Atomic Force Microscopy - Laser Scanning Confocal Microscopy imaging protocol for copepod fecal pellets

Within the marine carbon and nitrogen biogeochemical cycles, fecal pellets produced by pelagic and benthic copepods are important microbial activity hotspots as particle substrate for bacteria colonization and as sources of particulate and dissolved organic C and N. We developed a protocol combining Atomic Force Microscopy (AFM) and Laser Scanning Confocal Microscopy (LSCM) to study the peritrophic membrane structure and associated bacteria of fecal pellets produced by a benthic copepod, Paramphiascella fulvofasciata. AFM imaging revealed a fibrillar network structure of the peritrophic membrane, 0.7-5.9 nm thick similar to marine polysaccharides and a-chitin. Bacterial cell volume range was 0.006-0.117 µm3 in liquid. LSCM imaging showed a 3D-heterogeneous microenvironment. This protocol would allow high-resolution interrogation of structural changes and bacterial dynamics within the copepod fecal pellets and other heterogeneous particles such marine snow under environmental conditions

AMERICA-STYLE SOCIAL SCIENCE AND THE USE OF MODELS IN PUBLIC ADMINISTRATION

Autor razmatra mogućnost primjene formaliziranih modela u istraživanju problema javne uprave u federalno strukturiranoj američkoj upravi. Iz teorije američkog federalizma je poznato da su troškovi provedbe političkih odluka obrnuto razmjerni upravnoj razini njihove provedbe: troškovi su veći ako ih provode niže upravne razine, tj. državne i lokalne umjesto saveznih vlasti. S druge strane ta teorija tvrdi da su troškovi odlučivanja izravno razmjerni razini odlučivanja: oni su niži ako je niža upravna razina na kojoj se donose odluke. Američka iskustva na području politike eksploatiacije nafte i plina potvrđuju modelsku pretpostavku, te su primjenjiva i na drugim problemskim područjima: optimalni učinak i minimalni troškovi postignuti su u uvjetima u kojima se politič ki propisi donose na razini država, a njihova provedba je u nadležnosti saveznih vlasti.The author deals with the possibility of the application of the formalized models in the study of the public administration issue in the federally structured American administration. The theory of American federalism has taught us that the expenses of the implementation of political decisions are inversely proportionate to the administrative level of their application: the expenses are bigger if the implementation is done at lower administrative levels, i.e. state or local instead of federal authorities. On the other hand, that theory claims that the decision-making expenses are proportionate to the level of decision-making: the lower the decision-making level, the smaller the expenses. The American experience in the arena of the policy of oil and gas exploitation confirms the model’s rationale, and is applicable to other fields: the optimal effect and the minimal expenses have been achieved in the situation in which political regulations are decided upon at the state level, while their implementation lies within the domain of federal government

Fast Leakage Assessment

We describe a fast technique for performing the computationally heavy part of leakage assessment, in any statistical moment (or other property) of the leakage samples distributions. The proposed technique outperforms by orders of magnitude the approach presented at CHES 2015 by Schneider and Moradi. We can carry out evaluations that before took 90 CPU-days in 4 CPU-hours (about a 500-fold speed-up). As a bonus, we can work with exact arithmetic, we can apply kernel-based density estimation methods, we can employ arbitrary pre-processing functions such as absolute value to power traces, and we can perform information-theoretic leakage assessment. Our trick is simple and elegant, and lends itself to an easy and compact implementation. We fit a prototype implementation in about 130 lines of C code

Quantitative characterisation of contourite deposits using medical CT

Five sediment cores, retrieved from four different depositional contouritic morphological settings (a sheeted drift, a confined mounded drift, a mounded elongated drift and a plastered drift) from the Northern Gulf of Cadiz and the Alboran Sea have been analysed using medical X-ray computed tomography (medical CT). A quantitative approach has been used, resulting in a workflow that delineates several radio-density ranges based on the Hounsfield Unit (HU) histogram of each core and tracks these ranges throughout the cores. In order to derive the geological significance, the radio-density ranges of all cores have been compared to non-destructive, continuous chemical and physical proxies as well as grain size measurements. The highest correlations occurred between high HU and proxies indicating elevated bottom currents, such as Zr/Al and sortable silt. Additionally, a continuous increase in average HU and inferred bottom current velocities, needed for the creation of the specific contourite setting, could be observed throughout the five cores. Despite imperfections and the requirement of additional research, promising results have been obtained which could improve the detection of diagnostic criteria for contourites. Moreover, the CT data can give more conclusive evidence on the nature of the (contourite) sedimentary sequence boundaries

Constructing TI-Friendly Substitution Boxes Using Shift-Invariant Permutations

The threat posed by side channels requires ciphers that can be efficiently protected in both software and hardware against such attacks. In this paper, we proposed a novel Sbox construction based on iterations of shift-invariant quadratic permutations and linear diffusions. Owing to the selected quadratic permutations, all of our Sboxes enable uniform 3-share threshold implementations, which provide first order SCA protections without any fresh randomness. More importantly, because of the shift-invariant property, there are ample implementation trade-offs available, in software as well as hardware. We provide implementation results (software and hardware) for a four-bit and an eight-bit Sbox, which confirm that our constructions are competitive and can be easily adapted to various platforms as claimed. We have successfully verified their resistance to first order attacks based on real acquisitions. Because there are very few studies focusing on software-based threshold implementations, our software implementations might be of independent interest in this regard

Temperature stress differentially modulates transcription in meiotic anthers of heat-tolerant and heat-sensitive tomato plants

Contains fulltext : 92405.pdf (publisher's version ) (Open Access

Does Coupling Affect the Security of Masked Implementations?

Masking schemes achieve provable security against side-channel analysis by using secret sharing to decorrelate key-dependent intermediate values of the cryptographic algorithm and side-channel information. Masking schemes make assumptions on how the underlying leakage mechanisms of hardware or software behave to account for various physical effects. In this paper, we investigate the effect of the physical placement on the security using leakage assessment on power measurements collected from an FPGA. In order to differentiate other masking failures, we use threshold implementations as masking scheme in conjunction with a high-entropy pseudorandom number generator. We show that we can observe differences in---possibly---exploitable leakage by placing functions corresponding to different shares of a cryptographic implementation in close proximity