bluuebunny/crossref_metadata_2025 huggingface dataset:
Early undernutrition induces glucagon resistance and insulin hypersensitivity in the liver of suckling rats
Authors: Lizarraga-Mollinedo Esther , Fernández-Millán Elisa , Martín Juan de Toro , Martínez-Honduvilla Carlos , Escrivá Fernando , Álvarez Carmen
Published: February 2012

Developing brains are vulnerable to nutritional insults. Early undernutrition alters their structure and neurochemistry, inducing long-term pathological effects whose causal pathways are not well defined. During suckling, the brain uses glucose and ketone bodies as substrates. Milk is a high-fat low-carbohydrate diet, and the liver must maintain high rates of gluconeogenesis and ketogenesis to address the needs of these substrates. Insulin and glucagon play major roles in this adaptation: throughout suckling, their blood concentrations are low and high, respectively, and the liver maintains low insulin sensitivity and increased glucagon responsiveness. We propose that disturbances in the endocrine profile and available plasma substrates along with undernutrition-related changes in brain cortex capacity for ketone utilization may cause further alterations in some brain functions. We explored this hypothesis in 10-day-old suckling rats whose mothers were severely food restricted from the 14th day of gestation. We measured the plasma/serum concentrations of glucose, ketone body, insulin and glucagon, and hepatic insulin and glucagon responses. Undernutrition led to hypoglycemia and hyperketonemia to 84% ( P < 0.001) and 144% ( P < 0.001) of control values, respectively. Liver responsiveness to insulin and glucagon became increased and reduced, respectively; intraperitoneal glucagon reduced liver glycogen by 90% ( P < 0.01) in control and by 35% ( P < 0.05) in restricted. Cortical enzymes of ketone utilization remained unchanged, but their carrier proteins were altered: monocarboxylate transporter (MCT) 1 increased: 73 ± 14, controls; 169 ± 20, undernourished ( P < 0.01; densitometric units); MCT2 decreased: 103 ± 3, controls; 37 ± 4, undernourished ( P < 0.001; densitometric units). All of these changes, coinciding with the brain growth spurt, may cause some harmful effects associated with early undernutrition.
Nuclear factor-E2-related factor 2 is a major determinant of bile acid homeostasis in the liver and intestine
Authors: Weerachayaphorn Jittima , Mennone Albert , Soroka Carol J. , Harry Kathy , Hagey Lee R. , Kensler Thomas W. , Boyer James L.
Published: February 2012

The transcription factor nuclear factor-E2-related factor 2 (Nrf2) is a key regulator for induction of hepatic detoxification and antioxidant mechanisms, as well as for certain hepatobiliary transporters. To examine the role of Nrf2 in bile acid homeostasis and cholestasis, we assessed the determinants of bile secretion and bile acid synthesis and transport before and after bile duct ligation (BDL) in Nrf2−/− mice. Our findings indicate reduced rates of biliary bile acid and GSH excretion, higher levels of intrahepatic bile acids, and decreased expression of regulators of bile acid synthesis, Cyp7a1 and Cyp8b1, in Nrf2−/− compared with wild-type control mice. The mRNA expression of the bile acid transporters bile salt export pump ( Bsep) and organic solute transporter ( Ostα) were increased in the face of impaired expression of the multidrug resistance-associated proteins Mrp3 and Mrp4. Deletion of Nrf2 also decreased ileal apical sodium-dependent bile acid transporter ( Asbt) expression, leading to reduced bile acid reabsorption and increased loss of bile acid in feces. Finally, when cholestasis is induced by BDL, liver injury was not different from that in wild-type BDL mice. These Nrf2−/− mice also had increased pregnane X receptor ( Pxr) and Cyp3a11 mRNA expression in association with enhanced hepatic bile acid hydroxylation. In conclusion, this study finds that Nrf2 plays a major role in the regulation of bile acid homeostasis in the liver and intestine. Deletion of Nrf2 results in a cholestatic phenotype but does not augment liver injury following BDL.
Morphology and migration of podocytes are affected by CD151 levels
Authors: Blumenthal Antje , Giebel Jürgen , Ummanni Ramesh , Schlüter Rabea , Endlich Karlhans , Endlich Nicole
Published: February 2012

CD151, a member of the tetraspanin family of membrane proteins, is crucially involved in the formation of the glomerular filtration barrier in humans and mice. However, the role of CD151 in podocytes has not been investigated so far. In the present study, we utilized a conditionally immortalized mouse podocyte cell line to characterize CD151 in podocytes and to examine the consequences of manipulating CD151 expression levels. Mouse podocytes endogenously express CD151 as determined by RT-PCR and Western blotting. GFP-CD151 fusion protein localized to the cell membrane, to cell protrusions and cell-cell contacts, colocalizing with actin, β1-integrin, zonula occludens-1, and CD9. The expression of GFP-CD151 in cultured podocytes resulted in a marked increase in the presence of thin arborized protrusions (TAPs). TAPs are distinct from filopodia by increased length, protein composition, branched morphology, and slower dynamics. Furthermore, the migration rate of pEGFP-CD151-transfected podocytes was reduced in a wound assay. Fluorescence recovery after photo bleaching measurements revealed a half-time of 3 s for GFP-CD151 consistent with a high mobility of CD151 in the membrane and cytosol. CD151 knockdown in podocytes reduced β1-integrin expression and podocyte cell area, indicating diminished adherence and/or spreading. Our results indicate that CD151 importantly modulates podocyte function.
Basolateral membrane K+channels in renal epithelial cells
Authors: Hamilton Kirk L. , Devor Daniel C.
Published: February 2012

The major function of epithelial tissues is to maintain proper ion, solute, and water homeostasis. The tubule of the renal nephron has an amazingly simple structure, lined by epithelial cells, yet the segments (i.e., proximal tubule vs. collecting duct) of the nephron have unique transport functions. The functional differences are because epithelial cells are polarized and thus possess different patterns (distributions) of membrane transport proteins in the apical and basolateral membranes of the cell. K+channels play critical roles in normal physiology. Over 90 different genes for K+channels have been identified in the human genome. Epithelial K+channels can be located within either or both the apical and basolateral membranes of the cell. One of the primary functions of basolateral K+channels is to recycle K+across the basolateral membrane for proper function of the Na+-K+-ATPase, among other functions. Mutations of these channels can cause significant disease. The focus of this review is to provide an overview of the basolateral K+channels of the nephron, providing potential physiological functions and pathophysiology of these channels, where appropriate. We have taken a “K+channel gene family” approach in presenting the representative basolateral K+channels of the nephron. The basolateral K+channels of the renal epithelia are represented by members of the KCNK, KCNJ, KCNQ, KCNE, and SLO gene families.
Neurosyphilis versus Herpes Encephalitis in a Patient with Confusion, Memory Loss, and T2-Weighted Mesiotemporal Hyperintensity
Authors: Vedes Elisa , Geraldo Ana Filipa , Rodrigues Rita , Reimão Sofia , Ribeiro Alice , Antunes Francisco
Published: February 2012

Acute confusion and memory loss associated with asymmetrical mesiotemporal hyperintensity on T2-weighted MRI are characteristic of herpes encephalitis. The authors report the case of a patient with these symptoms and MRI presentation who had neurosyphilis. Recently clinical and imaging patterns usually associated with herpes simplex encephalitis have been seen in patients with neurosyphilis. Because syphilis is “The Great Pretender” not only clinically but also in imaging and because its numbers are rising, it must be sought as a differential diagnosis.
Successes and Challenges in an Integrated Tuberculosis/HIV Clinic in a Rural, Resource-Limited Setting: Experiences from Kericho, Kenya
Authors: Shaffer Douglas N. , Obiero Eunice T. , Bett Josphat B. , Kiptoo Ignatius N. , Maswai Jonah K. , Sawe Fredrick K. , Carter E. Jane
Published: February 2012

Objective. To describe TB/HIV clinic outcomes in a rural, Ministry of Health hospital.Design. Retrospective, secondary analyses. Descriptive statistics and logistic regression analyses evaluated baseline characteristics and outcomes.Results. Of 1,911 patients, 89.8% were adults aged 32.0 (±12.6) years with baselineCD4=243.3(±271.0), 18.2% < 50 cells/mm3. Pulmonary (84.8%, (32.2% smear positive)) exceeded extrapulmonary TB (15.2%). Over 5 years, treatment success rose from 40.0% to 74.6%, lost to follow-up dropped from 36.0% to 12.5%, and deaths fell from 20.0% to 5.4%. For patients starting ART after TB treatment, those with CD4 ≥ 50 cells/mm3were twice as likely to achieve treatment success (OR=2.0, 95% CI = 1.3–3.1) compared to those with CD4 < 50 cells/mm3. Patients initiating ART at/after 2 months were twice as likely to achieve treatment success (OR=2.0, 95% CI = 1.3–3.3). Yearly, odds of treatment success improved by 20% (OR=1.2, 95% CI = 1.0–1.5).Conclusions. An integrated TB/HIV clinic with acceptable outcomes is a feasible goal in resource-limited settings.
An Investigation of Self-Interference Reduction Strategy in a Spatially Correlated MIMO Channel
Authors: Nordin Rosdiadee
Published: February 2012

One of the efficient ways to transmit high data rate is by employing a multiple-input multiple-output (MIMO) transmission. One of the MIMO schemes, known as spatial multiplexing (SM), relies on the linear independence data streams from different transmit antennas to exploit the capacity from the fading channels. Consequently, SM suffers from the effect of spatial correlation which is the limiting factor in achieving the capacity benefit that SM can offer. In an attempt to increase the robustness of the SM transmission in a wide range of correlated channels, the use of dynamic subcarrier allocation (DSA) is investigated. The effective signal-to-interference-and-noise ratio (SINR) metric is used as the performance metric to determine the subcarrier quality which can then be utilised in the allocation. Two novel variants of the subcarrier allocation scheme are proposed. It is shown that the DSA-SINR approach improves the BER performance of SM transmission in highly correlated channels environment.
Removal of a Cationic Dye by Adsorption/Photodegradation Using Electrospun PAN/O-MMT Composite Nanofibrous Membranes Coated withTiO2
Authors: Wang Qingqing , Gao Dawei , Gao Chuntao , Wei Qufu , Cai Yibing , Xu Jing , Liu Xiaoya , Xu Yang
Published: February 2012

Polyacrylonitrile (PAN)/organic-modified montmorillonite (O-MMT) composite nanofibrous membranes were firstly prepared by electrospinning and then coated with titanium dioxide (TiO2) using spin coating technique. The structural morphology of the nanofibrous membranes with different mass ratio of O-MMT before and after spin coating was investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM). The chemical property of adsorbed methylene blue (MB) was analyzed by infrared spectroscopy (IR). The adsorption and photodegradation capability of the TiO2-coated PAN/O-MMT composite nanofibrous membranes were evaluated by adsorption rate of MB and K/S values of the membranes before and after UV irradiation. The experimental results indicated that with the increase of O-MMT amount, the diameters of the nanofibers decreased and the adsorption rate of MB was evidently improved. Besides, with the increase of TiO2film layers, the photocatalytic properties were enhanced while the adsorption process was slowed down.
Older Adults Accessing HIV Care and Treatment and Adherence in the IeDEA Central Africa Cohort
Authors: Newman Jamie , Iriondo-Perez Jeniffer , Hemingway-Foday Jennifer , Freeman Anna , Akam Wilfred , Balimba Ashu , Kalenga Lucien , Mbaya Marcel , Mfangam Molu Brigitte , Mukumbi Henri , Niyongabo Théodore , Atibu Joseph , Azinyue Innocent , Kiumbu Modeste
Published: February 2012

Background. Very little is known about older adults accessing HIV care in sub-Saharan Africa.Materials and Methods. Data were obtained from 18,839 HIV-positive adults at 10 treatment programs in Burundi, Cameroon, and the Democratic Republic of Congo. We compared characteristics of those aged 50+ with those aged 18–49 using chi-square tests. Logistic regression was used to determine if age was associated with medication adherence.Results. 15% of adults were 50+ years. Those aged 50+ were more evenly distributed between women and men (56% versus 44%) as compared to those aged 18–49 (71% versus 29%) and were more likely to be hypertensive (8% versus 3%) (P<0.05). Those aged 50+ were more likely to be adherent to their medications than those aged 18–49 (P<0.001). Adults who were not heavy drinkers reported better adherence as compared to those who reported drinking three or more alcoholic beverages per day (P<0.001).Conclusions. Older adults differed from their younger counterparts in terms of medication adherence, sociodemographic, behavioral, and clinical characteristics.
Status Data and Communication Aspects in Dynamically Clustered Network‐on‐Chip Monitoring
Authors: Rantala Ville , Liljeberg Pasi , Plosila Juha
Published: February 2012

Monitoring and diagnostic systems are required in modern Network‐on‐Chip implementations to assure high performance and reliability.
A dynamically clustered NoC monitoring structure for traffic and fault
monitoring is presented. It is a distributed monitoring approach which
does not require any centralized control. Essential issues concerning
status data diffusion, processing, and format are simulated and analyzed. The monitor communication and placement are also discussed.
The results show that the presented monitoring structure can be used
to improve the performance of an NoC. Even a small adjustment of parameters, for example, considering monitoring data format or monitoring placing, can have significant influence to the overall performance
of the NoC. The analysis shows that the monitoring system should be
carefully designed in terms of data diffusion and routing and monitoring algorithms to obtain the potential performance improvement.
Lyapunov‐Type Inequalities for the Quasilinear Difference Systems
Authors: Zhang Qi-Ming , Tang X. H.
Published: February 2012

We establish several Lyapunov‐type inequalities for quasilinear difference systems, which generalize or improve all related existing ones. Applying these results, we also obtain some lower bounds for the first eigencurve in the generalized spectra.
Gender Differences in Depression: Assessing Mediational Effects of Overt Behaviors and Environmental Reward through Daily Diary Monitoring
Authors: Ryba Marlena M. , Hopko Derek R.
Published: February 2012

Gender differences in the prevalence of depression are well documented. To further explore the relation between gender and depression, this study used daily diaries to examine gender differences within thirteen behavioral domains and whether differential frequency of overt behaviors and environmental reward mediated the relationship between gender and depression severity. The sample included 82 undergraduate students [66% females; 84% Caucasian; Mean age = 20.2 years]. Overall, females engaged in a significantly greater breadth of behavioral domains and reported a higher level of environmental reward. Females spent more time in the domains of health/hygiene, spiritual activities, and eating with others. Males spent more time in the domains of physical activity, sexual activity, and hobbies and recreational experiences. Females found social activities, passive/sedentary behaviors, eating with others, and engagement in “other” activities more rewarding. Gender had a significant direct effect on depression severity, with females reporting increased depression. This effect was attenuated by the mediator (total environmental reward) such that to the extent females exhibited increased environmental reward, the gender effect on depression was attenuated. These data support behavioral models of depression, indicate increased reinforcement sensitivity among females, and have clinical relevance in the context of assessment and behavioral activation interventions for depression.
Innovative Oral Treatments of Uterine Leiomyoma
Authors: Sabry Mohamed , Al-Hendy Ayman
Published: February 2012

Uterine fibroids (leiomyoma), the benign tumors of the uterine wall, are very common cause of morbidity in reproductive age women usually in the form of excessive vaginal bleeding, chronic pelvic pain, miscarriage and infertility. These tumors are the leading indication for hysterectomy in the United States. Uterine fibroids are about 4 times higher in blacks compared to whites and constitute a major health disparity challenge. The estimated cost of uterine fibroids is up to $34.4 billion annually. Additionally, women who suffer from this disease and desire to maintain their future fertility have very limited treatment choices. Currently, there is no effective long-term medicinal treatment for uterine fibroids. While surgery has traditionally been the gold standard for the treatment of uterine fibroids, there is growing interest towards orally administered medications for the management of leiomyoma-related symptoms. In this paper, we will discuss these promising innovative oral medical treatments in detail.
Thrombotic Stroke in the Anesthetized Monkey (Macaca mulatta): Characterization by MRI – A Pilot Study
Authors: Gauberti Maxime , Obiang Pauline , Guedin Pierre , Balossier Anne , Gakuba Clément , Diependaele Anne Sophie , Chazalviel Laurent , Vivien Denis , Young Alan R. , Agin Véronique , Orset Cyrille
Published: February 2012

Background: The lack of a relevant stroke model in large nonhuman primates hinders the development of innova- tive diagnostic/therapeutic approaches concerned with this cerebrovascular disease. Our objective was to develop a novel and clinically relevant model of embolic stroke in the anesthetized monkey that incorporates readily available clinical imaging techniques and that would allow the possibility of drug delivery including strategies of reperfusion. Methods: Thrombin was injected into the lumen of the middle cere- bral artery (MCA) in 12 anesthetized (sevoflurane) male rhesus macaques (Macaca mulatta). Sequential MRI studies (including angiography, FLAIR, PWI, DWI, and gadolinium-enhanced T1W imaging) were performed in a 3T clinical MRI. Physiological and biochemical parameters were monitored throughout the investigations. Results: Once standardized, the surgical procedure induced transient occlusion of the middle cerebral artery in all operated animals. All animals studied showed spontaneous reperfusion, which occurred some time between 2 h and 7 days post-ictus. Eighty percent of the studied animals showed diffusion/perfusion mismatch. The ischemic lesions at 24 h spared both superficial and profound territories of the MCA. Some animals presented hemorrhagic transformation at 7 days post-ictus. Conclusion: In this study, we developed a pre-clinically relevant model of embolic stroke in the anesthetized nonhuman primate.
A Comparative Analysis of the Mole Vole Sibling Species Ellobius tancrei and E. talpinus (Cricetidae, Rodentia) through Chromosome Painting and Examination of Synaptonemal Complex Structures in Hybrids
Authors: Bakloushinskaya I.Yu. , Matveevsky S.N. , Romanenko S.A. , Serdukova N.A. , Kolomiets O.L. , Spangenberg V.E. , Lyapunova E.A. , Graphodatsky A.S.
Published: February 2012

A comparative genomic analysis was carried out in the mole vole sibling species Ellobius tancrei and E. talpinus. Performing fluorescent in situ hybridisation (Zoo-FISH) using chromosome paints from the field vole Microtus agrestis showed no differences in the allocation of syntenic groups in the karyotypes of these sibling species. The only difference between their karyotypes was the position of the centromere in one pair of chromosomes, which is assumed to be the result of an inversion. To verify this hypothesis, we analysed chromosome synapsis in prophase I of meiosis. We utilised a synaptonemal complex (SC) surface-spreading technique to visualise the process of chromosome synapsis in the spermatocytes and oocytes of first-generation hybrids and back-crosses of these sibling species. In prophase I of meiosis, immunocytochemical and electron microscopy analyses revealed that all bivalents had been fully adjusted. Even in the case of a submetacentric-acrocentric bivalent with different centromere locations, synapsis of SC lateral elements was fulfilled along the entire length of the chromosomes and the formation of an inversion loop was not observed. We hypothesise that a possible mechanism leading to the change in centromere position is the repositioning and/or generation of a neocentromere. Despite the great similarity in the karyotypes of these sibling species, they exhibited significant genomic diversification, which manifested as hybrid sterility and parous female death.
Evaluating Pathogenicity of Rare Variants From Dilated Cardiomyopathy in the Exome Era
Authors: Norton Nadine , Robertson Peggy D. , Rieder Mark J. , Züchner Stephan , Rampersaud Evadnie , Martin Eden , Li Duanxiang , Nickerson Deborah A. , Hershberger Ray E.
Published: February 2012

Background—

Human exome sequencing is a recently developed tool to aid in the discovery of novel coding variants. Now broadly applied, exome sequencing data sets provide a novel opportunity to evaluate the allele frequencies of previously published pathogenic rare variants.

Methods and Results—

We examined the exome data set from the National Heart, Lung and Blood Institute Exome Sequencing Project and compared this data set with a catalog of 197 previously published rare variants reported as causative of dilated cardiomyopathy (DCM) from familial and sporadic cases. Of these 197, 33 (16.8%) were also present in the Exome Sequencing Project database, raising the question of whether they were uncommon polymorphisms. Supporting functional data has been published for 14 of the 33 (42%), suggesting they are unlikely to be false-positives. The frequencies of these functional variants in the Exome Sequencing Project data set ranged from 0.02 to 1.33% (median 0.04%), which when applied as a cutoff to filter variants in a DCM pedigree identified an additional DCM candidate gene. A greater proportion of sporadic DCM cases had variants that were present in the Exome Sequencing Project data set versus novel variants (ie, not in the Exome Sequencing Project; 44% versus 21%;
P
=0.002), suggesting some of the variants identified as disease causing in sporadic DCM are either false-positives or low penetrance alleles in human populations.

Conclusions—

Rare nonsynonymous variants identified in DCM subjects also present at very low frequencies in public databases are likely relevant for DCM. Allele frequencies >0.04% are of less certain pathogenicity, especially if identified in sporadic cases, although this cutoff should be viewed as preliminary.
How Agents' Turn-Taking Strategies Influence Impressions and Response Behaviors
Authors: ter Maat Mark
Published: February 2012

Different turn-taking strategies of an agent influence the impression that people have of it and the behaviors that they display in response. To study these influences, we carried out several studies. In the first study, subjects listened as bystanders to computer-generated, unintelligible conversations between two speakers. In the second study, subjects talked to an artificial interviewer which was controlled by a human in a Wizard of Oz setting. Questionnaires with semantic differential scales concerning personality, emotion, social skill, and interviewing skills were used in both studies to assess the impressions that the subjects have of the agents that carried out different turn-taking strategies. In addition, in order to assess the effects of these strategies on the subjects' behavior, we measured several aspects in the subjects' speech, such as speaking rate and turn length. We found that different turn-taking strategies indeed influence the user's perception. Starting too early (interrupting the user) is mostly associated with negative and strong personality attributes and is perceived as less agreeable and more assertive. Leaving pauses between turns is perceived as more agreeable, less assertive, and creates the feeling of having more rapport. Finally, we found that turn-taking strategies also influence the subjects' speaking behavior.
Optimal design of stiffened laminate composite cylinder using a hybrid SFL algorithm
Authors: Rao A Rama Mohan , Lakshmi K
Published: February 2012

Shuffled frog-leaping algorithm (SFLA), a memetic meta-heuristic, is proved to be a successful combinatorial optimization algorithm and applied to several engineering problems. However, its potential is not explored in the context of laminate stacking sequence optimization of composite structures. In this article, we propose a hybrid version of SFLA for solving the combinatorial optimization problem associated with lay-up sequence optimization of laminate composite structures. In order to improve the computational performance as well as reliability of the optimal solutions, a customized neighborhood search algorithm and an adaptive search factor are incorporated in to the SFL algorithm to accelerate the convergence characteristics. Apart from this, a crossover operator is suitably incorporated in the proposed hybrid SFLA. Numerical experiments have been carried out by first considering the problem of buckling and failure load optimization of composite plate and later, optimal design of stiffened composite cylindrical shells. Superior convergence characteristics and robustness of the proposed hybrid SFLA is demonstrated by comparing with other popular meta-heuristic algorithms including genetic algorithms.
Reinforcement of starch/polyvinyl alcohol blend using nano‐titanium dioxide
Authors: Sreekumar PA , Al-Harthi Mamdouh A , De SK
Published: February 2012

The article reports the results of the studies on the effect of nano‐titanium dioxide (TiO2) on the morphology, thermal, and mechanical properties of 1:1 starch/polyvinyl alcohol (PVA) composites. Degree of crystallinity of the starch/PVA blends increases with increase in the amount of nano‐TiO2 as determined by differential scanning calorimeter and X‐ray diffraction studies. Results of stress–strain studies indicate an increase in the tensile properties and a decrease in the percentage of elongation and energy at break particularly at higher amount of nano‐TiO2. Increase in peak width in the differential thermogram plot for the maximum decomposition temperature is indicative of increased blend heterogeneity in the presence of nanofillers. The degree of swelling in water decreases with increase in filler loading due to filler–matrix bonding.
Effects of compatibilizers on mechanical and antibacterial properties of injection molded nano-ZnO filled polypropylene
Authors: Altan Mirigul , Yildirim Huseyin
Published: February 2012

Polypropylene (PP)/zinc oxide (ZnO) nanocomposites were prepared by melt compounding. Prior compounding, surface of the particles were modified with different compatilibizers such as silane and stearic acid. Modification was also done by coating the particles with maleic anhydride grafted styrene-ethylene-butylene-styrene (SEBS-g-MA) block copolymer dissolved in toluene. Specimens of tensile test, impact test, and antibacterial efficiency test were obtained by injection molding. The results showed that stearic acid and silane containing composites gave structures with fine distributed particles while the presence of SEBS-g-MA induced agglomerates. The presence of stearic acid increased tensile strength and impact strength but reduced elastic modulus. Silane was more effective in increasing elastic modulus. Despite the elastomeric nature of SEBS-g-MA, it did not rise impact strength due to its limited amount of usage in coating of the particles. Antibacterial properties of the composites reduced with the increment of ZnO loading because of the weak UV absorption and insufficient photocatalytic activity of the particles. On contrary, at low ZnO content, satisfactorily high antibacterial effect was observed especially in well dispersed structures including stearic acid and silane.
Why IEP Teams Assign Low Performers With Mild Disabilities to the Alternate Assessment Based on Alternate Achievement Standards
Authors: Cho Hyun-Jeong , Kingston Neal
Published: February 2012

The purpose of this case study was to determine teachers’ rationales for assigning students with mild disabilities to alternate assessment based on alternate achievement standards (AA-AAS). In interviews, special educators stated that their primary considerations in making the assignments were low academic performance, student use of extended standard modifications, and the inflexible 1% cap. None of the teachers provided their students with grade-level content or appropriate modifications. Some students were competent in grade-level reading, but were assigned to the 2010 AA-AAS because read-aloud accommodation is not permitted in the reading passages of the general assessment. Findings raised concerns about the susceptibility of eligibility guidelines to lead to subjective decisions. Future research, implications of these findings, and limitations of the study are discussed.
Guilty Feelings, Targeted Actions
Authors: Cryder Cynthia E. , Springer Stephen , Morewedge Carey K.
Published: February 2012

Early investigations of guilt cast it as an emotion that prompts broad reparative behaviors that help guilty individuals feel better about themselves or about their transgressions. The current investigation found support for a more recent representation of guilt as an emotion designed to identify and correct specific social offenses. Across five experiments, guilt influenced behavior in a targeted and strategic way. Guilt prompted participants to share resources more generously with others, but only did so when those others were persons whom the participant had wronged and only when those wronged individuals could notice the gesture. Rather than trigger broad reparative behaviors that remediate one’s general reputation or self-perception, guilt triggers targeted behaviors intended to remediate specific social transgressions.
Can minimized cardiopulmonary bypass systems be safer?
Authors: Ganushchak YM , Ševerdija EE , Simons AP , van Garsse L , Weerwind PW
Published: February 2012

Although a growing body of evidence indicates superiority of minimized cardiopulmonary bypass (mCPB) systems over conventional CPB systems, limited venous return can result in severe fluctuations of venous line pressure which can result in gaseous emboli. In this study, we investigated the influence of sub-atmospheric pressures and volume buffer capacity added to the venous line on the generation of gaseous emboli in the mCPB circuit.

Two different mCPB systems (MEC - Maquet, n=7 and ECC.O - Sorin, n=8) and a conventional closed cardiopulmonary bypass (cCPB) system (n=12) were clinically evaluated. In the search for a way to increase volume buffer capacity of mCPB systems, we additionally evaluated the ‘Better Bladder’ (BB) in a mock circulation by simulating, repeatedly, decreased venous return while measuring pressure and gaseous embolic activity.

Arterial gaseous emboli activity during clinical perfusion with a cCPB system was the lowest in comparison to the mCPB systems (312±465 versus 311±421 with MEC and 1,966±1,782 with ECC.O, counts per 10 minute time interval, respectively; p=0.03). The average volume per bubble in the arterial line was the highest in cases with cCPB (12.5±8.3 nL versus 8.0±4.2 nL with MEC and 4.6±4.8 nL with ECC.O; p=0.04 for both). Significant cross-correlation was obtained at various time offsets from 0 to +35 s between sub-atmospheric pressure in the venous line and gaseous emboli activity in both the venous and arterial lines. The in vitro data showed that incorporation of the BB dampens fluctuations of venous line pressure by approximately 30% and decreases gaseous emboli by up to 85%.

In conclusion, fluctuations of sub-atmospheric venous line pressure during kinetic-assisted drainage are related to gaseous emboli. Volume buffer capacity added to the venous line can effectively dampen pressure fluctuations resulting from abrupt changes in venous return and, therefore, can help to increase the safety of minimized cardiopulmonary bypass by reducing gaseous microemboli formation resulting from degassing.
Work and settlement locations of immigrants: how are they connected? The case of the Oporto Metropolitan Area
Authors: Rebelo Emília Malcata
Published: February 2012

The research reported in this article aims to explain the residential and work location patterns of different groups of immigrants living in a particular metropolitan area, based on the following underlying causes: socio-spatial differentiation resulting from the characteristics of urban economies, the performance of housing and labour markets, spatial and socioeconomic/professional mobility, and immigrants’ own characteristics. Within this scope, census data are analysed and cartographically displayed, and classification trees are applied in order to understand the relationship between the residential and work locations of the different population groups and their respective demographic, economic and professional characteristics, on the one hand, and land occupation densities, on the other. Although this methodology is applied to the Oporto Metropolitan Area (Portugal), it can easily be used in other urban and metropolitan areas.
Scientific Sensationalism in American and British Press Coverage of Therapeutic Cloning
Authors: Jensen Eric
Published: February 2012

This study examines the production and content of press coverage of therapeutic cloning in the United States and Britain. The sample includes 5,128 news articles, as well as qualitative interviews with journalists who covered this science story. This article identifies variations in the valence, relative distribution, and quality of the hype found across the US, UK tabloid, and elite UK press samples. A dialectic of hope and fear is identified in the sampled press content and explained by the journalist interviews. Moreover, scientific hype emerges from the shared economic imperatives and concomitant news values defining American and British journalism.
Emissions from an extreme-compression, free-piston engine with diesel-style combustion
Authors: Svrcek Matthew N , Edwards Christopher F
Published: February 2012

As part of an ongoing effort to demonstrate operation of a free-piston internal combustion engine at extremely high compression ratios, this paper reports the measurement of emissions from diesel-style combustion of a single-cycle, free-piston research device capable of achieving compression ratios up to 100:1. The ability to measure gaseous and particulate emissions was added to the existing extreme-compression device. These systems and their characterization are described. Concentrations as well as specific emissions are reported for carbon monoxide, total oxides of nitrogen, unburned hydrocarbons, carbon dioxide, oxygen, and soot. A first set of emissions data is reported of a pure-component fuel (isooctane) at a moderate compression ratio (∼35:1) over a range of equivalence ratios, in order to characterize the emission measurement system as well as diesel-style combustion in the free-piston device. NOx emissions were essentially constant over the range of equivalence ratios. CO, HC, and soot emissions were low at the lowest equivalence ratio, and increased dramatically for equivalence ratios greater than ∼0.6. A second set of results is reported consisting of diesel combustion at ∼0.5 equivalence ratio, for compression ratios up to 100:1. CO, HC, and soot emissions remained low over the range of compression ratios, resulting in high combustion efficiency, even at 100:1 compression ratio. NOx emissions increased by a factor of 5 from 35:1 to 100:1 compression ratio, likely due to the far higher combustion temperatures.
Pressure Cooker Politics: Partisanship and Symbolism in State Certification of Federal Stimulus Funds
Authors: Miller Edward Alan , Blanding David
Published: February 2012

To access funds from the American Recovery and Reinvestment Act (ARRA) of 2009, state governors had to formally certify their intent to do so within 45 days of the law's enactment. All governors eventually certified, but with considerable variation in celerity. This study employs event history techniques to model the probability of certifying the ARRA. It argues that the statute's design combined with economic distress within the states rendered manifest rejection of the law politically infeasible but, for state officials with certain partisan commitments, left open the possibility of symbolic resistance or support in the form of time to certification. State leaders relied on party identification to guide their decisions, resulting in markedly different propensities toward certification for Republican and Democratic governors. Results lend credence to this thesis: States with Republican governors were nearly 60% less likely to certify the ARRA on a given day than states with Democratic governors. This finding suggests that when economic constraints and policy design foreclose actual rejection of a federal law, state policymakers may rely on party labels to register their approbation or disapprobation through other means, including the amount of time taken to accept federal funding.
The embryonic origins of erythropoiesis in mammals
Authors: Baron Margaret H. , Isern Joan , Fraser Stuart T.
Published: February 2012

Erythroid (red blood) cells are the first cell type to be specified in the postimplantation mammalian embryo and serve highly specialized, essential functions throughout gestation and postnatal life. The existence of 2 developmentally and morphologically distinct erythroid lineages, primitive (embryonic) and definitive (adult), was described for the mammalian embryo more than a century ago. Cells of the primitive erythroid lineage support the transition from rapidly growing embryo to fetus, whereas definitive erythrocytes function during the transition from fetal life to birth and continue to be crucial for a variety of normal physiologic processes. Over the past few years, it has become apparent that the ontogeny and maturation of these lineages are more complex than previously appreciated. In this review, we highlight some common and distinguishing features of the red blood cell lineages and summarize advances in our understanding of how these cells develop and differentiate throughout mammalian ontogeny.
Knowledge, Communication, and Organizational Capabilities
Authors: Garicano Luis , Wu Yanhui
Published: February 2012

This paper attempts to bridge a gap between organizational economics and strategy research through an analysis of knowledge and communication in organizations. We argue that organizations emerge to achieve the intensive use of the knowledge that is acquired to perform specific tasks and to integrate dispersed knowledge that is embodied in different human minds. The attributes of the tasks undertaken determine the optimal acquisition and distribution of knowledge. Depending on the codifiability of knowledge, different communication modes arise as a coordination mechanism to deepen the division of labor, leverage managerial talent, and exploit the increasing returns to knowledge. Organizational processes can be adapted through codes and culture to facilitate coordination; organizational structure can be designed to complement the limitations of human ability. We stress that organizational process and structure construct the core of organizational capital, which generates rent and sustains organizational growth. From the analysis, we draw implications for the strategic management of knowledge and human resources in organizations.
Constitutional Practices and British Crown Dependencies: The Gap between Theory and Practice
Authors: Morris Philip
Published: February 2012

Orthodox constitutional principle as endorsed in the Kilbrandon Report (1973) portrays the British Crown Dependencies of Jersey, Guernsey and the Isle of Man as largely self-governing jurisdictions with independent legislative, executive and judicial functions. Despite being constitutional backwaters, they have found themselves in conflictual relationships with both the European Union and successive UK New Labour Administrations. The underlying cause of this marked decline in the constitutional interface has been their rapid development as offshore jurisdictions, which has placed strains on constitutional practices in the spheres of policy-making, scrutiny of draft insular primary legislation and representation in international fora. This paper is a critical evaluation of UK/Crown Dependencies constitutional and administrative relationships, taking as its focal point the recent UK House of Commons Justice Committee Report on the operational functioning of the interface. It finds there is a significant discrepancy between ‘official’ and ‘operational reality’ versions of these relationships.
HTreeQA: Using Semi-Perfect Phylogeny Trees in Quantitative Trait Loci Study on Genotype Data
Authors: Zhang Zhaojun , Zhang Xiang , Wang Wei
Published: February 2012

With the advances in high-throughput genotyping technology, the study of quantitative trait loci (QTL) has emerged as a promising tool to understand the genetic basis of complex traits. Methodology development for the study of QTL recently has attracted significant research attention. Local phylogeny-based methods have been demonstrated to be powerful tools for uncovering significant associations between phenotypes and single-nucleotide polymorphism markers. However, most existing methods are designed for homozygous genotypes, and a separate haplotype reconstruction step is often needed to resolve heterozygous genotypes. This approach has limited power to detect nonadditive genetic effects and imposes an extensive computational burden. In this article, we propose a new method, HTreeQA, that uses a tristate semi-perfect phylogeny tree to approximate the perfect phylogeny used in existing methods. The semi-perfect phylogeny trees are used as high-level markers for association study. HTreeQA uses the genotype data as direct input without phasing. HTreeQA can handle complex local population structures. It is suitable for QTL mapping on any mouse populations, including the incipient Collaborative Cross lines. Applied HTreeQA, significant QTLs are found for two phenotypes of the PreCC lines, white head spot and running distance at day 5/6. These findings are consistent with known genes and QTL discovered in independent studies. Simulation studies under three different genetic models show that HTreeQA can detect a wider range of genetic effects and is more efficient than existing phylogeny-based approaches. We also provide rigorous theoretical analysis to show that HTreeQA has a lower error rate than alternative methods.
Accelerating the Inbreeding of Multi-Parental Recombinant Inbred Lines Generated By Sibling Matings
Authors: Welsh Catherine E , McMillan Leonard
Published: February 2012

Inbred model organisms are powerful tools for genetic studies because they provide reproducible genomes for use in mapping and genetic manipulation. Generating inbred lines via sibling matings, however, is a costly undertaking that requires many successive generations of breeding, during which time many lines fail. We evaluated several approaches for accelerating inbreeding, including the systematic use of back-crosses and marker-assisted breeder selection, which we contrasted with randomized sib-matings. Using simulations, we explored several alternative breeder-selection methods and monitored the gain and loss of genetic diversity, measured by the number of recombination-induced founder intervals, as a function of generation. For each approach we simulated 100,000 independent lines to estimate distributions of generations to achieve full-fixation as well as to achieve a mean heterozygosity level equal to 20 generations of randomized sib-mating. Our analyses suggest that the number of generations to fully inbred status can be substantially reduced with minimal impact on genetic diversity through combinations of parental backcrossing and marker-assisted inbreeding. Although simulations do not consider all confounding factors underlying the inbreeding process, such as a loss of fecundity, our models suggest many viable alternatives for accelerating the inbreeding process.
Haplotype Probabilities in Advanced Intercross Populations
Authors: Broman Karl W
Published: February 2012

Advanced intercross populations, in which multiple inbred strains are mated at random for many generations, have the advantage of greater precision of genetic mapping because of the accumulation of recombination events across the multiple generations. Related designs include heterogeneous stock and the diversity outcross population. In this article, I derive the two-locus haplotype probabilities on the autosome and X chromosome with these designs. These haplotype probabilities provide the key quantities for developing hidden Markov models for the treatment of missing genotype information. I further derive the map expansion in these populations, which is the frequency of recombination breakpoints on a random chromosome.
Experiments Probing Fundamental Mechanisms of Energetic Material Initiation and Ignition
Authors: Berg Christopher M. , Brown Kathryn E. , Conner Rusty W. , Fu Yuanxi , Fujiwara Hiroki , Lagutchev Alexei , Shaw William L. , Zheng Xianxu , Dlott Dana D.
Published: February 2012

Two fundamental processes associated with shock compression of energetic materials (EM) are initiation and ignition. Initiation occurs just behind a shock front and ignition occurs anywhere from a few nanoseconds to hundreds of nanoseconds later. Experiments are described that probe the fundamental mechanisms of these processes on relevant length and time scales: picosecond vibrational spectroscopy of nanometer thick layers of energetic materials (EM) with laser-driven shock waves, and nanosecond emission spectroscopy of micrometer thick layers of EM using laser-driven flyer plates.
An Extensive Theoretical Study of the Phonon Conductivity and Thermoelectric Properties of SiGe Alloys
Authors: Thomas Iowerth O. , Srivastava Gyaneshwar P.
Published: February 2012

We present an extensive theoretical study of the phonon conductivity and thermoelectric properties of SiGe alloys. Phonon dispersion relations and group velocities – required for conductivity calculations – are obtained by employing the density-functional-perturbation scheme. The cubic anharmonic potential has been expressed by treating the Gr¨uneisen constant as a semi-adjustable mode-averaged parameter. Calculations are also performed, within the nearly-free-electron approximation, for the temperature variation of the Fermi energy, Seebeck coefficient, electrical conductivity, and electronic polar and bipolar contributions to thermal conductivity. Results are compared with experimental measurements for n-doped pressure-sintered Si0.754Ge0.246 alloy. Using these results, we compare our results for the thermoelectric figure-of-merit with previously reported results based on an empirical approach for phonon conductivity.