bluuebunny/crossref_metadata_2025 huggingface dataset:
Horizontal exchange across the thermal bar front: laboratory and numerical modelling
Authors: Demchenko Natalia , Chubarenko Irina
Published: February 2013

Laboratory and numerical experiments have revealed physical reasons for the permeability of the thermal bar to horizontal transport. The thermal bar is understood as a front associated with the temperature of maximum density (Tm = 3.98 °C for fresh water). Laboratory experiments were performed in a 2-metre-long non-rotating channel with a sloping bottom, filled with water with T < Tm and naturally heated from above. Analysis of Particle Image Velocimetry (PIV) images revealed water dynamics in the presence of Tm. It was revealed that the compensating flow in intermediate layers is responsible for the horizontal exchange across the thermal bar front. We applied a 3D non-hydrostatic MIKE3-FlowModel (www.dhi.dk) to investigate the permeability of the spring thermal bar in basins on the scale of lakes and a laboratory flume. We performed an analysis of the concentration distribution of 12 passive tracers released at different locations in the flow domain. Scaling analysis, corroborated by the results of laboratory and numerical experiments, predicts the discharge across the thermal bar as Q = 0.1[g × Δρ/ρ0]1/2h3/2, where h is the depth of the upper thermo-active layer, ρ0 is a maximum density and Δρ is a characteristic horizontal density difference. A combined analysis of data shows that this law is obeyed.
Zooplankton induced currents and fluxes in stratified waters
Authors: Noss Christian , Lorke Andreas
Published: February 2013

This paper presents experimental results for the fluid transport induced by tethered as well as freely swimming zooplankton organisms (Daphnia) in a density-stratified water column. Particle image velocimetry and planar laser induced fluorescence were used to measure the instantaneous velocity and density distributions and to estimate kinetic energy, dissipation rates, vertical mass fluxes, and apparent diffusion coefficients around individual organisms. For freely swimming organism we found dissipation rates of kinetic energy of 10−6W kg−1 and an apparent diffusion coefficient of 10−5m2 s−1. Both values are valid for a volume of influence of approximately 1 cm3, which is about two orders of magnitude larger than the size of the organism. In the case of tethered Daphnia all measures are significantly larger but – associated with the artificial situation – of less environmental significance. The results indicate that swimming-induced fluid and mass transport in the vicinity of zooplankton organisms is characterized by apparent diffusion coefficients comparable in magnitude to turbulent diffusivities typically found in stratified aquatic environments. Upscaling of these results using abundances of Daphnia in lakes further suggests that biologically-induced fluid transport by zooplankton might potentially be important for vertical mixing in stratified waters if background mixing is weak.
The sensitivity of SDI and MFI to a change in particle concentration and properties under saline conditions
Authors: Prihasto N. , Kim Seung-Hyun
Published: February 2013

The sensitivity of existing fouling indices of SDI (silt density index) and MFI (modified fouling index) to a change in particle concentration and properties was evaluated in this study. The MFI formula predicts an increased fouling tendency when the particle concentration increases and the particle size and density decrease. Consequently, concentration, size and density were selected as parameters to examine. For this purpose, silica particles and Aldrich humic acid (HA) were selected as target foulants because of the substantial difference in their size and density. According to this study, both SDI and MFI were sensitive to a change in particle properties of size and density, while MFI was more sensitive to a change in particle concentration than SDI. It is also found that the fouling tendency could be represented better by separate evaluation of T0 and T15 than SDI, at which the ratio of T0 and T15 is evaluated. T15 is found to be as sensitive as the MFI for both silica suspension and HA solution. The saline condition increased the fouling index. MFI and T15 were sensitive to a change in ionic strength. When inorganic and organic foulants were mixed, their relative proportion determined the fouling index values.
Removal of lead from aqueous solutions by complexation ultrafiltration with chitosan
Authors: Shao Jiahui , Xie Zhangwang , He Yiliang , Liu Guowai
Published: February 2013

The removal of lead from aqueous dilute solutions by complexation-ultrafiltration with chitosan was studied. Experiments were performed as a function of aqueous pH, chitosan/Pb2+ ratio, and background electrolyte concentration. The value of pH was found to be the most important parameter to effect the lead removal. The lead removal rate reaches the plateau at almost 100% when the chitosan and lead ratio goes more than 4.0 at pH 6.0. With transmembrane pressure (TMP) 0.1 MPa, chitosan/Pb2+ ratio 4 and pH 6, the lead removal rate decreases sharply from 99.2% to 19.5% as the adding NaCl concentration increases from 0 to 500 mmol. The regeneration of the chitosan by acidification using diafiltration technique was further performed. In the end, the effect of regenerated chitosan on the lead removal was evaluated. At the optimum experimental condition of pH 6.0, regenerated chitosan/Pb2+ ratio 4 and TMP 0.10 MPa, the lead removal rate was found to be 96.2%, which is almost the same as that obtained on the original chitosan. The overall results from the two-step process of complexation-UF and decomplexation-UF separation showed that it could be a promising method for lead removal and recovery from aqueous solutions.
Influence of particle size and operating parameters on virus ultrafiltration efficiency
Authors: Pavanasam Angayar K. , Abbas Ali , Chen Vicki
Published: February 2013

In water treatment, virus removal using ultrafiltration is a major step towards better water quality. In this paper, we study virus filtration efficiency using surrogate virus particles and via statistical surface-response approach. We focus on the effect of particle size (20–100 nm range) as a key factor along with the effects of transmembrane pressure (20–60 kPa range) and feed flowrate (0.3–1.0 L/F;min range) on the filtration virus removal efficiency (LRV). The particle size is shown to impart a great deal of influence on surrogate particle removal. The effect of particle-to-pore-size ratio is reported for comparison of membrane molecular weight cut off (MWCO) performance. It was shown experimentally and through the developed empirical regression model that transmembrane pressure plays a major role in controlling the filtration efficiency along with flowrate. In the studied experimental range, higher LRV values are obtained at lower transmembrane pressure (20 kPa) and at higher feed flowrate (1 L/F;min). Further the effect on LRV of the interaction between transmembrane pressure and particle size seems to be more significant than that of the interaction of flowrate with particle size.
Adsorption of cadmium(II) from aqueous solutions by thiol-functionalized activated carbon
Authors: Kim Doyoon , Wook Jung Young , Kwon Seokjoon , Park Jae-Woo
Published: February 2013

Thiol groups of adsorbent surfaces offer strong affinities for heavy metal ions, such as Hg(II), Pb(II), Cd(II), and so on. In this study, thiol group was impregnated to activated carbon by a series of treatments of oxidation and chlorination followed by 1,2-ethanedithiol introduction in order to investigate the adsorption properties of Cd(II) in aqueous solution. Batch sorption experiments were carried out to study kinetics, and the effect of Mg(II) and different pH conditions on Cd(II) sorption. Sequential extraction experiments were performed to understand binding characteristics. In general, thiol-functionalization improved the removal of Cd(II) by activated carbon in aqueous solution. Compared to untreated activated carbon, over a factor of four of the maximum sorption capacity enhancement was achieved. The presence of Mg(II) interfered Cd(II) sorption, but the degree of the sorption interference was alleviated significantly. Cd(II) sorption occurred more rapidly due to more involvement of ion exhchange by thiol- functionalization.
Bacteriological and physico-chemical quality assessment of household drinking water in Ado-Ekiti, Nigeria
Authors: Oluyege J. O. , Koko A. E. , Aregbesola O. A.
Published: February 2013

An investigation on the bacteriological and physico-chemical properties of stored household drinking water in Ado-Ekiti, Nigeria was carried out between April and October, 2008. The drinking water sources considered for examination were harvested rain water, tap water and well water stored in plastic water pots for 2 to 4 days. The waterborne pathogens in the samples that were isolated were characterized for antibiotic resistance. Estimation of bacterial loads in the water samples revealed mean total bacterial count (TBC) of 1.17 × 105, 1.30 × 104 and 9.70 × 104 cfu/ml for rain water, tap water and well water respectively. The mean-total coliform count (TCC) were recorded as 1.57 × 106, 7.40 × 105 and 5.70 × 105 cfu/ml for rain water, tap water and well water respectively. Seven bacteria genera comprising Escherichia (41.7%), Shigella (75%), Klebsiella (33.3%), Pseudomonas (25%), Staphylococcus (25%), Streptococcus (50%) and Enterococcus (20%) were isolated from stored rain water .Three genera comprising Escherichia coli (8.3%), Staphylococcus (25%) and Pseudomonas (75%) were isolated from stored tap water. In well water samples, nine genera comprising Escherichia (50%), Salmonella (100%) Enterococcus (80%) and Shigella (25%) Proteus (100%) Serratia (100%), Klebsiella (66.6%), Staphylococcus (50%) and Streptococcus (50%) were isolated. The antibiotic susceptibility tests showed that the majority of the bacteria isolated particulaly, Escherichia, Salmonella, Enterococcus and Shigella were resistant to common antibiotics which are still available in Nigerian market. The resistance pattern of the bacterial isolates ranged from 50–100% to amoxicillin, tetracycline, streptomycin, cotrimoxazone, erythromycin, gentamicin. In terms of physico-chemical analysis, all the water samples met the WHO standard for drinking water. However, the results obtained revealed that adequate domestic water sanitation and disinfection programmes must be put in place to ensure safety against waterborne antibiotic resistant pathogens especially in developing countries.
Effect of floc structure and strength on membrane permeability in the hybrid coagulation-microfiltration process
Authors: Zhao Bingqing , Wang Dongsheng , Li Tao , Huang Chihpin
Published: February 2013

The relative importance of floc property on microfiltration and fouling mechanism remains a field of arguments. The effects of floc structure and strength on fouling rate of coagulation-microfiltration were investigated in dead-end microfiltration. Flocs varying in size, fractal structure and strength were prepared by AlCl3 and PACl (Polyaluminum Chloride) coagulation at various dosages followed by different slow mixing rates and filtration without any sedimentation step. The rates of flux decline for flocs formed under same coagulant dosage but different shear conditions showed only limited size and compactness dependence. However, the floc strength effect on membrane filtration performance was observed clearly with the floc strength constant exhibiting a strong positive linear correlation with the resulted cake compressibility index.
Ionizing Radiation Exposure among Kidney Transplant Recipients Due to Medical Imaging during the Pretransplant Evaluation
Authors: Nguyen Kim N. , Patel Anup M. , Weng Francis L.
Published: February 2013

Background and objectives

Kidney transplant recipients are at increased risk for malignancies. One recognized risk for malignancy is ionizing radiation. The purpose of this study was to determine, among kidney transplant recipients, the medical imaging procedures that contribute to radiation exposure and their cumulative radiation exposure, as a result of their pretransplant evaluation.

Design, setting, participants, & measurements

Medical records of patients who received a first, kidney-alone transplant during 2008 at a single transplant center were examined. This study identified medical imaging procedures that were performed as prerequisites for deceased donor wait-listing or receipt of live donor kidney transplants and to maintain active status on the wait list. Frequencies of medical imaging procedures and cumulative effective doses of radiation were calculated.

Results

Among the 172 kidney transplant recipients, 905 procedures were performed. Seventy patients (40.7%) were exposed to low dose (0–20 mSv), 51 (29.7%) were exposed to moderate dose (>20–50 mSv), 28 (16.3%) were exposed to high dose (>50–100 mSv), and 23 (13.4%) were exposed to very high dose (>100 mSv) cumulative effective radiation. Nuclear stress tests accounted for 82.9% of the total radiation exposure. In multivariate analysis, older age, diabetes, and black race were associated with exposure to >20 mSv radiation during the pretransplant evaluation.

Conclusions

Kidney transplant recipients are exposed to large amounts of ionizing radiation from medical imaging during the pretransplant evaluation. The effects of radiation upon malignancy risk and strategies to reduce this radiation exposure warrant further investigation.
Deformation behavior of two continuously cooled vanadium microalloyed steels at liquid nitrogen temperature
Authors: Glisic Dragomir , Fadel Abdunnaser , Radovic Nenad , Drobnjak Djordje , Zrilic Milorad
Published: February 2013

The aim of this work was to establish deformation behaviour of two vanadium
microalloyed medium carbon steels with different contents of carbon and
titanium by tensile testing at 77 K. Samples were reheated at 1250?C/30 min
and continuously cooled at still air. Beside acicular ferrite as dominant
morphology in both microstructures, the steel with lower content of carbon
and negligible amount of titanium contains considerable fraction of grain
boundary ferrite and pearlite. It was found that Ti-free steel exhibits
higher strain hardening rate and significantly lower elongation at 77 K than
the fully acicular ferrite steel. The difference in tensile behavior at 77 K
of the two steels has been associated with the influence of the pearlite,
together with higher dislocation density of acicular ferrite.
Removal of Duodenum Elicits GLP-1 Secretion
Authors: Muscogiuri Giovanna , Mezza Teresa , Prioletta Annamaria , Sorice Gian Pio , Clemente Gennaro , Sarno Gerardo , Nuzzo Gennaro , Pontecorvi Alfredo , Holst Jens J. , Giaccari Andrea
Published: February 2013

OBJECTIVE

To evaluate the effect of removal of the duodenum on the complex interplay between incretins, insulin, and glucagon in nondiabetic subjects.

RESEARCH DESIGN AND METHODS

For evaluation of hormonal secretion and insulin sensitivity, 10 overweight patients without type 2 diabetes (age 61 ± 19.3 years and BMI 27.9 ± 5.3 kg/m2) underwent a mixed-meal test and a hyperinsulinemic-euglycemic clamp before and after pylorus-preserving pancreatoduodenectomy for ampulloma.

RESULTS

All patients experienced a reduction in insulin (P = 0.002), C-peptide (P = 0.0002), and gastric inhibitory peptide (GIP) secretion (P = 0.0004), while both fasting and postprandial glucose levels increased (P = 0.0001); GLP-1 and glucagon responses to the mixed meal increased significantly after surgery (P = 0.02 and 0.031). While changes in GIP levels did not correlate with insulin, glucagon, and glucose levels, the increase in GLP-1 secretion was inversely related to the postsurgery decrease in insulin secretion (R2 = 0.56; P = 0.012) but not to the increased glucagon secretion, which correlated inversely with the reduction of insulin (R2 = 0.46; P = 0.03) and C-peptide (R2 = 0.37; P = 0.04). Given that the remaining pancreas presumably has preserved intraislet anatomy, insulin secretory capacity, and α- and β-cell interplay, our data suggest that the increased glucagon secretion is related to decreased systemic insulin.

CONCLUSIONS

Pylorus-preserving pancreatoduodenectomy was associated with a decrease in GIP and a remarkable increase in GLP-1 levels, which was not translated into increased insulin secretion. Rather, the hypoinsulinemia may have caused an increase in glucagon secretion.
Impact of Baseline Insulin Regimen on Glycemic Response to a Group Medical Clinic Intervention
Authors: Crowley Matthew J. , Melnyk Stephanie D. , Coffman Cynthia J. , Jeffreys Amy S. , Edelman David
Published: February 2013

OBJECTIVE

Group medical clinics (GMC) combine medication management and self-management training, and may improve diabetes outcomes. It remains unclear which patients benefit most from GMC. This secondary analysis examined the impact of baseline insulin regimen on GMC response.

RESEARCH DESIGN AND METHODS

We analyzed a trial of 239 veterans with type 2 diabetes randomized to GMC or usual care (UC). We categorized baseline insulin regimen as the following: no insulin; basal insulin only; or complex insulin (basal–prandial or mixed regimens). Using linear mixed models adjusted for clustering within GMC, we evaluated the differential impact of GMC relative to UC on hemoglobin A1c (HbA1c) and self-efficacy among patients on different baseline insulin regimens.

RESULTS

From linear mixed models, the effect of GMC on HbA1c differed by baseline insulin regimen versus UC (P = 0.05); there was no differential effect on self-efficacy (P = 0.29). Among those using complex insulin regimens at baseline, GMC reduced HbA1c by study end compared with UC (−1.0%; 95% CI −1.8 to −0.2; P = 0.01). We found no such HbA1c difference between GMC and UC patients using no insulin (P = 0.65) or basal insulin only (P = 0.71). There were no clinically significant differences in hypoglycemia by baseline insulin regimen and intervention group.

CONCLUSIONS

We found that compared with UC, GMC lowered HbA1c specifically among patients using complex insulin regimens at study baseline, which may relate to this group’s demanding medication and self-management requirements. Implementing GMC among patients using complex insulin regimens may maximize this care delivery strategy’s potential.
Clinical Reasoning and Advanced Practice Privileges Enable Physical Therapist Point-of-Care Decisions in the Military Health Care System: 3 Clinical Cases
Authors: Rhon Daniel I. , Deyle Gail D. , Gill Norman W.
Published: February 2013

Background and Purpose

Physical therapists frequently make important point-of-care decisions for musculoskeletal injuries and conditions. In the Military Health System (MHS), these decisions may occur while therapists are deployed in support of combat troops, as well as in a more traditional hospital setting. Proficiency with the musculoskeletal examination, including a fundamental understanding of the diagnostic role of musculoskeletal imaging, is an important competency for physical therapists. The purpose of this article is to present 3 cases managed by physical therapists in unique MHS settings, highlighting relevant challenges and clinical decision making.

Case Description

Three cases are presented involving conditions where the physical therapist was significantly involved in the diagnosis and clinical management plan. The physical therapist's clinical privileges, including the ability to order appropriate musculoskeletal imaging procedures, were helpful in making clinical decisions that facilitate timely management. The cases involve patients with an ankle sprain and Maisonneuve fracture, a radial head fracture, and a pelvic neoplasm referred through medical channels as knee pain.

Outcomes

Clinical pathways from point of care are discussed, as well as the reasoning that led to decisions affecting definitive care for each of these patients. In each case, emergent treatment and important combat evacuation decisions were based on a combination of examination and management decisions.

Discussion

Physical therapists can provide important contributions to the primary management of patients with musculoskeletal conditions in a variety of settings within the MHS. In the cases described, advanced clinical privileges contributed to the success in this role.
Psychometric Properties of the Outpatient Physical Therapy Improvement in Movement Assessment Log (OPTIMAL) in Patients With Musculoskeletal Disorders: A Replication Study With Additional Findings
Authors: Riddle Daniel L. , Stratford Paul W. , Carter Tracy L. , Cleland Joshua A.
Published: February 2013

Background

The Outpatient Physical Therapy Improvement in Movement Assessment Log (OPTIMAL) is a recently developed self-report outcome instrument designed to measure the extent of activity limitation as defined by the World Health Organization.

Objective

The purposes of the study were to replicate some aspects of the original study of the OPTIMAL Difficulty and Confidence scales and to conduct additional psychometric tests.

Design

A cross-sectional design was used in the study.

Methods

Of a total of 1,150 patients who received treatment at 4 outpatient centers over the study period, 1,030 patients were recruited for this study and completed the OPTIMAL instrument and previously validated region-specific functional status measures. A variety of analytic methods were used to examine the extent of redundancy between the OPTIMAL Difficulty and Confidence scales, as well as the internal consistency reliability, standard error of measurement, known-groups validity, and convergent validity of OPTIMAL Difficulty Scale scores.

Results

The OPTIMAL Difficulty and Confidence scale scores were found in a factor analysis to be load-based on anatomical region rather than on difficulty and confidence concepts. Internal consistency reliability for the subscales of the Confidence Scale varied and was .80 or higher for the lower-extremity subscale but .50 or less for the trunk and upper-extremity subscales.

Limitations

Only cross-sectional relationships were examined, and another pure measure of activity limitation was not used for comparison.

Conclusions

The findings generally did not support the psychometric properties of the OPTIMAL instrument. Although not conclusive, the data suggested that the OPTIMAL Difficulty and Confidence scales demonstrate substantial overlap. Reliability was generally low, with the exception of the lower-extremity subscale. Scores for the subscales of the Difficulty Scale differentiated among patients with lower-extremity versus trunk or upper-extremity diagnoses, but associations with previously validated region-specific measures were generally weak or absent. Clinicians treating outpatients with musculoskeletal disorders should consider alternative measures when attempting to quantify the extent of activity limitations.
Multipole polarizability of a nanodimer in optical waves
Authors: Grahn P. , Shevchenko A. , Kaivola M.
Published: February 2013

In this work we study the interaction of visible light with plasmonic nanodimers that, under particular illumination conditions, do not exhibit any electric dipole excitations. It has previously been found out that the dipole suppression phenomenon disappears when the illumination direction is reversed. As a consequence, a homogeneous nanomaterial consisting of such nanodimers can be expected to be spatially dispersive, such that the conventional electric polarization vanishes for certain directions of light propagation. In order to reveal the complete picture of the light-nanodimer interaction, we analyze the multipole excitations in a dimer at various illumination angles. In particular, we introduce an analytical model for the multipole polarizability tensors of the dimer that, in contrast to conventional polarizability tensors, depend on the light propagation direction. The model is verified by rigorous numerical calculations. It can be used to gain insight into the properties of optical nanomaterials, such as metamaterials, in which higher-order multipoles can be efficiently excited.
Determining the elements of procedural quality
Authors: Berkowitz Oren , Jones Kristen , Lunsford L. Dade , Kondziolka Douglas
Published: February 2013

Object

The definition and determination of quality health care is an important topic. The purpose of this study was to develop a longitudinal method to define a quality procedure by creating a formal approach to pre- and postoperative outcomes documentation. The authors worked to define quality outcomes by first documenting the patient's condition. Goals were determined together by the surgeon and the patient and then were evaluated to see if those goals were met.

Methods

The population consisted of cancer patients with newly diagnosed metastatic brain disease who were scheduled to undergo stereotactic radiosurgery. Surgeons recorded perioperatively objective information related to preoperative goals, clinical findings, surgical performance and/or error, and whether goals were met. In addition, patients completed pre- and postprocedure questionnaires (Rand 36-Item Short-Form Health Survey 1.0 [SF-36]).

Results

Procedural goals, defined as completing radiosurgery without error or complication and same-day discharge, were met in all patients. The clinically predetermined goal of tumor palliation was met in all but 1 patient at follow-up. The SF-36 scores remained stable except for the general health domain, which was lower (p = 0.006).

Conclusions

Procedural goals can be defined and objectively measured serially. The authors think that quality care can be defined as a process that achieves predefined goals without significant error and maintains or improves health.
Posterior fossa calcifying pseudoneoplasm of the central nervous system
Authors: Kerr Edward E. , Borys Ewa , Bobinski Matthew , Shahlaie Kiarash
Published: February 2013

Calcifying pseudoneoplasms of the neuraxis are rare, poorly understood masses that may arise throughout the CNS. Although these lesions are generally considered benign and noninfiltrative, reports exist that document growth of these masses on serial plain radiographs. The authors report a case of a posterior fossa calcifying pseudoneoplasm of the neuraxis demonstrating interval development of peritumoral edema on serial MRI. Their findings suggest that these lesions may sometimes behave in a more aggressive manner than commonly thought.
Beyond Bartleby and Bad Faith: Thinking Critically with Sartre and Deleuze
Authors: Smith Dominic
Published: February 2013

This essay argues that important critical and political perspective can be gained on Deleuze's famous essay, ‘Bartleby; or, The Formula’ by viewing it as an attempt to move beyond the Sartrean framework of ‘bad faith’. The argument comprises four sections. In section one, I contextualise Deleuze's essay in terms of contrasting readings of Bartleby, from a prior account by Georges Perec, to contemporary accounts indebted to Deleuze, from Hardt and Negri's Empire to Gisèle Berkman's recent L'Effet Bartleby. The argument of this section is that a problematically reductive image of Bartleby has emerged in the wake of Deleuze's essay, but that this can be challenged in favour of a more nuanced and politically significant reading by contextualising the essay as an attempt to overcome bad faith. In section two, I develop this by drawing out the nature and relevance of the threat posed by bad faith through a focus on Sartrean, Deleuzian and Badioucan critiques of Bartleby, before arguing, in section three, that attention to the concept of a ‘logic of presuppositions’ developed in Deleuze's essay shows how bad faith can be overcome. These sections all build towards the fourth and longest section, which draws out the wider political significance of what it means to overcome bad faith. To do so, I pay attention to how logics of presupposition function in Bartleby's story, and consider Deleuze's essay in relation to his work on ‘control societies’ and ‘collective assemblages of enunciation’.
Adaptive Generation and Diagnostics of Linear Few-Cycle Light Bullets
Authors: Bock Martin , Grunwald Ruediger
Published: February 2013

Recently we introduced the class of highly localized wavepackets (HLWs) as a generalization of optical Bessel-like needle beams. Here we report on the progress in this field. In contrast to pulsed Bessel beams and Airy beams, ultrashort-pulsed HLWs propagate with high stability in both spatial and temporal domain, are nearly paraxial (supercollimated), have fringe-less spatial profiles and thus represent the best possible approximation to linear “light bullets”. Like Bessel beams and Airy beams, HLWs show self-reconstructing behavior. Adaptive HLWs can be shaped by ultraflat three-dimensional phase profiles (generalized axicons) which are programmed via calibrated grayscale maps of liquid-crystal-on-silicon spatial light modulators (LCoS-SLMs). Light bullets of even higher complexity can either be freely formed from quasi-continuous phase maps or discretely composed from addressable arrays of identical nondiffracting beams. The characterization of few-cycle light bullets requires spatially resolved measuring techniques. In our experiments, wavefront, pulse and phase were detected with a Shack-Hartmann wavefront sensor, 2D-autocorrelation and spectral phase interferometry for direct electric-field reconstruction (SPIDER). The combination of the unique propagation properties of light bullets with the flexibility of adaptive optics opens new prospects for applications of structured light like optical tweezers, microscopy, data transfer and storage, laser fusion, plasmon control or nonlinear spectroscopy.
Morocco’s Rock Art: Age and Meaning
Authors: Searight Susan
Published: February 2013

The general distribution of the rock art sites in Morocco is indicated in this report. The vast majority are situated in southern Morocco, in the region of the River Draa and further south. One important exception is the High Atlas mountain range. The location of these sites is shown to be fairly standardised. Four different groups of engravings are identified, based on technique and theme. In the absence of any direct dating of the engravings, these groups can only be placed in a relative chronological order, using dates known for climatic conditions and the introduction of animals or objects. A problem concerns the reliability of these ‘known’ dates, often based on extrapolation from dated information from neighbouring countries. Two recent excavations close to rock art sites have yielded C14 dates for population presence in the area without advancing knowledge on the date of the rock art. The reason for sites’ geographical situation in the landscape can probably be surmised reasonably accurately, but the interpretation of this art remains largely a matter of speculation and intelligent guesswork. Current projects aimed to advance knowledge of the age of the art are described.
Why YRNAs? About Versatile RNAs and Their Functions
Authors: Köhn Marcel , Pazaitis Nikolaos , Hüttelmaier Stefan
Published: February 2013

Y RNAs constitute a family of highly conserved small noncoding RNAs (in humans: 83-112 nt; Y1, Y3, Y4 and Y5). They are transcribed from individual genes by RNA-polymerase III and fold into conserved stem-loop-structures. Although discovered 30 years ago, insights into the cellular and physiological role of Y RNAs remains incomplete. In this review, we will discuss knowledge on the structural properties, associated proteins and discuss proposed functions of Y RNAs. We suggest Y RNAs to be an integral part of ribonucleoprotein networks within cells and could therefore have substantial influence on many different cellular processes. Putative functions of Y RNAs include small RNA quality control, DNA replication, regulation of the cellular stress response and proliferation. This suggests Y RNAs as essential regulators of cell fate and indicates future avenues of research, which will provide novel insights into the role of small noncoding RNAs in gene expression.
Modeling of the Partial Discharge Process in a Liquid Dielectric: Effect of Applied Voltage, Gap Distance, and Electrode Type
Authors: Sima Wenxia , Jiang Chilong , Lewin Paul , Yang Qing , Yuan Tao
Published: February 2013

The partial discharge (PD) process in liquid dielectrics is influenced by several factors. Although the PD current contains the information representing the discharge process during the PD event, it is difficult to determine the detailed dynamics of what is happening in the bulk of the liquid. In this paper, a microscopic model describing the dynamics of the charge carriers is implemented. The model consists of drift-diffusion equations of electrons, positive and negative ions coupled with Poisson’s equation. The stochastic feature of PD events is included in the equation. First the model is validated through comparison between the calculated PD current and experimental data. Then experiments are conducted to study the effects of the amplitude of the applied voltage, gap distance and electrode type on the PD process. The PD currents under each condition are recorded. Simulations based on the model have been conducted to analyze the dynamics of the PD events under each condition, and thus explain the mechanism of how these factors influence the PD events. The space charge generated in the PD process is revealed as the main reason affecting the microscopic process of the PD events.
Inhibition of Poly(ADP-Ribose) Polymerase Enhances Radiochemosensitivity in Cancers Proficient in DNA Double-Strand Break Repair
Authors: Shunkwiler Lauren , Ferris Gina , Kunos Charles
Published: February 2013

Pharmacologic inhibitors of poly(ADP-ribose) polymerase (PARP) putatively enhance radiation toxicity in cancer cells. Although there is considerable information on the molecular interactions of PARP and BRCA1- and BRCA2-deficient cancers, very little is known of the PARP inhibition effect upon cancers proficient in DNA double-strand break repair after ionizing radiation or after stalled replication forks. In this work, we investigate whether PARP inhibition by ABT-888 (veliparib) augments death-provoking effects of ionizing radiation, or of the topoisomerase I poison topotecan, within uterine cervix cancers cells harboring an unfettered, overactive ribonucleotide reductase facilitating DNA double-strand break repair and contrast these findings with ovarian cancer cells whose regulation of ribonucleotide reductase is relatively intact. Cell lethality of a radiation-ABT-888 combination is radiation and drug dose dependent. Data particularly highlight an enhanced topotecan-ABT-888 cytotoxicity, and corresponds to an increased number of unrepaired DNA double-strand breaks. Overall, our findings support enhanced radiochemotherapy toxicity in cancers proficient in DNA double-strand break repair when PARP is inhibited by ABT-888.
Core RNAi Machinery and Sid1, a Component for Systemic RNAi, in the Hemipteran Insect, Aphis glycines
Authors: Bansal Raman , Michel Andy
Published: February 2013

RNA interference (RNAi) offers a novel tool to manage hemipteran pests. For the success of RNAi based pest control in the field, a robust and systemic RNAi response is a prerequisite. We identified and characterized major genes of the RNAi machinery, Dicer2 (Dcr2), Argonaute2 (Ago2), and R2d2 in Aphis glycines, a serious pest of soybean. The A. glycines genome encodes for at least one copy of Dcr2, R2d2 and Ago2. Comparative and molecular evolution analyses (dN/dS) showed that domain regions of encoded proteins are highly conserved, whereas linker (non-domain) regions are diversified. Sequence homology and phylogenetic analyses suggested that the RNAi machinery of A. glycines is more similar to that of Tribolium casteneum as compared to that of Drosophila melanogaster. We also characterized Sid1, a major gene implicated in the systemic response for RNAi-mediated gene knockdown. Through qPCR, Dcr2, R2d2, Ago2, and Sid1 were found to be expressed at similar levels in various tissues, but higher expression of Dcr2, R2d2, and Ago2 was seen in first and second instars. Characterization of RNAi pathway and Sid1 in A. glycines will provide the foundation of future work for controlling one of the most important insect pests of soybean in North America.
Downregulation of miR-17~92 Expression Increase Paclitaxel Sensitivity in Human Ovarian Carcinoma SKOV3-TR30 Cells via BIM Instead of PTEN
Authors: Shuang Ting , Shi Chunxue , Chang Shuang , Wang Min , Bai Cui
Published: February 2013

To better understand the molecular mechanisms of paclitaxel resistance in ovarian carcinoma, we evaluated the expression of miRNAs using miRNA microarray between human ovarian carcinoma SKOV3 cells and paclitaxel resistant SKOV3-TR30 cells. Results showed that 69 miRNAs were upregulated while 102 miRNAs were downregulated in SKOV3-TR30 cells. Using real-time PCR, we further clarified that miR-17~92 was overexpressed in SKOV3-TR30 cells compared with that in SKOV3 cells. We then established stable virally transduced SKOV3-TR30-m-PTIP-Sponge all SKOV3-TR30 cells and its vector-only control SKOV3-TR30-m-PTIP-GFP cells. Real time-PCR revealed that SKOV3-TR30-m-PTIP-Sponge all cells expressed approximately 6.18-fold lower levels of miR-17~92 compared with the control group. Decreased expression of miR-17~92 resulted in cell cycle arrest in the G2/M phase and growth inhibition. After the transduction, the BIM protein level was increased in SKOV3-TR30 cells and luciferase reporter assays revealed that miR-17~92 binds directly to the 3'-UTR of BIM. Results of luciferase reporter assays accompanied with Western Blot showed that although miR-17~92 binds directly to the 3'-UTR of PTEN, the PTEN protein expression level was upregulated slightly while the result is of no statistical significance. Our results showed that miR-17~92 could be a causal factor of the downregulation of BIM in SKOV3-TR30 cells and thus induce the paclitaxel resistance in SKOV3-TR30 cells.
Role of Akirin in Skeletal Myogenesis
Authors: Chen Xiaoling , Huang Zhiqing , Wang Huan , Jia Gang , Liu Guangmang , Guo Xiulan , Tang Renyong , Long Dingbiao
Published: February 2013

Akirin is a recently discovered nuclear factor that plays an important role in innate immune responses. Beyond its role in innate immune responses, Akirin has recently been shown to play an important role in skeletal myogenesis. In this article, we will briefly review the structure and tissue distribution of Akirin and discuss recent advances in our understanding of its role and signal pathway in skeletal myogenesis.
Anti-Escherichia coli O157:H7 Properties of Purple Prairie Clover and Sainfoin Condensed Tannins
Authors: Liu Xiu-Li , Hao Yong-Qing , Jin Long , Xu Zhong-Jun , McAllister Tim , Wang Yuxi
Published: February 2013

Condensed tannins (CT) from purple prairie clover (PPC; Dalea purpurea Vent.) and sainfoin (SF; Onobrychis viciifolia) were assessed for anti-Escherichia coli activity by comparing their ability to react with proteins and liposome, cause cell aggregation, and alter outer membrane (OM) morphology and permeability. The PPC CT had greater (P < 0.01) protein-precipitating capacity than SF CT using either bovine serum albumin or ribulose 1,5-disphosphate carboxylase as model proteins. Minimum inhibitory concentration of PPC CT for two strains of E. coli and five strains of E. coli O157:H7 was four to six times lower than that of SF CT. E. coli exposed to 10 µg/mL of both CT had higher (P < 0.05) OM permeability than controls and was greater (P < 0.05) for PPC than for SF CT. Addition of both CT at 50 and 200 µg/mL caused cell aggregation which was more evident (P < 0.05) for PPC than for SF CT. Transmission electron microscopy showed electron dense material on the cell surface when cells were exposed to 50 µg/mL of PPC CT. The greater anti-E. coli activity of PPC than SF CT was due to its enhanced ability to precipitate protein that increased OM permeability and promoted cell aggregation.
From Molecular to Nanotechnology Strategies for Delivery of Neurotrophins: Emphasis on Brain-Derived Neurotrophic Factor (BDNF)
Authors: Géral Claire , Angelova Angelina , Lesieur Sylviane
Published: February 2013

Neurodegenerative diseases represent a major public health problem, but beneficial clinical treatment with neurotrophic factors has not been established yet. The therapeutic use of neurotrophins has been restrained by their instability and rapid degradation in biological medium. A variety of strategies has been proposed for the administration of these leading therapeutic candidates, which are essential for the development, survival and function of human neurons. In this review, we describe the existing approaches for delivery of brain-derived neurotrophic factor (BDNF), which is the most abundant neurotrophin in the mammalian central nervous system (CNS). Biomimetic peptides of BDNF have emerged as a promising therapy against neurodegenerative disorders. Polymer-based carriers have provided sustained neurotrophin delivery, whereas lipid-based particles have contributed also to potentiation of the BDNF action. Nanotechnology offers new possibilities for the design of vehicles for neuroprotection and neuroregeneration. Recent developments in nanoscale carriers for encapsulation and transport of BDNF are highlighted.
Diverse Applications of Electronic-Nose Technologies in Agriculture and Forestry
Authors: Wilson Alphus
Published: February 2013

Electronic-nose (e-nose) instruments, derived from numerous types of aroma-sensor technologies, have been developed for a diversity of applications in the broad fields of agriculture and forestry. Recent advances in e-nose technologies within the plant sciences, including improvements in gas-sensor designs, innovations in data analysis and pattern-recognition algorithms, and progress in material science and systems integration methods, have led to significant benefits to both industries. Electronic noses have been used in a variety of commercial agricultural-related industries, including the agricultural sectors of agronomy, biochemical processing, botany, cell culture, plant cultivar selections, environmental monitoring, horticulture, pesticide detection, plant physiology and pathology. Applications in forestry include uses in chemotaxonomy, log tracking, wood and paper processing, forest management, forest health protection, and waste management. These aroma-detection applications have improved plant-based product attributes, quality, uniformity, and consistency in ways that have increased the efficiency and effectiveness of production and manufacturing processes. This paper provides a comprehensive review and summary of a broad range of electronic-nose technologies and applications, developed specifically for the agriculture and forestry industries over the past thirty years, which have offered solutions that have greatly improved worldwide agricultural and agroforestry production systems.
Energy Harvesting Thermoelectric Generators Manufactured Using the Complementary Metal Oxide Semiconductor Process
Authors: Yang Ming-Zhi , Wu Chyan-Chyi , Dai Ching-Liang , Tsai Wen-Jung
Published: February 2013

This paper presents the fabrication and characterization of energy harvesting thermoelectric micro generators using the commercial complementary metal oxide semiconductor (CMOS) process. The micro generator consists of 33 thermocouples in series. Thermocouple materials are p-type and n-type polysilicon since they have a large Seebeck coefficient difference. The output power of the micro generator depends on the temperature difference in the hot and cold parts of the thermocouples. In order to increase this temperature difference, the hot part of the thermocouples is suspended to reduce heat-sinking. The micro generator needs a post-CMOS process to release the suspended structures of hot part, which the post-process includes an anisotropic dry etching to etch the sacrificial oxide layer and an isotropic dry etching to remove the silicon substrate. Experiments show that the output power of the micro generator is 9.4 mW at a temperature difference of 15 K.
Inferring Community Structure in Healthcare Forums
Authors: Årsand E. , Fernandez-Luque L. , Lauritzen J. , Hartvigsen G. , Chomutare T.
Published: February 2013

Background: Detecting community structures in complex networks is a problem interesting to several domains. In healthcare, discovering communities may enhance the quality of web offerings for people with chronic diseases. Understanding the social dynamics and community attachments is key to predicting and influencing interaction and information flow to the right patients.

Objectives: The goal of the study is to empirically assess the extent to which we can infer meaningful community structures from implicit networks of peer interaction in online healthcare forums.

Methods: We used datasets from five online diabetes forums to design networks based on peer-interactions. A quality function based on user interaction similarity was used to assess the quality of the discovered communities to complement existing homophily measures.

Results: Results show that we can infer meaningful communities by observing forum interactions. Closely similar users tended to co-appear in the top communities, suggesting the discovered communities are intuitive. The number of years since diagnosis was a significant factor for cohesiveness in some diabetes communities.

Conclusion: Network analysis is a tool that can be useful in studying implicit networks that form in healthcare forums. Current analysis informs further work on predicting and influencing interaction, information flow and user interests that could be useful for personalizing medical social media.
Towards a biocompatible artificial lung: Covalent functionalization of poly(4-methylpent-1-ene) (TPX) with cRGD pentapeptide
Authors: Möller Lena , Hess Christian , Paleček Jiří , Su Yi , Haverich Axel , Kirschning Andreas , Dräger Gerald
Published: February 2013

Covalent multistep coating of poly(methylpentene), the membrane material in lung ventilators, by using a copper-free “click” approach with a modified cyclic RGD peptide, leads to a highly biocompatible poly(methylpentene) surface. The resulting modified membrane preserves the required excellent gas-flow properties while being densely seeded with lung endothelial cells.
La pénalisation de l'usage de stupéfiants en France au miroir des statistiques administratives
Authors: Obradovic Ivana
Published: February 2013

Contrairement à l’opinion courante selon laquelle la loi du 31 décembre 1970 serait de moins en moins appliquée, l’analyse des statistiques policières et judiciaires montre que la pénalisation de l’usage de stupéfiants est de plus en plus systématique en France. L’interprétation des évolutions dans la répression de l’usage de stupéfiants révèle différents usages possibles des chiffres. Si on réduit la pénalisation au rapport entre usagers interpellés et condamnés, elle a en effet reculé ; si on la comprend comme un recours accru au système pénal pour traiter les affaires d’usage, y compris en amont des tribunaux, on conclut au contraire à une pénalisation renforcée et à une diversification des modes de sanction de l’usage de stupéfiants entre 1986 et 2009.
Anorexie et maternité : un ventre plein pour apaiser un ventre vide ?
Authors: Gandouly Marion
Published: February 2013

Résumé La grossesse et les remaniements psychiques qu’elle induit sont aujourd’hui au cœur des préoccupations de nombreux psychanalystes, tant cette période peut être source du meilleur comme du pire. Sous l’effet de la transparence psychique, les fantasmes régressifs et les remémorations infantiles affluent à la conscience, permettant parfois à certaines problématiques, restées jusqu’alors latentes, de trouver une issue positive. Qu’en serait-il alors pour des femmes présentant des antécédents d’anorexie ? Cette authenticité psychique, cette folie maternelle ordinaire, pourrait-elle être l’occasion d’un remaniement identitaire leur permettant de se libérer de l’emprise maternelle, en accédant au statut de femme et à celui de mère, si longtemps refusés ?