Transcriptional burst kinetics are linked to short term transcriptional memory

Transcriptional bursting is thought to be a stochastic process that allows the dynamic regulation of most genes. The random telegraph model assumes the existence of two states, ON and OFF. However recent studies indicate the presence of additional ON states, suggesting that bursting kinetics and their regulation can be quite complex. We have developed a system to study transcriptional bursting in the context of p53 biology using the endogenous p21 gene tagged with MS2 in human cells. Remarkably, we find that transcriptional bursts from the p21 gene contain multiple ON and OFF states that can be regulated by elevation of p53 levels. Distinct ON states are characterized by differences in burst duration, classified as Short and Long, with long bursts associated with higher Pol II initiation rates. Importantly, the different ON states display memory effects that allow us to predict the likelihood of properties of future bursting events. Long bursting events result in faster re-activation, longer subsequent bursts and higher transcriptional output in the future compared to short bursts. Bursting memory persists up to 2 hours suggesting a stable inheritable promoter architecture. Bursting memory at the p21 gene is the strongest under basal conditions and is suppressed by UV and inhibition of H3K9me1/2, which also increase transcriptional noise. Stabilization of p53 by Nutlin-3a partially reverses suppression of bursting memory suggesting that higher p53 levels may be a key in enforcing memory under conditions of cellular stress. Overall our data uncover a new found bursting property termed Short-Term Transcriptional Memory (STTM) that has the potential to fine-tune transcriptional output at the p21 gene.

Collective Memory: Transposing Pavlov’s Experiment to Robot Swarms

Remembering information is a fundamental aspect of cognition present in numerous natural systems. It allows adaptation of the behavior as a function of previously encountered situations. For instance, many living organisms use memory to recall if a given situation incurred a penalty or a reward and rely on that information to avoid or reproduce that situation. In groups, memory is commonly studied in the case where individual members are themselves capable of learning and a few of them hold pieces of information that can be later retrieved for the benefits of the group. Here, we investigate how a group may display memory when the individual members have reactive behaviors and can not learn any information. The well known conditioning experiments of Pavlov illustrate how single animals can memorize stimuli associated with a reward and later trigger a related behavioral response even in the absence of reward. To study and demonstrate collective memory in artificial systems, we get inspiration from the Pavlov experiments and propose a setup tailored for testing our robotic swarm. We devised a novel behavior based on the fundamental process of aggregation with which robots exhibit collective memory. We show that the group is capable of encoding, storing, and retrieving information that is not present at the level of the individuals.

Pengujian Black Box pada Aplikasi Pertokoan Minimarket Menggunakan Metode Equivalence Partitioning

Quality measurements in software are currently required before the software will be used by users. This aims to determine the weakness of the system so that the data generated can match the data entered after the data is executed. This method focuses on data entry, system display, memory usage, and data execution speed so that if the input data does not match what is expected then the system fails.In implementation problems often arise when testers are never sure whether the software being tested has actually passed the test. This happens because there may be several execution paths that have never been tested. The minimarket stock management application will be tested using a black box test where this test is only intended to see if the program matches the function desired by the program without knowing the program code used. To generate test case designs automatically in black box method software testing with the equality.technique partition technique.

What Are Bucrania Doing in Tombs? Art and Agency in Neolithic Sardinia and Traditional South-East Asia

The interior of Neolithic tombs in Europe is frequently decorated with carved and painted motifs. In Sardinia (Italy), 116 rock-cut tombs have their walls covered with bucrania (schematic depictions of cattle head and horns), which have long been interpreted as representations of a bull-like divinity. This article reviews similar examples of bucranium ‘art’ in the tombs of three traditional societies in South-East Asia, focusing on the agency of the motifs and their roles within social relationships between the living, the dead, and the spiritual world. From these ethnographic examples and the archaeological evidence in Sardinia, it is suggested that bucrania in Neolithic tombs were a specialized form of material culture that had multiple, cumulative effects and functions associated with social display, memory, reproduction, death, and protection.

Memory of Germinant Stimuli in Bacterial Spores

ABSTRACT Bacterial spores, despite being metabolically dormant, possess the remarkable capacity to detect nutrients and other molecules in their environment through a biochemical sensory apparatus that can trigger spore germination, allowing the return to vegetative growth within minutes of exposure of germinants. We demonstrate here that bacterial spores of multiple species retain memory of transient exposures to germinant stimuli that can result in altered responses to subsequent exposure. The magnitude and decay of these memory effects depend on the pulse duration as well as on the separation time, incubation temperature, and pH values between the pulses. Spores of Bacillus species germinate in response to nutrients that interact with germinant receptors (GRs) in the spore's inner membrane, with different nutrient types acting on different receptors. In our experiments, B. subtilis spores display memory when the first and second germinant pulses target different receptors, suggesting that some components of spore memory are downstream of GRs. Furthermore, nonnutrient germinants, which do not require GRs, exhibit memory either alone or in combination with nutrient germinants, and memory of nonnutrient stimulation is found to be more persistent than that induced by GR-dependent stimuli. Spores of B. cereus and Clostridium difficile also exhibit germination memory, suggesting that memory may be a general property of bacterial spores. These observations along with experiments involving strains with mutations in various germination proteins suggest a model in which memory is stored primarily in the metastable states of SpoVA proteins, which comprise a channel for release of dipicolinic acid, a major early event in spore germination. IMPORTANCE Cellular memory is defined as a sustained response to a transient environmental stimulus, and yet its generation and storage have not been described in bacterial spores. We demonstrate here that bacterial spores of multiple species retain memory of transient exposures to germinant stimuli that can result in altered responses to subsequent exposure. Memory was induced by activation of germinant receptors (GRs) or by GR-independent germinants and was accessed by both GR-dependent and GR-independent germinants. Analysis of effects on memory of exposure to GR-dependent and GR-independent germinants as well as in spores lacking various germination proteins suggests a model in which memory is stored primarily in metastable states of SpoVA proteins which comprise a channel for release of spore dipicolinic acid. Spore memory can also significantly reduce the concentration of nutrient germinants necessary to trigger germination, and this may be used to respond to low levels of nutrient germinants.

Study on the Technology of Digital Image Processing

The paper aims to study a design and technique of the image processing based on the architecture of embedded system. Aimed at the own characteristic of embedded system, designing a platform been endowed with more operating functions of embedded image processing with versatility. The author adopts the method of the embedded system design based on the basic functions and characteristic of image processing system, summarizing and comparing of the characteristic and new developments of the EOS for the ARM processor, and finally chooses the embedded Linux for the operating system of our platform, also transplant it in the hardware platform. Aimed at the characteristic of Linux device architecture, the author introduces how to develop the image capture and display, memory the data of an image, the programming method of that. Some base arithmetic of image processing, such as image smooth, sharpen, edge detect and so on, and the graphics user interface are developed on the platform with using the Mini GUI, according to the intercommunion between the human and the platform. At last, some key program's code is given.

Switching in Polymer Memory Devices Based on Polymer and Nanoparticles Admixture

In this paper, a non-volatile memory device based on a blend of metal oxides (Known as NiO) and polymer has been investigated. These devices have shown to display memory effects; a marked difference in electrical conductivity between the ‘on’ and ‘off’ states. However, the exact mechanism under-pinning these two conductivities states are not very clear. The structures used in investigation are metal-admixture-metal (MAM) and metal-insulator-semiconductor (MIS) devices. Also, glass and p-types silicon (100 orientations) with a pre-prepared Ohmic back contact were used for the MAM and MIS substrates respectively. This work will address some of the questions in regard to the electrical bistability shown by polymer memory devices.

Design and Implementation on PC Control Interface of Robot Based on VxWorks Operating System

VxWorks operating system has been widely used in the field of embedded real-time operating system for its good reliability and excellent real-time performance. In this paper, the robot PC control interface is designed under VxWorks development environment. By reading the 24-bit true color bitmap, the image data is stored in memory, and window is created using WindMl multimedia database, bitmap is created and displayed in the window, background is displayed using the entire bitmap, buttons and text boxes are displayed by modifying and updating the corresponding position image display memory. The paper gives some modules of code, the method used is simple common, and the design interface is beautiful.

Lubricating Online Detecting System of Large Unit Based on the Virtual Instrument

Aiming the lubricating oil quality can cause the machine failure and decrease operating time, its impurities can also change the oil capacitance, the online detecting system which based on the LabVIEW virtual programming language is designed. LabVIEW can make data collection, processing, display, memory, etc, implementing the online monitoring of the lubricating oil. This design greatly decrease the workload of the staff, reduce the detecting time, raise the testing efficiency of the equipment and measure the various impurity content of lubricating oil more accuracy.