The Dorsal Visual System Predicts Future and Remembers Past Eye Position

Eye movements are essential to primate vision but introduce potentially disruptive displacements of the retinal image. To maintain stable vision, the brain is thought to rely on neurons that carry both visual signals and information about the current direction of gaze in their firing rates. We have shown previously that these neurons provide an accurate representation of eye position during fixation, but whether they are updated fast enough during saccadic eye movements to support real-time vision remains controversial. Here we show that not only do these neurons carry a fast and accurate eye-position signal, but also that they support in parallel a range of time-lagged variants, including predictive and postdictive signals. We recorded extracellular activity in four areas of the macaque dorsal visual cortex during a saccade task, including the lateral and ventral intraparietal areas (LIP, VIP), and the middle temporal (MT) and medial superior temporal (MST) areas. As reported previously, neurons showed tonic eye-position-related activity during fixation. In addition, they showed a variety of transient changes in activity around the time of saccades, including relative suppression, enhancement, and pre-saccadic bursts for one saccade direction over another. We show that a hypothetical neuron that pools this rich population activity through a weighted sum can produce an output that mimics the true spatiotemporal dynamics of the eye. Further, with different pooling weights, this downstream eye position signal could be updated long before (<100 ms) or after (<200 ms) an eye movement. The results suggest a flexible coding scheme in which downstream computations have access to past, current, and future eye positions simultaneously, providing a basis for visual stability and delay-free visually-guided behavior

Spatiotemporal profile of peri-saccadic contrast sensitivity

Sensitivity to luminance contrast is reduced just before and during saccades (saccadic suppression), whereas sensitivity to color contrast is unimpaired peri-saccadically and enhanced post-saccadically. The exact spatiotemporal map of these perceptual effects is as yet unknown. Here, we measured detection thresholds for briefly flashed Gaussian blobs modulated in either luminance or chromatic contrast, displayed at a range of eccentricities. Sensitivity to luminance contrast was reduced peri-saccadically by a scaling factor, which was almost constant across retinal space. Saccadic suppression followed a similar time course across all tested eccentricities and was maximal shortly after the saccade onset. Sensitivity to chromatic contrast was enhanced post-saccadically at all tested locations. The enhancement was not specifically linked to the execution of saccades, as it was also observed following a displacement of retinal images comparable to that caused by a saccade. We conclude that luminance and chromatic contrast sensitivities are subject to distinct modulations at the time of saccades, resulting from independent neural processes

Ondernemen met energie; Gedragsonderzoek naar de drijfveren van glastuinders ten aanzien van energiebesparing.

In de AMvB Glastuinbouw zijn individuele energieverbruiknormen voor 2010 vastgesteld. Doelstelling van dit onderzoek was om, met het oog op deze AMvB, duidelijk te krijgen welke belemmeringen en drijfveren er zijn voor verdere energiebesparing en inzet van duurzame energie door ondernemers in de glastuinbouw. Hiertoe zijn aan de hand van een uitgebreide vragenlijst interviews uitgevoerd op 29 glasbloemen-, 34 glasgroente- en 32 potplantenbedrijven. Op basis van variabelen met betrekking tot de perceptie, de houding en het gedrag van ondernemers ten aanzien van energiebesparing, zijn met behulp van clusteranalyse de bedrijven onderverdeeld in vijf clusters. Het rapport besluit met enkele hoofdlijnen uit de resultaten en een beschrijving per cluster van bedrijfssituaties, belemmeringen en drijfveren van ondernemers, in zogenaamde clusterprofielen

Quantitative proteomics identifies biomarkers to distinguish pulmonary from head and neck squamous cell carcinomas by immunohistochemistry

The differentiation between a pulmonary metastasis and a newly developed squamous cell carcinoma of the lung in patients with prior head and neck squamous cell carcinoma (HNSCC) is difficult due to a lack of biomarkers but is crucially important for the prognosis and therapy of the affected patient. By using high-resolution mass spectrometry in combination with stable isotope labelling by amino acids in cell culture, we identified 379 proteins that are differentially expressed in squamous cell carcinomas of the lung and the head and neck. Of those, CAV1, CAV2, LGALS1, LGALS7, CK19, and UGDH were tested by mmunohistochemistry on 194 tissue samples (98 lung and 96 HNSCCs). The combination of CAV1 and LGALS7 was able to distinguish the origin of the squamous cell carcinoma with high accuracy (area under the curve 0.876). This biomarker panel was tested on a cohort of 12 clinically classified lung tumours of unknown origin after HNSCC. Nine of those tumours were immunohistochemically classifiable

Proteomic profiling of cisplatin-resistant and cisplatin-sensitive germ cell tumour cell lines using quantitative mass spectrometry

\ua9 2022, The Author(s). Purpose: Advanced testicular germ cell tumours (GCT) generally have a good prognosis owing to their unique sensitivity towards cisplatin-based chemotherapies. However, cisplatin-resistant GCT have a poor outcome. Further studies are mandatory to better understand resistance mechanisms and develop therapeutic strategies for refractory GCTs. Methods: Protein levels in cisplatin-resistant GCT cell lines of NTERA-2, NCCIT and 2102EP were analyzed by quantitative proteomic mass spectrometry (MS) in combination with stable isotope labelling by amino acids in cell culture (SILAC). Differentially abundant protein markers of acquired cisplatin resistance were validated by Western blotting. Comprehensive bioinformatical annotation using gene set enrichment analyses (GSEA) and STRING interaction analysis were performed to identify commonly affected pathways in cisplatin resistance and the data were compared to the GCT cohort of the ‘The Cancer Genome Atlas’. Results: A total of 4375 proteins were quantified by MS, 144 of which were found to be differentially abundant between isogenic resistant and sensitive cell line pairs (24 proteins for NTERA-2, 60 proteins for NCCIT, 75 proteins for 2102EP). Western blotting confirmed regulation of key resistance-associated proteins (CBS, ANXA1, LDHA, CTH, FDXR). GSEA revealed a statistically significant enrichment of DNA repair-associated proteins in all three resistant cell lines and specific additional processes for individual cell lines. Conclusion: High resolution MS combined with SILAC is a powerful tool and 144 significantly deregulated proteins were found in cisplatin-resistant GCT cell lines. Our study provides the largest proteomic in vitro library for cisplatin resistance in GCT, yet, enabling further studies to develop new treatment options for patients with refractory GCT

Bran, Hypertriglyceridemia and Urate Clearance

Eight subjects having raised triglyceride levels associated with conditions such s diabetes, hyperuricaemia, obesity and hypothyroidism were given 50g of bran per day to determine the effect of increasing dietary fibre on triglyceride and purine metabolism. The study continued for two months. No significant effect was noted on the serum cholesterol or triglyceride level. There was a significant (

Regular fat and reduced fat dairy products show similar associations with markers of adolescent cardiometabolic health

Reduced fat dairy products are generally recommended for adults and children over the age of two years. However, emerging evidence suggests that dairy fat may not have detrimental health effects. We aimed to investigate prospective associations between consumption of regular versus reduced fat dairy products and cardiometabolic risk factors from early to late adolescence. In the West Australian Raine Study, dairy intake was assessed using semi-quantitative food frequency questionnaires in 860 adolescents at 14 and 17-year follow-ups; 582 of these also had blood biochemistry at both points. Using generalized estimating equations, we examined associations with cardiometabolic risk factors. Models incorporated reduced fat and regular fat dairy together (in serves/day) and were adjusted for a range of factors including overall dietary pattern. In boys, there was a mean reduction in diastolic blood pressure of 0.66 mmHg (95% CI 0.23–1.09) per serve of reduced fat dairy and an independent, additional reduction of 0.47 mmHg (95% CI 0.04–0.90) per serve of regular fat dairy. Each additional serve of reduced fat dairy was associated with a 2% reduction in HDL-cholesterol (95% CI 0.97–0.995) and a 2% increase in total: HDL-cholesterol ratio (95% CI 1.002–1.03); these associations were not observed with regular fat products. In girls, there were no significant independent associations observed in fully adjusted models. Although regular fat dairy was associated with a slightly better cholesterol profile in boys, overall, intakes of both regular fat and reduced fat dairy products were associated with similar cardiometabolic associations in adolescents

Herkennen en Spiegelen: Barrieres en kennishiaten bij energiebesparing in de glastuinbouw.

In dit rapport wordt verslag gedaan van een dieptestudie naar barrières en kennishiaten die glastuinders ervaren bij hun streven naar het besparen van energie. Glastuinders hebben in de loop der jaren een 'persoonlijk optimum' van produceren ontwikkeld dat een (kwetsbaar) evenwicht is tussen de inzet van productiemiddelen en de opbrengst. Besparing op alleen energie brengt dit evenwicht in gevaar. Een nieuw evenwicht kan pas gevonden worden wanneer de inzet van alle productiemiddelen simultaan wordt aangepast. De teler ontbeert de noodzakelijke teeltkundige kennis om zonder grote risico's te lopen zelfstandig op zoek te gaan naar het nieuwe evenwicht, en wordt in zijn mogelijkheden begrensd door de investeringscyclus. In this report, results are described of an in-depth study into barriers and knowledge gaps experienced by greenhouse growers saving energy. In the course of years, growers have found a balance between inputs and production. Merely saving energy endangers this balance. A new balance can only be found if all inputs are adjusted simultaneously. The grower lacks the necessary cultivation knowledge to search independently for a new balance without running huge risks, and is limited in his possibilities by the investment cycle

On Deformations of n-Lie algebras

The aim of this paper is to review the deformation theory of $n$-Lie algebras. We summarize the 1-parameter formal deformation theory and provide a generalized approach using any unital commutative associative algebra as a deformation base. Moreover, we discuss degenerations and quantization of $n$-Lie algebras.Comment: Proceeding of the conference Dakar's Workshop in honor of Pr Amin Kaidi. arXiv admin note: text overlap with arXiv:hep-th/9602016 by other author

Neuronal activity in medial superior temporal area (MST) during memory-based smooth pursuit eye movements in monkeys

We examined recently neuronal substrates for predictive pursuit using a memory-based smooth pursuit task that distinguishes the discharge related to memory of visual motion-direction from that related to movement preparation. We found that the supplementary eye fields (SEF) contain separate signals coding memory and assessment of visual motion-direction, decision not-to-pursue, and preparation for pursuit. Since medial superior temporal area (MST) is essential for visual motion processing and projects to SEF, we examined whether MST carried similar signals. We analyzed the discharge of 108 MSTd neurons responding to visual motion stimuli. The majority (69/108 = 64%) were also modulated during smooth pursuit. However, in nearly all (104/108 = 96%) of the MSTd neurons tested, there was no significant discharge modulation during the delay periods that required memory of visual motion-direction or preparation for smooth pursuit or not-to-pursue. Only 4 neurons of the 108 (4%) exhibited significantly higher discharge rates during the delay periods; however, their responses were non-directional and not instruction specific. Representative signals in the MSTd clearly differed from those in the SEF during memory-based smooth pursuit. MSTd neurons are unlikely to provide signals for memory of visual motion-direction or preparation for smooth pursuit eye movements