Retrograde semaphorin-plexin signalling drives homeostatic synaptic plasticity.

Homeostatic signalling systems ensure stable but flexible neural activity and animal behaviour. Presynaptic homeostatic plasticity is a conserved form of neuronal homeostatic signalling that is observed in organisms ranging from Drosophila to human. Defining the underlying molecular mechanisms of neuronal homeostatic signalling will be essential in order to establish clear connections to the causes and progression of neurological disease. During neural development, semaphorin-plexin signalling instructs axon guidance and neuronal morphogenesis. However, semaphorins and plexins are also expressed in the adult brain. Here we show that semaphorin 2b (Sema2b) is a target-derived signal that acts upon presynaptic plexin B (PlexB) receptors to mediate the retrograde, homeostatic control of presynaptic neurotransmitter release at the neuromuscular junction in Drosophila. Further, we show that Sema2b-PlexB signalling regulates presynaptic homeostatic plasticity through the cytoplasmic protein Mical and the oxoreductase-dependent control of presynaptic actin. We propose that semaphorin-plexin signalling is an essential platform for the stabilization of synaptic transmission throughout the developing and mature nervous system. These findings may be relevant to the aetiology and treatment of diverse neurological and psychiatric diseases that are characterized by altered or inappropriate neural function and behaviour

Aplicaciones del Laser Holmiun en Urología

Introducción: El laser es una tecnología de amplias aplicaciones industriales, biológicas y de investigación que se logra con grandes cantidades de energía transformada en radiación electromagnéti­ca que emite finalmente haces de luz produciendo un efecto fototérmico o fotoacústico. En el caso del láser Holmiun debido a su amplia longitud de onda (2120nm) permite realizar distintos procedimien­tos como la ablación y corte de tejidos, litotripsia y vapori­zación tisular. Objetivo: Presentar los tratamientos mínima­mente invasivos mediante laser Holmium (New Star®, 18W), en distintos padecimientos urológicos realizados hasta la fecha en el país. Material y Métodos: Se presentan los 10 primeros casos de cirugías endourológicas con el laser Holmium realizadas entre julio de 2011 y diciembre de 2012 en el Sanatorio Adventista de Asunción, principalmente litotripcias como nefrolitotripsia percutánea, ureterolitotripcia distal y proximal, nefrolitotripcia vía retrograda mediante uso de ureteroscopio flexible, cistolitotripsia y la cervicotomía vesical y uretrotomía interna, todos ellos em­pleando un equipo de laser Holmium de 18W. Resultados: Se realizaron un caso de nefrolitotripsia percutánea, dos litotripsias caliciales vía retrograda, seis uretero-litotripsias distales y una cistolitotripsia. En tres casos de uretero-litotripsia se requirió de uretrotomía por estrechez uretral bulbar y de anastomosis uretrovesical. Un caso de ureterolitotripsia fue reintervenido por los fragmentos residuales. No hubo perforaciones de mucosas y las retropulsiones fueron mínimas. Se efectuó uretrografía retrógrada de control y calibraciones uretrales en los casos de uretrotomía y de la cervicotomía con láser. Se ejecutaron radiografías simples de las vías urinarias en cistolitotripsia, ureterolitotripsia y nefrolitotripsia percutánea y retrograda, todos ellos mostrando  mejorías  anatómicas. Conclusiones: El laser Holmium es una herramienta que posee un excelente perfil de eficacia y seguridad. Se destaca su generalización en los últimos años para el manejo de las patologías obstructivas del tracto urinario y de la enferme­dad litiásica, de la cual actualmente se constituye como el “estándar de oro”. El campo de la endourología constituye un área primordial para el urólogo general, por lo cual el adiestramiento y empleo de la tecnología laser, constituye uno de los mayores retos en la forma­ción profesional del mismo ya que ha permitido incorporar el  endoscopio flexible  que abarca la totalidad del tracto urinario

A community study on burden and depressive symptoms among carers of demented relatives

Background: Most mild to moderate demented patients are cared at home. Studies have shown that carers face increased stress and are prone to depression. In order to understand their needs, a collaboration study between District Board, Community Rehabilitation Network and local hospitals was done. Objective: (1) To understand care needs of demented patients and their carers in the family. (2) To assess difficulties faced by carers and evaluate their stress. (3) To find out which factors may aggravate or relieve carer stress. Method: The study was performed by interviewing 100 carers by questionnaire. Three main themes were studied: (1) presence of depression by Center for Epidemiological Studies Depression Scale (CES-D), (2) caregiver burden by Zarit Burden Interview (ZBI), patients’ memory and behavioural problems by Revised Memory and Behaviour Problems Checklist (RMBPC), patient ADL performance, and (3) carer coping abilities by Brief COPE and perceived social support by Multidimensional Scale of Perceived Social Support (MSPSS). Results: 49% of patients are in moderate to severe stage, with moderate to high ADL dependency level (mean ADL score: 62.4, with 40% of patients scoring 60 or below). On average carers spent 13.8 hours per day on their relative. 24% of carers have rated self-perceived health status as poor or very poor. 36% have little or no knowledge about the dementia illness. Regarding carer depression, 49% had CES-D score in the moderately and severely depressed range. Caregiver burden was high with ZBI score of 38.2 (>24 being highly associated with depression). Memory and behavioural symptoms were common with mean RMBPC 38.2. Carer coping abilities as measured by Brief COPE was 24.6. Perceived social support as measured by MSPSS was 56.2. Carer depression was found to be correlated with cognitive and behaviour problems as well as carer burden; whereas it was negatively correlated with social support. After multiple linear regression analysis, caregiver burden was the most significant factor contributing to caregiver depression (β=0.55, T=5.43, p<0.001). Conclusions: This cohort of carers, having spent long hours caring for their demented relatives had limited knowledge, poor perceived health and emotional problems. They had high burden and showed signs of depression. Caregiver depression was found to be associated with a higher level of burden.published_or_final_versio

Parton Distributions for Event Generators

In this paper, conventional Global QCD analysis is generalized to produce parton distributions optimized for use with event generators at the LHC. This optimization is accomplished by combining the constraints due to existing hard-scattering experimental data with those from anticipated cross sections for key representative SM processes at LHC (by the best available theory) as joint input to the global analyses. The PDFs obtained in these new type of global analyses using matrix elements calculated in any given order will be best suited to work with event generators of that order, for predictions at the LHC. This is most useful for LO event generators at present. Results obtained from a few candidate PDF sets (labeled as CT09MCS, CT09MC1 and CT09MC2) for LO event generators produced in this way are compared with those from other approaches.Comment: 35 pages, 19 figures, and 4 table

Possible roles of Epstein-Barr virus in Castleman disease

<p>Abstract</p> <p>Background</p> <p>Complete resection seemed to be curative in patients with Castleman disease of any location but the disease is likely to be reactive in its pathogenesis. The relation between Epstein-Barr virus and Castleman disease has not been elucidated. We tried to define the role of Epstein-Barr virus in the pathogenesis of Castleman disease.</p> <p>Methods</p> <p>20 cases of Castleman disease were retrospectively reviewed from 1993 to 2006. At least 2 to 4 representative sections of formalin-fixed, paraffin-embedded specimens from each patient were obtained to examine the presence of EBV and its localization by hematoxylin-eosin stain, immunohistochemistry, polymerase chain reaction and In-situ hybridization</p> <p>Results</p> <p>Hyaline-vascular type was diagnosed in 18 cases, plasma cell type in 1 and mixed type in 1 case. All of them were positive for Epstein-Barr virus confirmed by PCR. For tumors that EBER(Epstein-Barr early region) signals mainly localized in the germinal centers have increased vascularity than cases with EBER detected in inter-follicular areas.</p> <p>Conclusion</p> <p>There is a strong association between Castleman disease and Epstein-Barr virus. EBV may have a potential role in angiogenesis of Castleman disease. For smaller lesion with high activity of angiogenesis but not amenable for curative resection, anti-angiogenesis medications may have a potential role to control the disease.</p

Energy Dependence of the Delta Resonance: Chiral Dynamics in Action

There is an important connection between the low energy theorems of QCD and the energy dependence of the Delta resonance in pi-N scattering, as well as the closely related gamma^{*} N -> pi N reaction. The resonance shape is due not only to the strong pi-N interaction in the p wave but the small interaction in the s wave; the latter is due to spontaneous chiral symmetry breaking in QCD (i.e. the Nambu-Goldstone nature of the pion). A brief overview of experimental tests of chiral perturbation theory and chiral based models is presentedComment: 11 pages, 6 figures, Festschrift for S.N. yan

A fMRI Study of Correlation Between Acupoints and Brain Cortical Sites Involved in Language Functions

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Tuning ultrafast electron thermalization pathways in a van der Waals heterostructure

Ultrafast electron thermalization - the process leading to Auger recombination, carrier multiplication via impact ionization and hot carrier luminescence - occurs when optically excited electrons in a material undergo rapid electron-electron scattering to redistribute excess energy and reach electronic thermal equilibrium. Due to extremely short time and length scales, the measurement and manipulation of electron thermalization in nanoscale devices remains challenging even with the most advanced ultrafast laser techniques. Here, we overcome this challenge by leveraging the atomic thinness of two-dimensional van der Waals (vdW) materials in order to introduce a highly tunable electron transfer pathway that directly competes with electron thermalization. We realize this scheme in a graphene-boron nitride-graphene (G-BN-G) vdW heterostructure, through which optically excited carriers are transported from one graphene layer to the other. By applying an interlayer bias voltage or varying the excitation photon energy, interlayer carrier transport can be controlled to occur faster or slower than the intralayer scattering events, thus effectively tuning the electron thermalization pathways in graphene. Our findings, which demonstrate a novel means to probe and directly modulate electron energy transport in nanoscale materials, represent an important step toward designing and implementing novel optoelectronic and energy-harvesting devices with tailored microscopic properties.Comment: Accepted to Nature Physic

Occurrence of Different Gynandromorphs and Ergatandromorphs in Laboratory Colonies of the Urban Ant, Monomorium floricola

Colonies of Monomorium floricola (Jerdon) in laboratory conditions showed gynandromorphic and ergatandromorphic specimens, the former with nine different combinations of male and female tissues and the latter with 6 different combinations. Their development from egg to adult was around 74.6 days for gynandromorphs, and 87.5 days for ergantandromorphs