Effect of Tree Phenology on LiDAR Measurement of Mediterranean Forest Structure

Retrieval of forest biophysical properties using airborne LiDAR is known to differ between leaf-on and leaf-off states of deciduous trees, but much less is understood about the within-season effects of leafing phenology. Here, we compare two LiDAR surveys separated by just six weeks in spring, in order to assess whether LiDAR variables were influenced by canopy changes in Mediterranean mixed-oak woodlands at this time of year. Maximum and, to a slightly lesser extent, mean heights were consistently measured, whether for the evergreen cork oak (Quercus suber) or semi-deciduous Algerian oak (Q. canariensis) woodlands. Estimates of the standard deviation and skewness of height differed more strongly, especially for Algerian oaks which experienced considerable leaf expansion in the time period covered. Our demonstration of which variables are more or less affected by spring-time leafing phenology has important implications for analyses of both canopy and sub-canopy vegetation layers from LiDAR surveys

Climatic variables and performance of center pivot at Cristalina, Goiás, Brazil

Objetivou-se, com este trabalho, avaliar o desempenho de um pivô central em função da velocidade do vento (VV), umidade relativa do ar (UR) e temperatura média do ar (T) e estabelecer um modelo estatístico para estimativa da eficiência de aplicação da água em função dessas variáveis independentes. Dados foram coletados nos períodos da manhã e tarde, em três épocas do ano (12 e 13/08/05; 22 e 23/09/05 e 27 e 28/10/05), considerando-se duas velocidades de deslocamento do equipamento, 50 e 100%. O delineamento experimental foi o de blocos ao acaso para o fator velocidade do pivô com o fator época do ano em subparcelas e se considerando o período do dia como repetição. A pressão média no final da linha lateral foi de 137,3 kPa e próxima ao valor previsto pelo fabricante, ou seja, de 127,5 kPa. A lâmina média aplicada foi de 12 e de 5,7 mm para as velocidades de 50 e 100%, respectivamente. Os coeficientes de uniformidade de Christiansen (CUC) calculados resultaram em valores considerados, na literatura, aceitáveis. As lâminas médias coletadas no período da manhã foram maiores que as coletadas no período da tarde. As variáveis independentes VV, T e UR, influenciaram o valor da eficiência de aplicação. _________________________________________________________________________________________ ABSRACTThis research aimed to evaluate center pivot performance as a function of wind speed (VV), relative humidity of air (UR) and mean air temperature (T) and establish a stochastic model to estimate application efficiency as a function of these independent variables. Data were collected, during the morning and the afternoon period, and during three times of the year (August, 12 and 13; September, 22 and 23; and October, 27 and 28, 2005), considering two speeds of outer driver unit (50 and 100%). A randomized block design was used for factor speed of outer driver with factor time of the year as a split plot of factor speed, and considering period of the day as replication. The mean pressure head at the end of the lateral was 137.3 kPa and close to the value predicted by the dealer of 127.5 kPa. The average water depths applied were 12 and 5.7 mm for 50 and 100% speed, respectively. Calculated Christiansen's uniformity coefficient (CUC) provided values considered in literature as standard. Average water depths collected in the morning period were greater than the ones collected in the afternoon. VV, T and UR independent variables influenced significantly water application efficiency values

Power-law bounds for increasing subsequences in Brownian separable permutons and homogeneous sets in Brownian cographons

The Brownian separable permutons are a one-parameter family -- indexed by $p\in(0,1)$ -- of universal limits of random constrained permutations. We show that for each $p\in (0,1)$, there are explicit constants $1/2 < \alpha_*(p) \leq \beta^*(p) < 1$ such that the length of the longest increasing subsequence in a random permutation of size $n$ sampled from the Brownian separable permuton is between $n^{\alpha_*(p) - o(1)}$ and $n^{\beta^*(p) + o(1)}$ with probability tending to 1 as $n\to\infty$. In the symmetric case $p=1/2$, we have $\alpha_*(p) \approx 0.812$ and $\beta^*(p)\approx 0.975$. We present numerical simulations which suggest that the lower bound $\alpha_*(p)$ is close to optimal in the whole range $p\in(0,1)$. Our results work equally well for the closely related Brownian cographons. In this setting, we show that for each $p\in (0,1)$, the size of the largest clique (resp. independent set) in a random graph on $n$ vertices sampled from the Brownian cographon is between $n^{\alpha_*(p) - o(1)}$ and $n^{\beta^*(p) + o(1)}$ (resp. $n^{\alpha_*(1-p) - o(1)}$ and $n^{\beta^*(1-p) + o(1)}$) with probability tending to 1 as $n\to\infty$. Our proofs are based on the analysis of a fragmentation process embedded in a Brownian excursion introduced by Bertoin (2002). We expect that our techniques can be extended to prove similar bounds for uniform separable permutations and uniform cographs.Comment: New version before journal submissio

Dense Circulant Lattices From Nonlinear Systems

Circulant lattices are those with a circulant generator matrix. They can be described by a basis containing a vector and its circular shifts. In this paper, we present certain conditions under which the norm expression of an arbitrary vector of a circulant lattice is substantially simplified, and then investigate some of the lattices obtained under these conditions. We exhibit systems of nonlinear equations whose solutions yield lattices as dense as $D_n$ in odd dimensions.Comment: preprint, 21 pages, 5 figure

A trans10-18:1 enriched fraction from beef fed a barley grain-based diet induces lipogenic gene expression and reduces viability of HepG2 cells.

Beef fat is a natural source of trans (t) fatty acids, and is typically enriched with either t10-18:1 or t11-18:1. Little is known about the bioactivity of individual t-18:1 isomers, and the present study compared the effects of t9-18:1, cis (c)9-18:1 and trans (t)-18:1 fractions isolated from beef fat enriched with either t10-18:1 (HT10) or t11-18:1 (HT11). All 18:1 isomers resulted in reduced human liver (HepG2) cell viability relative to control. Both c9-18:1 and HT11were the least toxic, t9-18:1had dose response increased toxicity, and HT10 had the greatest toxicity (P&lt;0.05). Incorporation of t18:1 isomers was 1.8-2.5 fold greater in triacylglycerol (TG) than phospholipids (PL), whereas Δ9 desaturation products were selectively incorporated into PL. Culturing HepG2 cells with t9-18:1 and HT10 increased (P&lt;0.05) the Δ9 desaturation index (c9-16:1/16:0) compared to other fatty acid treatments. HT10 and t9-18:1 also increased expression of lipogenic genes (FAS, SCD1, HMGCR and SREBP2) compared to control (P&lt;0.05), whereas c9-18:1 and HT11 did not affect the expression of these genes. Our results suggest effects of HT11 and c9-18:1 were similar to BSA control, whereas HT10 and t-9 18:1 (i.e. the predominant trans fatty acid isomer found in partially hydrogenated vegetable oils) were more cytotoxic and led to greater expression of lipogenic genes

The scaling limit of the volume of loop O(n) quadrangulations

We study the volume of rigid loop-$O(n)$ quadrangulations with a boundary of length $2p$ in the critical non-generic regime. We prove that, as the half-perimeter $p$ goes to infinity, the volume scales in distribution to an explicit random variable. This limiting random variable is described in terms of the multiplicative cascades of Chen, Curien and Maillard arXiv:1702.06916, or alternatively (in the dilute case) as the law of the area of a unit-boundary $\gamma$-quantum disc, as determined by Ang and Gwynne arXiv:1903.09120, for suitable $\gamma$. Our arguments go through a classification of the map into several regions, where we rule out the contribution of bad regions to be left with a tractable portion of the map. One key observable for this classification is a Markov chain which explores the nested loops around a size-biased vertex pick in the map, making explicit the spinal structure of the discrete multiplicative cascade.Comment: 45 pages, 6 figures, comments welcome

The Case for Public Interventions during a Pandemic

Funding Information: This work has been supported by Marie Skłodowska Curie Actions ITN AffecTech (ERC H2020 Project 1059 ID: 722022). Publisher Copyright: © 2022 by the authors.Within the field of movement sensing and sound interaction research, multi-user systems have gradually gained interest as a means to facilitate an expressive non-verbal dialogue. When tied with studies grounded in psychology and choreographic theory, we consider the qualities of interaction that foster an elevated sense of social connectedness, non-contingent to occupying one’s personal space. Upon reflection of the newly adopted social distancing concept, we orchestrate a technological intervention, starting with interpersonal distance and sound at the core of interaction. Materialised as a set of sensory face-masks, a novel wearable system was developed and tested in the context of a live public performance from which we obtain the user’s individual perspectives and correlate this with patterns identified in the recorded data. We identify and discuss traits of the user’s behaviour that were accredited to the system’s influence and construct four fundamental design considerations for physically distanced sound interaction. The study concludes with essential technical reflections, accompanied by an adaptation for a pervasive sensory intervention that is finally deployed in an open public space.publishersversionpublishe