bluuebunny/crossref_metadata_2025 huggingface dataset:
Network recruitment to coherent oscillations in a hippocampal computer model
Authors: Stacey William C. , Krieger Abba , Litt Brian
Published: January 2011

Coherent neural oscillations represent transient synchronization of local neuronal populations in both normal and pathological brain activity. These oscillations occur at or above gamma frequencies (>30 Hz) and often are propagated to neighboring tissue under circumstances that are both normal and abnormal, such as gamma binding or seizures. The mechanisms that generate and propagate these oscillations are poorly understood. In the present study we demonstrate, via a detailed computational model, a mechanism whereby physiological noise and coupling initiate oscillations and then recruit neighboring tissue, in a manner well described by a combination of stochastic resonance and coherence resonance. We develop a novel statistical method to quantify recruitment using several measures of network synchrony. This measurement demonstrates that oscillations spread via preexisting network connections such as interneuronal connections, recurrent synapses, and gap junctions, provided that neighboring cells also receive sufficient inputs in the form of random synaptic noise. “Epileptic” high-frequency oscillations (HFOs), produced by pathologies such as increased synaptic activity and recurrent connections, were superior at recruiting neighboring tissue. “Normal” HFOs, associated with fast firing of inhibitory cells and sparse pyramidal cell firing, tended to suppress surrounding cells and showed very limited ability to recruit. These findings point to synaptic noise and physiological coupling as important targets for understanding the generation and propagation of both normal and pathological HFOs, suggesting potential new diagnostic and therapeutic approaches to human disorders such as epilepsy.
l-arginine via nitric oxide is an inhibitory feedback modulator ofAplysiafeeding
Authors: Miller N. , Saada R. , Markovich S. , Hurwitz I. , Susswein A. J.
Published: January 2011

An increase in l-arginine hemolymph concentration acts as a postingestion signal inhibiting Aplysia feeding. At physiological concentrations (a 10-μM increase over background), the inhibitory effect of l-arginine is too weak to block feeding in hungry animals. However, a 10-μM increase in l-arginine concentration acts along with another inhibitory stimulus, the sustained presence of food odor, to inhibit feeding after a period of access to food. A physiological concentration of l-arginine also blocked the excitatory effect of a stimulus enhancing feeding, pheromones secreted by mating conspecifics. High concentrations of l-arginine (2.5 mM) alone also inhibited ad libitum feeding. l-arginine is the substrate from which nitric oxide synthase (NOS) produces nitric oxide (NO). Both an NO donor and a 10-μM increase in l-arginine inhibited biting in response to a weak food stimulus. Treatment with NOS inhibitors initiated food-finding and biting in the absence of food, indicating that food initiates feeding against a background of tonic nitrergic inhibition. Increased feeding in response to blocking NOS is accompanied by firing of the metacerebral (MCC) neuron, a monitor of food arousal. The excitatory effect on the MCC of blocking NOS is indirect. The data suggest that l-arginine acts by amplifying NO synthesis, which acts as a background stimulus inhibiting feeding. Background modulation of neural activity and behavior by NO may also be present in other systems, but such modulation may be difficult to identify because its effects are evident only in the context of additional stimuli modulating behavior.
Glucose-dependent insulinotropic polypeptide receptor knockout mice are impaired in learning, synaptic plasticity, and neurogenesis
Authors: Faivre Emilie , Gault Victor A. , Thorens Bernard , Hölscher Christian
Published: January 2011

Glucose-dependent insulinotropic polypeptide (GIP) is a key incretin hormone, released from intestine after a meal, producing a glucose-dependent insulin secretion. The GIP receptor (GIPR) is expressed on pyramidal neurons in the cortex and hippocampus, and GIP is synthesized in a subset of neurons in the brain. However, the role of the GIPR in neuronal signaling is not clear. In this study, we used a mouse strain with GIPR gene deletion (GIPR KO) to elucidate the role of the GIPR in neuronal communication and brain function. Compared with C57BL/6 control mice, GIPR KO mice displayed higher locomotor activity in an open-field task. Impairment of recognition and spatial learning and memory of GIPR KO mice were found in the object recognition task and a spatial water maze task, respectively. In an object location task, no impairment was found. GIPR KO mice also showed impaired synaptic plasticity in paired-pulse facilitation and a block of long-term potentiation in area CA1 of the hippocampus. Moreover, a large decrease in the number of neuronal progenitor cells was found in the dentate gyrus of transgenic mice, although the numbers of young neurons was not changed. Together the results suggest that GIP receptors play an important role in cognition, neurotransmission, and cell proliferation.
Analysis of Gene Function in Cultured Embryonic Mouse Gonads Using Nucleofection
Authors: Ryan J. , Ludbrook L. , Wilhelm D. , Sinclair A. , Koopman P. , Bernard P. , Harley V.R.
Published: January 2011

Mammalian sex determination is a dynamic process involving balanced gene expression leading to the development of either a testis or an ovary. Candidate sex-determining genes have been identified through microarray-based studies of gonadal gene expression; however, few methods exist for validation. This study describes a new technique for transfecting gonads using nucleofection. Fifteen micrograms of expression plasmid DNA was transfected into E11.5 gonads, cultured for 3 days and gene expression analyzed. Following optimization, we consistently achieved cell transfection efficiencies of 11% of cells using pMax-GFP plasmid. To test the applicability of nucleofection to studies of gene function, a testis-determining gene was transfected into gonads and its ability to sex-reverse was examined. When Sry was transfected into female (XX) gonads, upregulation of its target gene Sox9 was observed, as well as a downregulation of the ovarian gene Foxl2. Conversely, when shSox9 was introduced into male (XY) gonads, reduction of Sox9 and its target gene, Amh was observed, with a concomitant upregulation of Foxl2. Nucleofection-based gene delivery can recapitulate in vivo events of gonadal development that demonstrates ‘proof-of-principle’ of the method as a screening tool to evaluate the cellular function of potential sex-determining and gonadal differentiation genes.
Elevated amh Gene Expression in the Brain of Male Tilapia (Oreochromis niloticus) during Testis Differentiation
Authors: Poonlaphdecha S. , Pepey E. , Huang S.-H. , Canonne M. , Soler L. , Mortaji S. , Morand S. , Pfennig F. , Mélard C. , Baroiller J.F. , D’Cotta H.
Published: January 2011

Anti-müllerian hormone (AMH) is expressed in male embryos and represses development of müllerian ducts during testis differentiation in mammals, birds and reptiles. Amh orthologues have been identified in teleosts despite them lacking müllerian ducts. Previously we found sexually dimorphic aromatase activity in tilapia brains before ovarian differentiation. This prompted us to search for further dimorphisms in tilapia brains during sex differentiation and see whether amh is expressed. We cloned the tilapia amh gene and found that it contains 7 exons but no spliced forms. The putative protein presents highest homologies with Amh proteins of pejerrey and medaka as compared to other Perciformes. We analysed amh expression in adult tissues and found elevated levels in testes, ovary and brain. Amh expression was dimorphic with higher levels in XY male brains at 10–15 dpf, when the gonads were still undifferentiated and gonadal amh was not dimorphic. Male brains had 2.7-fold higher amh expression than gonads. Thereafter, amh levels decreased in the brain while they were up-regulated in differentiating testes. Our study indicates that amh is transcribed in male brains already at 10 dpf, suggesting that sexual differentiation may be occurring earlier in tilapia brain than in gonads.
Circulating Proprotein Convertase Subtilisin/Kexin 9 (PCSK9) Regulates VLDLR Protein and Triglyceride Accumulation in Visceral Adipose Tissue
Authors: Roubtsova Anna , Munkonda Mercedes Nancy , Awan Zuhier , Marcinkiewicz Jadwiga , Chamberland Ann , Lazure Claude , Cianflone Katherine , Seidah Nabil G. , Prat Annik
Published: January 2011

Objective—

Proprotein convertase subtilisin/kexin 9 (PCSK9) promotes the degradation of the low-density lipoprotein receptor (LDLR), and its gene is the third locus implicated in familial hypercholesterolemia. Herein, we investigated the role of PCSK9 in adipose tissue metabolism.

Methods and Results—

At 6 months of age,
Pcsk9
−/−
mice accumulated ≈80% more visceral adipose tissue than wild-type mice. This was associated with adipocyte hypertrophy and increased in vivo fatty acid uptake and ex vivo triglyceride synthesis. Moreover, adipocyte hypertrophy was also observed in
Pcsk9
−/−
Ldlr
−/−
mice, indicating that the LDLR is not implicated. Rather, we show here by immunohistochemistry that
Pcsk9
−/−
males and females exhibit 4- and ≈40-fold higher cell surface levels of very-low-density lipoprotein receptor (VLDLR) in perigonadal depots, respectively. Expression of PCSK9 in the liver of
Pcsk9
−/−
females reestablished both circulating PCSK9 and normal VLDLR levels. In contrast, specific inactivation of PCSK9 in the liver of wild-type females led to ≈50-fold higher levels of perigonadal VLDLR.

Conclusion—

In vivo, endogenous PCSK9 regulates VLDLR protein levels in adipose tissue. This regulation is achieved by circulating PCSK9 that originates entirely in the liver. PCSK9 is thus pivotal in fat metabolism: it maintains high circulating cholesterol levels via hepatic LDLR degradation, but it also limits visceral adipogenesis likely via adipose VLDLR regulation.
Macrophage Activation Is Responsible for Loss of Anticontractile Function in Inflamed Perivascular Fat
Authors: Withers Sarah B. , Agabiti-Rosei Claudia , Livingstone Daniel M. , Little Matthew C. , Aslam Rehima , Malik Rayaz A. , Heagerty Anthony M.
Published: January 2011

Objective—

The aim of this study was to determine whether macrophages dispersed throughout perivascular fat are crucial to the loss of anticontractile function when healthy adipose tissue becomes inflamed and to gain an understanding of the mechanisms involved.

Methods and Results—

Pharmacological studies on in vitro small arterial segments from a mouse model of inducible macrophage ablation and on wild-type animals were carried out with and without perivascular fat using 2 physiological stimuli of inflammation: aldosterone and hypoxia. Both inflammatory insults caused a similar loss of anticontractile capacity of perivascular fat and increased macrophage activation. Aldosterone receptor antagonism and free radical scavengers were able to restore this capacity and reduce macrophage activation. However, in a mouse deficient of macrophages CD11b-diptheria toxin receptor (CD11b-DTR), there was no increase in contractility of arteries following aldosterone incubation or hypoxia.

Conclusion—

The presence and activation of macrophages in adipose tissue is the key modulator of the increase in contractility in arteries with perivascular fat following induction of inflammation. Despite multiple factors that may be involved in bringing about the vascular consequences of obesity, the ability of eplerenone to ameliorate the inflammatory effects of both aldosterone and hypoxia may be of potential therapeutic interest.
Soluble M6P/IGF2R Released by TACE Controls Angiogenesis via Blocking Plasminogen Activation
Authors: Leksa Vladimir , Loewe Robert , Binder Brigitte , Schiller Herbert B. , Eckerstorfer Paul , Forster Florian , Soler-Cardona Ana , Ondrovičová Gabriela , Kutejová Eva , Steinhuber Eva , Breuss Johannes , Drach Johannes , Petzelbauer Peter , Binder Bernd R. , Stockinger Hannes
Published: January 2011

Rationale:

The urokinase plasminogen activator (uPA) system is among the most crucial pericellular proteolytic systems associated with the processes of angiogenesis. We previously identified an important regulator of the uPA system in the mannose 6-phosphate/insulin-like growth factor 2 receptor (M6P/IGF2R).

Objective:

Here, we wanted to clarify whether and how did the soluble form of M6P/IGF2R (sM6P/IGF2R) contribute to modulation of the uPA system.

Methods and Results:

By using specific inhibitors and RNA interference, we show that the tumor necrosis factor α convertase (TACE, ADAM-17) mediates the release of the ectodomain of M6P/IGF2R from human endothelial cells. We demonstrate further that sM6P/IGF2R binds plasminogen (Plg) and thereby prevents Plg from binding to the cell surface and uPA, ultimately inhibiting in this manner Plg activation. Furthermore, peptide 18-36 derived from the Plg-binding site of M6P/IGF2R mimics sM6P/IGF2R in the inhibition of Plg activation and blocks cancer cell invasion in vitro, endothelial cell invasion in vivo, and tumor growth in vivo.

Conclusions:

The interaction of sM6P/IGF2R with Plg may be an important regulatory mechanism to inhibit migration of cells using the uPA/uPAR system.
A Peptide Mimetic of the Connexin43 Carboxyl Terminus Reduces Gap Junction Remodeling and Induced Arrhythmia Following Ventricular Injury
Authors: O'Quinn Michael P. , Palatinus Joseph A. , Harris Brett S. , Hewett Kenneth W. , Gourdie Robert G.
Published: January 2011

Rationale:

Remodeling of connexin (Cx)43 gap junctions (GJs) is linked to ventricular arrhythmia.

Objectives:

A peptide mimetic of the carboxyl terminal (CT) of Cx43, incorporating a postsynaptic density-95/
d
isks-large/
Z
O-1 (PDZ)-binding domain, reduces Cx43/ZO-1 interaction and GJ size remodeling in vitro. Here, we determined: (1) whether the Cx43-CT mimetic αCT1 altered GJ remodeling following left ventricular (LV) injury in vivo; (2) whether αCT1 affected arrhythmic propensity; and (3) the mechanism of αCT1 effects on arrhythmogenicity and GJ remodeling.

Methods and Results:

A cryoinjury model generating a reproducible wound and injury border zone (IBZ) in the LV was used. Adherent methylcellulose patches formulated to locally release αCT1 (<48 hours) were placed on cryoinjuries. Relative to controls, Cx43/ZO-1 colocalization in the IBZ was reduced by αCT1 by 24 hours after injury. Programmed electric stimulation ex vivo and optical mapping of voltage transients indicated that peptide-treated hearts showed reduced inducible arrhythmias and increased ventricular depolarization rates 7 to 9 days after injury. At 24 hours and 1 week after injury, αCT1-treated hearts maintained Cx43 in intercalated disks (IDs) in the IBZ, whereas by 1 week after injury, controls demonstrated Cx43 remodeling from IDs to lateralized distributions. Over a postinjury time course of 1 week, αCT1-treated IBZs showed increased Cx43 phosphorylation at serine368 (Cx43-pS368) relative to control tissues. In biochemical assays, αCT1 promoted phosphorylation of serine368 by protein kinase (PK)C-ε in a dose-dependent manner that was modulated by, but did not require ZO-1 PDZ2.

Conclusions:

αCT1 increases Cx43-pS368 in vitro in a PKC-ε–dependent manner and in the IBZ in vivo acutely following ventricular injury. αCT1-mediated increase in Cx43-pS368 phosphorylation may contribute to reductions in inducible-arrhythmia following injury.
Novel Dynamic Four-Dimensional CT Angiography Revealing 2-Type Motions of Cerebral Arteries
Authors: Umeda Yasuyuki , Ishida Fujimaro , Hamada Kazuhide , Fukazawa Keiji , Miura Yoichi , Toma Naoki , Suzuki Hidenori , Matsushima Satoshi , Shimosaka Shinichi , Taki Waro
Published: January 2011

Background and Purpose—

We developed a novel dynamic 4-dimensional CT angiography to accurately evaluate dynamics in cerebral aneurysm.

Methods—

Dynamic 4-dimensional CT angiography achieved high-resolution 3-dimensional imaging with temporal resolution in a beating heart using dynamic scanning data sets reconstructed with a retrospective simulated R-R interval reconstruction algorithm.

Results—

Movie artifacts disappeared on dynamic 4-dimensional CT angiography movies of 2 kinds of stationary phantoms (titanium clips and dry bone). In the virtual pulsating aneurysm model, pulsation on the dynamic 4-dimensional CT angiography movie resembled actual movement in terms of pulsation size. In a clinical study, dynamic 4-dimensional CT angiography showed 2-type motions: pulsation and anatomic positional changes of the cerebral artery.

Conclusions—

This newly developed 4-dimensional visualizing technique may deliver some clues to clarify the pathophysiology of cerebral aneurysms.
A 5-Item Scale to Predict Stroke Outcome After Cortical Middle Cerebral Artery Territory Infarction
Authors: Vora Nirav A. , Shook Steven J. , Schumacher H. Christian , Tievsky Andrew L. , Albers Greg W. , Wechsler Lawrence R. , Gupta Rishi
Published: January 2011

Background and Purpose—

Various clinical, laboratory, and radiographic parameters have been identified as predictors of outcome for ischemic stroke. The purpose of this study was to combine these parameters into a validated scale for outcome prognostication in patients with a middle cerebral artery territory infarction.

Methods—

We retrospectively reviewed 129 patients over a 2-year period and considered demographic, clinical, laboratory, and radiographic parameters as potential predictors of outcome. Inclusion criteria were unilateral hemispheric infarcts within the middle cerebral artery territory >15 mm in diameter. Our primary outcome measure was a favorable recovery defined as a modified Rankin Score was ≤2 at 30 days. A multivariable model was used to determine independent predictors of outcome and weighted to create a 5-item scale to predict stroke recovery. External validation of this model was done using data from the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution (DEFUSE) study.

Results—

The 5 independent predictors of outcome were as follows: age (OR, 1.09; 95% CI, 1.03 to 1.14;
P
=0.001), National Institutes of Health Stroke Scale score (OR, 1.17; 95% CI, 1.06 to 1.30;
P
=0.003), infarct volume (OR, 1.01; 95% CI, 1.00 to 1.02;
P
=0.03), admission white blood cell count (8.5×10
3
/mm
3
; OR, 1.16; 95% CI, 1.03 to 1.27;
P
=0.04), and presence of hyperglycemia (OR, 4.2; 95% CI, 1.1 to 16.4;
P
=0.04). Combining these variables into a point scale significantly improved prediction over the individual variables accounted alone as evidenced by the area underneath the receiver operating curve (OR, 0.91; 95% CI, 0.87 to 0.96;
P
=0.0001). When applied to the DEFUSE study population for validation, the model achieved a sensitivity of 83% and specificity of 86%.

Conclusions—

With validation from a prospective study of similar patients, this model serves as a useful clinical and research tool to predict stroke recovery after cortical middle cerebral artery territory infarction.
Osteopontin Reduced Hypoxia–Ischemia Neonatal Brain Injury by Suppression of Apoptosis in a Rat Pup Model
Authors: Chen Wanqiu , Ma Qingyi , Suzuki Hidenori , Hartman Richard , Tang Jiping , Zhang John H.
Published: January 2011

Background and Purpose—

Osteopontin (OPN) is neuroprotective in ischemic brain injuries in adult experimental models; therefore, we hypothesized that OPN would provide neuroprotection and improve long-term neurological function in the immature brain after hypoxic–ischemic (HI) injury.

Methods—

HI was induced by unilateral ligation of the right carotid artery followed by hypoxia (8% O
2
for 2 hours) in postnatal Day 7 rats. OPN (0.03 μg or 0.1 μg) was injected intracerebroventricularly at 1 hour post-HI. Temporal expression of endogenous OPN was evaluated in the normal rat brain at the age of 0, 4, 7, 11, 14, and 21 days and in the ipsilateral hemisphere after HI. The effects of OPN were evaluated using 2-3-5-triphenyl tetrazolium chloride staining, apoptotic cell death assay, and cleaved caspase-3 expression. Neurological function was assessed by the Morris water maze test.

Results—

Endogenous OPN expression in the brain was the highest at the age of 0 day with continuous reduction until the age of 21 days during development. After HI injury, endogenous OPN expression was increased and peaked at 48 hours. Exogenous OPN decreased infarct volume and improved neurological outcomes 7 weeks after HI injury. OPN-induced neuroprotection was blocked by an integrin antagonist.

Conclusions—

OPN-induced neuroprotection was associated with cleaved-caspase-3 inhibition and antiapoptotic cell death. OPN treatment improved long-term neurological function against neonatal HI brain injury.
Stem Cell Therapy as an Emerging Paradigm for Stroke (STEPS) II
Authors: Savitz Sean I. , Chopp Michael , Deans Robert , Carmichael S. T. , Phinney Donald , Wechsler Larry
Published: January 2011

Cell-based therapies represent a new therapeutic approach for stroke. In 2007, investigators from academia, industry leaders, and members of the National Institutes of Health crafted recommendations to facilitate the translational development of cellular therapies as a novel, emerging modality for stroke from animal studies to clinical trials. This meeting was called Stem Cell Therapies as an Emerging Paradigm in Stroke (STEPS) and was modeled on the format of the Stroke Therapy Academic Industry Roundtable (STAIR) meetings. Since publication of the original STEPS guidelines, there has been an explosive growth in the number of cellular products and in the number of new laboratory discoveries that impact the safety and potential efficacy of cell therapies for stroke. Any successful development of a cell product will need to take into consideration several factors, including the preclinical safety and efficacy profile, cell characterization, delivery route, in vivo biodistribution, and mechanism of action. In 2010, a second meeting called STEPS 2 was held to bring together clinical and basic science researchers with industry, regulatory, and National Institutes of Health representatives. At this meeting, participants identified critical gaps in knowledge and research areas that require further studies, updated prior guidelines, and drafted new recommendations to create a framework to guide future investigations in cell-based therapies for stroke.
AMIP GCM Simulations of Precipitation Variability over the Yangtze River Valley
Authors: Wang Chenghai , Liang Xin-Zhong , Samel Arthur N.
Published: January 2011

Analysis of 26 simulations from 11 general circulation models (GCMs) of the Atmospheric Model Intercomparison Project (AMIP) II reveals a basic inability to simultaneously predict the Yangtze River Valley (YRV) precipitation (PrYRV) annual cycle and summer interannual variability in response to observed global SST distributions. Only the Community Climate System Model (CCSM) and L’Institut Pierre-Simon Laplace (IPSL) models reproduce the observed annual cycle, but both fail to capture the interannual variability. Conversely, only Max Planck Institute (MPI) simulates interannual variability reasonably well, but its annual cycle leads observations by 2 months.

The interannual variability of PrYRV reveals two distinct signals in observations, which are identified with opposite subtropical Pacific SST anomalies in the east (SSTe) and west (SSTw). First, negative SSTe anomalies are associated with equatorward displacement of the upper-level East Asian jet (ULJ) over China. The resulting transverse circulation enhances low-level southerly flow over the South China Sea and south China while convergent flow and upward motion increase over the YRV. Second, positive SSTw anomalies are linked with westward movement of the subtropical high over the west-central Pacific. This strengthens the low-level jet (LLJ) to the south of the YRV. These two signals act together to enhance PrYRV. The AMIP II suite, however, generally fails to reproduce these features. Only the MPI.3 realization is able to simulate both signals and, consequently, realistic PrYRV interannual variations. It appears that PrYRV is governed primarily by coherent ULJ and LLJ variations that act as the atmospheric bridges to remote SSTe and SSTw forcings, respectively. The PrYRV response to global SST anomalies may then be realistically depicted only when both bridges are correctly simulated. The above hypothesis does not exclude other signals that may play important roles linking PrYRV with remote SST forcings through certain atmospheric bridges, which deserve further investigation.
The Impacts of Inter–El Niño Variability on the Tropical Atlantic and Northeast Brazil Climate
Authors: Rodrigues Regina R. , Haarsma Reindert J. , Campos Edmo J. D. , Ambrizzi Tércio
Published: January 2011

In this study, observations and numerical simulations are used to investigate how different El Niño events affect the development of SST anomalies in the Atlantic and how this relates to the Brazilian northeast (NE) precipitation. The results show that different types of El Niño have different impacts on the SST anomalies of the equatorial and tropical South Atlantic but a similar SST response in the tropical North Atlantic. Strong and long (weak and short) El Niños with the main heating source located in the eastern (central) Pacific generate cold (warm) anomalies in the cold tongue and Benguela upwelling regions during boreal winter and spring. When the SST anomalies in the eastern equatorial and tropical South Atlantic are cold (warm), the meridional SST gradient across the equator is positive (negative) and the ITCZ is not allowed (allowed) to move southward during the boreal spring; as a consequence, the precipitation is below (above) the average over the NE. Thus, strong and long (weak and short) El Niños are followed by dry (wet) conditions in the NE. During strong and long El Niños, changes in the Walker circulation over the Atlantic and in the Pacific–South Atlantic (PSA) wave train cause easterly wind anomalies in the western equatorial Atlantic, which in turn activate the Bjerknes mechanism, establishing the cold tongue in boreal spring and summer. These easterly anomalies are also responsible for the Benguela upwelling. During short and weak El Niños, westerly wind anomalies are present in the western equatorial Atlantic accompanied by warm anomalies in the eastern equatorial and tropical South Atlantic; a positive phase of the South Atlantic dipole develops during boreal winter. The simulations highlight the importance of ocean dynamics in establishing the correct slope of the equatorial thermocline and SST anomalies, which in turn determine the correct rainfall response over the NE.
The Role of Human Activity in the Recent Warming of Extremely Warm Daytime Temperatures
Authors: Christidis Nikolaos , Stott Peter A. , Brown Simon J.
Published: January 2011

Formal detection and attribution analyses of changes in daily extremes give evidence of a significant human influence on the increasing severity of extremely warm nights and decreasing severity of extremely cold days and nights. This paper presents an optimal fingerprinting analysis that also detects the contributions of external forcings to recent changes in extremely warm days using nonstationary extreme value theory. The authors’ analysis is the first that attempts to partition the observed change in warm daytime extremes between its anthropogenic and natural components and hence attribute part of the change to possible causes. Changes in the extreme temperatures are represented by the temporal changes in a parameter of an extreme value distribution. Regional distributions of the trend in the parameter are computed with and without human influence using constraints from the global optimal fingerprinting analysis. Anthropogenic forcings alter the regional distributions, indicating that extremely warm days have become hotter.
Near-Surface and Land Surface Forecast System of the Vancouver 2010 Winter Olympic and Paralympic Games
Authors: Bernier Natacha B. , Bélair Stéphane , Bilodeau Bernard , Tong Linying
Published: January 2011

A high-resolution 2D near-surface and land surface model was developed to produce snow and temperature forecasts over the complex alpine region of the Vancouver 2010 Winter Olympic and Paralympic Games. The model is driven by downscaled operational outputs from the Meteorological Service of Canada’s regional and global forecast models. Downscaling is applied to correct forcings for elevation differences between the operational forecast models and the high-resolution surface model. The high-resolution near-surface and land surface model is then used to further refine the forecasts. The model was validated against temperature and snow depth observations. The largest improvements were found in regions where low-resolution (i.e., on the order of 10 km or more) operational models typically lack the spatial resolution to capture rapid elevation changes. The model was found to better reproduce the intermittent snow cover at low-lying stations and to reduce snow depth error by as much as 3 m at alpine stations.
Booker T. and the New Green Collar Workforce: An Earth-Based Reassessment of the Philosophy of Booker T. Washington
Authors: Pope Blaine D. , Smith Ernie A. , Shacks Samuel J. , Hargrove Joyce Keith
Published: January 2011

This article suggests the need for a new “green” and “Earth-based” reassessment of the work of Booker Taliafaro Washington. Although it includes global and national perspectives, the African American community of South Central Los Angeles will provide the primary perspective. A general societal overreliance on petroleum-based chemicals has worked to the long-term environmental detriment of the African American community there. This article draws upon the works of four key environmental activists: Benjamin Chavis Muhammad, Robert Bullard, Van Jones, and Majora Carter. Working across a range of academic disciplines, the authors integrate contemporary “diagnostic” concepts of community health and environmental justice with older “prescriptive” concepts of employment in the primary trades and community self-reliance. The authors suggest that these old “Bookerite” concepts merit reconsideration, reframing, and re-messaging. The life’s work of Washington has therefore been recast here, in light of its newfound green relevance for the African American community, today.
Haiti in the Aftermath of the Earthquake: The Politics of Catastrophe
Authors: Fatton Robert
Published: January 2011

This article examines whether the earthquake of January 2010 has the potential to generate a seismic transformation of the Haitian political and social structure. In other words, will the practices of the past persist under new forms in the period of reconstruction facing the country? Will the “politics of the belly” as well as the acute dependence of Haiti on outside forces of power continue to mould the future? Or is there room to imagine under current conditions the creation of a new state based on greater social and economic equality.
Please Mind the Culture Gap: Intercultural Development During a Teacher Education Study Abroad Program
Authors: Marx Helen , Moss David M.
Published: January 2011

Seeking to deepen our understandings of the ways international study abroad programs may enhance efforts to prepare culturally responsive teachers, the purpose of this case study was to explore a preservice teacher’s intercultural development during a semester-long teacher education program in London, England. Such study abroad teacher education programs are offered as an innovative means to promote preservice teachers’ intercultural development, providing unique opportunities for these students to confront their ethnocentric worldviews and begin to consider the ways culture influences teaching and learning. Findings from this study reveal that participation in the program positively influenced intercultural development. Themes that illuminate aspects of the participant’s study abroad experience that both challenged and supported intercultural development included immersion within both a culture and school along with the essential role of an intercultural guide who promoted reflective practices around issues of culture and self. Implications for preservice teacher education program design are addressed.
Is there a buffering effect of flexibility for job attitudes and work-related strain under conditions of high job insecurity and regional unemployment rate?
Authors: Otto Kathleen , Hoffmann-Biencourt Anja , Mohr Gisela
Published: January 2011

This article explores the relationships of job insecurity and regional unemployment rate with job attitudes and work-related strain. The authors considered the personality attribute flexibility as a potential moderator. Their results revealed job insecurity to be negatively associated with job involvement and career satisfaction and positively with readiness to make concessions and strain. Moreover, with an increasing level of subjective (qualitative) job insecurity, individuals low in flexibility reported lower career satisfaction. In contrast, where objective job insecurity (unemployment rate) was high, these low flexibility participants showed higher career satisfaction. They were also more ready to make concessions and more involved with their job than those high in flexibility. Finally, the study found the proposed buffering effect, as those high in flexibility experienced less health impairment when perceived (quantitative) job insecurity and regional unemployment rate were high. Strategies of coping with uncertainty as well as options regarding strengthening flexibility are discussed.
Perceived barriers and facilitators for general practitioner–patient communication in palliative care: A systematic review
Authors: Slort W , Schweitzer BPM , Blankenstein AH , Abarshi EA , Riphagen Il , Echteld MA , Aaronson NK , der Horst HE Van , Deliens L
Published: January 2011

While effective general practitioner (GP)–patient communication is required for the provision of good palliative care, barriers and facilitators for this communication are largely unknown. We aimed to identify barriers and facilitators for GP–patient communication in palliative care. In a systematic review seven computerized databases were searched to find empirical studies on GP–patient communication in palliative care. Fifteen qualitative studies and seven quantitative questionnaire studies were included. The main perceived barriers were GPs’ lack of availability, and patients’ and GPs’ ambivalence to discuss ‘bad prognosis’. Main perceived facilitators were GPs being available, initiating discussion about several end-of-life issues and anticipating various scenarios. Lack of availability and failure to discuss former mistakes appear to be blind spots of GPs. GPs should be more forthcoming to initiate discussions with palliative care patients about prognosis and end-of-life issues. Empirical studies are needed to investigate the effectiveness of the perceived barriers and facilitators.
Encephalitis and Neuronal Necrosis in a 3-Month-Old Suckled Beef Calf
Authors: Benavides J. , Willoughby K. , Underwood C. , Newman B , Mitchell G. , Carty H.
Published: January 2011

A 3-month-old suckled beef calf from the west coast of Scotland showed neurologic clinical signs for 1 week and was euthanized after failing to respond to treatment. Blood and tissue samples, including the brain, were submitted for diagnosis. Histologic examination of the brain showed neuronal chromatolysis and necrosis in the hind brain and loss of Purkinje cells in the cerebellum, accompanied by mild nonsuppurative encephalitis in the hind brain with a striking lack of inflammation in the cerebellar layers. Other microscopic lesions present were mild nonsuppurative meningitis with perivascular cuffs, diffuse hypergliosis, and occasional foci of neuronophagia. Polymerase chain reaction amplification of viral nucleic acids and specific immunohistochemical labeling allowed the identification of louping ill virus, and serology showed high titers of immunoglobulin M, indicating a recent infection.
Investigation of PEG-PLGA-PEG Nanoparticles-based Multipolyplexes for IL-18 Gene Delivery
Authors: Nie Yu , Zhang Zhi-Rong , He Bin , Gu Zhongwei
Published: January 2011

Nanoparticles were formulated with biodegradable monomethoxy (poly ethylene glycol)–poly(lactide-co-glycolide)–monomethoxy (poly ethylene glycol) of three different proportional (PEG-PLGA-PEG, lactic acid: glycolic acid = 80/20, 70/30, 50/50) and the cytotoxicity of nanoparticle was characterized according to US Pharmacopoeia XXIII recommendations on various cell lines, including L929, Chang’s hepatocytes, primary mouse myoblasts, osteoblasts, and renal vascular endothelial cells. mIL-18 gene was first condensed by polycationic peptide polylysine (PLL), and then encapsulated in the PEG-PLGA-PEG NPs as a novel multi-polyplex gene delivery system – Polymer-PLL-DNA. (PPDs) After lyopholization, the morphology, particle size, zeta potential, and the integrity of DNA in the NPs were investigated. The expression of mIL-18 gene on CT-26 cells in vitro were determined by western blot, while in vivo efficacy was evaluated by tumor inhibition rate, histological section, and survival curve in pulmonary metastasis of colon cancer in BALB/c mice model. Results showed that the cytotoxicity of blank nanoparticles was related to the degradation properties of the polymers with different compositions. The NPs with LA:GA = 70/30 (NPs-73) was optimal for intravenous injection due to its low cytotoxicity. Physicochemical properties of the PPDs were not changed during the lyopholization, while mIL-18 was successfully expressed in vitro. The anti-tumor efficacy in vivo of PPDs showed improvement especially combined with chemotherapy of cisplatin, and confirmed the promising application of the PPDs system, which compared with any single treatment.
Structural Characteristics of Small Intestinal Submucosa Constructs Dictate In Vivo Incorporation and Angiogenic Response
Authors: Janis Abram Daved , Johnson Chad C. , Ernst David M. , Brightman Andrew O.
Published: January 2011

The rate of angiogenesis and cellular infiltration into degradable biomaterials determines scaffold persistence in vivo. The ability to tune the degradation properties of naturally derived biomaterials has been a popular goal in tissue engineering, yet has often depended on chemical crosslinking. Small intestinal submucosa (SIS) is a naturally derived, collagen-based, bioactive scaffold that has broad clinical success in many therapeutic applications. Two methods for producing multilayer, non-crosslinked SIS constructs were compared in vitro and in vivo. Traditional and cryo SEM, mercury intrusion porosimetry, and a novel enzymatic degradation assay determined that lyophilization produced an open, porous scaffold, in contrast to the collapsed, denser structure of SIS constructs produced using a vacuum press process. The angiogenic responses to lyophilized and vacuum-pressed SIS constructs were evaluated in vivo using a subcutaneous implant assay in mice. Explanted samples were compared after 7 and 21 days using fluorescence microangiography and light microscopy. Capacity of the implant neovasculature was also determined. These experiments revealed that the lyophilized SIS was infiltrated and vascularized more rapidly than the vacuum pressed. These data demonstrate the tunable incorporation of a non-crosslinked ECM-based biomaterial, which may have implications for the persistence of this degradable scaffold in tissue engineering.
Onsite Health Centers: A Strategic Perspective
Authors: Reuter Charles D.
Published: January 2011

Stand-alone worksite health centers, often called onsite health clinics, are fast-growing alternatives for employers, according to many consultant surveys. Midsize and large employers generally implement onsite health and wellness centers with the objective of improving access to health services, cost performance and quality of care outcomes for their health benefit plan investment. This article outlines the range of potential health center models, summarizes important financial considerations and provides examples of key questions for the procurement process to ensure financial and clinical performance.
Socioeconomic Status, Marital Status Continuity and Change, Marital Conflict, and Mortality
Authors: Choi Heejeong , Marks Nadine F.
Published: January 2011

Objective: The authors investigated (a) whether being continuously married compared with other marital status trajectories over 5 years attenuates the adverse effects of lower education and lower income on longevity, (b) whether being in higher conflict as well as lower conflict marriage compared with being single provides a buffer against socioeconomic status inequalities in mortality, and (c) whether the conditional effects of marital factors on the SES—mortality association vary by gender. Method: The authors estimated logistic regression models with data from adults aged 30 or above who participated in the National Survey of Families and Households 1987— 2002. Results: Being continuously married, compared with being continuously never married or making a transition to separation/divorce, buffered mortality risks among men with low income. Mortality risk for low-income men was also lower in higher conflict marriages compared with being never married or previously married. Discussion: Marriage ameliorates mortality risks for some low-income men.
Social Activity and Depressive Symptoms in Korean American Older Adults
Authors: Jang Yuri , Chiriboga David A.
Published: January 2011

Objective: This study examined the independent and interactive effects of acculturation and social activity on depressive symptoms. Method: Using a sample of community-dwelling Korean American older adults ( N = 675), hierarchical regression models of depressive symptoms were estimated with an array of predictors: (a) demographic variables, (b) health-related variables, (c) acculturation, (d) social activity, and (e) an interaction between acculturation and social activity. Results: After controlling for the effects of demographic and health-related variables, both acculturation and social activity were identified as significant predictors. Moreover, their interaction was significant (β = .09, p < .05). Further analysis showed that the beneficial effect of social activity on mental health was particularly strong among those with lower levels of acculturation. Discussion: Our findings suggest that enhancing opportunities for social engagement may serve to protect and promote the mental health of vulnerable older immigrants, particularly those who are less acculturated.
Holocene settlement shifts and palaeoenvironments on the Central Iranian Plateau: Investigating linked systems
Authors: Schmidt Armin , Quigley Mark , Fattahi Morteza , Azizi Ghasem , Maghsoudi Mehran , Fazeli Hassan
Published: January 2011

For thousands of years, humans have inhabited locations that are highly vulnerable to the impacts of climate change, earthquakes, and floods. In order to investigate the extent to which Holocene environmental changes may have impacted on cultural evolution, we present new geologic, geomorphic, and chronologic data from the Qazvin Plain in northwest Iran that provides a backdrop of natural environmental changes for the simultaneous cultural dynamics observed on the Central Iranian Plateau. Well-resolved archaeological data from the neighbouring settlements of Zagheh (7170—6300 yr BP), Ghabristan (6215—4950 yr BP) and Sagzabad (4050—2350 yr BP) indicate that Holocene occupation of the Hajiarab alluvial fan was interrupted by a 900 year settlement hiatus. Multiproxy climate data from nearby lakes in northwest Iran suggest a transition from arid early-Holocene conditions to more humid middle-Holocene conditions from c. 7550 to 6750 yr BP, coinciding with the settlement of Zagheh, and a peak in aridity at c. 4550 yr BP during the settlement hiatus. Palaeoseismic investigations indicate that large active fault systems in close proximity to the tell sites incurred a series of large (MW ~7.1) earthquakes with return periods of ~500—1000 years during human occupation of the tells. Mapping and optically stimulated luminescence (OSL) chronology of the alluvial sequences reveals changes in depositional style from coarse-grained unconfined sheet flow deposits to proximal channel flow and distally prograding alluvial deposits sometime after c. 8830 yr BP, possibly reflecting an increase in moisture following the early-Holocene arid phase. The coincidence of major climate changes, earthquake activity, and varying sedimentation styles with changing patterns of human occupation on the Hajiarab fan indicate links between environmental and anthropogenic systems. However, temporal coincidence does not necessitate a fundamental causative dependency.
Reconstruction of a regional drought index in southern Sweden since AD 1750
Authors: Drobyshev Igor , Niklasson Mats , Linderholm Hans W. , Seftigen Kristina , Hickler Thomas , Eggertsson Olafur
Published: January 2011

We used a network of eight pedunculate oak ( Quercus robur L.) sites ( ntrees = 70) and one Scots pine ( Pinus sylvestris L.) site ( ntrees = 53) to develop drought-sensitive master chronologies for the two areas in southern Scandinavia: a SW-area centred on 57°N 12.7°E and a NE-area centred on 58.8°N 18.2°E. The ratio of actual to equilibrium evapotranspiration (AET/EET) was used as a measure of drought during the growing season defined as the period with average daily temperatures above 9°C. Instrumental data were used to parameterize the relationship between tree-ring data and the drought index (DI) over 1922—2000 for the SW area and over 1922—1995 for the NE area. The DI reconstructions explained 29.7% (SW area) and 43.7% (NE area) of the variance in the observed DI index in the calibration period, and were extended back to AD 1770 for the SW area and to AD 1750 for the NE area. Reconstructed drought dynamics suggested strong decadal- and century-scale temporal variability and limited regional synchronicity over 1770—2000. Large variations in DI were observed in both regions in the second half of the 1700s. Dry conditions were synchronously reconstructed in both sub-regions during 1781—1784, 1853—1855, and, to a lesser degree, during 1974—1978. Over the 1945—1975 period the SW area exhibited a trend towards drier growing seasons, whereas no such trend could be identified for the NE area. Analysis of correlation maps indicated that regional DI dynamics reflected two different climate regimes, associated with the Kattegat area (SW reconstruction) and southeastern Swedish coast of the Baltic sea (NE reconstruction).
New Terror Architecture in South Asia
Authors: Rath Saroj Kumar
Published: January 2011

Mumbai attacks remain a mystery for long despite the capture of a ‘Lashkar-e-Taiba’ terrorist on the night of 26 November 2008. Pakistan took 77 days to admit its citizen’s involvement, Mumbai police consumed 90 days to file the chargesheet and Federal Bureau of Investigation (FBI) spent a year to arrest a couple of conspirators. The plotters of the attacks belong to five countries (US, Canada, Italy, Pakistan and India) involving three continents. Presently nearly a dozen courts across the world are hearing the case. ‘LeT’ is now considered as the most dangerous terror group in recent time after al Qaeda. Unravelling the Mumbai conspiracy and the new terror architecture in South Asia is challenging as with each passing day mysterious but fresh facts related to the attacks are trickling. The new terror architecture employed in South Asia in recent time is a shift in tactics from suicide bombs to a commando-style military assault with small teams of highly trained, heavily armed operatives launching simultaneous, sustained attacks.