An algebraic topological method for multimodal brain networks comparison

Understanding brain connectivity is one of the most important issues in neuroscience. Nonetheless, connectivity data can reflect either functional relationships of brain activities or anatomical connections between brain areas. Although both representations should be related, this relationship is not straightforward. We have devised a powerful method that allows different operations between networks that share the same set of nodes, by embedding them in a common metric space, enforcing transitivity to the graph topology. Here, we apply this method to construct an aggregated network from a set of functional graphs, each one from a different subject. Once this aggregated functional network is constructed, we use again our method to compare it with the structural connectivity to identify particular brain regions that differ in both modalities (anatomical and functional). Remarkably, these brain regions include functional areas that form part of the classical resting state networks. We conclude that our method -based on the comparison of the aggregated functional network- reveals some emerging features that could not be observed when the comparison is performed with the classical averaged functional network

False vacuum decay in kink scattering

In this work we consider kink-antikink and antikink-kink collisions in a modified $\phi^4$ model with a false vacuum characterized by a dimensionless parameter $\epsilon$. The usual $\phi^4$ model is recovered for $\epsilon=0$. We investigate the $\epsilon<<1$ regime where the kink in the presence of false vacuum can be understood as a small deformation of the standard kink for the $\phi^4$ model. We show that the attractive interaction between the kink-antikink pair leads to a rich scattering pattern, in some cases delaying considerably the false vacuum decay.Comment: 16 pages, 17 figure

Software-Defined Radio Implementation of a LoRa Transceiver

The number of applications of low-power wide-area networks (LPWANs) has been growing quite considerably in the past few years and so has the number of protocol stacks. Despite this fact, there is still no fully open LPWAN protocol stack available to the public, which limits the flexibility and ease of integration of the existing ones. The closest to being fully open is LoRa; however, only its medium access control (MAC) layer, known as LoRaWAN, is open and its physical and logical link control layers, also known as LoRa PHY, are still only partially understood. In this paper, the essential missing aspects of LoRa PHY are not only reverse engineered, but also, a new design of the transceiver and its sub-components are proposed and implemented in a modular and flexible way using GNU Radio. Finally, some examples of applications of both the transceiver and its components, which are made to be run in a simple setup by using cheap and widely available off-the-shelf hardware, are given to show how the library can be used and extended

Ornithogenic soil toposequence on Rata island, Fernando de Noronha archipelago, south atlantic and quaternary paleoclimatic implications.

The formation of highly phosphatized soils on sites of avian activity is a common feature of oceanic islands. We characterized a toposequence of phosphatic soils on Rata Island, to evaluate the soil genesis based on local topographic variations. For this purpose, four soils ranging from the upper hill down to the lowest landscape position on the island, representing a range of parent materials (basalt and calcareous sands), were analyzed. In the lowest landscape position a shallow Entisol was identified, strongly influenced by birds and marine sprays (Litholic Neosol), developed on " karstified" Pleistocene calcarenites; the three other soils in the upper part of the toposequence are Ornithogenic Inceptsols (Cambisols), ranging from a deep Cambisol profile on Basalt lava to intermediate Cambisols on mixed colluvial sediments of the basalt/calcareous. The lowermost Litholic Neosol is associated with a rugged landscape with strong calcarenite dissolution and karstification, related to a former wetter climate. The soil phosphatization is clearly an inherited process of the Late Quaternary age, when climate conditions were different. Initial weathering took place in the last interglacial period, under wetter conditions during which the Tertiary basalts were strongly weathered, leaving corestones in a saprolitic, oxidized mass. In the late Pleistocene, a gentle surface distributed these weathering products along the pediment slopes as colluvial materials, whereas in the coastal areas aeolian processes formed large sand dunes composed of reworked calcareous sands from marine sources during a time of very low sea level. During this time, widespread bird activity accounted for secondary apatite formation on the surface of calcareous oolites. Finally, the Holocene warming was accompanied by increasing sea level, enhanced tropical weathering, Fe and Al mobility and variscite formation superimposed on degraded Ca-phosphates, forming two phase phosphatic aggregates

Kinetic resolution of (R,S)-1,2-isopropylidene glycerol (solketal) ester derivatives by lipases

AbstractA study on the enantioselective hydrolysis of (R,S)-1,2-isopropylidene glycerol (4-hydroxymethyl-2,2-dimethyl-1,3-dioxolane, solketal) octanoate catalyzed by different lipases was carried out. Among them, Pseudomonas sp. lipase proved to be the most effective. It was shown that the ester bearing the longer octanoyl acyl chain is a more suitable substrate for this lipase compared to the acetate counterpart. By properly combining enzyme load, temperature and reaction time, either the (S)-alcohol or the remaining ester could be obtained in moderate to high selectivities. Ethyl acetate was found to be the best solvent for the kinetic resolutions effected by such lipase but our results show that toluene may prove useful

Effects of Dry Matter Content and Microbial Additive on Tifton 85 \u3ci\u3e(Cynodon dactylon ssp.)\u3c/i\u3e Wilted Silage Fermentation Parameters

The objective of this study was to evaluate the wilting and the addition of a bacterial-enzymatic additive effects on the fermentation parameters of Tifton 85 (Cynodon dactylon spp.) silage. Forage was stored as 326 kg bales wrapped with a plastic film. Treatments consisted of 5 forage dry matter levels (20-30%, 30-40%, 40-50%, 50 -60% e 60 a 70%) without additive and 3 dry matter levels (20-30%, 40-50%, e 60-70%) with additive. Buffered propionic acid solution was sprayed onto 60-70% dry matter bales, prior to wrapping, determining an additional treatment. Core samples were taken at 0, 6, 12 hours and 1, 2, 4, 8, 16, and 32 days after wrapping to establish silage pH and temperature trends. Field dry matter losses during the baling process were also evaluated. Bale weight with no additive decreased (364 kg to 254 kg) with increased forage DM content, which in turn resulted in lower bale bulk density (310 to 216 kg/m3 ). Lower field DM losses (281 to 177 kg/ha) were associated with higher forage DM content. Final silage pH and temperature peaks were increased at higher DM content, whereas the presence of microbial additive prevented temperature surge

Use of a load carriage assistance device for specialist police

Aim: to examine the effectiveness of a load carriage assistance device (LCAD) on specialist police mobility and marksmanship.Design: A randomized counter-balanced study.Method: Six specialist police officers (age = 41.1±6.2 years, weight = 88.4±9.2 kg) completed 2x2 trials of a tactical course as quickly as possible with and without a Reaper™ LCAD (randomised), worn to support the load of their ballistic shield (±20 kg). Heart rate was measured via an Equivital™ harnesses and marksmanship via distance from centre of target (DCOT). Perceived LCAD impacts were measured with a visual analogue scale (VAS). Bond University Human Research Ethics Committee provided ethics approval (RO1585).Results: No significant differences were found for heart rate (non-Reaper™=152.20±7.29 bpm; Reaper™=152.01±12.97 bpm, p=0.910) or completion time (non-Reaper™=80.46±13.98 secs, Reaper™=76.82±11.23 secs, p=0.130); although a trend towards faster times wearing the ReaperTM was found. Marksmanship was not significantly different between trials however officers lowered the shield on the ground during the non-Reaper™ trials to engage the target. The VAS results were significantly poorer (p&lt;0.001) in non-Reaper™ (-5.58±1.93 mm) versus Reaper™ (2.88±4.90 mm) trials.Conclusion: Officers considered the riot shield to negatively impact their performance to a lesser degree when assisted by the LCAD. The ability to support the shield on the LCAD allowed officers to maintain protection behind a riot shield.</div