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The arachnoid barrier delineates the border between the central nervous system and dura mater. Although the arachnoid barrier creates a partition, communication between the central nervous system and the dura mater is crucial for waste clearance and immune surveillance1,2. How the arachnoid barrier balances separation and communication is poorly understood. Here, using transcriptomic data, we developed transgenic mice to examine specific anatomical structures that function as routes across the arachnoid barrier. Bridging veins create discontinuities where they cross the arachnoid barrier, forming structures that we termed arachnoid cuff exit (ACE) points. The openings that ACE points create allow the exchange of fluids and molecules between the subarachnoid space and the dura, enabling the drainage of cerebrospinal fluid and limited entry of molecules from the dura to the subarachnoid space. In healthy human volunteers, magnetic resonance imaging tracers transit along bridging veins in a similar manner to access the subarachnoid space. Notably, in neuroinflammatory conditions such as experimental autoimmune encephalomyelitis, ACE points also enable cellular trafficking, representing a route for immune cells to directly enter the subarachnoid space from the dura mater. Collectively, our results indicate that ACE points are a critical part of the anatomy of neuroimmune communication in both mice and humans that link the central nervous system with the dura and its immunological diversity and waste clearance systems.Arachnoid cuff exit points create openings in the arachnoid barrier enabling the drainage of cerebrospinal fluid and exchange of molecules and cells between the dura and the subarachnoid space, therefore physically connecting the brain and the dura. [ABSTRACT FROM AUTHOR]

The wealth of complex polar topologies1–10 recently found in nanoscale ferroelectrics results from a delicate balance between the intrinsic tendency of the materials to develop a homogeneous polarization and the electric and mechanical boundary conditions imposed on them. Ferroelectric–dielectric interfaces are model systems in which polarization curling originates from open circuit-like electric boundary conditions, to avoid the build-up of polarization charges through the formation of flux-closure11–14 domains that evolve into vortex-like structures at the nanoscale15–17 level. Although ferroelectricity is known to couple strongly with strain (both homogeneous18 and inhomogeneous19,20), the effect of mechanical constraints21 on thin-film nanoscale ferroelectrics has been comparatively less explored because of the relative paucity of strain patterns that can be implemented experimentally. Here we show that the stacking of freestanding ferroelectric perovskite layers with controlled twist angles provides an opportunity to tailor these topological nanostructures in a way determined by the lateral strain modulation associated with the twisting. Furthermore, we find that a peculiar pattern of polarization vortices and antivortices emerges from the flexoelectric coupling of polarization to strain gradients. This finding provides opportunities to create two-dimensional high-density vortex crystals that would enable us to explore previously unknown physical effects and functionalities.The stacking of freestanding ferroelectric perovskite layers with controlled twist angles results in a peculiar pattern of polarization vortices and antivortices that emerges from the flexoelectric coupling of polarization to strain gradients. [ABSTRACT FROM AUTHOR]

Silicon-based spin qubits offer a potential pathway toward realizing a scalable quantum computer owing to their compatibility with semiconductor manufacturing technologies. Recent experiments in this system have demonstrated crucial technologies, including high-fidelity quantum gates and multiqubit operation. However, the realization of a fault-tolerant quantum computer requires a high-fidelity spin measurement faster than decoherence. To address this challenge, we characterize and optimize the initialization and measurement procedures using the parity-mode Pauli spin blockade technique. Here, we demonstrate a rapid (with a duration of a few μs) and accurate (with >99% fidelity) parity spin measurement in a silicon double quantum dot. These results represent a significant step forward toward implementing measurement-based quantum error correction in silicon. [ABSTRACT FROM AUTHOR]

Because of their long coherence time and compatibility with industrial foundry processes, electron spin qubits are a promising platform for scalable quantum processors. A full-fledged quantum computer will need quantum error correction, which requires high-fidelity quantum gates. Analyzing and mitigating gate errors are useful to improve gate fidelity. Here, we demonstrate a simple yet reliable calibration procedure for a high-fidelity controlled-rotation gate in an exchange-always-on Silicon quantum processor, allowing operation above the fault-tolerance threshold of quantum error correction. We find that the fidelity of our uncalibrated controlled-rotation gate is limited by coherent errors in the form of controlled phases and present a method to measure and correct these phase errors. We then verify the improvement in our gate fidelities by randomized benchmark and gate-set tomography protocols. Finally, we use our phase correction protocol to implement a virtual, high-fidelity, controlled-phase gate. [ABSTRACT FROM AUTHOR]

Background: Tumour hypoxia is a negative predictive and prognostic biomarker in colorectal cancer typically assessed by invasive sampling methods, which suffer from many shortcomings. This retrospective proof-of-principle study explores the potential of MRI-derived imaging markers in predicting tumour hypoxia non-invasively in patients with colorectal liver metastases (CLM). Methods: A single-centre cohort of 146 CLMs from 112 patients were segmented on preoperative T2-weighted (T2W) images and diffusion-weighted imaging (DWI). HIF-1 alpha immunohistochemical staining index (high/low) was used as a reference standard. Radiomic features were extracted, and machine learning approaches were implemented to predict the degree of histopathological tumour hypoxia. Results: Radiomic signatures from DWI b200 (AUC = 0.79, 95% CI 0.61–0.93, p = 0.002) and ADC (AUC = 0.72, 95% CI 0.50–0.90, p = 0.019) were significantly predictive of tumour hypoxia. Morphological T2W TE75 (AUC = 0.64, 95% CI 0.42–0.82, p = 0.092) and functional DWI b0 (AUC = 0.66, 95% CI 0.46–0.84, p = 0.069) and b800 (AUC = 0.64, 95% CI 0.44–0.82, p = 0.071) images also provided predictive information. T2W TE300 (AUC = 0.57, 95% CI 0.33–0.78, p = 0.312) and b = 10 (AUC = 0.53, 95% CI 0.33–0.74, p = 0.415) images were not predictive of tumour hypoxia. Conclusions: T2W and DWI sequences encode information predictive of tumour hypoxia. Prospective multicentre studies could help develop and validate robust non-invasive hypoxia-detection algorithms. Critical relevance statement: Hypoxia is a negative prognostic biomarker in colorectal cancer. Hypoxia is usually assessed by invasive sampling methods. This proof-of-principle retrospective study explores the role of AI-based MRI-derived imaging biomarkers in non-invasively predicting tumour hypoxia in patients with colorectal liver metastases (CLM). Key points: Tumour hypoxia is a valuable prognostic/predictive biomarker in colorectal cancer. This proof-of-principle study demonstrates non-invasive associations between MR-radiomics and tumour hypoxia. Radiomics from DWI b200, ADC, and T2W TE75 predicted tumour hypoxia. [ABSTRACT FROM AUTHOR]

The application of thermodynamic reasoning in the study of learning systems has a long tradition. Recently, new tools relating perfect thermodynamic adaptation to the adaptation process have been developed. These results, known as fluctuation theorems, have been tested experimentally in several physical scenarios and, moreover, they have been shown to be valid under broad mathematical conditions. Hence, although not experimentally challenged yet, they are presumed to apply to learning systems as well. Here we address this challenge by testing the applicability of fluctuation theorems in learning systems, more specifically, in human sensorimotor learning. In particular, we relate adaptive movement trajectories in a changing visuomotor rotation task to fully adapted steady-state behavior of individual participants. We find that human adaptive behavior in our task is generally consistent with fluctuation theorem predictions and discuss the merits and limitations of the approach. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is characterised by the progressive loss of midbrain dopaminergic neurons and the presence of aggregated α-synuclein (α-syn). Pericytes and microglia, two non-neuronal cells contain α-syn in the human brain, however, their role in disease processes is poorly understood. Pericytes, found surrounding the capillaries in the brain are important for maintaining the blood–brain barrier, controlling blood flow and mediating inflammation. In this study, primary human brain pericytes and microglia were exposed to two different α-synuclein aggregates. Inflammatory responses were assessed using immunocytochemistry, cytometric bead arrays and proteome profiler cytokine array kits. Fixed flow cytometry was used to investigate the uptake and subsequent degradation of α-syn in pericytes. We found that the two α-syn aggregates are devoid of inflammatory and cytotoxic actions on human brain derived pericytes and microglia. Although α-syn did not induce an inflammatory response, pericytes efficiently take up and degrade α-syn through the lysosomal pathway but not the ubiquitin–proteasome system. Furthermore, when pericytes were exposed the ubiquitin proteasome inhibitor—MG132 and α-syn aggregates, there was profound cytotoxicity through the production of reactive oxygen species resulting in apoptosis. These results suggest that the observed accumulation of α-syn in pericytes in human PD brains likely plays a role in PD pathogenesis, perhaps by causing cerebrovascular instability, under conditions of cellular stress. [ABSTRACT FROM AUTHOR]

Adipose tissue dysfunction is strongly linked to the development of chronic inflammation and cardiometabolic disorders in aging. While much attention has been given to the role of resident adipose tissue immune cells in the disruption of homeostasis in obesity, age-specific effects remain understudied. Here, we identified and characterized a population of γδ T cells, which show unique age-dependent accumulation in the visceral adipose tissue (VAT) of both mice and humans. Diet-induced obesity likewise increased γδ T cell numbers; however, the effect was greater in the aged where the increase was independent of fat mass. γδ T cells in VAT express a tissue-resident memory T cell phenotype (CD44hiCD62LlowCD69+) and are predominantly IL-17A-producing cells. Transcriptome analyses of immunomagnetically purified γδ T cells identified significant age-associated differences in expression of genes related to inflammation, immune cell composition, and adipocyte differentiation, suggesting age-dependent qualitative changes in addition to the quantitative increase. Genetic deficiency of γδ T cells in old age improved the metabolic phenotype, characterized by increased respiratory exchange ratio, and lowered levels of IL-6 both systemically and locally in VAT. Decreased IL-6 was predominantly due to reduced production by non-immune stromal cells, primarily preadipocytes, and adipose-derived stem cells. Collectively, these findings suggest that an age-dependent increase of tissue-resident γδ T cells in VAT contributes to local and systemic chronic inflammation and metabolic dysfunction in aging. [ABSTRACT FROM AUTHOR]

Platelet-derived growth factor-BB (PDGF-BB):PDGF receptor-β (PDGFRβ) signalling in brain pericytes is critical to the development, maintenance and function of a healthy blood-brain barrier (BBB). Furthermore, BBB impairment and pericyte loss in Alzheimer's disease (AD) is well documented. We found that PDGF-BB:PDGFRβ signalling components were altered in human AD brains, with a marked reduction in vascular PDGFB. We hypothesised that reduced PDGF-BB:PDGFRβ signalling in pericytes may impact on the BBB. We therefore tested the effects of PDGF-BB on primary human brain pericytes in vitro to define pathways related to BBB function. Using pharmacological inhibitors, we dissected distinct aspects of the PDGF-BB response that are controlled by extracellular signal-regulated kinase (ERK) and Akt pathways. PDGF-BB promotes the proliferation of pericytes and protection from apoptosis through ERK signalling. In contrast, PDGF-BB:PDGFRβ signalling through Akt augments pericyte-derived inflammatory secretions. It may therefore be possible to supplement PDGF-BB signalling to stabilise the cerebrovasculature in AD. Smyth et al. use tissue microarrays from Alzheimer's disease (AD) patient brains to show that PDGF-BB:PDGFRβ signalling components are reduced in AD. They then use primary human brain pericytes to elucidate a pathway by which PDGF-BB:PDGFRβ signalling in brain pericytes is disrupted in AD, thus impairing the blood brain barrier. [ABSTRACT FROM AUTHOR]

This review aims to identify factors causing heterogeneity in breast DWI–MRI and their impact on its value for identifying breast cancer patients with pathological complete response (pCR) on neoadjuvant systemic therapy (NST). A search was performed on PubMed until April 2020 for studies analyzing DWI for identifying breast cancer patients with pCR on NST. Technical and clinical study aspects were extracted and assessed for variability. Twenty studies representing 1455 patients/lesions were included. The studies differed with respect to study population, treatment type, DWI acquisition technique, post-processing (e.g., mono-exponential/intravoxel incoherent motion/stretched exponential modeling), and timing of follow-up studies. For the acquisition and generation of ADC-maps, various b-value combinations were used. Approaches for drawing regions of interest on longitudinal MRIs were highly variable. Biological variability due to various molecular subtypes was usually not taken into account. Moreover, definitions of pCR varied. The individual areas under the curve for the studies range from 0.50 to 0.92. However, overlapping ranges of mean/median ADC-values at pre- and/or during and/or post-NST were found for the pCR and non-pCR groups between studies. The technical, clinical, and epidemiological heterogeneity may be causal for the observed variability in the ability of DWI to predict pCR accurately. This makes implementation of DWI for pCR prediction and evaluation based on one absolute ADC threshold for all breast cancer types undesirable. Multidisciplinary consensus and appropriate clinical study design, taking biological and therapeutic variation into account, is required for obtaining standardized, reliable, and reproducible DWI measurements for pCR/non-pCR identification. [ABSTRACT FROM AUTHOR]

The term "lean in" was popularized by Sheryl Sandberg, Facebook COO, via her #1 Best Seller encouraging women to defy their fears and dare to be leaders in their fields. She received criticism because although admitting to external barriers contributing to the gender gap in leadership, the scope of her book focused on the internal shortcomings of women. She asserted that women are hindered by barriers that exist within themselves, and provided practical tips, backed by research, to equip women with strategies to proactively progress in the workplace instead of shying away. Sandberg is not the first to raise concern about gender inequality. Other women in history like Susan B. Anthony and Maggie Lena Walker also challenged lopsided gender roles through their words and actions. Using the critical biography methodology, this paper explores these women's experiences, philosophies and contributions, reflects on Sandberg's insight, and develops a framework, based on the theory of planned behavior as well as the ethical principles of utilitarianism and corporate social responsibility, that links internal factors (e.g., self-efficacy, leadership ambition etc.), organizational external factors (e.g., culture, support etc.), and societal external factors (e.g., societal expectations, public policy etc.) to intentions to lean in and leaning in behavior. Thus, via critical biography, this paper examines both internal and external factors, showing how they are linked, and how they may impact leaning in intentions and behavior. The paper also discusses how leaning in may influence both individual and gender mobility for women, and ultimately, increased gender equality. [ABSTRACT FROM AUTHOR]

Methods for predicting circadian phase have been developed for healthy individuals. It is unknown whether these methods generalize to clinical populations, such as delayed sleep–wake phase disorder (DSWPD), where circadian timing is associated with functional outcomes. This study evaluated two methods for predicting dim light melatonin onset (DLMO) in 154 DSWPD patients using ~ 7 days of sleep–wake and light data: a dynamic model and a statistical model. The dynamic model has been validated in healthy individuals under both laboratory and field conditions. The statistical model was developed for this dataset and used a multiple linear regression of light exposure during phase delay/advance portions of the phase response curve, as well as sleep timing and demographic variables. Both models performed comparably well in predicting DLMO. The dynamic model predicted DLMO with root mean square error of 68 min, with predictions accurate to within ± 1 h in 58% of participants and ± 2 h in 95%. The statistical model predicted DLMO with root mean square error of 57 min, with predictions accurate to within ± 1 h in 75% of participants and ± 2 h in 96%. We conclude that circadian phase prediction from light data is a viable technique for improving screening, diagnosis, and treatment of DSWPD. [ABSTRACT FROM AUTHOR]

Neuroinflammation is a key component of virtually all neurodegenerative diseases, preceding neuronal loss and associating directly with cognitive impairment. Neuroinflammatory signals can originate and be amplified at barrier tissues such as brain vasculature, surrounding meninges and the choroid plexus. We designed a high content screening system to target inflammation in human brain-derived cells of the blood–brain barrier (pericytes and endothelial cells) to identify inflammatory modifiers. Screening an FDA-approved drug library we identify digoxin and lanatoside C, members of the cardiac glycoside family, as inflammatory-modulating drugs that work in blood–brain barrier cells. An ex vivo assay of leptomeningeal and choroid plexus explants confirm that these drugs maintain their function in 3D cultures of brain border tissues. These results suggest that cardiac glycosides may be useful in targeting inflammation at border regions of the brain and offer new options for drug discovery approaches for neuroinflammatory driven degeneration. Jansson et al. design a high content screening system to target inflammation in human brain cells of the blood–brain barrier (pericytes and endothelial cells) to identify inflammatory modifiers. They identify cardiac glycosides as powerful regulators of neuroinflammatory pathways in brain barrier tissues such as vasculature, meninges and choroid plexus. [ABSTRACT FROM AUTHOR]

Swallowing muscle strength exercises are effective in restoring swallowing function. In order to perform the exercises with progressive load, the swallow exercise aid (SEA) was developed. Precise knowledge on which muscles are activated with swallowing exercises, especially with the SEA, is lacking. This knowledge would aid in optimizing the training program to target the relevant swallowing muscles, if necessary. Three healthy volunteers performed the three SEA exercises (chin tuck against resistance, jaw opening against resistance and effortful swallow) and three conventional exercises [conventional effortful swallow (cES), Shaker and Masako] in supine position inside an MRI scanner. Fast muscle functional MRI scans (generating quantitative T2-maps) were made immediately before and after the exercises. Median T2 values at rest and after exercise were compared to identify activated muscles. After the three SEA exercises, the suprahyoid, infrahyoid, sternocleidomastoid, and lateral pterygoid muscles showed significant T2 value increase. After the Shaker, the lateral pterygoid muscles did not show such an increase, but the three other muscle groups did. The cES and Masako caused no significant increase in any of these muscle groups. During conventional (Shaker) exercises, the suprahyoid, infrahyoid, and sternocleidomastoid muscles are activated. During the SEA exercises, the suprahyoid, infrahyoid, sternocleidomastoid, and lateral pterygoid muscles are activated. The findings of this explorative study further support the potential of the SEA to improve swallowing rehabilitation. [ABSTRACT FROM AUTHOR]

Purpose: In about 30% of patients treated with neoadjuvant chemoradiotherapy (nCRT) followed by surgical resection for locally advanced oesophageal cancer no vital tumour is found in the resection specimen. Accurate clinical response assessment is critical if deferral from surgery is considered in complete responders. Our study aimed to compare the performance of MRI and of FDG-PET/CT for the detection of residual disease after nCRT. Methods: Patients with oesophageal cancer eligible for nCRT and oesophagectomy were prospectively included. All patients underwent FDG-PET/CT and MRI before and between 6 and 8 weeks after nCRT. Two radiologists scored the MRI scans, and two nuclear medicine physicians scored the FDG-PET/CT scans using a 5-point score for residual disease. Histopathology after oesophagectomy represented the reference standard. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were calculated for detection of residual tumour (ypT+), residual nodal disease (ypN+), and any residual disease (ypT+Nx/ypT0N+). Results: Seven out of 33 (21%) patients had a pathological complete response. The AUCs for individual readers to detect ypT+ were 0.71/0.70 on diffusion-weighted (DW)-MRI and 0.54/0.57 on FDG-PET/CT, and to detect ypN+ were 0.89/0.81 on DW-MRI and 0.75/0.71 on FDG-PET/CT. The AUCs/sensitivities/specificities for the individual readers to detect any residual disease were 0.74/92%/57% and 0.70/96%/43% on MRI; these were 0.49/69%/29% and 0.60/69%/43% on FDG-PET/CT, respectively. Conclusion: MRI reached higher diagnostic accuracies than FDG-PET/CT for the detection of residual tumour in oesophageal cancer patients at 6 to 8 weeks after nCRT. [ABSTRACT FROM AUTHOR]

The term tunnel electroresistance (TER) denotes a fast, non-volatile, reversible resistance switching triggered by voltage pulses in ferroelectric tunnel junctions. It is explained by subtle mechanisms connected to the voltage-induced reversal of the ferroelectric polarization. Here we demonstrate that effects functionally indistinguishable from the TER can be produced in a simpler junction scheme—a direct contact between a metal and an oxide—through a different mechanism: a reversible redox reaction that modifies the oxide's ground-state. This is shown in junctions based on a cuprate superconductor, whose ground-state is sensitive to the oxygen stoichiometry and can be tracked in operando via changes in the conductance spectra. Furthermore, we find that electrochemistry is the governing mechanism even if a ferroelectric is placed between the metal and the oxide. Finally, we extend the concept of electroresistance to the tunnelling of superconducting quasiparticles, for which the switching effects are much stronger than for normal electrons. Besides providing crucial understanding, our results provide a basis for non-volatile Josephson memory devices. The non-volatile switching of tunnel electroresistance in ferroelectric junctions provides the basis for memory and neuromorphic computing devices. Rouco et al. show tunnel electroresistance in superconductor-based junctions that arises from a redox rather than ferroelectric mechanism and is enhanced by superconductivity. [ABSTRACT FROM AUTHOR]

Chemotherapy-induced cognitive impairment, also known as "chemobrain," is a common side effect. The purpose of this study was to examine whether ginsenoside Rg1, a ginseng-derived compound, could prevent chemobrain and its underlying mechanisms. A mouse model of chemobrain was developed with three injections of docetaxel, adriamycin, and cyclophosphamide (DAC) in combination at a 2-day interval. Rg1 (5 and 10 mg/kg daily) was given 1 week prior to DAC regimen for 3 weeks. An amount of 10 mg/kg Rg1 significantly improved chemobrain-like behavior in water maze test. In vivo neuroimaging revealed that Rg1 co-treatment reversed DAC-induced decreases in prefrontal and hippocampal neuronal activity and ameliorated cortical neuronal dendritic spine elimination. It normalized DAC-caused abnormalities in the expression of multiple neuroplasticity biomarkers in the two brain regions. Rg1 suppressed DAC-induced elevation of the proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), but increased levels of the anti-inflammatory cytokines IL-4 and IL-10 in multiple sera and brain tissues. Rg1 also modulated cytokine mediators and inhibited DAC-induced microglial polarization from M2 to M1 phenotypes. In in vitro experiments, while impaired viability of PC12 neuroblastic cells and hyperactivation of BV-2 microglial cells, a model of neuroinflammation, were observed in the presence of DAC, Rg1 co-treatment strikingly reduced DAC's neurotoxic effects and neuroinflammatory response. These results indicate that Rg1 exerts its anti-chemobrain effect in an association with the inhibition of neuroinflammation by modulating microglia-mediated cytokines and the related upstream mediators, protecting neuronal activity and promoting neuroplasticity in particular brain regions associated with cognition processing. [ABSTRACT FROM AUTHOR]

Chemotherapy-induced cognitive impairment, often referred to as "chemobrain," is a common side effect. In this study, mice received three intraperitoneal injections of a combination of docetaxel, adriamycin, and cyclophosphamide (DAC) at 2-day intervals. A water maze test was used to examine cognitive performance, and manganese-enhanced magnetic resonance imaging (MEMRI) was used to examine hippocampal neuronal activity. The whole brain, prefrontal cortex, hippocampus, and blood samples were then collected for cytokine measurement. The DAC-treated mice displayed a significantly shorter duration spent in and fewer entries into the target quadrant of the water maze than the control mice and a pronounced decrease in MEMRI signal intensity in the hippocampal subregions. In a separate experiment using in vivo transcranial two-photon imaging, DAC markedly eliminated dendritic spines without changing the rate of spine formation, leading to a striking loss of spines in the medial prefrontal cortex. DAC treatment resulted in significant elevations in the levels of the proinflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) and in significant decreases in the levels of the anti-inflammatory cytokines IL-4 and IL-10 in most of the sera and brain tissues examined. The IL-6 and TNF-α levels of several sera and brain tissues showed strong inverse correlations with the duration and number of entries in the target quadrant of the water maze and with the hippocampal MEMRI signal intensity, but also showed striking positive correlations with spine elimination and loss. These results indicate that chemobrain is associated with cytokine dysregulation and disrupted neuroplasticity of the brain. [ABSTRACT FROM AUTHOR]

Understanding and control of the spin relaxation time T1 is among the key challenges for spin-based qubits. A larger T1 is generally favored, setting the fundamental upper limit to the qubit coherence and spin readout fidelity. In GaAs quantum dots at low temperatures and high in-plane magnetic fields B, the spin relaxation relies on phonon emission and spin-orbit coupling. The characteristic dependence T1 ∝ B-5 and pronounced B-field anisotropy were already confirmed experimentally. However, it has also been predicted 15 years ago that at low enough fields, the spin-orbit interaction is replaced by the coupling to the nuclear spins, where the relaxation becomes isotropic, and the scaling changes to T1 ∝ B-3. Here, we establish these predictions experimentally, by measuring T1 over an unprecedented range of magnetic fields--made possible by lower temperature--and report a maximum T1 = 57 ± 15 s at the lowest fields, setting a record electron spin lifetime in a nanostructure. [ABSTRACT FROM AUTHOR]

This paper provides an analysis of the spectrum of arguments associated with the term biodiversity, as expressed in the literature. Through sampling of the grey and peer-review literature, and testing of results through semi-structured interviews, this review presents a total of 31 different instrumental and non-instrumental premises used in arguments for biodiversity. Based on the identified premise statements, this review offers a simple classification by which to understand the complex public discourse associated with arguments for biodiversity, and outlines the current frequency of use of arguments in the literature. Although a wide range of premise statements were identified, the majority of arguments were instrumental with the most frequently used ones putting forward economic perspectives as well as emphasising the role of biodiversity in underpinning ecosystem services. Results from interviews with decision-makers emphasise the need to combine arguments in order to strengthen biodiversity conservation generally, and minimise possible risks associated with individual arguments. [ABSTRACT FROM AUTHOR]

This paper presents a feasibility study of a non-aqueous rechargeable battery based on aluminum and poly-(3,4-ethylenedioxythiophene) conductive polymer in a chloroaluminate ionic liquid. The polymer was electrodeposited on a vitreous carbon working electrode in a chloride aqueous solution and the structure was analyzed by scanning electron microscopy. The doping/de-doping mechanism of chloride ions into the polymer structure was studied using a quartz crystal microbalance and cyclic voltammetry. The deposition/dissolution of the aluminum negative electrode were investigated by electrochemical and microscopic methods. Performance data were obtained with a laboratory-scale aluminum-conductive polymer battery at constant current showing an average cell discharge voltage of 1 V and specific energies of at least 84 Wh kg referred to the mass of the polymer and aluminum. The system is novel and the paper outlines further research to improve the cell performance. [ABSTRACT FROM AUTHOR]

Over the last 40 years, electrically conductive polymers have become well established as important electrode materials. Polyanilines, polythiophenes and polypyrroles have received particular attention due to their ease of synthesis, chemical stability, mechanical robustness and the ability to tailor their properties. Electrochemical synthesis of these materials as films have proved to be a robust and simple way to realise surface layers with controlled thickness, electrical conductivity and ion transport. In the last decade, the biomedical compatibility of electrodeposited polymers has become recognised; in particular, polypyrroles have been studied extensively and can provide an effective route to pharmaceutical drug release. The factors controlling the electrodeposition of this polymer from practical electrolytes are considered in this review including electrolyte composition and operating conditions such as the temperature and electrode potential. Voltammetry and current-time behaviour are seen to be effective techniques for film characterisation during and after their formation. The degree of take-up and the rate of drug release depend greatly on the structure, composition and oxidation state of the polymer film. Specialised aspects are considered, including galvanic cells with a Mg anode, use of catalytic nanomotors or implantable biofuel cells for a self-powered drug delivery system and nanoporous surfaces and nanostructures. Following a survey of polymer and drug types, progress in this field is summarised and aspects requiring further research are highlighted. [ABSTRACT FROM AUTHOR]

Purpose: The present study examines religiousness and its connection to suicidal thoughts, plans, and attempts among Trinidad and Tobago adolescents and young adults.Method: Data are from Trend Research Empowering National Development on adolescents and young adults in Trinidad and Tobago (N = 4448). Religious affiliation, self-perceived religiousness, attendance at religious services, prayer frequency, socio-demographic variables, and suicidal thoughts, plans, and attempts were assessed.Results: Compared to nonreligious, Catholics (OR 0.63, p < 0.05) and Seventh-day Adventists (OR 0.47, p < 0.01) were less likely to think about suicide, and hindus (OR 5.81, p < 0.05) and other affiliates (OR 7.28, p < 0.01) were more likely to be treated for suicide. Higher self-rated religiosity was related to lower likelihood of thinking about suicide (OR 0.86, p < 0.01) and lower likelihood of planning suicide (OR 0.78, p < 0.001). Attendance at religious services was related to lower likelihood of thinking about suicide (OR 0.94, p < 05) and fewer suicide attempts (β = -0.11, p < 0.01). More frequent prayer was related to lower likelihood of thinking about suicide (OR 0.92, p < 0.01) and lower likelihood of planning suicide (OR 0.90, p < 0.001).Conclusions: Religiousness may offer benefits for adolescents and young adults in Trinidad and Tobago by reducing the likelihood that they engage in suicide thoughts and behaviors. Results may hold implications for counselors, clergy, teachers, and others working with adolescents and young adults in Trinidad and Tobago. [ABSTRACT FROM AUTHOR]

Background: Objective: The aim of this study was to investigate the perception, knowledge, opinions and beliefs about AD in the French population to improve care for patients with Alzheimer's disease. Design: A cross-sectional telephone survey in 2008. Setting: French 'Alzheimer Plan 2008-2012'. Participants: 2013 respondents, representative of the French population. Measurements: The respondents answered a questionnaire in which they were presented with a series of attitudinal statements about health in general and AD. Results: Main results are summarized as followed: (a) Respondents think that AD can be devastating for a family (93%). This devastating feeling prevails in the population >75 years old and in people who know patient with AD. (b) General population has a reasonable knowledge about AD, but is still unable to recognize early stages: 95% of respondents considered that difficulties to manage administrative papers and find their way back home suggest early AD. (c) 91% of the population would like to know the diagnosis if they had AD. (d) 38% of the population know or have known at least one patient within their social circle. People think that the care of AD's patient can be better but they trust in the French government to improve it. Conclusion: General representation of AD is changing in a positive way and, even though AD is perceived as a calamity, people are confident that solutions will be found in the future. [ABSTRACT FROM AUTHOR]

Recent disruptions in the molybdenum-technetium generator supply chain prompted a review of non-reactor based production methods for both Mo and Tc. Small medical cyclotrons ( E ~ 16-24 MeV) are capable of producing Curie quantities of Tc from isotopically enriched Mo using the Mo(p,2n)Tc reaction. Unlike most other metallic target materials for routine production of medical radioisotopes, molybdenum cannot be deposited by reductive electroplating from aqueous salt solutions. To overcome this issue, we developed a new process for solid molybdenum targets based on the electrophoretic deposition of fine Mo powder onto a tantalum plate, followed by high temperature sintering. The targets obtained were mechanically robust and thermally stable when irradiated with protons at high power density. [ABSTRACT FROM AUTHOR]

An Au-coated TiO nanotubular array, in the vertically aligned form, was investigated as a highly porous nanostructured electrode for the electrochemical reduction of HO in an acidic sulphate electrolyte at 295 K. The TiO nanotubular arrays were formed via a two-stage anodising then nanosized Au particles were sputter deposited onto the surface. The following aspects were studied: (a) the shape evolution of Au particles on the nanotubular array (via surface microstructural imaging), (b) the effect of different degrees of Au loading on the nanotubular array (via voltammetric analysis) and (c) the electrochemical response of an Au-TiO nanotubular array compared to a plain, 2-D Au foil. The Au particles could be deposited as a thin 3-D coated layer or as nodular nanostructures on the array. The highly nanoporous structure of the Au-TiO electrode led to a large enhancement in the limiting current (enhancement factor up to 6.6) and charge density (enhancement factor up to 8.9) for peroxide reduction compared to a plain Au foil due to the architecture of the ordered, high surface area of the nanotubular array. [ABSTRACT FROM AUTHOR]

Conventional superconductivity is incompatible with ferromagnetism, because the magnetic exchange field tends to spin-polarize electrons and breaks apart the opposite-spin singlet Cooper pairs. Yet, the possibility of a long-range penetration of superconducting correlations into strong ferromagnets has been evinced by experiments that found Josephson coupling between superconducting electrodes separated afar by a ferromagnetic spacer. This is considered a proof of the emergence at the superconductor/ferromagnetic (S/F) interfaces of equal-spin triplet pairing, which is immune to the exchange field and can therefore propagate over long distances into the F (ref. ). This effect bears much fundamental interest and potential for spintronic applications. However, a spectroscopic signature of the underlying microscopic mechanisms has remained elusive. Here we do show this type of evidence, notably in a S/F system for which the possible appearance of equal-spin triplet pairing is controversial: heterostructures that combine a half-metallic F (La0.7Ca0.3MnO3) with a d-wave S (YBa2Cu3O7). We found quasiparticle and electron interference effects in the conductance across the S/F interfaces that directly demonstrate the long-range propagation across La0.7Ca0.3MnO3 of superconducting correlations, and imply the occurrence of unconventional equal-spin Andreev reflection. This allows for an understanding of the unusual proximity behaviour observed in this type of heterostructures. [ABSTRACT FROM AUTHOR]

Stream habitat assessments are conducted to evaluate biological potential, determine anthropogenic impacts, and guide restoration projects. Utilizing these procedures, managers must first select a representative stream reach, which is typically selected based on several criteria. To develop a consistent and unbiased procedure for choosing sampling locations, the Illinois Department of Natural Resources and the Illinois Natural History Survey have proposed a technique by which watersheds are divided into homogeneous stream segments called valley segments. Valley segments are determined by GIS parameters including surficial geology, predicted flow, slope, and drainage area. To date, no research has been conducted to determine if the stream habitat within a valley segment is homogeneous and if different valley segments have varying habitat variables. Two abutting valley segments were randomly selected within 13 streams in the Embarras River watershed, located in east-central Illinois. One hundred meter reaches were randomly selected within each valley segment, and a transect method was used to quantify habitat characteristics of the stream channel. Habitat variables for each stream were combined through a principal components analysis (PCA) to measure environmental variation between abutting valley segments. A multivariate analysis of variance (MANOVA) was performed on PCA axes 1-3. The majority of abutting valley segments were significantly different from each other indicating that habitat variability within each valley segment was less than variability between valley segments (5.37 ≤ F ≤ 245.13; P ≤ 0.002). This comparison supports the use of the valley segment model as an effective management tool for identifying representative sampling locations and extrapolating reach-specific information. [ABSTRACT FROM AUTHOR]

Using the powder metallurgy (PM) route, metal foam precursors were produced from pure aluminum, Al–1 Mg, Al–7Cu, and Al–11.5Si containing 1 wt% TiH2 as blowing agent and 8 vol% Al2O3 as stabilizer. Subsequent foaming of these precursors in an expandometer at 90 and 140 °C above the melting point or the liquidus temperature of the metal produced expansion curves for each metal/Al2O3 composition. These expansion curves, as well as foaming experiments (interrupted at maximum expansion as well as 5 min after maximum expansion), were used to judge the stability of the foams produced from the different metal/Al2O3 compositions. Foam stability and wetting behavior of the same metal/Al2O3 combinations were used to evaluate the validity of contact angle measurements during idealized wetting experiments to be used to predict promising metal/stabilizing ceramic particle combinations for foam production based on the model proposed by Kaptay. [ABSTRACT FROM AUTHOR]

To help elucidate the causes of irregular tubular flow oscillations found in the nephrons of spontaneously hypertensive rats (SHR), we have conducted a bifurcation analysis of a mathematical model of two nephrons that are coupled through their tubuloglomerular feedback (TGF) systems. This analysis was motivated by a previous modeling study which predicts that NaCl backleak from a nephron's thick ascending limb permits multiple stable oscillatory states that are mediated by TGF (Layton et al. in Am. J. Physiol. Renal Physiol. 291:F79-F97, 2006); that prediction served as the basis for a comprehensive, multifaceted hypothesis for the emergence of irregular flow oscillations in SHR. However, in that study, we used a characteristic equation obtained via linearization from a single-nephron model, in conjunction with numerical solutions of the full, nonlinear model equations for two and three coupled nephrons. In the present study, we have derived a characteristic equation for a model of any finite number of mutually coupled nephrons having NaCl backleak. Analysis of that characteristic equation for the case of two coupled nephrons has revealed a number of parameter regions having the potential for differing stable dynamic states. Numerical solutions of the full equations for two model nephrons exhibit a variety of behaviors in these regions. Some behaviors exhibit a degree of complexity that is consistent with our hypothesis for the emergence of irregular oscillations in SHR. [ABSTRACT FROM AUTHOR]

Many individuals tend to sleep-in later over the weekend, possibly in an attempt to catch up on accumulated sleep loss from the working week. Previous studies have found that delaying bedtime and waking-up time (WUT) results in a delayed circadian rhythm and a decline in subsequent mood and cognitive functioning. The present study investigated the effect of delaying only WUT for two weekend mornings on the timing of the dim light melatonin onset circadian rhythm (DLMO), as well as sleep, daytime sleepiness and fatigue. In a repeated measures design with 16 participants, the delayed weekend WUT condition (DS) was compared with a weekend in which they kept their habitual weekday WUT (HS). On average, participants in the DS condition delayed their weekend WUT by about 3 h. When compared to the HS condition, participants in the DS condition had a significant delay in salivary DLMO of 42 min between Friday and Sunday nights. They also indicated an 8-min increased sleep onset latency on Sunday night and significantly greater daytime fatigue and sleepiness on Monday and Tuesday of the following week. Sleeping-in late on the weekend appears to have a subsequent cost of delaying circadian rhythm, delaying sleep on Sunday night and increased daytime sleepiness and fatigue, the so-called ‘Monday morning blues’. [ABSTRACT FROM AUTHOR]

When large structures such as residential compounds or public buildings are under the influence of extremely low frequency (ELF) magnetic fields, such as the one generated by a system of railways fed by 16.67 Hz, standard methods of designing shielding structures by numerical methods usually fail. The latter can be explained by the difficulty posed in the computing process by the large aspect ratios involved due to thin layers of metal (a few millimetres or centimetres) in contrast to the large dimensions of the affected structure (several tens of meters). In some cases one has to utilize special approximations such as surface conductivity, which are not easy to handle when the designed shielding structure is clearly three -dimensional. Other alternatives such as experimentation in situ are very costly. Here, a new technique is presented of mitigating the field by using three-dimensional propagation of induced currents optimizing the field reduction factors and minimizing the cost of shielding material. The particular designing method is a hybrid of numerical simulations combined with lab experimentation using scaled models of the large structure. The method is rather cost-effective and flexible as various designs can be easily tested. Results are presented in the form of magnetic field values, at various locations in the buildings, before and after this mitigation technique is applied. [ABSTRACT FROM AUTHOR]

Abstract Orchestrated modulation of cell adhesion is essential for development and homeostasis in multicellular organisms. It optimizes embedding of the cell in its dynamic environment and facilitates appropriate cell responses and intercellular communication. Chronic disturbance of this delicate equilibrium causes defects in tissue architecture and sometimes cancer. In tumor cell biology, dynamic control of adhesion molecules is important to proceed through the metastatic cascade and to allow cell release from the primary tumor, invasion of the surrounding matrix, intravasation and adhesion to vascular endothelial cells to facilitate extravasation. Intertwined and multiple adhesive interactions rather than individual interactions presumably play critical roles in neoplastic development. Yet, knowledge of the contribution of each individual adhesion molecule is essential to unravel this network of interactions. This review will focus on activated leukocyte cell adhesion molecule (ALCAM/CD166) and its role in human melanoma progression. It is hypothesized that ALCAM may function as a cell surface sensor to register local growth saturation and to regulate cellular signaling and dynamic responses. [ABSTRACT FROM AUTHOR]

Previously, we developed a dynamic model for the tubuloglomerular feedback (TGF) system in a single, short-looped nephron of the mammalian kidney. In that model, a semi-linear hyperbolic partial differential equation was used to represent two fundamental processes of solute transport in the nephron’s thick ascending limb (TAL): chloride advection by fluid flow along the TAL lumen and transepithelial chloride transport from the lumen to the interstitium. An empirical function and a time delay were used to relate glomerular filtration rate to the chloride concentration at the macula densa of the TAL. Analysis of the model equations indicated that stable limit-cycle oscillations (LCO) in nephron fluid flow and chloride concentration can emerge for sufficiently large feedback gain magnitude and time delay. In this study, the single-nephron model was extended to two nephrons, which were coupled through their filtration rates. Explicit analytical conditions were obtained for bifurcation loci corresponding to two special cases: (1) identical time delays but differing feedback gains, and (2) identical gains but differing delays. Similar to the case of a single nephron, our analysis indicates that stable LCO can emerge in coupled nephrons for sufficiently large gains and delays. However, these LCO may emerge at lower values of the feedback gain, relative to a single (i.e., uncoupled) nephron, or at shorter delays, provided the delays are sufficiently close. These results suggest that, in vivo, if two nephrons are sufficiently similar, then coupling will tend to increase the likelihood of LCO. [Copyright &y& Elsevier]

We examine the interplay between ferromagnetism and superconductivity in La0.3Ca0.7MnO3/YBa2Cu3O7 superlattices showing “coexistence” of magnetism and superconductivity. A depression of the critical temperature is observed when manganite layer thickness is increased between 0.9 and 8 nm, pointing to an interplay between ferromagnetism and superconductivity over nanometer length scales. The possibility of a ferromagnetic/superconducting proximity effect to explain these results is analyzed. [ABSTRACT FROM AUTHOR]

The objectives of this study are to investigate the relationships between abdominal fat and risk factors for cardiovascular disease (CVD) among normal-weight (NW) white subjects and to determine how these relationships differ by sex. NW adults (177 males and 258 females) and overweight adults (133 males and 111 females) from the Québec Family Study and the HERITAGE Family Study were retained for this study. Risk factors included systolic and diastolic blood pressures, low-density lipoprotein and high-density lipoprotein cholesterols, triglycerides, and fasting glucose. Only in NW female adults, abdominal visceral fat (AVF) area assessed by computed tomography was significantly correlated with all risk factors, except for fasting glucose, even after age, study cohort, and fat mass were taken into account. NW female subjects with at least one risk factor had a significantly higher AVF than those without risk factors, although the difference was small. Thus, only NW female adults with more AVF tended to have a more adverse CVD risk factor profile.International Journal of Obesity (2004) 28, 320-323. doi:10.1038/sj.ijo.0802545 Published online 25 November 2003 [ABSTRACT FROM AUTHOR]

The effect of alloying elements on the wettability of TiC by commercial aluminum alloys (1010, 2024, 6061 and 7075) was investigated at 900°C using a sessile drop technique. Wetting increased in the order 6061 < 7075 < 2024 < 1010 for both, static argon or vacuum atmospheres. Alloys 1010 and 2024 wet TiC under both atmospheres, leading to contact angles in the order of 60° and less, while 7075 only wets under vacuum, with the poorest wettability being exhibited by 6061. Evaporation of Zn and Mg under vacuum conditions contributed to the rupture of the oxide film covering the aluminum drop and thereby improving wetting and spreading. Continuous and isolate Al4C3 was detected in all the cases. CuAl2 precipitation at the interface slightly decreased Al4C3 formation and increased the adhesion of 2024 to TiC. [ABSTRACT FROM AUTHOR]

The preparation of nickel-coated ceramic particles as precursors for MMC fabrication was studied. Al2O3 and SiC powders of three different particle sizes were successfully coated with Ni using an electroless metal plating technique. Uniform and continuous nickel films were deposited on both, alumina and silicon carbide powders, with a final composition ranging from 1.6 to 1.9wt% phosphorus, 18–21wt% of metallic nickel and the balance is ceramic. XRD showed that the Ni-P deposit was predominantly amorphous. However, after heat treatment, the metallic deposits crystallize into Ni and Ni3P phases, as confirmed by DSC analyses. Preliminary results showed that the use of Ni-coated powders enhances the wettability between the matrix and ceramic phase when processing particulate MMCs by infiltration techniques. The coating promoted easy metal flow through the preform, compared to the non-infiltration behavior of the uncoated counterpart samples. [ABSTRACT FROM AUTHOR]