bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular and Morphological Configuration for 2-Arachidonoylglycerol-Mediated Retrograde Signaling at Mossy Cell–Granule Cell Synapses in the Dentate Gyrus
Authors: Uchigashima Motokazu , Yamazaki Maya , Yamasaki Miwako , Tanimura Asami , Sakimura Kenji , Kano Masanobu , Watanabe Masahiko
Published: May 2011

2-Arachidonoylglycerol (2-AG) is the endocannabinoid that mediates retrograde suppression of neurotransmission in the brain. In the present study, we investigated the 2-AG signaling system at mossy cell (MC)–granule cell (GC) synapses in the mouse dentate gyrus, an excitatory recurrent circuit where endocannabinoids are thought to suppress epileptogenesis. First, we showed by electrophysiology that 2-AG produced by diacylglycerol lipase α (DGLα) mediated both depolarization-induced suppression of excitation and its enhancement by group I metabotropic glutamate receptor activation at MC–GC synapses, as they were abolished in DGLα-knock-out mice. Immunohistochemistry revealed that DGLα was enriched in the neck portion of GC spines forming synapses with MC terminals, whereas cannabinoid CB1receptors accumulated in the terminal portion of MC axons. On the other hand, the major 2-AG-degrading enzyme, monoacylglycerol lipase (MGL), was absent at MC–GC synapses but was expressed in astrocytes and some inhibitory terminals. Serial electron microscopy clarified that a given GC spine was innervated by a single MC terminal and also contacted nonsynaptically by other MC terminals making synapses with other GC spines in the neighborhood. MGL-expressing elements, however, poorly covered GC spines, amounting to 17% of the total surface of GC spines by astrocytes and 4% by inhibitory terminals. Our findings provide a basis for 2-AG-mediated retrograde suppression of MC–GC synaptic transmission and also suggest that 2-AG released from activated GC spines is readily accessible to nearby MC–GC synapses by escaping from enzymatic degradation. This molecular–anatomical configuration will contribute to adjust network activity in the dentate gyrus after enhanced excitation.
Reinforcement-Related Regulation of AMPA Glutamate Receptor Subunits in the Ventral Tegmental Area Enhances Motivation for Cocaine
Authors: Choi Kwang Ho , Edwards Scott , Graham Danielle L. , Larson Erin B. , Whisler Kimberly N. , Simmons Diana , Friedman Allyson K. , Walsh Jessica J. , Rahman Zia , Monteggia Lisa M. , Eisch Amelia J. , Neve Rachael L. , Nestler Eric J. , Han Ming-Hu , Self David W.
Published: May 2011

Chronic cocaine use produces numerous biological changes in brain, but relatively few are functionally associated with cocaine reinforcement. Here we show that daily intravenous cocaine self-administration, but not passive cocaine administration, induces dynamic upregulation of the AMPA glutamate receptor subunits GluR1 and GluR2 in the ventral tegmental area (VTA) of rats. Increases in GluR1 protein and GluR1S845phosphorylation are associated with increased GluR1 mRNA in self-administering animals, whereas increased GluR2 protein levels occurred despite substantial decreases in GluR2 mRNA. We investigated the functional significance of GluR1 upregulation in the VTA on cocaine self-administration using localized viral-mediated gene transfer. Overexpression of GluR1WTin rat VTA primarily infected dopamine neurons (75%) and increased AMPA receptor-mediated membrane rectification in these neurons with AMPA application. Similar GluR1WToverexpression potentiated locomotor responses to intra-VTA AMPA, but not NMDA, infusions. In cocaine self-administering animals, overexpression of GluR1WTin the VTA markedly increased the motivation for cocaine injections on a progressive ratio schedule of cocaine reinforcement. In contrast, overexpression of protein kinase A-resistant GluR1S845Ain the VTA reduced peak rates of cocaine self-administration on a fixed ratio reinforcement schedule. Neither viral vector altered sucrose self-administration, and overexpression of GluR1WTor GluR1S845Ain the adjacent substantia nigra had no effect on cocaine self-administration. Together, these results suggest that dynamic regulation of AMPA receptors in the VTA during cocaine self-administration contributes to cocaine addiction by acting to facilitate subsequent cocaine use.
Emotion-Associated Tones Attract Enhanced Attention at Early Auditory Processing: Magnetoencephalographic Correlates
Authors: Bröckelmann Ann-Kathrin , Steinberg Christian , Elling Ludger , Zwanzger Peter , Pantev Christo , Junghöfer Markus
Published: May 2011

Emotionally significant objects and events in our environment attract attention based on their motivational relevance for survival. Such kind of emotional attention is thought to lead to affect-specific amplified processing that closely resembles effects of directed attention. Although there has been extensive research on prioritized processing of visual emotional stimuli, the spatio-temporal dynamics of motivated attention mechanisms in auditory processing are less clearly understood. We investigated modulatory effects of emotional attention at early auditory processing stages using time-sensitive whole-head magnetoencephalography. A novel associative learning procedure involving multiple conditioned stimuli (CSs) per affective category was introduced to specifically test whether affect-specific modulation can proceed in a rapid and highly differentiating fashion in humans. Auditory evoked fields (AEFs) were recorded in response to 42 different ultrashort, click-like sounds before and after affective conditioning with pleasant, unpleasant, or neutral auditory scenes. As hypothesized, emotional attention affected neural click tone processing at time intervals of the P20-50m (20–50 ms) and the N1m (100–130 ms), two early AEF components sensitive to directed selective attention (Woldorff et al., 1993). Distributed source localization revealed amplified processing of tones associated with aversive or pleasant compared with neutral auditory scenes at auditory sensory, frontal and parietal cortex regions. Behavioral tests did not indicate any awareness for the contingent CS–UCS (unconditioned stimulus) relationships in the participants, suggesting affective associative learning in absence of contingency awareness. Our findings imply early and highly differentiating affect-specific modulation of auditory stimulus processing supported by neural mechanisms and circuitry comparable with those reported for directed auditory attention.
Similar Odorants Elicit Different Behavioral and Physiological Responses, Some Supersustained
Authors: Montague Shelby A. , Mathew Dennis , Carlson John R.
Published: May 2011

An intriguing question in the field of olfaction is how animals distinguish among structurally similar odorants. We systematically analyzed olfactory responses elicited by a panel of 25 pyrazines. We found that structurally similar pyrazines elicit a wide range of behavioral responses fromDrosophilalarvae. Each pyrazine was tested against all functional receptors of the larval Odor receptor (Or) repertoire, yielding 525 odorant–receptor combinations. Different pyrazines vary markedly in the responses they elicit from the Or repertoire, with most strong responses deriving from two receptors, Or33b and Or59a. Surprisingly, 2-ethylpyrazine and 2-methylpyrazine, which elicit strikingly similar physiological responses across the receptor repertoire, elicit dramatically different behavioral responses. A small fraction of odorant-receptor combinations elicit remarkably long responses. These responses, which we term “supersustained” responses, are receptor specific and odorant specific, and can last for minutes. Such supersustained responses may prevent olfactory neurons from reporting contemporaneous information about the local odor environment. Odors that elicit such responses could provide a novel means of controlling insect pests and vectors of human disease by impairing the location of human hosts, food sources, and mates.
Action Dominates Valence in Anticipatory Representations in the Human Striatum and Dopaminergic Midbrain
Authors: Guitart-Masip Marc , Fuentemilla Lluis , Bach Dominik R. , Huys Quentin J. M. , Dayan Peter , Dolan Raymond J. , Duzel Emrah
Published: May 2011

The acquisition of reward and the avoidance of punishment could logically be contingent on either emitting or withholding particular actions. However, the separate pathways in the striatum for go and no-go appear to violate this independence, instead coupling affect and effect. Respect for this interdependence has biased many studies of reward and punishment, so potential action–outcome valence interactions during anticipatory phases remain unexplored. In a functional magnetic resonance imaging study with healthy human volunteers, we manipulated subjects' requirement to emit or withhold an action independent from subsequent receipt of reward or avoidance of punishment. During anticipation, in the striatum and a lateral region within the substantia nigra/ventral tegmental area (SN/VTA), action representations dominated over valence representations. Moreover, we did not observe any representation associated with different state values through accumulation of outcomes, challenging a conventional and dominant association between these areas and state value representations. In contrast, a more medial sector of the SN/VTA responded preferentially to valence, with opposite signs depending on whether action was anticipated to be emitted or withheld. This dominant influence of action requires an enriched notion of opponency between reward and punishment.
Mechanisms of oocyte development in European sea bass (Dicentrarchus labrax L.): investigations via application of unilateral ovariectomy
Authors: García-López Ángel , Sánchez-Amaya María I , Tyler Charles R , Prat Francisco
Published: May 2011

Unilateral ovariectomy (ULO) was performed in European sea bass (Dicentrarchus labrax L.) during late pre-vitellogenesis/early vitellogenesis. Plasma steroid levels and the expression of a suite of potential oogenesis-relevant genes in the ovary, brain, and pituitary were evaluated with the aim of understanding their involvement in the compensatory oocyte development occurring within the remaining ovarian lobe. After 69 days of surgery the remaining ovarian lobe in ULO fish was gravimetrically equivalent to an intact-paired ovary of sham operated, control fish. This compensatory ovarian growth was based on an increased number of early perinucleolar oocytes and mid-late stage vitellogenic follicles without an apparent recruitment of primary oocytes into the secondary growth phase. Plasma steroid levels were similar in ULO and control females at all time points analyzed, suggesting an increased steroid production of the remaining ovarian lobe in hemi-castrated females. Results of the gene expression survey conducted indicate that the signaling pathways mediated by Fsh and Gnrh1 constitute the central axes orchestrating the observed ovarian compensatory growth. In addition, steroid receptors, Star protein, Igfs, and members of the transforming growth factor beta superfamily including anti-Mullerian hormone and bone morphogenetic protein 4 were identified as potentially relevant players within this process, although their specific actions and interactions remain to be established. Our results demonstrate that ULO provides an excellent in vivo model for elucidating the interconnected endocrine and molecular mechanisms controlling oocyte development in European sea bass.
Pre-treatment of sperm reduces success of ICSI in the pig
Authors: Nakai Michiko , Ito Junya , Sato Ken-ichi , Noguchi Junko , Kaneko Hiroyuki , Kashiwazaki Naomi , Kikuchi Kazuhiro
Published: May 2011

In pigs, although ICSI is a feasible fertilization technique, its efficiency is low. In general, injected pig sperm are insufficient to induce oocyte activation and embryonic development. Pretreatments for disrupting sperm membranes have been applied to improve the fertility of ICSI oocytes; however, we hypothesize that such pretreatment(s) may reduce the ability of the sperm to induce oocyte activation. We first evaluated the effects of sperm pretreatments (sonication (SO) to isolate the sperm heads from the tails, Triton X-100 (TX), and three cycles of repeated freezing/thawing (3×-FT) for disrupting sperm membranes) on the rate of pronucleus (PN) formation after ICSI. We found that oocytes injected with control (whole) sperm had higher rates of PN formation than those obtained after subjecting the sperm to SO, TX, and 3×-FT. The amounts of phospholipase Cζ (PLCζ), which is thought to be the oocyte-activating factor in mammalian sperm, in sperm treated by each method was significantly lower than that in whole untreated sperm. Furthermore, using immunofluorescence, it was found that in pig sperm, PLCζ was localized to both the post-acrosomal region and the tail area. Thus we demonstrated for the first time that sperm pretreatment leads to a reduction of oocyte-activating capacity. Our data also show that in addition to its expected localization to the sperm head, PLCζ is also localized in the tail of pig sperm, thus raising the possibility that injection of whole sperm may be required to attain successful activation in pigs.
Practical considerations and questions in the treatment of chronic lymphocytic leukemia
Authors: Telek Béla , Rejtő László , Batár Péter , Reményi Gyula , Szász Róbert , Kiss Attila , Udvardy Miklós
Published: May 2011

Understanding the pathogenesis and refine the treatment of chronic lymphocytic leukemia have been tremendously improved in the past decade. Treatment outcome and estimated prognosis have become more accurate due to the advanced molecular biological techniques and the classical prognostic markers. Incorporation of fludarabine and rituximab into the standard protocols fundamentally improved treatment outcome in chronic lymphocytic leukemia. Chemoimmunotherapy has improved not only the remission rates but had a significant impact on overall survival, as well. Eliminating residual leukemia and achieving complete hematological remissions at such high rates establish potential background for cure. Still, a great deal of dispute has been emerged regarding everyday clinical practice. Authors present their institutional experiences and review the literature. Orv. Hetil., 2011, 152, 958–963.
Hydration reactions of the system C3A-CaSO4.2H2O (1 : 1 mole ratio) at 30 and 50°C. Part II: Effect of naphthalene formaldehyde sulfonate
Authors: A Essam , Hegazy Wafaa S. , Ahmed Doaa Abd El monem
Published: May 2011

Hydration characteristics of tricalcium aluminate and gypsum mixture with a mole ratio of 1 : 1 in the presence and absence of sodium salt of naphthalene formaldehyde sulfonic acid polycondensate (NFS) at 30 and 50°C were investigated. Different ratios of NFS were used, namely 0, 1, and 3% by weight. The water-to-solid ratio used was 10. Hydration was carried out for various time intervals from 0·5 h and up to 90 days. The results of combined water content, X-ray diffraction and scanning electron microscopy indicate that NFS retards the formation of ettringite and accelerates its transformation to monosulfate at early hydration ages. The extent of transformation is inversely proportional to the ratio of NFS.
Portland pozzolana cement in India with respect to total chromium and hexavalent chromium content
Authors: Vaity Rina S. , Verma Jayant K.
Published: May 2011

The objective of the present research work was to evaluate total chromium and hexavalent chromium [Cr(VI)] in Portland cement in India especially for fly ash-based Portland pozzolana cement. Various additives have been used for the effective reduction of Cr(VI) in wet cement. All cement samples from various regions were collected to determine the total chromium and Cr(VI). Total chromium was analysed on an inductively coupled plasma optical emission spectrometer, whereas Cr(VI) was analysed using the 1,5-diphenyl carbazide method on a UV-visible spectrophotometer. A group of additives was studied to evaluate their effectiveness for Cr(VI) reduction in the cement samples. The additives were incorporated and mixed in cement for experimentation purposes using a disc mill. The difference in Cr(VI) before and after addition for the particular additive was checked using a spectrophotometer by the 1,5-diphenyl carbazide method at 540 nm. The reduction in Cr(VI) due to use of additives was reconfirmed at two wavelengths, 372 and 274 nm, respectively. Sodium borohydride (NaBH4) and stannous sulfate (SnSO4) were found to be the best additives for reducing Cr(VI) in cement among the additives under investigation in this study.
THE THAMES-LEE WATER MAIN.
Authors: CUTHBERT E W , WOOD F
Published: May 2011

The Paper describes the design and construction of a concrete-lined tunnel, together with the necessary pumping plant, which will be used to transfer water from the River Thames to the Lee Valley storage reservoirs of the Metropolitan Water Board. This tunnel is believed to be the longest in Europe and the longest tunnel in soft strata in the world. This tunnel main has been made necessary because insufficient water is available from the River Lee to meet the needs of East London.

The main was designed as a gravity main. Electrically driven boreholetype pumps located in a shaft at the Lee Valley end of the main deliver the water into the reservoirs.

Whilst the shafts were lined with bolted reinforced concrete and cast iron segmental rings of conventional design. the tunnel was lined with unreinforced tapered concrete blocks which were expanded against the ground under the pressure of the rams of the shield used in driving the tunnel, thus avoiding the use of grout or bolts.

Other features dealt with in the Paper include a new form of rotary shield which sustained a rate of driving of 360 ft per week for long periods, lining the tunnel with cement mortar by mechanical means, the design and construction of a siphon intake, and a Venturi meter in tunnel.
Utilizing Formative Assessments to Guide Student Learning in an Interactive Physics Learning Environment
Authors: Lee Young-Jin
Published: May 2011

In the last decades, many education researchers have been trying to use computerized learning environments to enhance student learning. Without proper instructional supports and guidance, however, students often failed to acquire knowledge from computer-based learning activities. The objective of this study was to demonstrate how research-based formative assessment questions could be used as a framework for providing appropriate scaffolding in a computerized physics learning environment. To achieve this goal, an interactive physics tutor named APT (Assessment-based interactive Physics Tutor) was developed using Java and Open Source Physics. Examples of learning activities in APT were presented in order to highlight how formative assessment questions could be utilized to provide various instructional supports and guidance (e.g., prompting questions, descriptive statements, and computer simulations) tailored to the student's misconceptions. Educational implications of using APT were also discussed.
Can Distance Learning Be Used to Teach Automotive Management Skills?
Authors: Noto Teresa L.
Published: May 2011

Today's automotive college students will shape the future of the automobile industry. The success of college-level automotive programs has long been dependent on the students' ability to participate in hands-on classroom based interactions. In this article, distance learning and how it can be used to teach automotive management skills, as well as why it is important for students to learn from places such as home or work, are discussed. Distance learning, an increasingly popular trend of content delivery, requires teachers to take on multiple roles. In addition to responding to individual students, facilitators moderate discussions and manage the flow of content through activities and assessments. To help understand how distance learning might be used to teach automotive management skills, and to provide an opportunity for automotive students to learn these vital skills in non-traditional settings, a sample distance education course for the automotive department at Farmingdale State College has been developed. The project has taken into account many areas of related research in cognitive learning patterns of college students with regard to distance education and traditional automotive skill building courses.
Instructors as Architects—Designing Learning Spaces for Discussion-Based Online Courses
Authors: Wang Yu-Mei , Chen Derthanq Victor
Published: May 2011

Online learning space design becomes a significant issue with the proliferation of online learning in higher education. Never before has the instructor been given such a privilege in building and molding the learning space to fulfill his/her instructional aspirations. However, enormous challenges are present to the instructor in taking advantage of this newly gained freedom. Most instructors have limited awareness of their new roles as learning space designers. Although learning space plays an important role in mediating student learning, it is a topic that is least understood. Therefore, it is important for online course instructors to start a dialogue in learning space design. This article reports our experiences of designing learning spaces in a discussion-based online course to facilitate and organize student learning.
Teaching Using Computer Games
Authors: Miller Lee Dee , Shell Duane , Khandaker Nobel , Soh Leen-Kiat
Published: May 2011

Computer games have long been used for teaching. Current reviews lack categorization and analysis using learning models which would help instructors assess the usefulness of computer games. We divide the use of games into two classes: game playing and game development. We discuss the Input-Process-Outcome (IPO) model for the learning process when playing computer games. We also propose a new Input-Process-Outcome model for explaining the learning through game development (IPO-GD). Using both learning models, we review recent uses of computer games. Based on our review, we recommend: 1) using the IPO model when selecting games; 2) using the IPO-GD model for game development; and 3) creating support repositories for related curriculum material.
Fish Consumption and Risk of Stroke
Authors: Panagiotakos Demosthenes B , Kastorini Christina-Maria
Published: May 2011

Evaluation of: Larsson SC, Virtamo J, Wolk A: Fish consumption and risk of stroke in Swedish women. Am. J. Clin. Nutr. 93(3), 487–493 (2010). A population-based prospective study of 34,670 women in the Swedish Mammography Cohort was conducted, aiming to examine the associations between fish consumption and stroke incidence in women. After a mean follow-up of 10.4 years, 1680 cases of stroke were recorded. Fish consumption was inversely associated with risk of total stroke, but not cerebral infarction or hemorrhagic stroke. Compared with women in the lowest quintile of fish consumption, those in the highest quintile had a 16% lower risk of stroke. In addition, consumption of lean fish, but not of other fish types, was inversely associated with risk of stroke.
Pregnancy and Stroke Risk in Women
Authors: Tate Jessica , Bushnell Cheryl
Published: May 2011

Stroke, the sudden onset of brain dysfunction from a vascular cause, is one of the most common causes of long-term disability. Although rare during childbearing years, stroke is even more devastating when it occurs in a young woman trying to start a family. Pregnancy and the postpartum period are associated with an increased risk of ischemic stroke and intracerebral hemorrhage, although the incidence estimates have varied. There are several causes of stroke that are in fact unique to pregnancy and the postpartum period, such as preeclampsia and eclampsia, amniotic fluid embolus, postpartum angiopathy and postpartum cardiomyopathy. Data regarding these individual entities are scant. Most concerning is the lack of data regarding both prevention and acute management of pregnancy-related stroke. The purpose of this article is to summarize existing data regarding incidence, risk factors and potential etiologies, as well as treatment strategies for stroke in pregnancy.
Secondary Stroke Prevention in Women
Authors: Acciarresi Monica , De Rango Paola , Pezzella Francesca Romana , Santalucia Paola , Amici Serena , Paciaroni Maurizio , Mommi Valeria , Agnelli Giancarlo , Caso Valeria
Published: May 2011

In a meta-analysis of results from 21 randomized trials comparing antiplatelet therapy with placebo in 18,270 patients with prior stroke or transient ischemic attack, antiplatelet therapy was associated with a 28% relative odds reduction in nonfatal strokes and a 16% reduction in fatal strokes, while another trial for secondary prevention with atorvastastin 80 mg showed a 16% risk reduction in time to first occurrence of stroke (adjusted hazard ratio: 0·84, 95% CI: 0·71–0·99). However, few studies have examined the sex differences regarding the efficacy of these treatments. Specifically, recent studies have reported higher rates of perioperative complications during endarterectomy in women. Nonetheless, to date, the data on the effects of carotid artery stenting in women, coming from diverse studies and meta-analyses, have been limited owing to the small number of female patients examined. Owing to this, the evidence of the benefit for women is unclear. Peculiar pathophysiological aspects of stroke, the higher stroke risk in some specific periods in life (e.g., pregnancy, puerperium and older age) and worse documented stroke outcome in women suggest that sex does matter in stroke management. Thus, future randomized controlled trials need to be sex-balanced, in order to better understand the efficacy of appropriate secondary stroke prevention therapy in women.
Gender Differences in the Primary Prevention of Stroke with Aspirin
Authors: Adelman Eric E , Lisabeth Lynda , Brown Devin L
Published: May 2011

Aspirin is used to prevent ischemic stroke and other types of cardiovascular disease. Seven trials of aspirin focusing on the effectiveness of primary prevention of stroke and other cardiovascular events have been performed, but three of these did not include women. Data from these trials, and one meta-analysis, suggest that aspirin prevents myocardial infarction in men and stroke in women, although the findings in women were driven by the results of a single large study, and a subsequent meta-analysis did not find a gender difference. The reasons for the possible gender differences in aspirin's effectiveness are not entirely clear.
Sexual Dimorphism in Ischemic Stroke: Lessons from the Laboratory
Authors: Manwani Bharti , McCullough Louise D
Published: May 2011

Ischemic stroke is emerging as a major health problem for elderly women. Women have lower stroke incidence than men until an advanced age, when the epidemiology of ischemic stroke shifts and incidence rises dramatically in women. Experimental models of rodent stroke have replicated this clinical epidemiology, with exacerbated injury in older compared with young female rodents. Many of the detrimental effects of aging on ischemic stroke outcome in females can be replicated by ovariectomy, suggesting that hormones such as estrogen play a neuroprotective role. However, emerging data suggest that the molecular mechanisms leading to ischemic cell death differ in the two sexes, and these effects may be independent of circulating hormone levels. This article highlights recent clinical and experimental literature on sex differences in stroke outcomes and mechanisms.
Characterization of hydroxybenzoic acid chelating resins: Equilibrium, kinetics, and isotherm profiles for Cd(II) and Pb(II) uptake
Authors: Shah Bhavna , Shah Ajay , Tailor Ritesh
Published: May 2011

Chelating ion-exchange resins were synthesized by polycondensation of
ortho/para hydroxybenzoic acid with resorcinol/catechol employing
formaldehyde as cross-linking agent at 80?5?C in DMF. The resins were
characterized by FTIR and XRD. The uptake behaviour of synthesized resins for
Cd(II) and Pb(II) ions have been studied depending on contact time, pH, metal
ion concentration and temperature. The sorption data obtained at optimized
conditions were analyzed by the Langmuir and Freundlich isotherms.
Experimental data of all metal-resin system were best represented by the
Freundlich isotherm. The maximum obtained sorption capacity for cadmium was
69.53 mg g-1 and 169.32 mg g-1 for Lead. The adsorption process follows first
order kinetics and the specific rate constant Kr was obtained by the
application of the Lagergan equation. Thermodynamic parameters ?Gads, ?Sads
and ?Hads were calculated for the metal-resin systems. The external diffusion
rate constant (Ks) and the intra-particle diffusion rate constant (Kid) were
calculated by the Spahn-Schlunder and Weber-Morris models, respectively. The
sorption process was found to follow an intra-particle diffusion phenomenon.
Impact of Glycemic and Blood Pressure Variability on Surrogate Measures of Cardiovascular Outcomes in Type 2 Diabetic Patients
Authors: Di Flaviani Alessandra , Picconi Fabiana , Di Stefano Paola , Giordani Ilaria , Malandrucco Ilaria , Maggio Paola , Palazzo Paola , Sgreccia Fabrizio , Peraldo Carlo , Farina Fabrizio , Frajese Gaetano , Frontoni Simona
Published: May 2011

OBJECTIVE

The effect of glycemic variability (GV) on cardiovascular risk has not been fully clarified in type 2 diabetes. We evaluated the effect of GV, blood pressure (BP), and oxidative stress on intima-media thickness (IMT), left ventricular mass index (LVMI), flow-mediated dilation (FMD), and sympathovagal balance (low frequency [LF]/high frequency [HF] ratio) in 26 type 2 diabetic patients (diabetes duration 4.41 ± 4.81 years; HbA1c 6.70 ± 1.25%) receiving diet and/or metformin treatment, with no hypotensive treatment or complications.

RESEARCH DESIGN AND METHODS

Continuous glucose monitoring (CGM) data were used to calculate mean amplitude of glycemic excursion (MAGE), continuous overall net glycemic action (CONGA)-2, mean blood glucose (MBG), mean postprandial glucose excursion (MPPGE), and incremental area under the curve (IAUC). Blood pressure (BP), circadian rhythm, and urinary 15-F2t-isoprostane (8-iso-prostaglandin F2α [PGF2α]) were also evaluated. Subjects were divided into dipper (D) and nondipper (ND) groups according to ΔBP.

RESULTS

IMT and LVMI were increased in ND versus D (0.77 ± 0.08 vs. 0.68 ± 0.13 [P = 0.04] and 67 ± 14 vs. 55 ± 11 [P = 0.03], respectively). MBG, MAGE, and IAUC were significantly associated with LF/HF ratio at night (r = 0.50, P = 0.01; r = 0.40, P = 0.04; r = 0.41, P = 0.04, respectively), MPPGE was negatively associated with FMD (r = −0.45, P = 0.02), and CONGA-2 was positively associated with LVMI (r = 0.55, P = 0.006). The Δsystolic BP was negatively associated with IMT (r = −0.43, P = 0.03) and with LVMI (r = −0.52, P = 0.01). Urinary 8-iso-PGF2α was positively associated with LVMI (r = 0.68 P < 0.001).

CONCLUSIONS

An impaired GV and BP variability is associated with endothelial and cardiovascular damage in short-term diabetic patients with optimal metabolic control. Oxidative stress is the only independent predictor of increased LV mass and correlates with glucose and BP variability.
Effect of Diacerein on Insulin Secretion and Metabolic Control in Drug-Naïve Patients With Type 2 Diabetes
Authors: Ramos-Zavala Maria G. , González-Ortiz Manuel , Martínez-Abundis Esperanza , Robles-Cervantes José A. , González-López Roberto , Santiago-Hernández Nestor J.
Published: May 2011

OBJECTIVE

To assess the effect of diacerein on insulin secretion and metabolic control in drug-naïve patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A randomized, double-blind, placebo-controlled clinical trial was carried out in 40 drug-naïve adult patients with type 2 diabetes. A metabolic profile including interleukin (IL)-1β, tumor necrosis factor-α, IL-6, and fasting insulin levels was carried out before the intervention and 2 months afterward. A hyperglycemic-hyperinsulinemic clamp technique was performed to assess the phases of insulin secretion and insulin sensitivity. After randomization, 20 patients received diacerein (50 mg once daily) for the first 15 days and twice daily for 45 additional days. The remaining patients received placebo. Intra- and intergroup differences were calculated by Wilcoxon signed rank and Mann-Whitney U tests.

RESULTS

There were significant increases in first (102 ± 63 vs. 130 ± 75 pmol/L; P < 0.01), late (219 ± 111 vs. 280 ± 135 pmol/L; P < 0.01), and total insulin (178 ± 91 vs. 216 ± 99 pmol/L; P < 0.01) secretions without changes in insulin sensitivity after diacerein administration. There were significant decreases in fasting glucose (7.9 ± 1.4 vs. 6.8 ± 1.0 mmol/L; P < 0.01) and in A1C levels (8.3 ± 1.0 vs. 7.0 ± 0.8%; P < 0.001) after diacerein administration. There were no significant changes after placebo administration in the above-mentioned evaluations.

CONCLUSIONS

Insulin secretion increased and metabolic control improved after diacerein administration in drug-naïve patients with type 2 diabetes.
Exploring the binding dynamics of BAR proteins
Authors: Kabaso Doron , Gongadze Ekaterina , Jorgačevski Jernej , Kreft Marko , Rienen Ursula , Zorec Robert , Iglič Aleš
Published: May 2011

We used a continuum model based on the Helfrich free energy to investigate the binding dynamics of a lipid bilayer to a BAR domain surface of a crescent-like shape of positive (e.g. I-BAR shape) or negative (e.g. F-BAR shape) intrinsic curvature. According to structural data, it has been suggested that negatively charged membrane lipids are bound to positively charged amino acids at the binding interface of BAR proteins, contributing a negative binding energy to the system free energy. In addition, the cone-like shape of negatively charged lipids on the inner side of a cell membrane might contribute a positive intrinsic curvature, facilitating the initial bending towards the crescent-like shape of the BAR domain. In the present study, we hypothesize that in the limit of a rigid BAR domain shape, the negative binding energy and the coupling between the intrinsic curvature of negatively charged lipids and the membrane curvature drive the bending of the membrane. To estimate the binding energy, the electric potential at the charged surface of a BAR domain was calculated using the Langevin-Bikerman equation. Results of numerical simulations reveal that the binding energy is important for the initial instability (i.e. bending of a membrane), while the coupling between the intrinsic shapes of lipids and membrane curvature could be crucial for the curvature-dependent aggregation of negatively charged lipids near the surface of the BAR domain. In the discussion, we suggest novel experiments using patch clamp techniques to analyze the binding dynamics of BAR proteins, as well as the possible role of BAR proteins in the fusion pore stability of exovesicles.
Microstructure and properties of polyhydroxybutyrate-calcium phosphate cement composites
Authors: Medvecký Ľubomír , Štulajterová Radoslava , Kutsev Sergey
Published: May 2011

The biopolymer (polyhydroxybutyrate) microparticles-calcium phosphate composites were prepared by mechanical mixing of the basic composite components with the addition of hardening liquid after ethanol-composite mixture suspension moulding. The composite microstructures were more compact than the pure cement samples as confirmed by the lower values of specific areas and mesopore volumes. Both the specific areas and mesopore volumes decreased with soaking time in a simulated body fluid. The low polyhydroxybutyrate degradation in composites was found after soaking in simulated body fluid, which was terminated after one week. The formation of a dense apatite layer bonded directly to the surface of polyhydroxybutyrate microparticles was observed. The highest diametral tensile strength (13 MPa) and compressive strength (95 MPa) values of up to 50 % higher than in pure cement were measured in samples with 10 % of polyhydroxybutyrate. The addition of polyhydroxybutyrate microparticles had no effect on the setting time.
Investigation of new chiral fluorosubstituted compound exhibiting room temperature antiferroelectric phase
Authors: Czerwiec J. , Żurowska M. , Garbat K. , Dąbrowski R. , Marzec M. , Wróbel S.
Published: May 2011

Influence of the electric field upon alignment of molecules in ferro- and antiferroelectric phases has been studied for two fluoro-substituted compounds exhibiting antiferroelectric phase at room temperature. Two different relaxation processes have been revealed in the ferroelectric as well as antiferroelectric phase. Low temperature value of spontaneous polarization is ca. 130 nC/cm2 for both substances studied. The substances align very well in the external electric field — a mono-domain of the ferroelectric SmC* phase can be obtained in about 3.5 hours.
Investigating the resetting of OSL signals in rock surfaces
Authors: Sohbati Reza , Murray Andrew , Jain Mayank , Buylaert Jan-Pieter , Thomsen Kristina
Published: May 2011

There are many examples of buried rock surfaces whose age is of interest to geologists and archaeologists. Luminescence dating is a potential method which can be applied to dating such surfaces; as part of a research project which aims to develop such an approach, the degree of resetting of OSL signals in grains and slices from five different cobbles/boulders collected from a modern beach is investigated. All the rock surfaces are presumed to have been exposed to daylight for a prolonged period of time (weeks to years). Feldspar was identified as the preferred dosimeter because quartz extracts were insensitive. Dose recovery tests using solar simulator and IR diodes on both K-feldspar grains and solid slices taken from the inner parts of the rocks are discussed. Preheat plateau results using surface grains and slices show that significant thermal transfer in naturally bleached samples can be avoided by keeping preheat temperatures low. Equivalent doses from surface K-feldspar grains were highly scattered and much larger than expected (0.02 Gy to >100 Gy), while solid surface slices gave more reproducible small doses (mean = 0.17±0.02 Gy, n = 32). Neither crushing nor partial bleaching were found to be responsible for the large scattered doses from grains, nor did the inevitable contribution from Na-feldspar to the signal from solid slices explain the improved reproducibility in the slices. By modelling the increase of luminescence signal with distance into the rock surface, attenuation factors were derived for two samples. These indicate that, for instance, bleaching at a depth of 2 mm into these samples occurs at about ∼28% of the rate at the surface. We conclude that it should be possible to derive meaningful burial doses of >1 Gy from such cobbles; younger samples would probably require a correction for incomplete bleaching.
A Comparison of Maximum Likelihood and Bayesian Estimation for Polychoric Correlation Using Monte Carlo Simulation
Authors: Choi Jaehwa , Kim Sunhee , Chen Jinsong , Dannels Sharon
Published: May 2011

The purpose of this study is to compare the maximum likelihood (ML) and Bayesian estimation methods for polychoric correlation (PCC) under diverse conditions using a Monte Carlo simulation. Two new Bayesian estimates, maximum a posteriori (MAP) and expected a posteriori (EAP), are compared to ML, the classic solution, to estimate PCC. Different types of prior distributions are used to investigate the sensitivity of a prior distribution onto the Bayesian PCC estimation. In this simulation study, it appears that the MAP would be the estimator of choice for the PCC. The performance of the MAP is not only better than the ML but also appears to overcome the limitations of the EAP (i.e., the shrinkage effect).
Social discrimination in community forestry: Socio-economic and gender perspectives
Authors: Parajuli R , Pokharel RK , Lamichhane D
Published: May 2011

A study was carried out to analyze the existing social discrimination among Community Forest User Group (CFUG) members. Two CFUGs representing heterogeneous ethnic groups in Syangja district were selected to examine the participation of CFUG members in Community Forestry (CF) activities, benefit sharing and fund mobilization system. PRA/RRA tools like questionnaire survey, wealth ranking, key informant survey, triangulation, and informal discussion were employed to generate primary data. Statistical parameters such as percentage, mean, ANOVA, and contingency coefficient were used to interpret this data. The perception of local people was measured on the five point Likert scale, and Chi-square test was applied to interpret this result. The participation of the poor, disadvantaged group and women were minimal in CF activities but their presence was more at the time of forest product distribution. Timber had been distributed less to the poor and disadvantaged group (DAG) households than to others. More than 65% CFUG members were unaware about CFUG fund. Their overall perceptions of CF management were not positive. The result clearly demonstrated discrimination between the rich and the poor, male and female, and DAG and non-DAG within the CFUG. Key words: Community forest user group; discrimination; participation; disadvantaged group; poor DOI: 10.3126/banko.v20i2.4799 Banko Janakari Vol.20(2) 2010 pp.26-33
Soil and vegetation carbon pools in two community forests of Palpa district, Nepal
Authors: Khanal Y , Sharma RP , Upadhyaya CP
Published: May 2011

Quantification of carbon in any vegetation and soil type is a basic step for evaluating the carbon sequestration potential of an ecosystem. For quantification, soil samples from varying depths (0–20, 20–40, 40–60, 60-80 and 80–100 cm) of each soil profile were collected for each sample plot laid out in Jarneldhara and Lipindevi Thulopakho Community Forests (CFs) of Palpa district. Individual trees in the sample plots of both CFs were measured. Biomass of standing trees, poles and saplings were estimated indirectly from diameter at breast height (dbh) and total height by using allometric relationships, while the biomass of grass, herb and litter were calculated directly from field measurements. Above-ground and below-ground (root) carbon pools in Jarneldhara CF were found to be 36.6 ± 3.4 t ha-1 and 10.5 ± 1.0 t ha-1 , respectively; while those on Lipindevi Thulopakho CF were 40.2 ± 4 and 11.4 ± 1.1 t ha-1, respectively. Soil organic carbon pool in Jarneldhara and Lipindevi Thulopakho CF were 121.4 ± 7.4 and 94.6 ± 4.4 t ha-1, respectively. This indicates that CFs have high potential to offset large portion of carbon emission through sequestration into both soil and vegetation, and act as a natural carbon sink. Key words: Carbon pool; community forest; soil organic carbon; vegetation carbon; biomass DOI: 10.3126/banko.v20i2.4800 Banko Janakari Vol.20(2) 2010 pp.34-40
Economic potential of forest resources of Nepal
Authors: Pandey SS , Subedi BP , Dhungana H
Published: May 2011

Nepal’s forest resources underpin the livelihoods of rural people in important ways. During the country's "planned development" over the past 50 years, the government, donors and policy makers have viewed these resources as a key vehicle for ushering in economic growth and for meeting basic needs. They underscore the potential value of forest resources for achieving conservation and socio-economic objectives. To what extent have economic incentives been generated to effectively harness these resources to meet the said objectives is an open question. To address this question, this paper reviews briefly and broadly the economic potential of the country’s forest resources in terms of forest goods and services. Estimates of economic potential of timber and non-timber forest products and environmental services have been assessed. A number of recommendations for realizing the potential for achieving development and poverty reduction objectives is provided. Key words: Forestry; non-timber forest products; ecosystem services; economic potential; livelihood DOI: 10.3126/banko.v20i2.4803 Banko Janakari Vol.20(2) 2010 pp.48-52
Environmental Impacts and Costs of Hydrotreated Vegetable Oils, Transesterified Lipids and Woody BTL—A Review
Authors: Sunde Kathrin , Brekke Andreas , Solberg Birger
Published: May 2011

This article reviews and compares assessments of three biodiesel fuels: (1) transesterified lipids, (2) hydrotreated vegetable oils (HVO), and (3) woody biomass-to-liquid (BTL) Fischer-Tropsch diesel and selected feedstock options. The article attempts to rank the environmental performance and costs of fuel and feedstock combinations. Due to inter-study differences in goal and study assumptions, the ranking was mostly qualitative and intra-study results are emphasized. Results indicate that HVO made from wastes or by-products such as tall oil, tallow or used cooking oil outperform transesterified lipids and BTL from woody material, both with respect to environmental life cycle impacts and costs. These feedstock options are, however, of limited availability, and to produce larger volumes of biofuels other raw materials must also be used. BTL from woody biomass seems promising with good environmental performance and the ability not to compete with food production. Production of biofuels from agricultural feedstock sources requires much energy and leads to considerable emissions due to agrochemical inputs. Thus, such biodiesel fuels are ranked lowest in this comparison. Production of feedstock is the most important life cycle stage. Avoiding detrimental land use changes and maintaining good agricultural or forestry management practices are the main challenges to ensure that biofuels can be a sustainable option for the future transport sector.
Making the Environmental Justice Grade: The Relative Burden of Air Pollution Exposure in the United States
Authors: Miranda Marie Lynn , Edwards Sharon E. , Keating Martha H. , Paul Christopher J.
Published: May 2011

This paper assesses whether the Clean Air Act and its Amendments have been equally successful in ensuring the right to healthful air quality in both advantaged and disadvantaged communities in the United States. Using a method to rank air quality established by the American Lung Association in its 2009 State of the Air report along with EPA air quality data, we assess the environmental justice dimensions of air pollution exposure and access to air quality information in the United States. We focus on the race, age, and poverty demographics of communities with differing levels of ozone and particulate matter exposure, as well as communities with and without air quality information. Focusing on PM2.5 and ozone, we find that within areas covered by the monitoring networks, non-Hispanic blacks are consistently overrepresented in communities with the poorest air quality. The results for older and younger age as well as poverty vary by the pollution metric under consideration. Rural areas are typically outside the bounds of air quality monitoring networks leaving large segments of the population without information about their ambient air quality. These results suggest that substantial areas of the United States lack monitoring data, and among areas where monitoring data are available, low income and minority communities tend to experience higher ambient pollution levels.