bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal aggregation impacts on epidemiological simulations employing microcontact data
Authors: Hashemian Mohammad , Qian Weicheng , Stanley Kevin G , Osgood Nathaniel D
Published: November 2012

Background

Microcontact datasets gathered automatically by electronic devices have the potential augment the study of the spread of contagious disease by providing detailed representations of the study population’s contact dynamics. However, the impact of data collection experimental design on the subsequent simulation studies has not been adequately addressed. In particular, the impact of study duration and contact dynamics data aggregation on the ultimate outcome of epidemiological models has not been studied in detail, leaving the potential for erroneous conclusions to be made based on simulation outcomes.

Methods

We employ a previously published data set covering 36 participants for 92 days and a previously published agent-based H1N1 infection model to analyze the impact of contact dynamics representation on the simulated outcome of H1N1 transmission. We compared simulated attack rates resulting from the empirically recorded contact dynamics (ground truth), aggregated, typical day, and artificially generated synthetic networks.

Results

No aggregation or sampling policy tested was able to reliably reproduce results from the ground-truth full dynamic network. For the population under study, typical day experimental designs – which extrapolate from data collected over a brief period – exhibited too high a variance to produce consistent results. Aggregated data representations systematically overestimated disease burden, and synthetic networks only reproduced the ground truth case when fitting errors systemically underestimated the total contact, compensating for the systemic overestimation from aggregation.

Conclusions

The interdepedendencies of contact dynamics and disease transmission require that detailed contact dynamics data be employed to secure high fidelity in simulation outcomes of disease burden in at least some populations. This finding serves as motivation for larger, longer and more socially diverse contact dynamics tracing experiments and as a caution to researchers employing calibrated aggregate synthetic representations of contact dynamics in simulation, as the calibration may underestimate disease parameters to compensate for the overestimation of disease burden imposed by the aggregate contact network representation.
Improving N-terminal protein annotation of Plasmodium species based on signal peptide prediction of orthologous proteins
Authors: Neto Armando de Menezes , Alvarenga Denise A , Rezende Antônio M , Resende Sarah S , Ribeiro Ricardo de Souza , Fontes Cor JF , Carvalho Luzia H , de Brito Cristiana F Alves
Published: November 2012

Background

Signal peptide is one of the most important motifs involved in protein trafficking and it ultimately influences protein function. Considering the expected functional conservation among orthologs it was hypothesized that divergence in signal peptides within orthologous groups is mainly due to N-terminal protein sequence misannotation. Thus, discrepancies in signal peptide prediction of orthologous proteins were used to identify misannotated proteins in five Plasmodium species.

Methods

Signal peptide (SignalP) and orthology (OrthoMCL) were combined in an innovative strategy to identify orthologous groups showing discrepancies in signal peptide prediction among their protein members (Mixed groups). In a comparative analysis, multiple alignments for each of these groups and gene models were visually inspected in search of misannotated proteins and, whenever possible, alternative gene models were proposed. Thresholds for signal peptide prediction parameters were also modified to reduce their impact as a possible source of discrepancy among orthologs. Validation of new gene models was based on RT-PCR (few examples) or on experimental evidence already published (ApiLoc).

Results

The rate of misannotated proteins was significantly higher in Mixed groups than in Positive or Negative groups, corroborating the proposed hypothesis. A total of 478 proteins were reannotated and change of signal peptide prediction from negative to positive was the most common. Reannotations triggered the conversion of almost 50% of all Mixed groups, which were further reduced by optimization of signal peptide prediction parameters.

Conclusions

The methodological novelty proposed here combining orthology and signal peptide prediction proved to be an effective strategy for the identification of proteins showing wrongly N-terminal annotated sequences, and it might have an important impact in the available data for genome-wide searching of potential vaccine and drug targets and proteins involved in host/parasite interactions, as demonstrated for five Plasmodium species.
Myxofibrosarcoma of the sinus piriformis: case report and literature review
Authors: Qiubei Zhu , Cheng Lin , Yaping Xu , Shunzhang Lin , Jingping Fan
Published: November 2012

Myxofibrosarcoma is a common sarcoma in the extremities of older people, but is rare in the head and neck region. Here, we report the case of a 42-year-old male patient in whom myxofibrosarcoma generated from the sinus piriformis. Histopathologically, the tumor was characterized by spindle cellular proliferation with moderate cellular density in fibromyxoid stroma. Immunohistochemically, the tumor cells showed positive reactivity for vimentin, Ki-67, smooth muscle actin, and CD34, but negative staining for S-100. Based on these results, the tumor was diagnosed as a low-grade myxofibrosarcoma. Resection of the tumor was performed via a transcervical approach. The patient’s postoperative clinical course was uneventful and no local recurrence or distant metastasis has been found so far. The pathology, clinical characteristics, and treatment of myxofibrosarcoma are also reviewed.
Clinical practice guidelines for patients with gastrointestinal stromal tumor in Taiwan
Authors: Yeh Chun-Nan , Hwang Tsann-Long , Huang Ching-Shui , Lee Po-Huang , Wu Chew-Wun , Chen-Guo Ker , Jan Yi-Yin , Chen Miin-Fu
Published: November 2012

For many years, the understanding of gastrointestinal stromal tumors (GISTs), which are the most common mesenchymal tumors of the gastrointestinal tract, has been very limited. However, it is now possible to provide a more precise definition through the use of pathology classification and molecular techniques. Coupled with the advancement of clinical practice, especially the development of targeted therapy, there is now a much better insight into its treatment. At present, organizations such as the National Comprehensive Cancer Network in the USA and the European Society for Medical Oncology in Europe have established a consensus and drawn up guidelines for the diagnosis, treatment, and follow-up of GISTs.

With experts coming from various districts in Taiwan and combining the most recent clinical data and experiences, the Taiwan Surgical Society of Gastroenterology drafted the first national GIST treatment guidelines after a consensus meeting in 2007. Following subsequent advances in GIST diagnosis and treatment, further revisions and modifications have been made to the original guidelines. We present here the updated consensus and recommendations of the Taiwan Surgical Society of Gastroenterology for the diagnosis and treatment of GIST. We hope these guidelines can help enhance the quality of diagnosis, treatment, and care of patients with GIST in Taiwan.
Compensatory substitutions in the HCV NS3/4A protease cleavage sites are not observed in patients treated unsuccessfully with telaprevir combination treatment
Authors: Sullivan James C , Zhang Eileen Z , Bartels Doug J , Tigges Ann , Dorrian Jennifer L , Kwong Ann D , Kieffer Tara L
Published: November 2012

Background

Development of compensatory mutations within the HIV p7/p1 and p1/p6 protease cleavage site region has been observed in HIV-infected patients treated with protease inhibitors. Mechanisms of fitness compensation may occur in HCV populations upon treatment of HCV protease inhibitors as well.

Findings

In this study, we investigated whether substitutions in protease cleavage site regions of HCV occur in response to a treatment regimen containing the NS3/4A protease inhibitor telaprevir (TVR). Evaluation of viral populations from 569 patients prior to treatment showed that the four NS3/4A cleavage sites were well conserved. Few changes in the cleavage site regions were observed in the 159 patients who failed TVR combination treatment, and no residues displayed evidence of directional selection after the acquisition of TVR-resistance.

Conclusions

Cleavage site mutations did not occur after treatment with the HCV protease inhibitor telaprevir.
Impact of sustained RNAi-mediated suppression of cellular cofactor Tat-SF1 on HIV-1 replication in CD4+ T cells
Authors: Green Victoria A , Arbuthnot Patrick , Weinberg Marc S
Published: November 2012

Background

Conventional anti-HIV drug regimens targeting viral enzymes are plagued by the emergence of drug resistance. There is interest in targeting HIV-dependency factors (HDFs), host proteins that the virus requires for replication, as drugs targeting their function may prove protective. Reporter cell lines provide a rapid and convenient method of identifying putative HDFs, but this approach may lead to misleading results and a failure to detect subtle detrimental effects on cells that result from HDF suppression. Thus, alternative methods for HDF validation are required. Cellular Tat-SF1 has long been ascribed a cofactor role in Tat-dependent transactivation of viral transcription elongation. Here we employ sustained RNAi-mediated suppression of Tat-SF1 to validate its requirement for HIV-1 replication in a CD4+ T cell-derived line and its potential as a therapeutic target.

Results

shRNA-mediated suppression of Tat-SF1 reduced HIV-1 replication and infectious particle production from TZM-bl reporter cells. This effect was not a result of increased apoptosis, loss of cell viability or an immune response. To validate its requirement for HIV-1 replication in a more relevant cell line, CD4+ SupT1 cell populations were generated that stably expressed shRNAs. HIV-1 replication was significantly reduced for two weeks (~65%) in cells with depleted Tat-SF1, although the inhibition of viral replication was moderate when compared to SupT1 cells expressing a shRNA targeting the integration cofactor LEDGF/p75. Tat-SF1 suppression was attenuated over time, resulting from decreased shRNA guide strand expression, suggesting that there is a selective pressure to restore Tat-SF1 levels.

Conclusions

This study validates Tat-SF1 as an HDF in CD4+ T cell-derived SupT1 cells. However, our findings also suggest that Tat-SF1 is not a critical cofactor required for virus replication and its suppression may affect cell growth. Therefore, this study demonstrates the importance of examining HIV-1 replication kinetics and cytotoxicity in cells with sustained HDF suppression to validate their therapeutic potential as targets.
The impact of insecticide-treated school uniforms on dengue infections in school-aged children: study protocol for a randomised controlled trial in Thailand
Authors: Wilder-Smith Annelies , Byass Peter , Olanratmanee Phanthip , Maskhao Pongsri , Sringernyuang Luechai , Logan James G , Lindsay Steve W , Banks Sarah , Gubler Duane , Louis Valérie R , Tozan Yesim , Kittayapong Pattamaporn
Published: November 2012

Background

There is an urgent need to protect children against dengue since this age group is particularly sensitive to the disease. Since dengue vectors are active mainly during the day, a potential target for control should be schools where children spend a considerable amount of their day. School uniforms are the cultural norm in most developing countries, worn throughout the day. We hypothesise that insecticide-treated school uniforms will reduce the incidence of dengue infection in school-aged children. Our objective is to determine the impact of impregnated school uniforms on dengue incidence.

Methods

A randomised controlled trial will be conducted in eastern Thailand in a group of schools with approximately 2,000 students aged 7–18 years. Pre-fabricated school uniforms will be commercially treated to ensure consistent, high-quality insecticide impregnation with permethrin. A double-blind, randomised, crossover trial at the school level will cover two dengue transmission seasons.

Discussion

Practical issues and plans concerning intervention implementation, evaluation, analysing and interpreting the data, and possible policy implications arising from the trial are discussed.

Trial registration

clinicaltrial.gov. Registration number: NCT01563640
Effects of neuromuscular electrostimulation in patients with heart failure admitted to ward
Authors: de Araújo Carlos José Soares , Gonçalves Fernanda Souza , Bittencourt Hugo Souza , dos Santos Noélia Gonçalves , Junior Sérgio Vitor Mecca , Neves Júlio Leal Bandeira , Fernandes André Maurício Souza , Junior Roque Aras , dos Reis FranciscoJoséFariasBorges , Guimarães Armênio Costa , Junior ErenaldodeSouzaRodrigues , Carvalho Vitor Oliveira
Published: November 2012

Background

Neuromuscular electrostimulation has become a promising issue in cardiovascular rehabilitation. However there are few articles published in the literature regarding neuromuscular electrostimulation in patients with heart failure during hospital stay.

Methods

This is a randomized controlled pilot trial that aimed to investigate the effect of neuromuscular electrostimulation in the walked distance by the six-minute walking test in 30 patients admitted to ward for heart failure treatment in a tertiary cardiology hospital. Patients in the intervention group performed a conventional rehabilitation and neuromuscular electrostimulation. Patients underwent 60 minutes of electrostimulation (wave frequency was 20 Hz, pulse duration of 20 us) two times a day for consecutive days until hospital discharge.

Results

The walked distance in the six-minute walking test improved 75% in the electrostimulation group (from 379.7 ± 43.5 to 372.9 ± 46.9 meters to controls and from 372.9 ± 62.4 to 500 ± 68 meters to electrostimulation, p<0.001). On the other hand, the walked distance in the control group did not change.

Conclusion

The neuromuscular electrostimulation group showed greater improvement in the walked distance in the six-minute walking test in patients admitted to ward for compensation of heart failure.
Simultaneous nephrectomy and coronary artery bypass grafting through extended sternotomy
Authors: Budrikis Algimantas , Jievaltas Mindaugas , Al Assaad Sami , Kinduris Sarunas
Published: November 2012

Background

The advances in surgical techniques, resuscitation and anesthesiology support over the last years have allowed simultaneous thoracic and abdominal operations to be made for cancer and concomitant severe heart vessel disease relieving the patient from several diseases simultaneously and achieving long lasting remission or cure.

Clinical case

A simultaneous nephrectomy and coronary artery bypass grafting procedure through extended sternotomy is reported. A 63-year-old man with severe coronary artery disease was found to have renal carcinoma.

Diagnosis

Postoperative pathological investigation of the tumor revealed the presence of renal cell carcinoma pT3a N0 M0, G2. Coronarography revealed advanced three-vessel coronary artery disease.

Treatment

We successfully performed a simultaneous curative surgery for renal carcinoma and coronary artery bypass graft surgery under cardiopulmonary bypass using a novel technique of extended sternotomy. Simultaneous surgery thus appears to be a beneficial and safe approach for the treatment of coronary artery disease and resectable renal cancer in carefully selected patients.
Rising popularity of anal intercourse and sexual risk taking: findings from two national probability studies of young Croatian adults
Authors: Ajduković D , Štulhofer A , Baćak V
Published: November 2012

This study examined the prevalence and correlates of heterosexual anal intercourse in two national probability samples of young Croatian adults aged 18–25 years, which were collected in 2005 and 2010. The lifetime prevalence of anal intercourse increased from 27% to 36%. In multivariate analysis, reporting four or more lifetime sexual partners was the only correlate of the experience of anal intercourse that was significant among both women (odds ratios [ORs] = 1.78–3.27, P < 0.05) and men (ORs = 3.14–4.63, P < 0.01). Information about condom use at most recent anal intercourse was collected in the 2010 study wave only. Age (OR = 0.80, P < 0.05), female gender (OR = 0.29, P < 0.01), holding more negative attitudes towards condoms (OR = 0.28–0.32, P < 0.05) and reporting condom use at most recent vaginal intercourse (OR = 11.45, 95% Confidence interval [CI] = 5.68–23.06) were associated with using a condom at most recent anal intercourse. Given the substantial prevalence of anal intercourse among young heterosexual adults and considerable sexually transmitted infection/HIV risks associated with the practice, sex education programmes should promote the discussion of health risks associated with anal eroticism.
Idiopathic ileocolitis with perforation associated with HIV infection: thalidomide treatment
Authors: Ramos J M , Masiá M , Durán R , Gutiérrez F
Published: November 2012

Idiopathic cutaneous ulcers, oesophageal ulcers and severe ulcerative ileocolitis occurred in a human immunodeficiency virus (HIV)-infected patient early after the initiation of combination antiretroviral therapy. This massive inflammatory process led to acute colonic perforation on two occasions. The disease was refractory to standard therapy, but responded successfully to thalidomide. Here, we discuss the potential benefits of thalidomide in refractory inflammatory processes in HIV-infected patients.
Visiting friends and relatives may be a risk for non-adherence for HIV-positive travellers
Authors: Woolley I , Bailey C
Published: November 2012

We report three cases of immigrants to Australia, living with HIV/AIDS, who, while travelling in countries of origin or migration, were unable to continue to take their antiretrovirals appropriately. We discuss the possible reasons for this and ways to reduce the possibility of it happening. Travel may be a significant risk factor for non-adherence; pre-travel advice and planning might help to prevent it occurring.
Effect of web formation on properties of hydroentangled nonwoven fabrics
Authors: Sawhney Paul , Allen Hiram , Reynolds Michael , Slopek Ryan , Condon Brian , Hui David , Wojkowski Suhad
Published: November 2012

The aim of this study was to determine the effects of two popular web-forming technologies, viz., the Rando air-laid technology and the traditional carding and cross-laying technology, on properties of the hydroentangled nonwoven fabrics made therewith. A mill-like fiber processing study was conducted in a commercial-grade pilot plant using a variety of short staple fibers and their blends. The fibers used in the study were greige cotton, bleached cotton, cotton derivatives, and cut-staple polyester. The hydroentangled fabrics produced with the two systems were mainly evaluated for their physical and mechanical properties, absorbency, absorbency capacity, and whiteness. The study has shown that, with the exception of greige cotton linters, the greige cotton lint, greige cotton gin motes, and even greige cotton comber noils, either alone or in blend with the other fibers mentioned, can be mechanically processed into hydroentangled nonwoven fabric structures without any insurmountable difficulties. The drop test and sink time followed each other pretty closely, as the drop test time increased so did the sink times. The "whiteness" of fabric, which is significantly more dependent on the fabric's constituent fiber content than on the fabric's surface-based light reflection, obviously varied considerably. However, the whiteness index within the same fiber types and their blends shows no trend of significant difference between the fabric produced with carded fiber web and the fabric produced with random Rando fiber web. Incidentally, the Rando sample of bleached cotton was not available. Since the nonwoven fabrics of this discussion generally are disposable, the optional use of ‘brighteners’ to improve whiteness of certain whiteness-deficient fabrics may be considered as long as the brighteners do not easily bleed from the fabrics.
Design and development of programmable frequency synthesizer for WiMAX/WiFi wireless communication
Authors: Devendra S. , Verma K. , Barhai P.
Published: November 2012

Rapid advancements in nanotechnology are going to bring radical changes in the society and particularly in wireless communication where small, smart and speedy systems are everyone's first choice. This is possible as application of nanotechnology is taking place in WiMAX/WiFi and other wireless communication systems, which is ‘State-of-the-Art’ technology at the moment. Evolution of microelectronics towards miniaturization is one of the main motivations for nanotechnology. The continued improvements in miniaturization, speed and power reduction in information processing devices, sensors, displays, logic devices, storage devices, transmission devices, etc. will bring another technical revolution, which will change our life. In our research work, we would like to focus on design and development of programmable frequency synthesizer for WiMAX/WiFi wireless communication (to the scale of < 50 nanometer). The transceiver will support fixed, portable, and mobile WiMAX operation. The design strategies focus on maximum operating frequency, low power consumption, low voltage operation, minimize number of gates/transistors, CMOS Technology (< 50 nanometer), reduced fabrication cost, high speed applications in WiMAX/WiFi/Satellite communications, flexibility, programmability, and service efficiency. The proposed ‘Programmable frequency synthesizer will be a new device with its varied application for WiMAX/WiFi/Satellite and other wireless communication systems. The transceiver will support fixed, portable, and mobile WiMAX operation.
Elastic buckling of web-post in cellular beams with various opening shapes
Authors: Mimoune Mostefa , Siouane Saad , Mimoune Fatima
Published: November 2012

This paper develops a finite-element model using ANSYS for the buckling analysis of perforated beams and uses it to investigate the effects of slenderness on the moment-gradient factor of simply supported perforated web beams. Web post buckling is studied by using numerical model. An investigation on steel beams with various shapes and sizes is reported based on web post buckling. A parameter study was conducted based on web post width and the effect of various openings is described.
Reservoir history matching using a stochastic method
Authors: Yan Xia , Zhang Kai , Nawaz Mudassir , Rai Sanchit
Published: November 2012

In reservoir history matching the least square objective function is usually used to minimize the mismatch between the predicted production data and the observations. However, as history matching is an ill-posed inverse problem with non-unique solutions, the reservoir model after calibrating may be far from the real geology model by only matching the production data. In order to solve this problem, a regularization method for reservoir history matching is implemented, in which not only the production data is matched, but prior geological information is also used to correct and update the current reservoir model so that the updated model will be consistent with the geologic model. In this paper, the simultaneous perturbation stochastic approximation method (SPSA) coupled with fast streamline simulation provides an effective method (SLSPSA) to optimize the objective function. As a stochastic approximation algorithm, SLSPSA can guarantee the convergence of the algorithm. Compared to the gradient-based algorithms, it avoids the massive calculation and storage for adjoint or sensitivity matrix. In the calculation process of algorithm, parallel computing is implemented, which reduces the simulation time and improves the computational efficiency. The method was verified by matching an example test.
Computational methods for vibrations and noise reduction of textile machines
Authors: Votrubec Vlastimil , Pustka Martin , Šidlof Pavel
Published: November 2012

This paper deals with computational methods that lead to vibrations and noise reduction of textile machines. The reduction is achieved by dynamic balancing of the machine and by vibroisolation. The method of calculation of balancer parameters in software MathModelica and Mathematica is described and optimization of vibroisolation is explained. These methods are verified on industrial sewing machine.
Properties of knitted fabrics produced by kapok blended yarns
Authors: Üzümcü M. , ÜTE Tuba , Çelik Pınar , Oğlakcioğlu Nida , Kadoğlu Hüseyin
Published: November 2012

In need of improving the properties of textiles, researchers investigate how to obtain surface with better mechanical and physical characteristics. On the other hand, for clothing purposes, it is also required to enhance comfortable properties. However, uniting these properties in the end product is difficult. For this objective, new fibers those allow what is desired are developed. This is one of the easiest ways. Because, if these characteristics can be found on the raw material, less treatments will be needed for gaining wanted surface quality. Another way is producing yarns that could enable end products with better mechanical, physical and comfortable properties. For these "new yarns", some of the production parameters can be changed or modified. As another way fibers can be blended, which is preferred in this study. The main aim is to evaluate the effect of kapok fibers on fabric properties. For this aim, kapok fibers were blended with three most common fibers: Tencel, PET and Cotton.
Simulation and experimental characterization of the point spread function, pixel saturation, and blooming of a mercury cadmium telluride focal plane array
Authors: Soehnel Grant , West Rynes Anthony
Published: November 2012

A custom IR spot scanning experiment was constructed to project
subpixel spots on a mercury cadmium telluride focal plane array (FPA).
The hardware consists of an FPA in a liquid nitrogen cooled Dewar,
high precision motorized stages, a custom aspheric lens, and a 1.55
and 3.39 μm laser source. By controlling the position and intensity of
the spot, characterizations of cross talk, saturation, blooming, and
(indirectly) the minority
carrier lifetime were performed. In addition, a Monte–Carlo-based
charge diffusion model
was developed to validate experimental data and make predictions.
Results show very good agreement between the model and experimental
data. Parameters such as wavelength, reverse bias, and operating
temperature were found to have little effect on pixel crosstalk in the
absorber layer of the
detector. Saturation characterizations show that these FPAs, which do
not have antiblooming
circuitry, exhibit an
increase in cross talk due to blooming at ∼39%
beyond the flux required for analog saturation.
Facile approach to the synthesis of substituted thieno[2,3-d]pyrimidin-4-ones
Authors: Hovhannisyan Anna , Aristakesyan Lilit , Melikyan Gagik
Published: November 2012

Condensation of Gewald’s thiophenes substituted with a dimethylaminomethyleneamino group at position 2 with primary amines yields 5/6-aryl-thieno[2,3-d]pyrimidin-4-ones with variable substituents at the N3 position.
Fragmentation mechanism of the phenylcoumaran-type lignin model compound by ToF-SIMS
Authors: Matsushita Yasuyuki , Ioka Kousuke , Saito Kaori , Takama Ruka , Aoki Dan , Fukushima Kazuhiko
Published: November 2012

The experiments with model compounds revealed that time-of-flight secondary ion mass spectrometry (ToF-SIMS) is able to split the common interunit linkages of lignin, except the 5-5 linkage. In a previous study, ToF-SIMS produced characteristic secondary ions with m/z 137 and 151 (C6-C1 fragments) from the phenylcoumaran-type lignin model compound, the benzofuran ring of which has a β-5 linkage and an α-O-4 linkage. However, it is still unclear whether the fragments are from ring A with the free phenolic OH as a result of the sole cleavage of the α-O-4 link by opening the furan ring or from ring B as a result of the β-5 cleavage. In this study, the phenylcoumaran-type lignin model compound and its deuterium- and/or 13C-labeled analogues were synthesized and analyzed by ToF-SIMS. It could be clarified that the β-5 linkage is not cleaved by ToF-SIMS.
On Mullin's Second Sequence of Primes
Authors: Booker Andrew R.
Published: November 2012

We consider the second of Mullin's sequences of prime numbers related to Euclid's proof that there are infinitely many primes. We show in particular that it omits infinitely many primes, confirming a conjecture of Cox and van der Poorten.
Laufregelung redundanter humanoider Roboter — ein modellbasierter Ansatz
Authors: Buschmann Thomas , Schwienbacher Markus , Favot Valerio , Ewald Alexander , Ulbrich Heinz
Published: November 2012

Dieser Beitrag beschreibt ein System zur Regelung redundanter zweibeiniger Roboter. Das hierarchisch angelegte System erzeugt aus groben Vorgaben zum gewünschten Gang in Echtzeit eine stabile Laufbewegung. Die stabilisierende Regelung kompensiert Modellfehler, externe Kräfte und Bodenunebenheiten. Durch Nutzung kinematischer Redundanzen können erforderliche Gelenkwinkelgeschwindigkeiten minimiert und die Gefahr des Rutschens reduziert werden. In dem Artikel wird die von uns für experimentelle Arbeiten entwickelte Laufmaschine Lola beschrieben und ein Überblick der mit diesem Roboter erzielten experimentellen Ergebnisse gegeben.
Quadrupedal Robots with Stiff and Compliant Actuation
Authors: Remy C. David , Hutter Marco , Hoepflinger Mark , Bloesch Michael , Gehring Christian , Siegwart Roland
Published: November 2012

In the broader context of quadrupedal locomotion, this overview article introduces and compares two platforms that are similar in structure, size, and morphology, yet differ greatly in their concept of actuation. The first, ALoF, is a classically stiff actuated robot that is controlled kinematically, while the second, StarlETH, uses a soft actuation scheme based on Changedhighly compliant series elastic actuators. We show how this conceptual difference influences design and control of the robots, compare the hardware of the two systems, and show exemplary their advantages in different applications.
Posttranslational regulation of thioredoxin-interacting protein
Authors: Robinson Katherine A , Brock Jonathan W , Buse Maria G
Published: November 2012

Thioredoxin-interacting protein (Txnip) is a metabolic regulator, which modulates insulin sensitivity and likely plays a role in type 2 diabetes. We studied the regulation of Txnip in 3T3-L1 adipocytes. Cells were incubated under different conditions and Txnip was measured by immunoblotting. We confirmed that high glucose markedly increases Txnip expression by promoting transcription. Insulin decreases Txnip protein levels. Rapamycin under most conditions decreased Txnip, suggesting that mTOR complex-1 is involved. The acute effects of insulin are mainly posttranscriptional; insulin (100 nM) accelerates Txnip degradation more than tenfold. This effect is cell type specific. It works in adipocytes, preadipocytes and in L6 myotubes but not in HepG2 or in HEK 293 cells or in a pancreatic β-cell line. The ubiquitin/proteasome pathway is involved. Degradation of Txnip occurred within 15 min in the presence of 3 nM insulin and overnight with 0.6 nM insulin. Proteasomal Txnip degradation is not mediated by a cysteine protease or an anti-calpain enzyme. Okadaic acid (OKA), an inhibitor of phosphoprotein phosphatases (pp), markedly reduced Txnip protein and stimulated its further decrease by insulin. The latter occurred after incubation with 1 or 1000 nM OKA, suggesting that insulin enhances the phosphorylation of a pp2A substrate. Incubation with 0.1 μM Wortmannin, a PI3 kinase inhibitor, increased Txnip protein twofold and significantly inhibited its insulin-induced decrease. Thus, while OKA mimics the effect of insulin, Wortmannin opposes it. In summary, insulin stimulates Txnip degradation by a PI3 kinase-dependent mechanism, which activates the ubiquitin/proteasome pathway and likely serves to mitigate insulin resistance.
The lipocalin-type prostaglandin D2 synthase knockout mouse model of insulin resistance and obesity demonstrates early hypothalamic–pituitary–adrenal axis hyperactivity
Authors: Evans Jodi F , Islam Shahidul , Urade Yoshihiro , Eguchi Naomi , Ragolia Louis
Published: November 2012

Obesity and diabetes are closely associated with hyperactivation of the hypothalamic–pituitary–adrenal (HPA) axis. In this study, the diet-induced obese C57BL/6 mouse was used to test the hypothesis that chronically elevated metabolic parameters associated with the development of obesity such as cholesterol and glucose can aggravate basal HPA axis activity. Because the lipocalin-type prostaglandin D2synthase (L-PGDS) knockout (KO) mouse is a model of accelerated insulin resistance, glucose intolerance, and obesity, it was further hypothesized that HPA activity would be greater in this model. Starting at 8 weeks of age, the L-PGDS KO and C57BL/6 mice were maintained on a low-fat or high-fat diet. After 20 or 37 weeks, fasting metabolic parameters and basal HPA axis hormones were measured and compared between genotypes. Correlation analyses were performed to identify associations between obesity-related chronic metabolic changes and changes in the basal activity of the HPA axis. Our results have identified strong positive correlations between total cholesterol, LDL-cholesterol, glucose, and HPA axis hormones that increase with age in the C57BL/6 mice. These data confirm that obesity-related elevations in cholesterol and glucose can heighten basal HPA activity. Additionally, the L-PGDS KO mice show early elevations in HPA activity with no age-related changes relative to the C57BL/6 mice.
When Concealed Handgun Licensees Break Bad: Criminal Convictions of Concealed Handgun Licensees in Texas, 2001–2009
Authors: Phillips Charles D. , Nwaiwu Obioma , McMaughan Moudouni Darcy K. , Edwards Rachel , Lin Szu-hsuan
Published: November 2012

Objectives. We explored differences in criminal convictions between holders and nonholders of a concealed handgun license (CHL) in Texas.

Methods. The Texas Department of Public Safety (DPS) provides annual data on criminal convictions of holders and nonholders of CHLs. We used 2001 to 2009 DPS data to investigate the differences in the distribution of convictions for these 2 groups across 9 types of criminal offenses. We calculated z scores for the differences in the types of crimes for which CHL holders and nonholders were convicted.

Results. CHL holders were much less likely than nonlicensees to be convicted of crimes. Most nonholder convictions involved higher-prevalence crimes (burglary, robbery, or simple assault). CHL holders’ convictions were more likely to involve lower-prevalence crimes, such as sexual offenses, gun offenses, or offenses involving a death.

Conclusions. Our results imply that expanding the settings in which concealed carry is permitted may increase the risk of specific types of crimes, some quite serious in those settings. These increased risks may be relatively small. Nonetheless, policymakers should consider these risks when contemplating reducing the scope of gun-free zones.
Sex, Drugs (Methamphetamines), and the Internet: Increasing Syphilis Among Men Who Have Sex With Men in California, 2004–2008
Authors: Chew Ng Rilene A. , Samuel Michael C. , Lo Terrence , Bernstein Kyle T. , Aynalem Getahun , Klausner Jeffrey D. , Bolan Gail
Published: November 2012

Objectives. We examined primary and secondary syphilis cases among men who have sex with men (MSM) in California, and the association of methamphetamine use and Internet use to meet sex partners (Internet use) with number of sex partners.

Methods. We analyzed California surveillance data for MSM who were diagnosed with syphilis between 2004 and 2008, to assess differences in the mean number of sex partners by methamphetamine use and mutually exclusive groups of patients reporting Internet use (Internet users).

Results. Large proportions of patients reported methamphetamine use (19.2%) and Internet use (36.4%). From 2006 through 2008, Adam4Adam was the most frequently reported Web site statewide, despite temporal and regional differences in Web site usage. Methamphetamine users reported more sex partners (mean = 11.7) than nonmethamphetamine users (mean = 5.6; P < .001). Internet users reported more sex partners (mean = 9.8) than non-Internet users (mean = 5.0; P < .001). Multivariable analysis of variance confirmed an independent association of methamphetamine and Internet use with increased numbers of sex partners.

Conclusions. Higher numbers of partners among MSM syphilis patients were associated with methamphetamine and Internet use. Collaboration between currently stand-alone interventions targeting methamphetamine users and Internet users may offer potential advances in sexually transmitted disease control efforts.
Nonresponse to a Question on Self-Identified Sexual Orientation in a Public Health Survey and Its Relationship to Race and Ethnicity
Authors: Kim Hyun-Jun , Fredriksen-Goldsen Karen I.
Published: November 2012

We examined whether nonresponse to the survey question on self-identified sexual orientation was associated with race and ethnicity, utilizing Washington State Behavioral Risk Factor Surveillance System data. The results of adjusted multinomial logistic regression indicated that the nonresponse rates of Asian Americans, Hispanics, and African Americans are higher than those of non-Hispanic Whites. Innovative ways of measuring sexual orientation to reduce racially and ethnically driven bias need to be developed and integrated into public health surveys.
Suicide, Guns, and Public Policy
Authors: Lewiecki E. Michael , Miller Sara A.
Published: November 2012

Suicide is a serious public health concern that is responsible for almost 1 million deaths each year worldwide. It is commonly an impulsive act by a vulnerable individual. The impulsivity of suicide provides opportunities to reduce the risk of suicide by restricting access to lethal means.

In the United States, firearms, particularly handguns, are the most common means of suicide. Despite strong empirical evidence that restriction of access to firearms reduces suicides, access to firearms in the United States is generally subject to few restrictions.

Implementation and evaluation of measures such as waiting periods and permit requirements that restrict access to handguns should be a top priority for reducing deaths from impulsive suicide in the United States.
Efficacy of Frequent Monitoring With Swift, Certain, and Modest Sanctions for Violations: Insights From South Dakota’s 24/7 Sobriety Project
Authors: Kilmer Beau , Nicosia Nancy , Heaton Paul , Midgette Greg
Published: November 2012

Objectives. We examined the public health impact of South Dakota’s 24/7 Sobriety Project, an innovative program requiring individuals arrested for or convicted of alcohol-involved offenses to submit to breathalyzer tests twice per day or wear a continuous alcohol monitoring bracelet. Those testing positive are subject to swift, certain, and modest sanctions.

Methods. We conducted differences-in-differences analyses comparing changes in arrests for driving while under the influence of alcohol (DUI), arrests for domestic violence, and traffic crashes in counties with the program to counties without the program.

Results. Between 2005 and 2010, more than 17 000 residents of South Dakota—including more than 10% of men aged 18 to 40 years in some counties—had participated in the 24/7 program. At the county level, we documented a 12% reduction in repeat DUI arrests (P = .023) and a 9% reduction in domestic violence arrests (P = .035) following adoption of the program. Evidence for traffic crashes was mixed.

Conclusions. In community supervision settings, frequent alcohol testing with swift, certain, and modest sanctions for violations can reduce problem drinking and improve public health outcomes.
Network Mixing and Network Influences Most Linked to HIV Infection and Risk Behavior in the HIV Epidemic Among Black Men Who Have Sex With Men
Authors: Schneider John A. , Cornwell Benjamin , Ostrow David , Michaels Stuart , Schumm Phil , Laumann Edward O. , Friedman Samuel
Published: November 2012

Objectives. We evaluated network mixing and influences by network members upon Black men who have sex with men.

Methods. We conducted separate social and sexual network mixing analyses to determine the degree of mixing on risk behaviors (e.g., unprotected anal intercourse [UAI]). We used logistic regression to assess the association between a network “enabler” (would not disapprove of the respondent’s behavior) and respondent behavior.

Results. Across the sample (n = 1187) network mixing on risk behaviors was more assortative (like with like) in the sexual network (rsex, 0.37–0.54) than in the social network (rsocial, 0.21–0.24). Minimal assortativity (heterogeneous mixing) among HIV-infected men on UAI was evident. Black men who have sex with men reporting a social network enabler were more likely to practice UAI (adjusted odds ratio = 4.06; 95% confidence interval = 1.64, 10.05) a finding not observed in the sexual network (adjusted odds ratio = 1.31; 95% confidence interval = 0.44, 3.91).

Conclusions. Different mixing on risk behavior was evident with more disassortativity among social than sexual networks. Enabling effects of social network members may affect risky behavior. Attention to of high-risk populations’ social networks is needed for effective and sustained HIV prevention.
Revisiting Sample Size: Are Big Trials the Answer?
Authors: Lurati Buse Giovanna A.L. , Botto Fernando , Devereaux P.J.
Published: November 2012

The superiority of the evidence generated in randomized controlled trials over observational data is not only conditional to randomization. Randomized controlled trials require proper design and implementation to provide a reliable effect estimate. Adequate random sequence generation, allocation implementation, analyses based on the intention-to-treat principle, and sufficient power are crucial to the quality of a randomized controlled trial. Power, or the probability of the trial to detect a difference when a real difference between treatments exists, strongly depends on sample size. The quality of orthopaedic randomized controlled trials is frequently threatened by a limited sample size. This paper reviews basic concepts and pitfalls in sample-size estimation and focuses on the importance of large trials in the generation of valid evidence.
The Dangers of Stopping a Trial Too Early
Authors: Briel Matthias , Bassler Dirk , Wang Amy T. , Guyatt Gordon H. , Montori Victor M.
Published: November 2012

To ensure that participants in randomized controlled trials are protected from harm, interim analyses and review of results by an independent data monitoring committee have become standard practice. If an analysis of accumulating data partway through a trial reveals an unanticipated degree of benefit or toxicity, or differences in outcomes between the intervention and control groups are so unimpressive that any prospect of a positive result with the planned sample size is extremely unlikely, investigators may stop the trial earlier than originally scheduled. The practice of stopping randomized controlled trials early is, however, problematic, especially if the trial is stopped for apparent benefit. Concerns in trials stopped early for apparent benefit include appropriate interpretation of results and ethical problems concerning trial participants, clinicians, and society as a whole. In this article, we review the epidemiology of trials stopped early and illustrate some of the problems and controversies associated with stopping randomized controlled trials early for apparent benefit. Finally, we offer guidance for clinicians, those running clinical trials, and authors of systematic reviews.
Emerging Designs in Orthopaedics: Expertise-Based Randomized Controlled Trials
Authors: Scholtes Vanessa A. , Nijman Thomas H. , van Beers Loes , Devereaux P.J. , Poolman Rudolf W.
Published: November 2012

In this article, we discuss the limitations of conventional randomized controlled trials (RCTs) in the surgical field. Surgeons are often believers in certain surgical techniques and therefore can be reluctant to learn new interventions. In expertise-based trials, the patients are randomized to surgeons with expertise in the intervention under investigation. In conventional RCTs, patients are randomized to an intervention, and surgeons will perform this intervention regardless of whether this is the surgery they typically undertake. Conventional randomization may lead to surgery performed by a less experienced or less motivated surgeon, resulting in differential expertise bias. Expertise-based trials can overcome these limitations if potential pitfalls are taken into account.
The Darker Side of Randomized Trials
Authors: Sibai Tarek , Carlisle Hope , Tornetta Paul
Published: November 2012

Randomized trials are thought to provide optimal evidence if carried out correctly. Their application to important questions is the best guide to clinical decision-making. However, these trials are expensive to complete and have a variety of challenges in design and application. This article will review some of the factors that affect our ability to recruit patients into randomized controlled trials for conditions that may be treated surgically by different methods or for conditions for which both nonsurgical and surgical treatments exist.
The validity of the general polarization curve equation approximation for the process of metal deposition
Authors: Zivkovic Predrag , Grgur Branimir , Popov Konstantin
Published: November 2012

Digital simulation was employed for the solution of the general polarization curve equation of metal deposition processes. By approximating the dependence of the exchange current density on concentration with a linear function for one- and two-electron transfer processes, an error lower than 20% was obtained.
Palladium(II) complexes with R2edda derived ligands, Part III: Diisobutyl (s,s)-2,2'-(1,2-ethanediyldiimino)di(4-methylpentanoate) and its palladium(II) complex: Synthesis and characterization
Authors: Zmejkovski Bojana , Kaludjerovic Goran , Gómez-Ruiz Santiago , Sabo Tibor
Published: November 2012

A new R2edda-type ester, diisobutyl (S,S)-2,2'-(1,2-ethane-diyldiimino) di(4-methylpentanoate) dihydrochloride, [(S,S)-H2iBu2eddl]Cl2, 1, and its palladium(II) complex, dichloro(diisobutyl (S,S)-2,2'-(1,2-ethanediyldiimino) di(4-methylpentanoate))palladium(II), [PdCl2{(S,S)-iBu2eddl}], 2, were synthesized and characterized by elemental analysis, as well as IR and NMR spectroscopy. It was found that complex 2 was obtained as mixture of two diastereoisomers, observed in NMR spectra. The crystal structure of compound 1 was determined by X-ray diffraction studies and is described. The isolated crystals consisted of one dicationic species [(S,S)-H2iBu2eddl]2+ and two Cl-. The crystal system was tetragonal with the space group P42. Hydrogen bonds significant for the manner of packing are N-H1N???Cl, 3.049(3) ?, 159(3)? and N-H2N???Cl, 3.100(3) ?, 164(3)?. An infinite chain was formed building a one layer structure, usual for these types of compounds. The C2 symmetry axis of the compound passes through the C1-C1i bond vector and lies perpendicular to the plane N2Cl2.