Age-related dendritic changes in human occipital and prefrontal cortices: a quantitative Golgi study

Qualitative (Scheibe!, 1992) and quantitative (Jacobs & Scheibel, 1993) research indicates a general decline in dendritic neuropil with increasing age. The present study extends previous human dendritic research by examining quantitatively age-related changes in 2 cortical areas: prefrontal cortex (area 10) and occipital cortex (area 18). Tissue blocks were obtained from the left hemisphere of 10 neurologically normal subjects, ranging in age from 23 to 81 years. Blocks were stained with a modified rapid Golgi technique. Supragranular pyramidal cells were quantified on a Neurolucida computer/microscope interface system (Microbrightfield, Inc.). Dendritic system complexity was determined by several dependent measures: total dendritic length, mean dendritic length , dendritic segment count (DSC), dendritic spine number, and dendritic spine density. All dependent measures, except DSC, decreased with age, with a substantial (approximately 50%) decrease in dendritic spines. Although area 10 exhibited greater dendritic aborizations than area 18, dendritic declines were slightly more pronounced in area 10 than in area 18. The present results quantitatively document the ongoing, dynamic refinement of dendritic systems across the human life span, and suggest that higher order cortical areas (e.g., area 10) may be more susceptible to age-related changes

A quantitative dendritic analysis of four functionally distinct areas of human cerebral cortex

Recent investigations have begun to elucidate the function of dendritic arbors, revealing that the geometry of dendrites and the presence of dendritic spines play important roles in both simulated and actual dendritic function (Midtgaard, 1994). The present study attempts to correlate dendritic complexity with cortical function under the assumption that connectivity in a local cortical area may determine its more holistic functional properties. Two human brains (ages: 23 and 69 years) were used for the present study. Four cortical areas (Brodmann\u27s [1908] areas 3, 1, and 2; area 22; area 44; and area 10), respectively representing Benson\u27s four levels of cortical function (primary, unimodal, heteromodal, and supramodal; 1993, 1994), were stained with the modified rapid Golgi technique (Scheibel & Scheibel, 1978). Twenty supragranular pyramidal cells per cortical level were selected (N = 80). Basilar dendritic systems were analyzed using the Neurolucida computer/microscope interface system (Microbrightfield, Inc.). Dendritic measures, which included total dendritic length (TDL), mean dendritic length (MDL), dendritic segment count (DSC), dendritic spine number (DSN), and dendritic spine density (DSD), were used to determine dendritic complexity. All dendritic measures, with the exception of MDL, increased from primary to supramodal cortex. The present findings are consistent with previous research correlating dendritic measures and cortical function (Larsen, Wainwright, Swanson, & Jacobs, 1994; Scheibel, Conrad, Perdue, Tomiyasu, & Wechsler, 1990; Scheibel et al., 1985) and suggest that dendritic extent is related to the functional capabilities of human cerebral cortex

The Copernicus project

The Copernicus spacecraft, to be launched on May 4, 2009, is designed for scientific exploration of the planet Pluto. The main objectives of this exploration is to accurately determine the mass, density, and composition of the two bodies in the Pluto-Charon system. A further goal of the exploration is to obtain precise images of the system. The spacecraft will be designed for three axis stability control. It will use the latest technological advances to optimize the performance, reliability, and cost of the spacecraft. Due to the long duration of the mission, nominally 12.6 years, the spacecraft will be powered by a long lasting radioactive power source. Although this type of power may have some environmental drawbacks, currently it is the only available source that is suitable for this mission. The planned trajectory provides flybys of Jupiter and Saturn. These flybys provide an opportunity for scientific study of these planets in addition to Pluto. The information obtained on these flybys will supplement the data obtained by the Voyager and Galileo missions. The topics covered include: (1) scientific instrumentation; (2) mission management, planning, and costing; (3) power and propulsion system; (4) structural subsystem; (5) command, control, and communication; and (6) attitude and articulation control

Biochemical Specificity of von Economo Neurons in Hominoids

Objectives: Von Economo neurons (VENs) are defined by their thin, elongated cell body and long dendrites projecting from apical and basal ends. These distinctive neurons are mostly present in anterior cingulate (ACC) and fronto-insular (FI) cortex, with particularly high densities in cetaceans, elephants, and hominoid primates (i.e., humans and apes). This distribution suggests that VENs contribute to specializations of neural circuits in species that share both large brain size and complex social cognition, possibly representing an adaptation to rapidly relay socially-relevant information over long distances across the brain. Recent evidence indicates that unique patterns of protein expression may also characterize VENs, particularly involving molecules that are known to regulate gut and immune function. Methods: In this study, we used quantitative stereologic methods to examine the expression of three such proteins that are localized in VENs—activating-transcription factor 3 (ATF3), interleukin 4 receptor (IL4Rα), and neuromedin B (NMB). We quantified immunoreactivity against these proteins in different morphological classes of ACC layer V neurons of hominoids. Results:Among the different neuron types analyzed (pyramidal, VEN, fork, enveloping, and other multipolar), VENs showed the greatest percentage that displayed immunostaining. Additionally, a higher proportion of VENs in humans were immunoreactive to ATF3, IL4Rα, and NMB than in other apes. No other ACC layer V neuron type displayed a significant species difference in the percentage of immunoreactive neurons. Conclusions: These findings demonstrate that phylogenetic variation exists in the protein expression profile of VENs, suggesting that humans might have evolved biochemical specializations for enhanced interoceptive sensitivity

Campus Vol VIII N 1

Howard Studio. Chris Doner . Picture. 0. Hawk, Pete and Don Shackelford. Prose. 2. Lefevre, Ioe. A Matter Of Propriety. Prose. 3. Porter, Bob. And, In Just 7 Days-You Too Can Be a Freshman! . Picture. 4. Martin, Lyn. And, In Just 7 Days-You Too Can Be a Freshman! . Prose. 4. Clapp, joy. Resignation . Prose. 6. Hawk, Pete. Mile Faces Life: A Case History . Prose. 8. Cook, Mike. A Definition of modernity . Poem. 9.; Miller, Ted. Untitled. Poem.9. Moore, Jules. On Picnics . Poem. 9. Emmet, June. Untitled. Poem. 9. Jacobs, Edward R. Orson Got Angry Again . Prose. 10. Ski-U-Mah. Contemporary Humor . Prose. 13. Pine Needle. Untitled. Prose. 13.; Anonymous. Untitled. Prose. 13

BSE infectivity in jejunum, ileum and ileocaecal junction of incubating cattle

To establish bovine spongiform encephalopathy (BSE) public health protection measures it is important to precisely define the cattle tissues considered as specified risk materials (SRM). To date, in pre-clinical BSE infected cattle, no evidence of the BSE agent had been found in the gut outside of the ileal Peyer's Patches. This study was undertaken to determine when and where the pathological prion protein (PrPSc) and/or BSE infectivity can be found in the small intestine of cattle 4 to 6 months of age, orally challenged with BSE. Samples of the jejunum, the ileum and the ileocaecal junction from 46 BSE infected cattle, culled from 1 up to 44 months post infection (mpi) were examined by immunohistochemistry. Samples from cattle 8 mpi to 20 mpi were additionally studied by PTA Western blot, rapid tests, and by mouse (TgbovXV) bioassay. In doing so nearly all of the cattle, from 4 up to 44 mpi, had detectable amounts of PrPSc and/or infectivity in the distal ileum. In the distal ileum clear time-dependent variations were visible concerning the amount of PrPSc, the tissue structures affected, and the cells involved. BSE infectivity was found not only in the ileum and ileocaecal junction but also in the jejunum. The systematic approach of this study provides new data for qualitative and quantitative risk assessments and allows defining bovine SRM more precisely

The ethical implications of HCI’s turn to the cultural

We explore the ethical implications of HCI’s turn to the ‘cultural’. This is motivated by an awareness of how cultural applications, in our case interactive performances, raise ethical issues that may challenge established research ethics processes. We review research ethics, HCI’s engagement with ethics and the ethics of theatrical performance. Following an approach grounded in Responsible Research Innovation, we present the findings from a workshop in which artists, curators, commissioners, and researchers explored ethical challenges revealed by four case studies. We identify six ethical challenges for HCI’s engagement with cultural applications: transgression, boundaries, consent, withdrawal, data, and integrity. We discuss two broader implications of these: managing tensions between multiple overlapping ethical frames; and the importance of managing ethical challenges during and after an experience as well as beforehand. Finally, we discuss how our findings extend previous discussions of Value Sensitive Design in HCI

Efficacy of different types of cognitive enhancers for patients with schizophrenia:a meta-analysis

Cognitive impairment is a core feature of schizophrenia, which is predictive for functional outcomes and is, therefore, a treatment target in itself. Yet, literature on efficacy of different pharmaco-therapeutic options is inconsistent. This quantitative review provides an overview of studies that investigated potential cognitive enhancers in schizophrenia. We included pharmacological agents, which target different neurotransmitter systems and evaluated their efficacy on overall cognitive functioning and seven separate cognitive domains. In total, 93 studies with 5630 patients were included. Cognitive enhancers, when combined across all different neurotransmitter systems, which act on a large number of different mechanisms, showed a significant (yet small) positive effect size of 0.10 (k = 51, p = 0.023; 95% CI = 0.01 to 0.18) on overall cognition. Cognitive enhancers were not superior to placebo for separate cognitive domains. When analyzing each neurotransmitter system separately, agents acting predominantly on the glutamatergic system showed a small significant effect on overall cognition (k = 29, Hedges' g = 0.19, p = 0.01), as well as on working memory (k = 20, Hedges' g = 0.13, p = 0.04). A sub-analysis of cholinesterase inhibitors (ChEI) showed a small effect on working memory (k = 6, Hedges' g = 0.26, p = 0.03). Other sub-analyses were positively nonsignificant, which may partly be due to the low number of studies we could include per neurotransmitter system. Overall, this meta-analysis showed few favorable effects of cognitive enhancers for patients with schizophrenia, partly due to lack of power. There is a lack of studies involving agents acting on other than glutamatergic and cholinergic systems, especially of those targeting the dopaminergic system.</p

Probing reflection from aerosols with the near-infrared dayside spectrum of WASP-80b

The presence of aerosols is intimately linked to the global energy budget and the composition of a planet's atmospheres. Their ability to reflect incoming light prevents energy from being deposited into the atmosphere, and they shape spectra of exoplanets. We observed five near-infrared secondary eclipses of WASP-80b with the Wide Field Camera 3 (WFC3) aboard the \textit{Hubble Space Telescope} to provide constraints on the presence and properties of atmospheric aerosols. We detect a broadband eclipse depth of $34\pm10$\,ppm for WASP-80b. We detect a higher planetary flux than expected from thermal emission alone at $1.6\sigma$, which hints toward the presence of reflecting aerosols on this planet's dayside, indicating a geometric albedo of $A_g<0.33$ at 3$\sigma$. We paired the WFC3 data with Spitzer data and explored multiple atmospheric models with and without aerosols to interpret this spectrum. Albeit consistent with a clear dayside atmosphere, we found a slight preference for near-solar metallicities and for dayside clouds over hazes. We exclude soot haze formation rates higher than $10^{-10.7}$ g cm$^{-2}$s$^{-1}$ and tholin formation rates higher than $10^{-12.0}$ g cm$^{-2}$s$^{-1}$ at $3\sigma$. We applied the same atmospheric models to a previously published WFC3/Spitzer transmission spectrum for this planet and found weak haze formation. A single soot haze formation rate best fits both the dayside and the transmission spectra simultaneously. However, we emphasize that no models provide satisfactory fits in terms of the chi-square of both spectra simultaneously, indicating longitudinal dissimilarity in the atmosphere's aerosol composition.Comment: Published in ApJ Letters (20 Oct 2023