2013

A paper by Wearn
et al
. (Reports, 13 July 2012, p. 228) yields new insights on extinction debt. However, it leaves out the area dependence of the relaxation process. We show that this is not warranted on theoretical or observational grounds and that it may lead to erroneous conservation recommendations.
Hormones and the Social Brain
Authors: McEwen Bruce S.
Published: January 2013

Social stress can act through glucocorticoids on discrete dopamine-controlled neuronal pathways in the rodent brain to influence behavior.

[Also see Reports by

Barik
et al.

and

Niwa
et al.

]
The Complexities of Genomic Identifiability
Authors: Rodriguez Laura L. , Brooks Lisa D. , Greenberg Judith H. , Green Eric D.
Published: January 2013

Recent work reveals the need to re-examine the current paradigms for managing the potential identifiability of genomic and other "omic"-type data.

[Also see
News story
and Report by

Gymrek
et al.

]
Genealogy Databases Enable Naming of Anonymous DNA Donors
Authors: Bohannon John
Published: January 2013

An algorithm and Web sleuthing has led researchers to discover the identities of anonymous DNA donors.
Who Will Step Up to Exascale?
Authors: Service Robert F.
Published: January 2013

The next big step in high-powered computers lies just ahead, but only if major players are willing to back their talk with coordinated programs and lots of money.
LIFE SCIENCE TECHNOLOGIES: This Is Your Brain: Mapping the Connectome
Authors: Perkel Jeffrey M.
Published: January 2013

It's been 20 years since Francis Crick and Edward Jones, in the midst of the so-called Decade of the Brain, lamented science's lack of even a basic understanding of human neuroanatomy. "Clearly what is needed for a modern human brain anatomy is the introduction of some radically new techniques," the pair wrote in 1993. Clearly, researchers were listening. Today, they are using novel technologies and automation to map neural circuitry with unparalleled resolution and completeness. The NIH has dedicated nearly $40 million to chart the wiring of the human brain, and the Allen Brain Institute has poured in millions more to map the mouse brain. The data will take years to compile, and even longer to understand. But the results may reveal nothing less than the nature of human individuality. As MIT neuroscientist Sebastian Seung writes, "You are more than your genes. You are your connectome."
A Mixture of Functionally Oligoclonal Humanized Monoclonal Antibodies That Neutralize Clostridium difficile TcdA and TcdB with High Levels ofIn VitroPotency ShowsIn VivoProtection in a Hamster Infection Model
Authors: Davies Nicola L. , Compson Joanne E. , MacKenzie Brendon , O'Dowd Victoria L. , Oxbrow Amanda K. F. , Heads James T. , Turner Alison , Sarkar Kaushik , Dugdale Sarah L. , Jairaj Mark , Christodoulou Louis , Knight David E. O. , Cross Amanda S. , Hervé Karine J. M. , Tyson Kerry L. , Hailu Hanna , Doyle Carl B. , Ellis Mark , Kriek Marco , Cox Matthew , Page Matthew J. T. , Moore Adrian R. , Lightwood Daniel J. , Humphreys David P.
Published: January 2013

Clostridium difficileinfections are a major cause of antibiotic-associated diarrhea in hospital and care facility patients. In spite of the availability of effective antibiotic treatments,C. difficileinfection (CDI) is still a major cause of patient suffering, death, and substantial health care costs.Clostridium difficileexerts its major pathological effects through the actions of two protein exotoxins, TcdA and TcdB, which bind to and disrupt gut tissue. Antibiotics target the infecting bacteria but not the exotoxins. Administering neutralizing antibodies against TcdA and TcdB to patients receiving antibiotic treatment might modulate the effects of the exotoxins directly. We have developed a mixture of three humanized IgG1 monoclonal antibodies (MAbs) which neutralize TcdA and TcdB to address three clinical needs: reduction of the severity and duration of diarrhea, reduction of death rates, and reduction of the rate of recurrence. The UCB MAb mixture showed higher potency in a variety ofin vitrobinding and neutralization assays (∼10-fold improvements), higher levels of protection in a hamster model of CDI (82% versus 18% at 28 days), and higher valencies of toxin binding (12 versus 2 for TcdA and 3 versus 2 for TcdB) than other agents in clinical development. Comparisons of the MAb properties also offered some insight into the potential relative importance of TcdA and TcdB in the disease process.
Performance of a Rapid Self-Test for Detection of Trichomonas vaginalis in South Africa and Brazil
Authors: Jones Heidi E. , Lippman Sheri A. , Caiaffa-Filho Helio H. , Young Taryn , van de Wijgert Janneke H. H. M.
Published: January 2013

Women participating in studies in Brazil (
n
= 695) and South Africa (
n
= 230) performed rapid point-of-care tests for
Trichomonas vaginalis
on self-collected vaginal swabs. Using PCR as the gold standard, rapid self-testing achieved high specificity (99.1%; 95% confidence interval [CI], 98.2 to 99.6%) and moderate sensitivity (76.7%; 95% CI, 61.4 to 88.2%). These tests may be considered an alternative to syndromic management in resource-poor settings.
Towards a Molecular Definition of Enterohemorrhagic Escherichia coli (EHEC): Detection of Genes Located on O Island 57 as Markers To Distinguish EHEC from Closely Related Enteropathogenic E. coli Strains
Authors: Delannoy Sabine , Beutin Lothar , Fach Patrick
Published: January 2013

Among strains of Shiga-toxin (Stx) producing
Escherichia coli
(STEC), seven serogroups (O26, O45, O103, O111, O121, O145, and O157) are associated with severe clinical illness in humans. These strains are also called enterohemorrhagic
E. coli
(EHEC), and the development of methods for their reliable detection from food has been challenging thus far. PCR detection of major EHEC virulence genes
stx
1
,
stx
2
,
eae
, and O-serogroup-specific genes is useful but does not identify EHEC strains specifically. Searching for the presence of additional genes issued from
E. coli
O157:H7 genomic islands OI-122 and OI-71 increases the specificity but does not clearly discriminate EHEC from enteropathogenic
E. coli
(EPEC) strains. Here, we identified two putative genes, called Z2098 and Z2099, from the genomic island OI-57 that were closely associated with EHEC and their
stx
-negative derivative strains (87% for Z2098 and 91% for Z2099). Z2098 and Z2099 were rarely found in EPEC (10% for Z2098 and 12% for Z2099), STEC (2 and 15%), and apathogenic
E. coli
(1% each) strains. Our findings indicate that Z2098 and Z2099 are useful genetic markers for a more targeted diagnosis of typical EHEC and new emerging EHEC strains.
Cyclophilin A-Dependent Restriction to Capsid N121K Mutant Human Immunodeficiency Virus Type 1 in a Broad Range of Cell Lines
Authors: Takemura Taichiro , Kawamata Miyako , Urabe Miho , Murakami Tsutomu
Published: January 2013

Human immunodeficiency virus type 1 (HIV-1) infection of most human cells is dependent on cyclophilin A (CypA); however, the opposite phenomenon, known as CypA-dependent inhibition, is also observed in the combination of some capsid (CA) mutations and cell lines. Here, we identified a CA N121K mutant whose infection of 293T, Jurkat, and HeLa cells was impaired by CypA. The N121K mutant could be a useful tool for analyzing the mechanisms underlying CypA-dependent restriction.
Similar Patterns of Infection with Bovine Foamy Virus in Experimentally Inoculated Calves and Sheep
Authors: Materniak Magdalena , Hechler Torsten , Löchelt Martin , Kuźmak Jacek
Published: January 2013

Foamy viruses (FVs) are the least known retroviruses commonly found in primates, cats, horses, and cattle. Although FVs are considered apathogenic, simian and feline FVs have been shown to be associated with some transient health abnormalities in animal models. Currently, data regarding the course of infection with bovine FV (BFV) are not available. In this study, we conducted experimental infections of natural (cattle) and heterologous (sheep) hosts with the BFV
100
isolate and monitored infection patterns in both hosts during the early phase postinoculation as well as after long-term infection. Four calves and six sheep inoculated with BFV
100
showed no signs of pathology but developed persistent infection, as confirmed by virus rescue, consistent detection of BFV-specific antibodies, and presence of viral DNA. In both hosts, antibodies against BFV Gag and Bet appeared early after infection and persisted at high and stable levels while seroreactivity toward Env was consistently detectable only in BFV-infected sheep. Interestingly, the BFV proviral DNA load was highest in lung, spleen, and liver and moderate in leukocytes, while salivary glands contained either low or undetectable DNA loads in calves or sheep, respectively. Additionally, comparison of partial BFV sequences from inoculum and infected animals demonstrated very limited changes after long-term infection in the heterologous host, clearly less than those found in BFV field isolates. The persistence of BFV infection in both hosts suggests full replication competence of the BFV
100
isolate with no requirement of genetic adaptation for productive replication in the authentic and even in a heterologous host.
Is the TAM Receptor Axl a Receptor for Lymphocytic Choriomeningitis Virus?
Authors: Sullivan Brian M. , Welch Megan J. , Lemke Greg , Oldstone Michael B. A.
Published: January 2013

A recent publication indicated that overexpression of Axl, a cellular receptor that negatively regulates Toll-like receptor signaling, enhanced the entry of viruses pseudotyped with the glycoprotein of lymphocytic choriomeningitis virus (LCMV)
in vitro
. In testing the biological relevance of these observations, we found differences in neither viral kinetics between LCMV infections of
Axl
−/−
and wild-type mice nor T-cell responses prior to spontaneous viral clearance. Thus, Axl is not required for productive LCMV infection of mice.
A Key Interaction between the Alphavirus Envelope Proteins Responsible for Initial Dimer Dissociation during Fusion
Authors: Fields Whitney , Kielian Margaret
Published: January 2013

Alphaviruses such as Semliki Forest virus (SFV) are enveloped viruses whose surface is covered by an organized lattice composed of trimers of E2-E1 heterodimers. The E1 envelope protein, a class II fusion protein, contains the hydrophobic fusion loop and refolds to drive virus fusion with the endosome membrane. The E2 protein is synthesized as a precursor p62, whose processing by furin primes the heterodimer for dissociation during virus entry. Dissociation of the E2-E1 heterodimer is an essential step during low-pH-triggered fusion, while the dissociation of the immature p62-E1 dimer is relatively pH resistant. Previous structural studies described an “acid-sensitive region” in E2 that becomes disordered at low pH. Within this region, the conserved E2 H170 is in position to form a hydrogen bond with the underlying E1 S57. Here we experimentally tested the role of this interaction in regulating dimer dissociation in mature and immature virus. Alanine substitutions of E1 S57 and E2 H170 destabilized the heterodimer and produced a higher pH threshold for exposure of the E1 fusion loop and for fusion of the immature virus. E1 S57K or S57D mutations were lethal and caused transport and assembly defects that were partially abrogated by neutralization of the exocytic pathway. The lethal phenotype of E1 S57K was rescued by second-site mutations at E2 H170/M171. Together, our results define a key role for the E1 S57-E2 H170 interaction in dimer stability and the pH dependence of fusion and provide evidence for stepwise dissociation of the E2-E1 dimer at low pH.
Water is a safe and effective alternative to sterile normal saline for wound irrigation prior to suturing: a prospective, double-blind, randomised, controlled clinical trial
Authors: Weiss Eric Alan , Oldham George , Lin Michelle , Foster Tammy , Quinn James Victor
Published: January 2013

Objective

To determine if there is a significant difference in the infection rates of wounds irrigated with sterile normal saline (SS) versus tap water (TW), before primary wound closure.

Design

Single centre, prospective, randomised, double-blind controlled trial. Wound irrigation solution type was computer randomised and allocation was done on a sequential basis.

Setting

Stanford University Medical Center Department of Emergency Medicine.

Participants

Patients older than 1 year of age, who presented to the emergency department with a soft tissue laceration requiring repair, were entered into the study under informed consent. Exclusion criteria included any underlying immunocompromising illness, current use of antibiotics, puncture or bite wounds, underlying tendon or bone involvement, or wounds more than 9 h old.

Interventions

Non-caregivers used a computer generated randomisation code to prepare irrigation basins prior to treatment. Patients had their wounds irrigated either with TW or SS prior to closure, controlling for the volume and irrigation method used. The patient, the treating physician and the physician checking the wound for infection were all blind regarding solution type. Structured follow-up was completed at 48 h and 30 days to determine the presence of infection.

Main outcome measures

The primary outcome measured was the difference in wound infection rates between the two randomised groups.

Results

During the 18-month study period, 663 consecutive patients were enrolled. After enrolment, 32 patients were later excluded; 29 patients because they were concurrently on antibiotics; two patients secondary to steroid use and one because of tendon involvement. Of the 631 remaining patients, 318 were randomised into the TW group and 313 into the SS group. Six patients were lost to follow-up (5 SS, 1 TW). A total of 625 patients were included in the statistical analysis. There were no differences in the demographic and clinical characteristics of the two groups. There were 20 infections 6.4% (95% CI 9.1% to 3.7%) in the SS group compared with 11 infections 3.5% (95% CI 5.5% to 1.5%) in the TW group, a difference of 2.9% (95% CI −0.4% to 5.7%).

Conclusions

There is no difference in the infection rate of wounds irrigated with either TW or SS solution, with a clinical trend towards fewer wound infections in the TW group, making it a safe and cost-effective alternative to SS for wound irrigation.
DIELECTRIC PROPERTIES OF Zr-DOPED Ba0.985Bi0.01TiO3 SYNTHESIZED BY INORGANIC DISTILLATION UNDER ATMOSPHERIC PRESSURE
Authors: WANG JING , JIANG SHENGLIN , SONG LINHUA
Published: January 2013

To meet the requirement of next-generation multilayer ceramic capacitors, the synthesis and characterization of Ba 0.985 Bi 0.01 TiO 3-based high-k dielectric compositions are reported. Solid solutions with a nominal composition of 0.4 Ba 0.985 Bi 0.01 TiO 3–0.6 BaTi 1-x Zr x O 3 (x = 0.001, 0.005, 0.01, 0.02, 0.04, 0.06, 0.1) was synthesized by distillation method. Room-temperature X-ray diffraction patterns showed an increase and then a decrease in the tetragonality of Ba 0.985 Bi 0.01 TiO 3 after modifying with BaTi 1-x Zr x O 3. The decrement in tetragonality (c/a ratio) was accompanied by lowering of Curie temperature. 0.4 Ba 0.985 Bi 0.01 TiO 3–0.6 BaTi 0.995 Zr 0.005 O 3 was found to exhibit diffuse phase transition accompanied by an ultrahigh dielectric constant of 77,619, a loss tangent < 1 and a grain size < 1 μm.
A NONINTRUSIVE PACKET-BASED METHODOLOGY TO DYNAMICALLY MONITOR SENSOR-BASED SYSTEMS
Authors: SRIDHARAN SRIHARI , LYSECKY SUSAN
Published: January 2013

Application specific tuning has been shown to be beneficial for a variety of platforms, sensor-based systems are no exception. However, accurately capturing external stimuli or modeling application specific stimuli remains a challenge. Tuning a sensor-based system to erroneous or incomplete application information can limit the optimization achieved or even negatively impact the resulting system performance. We propose to obtain accurate application stimuli by dynamically observing the sensor-based system in the intended deployment location, storing application characteristics for later analysis or optimization. A packet-based profiling methodology is introduced incurring overheads ranging from 0.07% to 27.8%, depending on the amount of sensor activity within the deployed system. Additionally, the profiler module and proposed packet-based profiling methodology have been implemented on the eBlocks platform to demonstrate the feasibility of the approach.
Synthesis and biological investigations of a ZnPc-antiCEA bioconjugate for imaging of colorectal cancer
Authors: Sehgal Inder , Li Hairong , Ongarora Benson , Devillier Daniel , Vicente M. Graça H.
Published: January 2013

Two zinc(II) phthalocyanines (ZnPcs) were conjugated with a monoclonal antibody (MAb) directed against carcinoembryonic antigen (CEA), using an in situ activated carboxylic acid on the ZnPcs . The bioconjugate with the highest ZnPc /MAb ratio of 3 was investigated in vitro for its ability to target and fluorescently label human colorectal HT-29 cells. The ZnPc -CEA MAb 2 was observed to efficiently target HT-29 cells, about 37 times more than unconjugated ZnPc . Furthermore, in the presence of a 4-fold excess of unlabelled anti-CEA antibody, the fluorescence signal of 2 was reduced by ~90% showing that the targeting is CEA-mediated. These studies further confirm the high specificity of Pc-antibody conjugates for antigens over-expressed on tumor cells and warrant further investigations of these immunoconjugates and their derivatives for imaging of colorectal cancer.
AMP-activated protein kinase inhibits TGF-β-, angiotensin II-, aldosterone-, high glucose-, and albumin-induced epithelial-mesenchymal transition
Authors: Lee Jang Han , Kim Ji Hyun , Kim Ja Seon , Chang Jai Won , Kim Soon Bae , Park Jung Sik , Lee Sang Koo
Published: January 2013

The epithelial-mesenchymal transition (EMT) is a novel mechanism that promotes renal fibrosis. Transforming growth factor-β (TGF-β), angiotensin II, aldosterone, high glucose, and urinary albumin are well-known causes of EMT and renal fibrosis. We examined whether and how activation of AMP-activated protein kinase (AMPK) suppressed EMT induced by the above agents in tubular epithelial cells. All experiments were performed using HK-2 cells. Protein expression was measured by Western blot analysis. Intracellular reactive oxygen species (ROS) were analyzed by flow cytometry. Exposure of tubular cells to TGF-β (10 ng/ml), angiotensin II (1 μM), aldosterone (100 nM), high glucose (30 mM), and albumin (5 mg/ml) for 5 days induced EMT, as shown by upregulation of α-smooth muscle actin and downregulation of E-cadherin. ROS and NADPH oxidase 4 (Nox4) expression were increased, and antioxidants such as tiron and N-acetylcysteine inhibited EMT induction. Metformin (the best known clinical activator of AMPK) suppressed EMT induction through inhibition of ROS via induction of heme oxygenase-1 and endogenous antioxidant thioredoxin. An AMPK inhibitor (compound C) and AMPK small interfering RNA blocked the effect of metformin, and another AMPK activator [5-aminoimidazole-4-carboxamide-1β riboside (AICAR)] exerted the same effects as metformin. In conclusion, AMPK activation might be beneficial in attenuating the tubulointerstitial fibrosis induced by TGF-β, angiotensin II, aldosterone, high glucose, and urinary albumin.
ENaC is regulated by natriuretic peptide receptor-dependent cGMP signaling
Authors: Guo Lai-Jing , Alli Abdel A. , Eaton Douglas C. , Bao Hui-Fang
Published: January 2013

Epithelial sodium channels (ENaCs) located at the apical membrane of polarized epithelial cells are regulated by the second messenger guanosine 3′,5′-cyclic monophosphate (cGMP). The mechanism for this regulation has not been completely characterized. Guanylyl cyclases synthesize cGMP in response to various intracellular and extracellular signals. We investigated the regulation of ENaC activity by natriuretic peptide-dependent activation of guanylyl cyclases in Xenopus 2F3 cells. Confocal microscopy studies show natriuretic peptide receptors (NPRs), including those coupled to guanylyl cyclases, are expressed at the apical membrane of 2F3 cells. Single-channel patch-clamp studies using 2F3 cells revealed that atrial natriuretic peptide (ANP) or 8-(4-chlorophenylthio)-cGMP, but not C-type natriuretic peptide or cANP, decreased the open probability of ENaC. This suggests that NPR-A, but not NPR-B or NPR-C, is involved in the natriuretic peptide-mediated regulation of ENaC activity. Also, it is likely that a signaling pathway involving cGMP and nitric oxide (NO) are involved in this mechanism, since inhibitors of soluble guanylyl cyclase, protein kinase G, inducible NO synthase, or an NO scavenger blocked or reduced the effect of ANP on ENaC activity.
Chronic electrical stimulation homeostatically decreases spontaneous activity, but paradoxically increases evoked network activity
Authors: Goel Anubhuti , Buonomano Dean V.
Published: January 2013

Neural dynamics generated within cortical networks play a fundamental role in brain function. However, the learning rules that allow recurrent networks to generate functional dynamic regimes, and the degree to which these regimes are themselves plastic, are not known. In this study we examined plasticity of network dynamics in cortical organotypic slices in response to chronic changes in activity. Studies have typically manipulated network activity pharmacologically; we used chronic electrical stimulation to increase activity in in vitro cortical circuits in a more physiological manner. Slices were stimulated with “implanted” electrodes for 4 days. Chronic electrical stimulation or treatment with bicuculline decreased spontaneous activity as predicted by homeostatic learning rules. Paradoxically, however, whereas bicuculline decreased evoked network activity, chronic stimulation actually increased the likelihood that evoked stimulation elicited polysynaptic activity, despite a decrease in evoked monosynaptic strength. Furthermore, there was an inverse correlation between spontaneous and evoked activity, suggesting a homeostatic tradeoff between spontaneous and evoked activity. Within-slice experiments revealed that cells close to the stimulated electrode exhibited more evoked polysynaptic activity and less spontaneous activity than cells close to a control electrode. Collectively, our results establish that chronic stimulation changes the dynamic regimes of networks. In vitro studies of homeostatic plasticity typically lack any external input, and thus neurons must rely on “spontaneous” activity to reach homeostatic “set points.” However, in the presence of external input we propose that homeostatic learning rules seem to shift networks from spontaneous to evoked regimes.
Preparation and Evaluation of Intravaginal Ring Containing Drospirenone
Authors: Zhang Ying , Li Chun-Xiao , Ning Mei-Ying , Duan Xue-Yan , Liu Ying
Published: January 2013

In the present study, we investigated the feasibility of the vaginal administration of drospirenone silicone IVR. The in vitro release characteristics of matrix-type and reservoir-type IVR were compared under sink conditions in 21 days. At the same time, API excipients compatibility and preformulation study was performed by HPLC, IR, and DSC methods. Biocompatibility of reservoir system was evaluated by tolerability on tissue level in rats. It was found that, under strong light exposure, high temperature, and high humidity conditions, drospirenone and excipients had no significant interactions. The daily release of reservoir-type IVR was about 0.5 mg/d sustaining 21 days, which significantly decreased the burst effect compared with the matrix system. When drospirenone was modified by the PVPk30 in the reservoir system formulation, the daily release rate increased to 1.0 mg/d sustaining 21 days. The cumulative release of reservoir-type IVR was fitted to zero release equation. In addition, biocompatibility of drospirenone IVR system in this dosage is safe. It is feasibility feasibile to further developed for safe, convenient, and effective contraceptive drug delivery with reduced dosing interval.