PAC-Bayesian Theory Meets Bayesian Inference

We exhibit a strong link between frequentist PAC-Bayesian risk bounds and the Bayesian marginal likelihood. That is, for the negative log-likelihood loss function, we show that the minimization of PAC-Bayesian generalization risk bounds maximizes the Bayesian marginal likelihood. This provides an alternative explanation to the Bayesian Occam's razor criteria, under the assumption that the data is generated by an i.i.d distribution. Moreover, as the negative log-likelihood is an unbounded loss function, we motivate and propose a PAC-Bayesian theorem tailored for the sub-gamma loss family, and we show that our approach is sound on classical Bayesian linear regression tasks.Comment: Published at NIPS 2015 (http://papers.nips.cc/paper/6569-pac-bayesian-theory-meets-bayesian-inference

Влияние различных агрометеорологических условий на фотосинтез гороха

Рассматривается влияние различных агрометеорологических условий на интенсивность фотосинтеза гороха. Процессы фотосинтеза, дыхания, роста в агрометеорологических расчетах описываются с помощью динамических моделей продукционного процесса растений. Однако все эти модели основаны на аппроксимированных результатах эмпирических исследований, на отдельных территориях по отдельным культурам и предназначены для реализации конкретных целей. Получена количественная оценка влияния солнечной радиации, температуры воздуха, влагообеспеченности, при которых интенсивность фотосинтеза гороха достигает максимальных значений.Розглядається вплив різних агрометеорологічних умов на інтенсивність фотосинтезу гороху. Процеси фотосинтезу, дихання, росту в агрометеорологічних розрахунках описуються за допомогою динамічних моделей продуційного процесу рослин. Проте всі ці моделі засновані на апроксимованих результатах емпіричних досліджень, на окремих територіях по окремих культурах і призначені для реалізації конкретних цілей. Отримана кількісна оцінка впливу сонячної радіації, температури повітря, вологозабезпеченості, при яких інтенсивність фотосинтезу гороху досягає максимальних значень.The influence of the different agro-meteorological conditions on the rate of photosynthesis of pea. Plant development and yield formation - this is a very complex set of a number of physiological processes associated with environmental factors. The processes of photosynthesis, respiration, growth in the agrometeorological calculations are described using dynamic models of the production process of plants. Dynamic models of growth and development of leguminous crops in some way a good description of the specific features of physiological processes in plants. However, all these models are based on the approximate results of empirical research in selected areas for some crops and are designed for specific purposes, so the application of any of them for legume crops need to be very careful . The main processes , which are formed as a result of plant biomass is photosynthesis and respiration. The productivity of photosynthesis is determined by the agrometeorological factors, which are constantly changing during the growing season. At a certain stage of development of the plant photosynthesis productivity per unit area of leaves under given lighting conditions depends on the agro-meteorological conditions, namely the temperature and moisture conditions with the help of numerical experiments determined the effects of different features of agro-meteorological conditions on the rate of photosynthesis . Obtain quantitative estimates of the effect of solar radiation, air temperature, moisture content at which the rate of photosynthesis of pea is highest

Les espaces de l'halieutique

Trois espèces de thons constituent la ressource cible des pêcheries palangrières en Polynésie française : le germon (#Thunnus alalunga), le thon à nageoires jaunes (#Thunnus albacares) et le thon obèse (#Thunnus obesus$). Les distributions géographique et bathymétrique de cette ressource sont étroitement liées aux paramètres hydrologiques et trophiques de l'environnement. Dans le cadre du programme Ecotap, des pêches expérimentales réalisées à l'aide d'une palangre instrumentée ont été couplées à des relevés hydrologiques et des prospections acoustiques. La structure hydrologique est étudiée à l'aide de profils de température, salinité et d'oxygène dissous jusqu'à 500 mètres de profondeur. Une analyse typologique des stations menée à partir de ces variables permet de définir trois zones hydrologiques. Les écho-prospections réalisées entre 0 et 500 mètres, à l'aide d'un sondeur Simrad EK 500 permettent de mesurer une réponse acoustique considérée comme représentative de la biomasse en poissons micronectoniques. Cette biomasse est considérée comme un indice de la capacité trophique du milieu pour les thons. L'étude de la distribution verticale et horizontale du micronecton permet de définir trois zones assez similaires aux zones hydrologiques quant à leur distribution spatiale. La distribution des thons est étudiée à partir des captures réalisées à la palangre instrumentée ainsi qu'à l'aide des échos individualisés détectés par acoustique pouvant être considérés comme étant des thonidés. Dans les deux cas, des informations spatio-temporelles précises sont disponibles pour chaque poisson. Les distributions horizontale et verticale des thons sont étudiées en fonction du volume d'habitat et de la capacité trophqiue du milieu. La stratégie d'occupation de l'espace apparaît différente selon les espèces... (D'après résumé d'auteur

Buoy Gear- a Potential for Bycatch Reduction in the Small-Scale Swordfish Fisheries: a Florida Experience and Indian Ocean Perspective.

A swordfish buoy gear, an innovative fishing practice developed in USA in early 2000s, provide a possibility of direct swordfish targeting yielding high CPUE of target species and very low bycatch levels. Here we present a summary of US experience and discuss potential application of this gear in the Indian Ocean region in the perspective of small-scale fisheries development and bycatch reduction

SIAMESE-RELATED1 Is Regulated Posttranslationally and Participates in Repression of Leaf Growth under Moderate Drought.

The plant cell cycle is tightly regulated by factors that integrate endogenous cues and environmental signals to adapt plant growth to changing conditions. Under drought, cell division in young leaves is blocked by an active mechanism, reducing the evaporative surface and conserving energy resources. The molecular function of cyclin-dependent kinase-inhibitory proteins (CKIs) in regulating the cell cycle has already been well studied, but little is known about their involvement in cell cycle regulation under adverse growth conditions. In this study, we show that the transcript of the CKI gene SIAMESE-RELATED1 (SMR1) is quickly induced under moderate drought in young Arabidopsis thaliana leaves. Functional characterization further revealed that SMR1 inhibits cell division and affects meristem activity, thereby restricting the growth of leaves and roots. Moreover, we demonstrate that SMR1 is a short-lived protein that is degraded by the 26S proteasome after being ubiquitinated by a Cullin-RING E3 ubiquitin ligase. Consequently, overexpression of a more stable variant of the SMR1 protein leads to a much stronger phenotype than overexpression of the native SMR1. Under moderate drought, both the SMR1 transcript and SMR1 protein accumulate. Despite this induction, smr1 mutants do not show overall tolerance to drought stress but do show less growth inhibition of young leaves under drought. Surprisingly, the growth-repressive hormone ethylene promotes SMR1 induction, but the classical drought hormone abscisic acid does not

Local indicators for global species: Pelagic sharks in the tropical northeast Atlantic, Cabo Verde islands region

Pelagic sharks are an important bycatch in pelagic fisheries, especially for drifting longlines targeting swordfish. In the Cabo Verde Archipelago (tropical NE Atlantic), pelagic shark catches can reach a significant proportion of the total catches. Due to the increased concern on the status of pelagic shark species, this study was developed to enhance the current knowledge of those sharks in the Cabo Verde region in comparison to the adjacent areas, especially associated with European Union (EU) pelagic longline fishing activity. Stock status indicators for the two main species, blue shark (Prionace glauca) and shortfin mako (Isurus oxyrinchus), were developed, based on fisheries data from logbooks and onboard scientific observers, including analysis of size frequency distributions and standardized catch-per-unit-of-effort (CPUE) indexes over time. The standardized CPUEs have been stable or increasing for both species in the past 10 years, indicating no signs of local depletion. In terms of sizes, the blue shark catch is composed mainly of adults, which can be a sign of a stable population. On the contrary, the catch of shortfin mako is composed mainly of juveniles, which in conjunction of a decrease of mean size might be a cause of concern, highlighting possible overfishing on the species in the region. Thirty satellite tags, 25 archival miniPATs and 5 SPOT GPS, were deployed in the Cabo Verde Exclusive Economic Zone (EEZ), showing that those species are highly mobile. The biomass and size distributions were modeled with spatial and seasonal models (GAMs) identifying locations where juveniles are predominantly concentrated and that should be prioritized for conservation. This work presents new information on the status of pelagic sharks in the Cabo Verde region in the context of those highly migratory species, and can now be used to promote more sustainable fisheries in the region.FCT IF/00253/2014, SFRH/BD/136074/2018, SFRH/BD/139187/2018, EU/MARE/2012/21: “Scientific advice for fisheries beyond EU waters”, specifically within Specific Contract N° 7: “The provision of advice on the conservation of pelagic sharks associated to fishing activity under EU Sustainable Fisheries Partnership Agreements in the Atlantic Ocean”.info:eu-repo/semantics/publishedVersio