Search results for "clock"

Properties of Halococcus salifodinae, an Isolate from Permian Rock Salt Deposits, Compared with Halococci from Surface Waters

2013

Halococcus salifodinae BIpT DSM 8989T, an extremely halophilic archaeal isolate from an Austrian salt deposit (Bad Ischl), whose origin was dated to the Permian period, was described in 1994. Subsequently, several strains of the species have been isolated, some from similar but geographically separated salt deposits. Hcc. salifodinae may be regarded as one of the most ancient culturable species which existed already about 250 million years ago. Since its habitat probably did not change during this long period, its properties were presumably not subjected to the needs of mutational adaptation. Hcc. salifodinae and other isolates from ancient deposits would be suitable candidates for testing …

Partial Melting and Counterclockwise P T Path of Subducted Oceanic Crust (Sierra del Convento Melange, Cuba)

2007

A Novel Systolic Parallel Hardware Architecture for the FPGA Acceleration of Feedforward Neural Networks

2019

New chips for machine learning applications appear, they are tuned for a specific topology, being efficient by using highly parallel designs at the cost of high power or large complex devices. However, the computational demands of deep neural networks require flexible and efficient hardware architectures able to fit different applications, neural network types, number of inputs, outputs, layers, and units in each layer, making the migration from software to hardware easy. This paper describes novel hardware implementing any feedforward neural network (FFNN): multilayer perceptron, autoencoder, and logistic regression. The architecture admits an arbitrary input and output number, units in la…

A morphology-based approach to the evaluation of atrial fibrillation organization.

2007

Overlooked cryptic endemism in copepods: Systematics and natural history of the calanoid subgenus Occidodiaptomus Borutzky 1991 (Copepoda, Calanoida,…

2012

Abstract Our comprehension of the phylogeny and diversity of most inland–water crustaceans is currently hampered by their pronounced morphological bradytely, which contributed to the affirmation of the “Cosmopolitanism Paradigm” of freshwater taxa. However, growing evidence of the existence of cryptic diversity and molecular regionalism is available for calanoid copepods, thus stressing the need for careful morphological and molecular studies in order to soundly investigate the systematics, diversity and distribution patterns of the group. Diaptomid copepods were here chosen as model taxa, and the morphological and molecular diversity of the species belonging to the west-Mediterranean diapt…

Mutual antagonism between clock protein Period2 and hepatitis C virus replication in hepatocytes.

2013

Background: Hepatitis C virus (HCV) infects approximately 3% of the world population and is the leading cause of liver disease, impacting hepatocyte metabolism, depending on virus genotype. Hepatic metabolic functions show rhythmic fluctuations with 24-h periodicity (circadian), driven by molecular clockworks ticking through translational-transcriptional feedback loops, operated by a set of genes, called clock genes, encoding circadian proteins. Disruption of biologic clocks is implicated in a variety of disorders including fatty liver disease, obesity and diabetes. The relation between HCV replication and the circadian clock is unknown. Methods: We investigated the relationship between HCV…

Non-alcoholic fatty pancreas disease pathogenesis: a role for developmental programming and altered circadian rhythms.

2013

Objectives Emerging evidence suggests that maternal obesity (MO) predisposes offspring to obesity and the recently described non-alcoholic fatty pancreas disease (NAFPD) but involved mechanisms remain unclear. Using a pathophysiologically relevant murine model, we here investigated a role for the biological clock - molecular core circadian genes (CCG) in the generation of NAFPD. Design Female C57BL6 mice were fed an obesogenic diet (OD) or standard chow (SC) for 6 weeks, prior to pregnancy and throughout gestation and lactation: resulting offspring were subsequently weaned onto either OD (Ob_Ob and Con_Ob) or standard chow (Ob_Con and Con_Con) for 6 months. Biochemical, pro-inflammatory and…

The quantum clock: a critical discussion on space-time

2016

We critically discuss the measure of very short time intervals. By means of a Gedankenexperiment, we describe an ideal clock based on the occurrence of completely random events. Many previous thought experiments have suggested fundamental Planck-scale limits on measurements of distance and time. Here we present a new type of thought experiment, based on a different type of clock, that provide further support for the existence of such limits. We show that the minimum time interval $\Delta t$ that this clock can measure scales as the inverse of its size $\Delta r$. This implies an uncertainty relation between space and time: $\Delta r$ $\Delta t$ $> G \hbar / c^4$; where G, $\hbar$ and c are …

Metabolic comorbidities of adrenal insufficiency: Focus on steroid replacement therapy and chronopharmacology

2021

Adrenal insufficiency (AI) is characterized by higher mortality and morbidity compared with the general population. Conventional replacement steroid therapy, currently recommended for the treatment of AI, is associated with increased frequency of metabolic comorbidities due to daily overexposure. By contrast, dual-release hydrocortisone is associated with a decreased risk of metabolic comorbidities, providing an adequate release of hydrocortisone and mimicking the physiological profile of cortisol. These favorable effects are due to a reduced daily steroid exposure that does not affect the expression of the clock genes which are involved in metabolic pathways and are regulated by the normal…

Molecular evolution of the arthropod hemocyanin superfamily.

2001

Arthropod hemocyanins are members of a protein superfamily that also comprises the arthropod phenoloxidases (tyrosinases), crustacean pseudohemocyanins (cryptocyanins), and insect storage hexamerins. The evolution of these proteins was inferred by neighbor-joining, maximum-parsimony, and maximum-likelihood methods. Monte Carlo shuffling approaches provided evidence against a discernible relationship of the arthropod hemocyanin superfamily and molluscan hemocyanins or nonarthropodan tyrosinases. Within the arthropod hemocyanin superfamily, the phenoloxidase probably emerged early in the (eu-)arthropod stemline and thus form the most likely outgroup. The respiratory hemocyanins evolved from t…