Activity in the human superior colliculus relating to endogenous saccade preparation and execution

In recent years a small number of studies have applied functional imaging techniques to investigate visual responses in the human superior colliculus (SC), but few have investigated its oculomotor functions. Here, in two experiments, we examined activity associated with endogenous saccade preparation. We used 3-T fMRI to record the hemodynamic activity in the SC while participants were either preparing or executing saccadic eye movements. Our results showed that not only executing a saccade (as previously shown) but also preparing a saccade produced an increase in the SC hemodynamic activity. The saccade-related activity was observed in the contralateral and to a lesser extent the ipsilateral SC. A second experiment further examined the contralateral mapping of saccade-related activity with a larger range of saccade amplitudes. Increased activity was again observed in both the contralateral and ipsilateral SC that was evident for large as well as small saccades. This suggests that the ipsilateral component of the increase in BOLD is not due simply to small-amplitude saccades producing bilateral activity in the foveal fixation zone. These studies provide the first evidence of presaccadic preparatory activity in the human SC and reveal that fMRI can detect activity consistent with that of buildup neurons found in the deeper layers of the SC in studies of nonhuman primates

The impact of the novel coronavirus movement restrictions in the United Kingdom on food outlet usage and body mass index

Research funding University of Tabuk. Grant Number: 14451 ACKNOWLEDGMENTS The authors thank Vasileios Kyparissis and Florina Birkert for their work with us in distributing and collecting the surveys. Ahmad Albalawi was supported by a studentship from the University of Tabuk, Saudi Arabia (KSA) project code CF10434-63. John R, Speakman was supported by a Wolfson merit award from the Royal Society and a Presidents International Fellowship Initiative award from the Chinese Academy of Sciences.Peer reviewedPublisher PD

Identification of signaling pathways in early mammary gland development by mouse genetics

The mammary gland develops as an appendage of the ectoderm. The prenatal stage of mammary development is hormone independent and is regulated by sequential and reciprocal signaling between the epithelium and the mesenchyme. A number of recent studies using human and mouse genetics, in particular targeted gene deletion and transgenic expression, have identified some of the signals that control specific steps in development. This process involves cell specification and proliferation, reciprocal tissue interactions and cell migration. Since some of these events are recapitulated during tumorigenesis, an understanding of these signaling pathways may contribute to the development of targeted therapies and novel drugs

Towards Constructing Fully Homomorphic Encryption without Ciphertext Noise from Group Theory

In CRYPTO 2008, one year earlier than Gentry\u27s pioneering \lq\lq bootstrapping\u27\u27 technique on constructing the first fully homomorphic encryption (FHE) scheme, Ostrovsky and Skeith III had suggested a completely different approach towards achieving FHE. Namely, they showed that the $\mathsf{NAND}$ operator can be realized in some \emph{non-commutative} groups; consequently, in combination with the $\mathsf{NAND}$ operator realized in such a group, homomorphically encrypting the elements of the group will yield an FHE scheme. However, no observations on how to homomorphically encrypt the group elements were presented in their paper, and there have been no follow-up studies in the literature based on their approach. The aim of this paper is to exhibit more clearly what is sufficient and what seems to be effective for constructing FHE schemes based on their approach. First, we prove that it is sufficient to find a surjective homomorphism $\pi \colon \widetilde{G} \to G$ between finite groups for which bit operators are realized in $G$ and the elements of the kernel of $\pi$ are indistinguishable from the general elements of $\widetilde{G}$. Secondly, we propose new methodologies to realize bit operators in some groups, which enlarges the possibility of the group $G$ to be used in our framework. Thirdly, we give an observation that a naive approach using matrix groups would never yield secure FHE due to an attack utilizing the \lq\lq linearity\u27\u27 of the construction. Then we propose an idea to avoid such \lq\lq linearity\u27\u27 by using combinatorial group theory, and give a prototypical but still \emph{incomplete} construction in the sense that it is \lq\lq non-compact\u27\u27 FHE, i.e., the ciphertext size is unbounded (though the ciphertexts are noise-free as opposed to the existing FHE schemes). Completely realizing FHE schemes based on our proposed framework is left as a future research topic

Epiparasitic plants specialized on arbuscular mycorrhizal fungi

Over 400 non-photosynthetic species from 10 families of vascular plants obtain their carbon from fungi and are thus defined as myco-heterotrophs. Many of these plants are epiparasitic on green plants from which they obtain carbon by 'cheating' shared mycorrhizal fungi. Epiparasitic plants examined to date depend on ectomycorrhizal fungi for carbon transfer and exhibit exceptional specificity for these fungi, but for most myco-heterotrophs neither the identity of the fungi nor the sources of their carbon are known. Because many myco-heterotrophs grow in forests dominated by plants associated with arbuscular mycorrhizal fungi (AMF; phylum Glomeromycota), we proposed that epiparasitism would occur also between plants linked by AMF. On a global scale AMF form the most widespread mycorrhizae, thus the ability of plants to cheat this symbiosis would be highly significant. We analysed mycorrhizae from three populations of Arachnitis uniflora (Corsiaceae, Monocotyledonae), five Voyria species and one Voyriella species (Gentianaceae, Dicotyledonae), and neighbouring green plants. Here we show that non-photosynthetic plants associate with AMF and can display the characteristic specificity of epiparasites. This suggests that AMF mediate significant inter-plant carbon transfer in nature

Winter wheat roots grow twice as deep as spring wheat roots, is this important for N uptake and N leaching losses?

Cropping systems comprising winter catch crops followed by spring wheat could reduce N leaching risks compared to traditional winter wheat systems in humid climates. We studied the soil mineral N (Ninorg) and root growth of winter- and spring wheat to 2.5 m depth during three years. Root depth of winter wheat (2.2 m) was twice that of spring wheat, and this was related to much lower amounts of Ninorg in the 1 to 2.5 m layer after winter wheat (81 kg Ninorg ha-1 less). When growing winter catch crops before spring wheat, N content in the 1 to 2.5 m layer after spring wheat was not different from that after winter wheat. The results suggest that by virtue of its deep rooting, winter wheat may not lead to high levels of leaching as it is often assumed in humid climates. Deep soil and root measurements (below 1 m) in this experiment were essential to answer the questions we posed

Cross-frequency coupling of brain oscillations in studying motivation and emotion

Research has shown that brain functions are realized by simultaneous oscillations in various frequency bands. In addition to examining oscillations in pre-specified bands, interactions and relations between the different frequency bandwidths is another important aspect that needs to be considered in unraveling the workings of the human brain and its functions. In this review we provide evidence that studying interdependencies between brain oscillations may be a valuable approach to study the electrophysiological processes associated with motivation and emotional states. Studies will be presented showing that amplitude-amplitude coupling between delta-alpha and delta-beta oscillations varies as a function of state anxiety and approach-avoidance-related motivation, and that changes in the association between delta-beta oscillations can be observed following successful psychotherapy. Together these studies suggest that cross-frequency coupling of brain oscillations may contribute to expanding our understanding of the neural processes underlying motivation and emotion

Use of endovascular embolization to treat a ruptured arteriovenous malformation in a pregnant woman: a case report

<p>Abstract</p> <p>Introduction</p> <p>Pregnancy has been linked to increased rates of arteriovenous malformation rupture. This link remains a matter of debate and very few studies have addressed the management of arteriovenous malformation in pregnancy. Unruptured arteriovenous malformations in pregnant woman generally warrant conservative management due to the low rupture risk. When pregnant women present with ruptured arteriovenous malformation, however, surgery is often indicated due to the increased risk of re-rupture and associated mortality. Endovascular embolization is widely accepted as an important component of contemporary, multimodal therapy for arteriovenous malformations. Although rarely curative, embolization can facilitate subsequent surgical resection or radiosurgery. No previous reports have been devoted to the endovascular management of an arteriovenous malformation in a pregnant woman.</p> <p>Case presentation</p> <p>A 23-year-old Caucasian woman presented with headache and visual disturbance after the rupture of a left parieto-occipital arteriovenous malformation in the 22nd week of her pregnancy. After involving high-risk obstetric consultants and taking precautions to shield the fetus from ionizing radiation, we proceeded with a single stage of endovascular embolization followed soon after by open surgical resection of the arteriovenous malformation. There were several goals for the angiography in this patient: to better understand the anatomy of the arteriovenous malformation, including the number and orientation of feeding arteries and draining veins; to look for associated pre-nidal or intra-nidal aneurysms; and to partially embolize the arteriovenous malformation via safely-accessible feeders to facilitate surgical resection and minimize blood loss and operative morbidity.</p> <p>Conclusion</p> <p>From our experience and review of the literature, we maintain that ruptured arteriovenous malformations in pregnancy may be managed in a similar manner to those in non-gravid women. Precautions should be taken to reduce the operative time and exposure of the fetus to ionizing radiation and contrast agents.</p

General practitioners’ perspectives on campaigns to promote rapid help-seeking behaviour at the onset of rheumatoid arthritis

Objective. To explore general practitioners’ (GPs’ ) perspectives on public health campaigns to encourage people with the early symptoms of rheumatoid arthritis (RA) to seek medical help rapidly. Design. Nineteen GPs participated in four semistructured focus groups. Focus groups were audio-recorded, transcribed verbatim, and analysed using thematic analysis. Results. GPs recognised the need for the early treatment of RA and identified that facilitating appropriate access to care was important. However, not all held the view that a delay in help seeking was a clinically significant issue. Furthermore, many were concerned that the early symptoms of RA were often non-specific, and that current knowledge about the nature of symptoms at disease onset was inadequate to inform the content of a help-seeking campaign. They argued that a campaign might not be able to specifically target those who need to present urgently. Poorly designed campaigns were suggested to have a negative impact on GPs’ workloads, and would “clog up” the referral pathway for genuine cases of RA. Conclusions. GPs were supportive of strategies to improve access to Rheumatological care and increase public awareness of RA symptoms. However, they have identified important issues that need to be considered in developing a public health campaign that forms part of an overall strategy to reduce time to treatment for patients with new onset RA. This study highlights the value of gaining GPs’ perspectives before launching health promotion campaigns

Simulating radiation damage cascades in graphite

Molecular dynamics simulation is used to study radiation damage cascades in graphite. High statistical precision is obtained by sampling a wide energy range (100–2500 eV) and a large number of initial directions of the primary knock-on atom. Chemical bonding is described using the Environment Dependent Interaction Potential for carbon. Graphite is found to exhibit a radiation response distinct from metals and oxides primarily due to the absence of a thermal spike which results in point defects and disconnected regions of damage. Other unique attributes include exceedingly short cascade lifetimes and fractal-like atomic trajectories. Unusually for a solid, the binary collision approximation is useful across a wide energy range, and as a consequence residual damage is consistent with the Kinchin–Pease model. The simulations are in agreement with known experimental data and help to clarify substantial uncertainty in the literature regarding the extent of the cascade and the associated damage