Fast Exact Search in Hamming Space With Multi-Index Hashing.

PubMed

Norouzi, Mohammad; Punjani, Ali; Fleet, David J

2014-06-01

There is growing interest in representing image data and feature descriptors using compact binary codes for fast near neighbor search. Although binary codes are motivated by their use as direct indices (addresses) into a hash table, codes longer than 32 bits are not being used as such, as it was thought to be ineffective. We introduce a rigorous way to build multiple hash tables on binary code substrings that enables exact k-nearest neighbor search in Hamming space. The approach is storage efficient and straight-forward to implement. Theoretical analysis shows that the algorithm exhibits sub-linear run-time behavior for uniformly distributed codes. Empirical results show dramatic speedups over a linear scan baseline for datasets of up to one billion codes of 64, 128, or 256 bits.

Using Distinct Sectors in Media Sampling and Full Media Analysis to Detect Presence of Documents from a Corpus

DTIC Science & Technology

2012-09-01

relative performance of several conventional SQL and NoSQL databases with a set of one billion file block hashes. Digital Forensics, Sector Hashing, Full... NoSQL databases with a set of one billion file block hashes. v THIS PAGE INTENTIONALLY LEFT BLANK vi Table of Contents List of Acronyms and...Operating System NOOP No Operation assembly instruction NoSQL “Not only SQL” model for non-relational database management NSRL National Software

Improving management performance of P2PSIP for mobile sensing in wireless overlays.

PubMed

Sendín-Raña, Pablo; González-Castaño, Francisco Javier; Gómez-Cuba, Felipe; Asorey-Cacheda, Rafael; Pousada-Carballo, José María

2013-11-08

Future wireless communications are heading towards an all-Internet Protocol (all-IP) design, and will rely on the Session Initiation Protocol (SIP) to manage services, such as voice over IP (VoIP). The centralized architecture of traditional SIP has numerous disadvantages for mobile ad hoc services that may be possibly overcome by advanced peer-to-peer (P2P) technologies initially developed for the Internet. In the context of mobile sensing, P2PSIP protocols facilitate decentralized and fast communications with sensor-enabled terminals. Nevertheless, in order to make P2PSIP protocols feasible in mobile sensing networks, it is necessary to minimize overhead transmissions for signaling purposes, which reduces the battery lifetime. In this paper, we present a solution to improve the management of wireless overlay networks by defining an adaptive algorithm for the calculation of refresh time. The main advantage of the proposed algorithm is that it takes into account new parameters, such as the delay between nodes, and provides satisfactory performance and reliability levels at a much lower management overhead than previous approaches. The proposed solution can be applied to many structured P2P overlays or P2PSIP protocols. We evaluate it with Kademlia-based distributed hash tables (DHT) and dSIP.

Improving Management Performance of P2PSIP for Mobile Sensing in Wireless Overlays

PubMed Central

Sendín-Raña, Pablo; González-Castaño, Francisco Javier; Gómez-Cuba, Felipe; Asorey-Cacheda, Rafael; Pousada-Carballo, José María

2013-01-01

Future wireless communications are heading towards an all-Internet Protocol (all-IP) design, and will rely on the Session Initiation Protocol (SIP) to manage services, such as voice over IP (VoIP). The centralized architecture of traditional SIP has numerous disadvantages for mobile ad hoc services that may be possibly overcome by advanced peer-to-peer (P2P) technologies initially developed for the Internet. In the context of mobile sensing, P2PSIP protocols facilitate decentralized and fast communications with sensor-enabled terminals. Nevertheless, in order to make P2PSIP protocols feasible in mobile sensing networks, it is necessary to minimize overhead transmissions for signaling purposes, which reduces the battery lifetime. In this paper, we present a solution to improve the management of wireless overlay networks by defining an adaptive algorithm for the calculation of refresh time. The main advantage of the proposed algorithm is that it takes into account new parameters, such as the delay between nodes, and provides satisfactory performance and reliability levels at a much lower management overhead than previous approaches. The proposed solution can be applied to many structured P2P overlays or P2PSIP protocols. We evaluate it with Kademlia-based distributed hash tables (DHT) and dSIP PMID:24217358

SGFSC: speeding the gene functional similarity calculation based on hash tables.

PubMed

Tian, Zhen; Wang, Chunyu; Guo, Maozu; Liu, Xiaoyan; Teng, Zhixia

2016-11-04

In recent years, many measures of gene functional similarity have been proposed and widely used in all kinds of essential research. These methods are mainly divided into two categories: pairwise approaches and group-wise approaches. However, a common problem with these methods is their time consumption, especially when measuring the gene functional similarities of a large number of gene pairs. The problem of computational efficiency for pairwise approaches is even more prominent because they are dependent on the combination of semantic similarity. Therefore, the efficient measurement of gene functional similarity remains a challenging problem. To speed current gene functional similarity calculation methods, a novel two-step computing strategy is proposed: (1) establish a hash table for each method to store essential information obtained from the Gene Ontology (GO) graph and (2) measure gene functional similarity based on the corresponding hash table. There is no need to traverse the GO graph repeatedly for each method with the help of the hash table. The analysis of time complexity shows that the computational efficiency of these methods is significantly improved. We also implement a novel Speeding Gene Functional Similarity Calculation tool, namely SGFSC, which is bundled with seven typical measures using our proposed strategy. Further experiments show the great advantage of SGFSC in measuring gene functional similarity on the whole genomic scale. The proposed strategy is successful in speeding current gene functional similarity calculation methods. SGFSC is an efficient tool that is freely available at http://nclab.hit.edu.cn/SGFSC . The source code of SGFSC can be downloaded from http://pan.baidu.com/s/1dFFmvpZ .

HIA: a genome mapper using hybrid index-based sequence alignment.

PubMed

Choi, Jongpill; Park, Kiejung; Cho, Seong Beom; Chung, Myungguen

2015-01-01

A number of alignment tools have been developed to align sequencing reads to the human reference genome. The scale of information from next-generation sequencing (NGS) experiments, however, is increasing rapidly. Recent studies based on NGS technology have routinely produced exome or whole-genome sequences from several hundreds or thousands of samples. To accommodate the increasing need of analyzing very large NGS data sets, it is necessary to develop faster, more sensitive and accurate mapping tools. HIA uses two indices, a hash table index and a suffix array index. The hash table performs direct lookup of a q-gram, and the suffix array performs very fast lookup of variable-length strings by exploiting binary search. We observed that combining hash table and suffix array (hybrid index) is much faster than the suffix array method for finding a substring in the reference sequence. Here, we defined the matching region (MR) is a longest common substring between a reference and a read. And, we also defined the candidate alignment regions (CARs) as a list of MRs that is close to each other. The hybrid index is used to find candidate alignment regions (CARs) between a reference and a read. We found that aligning only the unmatched regions in the CAR is much faster than aligning the whole CAR. In benchmark analysis, HIA outperformed in mapping speed compared with the other aligners, without significant loss of mapping accuracy. Our experiments show that the hybrid of hash table and suffix array is useful in terms of speed for mapping NGS sequencing reads to the human reference genome sequence. In conclusion, our tool is appropriate for aligning massive data sets generated by NGS sequencing.

Self-Organized Link State Aware Routing for Multiple Mobile Agents in Wireless Network

NASA Astrophysics Data System (ADS)

Oda, Akihiro; Nishi, Hiroaki

Recently, the importance of data sharing structures in autonomous distributed networks has been increasing. A wireless sensor network is used for managing distributed data. This type of distributed network requires effective information exchanging methods for data sharing. To reduce the traffic of broadcasted messages, reduction of the amount of redundant information is indispensable. In order to reduce packet loss in mobile ad-hoc networks, QoS-sensitive routing algorithm have been frequently discussed. The topology of a wireless network is likely to change frequently according to the movement of mobile nodes, radio disturbance, or fading due to the continuous changes in the environment. Therefore, a packet routing algorithm should guarantee QoS by using some quality indicators of the wireless network. In this paper, a novel information exchanging algorithm developed using a hash function and a Boolean operation is proposed. This algorithm achieves efficient information exchanges by reducing the overhead of broadcasting messages, and it can guarantee QoS in a wireless network environment. It can be applied to a routing algorithm in a mobile ad-hoc network. In the proposed routing algorithm, a routing table is constructed by using the received signal strength indicator (RSSI), and the neighborhood information is periodically broadcasted depending on this table. The proposed hash-based routing entry management by using an extended MAC address can eliminate the overhead of message flooding. An analysis of the collision of hash values contributes to the determination of the length of the hash values, which is minimally required. Based on the verification of a mathematical theory, an optimum hash function for determining the length of hash values can be given. Simulations are carried out to evaluate the effectiveness of the proposed algorithm and to validate the theory in a general wireless network routing algorithm.

HECLIB. Volume 2: HECDSS Subroutines Programmer’s Manual

DTIC Science & Technology

1991-05-01

algorithm and hierarchical design for database accesses. This algorithm provides quick access to data sets and an efficient means of adding new data set...Description of How DSS Works DSS version 6 utilizes a modified hash algorithm based upon the pathname to store and retrieve data. This structure allows...balancing disk space and record access times. A variation in this algorithm is for "stable" files. In a stable file, a hash table is not utilized

Design Considerations for a Computationally-Lightweight Authentication Mechanism for Passive RFID Tags

DTIC Science & Technology

2009-09-01

suffer the power and complexity requirements of a public key system. 28 In [18], a simulation of the SHA –1 algorithm is performed on a Xilinx FPGA ... 256 bits. Thus, the construction of a hash table would need 2512 independent comparisons. It is known that hash collisions of the SHA –1 algorithm... SHA –1 algorithm for small-core FPGA design. Small-core FPGA design is the process by which a circuit is adapted to use the minimal amount of logic

A new pre-classification method based on associative matching method

NASA Astrophysics Data System (ADS)

Katsuyama, Yutaka; Minagawa, Akihiro; Hotta, Yoshinobu; Omachi, Shinichiro; Kato, Nei

2010-01-01

Reducing the time complexity of character matching is critical to the development of efficient Japanese Optical Character Recognition (OCR) systems. To shorten processing time, recognition is usually split into separate preclassification and recognition stages. For high overall recognition performance, the pre-classification stage must both have very high classification accuracy and return only a small number of putative character categories for further processing. Furthermore, for any practical system, the speed of the pre-classification stage is also critical. The associative matching (AM) method has often been used for fast pre-classification, because its use of a hash table and reliance solely on logical bit operations to select categories makes it highly efficient. However, redundant certain level of redundancy exists in the hash table because it is constructed using only the minimum and maximum values of the data on each axis and therefore does not take account of the distribution of the data. We propose a modified associative matching method that satisfies the performance criteria described above but in a fraction of the time by modifying the hash table to reflect the underlying distribution of training characters. Furthermore, we show that our approach outperforms pre-classification by clustering, ANN and conventional AM in terms of classification accuracy, discriminative power and speed. Compared to conventional associative matching, the proposed approach results in a 47% reduction in total processing time across an evaluation test set comprising 116,528 Japanese character images.

High-performance sparse matrix-matrix products on Intel KNL and multicore architectures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagasaka, Y; Matsuoka, S; Azad, A

Sparse matrix-matrix multiplication (SpGEMM) is a computational primitive that is widely used in areas ranging from traditional numerical applications to recent big data analysis and machine learning. Although many SpGEMM algorithms have been proposed, hardware specific optimizations for multi- and many-core processors are lacking and a detailed analysis of their performance under various use cases and matrices is not available. We firstly identify and mitigate multiple bottlenecks with memory management and thread scheduling on Intel Xeon Phi (Knights Landing or KNL). Specifically targeting multi- and many-core processors, we develop a hash-table-based algorithm and optimize a heap-based shared-memory SpGEMM algorithm. Wemore » examine their performance together with other publicly available codes. Different from the literature, our evaluation also includes use cases that are representative of real graph algorithms, such as multi-source breadth-first search or triangle counting. Our hash-table and heap-based algorithms are showing significant speedups from libraries in the majority of the cases while different algorithms dominate the other scenarios with different matrix size, sparsity, compression factor and operation type. We wrap up in-depth evaluation results and make a recipe to give the best SpGEMM algorithm for target scenario. A critical finding is that hash-table-based SpGEMM gets a significant performance boost if the nonzeros are not required to be sorted within each row of the output matrix.« less

G-Hash: Towards Fast Kernel-based Similarity Search in Large Graph Databases.

PubMed

Wang, Xiaohong; Smalter, Aaron; Huan, Jun; Lushington, Gerald H

2009-01-01

Structured data including sets, sequences, trees and graphs, pose significant challenges to fundamental aspects of data management such as efficient storage, indexing, and similarity search. With the fast accumulation of graph databases, similarity search in graph databases has emerged as an important research topic. Graph similarity search has applications in a wide range of domains including cheminformatics, bioinformatics, sensor network management, social network management, and XML documents, among others.Most of the current graph indexing methods focus on subgraph query processing, i.e. determining the set of database graphs that contains the query graph and hence do not directly support similarity search. In data mining and machine learning, various graph kernel functions have been designed to capture the intrinsic similarity of graphs. Though successful in constructing accurate predictive and classification models for supervised learning, graph kernel functions have (i) high computational complexity and (ii) non-trivial difficulty to be indexed in a graph database.Our objective is to bridge graph kernel function and similarity search in graph databases by proposing (i) a novel kernel-based similarity measurement and (ii) an efficient indexing structure for graph data management. Our method of similarity measurement builds upon local features extracted from each node and their neighboring nodes in graphs. A hash table is utilized to support efficient storage and fast search of the extracted local features. Using the hash table, a graph kernel function is defined to capture the intrinsic similarity of graphs and for fast similarity query processing. We have implemented our method, which we have named G-hash, and have demonstrated its utility on large chemical graph databases. Our results show that the G-hash method achieves state-of-the-art performance for k-nearest neighbor (k-NN) classification. Most importantly, the new similarity measurement and the index structure is scalable to large database with smaller indexing size, faster indexing construction time, and faster query processing time as compared to state-of-the-art indexing methods such as C-tree, gIndex, and GraphGrep.

Tuple spaces in hardware for accelerated implicit routing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, Zachary Kent; Tripp, Justin

2010-12-01

Organizing and optimizing data objects on networks with support for data migration and failing nodes is a complicated problem to handle as systems grow. The goal of this work is to demonstrate that high levels of speedup can be achieved by moving responsibility for finding, fetching, and staging data into an FPGA-based network card. We present a system for implicit routing of data via FPGA-based network cards. In this system, data structures are requested by name, and the network of FPGAs finds the data within the network and relays the structure to the requester. This is acheived through successive examinationmore » of hardware hash tables implemented in the FPGA. By avoiding software stacks between nodes, the data is quickly fetched entirely through FPGA-FPGA interaction. The performance of this system is orders of magnitude faster than software implementations due to the improved speed of the hash tables and lowered latency between the network nodes.« less

Performance-Oriented Privacy-Preserving Data Integration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pon, R K; Critchlow, T

2004-09-15

Current solutions to integrating private data with public data have provided useful privacy metrics, such as relative information gain, that can be used to evaluate alternative approaches. Unfortunately, they have not addressed critical performance issues, especially when the public database is very large. The use of hashes and noise yields better performance than existing techniques while still making it difficult for unauthorized entities to distinguish which data items truly exist in the private database. As we show here, leveraging the uncertainty introduced by collisions caused by hashing and the injection of noise, we present a technique for performing a relationalmore » join operation between a massive public table and a relatively smaller private one.« less

Field Acceptance and Nutritional Intake of the Meal, Ready-to-Eat and Heat and Serve Ration.

DTIC Science & Technology

1998-05-01

Scrambled Eggs (Natick) and Scrambled Eggs w/Bacon(Natick). These two mean ratings were received from the control group. Table 4A Control Group H&S...6.4 Creamed Ground Beef 6.3 Corned Beef Hash 6.1 Western Scrambled Eggs (Natick)* 4.6 Scrambled Eggs w...5.4 20 38 33 * Natick - NRDEC developed eggs Table 4B Test Group H&S Breakfast Acceptability Ratings (n=39) Food Groups Food Item Entrees

Compact modalities for forward-error correction

NASA Astrophysics Data System (ADS)

Fang, Dejian

2013-10-01

Hash tables [1] must work. In fact, few leading analysts would disagree with the refinement of thin clients. In our research, we disprove not only that the infamous read-write algorithm for the exploration of object-oriented languages by W. White et al. is NP-complete, but that the same is true for the lookaside buffer.

Status of MAPA (Modular Accelerator Physics Analysis) and the Tech-X Object-Oriented Accelerator Library

NASA Astrophysics Data System (ADS)

Cary, J. R.; Shasharina, S.; Bruhwiler, D. L.

1998-04-01

The MAPA code is a fully interactive accelerator modeling and design tool consisting of a GUI and two object-oriented C++ libraries: a general library suitable for treatment of any dynamical system, and an accelerator library including many element types plus an accelerator class. The accelerator library inherits directly from the system library, which uses hash tables to store any relevant parameters or strings. The GUI can access these hash tables in a general way, allowing the user to invoke a window displaying all relevant parameters for a particular element type or for the accelerator class, with the option to change those parameters. The system library can advance an arbitrary number of dynamical variables through an arbitrary mapping. The accelerator class inherits this capability and overloads the relevant functions to advance the phase space variables of a charged particle through a string of elements. Among other things, the GUI makes phase space plots and finds fixed points of the map. We discuss the object hierarchy of the two libraries and use of the code.

Efficient Deterministic Finite Automata Minimization Based on Backward Depth Information.

PubMed

Liu, Desheng; Huang, Zhiping; Zhang, Yimeng; Guo, Xiaojun; Su, Shaojing

2016-01-01

Obtaining a minimal automaton is a fundamental issue in the theory and practical implementation of deterministic finite automatons (DFAs). A minimization algorithm is presented in this paper that consists of two main phases. In the first phase, the backward depth information is built, and the state set of the DFA is partitioned into many blocks. In the second phase, the state set is refined using a hash table. The minimization algorithm has a lower time complexity O(n) than a naive comparison of transitions O(n2). Few states need to be refined by the hash table, because most states have been partitioned by the backward depth information in the coarse partition. This method achieves greater generality than previous methods because building the backward depth information is independent of the topological complexity of the DFA. The proposed algorithm can be applied not only to the minimization of acyclic automata or simple cyclic automata, but also to automata with high topological complexity. Overall, the proposal has three advantages: lower time complexity, greater generality, and scalability. A comparison to Hopcroft's algorithm demonstrates experimentally that the algorithm runs faster than traditional algorithms.

Application of kernel functions for accurate similarity search in large chemical databases.

PubMed

Wang, Xiaohong; Huan, Jun; Smalter, Aaron; Lushington, Gerald H

2010-04-29

Similarity search in chemical structure databases is an important problem with many applications in chemical genomics, drug design, and efficient chemical probe screening among others. It is widely believed that structure based methods provide an efficient way to do the query. Recently various graph kernel functions have been designed to capture the intrinsic similarity of graphs. Though successful in constructing accurate predictive and classification models, graph kernel functions can not be applied to large chemical compound database due to the high computational complexity and the difficulties in indexing similarity search for large databases. To bridge graph kernel function and similarity search in chemical databases, we applied a novel kernel-based similarity measurement, developed in our team, to measure similarity of graph represented chemicals. In our method, we utilize a hash table to support new graph kernel function definition, efficient storage and fast search. We have applied our method, named G-hash, to large chemical databases. Our results show that the G-hash method achieves state-of-the-art performance for k-nearest neighbor (k-NN) classification. Moreover, the similarity measurement and the index structure is scalable to large chemical databases with smaller indexing size, and faster query processing time as compared to state-of-the-art indexing methods such as Daylight fingerprints, C-tree and GraphGrep. Efficient similarity query processing method for large chemical databases is challenging since we need to balance running time efficiency and similarity search accuracy. Our previous similarity search method, G-hash, provides a new way to perform similarity search in chemical databases. Experimental study validates the utility of G-hash in chemical databases.

Automated Handling of Garments for Pressing

DTIC Science & Technology

1991-09-30

Parallel Algorithms for 2D Kalman Filtering ................................. 47 DJ. Potter and M.P. Cline Hash Table and Sorted Array: A Case Study of... Kalman Filtering on the Connection Machine ............................ 55 MA. Palis and D.K. Krecker Parallel Sorting of Large Arrays on the MasPar...ALGORITHM’VS FOR SEAM SENSING. .. .. .. ... ... .... ..... 24 6.1 KarelTW Algorithms .. .. ... ... ... ... .... ... ...... 24 6.1.1 Image Filtering

Efficient Deterministic Finite Automata Minimization Based on Backward Depth Information

PubMed Central

Liu, Desheng; Huang, Zhiping; Zhang, Yimeng; Guo, Xiaojun; Su, Shaojing

2016-01-01

Obtaining a minimal automaton is a fundamental issue in the theory and practical implementation of deterministic finite automatons (DFAs). A minimization algorithm is presented in this paper that consists of two main phases. In the first phase, the backward depth information is built, and the state set of the DFA is partitioned into many blocks. In the second phase, the state set is refined using a hash table. The minimization algorithm has a lower time complexity O(n) than a naive comparison of transitions O(n2). Few states need to be refined by the hash table, because most states have been partitioned by the backward depth information in the coarse partition. This method achieves greater generality than previous methods because building the backward depth information is independent of the topological complexity of the DFA. The proposed algorithm can be applied not only to the minimization of acyclic automata or simple cyclic automata, but also to automata with high topological complexity. Overall, the proposal has three advantages: lower time complexity, greater generality, and scalability. A comparison to Hopcroft’s algorithm demonstrates experimentally that the algorithm runs faster than traditional algorithms. PMID:27806102

A high-speed drug interaction search system for ease of use in the clinical environment.

PubMed

Takada, Masahiro; Inada, Hiroshi; Nakazawa, Kazuo; Tani, Shoko; Iwata, Michiaki; Sugimoto, Yoshihisa; Nagata, Satoru

2012-12-01

With the advancement of pharmaceutical development, drug interactions have become increasingly complex. As a result, a computer-based drug interaction search system is required to organize the whole of drug interaction data. To overcome problems faced with the existing systems, we developed a drug interaction search system using a hash table, which offers higher processing speeds and easier maintenance operations compared with relational databases (RDB). In order to compare the performance of our system and MySQL RDB in terms of search speed, drug interaction searches were repeated for all 45 possible combinations of two out of a group of 10 drugs for two cases: 5,604 and 56,040 drug interaction data. As the principal result, our system was able to process the search approximately 19 times faster than the system using the MySQL RDB. Our system also has several other merits such as that drug interaction data can be created in comma-separated value (CSV) format, thereby facilitating data maintenance. Although our system uses the well-known method of a hash table, it is expected to resolve problems common to existing systems and to be an effective system that enables the safe management of drugs.

Algorithm That Synthesizes Other Algorithms for Hashing

NASA Technical Reports Server (NTRS)

James, Mark

2010-01-01

An algorithm that includes a collection of several subalgorithms has been devised as a means of synthesizing still other algorithms (which could include computer code) that utilize hashing to determine whether an element (typically, a number or other datum) is a member of a set (typically, a list of numbers). Each subalgorithm synthesizes an algorithm (e.g., a block of code) that maps a static set of key hashes to a somewhat linear monotonically increasing sequence of integers. The goal in formulating this mapping is to cause the length of the sequence thus generated to be as close as practicable to the original length of the set and thus to minimize gaps between the elements. The advantage of the approach embodied in this algorithm is that it completely avoids the traditional approach of hash-key look-ups that involve either secondary hash generation and look-up or further searching of a hash table for a desired key in the event of collisions. This algorithm guarantees that it will never be necessary to perform a search or to generate a secondary key in order to determine whether an element is a member of a set. This algorithm further guarantees that any algorithm that it synthesizes can be executed in constant time. To enforce these guarantees, the subalgorithms are formulated to employ a set of techniques, each of which works very effectively covering a certain class of hash-key values. These subalgorithms are of two types, summarized as follows: Given a list of numbers, try to find one or more solutions in which, if each number is shifted to the right by a constant number of bits and then masked with a rotating mask that isolates a set of bits, a unique number is thereby generated. In a variant of the foregoing procedure, omit the masking. Try various combinations of shifting, masking, and/or offsets until the solutions are found. From the set of solutions, select the one that provides the greatest compression for the representation and is executable in the minimum amount of time. Given a list of numbers, try to find one or more solutions in which, if each number is compressed by use of the modulo function by some value, then a unique value is generated.

A fast exact simulation method for a class of Markov jump processes.

PubMed

Li, Yao; Hu, Lili

2015-11-14

A new method of the stochastic simulation algorithm (SSA), named the Hashing-Leaping method (HLM), for exact simulations of a class of Markov jump processes, is presented in this paper. The HLM has a conditional constant computational cost per event, which is independent of the number of exponential clocks in the Markov process. The main idea of the HLM is to repeatedly implement a hash-table-like bucket sort algorithm for all times of occurrence covered by a time step with length τ. This paper serves as an introduction to this new SSA method. We introduce the method, demonstrate its implementation, analyze its properties, and compare its performance with three other commonly used SSA methods in four examples. Our performance tests and CPU operation statistics show certain advantages of the HLM for large scale problems.

A fast exact simulation method for a class of Markov jump processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yao, E-mail: yaoli@math.umass.edu; Hu, Lili, E-mail: lilyhu86@gmail.com

2015-11-14

A new method of the stochastic simulation algorithm (SSA), named the Hashing-Leaping method (HLM), for exact simulations of a class of Markov jump processes, is presented in this paper. The HLM has a conditional constant computational cost per event, which is independent of the number of exponential clocks in the Markov process. The main idea of the HLM is to repeatedly implement a hash-table-like bucket sort algorithm for all times of occurrence covered by a time step with length τ. This paper serves as an introduction to this new SSA method. We introduce the method, demonstrate its implementation, analyze itsmore » properties, and compare its performance with three other commonly used SSA methods in four examples. Our performance tests and CPU operation statistics show certain advantages of the HLM for large scale problems.« less

Architectural design of an Algol interpreter

NASA Technical Reports Server (NTRS)

Jackson, C. K.

1971-01-01

The design of a syntax-directed interpreter for a subset of Algol is described. It is a conceptual design with sufficient details and completeness but as much independence of implementation as possible. The design includes a detailed description of a scanner, an analyzer described in the Floyd-Evans productions, a hash-coded symbol table, and an executor. Interpretation of sample programs is also provided to show how the interpreter functions.

Improving the Rainbow Attack by Reusing Colours

NASA Astrophysics Data System (ADS)

Ågren, Martin; Johansson, Thomas; Hell, Martin

Hashing or encrypting a key or a password is a vital part in most network security protocols. The most practical generic attack on such schemes is a time memory trade-off attack. Such an attack inverts any one-way function using a trade-off between memory and execution time. Existing techniques include the Hellman attack and the rainbow attack, where the latter uses different reduction functions ("colours") within a table.

Sex differences and plasticity in dehydration tolerance: insight from a tropical liverwort

PubMed Central

Marks, Rose A.; Burton, James F.; McLetchie, D. Nicholas

2016-01-01

Background and Aims Adaptations allowing plants to cope with drying are particularly relevant in the light of predicted climate change. Dehydration tolerance (DhT, also dehydration-tolerant) is one such adaptation enabling tissue to survive substantial drying. A great deal of work has been conducted on highly DhT species. However, bryophytes showing less intense and variable DhT are understudied, despite the potential for these species to provide an informative link between highly tolerant and sensitive species. In this study, we tested the degree to which DhT varies across populations and the sexes of a species expected to exhibit a moderate DhT phenotype. Methods To test predicted patterns of tolerance we assessed DhT in males and females of Marchantia inflexa from two distinct habitat types that differ in water availability. Both common garden and field-collected tissue was subjected to drying assays at multiple intensities and recovery was monitored by chlorophyll florescence. Verification studies were conducted to confirm the level of dehydration, the rate of drying and the associated changes in photosynthetic physiology. Key Results We confirmed our expectation that M. inflexa is able to tolerate moderate dehydration. We also found that females exhibited higher DhT than males, but populations did not differ in DhT when cultured in a common garden. However, field-collected samples exhibited differences in DhT corresponding to environmental dryness, suggesting plasticity in DhT. Conclusions By studying a less extreme DhT phenotype we gained insight into how more sensitive (yet still tolerant) organisms cope with dehydration. Additionally, the identified sex-specific variation in DhT may explain ecological patterns such as female-biased sex ratios. Furthermore, plasticity in DhT has the potential to inform management practices aimed at increasing tolerance to drought conditions. PMID:27325895

Mechanisms of dihydrotestosterone action on resveratrol-induced anti-proliferation in breast cancer cells with different ERα status

PubMed Central

Chang, Tung-Cheng; Changou, Chun A.; Lai, Hsuan-Yu; Fu, Earl; HuangFu, Wei-Chun; Davis, Paul J.; Lin, Hung-Yun; Liu, Leroy F.

2015-01-01

Dihydrotestosterone (DHT) has been shown to promote breast cancer growth via different mechanisms. In addition to binding to ERα, the DHT membrane receptor exists on integrin αvβ3. Resveratrol induces p53-dependent apoptosis via plasma membrane integrin αvβ3. Resveratrol and DHT signals are both transduced by activated ERK1/2; however, DHT promotes cell proliferation in cancer cells, whereas resveratrol is pro-apoptotic. In this study, we examined the mechanism by which DHT inhibits resveratrol-induced apoptosis in human ERα positive (MCF-7) and negative (MDA-MB-231) breast cancer cells. DHT inhibited resveratrol-stimulated phosphorylation of Ser-15 of p53 in a concentration-dependent manner. These effects of DHT on resveratrol action were blocked by an ERα antagonist, ICI 182,780, in MCF-7 breast cancer cells. DHT inhibited resveratrol-induced nuclear complex of p53-COX-2 formation which is required p53-dependent apoptosis. ChIP studies of COX-2/p53 binding to DNA and expression of p53-responsive genes indicated that DHT inhibited resveratrol-induced p53-directed transcriptional activity. In addition, DHT did inhibit resveratrol-induced COX-2/p53-dependent gene expression. These results suggest that DHT inhibits p53-dependent apoptosis in breast cancer cells by interfering with nuclear COX-2 accumulation which is essential for stimulation of apoptotic pathways. Thus, the surface receptor sites for resveratrol and DHT are discrete and activate ERK1/2-dependent downstream effects on apoptosis that are distinctive. These studies provide new insights into the antagonizing effects of resveratrol versus DHT, an important step toward better understanding and eventually treating breast cancer. It also indicates the complex pathways by which apoptosis is induced by resveratrol in DHT-depleted and -repleted environments. PMID:26456774

Robust hashing with local models for approximate similarity search.

PubMed

Song, Jingkuan; Yang, Yi; Li, Xuelong; Huang, Zi; Yang, Yang

2014-07-01

Similarity search plays an important role in many applications involving high-dimensional data. Due to the known dimensionality curse, the performance of most existing indexing structures degrades quickly as the feature dimensionality increases. Hashing methods, such as locality sensitive hashing (LSH) and its variants, have been widely used to achieve fast approximate similarity search by trading search quality for efficiency. However, most existing hashing methods make use of randomized algorithms to generate hash codes without considering the specific structural information in the data. In this paper, we propose a novel hashing method, namely, robust hashing with local models (RHLM), which learns a set of robust hash functions to map the high-dimensional data points into binary hash codes by effectively utilizing local structural information. In RHLM, for each individual data point in the training dataset, a local hashing model is learned and used to predict the hash codes of its neighboring data points. The local models from all the data points are globally aligned so that an optimal hash code can be assigned to each data point. After obtaining the hash codes of all the training data points, we design a robust method by employing l2,1 -norm minimization on the loss function to learn effective hash functions, which are then used to map each database point into its hash code. Given a query data point, the search process first maps it into the query hash code by the hash functions and then explores the buckets, which have similar hash codes to the query hash code. Extensive experimental results conducted on real-life datasets show that the proposed RHLM outperforms the state-of-the-art methods in terms of search quality and efficiency.

Equol an isoflavonoid: potential for improved prostate health, in vitro and in vivo evidence

PubMed Central

2011-01-01

Background To determine: in vitro binding affinity of equol for 5alpha-dihydrotestosterone (5alpha-DHT), in vitro effects of equol treatment in human prostate cancer (LNCap) cells, and in vivo effects of equol on rat prostate weight and circulating levels of sex steroid hormones. Methods First, in vitro equol binding affinity for 5alpha-DHT was determined using 14C5alpha-DHT combined with cold 5alpha-DHT (3.0 nM in all samples). These steroids were incubated with increasing concentrations of equol (0-2,000 nM) and analyzed by Sephadex LH-20 column chromatography. 14C5alpha-DHT peak/profiles were determined by scintillation counting of column fractions. Using the 14C5alpha-DHT peak (0 nM equol) as a reference standard, a binding curve was generated by quantifying shifts in the 14C5alpha-DHT peaks as equol concentrations increased. Second, equol's in vitro effects on LNCap cells were determined by culturing cells (48 hours) in the presence of increasing concentrations of dimethyl sulfoxide (DMSO) (vehicle-control), 5alpha-DHT, equol or 5alpha-DHT+equol. Following culture, prostate specific antigen (PSA) levels were quantified via ELISA. Finally, the in vivo effects of equol were tested in sixteen male Long-Evans rats fed a low isoflavone diet. From 190-215 days, animals received 0.1cc s.c. injections of either DMSO-control vehicle (n = 8) or 1.0 mg/kg (body weight) of equol (in DMSO) (n = 8). At 215 days, body and prostate weights were recorded, trunk blood was collected and serum assayed for luteinizing hormone (LH), 5alpha-DHT, testosterone and 17beta-estradiol levels. Results Maximum and half maximal equol binding to 5alpha-DHT occurred at approximately 100 nM and 4.8 nM respectively. LNCap cells cultured in the presence of 5alpha-DHT significantly increased PSA levels. However, in the presence of 5alpha-DHT+equol, equol blocked the significant increases in PSA levels from LNCap cells. In vivo equol treatment significantly decreased rat prostate weights and serum 5alpha-DHT levels but did not alter LH, testosterone, and estradiol levels. Conclusions Equol administration appears to have potential beneficial effects for prostate health and other 5alpha-DHT mediated disorders. Equol administration: reduces PSA levels from LNCap cells under 5alpha-DHT stimulation, decreases rat prostate size, decreases serum 5alpha-DHT levels and androgen hormone action, while not altering other circulating sex steroids or LH levels. PMID:21232127

Sex differences and plasticity in dehydration tolerance: insight from a tropical liverwort.

PubMed

Marks, Rose A; Burton, James F; McLetchie, D Nicholas

2016-08-01

Adaptations allowing plants to cope with drying are particularly relevant in the light of predicted climate change. Dehydration tolerance (DhT, also dehydration-tolerant) is one such adaptation enabling tissue to survive substantial drying. A great deal of work has been conducted on highly DhT species. However, bryophytes showing less intense and variable DhT are understudied, despite the potential for these species to provide an informative link between highly tolerant and sensitive species. In this study, we tested the degree to which DhT varies across populations and the sexes of a species expected to exhibit a moderate DhT phenotype. To test predicted patterns of tolerance we assessed DhT in males and females of Marchantia inflexa from two distinct habitat types that differ in water availability. Both common garden and field-collected tissue was subjected to drying assays at multiple intensities and recovery was monitored by chlorophyll florescence. Verification studies were conducted to confirm the level of dehydration, the rate of drying and the associated changes in photosynthetic physiology. We confirmed our expectation that M. inflexa is able to tolerate moderate dehydration. We also found that females exhibited higher DhT than males, but populations did not differ in DhT when cultured in a common garden. However, field-collected samples exhibited differences in DhT corresponding to environmental dryness, suggesting plasticity in DhT. By studying a less extreme DhT phenotype we gained insight into how more sensitive (yet still tolerant) organisms cope with dehydration. Additionally, the identified sex-specific variation in DhT may explain ecological patterns such as female-biased sex ratios. Furthermore, plasticity in DhT has the potential to inform management practices aimed at increasing tolerance to drought conditions. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The Narcotics Emirate of Afghanistan: Armed Polities and Their Roles in Illicit Drug Production and Conflict 1980-2010

DTIC Science & Technology

2010-12-01

yields in 1969 and 1970.78 American and European smugglers facilitated the movement of Afghan hash throughout the world until U.S. drug enforcement...significantly affected opium yields . *Denotes approximation from UNDCP records. Table 4. Sampling of Opium Production (metric tons) According to the...shorter grow-cycle than food crops like wheat, allowing farmers to double-crop with livestock fodder, such as maize following the opium harvest

A Hybrid Spatio-Temporal Data Indexing Method for Trajectory Databases

PubMed Central

Ke, Shengnan; Gong, Jun; Li, Songnian; Zhu, Qing; Liu, Xintao; Zhang, Yeting

2014-01-01

In recent years, there has been tremendous growth in the field of indoor and outdoor positioning sensors continuously producing huge volumes of trajectory data that has been used in many fields such as location-based services or location intelligence. Trajectory data is massively increased and semantically complicated, which poses a great challenge on spatio-temporal data indexing. This paper proposes a spatio-temporal data indexing method, named HBSTR-tree, which is a hybrid index structure comprising spatio-temporal R-tree, B*-tree and Hash table. To improve the index generation efficiency, rather than directly inserting trajectory points, we group consecutive trajectory points as nodes according to their spatio-temporal semantics and then insert them into spatio-temporal R-tree as leaf nodes. Hash table is used to manage the latest leaf nodes to reduce the frequency of insertion. A new spatio-temporal interval criterion and a new node-choosing sub-algorithm are also proposed to optimize spatio-temporal R-tree structures. In addition, a B*-tree sub-index of leaf nodes is built to query the trajectories of targeted objects efficiently. Furthermore, a database storage scheme based on a NoSQL-type DBMS is also proposed for the purpose of cloud storage. Experimental results prove that HBSTR-tree outperforms TB*-tree in some aspects such as generation efficiency, query performance and query type. PMID:25051028

A hybrid spatio-temporal data indexing method for trajectory databases.

PubMed

Ke, Shengnan; Gong, Jun; Li, Songnian; Zhu, Qing; Liu, Xintao; Zhang, Yeting

2014-07-21

In recent years, there has been tremendous growth in the field of indoor and outdoor positioning sensors continuously producing huge volumes of trajectory data that has been used in many fields such as location-based services or location intelligence. Trajectory data is massively increased and semantically complicated, which poses a great challenge on spatio-temporal data indexing. This paper proposes a spatio-temporal data indexing method, named HBSTR-tree, which is a hybrid index structure comprising spatio-temporal R-tree, B*-tree and Hash table. To improve the index generation efficiency, rather than directly inserting trajectory points, we group consecutive trajectory points as nodes according to their spatio-temporal semantics and then insert them into spatio-temporal R-tree as leaf nodes. Hash table is used to manage the latest leaf nodes to reduce the frequency of insertion. A new spatio-temporal interval criterion and a new node-choosing sub-algorithm are also proposed to optimize spatio-temporal R-tree structures. In addition, a B*-tree sub-index of leaf nodes is built to query the trajectories of targeted objects efficiently. Furthermore, a database storage scheme based on a NoSQL-type DBMS is also proposed for the purpose of cloud storage. Experimental results prove that HBSTR-tree outperforms TB*-tree in some aspects such as generation efficiency, query performance and query type.

A Simple Secure Hash Function Scheme Using Multiple Chaotic Maps

NASA Astrophysics Data System (ADS)

Ahmad, Musheer; Khurana, Shruti; Singh, Sushmita; AlSharari, Hamed D.

2017-06-01

The chaotic maps posses high parameter sensitivity, random-like behavior and one-way computations, which favor the construction of cryptographic hash functions. In this paper, we propose to present a novel hash function scheme which uses multiple chaotic maps to generate efficient variable-sized hash functions. The message is divided into four parts, each part is processed by a different 1D chaotic map unit yielding intermediate hash code. The four codes are concatenated to two blocks, then each block is processed through 2D chaotic map unit separately. The final hash value is generated by combining the two partial hash codes. The simulation analyses such as distribution of hashes, statistical properties of confusion and diffusion, message and key sensitivity, collision resistance and flexibility are performed. The results reveal that the proposed anticipated hash scheme is simple, efficient and holds comparable capabilities when compared with some recent chaos-based hash algorithms.

A novel image retrieval algorithm based on PHOG and LSH

NASA Astrophysics Data System (ADS)

Wu, Hongliang; Wu, Weimin; Peng, Jiajin; Zhang, Junyuan

2017-08-01

PHOG can describe the local shape of the image and its relationship between the spaces. The using of PHOG algorithm to extract image features in image recognition and retrieval and other aspects have achieved good results. In recent years, locality sensitive hashing (LSH) algorithm has been superior to large-scale data in solving near-nearest neighbor problems compared with traditional algorithms. This paper presents a novel image retrieval algorithm based on PHOG and LSH. First, we use PHOG to extract the feature vector of the image, then use L different LSH hash table to reduce the dimension of PHOG texture to index values and map to different bucket, and finally extract the corresponding value of the image in the bucket for second image retrieval using Manhattan distance. This algorithm can adapt to the massive image retrieval, which ensures the high accuracy of the image retrieval and reduces the time complexity of the retrieval. This algorithm is of great significance.

FBC: a flat binary code scheme for fast Manhattan hash retrieval

NASA Astrophysics Data System (ADS)

Kong, Yan; Wu, Fuzhang; Gao, Lifa; Wu, Yanjun

2018-04-01

Hash coding is a widely used technique in approximate nearest neighbor (ANN) search, especially in document search and multimedia (such as image and video) retrieval. Based on the difference of distance measurement, hash methods are generally classified into two categories: Hamming hashing and Manhattan hashing. Benefitting from better neighborhood structure preservation, Manhattan hashing methods outperform earlier methods in search effectiveness. However, due to using decimal arithmetic operations instead of bit operations, Manhattan hashing becomes a more time-consuming process, which significantly decreases the whole search efficiency. To solve this problem, we present an intuitive hash scheme which uses Flat Binary Code (FBC) to encode the data points. As a result, the decimal arithmetic used in previous Manhattan hashing can be replaced by more efficient XOR operator. The final experiments show that with a reasonable memory space growth, our FBC speeds up more than 80% averagely without any search accuracy loss when comparing to the state-of-art Manhattan hashing methods.

The Design and Emulation of a System Kernel for X-Tree,

DTIC Science & Technology

1979-03-30

DECLASSIFICATIONIDOWNGRADING I SCHEDULE 16. DISTRIBUTION STATEMENT (ol this Report) Approved for public release; distributi.- ti4imited -; T ? A~ 17. DISTRIBUTION STATEMENT...level of the tPee. ManvIL different schemes for these additional interconnections have been Proposed. No final selection h-as set been made. Pic- tured...comFletion, 5_U (b) Irenoves the Process name from the hash table, (c) F’uts the PCB back on the FREEPCB aueue for later reuse# ( d) Goes L:ack to sleep . Ai

Fast perceptual image hash based on cascade algorithm

NASA Astrophysics Data System (ADS)

Ruchay, Alexey; Kober, Vitaly; Yavtushenko, Evgeniya

2017-09-01

In this paper, we propose a perceptual image hash algorithm based on cascade algorithm, which can be applied in image authentication, retrieval, and indexing. Image perceptual hash uses for image retrieval in sense of human perception against distortions caused by compression, noise, common signal processing and geometrical modifications. The main disadvantage of perceptual hash is high time expenses. In the proposed cascade algorithm of image retrieval initializes with short hashes, and then a full hash is applied to the processed results. Computer simulation results show that the proposed hash algorithm yields a good performance in terms of robustness, discriminability, and time expenses.

Hierarchical Recurrent Neural Hashing for Image Retrieval With Hierarchical Convolutional Features.

PubMed

Lu, Xiaoqiang; Chen, Yaxiong; Li, Xuelong

Hashing has been an important and effective technology in image retrieval due to its computational efficiency and fast search speed. The traditional hashing methods usually learn hash functions to obtain binary codes by exploiting hand-crafted features, which cannot optimally represent the information of the sample. Recently, deep learning methods can achieve better performance, since deep learning architectures can learn more effective image representation features. However, these methods only use semantic features to generate hash codes by shallow projection but ignore texture details. In this paper, we proposed a novel hashing method, namely hierarchical recurrent neural hashing (HRNH), to exploit hierarchical recurrent neural network to generate effective hash codes. There are three contributions of this paper. First, a deep hashing method is proposed to extensively exploit both spatial details and semantic information, in which, we leverage hierarchical convolutional features to construct image pyramid representation. Second, our proposed deep network can exploit directly convolutional feature maps as input to preserve the spatial structure of convolutional feature maps. Finally, we propose a new loss function that considers the quantization error of binarizing the continuous embeddings into the discrete binary codes, and simultaneously maintains the semantic similarity and balanceable property of hash codes. Experimental results on four widely used data sets demonstrate that the proposed HRNH can achieve superior performance over other state-of-the-art hashing methods.Hashing has been an important and effective technology in image retrieval due to its computational efficiency and fast search speed. The traditional hashing methods usually learn hash functions to obtain binary codes by exploiting hand-crafted features, which cannot optimally represent the information of the sample. Recently, deep learning methods can achieve better performance, since deep learning architectures can learn more effective image representation features. However, these methods only use semantic features to generate hash codes by shallow projection but ignore texture details. In this paper, we proposed a novel hashing method, namely hierarchical recurrent neural hashing (HRNH), to exploit hierarchical recurrent neural network to generate effective hash codes. There are three contributions of this paper. First, a deep hashing method is proposed to extensively exploit both spatial details and semantic information, in which, we leverage hierarchical convolutional features to construct image pyramid representation. Second, our proposed deep network can exploit directly convolutional feature maps as input to preserve the spatial structure of convolutional feature maps. Finally, we propose a new loss function that considers the quantization error of binarizing the continuous embeddings into the discrete binary codes, and simultaneously maintains the semantic similarity and balanceable property of hash codes. Experimental results on four widely used data sets demonstrate that the proposed HRNH can achieve superior performance over other state-of-the-art hashing methods.

Does anti-androgen, flutamide cancel out the in vivo effects of the androgen, dihydrotestosterone on sexual development in juvenile Murray rainbowfish (Melanotaenia fluviatilis)?

PubMed

Bhatia, Harpreet; Kumar, Anupama

2016-01-01

The aim of the present study was to investigate if the effects of the androgen, dihydrotestosterone (DHT) on the sexual development in juvenile Murray rainbowfish (Melanotaenia fluviatilis) are canceled out by the anti-androgen, flutamide. Fish (60 days post hatch) were exposed to 250ng/L of DHT, 25μg/L of flutamide (Flu-low), 250μg/L of flutamide (Flu-high), DHT+Flu low and DHT+Flu high. After 35 days of exposure, lengths and weights of the fish were measured and the condition factor (CF) calculated; vitellogenin (VTG) concentrations were measured in tail tissue; sex steroid hormones (17β-estradiol [E2] and 11-keto testosterone [11-KT]) were measured in the head tissue and abdominal regions were used in histological investigation of the gonads. Treatment with DHT reduced the body-length of both male and female fish, an effect which was canceled out by low and high concentrations of flutamide. However, flutamide (low or high) could not nullify the DHT-induced reduction in the CF in either sex. The E2 levels were reduced only in female fish after exposure to DHT but returned to normal after treatment with Flu-high. DHT increased the levels of 11-KT and decreased the E2/11-KT ratio in both sexes. Flu-high, but not Flu-low, could nullify these effects. Both DHT and flutamide (low or high) induced VTG production and this effect persisted when both chemicals were co-administered. Treatment with DHT did not affect gonadal cell development in the testes. However, the female fish treated with DHT contained ovaries in early-vitellogenic stage in comparison to the pre-vitellogenic ovaries in control fish. Co-treatment with flutamide (low or high) resulted in oocyte atresia. The results from the present study suggest that treatment with Flu-high could cancel out DHT-induced effects only on the hormonal profile and body-length in both male and female fish. Juvenile fish co-treated with DHT and flutamide (low or high) had high VTG levels and low CF. In addition, the ovaries in female fish were atretic. These data represent potential adverse effects on the ability of the fish to reproduce successfully. Copyright © 2015 Elsevier B.V. All rights reserved.

Collision attack against Tav-128 hash function

NASA Astrophysics Data System (ADS)

Hariyanto, Fajar; Hayat Susanti, Bety

2017-10-01

Tav-128 is a hash function which is designed for Radio Frequency Identification (RFID) authentication protocol. Tav-128 is expected to be a cryptographically secure hash function which meets collision resistance properties. In this research, a collision attack is done to prove whether Tav-128 is a collision resistant hash function. The results show that collisions can be obtained in Tav-128 hash function which means in other word, Tav-128 is not a collision resistant hash function.

On the concept of cryptographic quantum hashing

NASA Astrophysics Data System (ADS)

Ablayev, F.; Ablayev, M.

2015-12-01

In the letter we define the notion of a quantum resistant ((ε ,δ ) -resistant) hash function which consists of a combination of pre-image (one-way) resistance (ε-resistance) and collision resistance (δ-resistance) properties. We present examples and discussion that supports the idea of quantum hashing. We present an explicit quantum hash function which is ‘balanced’, one-way resistant and collision resistant and demonstrate how to build a large family of quantum hash functions. Balanced quantum hash functions need a high degree of entanglement between the qubits. We use a phase transformation technique to express quantum hashing constructions, which is an effective way of mapping hash states to coherent states in a superposition of time-bin modes. The phase transformation technique is ready to be implemented with current optical technology.

Synergistic activation of the androgen receptor by bombesin and low-dose androgen.

PubMed

Dai, Jie; Shen, Ruoqian; Sumitomo, Makoto; Stahl, Rosalyn; Navarro, Daniel; Gershengorn, Marvin C; Nanus, David M

2002-07-01

Neuropeptide growth factors such as bombesinare implicated in progression to androgen-independent prostate cancer (PC). We examined the impact of bombesin on androgen receptor (AR)-mediated gene expression. The AR together with the AR-responsive probasin ARR(3)tk-luc or PSA-pPUE-ELB-luc promoter was cotransfected into Swiss 3T3 and PC-3 cells, both of which express high-affinity bombesin receptors; the cells were incubated with bombesin (0-50 nM) and dihydrotestosterone (DHT; 0-10 nM), and luciferase activities were measured. DHT increased transcription approximately 40-fold at doses of 1 and 10 nM but had no effect at 10 pM. Bombesin alone, or with 1 or 10 nM DHT, did not further increase transcription. However, 5 nM bombesin and 10 pM DHT, doses that by themselves had no effect, resulted in a approximately 20 fold increase in transcription (P < 0.005). This synergistic effect was blocked by bombesin receptor antagonists and recombinant neutral endopeptidase, which hydrolyzes bombesin. Bombesin and DHT together also increased binding of nuclear extracts from PC-3 cells transfected with AR to a consensus androgen response element in mobility shift assays and increased the level of secreted prostate-specific antigen in LNCaP cell supernatant compared with DHT or bombesin alone. Immunoprecipitation of AR from (32)P-labeled LNCaP cells revealed that 5 nM bombesin + 10 pM DHT induced AR phosphorylation comparable with 1 nM DHT, whereas bombesin or 10 pM DHT alone did not. These data indicate that bombesin can synergize with low (castrate) levels of DHT to induce AR-mediated transcription and suggest that neuropeptides promote AR-mediated signaling in androgen-independent prostate cancer.

Combined peak-to-average power ratio reduction and physical layer security enhancement in optical orthogonal frequency division multiplexing visible-light communication systems

NASA Astrophysics Data System (ADS)

Wang, Zhongpeng; Chen, Shoufa

2016-07-01

A physical encryption scheme for discrete Hartley transform (DHT) precoded orthogonal frequency division multiplexing (OFDM) visible-light communication (VLC) systems using frequency domain chaos scrambling is proposed. In the scheme, the chaos scrambling, which is generated by a modified logistic mapping, is utilized to enhance the physical layer of security, and the DHT precoding is employed to reduce of OFDM signal for OFDM-based VLC. The influence of chaos scrambling on peak-to-average power ratio (PAPR) and bit error rate (BER) of systems is studied. The experimental simulation results prove the efficiency of the proposed encryption method for DHT-precoded, OFDM-based VLC systems. Furthermore, the influence of the proposed encryption to the PAPR and BER of systems is evaluated. The experimental results show that the proposed security scheme can protect the DHT-precoded, OFDM-based VLC from eavesdroppers, while keeping the good BER performance of DHT-precoded systems. The BER performance of the encrypted and DHT-precoded system is almost the same as that of the conventional DHT-precoded system without encryption.

Evaluation of the cytotoxicity of dihydroxytryptamines and 5-hydroxytryptamine antagonists as cytotoxic agents in dimethylhydrazine-induced adenocarcinomata.

PubMed

Tutton, P J; Barkla, D H

1978-01-01

The cytotoxicity of 5,6-dihydroxytryptamine (5,6-DHT), 5,7-dihydroxytryptamine (5,7-DHT), bromolysergic acid diethylamide (BOL), methysergide, and cyproheptadine, and also of 5,6-DHT together with either BOL, methysergide, or cyproheptadine in dimethylhydrazine-induced (DMH) carcinomata of rat colon was evaluated by estimating the percentage of necrotic cells in histological sections of tissues taken 15 h after injection of each of the drugs. In addition, the influence of methysergide and cyproheptadine on the tumour cell mitotic rate was estimated by means of a stathmokinetic technique. Both 5,6-DHT and 5,7-DHT were cytotoxic at each dose tested and for each of these agents the percentage of necrotic cells was directly correlated with the dose of drug used. BOL was not found to be cytotoxic to the colonic carcinomata, whereas both methysergide and cyproheptadine did cause detectable tumour cell necrosis. Methysergide was also found to accelerate tumour cell proliferation, whereas cyproheptadine did not. BOL competitively inhibited the cytotoxicity of 5,6-DHT and neither methysergide nor cyproheptadine potentiated the effect of 5,6 DHT.

Dihydrotestosterone inhibits hair growth in mice by inhibiting insulin-like growth factor-I production in dermal papillae.

PubMed

Zhao, Juan; Harada, Naoaki; Okajima, Kenji

2011-10-01

We demonstrated that insulin-like growth factor-I (IGF-I) production in dermal papillae was increased and hair growth was promoted after sensory neuron stimulation in mice. Although the androgen metabolite dihydrotestosterone (DHT) inhibits hair growth by negatively modulating growth-regulatory effects of dermal papillae, relationship between androgen metabolism and IGF-I production in dermal papillae is not fully understood. We examined whether DHT inhibits IGF-I production by inhibiting sensory neuron stimulation, thereby preventing hair growth in mice. Effect of DHT on sensory neuron stimulation was examined using cultured dorsal root ganglion (DRG) neurons isolated from mice. DHT inhibits calcitonin gene-related peptide (CGRP) release from cultured DRG neurons. The non-steroidal androgen-receptor antagonist flutamide reversed DHT-induced inhibition of CGRP release. Dermal levels of IGF-I and IGF-I mRNA, and the number of IGF-I-positive fibroblasts around hair follicles were increased at 6h after CGRP administration. DHT administration for 3weeks decreased dermal levels of CGRP, IGF-I, and IGF-I mRNA in mice. Immunohistochemical expression of IGF-I and the number of proliferating cells in hair follicles were decreased and hair re-growth was inhibited in animals administered DHT. Co-administration of flutamide and CGRP reversed these changes induced by DHT administration. These observations suggest that DHT may decrease IGF-I production in dermal papillae by inhibiting sensory neuron stimulation through interaction with the androgen receptor, thereby inhibiting hair growth in mice. Copyright © 2011 Elsevier Ltd. All rights reserved.

Neighborhood Discriminant Hashing for Large-Scale Image Retrieval.

PubMed

Tang, Jinhui; Li, Zechao; Wang, Meng; Zhao, Ruizhen

2015-09-01

With the proliferation of large-scale community-contributed images, hashing-based approximate nearest neighbor search in huge databases has aroused considerable interest from the fields of computer vision and multimedia in recent years because of its computational and memory efficiency. In this paper, we propose a novel hashing method named neighborhood discriminant hashing (NDH) (for short) to implement approximate similarity search. Different from the previous work, we propose to learn a discriminant hashing function by exploiting local discriminative information, i.e., the labels of a sample can be inherited from the neighbor samples it selects. The hashing function is expected to be orthogonal to avoid redundancy in the learned hashing bits as much as possible, while an information theoretic regularization is jointly exploited using maximum entropy principle. As a consequence, the learned hashing function is compact and nonredundant among bits, while each bit is highly informative. Extensive experiments are carried out on four publicly available data sets and the comparison results demonstrate the outperforming performance of the proposed NDH method over state-of-the-art hashing techniques.

Perceptual Audio Hashing Functions

NASA Astrophysics Data System (ADS)

Özer, Hamza; Sankur, Bülent; Memon, Nasir; Anarım, Emin

2005-12-01

Perceptual hash functions provide a tool for fast and reliable identification of content. We present new audio hash functions based on summarization of the time-frequency spectral characteristics of an audio document. The proposed hash functions are based on the periodicity series of the fundamental frequency and on singular-value description of the cepstral frequencies. They are found, on one hand, to perform very satisfactorily in identification and verification tests, and on the other hand, to be very resilient to a large variety of attacks. Moreover, we address the issue of security of hashes and propose a keying technique, and thereby a key-dependent hash function.

Implementation of cryptographic hash function SHA256 in C++

NASA Astrophysics Data System (ADS)

Shrivastava, Akash

2012-02-01

This abstract explains the implementation of SHA Secure hash algorithm 256 using C++. The SHA-2 is a strong hashing algorithm used in almost all kinds of security applications. The algorithm consists of 2 phases: Preprocessing and hash computation. Preprocessing involves padding a message, parsing the padded message into m-bits blocks, and setting initialization values to be used in the hash computation. It generates a message schedule from padded message and uses that schedule, along with functions, constants, and word operations to iteratively generate a series of hash values. The final hash value generated by the computation is used to determine the message digest. SHA-2 includes a significant number of changes from its predecessor, SHA-1. SHA-2 consists of a set of four hash functions with digests that are 224, 256, 384 or 512 bits. The algorithm outputs a 256 bits message block with an internal state block of 256 bits and initial block size of 512 bits. Maximum message length in bit is generated is 2^64 -1, over all computed over a series of 64 rounds consisting or several operations such as and, or, Xor, Shr, Rot. The code will provide clear understanding of the hash algorithm and generates hash values to retrieve message digest.

Effects of model aromatizable (17α-methyltestosterone) and non-aromatizable (5α-dihydrotestosterone) androgens on the adult mummichog (Fundulus heteroclitus) in a short-term reproductive endocrine bioassay.

PubMed

Rutherford, Robert; Lister, Andrea; Hewitt, L Mark; MacLatchy, Deborah

2015-04-01

Androgens originating from pulp mill processing, sewage treatment facilities and agricultural activities have the potential for discharge into aquatic receiving environments. To assess androgen effects on reproductive endocrine status in fish in estuarine environments, male and female adult northern mummichog (Fundulus heteroclitus macrolepidotus) were exposed to an aromatizable androgen (17α-methyltestosterone; MT) and a non-aromatizable androgen (5α-dihydrotestosterone; DHT) in a short-term reproductive endocrine bioassay. Fish were nominally exposed to 10 μg/L or 100 μg/L DHT, or 0.1 μg/L or 1 μg/L MT for 14 days during gonadal recrudescence. Actual concentrations of androgens, as measured by enzyme immunoassay (EIA), were 10-49% of nominal MT 0.1, 3-6% of nominal MT 1, 5-10% of nominal DHT 10 and 3-25% of nominal DHT 100. Female mummichog were impacted to a greater degree by androgen exposure, with increased plasma testosterone (T) at 100 μg/L DHT, depressed plasma 17β-estradiol (E2) at both DHT concentrations and at 1 μg/L MT, as well as depressed in vitro E2 at both MT concentrations and 100 μg/L DHT. Males had depressed plasma T in the 10 μg/L DHT treatment and depressed in vitro 11-ketotestosterone production for both MT concentrations and 10 μg/L DHT. Ovarian aromatase gene expression was induced in females exposed to 1 μg/L MT. DHT at 100 μg/L increased hepatic vitellogenin-1 (VTG1) expression in males and depressed VTG1 expression in females. The range of responses between sexes and among species provides evidence for modes of actions and potential impacts of androgens in aquatic receiving environments. Copyright © 2015 Elsevier Inc. All rights reserved.

ProGeRF: Proteome and Genome Repeat Finder Utilizing a Fast Parallel Hash Function

PubMed Central

Moraes, Walas Jhony Lopes; Rodrigues, Thiago de Souza; Bartholomeu, Daniella Castanheira

2015-01-01

Repetitive element sequences are adjacent, repeating patterns, also called motifs, and can be of different lengths; repetitions can involve their exact or approximate copies. They have been widely used as molecular markers in population biology. Given the sizes of sequenced genomes, various bioinformatics tools have been developed for the extraction of repetitive elements from DNA sequences. However, currently available tools do not provide options for identifying repetitive elements in the genome or proteome, displaying a user-friendly web interface, and performing-exhaustive searches. ProGeRF is a web site for extracting repetitive regions from genome and proteome sequences. It was designed to be efficient, fast, and accurate and primarily user-friendly web tool allowing many ways to view and analyse the results. ProGeRF (Proteome and Genome Repeat Finder) is freely available as a stand-alone program, from which the users can download the source code, and as a web tool. It was developed using the hash table approach to extract perfect and imperfect repetitive regions in a (multi)FASTA file, while allowing a linear time complexity. PMID:25811026

Sudden sensorineural hearing loss with positional vertigo: Initial findings of positional nystagmus and hearing outcomes.

PubMed

Kim, Chang-Hee; Shin, Jung Eun; Yang, Young Soo; Im, Donghyuk

2016-10-01

To investigate the initial findings of positional nystagmus in patients with sudden sensorineural hearing loss (SSNHL) and positional vertigo, and to compare hearing improvement among patients with different types of positional nystagmus. The characteristics of positional nystagmus upon initial examination were analysed, and the initial mean pure-tone audiometry (PTA) threshold was compared with that at three months after treatment. Forty-four SSNHL patients with concomitant positional vertigo were included. Positional nystagmus was classified into five subgroups; persistent geotropic direction-changing positional nystagmus (DCPN) in head-roll test (HRT) and negative Dix-Hallpike test (DHT), persistent apogeotropic DCPN in HRT and negative DHT, positive DHT and negative HRT, persistent geotropic DCPN in HRT and positive DHT, and persistent apogeotropic DCPN in HRT and positive DHT. PTA threshold improvement was significantly greater in SSNHL patients with negative DHT than with positive DHT (p = 0.027). When geotropic DCPN was elicited by HRT, the nystagmus was persistent, which suggests that alteration of specific gravity of the endolymph, rather than the lateral canal canalolithiasis, may be a cause of this characteristic positional nystagmus. Positive DTH may be a prognostic factor for worse hearing recovery among patients with SSNHL and positional vertigo.

Multimodal Discriminative Binary Embedding for Large-Scale Cross-Modal Retrieval.

PubMed

Wang, Di; Gao, Xinbo; Wang, Xiumei; He, Lihuo; Yuan, Bo

2016-10-01

Multimodal hashing, which conducts effective and efficient nearest neighbor search across heterogeneous data on large-scale multimedia databases, has been attracting increasing interest, given the explosive growth of multimedia content on the Internet. Recent multimodal hashing research mainly aims at learning the compact binary codes to preserve semantic information given by labels. The overwhelming majority of these methods are similarity preserving approaches which approximate pairwise similarity matrix with Hamming distances between the to-be-learnt binary hash codes. However, these methods ignore the discriminative property in hash learning process, which results in hash codes from different classes undistinguished, and therefore reduces the accuracy and robustness for the nearest neighbor search. To this end, we present a novel multimodal hashing method, named multimodal discriminative binary embedding (MDBE), which focuses on learning discriminative hash codes. First, the proposed method formulates the hash function learning in terms of classification, where the binary codes generated by the learned hash functions are expected to be discriminative. And then, it exploits the label information to discover the shared structures inside heterogeneous data. Finally, the learned structures are preserved for hash codes to produce similar binary codes in the same class. Hence, the proposed MDBE can preserve both discriminability and similarity for hash codes, and will enhance retrieval accuracy. Thorough experiments on benchmark data sets demonstrate that the proposed method achieves excellent accuracy and competitive computational efficiency compared with the state-of-the-art methods for large-scale cross-modal retrieval task.

FSH: fast spaced seed hashing exploiting adjacent hashes.

PubMed

Girotto, Samuele; Comin, Matteo; Pizzi, Cinzia

2018-01-01

Patterns with wildcards in specified positions, namely spaced seeds , are increasingly used instead of k -mers in many bioinformatics applications that require indexing, querying and rapid similarity search, as they can provide better sensitivity. Many of these applications require to compute the hashing of each position in the input sequences with respect to the given spaced seed, or to multiple spaced seeds. While the hashing of k -mers can be rapidly computed by exploiting the large overlap between consecutive k -mers, spaced seeds hashing is usually computed from scratch for each position in the input sequence, thus resulting in slower processing. The method proposed in this paper, fast spaced-seed hashing (FSH), exploits the similarity of the hash values of spaced seeds computed at adjacent positions in the input sequence. In our experiments we compute the hash for each positions of metagenomics reads from several datasets, with respect to different spaced seeds. We also propose a generalized version of the algorithm for the simultaneous computation of multiple spaced seeds hashing. In the experiments, our algorithm can compute the hashing values of spaced seeds with a speedup, with respect to the traditional approach, between 1.6[Formula: see text] to 5.3[Formula: see text], depending on the structure of the spaced seed. Spaced seed hashing is a routine task for several bioinformatics application. FSH allows to perform this task efficiently and raise the question of whether other hashing can be exploited to further improve the speed up. This has the potential of major impact in the field, making spaced seed applications not only accurate, but also faster and more efficient. The software FSH is freely available for academic use at: https://bitbucket.org/samu661/fsh/overview.

Sexual incentive motivation in male rats requires both androgens and estrogens.

PubMed

Attila, Martti; Oksala, Riikka; Agmo, Anders

2010-07-01

In Experiment 1 castrated male rats were implanted with a Silastic capsule containing either E or cholesterol (CHOL) 35 days after castration. They were then tested for sexual incentive motivation and copulatory behaviors every 5th day for 3 weeks. None of the treatments affected sexual incentive motivation. After the last test, all subjects were implanted with DHT-containing Silastic capsules, and tests continued for another 3 weeks. While E+DHT enhanced sexual incentive motivation and copulatory behavior, DHT alone failed to do so. In Experiment 2 the aromatase inhibitor fadrozole (F) was combined with testosterone (T). T restored all behaviors to the level seen in intact rats, and F significantly reduced these effects. In fact, T+F was not different from DHT. T and DHT restored the weight of the prostate and seminal vesicles to levels close to those of intact rats. In Experiment 3 a lower dose of E was employed. Also this dose of E failed to affect sexual incentive motivation while E+DHT restored it to the level of intact animals. Castration enhanced the serum concentrations of LH and FSH. E alone caused a marked reduction, and E+DHT brought both gonadotropins back to the level of intact animals. It was concluded that the doses of E and DHT employed in these experiments were within or close to the physiological range, and that such doses of E completely fail to enhance sexual incentive motivation in castrated animals. DHT has small or no effects. It appears that sexual incentive motivation and copulation require simultaneous stimulation of androgen and estrogen receptors. Copyright 2009 Elsevier Inc. All rights reserved.

Harmonisation of serum dihydrotestosterone analysis: establishment of an external quality assurance program.

PubMed

Greaves, Ronda F; Jolly, Lisa; Hartmann, Michaela F; Ho, Chung Shun; Kam, Richard K T; Joseph, John; Boyder, Conchita; Wudy, Stefan A

2017-03-01

Serum dihydrotestosterone (DHT) is an important analyte for the clinical assessment of disorders of sex development. It is also reportedly a difficult analyte to measure. Currently, there are significant gaps in the standardisation of this analyte, including no external quality assurance (EQA) program available worldwide to allow for peer review performance of DHT. We therefore proposed to establish a pilot EQA program for serum DHT. DHT was assessed in the 2015 Royal College of Pathologists of Australasia Quality Assurance Programs' Endocrine program material. The material's target (i.e. "true") values were established using a measurement procedure based on isotope dilution gas chromatography (GC) tandem mass spectrometry (MS/MS). DHT calibrator values were based on weighed values of pure DHT material (>97.5% purity) from Sigma. The allowable limits of performance (ALP) were established as ±0.1 up to 0.5 nmol/L and ±15% for targets >0.5 nmol/L. Target values for the six levels of RCPAQAP material for DHT ranged from 0.02 to 0.43 nmol/L (0.01-0.12 ng/mL). The material demonstrated linearity across the six levels. There were seven participating laboratories for this pilot study. Results of the liquid chromatography (LC) MS/MS methods were within the ALP; whereas the results from the immunoassay methods were consistently higher than the target values and outside the ALP. This report provides the first peer comparison of serum DHT measured by mass spectrometry (MS) and immunoassay laboratories. Establishment of this program provides one of the pillars to achieve method harmonisation. This supports accurate clinical decisions where DHT measurement is required.

Quantum Hash function and its application to privacy amplification in quantum key distribution, pseudo-random number generation and image encryption

NASA Astrophysics Data System (ADS)

Yang, Yu-Guang; Xu, Peng; Yang, Rui; Zhou, Yi-Hua; Shi, Wei-Min

2016-01-01

Quantum information and quantum computation have achieved a huge success during the last years. In this paper, we investigate the capability of quantum Hash function, which can be constructed by subtly modifying quantum walks, a famous quantum computation model. It is found that quantum Hash function can act as a hash function for the privacy amplification process of quantum key distribution systems with higher security. As a byproduct, quantum Hash function can also be used for pseudo-random number generation due to its inherent chaotic dynamics. Further we discuss the application of quantum Hash function to image encryption and propose a novel image encryption algorithm. Numerical simulations and performance comparisons show that quantum Hash function is eligible for privacy amplification in quantum key distribution, pseudo-random number generation and image encryption in terms of various hash tests and randomness tests. It extends the scope of application of quantum computation and quantum information.

Quantum Hash function and its application to privacy amplification in quantum key distribution, pseudo-random number generation and image encryption

PubMed Central

Yang, Yu-Guang; Xu, Peng; Yang, Rui; Zhou, Yi-Hua; Shi, Wei-Min

2016-01-01

Quantum information and quantum computation have achieved a huge success during the last years. In this paper, we investigate the capability of quantum Hash function, which can be constructed by subtly modifying quantum walks, a famous quantum computation model. It is found that quantum Hash function can act as a hash function for the privacy amplification process of quantum key distribution systems with higher security. As a byproduct, quantum Hash function can also be used for pseudo-random number generation due to its inherent chaotic dynamics. Further we discuss the application of quantum Hash function to image encryption and propose a novel image encryption algorithm. Numerical simulations and performance comparisons show that quantum Hash function is eligible for privacy amplification in quantum key distribution, pseudo-random number generation and image encryption in terms of various hash tests and randomness tests. It extends the scope of application of quantum computation and quantum information. PMID:26823196

Quantum Hash function and its application to privacy amplification in quantum key distribution, pseudo-random number generation and image encryption.

PubMed

Yang, Yu-Guang; Xu, Peng; Yang, Rui; Zhou, Yi-Hua; Shi, Wei-Min

2016-01-29

Quantum information and quantum computation have achieved a huge success during the last years. In this paper, we investigate the capability of quantum Hash function, which can be constructed by subtly modifying quantum walks, a famous quantum computation model. It is found that quantum Hash function can act as a hash function for the privacy amplification process of quantum key distribution systems with higher security. As a byproduct, quantum Hash function can also be used for pseudo-random number generation due to its inherent chaotic dynamics. Further we discuss the application of quantum Hash function to image encryption and propose a novel image encryption algorithm. Numerical simulations and performance comparisons show that quantum Hash function is eligible for privacy amplification in quantum key distribution, pseudo-random number generation and image encryption in terms of various hash tests and randomness tests. It extends the scope of application of quantum computation and quantum information.

Model-based vision using geometric hashing

NASA Astrophysics Data System (ADS)

Akerman, Alexander, III; Patton, Ronald

1991-04-01

The Geometric Hashing technique developed by the NYU Courant Institute has been applied to various automatic target recognition applications. In particular, I-MATH has extended the hashing algorithm to perform automatic target recognition ofsynthetic aperture radar (SAR) imagery. For this application, the hashing is performed upon the geometric locations of dominant scatterers. In addition to being a robust model-based matching algorithm -- invariant under translation, scale, and 3D rotations of the target -- hashing is of particular utility because it can still perform effective matching when the target is partially obscured. Moreover, hashing is very amenable to a SIMD parallel processing architecture, and thus potentially realtime implementable.

Diet-induced obesity exacerbates metabolic and behavioral effects of polycystic ovary syndrome in a rodent model.

PubMed

Ressler, Ilana B; Grayson, Bernadette E; Ulrich-Lai, Yvonne M; Seeley, Randy J

2015-06-15

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting women of reproductive age. Although a comorbidity of PCOS is obesity, many are lean. We hypothesized that increased saturated fat consumption and obesity would exacerbate metabolic and stress indices in a rodent model of PCOS. Female rats were implanted with the nonaromatizable androgen dihydrotestosterone (DHT) or placebo pellets prior to puberty. Half of each group was maintained ad libitum on either a high-fat diet (HFD; 40% butter fat calories) or nutrient-matched low-fat diet (LFD). Irrespective of diet, DHT-treated animals gained more body weight, had irregular cycles, and were glucose intolerant compared with controls on both diets. HFD/DHT animals had the highest levels of fat mass and insulin resistance. DHT animals demonstrated increased anxiety-related behavior in the elevated plus maze by decreased distance traveled and time in the open arms. HFD consumption increased immobility during the forced-swim test. DHT treatment suppressed diurnal corticosterone measurements in both diet groups. In parallel, DHT treatment significantly dampened stress responsivity to a mild stressor. Brains of DHT animals showed attenuated c-Fos activation in the ventromedial hypothalamus and arcuate nucleus; irrespective of DHT-treatment, however, all HFD animals had elevated hypothalamic paraventricular nucleus c-Fos activation. Whereas hyperandrogenism drives overall body weight gain, glucose intolerance, anxiety behaviors, and stress responsivity, HFD consumption exacerbates the effect of androgens on adiposity, insulin resistance, and depressive behaviors. Copyright © 2015 the American Physiological Society.

Diet-induced obesity exacerbates metabolic and behavioral effects of polycystic ovary syndrome in a rodent model

PubMed Central

Ressler, Ilana B.; Grayson, Bernadette E.; Ulrich-Lai, Yvonne M.

2015-01-01

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting women of reproductive age. Although a comorbidity of PCOS is obesity, many are lean. We hypothesized that increased saturated fat consumption and obesity would exacerbate metabolic and stress indices in a rodent model of PCOS. Female rats were implanted with the nonaromatizable androgen dihydrotestosterone (DHT) or placebo pellets prior to puberty. Half of each group was maintained ad libitum on either a high-fat diet (HFD; 40% butter fat calories) or nutrient-matched low-fat diet (LFD). Irrespective of diet, DHT-treated animals gained more body weight, had irregular cycles, and were glucose intolerant compared with controls on both diets. HFD/DHT animals had the highest levels of fat mass and insulin resistance. DHT animals demonstrated increased anxiety-related behavior in the elevated plus maze by decreased distance traveled and time in the open arms. HFD consumption increased immobility during the forced-swim test. DHT treatment suppressed diurnal corticosterone measurements in both diet groups. In parallel, DHT treatment significantly dampened stress responsivity to a mild stressor. Brains of DHT animals showed attenuated c-Fos activation in the ventromedial hypothalamus and arcuate nucleus; irrespective of DHT-treatment, however, all HFD animals had elevated hypothalamic paraventricular nucleus c-Fos activation. Whereas hyperandrogenism drives overall body weight gain, glucose intolerance, anxiety behaviors, and stress responsivity, HFD consumption exacerbates the effect of androgens on adiposity, insulin resistance, and depressive behaviors. PMID:26078189

Prostate cancer cells differ in testosterone accumulation, dihydrotestosterone conversion, and androgen receptor signaling response to steroid 5α-reductase inhibitors.

PubMed

Wu, Yue; Godoy, Alejandro; Azzouni, Faris; Wilton, John H; Ip, Clement; Mohler, James L

2013-09-01

Blocking 5α-reductase-mediated testosterone conversion to dihydrotestosterone (DHT) with finasteride or dutasteride is the driving hypothesis behind two prostate cancer prevention trials. Factors affecting intracellular androgen levels and the androgen receptor (AR) signaling axis need to be examined systematically in order to fully understand the outcome of interventions using these drugs. The expression of three 5α-reductase isozymes, as determined by immunohistochemistry and qRT-PCR, was studied in five human prostate cancer cell lines. Intracellular testosterone and DHT were analyzed using mass spectrometry. A luciferase reporter assay and AR-regulated genes were used to evaluate the modulation of AR activity. Prostate cancer cells were capable of accumulating testosterone to a level 15-50 times higher than that in the medium. The profile and expression of 5α-reductase isozymes did not predict the capacity to convert testosterone to DHT. Finasteride and dutasteride were able to depress testosterone uptake in addition to lowering intracellular DHT. The inhibition of AR activity following drug treatment often exceeded the expected response due to reduced availability of DHT. The ability to maintain high intracellular testosterone might compensate for the shortage of DHT. The biological effect of finasteride or dutasteride appears to be complex and may depend on the interplay of several factors, which include testosterone turnover, enzymology of DHT production, ability to use testosterone and DHT interchangeably, and propensity of cells for off-target AR inhibitory effect. © 2013 Wiley Periodicals, Inc.

Digital camera with apparatus for authentication of images produced from an image file

NASA Technical Reports Server (NTRS)

Friedman, Gary L. (Inventor)

1993-01-01

A digital camera equipped with a processor for authentication of images produced from an image file taken by the digital camera is provided. The digital camera processor has embedded therein a private key unique to it, and the camera housing has a public key that is so uniquely based upon the private key that digital data encrypted with the private key by the processor may be decrypted using the public key. The digital camera processor comprises means for calculating a hash of the image file using a predetermined algorithm, and second means for encrypting the image hash with the private key, thereby producing a digital signature. The image file and the digital signature are stored in suitable recording means so they will be available together. Apparatus for authenticating at any time the image file as being free of any alteration uses the public key for decrypting the digital signature, thereby deriving a secure image hash identical to the image hash produced by the digital camera and used to produce the digital signature. The apparatus calculates from the image file an image hash using the same algorithm as before. By comparing this last image hash with the secure image hash, authenticity of the image file is determined if they match, since even one bit change in the image hash will cause the image hash to be totally different from the secure hash.

Hash Bit Selection for Nearest Neighbor Search.

PubMed

Xianglong Liu; Junfeng He; Shih-Fu Chang

2017-11-01

To overcome the barrier of storage and computation when dealing with gigantic-scale data sets, compact hashing has been studied extensively to approximate the nearest neighbor search. Despite the recent advances, critical design issues remain open in how to select the right features, hashing algorithms, and/or parameter settings. In this paper, we address these by posing an optimal hash bit selection problem, in which an optimal subset of hash bits are selected from a pool of candidate bits generated by different features, algorithms, or parameters. Inspired by the optimization criteria used in existing hashing algorithms, we adopt the bit reliability and their complementarity as the selection criteria that can be carefully tailored for hashing performance in different tasks. Then, the bit selection solution is discovered by finding the best tradeoff between search accuracy and time using a modified dynamic programming method. To further reduce the computational complexity, we employ the pairwise relationship among hash bits to approximate the high-order independence property, and formulate it as an efficient quadratic programming method that is theoretically equivalent to the normalized dominant set problem in a vertex- and edge-weighted graph. Extensive large-scale experiments have been conducted under several important application scenarios of hash techniques, where our bit selection framework can achieve superior performance over both the naive selection methods and the state-of-the-art hashing algorithms, with significant accuracy gains ranging from 10% to 50%, relatively.

Deep Constrained Siamese Hash Coding Network and Load-Balanced Locality-Sensitive Hashing for Near Duplicate Image Detection.

PubMed

Hu, Weiming; Fan, Yabo; Xing, Junliang; Sun, Liang; Cai, Zhaoquan; Maybank, Stephen

2018-09-01

We construct a new efficient near duplicate image detection method using a hierarchical hash code learning neural network and load-balanced locality-sensitive hashing (LSH) indexing. We propose a deep constrained siamese hash coding neural network combined with deep feature learning. Our neural network is able to extract effective features for near duplicate image detection. The extracted features are used to construct a LSH-based index. We propose a load-balanced LSH method to produce load-balanced buckets in the hashing process. The load-balanced LSH significantly reduces the query time. Based on the proposed load-balanced LSH, we design an effective and feasible algorithm for near duplicate image detection. Extensive experiments on three benchmark data sets demonstrate the effectiveness of our deep siamese hash encoding network and load-balanced LSH.

Study of the similarity function in Indexing-First-One hashing

NASA Astrophysics Data System (ADS)

Lai, Y.-L.; Jin, Z.; Goi, B.-M.; Chai, T.-Y.

2017-06-01

The recent proposed Indexing-First-One (IFO) hashing is a latest technique that is particularly adopted for eye iris template protection, i.e. IrisCode. However, IFO employs the measure of Jaccard Similarity (JS) initiated from Min-hashing has yet been adequately discussed. In this paper, we explore the nature of JS in binary domain and further propose a mathematical formulation to generalize the usage of JS, which is subsequently verified by using CASIA v3-Interval iris database. Our study reveals that JS applied in IFO hashing is a generalized version in measure two input objects with respect to Min-Hashing where the coefficient of JS is equal to one. With this understanding, IFO hashing can propagate the useful properties of Min-hashing, i.e. similarity preservation, thus favorable for similarity searching or recognition in binary space.

Linear Subspace Ranking Hashing for Cross-Modal Retrieval.

PubMed

Li, Kai; Qi, Guo-Jun; Ye, Jun; Hua, Kien A

2017-09-01

Hashing has attracted a great deal of research in recent years due to its effectiveness for the retrieval and indexing of large-scale high-dimensional multimedia data. In this paper, we propose a novel ranking-based hashing framework that maps data from different modalities into a common Hamming space where the cross-modal similarity can be measured using Hamming distance. Unlike existing cross-modal hashing algorithms where the learned hash functions are binary space partitioning functions, such as the sign and threshold function, the proposed hashing scheme takes advantage of a new class of hash functions closely related to rank correlation measures which are known to be scale-invariant, numerically stable, and highly nonlinear. Specifically, we jointly learn two groups of linear subspaces, one for each modality, so that features' ranking orders in different linear subspaces maximally preserve the cross-modal similarities. We show that the ranking-based hash function has a natural probabilistic approximation which transforms the original highly discontinuous optimization problem into one that can be efficiently solved using simple gradient descent algorithms. The proposed hashing framework is also flexible in the sense that the optimization procedures are not tied up to any specific form of loss function, which is typical for existing cross-modal hashing methods, but rather we can flexibly accommodate different loss functions with minimal changes to the learning steps. We demonstrate through extensive experiments on four widely-used real-world multimodal datasets that the proposed cross-modal hashing method can achieve competitive performance against several state-of-the-arts with only moderate training and testing time.

Current perspectives on the androgen 5 alpha-dihydrotestosterone (DHT) and 5 alpha-reductases in teleost fishes and amphibians.

PubMed

Martyniuk, Christopher J; Bissegger, Sonja; Langlois, Valérie S

2013-12-01

The androgen 5 alpha-dihydrotestosterone (DHT) is a steroidogenic metabolite that has received little attention in non-mammalian species. DHT is produced by the reduction of the double-bond of testosterone by a group of enzymes called 5 alpha-reductases of which there can be multiple isoforms (i.e., srd5a1, srd5a2, and srd5a3). Data from amphibians suggest that the expression of the srd5a genes occurs in early development, and continues until adulthood; however insufficient data exist in fish species, where DHT is thought to be relatively biologically inactive. Here, we demonstrate that fathead minnow (FHM; Pimephales promelas) developing embryos and adults express srd5a enzyme isoforms. During FHM embryogenesis, both srd5a1 and srd5a3 mRNA levels were significantly correlated in expression levels while srd5a2 showed a more unique pattern of expression. In adult FHMs, males had significantly higher levels of srd5a2 in the liver and gonad compared to females. In the male and female liver, transcript levels for srd5a2 were more abundant compared to srd5a1 and srd5a3, suggesting a prominent role for srd5a2 in this tissue. Interestingly, the ovary expressed higher mRNA levels of srd5a3 than the testis. Thus, data suggest that srd5a isoforms can show sexually dimorphic expression patterns in fish. We also conducted a literature review of the biological effects observed in embryonic and adult fish and amphibians after treatments with DHT and DHT-related compounds. Treatments with DHT in teleost fishes and amphibians have resulted in unexpected biological responses that are characteristic of both androgens and anti-androgens. For example, in fish DHT can induce vitellogenin in vitro from male and female hepatocytes and can increase 17β-estradiol production from the teleost ovary. We propose, that to generate further understanding of the roles of DHT in non-mammals, studies are needed that (1) address how DHT is synthesized within tissues of fish and amphibians; (2) examine the full range of biological responses to endogenous DHT, and its interactions with other signaling pathways; and (3) investigate how DHT production varies with reproductive stage. Lastly, we suggest that the Srd5a enzymes can be targets of endocrine disruptors in fish and frogs, which may result in disruptions in the estrogen:androgen balance in aquatic organisms. Copyright © 2013 Elsevier Inc. All rights reserved.

Reprint of "Current perspectives on the androgen 5 alpha-dihydrotestosterone (DHT) and 5 alpha-reductases in teleost fishes and amphibians".

PubMed

Martyniuk, Christopher J; Bissegger, Sonja; Langlois, Valérie S

2014-07-01

The androgen 5 alpha-dihydrotestosterone (DHT) is a steroidogenic metabolite that has received little attention in non-mammalian species. DHT is produced by the reduction of the double-bond of testosterone by a group of enzymes called 5 alpha-reductases of which there can be multiple isoforms (i.e., srd5a1, srd5a2, and srd5a3). Data from amphibians suggest that the expression of the srd5a genes occurs in early development, and continues until adulthood; however insufficient data exist in fish species, where DHT is thought to be relatively biologically inactive. Here, we demonstrate that fathead minnow (FHM; Pimephales promelas) developing embryos and adults express srd5a enzyme isoforms. During FHM embryogenesis, both srd5a1 and srd5a3 mRNA levels were significantly correlated in expression levels while srd5a2 showed a more unique pattern of expression. In adult FHMs, males had significantly higher levels of srd5a2 in the liver and gonad compared to females. In the male and female liver, transcript levels for srd5a2 were more abundant compared to srd5a1 and srd5a3, suggesting a prominent role for srd5a2 in this tissue. Interestingly, the ovary expressed higher mRNA levels of srd5a3 than the testis. Thus, data suggest that srd5a isoforms can show sexually dimorphic expression patterns in fish. We also conducted a literature review of the biological effects observed in embryonic and adult fish and amphibians after treatments with DHT and DHT-related compounds. Treatments with DHT in teleost fishes and amphibians have resulted in unexpected biological responses that are characteristic of both androgens and anti-androgens. For example, in fish DHT can induce vitellogenin in vitro from male and female hepatocytes and can increase 17β-estradiol production from the teleost ovary. We propose, that to generate further understanding of the roles of DHT in non-mammals, studies are needed that (1) address how DHT is synthesized within tissues of fish and amphibians; (2) examine the full range of biological responses to endogenous DHT, and its interactions with other signaling pathways; and (3) investigate how DHT production varies with reproductive stage. Lastly, we suggest that the Srd5a enzymes can be targets of endocrine disruptors in fish and frogs, which may result in disruptions in the estrogen:androgen balance in aquatic organisms. Copyright © 2013 Elsevier Inc. All rights reserved.

Enantioselective Separation of 4,8-DHT and Phytotoxicity of the Enantiomers on Various Plant Species.

PubMed

Yang, Li; Ma, Xiao-Yan; Ruan, Xiao; Jiang, De-An; Pan, Cun-De; Wang, Qiang

2016-04-22

As a candidate for bioherbicide, 4,8-dihydroxy-1-tetralone (4,8-DHT) was isolated from Caryospora callicarpa epicarp and its two enantiomers, S-(+)-isosclerone and R-(-)-regiolone, were separated by chiral high-performance liquid chromatography (HPLC) on a Chiralcel OD column with chiral stationary phase (CSP)-coated cellulose-tris(3,5-dimethylphenylcarbamate). Then, the phytotoxicity of 4,8-DHT and its enantiomers toward the seeds germination and seedling growth of the five tested plant species, including lettuce (Latuca sativa), radish (Raphanus sativus), cucumber (Cucumis sativus), onion (Allium cepa), and wheat (Triticum aestivum), were investigated and the results indicated a hormesis at low concentration of 4,8-DHT and its enantiomers, but a retardant effect at high concentration. Between the two enantiomers of 4,8-DHT, the S-(+)-isosclerone was more toxic to seeds germination and seedling growth of the five tested plant species than the R-(-)-regiolone, and also the phytotoxicity of S-(+)-isosclerone varied with different plants. For example, S-(+)-isosclerone was the most active to seedling growth of lettuce, indicating that S-(+)-isosclerone had specific effects on different organisms. Thus, all of the chirality and concentration of 4,8-DHT, as well as the affected plant species, need to be taken into consideration in the development and utilization of 4,8-DHT.

Spherical hashing: binary code embedding with hyperspheres.

PubMed

Heo, Jae-Pil; Lee, Youngwoon; He, Junfeng; Chang, Shih-Fu; Yoon, Sung-Eui

2015-11-01

Many binary code embedding schemes have been actively studied recently, since they can provide efficient similarity search, and compact data representations suitable for handling large scale image databases. Existing binary code embedding techniques encode high-dimensional data by using hyperplane-based hashing functions. In this paper we propose a novel hypersphere-based hashing function, spherical hashing, to map more spatially coherent data points into a binary code compared to hyperplane-based hashing functions. We also propose a new binary code distance function, spherical Hamming distance, tailored for our hypersphere-based binary coding scheme, and design an efficient iterative optimization process to achieve both balanced partitioning for each hash function and independence between hashing functions. Furthermore, we generalize spherical hashing to support various similarity measures defined by kernel functions. Our extensive experiments show that our spherical hashing technique significantly outperforms state-of-the-art techniques based on hyperplanes across various benchmarks with sizes ranging from one to 75 million of GIST, BoW and VLAD descriptors. The performance gains are consistent and large, up to 100 percent improvements over the second best method among tested methods. These results confirm the unique merits of using hyperspheres to encode proximity regions in high-dimensional spaces. Finally, our method is intuitive and easy to implement.

Binary Multidimensional Scaling for Hashing.

PubMed

Huang, Yameng; Lin, Zhouchen

2017-10-04

Hashing is a useful technique for fast nearest neighbor search due to its low storage cost and fast query speed. Unsupervised hashing aims at learning binary hash codes for the original features so that the pairwise distances can be best preserved. While several works have targeted on this task, the results are not satisfactory mainly due to the oversimplified model. In this paper, we propose a unified and concise unsupervised hashing framework, called Binary Multidimensional Scaling (BMDS), which is able to learn the hash code for distance preservation in both batch and online mode. In the batch mode, unlike most existing hashing methods, we do not need to simplify the model by predefining the form of hash map. Instead, we learn the binary codes directly based on the pairwise distances among the normalized original features by Alternating Minimization. This enables a stronger expressive power of the hash map. In the online mode, we consider the holistic distance relationship between current query example and those we have already learned, rather than only focusing on current data chunk. It is useful when the data come in a streaming fashion. Empirical results show that while being efficient for training, our algorithm outperforms state-of-the-art methods by a large margin in terms of distance preservation, which is practical for real-world applications.

Achaete-Scute Homolog 1 Expression Controls Cellular Differentiation of Neuroblastoma

PubMed Central

Kasim, Mumtaz; Heß, Vicky; Scholz, Holger; Persson, Pontus B.; Fähling, Michael

2016-01-01

Neuroblastoma, the major cause of infant cancer deaths, results from fast proliferation of undifferentiated neuroblasts. Treatment of high-risk neuroblastoma includes differentiation with retinoic acid (RA); however, the resistance of many of these tumors to RA-induced differentiation poses a considerable challenge. Human achaete-scute homolog 1 (hASH1) is a proneural basic helix-loop-helix transcription factor essential for neurogenesis and is often upregulated in neuroblastoma. Here, we identified a novel function for hASH1 in regulating the differentiation phenotype of neuroblastoma cells. Global analysis of 986 human neuroblastoma datasets revealed a negative correlation between hASH1 and neuron differentiation that was independent of the N-myc (MYCN) oncogene. Using RA to induce neuron differentiation in two neuroblastoma cell lines displaying high and low levels of hASH1 expression, we confirmed the link between hASH1 expression and the differentiation defective phenotype, which was reversed by silencing hASH1 or by hypoxic preconditioning. We further show that hASH1 suppresses neuronal differentiation by inhibiting transcription at the RA receptor element. Collectively, our data indicate hASH1 to be key for understanding neuroblastoma resistance to differentiation therapy and pave the way for hASH1-targeted therapies for augmenting the response of neuroblastoma to differentiation therapy. PMID:28066180

Further insights into the oxidation chemistry and biochemistry of the serotonergic neurotoxin 5,6-dihydroxytryptamine.

PubMed

Singh, S; Dryhurst, G

1990-11-01

The neurodegenerative properties of the serotonergic neurotoxin 5,6-dihydroxytryptamine (5,6-DHT) are widely believed to result from its autoxidation in the central nervous system. The autoxidation chemistry of 5,6-DHT has been studied in aqueous solution at pH 7.2. The reaction is initiated by direct oxidation of the indolamine by molecular oxygen with resultant formation of the corresponding o-quinone 1 and H2O2. A rapid nucleophilic attack by 5,6-DHT on 1 leads to 2,7'-bis(5,6-dihydroxytryptamine) (6) which is more rapidly autoxidized than 5,6-DHT to give the corresponding diquinone 7 along with 2 mol of H2O2. The accumulation of 6 in the reaction solution during the autoxidation of 5,6-DHT despite its more rapid autoxidation indicates that diquinone 7 chemically oxidizes 5,6-DHT (2 mol) to quinone 1 so that an autocatalytic cycle is established. The H2O2 formed as a byproduct of these autoxidation reactions can undergo Fenton chemistry catalyzed by trace transition metal ion contaminants with resultant formation of the hydroxyl radical, HO., which directly oxidizes 5,6-DHT to a radical intermediate (9a/9b). This radical is directly attacked by O2 to yield quinone 1 and superoxide radical anion, O2.-, which further facilitates Fenton chemistry by reducing, inter alia, Fe3+ to Fe2+. A minor side reaction of 1 with water leads to formation of at least two trihydroxytryptamines. Diquinone 7 ultimately reacts with 6, 5,6-DHT, and perhaps trihydroxytryptamines, leading via a sequence of coupling and oxidation reactions to a black indolic melanin polymer. Enzymes such as tyrosinase, ceruloplasmin, and peroxidase and rat brain mitochondria catalyze the oxidation of 5,6-DHT to form dimer 7 and, ultimately, indolic melanin. The role of the autoxidation and the enzyme-mediated and mitochondria-promoted oxidations of 5,6-DHT in expressing the neurodegenerative properties of the indolamine are discussed.

Preventable effect of L-threonate, an ascorbate metabolite, on androgen-driven balding via repression of dihydrotestosterone-induced dickkopf-1 expression in human hair dermal papilla cells.

PubMed

Kwack, Mi Hee; Ahn, Ji Sup; Kim, Moon Kyu; Kim, Jung Chul; Sung, Young Kwan

2010-10-01

In a previous study, we recently claimed that dihydrotestosterone (DHT)-inducible dickkopf-1 (DKK-1) expression is one of the key factors involved in androgen-potentiated balding. We also demonstrated that L-ascorbic acid 2-phosphate (Asc 2-P) represses DHT-induced DKK-1 expression in cultured dermal papilla cells (DPCs). Here, we investigated whether or not L-threonate could attenuate DHT-induced DKK-1 expression. We observed via RT-PCR analysis and enzyme-linked immunosorbent assay that DHT-induced DKK-1 expression was attenuated in the presence of L-threonate. We also found that DHT-induced activation of DKK-1 promoter activity was significantly repressed by L-threonate. Moreover, a co-culture system featuring outer root sheath (ORS) keratinocytes and DPCs showed that DHT inhibited the growth of ORS cells, which was then significantly reversed by L-threonate. Collectively, these results indicate that L-threonate inhibited DKK-1 expression in DPCs and therefore is a good treatment for the prevention of androgen-driven balding.

Collision analysis of one kind of chaos-based hash function

NASA Astrophysics Data System (ADS)

Xiao, Di; Peng, Wenbing; Liao, Xiaofeng; Xiang, Tao

2010-02-01

In the last decade, various chaos-based hash functions have been proposed. Nevertheless, the corresponding analyses of them lag far behind. In this Letter, we firstly take a chaos-based hash function proposed very recently in Amin, Faragallah and Abd El-Latif (2009) [11] as a sample to analyze its computational collision problem, and then generalize the construction method of one kind of chaos-based hash function and summarize some attentions to avoid the collision problem. It is beneficial to the hash function design based on chaos in the future.

Providing Cryptographic Security and Evidentiary Chain-of-Custody with the Advanced Forensic Format, Library, and Tools

DTIC Science & Technology

2008-08-19

1 hash of the page page%d sha256 The segment for the SHA256 hash of the page Bad Sector Management: badsectors The number of sectors in the image...written, AFFLIB can automatically compute the page’s MD5, SHA-1, and/or SHA256 hash and write an associated segment containing the hash value. The...are written into segments themselves, with the segment name being name/ sha256 where name is the original segment name sha256 is the hash algorithm used

Computing quantum hashing in the model of quantum branching programs

NASA Astrophysics Data System (ADS)

Ablayev, Farid; Ablayev, Marat; Vasiliev, Alexander

2018-02-01

We investigate the branching program complexity of quantum hashing. We consider a quantum hash function that maps elements of a finite field into quantum states. We require that this function is preimage-resistant and collision-resistant. We consider two complexity measures for Quantum Branching Programs (QBP): a number of qubits and a number of compu-tational steps. We show that the quantum hash function can be computed efficiently. Moreover, we prove that such QBP construction is optimal. That is, we prove lower bounds that match the constructed quantum hash function computation.

Characterization of the FoxL2 proximal promoter and coding sequence from the common snapping turtle (Chelydra serpentina).

PubMed

Guo, Lei; Rhen, Turk

2017-10-01

Sex is determined by temperature during embryogenesis in snapping turtles, Chelydra serpentina. Previous studies in this species show that dihydrotestosterone (DHT) induces ovarian development at temperatures that normally produce males or mixed sex ratios. The feminizing effect of DHT is associated with increased expression of FoxL2, suggesting that androgens regulate transcription of FoxL2. To test this hypothesis, we cloned the proximal promoter (1.6kb) and coding sequence for snapping turtle FoxL2 (tFoxL2) in frame with mCherry to produce a fluorescent reporter. The tFoxL2-mCherry fusion plasmid or mCherry control plasmid were stably transfected into mouse KK1 granulosa cells. These cells were then treated with 0, 1, 10, or 100nM DHT to assess androgen effects on tFoxL2-mCherry expression. In contrast to the main hypothesis, DHT did not alter expression of the tFoxL2-mCherry reporter. However, normal serum increased expression of tFoxL2-mCherry when compared to charcoal-stripped serum, indicating that the cloned region of tFoxL2 contains cis regulatory elements. We also used the tFoxL2-mCherry plasmid as an expression vector to test the hypothesis that DHT and tFoxL2 interact to regulate expression of endogenous genes in granulosa cells. While tFoxL2-mCherry and DHT had independent effects on mouse FoxL2, FshR, GnRHR, and StAR expression, tFoxL2-mCherry potentiated low concentration DHT effects on mouse aromatase expression. Further studies will be required to determine whether synergistic regulation of aromatase by DHT and FoxL2 also occurs in turtle gonads during the sex-determining period, which would explain the feminizing effect of DHT in this species. Copyright © 2017 Elsevier Inc. All rights reserved.

Human 3α-hydroxysteroid dehydrogenase type 3: structural clues of 5α-DHT reverse binding and enzyme down-regulation decreasing MCF7 cell growth.

PubMed

Zhang, Bo; Hu, Xiao-Jian; Wang, Xiao-Qiang; Thériault, Jean-François; Zhu, Dao-Wei; Shang, Peng; Labrie, Fernand; Lin, Sheng-Xiang

2016-04-15

Human 3α-HSD3 (3α-hydroxysteroid dehydrogenase type 3) plays an essential role in the inactivation of the most potent androgen 5α-DHT (5α-dihydrotestosterone). The present study attempts to obtain the important structure of 3α-HSD3 in complex with 5α-DHT and to investigate the role of 3α-HSD3 in breast cancer cells. We report the crystal structure of human 3α-HSD3·NADP(+)·A-dione (5α-androstane-3,17-dione)/epi-ADT (epiandrosterone) complex, which was obtained by co-crystallization with 5α-DHT in the presence of NADP(+) Although 5α-DHT was introduced during the crystallization, oxidoreduction of 5α-DHT occurred. The locations of A-dione and epi-ADT were identified in the steroid-binding sites of two 3α-HSD3 molecules per crystal asymmetric unit. An overlay showed that A-dione and epi-ADT were oriented upside-down and flipped relative to each other, providing structural clues for 5α-DHT reverse binding in the enzyme with the generation of different products. Moreover, we report the crystal structure of the 3α-HSD3·NADP(+)·4-dione (4-androstene-3,17-dione) complex. When a specific siRNA (100 nM) was used to suppress 3α-HSD3 expression without interfering with 3α-HSD4, which shares a highly homologous active site, the 5α-DHT concentration increased, whereas MCF7 cell growth was suppressed. The present study provides structural clues for 5α-DHT reverse binding within 3α-HSD3, and demonstrates for the first time that down-regulation of 3α-HSD3 decreases MCF7 breast cancer cell growth. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Assessment of the usefulness of dihydrotestosterone in the diagnostics of patients with androgenetic alopecia

PubMed Central

Urysiak-Czubatka, Izabela; Broniarczyk-Dyła, Grażyna

2014-01-01

Introduction Androgenetic alopecia (AGA) is the most common form of hair loss. Clinically observed hair loss is due to the continuous miniaturization of affected hair follicles. Genetic factors and androgenic factors especially dihydrotestosterone (DHT), which is a testosterone tissue metabolite, play major roles in the pathogenesis of AGA. However, expert opinions about the usefulness of DHT in the diagnosis of this type of alopecia are divided. Aim To evaluate the usefulness of DHT level in patients with androgenetic alopecia compared with the control group. Material and methods The study comprised 49 subjects: 19 women and 9 men with androgenetic alopecia. The control group consisted of 17 healthy women and 4 men without hair loss. Results Increased serum concentrations of DHT were observed in patients with androgenetic alopecia (17 women, 5 men), but also in the control group. The differences in mean values of DHT were not significant according to the types of alopecia and the control group. Increased serum concentrations of DHT were not correlated with the advance of alopecia. Conclusions Dihydrotestosterone is the most influential androgen and seems to play a very important role in the pathogenesis of androgenetic alopecia. Based on the results of our study and others, the most important factors would appear to be the genetically-determined sensitivity of the follicles to DHT and their different reactions to androgen concentration. PMID:25254005

Robust hashing for 3D models

NASA Astrophysics Data System (ADS)

Berchtold, Waldemar; Schäfer, Marcel; Rettig, Michael; Steinebach, Martin

2014-02-01

3D models and applications are of utmost interest in both science and industry. With the increment of their usage, their number and thereby the challenge to correctly identify them increases. Content identification is commonly done by cryptographic hashes. However, they fail as a solution in application scenarios such as computer aided design (CAD), scientific visualization or video games, because even the smallest alteration of the 3D model, e.g. conversion or compression operations, massively changes the cryptographic hash as well. Therefore, this work presents a robust hashing algorithm for 3D mesh data. The algorithm applies several different bit extraction methods. They are built to resist desired alterations of the model as well as malicious attacks intending to prevent correct allocation. The different bit extraction methods are tested against each other and, as far as possible, the hashing algorithm is compared to the state of the art. The parameters tested are robustness, security and runtime performance as well as False Acceptance Rate (FAR) and False Rejection Rate (FRR), also the probability calculation of hash collision is included. The introduced hashing algorithm is kept adaptive e.g. in hash length, to serve as a proper tool for all applications in practice.

Kinetic and Thermodynamic Characterization of Dihydrotestosterone-Induced Conformational Perturbations in Androgen Receptor Ligand-Binding Domain

PubMed Central

Jasuja, Ravi; Ulloor, Jagadish; Yengo, Christopher M.; Choong, Karen; Istomin, Andrei Y.; Livesay, Dennis R.; Jacobs, Donald J.; Swerdloff, Ronald S.; Mikšovská, Jaroslava; Larsen, Randy W.; Bhasin, Shalender

2009-01-01

Ligand-induced conformational perturbations in androgen receptor (AR) are important in coactivator recruitment and transactivation. However, molecular rearrangements in AR ligand-binding domain (AR-LBD) associated with agonist binding and their kinetic and thermodynamic parameters are poorly understood. We used steady-state second-derivative absorption and emission spectroscopy, pressure and temperature perturbations, and 4,4′-bis-anilinonaphthalene 8-sulfonate (bis-ANS) partitioning to determine the kinetics and thermodynamics of the conformational changes in AR-LBD after dihydrotestosterone (DHT) binding. In presence of DHT, the second-derivative absorption spectrum showed a red shift and a change in peak-to-peak distance. Emission intensity increased upon DHT binding, and center of spectral mass was blue shifted, denoting conformational changes resulting in more hydrophobic environment for tyrosines and tryptophans within a more compact DHT-bound receptor. In pressure perturbation calorimetry, DHT-induced energetic stabilization increased the Gibbs free energy of unfolding to 8.4 ± 1.3 kcal/mol from 3.5 ± 1.6 kcal/mol. Bis-ANS partitioning studies revealed that upon DHT binding, AR-LBD underwent biphasic rearrangement with a high activation energy (13.4 kcal/mol). An initial, molten globule-like burst phase (k ∼30 sec−1) with greater solvent accessibility was followed by rearrangement (k ∼0.01 sec−1), leading to a more compact conformation than apo-AR-LBD. Molecular simulations demonstrated unique sensitivity of tyrosine and tryptophan residues during pressure unfolding with rearrangement of residues in the coactivator recruitment surfaces distant from the ligand-binding pocket. In conclusion, DHT binding leads to energetic stabilization of AR-LBD domain and substantial rearrangement of residues distant from the ligand-binding pocket. DHT binding to AR-LBD involves biphasic receptor rearrangement including population of a molten globule-like intermediate state. PMID:19443608

Neo-synthesis of estrogenic or androgenic neurosteroids determine whether long-term potentiation or depression is induced in hippocampus of male rat.

PubMed

Di Mauro, Michela; Tozzi, Alessandro; Calabresi, Paolo; Pettorossi, Vito Enrico; Grassi, Silvarosa

2015-01-01

Estrogenic and androgenic steroids synthesized in the brain may rapidly modulate synaptic plasticity interacting with specific membrane receptors. We explored by electrophysiological recordings in hippocampal slices of male rat the influence of 17β-estradiol (E2) and 5α-dihydrotestosterone (DHT) neo-synthesis on the synaptic changes induced in the CA1 region. Induction of long-term depression (LTD) and depotentiation (DP) by low frequency stimulation (LFS, 15 min-1 Hz) and of long-term potentiation (LTP) by high frequency stimulation (HFS, 1 s-100 Hz), medium (MFS, 1 s-50 Hz), or weak (WFS, 1 s-25 Hz) frequency stimulation was assayed under inhibitors of enzymes converting testosterone (T) into DHT (5α-reductase) and T into E2 (P450-aromatase). We found that LFS-LTD depends on DHT synthesis, since it was fully prevented under finasteride, an inhibitor of DHT synthesis, and rescued by exogenous DHT, while the E2 synthesis was not involved. Conversely, the full development of HFS-LTP requires the synthesis of E2, as demonstrated by the LTP reduction observed under letrozole, an inhibitor of E2 synthesis, and its full rescue by exogenous E2. For intermediate stimulation protocols DHT, but not E2 synthesis, was involved in the production of a small LTP induced by WFS, while the E2 synthesis was required for the MFS-dependent LTP. Under the combined block of DHT and E2 synthesis all stimulation frequencies induced partial LTP. Overall, these results indicate that DHT is required for converting the partial LTP into LTD whereas E2 is needed for the full expression of LTP, evidencing a key role of the neo-synthesis of sex neurosteroids in determining the direction of synaptic long-term effects.

Efficient computation of hashes

NASA Astrophysics Data System (ADS)

Lopes, Raul H. C.; Franqueira, Virginia N. L.; Hobson, Peter R.

2014-06-01

The sequential computation of hashes at the core of many distributed storage systems and found, for example, in grid services can hinder efficiency in service quality and even pose security challenges that can only be addressed by the use of parallel hash tree modes. The main contributions of this paper are, first, the identification of several efficiency and security challenges posed by the use of sequential hash computation based on the Merkle-Damgard engine. In addition, alternatives for the parallel computation of hash trees are discussed, and a prototype for a new parallel implementation of the Keccak function, the SHA-3 winner, is introduced.

Deep classification hashing for person re-identification

NASA Astrophysics Data System (ADS)

Wang, Jiabao; Li, Yang; Zhang, Xiancai; Miao, Zhuang; Tao, Gang

2018-04-01

As the development of surveillance in public, person re-identification becomes more and more important. The largescale databases call for efficient computation and storage, hashing technique is one of the most important methods. In this paper, we proposed a new deep classification hashing network by introducing a new binary appropriation layer in the traditional ImageNet pre-trained CNN models. It outputs binary appropriate features, which can be easily quantized into binary hash-codes for hamming similarity comparison. Experiments show that our deep hashing method can outperform the state-of-the-art methods on the public CUHK03 and Market1501 datasets.

High-throughput and direct measurement of androgen levels using turbulent flow chromatography liquid chromatography-triple quadrupole mass spectrometry (TFC-LC-TQMS) to discover chemicals that modulate dihydrotestosterone production in human prostate cancer cells.

PubMed

Kang, Kyungsu; Peng, Lei; Jung, Yu-Jin; Kim, Joo Yeon; Lee, Eun Ha; Lee, Hee Ju; Kim, Sang Min; Sung, Sang Hyun; Pan, Cheol-Ho; Choi, Yongsoo

2018-02-01

To develop a high-throughput screening system to measure the conversion of testosterone to dihydrotestosterone (DHT) in cultured human prostate cancer cells using turbulent flow chromatography liquid chromatography-triple quadrupole mass spectrometry (TFC-LC-TQMS). After optimizing the cell reaction system, this method demonstrated a screening capability of 103 samples, including 78 single compounds and 25 extracts, in less than 12 h without manual sample preparation. Consequently, fucoxanthin, phenethyl caffeate, and Curcuma longa L. extract were validated as bioactive chemicals that inhibited DHT production in cultured DU145 cells. In addition, naringenin boosted DHT production in DU145 cells. The method can facilitate the discovery of bioactive chemicals that modulate the DHT production, and four phytochemicals are potential candidates of nutraceuticals to adjust DHT levels in male hormonal dysfunction.

Fast underdetermined BSS architecture design methodology for real time applications.

PubMed

Mopuri, Suresh; Reddy, P Sreenivasa; Acharyya, Amit; Naik, Ganesh R

2015-01-01

In this paper, we propose a high speed architecture design methodology for the Under-determined Blind Source Separation (UBSS) algorithm using our recently proposed high speed Discrete Hilbert Transform (DHT) targeting real time applications. In UBSS algorithm, unlike the typical BSS, the number of sensors are less than the number of the sources, which is of more interest in the real time applications. The DHT architecture has been implemented based on sub matrix multiplication method to compute M point DHT, which uses N point architecture recursively and where M is an integer multiples of N. The DHT architecture and state of the art architecture are coded in VHDL for 16 bit word length and ASIC implementation is carried out using UMC 90 - nm technology @V DD = 1V and @ 1MHZ clock frequency. The proposed architecture implementation and experimental comparison results show that the DHT design is two times faster than state of the art architecture.

HashDist: Reproducible, Relocatable, Customizable, Cross-Platform Software Stacks for Open Hydrological Science

NASA Astrophysics Data System (ADS)

Ahmadia, A. J.; Kees, C. E.

2014-12-01

Developing scientific software is a continuous balance between not reinventing the wheel and getting fragile codes to interoperate with one another. Binary software distributions such as Anaconda provide a robust starting point for many scientific software packages, but this solution alone is insufficient for many scientific software developers. HashDist provides a critical component of the development workflow, enabling highly customizable, source-driven, and reproducible builds for scientific software stacks, available from both the IPython Notebook and the command line. To address these issues, the Coastal and Hydraulics Laboratory at the US Army Engineer Research and Development Center has funded the development of HashDist in collaboration with Simula Research Laboratories and the University of Texas at Austin. HashDist is motivated by a functional approach to package build management, and features intelligent caching of sources and builds, parametrized build specifications, and the ability to interoperate with system compilers and packages. HashDist enables the easy specification of "software stacks", which allow both the novice user to install a default environment and the advanced user to configure every aspect of their build in a modular fashion. As an advanced feature, HashDist builds can be made relocatable, allowing the easy redistribution of binaries on all three major operating systems as well as cloud, and supercomputing platforms. As a final benefit, all HashDist builds are reproducible, with a build hash specifying exactly how each component of the software stack was installed. This talk discusses the role of HashDist in the hydrological sciences, including its use by the Coastal and Hydraulics Laboratory in the development and deployment of the Proteus Toolkit as well as the Rapid Operational Access and Maneuver Support project. We demonstrate HashDist in action, and show how it can effectively support development, deployment, teaching, and reproducibility for scientists working in the hydrological sciences. The HashDist documentation is available from: http://hashdist.readthedocs.org/en/latest/ HashDist is currently hosted at: https://github.com/hashdist/hashdist

Implementation of 4-way Superscalar Hash MIPS Processor Using FPGA

NASA Astrophysics Data System (ADS)

Sahib Omran, Safaa; Fouad Jumma, Laith

2018-05-01

Due to the quick advancements in the personal communications systems and wireless communications, giving data security has turned into a more essential subject. This security idea turns into a more confounded subject when next-generation system requirements and constant calculation speed are considered in real-time. Hash functions are among the most essential cryptographic primitives and utilized as a part of the many fields of signature authentication and communication integrity. These functions are utilized to acquire a settled size unique fingerprint or hash value of an arbitrary length of message. In this paper, Secure Hash Algorithms (SHA) of types SHA-1, SHA-2 (SHA-224, SHA-256) and SHA-3 (BLAKE) are implemented on Field-Programmable Gate Array (FPGA) in a processor structure. The design is described and implemented using a hardware description language, namely VHSIC “Very High Speed Integrated Circuit” Hardware Description Language (VHDL). Since the logical operation of the hash types of (SHA-1, SHA-224, SHA-256 and SHA-3) are 32-bits, so a Superscalar Hash Microprocessor without Interlocked Pipelines (MIPS) processor are designed with only few instructions that were required in invoking the desired Hash algorithms, when the four types of hash algorithms executed sequentially using the designed processor, the total time required equal to approximately 342 us, with a throughput of 4.8 Mbps while the required to execute the same four hash algorithms using the designed four-way superscalar is reduced to 237 us with improved the throughput to 5.1 Mbps.

Effects of 5,7-DHT Injection into the Optic Lobe on the Circadian Locomotor Rhythm in the Cricket, Gryllus bimaculatus.

PubMed

Germ, M; Tomioka, K

1998-06-01

The effect of direct 5,7-dihydroxytryptamine (5,7-DHT) injection into the medulla region of the optic lobe on the locomotor activity was investigated in the adult male cricket, Gryllus bimaculatus. After a 6 hr phase advance of a light-dark cycle, the 5,7-DHT injected animals needed significantly longer time for resynchronization to the new cycle (6.55 +/- 0.62 days) than the control, Ringer's solution injected animals (3.17 +/- 0.15 days; P < 0.001, t-test). Light induced a bout of activity (i.e., masking effect) when light-dark cycle was phase advanced by 6 hr and the duration of the masking effect was significantly longer in 5,7-DHT injected animals. An initial bout of the nocturnal activity was significantly greater in the 5,7-DHT injected animal. Under constant darkness, the freerunning periods of both groups were not significantly different. Under constant light, a significantly higher percentage of 5,7-DHT injected animals showed arrhythmicity compared with the control group. An analysis carried by high-pressure liquid chromatography with electro-chemical detection (HPLC-ECD) revealed that the serotonin content in the optic lobe was significantly reduced to less than 50% in the 5,7-DHT injected animals, even one month after the injection. These results suggest that serotonin plays important roles in the regulation of circadian locomotor rhythms of the cricket mainly by regulating the sensitivity of the photoreceptive system.

Speaker Linking and Applications using Non-Parametric Hashing Methods

DTIC Science & Technology

2016-09-08

clustering method based on hashing—canopy- clustering . We apply this method to a large corpus of speaker recordings, demonstrate performance tradeoffs...and compare to other hash- ing methods. Index Terms: speaker recognition, clustering , hashing, locality sensitive hashing. 1. Introduction We assume...speaker in our corpus. Second, given a QBE method, how can we perform speaker clustering —each clustering should be a single speaker, and a cluster should

Sparse Partial Equilibrium Tables in Chemically Resolved Reactive Flow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vitello, P; Fried, L E; Pudliner, B

2003-07-14

The detonation of an energetic material is the result of a complex interaction between kinetic chemical reactions and hydrodynamics. Unfortunately, little is known concerning the detailed chemical kinetics of detonations in energetic materials. CHEETAH uses rate laws to treat species with the slowest chemical reactions, while assuming other chemical species are in equilibrium. CHEETAH supports a wide range of elements and condensed detonation products and can also be applied to gas detonations. A sparse hash table of equation of state values, called the ''cache'' is used in CHEETAH to enhance the efficiency of kinetic reaction calculations. For large-scale parallel hydrodynamicmore » calculations, CHEETAH uses MPI communication to updates to the cache. We present here details of the sparse caching model used in the CHEETAH. To demonstrate the efficiency of modeling using a sparse cache model we consider detonations in energetic materials.« less

Sparse Partial Equilibrium Tables in Chemically Resolved Reactive Flow

NASA Astrophysics Data System (ADS)

Vitello, Peter; Fried, Laurence E.; Pudliner, Brian; McAbee, Tom

2004-07-01

The detonation of an energetic material is the result of a complex interaction between kinetic chemical reactions and hydrodynamics. Unfortunately, little is known concerning the detailed chemical kinetics of detonations in energetic materials. CHEETAH uses rate laws to treat species with the slowest chemical reactions, while assuming other chemical species are in equilibrium. CHEETAH supports a wide range of elements and condensed detonation products and can also be applied to gas detonations. A sparse hash table of equation of state values is used in CHEETAH to enhance the efficiency of kinetic reaction calculations. For large-scale parallel hydrodynamic calculations, CHEETAH uses parallel communication to updates to the cache. We present here details of the sparse caching model used in the CHEETAH coupled to an ALE hydrocode. To demonstrate the efficiency of modeling using a sparse cache model we consider detonations in energetic materials.

Testosterone and dihydrotestosterone levels in the transition zone correlate with prostate volume.

PubMed

Pejčić, Tomislav; Tosti, Tomislav; Tešić, Živoslav; Milković, Borivoj; Dragičević, Dejan; Kozomara, Milutin; Čekerevac, Milica; Džamić, Zoran

2017-07-01

There is still no consensus regarding intraprostatic androgen levels and the accumulation of androgens in the hyperplastic prostatic tissue. The current opinion is that intraprostatic dihydrotestosterone (DHT) concentrations are maintained but not elevated in benign prostatic hyperplasia (BPH), while there is no similar data concerning intraprostatic testosterone (T). Tissue T (tT) and tissue DHT (tDHT) concentration were determined in 93 patients scheduled for initial prostate biopsy. The criteria for biopsy were abnormal DRE and/or PSA > 4 ng/mL. Total prostate volume (TPV) was determined by transrectal ultrasound (TRUS). During TRUS- guided prostate biopsy, 10-12 samples were collected from the peripheral zone (PZ) and two additional samples were collected from the transition zone (TZ). The samples from the TZ were immediately frozen in liquid nitrogen at -70°C, and transported for tissue androgen determination, using liquid chromatography mass spectrometry (LC-MS). Pathological analysis revealed that prostate cancer (PCa) was present in 45 and absent in 48 patients. In the whole group, there were 42 men with small prostate (TPV < 30 mL) and 51 with enlarged prostate (TPV ≥ 31 mL). The overall average tT level was 0.79 ± 0.66 ng/g, while the average tDHT level was 10.27 ± 7.15 ng/g. There were no differences in tT and tDHT level in prostates with and without PCa. However, tT and tDHT levels were significantly higher in larger, than in smaller prostates (tT: 1.05 ± 0.75 and 0.46 ± 0.29 ng/g, and tDHT: 15.0 ± 6.09 and 4.51 ± 2.75 ng/g, respectively). There were strong correlations between tT and TPV (r = 0.71), and tDHT and TPV (r = 0.74). The present study confirmed that both T and DHT accumulated in the stroma of enlarged prostates; the degree of accumulation correlated with prostate volume. © 2017 Wiley Periodicals, Inc.

Prostate Cancer Characteristics Associated with Response to Pre-Receptor Targeting of the Androgen Axis

PubMed Central

Mostaghel, Elahe A.; Morgan, Andrew; Zhang, Xiaotun; Marck, Brett T.; Xia, Jing; Hunter-Merrill, Rachel; Gulati, Roman; Plymate, Stephen; Vessella, Robert L.; Corey, Eva; Higano, Celestia S.; Matsumoto, Alvin M.; Montgomery, R. Bruce; Nelson, Peter S.

2014-01-01

Background Factors influencing differential responses of prostate tumors to androgen receptor (AR) axis-directed therapeutics are poorly understood, and predictors of treatment efficacy are needed. We hypothesized that the efficacy of inhibiting DHT ligand synthesis would associate with intra-tumoral androgen ratios indicative of relative dependence on DHT-mediated growth. Methods We characterized two androgen-sensitive prostate cancer xenograft models after androgen suppression by castration in combination with the SRD5A inhibitor, dutasteride, as well as a panel of castration resistant metastases obtained via rapid autopsy. Results In LuCaP35 tumors (intra-tumoral T:DHT ratio 2∶1) dutasteride suppressed DHT to 0.02 ng/gm and prolonged survival vs. castration alone (337 vs.152 days, HR 2.8, p = 0.0015). In LuCaP96 tumors (T:DHT 10∶1), survival was not improved despite similar DHT reduction (0.02 ng/gm). LuCaP35 demonstrated higher expression of steroid biosynthetic enzymes maintaining DHT levels (5-fold higher SRD5A1, 41 fold higher, 99-fold higher RL-HSD, p<0.0001 for both), reconstitution of intra-tumoral DHT (to ∼30% of untreated tumors), and ∼2 fold increased expression of full length AR. In contrast, LuCaP96 demonstrated higher levels of steroid catabolizing enzymes (6.9-fold higher AKR1C2, 3000-fold higher UGT2B15, p = 0.002 and p<0.0001 respectively), persistent suppression of intra-tumoral DHT, and 6–8 fold induction of full length AR and the ligand independent V7 AR splice variant. Human metastases demonstrated bio-active androgen levels and AR full length and AR splice-variant expression consistent with the range observed in xenografts. Conclusions Intrinsic differences in basal steroidogenesis, as well as variable expression of full length and splice-variant AR, associate with response and resistance to pre-receptor AR ligand suppression. Expression of steroidogenic enzymes and AR isoforms may serve as potential biomarkers of sensitivity to potent AR-axis inhibition and should be validated in additional models. PMID:25356728

Prostate cancer characteristics associated with response to pre-receptor targeting of the androgen axis.

PubMed

Mostaghel, Elahe A; Morgan, Andrew; Zhang, Xiaotun; Marck, Brett T; Xia, Jing; Hunter-Merrill, Rachel; Gulati, Roman; Plymate, Stephen; Vessella, Robert L; Corey, Eva; Higano, Celestia S; Matsumoto, Alvin M; Montgomery, R Bruce; Nelson, Peter S

2014-01-01

Factors influencing differential responses of prostate tumors to androgen receptor (AR) axis-directed therapeutics are poorly understood, and predictors of treatment efficacy are needed. We hypothesized that the efficacy of inhibiting DHT ligand synthesis would associate with intra-tumoral androgen ratios indicative of relative dependence on DHT-mediated growth. We characterized two androgen-sensitive prostate cancer xenograft models after androgen suppression by castration in combination with the SRD5A inhibitor, dutasteride, as well as a panel of castration resistant metastases obtained via rapid autopsy. In LuCaP35 tumors (intra-tumoral T:DHT ratio 2:1) dutasteride suppressed DHT to 0.02 ng/gm and prolonged survival vs. castration alone (337 vs.152 days, HR 2.8, p = 0.0015). In LuCaP96 tumors (T:DHT 10:1), survival was not improved despite similar DHT reduction (0.02 ng/gm). LuCaP35 demonstrated higher expression of steroid biosynthetic enzymes maintaining DHT levels (5-fold higher SRD5A1, 41 fold higher, 99-fold higher RL-HSD, p<0.0001 for both), reconstitution of intra-tumoral DHT (to ∼30% of untreated tumors), and ∼2 fold increased expression of full length AR. In contrast, LuCaP96 demonstrated higher levels of steroid catabolizing enzymes (6.9-fold higher AKR1C2, 3000-fold higher UGT2B15, p = 0.002 and p<0.0001 respectively), persistent suppression of intra-tumoral DHT, and 6-8 fold induction of full length AR and the ligand independent V7 AR splice variant. Human metastases demonstrated bio-active androgen levels and AR full length and AR splice-variant expression consistent with the range observed in xenografts. Intrinsic differences in basal steroidogenesis, as well as variable expression of full length and splice-variant AR, associate with response and resistance to pre-receptor AR ligand suppression. Expression of steroidogenic enzymes and AR isoforms may serve as potential biomarkers of sensitivity to potent AR-axis inhibition and should be validated in additional models.

Low-peak-to-average power ratio and low-complexity asymmetrically clipped optical orthogonal frequency-division multiplexing uplink transmission scheme for long-reach passive optical network.

PubMed

Zhou, Ji; Qiao, Yaojun

2015-09-01

In this Letter, we propose a discrete Hartley transform (DHT)-spread asymmetrically clipped optical orthogonal frequency-division multiplexing (DHT-S-ACO-OFDM) uplink transmission scheme in which the multiplexing/demultiplexing process also uses the DHT algorithm. By designing a simple encoding structure, the computational complexity of the transmitter can be reduced from O(Nlog(2)(N)) to O(N). At the probability of 10(-3), the peak-to-average power ratio (PAPR) of 2-ary pulse amplitude modulation (2-PAM)-modulated DHT-S-ACO-OFDM is approximately 9.7 dB lower than that of 2-PAM-modulated conventional ACO-OFDM. To verify the feasibility of the proposed scheme, a 4-Gbit/s DHT-S-ACO-OFDM uplink transmission scheme with a 1∶64 way split has been experimentally implemented using 100-km standard single-mode fiber (SSMF) for a long-reach passive optical network (LR-PON).

Sulforaphane promotes murine hair growth by accelerating the degradation of dihydrotestosterone.

PubMed

Sasaki, Mari; Shinozaki, Shohei; Shimokado, Kentaro

2016-03-25

Dihydrotestosterone (DHT) causes the regression of human hair follicles in the parietal scalp, leading to androgenic alopecia (AGA). Sulforaphane (SFN) increases the expression of DHT degrading enzymes, such as 3α-hydroxysteroid dehydrogenases (3α-HSDs), and, therefore, SFN treatment may improve AGA. To determine the effects of SFN on hair growth, we administered SFN (10 mg/kg BW, IP) or vehicle (DMSO) to ob/ob mice for six weeks and examined hair regeneration and the plasma levels of testosterone and DHT. We also tested the effects of SFN on the expression of two forms of 3α-HSD, aldo-keto reductase 1c21 and dehydrogenase/reductase (SDR family) member 9, both in vitro and in vivo. SNF significantly enhanced hair regeneration in ob/ob mice. The mice treated with SFN showed lower plasma levels of testosterone and DHT than those treated with vehicle. SFN increased the mRNA and protein levels of the two forms of 3α-HSD in the liver of the mice and in cultured murine hepatocyte Hepa1c1c7 cells. These results suggest that SFN treatment increases the amount of 3α-HSDs in the liver, accelerates the degradation of blood DHT, and subsequently blocks the suppression of hair growth by DHT. Copyright © 2016 Elsevier Inc. All rights reserved.

Finasteride accelerates prostate wound healing after thulium laser resection through DHT and AR signalling.

PubMed

Zhao, Ruizhe; Wang, Xingjie; Jiang, Chenyi; Shi, Fei; Zhu, Yiping; Yang, Boyu; Zhuo, Jian; Jing, Yifeng; Luo, Guangheng; Xia, Shujie; Han, Bangmin

2018-06-01

Urinary tract infection, urinary frequency, urgency, urodynia and haemorrhage are common post-operative complications of thulium laser resection of the prostate (TmLRP). Our study mainly focuses on the role of finasteride in prostate wound healing through AR signalling. TmLRP beagles were randomly distributed into different treatment groups. Serum and intra-prostatic testosterone and DHT level were determined. Histological analysis was conducted to study the re-epithelialization and inflammatory response of the prostatic urethra in each group. We investigated the role of androgen in proliferation and inflammatory response in prostate. In addition, the effects of TNF-α on prostate epithelium and stromal cells were also investigated. Testosterone and DHT level increased in testosterone group and DHT decreased in finasteride group. Accelerated wound healing of prostatic urethra was observed in the finasteride group. DHT suppressed proliferation of prostate epithelium and enhanced inflammatory response in prostate. We confirmed that DHT enhanced macrophages TNF-α secretion through AR signalling. TNF-α suppressed proliferation of prostate epithelial cells and retarded cell migration. TNF-α also played a pivotal role in suppressing fibroblasts activation and contraction. Testosterone treatment repressed re-epithelialization and wound healing of prostatic urethra. Finasteride treatment may be an effective way to promote prostate re-epithelialization. © 2017 John Wiley & Sons Ltd.

Multiview alignment hashing for efficient image search.

PubMed

Liu, Li; Yu, Mengyang; Shao, Ling

2015-03-01

Hashing is a popular and efficient method for nearest neighbor search in large-scale data spaces by embedding high-dimensional feature descriptors into a similarity preserving Hamming space with a low dimension. For most hashing methods, the performance of retrieval heavily depends on the choice of the high-dimensional feature descriptor. Furthermore, a single type of feature cannot be descriptive enough for different images when it is used for hashing. Thus, how to combine multiple representations for learning effective hashing functions is an imminent task. In this paper, we present a novel unsupervised multiview alignment hashing approach based on regularized kernel nonnegative matrix factorization, which can find a compact representation uncovering the hidden semantics and simultaneously respecting the joint probability distribution of data. In particular, we aim to seek a matrix factorization to effectively fuse the multiple information sources meanwhile discarding the feature redundancy. Since the raised problem is regarded as nonconvex and discrete, our objective function is then optimized via an alternate way with relaxation and converges to a locally optimal solution. After finding the low-dimensional representation, the hashing functions are finally obtained through multivariable logistic regression. The proposed method is systematically evaluated on three data sets: 1) Caltech-256; 2) CIFAR-10; and 3) CIFAR-20, and the results show that our method significantly outperforms the state-of-the-art multiview hashing techniques.

Learning Discriminative Binary Codes for Large-scale Cross-modal Retrieval.

PubMed

Xu, Xing; Shen, Fumin; Yang, Yang; Shen, Heng Tao; Li, Xuelong

2017-05-01

Hashing based methods have attracted considerable attention for efficient cross-modal retrieval on large-scale multimedia data. The core problem of cross-modal hashing is how to learn compact binary codes that construct the underlying correlations between heterogeneous features from different modalities. A majority of recent approaches aim at learning hash functions to preserve the pairwise similarities defined by given class labels. However, these methods fail to explicitly explore the discriminative property of class labels during hash function learning. In addition, they usually discard the discrete constraints imposed on the to-be-learned binary codes, and compromise to solve a relaxed problem with quantization to obtain the approximate binary solution. Therefore, the binary codes generated by these methods are suboptimal and less discriminative to different classes. To overcome these drawbacks, we propose a novel cross-modal hashing method, termed discrete cross-modal hashing (DCH), which directly learns discriminative binary codes while retaining the discrete constraints. Specifically, DCH learns modality-specific hash functions for generating unified binary codes, and these binary codes are viewed as representative features for discriminative classification with class labels. An effective discrete optimization algorithm is developed for DCH to jointly learn the modality-specific hash function and the unified binary codes. Extensive experiments on three benchmark data sets highlight the superiority of DCH under various cross-modal scenarios and show its state-of-the-art performance.

Estrogen-Induced Developmental Disorders of the Rat Penis Involve Both Estrogen Receptor (ESR)- and Androgen Receptor (AR)-Mediated Pathways1

PubMed Central

Goyal, H.O.; Braden, T.D.; Williams, C.S.; Williams, J.W.

2009-01-01

This study tested the hypothesis that the estrogen receptor (ESR) pathway, androgen receptor (AR) pathway, or both mediate estrogen-induced developmental penile disorders. Rat pups received diethylstilbestrol (DES), with or without the ESR antagonist ICI 182,780 (ICI) or the AR agonist dihydrotestosterone (DHT) or testosterone (T), from Postnatal Days 1 to 6. Testicular T concentration, penile morphology and morphometry, and/or fertility was determined at age 7, 28, or 150 days. DES treatment alone caused 90% reduction in the neonatal intratesticular T surge; this reduction was prevented by ICI coadministration, but not by DHT or T coadministration. Unlike the T surge, coadministration of ICI and coadministration of DHT or T mitigated penile deformities and loss of fertility. Generally, ICI, DHT, or T treatment alone did not alter penile morphology; however, fertility was 20% that of controls in ICI-treated rats vs. 70%–90% in DHT- or T-treated rats. The lower fertility in the rats treated with ICI alone could be due to altered sexual behavior, as these males did not deposit vaginal plugs. In conclusion, observations that both an ESR antagonist and AR agonists prevent penile deformities and infertility suggest that both pathways are involved in estrogen-induced penile disorders. Observations that coadministration of ICI, but not DHT or T, prevents the DES-induced reduction in the neonatal T surge suggest that, although ICI exerts its mitigating effect both at the level of Leydig cells and penile stromal cells, DHT and T do so only at the level of stromal cells. PMID:19420389

Barriers and facilitators to ED physician use of the test and treatment for BPPV

PubMed Central

Forman, Jane; Damschroder, Laura; Telian, Steven A.; Fagerlin, Angela; Johnson, Patricia; Brown, Devin L.; An, Lawrence C.; Morgenstern, Lewis B.; Meurer, William J.

2017-01-01

Abstract Background: The test and treatment for benign paroxysmal positional vertigo (BPPV) are evidence-based practices supported by clinical guideline statements. Yet these practices are underutilized in the emergency department (ED) and interventions to promote their use are needed. To inform the development of an intervention, we interviewed ED physicians to explore barriers and facilitators to the current use of the Dix-Hallpike test (DHT) and the canalith repositioning maneuver (CRM). Methods: We conducted semi-structured in-person interviews with ED physicians who were recruited at annual ED society meetings in the United States. We analyzed data thematically using qualitative content analysis methods. Results: Based on 50 interviews with ED physicians, barriers that contributed to infrequent use of DHT/CRM that emerged were (1) prior negative experiences or forgetting how to perform them and (2) reliance on the history of present illness to identify BPPV, or using the DHT but misattributing patterns of nystagmus. Based on participants' responses, the principal facilitator of DHT/CRM use was prior positive experiences using these, even if infrequent. When asked which clinical supports would facilitate more frequent use of DHT/CRM, participants agreed supports needed to be brief, readily accessible, and easy to use, and to include well-annotated video examples. Conclusions: Interventions to promote the use of the DHT/CRM in the ED need to overcome prior negative experiences with the DHT/CRM, overreliance on the history of present illness, and the underuse and misattribution of patterns of nystagmus. Future resources need to be sensitive to provider preferences for succinct information and video examples. PMID:28680765

5,7-Dihydroxitryptamine toxicity to serotonergic neurons in serum free raphe cultures.

PubMed

Capela, João Paulo; Lautenschlager, Marion; Dirnagl, Ulrich; Bastos, Maria Lourdes; Carvalho, Félix; Meisel, Andreas

2008-07-07

5,7-Dihydroxytryptamine (5,7-DHT), is an experimentally widely used selective serotonergic neurotoxin, though the mechanisms of toxicity remain to be fully elucidated. In the present study, we evaluated 5,7-dihydroxitryptamine (5,7-DHT) induced serotonergic neurotoxicity in foetal raphe serum free cultures from the rat. For this purpose, a model of foetal raphe serum free neuronal cultures from the rat was established, containing about 16% serotonergic neurons and studied up to 3 months. Two weeks old raphe cultures were exposed to the serotonergic neurotoxin 5,7-DHT (concentration range 10-100 microM) for 72 h, after which the medium was replaced and neurotoxicity was evaluated by immunocitochemistry 1 week later. Lactate dehydrogenase release into the medium, 72 h after exposure to 5,7-DHT, showed a concentration-dependent neurotoxicity. To access morphologically the serotonergic toxicity tryptophan hydroxylase (TPH) was used as a specific marker of these neurons. Immunocitochemistry using TPH antisera showed a concentration-dependent serotonergic neurotoxicity induced by 5,7-DHT. Serotonergic neurons showed the typical pattern of "pruning" accompanied by axon terminals and dendrites loss, which were either partial or total. The axotomy induced by the neurotoxin was morphologically characteristic of retrograde axonal degeneration. Fluoxetine (0.1 microM) pre-treatment reduced 5,7-DHT-induced serotonergic neurotoxicity. These results indicate that the mechanism by which 5,7-DHT-induces serotonergic neurotoxicity is, at least partially, dependent on the toxin uptake by the serotonin transporter. Finally, we have established a robust model of primary raphe neuronal culture to evaluate serotonergic neurons development and the mechanisms of toxicity involving this neuronal population.

DHT and IGF-1 in peripheral blood lymphocytes: new markers for the biological passport of athletes.

PubMed

Mancini, A; Imperlini, E; Alfieri, A; Spaziani, S; Martone, D; Parisi, A; Orru, S; Buono, P

2013-01-01

We performed a pilot study using human peripheral blood lymphocytes (PBL) as a novel system to identify new biomarkers of dihydrotestosterone (DHT) and insulin-like growth factor-1 (IGF-1) abuse in sport. First, to obtain a gene signature, we treated cultures of lymphocytes from sedentary males with three doses of 0.237 microg/ml DHT, each of which is 80-fold the physiological concentration in young adult male serum, at days 0, 2 and 4, or with a single dose of 1.25 microg/ml IGF-1, which is 5-fold the physiological concentration in young adult male serum. We then used the Human Genome U133 Plus 2.0 microarray to identify a gene signature related to DHT or IGF-1 administration. Gene expression was evaluated after 7 and 21 days of DHT treatment, and after 24 h, 72 h and 7 days of IGF-1 treatment. Microarray analysis yielded a list of genes whose expression was altered after DHT or IGF-1 treatment. Among these we selected the genes that are most representative of the pathways associated with skeletal and muscular disorders using the IPA bioinformatics tool. We identified six (IDO1, CXCL13, CCL1, GZMB, VDR and IL2RA) and two (FN1 and RAB31) genes that were up-regulated in lymphocytes from sedentary subjects after 7 days of DHT and IGF-1 treatment, respectively. The expression of these genes in lymphocytes from differently trained athletes was either down-regulated or similar to that in lymphocytes from sedentary subjects. This finding suggests that up-regulation was due to the drug and not to physical exercise. In conclusion, we demonstrate that PBL can be useful in anti-doping checks, and we describe new biomarkers of DHT and IGF-1 abuse which can be included in the Athlete's Biological Passport.

Neo-synthesis of estrogenic or androgenic neurosteroids determine whether long-term potentiation or depression is induced in hippocampus of male rat

PubMed Central

Di Mauro, Michela; Tozzi, Alessandro; Calabresi, Paolo; Pettorossi, Vito Enrico; Grassi, Silvarosa

2015-01-01

Estrogenic and androgenic steroids synthesized in the brain may rapidly modulate synaptic plasticity interacting with specific membrane receptors. We explored by electrophysiological recordings in hippocampal slices of male rat the influence of 17β-estradiol (E2) and 5α-dihydrotestosterone (DHT) neo-synthesis on the synaptic changes induced in the CA1 region. Induction of long-term depression (LTD) and depotentiation (DP) by low frequency stimulation (LFS, 15 min-1 Hz) and of long-term potentiation (LTP) by high frequency stimulation (HFS, 1 s-100 Hz), medium (MFS, 1 s-50 Hz), or weak (WFS, 1 s-25 Hz) frequency stimulation was assayed under inhibitors of enzymes converting testosterone (T) into DHT (5α-reductase) and T into E2 (P450-aromatase). We found that LFS-LTD depends on DHT synthesis, since it was fully prevented under finasteride, an inhibitor of DHT synthesis, and rescued by exogenous DHT, while the E2 synthesis was not involved. Conversely, the full development of HFS-LTP requires the synthesis of E2, as demonstrated by the LTP reduction observed under letrozole, an inhibitor of E2 synthesis, and its full rescue by exogenous E2. For intermediate stimulation protocols DHT, but not E2 synthesis, was involved in the production of a small LTP induced by WFS, while the E2 synthesis was required for the MFS-dependent LTP. Under the combined block of DHT and E2 synthesis all stimulation frequencies induced partial LTP. Overall, these results indicate that DHT is required for converting the partial LTP into LTD whereas E2 is needed for the full expression of LTP, evidencing a key role of the neo-synthesis of sex neurosteroids in determining the direction of synaptic long-term effects. PMID:26483631

A novel class sensitive hashing technique for large-scale content-based remote sensing image retrieval

NASA Astrophysics Data System (ADS)

Reato, Thomas; Demir, Begüm; Bruzzone, Lorenzo

2017-10-01

This paper presents a novel class sensitive hashing technique in the framework of large-scale content-based remote sensing (RS) image retrieval. The proposed technique aims at representing each image with multi-hash codes, each of which corresponds to a primitive (i.e., land cover class) present in the image. To this end, the proposed method consists of a three-steps algorithm. The first step is devoted to characterize each image by primitive class descriptors. These descriptors are obtained through a supervised approach, which initially extracts the image regions and their descriptors that are then associated with primitives present in the images. This step requires a set of annotated training regions to define primitive classes. A correspondence between the regions of an image and the primitive classes is built based on the probability of each primitive class to be present at each region. All the regions belonging to the specific primitive class with a probability higher than a given threshold are highly representative of that class. Thus, the average value of the descriptors of these regions is used to characterize that primitive. In the second step, the descriptors of primitive classes are transformed into multi-hash codes to represent each image. This is achieved by adapting the kernel-based supervised locality sensitive hashing method to multi-code hashing problems. The first two steps of the proposed technique, unlike the standard hashing methods, allow one to represent each image by a set of primitive class sensitive descriptors and their hash codes. Then, in the last step, the images in the archive that are very similar to a query image are retrieved based on a multi-hash-code-matching scheme. Experimental results obtained on an archive of aerial images confirm the effectiveness of the proposed technique in terms of retrieval accuracy when compared to the standard hashing methods.

Object-Location-Aware Hashing for Multi-Label Image Retrieval via Automatic Mask Learning.

PubMed

Huang, Chang-Qin; Yang, Shang-Ming; Pan, Yan; Lai, Han-Jiang

2018-09-01

Learning-based hashing is a leading approach of approximate nearest neighbor search for large-scale image retrieval. In this paper, we develop a deep supervised hashing method for multi-label image retrieval, in which we propose to learn a binary "mask" map that can identify the approximate locations of objects in an image, so that we use this binary "mask" map to obtain length-limited hash codes which mainly focus on an image's objects but ignore the background. The proposed deep architecture consists of four parts: 1) a convolutional sub-network to generate effective image features; 2) a binary "mask" sub-network to identify image objects' approximate locations; 3) a weighted average pooling operation based on the binary "mask" to obtain feature representations and hash codes that pay most attention to foreground objects but ignore the background; and 4) the combination of a triplet ranking loss designed to preserve relative similarities among images and a cross entropy loss defined on image labels. We conduct comprehensive evaluations on four multi-label image data sets. The results indicate that the proposed hashing method achieves superior performance gains over the state-of-the-art supervised or unsupervised hashing baselines.

A cryptographic hash function based on chaotic network automata

NASA Astrophysics Data System (ADS)

Machicao, Jeaneth; Bruno, Odemir M.

2017-12-01

Chaos theory has been used to develop several cryptographic methods relying on the pseudo-random properties extracted from simple nonlinear systems such as cellular automata (CA). Cryptographic hash functions (CHF) are commonly used to check data integrity. CHF “compress” arbitrary long messages (input) into much smaller representations called hash values or message digest (output), designed to prevent the ability to reverse the hash values into the original message. This paper proposes a chaos-based CHF inspired on an encryption method based on chaotic CA rule B1357-S2468. Here, we propose an hybrid model that combines CA and networks, called network automata (CNA), whose chaotic spatio-temporal outputs are used to compute a hash value. Following the Merkle and Damgård model of construction, a portion of the message is entered as the initial condition of the network automata, so that the rest parts of messages are iteratively entered to perturb the system. The chaotic network automata shuffles the message using flexible control parameters, so that the generated hash value is highly sensitive to the message. As demonstrated in our experiments, the proposed model has excellent pseudo-randomness and sensitivity properties with acceptable performance when compared to conventional hash functions.

A separable two-dimensional discrete Hartley transform

NASA Technical Reports Server (NTRS)

Watson, A. B.; Poirson, A.

1985-01-01

Bracewell has proposed the Discrete Hartley Transform (DHT) as a substitute for the Discrete Fourier Transform (DFT), particularly as a means of convolution. Here, it is shown that the most natural extension of the DHT to two dimensions fails to be separate in the two dimensions, and is therefore inefficient. An alternative separable form is considered, corresponding convolution theorem is derived. That the DHT is unlikely to provide faster convolution than the DFT is also discussed.

Sphingosine kinase-1 mediates androgen-induced osteoblast cell growth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Claire; Universite de Toulouse, UPS, IPBS, Toulouse F-31000; Lafosse, Jean-Michel

Herein we report that the lipid kinase sphingosine kinase-1 (SphK1) is instrumental in mediating androgen-induced cell proliferation in osteoblasts. Dihydrotestosterone (DHT) triggered cell growth in steroid-deprived MC3T3 cells, which was associated with a rapid stimulation of SphK1 and activation of both Akt and ERK signaling pathways. This mechanism relied on functional androgen receptor/PI3K/Akt nongenotropic signaling as pharmacological antagonists could block SphK1 stimulation by DHT and its consequences. Finally, SphK1 inhibition not only abrogated DHT-induced ERK activation but also blocked cell proliferation, while ERK inhibition had no impact, suggesting that SphK1 was critical for DHT signaling yet independently of the ERK.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Draelos, Timothy John; Dautenhahn, Nathan; Schroeppel, Richard Crabtree

The security of the widely-used cryptographic hash function SHA1 has been impugned. We have developed two replacement hash functions. The first, SHA1X, is a drop-in replacement for SHA1. The second, SANDstorm, has been submitted as a candidate to the NIST-sponsored SHA3 Hash Function competition.

Dihydrotestosterone and testosterone levels in men screened for prostate cancer: a study of a randomized population.

PubMed

Gustafsson, O; Norming, U; Gustafsson, S; Eneroth, P; Aström, G; Nyman, C R

1996-03-01

To investigate the possible relationship between serum levels of prostate specific antigen (PSA), dihydrotestosterone (DHT), testosterone, sexual-hormone binding globulin (SHBG) and tumour stage, grade and ploidy in 65 cases of prostate cancer diagnosed in a screening study compared to 130 controls from the same population. From a population of 26,602 men between the ages of 55 and 70 years, 2400 were selected randomly and invited to undergo screening for prostate cancer using a digital rectal examination, transrectal ultrasonography and PSA analysis. Among the 1782 attendees, 65 cases of prostate cancer were diagnosed. Each case was matched with two control subjects of similar age and prostate volume from the screening population. Frozen serum samples were analysed for PSA, DHT, testosterone and SHBG, and compared to the diagnosis and tumour stage, grade and ploidy. Comparisons between these variables, and multivariate and regression analyses were performed. There were significant differences in PSA level with all variables except tumour ploidy. DHT levels were slightly lower in patients with prostate cancer but the difference was not statistically significant. There was a trend towards lower DHT values in more advanced tumours and the difference for T-stages was close to statistical significance (P = 0.059). Testosterone levels were lower in patients with cancer than in the control group, but the differences were not significant. There was no correlation between testosterone levels, tumour stage and ploidy, but the differences in testosterone level in tumours of a low grade of differentiation compared to those with intermediate and high grade was nearly significant (P = 0.058). The testosterone/DHT ratio tended to be higher in patients with more advanced tumours. SHBG levels were lower in patients with cancer than in controls but the differences were not statistically significant. There were no systematic variations of tumour stage, grade and ploidy. Multivariate analysis showed that if the PSA level was known, then DHT, testosterone or SHBG added no further information concerning diagnosis, stage, grade or ploidy. Regression analysis on T-stage, PSA level and DHT showed an inverse linear relationship between PSA and DHT for stage T-3 (P = 0.035), but there was no relationship between PSA and testosterone. PSA was of value in discriminating between cases and controls and between various tumour stages and grades, but no statistically significant correlation was found for ploidy. If PSA level was known, no other variable added information in individual cases. Within a group, DHT levels tended to be lower among cases and in those with more advanced tumours. There was an inverse relationship between tumour volume, as defined by PSA level, and 5 alpha-reductase activity, as defined by DHT level, and the testosterone/DHT ratio. This trend was most obvious with T-stage. No systematic variation were found in the levels of testosterone or SHBG.

Serenoa repens extracts promote hair regeneration and repair of hair loss mouse models by activating TGF-β and mitochondrial signaling pathway.

PubMed

Zhu, H-L; Gao, Y-H; Yang, J-Q; Li, J-B; Gao, J

2018-06-01

Plenty of plant extracts have been used for treating hair loss. This study aims to investigate the effects of liposterolic extracts of Serenoa repens (LSESr) on hair cell growth and regeneration of hair, and clarify the associated mechanisms. Human keratinocyte cells (HACAT) were cultured, incubated with dihydrotestosterone (DHT) and treated with LSESr. Cell viability was examined by using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H- tetrazolium bromide (MTT) assay. Hair loss C57BL/6 mouse model was established by inducing with DHT. Hair growth, density, and thickness were evaluated. Back skin samples were collected and stained with hematoxylin and eosin (HE) assay. B-cell lymphoma-2 (Bcl-2), Bcl-2 associated protein X (Bax), cleaved caspase 3 and transforming growth factor β2 (TGF-β2) were examined using Western blot assay. LSESr treatment significantly increased HACAT cell viabilities compared to DHT-only treated cells (p<0.05). LSESr treatment post injection of DHT significantly converted skin color from pink to gray and increased hair density, weight and thickness compared to DHT-only treated mice (p<0.05). LSESr treatment significantly triggered follicle growth and decreased inflammatory response. LSESr treatment significantly decreased TGF-β2 and cleaved caspase 3 expression of hair loss mouse models compared to that of DHT treated mice (p<0.05). LSESr treatment significantly enhanced Bcl-2 expression and reduced Bax expression compared to that of DHT treated mice (p<0.05). Meanwhile, effects of LSESr were substantial even achieving to the potential of finasteride. LSESr promoted the hair regeneration and repair of hair loss mouse models by activating TGF-β signaling and mitochondrial signaling pathway.

Lower-limb veins are thicker and vascular reactivity is decreased in a rat PCOS model: concomitant vitamin D3 treatment partially prevents these changes.

PubMed

Várbíró, Szabolcs; Sára, Levente; Antal, Péter; Monori-Kiss, Anna; Tőkés, Anna-Mária; Monos, Emil; Benkő, Rita; Csibi, Noémi; Szekeres, Maria; Tarszabo, Robert; Novak, Agnes; Paragi, Péter; Nádasy, György L

2014-09-15

Polycystic ovary syndrome (PCOS) causes vascular damage to arteries; however, there are no data for its effect on veins. Our aim was to clarify the effects of dihydrotestosterone (DHT)-induced PCOS both on venous biomechanics and on pharmacological reactivity in a rat model and to test the possible modulatory role of vitamin D3 (vitD). PCOS was induced in female Wistar rats by DHT treatment (83 μg/day, subcutaneous pellet). After 10 wk, the venous biomechanics, norepinephrine (NE)-induced contractility, and acetylcholine-induced relaxation were tested in saphenous veins from control animals and from animals treated with DHT or DHT with vitD using pressure angiography. Additionally, the expression levels of endothelial nitric oxide synthase (eNOS) and cyclooxygenase (COX-2) were measured using immunohistochemistry. Increased diameter, wall thickness, and distensibility as well as decreased vasoconstriction were detected after the DHT treatment. Concomitant vitD treatment lowered the mechanical load on the veins, reduced distensibility, and resulted in vessels that were more relaxed. Although there was no difference in the endothelial dilation tested using acetylcholine (ACh), the blocking effect of N(G)-nitro-l-arginine methyl ester (l-NAME) was lower and was accompanied by lower COX-2 expression in the endothelium after the DHT treatment. Supplementation with vitD prevented these alterations. eNOS expression did not differ among the three groups. We conclude that the hyperandrogenic state resulted in thicker vein walls. These veins showed early remodeling and altered vasorelaxant mechanisms similar to those of varicose veins. Alterations caused by the chronic DHT treatment were prevented partially by concomitant vitD administration. Copyright © 2014 the American Physiological Society.

Marked suppression of dihydrotestosterone in men with benign prostatic hyperplasia by dutasteride, a dual 5alpha-reductase inhibitor.

PubMed

Clark, Richard V; Hermann, David J; Cunningham, Glenn R; Wilson, Timothy H; Morrill, Betsy B; Hobbs, Stuart

2004-05-01

Dihydrotestosterone (DHT) is the primary metabolite of testosterone in the prostate and skin. Testosterone is converted to DHT by 5alpha-reductase, which exists in two isoenzyme forms (types 1 and 2). DHT is associated with development of benign prostatic hyperplasia (BPH), and reduction in its level with 5alpha-reductase inhibitors improves the symptoms associated with BPH and reduces the risk of acute urinary retention and prostate surgery. A selective inhibitor of the type 2 isoenzyme (finasteride) has been shown to decrease serum DHT by about 70%. We hypothesized that inhibition of both isoenzymes with the dual inhibitor dutasteride would more effectively suppress serum DHT levels than selective inhibition of only the type 2 isoenzyme. A total of 399 patients with BPH were randomized to receive once-daily dosing for 24 wk of dutasteride (0.01, 0.05, 0.5, 2.5, or 5.0 mg), 5 mg finasteride, or placebo. The mean percent decrease in DHT was 98.4 +/- 1.2% with 5.0 mg dutasteride and 94.7 +/- 3.3% with 0.5 mg dutasteride, significantly lower (P < 0.001) and with less variability than the 70.8 +/- 18.3% suppression observed with 5 mg finasteride. Mean testosterone levels increased but remained in the normal range for all treatment groups. Dutasteride appeared to be well tolerated with an adverse event profile similar to placebo.

Paternal behavior in the Mongolian gerbil (Meriones unguiculatus): Estrogenic and androgenic regulation.

PubMed

Martínez, Ana; Ramos, Guillermo; Martínez-Torres, Martín; Nicolás, Leticia; Carmona, Agustín; Cárdenas, Mario; Luis, Juana

2015-05-01

Here, we analyzed the effects of testosterone (T) and its metabolites, estradiol (E2) and dihydrotestosterone (DHT), on the onset of paternal behavior in virgin male Mongolian gerbils (Meriones unguiculatus). We hypothesized that T and E2, but not DHT, would facilitate the onset of paternal behavior. Seventy males displaying aggression toward pups were selected through a paternal behavior screening test. Forty males were bilaterally castrated. Of them, 10 were implanted with T, 10 with E2, and 10 with DHT, and 10 received no treatment. Another 30 males underwent a sham procedure. In these gerbils, T, E2 and DHT were measured to obtain the basal levels of these hormones. After treatment, the paternal behavior test was conducted again. Blood samples were obtained immediately after the administration of the test for the quantification of T, E2 and DHT by radioimmunoassay. Surprisingly, 100% of the males that received T, E2 and DHT implants stopped being aggressive and became paternal. Castrated and sham-operated males displayed no changes in their aggressive behaviors. This is the first report that T and its metabolites are involved in neuroendocrine mechanisms that inhibit aggression toward pups and facilitate paternal behavior in virgin male Mongolian gerbils. In addition, this is the first report of regulation of paternal behavior in a rodent by estrogenic and androgenic pathways. Copyright © 2015 Elsevier Inc. All rights reserved.

Steady-state pharmacokinetics of oral testosterone undecanoate with concomitant inhibition of 5α-reductase by finasteride

PubMed Central

Roth, M. Y.; Dudley, R. E.; Hull, L.; Leung, A.; Christenson, P.; Wang, C.; Swerdloff, R.; Amory, J. K.

2014-01-01

Summary Oral testosterone undecanoate (TU) is used to treat testosterone deficiency; however, oral TU treatment elevates dihydrotestosterone (DHT), which may be associated with an increased risk of acne, male pattern baldness and prostate hyperplasia. Co-administration of 5α-reductase inhibitors with other formulations of oral testosterone suppresses DHT production and increases serum testosterone. We hypothesized that finasteride would increase serum testosterone and lower DHT during treatment with oral TU. Therefore, we studied the steady-state pharmacokinetics of oral TU, 200 mg equivalents of testosterone twice daily for 7 days, alone and with finasteride 0.5 and 1.0 mg po twice daily in an open-label, three-way crossover study in 11 young men with experimentally induced hypogonadism. On the seventh day of each dosing period, serum testosterone, DHT and oestradiol were measured at baseline and 1, 2, 4, 8, 12, 13, 14, 16, 20 and 24 h after the morning dose. Serum testosterone and DHT were significantly increased into and above their normal ranges similarly by all three treatments. Co-administration of finasteride at 0.5 and 1.0 mg po twice daily had no significant effect on either serum testosterone or DHT. Oral TU differs from other formulations of oral testosterone in its response to concomitant inhibition of 5α-reductase, perhaps because of its unique lymphatic route of absorption. PMID:20969601

Distributed design approach in persistent identifiers systems

NASA Astrophysics Data System (ADS)

Golodoniuc, Pavel; Car, Nicholas; Klump, Jens

2017-04-01

The need to identify both digital and physical objects is ubiquitous in our society. Past and present persistent identifier (PID) systems, of which there is a great variety in terms of technical and social implementations, have evolved with the advent of the Internet, which has allowed for globally unique and globally resolvable identifiers. PID systems have catered for identifier uniqueness, integrity, persistence, and trustworthiness, regardless of the identifier's application domain, the scope of which has expanded significantly in the past two decades. Since many PID systems have been largely conceived and developed by small communities, or even a single organisation, they have faced challenges in gaining widespread adoption and, most importantly, the ability to survive change of technology. This has left a legacy of identifiers that still exist and are being used but which have lost their resolution service. We believe that one of the causes of once successful PID systems fading is their reliance on a centralised technical infrastructure or a governing authority. Golodoniuc et al. (2016) proposed an approach to the development of PID systems that combines the use of (a) the Handle system, as a distributed system for the registration and first-degree resolution of persistent identifiers, and (b) the PID Service (Golodoniuc et al., 2015), to enable fine-grained resolution to different information object representations. The proposed approach solved the problem of guaranteed first-degree resolution of identifiers, but left fine-grained resolution and information delivery under the control of a single authoritative source, posing risk to the long-term availability of information resources. Herein, we develop these approaches further and explore the potential of large-scale decentralisation at all levels: (i) persistent identifiers and information resources registration; (ii) identifier resolution; and (iii) data delivery. To achieve large-scale decentralisation, we propose using Distributed Hash Tables (DHT), Peer Exchange networks (PEX), Magnet Links, and peer-to-peer (P2P) file sharing networks - the technologies that enable applications such as BitTorrent (Wu et al., 2010). The proposed approach introduces reliable information replication and caching mechanisms, eliminating the need for a central PID data store, and increases overall system fault tolerance due to the lack of a single point of failure. The proposed PID system's design aims to ensure trustworthiness of the system and incorporates important aspects of governance, such as the notion of the authoritative source, data integrity, caching, and data replication control.

Hash function based on chaotic map lattices.

PubMed

Wang, Shihong; Hu, Gang

2007-06-01

A new hash function system, based on coupled chaotic map dynamics, is suggested. By combining floating point computation of chaos and some simple algebraic operations, the system reaches very high bit confusion and diffusion rates, and this enables the system to have desired statistical properties and strong collision resistance. The chaos-based hash function has its advantages for high security and fast performance, and it serves as one of the most highly competitive candidates for practical applications of hash function for software realization and secure information communications in computer networks.

Digital data storage systems, computers, and data verification methods

DOEpatents

Groeneveld, Bennett J.; Austad, Wayne E.; Walsh, Stuart C.; Herring, Catherine A.

2005-12-27

Digital data storage systems, computers, and data verification methods are provided. According to a first aspect of the invention, a computer includes an interface adapted to couple with a dynamic database; and processing circuitry configured to provide a first hash from digital data stored within a portion of the dynamic database at an initial moment in time, to provide a second hash from digital data stored within the portion of the dynamic database at a subsequent moment in time, and to compare the first hash and the second hash.

Hash function based on chaotic map lattices

NASA Astrophysics Data System (ADS)

Wang, Shihong; Hu, Gang

2007-06-01

A new hash function system, based on coupled chaotic map dynamics, is suggested. By combining floating point computation of chaos and some simple algebraic operations, the system reaches very high bit confusion and diffusion rates, and this enables the system to have desired statistical properties and strong collision resistance. The chaos-based hash function has its advantages for high security and fast performance, and it serves as one of the most highly competitive candidates for practical applications of hash function for software realization and secure information communications in computer networks.

On the balanced quantum hashing

NASA Astrophysics Data System (ADS)

Ablayev, F.; Ablayev, M.; Vasiliev, A.

2016-02-01

In the paper we define a notion of a resistant quantum hash function which combines a notion of pre-image (one-way) resistance and the notion of collision resistance. In the quantum setting one-way resistance property and collision resistance property are correlated: the “more” a quantum function is one-way resistant the “less” it is collision resistant and vice versa. We present an explicit quantum hash function which is “balanced” one-way resistant and collision resistant and demonstrate how to build a large family of balanced quantum hash functions.

Distributed Adaptive Binary Quantization for Fast Nearest Neighbor Search.

PubMed

Xianglong Liu; Zhujin Li; Cheng Deng; Dacheng Tao

2017-11-01

Hashing has been proved an attractive technique for fast nearest neighbor search over big data. Compared with the projection based hashing methods, prototype-based ones own stronger power to generate discriminative binary codes for the data with complex intrinsic structure. However, existing prototype-based methods, such as spherical hashing and K-means hashing, still suffer from the ineffective coding that utilizes the complete binary codes in a hypercube. To address this problem, we propose an adaptive binary quantization (ABQ) method that learns a discriminative hash function with prototypes associated with small unique binary codes. Our alternating optimization adaptively discovers the prototype set and the code set of a varying size in an efficient way, which together robustly approximate the data relations. Our method can be naturally generalized to the product space for long hash codes, and enjoys the fast training linear to the number of the training data. We further devise a distributed framework for the large-scale learning, which can significantly speed up the training of ABQ in the distributed environment that has been widely deployed in many areas nowadays. The extensive experiments on four large-scale (up to 80 million) data sets demonstrate that our method significantly outperforms state-of-the-art hashing methods, with up to 58.84% performance gains relatively.

Fully Integrated Passive UHF RFID Tag for Hash-Based Mutual Authentication Protocol.

PubMed

Mikami, Shugo; Watanabe, Dai; Li, Yang; Sakiyama, Kazuo

2015-01-01

Passive radio-frequency identification (RFID) tag has been used in many applications. While the RFID market is expected to grow, concerns about security and privacy of the RFID tag should be overcome for the future use. To overcome these issues, privacy-preserving authentication protocols based on cryptographic algorithms have been designed. However, to the best of our knowledge, evaluation of the whole tag, which includes an antenna, an analog front end, and a digital processing block, that runs authentication protocols has not been studied. In this paper, we present an implementation and evaluation of a fully integrated passive UHF RFID tag that runs a privacy-preserving mutual authentication protocol based on a hash function. We design a single chip including the analog front end and the digital processing block. We select a lightweight hash function supporting 80-bit security strength and a standard hash function supporting 128-bit security strength. We show that when the lightweight hash function is used, the tag completes the protocol with a reader-tag distance of 10 cm. Similarly, when the standard hash function is used, the tag completes the protocol with the distance of 8.5 cm. We discuss the impact of the peak power consumption of the tag on the distance of the tag due to the hash function.

Perl Modules for Constructing Iterators

NASA Technical Reports Server (NTRS)

Tilmes, Curt

2009-01-01

The Iterator Perl Module provides a general-purpose framework for constructing iterator objects within Perl, and a standard API for interacting with those objects. Iterators are an object-oriented design pattern where a description of a series of values is used in a constructor. Subsequent queries can request values in that series. These Perl modules build on the standard Iterator framework and provide iterators for some other types of values. Iterator::DateTime constructs iterators from DateTime objects or Date::Parse descriptions and ICal/RFC 2445 style re-currence descriptions. It supports a variety of input parameters, including a start to the sequence, an end to the sequence, an Ical/RFC 2445 recurrence describing the frequency of the values in the series, and a format description that can refine the presentation manner of the DateTime. Iterator::String constructs iterators from string representations. This module is useful in contexts where the API consists of supplying a string and getting back an iterator where the specific iteration desired is opaque to the caller. It is of particular value to the Iterator::Hash module which provides nested iterations. Iterator::Hash constructs iterators from Perl hashes that can include multiple iterators. The constructed iterators will return all the permutations of the iterations of the hash by nested iteration of embedded iterators. A hash simply includes a set of keys mapped to values. It is a very common data structure used throughout Perl programming. The Iterator:: Hash module allows a hash to include strings defining iterators (parsed and dispatched with Iterator::String) that are used to construct an overall series of hash values.

System using data compression and hashing adapted for use for multimedia encryption

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coffland, Douglas R

2011-07-12

A system and method is disclosed for multimedia encryption. Within the system of the present invention, a data compression module receives and compresses a media signal into a compressed data stream. A data acquisition module receives and selects a set of data from the compressed data stream. And, a hashing module receives and hashes the set of data into a keyword. The method of the present invention includes the steps of compressing a media signal into a compressed data stream; selecting a set of data from the compressed data stream; and hashing the set of data into a keyword.

Practical security and privacy attacks against biometric hashing using sparse recovery

NASA Astrophysics Data System (ADS)

Topcu, Berkay; Karabat, Cagatay; Azadmanesh, Matin; Erdogan, Hakan

2016-12-01

Biometric hashing is a cancelable biometric verification method that has received research interest recently. This method can be considered as a two-factor authentication method which combines a personal password (or secret key) with a biometric to obtain a secure binary template which is used for authentication. We present novel practical security and privacy attacks against biometric hashing when the attacker is assumed to know the user's password in order to quantify the additional protection due to biometrics when the password is compromised. We present four methods that can reconstruct a biometric feature and/or the image from a hash and one method which can find the closest biometric data (i.e., face image) from a database. Two of the reconstruction methods are based on 1-bit compressed sensing signal reconstruction for which the data acquisition scenario is very similar to biometric hashing. Previous literature introduced simple attack methods, but we show that we can achieve higher level of security threats using compressed sensing recovery techniques. In addition, we present privacy attacks which reconstruct a biometric image which resembles the original image. We quantify the performance of the attacks using detection error tradeoff curves and equal error rates under advanced attack scenarios. We show that conventional biometric hashing methods suffer from high security and privacy leaks under practical attacks, and we believe more advanced hash generation methods are necessary to avoid these attacks.

Fully Integrated Passive UHF RFID Tag for Hash-Based Mutual Authentication Protocol

PubMed Central

Mikami, Shugo; Watanabe, Dai; Li, Yang; Sakiyama, Kazuo

2015-01-01

Passive radio-frequency identification (RFID) tag has been used in many applications. While the RFID market is expected to grow, concerns about security and privacy of the RFID tag should be overcome for the future use. To overcome these issues, privacy-preserving authentication protocols based on cryptographic algorithms have been designed. However, to the best of our knowledge, evaluation of the whole tag, which includes an antenna, an analog front end, and a digital processing block, that runs authentication protocols has not been studied. In this paper, we present an implementation and evaluation of a fully integrated passive UHF RFID tag that runs a privacy-preserving mutual authentication protocol based on a hash function. We design a single chip including the analog front end and the digital processing block. We select a lightweight hash function supporting 80-bit security strength and a standard hash function supporting 128-bit security strength. We show that when the lightweight hash function is used, the tag completes the protocol with a reader-tag distance of 10 cm. Similarly, when the standard hash function is used, the tag completes the protocol with the distance of 8.5 cm. We discuss the impact of the peak power consumption of the tag on the distance of the tag due to the hash function. PMID:26491714

Digital Camera with Apparatus for Authentication of Images Produced from an Image File

NASA Technical Reports Server (NTRS)

Friedman, Gary L. (Inventor)

1996-01-01

A digital camera equipped with a processor for authentication of images produced from an image file taken by the digital camera is provided. The digital camera processor has embedded therein a private key unique to it, and the camera housing has a public key that is so uniquely related to the private key that digital data encrypted with the private key may be decrypted using the public key. The digital camera processor comprises means for calculating a hash of the image file using a predetermined algorithm, and second means for encrypting the image hash with the private key, thereby producing a digital signature. The image file and the digital signature are stored in suitable recording means so they will be available together. Apparatus for authenticating the image file as being free of any alteration uses the public key for decrypting the digital signature, thereby deriving a secure image hash identical to the image hash produced by the digital camera and used to produce the digital signature. The authenticating apparatus calculates from the image file an image hash using the same algorithm as before. By comparing this last image hash with the secure image hash, authenticity of the image file is determined if they match. Other techniques to address time-honored methods of deception, such as attaching false captions or inducing forced perspectives, are included.

Endothelin-1 mediates natriuresis but not polyuria during vitamin D-induced acute hypercalcaemia.

PubMed

Tokonami, Natsuko; Cheval, Lydie; Monnay, Isabelle; Meurice, Guillaume; Loffing, Johannes; Feraille, Eric; Houillier, Pascal

2017-04-15

Hypercalcaemia can occur under various pathological conditions, such as primary hyperparathyroidism, malignancy or granulomatosis, and it induces natriuresis and polyuria in various species via an unknown mechanism. A previous study demonstrated that hypercalcaemia induced by vitamin D in rats increased endothelin (ET)-1 expression in the distal nephron, which suggests the involvement of the ET system in hypercalcaemia-induced effects. In the present study, we demonstrate that, during vitamin D-induced hypercalcaemia, the activation of ET system by increased ET-1 is responsible for natriuresis but not for polyuria. Vitamin D-treated hypercalcaemic mice showed a blunted response to amiloride, suggesting that epithelial sodium channel function is inhibited. We have identified an original pathway that specifically mediates the effects of vitamin D-induced hypercalcaemia on sodium handling in the distal nephron without affecting water handling. Acute hypercalcaemia increases urinary sodium and water excretion; however, the underlying molecular mechanism remains unclear. Because vitamin D-induced hypercalcaemia increases the renal expression of endothelin (ET)-1, we hypothesized that ET-1 mediates the effects of hypercalcaemia on renal sodium and water handling. Hypercalcaemia was induced in 8-week-old, parathyroid hormone-supplemented, male mice by oral administration of dihydrotachysterol (DHT) for 3 days. DHT-treated mice became hypercalcaemic and displayed increased urinary water and sodium excretion compared to controls. mRNA levels of ET-1 and the transcription factors CCAAT-enhancer binding protein β and δ were specifically increased in the distal convoluted tubule and downstream segments in DHT-treated mice. To examine the role of the ET system in hypercalcaemia-induced natriuresis and polyuria, mice were treated with the ET-1 receptor antagonist macitentan, with or without DHT. Mice treated with both macitentan and DHT displayed hypercalcaemia and polyuria similar to that in mice treated with DHT alone; however, no increase in urinary sodium excretion was observed. To identify the affected sodium transport mechanism, we assessed the response to various diuretics in control and DHT-treated hypercalcaemic mice. Amiloride, an inhibitor of the epithelial sodium channel (ENaC), increased sodium excretion to a lesser extent in DHT-treated mice compared to control mice. Mice treated with either macitentan+DHT or macitentan alone had a similar response to amiloride. In summary, vitamin D-induced hypercalcaemia increases the renal production of ET-1 and decreases ENaC activity, which is probably responsible for the rise in urinary sodium excretion but not for polyuria. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

9 CFR 319.303 - Corned beef hash.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Corned beef hash. 319.303 Section 319.303 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... Products § 319.303 Corned beef hash. (a) “Corned Beef Hash” is the semi-solid food product in the form of a...

9 CFR 319.303 - Corned beef hash.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Corned beef hash. 319.303 Section 319.303 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... Products § 319.303 Corned beef hash. (a) “Corned Beef Hash” is the semi-solid food product in the form of a...

9 CFR 319.303 - Corned beef hash.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Corned beef hash. 319.303 Section 319.303 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... Products § 319.303 Corned beef hash. (a) “Corned Beef Hash” is the semi-solid food product in the form of a...

9 CFR 319.303 - Corned beef hash.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Corned beef hash. 319.303 Section 319.303 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... Products § 319.303 Corned beef hash. (a) “Corned Beef Hash” is the semi-solid food product in the form of a...

Geographically distributed hybrid testing & collaboration between geotechnical centrifuge and structures laboratories

NASA Astrophysics Data System (ADS)

Ojaghi, Mobin; Martínez, Ignacio Lamata; Dietz, Matt S.; Williams, Martin S.; Blakeborough, Anthony; Crewe, Adam J.; Taylor, Colin A.; Madabhushi, S. P. Gopal; Haigh, Stuart K.

2018-01-01

Distributed Hybrid Testing (DHT) is an experimental technique designed to capitalise on advances in modern networking infrastructure to overcome traditional laboratory capacity limitations. By coupling the heterogeneous test apparatus and computational resources of geographically distributed laboratories, DHT provides the means to take on complex, multi-disciplinary challenges with new forms of communication and collaboration. To introduce the opportunity and practicability afforded by DHT, here an exemplar multi-site test is addressed in which a dedicated fibre network and suite of custom software is used to connect the geotechnical centrifuge at the University of Cambridge with a variety of structural dynamics loading apparatus at the University of Oxford and the University of Bristol. While centrifuge time-scaling prevents real-time rates of loading in this test, such experiments may be used to gain valuable insights into physical phenomena, test procedure and accuracy. These and other related experiments have led to the development of the real-time DHT technique and the creation of a flexible framework that aims to facilitate future distributed tests within the UK and beyond. As a further example, a real-time DHT experiment between structural labs using this framework for testing across the Internet is also presented.

Random multispace quantization as an analytic mechanism for BioHashing of biometric and random identity inputs.

PubMed

Teoh, Andrew B J; Goh, Alwyn; Ngo, David C L

2006-12-01

Biometric analysis for identity verification is becoming a widespread reality. Such implementations necessitate large-scale capture and storage of biometric data, which raises serious issues in terms of data privacy and (if such data is compromised) identity theft. These problems stem from the essential permanence of biometric data, which (unlike secret passwords or physical tokens) cannot be refreshed or reissued if compromised. Our previously presented biometric-hash framework prescribes the integration of external (password or token-derived) randomness with user-specific biometrics, resulting in bitstring outputs with security characteristics (i.e., noninvertibility) comparable to cryptographic ciphers or hashes. The resultant BioHashes are hence cancellable, i.e., straightforwardly revoked and reissued (via refreshed password or reissued token) if compromised. BioHashing furthermore enhances recognition effectiveness, which is explained in this paper as arising from the Random Multispace Quantization (RMQ) of biometric and external random inputs.

Compact binary hashing for music retrieval

NASA Astrophysics Data System (ADS)

Seo, Jin S.

2014-03-01

With the huge volume of music clips available for protection, browsing, and indexing, there is an increased attention to retrieve the information contents of the music archives. Music-similarity computation is an essential building block for browsing, retrieval, and indexing of digital music archives. In practice, as the number of songs available for searching and indexing is increased, so the storage cost in retrieval systems is becoming a serious problem. This paper deals with the storage problem by extending the supervector concept with the binary hashing. We utilize the similarity-preserving binary embedding in generating a hash code from the supervector of each music clip. Especially we compare the performance of the various binary hashing methods for music retrieval tasks on the widely-used genre dataset and the in-house singer dataset. Through the evaluation, we find an effective way of generating hash codes for music similarity estimation which improves the retrieval performance.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roehm, Dominic; Pavel, Robert S.; Barros, Kipton

We present an adaptive sampling method supplemented by a distributed database and a prediction method for multiscale simulations using the Heterogeneous Multiscale Method. A finite-volume scheme integrates the macro-scale conservation laws for elastodynamics, which are closed by momentum and energy fluxes evaluated at the micro-scale. In the original approach, molecular dynamics (MD) simulations are launched for every macro-scale volume element. Our adaptive sampling scheme replaces a large fraction of costly micro-scale MD simulations with fast table lookup and prediction. The cloud database Redis provides the plain table lookup, and with locality aware hashing we gather input data for our predictionmore » scheme. For the latter we use kriging, which estimates an unknown value and its uncertainty (error) at a specific location in parameter space by using weighted averages of the neighboring points. We find that our adaptive scheme significantly improves simulation performance by a factor of 2.5 to 25, while retaining high accuracy for various choices of the algorithm parameters.« less

Distributed database kriging for adaptive sampling (D²KAS)

DOE PAGES

Roehm, Dominic; Pavel, Robert S.; Barros, Kipton; ...

2015-03-18

We present an adaptive sampling method supplemented by a distributed database and a prediction method for multiscale simulations using the Heterogeneous Multiscale Method. A finite-volume scheme integrates the macro-scale conservation laws for elastodynamics, which are closed by momentum and energy fluxes evaluated at the micro-scale. In the original approach, molecular dynamics (MD) simulations are launched for every macro-scale volume element. Our adaptive sampling scheme replaces a large fraction of costly micro-scale MD simulations with fast table lookup and prediction. The cloud database Redis provides the plain table lookup, and with locality aware hashing we gather input data for our predictionmore » scheme. For the latter we use kriging, which estimates an unknown value and its uncertainty (error) at a specific location in parameter space by using weighted averages of the neighboring points. We find that our adaptive scheme significantly improves simulation performance by a factor of 2.5 to 25, while retaining high accuracy for various choices of the algorithm parameters.« less

Synergistic effects of androgen and estrogen on the mouse uterus and mammary gland.

PubMed

Zhang, Jian; Sun, Yibin; Liu, Yunhai; Sun, Yi; Liao, Dezhong Joshua

2004-10-01

Many studies have suggested that elevated estrogens and androgens may be etiologically related to the development of breast cancer, endometrial cancer and uterine leiomyomas. We and other investigators have previously shown that estrogen and androgen are synergistic in the induction of mammary carcinogenesis in the Noble rat. However, the mechanisms behind the synergy is unknown, and it is unclear whether such synergy is unique for the Noble rat and for the mammary gland. In this study we treated female FVB mice with 17beta-estradiol (E2) and 5alpha-dihydrotestosterone-bezonate (DHT-B), alone and in combination, using silastic tubing for 2-7 months. The results showed that DHT-B alone induced proliferation of uterine endometrial epithelium and myometrial smooth muscle cells, whereas E2 alone induced much more pronounced growth of endometrial epithelium without affecting smooth muscle cells. Combined treatment with E2+DHT-B caused an even more severe hyperplasia of endometrial epithelium and myometrial muscle cells, compared with the treatment with each hormone alone. Uterine leiomyomas were observed in 2 of 6 mice at 7 months of combined treatment but not in any of 6 or 7 mice receiving each single hormone. DHT-B alone induced growth and secretion of mammary ductal cells, as well as growth of mammary stroma. E2 alone stimulated much more pronounced growth of both ductal cells and alveolar cells and secretion of alveolar cells, but had no effect on mammary stroma. Treatment with both E2 and DHT-B caused more severe hyperplasia of mammary ducts and alveoli, compared to the treatment with each hormone alone. Intraductal hyperplasia occurred early and frequently in the E2+DHT-B- treated mice, but no mammary tumors were observed. These results suggest that E2 and DHT-B have synergistic effects on the growth of uterine endometrial epithelium and myometrial muscle cells, as well as mammary epithelial ducts and alveoli.

Transcriptome Analysis of the Dihydrotestosterone-Exposed Fetal Rat Gubernaculum Identifies Common Androgen and Insulin-Like 3 Targets1

PubMed Central

Barthold, Julia S.; Wang, Yanping; Robbins, Alan; Pike, Jack; McDowell, Erin; Johnson, Kamin J.; McCahan, Suzanne M.

2013-01-01

ABSTRACT Androgens and insulin-like 3 (INSL3) are required for development of the fetal gubernaculum and testicular descent. Previous studies suggested that the INSL3-exposed fetal gubernacular transcriptome is enriched for genes involved in neural pathways. In the present study, we profiled the transcriptome of fetal gubernaculum explants exposed to dihydrotestosterone (DHT) and compared this response to that with INSL3. We exposed fetal (Embryonic Day 17) rat gubernacula to DHT for 24 h (10 and 30 nM) or 6 h (1 and 10 nM) in organ culture and analyzed gene expression relative to that of vehicle-treated controls using Affymetrix arrays. Results were annotated using functional, pathway, and promoter analyses and independently validated for selected transcripts using quantitative RT-PCR (qRT-PCR). Transcripts were differentially expressed after 24 h but not 6 h. Most highly overrepresented functional categories included those related to gene expression, skeletal and muscular development and function, and Wnt signaling. Promoter response elements enriched in the DHT-specific transcriptome included consensus sequences for c-ETS1, ELK1, CREB, CRE-BP1/c-June, NRF2, and USF. We observed that 55% of DHT probe sets were also differentially expressed after INSL3 exposure and that the direction of change was the same in 96%. The qRT-PCR results confirmed that DHT increased expression of the INSL3-responsive genes Crlf1 and Chrdl2 but reduced expression of Wnt4. We also validated reduced Tgfb2 and Cxcl12 and increased Slit3 expression following DHT exposure. These data suggest a robust overlap in the DHT- and INSL3-regulated transcriptome that may be mediated in part by CREB signaling and a common Wnt pathway response for both hormones in the fetal gubernaculum. PMID:24174575

Single-pixel non-imaging object recognition by means of Fourier spectrum acquisition

NASA Astrophysics Data System (ADS)

Chen, Huichao; Shi, Jianhong; Liu, Xialin; Niu, Zhouzhou; Zeng, Guihua

2018-04-01

Single-pixel imaging has emerged over recent years as a novel imaging technique, which has significant application prospects. In this paper, we propose and experimentally demonstrate a scheme that can achieve single-pixel non-imaging object recognition by acquiring the Fourier spectrum. In an experiment, a four-step phase-shifting sinusoid illumination light is used to irradiate the object image, the value of the light intensity is measured with a single-pixel detection unit, and the Fourier coefficients of the object image are obtained by a differential measurement. The Fourier coefficients are first cast into binary numbers to obtain the hash value. We propose a new method of perceptual hashing algorithm, which is combined with a discrete Fourier transform to calculate the hash value. The hash distance is obtained by calculating the difference of the hash value between the object image and the contrast images. By setting an appropriate threshold, the object image can be quickly and accurately recognized. The proposed scheme realizes single-pixel non-imaging perceptual hashing object recognition by using fewer measurements. Our result might open a new path for realizing object recognition with non-imaging.

ADAPTIVE TETRAHEDRAL GRID REFINEMENT AND COARSENING IN MESSAGE-PASSING ENVIRONMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hallberg, J.; Stagg, A.

2000-10-01

A grid refinement and coarsening scheme has been developed for tetrahedral and triangular grid-based calculations in message-passing environments. The element adaption scheme is based on an edge bisection of elements marked for refinement by an appropriate error indicator. Hash-table/linked-list data structures are used to store nodal and element formation. The grid along inter-processor boundaries is refined and coarsened consistently with the update of these data structures via MPI calls. The parallel adaption scheme has been applied to the solution of a transient, three-dimensional, nonlinear, groundwater flow problem. Timings indicate efficiency of the grid refinement process relative to the flow solvermore » calculations.« less

[Linking anonymous databases for national and international multicenter epidemiological studies: a cryptographic algorithm].

PubMed

Quantin, C; Fassa, M; Coatrieux, G; Riandey, B; Trouessin, G; Allaert, F A

2009-02-01

Compiling individual records which come from different sources remains very important for multicenter epidemiological studies, but at the same time European directives or other national legislation concerning nominal data processing have to be respected. These legal aspects can be satisfied by implementing mechanisms that allow anonymization of patient data (such as hashing techniques). Moreover, for security reasons, official recommendations suggest using different cryptographic keys in combination with a cryptographic hash function for each study. Unfortunately, such an anonymization procedure is in contradiction with the common requirement in public health and biomedical research as it becomes almost impossible to link records from separate data collections where the same entity is not referenced in the same way. Solving this paradox by using methodology based on the combination of hashing and enciphering techniques is the main aim of this article. The method relies on one of the best known hashing functions (the secure hash algorithm) to ensure the anonymity of personal information while providing greater resistance to dictionary attacks, combined with encryption techniques. The originality of the method relies on the way the combination of hashing and enciphering techniques is performed: like in asymmetric encryption, two keys are used but the private key depends on the patient's identity. The combination of hashing and enciphering techniques provides a great improvement in the overall security of the proposed scheme. This methodology makes the stored data available for use in the field of public health for the benefit of patients, while respecting legal security requirements.

Dihydrotestosterone deteriorates cardiac insulin signaling and glucose transport in the rat model of polycystic ovary syndrome.

PubMed

Tepavčević, Snežana; Vojnović Milutinović, Danijela; Macut, Djuro; Žakula, Zorica; Nikolić, Marina; Božić-Antić, Ivana; Romić, Snježana; Bjekić-Macut, Jelica; Matić, Gordana; Korićanac, Goran

2014-05-01

It is supposed that women with polycystic ovary syndrome (PCOS) are prone to develop cardiovascular disease as a consequence of multiple risk factors that are mostly related to the state of insulin resistance and consequent hyperinsulinemia. In the present study, we evaluated insulin signaling and glucose transporters (GLUT) in cardiac cells of dihydrotestosterone (DHT) treated female rats as an animal model of PCOS. Expression of proteins involved in cardiac insulin signaling pathways and glucose transporters, as well as their phosphorylation or intracellular localization were studied by Western blot analysis in DHT-treated and control rats. Treatment with DHT resulted in increased body mass, absolute mass of the heart, elevated plasma insulin concentration, dyslipidemia and insulin resistance. At the molecular level, DHT treatment did not change protein expression of cardiac insulin receptor and insulin receptor substrate 1, while phosphorylation of the substrate at serine 307 was increased. Unexpectedly, although expression of downstream Akt kinase and its phosphorylation at threonine 308 were not altered, phosphorylation of Akt at serine 473 was increased in the heart of DHT-treated rats. In contrast, expression and phosphorylation of extracellular signal regulated kinases 1/2 were decreased. Plasma membrane contents of GLUT1 and GLUT4 were decreased, as well as the expression of GLUT4 in cardiac cells at the end of androgen treatment. The obtained results provide evidence for alterations in expression and especially in functional characteristics of insulin signaling molecules and glucose transporters in the heart of DHT-treated rats with PCOS, indicating impaired cardiac insulin action. Copyright © 2014 Elsevier Ltd. All rights reserved.

Androgen Control of Cell Proliferation and Cytoskeletal Reorganization in Human Fibrosarcoma Cells

PubMed Central

Chauhan, Sanjay; Kunz, Susan; Davis, Kelli; Roberts, Jordan; Martin, Greg; Demetriou, Manolis C.; Sroka, Thomas C.; Cress, Anne E.; Miesfeld, Roger L.

2009-01-01

We recently generated an HT-1080-derived cell line called HT-AR1 that responds to dihydrotestosterone (DHT) treatment by undergoing cell growth arrest in association with cytoskeletal reorganization and induction of neuroendocrine-like cell differentiation. In this report, we show that DHT induces a dose-dependent increase in G0/G1 growth-arrested cells using physiological levels of hormone. The arrested cells increase in cell size and contain a dramatic redistribution of desmoplakin, keratin 5, and chromogranin A proteins. DHT-induced cytoskeletal changes were also apparent from time lapse video microscopy that showed that androgen treatment resulted in the rapid appearance of neuronal-like membrane extensions. Expression profiling analysis using RNA isolated from DHT-treated HT-AR1 cells revealed that androgen receptor activation leads to the coordinate expression of numerous cell signaling genes including RhoB, PTGF-β, caveolin-2, Egr-1, myosin 1B, and EHM2. Because RhoB has been shown to have a role in tumor suppression and neuronal differentiation in other cell types, we investigated RhoB signaling functions in the HT-AR1 steroid response. We found that steroid induction of RhoB was DHT-specific and that newly synthesized RhoB protein was post-translationally modified and localized to endocytic vesicles. Moreover, treatment with a farnesyl transferase inhibitor reduced DHT-dependent growth arrest, suggesting that prenylated RhoB might function to inhibit HT-AR1 cell proliferation. This was directly shown by transfecting HT-AR1 cells with RhoB coding sequences containing activating or dominant negative mutations. PMID:14576147

Pharmacological depletion of serotonin in the basolateral amygdala complex reduces anxiety and disrupts fear conditioning.

PubMed

Johnson, Philip L; Molosh, Andrei; Fitz, Stephanie D; Arendt, Dave; Deehan, Gerald A; Federici, Lauren M; Bernabe, Cristian; Engleman, Eric A; Rodd, Zachary A; Lowry, Christopher A; Shekhar, Anantha

2015-11-01

The basolateral and lateral amygdala nuclei complex (BLC) is implicated in a number of emotional responses including conditioned fear and social anxiety. Based on previous studies demonstrating that enhanced serotonin release in the BLC leads to increased anxiety and fear responses, we hypothesized that pharmacologically depleting serotonin in the BLC using 5,7-dihydroxytryptamine (5,7-DHT) injections would lead to diminished anxiety and disrupted fear conditioning. To test this hypothesis, 5,7-DHT(a serotonin-depleting agent) was bilaterally injected into the BLC. Desipramine (a norepinephrine reuptake inhibitor) was systemically administered to prevent non-selective effects on norepinephrine. After 5days, 5-7-DHT-treated rats showed increases in the duration of social interaction (SI) time, suggestive of reduced anxiety-like behavior. We then used a cue-induced fear conditioning protocol with shock as the unconditioned stimulus and tone as the conditioned stimulus for rats pretreated with bilateral 5,7-DHT, or vehicle, injections into the BLC. Compared to vehicle-treated rats, 5,7-DHT rats had reduced acquisition of fear during conditioning (measured by freezing time during tone), also had reduced fear retrieval/recall on subsequent testing days. Ex vivo analyses revealed that 5,7-DHT reduced local 5-HT concentrations in the BLC by ~40% without altering local norepinephrine or dopamine concentrations. These data provide additional support for 5-HT playing a critical role in modulating anxiety-like behavior and fear-associated memories through its actions within the BLC. Copyright © 2015 Elsevier Inc. All rights reserved.

Microbiological quality of five potato products obtained at retail markets.

PubMed Central

Duran, A P; Swartzentruber, A; Lanier, J M; Wentz, B A; Schwab, A H; Barnard, R J; Read, R B

1982-01-01

The microbiological quality of frozen hash brown potatoes, dried hash brown potatoes with onions, frozen french fried potatoes, dried instant mashed potatoes, and potato salad was determined by a national sampling at the retail level. A wide range of results was obtained, with most sampling units of each products having excellent microbiological quality. Geometric mean aerobic plate counts were as follows: dried hash brown potatoes, 270/g; frozen hash brown potatoes with onions, 580/g; frozen french fried potatoes 78/g; dried instant mashed potatoes, 1.1 x 10(3)/g; and potato salad, 3.6 x 10(3)/g. Mean values of coliforms, Escherichia coli, and Staphylococcus aureus were less than 10/g. PMID:6758695

Forensic hash for multimedia information

NASA Astrophysics Data System (ADS)

Lu, Wenjun; Varna, Avinash L.; Wu, Min

2010-01-01

Digital multimedia such as images and videos are prevalent on today's internet and cause significant social impact, which can be evidenced by the proliferation of social networking sites with user generated contents. Due to the ease of generating and modifying images and videos, it is critical to establish trustworthiness for online multimedia information. In this paper, we propose novel approaches to perform multimedia forensics using compact side information to reconstruct the processing history of a document. We refer to this as FASHION, standing for Forensic hASH for informatION assurance. Based on the Radon transform and scale space theory, the proposed forensic hash is compact and can effectively estimate the parameters of geometric transforms and detect local tampering that an image may have undergone. Forensic hash is designed to answer a broader range of questions regarding the processing history of multimedia data than the simple binary decision from traditional robust image hashing, and also offers more efficient and accurate forensic analysis than multimedia forensic techniques that do not use any side information.

A more secure parallel keyed hash function based on chaotic neural network

NASA Astrophysics Data System (ADS)

Huang, Zhongquan

2011-08-01

Although various hash functions based on chaos or chaotic neural network were proposed, most of them can not work efficiently in parallel computing environment. Recently, an algorithm for parallel keyed hash function construction based on chaotic neural network was proposed [13]. However, there is a strict limitation in this scheme that its secret keys must be nonce numbers. In other words, if the keys are used more than once in this scheme, there will be some potential security flaw. In this paper, we analyze the cause of vulnerability of the original one in detail, and then propose the corresponding enhancement measures, which can remove the limitation on the secret keys. Theoretical analysis and computer simulation indicate that the modified hash function is more secure and practical than the original one. At the same time, it can keep the parallel merit and satisfy the other performance requirements of hash function, such as good statistical properties, high message and key sensitivity, and strong collision resistance, etc.

A Complete and Accurate Ab Initio Repeat Finding Algorithm.

PubMed

Lian, Shuaibin; Chen, Xinwu; Wang, Peng; Zhang, Xiaoli; Dai, Xianhua

2016-03-01

It has become clear that repetitive sequences have played multiple roles in eukaryotic genome evolution including increasing genetic diversity through mutation, changes in gene expression and facilitating generation of novel genes. However, identification of repetitive elements can be difficult in the ab initio manner. Currently, some classical ab initio tools of finding repeats have already presented and compared. The completeness and accuracy of detecting repeats of them are little pool. To this end, we proposed a new ab initio repeat finding tool, named HashRepeatFinder, which is based on hash index and word counting. Furthermore, we assessed the performances of HashRepeatFinder with other two famous tools, such as RepeatScout and Repeatfinder, in human genome data hg19. The results indicated the following three conclusions: (1) The completeness of HashRepeatFinder is the best one among these three compared tools in almost all chromosomes, especially in chr9 (8 times of RepeatScout, 10 times of Repeatfinder); (2) in terms of detecting large repeats, HashRepeatFinder also performed best in all chromosomes, especially in chr3 (24 times of RepeatScout and 250 times of Repeatfinder) and chr19 (12 times of RepeatScout and 60 times of Repeatfinder); (3) in terms of accuracy, HashRepeatFinder can merge the abundant repeats with high accuracy.

Implementation of the AES as a Hash Function for Confirming the Identity of Software on a Computer System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hansen, Randy R.; Bass, Robert B.; Kouzes, Richard T.

2003-01-20

This paper provides a brief overview of the implementation of the Advanced Encryption Standard (AES) as a hash function for confirming the identity of software resident on a computer system. The PNNL Software Authentication team chose to use a hash function to confirm software identity on a system for situations where: (1) there is limited time to perform the confirmation and (2) access to the system is restricted to keyboard or thumbwheel input and output can only be displayed on a monitor. PNNL reviewed three popular algorithms: the Secure Hash Algorithm - 1 (SHA-1), the Message Digest - 5 (MD-5),more » and the Advanced Encryption Standard (AES) and selected the AES to incorporate in software confirmation tool we developed. This paper gives a brief overview of the SHA-1, MD-5, and the AES and sites references for further detail. It then explains the overall processing steps of the AES to reduce a large amount of generic data-the plain text, such is present in memory and other data storage media in a computer system, to a small amount of data-the hash digest, which is a mathematically unique representation or signature of the former that could be displayed on a computer's monitor. This paper starts with a simple definition and example to illustrate the use of a hash function. It concludes with a description of how the software confirmation tool uses the hash function to confirm the identity of software on a computer system.« less

Glucosensing by GnRH Neurons: Inhibition by Androgens and Involvement of AMP-Activated Protein Kinase

PubMed Central

Roland, Alison V.

2011-01-01

GnRH neurons integrate steroidal and metabolic cues to regulate fertility centrally. Central glucoprivation reduces LH secretion, which is governed by GnRH release, suggesting GnRH neuron activity is modulated by glucose availability. Here we tested whether GnRH neurons can sense changes in extracellular glucose, and whether glucosensing is altered by the steroids dihydrotestosterone (DHT) and/or estradiol (E). Extracellular recordings were made from GnRH neurons in brain slices from ovariectomized (OVX) mice ± DHT and/or E implants. Firing rate was reduced by a switch from 4.5 to 0.2 mm glucose in cells from OVX, OVX+E, and OVX+DHT+E mice, but not OVX+DHT mice. This suggests that androgens reduce the sensitivity of GnRH neurons to changes in extracellular glucose, but E mitigates this effect. Next we investigated potential mechanisms. In the presence of the ATP-sensitive potassium channel antagonist tolbutamide, glucosensing persisted. In contrast, glucosensing was attenuated in the presence of compound C, an antagonist of AMP-activated protein kinase (AMPK), suggesting a role for AMPK in glucosensing. The AMPK activator N1-(b-d-ribofuranosyl)-5-aminoimidazole-4-carboxamide (AICAR) mimicked the effect of low glucose and was less effective in cells from DHT-treated mice. The effect of DHT to diminish responses to low glucose and AICAR was abolished by blockade of fast synaptic transmission. Both AICAR and low glucose activated a current with a reversal potential near −50 mV, suggesting a nonspecific cation current. These studies indicate that glucosensing is one mechanism by which GnRH neurons sense fuel availability and point to a novel role for AMPK in the central regulation of fertility. PMID:21393446

Different synaptic stimulation patterns influence the local androgenic and estrogenic neurosteroid availability triggering hippocampal synaptic plasticity in the male rat.

PubMed

Di Mauro, Michela; Tozzi, Alessandro; Calabresi, Paolo; Pettorossi, Vito Enrico; Grassi, Silvarosa

2017-02-01

Electrophysiological recordings were used to investigate the role of the local synthesis of 17β-estradiol (E2) and 5α-dihydrotestosterone (DHT) on synaptic long-term effects induced in the hippocampal CA1 region of male rat slices. Long-term depression (LTD) and long-term potentiation (LTP), induced by different stimulation patterns, were examined under the block of the DHT synthesis by finasteride (FIN), and the E2 synthesis by letrozole (LET). We used low frequency stimulation (LFS) for LTD, high frequency stimulation (HFS) for LTP, and intermediate patterns differing in duration or frequency. We found that FIN reverted the LFS-LTD into LTP and enhanced LTP induced by intermediate and HFSs. These effects were abolished by exogenous DHT at concentration higher than the basal one, suggesting a stimulus dependent increase in DHT availability. No effect on the synaptic responses was observed giving DHT alone. Moreover, we found that the inhibition of E2 synthesis influenced the HFS-LTP by reducing its amplitude, and the exogenous E2 either enhanced HFS-LTP or reverted the LFS-LTD into LTP. The equivalence of the E2 concentration for rescuing the full HFS-LTP under LET and reverting the LFS-LTD into LTP suggests an enhancement of the endogenous E2 availability that is specifically driven by the HFS. No effect of FIN or LET was observed on the responses to stimuli that did not induce either LTD or LTP. This study provides evidence that the E2 and DHT availability combined with specific stimulation patterns is determinant for the sign and amplitude of the long-term effects. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Topical dihydrotestosterone to treat micropenis secondary to partial androgen insensitivity syndrome (PAIS) before, during, and after puberty - a case series.

PubMed

Becker, David; Wain, Lisa M; Chong, Yih Harng; Gosai, Sonal J; Henderson, Nina K; Milburn, Jacqui; Stott, Victoria; Wheeler, Benjamin J

2016-02-01

X-linked partial androgen insensitivity syndrome (PAIS) causes under-virilization at all stages of development. In two thirds of males, this results in micropenis. Dihydrotestosterone (DHT) is a potent androgen that is critical for male genital development, which when applied topically, has been shown to increase penile length with micropenis of varying etiologies. We present the first case series using topical DHT gel to treat micropenis in 46,XY males with PAIS, before, during, and after puberty. Three related 46,XY males with confirmed p.L712F androgen receptor mutations exhibited varying degrees of micropenis post-surgical correction. They were of pre-pubertal, peri-pubertal and adult ages, respectively. Following baseline clinical and laboratory assessments all completed a 4-month course of daily DHT gel 2.5% (androstanolone) topically to penis (0.3 mg/kg body weight), with monitoring for adverse effects. Primary outcome was change in stretched penile length (SPL) following treatment. Mixed results were obtained following topical DHT therapy. In the pre- and peri- pubertal patients, SPL changed from 2.5 cm to 3.5 cm (+40%), and 3.5 cm to 5.7 cm (+63%), respectively. In the adult patient with 1 year of prior high-dose weekly testosterone therapy, no additional change in SPL was seen. No adverse effects of topical DHT were reported or observed throughout the 4 months of treatment. Topical DHT treatment appears to be a safe and well-tolerated method of virilising micropenis both prior to and during puberty in children with PAIS. Questions remain about long-term outcomes into adulthood, and efficacy in adults with prior lengthy exposure to high-dose testosterone.

Characterization of reproductive, metabolic, and endocrine features of polycystic ovary syndrome in female hyperandrogenic mouse models.

PubMed

Caldwell, A S L; Middleton, L J; Jimenez, M; Desai, R; McMahon, A C; Allan, C M; Handelsman, D J; Walters, K A

2014-08-01

Polycystic ovary syndrome (PCOS) affects 5-10% of women of reproductive age, causing a range of reproductive, metabolic and endocrine defects including anovulation, infertility, hyperandrogenism, obesity, hyperinsulinism, and an increased risk of type 2 diabetes and cardiovascular disease. Hyperandrogenism is the most consistent feature of PCOS, but its etiology remains unknown, and ethical and logistic constraints limit definitive experimentation in humans to determine mechanisms involved. In this study, we provide the first comprehensive characterization of reproductive, endocrine, and metabolic PCOS traits in 4 distinct murine models of hyperandrogenism, comprising prenatal dihydrotestosterone (DHT, potent nonaromatizable androgen) treatment during days 16-18 of gestation, or long-term treatment (90 days from 21 days of age) with DHT, dehydroepiandrosterone (DHEA), or letrozole (aromatase inhibitor). Prenatal DHT-treated mature mice exhibited irregular estrous cycles, oligo-ovulation, reduced preantral follicle health, hepatic steatosis, and adipocyte hypertrophy, but lacked overall changes in body-fat composition. Long-term DHT treatment induced polycystic ovaries displaying unhealthy antral follicles (degenerate oocyte and/or > 10% pyknotic granulosa cells), as well as anovulation and acyclicity in mature (16-week-old) females. Long-term DHT also increased body and fat pad weights and induced adipocyte hypertrophy and hypercholesterolemia. Long-term letrozole-treated mice exhibited absent or irregular cycles, oligo-ovulation, polycystic ovaries containing hemorrhagic cysts atypical of PCOS, and displayed no metabolic features of PCOS. Long-term dehydroepiandrosterone treatment produced no PCOS features in mature mice. Our findings reveal that long-term DHT treatment replicated a breadth of ovarian, endocrine, and metabolic features of human PCOS and provides the best mouse model for experimental studies of PCOS pathogenesis.

The antiandrogenic effect of finasteride against a mutant androgen receptor

PubMed Central

Chhipa, Rishi Raj; Zhang, Haitao; Ip, Clement

2011-01-01

Finasteride is known to inhibit Type 2 5α-reductase and thus block the conversion of testosterone to dihydrotestosterone (DHT). The structural similarity of finasteride to DHT raises the possibility that finasteride may also interfere with the function of the androgen receptor (AR). Experiments were carried out to evaluate the antiandrogenic effect of finasteride in LNCaP, C4-2 and VCaP human prostate cancer cells. Finasteride decreased DHT binding to AR, and DHT-stimulated AR activity and cell growth in LNCaP and C4-2 cells, but not in VCaP cells. LNCaP and C4-2 (derived from castration-resistant LNCaP) cells express the T877A mutant AR, while VCaP cells express the wild-type AR. When PC-3 cells, which are AR-null, were transfected with either the wild-type or the T877A mutant AR, only the mutant AR-expressing cells were sensitive to finasteride inhibition of DHT binding. Peroxiredoxin-1 (Prx1) is a novel endogenous facilitator of AR binding to DHT. In Prx1-rich LNCaP cells, the combination of Prx1 knockdown and finasteride was found to produce a greater inhibitory effect on AR activity and cell growth than either treatment alone. The observation suggests that cells with a low expression of Prx1 are likely to be more responsive to the antiandrogenic effect of finasteride. Additional studies showed that the efficacy of finasteride was comparable to that of bicalutamide (a widely used non-steroidal antiandrogen). The implication of the above findings is discussed in the context of developing strategies to improve the outcome of androgen deprivation therapy. PMID:21386657

Anatomy of a hash-based long read sequence mapping algorithm for next generation DNA sequencing.

PubMed

Misra, Sanchit; Agrawal, Ankit; Liao, Wei-keng; Choudhary, Alok

2011-01-15

Recently, a number of programs have been proposed for mapping short reads to a reference genome. Many of them are heavily optimized for short-read mapping and hence are very efficient for shorter queries, but that makes them inefficient or not applicable for reads longer than 200 bp. However, many sequencers are already generating longer reads and more are expected to follow. For long read sequence mapping, there are limited options; BLAT, SSAHA2, FANGS and BWA-SW are among the popular ones. However, resequencing and personalized medicine need much faster software to map these long sequencing reads to a reference genome to identify SNPs or rare transcripts. We present AGILE (AliGnIng Long rEads), a hash table based high-throughput sequence mapping algorithm for longer 454 reads that uses diagonal multiple seed-match criteria, customized q-gram filtering and a dynamic incremental search approach among other heuristics to optimize every step of the mapping process. In our experiments, we observe that AGILE is more accurate than BLAT, and comparable to BWA-SW and SSAHA2. For practical error rates (< 5%) and read lengths (200-1000 bp), AGILE is significantly faster than BLAT, SSAHA2 and BWA-SW. Even for the other cases, AGILE is comparable to BWA-SW and several times faster than BLAT and SSAHA2. http://www.ece.northwestern.edu/~smi539/agile.html.

Unified Communications: Simplifying DoD Communication Methods

DTIC Science & Technology

2013-04-18

private key to encrypt the hash. The encrypted hash, together with some other information, such as the hashing algorithm , is known as a digital...virtual private network (VPN). The use of a VPN would allow users to access corporate data while encrypting traffic.35 Another layer of protection would...sign and encrypt emails as well as controlling access to restricted sites. PKI uses a combination of public and private keys for encryption and

Secure Image Hash Comparison for Warhead Verification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruillard, Paul J.; Jarman, Kenneth D.; Robinson, Sean M.

2014-06-06

The effort to inspect and verify warheads in the context of possible future arms control treaties is rife with security and implementation issues. In this paper we review prior work on perceptual image hashing for template-based warhead verification. Furthermore, we formalize the notion of perceptual hashes and demonstrate that large classes of such functions are likely not cryptographically secure. We close with a brief discussion of fully homomorphic encryption as an alternative technique.

Serum testosterone, dihydrotestosterone and estradiol concentrations in older men self-reporting very good health: the healthy man study.

PubMed

Sartorius, Gideon; Spasevska, Sasa; Idan, Amanda; Turner, Leo; Forbes, Elise; Zamojska, Anna; Allan, Carolyn A; Ly, Lam P; Conway, Ann J; McLachlan, Robert I; Handelsman, David J

2012-11-01

To determine serum concentrations, intra-individual variability and impact of age-related co-morbidities on serum testosterone (T), dihydrotestosterone (DHT), estradiol (E(2)) and estrone (E(1)) in older men. Observational, repeated measures study. Men (n = 325) with 40 years and older self-reporting very good or excellent health. Standardized history, physical examination and collection of nine blood samples at fixed time intervals were measured over 3 months (three at 20 min intervals on days 1 (fasting) and 2 (non-fasting), one at days 7, 30 and 90). Serum T, DHT, E(2) and E(1) (n = 2900, > 99% of scheduled samples) measured by liquid chromatography-tandem mass spectrometry (LC-MS) were analysed by linear mixed model analysis with fasting, age and obesity as covariables. Mean serum T did not vary with age (P = 0·76) but obesity (-0·35 nM per body mass index (BMI) unit, P < 0·0001) and ex-smoker status (-1·6 nM, P < 0·001) had significant effects. Serum DHT was increased with age (+0·011 nM per year, P = 0·001) but decreased with obesity (-0·05 nM per BMI unit, P < 0·0001). Serum E(2) did not vary with age (P = 0·31) or obesity (P = 0·12). Overnight fasting increased (by 9-16%, all P < 0·001) and reduced variability in morning serum T, DHT, E(2) and E(1). Non-fasting serum T and DHT were stable over time (day, week, month or 3 months; P > 0·28). Serum T, DHT and E(2) displayed no decrease associated with age among men over 40 years of age who self-report very good or excellent health although obesity and ex-smoking status were associated with decreased serum androgens (T and DHT) but not E(2). These findings support the interpretation that the age-related decline in blood T accompanying non-specific symptoms in older men may be due to accumulating age-related co-morbidities rather than a symptomatic androgen deficiency state. © 2012 Blackwell Publishing Ltd.

Next-generation steroidogenesis inhibitors, dutasteride and abiraterone, attenuate but still do not eliminate androgen biosynthesis in 22RV1 cells in vitro.

PubMed

Pham, Steven; Deb, Subrata; Ming, Dong Sheng; Adomat, Hans; Hosseini-Beheshti, Elham; Zoubeidi, Amina; Gleave, Martin; Guns, Emma S Tomlinson

2014-10-01

Castration resistant prostate cancer (CRPC) is often lethal and inevitably develops after androgen ablation therapy. However, in the majority of cases it remains androgen dependent. CRPC tumors have the ability to synthesize their own androgens from cholesterol by engaging in de novo steroidogenesis. We investigated the potential of 22RV1 prostate cancer cells to convert the supplemented steroid precursors within this pathway under the effects of current clinical steroidogenesis inhibitors such as abiraterone and dutasteride, either alone or in combination. Under steroid starved conditions, enzymes responsible for de novo steroidogenesis were upregulated. Testosterone and dihydrotestosterone (DHT) were formed by using both dehydroepiandrosterone (DHEA) and progesterone as substrates. Formation of testosterone and DHT was higher following incubation with DHEA compared to progesterone. Progesterone decreased the mRNA expression of enzymes responsible for steroidogenesis. Abiraterone treatment decreased testosterone production but increased several precursor steroids in both classical and backdoor pathways in the presence of progesterone. In contrast, the DHT levels were elevated following treatment with abiraterone when progesterone was absent. Dutasteride decreased the formation of testosterone, DHT and precursor steroids in the backdoor pathway but increased steroid precursors in the classical steroidogenesis pathway. The combination of abiraterone and dutasteride decreased testosterone and DHT in the presence of progesterone but increased DHT in the absence of progesterone. Abiraterone inhibited androgen receptor (AR) activation but not to the same extent as MDV3100. However, abiraterone and dutasteride treatment, either alone or in combination, were more effective in decreasing prostate specific antigen secretion into the media than MDV3100. Thus, while interventions with these drugs alone or in combination fail to completely inhibit steroidogenesis in the 22RV1 cells, the combined inhibition of androgen production and blockade of AR can exceed the effect of MDV3100. Further characterization of bypass mechanisms that may develop as a response to these inhibitors is necessary to achieve optimal suppression of testosterone and DHT synthesis as a part of therapeutic regimens for the treatment of CRPC. Copyright © 2014 Elsevier Ltd. All rights reserved.

Antioxidant Response of Osteoblasts to Doxycycline in an Inflammatory Model Induced by C-reactive Protein and Interleukin-6

PubMed Central

Tilakaratne, A.; Soory, Mena

2016-01-01

Objectives: Investigation of osteoblastic responses to oxidative stress, induced by C-reactive protein (CRP) and IL-6 and ameliorating effects of doxycycline (Dox); using assays for 5-alpha dihydrotestosterone (DHT) as an antioxidant marker of healing. IL-6 and CRP are risk markers of periodontitis and prevalent comorbidities in periodontitis subjects. Methods: Confluent monolayer cultures of osteoblasts were incubated with radiolabelled testosterone (14C-T) as substrate, in the presence or absence (Control) of pre-determined optimal concentrations of CRP, IL-6, Dox; alone and in combination (n=8) for 24h in MEM. The eluent was solvent-extracted for steroid metabolites. They were separated using TLC in a benzene/ acetone solvent system 4:1 v/v; and quantified using radioisotope scanning. The identity of formed metabolites was confirmed using the mobility of cold standards added to the samples and disclosed in iodine. Further confirmation of the authenticity of DHT was carried out by combined gas chromatrography-mass spectrometry, after derivatization to pentafluorobenzyloxime trimethyl silyl ether. Results: The yields of DHT from 14C-testosterone showed 2-fold and 1.8-fold- inhibition in response to IL-6 and CRP respectively and 28% stimulation in response to Dox, via the 5-alpha reductase pathway. The combination of IL-6 + CRP showed a 2-fold reduction in the yields of DHT, elevated to control values when combined with Dox (n=8; p<0.001). Yields of 4-androstenedione showed an inverse relationship to those of DHT, in response to the agents tested, in keeping with the 17-beta hydroxysteroid dehydrogenase pathway. Conclusions: Inhibition of DHT synthesis in osteoblasts by IL-6 and CRP was overcome by doxycycline. Oxidative actions of IL-6 and CRP; and antioxidant actions of Dox are reinforced by the metabolic yields of DHT in response to agents tested. Using a novel metabolically active model allows closer extrapolation to in vivo conditions; in the context of adjunctive therapeutic applications for periodontitis and prevalent comorbidities. PMID:25159306

Dihydrotestosterone synthesis bypasses testosterone to drive castration-resistant prostate cancer

PubMed Central

Chang, Kai-Hsiung; Li, Rui; Papari-Zareei, Mahboubeh; Watumull, Lori; Zhao, Yan Daniel; Auchus, Richard J.; Sharifi, Nima

2011-01-01

In the majority of cases, advanced prostate cancer responds initially to androgen deprivation therapy by depletion of gonadal testosterone. The response is usually transient, and metastatic tumors almost invariably eventually progress as castration-resistant prostate cancer (CRPC). The development of CRPC is dependent upon the intratumoral generation of the potent androgen, dihydrotestosterone (DHT), from adrenal precursor steroids. Progression to CRPC is accompanied by increased expression of steroid-5α-reductase isoenzyme-1 (SRD5A1) over SRD5A2, which is otherwise the dominant isoenzyme expressed in the prostate. DHT synthesis in CRPC is widely assumed to require 5α-reduction of testosterone as the obligate precursor, and the increased expression of SRD5A1 is thought to reflect its role in converting testosterone to DHT. Here, we show that the dominant route of DHT synthesis in CRPC bypasses testosterone, and instead requires 5α-reduction of androstenedione by SRD5A1 to 5α-androstanedione, which is then converted to DHT. This alternative pathway is operational and dominant in both human CRPC cell lines and fresh tissue obtained from human tumor metastases. Moreover, CRPC growth in mouse xenograft models is dependent upon this pathway, as well as expression of SRD5A1. These findings reframe the fundamental metabolic pathway that drives CRPC progression, and shed light on the development of new therapeutic strategies. PMID:21795608

Dihydrotestosterone synthesis bypasses testosterone to drive castration-resistant prostate cancer.

PubMed

Chang, Kai-Hsiung; Li, Rui; Papari-Zareei, Mahboubeh; Watumull, Lori; Zhao, Yan Daniel; Auchus, Richard J; Sharifi, Nima

2011-08-16

In the majority of cases, advanced prostate cancer responds initially to androgen deprivation therapy by depletion of gonadal testosterone. The response is usually transient, and metastatic tumors almost invariably eventually progress as castration-resistant prostate cancer (CRPC). The development of CRPC is dependent upon the intratumoral generation of the potent androgen, dihydrotestosterone (DHT), from adrenal precursor steroids. Progression to CRPC is accompanied by increased expression of steroid-5α-reductase isoenzyme-1 (SRD5A1) over SRD5A2, which is otherwise the dominant isoenzyme expressed in the prostate. DHT synthesis in CRPC is widely assumed to require 5α-reduction of testosterone as the obligate precursor, and the increased expression of SRD5A1 is thought to reflect its role in converting testosterone to DHT. Here, we show that the dominant route of DHT synthesis in CRPC bypasses testosterone, and instead requires 5α-reduction of androstenedione by SRD5A1 to 5α-androstanedione, which is then converted to DHT. This alternative pathway is operational and dominant in both human CRPC cell lines and fresh tissue obtained from human tumor metastases. Moreover, CRPC growth in mouse xenograft models is dependent upon this pathway, as well as expression of SRD5A1. These findings reframe the fundamental metabolic pathway that drives CRPC progression, and shed light on the development of new therapeutic strategies.

The self-crosslinking smart hyaluronic acid hydrogels as injectable three-dimensional scaffolds for cells culture.

PubMed

Bian, Shaoquan; He, Mengmeng; Sui, Junhui; Cai, Hanxu; Sun, Yong; Liang, Jie; Fan, Yujiang; Zhang, Xingdong

2016-04-01

Although the disulfide bond crosslinked hyaluronic acid hydrogels have been reported by many research groups, the major researches were focused on effectively forming hydrogels. However, few researchers paid attention to the potential significance of controlling the hydrogel formation and degradation, improving biocompatibility, reducing the toxicity of exogenous and providing convenience to the clinical operations later on. In this research, the novel controllable self-crosslinking smart hydrogels with in-situ gelation property was prepared by a single component, the thiolated hyaluronic acid derivative (HA-SH), and applied as a three-dimensional scaffold to mimic native extracellular matrix (ECM) for the culture of fibroblasts cells (L929) and chondrocytes. A series of HA-SH hydrogels were prepared depending on different degrees of thiol substitution (ranging from 10 to 60%) and molecule weights of HA (0.1, 0.3 and 1.0 MDa). The gelation time, swelling property and smart degradation behavior of HA-SH hydrogel were evaluated. The results showed that the gelation and degradation time of hydrogels could be controlled by adjusting the component of HA-SH polymers. The storage modulus of HA-SH hydrogels obtained by dynamic modulus analysis (DMA) could be up to 44.6 kPa. In addition, HA-SH hydrogels were investigated as a three-dimensional scaffold for the culture of fibroblasts cells (L929) and chondrocytes cells in vitro and as an injectable hydrogel for delivering chondrocytes cells in vivo. These results illustrated that HA-SH hydrogels with controllable gelation process, intelligent degradation behavior, excellent biocompatibility and convenient operational characteristics supplied potential clinical application capacity for tissue engineering and regenerative medicine. Copyright © 2016 Elsevier B.V. All rights reserved.

A Comparison of Nutrient Intakes between a Ft. Riley Contractor-Operated and a Ft. Lewis Military-Operated Garrison Dining Facility

DTIC Science & Technology

1987-10-01

Meatsauce Rissole Potatoes Turkey Nuggets (I/o) Hash Browned Potatoes (I/o) Mashed Potatoes Buttered Mixed Vegetables Toasted Garlic Bread Brussels...Chicken Curry Baked Ham/P/A Sauce Parsley Buttered Potatoes Brown Gravy Hash Browned Potatoes (I/o) Steamed Rice Steamed Carrots Mashed Potatoes...Steak Mashed Potatoes Mashed Potatoes Rissole Potatoes Steamed Rice Hash Browned Potatoes (I/o) Green Beans Steamed Carrots Broccoli w/Cheese sauce

Optimal hash arrangement of tentacles in jellyfish

NASA Astrophysics Data System (ADS)

Okabe, Takuya; Yoshimura, Jin

2016-06-01

At first glance, the trailing tentacles of a jellyfish appear to be randomly arranged. However, close examination of medusae has revealed that the arrangement and developmental order of the tentacles obey a mathematical rule. Here, we show that medusa jellyfish adopt the best strategy to achieve the most uniform distribution of a variable number of tentacles. The observed order of tentacles is a real-world example of an optimal hashing algorithm known as Fibonacci hashing in computer science.

Large-scale Cross-modality Search via Collective Matrix Factorization Hashing.

PubMed

Ding, Guiguang; Guo, Yuchen; Zhou, Jile; Gao, Yue

2016-09-08

By transforming data into binary representation, i.e., Hashing, we can perform high-speed search with low storage cost, and thus Hashing has collected increasing research interest in the recent years. Recently, how to generate Hashcode for multimodal data (e.g., images with textual tags, documents with photos, etc) for large-scale cross-modality search (e.g., searching semantically related images in database for a document query) is an important research issue because of the fast growth of multimodal data in the Web. To address this issue, a novel framework for multimodal Hashing is proposed, termed as Collective Matrix Factorization Hashing (CMFH). The key idea of CMFH is to learn unified Hashcodes for different modalities of one multimodal instance in the shared latent semantic space in which different modalities can be effectively connected. Therefore, accurate cross-modality search is supported. Based on the general framework, we extend it in the unsupervised scenario where it tries to preserve the Euclidean structure, and in the supervised scenario where it fully exploits the label information of data. The corresponding theoretical analysis and the optimization algorithms are given. We conducted comprehensive experiments on three benchmark datasets for cross-modality search. The experimental results demonstrate that CMFH can significantly outperform several state-of-the-art cross-modality Hashing methods, which validates the effectiveness of the proposed CMFH.

Internet traffic load balancing using dynamic hashing with flow volume

NASA Astrophysics Data System (ADS)

Jo, Ju-Yeon; Kim, Yoohwan; Chao, H. Jonathan; Merat, Francis L.

2002-07-01

Sending IP packets over multiple parallel links is in extensive use in today's Internet and its use is growing due to its scalability, reliability and cost-effectiveness. To maximize the efficiency of parallel links, load balancing is necessary among the links, but it may cause the problem of packet reordering. Since packet reordering impairs TCP performance, it is important to reduce the amount of reordering. Hashing offers a simple solution to keep the packet order by sending a flow over a unique link, but static hashing does not guarantee an even distribution of the traffic amount among the links, which could lead to packet loss under heavy load. Dynamic hashing offers some degree of load balancing but suffers from load fluctuations and excessive packet reordering. To overcome these shortcomings, we have enhanced the dynamic hashing algorithm to utilize the flow volume information in order to reassign only the appropriate flows. This new method, called dynamic hashing with flow volume (DHFV), eliminates unnecessary flow reassignments of small flows and achieves load balancing very quickly without load fluctuation by accurately predicting the amount of transferred load between the links. In this paper we provide the general framework of DHFV and address the challenges in implementing DHFV. We then introduce two algorithms of DHFV with different flow selection strategies and show their performances through simulation.

Adoption of the Hash algorithm in a conceptual model for the civil registry of Ecuador

NASA Astrophysics Data System (ADS)

Toapanta, Moisés; Mafla, Enrique; Orizaga, Antonio

2018-04-01

The Hash security algorithm was analyzed in order to mitigate information security in a distributed architecture. The objective of this research is to develop a prototype for the Adoption of the algorithm Hash in a conceptual model for the Civil Registry of Ecuador. The deductive method was used in order to analyze the published articles that have a direct relation with the research project "Algorithms and Security Protocols for the Civil Registry of Ecuador" and articles related to the Hash security algorithm. It resulted from this research: That the SHA-1 security algorithm is appropriate for use in Ecuador's civil registry; we adopted the SHA-1 algorithm used in the flowchart technique and finally we obtained the adoption of the hash algorithm in a conceptual model. It is concluded that from the comparison of the DM5 and SHA-1 algorithm, it is suggested that in the case of an implementation, the SHA-1 algorithm is taken due to the amount of information and data available from the Civil Registry of Ecuador; It is determined that the SHA-1 algorithm that was defined using the flowchart technique can be modified according to the requirements of each institution; the model for adopting the hash algorithm in a conceptual model is a prototype that can be modified according to all the actors that make up each organization.

Learning binary code via PCA of angle projection for image retrieval

NASA Astrophysics Data System (ADS)

Yang, Fumeng; Ye, Zhiqiang; Wei, Xueqi; Wu, Congzhong

2018-01-01

With benefits of low storage costs and high query speeds, binary code representation methods are widely researched for efficiently retrieving large-scale data. In image hashing method, learning hashing function to embed highdimensions feature to Hamming space is a key step for accuracy retrieval. Principal component analysis (PCA) technical is widely used in compact hashing methods, and most these hashing methods adopt PCA projection functions to project the original data into several dimensions of real values, and then each of these projected dimensions is quantized into one bit by thresholding. The variances of different projected dimensions are different, and with real-valued projection produced more quantization error. To avoid the real-valued projection with large quantization error, in this paper we proposed to use Cosine similarity projection for each dimensions, the angle projection can keep the original structure and more compact with the Cosine-valued. We used our method combined the ITQ hashing algorithm, and the extensive experiments on the public CIFAR-10 and Caltech-256 datasets validate the effectiveness of the proposed method.

Spectroscopic observation of Gaia17dht and Gaia17diu by NUTS (NOT Un-biased Transient Survey)

NASA Astrophysics Data System (ADS)

Fraser, M.; Dyrbye, S.; Cappella, E.

2017-12-01

The Nordic Optical Telescope (NOT) Unbiased Transient Survey (NUTS; ATel #8992) reports the spectroscopic classification of Gaia17dht/SN2017izz and Gaia17diu/SN2017jdb (in host galaxies SDSS J145121.24+283521.6 and LEDA 2753585 respectively).

Data Collision Prevention with Overflow Hashing Technique in Closed Hash Searching Process

NASA Astrophysics Data System (ADS)

Rahim, Robbi; Nurjamiyah; Rafika Dewi, Arie

2017-12-01

Hash search is a method that can be used for various search processes such as search engines, sorting, machine learning, neural network and so on, in the search process the possibility of collision data can happen and to prevent the occurrence of collision can be done in several ways one of them is to use Overflow technique, the use of this technique perform with varying length of data and this technique can prevent the occurrence of data collisions.

9 CFR 319.303 - Corned beef hash.

Code of Federal Regulations, 2010 CFR

2010-01-01

... combination, are salt, sugar (sucrose or dextrose), spice, and flavoring, including essential oils, oleoresins, and other spice extractives. (b) Corned beef hash may contain one or more of the following optional...

Toward Optimal Manifold Hashing via Discrete Locally Linear Embedding.

PubMed

Rongrong Ji; Hong Liu; Liujuan Cao; Di Liu; Yongjian Wu; Feiyue Huang

2017-11-01

Binary code learning, also known as hashing, has received increasing attention in large-scale visual search. By transforming high-dimensional features to binary codes, the original Euclidean distance is approximated via Hamming distance. More recently, it is advocated that it is the manifold distance, rather than the Euclidean distance, that should be preserved in the Hamming space. However, it retains as an open problem to directly preserve the manifold structure by hashing. In particular, it first needs to build the local linear embedding in the original feature space, and then quantize such embedding to binary codes. Such a two-step coding is problematic and less optimized. Besides, the off-line learning is extremely time and memory consuming, which needs to calculate the similarity matrix of the original data. In this paper, we propose a novel hashing algorithm, termed discrete locality linear embedding hashing (DLLH), which well addresses the above challenges. The DLLH directly reconstructs the manifold structure in the Hamming space, which learns optimal hash codes to maintain the local linear relationship of data points. To learn discrete locally linear embeddingcodes, we further propose a discrete optimization algorithm with an iterative parameters updating scheme. Moreover, an anchor-based acceleration scheme, termed Anchor-DLLH, is further introduced, which approximates the large similarity matrix by the product of two low-rank matrices. Experimental results on three widely used benchmark data sets, i.e., CIFAR10, NUS-WIDE, and YouTube Face, have shown superior performance of the proposed DLLH over the state-of-the-art approaches.

Gene function prediction based on Gene Ontology Hierarchy Preserving Hashing.

PubMed

Zhao, Yingwen; Fu, Guangyuan; Wang, Jun; Guo, Maozu; Yu, Guoxian

2018-02-23

Gene Ontology (GO) uses structured vocabularies (or terms) to describe the molecular functions, biological roles, and cellular locations of gene products in a hierarchical ontology. GO annotations associate genes with GO terms and indicate the given gene products carrying out the biological functions described by the relevant terms. However, predicting correct GO annotations for genes from a massive set of GO terms as defined by GO is a difficult challenge. To combat with this challenge, we introduce a Gene Ontology Hierarchy Preserving Hashing (HPHash) based semantic method for gene function prediction. HPHash firstly measures the taxonomic similarity between GO terms. It then uses a hierarchy preserving hashing technique to keep the hierarchical order between GO terms, and to optimize a series of hashing functions to encode massive GO terms via compact binary codes. After that, HPHash utilizes these hashing functions to project the gene-term association matrix into a low-dimensional one and performs semantic similarity based gene function prediction in the low-dimensional space. Experimental results on three model species (Homo sapiens, Mus musculus and Rattus norvegicus) for interspecies gene function prediction show that HPHash performs better than other related approaches and it is robust to the number of hash functions. In addition, we also take HPHash as a plugin for BLAST based gene function prediction. From the experimental results, HPHash again significantly improves the prediction performance. The codes of HPHash are available at: http://mlda.swu.edu.cn/codes.php?name=HPHash. Copyright © 2018 Elsevier Inc. All rights reserved.

Developmental Programming

PubMed Central

Veiga-Lopez, A.; Wurst, A. K.; Steckler, T. L.; Ye, W.

2014-01-01

Excess of prenatal testosterone (T) induces reproductive defects including follicular persistence. Comparative studies with T and dihydrotestosterone (DHT) have suggested that follicular persistence is programmed via estrogenic actions of T. This study addresses the androgenic and estrogenic contributions in programming follicular persistence. Because humans are exposed to estrogenic environmental steroids from various sources throughout their life span and postnatal insults may also induce organizational and/or activational changes, we tested whether continuous postnatal exposure to estradiol (E) will amplify effects of prenatal steroids on ovarian function. Pregnant sheep were treated with T, DHT, E, or ED (E and DHT) from days 30 to 90 of gestation. Postnatally, a subset of the vehicle (C), T, and DHT females received an E implant. Transrectal ultrasonography was performed in the first breeding season during a synchronized cycle to monitor ovarian follicular dynamics. As expected, number of ≥8 mm follicles was higher in the T versus C group. Postnatal E reduced the number of 4 to 8 mm follicles in the DHT group. Percentage of females bearing luteinized follicles and the number of luteinized follicles differed among prenatal groups. Postnatal E increased the incidence of subluteal cycles in the prenatal T-treated females. Findings from this study confirm previous findings of divergences in programming effects of prenatal androgens and estrogens. They also indicate that some aspects of follicular dynamics are subject to postnatal modulation as well as support the existence of an extended organizational period or the need for a second insult to uncover the previously programmed event. PMID:24077439

Mitochondrial redox signaling by p66Shc is involved in regulating androgenic growth stimulation of human prostate cancer cells

PubMed Central

Veeramani, S; Yuan, T-C; Lin, F-F; Lin, M-F

2009-01-01

p66Shc is shown to negatively regulate the life span in mice through reactive oxygen species (ROS) production. Recent reports, however, revealed that p66Shc protein level is significantly elevated in several human cancer tissues and growth-stimulated carcinoma cells, suggesting a mitogenic and carcinogenic role for p66Shc. In this communication, we demonstrate for the first time that p66Shc mediates androgenic growth signals in androgen-sensitive human prostate cancer cells through mitochondrial ROS production. Growth stimulation of prostate cancer cells with 5α-dihydrotestosterone (DHT) is accompanied by increased p66Shc level and ROS production, which is abolished by antioxidant treatments. However, antioxidant treatments do not affect the transcriptional activity of androgen receptor (AR) as observed by its inability to block DHT-induced prostate-specific antigen expression, an AR-dependent correlate of prostate cancer progression. Elevated expression of p66Shc by cDNA transfection increases the basal cell proliferation and, thus, reduces additional DHT-induced cell proliferation. Furthermore, DHT increases the translocation of p66Shc into mitochondria and its interaction with cytochrome c. Conversely, both redox-negative p66Shc mutant (W134F), which is deficient in cytochrome c interaction, and p66Shc small interfering RNA decrease DHT-induced cell proliferation. These results collectively reveal a novel role for p66Shc–ROS pathway in androgen-induced prostate cancer cell proliferation and, thus, may play a role in early prostate carcinogenesis. PMID:18504439

Dihydrotestosterone stimulates amino acid uptake and the expression of LAT2 in mouse skeletal muscle fibres through an ERK1/2-dependent mechanism

PubMed Central

Hamdi, M M; Mutungi, G

2011-01-01

Abstract Dihydrotestosterone (DHT) has acute/non-genomic actions in adult mammalian skeletal muscles whose physiological functions are still poorly understood. Therefore, the primary aim of this study was to investigate the acute/non-genomic effects of DHT on amino acid uptake as well as the cellular signal transduction events underlying these actions in mouse fast- and slow-twitch skeletal muscle fibre bundles. 14C-Labelled amino acids were used to investigate the effects of DHT and testosterone (T) on amino acid uptake and pharmacological interventions were used to determine the cellular signal transduction events mediating these actions. While T had no effect on the uptake of isoleucine (Ile) and α-methylaminoisobutyric acid (MeAIB) in both fibre types, DHT increased their uptake in the fast-twitch fibre bundles. This effect was reversed by inhibitors of protein translation, the epidermal growth factor receptor (EGFR), system A, system L, mTOR and MEK. However, it was relatively insensitive to inhibitors of transcription, androgen receptors and PI3K/Akt. Additionally, DHT treatment increased the expression of LAT2 and the phosphorylation of the EGFR in the fast-twitch fibre bundles and that of ERK1/2, RSK1/2 and ATF2 in both fibre types. Also, it decreased the phosphorylation of eEF2 and increased the incorporation of Ile into proteins in both fibre types. Most of these effects were reversed by EGFR and MEK inhibitors. From these findings we suggest that another physiological function of the acute/non-genomic actions of DHT in isolated mammalian skeletal muscle fibres is to stimulate amino acid uptake. This effect is mediated through the EGFR and involves the activation of the MAPK pathway and an increase in LAT2 expression. PMID:21606113

Ginsenoside F2 reduces hair loss by controlling apoptosis through the sterol regulatory element-binding protein cleavage activating protein and transforming growth factor-β pathways in a dihydrotestosterone-induced mouse model.

PubMed

Shin, Heon-Sub; Park, Sang-Yong; Hwang, Eun-Son; Lee, Don-Gil; Mavlonov, Gafurjon Turdalievich; Yi, Tae-Hoo

2014-01-01

This study was conducted to test whether ginsenoside F2 can reduce hair loss by influencing sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP) and the transforming growth factor beta (TGF-β) pathway of apoptosis in dihydrotestosterone (DHT)-treated hair cells and in a DHT-induced hair loss model in mice. Results for ginsenoside F2 were compared with finasteride. DHT inhibits proliferation of hair cells and induces androgenetic alopecia and was shown to activate an apoptosis signal pathway both in vitro and in vivo. The cell-based 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the proliferation rates of DHT-treated human hair dermal papilla cells (HHDPCs) and HaCaTs increased by 48% in the ginsenoside F2-treated group and by 12% in the finasteride-treated group. Western blot analysis showed that ginsenoside F2 decreased expression of TGF-β2 related factors involved in hair loss. The present study suggested a hair loss related pathway by changing SCAP related apoptosis pathway, which has been known to control cholesterol metabolism. SCAP, sterol regulatory element-binding protein (SREBP) and caspase-12 expression in the ginsenoside F2-treated group were decreased compared to the DHT and finasteride-treated group. C57BL/6 mice were also prepared by injection with DHT and then treated with ginsenoside F2 or finasteride. Hair growth rate, density, thickness measurements and tissue histotological analysis in these groups suggested that ginsenoside F2 suppressed hair cell apoptosis and premature entry to catagen more effectively than finasteride. Our results indicated that ginsenoside F2 decreased the expression of TGF-β2 and SCAP proteins, which have been suggested to be involved in apoptosis and entry into catagen. This study provides evidence those factors in the SCAP pathway could be targets for hair loss prevention drugs.

Characterization of 5α-reductase activity and isoenzymes in human abdominal adipose tissues.

PubMed

Fouad Mansour, Mohamed; Pelletier, Mélissa; Tchernof, André

2016-07-01

The substrate for the generation of 5α-dihydrotestosterone (DHT) is either androstenedione (4-dione) which is first converted to androstanedione and then to DHT through 17-oxoreductase activity, or testosterone, which is directly converted to DHT. Three 5α-reductase isoenzymes have been characterized and designated as types 1, 2 and 3 (SRD5A1, 2 and 3). To define the predominant source of local DHT production in human adipose tissues, identify 5α-reductase isoenzymes and test their impact on preadipocyte differentiation. Cultures of omental (OM) and subcutaneous (SC) preadipocytes were treated for 0, 6 or 24h with 30nM (14)C-4-dione or (14)C-testosterone, with and without 500nM 5α-reductase inhibitors 17-N,N-diethylcarbamoyl-4-methyl-4-aza-5-androstan-3-one (4-MA) or finasteride. Protein level and mRNA abundance of 5α-reductase isoenzymes/transcripts were examined in whole SC and OM adipose tissue. HEK-293 cells stably transfected with 5α-reductase type 1, 2 or 3 were used to test 5α-reductase inhibitors. We also assessed the impact of 5α-reductase inhibitors on preadipocyte differentiation. Over 24h, DHT formation from 4-dione increased gradually (p<0.05) and was significantly higher compared to that generated from testosterone (p<0.001). DHT formation from both 4-dione and testosterone was blocked by both 5α-reductase inhibitors. In whole adipose tissue from both fat compartments, SRD5A3 was the most highly expressed isoenzyme followed by SRD5A1 (p<0.001). SRD5A2 was not expressed. In HEK-293 cells, 4-MA and finasteride inhibited activity of 5α-reductases types 2 and 3 but not type 1. In preadipocyte cultures where differentiation was inhibited by 4-dione (p<0.05, n=7) or testosterone (p<0.05, n=5), the inhibitors 4-MA and finasteride abolished these effects. Although 4-dione is the main source of DHT in human preadipocytes, production of this steroid by 5α-reductase isoenzymes mediates the inhibitory effect of both 4-dione and testosterone on preadipocyte differentiation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison between testosterone enanthate-induced azoospermia and oligozoospermia in a male contraceptive study. III. Higher 5 alpha-reductase activity in oligozoospermic men administered supraphysiological doses of testosterone.

PubMed

Anderson, R A; Wallace, A M; Wu, F C

1996-03-01

The administration of exogenous testosterone (T) to eugonadal men causes suppression of gonadotropin secretion and thus of spermatogenesis. This is currently being investigated as a possible method of hormonal male contraceptive, but complete suppression of spermatogenesis to azoospermia is induced in only 50-70% of Caucasian men; the remainder maintain a low rate of spermatogenesis. The basis for this polymorphism in response is unclear. The enzyme 5 alpha-reductase (5 alpha R) converts T to dihydrotestosterone (DHT) and is important in determining the magnitude of the androgen stimulus in some tissues. We investigated whether the maintenance of spermatogenesis in men remaining oligozoospermic while receiving suppressive doses of T is associated with evidence of increased 5 alpha R activity. Thirty-three normal men were given 200 mg T enanthate (TE), im, weekly in a clinical trial of hormonal male contraception. The MCR of T (MCRT) and the conversion ratio of T to DHT (CRT-DHT) were measured by infusion of [3H]T, plasma levels of DHT and androstanediol glucuronide (AdiolG) were measured by RIA, and 24-h urinary steroid metabolites were measured by capillary column gas chromatography. Sperm density decreased in all men; 18 achieved azoospermia by 20 weeks of treatment, and the remainder had a mean sperm density of 2.0 +/- 0.8 x 10(5)/mL at that time. This treatment caused increases in plasma T levels and MCRT, but with no differences between azoospermic and oligozoospermic responders. There were no differences in CRT-DHT plasma DHT, or AdiolG before treatment, but after 16 weeks, CRT-DHT had increased in the oligozoospermic responders, but not in the azoospermic responders. TE treatment increased plasma DHT and AdiolG levels in both groups, but the increases in both 5 alpha R metabolites were significantly greater in the oligozoospermic responders. Urinary excretion of etiocholanolone and androsterone was increased after 16 weeks of TE treatment, but did not differ between the two groups, andetiocholanolone/androsterone ratios did not differ greatly from unity. There was no change in urinary excretion of tetrahydrocortisol, allo-tetrahydrocortisol, or cortisone after 16 weeks of TE treatment in either group. These results suggest that after TE administration there is a selective increase in 5 alpha R activity in those men who remain oligozoospermic, but not in those becoming azoospermic. This difference in the androgenic milieu may underlie the incomplete suppression in the oligozoospermic responders, in whom a low rate of spermatogenesis is maintained despite the apparent absence of gonadotropins.

Self-Supervised Video Hashing With Hierarchical Binary Auto-Encoder.

PubMed

Song, Jingkuan; Zhang, Hanwang; Li, Xiangpeng; Gao, Lianli; Wang, Meng; Hong, Richang

2018-07-01

Existing video hash functions are built on three isolated stages: frame pooling, relaxed learning, and binarization, which have not adequately explored the temporal order of video frames in a joint binary optimization model, resulting in severe information loss. In this paper, we propose a novel unsupervised video hashing framework dubbed self-supervised video hashing (SSVH), which is able to capture the temporal nature of videos in an end-to-end learning to hash fashion. We specifically address two central problems: 1) how to design an encoder-decoder architecture to generate binary codes for videos and 2) how to equip the binary codes with the ability of accurate video retrieval. We design a hierarchical binary auto-encoder to model the temporal dependencies in videos with multiple granularities, and embed the videos into binary codes with less computations than the stacked architecture. Then, we encourage the binary codes to simultaneously reconstruct the visual content and neighborhood structure of the videos. Experiments on two real-world data sets show that our SSVH method can significantly outperform the state-of-the-art methods and achieve the current best performance on the task of unsupervised video retrieval.

Self-Supervised Video Hashing With Hierarchical Binary Auto-Encoder

NASA Astrophysics Data System (ADS)

Song, Jingkuan; Zhang, Hanwang; Li, Xiangpeng; Gao, Lianli; Wang, Meng; Hong, Richang

2018-07-01

Existing video hash functions are built on three isolated stages: frame pooling, relaxed learning, and binarization, which have not adequately explored the temporal order of video frames in a joint binary optimization model, resulting in severe information loss. In this paper, we propose a novel unsupervised video hashing framework dubbed Self-Supervised Video Hashing (SSVH), that is able to capture the temporal nature of videos in an end-to-end learning-to-hash fashion. We specifically address two central problems: 1) how to design an encoder-decoder architecture to generate binary codes for videos; and 2) how to equip the binary codes with the ability of accurate video retrieval. We design a hierarchical binary autoencoder to model the temporal dependencies in videos with multiple granularities, and embed the videos into binary codes with less computations than the stacked architecture. Then, we encourage the binary codes to simultaneously reconstruct the visual content and neighborhood structure of the videos. Experiments on two real-world datasets (FCVID and YFCC) show that our SSVH method can significantly outperform the state-of-the-art methods and achieve the currently best performance on the task of unsupervised video retrieval.

Enhanced K-means clustering with encryption on cloud

NASA Astrophysics Data System (ADS)

Singh, Iqjot; Dwivedi, Prerna; Gupta, Taru; Shynu, P. G.

2017-11-01

This paper tries to solve the problem of storing and managing big files over cloud by implementing hashing on Hadoop in big-data and ensure security while uploading and downloading files. Cloud computing is a term that emphasis on sharing data and facilitates to share infrastructure and resources.[10] Hadoop is an open source software that gives us access to store and manage big files according to our needs on cloud. K-means clustering algorithm is an algorithm used to calculate distance between the centroid of the cluster and the data points. Hashing is a algorithm in which we are storing and retrieving data with hash keys. The hashing algorithm is called as hash function which is used to portray the original data and later to fetch the data stored at the specific key. [17] Encryption is a process to transform electronic data into non readable form known as cipher text. Decryption is the opposite process of encryption, it transforms the cipher text into plain text that the end user can read and understand well. For encryption and decryption we are using Symmetric key cryptographic algorithm. In symmetric key cryptography are using DES algorithm for a secure storage of the files. [3

Discriminative Projection Selection Based Face Image Hashing

NASA Astrophysics Data System (ADS)

Karabat, Cagatay; Erdogan, Hakan

Face image hashing is an emerging method used in biometric verification systems. In this paper, we propose a novel face image hashing method based on a new technique called discriminative projection selection. We apply the Fisher criterion for selecting the rows of a random projection matrix in a user-dependent fashion. Moreover, another contribution of this paper is to employ a bimodal Gaussian mixture model at the quantization step. Our simulation results on three different databases demonstrate that the proposed method has superior performance in comparison to previously proposed random projection based methods.

Novel structures for Discrete Hartley Transform based on first-order moments

NASA Astrophysics Data System (ADS)

Xiong, Jun; Zheng, Wenjuan; Wang, Hao; Liu, Jianguo

2018-03-01

Discrete Hartley Transform (DHT) is an important tool in digital signal processing. In the present paper, the DHT is firstly transformed into the first-order moments-based form, then a new fast algorithm is proposed to calculate the first-order moments without multiplication. Based on the algorithm theory, the corresponding hardware architecture for DHT is proposed, which only contains shift operations and additions with no need for multipliers and large memory. To verify the availability and effectiveness, the proposed design is implemented with hardware description language and synthesized by Synopsys Design Compiler with 0.18-μm SMIC library. A series of experiments have proved that the proposed architecture has better performance in terms of the product of the hardware consumption and computation time.

Theory and operational rules for the discrete Hankel transform.

PubMed

Baddour, Natalie; Chouinard, Ugo

2015-04-01

Previous definitions of a discrete Hankel transform (DHT) have focused on methods to approximate the continuous Hankel integral transform. In this paper, we propose and evaluate the theory of a DHT that is shown to arise from a discretization scheme based on the theory of Fourier-Bessel expansions. The proposed transform also possesses requisite orthogonality properties which lead to invertibility of the transform. The standard set of shift, modulation, multiplication, and convolution rules are derived. In addition to the theory of the actual manipulated quantities which stand in their own right, this DHT can be used to approximate the continuous forward and inverse Hankel transform in the same manner that the discrete Fourier transform is known to be able to approximate the continuous Fourier transform.

Changes in Benthos Associated with Mussel (Mytilus edulis L.) Farms on the West-Coast of Scotland

PubMed Central

Wilding, Thomas A.; Nickell, Thomas D.

2013-01-01

Aquaculture, as a means of food production, is growing rapidly in response to an increasing demand for protein and the over-exploitation of wild fisheries. This expansion includes mussels (family Mytilidae) where production currently stands at 1.5 million tonnes per annum. Mussel culture is frequently perceived as having little environmental impact yet mussel biodeposits and shell debris accumulate around the production site and are linked to changes in the benthos. To assess the extent and nature of changes in benthos associated with mussel farming grab and video sampling around seven mussel farms was conducted. Grab samples were analysed for macrofauna and shell-hash content whilst starfish were counted and the shell-hash cover estimated from video imaging. Shell-hash was patchily distributed and occasionally dominated sediments (maximum of 2116 g per 0.1 m2 grab). Mean shell-hash content decreased rapidly at distances >5 m from the line and, over the distance 1–64 m, decreased by three orders of magnitude. The presence of shell-hash and the distance-from-line influenced macrofaunal assemblages but this effect differed between sites. There was no evidence that mussel farming was associated with changes in macrobenthic diversity, species count or feeding strategy. However, total macrofaunal count was estimated to be 2.5 times higher in close proximity to the lines, compared with 64 m distance, and there was evidence that this effect was conditional on the presence of shell-hash. Starfish density varied considerably between sites but, overall, they were approximately 10 times as abundant close to the mussel-lines compared with 64 m distance. There was no evidence that starfish were more abundant in the presence of shell-hash visible on the sediment surface. In terms of farm-scale benthic impacts these data suggest that mussel farming is a relatively benign way of producing food, compared with intensive fish-farming, in similar environments. PMID:23874583

Building Application-Related Patient Identifiers: What Solution for a European Country?

PubMed Central

Quantin, Catherine; Allaert, François-André; Avillach, Paul; Fassa, Maniane; Riandey, Benoît; Trouessin, Gilles; Cohen, Olivier

2008-01-01

We propose a method utilizing a derived social security number with the same reliability as the social security number. We show the anonymity techniques classically based on unidirectional hash functions (such as the secure hash algorithm (SHA-2) function that can guarantee the security, quality, and reliability of information if these techniques are applied to the Social Security Number). Hashing produces a strictly anonymous code that is always the same for a given individual, and thus enables patient data to be linked. Different solutions are developed and proposed in this article. Hashing the social security number will make it possible to link the information in the personal medical file to other national health information sources with the aim of completing or validating the personal medical record or conducting epidemiological and clinical research. This data linkage would meet the anonymous data requirements of the European directive on data protection. PMID:18401447

Exploiting the HASH Planetary Nebula Research Platform

NASA Astrophysics Data System (ADS)

Parker, Quentin A.; Bojičić, Ivan; Frew, David J.

2017-10-01

The HASH (Hong Kong/ AAO/ Strasbourg/ Hα) planetary nebula research platform is a unique data repository with a graphical interface and SQL capability that offers the community powerful, new ways to undertake Galactic PN studies. HASH currently contains multi-wavelength images, spectra, positions, sizes, morphologies and other data whenever available for 2401 true, 447 likely, and 692 possible Galactic PNe, for a total of 3540 objects. An additional 620 Galactic post-AGB stars, pre-PNe, and PPN candidates are included. All objects were classified and evaluated following the precepts and procedures established and developed by our group over the last 15 years. The complete database contains over 6,700 Galactic objects including the many mimics and related phenomena previously mistaken or confused with PNe. Curation and updating currently occurs on a weekly basis to keep the repository as up to date as possible until the official release of HASH v1 planned in the near future.

Comparison of Grouping Methods for Template Extraction from VA Medical Record Text.

PubMed

Redd, Andrew M; Gundlapalli, Adi V; Divita, Guy; Tran, Le-Thuy; Pettey, Warren B P; Samore, Matthew H

2017-01-01

We investigate options for grouping templates for the purpose of template identification and extraction from electronic medical records. We sampled a corpus of 1000 documents originating from Veterans Health Administration (VA) electronic medical record. We grouped documents through hashing and binning tokens (Hashed) as well as by the top 5% of tokens identified as important through the term frequency inverse document frequency metric (TF-IDF). We then compared the approaches on the number of groups with 3 or more and the resulting longest common subsequences (LCSs) common to all documents in the group. We found that the Hashed method had a higher success rate for finding LCSs, and longer LCSs than the TF-IDF method, however the TF-IDF approach found more groups than the Hashed and subsequently more long sequences, however the average length of LCSs were lower. In conclusion, each algorithm appears to have areas where it appears to be superior.

Inhibition of 5α-Reductase in Rat Prostate Reveals Differential Regulation of Androgen-Response Gene Expression by Testosterone and Dihydrotestosterone

PubMed Central

Dadras, Soheil S.; Cai, Xiaoyan; Abasolo, Ibane; Wang, Zhou

2001-01-01

The growth and development of some of the male sex accessory organs such as the prostate requires the conversion of testosterone to dihydrotestosterone (DHT) by 5α-reductase. To provide insights into the role of testosterone versus DHT in the prostate, we studied the impact of finasteride, a potent and specific inhibitor of 5α-reductase, on the expression of prostatic androgen-response genes in testis-intact rats and in 7-day castrated rats. Finasteride inhibition of the conversion of testosterone to DHT was confirmed by measuring serum and intraprostatic androgens. As expected, finasteride treatment caused a reduction in the wet weight of the prostate in the testis-intact rats and inhibited the testosterone-stimulated prostatic regrowth in the 7-day castrated rats. Although finasteride treatment had little or no effect on the expression of the surveyed androgen-response genes in testis-intact rats, its administration enhanced the expression of many androgen-response genes during the testosterone-stimulated regrowth of the regressed prostate in castrated rats. These observations suggest that testosterone is more potent than DHT in stimulating the expression of many androgen-response genes in the regressed prostate. The expression of androgen-response genes is mainly prostate specific and thus is likely to be associated with androgen-dependent prostatic differentiation. Therefore, testosterone is more potent than DHT in inducing differentiation and weaker in stimulating proliferation during prostate regrowth. The fact that testosterone is a strong inducer of prostatic differentiation has potential clinical implications. PMID:11444528

Developmental programming: postnatal estradiol amplifies ovarian follicular defects induced by fetal exposure to excess testosterone and dihydrotestosterone in sheep.

PubMed

Veiga-Lopez, A; Wurst, A K; Steckler, T L; Ye, W; Padmanabhan, V

2014-04-01

Excess of prenatal testosterone (T) induces reproductive defects including follicular persistence. Comparative studies with T and dihydrotestosterone (DHT) have suggested that follicular persistence is programmed via estrogenic actions of T. This study addresses the androgenic and estrogenic contributions in programming follicular persistence. Because humans are exposed to estrogenic environmental steroids from various sources throughout their life span and postnatal insults may also induce organizational and/or activational changes, we tested whether continuous postnatal exposure to estradiol (E) will amplify effects of prenatal steroids on ovarian function. Pregnant sheep were treated with T, DHT, E, or ED (E and DHT) from days 30 to 90 of gestation. Postnatally, a subset of the vehicle (C), T, and DHT females received an E implant. Transrectal ultrasonography was performed in the first breeding season during a synchronized cycle to monitor ovarian follicular dynamics. As expected, number of ≥8 mm follicles was higher in the T versus C group. Postnatal E reduced the number of 4 to 8 mm follicles in the DHT group. Percentage of females bearing luteinized follicles and the number of luteinized follicles differed among prenatal groups. Postnatal E increased the incidence of subluteal cycles in the prenatal T-treated females. Findings from this study confirm previous findings of divergences in programming effects of prenatal androgens and estrogens. They also indicate that some aspects of follicular dynamics are subject to postnatal modulation as well as support the existence of an extended organizational period or the need for a second insult to uncover the previously programmed event.

Androgen-androgen receptor system improves chronic inflammatory conditions by suppressing monocyte chemoattractant protein-1 gene expression in adipocytes via transcriptional regulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morooka, Nobukatsu, E-mail: amorooka@gunma-u.ac.jp; Ueguri, Kei; Yee, Karen Kar Lye

Age-related decreases in sex hormones are closely related to chronic inflammation in obesity and metabolic diseases. Particularly, the molecular basis of androgen activity in regulating inflammation and controlling metabolism remains largely unknown. Obese adipocytes secrete monocyte chemoattractant protein-1 (MCP-1), a key chemokine that promotes the infiltration of monocytes/macrophages into adipose tissue, thereby leading to metabolic disorders. Here, we studied the role of androgen-androgen receptor (AR) action in regulating MCP-1 expression in adipose tissue. We observed the induction of Mcp-1 expression in 3T3-L1 adipocytes co-cultured with RAW264.7 macrophages. Additionally, Mcp-1 expression was upregulated by culturing in conditioned medium derived from inflammatorymore » macrophages (M1-Mφ) containing tumor necrosis factor-alpha (TNF-α). We found that sex hormones downregulated TNF-α-induced Mcp-1 and interleukin (Il)-6 expression in 3T3-L1 adipocytes. Furthermore, luciferase-reporter analysis indicated that MCP-1 promoter activity was predominantly suppressed by dihydrotestosterone (DHT)-AR interactions through functional canonical nuclear factor-kappa B (NF-κB) sites, whereas non-canonical NF-κB site containing important flanking sequences exhibited minor contributions to DHT-AR transcriptional repression. These findings suggested that androgen-AR suppressed obesity-induced chronic inflammation in adipose tissue. - Highlights: • DHT, non-aromatizable androgen suppresses Mcp-1 expression in adipocytes. • Mcp-1 transcription was negatively regulated by DHT-AR action. • DHT-AR selectively regulates Mcp-1 transcription through distinct NF-κB sites.« less

Pattern recognition of estradiol, testosterone and dihydrotestosterone in children's saliva samples using stochastic microsensors

NASA Astrophysics Data System (ADS)

Staden, Raluca-Ioana Stefan-Van; Gugoaşă, Livia Alexandra; Calenic, Bogdan; Legler, Juliette

2014-07-01

Stochastic microsensors based on diamond paste and three types of electroactive materials (maltodextrin (MD), α-cyclodextrin (α-CD) and 5,10,15,20-tetraphenyl-21H,23H porphyrin (P)) were developed for the assay of estradiol (E2), testosterone (T2) and dihydrotestosterone (DHT) in children's saliva. The main advantage of utilization of such tools is the possibility to identify and quantify all three hormones within minutes in small volumes of childen's saliva. The limits of quantification obtained for DHT, T2, and E2 (1 fmol/L for DHT, 1 pmol/L for T2, and 66 fmol/L for E2) determined using the proposed tools allows the utilization of these new methods with high reliability for the screening of saliva samples from children. This new method proposed for the assay of the three hormones overcomes the limitations (regarding limits of determination) of ELISA method which is the standard method used in clinical laboratories for the assay of DHT, T2, and E2 in saliva samples. The main feature of its utilization for children's saliva is to identify earlier problems related to early puberty and obesity.

Potential prostate cancer drug target: bioactivation of androstanediol by conversion to dihydrotestosterone.

PubMed

Mohler, James L; Titus, Mark A; Wilson, Elizabeth M

2011-09-15

High-affinity binding of dihydrotestosterone (DHT) to the androgen receptor (AR) initiates androgen-dependent gene activation, required for normal male sex development in utero, and contributes to prostate cancer development and progression in men. Under normal physiologic conditions, DHT is synthesized predominantly by 5α-reduction of testosterone, the major circulating androgen produced by the testis. During androgen deprivation therapy, intratumoral androgen production is sufficient for AR activation and prostate cancer growth, even though circulating testicular androgen levels are low. Recent studies indicate that the metabolism of 5α-androstane-3α, 17β-diol by 17β-hydroxysteroid dehydrogenase 6 in benign prostate and prostate cancer cells is a major biosynthetic pathway for intratumoral synthesis of DHT, which binds AR and initiates transactivation to promote prostate cancer growth during androgen deprivation therapy. Drugs that target the so-called backdoor pathway of DHT synthesis provide an opportunity to enhance clinical response to luteinizing-hormone-releasing hormone (LHRH) agonists or antagonists, AR antagonists, and inhibitors of 5α-reductase enzymes (finasteride or dutasteride), and other steroid metabolism enzyme inhibitors (ketoconazole or the recently available abiraterone acetate). ©2011 AACR.

Phytotoxicity of 4,8-dihydroxy-1-tetralone isolated from Carya cathayensis Sarg. to various plant species.

PubMed

Li, Xian-Xian; Yu, Min-Feng; Ruan, Xiao; Zhang, Yu-Zhu; Wang, Qiang

2014-09-26

The aqueous extract from Carya cathayensis Sarg. exocarp was centrifuged, filtered, and separated into 11 elution fractions by X-5 macroporous resin chromatography. A phenolic compound, 4,8-dihydroxy-1-tetralone (4,8-DHT) was isolated from the fractions with the strongest phytotoxicity by bioassy-guided fractionation, and investigated for phytotoxicity on lettuce (Latuca sativa L.), radish (Raphanus sativus L.), cucumber (Cucumis sativus L.), onion (Allium cepa L.) and wheat (Triticum aestivum L.). The testing results showed that the treatment with 0.6 mM 4,8-DHT could significantly depress the germination vigor of lettuce and wheat, reduce the germination rate of lettuce and cucumber, and also inhibit radicle length, plumule length, and fresh weight of seedlings of lettuce and onion, but could significantly promote plumule length and fresh weight of seedlings of cucumber (p < 0.05). For the tested five plants, the 4,8-DHT was the most active to the seed germination and seedling growth of lettuce, indicating that the phytotoxicity of 4,8-DHT had the selectivity of dosage, action target (plant type) and content (seed germination or seedling growth).

Finasteride therapy does not alter bone turnover in men with benign prostatic hyperplasia--a Clinical Research Center study.

PubMed

Tollin, S R; Rosen, H N; Zurowski, K; Saltzman, B; Zeind, A J; Berg, S; Greenspan, S L

1996-03-01

Benign prostatic hyperplasia is often treated with finasteride, which inhibits the conversion of testosterone to dihydrotestosterone (DHT). Aside from the prostate, other androgen-dependent tissues seem to be unaffected by selective DHT deficiency, but the effect on bone density in humans has not yet been defined. To study this question, we compared indices of bone turnover and bone mineral density in 35 men treated with finasteride with controls. Bone resorption was assessed by measuring urinary excretion of N-telopeptide cross-links of type I collagen and hydroxyproline, and bone formation was assessed by measuring serum osteoncalcin and bone-specific alkaline phosphatase. Bone density of the spine and hip were assessed by dual energy x-ray absorptiometry. We found that finasteride-treated patients had mean DHT levels 81% lower than controls (P < 0.0001). There were no significant differences between the two groups in any of the markers of bone turnover or measures of bone density. These results suggest that testosterone can maintain bone density in men even in the absence of DHT. Although long term studies are needed, our results suggest that men who take finasteride are not at increased risk for bone loss.

Text image authenticating algorithm based on MD5-hash function and Henon map

NASA Astrophysics Data System (ADS)

Wei, Jinqiao; Wang, Ying; Ma, Xiaoxue

2017-07-01

In order to cater to the evidentiary requirements of the text image, this paper proposes a fragile watermarking algorithm based on Hash function and Henon map. The algorithm is to divide a text image into parts, get flippable pixels and nonflippable pixels of every lump according to PSD, generate watermark of non-flippable pixels with MD5-Hash, encrypt watermark with Henon map and select embedded blocks. The simulation results show that the algorithm with a good ability in tampering localization can be used to authenticate and forensics the authenticity and integrity of text images

Interactions between colour and synaesthetic colour: an effect of simultaneous colour contrast on synaesthetic colours.

PubMed

Nijboer, Tanja C W; Gebuis, Titia; te Pas, Susan F; van der Smagt, Maarten J

2011-01-01

We investigated whether simultaneous colour contrast affects the synaesthetic colour experience and normal colour percept in a similar manner. We simultaneously presented a target stimulus (i.e. grapheme) and a reference stimulus (i.e. hash). Either the grapheme or the hash was presented on a saturated background of the same or opposite colour category as the synaesthetic colour and the other stimulus on a grey background. In both conditions, grapheme-colour synaesthetes were asked to colour the hash in a colour similar to the synaesthetic colour of the grapheme. Controls that were pair-matched to the synaesthetes performed the same experiment, but for them, the grapheme was presented in the colour induced by the grapheme in synaesthetes. When graphemes were presented on a grey and the hash on a coloured background, a traditional simultaneous colour-contrast effect was found for controls as well as synaesthetes. When graphemes were presented on colour and the hash on grey, the controls again showed a traditional simultaneous colour-contrast effect, whereas the synaesthetes showed the opposite effect. Our results show that synaesthetic colour experiences differ from normal colour perception; both are susceptible to different surrounding colours, but not in a comparable manner. Copyright © 2010 Elsevier Ltd. All rights reserved.

Epidemiological and Mendelian Randomization Studies of Dihydrotestosterone and Estradiol and Leukocyte Telomere Length in Men.

PubMed

Yeap, Bu B; Knuiman, Matthew W; Divitini, Mark L; Hui, Jennie; Arscott, Gillian M; Handelsman, David J; McLennan, Susan V; Twigg, Stephen M; McQuillan, Brendan; Hung, Joseph; Beilby, John P

2016-03-01

Advancing age is accompanied by an accumulation of ill health and shortening of chromosomal telomeres signifying biological aging. T is metabolized to DHT by 5α-reductase (SRD5A2) and to estradiol (E2) by aromatase (CYP19A1). Telomerase preserves telomeres, and T and E2 regulate telomerase expression and activity in vitro. The objective of the study was to establish whether circulating T or its metabolites, DHT or E2, and single-nucleotide polymorphisms in SRD5A2 or CYP19A1 associate with leucocyte telomere length (LTL) in men. Early-morning serum T, DHT, and E2 were assayed using mass spectrometry, and SRD5A2 and CYP19A1 single-nucleotide polymorphisms and LTL analyzed by PCR in 980 men from the Western Australian Busselton Health Survey who participated in the study. LTL was expressed as the T/S ratio. Men were aged (mean ± SD) 53.7 ± 15.6 years. LTL decreased linearly with age, from the T/S ratio of 1.89 ± 0.41 at younger than 30 years to 1.50 ± 0.49 at 70 to younger than 80 years (r = -0.225, P < .0001). After adjustment for age, DHT and E2 were positively correlated with LTL (DHT, r = 0.069, P = .030; E2, r = 0.068, P = .034). The SRD5A2 rs9282858 polymorphism was associated with serum DHT but not with LTL. Three dominant alleles of CYP19A1 were each associated with lower serum E2 and shorter LTL: rs2899470 T (E2, 59.3 vs 68.6 pmol/L, P < .0001; T/S ratio, 1.54 vs 1.62, P = .045), rs10046 C (60.5 vs 68.1 pmol/L, P = .0005, 1.54 vs 1.62, P = .035), and rs700518 A (59.9 vs 68.9 pmol/L, P < .0001, 1.54 vs 1.63, P = .020). A single-copy haplotype C/T/I/A/T rs10046/rs2899470/rs11575899/rs700518/rs17703883 (52% prevalence) was associated with both lower E2 and shorter LTL. In men, serum DHT and E2 correlate with LTL independently of age. Aromatase gene polymorphisms include three dominant alleles that are associated with both lower serum E2 and shorter LTL. E2 influences telomere length in vivo, thus warranting further studies to examine whether hormonal interventions might slow biological aging in men.

Paleointensity study of the historical andesitic lava flows: LTD-DHT Shaw and Thellier paleointensities from the Sakurajima 1914 and 1946 lavas in Japan

NASA Astrophysics Data System (ADS)

Yamamoto, Y.; Hoshi, H.

2005-12-01

Correct determination of absolute paleointensities is essential to investigate past geomagnetic field. There are two types of methods to obtain the paleointensities: the Thellier-type and Shaw-type methods. Many paleomagnetists have so far regarded the former method as reliable. However, there are increasing evidences that it is sometimes not robust for basaltic lavas resulting in systematic high paleointensities (e.g. Calvo et al., 2002; Yamamoto et al., 2003). Alternatively, the double heating technique of the Shaw method combined with low temperature demagnetization (LTD-DHT Shaw method; Tsunakawa et al., 1997; Yamamoto et al., 2003), a lately developed paleointensity technique in Japan, can yield reliable answers even from such basaltic samples (e.g. Yamamoto et al., 2003; Mochizuki et al., 2004; Oishi et al., 2005). In the Japanese archipelago, there are not only basaltic lavas but also andesitic lavas. They are important candidates of the absolute paleointensity determination in Japan. For a case study, we sampled oriented paleomagnetic cores from three sites of the Sakurajima 1914 (TS01 and TS02) and 1946 (SW01) lavas in Japan. Several rock magnetic experiments revealed that main magnetic carriers of the present samples are titanomagnetites with Curie temperatures of about 300-550 C, and that high temperature oxidation progresses in the order of SW01, TS01 and TS02. The LTD-DHT Shaw and Coe-Thellier experiments were conducted on 72 and 63 specimens, respectively. They gave 64 and 60 successful determinations. If the results are normalized by expected field intensities calculated from IGRF-9 (Macmillan et al., 2003) and grouped into LTD-DHT Shaw and Thellier datasets, their averages and standard deviations (1 sigma) resulted in 0.98+/-0.11 (LTD-DHT Shaw) and 1.13+/-0.13 (Thellier). Considering the standard deviations, we can say that both paleointensity methods recovered correct geomagnetic field. However, it is apparent that the LTD-DHT Shaw method has higher reliability than the Thellier method.

Long-term outcome and health-related quality of life in benign paroxysmal positional vertigo.

PubMed

Lopez-Escamez, Jose A; Gamiz, Maria J; Fernandez-Perez, Antonio; Gomez-Fiñana, Manuel

2005-06-01

A prospective cohort study was designed to evaluate the long-term outcome and health-related quality of life (HRQoL) in patients with posterior canal benign paroxysmal positional vertigo (PC-BPPV) treated by the particle repositioning maneuver (PRM) in the outpatient clinic of a general community hospital. Fifty individuals with PC-BPPV were included, and 45 (90%) completed the study. The diagnosis was based on the history of short episodes of vertigo and a positional nystagmus during the Dix-Hallpike test (DHT). All patients were treated by a single PRM, and relapses were evaluated by DHT at 30, 180 and 360 days post-treatment; a new PRM was performed if the DHT was positive. The main outcome measures were: percentage of patients with a negative DHT after treatment, scores obtained on the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) and the Dizziness Handicap Inventory Short Form (DHI-S) before and 30, 180 and 360 days post-treatment. The DHT was found negative in 80% (40/50) of individuals at 30 days. Ten, seven and five patients presented a positive DHT at 30, 180 and 360 days, respectively. Persistent BPPV was observed in 5% (2/50) of patients at 360 days, despite repeated PRM. Relapses (DH+ after successful PRM) were observed in 7.5% (3/50) at 180 days and 360 days. Both questionnaires showed a reliability Cronbach's alpha >0.7. The average standardized score for each SF-36 scale was compared with the reference population normative data, showing differences with norms for all scales except for vitality. After PRM, patients improved their scores with both instruments, indicating a restoration of HRQoL at 30 days. Physical dimension scores of the SF-36 improved from day 30 to 360. DHI-S scores were statistically better after PRM (P < 0.001). Our results show that the effectiveness of PRM is 88% after 1 year of follow-up. Patients with BPPV experienced a decrease in HRQoL, which was restored after PRM. Although relapses were observed in 7.5% of individuals, they did not affect HRQoL.

Antiandrogenic mechanisms of pesticides in human LNCaP prostate and H295R adrenocortical carcinoma cells.

PubMed

Robitaille, Christina N; Rivest, Patricia; Sanderson, J Thomas

2015-01-01

Several pesticides suspected or known to have endocrine disrupting effects were screened for pro- or antiandrogenic properties by determining their effects on proliferation, prostatic-specific antigen (PSA) secretion and androgen receptor (AR) expression, and AR phosphorylation in androgen-dependent LNCaP human prostate cancer cells, as well as on the expression and catalytic activity of the enzyme CYP17 in H295R human adrenocortical carcinoma cells, an in vitro model of steroidogenesis. Effects on SRD5A gene expression were determined in both cell lines. Benomyl, vinclozolin, and prochloraz, but not atrazine, concentration dependently (1-30 μM) decreased dihydrotestosterone (DHT)-stimulated proliferation of LNCaP cells. All pesticides except atrazine decreased DHT-stimulated PSA secretion, AR nuclear accumulation, and AR phosphorylation on serines 81 and 213 in LNCaP cells. Benomyl and prochloraz, but not vinclozolin or atrazine, decreased levels of CYP17 gene and protein expression, as well as catalytic activity in H295R cells. In the case of prochloraz, some of these effects corresponded with cytotoxicity. H295R cells expressed AR protein and SRD5A1, but not SRD5A2 transcripts. SRD5A1 gene expression in H295R cells was increased by 10 nM DHT, whereas in LNCaP cells significant induction was observed by 0.1 nM DHT. AR protein expression in H295R cells was not increased by DHT. Vinclozolin decreased DHT-induced SRD5A1 gene expression in LNCaP, but not H295R cells, indicating a functional difference of AR between the cell lines. In conclusion, pesticides may exert antiandrogenic effects through several mechanisms that are cell type-specific, including AR antagonism and down-regulation or catalytic inhibition of androgen biosynthetic enzymes, such as CYP17 and SRD5A1. © The Author 2014. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

9 CFR 319.302 - Hash.

Code of Federal Regulations, 2011 CFR

2011-01-01

... CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Canned, Frozen, or Dehydrated Meat Food... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Hash. 319.302 Section 319.302 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION...

9 CFR 319.302 - Hash.

Code of Federal Regulations, 2010 CFR

2010-01-01

... CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Canned, Frozen, or Dehydrated Meat Food... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Hash. 319.302 Section 319.302 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION...

The Speech multi features fusion perceptual hash algorithm based on tensor decomposition

NASA Astrophysics Data System (ADS)

Huang, Y. B.; Fan, M. H.; Zhang, Q. Y.

2018-03-01

With constant progress in modern speech communication technologies, the speech data is prone to be attacked by the noise or maliciously tampered. In order to make the speech perception hash algorithm has strong robustness and high efficiency, this paper put forward a speech perception hash algorithm based on the tensor decomposition and multi features is proposed. This algorithm analyses the speech perception feature acquires each speech component wavelet packet decomposition. LPCC, LSP and ISP feature of each speech component are extracted to constitute the speech feature tensor. Speech authentication is done by generating the hash values through feature matrix quantification which use mid-value. Experimental results showing that the proposed algorithm is robust for content to maintain operations compared with similar algorithms. It is able to resist the attack of the common background noise. Also, the algorithm is highly efficiency in terms of arithmetic, and is able to meet the real-time requirements of speech communication and complete the speech authentication quickly.

Unsupervised Deep Hashing With Pseudo Labels for Scalable Image Retrieval.

PubMed

Zhang, Haofeng; Liu, Li; Long, Yang; Shao, Ling

2018-04-01

In order to achieve efficient similarity searching, hash functions are designed to encode images into low-dimensional binary codes with the constraint that similar features will have a short distance in the projected Hamming space. Recently, deep learning-based methods have become more popular, and outperform traditional non-deep methods. However, without label information, most state-of-the-art unsupervised deep hashing (DH) algorithms suffer from severe performance degradation for unsupervised scenarios. One of the main reasons is that the ad-hoc encoding process cannot properly capture the visual feature distribution. In this paper, we propose a novel unsupervised framework that has two main contributions: 1) we convert the unsupervised DH model into supervised by discovering pseudo labels; 2) the framework unifies likelihood maximization, mutual information maximization, and quantization error minimization so that the pseudo labels can maximumly preserve the distribution of visual features. Extensive experiments on three popular data sets demonstrate the advantages of the proposed method, which leads to significant performance improvement over the state-of-the-art unsupervised hashing algorithms.

Feature hashing for fast image retrieval

NASA Astrophysics Data System (ADS)

Yan, Lingyu; Fu, Jiarun; Zhang, Hongxin; Yuan, Lu; Xu, Hui

2018-03-01

Currently, researches on content based image retrieval mainly focus on robust feature extraction. However, due to the exponential growth of online images, it is necessary to consider searching among large scale images, which is very timeconsuming and unscalable. Hence, we need to pay much attention to the efficiency of image retrieval. In this paper, we propose a feature hashing method for image retrieval which not only generates compact fingerprint for image representation, but also prevents huge semantic loss during the process of hashing. To generate the fingerprint, an objective function of semantic loss is constructed and minimized, which combine the influence of both the neighborhood structure of feature data and mapping error. Since the machine learning based hashing effectively preserves neighborhood structure of data, it yields visual words with strong discriminability. Furthermore, the generated binary codes leads image representation building to be of low-complexity, making it efficient and scalable to large scale databases. Experimental results show good performance of our approach.

[Evaluation of the treatment of benign paroxysmal positional vertigo with the DHI-S questionnaire].

PubMed

López-Escámez, J A; Gómez Fiñana, M; Fernández, A; Sánchez Canet, I; Palma, M J; Rodríguez, J

2001-01-01

Benign paroxysmal positional vertigo (BPPV) is a recurrent chronic disease and its handicap is usually underestimated. The aim of this study is to determine the impact of the treatment by Epley maneuver on short-term BPPV-related quality of life. Forty-two individuals with BPPV were included: 39 with posterior canal affected, 2 with the lateral canal and one with the anterior canal. Diagnosis was established if a consistent clinical history was found and Dix-Hallpike test (DHT) in cases with canal posterior involvement. Subjects with positive DHT were treated by a single Epley maneuver and were recommended to avoid supine for the next 48 hours. The BPPV relapses were investigated at 7th and 30th day post-treatment. BPPV-associated quality of life was evaluated by the Dizzness Handicap Inventory Short-form (DHI-S) at days 1st and 30th post-treatment. Total and partial scores for emotional, physical and functional subscales were compared by Wilcoxon test for paired samples. Dix-Hallpike test was found positive in el 59% individuals (23/39), and 41% cases did not required any treatment. Among 23 patients treated with Epley maneuver, DHT was found negative in 90% at 30th day follow-up. Mean and standard deviation of the total scores obtained in the DHI-S at the first day were 19.22 +/- 9.66 in the DHT positive-patients and 19.79 +/- 10.14 in the whole group (DHT positive or negative). These scores significantly decreased to 10.84 +/- 10.99 at 30 days post-treatment (p = 0.002 and p = 0.001, respectively). In conclusion, the DHI-S is a specific health questionnaire able to assess BPPV-related health and the effectiveness of treatment.

Consequences of advanced aging on renal function in chronic hyperandrogenemic female rat model: implications for aging women with polycystic ovary syndrome.

PubMed

Patil, Chetan N; Racusen, Lorraine C; Reckelhoff, Jane F

2017-11-01

Polycystic ovary syndrome (PCOS) is the most common endocrine and reproductive disorder in premenopausal women, characterized by hyperandrogenemia, metabolic syndrome, and inflammation. Women who had PCOS during their reproductive years remain hyperandrogenemic after menopause. The consequence of chronic hyperandrogenemia with advanced aging has not been studied to our knowledge. We have characterized a model of hyperandrogenemia in female rats and have aged them to 22-25 months to mimic advanced aging in hyperandrogenemic women, and tested the hypothesis that chronic exposure to hyperandrogenemia with aging has a deleterious effect on renal function. Female rats were chronically implanted with dihydrotestosterone pellets (DHT 7.5 mg/90 days) that were changed every 85 days or placebo pellets, and renal function was measured by clearance methods. Aging DHT-treated females had a threefold higher level of DHT with significantly higher body weight, mean arterial pressure, left kidney weight, proteinuria, and kidney injury molecule-1 (KIM-1), than did age-matched controls. In addition, DHT-treated-old females had a 60% reduction in glomerular filtration rate, 40% reduction in renal plasma flow, and significant reduction in urinary nitrate and nitrite excretion (UNOxV), an index of nitric oxide production. Morphological examination of kidneys showed that old DHT-treated females had significant focal segmental glomerulosclerosis, global sclerosis, and interstitial fibrosis compared to controls. Thus chronic hyperandrogenemia that persists into old age in females is associated with renal injury. These data suggest that women with chronic hyperandrogenemia such as in PCOS may be at increased risk for development of chronic kidney disease with advanced age. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Effects of dynamic head tilts on sensory organization test performance: a comparison between college-age athletes and nonathletes.

PubMed

Clark, Sean; Iltis, Peter W

2008-05-01

Controlled laboratory study. To compare postural performance measures of athletes with those of nonathletes when completing the standard Sensory Organization Test (SOT) and a modified SOT that included dynamic head tilts (DHT-SOT). Authors of recently published research have suggested that modifications to the SOT protocol (eg, introduction of pitch and roll head tilts) may enhance the test's sensitivity when assessing postural stability in individuals with higher balance capabilities or with well-compensated sensory deficits. Nineteen athletes and 19 nonathletes (group) completed both the SOT and DHT-SOT (protocol). During the SOT, participants stood upright as steadily as possible for 20 seconds during each of 6 different sensory conditions. As a variation of the SOT, the DHT-SOT incorporated active pitch and roll head tilts into the SOT protocol. Four 2-way mixed-model analyses of variance (with protocol as the repeated factor) were performed to determine if the composite equilibrium score or the visual, vestibular, or somatosensory ratio scores differed between the 2 groups across the 2 testing protocols. Significant group-by-protocol interaction effects were present for both the composite equilibrium score and visual ratio. Follow-up simple main-effects analyses indicated that these measures did not differ between groups for the SOT protocol but were significantly different on the DHT-SOT. The addition of dynamic head tilts to the SOT protocol resulted in subtle differences in balance function between athletes and nonathletes. Athletes demonstrated an increased ability to adapt to sensory disruptions during the DHT-SOT. Therapists should consider including active pitch and roll head tilts to the SOT when evaluating individuals with higher balance function or to detect subtle deficits in balance function. Diagnosis, level 3b.

The Direct Inhibitory Effect of Dutasteride or Finasteride on Androgen Receptor Activity is Cell Line Specific

PubMed Central

Chhipa, Rishi Raj; Halim, Danny; Cheng, Jinrong; Zhang, Huan Yi; Mohler, James L.; Ip, Clement; Wu, Yue

2014-01-01

BACKGROUND Finasteride and dutasteride were developed originally as 5α-reductase inhibitors to block the conversion of testosterone to dihydrotestosterone (DHT). These drugs may possess off-target effects on the androgen receptor (AR) due to their structural similarity to DHT. METHODS A total of 4 human prostate cancer cell models were examined: LNCaP (T877A mutant AR), 22Rv1 (H874Y mutant AR), LAPC4 (wild type AR) and VCaP (wild type AR). Cells were cultured in 10% charcoal-stripped fetal bovine serum, either with or without DHT added to the medium. AR activity was evaluated using the ARE-luciferase assay or the expression of AR regulated genes. RESULTS Dutasteride was more potent than finasteride in interfering with DHT-stimulated AR signaling. Disruption of AR function was accompanied by decreased cell growth. Cells that rely on DHT for protection against death were particularly vulnerable to dutasteride. Different prostate cancer cell models exhibited different sensitivities to dutasteride and finasteride. LNCaP was most sensitive, LAPC4 and VCaP were intermediate, while 22Rv1 was least sensitive. Regardless of the AR genotype, if AR was transfected into drug-sensitive cells, AR was inhibited by drug treatment; and if AR was transfected into drug-resistant cells, AR was not inhibited. CONCLUSIONS The direct inhibitory effect of dutasteride or finasteride on AR signaling is cell line specific. Mutations in the ligand binding domain of AR do not appear to play a significant role in influencing the AR antagonistic effect of these drugs. Subcellular constituent is an important factor in determining the drug effect on AR function. PMID:23813737

Totally S-protected hyaluronic acid: Evaluation of stability and mucoadhesive properties as liquid dosage form.

PubMed

Pereira de Sousa, Irene; Suchaoin, Wongsakorn; Zupančič, Ožbej; Leichner, Christina; Bernkop-Schnürch, Andreas

2016-11-05

It is the aim of this study to synthesize hyaluronic acid (HA) derivatives bearing mucoadhesive properties and showing prolonged stability at pH 7.4 and under oxidative condition as liquid dosage form. HA was modified by thiolation with l-cysteine (HA-SH) and by conjugation with 2-mercaptonicotinic acid-l-cysteine ligand to obtain an S-protected derivative (HA-MNA). The polymers were characterized by determination of thiol group content and mercaptonicotinic acid content. Cytotoxicity, stability and mucoadhesive properties (rheological evaluation and tensile test) of the polymers were evaluated. HA-SH and HA-MNA could be successfully synthesized with a degree of modification of 5% and 9% of the total moles of carboxylic acid groups, respectively. MTT assay revealed no toxicity for the polymers. HA-SH resulted to be unstable both at pH 7.4 and under oxidative conditions, whereas HA-MNA was stable under both conditions. Rheological assessment showed a 52-fold and a 3-fold increase in viscosity for HA-MNA incubated with mucus compared to unmodified HA and HA-SH, respectively. Tensile evaluation carried out with intestinal and conjunctival mucosa confirmed the higher mucoadhesive properties of HA-MNA compared to HA-SH. According to the presented results, HA-MNA appears to be a potent excipient for the formulation of stable liquid dosage forms showing comparatively high mucodhesive properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stockmeier, C.A.; Kellar, K.J.

Serotonin-2 (5-HT-2) receptors in brain were measured using (/sup 3/H)ketanserin. The authors examined the effects of amitriptyline, an anti-depressant drug, of electroconvulsive shock (ECS) and of drug-induced alterations in presynaptic 5-HT function on (/sup 3/H)ketanserin binding to 5-HT-2 receptors in rat brain. The importance of intact 5-HT axons to the up-regulation of 5-HT-2 receptors by ECS was also investigated, and an attempt was made to relate the ECS-induced increase in this receptor to changes in 5-HT presynaptic mechanisms. Twelve days of ECS increased the number of 5-HT-2 receptors in frontal cortex. Neither the IC/sub 50/ nor the Hill coefficient ofmore » 5-HT in competing for (/sup 3/H)ketanserin binding sites was altered by ECS. Repeated injections of amitriptyline reduced the number of 5-HT-2 receptors in frontal cortex. Reserpine, administered daily for 12 days, caused a significant increase in 5-HT-2 receptors, but neither daily injections of p-chlorophenylalanine (PCPA) nor lesions of 5-HT axons with 5,7-dihydroxytryptamine (5,7-DHT) affected 5-HT-2 receptors. However, regulation of 5-HT-2 receptors by ECS was dependent on intact 5-HT axons since ECS could not increase the number of 5-HT-2 receptors in rats previously lesioned with 5,7-DHT. Repeated ECS, however, does not appear to affect either the high-affinity uptake of (/sup 3/H)5-HT or (/sup 3/H)imipramine binding, two presynaptic markers of 5-HT neuronal function. 5-HT-2 receptors appear to be under complex control. ECS or drug treatments such as reserpine or amitriptyline, which affect several monoamine neurotransmission systems including 5-HT, can alter 5-HT-2 receptors. 28 references, 1 figure, 7 tables.« less

Depletion of Serotonin Selectively Impairs Short-Term Memory without Affecting Long-Term Memory in Odor Learning in the Terrestrial Slug "Limax Valentianus"

ERIC Educational Resources Information Center

Santa, Tomofumi; Kirino, Yutaka; Watanabe, Satoshi; Shirahata, Takaaki; Tsunoda, Makoto

2006-01-01

The terrestrial slug "Limax" is able to acquire short-term and long-term memories during aversive odor-taste associative learning. We investigated the effect of the selective serotonergic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) on memory. Behavioral studies indicated that 5,7-DHT impaired short-term memory but not long-term memory. HPLC…

Selection for rapid embryo development correlates with embryo exposure to maternal androgens among passerine birds

USGS Publications Warehouse

Schwabl, H.; Palacios, M.G.; Martin, T.E.

2007-01-01

Greater offspring predation favors evolution of faster development among species. We hypothesized that greater offspring predation exerts selection on mothers to increase levels of anabolic androgens in egg yolks to achieve faster development. Here, we tested whether (1) concentrations of yolk androgens in passerine species were associated with offspring predation and (2) embryo and nestling development rates were associated with yolk androgen concentrations. We examined three androgens that increase in potency along the synthesis pathway: androstenedione (A4) to testosterone (T) to 5??- dihydrotestosterone (5??-DHT). Concentrations of none of these steroids were related to clutch size; only A4 was allometrically related to egg volume. Species that experience greater predation showed higher yolk concentrations of T and 5??-DHT. Higher concentrations of T and particularly 5??-DHT were strongly correlated with faster development during the embryo period and less so during the nestling period. Development rates were most strongly correlated with 5??-DHT, suggesting that potency increases along the androgen synthesis pathway and that effects are mediated by the androgen receptor pathway. These results are consistent with the hypothesis that selection for faster development by time-dependent offspring mortality may be achieved epigenetically by varying embryo exposure to maternal anabolic steroids. ?? 2007 by The University of Chicago. All rights reserved.

Modulation of defensive reflex conditioning in snails by serotonin

PubMed Central

Andrianov, Vyatcheslav V.; Bogodvid, Tatiana K.; Deryabina, Irina B.; Golovchenko, Aleksandra N.; Muranova, Lyudmila N.; Tagirova, Roza R.; Vinarskaya, Aliya K.; Gainutdinov, Khalil L.

2015-01-01

Highlights Daily injection of serotonin before a training session accelerated defensive reflex conditioning in snails.Daily injection of 5-hydroxytryptophan before a training session in snails with a deficiency of serotonin induced by the “neurotoxic” analog of serotonin 5,7-dihydroxytryptamine, restored the ability of snails to learn.After injection of the “neurotoxic” analogs of serotonin 5,6- and 5,7-dihydroxytryptamine as well as serotonin, depolarization of the membrane and decrease of the threshold potential of premotor interneurons was observed. We studied the role of serotonin in the mechanisms of learning in terrestrial snails. To produce a serotonin deficit, the “neurotoxic” analogs of serotonin, 5,6- or 5,7-dihydroxytryptamine (5,6/5,7-DHT) were used. Injection of 5,6/5,7-DHT was found to disrupt defensive reflex conditioning. Within 2 weeks of neurotoxin application, the ability to learn had recovered. Daily injection of serotonin before a training session accelerated defensive reflex conditioning and daily injections of 5-HTP in snails with a deficiency of serotonin induced by 5,7-DHT restored the snail's ability to learn. We discovered that injections of the neurotoxins 5,6/5,7-DHT as well as serotonin, caused a decrease in the resting and threshold potentials of the premotor interneurons LPa3 and RPa3. PMID:26557063

Backdoor pathway for dihydrotestosterone biosynthesis: implications for normal and abnormal human sex development.

PubMed

Fukami, Maki; Homma, Keiko; Hasegawa, Tomonobu; Ogata, Tsutomu

2013-04-01

We review the current knowledge about the "backdoor" pathway for the biosynthesis of dihydrotestosterone (DHT). While DHT is produced from cholesterol through the conventional "frontdoor" pathway via testosterone, recent studies have provided compelling evidence for the presence of an alternative "backdoor" pathway to DHT without testosterone intermediacy. This backdoor pathway is known to exist in the tammar wallaby pouch young testis and the immature mouse testis, and has been suggested to be present in the human as well. Indeed, molecular analysis has identified pathologic mutations of genes involved in the backdoor pathway in genetic male patients with undermasculinized external genitalia, and urine steroid profile analysis has argued for the relevance of the activated backdoor pathway to abnormal virilization in genetic females with cytochrome P450 oxidoreductase deficiency and 21-hydroxylase deficiency. It is likely that the backdoor pathway is primarily operating in the fetal testis in a physiological condition to produce a sufficient amount of DHT for male sex development, and that the backdoor pathway is driven with a possible interaction between fetal and permanent adrenals in pathologic conditions with increased 17-hydroxyprogesterone levels. These findings provide novel insights into androgen biosynthesis in both physiological and pathological conditions. Copyright © 2012 Wiley Periodicals, Inc., a Wiley company.

Sexual steroids in serum and prostatic tissue of human non-cancerous prostate (STERPROSER trial).

PubMed

Neuzillet, Yann; Raynaud, Jean-Pierre; Radulescu, Camélia; Fiet, Jean; Giton, Franck; Dreyfus, Jean-François; Ghoneim, Tarek P; Lebret, Thierry; Botto, Henry

2017-11-01

The specific involvement of the sex steroids in the growth of the prostatic tissue remains unclear. Sex steroid concentrations in plasma and in fresh surgical samples of benign central prostate were correlated to prostate volume. Monocentric prospective study performed between September 2014 and January 2017. Age, obesity parameters, and both serum and intraprostatic concentrations of sex steroids were collected complying with the latest Endocrine Society guidelines and the steroids assessed by GC/MS. Statistical calculations were adjusted for age and body mass index (BMI). Thirty-two patients, equally divided between normal- and high-volume prostate groups, were included in the analysis. High-volume prostate patients were older, heavier and had higher BMI. Comparison adjusted for age and BMI showed higher DHT concentrations in high-volume prostate. Both normal- and high-volume prostate tissues concentrate sex steroids in a similar way. Comparison of enzymatic activity surrogate marker ratios within tissue highlighted similar TT/E1 and TT/E2 ratios, and higher DHT/E1 ratio and lower DHT/PSA ratio in the high-volume prostates. STERPROSER trial provides evidence for higher DHT concentration in highvolume prostates, that could reflect either higher 5-alpha reductase expression or lower expression of downstream metabolizing enzymes such as 3a-hydoxysteroid dehydrogenase. © 2017 Wiley Periodicals, Inc.

Anoctamin 1 (TMEM16A) is essential for testosterone-induced prostate hyperplasia.

PubMed

Cha, Joo Young; Wee, Jungwon; Jung, Jooyoung; Jang, Yongwoo; Lee, Byeongjun; Hong, Gyu-Sang; Chang, Beom Chul; Choi, Yoon-La; Shin, Young Kee; Min, Hye-Young; Lee, Ho-Young; Na, Tae-Young; Lee, Mi-Ock; Oh, Uhtaek

2015-08-04

Benign prostatic hyperplasia (BPH) is characterized by an enlargement of the prostate, causing lower urinary tract symptoms in elderly men worldwide. However, the molecular mechanism underlying the pathogenesis of BPH is unclear. Anoctamin1 (ANO1) encodes a Ca(2+)-activated chloride channel (CaCC) that mediates various physiological functions. Here, we demonstrate that it is essential for testosterone-induced BPH. ANO1 was highly amplified in dihydrotestosterone (DHT)-treated prostate epithelial cells, whereas the selective knockdown of ANO1 inhibited DHT-induced cell proliferation. Three androgen-response elements were found in the ANO1 promoter region, which is relevant for the DHT-dependent induction of ANO1. Administration of the ANO1 blocker or Ano1 small interfering RNA, inhibited prostate enlargement and reduced histological abnormalities in vivo. We therefore concluded that ANO1 is essential for the development of prostate hyperplasia and is a potential target for the treatment of BPH.

Anoctamin 1 (TMEM16A) is essential for testosterone-induced prostate hyperplasia

PubMed Central

Cha, Joo Young; Wee, Jungwon; Jung, Jooyoung; Jang, Yongwoo; Lee, Byeongjun; Hong, Gyu-Sang; Chang, Beom Chul; Choi, Yoon-La; Shin, Young Kee; Min, Hye-Young; Lee, Ho-Young; Na, Tae-Young; Lee, Mi-Ock; Oh, Uhtaek

2015-01-01

Benign prostatic hyperplasia (BPH) is characterized by an enlargement of the prostate, causing lower urinary tract symptoms in elderly men worldwide. However, the molecular mechanism underlying the pathogenesis of BPH is unclear. Anoctamin1 (ANO1) encodes a Ca2+-activated chloride channel (CaCC) that mediates various physiological functions. Here, we demonstrate that it is essential for testosterone-induced BPH. ANO1 was highly amplified in dihydrotestosterone (DHT)-treated prostate epithelial cells, whereas the selective knockdown of ANO1 inhibited DHT-induced cell proliferation. Three androgen-response elements were found in the ANO1 promoter region, which is relevant for the DHT-dependent induction of ANO1. Administration of the ANO1 blocker or Ano1 small interfering RNA, inhibited prostate enlargement and reduced histological abnormalities in vivo. We therefore concluded that ANO1 is essential for the development of prostate hyperplasia and is a potential target for the treatment of BPH. PMID:26153424

The Effect of Temperature on Moisture Transport in Concrete

PubMed Central

Wang, Yao; Xi, Yunping

2017-01-01

Most concrete structures and buildings are under temperature and moisture variations simultaneously. Thus, the moisture transport in concrete is driven by the moisture gradient as well as the temperature gradient. This paper presents an experimental approach for determining the effect of different temperature gradients on moisture distribution profiles in concrete. The effect of elevated temperatures under isothermal conditions on the moisture transport was also evaluated, and found not to be significant. The non-isothermal tests show that the temperature gradient accelerates the moisture transport in concrete. The part of increased moisture transfer due to the temperature gradient can be quantified by a coupling parameter DHT, which can be determined by the present test data. The test results indicated that DHT is not a constant but increases linearly with the temperature variation. A material model was developed for DHT based on the experimental results obtained in this study. PMID:28792460

Secure Minutiae-Based Fingerprint Templates Using Random Triangle Hashing

NASA Astrophysics Data System (ADS)

Jin, Zhe; Jin Teoh, Andrew Beng; Ong, Thian Song; Tee, Connie

Due to privacy concern on the widespread use of biometric authentication systems, biometric template protection has gained great attention in the biometric research recently. It is a challenging task to design a biometric template protection scheme which is anonymous, revocable and noninvertible while maintaining acceptable performance. Many methods have been proposed to resolve this problem, and cancelable biometrics is one of them. In this paper, we propose a scheme coined as Random Triangle Hashing which follows the concept of cancelable biometrics in the fingerprint domain. In this method, re-alignment of fingerprints is not required as all the minutiae are translated into a pre-defined 2 dimensional space based on a reference minutia. After that, the proposed Random Triangle hashing method is used to enforce the one-way property (non-invertibility) of the biometric template. The proposed method is resistant to minor translation error and rotation distortion. Finally, the hash vectors are converted into bit-strings to be stored in the database. The proposed method is evaluated using the public database FVC2004 DB1. An EER of less than 1% is achieved by using the proposed method.

In Vitro and Ex Vivo Evaluation of Novel Curcumin-Loaded Excipient for Buccal Delivery.

PubMed

Laffleur, Flavia; Schmelzle, Franziska; Ganner, Ariane; Vanicek, Stefan

2017-08-01

This study aimed to develop a mucoadhesive polymeric excipient comprising curcumin for buccal delivery. Curcumin encompasses broad range of benefits such as antioxidant, anti-inflammatory, and chemotherapeutic activity. Hyaluronic acid (HA) as polymeric excipient was modified by immobilization of thiol bearing ligands. L-Cysteine (SH) ethyl ester was covalently attached via amide bond formation between cysteine and the carboxylic moiety of hyaluronic acid. Succeeded synthesis was proved by H-NMR and IR spectra. The obtained thiolated polymer hyaluronic acid ethyl ester (HA-SH) was evaluated in terms of stability, safety, mucoadhesiveness, drug release, and permeation-enhancing properties. HA-SH showed 2.75-fold higher swelling capacity over time in comparison to unmodified polymer. Furthermore, mucoadhesion increased 3.4-fold in case of HA-SH and drug release was increased 1.6-fold versus HA control, respectively. Curcumin-loaded HA-SH exhibits a 4.4-fold higher permeation compared with respective HA. Taking these outcomes in consideration, novel curcumin-loaded excipient, namely thiolated hyaluronic acid ethyl ester appears as promising tool for pharyngeal diseases.

Crystallization and X-ray diffraction analysis of an l-arabinonate dehydratase from Rhizobium leguminosarum bv. trifolii and a d-xylonate dehydratase from Caulobacter crescentus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rahman, Mohammad Mubinur; Andberg, Martina; Koivula, Anu

l-Arabinonate dehydratase and d-xylonate dehydratase from the IlvD/EDD family were crystallized by the vapour-diffusion method. Diffraction data sets were collected to resolutions of 2.40 and 2.66 Å from crystals of l-arabinonate dehydratase and d-xylonate dehydratase, respectively. l-Arabinonate dehydratase (EC 4.2.1.25) and d-xylonate dehydratase (EC 4.2.1.82) are two enzymes that are involved in a nonphosphorylative oxidation pathway of pentose sugars. l-Arabinonate dehydratase converts l-arabinonate into 2-dehydro-3-deoxy-l-arabinonate, and d-xylonate dehydratase catalyzes the dehydration of d-xylonate to 2-dehydro-3-deoxy-d-xylonate. l-Arabinonate and d-xylonate dehydratases belong to the IlvD/EDD family, together with 6-phosphogluconate dehydratases and dihydroxyacid dehydratases. No crystal structure of any l-arabinonate or d-xylonate dehydratasemore » is available in the PDB. In this study, recombinant l-arabinonate dehydratase from Rhizobium leguminosarum bv. trifolii (RlArDHT) and d-xylonate dehydratase from Caulobacter crescentus (CcXyDHT) were heterologously expressed in Escherichia coli and purified by the use of affinity chromatography followed by gel-filtration chromatography. The purified proteins were crystallized using the hanging-drop vapour-diffusion method at 293 K. Crystals of RlArDHT that diffracted to 2.40 Å resolution were obtained using sodium formate as a precipitating agent. They belonged to space group P2{sub 1}, with unit-cell parameters a = 106.07, b = 208.61, c = 147.09 Å, β = 90.43°. Eight RlArDHT molecules (two tetramers) in the asymmetric unit give a V{sub M} value of 3.2 Å{sup 3} Da{sup −1} and a solvent content of 62%. Crystals of CcXyDHT that diffracted to 2.66 Å resolution were obtained using sodium formate and polyethylene glycol 3350. They belonged to space group C2, with unit-cell parameters a = 270.42, b = 236.13, c = 65.17 Å, β = 97.38°. Four CcXyDHT molecules (a tetramer) in the asymmetric unit give a V{sub M} value of 4.0 Å{sup 3} Da{sup −1} and a solvent content of 69%.« less

Pharmacologic basis for the enhanced efficacy of dutasteride against prostatic cancers.

PubMed

Xu, Yi; Dalrymple, Susan L; Becker, Robyn E; Denmeade, Samuel R; Isaacs, John T

2006-07-01

Prostatic dihydrotestosterone (DHT) concentration is regulated by precursors from systemic circulation and prostatic enzymes of androgen metabolism, particularly 5alpha-reductases (i.e., SRD5A1 and SRD5A2). Therefore, the levels of expression SRD5A1 and SRD5A2 and the antiprostatic cancer growth response to finasteride, a selective SRD5A2 inhibitor, versus the dual SRD5A1 and SRD5A2 inhibitor, dutasteride, were compared. Real-time PCR and enzymatic assays were used to determine the levels of SRD5A1 and SRD5A2 in normal versus malignant rat and human prostatic tissues. Rats bearing the Dunning R-3327H rat prostate cancer and nude mice bearing LNCaP or PC-3 human prostate cancer xenografts were used as model systems. Tissue levels of testosterone and DHT were determined using liquid chromatography-mass spectrometry. Prostate cancer cells express undetectable to low levels of SRD5A2 but elevated levels of SRD5A1 activity compared with nonmalignant prostatic tissue. Daily oral treatment of rats with the SRD5A2 selective inhibitor, finasteride, reduces prostate weight and DHT content but did not inhibit R-3327H rat prostate cancer growth or DHT content in intact (i.e., noncastrated) male rats. In contrast, daily oral treatment with even a low 1 mg/kg/d dose of the dual SRD5A1 and SRD5A2 inhibitor, dutasteride, reduces both normal prostate and H tumor DHT content and weight in intact rats while elevating tissue testosterone. Daily oral treatment with finasteride significantly (P < 0.05) inhibits growth of LNCaP human prostate cancer xenografts in intact male nude mice, but this inhibition is not as great as that by equimolar oral dosing with dutasteride. This anticancer efficacy is not equivalent, however, to that produced by castration. Only combination of dutasteride and castration produces a greater tumor inhibition (P < 0.05) than castration monotherapy against androgen-responsive LNCaP cancers. In contrast, no response was induced by dutasteride in nude mice bearing androgen-independent PC-3 human prostatic cancer xenografts. These results document that testosterone is not as potent as DHT but does stimulate prostate cancer growth, thus combining castration with dutasteride enhances therapeutic efficacy.

[PREPARATION AND BIOCOMPATIBILITY OF IN SITU CROSSLINKING HYALURONIC ACID HYDROGEL].

PubMed

Liang, Jiabi; Li, Jun; Wang, Ting; Liang, Yuhong; Zou, Xuenong; Zhou, Guangqian; Zhou, Zhiyu

2016-06-08

To fabricate in situ crosslinking hyaluronic acid hydrogel and evaluate its biocompatibility in vitro. The acrylic acid chloride and polyethylene glycol were added to prepare crosslinking agent polyethylene glycol acrylate (PEGDA), and the molecular structure of PEGDA was analyzed by Flourier transformation infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy. Hyaluronic acid hydrogel was chemically modified to prepare hyaluronic acid thiolation (HA-SH). And the degree of HA-SH was analyzed qualitatively and quantitatively by Ellman method. HA-SH solution in concentrations ( W/V ) of 0.5%, 1.0%, and 1.5% and PEGDA solution in concentrations ( W/V ) of 2%, 4%, and 6% were prepared with PBS. The two solutions were mixed in different ratios, and in situ crosslinking hyaluronic acid hydrogel was obtained; the crosslinking time was recorded. The cellular toxicity of in situ crosslinking hyaluronic acid hydrogel (1.5% HA-SH and 4% PEGDA mixed) was tested by L929 cells. Meanwhile, the biocompatibility of hydrogel was tested by co-cultured with human bone mesenchymal stem cells (hBMSCs). Flourier transformation infrared spectroscopy showed that most hydroxyl groups were replaced by acrylate groups; 1H nuclear magnetic resonance spectroscopy showed 3 characteristic peaks of hydrogen representing acrylate and olefinic bond at 5-7 ppm. The thiolation yield of HA-SH was 65.4%. In situ crosslinking time of hyaluronic acid hydrogel was 2 to 70 minutes in the PEGDA concentrations of 2%-6% and HA-SH concentrations of 0.5%-1.5%. The hyaluronic acid hydrogel appeared to be transparent. The toxicity grade of leaching solution of hydrogel was grade 1. hBMSCs grew well and distributed evenly in hydrogel with a very high viability. In situ crosslinking hyaluronic acid hydrogel has low cytotoxicity, good biocompatibility, and controllable crosslinking time, so it could be used as a potential tissue engineered scaffold or repairing material for tissue regeneration.

The effect of androgen excess on maternal metabolism, placental function and fetal growth in obese dams.

PubMed

Fornes, Romina; Maliqueo, Manuel; Hu, Min; Hadi, Laila; Jimenez-Andrade, Juan M; Ebefors, Kerstin; Nyström, Jenny; Labrie, Fernand; Jansson, Thomas; Benrick, Anna; Stener-Victorin, Elisabet

2017-08-14

Pregnant women with polycystic ovary syndrome (PCOS) are often overweight or obese. To study the effects of maternal androgen excess in obese dams on metabolism, placental function and fetal growth, female C57Bl6J mice were fed a control (CD) or a high fat/high sucrose (HF/HS) diet for 4-10 weeks, and then mated. On gestational day (GD) 15.5-17.5, dams were injected with dihydrotestosterone (CD-DHT, HF/HS-DHT) or a vehicle (CD-Veh, HF/HS-Veh). HF/HS dams had higher fat content, both before mating and on GD18.5, with no difference in glucose homeostasis, whereas the insulin sensitivity was higher in DHT-exposed dams. Compared to the CD groups, the livers from HF/HS dams weighed more on GD18.5, the triglyceride content was higher, and there was a dysregulation of liver enzymes related to lipogenesis and higher mRNA expression of Fitm1. Fetuses from HF/HS-Veh dams had lower liver triglyceride content and mRNA expression of Srebf1c. Maternal DHT exposure, regardless of diet, decreased fetal liver Pparg mRNA expression and increased placental androgen receptor protein expression. Maternal diet-induced obesity, together with androgen excess, affects maternal and fetal liver function as demonstrated by increased triglyceride content and dysfunctional expression of enzymes and transcription factors involved in de novo lipogenesis and fat storage.

Androgens and alopecia.

PubMed

Kaufman, Keith D

2002-12-30

Androgens have profound effects on scalp and body hair in humans. Scalp hair grows constitutively in the absence of androgens, while body hair growth is dependent on the action of androgens. Androgenetic alopecia, referred to as male pattern hair loss (MPHL) in men and female pattern hair loss (FPHL) in women, is due to the progressive miniaturization of scalp hair. Observations in both eunuchs, who have low levels of testicular androgens, and males with genetic 5alpha-reductase (5alphaR) deficiency, who have low levels of dihydrotestosterone (DHT), implicate DHT as a key androgen in the pathogenesis of MPHL in men. The development of finasteride, a type 2-selective 5alphaR inhibitor, further advanced our understanding of the role of DHT in the pathophysiology of scalp alopecia. Controlled clinical trials with finasteride demonstrated improvements in scalp hair growth in treated men associated with reductions in scalp DHT content, and a trend towards reversal of scalp hair miniaturization was evident by histopathologic evaluation of scalp biopsies. In contrast to its beneficial effects in men, finasteride did not improve hair growth in postmenopausal women with FPHL. Histopathological evaluation of scalp biopsies confirmed that finasteride treatment produced no benefit on scalp hair in these women. These findings suggest that MPHL and FPHL are distinct clinical entities, with disparate pathophysiologies. Studies that elucidate the molecular mechanisms by which androgens regulate hair growth would provide greater understanding of these differences. Copyright 2002 Elsevier Science Ireland Ltd.

Opposite long-term synaptic effects of 17β-estradiol and 5α-dihydrotestosterone and localization of their receptors in the medial vestibular nucleus of rats.

PubMed

Grassi, Silvarosa; Scarduzio, Mariangela; Panichi, Roberto; Dall'Aglio, Cecilia; Boiti, Cristiano; Pettorossi, Vito E

2013-08-01

In brainstem slices of male rats, we examined in single neurons of the medial vestibular nucleus (MVN) the effect of exogenous administration of estrogenic (17β-estradiol, E2) and androgenic (5α-dihydrotestosterone, DHT) steroids on the synaptic response to vestibular afferent stimulation. By whole cell patch clamp recordings we showed that E2 induced synaptic long-term potentiation (LTP) that was cancelled by the subsequent administration of DHT. Conversely, DHT induced synaptic long-term depression (LTD) that was partially reversed by E2. The electrophysiological findings were supported by immunohistochemical analysis showing the presence of estrogen (ER: α and β) and androgen receptors (AR) in the MVN neurons. We found that a large number of neurons were immunoreactive for ERα, ERβ, and AR and most of them co-localized ERβ and AR. We also showed the presence of P450-aromatase (ARO) in the MVN neurons, clearly proving that E2 can be locally synthesized in the MVN. On the whole, these results demonstrate a role of estrogenic and androgenic signals in modulating vestibular synaptic plasticity and suggest that the enhancement or depression of vestibular synaptic response may depend on the local conversion of T into E2 or DHT. Copyright © 2013 Elsevier Inc. All rights reserved.

Steroid 5alpha-reductase 1 polymorphisms and testosterone/dihydrotestosterone ratio in male patients with hypospadias.

PubMed

Tria, Antje; Hiort, Olaf; Sinnecker, Gernot H G

2004-01-01

Defects in the steroid 5alpha-reductase type 2 (SRD5A2) activity cause decreased formation of dihydrotestosterone (DHT) from testosterone (T), resulting in defective masculinization of external genitalia; the T/DHT ratio is increased. We investigated 10 patients with elevated T/DHT ratios in whom mutations in the SRD5A2 and AR genes had been excluded to find out whether structural alterations of the SRD5A1 gene could contribute to their genital malformations. Single-strand conformation polymorphism analysis and direct sequencing were used to detect variations in the SRD5A1 gene of the patients and of 49 adult fertile men who served as controls. The sequence analysis of exon 3 of the SRD5A1 gene indicated an adenine-to-guanine change (ACA vs. ACG), both triplets encoding the amino acid residue threonine. The ACG sequence was detected in 57% of all subjects and was equally distributed in patients and controls. The T/DHT ratio was significantly higher in controls with the ACG variant as compared with those having the ACA variant. However, no particular sequence aberration was found in the SRD5A1 genes of either group. Mutant SRD5A1 isoenzyme does not seem to play a crucial role in the development of hypospadias. Copyright 2004 S. Karger AG, Basel

SHBG Is an Important Factor in Stemness Induction of Cells by DHT In Vitro and Associated with Poor Clinical Features of Prostate Carcinomas

PubMed Central

Ma, Yuanyuan; Liang, Dongming; Liu, Jian; Wen, Jian-Guo; Servoll, Einar; Waaler, Gudmund; Sæter, Thorstein; Axcrona, Karol; Vlatkovic, Ljiljana; Axcrona, Ulrika; Paus, Elisabeth; Yang, Yue; Zhang, Zhiqian; Kvalheim, Gunnar; Nesland, Jahn M.; Suo, Zhenhe

2013-01-01

Androgen plays a vital role in prostate cancer development. However, it is not clear whether androgens influence stem-like properties of prostate cancer, a feature important for prostate cancer progression. In this study, we show that upon DHT treatment in vitro, prostate cancer cell lines LNCaP and PC-3 were revealed with higher clonogenic potential and higher expression levels of stemness related factors CD44, CD90, Oct3/4 and Nanog. Moreover, sex hormone binding globulin (SHBG) was also simultaneously upregulated in these cells. When the SHBG gene was blocked by SHBG siRNA knock-down, the induction of Oct3/4, Nanog, CD44 and CD90 by DHT was also correspondingly blocked in these cells. Immunohistochemical evaluation of clinical samples disclosed weakly positive, and areas negative for SHBG expression in the benign prostate tissues, while most of the prostate carcinomas were strongly positive for SHBG. In addition, higher levels of SHBG expression were significantly associated with higher Gleason score, more seminal vesicle invasions and lymph node metastases. Collectively, our results show a role of SHBG in upregulating stemness of prostate cancer cells upon DHT exposure in vitro, and SHBG expression in prostate cancer samples is significantly associated with poor clinicopathological features, indicating a role of SHBG in prostate cancer progression. PMID:23936228

The progestational and androgenic properties of medroxyprogesterone acetate: gene regulatory overlap with dihydrotestosterone in breast cancer cells

PubMed Central

Ghatge, Radhika P; Jacobsen, Britta M; Schittone, Stephanie A; Horwitz, Kathryn B

2005-01-01

Introduction Medroxyprogesterone acetate (MPA), the major progestin used for oral contraception and hormone replacement therapy, has been implicated in increased breast cancer risk. Is this risk due to its progestational or androgenic properties? To address this, we assessed the transcriptional effects of MPA as compared with those of progesterone and dihydrotestosterone (DHT) in human breast cancer cells. Method A new progesterone receptor-negative, androgen receptor-positive human breast cancer cell line, designated Y-AR, was engineered and characterized. Transcription assays using a synthetic promoter/reporter construct, as well as endogenous gene expression profiling comparing progesterone, MPA and DHT, were performed in cells either lacking or containing progesterone receptor and/or androgen receptor. Results In progesterone receptor-positive cells, MPA was found to be an effective progestin through both progesterone receptor isoforms in transient transcription assays. Interestingly, DHT signaled through progesterone receptor type B. Expression profiling of endogenous progesterone receptor-regulated genes comparing progesterone and MPA suggested that although MPA may be a somewhat more potent progestin than progesterone, it is qualitatively similar to progesterone. To address effects of MPA through androgen receptor, expression profiling was performed comparing progesterone, MPA and DHT using Y-AR cells. These studies showed extensive gene regulatory overlap between DHT and MPA through androgen receptor and none with progesterone. Interestingly, there was no difference between pharmacological MPA and physiological MPA, suggesting that high-dose therapeutic MPA may be superfluous. Conclusion Our comparison of the gene regulatory profiles of MPA and progesterone suggests that, for physiologic hormone replacement therapy, the actions of MPA do not mimic those of endogenous progesterone alone. Clinically, the complex pharmacology of MPA not only influences its side-effect profile; but it is also possible that the increased breast cancer risk and/or the therapeutic efficacy of MPA in cancer treatment is in part mediated by androgen receptor. PMID:16457685

Developmental programming: prenatal steroid excess disrupts key members of intraovarian steroidogenic pathway in sheep.

PubMed

Padmanabhan, Vasantha; Salvetti, Natalia R; Matiller, Valentina; Ortega, Hugo H

2014-09-01

Prenatal testosterone (T) excess disrupts ovarian cyclicity and increases circulating estradiol levels as well as follicular recruitment and persistence culminating in multifollicular ovary similar to women with polycystic ovary syndrome. We tested whether prenatal T excess, by androgenic or estrogenic action, disrupts the steroid biosynthetic machinery in sheep in a cell-, follicle stage-, age-, and treatment-specific manner consistent with the ovarian disruptions and increased estradiol release. Impact of T/dihydrotestosterone (DHT) treatments from days 30-90 of gestation on steroidogenic acute regulatory protein, 3β-hydroxysteroid dehydrogenase, cytochrome P-450 17α-hydroxylase/C17, 20-lyase (CYP17A1), and cytochrome P-450 aromatase (CYP19A1) were examined on fetal day 90, 140 and 10 months (postpubertal), and 21 months (adult, no DHT group) of age by immunohistochemistry. All 4 markers changed in a cell-, follicle stage-, and age-specific manner. Both treatments increased steroidogenic acute regulatory protein expression in preantral follicles of postpubertal and adult females. Effects of prenatal T and DHT on 3β-hydroxysteroid dehydrogenase differed in a follicle- and age-specific manner. CYP17A1 was reduced in the theca interna of antral follicles by T, but not DHT, in 10- and 21-month-old females. CYP19A1 was reduced by both T and DHT at all ages barring an increase on fetal day 140. Reduced granulosa CYP19A1 and thecal CYP17A1 in adults likely disrupt the intrafollicular androgen/estrogen balance contributing to follicular persistence. The reduced thecal CYP17A1 expression suggests that the hyperandrogenic ovarian phenotype may originate from increased enzyme activity or alternatively via a different isoform of CYP17. The reduced CYP19A1 in antral follicles of adults indicates that the increased circulating estradiol release likely arises from the increased number of persisting follicles.

Genetic variation of genes involved in dihydrotestosterone metabolism and the risk of prostate cancer.

PubMed

Setlur, Sunita R; Chen, Chen X; Hossain, Ruhella R; Ha, Jung Sook; Van Doren, Vanessa E; Stenzel, Birgit; Steiner, Eberhard; Oldridge, Derek; Kitabayashi, Naoki; Banerjee, Samprit; Chen, Jin Yun; Schäfer, Georg; Horninger, Wolfgang; Lee, Charles; Rubin, Mark A; Klocker, Helmut; Demichelis, Francesca

2010-01-01

Dihydrotestosterone (DHT) is an important factor in prostate cancer (PCA) genesis and disease progression. Given PCA's strong genetic component, we evaluated the possibility that variation in genes involved in DHT metabolism influence PCA risk. We investigated copy number variants (CNV) and single nucleotide polymorphisms (SNP). We explored associations between CNV of uridine diphospho-glucuronosyltransferase (UGT) genes from the 2B subclass, given their prostate specificity and/or involvement in steroid metabolism and PCA risk. We also investigated associations between SNPs in genes (HSD3B1, SRD5A1/2, and AKR1C2) involved in the conversion of testosterone to DHT, and in DHT metabolism and PCA risk. The population consisted of 426 men (205 controls and 221 cases) who underwent prostate-specific antigen screening as part of a PCA early detection program in Tyrol, Austria. No association between CNV in UGT2B17 and UGT2B28 and PCA risk was identified. Men carrying the AA genotype at SNP rs6428830 (HSD3B1) had an odds ratio (OR) of 2.0 [95% confidence intervals (95% CI), 1.1-4.1] compared with men with GG, and men with AG or GG versus AA in rs1691053 (SRD5A1) had an OR of 1.8 (95% CI, 1.04-3.13). Individuals carrying both risk alleles had an OR of 3.1 (95% CI, 1.4-6.7) when compared with men carrying neither (P = 0.005). Controls with the AA genotype on rs7594951 (SRD5A2) tended toward higher serum DHT levels (P = 0.03). This is the first study to implicate the 5alpha-reductase isoform 1 (SRD5A1) and PCA risk, supporting the rationale of blocking enzymatic activity of both isoforms of 5alpha-reductase for PCA chemoprevention.

PLAT: An Automated Fault and Behavioural Anomaly Detection Tool for PLC Controlled Manufacturing Systems.

PubMed

Ghosh, Arup; Qin, Shiming; Lee, Jooyeoun; Wang, Gi-Nam

2016-01-01

Operational faults and behavioural anomalies associated with PLC control processes take place often in a manufacturing system. Real time identification of these operational faults and behavioural anomalies is necessary in the manufacturing industry. In this paper, we present an automated tool, called PLC Log-Data Analysis Tool (PLAT) that can detect them by using log-data records of the PLC signals. PLAT automatically creates a nominal model of the PLC control process and employs a novel hash table based indexing and searching scheme to satisfy those purposes. Our experiments show that PLAT is significantly fast, provides real time identification of operational faults and behavioural anomalies, and can execute within a small memory footprint. In addition, PLAT can easily handle a large manufacturing system with a reasonable computing configuration and can be installed in parallel to the data logging system to identify operational faults and behavioural anomalies effectively.

PLAT: An Automated Fault and Behavioural Anomaly Detection Tool for PLC Controlled Manufacturing Systems

PubMed Central

Ghosh, Arup; Qin, Shiming; Lee, Jooyeoun

2016-01-01

Operational faults and behavioural anomalies associated with PLC control processes take place often in a manufacturing system. Real time identification of these operational faults and behavioural anomalies is necessary in the manufacturing industry. In this paper, we present an automated tool, called PLC Log-Data Analysis Tool (PLAT) that can detect them by using log-data records of the PLC signals. PLAT automatically creates a nominal model of the PLC control process and employs a novel hash table based indexing and searching scheme to satisfy those purposes. Our experiments show that PLAT is significantly fast, provides real time identification of operational faults and behavioural anomalies, and can execute within a small memory footprint. In addition, PLAT can easily handle a large manufacturing system with a reasonable computing configuration and can be installed in parallel to the data logging system to identify operational faults and behavioural anomalies effectively. PMID:27974882

Patient identity management for secondary use of biomedical research data in a distributed computing environment.

PubMed

Nitzlnader, Michael; Schreier, Günter

2014-01-01

Dealing with data from different source domains is of increasing importance in today's large scale biomedical research endeavours. Within the European Network for Cancer research in Children and Adolescents (ENCCA) a solution to share such data for secondary use will be established. In this paper the solution arising from the aims of the ENCCA project and regulatory requirements concerning data protection and privacy is presented. Since the details of secondary biomedical dataset utilisation are often not known in advance, data protection regulations are met with an identity management concept that facilitates context-specific pseudonymisation and a way of data aggregation using a hidden reference table later on. Phonetic hashing is proposed to prevent duplicated patient registration and re-identification of patients is possible via a trusted third party only. Finally, the solution architecture allows for implementation in a distributed computing environment, including cloud-based elements.

AmpliVar: mutation detection in high-throughput sequence from amplicon-based libraries.

PubMed

Hsu, Arthur L; Kondrashova, Olga; Lunke, Sebastian; Love, Clare J; Meldrum, Cliff; Marquis-Nicholson, Renate; Corboy, Greg; Pham, Kym; Wakefield, Matthew; Waring, Paul M; Taylor, Graham R

2015-04-01

Conventional means of identifying variants in high-throughput sequencing align each read against a reference sequence, and then call variants at each position. Here, we demonstrate an orthogonal means of identifying sequence variation by grouping the reads as amplicons prior to any alignment. We used AmpliVar to make key-value hashes of sequence reads and group reads as individual amplicons using a table of flanking sequences. Low-abundance reads were removed according to a selectable threshold, and reads above this threshold were aligned as groups, rather than as individual reads, permitting the use of sensitive alignment tools. We show that this approach is more sensitive, more specific, and more computationally efficient than comparable methods for the analysis of amplicon-based high-throughput sequencing data. The method can be extended to enable alignment-free confirmation of variants seen in hybridization capture target-enrichment data. © 2015 WILEY PERIODICALS, INC.

Androgen Metabolism in Progression to Androgen-Independent Prostate Cancer

DTIC Science & Technology

2009-06-01

transcripts (TMPRSS2 exon 2-ERG exon 4) in 11 of 29 cases. Affymetrix oligonucleotide microarray data on these tumors versus a group of 27...medium were treated with DHT and immunoblotted. B, RT-PCR for ERG ( exon 9/10), TMPRSS2 ( exon 5/6), and PSA mRNA after DHT stimulation. C, cells in...therapeutic index CYP3A4 substrates were excluded. The treatment was ketoconazole 400 mg po TID, hydrocortisone (30 mg in AM and 10 mg in PM) and

Simultenious binary hash and features learning for image retrieval

NASA Astrophysics Data System (ADS)

Frantc, V. A.; Makov, S. V.; Voronin, V. V.; Marchuk, V. I.; Semenishchev, E. A.; Egiazarian, K. O.; Agaian, S.

2016-05-01

Content-based image retrieval systems have plenty of applications in modern world. The most important one is the image search by query image or by semantic description. Approaches to this problem are employed in personal photo-collection management systems, web-scale image search engines, medical systems, etc. Automatic analysis of large unlabeled image datasets is virtually impossible without satisfactory image-retrieval technique. It's the main reason why this kind of automatic image processing has attracted so much attention during recent years. Despite rather huge progress in the field, semantically meaningful image retrieval still remains a challenging task. The main issue here is the demand to provide reliable results in short amount of time. This paper addresses the problem by novel technique for simultaneous learning of global image features and binary hash codes. Our approach provide mapping of pixel-based image representation to hash-value space simultaneously trying to save as much of semantic image content as possible. We use deep learning methodology to generate image description with properties of similarity preservation and statistical independence. The main advantage of our approach in contrast to existing is ability to fine-tune retrieval procedure for very specific application which allow us to provide better results in comparison to general techniques. Presented in the paper framework for data- dependent image hashing is based on use two different kinds of neural networks: convolutional neural networks for image description and autoencoder for feature to hash space mapping. Experimental results confirmed that our approach has shown promising results in compare to other state-of-the-art methods.

A new method of cannabis ingestion: the dangers of dabs?

PubMed

Loflin, Mallory; Earleywine, Mitch

2014-10-01

A new method for administering cannabinoids, called butane hash oil ("dabs"), is gaining popularity among marijuana users. Despite press reports that suggest that "dabbing" is riskier than smoking flower cannabis, no data address whether dabs users experience more problems from use than those who prefer flower cannabis. The present study aimed to gather preliminary information on dabs users and test whether dabs use is associated with more problems than using flower cannabis. Participants (n=357) reported on their history of cannabis use, their experience with hash oil and the process of "dabbing," reasons for choosing "dabs" over other methods, and any problems related to both flower cannabis and butane hash oil. Analyses revealed that using "dabs" created no more problems or accidents than using flower cannabis. Participants did report that "dabs" led to higher tolerance and withdrawal (as defined by the participants), suggesting that the practice might be more likely to lead to symptoms of addiction or dependence. The use of butane hash oil has spread outside of the medical marijuana community, and users view it as significantly more dangerous than other forms of cannabis use. Published by Elsevier Ltd.

Novel Duplicate Address Detection with Hash Function

PubMed Central

Song, GuangJia; Ji, ZhenZhou

2016-01-01

Duplicate address detection (DAD) is an important component of the address resolution protocol (ARP) and the neighbor discovery protocol (NDP). DAD determines whether an IP address is in conflict with other nodes. In traditional DAD, the target address to be detected is broadcast through the network, which provides convenience for malicious nodes to attack. A malicious node can send a spoofing reply to prevent the address configuration of a normal node, and thus, a denial-of-service attack is launched. This study proposes a hash method to hide the target address in DAD, which prevents an attack node from launching destination attacks. If the address of a normal node is identical to the detection address, then its hash value should be the same as the “Hash_64” field in the neighboring solicitation message. Consequently, DAD can be successfully completed. This process is called DAD-h. Simulation results indicate that address configuration using DAD-h has a considerably higher success rate when under attack compared with traditional DAD. Comparative analysis shows that DAD-h does not require third-party devices and considerable computing resources; it also provides a lightweight security resolution. PMID:26991901

GSHR-Tree: a spatial index tree based on dynamic spatial slot and hash table in grid environments

NASA Astrophysics Data System (ADS)

Chen, Zhanlong; Wu, Xin-cai; Wu, Liang

2008-12-01

Computation Grids enable the coordinated sharing of large-scale distributed heterogeneous computing resources that can be used to solve computationally intensive problems in science, engineering, and commerce. Grid spatial applications are made possible by high-speed networks and a new generation of Grid middleware that resides between networks and traditional GIS applications. The integration of the multi-sources and heterogeneous spatial information and the management of the distributed spatial resources and the sharing and cooperative of the spatial data and Grid services are the key problems to resolve in the development of the Grid GIS. The performance of the spatial index mechanism is the key technology of the Grid GIS and spatial database affects the holistic performance of the GIS in Grid Environments. In order to improve the efficiency of parallel processing of a spatial mass data under the distributed parallel computing grid environment, this paper presents a new grid slot hash parallel spatial index GSHR-Tree structure established in the parallel spatial indexing mechanism. Based on the hash table and dynamic spatial slot, this paper has improved the structure of the classical parallel R tree index. The GSHR-Tree index makes full use of the good qualities of R-Tree and hash data structure. This paper has constructed a new parallel spatial index that can meet the needs of parallel grid computing about the magnanimous spatial data in the distributed network. This arithmetic splits space in to multi-slots by multiplying and reverting and maps these slots to sites in distributed and parallel system. Each sites constructs the spatial objects in its spatial slot into an R tree. On the basis of this tree structure, the index data was distributed among multiple nodes in the grid networks by using large node R-tree method. The unbalance during process can be quickly adjusted by means of a dynamical adjusting algorithm. This tree structure has considered the distributed operation, reduplication operation transfer operation of spatial index in the grid environment. The design of GSHR-Tree has ensured the performance of the load balance in the parallel computation. This tree structure is fit for the parallel process of the spatial information in the distributed network environments. Instead of spatial object's recursive comparison where original R tree has been used, the algorithm builds the spatial index by applying binary code operation in which computer runs more efficiently, and extended dynamic hash code for bit comparison. In GSHR-Tree, a new server is assigned to the network whenever a split of a full node is required. We describe a more flexible allocation protocol which copes with a temporary shortage of storage resources. It uses a distributed balanced binary spatial tree that scales with insertions to potentially any number of storage servers through splits of the overloaded ones. The application manipulates the GSHR-Tree structure from a node in the grid environment. The node addresses the tree through its image that the splits can make outdated. This may generate addressing errors, solved by the forwarding among the servers. In this paper, a spatial index data distribution algorithm that limits the number of servers has been proposed. We improve the storage utilization at the cost of additional messages. The structure of GSHR-Tree is believed that the scheme of this grid spatial index should fit the needs of new applications using endlessly larger sets of spatial data. Our proposal constitutes a flexible storage allocation method for a distributed spatial index. The insertion policy can be tuned dynamically to cope with periods of storage shortage. In such cases storage balancing should be favored for better space utilization, at the price of extra message exchanges between servers. This structure makes a compromise in the updating of the duplicated index and the transformation of the spatial index data. Meeting the needs of the grid computing, GSHRTree has a flexible structure in order to satisfy new needs in the future. The GSHR-Tree provides the R-tree capabilities for large spatial datasets stored over interconnected servers. The analysis, including the experiments, confirmed the efficiency of our design choices. The scheme should fit the needs of new applications of spatial data, using endlessly larger datasets. Using the system response time of the parallel processing of spatial scope query algorithm as the performance evaluation factor, According to the result of the simulated the experiments, GSHR-Tree is performed to prove the reasonable design and the high performance of the indexing structure that the paper presented.

Testosterone administration decreases generosity in the ultimatum game.

PubMed

Zak, Paul J; Kurzban, Robert; Ahmadi, Sheila; Swerdloff, Ronald S; Park, Jang; Efremidze, Levan; Redwine, Karen; Morgan, Karla; Matzner, William

2009-12-16

How do human beings decide when to be selfish or selfless? In this study, we gave testosterone to 25 men to establish its impact on prosocial behaviors in a double-blind within-subjects design. We also confirmed participants' testosterone levels before and after treatment through blood draws. Using the Ultimatum Game from behavioral economics, we find that men with artificially raised T, compared to themselves on placebo, were 27% less generous towards strangers with money they controlled (95% CI placebo: (1.70, 2.72); 95% CI T: (.98, 2.30)). This effect scales with a man's level of total-, free-, and dihydro-testosterone (DHT). Men in the lowest decile of DHT were 560% more generous than men in the highest decile of DHT. We also found that men with elevated testosterone were more likely to use their own money punish those who were ungenerous toward them. Our results continue to hold after controlling for altruism. We conclude that elevated testosterone causes men to behave antisocially.

Testosterone Administration Decreases Generosity in the Ultimatum Game

PubMed Central

Zak, Paul J.; Kurzban, Robert; Ahmadi, Sheila; Swerdloff, Ronald S.; Park, Jang; Efremidze, Levan; Redwine, Karen; Morgan, Karla; Matzner, William

2009-01-01

How do human beings decide when to be selfish or selfless? In this study, we gave testosterone to 25 men to establish its impact on prosocial behaviors in a double-blind within-subjects design. We also confirmed participants' testosterone levels before and after treatment through blood draws. Using the Ultimatum Game from behavioral economics, we find that men with artificially raised T, compared to themselves on placebo, were 27% less generous towards strangers with money they controlled (95% CI placebo: (1.70, 2.72); 95% CI T: (.98, 2.30)). This effect scales with a man's level of total-, free-, and dihydro-testosterone (DHT). Men in the lowest decile of DHT were 560% more generous than men in the highest decile of DHT. We also found that men with elevated testosterone were more likely to use their own money punish those who were ungenerous toward them. Our results continue to hold after controlling for altruism. We conclude that elevated testosterone causes men to behave antisocially. PMID:20016825

Image encryption algorithm based on multiple mixed hash functions and cyclic shift

NASA Astrophysics Data System (ADS)

Wang, Xingyuan; Zhu, Xiaoqiang; Wu, Xiangjun; Zhang, Yingqian

2018-08-01

This paper proposes a new one-time pad scheme for chaotic image encryption that is based on the multiple mixed hash functions and the cyclic-shift function. The initial value is generated using both information of the plaintext image and the chaotic sequences, which are calculated from the SHA1 and MD5 hash algorithms. The scrambling sequences are generated by the nonlinear equations and logistic map. This paper aims to improve the deficiencies of traditional Baptista algorithms and its improved algorithms. We employ the cyclic-shift function and piece-wise linear chaotic maps (PWLCM), which give each shift number the characteristics of chaos, to diffuse the image. Experimental results and security analysis show that the new scheme has better security and can resist common attacks.

HASH: the Hong Kong/AAO/Strasbourg Hα planetary nebula database

NASA Astrophysics Data System (ADS)

Parker, Quentin A.; Bojičić, Ivan S.; Frew, David J.

2016-07-01

By incorporating our major recent discoveries with re-measured and verified contents of existing catalogues we provide, for the first time, an accessible, reliable, on-line SQL database for essential, up-to date information for all known Galactic planetary nebulae (PNe). We have attempted to: i) reliably remove PN mimics/false ID's that have biased previous studies and ii) provide accurate positions, sizes, morphologies, multi-wavelength imagery and spectroscopy. We also provide a link to CDS/Vizier for the archival history of each object and other valuable links to external data. With the HASH interface, users can sift, select, browse, collate, investigate, download and visualise the entire currently known Galactic PNe diversity. HASH provides the community with the most complete and reliable data with which to undertake new science.

Classifying chemical mode of action using gene networks and machine learning: a case study with the herbicide linuron.

PubMed

Ornostay, Anna; Cowie, Andrew M; Hindle, Matthew; Baker, Christopher J O; Martyniuk, Christopher J

2013-12-01

The herbicide linuron (LIN) is an endocrine disruptor with an anti-androgenic mode of action. The objectives of this study were to (1) improve knowledge of androgen and anti-androgen signaling in the teleostean ovary and to (2) assess the ability of gene networks and machine learning to classify LIN as an anti-androgen using transcriptomic data. Ovarian explants from vitellogenic fathead minnows (FHMs) were exposed to three concentrations of either 5α-dihydrotestosterone (DHT), flutamide (FLUT), or LIN for 12h. Ovaries exposed to DHT showed a significant increase in 17β-estradiol (E2) production while FLUT and LIN had no effect on E2. To improve understanding of androgen receptor signaling in the ovary, a reciprocal gene expression network was constructed for DHT and FLUT using pathway analysis and these data suggested that steroid metabolism, translation, and DNA replication are processes regulated through AR signaling in the ovary. Sub-network enrichment analysis revealed that FLUT and LIN shared more regulated gene networks in common compared to DHT. Using transcriptomic datasets from different fish species, machine learning algorithms classified LIN successfully with other anti-androgens. This study advances knowledge regarding molecular signaling cascades in the ovary that are responsive to androgens and anti-androgens and provides proof of concept that gene network analysis and machine learning can classify priority chemicals using experimental transcriptomic data collected from different fish species. © 2013.

Developmental Programming: Postnatal Estradiol Modulation of Prenatally Organized Reproductive Neuroendocrine Function in Sheep

PubMed Central

Puttabyatappa, Muraly; Cardoso, Rodolfo C.; Herkimer, Carol; Veiga-Lopez, Almudena; Padmanabhan, Vasantha

2016-01-01

Gestational testosterone (T) excess, acting via both the androgenic and estrogenic pathways, advances puberty and disrupts the neuroendocrine estradiol (E) feedback and periovulatory hormonal dynamics in female sheep. These prenatally programmed defects may be subject to postnatal modifications by continued organizational and/or activational effects of steroids. The present study investigated 1) the organizational contribution of prenatal estrogen excess and 2) the impact of postnatal exposure to E in modulating the effects of prenatal androgen excess (T and dihydrotestosterone [DHT]) on puberty, neuroendocrine feedback mechanisms, and periovulatory hormonal dynamics in sheep. Pregnant Suffolk sheep were treated with T, DHT, E, or E plus DHT (ED) from days 30 to 90 of gestation. A subset of the control (C), T, and DHT female offspring received a constant-release E implant postnatally. Findings revealed that 1) prenatal E-treatment failed to reproduce the neuroendocrine disruptions predicted to be programmed by the estrogenic pathway and 2) prenatal ED-treatment did not adequately replicate the reproductive neuroendocrine defects induced by prenatal T excess. More importantly, continuous postnatal E-treatment, while delaying the onset of puberty and reducing the inhibitory effects of E on tonic luteinizing hormone (LH) release, failed to amplify the E positive feedback and periovulatory defects induced by prenatal T-treatment. Our results indicate that disruptions in E positive feedback mechanisms and periovulatory gonadotropin secretion induced by prenatal T-treatment are programmed predominantly during the prenatal life with postnatal exposure to E excess not contributing further to these disruptions. PMID:27222598

Functional mechanism of C-terminal tail in the enzymatic role of porcine testicular carbonyl reductase: a combined experiment and molecular dynamics simulation study of the C-terminal tail in the enzymatic role of PTCR.

PubMed

Son, Minky; Bang, Woo Young; Park, Chanin; Lee, Yuno; Kwon, Seul Gi; Kim, Sam Woong; Kim, Chul Wook; Lee, Keun Woo

2014-01-01

Porcine testicular carbonyl reductase, PTCR which is one of the short chain dehydrogenases/reductases (SDR) superfamily catalyzes the NADPH-dependent reduction of carbonyl compounds including steroids and prostaglandins. Previously we reported C-terminal tail of PTCR was deleted due to a nonsynonymous single nucleotide variation (nsSNV). Here we identified from kinetic studies that the enzymatic properties for 5α-dihydrotestosterone (5α-DHT) were different between wild-type and C-terminal-deleted PTCRs. Compared to wild-type PTCR, C-terminal-deleted PTCR has much higher reduction rate. To investigate structural difference between wild-type and C-terminal-deleted PTCRs upon 5α-DHT binding, we performed molecular dynamics simulations for two complexes. Using trajectories, molecular interactions including hydrogen bonding patterns, distance between 5α-DHT and catalytic Tyr193, and interaction energies are analyzed and compared. During the MD simulation time, the dynamic behavior of C-terminal tail in wild-type PTCR is also examined using essential dynamics analysis. The results of our simulations reveal that the binding conformation of 5α-DHT in C-terminal-deleted PTCR is more favorable for reduction reaction in PTCR, which shows strong agreement with kinetic data. These structural findings provide valuable information to understand substrate specificity of PTCR and further kinetic properties of enzymes belonging to the SDR superfamily.

Expression of AR, 5αR1 and 5αR2 in bladder urothelial carcinoma and relationship to clinicopathological factors.

PubMed

Hata, Shuko; Ise, Kazue; Azmahani, Abdullah; Konosu-Fukaya, Sachiko; McNamara, Keely May; Fujishima, Fumiyoshi; Shimada, Keiji; Mitsuzuka, Koji; Arai, Yoichi; Sasano, Hironobu; Nakamura, Yasuhiro

2017-12-01

Bladder urothelial carcinoma is increasing in incidence with age and its prognosis could become worse when accompanied with metastasis. Effective treatment of these advanced patients is required and it becomes important to understand its underlying biology of this neoplasm, especially with regard to its biological pathways. A potential proposed pathway is androgen receptor (AR)-mediated intracellular signaling but the details have remained relatively unexplored. The expression of AR, 5α-reductase type1 (5αR1) and 5α-reductase type2 (5αR2) were examined in the bladder cancer cell line T24 and surgical pathology specimens. We also evaluated the status of androgen related cell proliferation and migration using the potent, non-aromatizable androgen agonist 5α-dihydrotestosterone (DHT). DHT treatment significantly increased AR mRNA expression level, but not those of 5αR1 and 5αR2 in T24 cells. DHT also suppressed cellular migration with weaker and opposite effects on cell proliferation. A significant inverse correlation was detected between pT stage and AR, 5αR1 and 5αR2 immunoreactivity. Inverse correlations detected between tumor grade and AR/androgen metabolizing enzyme also suggested that the loss of AR and androgen-producing enzymes could be associated with tumor progression. Effects of DHT on cells also suggest that androgens may regulate cellular behavior. Copyright © 2017 Elsevier Inc. All rights reserved.

Functional Mechanism of C-Terminal Tail in the Enzymatic Role of Porcine Testicular Carbonyl Reductase: A Combined Experiment and Molecular Dynamics Simulation Study of the C-Terminal Tail in the Enzymatic Role of PTCR

PubMed Central

Park, Chanin; Lee, Yuno; Kwon, Seul Gi; Kim, Sam Woong; Kim, Chul Wook; Lee, Keun Woo

2014-01-01

Porcine testicular carbonyl reductase, PTCR which is one of the short chain dehydrogenases/reductases (SDR) superfamily catalyzes the NADPH-dependent reduction of carbonyl compounds including steroids and prostaglandins. Previously we reported C- terminal tail of PTCR was deleted due to a nonsynonymous single nucleotide variation (nsSNV). Here we identified from kinetic studies that the enzymatic properties for 5α-dihydrotestosterone (5α-DHT) were different between wild-type and C-terminal-deleted PTCRs. Compared to wild-type PTCR, C-terminal-deleted PTCR has much higher reduction rate. To investigate structural difference between wild-type and C-terminal-deleted PTCRs upon 5α-DHT binding, we performed molecular dynamics simulations for two complexes. Using trajectories, molecular interactions including hydrogen bonding patterns, distance between 5α-DHT and catalytic Tyr193, and interaction energies are analyzed and compared. During the MD simulation time, the dynamic behavior of C-terminal tail in wild-type PTCR is also examined using essential dynamics analysis. The results of our simulations reveal that the binding conformation of 5α-DHT in C-terminal-deleted PTCR is more favorable for reduction reaction in PTCR, which shows strong agreement with kinetic data. These structural findings provide valuable information to understand substrate specificity of PTCR and further kinetic properties of enzymes belonging to the SDR superfamily. PMID:24646606

Effects of cross-linking on mechanical, biological properties and biodegradation behavior of Nile tilapia skin collagen sponge as a biomedical material.

PubMed

Sun, Leilei; Li, Bafang; Yao, Di; Song, Wenkui; Hou, Hu

2018-04-01

The objective of this study was to explore the effects of dehydrothermal treatment (DHT) and glutaraldehyde (GTA) cross-linking on mechanical, biological properties and biodegradation behavior of Nile tilapia skin collagen sponge fabricated by freeze-drying technology. It was found that the GTA cross-linked collagen sponge exhibited a higher degree of cross-linking in comparison with DHT. The extent of increased tensile strength as well as hygroscopicity indicated that GTA cross-linking was superior to DHT in mechanical properties and liquid absorption, which was attributed to different cross-linking mechanisms. Hygroscopicity assay indicated that cross-linking could improve stability of collagen in solutions. No obvious changes in porosity and blood coagulation time were observed whether cross-linking or not. Results from collagenase biodegradation assay in vitro illustrated that GTA-treated collagen sponge was more resistant to collagenase biodegradation, while DHT exhibited negligible resistance. In addition, photochemical stability of collagen sponge was studied by Fourier transforms infrared spectroscopy (FTIR), which indicated that both cross-linking treatments could not change the backbone structure of collagen. Furthermore, the microstructure of collagen sponge was stable after cross-linking. The highly porous and interconnected structure of collagen sponge was helpful to the absorption of wound exudates, supplement of oxygen and cell proliferation, accompanied with good blood compatibility, which indicated that our fabricated collagen sponge could be applied in biomedical materials field as wound dressings. Copyright © 2018. Published by Elsevier Ltd.

Construction of FuzzyFind Dictionary using Golay Coding Transformation for Searching Applications

NASA Astrophysics Data System (ADS)

Kowsari, Kamram

2015-03-01

searching through a large volume of data is very critical for companies, scientists, and searching engines applications due to time complexity and memory complexity. In this paper, a new technique of generating FuzzyFind Dictionary for text mining was introduced. We simply mapped the 23 bits of the English alphabet into a FuzzyFind Dictionary or more than 23 bits by using more FuzzyFind Dictionary, and reflecting the presence or absence of particular letters. This representation preserves closeness of word distortions in terms of closeness of the created binary vectors within Hamming distance of 2 deviations. This paper talks about the Golay Coding Transformation Hash Table and how it can be used on a FuzzyFind Dictionary as a new technology for using in searching through big data. This method is introduced by linear time complexity for generating the dictionary and constant time complexity to access the data and update by new data sets, also updating for new data sets is linear time depends on new data points. This technique is based on searching only for letters of English that each segment has 23 bits, and also we have more than 23-bit and also it could work with more segments as reference table.

Mercury⊕: An evidential reasoning image classifier

NASA Astrophysics Data System (ADS)

Peddle, Derek R.

1995-12-01

MERCURY⊕ is a multisource evidential reasoning classification software system based on the Dempster-Shafer theory of evidence. The design and implementation of this software package is described for improving the classification and analysis of multisource digital image data necessary for addressing advanced environmental and geoscience applications. In the remote-sensing context, the approach provides a more appropriate framework for classifying modern, multisource, and ancillary data sets which may contain a large number of disparate variables with different statistical properties, scales of measurement, and levels of error which cannot be handled using conventional Bayesian approaches. The software uses a nonparametric, supervised approach to classification, and provides a more objective and flexible interface to the evidential reasoning framework using a frequency-based method for computing support values from training data. The MERCURY⊕ software package has been implemented efficiently in the C programming language, with extensive use made of dynamic memory allocation procedures and compound linked list and hash-table data structures to optimize the storage and retrieval of evidence in a Knowledge Look-up Table. The software is complete with a full user interface and runs under Unix, Ultrix, VAX/VMS, MS-DOS, and Apple Macintosh operating system. An example of classifying alpine land cover and permafrost active layer depth in northern Canada is presented to illustrate the use and application of these ideas.

Significance of cannabis use to dental practice.

PubMed

Maloney, William James

2011-04-01

The illicit use of the three main forms of cannabis-marijuana, hash, hash oil-pose certain obstacles and challenges to the dental professional. There are a number of systemic, as well as oral/head and neck manifestations, associated with cannabis use. Dentists need to be aware of these manifestations in order to take whatever precautions and/or modifications to the proposed treatment that might be necessary.

Portable Language-Independent Adaptive Translation from OCR. Phase 1

DTIC Science & Technology

2009-04-01

including brute-force k-Nearest Neighbors ( kNN ), fast approximate kNN using hashed k-d trees, classification and regression trees, and locality...achieved by refinements in ground-truthing protocols. Recent algorithmic improvements to our approximate kNN classifier using hashed k-D trees allows...recent years discriminative training has been shown to outperform phonetic HMMs estimated using ML for speech recognition. Standard ML estimation

Image Hashes as Templates for Verification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Janik, Tadeusz; Jarman, Kenneth D.; Robinson, Sean M.

2012-07-17

Imaging systems can provide measurements that confidently assess characteristics of nuclear weapons and dismantled weapon components, and such assessment will be needed in future verification for arms control. Yet imaging is often viewed as too intrusive, raising concern about the ability to protect sensitive information. In particular, the prospect of using image-based templates for verifying the presence or absence of a warhead, or of the declared configuration of fissile material in storage, may be rejected out-of-hand as being too vulnerable to violation of information barrier (IB) principles. Development of a rigorous approach for generating and comparing reduced-information templates from images,more » and assessing the security, sensitivity, and robustness of verification using such templates, are needed to address these concerns. We discuss our efforts to develop such a rigorous approach based on a combination of image-feature extraction and encryption-utilizing hash functions to confirm proffered declarations, providing strong classified data security while maintaining high confidence for verification. The proposed work is focused on developing secure, robust, tamper-sensitive and automatic techniques that may enable the comparison of non-sensitive hashed image data outside an IB. It is rooted in research on so-called perceptual hash functions for image comparison, at the interface of signal/image processing, pattern recognition, cryptography, and information theory. Such perceptual or robust image hashing—which, strictly speaking, is not truly cryptographic hashing—has extensive application in content authentication and information retrieval, database search, and security assurance. Applying and extending the principles of perceptual hashing to imaging for arms control, we propose techniques that are sensitive to altering, forging and tampering of the imaged object yet robust and tolerant to content-preserving image distortions and noise. Ensuring that the information contained in the hashed image data (available out-of-IB) cannot be used to extract sensitive information about the imaged object is of primary concern. Thus the techniques are characterized by high unpredictability to guarantee security. We will present an assessment of the performance of our techniques with respect to security, sensitivity and robustness on the basis of a methodical and mathematically precise framework.« less

Octadecyl Chains Immobilized onto Hyaluronic Acid Coatings by Thiol-ene "Click Chemistry" Increase the Surface Antimicrobial Properties and Prevent Platelet Adhesion and Activation to Polyurethane.

PubMed

Felgueiras, Helena P; Wang, L M; Ren, K F; Querido, M M; Jin, Q; Barbosa, M A; Ji, J; Martins, M C L

2017-03-08

Infection and thrombus formation are still the biggest challenges for the success of blood contact medical devices. This work aims the development of an antimicrobial and hemocompatible biomaterial coating through which selective binding of albumin (passivant protein) from the bloodstream is promoted and, thus, adsorption of other proteins responsible for bacterial adhesion and thrombus formation can be prevented. Polyurethane (PU) films were coated with hyaluronic acid, an antifouling agent, that was previously modified with thiol groups (HA-SH), using polydopamine as the binding agent. Octadecyl acrylate (C18) was used to attract albumin since it resembles the circulating free fatty acids and albumin is a fatty acid transporter. Thiol-ene "click chemistry" was explored for C18 immobilization on HA-SH through a covalent bond between the thiol groups from the HA and the alkene groups from the C18 chains. Surfaces were prepared with different C18 concentrations (0, 5, 10, and 20%) and successful immobilization was demonstrated by scanning electron microscopy (SEM), water contact angle determinations, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The ability of surfaces to bind albumin selectively was determined by quartz crystal microbalance with dissipation (QCM-D). Albumin adsorption increased in response to the hydrophobic nature of the surfaces, which augmented with C18 saturation. HA-SH coating reduced albumin adsorption to PU. C18 immobilized onto HA-SH at 5% promoted selective binding of albumin, decreased Staphylococcus aureus adhesion and prevented platelet adhesion and activation to PU in the presence of human plasma. C18/HA-SH coating was established as an innovative and promising strategy to improve the antimicrobial properties and hemocompatibility of any blood contact medical device.

A Hash Based Remote User Authentication and Authenticated Key Agreement Scheme for the Integrated EPR Information System.

PubMed

Li, Chun-Ta; Weng, Chi-Yao; Lee, Cheng-Chi; Wang, Chun-Cheng

2015-11-01

To protect patient privacy and ensure authorized access to remote medical services, many remote user authentication schemes for the integrated electronic patient record (EPR) information system have been proposed in the literature. In a recent paper, Das proposed a hash based remote user authentication scheme using passwords and smart cards for the integrated EPR information system, and claimed that the proposed scheme could resist various passive and active attacks. However, in this paper, we found that Das's authentication scheme is still vulnerable to modification and user duplication attacks. Thereafter we propose a secure and efficient authentication scheme for the integrated EPR information system based on lightweight hash function and bitwise exclusive-or (XOR) operations. The security proof and performance analysis show our new scheme is well-suited to adoption in remote medical healthcare services.

Range image registration based on hash map and moth-flame optimization

NASA Astrophysics Data System (ADS)

Zou, Li; Ge, Baozhen; Chen, Lei

2018-03-01

Over the past decade, evolutionary algorithms (EAs) have been introduced to solve range image registration problems because of their robustness and high precision. However, EA-based range image registration algorithms are time-consuming. To reduce the computational time, an EA-based range image registration algorithm using hash map and moth-flame optimization is proposed. In this registration algorithm, a hash map is used to avoid over-exploitation in registration process. Additionally, we present a search equation that is better at exploration and a restart mechanism to avoid being trapped in local minima. We compare the proposed registration algorithm with the registration algorithms using moth-flame optimization and several state-of-the-art EA-based registration algorithms. The experimental results show that the proposed algorithm has a lower computational cost than other algorithms and achieves similar registration precision.

Matching CCD images to a stellar catalog using locality-sensitive hashing

NASA Astrophysics Data System (ADS)

Liu, Bo; Yu, Jia-Zong; Peng, Qing-Yu

2018-02-01

The usage of a subset of observed stars in a CCD image to find their corresponding matched stars in a stellar catalog is an important issue in astronomical research. Subgraph isomorphic-based algorithms are the most widely used methods in star catalog matching. When more subgraph features are provided, the CCD images are recognized better. However, when the navigation feature database is large, the method requires more time to match the observing model. To solve this problem, this study investigates further and improves subgraph isomorphic matching algorithms. We present an algorithm based on a locality-sensitive hashing technique, which allocates quadrilateral models in the navigation feature database into different hash buckets and reduces the search range to the bucket in which the observed quadrilateral model is located. Experimental results indicate the effectivity of our method.

Learning Short Binary Codes for Large-scale Image Retrieval.

PubMed

Liu, Li; Yu, Mengyang; Shao, Ling

2017-03-01

Large-scale visual information retrieval has become an active research area in this big data era. Recently, hashing/binary coding algorithms prove to be effective for scalable retrieval applications. Most existing hashing methods require relatively long binary codes (i.e., over hundreds of bits, sometimes even thousands of bits) to achieve reasonable retrieval accuracies. However, for some realistic and unique applications, such as on wearable or mobile devices, only short binary codes can be used for efficient image retrieval due to the limitation of computational resources or bandwidth on these devices. In this paper, we propose a novel unsupervised hashing approach called min-cost ranking (MCR) specifically for learning powerful short binary codes (i.e., usually the code length shorter than 100 b) for scalable image retrieval tasks. By exploring the discriminative ability of each dimension of data, MCR can generate one bit binary code for each dimension and simultaneously rank the discriminative separability of each bit according to the proposed cost function. Only top-ranked bits with minimum cost-values are then selected and grouped together to compose the final salient binary codes. Extensive experimental results on large-scale retrieval demonstrate that MCR can achieve comparative performance as the state-of-the-art hashing algorithms but with significantly shorter codes, leading to much faster large-scale retrieval.

The effects of the environmental antiandrogen vinclozolin on the induction of granulosa cell apoptosis during follicular atresia in pigs.

PubMed

Knet, Malgorzata; Tabarowski, Zbigniew; Slomczynska, Maria; Duda, Malgorzata

2014-06-01

The aim of this study was to investigate whether the androgens testosterone and dihydrotestosterone (DHT) and the antiandrogenic fungicide vinclozolin (Vnz) exert proapoptotic effects on porcine granulosa cells (GCs), and to examine the roles of these compounds in follicular atresia. Granulosa cells isolated from pig follicles were cultured for 24 hours, and then exposed to 0.1 μM testosterone, 0.1 μM DHT, 14 μM Vnz, or the equivalent concentrations of testosterone and Vnz or DHT and Vnz for a further 24 hours. Apoptosis and necrosis of the GCs were determined via Hoechst staining and flow cytometry analyses of annexin V-stained cells. Whole porcine follicles were also exposed to the same compounds and combinations of compounds for 24 hours. The sections were stained with hematoxylin and eosin for morphologic assessments, and a Terminal deoxynucleotidyl Transferase Biotyn-dUTP Nick-End Labeling (TUNEL) assay was performed to determine the number of apoptotic cells. The progesterone and estradiol concentrations secreted into the culture media by isolated GCs and follicles were also measured. Exposure to the androgens resulted in an increased number of apoptotic GCs both in vitro and in the organotypic model. Vinclozolin exposure increased and decreased the number of necrotic and apoptotic GCs, respectively. Furthermore, compared with control follicles, those exposed to testosterone, DHT, or Vnz displayed enhanced atresia, and coadministration of Vnz attenuated the promotive effect of these androgens on atresia. Estradiol secretion was stimulated by the combination of testosterone and Vnz, whereas exposure to Vnz alone reduced it. Progesterone production declined after the combined addition of androgens and the antiandrogen. In summary, Vnz caused massive necrosis of GCs in vitro and induced apoptosis of GCs in whole follicles. The androgens testosterone and DHT enhanced these effects. The results presented here suggest that selective destruction of porcine follicles is a serious consequence of exposure to Vnz, and may lead to premature ovarian failure in affected animals. Copyright © 2014 Elsevier Inc. All rights reserved.

Roles for the sympathetic nervous system, renal nerves, and CNS melanocortin-4 receptor in the elevated blood pressure in hyperandrogenemic female rats.

PubMed

Maranon, Rodrigo; Lima, Roberta; Spradley, Frank T; do Carmo, Jussara M; Zhang, Howei; Smith, Andrew D; Bui, Elizabeth; Thomas, R Lucas; Moulana, Mohadetheh; Hall, John E; Granger, Joey P; Reckelhoff, Jane F

2015-04-15

Women with polycystic ovary syndrome (PCOS) have hyperandrogenemia and increased prevalence of risk factors for cardiovascular disease, including elevated blood pressure. We recently characterized a hyperandrogenemic female rat (HAF) model of PCOS [chronic dihydrotestosterone (DHT) beginning at 4 wk of age] that exhibits similar characteristics as women with PCOS. In the present studies we tested the hypotheses that the elevated blood pressure in HAF rats is mediated in part by sympathetic activation, renal nerves, and melanocortin-4 receptor (MC4R) activation. Adrenergic blockade with terazosin and propranolol or renal denervation reduced mean arterial pressure (MAP by telemetry) in HAF rats but not controls. Hypothalamic MC4R expression was higher in HAF rats than controls, and central nervous system MC4R antagonism with SHU-9119 (1 nmol/h icv) reduced MAP in HAF rats. Taking a genetic approach, MC4R null and wild-type (WT) female rats were treated with DHT or placebo from 5 to 16 wk of age. MC4R null rats were obese and had higher MAP than WT control rats, and while DHT increased MAP in WT controls, DHT failed to further increase MAP in MC4R null rats. These data suggest that increases in MAP with chronic hyperandrogenemia in female rats are due, in part, to activation of the sympathetic nervous system, renal nerves, and MC4R and may provide novel insights into the mechanisms responsible for hypertension in women with hyperandrogenemia such as PCOS. Copyright © 2015 the American Physiological Society.

Identification of a new plant extract for androgenic alopecia treatment using a non-radioactive human hair dermal papilla cell-based assay.

PubMed

Jain, Ruchy; Monthakantirat, Orawan; Tengamnuay, Parkpoom; De-Eknamkul, Wanchai

2016-01-21

Androgenic alopecia (AGA) is a major type of human scalp hair loss, which is caused by two androgens: testosterone (T) and 5α-dihydrotestosterone (5α-DHT). Both androgens bind to the androgen receptor (AR) and induce androgen-sensitive genes within the human hair dermal papilla cells (HHDPCs), but 5α-DHT exhibits much higher binding affinity and potency than T does in inducing the involved androgen-sensitive genes. Changes in the induction of androgen-sensitive genes during AGA are caused by the over-production of 5α-DHT by the 5α-reductase (5α-R) enzyme; therefore, one possible method to treat AGA is to inhibit this enzymatic reaction. RT-PCR was used to identify the presence of the 5α-R and AR within HHDPCs. A newly developed AGA-relevant HHDPC-based assay combined with non-radioactive thin layer chromatography (TLC) detection was used for screening crude plant extracts for the identification of new 5α-R inhibitors. HHDPCs expressed both 5α-R type 1 isoform of the enzyme (5α-R1) and AR in all of the passages used in this study. Among the thirty tested extracts, Avicennia marina (AM) displayed the highest inhibitory activity at the final concentration of 10 μg/ml, as the production of 5α-DHT decreased by 52% (IC50 = 9.21 ± 0.38 μg/ml). Avicennia marina (AM) was identified as a potential candidate for the treatment of AGA based on its 5α-R1-inhibitory activity.

Developmental programming: postnatal estradiol modulation of prenatally organized reproductive neuroendocrine function in sheep.

PubMed

Puttabyatappa, Muraly; Cardoso, Rodolfo C; Herkimer, Carol; Veiga-Lopez, Almudena; Padmanabhan, Vasantha

2016-08-01

Gestational testosterone (TS) excess, acting via both the androgenic and estrogenic pathways, advances puberty and disrupts the neuroendocrine estradiol (E2) feedback and periovulatory hormonal dynamics in female sheep. These prenatally programmed defects may be subject to postnatal modifications by continued organizational and/or activational effects of steroids. This study investigated (1) the organizational contribution of prenatal estrogen excess and (2) the impact of postnatal exposure to E2 in modulating the effects of prenatal androgen excess (TS and dihydrotestosterone (DHT)) on puberty, neuroendocrine feedback mechanisms, and periovulatory hormonal dynamics in sheep. Pregnant Suffolk sheep were treated with TS, DHT, E2, or E2 plus DHT (ED) from days 30 to 90 of gestation. A subset of the control (C), TS, and DHT female offspring received a constant-release E2 implant postnatally. Findings revealed that (1) prenatal E2-treatment failed to reproduce the neuroendocrine disruptions predicted to be programmed by the estrogenic pathway and (2) prenatal E2D-treatment did not adequately replicate the reproductive neuroendocrine defects induced by prenatal TS excess. More importantly, continuous postnatal E2-treatment, while delaying the onset of puberty and reducing the inhibitory effects of E2 on tonic luteinizing hormone (LH) release, failed to amplify the E2-positive feedback and periovulatory defects induced by prenatal TS-treatment. Our results indicate that disruptions in E2-positive feedback mechanisms and periovulatory gonadotropin secretion induced by prenatal TS-treatment are programmed predominantly during the prenatal life with postnatal exposure to E2 excess not contributing further to these disruptions. © 2016 Society for Reproduction and Fertility.

Developmental Programming: Does Prenatal Steroid Excess Disrupt the Ovarian VEGF System in Sheep?1

PubMed Central

Ortega, Hugo Héctor; Veiga-Lopez, Almudena; Sreedharan, Shilpa; del Luján Velázquez, Melisa María; Salvetti, Natalia Raquel; Padmanabhan, Vasantha

2015-01-01

Prenatal testosterone (T), but not dihydrotestosterone (DHT), excess disrupts ovarian cyclicity and increases follicular recruitment and persistence. We hypothesized that the disruption in the vascular endothelial growth factor (VEGF) system contributes to the enhancement of follicular recruitment and persistence in prenatal T-treated sheep. The impact of T/DHT treatments from Days 30 to 90 of gestation on VEGFA, VEGFB, and their receptor (VEGFR-1 [FLT1], VEGFR-2 [KDR], and VEGFR-3 [FLT4]) protein expression was examined by immunohistochemistry on Fetal Days 90 and 140, 22 wk, 10 mo (postpubertal), and 21 mo (adult) of age. Arterial morphometry was performed in Fetal Day 140 and postpubertal ovaries. VEGFA and VEGFB expression were found in granulosa cells at all stages of follicular development with increased expression in antral follicles. VEGFA was present in theca interna, while VEGFB was present in theca interna/externa and stromal cells. All three receptors were expressed in the granulosa, theca, and stromal cells during all stages of follicular development. VEGFR-3 increased with follicular differentiation with the highest level seen in the granulosa cells of antral follicles. None of the members of the VEGF family or their receptor expression were altered by age or prenatal T/DHT treatments. At Fetal Day 140, area, wall thickness, and wall area of arteries from the ovarian hilum were larger in prenatal T- and DHT-treated females, suggestive of early androgenic programming of arterial differentiation. This may facilitate increased delivery of endocrine factors and thus indirectly contribute to the development of the multifollicular phenotype. PMID:26178718

Androgens regulate scarless repair of the endometrial "wound" in a mouse model of menstruation.

PubMed

Cousins, Fiona L; Kirkwood, Phoebe M; Murray, Alison A; Collins, Frances; Gibson, Douglas A; Saunders, Philippa T K

2016-08-01

The human endometrium undergoes regular cycles of synchronous tissue shedding (wounding) and repair that occur during menstruation before estrogen-dependent regeneration. Endometrial repair is normally both rapid and scarless. Androgens regulate cutaneous wound healing, but their role in endometrial repair is unknown. We used a murine model of simulated menses; mice were treated with a single dose of the nonaromatizable androgen dihydrotestosterone (DHT; 200 µg/mouse) to coincide with initiation of tissue breakdown. DHT altered the duration of vaginal bleeding and delayed restoration of the luminal epithelium. Analysis of uterine mRNAs 24 h after administration of DHT identified significant changes in metalloproteinases (Mmp3 and -9; P < 0.01), a snail family member (Snai3; P < 0.001), and osteopontin (Spp1; P < 0.001). Chromatin immunoprecipitation analysis identified putative androgen receptor (AR) binding sites in the proximal promoters of Mmp9, Snai3, and Spp1. Striking spatial and temporal changes in immunoexpression of matrix metalloproteinase (MMP) 3/9 and caspase 3 were detected after DHT treatment. These data represent a paradigm shift in our understanding of the role of androgens in endometrial repair and suggest that androgens may have direct impacts on endometrial tissue integrity. These studies provide evidence that the AR is a potential target for drug therapy to treat conditions associated with aberrant endometrial repair processes.-Cousins, F. L., Kirkwood, P. M., Murray, A. A., Collins, F., Gibson, D. A., Saunders, P. T. K. Androgens regulate scarless repair of the endometrial "wound" in a mouse model of menstruation. © The Author(s).

Antiandrogenic actions of medroxyprogesterone acetate on epithelial cells within normal human breast tissues cultured ex vivo.

PubMed

Ochnik, Aleksandra M; Moore, Nicole L; Jankovic-Karasoulos, Tanja; Bianco-Miotto, Tina; Ryan, Natalie K; Thomas, Mervyn R; Birrell, Stephen N; Butler, Lisa M; Tilley, Wayne D; Hickey, Theresa E

2014-01-01

Medroxyprogesterone acetate (MPA), a component of combined estrogen-progestin therapy (EPT), has been associated with increased breast cancer risk in EPT users. MPA can bind to the androgen receptor (AR), and AR signaling inhibits cell growth in breast tissues. Therefore, the aim of this study was to investigate the potential of MPA to disrupt AR signaling in an ex vivo culture model of normal human breast tissue. Histologically normal breast tissues from women undergoing breast surgical operation were cultured in the presence or in the absence of the native AR ligand 5α-dihydrotestosterone (DHT), MPA, or the AR antagonist bicalutamide. Ki67, bromodeoxyuridine, B-cell CLL/lymphoma 2 (BCL2), AR, estrogen receptor α, and progesterone receptor were detected by immunohistochemistry. DHT inhibited the proliferation of breast epithelial cells in an AR-dependent manner within tissues from postmenopausal women, and MPA significantly antagonized this androgenic effect. These hormonal responses were not commonly observed in cultured tissues from premenopausal women. In tissues from postmenopausal women, DHT either induced or repressed BCL2 expression, and the antiandrogenic effect of MPA on BCL2 was variable. MPA significantly opposed the positive effect of DHT on AR stabilization, but these hormones had no significant effect on estrogen receptor α or progesterone receptor levels. In a subset of postmenopausal women, MPA exerts an antiandrogenic effect on breast epithelial cells that is associated with increased proliferation and destabilization of AR protein. This activity may contribute mechanistically to the increased risk of breast cancer in women taking MPA-containing EPT.

Inhibitory effect of rape pollen supercritical CO2 fluid extract against testosterone-induced benign prostatic hyperplasia in rats

PubMed Central

YANG, BI-CHENG; JIN, LI-LI; YANG, YI-FANG; LI, KUN; PENG, DAN-MING

2014-01-01

Benign prostatic hyperplasia (BPH) can lead to lower urinary tract symptoms. Rape pollen is an apicultural product that is composed of nutritionally valuable and biologically active substances. The aim of the present study was to investigate the protective effect of rape pollen supercritical CO2 fluid extract (SFE-CO2) in BPH development using a testosterone-induced BPH rat model. BPH was induced in the experimental groups by daily subcutaneous injections of testosterone for a period of 30 days. Rape pollen SFE-CO2 was administered daily by oral gavage concurrently with the testosterone injections. Animals were sacrificed at the scheduled termination and the prostates were weighed and subjected to histopathological examination. Testosterone, dihydrotestosterone (DHT), 5α-reductase and cyclooxygenase-2 (COX-2) levels were also measured. BPH-induced animals exhibited an increase in prostate weight with increased testosterone, DHT, 5α-reductase and COX-2 expression levels. However, rape pollen SFE-CO2 treatment resulted in significant reductions in the prostate index and testosterone, DHT, 5α-reductase and COX-2 levels compared with those in BPH-induced animals. Histopathological examination also demonstrated that rape pollen SFE-CO2 treatment suppressed testosterone-induced BPH. These observations indicate that rape pollen SFE-CO2 inhibits the development of BPH in rats and these effects are closely associated with reductions in DHT, 5α-reductase and COX-2 levels. Therefore, the results of the present study clearly indicate that rape pollen SFE-CO2 extract may be a useful agent in BPH treatment. PMID:24944593

Cardiac Nitric Oxide Synthases and Na⁺/K⁺-ATPase in the Rat Model of Polycystic Ovary Syndrome Induced by Dihydrotestosterone.

PubMed

Tepavčević, S; Milutinović, D V; Macut, D; Stanišić, J; Nikolić, M; Božić-Antić, I; Rodaljević, S; Bjekić-Macut, J; Matić, G; Korićanac, G

2015-05-01

Nitric oxide synthases (NOSs) and Na(+)/K(+)-ATPase are enzymes essential for regular functioning of the heart. Since both enzymes are under insulin and androgen regulation and since insulin action and androgen level were disturbed in polycystic ovary syndrome (PCOS), we hypothesized that cardiac nitric oxide (NO) production and sodium/potassium transport would be deteriorated in PCOS. To test our hypothesis we introduced animal model of PCOS based on dihydrotestosterone (DHT) treatment of female Wistar rats and analyzed protein expression, phosphorylation or subcellular localization of endothelial NOS (eNOS), inducible NOS (iNOS) and alpha subunits of Na(+)/K(+)-ATPase in the heart. Obtained results indicate that DHT treatment significantly decreased cardiac eNOS protein level and activating phosphorylation at serine 1,177, while inhibitory phosphorylation at threonine 495 was increased. In contrast to expression of eNOS, iNOS protein level in the heart of DHT-treated rats was significantly elevated. Furthermore, cardiac protein level of alpha 1 subunit of the ATPase, as well as its plasma membrane content, were decreased in rats with PCOS. In line with this, alpha 2 subunit protein level in fraction of plasma membranes was also significantly below control level. In conclusion, DHT treatment impaired effectiveness of NOSs and Na(+)/K(+)-ATPase in the female rat heart. Regarding the importance of NO production and sodium/potassium transport in the cardiac contraction and blood flow regulation, it implicates strong consequences of PCOS for heart functioning. © Georg Thieme Verlag KG Stuttgart · New York.

Inhibitory effect of rape pollen supercritical CO2 fluid extract against testosterone-induced benign prostatic hyperplasia in rats.

PubMed

Yang, Bi-Cheng; Jin, Li-Li; Yang, Yi-Fang; Li, Kun; Peng, Dan-Ming

2014-07-01

Benign prostatic hyperplasia (BPH) can lead to lower urinary tract symptoms. Rape pollen is an apicultural product that is composed of nutritionally valuable and biologically active substances. The aim of the present study was to investigate the protective effect of rape pollen supercritical CO 2 fluid extract (SFE-CO 2 ) in BPH development using a testosterone-induced BPH rat model. BPH was induced in the experimental groups by daily subcutaneous injections of testosterone for a period of 30 days. Rape pollen SFE-CO 2 was administered daily by oral gavage concurrently with the testosterone injections. Animals were sacrificed at the scheduled termination and the prostates were weighed and subjected to histopathological examination. Testosterone, dihydrotestosterone (DHT), 5α-reductase and cyclooxygenase-2 (COX-2) levels were also measured. BPH-induced animals exhibited an increase in prostate weight with increased testosterone, DHT, 5α-reductase and COX-2 expression levels. However, rape pollen SFE-CO 2 treatment resulted in significant reductions in the prostate index and testosterone, DHT, 5α-reductase and COX-2 levels compared with those in BPH-induced animals. Histopathological examination also demonstrated that rape pollen SFE-CO 2 treatment suppressed testosterone-induced BPH. These observations indicate that rape pollen SFE-CO 2 inhibits the development of BPH in rats and these effects are closely associated with reductions in DHT, 5α-reductase and COX-2 levels. Therefore, the results of the present study clearly indicate that rape pollen SFE-CO 2 extract may be a useful agent in BPH treatment.

Androgens Exert a Cysticidal Effect upon Taenia crassiceps by Disrupting Flame Cell Morphology and Function

PubMed Central

Ambrosio, Javier R.; Valverde-Islas, Laura; Nava-Castro, Karen E.; Palacios- Arreola, M. Isabel; Ostoa-Saloma, Pedro; Reynoso-Ducoing, Olivia; Escobedo, Galileo; Ruíz-Rosado, Azucena; Dominguez-Ramírez, Lenin; Morales-Montor, Jorge

2015-01-01

The effects of testosterone (T4) and dihydrotestosterone (DHT) on the survival of the helminth cestode parasite Taenia crassiceps, as well as their effects on actin, tubulin and myosin expression and their assembly into the excretory system of flame cells are described in this paper. In vitro evaluations on parasite viability, flow cytometry, confocal microscopy, video-microscopy of live flame cells, and docking experiments of androgens interacting with actin, tubulin, and myosin were conducted. Our results show that T4 and DHT reduce T. crassiceps viability in a dose- and time-dependent fashion, reaching 90% of mortality at the highest dose used (40 ng/ml) and time exposed (10 days) in culture. Androgen treatment does not induce differences in the specific expression pattern of actin, tubulin, and myosin isoforms as compared with control parasites. Confocal microscopy demonstrated a strong disruption of the parasite tegument, with reduced assembly, shape, and motion of flame cells. Docking experiments show that androgens are capable of affecting parasite survival and flame cell morphology by directly interacting with actin, tubulin and myosin without altering their protein expression pattern. We show that both T4 and DHT are able to bind actin, tubulin, and myosin affecting their assembly and causing parasite intoxication due to impairment of flame cell function. Live flame cell video microscopy showing a reduced motion as well changes in the shape of flame cells are also shown. In summary, T4 and DHT directly act on T. crassiceps cysticerci through altering parasite survival as well as the assembly and function of flame cells. PMID:26076446

Concept and viability of androgen annihilation for advanced prostate cancer.

PubMed

Mohler, James L

2014-09-01

There remains no standard of care for patients with a rising prostate-specific antigen level after radical prostatectomy or radiotherapy but who have no radiographic metastases, even though this is the second largest group of patients with prostate cancer (CaP) in the United States. Androgen deprivation therapy (ADT) may cure some men with advanced CaP based on single-institution series and a randomized clinical trial of immediate versus delayed ADT for men found to have pelvic lymph node metastasis at the time of radical prostatectomy. ADT may be more effective when initiated for minimal disease burden, which can be detected using PSA after radical prostatectomy or radiotherapy, and if more complete disruption of the androgen axis using newer agents decreases the chance that androgen-sensitive cells survive to adapt to a low-androgen environment. Androgens may be "annihilated" simultaneously using a luteinizing hormone-releasing hormone antagonist or agonist to inhibit testicular production of testosterone, a P45017A1 (CYP17A1) inhibitor to diminish metabolism of testosterone via the adrenal pathway and dihydrotestosterone (DHT) via the backdoor pathway, a 5α-reductase (SRD5A) inhibitor to diminish testosterone reduction to DHT and backdoor metabolism of progesterone substrates to DHT, and a newer antiandrogen to compete better with DHT for the androgen receptor ligand-binding domain. Early initiation of androgen annihilation for induction as part of planned intermittent ADT should be safe, may reduce tumor burden below a threshold that allows eradication by the immune system, and may cure many men who have failed definitive local therapy. © 2014 American Cancer Society.

Crosslinking of micropatterned collagen-based nerve guides to modulate the expected half-life.

PubMed

Salvatore, L; Madaghiele, M; Parisi, C; Gatti, F; Sannino, A

2014-12-01

The microstructural, mechanical, compositional, and degradative properties of a nerve conduit are known to strongly affect the regenerative process of the injured peripheral nerve. Starting from the fabrication of micropatterned collagen-based nerve guides, according to a spin-casting process reported in the literature, this study further investigates the possibility to modulate the degradation rate of the scaffolds over a wide time frame, in an attempt to match different rates of nerve regeneration that might be encountered in vivo. To this aim, three different crosslinking methods, that is, dehydrothermal (DHT), carbodiimide-based (EDAC), and glutaraldehyde-based (GTA) crosslinking, were selected. The elastically effective degree of crosslinking, attained by each method and evaluated according to the classical rubber elasticity theory, was found to significantly tune the in vitro half-life (t1/2 ) of the matrices, with an exponential dependence of the latter on the crosslink density. The high crosslinking efficacy of EDAC and GTA treatments, respectively threefold and fourfold when compared to the one attained by DHT, led to a sharp increase of the corresponding in vitro half-lives (ca., 10, 172, and 690 h, for DHT, EDAC, and GTA treated matrices, respectively). As shown by cell viability assays, the cytocompatibility of both DHT and EDAC treatments, as opposed to the toxicity of GTA, suggests that such methods are suitable to crosslink collagen-based scaffolds conceived for clinical use. In particular, nerve guides with expected high residence times in vivo might be produced by finely controlling the biocompatible reaction(s) adopted for crosslinking. © 2014 Wiley Periodicals, Inc.

Multirate-based fast parallel algorithms for 2-D DHT-based real-valued discrete Gabor transform.

PubMed

Tao, Liang; Kwan, Hon Keung

2012-07-01

Novel algorithms for the multirate and fast parallel implementation of the 2-D discrete Hartley transform (DHT)-based real-valued discrete Gabor transform (RDGT) and its inverse transform are presented in this paper. A 2-D multirate-based analysis convolver bank is designed for the 2-D RDGT, and a 2-D multirate-based synthesis convolver bank is designed for the 2-D inverse RDGT. The parallel channels in each of the two convolver banks have a unified structure and can apply the 2-D fast DHT algorithm to speed up their computations. The computational complexity of each parallel channel is low and is independent of the Gabor oversampling rate. All the 2-D RDGT coefficients of an image are computed in parallel during the analysis process and can be reconstructed in parallel during the synthesis process. The computational complexity and time of the proposed parallel algorithms are analyzed and compared with those of the existing fastest algorithms for 2-D discrete Gabor transforms. The results indicate that the proposed algorithms are the fastest, which make them attractive for real-time image processing.

Exercise differentially affects metabolic functions and white adipose tissue in female letrozole- and dihydrotestosterone-induced mouse models of polycystic ovary syndrome.

PubMed

Marcondes, Rodrigo R; Maliqueo, Manuel; Fornes, Romina; Benrick, Anna; Hu, Min; Ivarsson, Niklas; Carlström, Mattias; Cushman, Samuel W; Stenkula, Karin G; Maciel, Gustavo A R; Stener-Victorin, Elisabet

2017-06-15

Here we hypothesized that exercise in dihydrotestosterone (DHT) or letrozole (LET)-induced polycystic ovary syndrome mouse models improves impaired insulin and glucose metabolism, adipose tissue morphology, and expression of genes related to adipogenesis, lipid metabolism, Notch pathway and browning in inguinal and mesenteric fat. DHT-exposed mice had increased body weight, increased number of large mesenteric adipocytes. LET-exposed mice displayed increased body weight and fat mass, decreased insulin sensitivity, increased frequency of small adipocytes and increased expression of genes related to lipolysis in mesenteric fat. In both models, exercise decreased fat mass and inguinal and mesenteric adipose tissue expression of Notch pathway genes, and restored altered mesenteric adipocytes morphology. In conclusion, exercise restored mesenteric adipocytes morphology in DHT- and LET-exposed mice, and insulin sensitivity and mesenteric expression of lipolysis-related genes in LET-exposed mice. Benefits could be explained by downregulation of Notch, and modulation of browning and lipolysis pathways in the adipose tissue. Copyright © 2017 Elsevier B.V. All rights reserved.

Hash Functions and Information Theoretic Security

NASA Astrophysics Data System (ADS)

Bagheri, Nasour; Knudsen, Lars R.; Naderi, Majid; Thomsen, Søren S.

Information theoretic security is an important security notion in cryptography as it provides a true lower bound for attack complexities. However, in practice attacks often have a higher cost than the information theoretic bound. In this paper we study the relationship between information theoretic attack costs and real costs. We show that in the information theoretic model, many well-known and commonly used hash functions such as MD5 and SHA-256 fail to be preimage resistant.

A Tree Locality-Sensitive Hash for Secure Software Testing

DTIC Science & Technology

2017-09-14

errors, or to look for vulnerabilities that could allow a nefarious actor to use our software against us. Ultimately, all testing is designed to find...and an equivalent number of feasible paths discovered by Klee. 1.5 Summary This document the Tree Locality-Sensitive Hash (TLSH), a locality-senstive...performing two groups of tests that verify the accuracy and usefulness of TLSH. Chapter 5 summarizes the contents of the dissertation and lists avenues

Best-First Heuristic Search for Multicore Machines

DTIC Science & Technology

2010-01-01

Otto, 1998) to implement an asynchronous version of PRA* that they call Hash Distributed A* ( HDA *). HDA * distributes nodes using a hash function in...nodes which are being communicated between peers are in transit. In contact with the authors of HDA *, we have created an implementation of HDA * for...Also, our implementation of HDA * allows us to make a fair comparison between algorithms by sharing common data structures such as priority queues and

Checking Questionable Entry of Personally Identifiable Information Encrypted by One-Way Hash Transformation

PubMed Central

Chen, Xianlai; Fann, Yang C; McAuliffe, Matthew; Vismer, David

2017-01-01

Background As one of the several effective solutions for personal privacy protection, a global unique identifier (GUID) is linked with hash codes that are generated from combinations of personally identifiable information (PII) by a one-way hash algorithm. On the GUID server, no PII is permitted to be stored, and only GUID and hash codes are allowed. The quality of PII entry is critical to the GUID system. Objective The goal of our study was to explore a method of checking questionable entry of PII in this context without using or sending any portion of PII while registering a subject. Methods According to the principle of GUID system, all possible combination patterns of PII fields were analyzed and used to generate hash codes, which were stored on the GUID server. Based on the matching rules of the GUID system, an error-checking algorithm was developed using set theory to check PII entry errors. We selected 200,000 simulated individuals with randomly-planted errors to evaluate the proposed algorithm. These errors were placed in the required PII fields or optional PII fields. The performance of the proposed algorithm was also tested in the registering system of study subjects. Results There are 127,700 error-planted subjects, of which 114,464 (89.64%) can still be identified as the previous one and remaining 13,236 (10.36%, 13,236/127,700) are discriminated as new subjects. As expected, 100% of nonidentified subjects had errors within the required PII fields. The possibility that a subject is identified is related to the count and the type of incorrect PII field. For all identified subjects, their errors can be found by the proposed algorithm. The scope of questionable PII fields is also associated with the count and the type of the incorrect PII field. The best situation is to precisely find the exact incorrect PII fields, and the worst situation is to shrink the questionable scope only to a set of 13 PII fields. In the application, the proposed algorithm can give a hint of questionable PII entry and perform as an effective tool. Conclusions The GUID system has high error tolerance and may correctly identify and associate a subject even with few PII field errors. Correct data entry, especially required PII fields, is critical to avoiding false splits. In the context of one-way hash transformation, the questionable input of PII may be identified by applying set theory operators based on the hash codes. The count and the type of incorrect PII fields play an important role in identifying a subject and locating questionable PII fields. PMID:28213343

Checking Questionable Entry of Personally Identifiable Information Encrypted by One-Way Hash Transformation.

PubMed

Chen, Xianlai; Fann, Yang C; McAuliffe, Matthew; Vismer, David; Yang, Rong

2017-02-17

As one of the several effective solutions for personal privacy protection, a global unique identifier (GUID) is linked with hash codes that are generated from combinations of personally identifiable information (PII) by a one-way hash algorithm. On the GUID server, no PII is permitted to be stored, and only GUID and hash codes are allowed. The quality of PII entry is critical to the GUID system. The goal of our study was to explore a method of checking questionable entry of PII in this context without using or sending any portion of PII while registering a subject. According to the principle of GUID system, all possible combination patterns of PII fields were analyzed and used to generate hash codes, which were stored on the GUID server. Based on the matching rules of the GUID system, an error-checking algorithm was developed using set theory to check PII entry errors. We selected 200,000 simulated individuals with randomly-planted errors to evaluate the proposed algorithm. These errors were placed in the required PII fields or optional PII fields. The performance of the proposed algorithm was also tested in the registering system of study subjects. There are 127,700 error-planted subjects, of which 114,464 (89.64%) can still be identified as the previous one and remaining 13,236 (10.36%, 13,236/127,700) are discriminated as new subjects. As expected, 100% of nonidentified subjects had errors within the required PII fields. The possibility that a subject is identified is related to the count and the type of incorrect PII field. For all identified subjects, their errors can be found by the proposed algorithm. The scope of questionable PII fields is also associated with the count and the type of the incorrect PII field. The best situation is to precisely find the exact incorrect PII fields, and the worst situation is to shrink the questionable scope only to a set of 13 PII fields. In the application, the proposed algorithm can give a hint of questionable PII entry and perform as an effective tool. The GUID system has high error tolerance and may correctly identify and associate a subject even with few PII field errors. Correct data entry, especially required PII fields, is critical to avoiding false splits. In the context of one-way hash transformation, the questionable input of PII may be identified by applying set theory operators based on the hash codes. The count and the type of incorrect PII fields play an important role in identifying a subject and locating questionable PII fields. ©Xianlai Chen, Yang C Fann, Matthew McAuliffe, David Vismer, Rong Yang. Originally published in JMIR Medical Informatics (http://medinform.jmir.org), 17.02.2017.

Git as an Encrypted Distributed Version Control System

DTIC Science & Technology

2015-03-01

options. The algorithm uses AES- 256 counter mode with an IV derived from SHA -1-HMAC hash (this is nearly identical to the GCM mode discussed earlier...built into the internal structure of Git. Every file in a Git repository is check summed with a SHA -1 hash, a one-way function with arbitrarily long...implementation. Git-encrypt calls OpenSSL cryptography library command line functions. The default cipher used is AES- 256 - Electronic Code Book (ECB), which is

The Amordad database engine for metagenomics.

PubMed

Behnam, Ehsan; Smith, Andrew D

2014-10-15

Several technical challenges in metagenomic data analysis, including assembling metagenomic sequence data or identifying operational taxonomic units, are both significant and well known. These forms of analysis are increasingly cited as conceptually flawed, given the extreme variation within traditionally defined species and rampant horizontal gene transfer. Furthermore, computational requirements of such analysis have hindered content-based organization of metagenomic data at large scale. In this article, we introduce the Amordad database engine for alignment-free, content-based indexing of metagenomic datasets. Amordad places the metagenome comparison problem in a geometric context, and uses an indexing strategy that combines random hashing with a regular nearest neighbor graph. This framework allows refinement of the database over time by continual application of random hash functions, with the effect of each hash function encoded in the nearest neighbor graph. This eliminates the need to explicitly maintain the hash functions in order for query efficiency to benefit from the accumulated randomness. Results on real and simulated data show that Amordad can support logarithmic query time for identifying similar metagenomes even as the database size reaches into the millions. Source code, licensed under the GNU general public license (version 3) is freely available for download from http://smithlabresearch.org/amordad andrewds@usc.edu Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Stable carbon and oxygen isotope record of central Lake Erie sediments

USGS Publications Warehouse

Tevesz, M.J.S.; Spongberg, A.L.; Fuller, J.A.

1998-01-01

Stable carbon and oxygen isotope data from mollusc aragonite extracted from sediment cores provide new information on the origin and history of sedimentation in the southwestern area of the central basin of Lake Erie. Sediments infilling the Sandusky subbasin consist of three lithologic units overlying glacial deposits. The lowest of these is a soft gray mud overlain by a shell hash layer containing Sphaerium striatinum fragments. A fluid mud unit caps the shell hash layer and extends upwards to the sediment-water interface. New stable isotope data suggest that the soft gray mud unit is of postglacial, rather than proglacial, origin. These data also suggest that the shell hash layer was derived from erosional winnowing of the underlying soft gray mud layer. This winnowing event may have occurred as a result of the Nipissing flood. The Pelee-Lorain moraine, which forms the eastern boundary of the Sandusky subbasin, is an elevated area of till capped by a sand deposit that originated as a beach. The presence of both the shell hash layer and relict beach deposit strengthens the interpretation that the Nipissing flood was a critical event in the development of the southwestern area of the central basin of Lake Erie. This event, which returned drainage from the upper lakes to the Lake Erie basin, was a dominant influence on regional stratigraphy, bathymetry, and depositional setting.

Improved One-Way Hash Chain and Revocation Polynomial-Based Self-Healing Group Key Distribution Schemes in Resource-Constrained Wireless Networks

PubMed Central

Chen, Huifang; Xie, Lei

2014-01-01

Self-healing group key distribution (SGKD) aims to deal with the key distribution problem over an unreliable wireless network. In this paper, we investigate the SGKD issue in resource-constrained wireless networks. We propose two improved SGKD schemes using the one-way hash chain (OHC) and the revocation polynomial (RP), the OHC&RP-SGKD schemes. In the proposed OHC&RP-SGKD schemes, by introducing the unique session identifier and binding the joining time with the capability of recovering previous session keys, the problem of the collusion attack between revoked users and new joined users in existing hash chain-based SGKD schemes is resolved. Moreover, novel methods for utilizing the one-way hash chain and constructing the personal secret, the revocation polynomial and the key updating broadcast packet are presented. Hence, the proposed OHC&RP-SGKD schemes eliminate the limitation of the maximum allowed number of revoked users on the maximum allowed number of sessions, increase the maximum allowed number of revoked/colluding users, and reduce the redundancy in the key updating broadcast packet. Performance analysis and simulation results show that the proposed OHC&RP-SGKD schemes are practical for resource-constrained wireless networks in bad environments, where a strong collusion attack resistance is required and many users could be revoked. PMID:25529204

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinnecker, G.H.G; Hiort, O.; Kruse, K.

Conversion of testosterone (T) to dihydrotestosterone (DHT) in genital tissue is catalysed by the enzyme 5{alpha}-reductase 2, which is encoded by the SRD5A2 gene. The potent androgen DHT is required for full masculinization of the external genitalia. Mutations of the SRD5A2 gene inhibit enzyme activity, diminish DHT formation, and hence cause masculinization defects of varying degree. The classical syndrome, formerly described as pseudovaginal perineoscrotal hypospadias, is characterized by a predominantly female phenotype at birth and significant virilization without gynecomastia at puberty. We investigated nine patients with steroid 5{alpha}-reductase 2 deficiency (SRD). T/DHT-ratios were highly increased in the classical syndrome, butmore » variable in the less severe affected patients. Mutations in the SRD5A2 gene had been characterized using PCR-SSCP analysis and direct DNA sequencing. A small deletion was encountered in two patients, while all other patients had single base mutations which result in amino acid substitutions. We conclude that phenotypes may vary widely in patients with SRD5A2 gene mutations spanning the whole range from completely female to normal male without distinctive clinical signs of the disease. Hence, steroid 5{alpha}-reductase deficiency should be considered not only in sex reversed patients with female or ambiguous phenotypes, but also in those with mild symptoms of undermasculinization as encountered in patients with hypospadias and/or micropenis. A classification based on the severity of the masculinization defect may be used for correlation of phenotypes with enzyme activities and genotypes, and for comparisons of phenotypes between different patients as the basis for clinical decisions to be made in patients with pseudohermaphroditism due to steroid 5{alpha}-reductase 2 deficiency. 22 refs., 2 figs., 2 tabs.« less

Eliminating medullary 5-HT neurons delays arousal and decreases the respiratory response to repeated episodes of hypoxia in neonatal rat pups

PubMed Central

Schneider, Robert W.; Tobia, Christine M.; Commons, Kathryn G.

2015-01-01

Arousal from sleep is a critical defense mechanism when infants are exposed to hypoxia, and an arousal deficit has been postulated as contributing to the etiology of the sudden infant death syndrome (SIDS). The brainstems of SIDS infants are deficient in serotonin (5-HT) and tryptophan hydroxylase (TPH) and have decreased binding to 5-HT receptors. This study explores a possible connection between medullary 5-HT neuronal activity and arousal from sleep in response to hypoxia. Medullary raphe 5-HT neurons were eliminated from neonatal rat pups with intracisterna magna (CM) injections of 5,7-dihydroxytryptamine (DHT) at P2-P3. Each pup was then exposed to four episodes of hypoxia during sleep at three developmental ages (P5, P15, and P25) to produce an arousal response. Arousal, heart rate, and respiratory rate responses of DHT-injected pups were compared with pups that received CM artificial cerebrospinal fluid (aCSF) and those that received DHT but did not have a significant reduction in medullary 5-HT neurons. During each hypoxia exposure, the time to arousal from the onset of hypoxia (latency) was measured together with continuous measurements of heart and respiratory rates, oxyhemoglobin saturation, and chamber oxygen concentration. DHT-injected pups with significant losses of medullary 5-HT neurons exhibited significantly longer arousal latencies and decreased respiratory rate responses to hypoxia compared with controls. These results support the hypothesis that in newborn and young rat pups, 5-HT neurons located in the medullary raphe contribute to the arousal response to hypoxia. Thus alterations medullary 5-HT mechanisms might contribute to an arousal deficit and contribute to death in SIDS infants. PMID:26702023

Inhibition of 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD) activity of human lung microsomes by genistein, daidzein, coumestrol and C(18)-, C(19)- and C(21)-hydroxysteroids and ketosteroids.

PubMed

Blomquist, Charles H; Lima, Paul H; Hotchkiss, John R

2005-07-01

Epidemiologic data suggest a relationship between dietary intake of phytochemicals and a lower incidence of some cancers. Modulation of steroid hormone metabolism has been proposed as a basis for this effect. It has been shown that aromatase, 3beta-hydroxysteroid dehydrogenase and 17beta-hydroxysteroid dehydrogenase (17beta-HSD) are inhibited by the isoflavones, genistein and daidzein, and by coumestrol. In general, the extent of inhibition has been expressed in terms of IC50-values, which do not give information as to the pattern of inhibition, i.e., competitive, non-competitive, or mixed. Less is known of the effects of these compounds on 3alpha-HSD. The human lung is known to have a high level of 17beta-HSD and 3alpha-HSD activity. During the course of studies to characterize both activities in normal and inflamed lung and lung tumors we noted that 3alpha-HSD activity with 5alpha-DHT of microsomes from normal, adult lung was particularly susceptible to inhibition by coumestrol. To clarify the pattern of inhibition, the inhibition constants Ki and K'i were evaluated from plots of 1/v versus [I] and [S]/v versus [I]. Genistein, daidzein and coumestrol gave mixed inhibition patterns versus both 5alpha-DHT and NADH. In contrast, 5alpha-androstane-3,17-dione and 5alpha-pregnane-3,20-dione were competitive with 5alpha-DHT. NAD inhibited competitively with NADH. Our findings demonstrate that phytochemicals have the potential to inhibit 5alpha-DHT metabolism and thereby affect the androgen status of the human lung. The observation of a mixed inhibition pattern suggests these compounds bind to more than one form of the enzyme within the catalytic pathway.

Opposite effects of dihydrotestosterone and estradiol on apoptosis in the anterior pituitary gland from male rats.

PubMed

Magri, María Laura; Gottardo, María Florencia; Zárate, Sandra; Eijo, Guadalupe; Ferraris, Jimena; Jaita, Gabriela; Ayala, Mariela Moreno; Candolfi, Marianela; Pisera, Daniel; Seilicovich, Adriana

2016-03-01

Hormones locally synthesized in the anterior pituitary gland are involved in regulation of pituitary cell renewal. In the pituitary, testosterone (T) may exert its actions per se or by conversion to dihydrotestosterone (DHT) or 17β-estradiol (E2) by 5α-reductase and aromatase activity, which are expressed in this gland. Previous reports from our laboratory showed that estrogens modulate apoptosis of lactotropes and somatotropes from female rats. Now, we examined the in vitro and in vivo effects of gonadal steroids on apoptosis of anterior pituitary cells from adult male rats. T in vitro did not modify apoptosis in anterior pituitary cells from gonadectomized (GNX) male rats. DHT, a non-aromatizable androgen, exerted direct antiapoptotic action on total anterior pituitary cells and folliculo-stellate cells, but not on lactotropes, somatotropes, or gonadotropes. On the contrary, E2 exerted a rapid apoptotic effect on total cells as well as on lactotropes and somatotropes. Incubation of anterior pituitary cells with T in presence of Finasteride, an inhibitor of 5α-reductase, increased the percentage of TUNEL-positive cells. In vivo administration of DHT to GNX rats reduced apoptosis in the anterior pituitary whereas E2 exerted proapoptotic action and reduced cells in G2/M-phase of the cell cycle. In summary, our results indicate that DHT and E2 have opposite effects on apoptosis in the anterior pituitary gland suggesting that local metabolization of T to these steroids could be involved in pituitary cell turnover in males. Changes in expression and/or activity of 5α-reductase and aromatase may play a role in the development of anterior pituitary tumors.

Long pentraxin-3 as an epithelial-stromal fibroblast growth factor-targeting inhibitor in prostate cancer.

PubMed

Ronca, Roberto; Alessi, Patrizia; Coltrini, Daniela; Di Salle, Emanuela; Giacomini, Arianna; Leali, Daria; Corsini, Michela; Belleri, Mirella; Tobia, Chiara; Garlanda, Cecilia; Bonomi, Elisa; Tardanico, Regina; Vermi, William; Presta, Marco

2013-06-01

Fibroblast growth factors (FGFs) exert autocrine/paracrine functions in prostate cancer by stimulating angiogenesis and tumour growth. Here dihydrotestosterone (DHT) up-regulates FGF2 and FGF8b production in murine TRAMP-C2 prostate cancer cells, activating a FGF-dependent autocrine loop of stimulation. The soluble pattern recognition receptor long pentraxin-3 (PTX3) acts as a natural FGF antagonist that binds FGF2 and FGF8b via its N-terminal domain. We demonstrate that recombinant PTX3 protein and the PTX3-derived pentapeptide Ac-ARPCA-NH2 abolish the mitogenic response of murine TRAMP-C2 cells and human LNCaP prostate cancer cells to DHT and FGFs. Also, PTX3 hampers the angiogenic activity of DHT-activated TRAMP-C2 cells on the chick embryo chorioallantoic membrane (CAM). Accordingly, human PTX3 overexpression inhibits the mitogenic activity exerted by DHT or FGFs on hPTX3_TRAMP-C2 cell transfectants and their angiogenic activity. Also, hPTX3_TRAMP-C2 cells show a dramatic decrease of their angiogenic and tumourigenic potential when grafted in syngeneic or immunodeficient athymic male mice. A similar inhibitory effect is observed when TRAMP-C2 cells overexpress only the FGF-binding N-terminal PTX3 domain. In keeping with the anti-tumour activity of PTX3 in experimental prostate cancer, immunohistochemical analysis of prostate needle biopsies from primary prostate adenocarcinoma patients shows that parenchymal PTX3 expression, abundant in basal cells of normal glands, is lost in high-grade prostatic intraepithelial neoplasia and in invasive tumour areas. These results identify PTX3 as a potent FGF antagonist endowed with anti-angiogenic and anti-neoplastic activity in prostate cancer. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Developmental Programming: Does Prenatal Steroid Excess Disrupt the Ovarian VEGF System in Sheep?

PubMed

Ortega, Hugo Héctor; Veiga-Lopez, Almudena; Sreedharan, Shilpa; del Luján Velázquez, Melisa María; Salvetti, Natalia Raquel; Padmanabhan, Vasantha

2015-09-01

Prenatal testosterone (T), but not dihydrotestosterone (DHT), excess disrupts ovarian cyclicity and increases follicular recruitment and persistence. We hypothesized that the disruption in the vascular endothelial growth factor (VEGF) system contributes to the enhancement of follicular recruitment and persistence in prenatal T-treated sheep. The impact of T/DHT treatments from Days 30 to 90 of gestation on VEGFA, VEGFB, and their receptor (VEGFR-1 [FLT1], VEGFR-2 [KDR], and VEGFR-3 [FLT4]) protein expression was examined by immunohistochemistry on Fetal Days 90 and 140, 22 wk, 10 mo (postpubertal), and 21 mo (adult) of age. Arterial morphometry was performed in Fetal Day 140 and postpubertal ovaries. VEGFA and VEGFB expression were found in granulosa cells at all stages of follicular development with increased expression in antral follicles. VEGFA was present in theca interna, while VEGFB was present in theca interna/externa and stromal cells. All three receptors were expressed in the granulosa, theca, and stromal cells during all stages of follicular development. VEGFR-3 increased with follicular differentiation with the highest level seen in the granulosa cells of antral follicles. None of the members of the VEGF family or their receptor expression were altered by age or prenatal T/DHT treatments. At Fetal Day 140, area, wall thickness, and wall area of arteries from the ovarian hilum were larger in prenatal T- and DHT-treated females, suggestive of early androgenic programming of arterial differentiation. This may facilitate increased delivery of endocrine factors and thus indirectly contribute to the development of the multifollicular phenotype. © 2015 by the Society for the Study of Reproduction, Inc.

Developmental programming: differential effects of prenatal testosterone and dihydrotestosterone on follicular recruitment, depletion of follicular reserve, and ovarian morphology in sheep.

PubMed

Smith, Peter; Steckler, Teresa L; Veiga-Lopez, Almudena; Padmanabhan, Vasantha

2009-04-01

Prenatal testosterone excess programs an array of adult reproductive disorders including luteinizing hormone excess, functional hyperandrogenism, neuroendocrine defects, polycystic ovarian morphology, and corpus luteum dysfunction, culminating in early reproductive failure. Polycystic ovarian morphology originates from enhanced follicular recruitment and follicular persistence. We tested to determine whether prenatal testosterone treatment, by its androgenic actions, enhances follicular recruitment, causes early depletion of follicular reserve, and disrupts the ovarian architecture. Pregnant sheep were given twice-weekly injections of testosterone or dihydrotestosterone (DHT), a nonaromatizable androgen, from Days 30 to 90 of gestation. Ovaries were obtained from Day-90 and Day-140 fetuses, and from 10-mo-old females during a synchronized follicular phase (n = 5-9 per treatment). Stereological techniques were used to quantify changes in ovarian follicle/germ cell populations. Results revealed no differences in numbers of oocytes and follicles between the three groups on Fetal Day 90. Greater numbers of early growing follicles were found in prenatal testosterone- and DHT-treated fetuses on Day 140. Increased numbers of growing follicles and reduced numbers of primordial follicles were found in 10-mo-old, prenatal testosterone-treated females, but not in those treated with DHT. Antral follicles of prenatal testosterone-treated females, but not those treated with DHT, manifested several abnormalities, which included the appearance of hemorrhagic and luteinized follicles and abnormal early antrum formation. Both treatment groups showed morphological differences in the rete ovarii. These findings suggest that increased follicular recruitment and morphologic changes in the rete ovarii of prenatal testosterone-treated females are facilitated by androgenic programming, but that postpubertal follicular growth, antral follicular disruptions, and follicular depletion largely occur through estrogenic programming.

Endothelial relaxation mechanisms and nitrative stress are partly restored by Vitamin D3 therapy in a rat model of polycystic ovary syndrome.

PubMed

Masszi, Gabriella; Benko, Rita; Csibi, Noemi; Horvath, Eszter M; Tokes, Anna-Maria; Novak, Agnes; Beres, Nora Judit; Tarszabo, Robert; Buday, Anna; Repas, Csaba; Bekesi, Gabor; Patocs, Attila; Nadasy, Gyorgy L; Hamar, Peter; Benyo, Zoltan; Varbiro, Szabolcs

2013-08-06

In polycystic ovary syndrome (PCOS), metabolic and cardiovascular dysfunction is related to hyperandrogenic status and insulin resistance, however, Vitamin D3 has a beneficial effect partly due to its anti-oxidant capacity. Nitrative stress is a major factor in the development of cardiovascular dysfunction and insulin resistance in various diseases. Our aim was to determine the effects of vitamin D3 in a rat model of PCOS, particularly the pathogenic role of nitrative stress. Female Wistar rats weighing 100-140g were administered vehicle (C), dihydrotestosterone (DHT) or dihydrotestosterone plus vitamin D3 (DHT+D) (n=10 per group). On the 10th week, acetylcholine (Ach) induced relaxation ability of the isolated thoracic aorta rings was determined. In order to examine the possible role of endothelial nitric oxide synthase (eNOS) and cyclooxygenase-2 (COX-2) pathways in the impaired endothelial function, immunohistochemical labeling of aortas with anti-eNOS and anti-COX-2 antibodies was performed. Leukocyte smears, aorta and ovary tissue sections were also immunostained with anti-nitrotyrosine antibody to determine nitrative stress. Relaxation ability of aorta was reduced in group DHT, and vitamin D3 partly restored Ach induced relaxation. eNOS labeling was significantly lower in DHT rats compared to the other two groups, however COX-2 staining showed an increment. Nitrative stress showed a significant increase in response to dihydrotestosterone, while vitamin D3 treatment, in case of the ovaries, was able to reverse this effect. Nitrative stress may play a role in the pathogenesis of PCOS and in the development of the therapeutic effect of vitamin D3. Copyright © 2013 Elsevier Inc. All rights reserved.

Visual habit formation in 3-month-old monkeys (Macaca mulatta): reversal of sex difference following neonatal manipulations of androgens.

PubMed

Hagger, C; Bachevalier, J

1991-10-25

The ability to perform on a concurrent visual discrimination task with 24-h intertrial intervals (24-h ITI task) develops a few weeks earlier in female than in male infant monkeys. To test whether this sex difference was related to the presence of perinatal androgens, plasma testosterone levels were reduced in male infant monkeys by neonatal orchiectomy and increased in neonatally ovariectomized female infant monkeys by treatment with either testosterone propionate (TP) or its reduced metabolite, dihydrotestosterone (DHT). At 3 months of age, the animals were tested on the 24-h ITI task and their performance compared with that of age-matched intact male and female monkeys. Orchiectomy which was followed by a slight but visible atrophy of the external genitalia, hastened performance of male infant monkeys to the level of intact infant females. Conversely, androgenization of ovariectomized female infant monkeys given DHT, which had only a slight virilizing effect on the external genitalia, showed the learning of these female infants to the rate of intact male infant monkeys. Curiously, although TP treatment in ovariectomized female infant monkeys was more effective than DHT in virilizing the external genitalia, it failed to slow the rate of learning. This dissociation between the effects of TP and DHT on external genital organs and learning abilities is discussed in terms of possible differences in dose-dependent, time-dependent, and receptor-binding mechanisms of the two androgens. The present study provides further evidence that early androgen secretions affect the organization not only of brain structures related to primary sexual characteristics but also of those related to learning abilities.

Red ginseng extract promotes the hair growth in cultured human hair follicles.

PubMed

Park, Gyeong-Hun; Park, Ki-young; Cho, Hong-il; Lee, Sang-Min; Han, Ji Su; Won, Chong Hyun; Chang, Sung Eun; Lee, Mi Woo; Choi, Jee Ho; Moon, Kee Chan; Shin, Hyoseung; Kang, Yong Jung; Lee, Dong Hun

2015-03-01

Ginseng has been shown to promote hair growth in several recent studies. However, its effects on human hair follicles and its mechanisms of action have not been sufficiently elucidated. This study aimed to investigate the hair growth-promoting effects of red ginseng extract (RGE) and its ginsenosides. The proliferative activities of cultured human hair follicles treated with RGE and ginsenoside-Rb1 were assessed using Ki-67 immunostaining. Their effects on isolated human dermal papilla cells (hDPCs) were evaluated using cytotoxicity assays, immunoblot analysis of signaling proteins, and the determination of associated growth factors. We examined the ability of RGE and ginsenosides to protect hair matrix keratinocyte proliferation against dihydrotestosterone (DHT)-induced suppression and their effects on the expression of androgen receptor. The in vivo hair growth-promoting effect of RGE was also investigated in C57BL/6 mice. Both RGE and ginsenoside-Rb1 enhanced the proliferation of hair matrix keratinocytes. hDPCs treated with RGE or ginsenoside-Rb1 exhibited substantial cell proliferation and the associated phosphorylation of ERK and AKT. Moreover, RGE, ginsenoside-Rb1, and ginsenoside-Rg3 abrogated the DHT-induced suppression of hair matrix keratinocyte proliferation and the DHT-induced upregulation of the mRNA expression of androgen receptor in hDPCs. Murine experiments revealed that the subcutaneous injection of 3% RGE resulted in more rapid hair growth than the negative control. In conclusion, RGE and its ginsenosides may enhance hDPC proliferation, activate ERK and AKT signaling pathways in hDPCs, upregulate hair matrix keratinocyte proliferation, and inhibit the DHT-induced androgen receptor transcription. These results suggest that red ginseng may promote hair growth in humans.

Red Ginseng Extract Promotes the Hair Growth in Cultured Human Hair Follicles

PubMed Central

Park, Gyeong-Hun; Park, Ki-young; Cho, Hong-il; Lee, Sang-Min; Han, Ji Su; Chang, Sung Eun; Lee, Mi Woo; Choi, Jee Ho; Moon, Kee Chan; Shin, Hyoseung; Kang, Yong Jung; Lee, Dong Hun

2015-01-01

Abstract Ginseng has been shown to promote hair growth in several recent studies. However, its effects on human hair follicles and its mechanisms of action have not been sufficiently elucidated. This study aimed to investigate the hair growth-promoting effects of red ginseng extract (RGE) and its ginsenosides. The proliferative activities of cultured human hair follicles treated with RGE and ginsenoside-Rb1 were assessed using Ki-67 immunostaining. Their effects on isolated human dermal papilla cells (hDPCs) were evaluated using cytotoxicity assays, immunoblot analysis of signaling proteins, and the determination of associated growth factors. We examined the ability of RGE and ginsenosides to protect hair matrix keratinocyte proliferation against dihydrotestosterone (DHT)-induced suppression and their effects on the expression of androgen receptor. The in vivo hair growth-promoting effect of RGE was also investigated in C57BL/6 mice. Both RGE and ginsenoside-Rb1 enhanced the proliferation of hair matrix keratinocytes. hDPCs treated with RGE or ginsenoside-Rb1 exhibited substantial cell proliferation and the associated phosphorylation of ERK and AKT. Moreover, RGE, ginsenoside-Rb1, and ginsenoside-Rg3 abrogated the DHT-induced suppression of hair matrix keratinocyte proliferation and the DHT-induced upregulation of the mRNA expression of androgen receptor in hDPCs. Murine experiments revealed that the subcutaneous injection of 3% RGE resulted in more rapid hair growth than the negative control. In conclusion, RGE and its ginsenosides may enhance hDPC proliferation, activate ERK and AKT signaling pathways in hDPCs, upregulate hair matrix keratinocyte proliferation, and inhibit the DHT-induced androgen receptor transcription. These results suggest that red ginseng may promote hair growth in humans. PMID:25396716

Pharmacokinetics of 2 Novel Formulations of Modified-Release Oral Testosterone Alone and With Finasteride in Normal Men With Experimental Hypogonadism

PubMed Central

Snyder, Christin N.; Clark, Richard V.; Caricofe, Ralph B.; Bush, Mark A.; Roth, Mara Y.; Page, Stephanie T.; Bremner, William J.; Amory, John K.

2011-01-01

Oral administration of testosterone might be useful for the treatment of testosterone deficiency. However, current “immediate-release” formulations of oral testosterone exhibit suboptimal pharmacokinetics, with supraphysiologic peaks of testosterone and its metabolite, dihydrotestosterone (DHT), immediately after dosing. To dampen these peaks, we have developed 2 novel modified-release formulations of oral testosterone designed to slow absorption from the gut and improve hormone delivery. We studied these testosterone formulations in 16 normal young men enrolled in a 2-arm, open-label clinical trial. Three hundred-mg and 600-mg doses of immediate-release and modified fast-release or slow-release formulations were administered sequentially to 8 normal men rendered hypogonadal by the administration of the gonadotropin-releasing hormone antagonist acyline. Blood for measurement of serum testosterone, DHT, and estradiol was obtained before and 0.5, 1, 2, 3, 4, 6, 8, 12, and 24 hours after each dose. A second group of 8 men was studied with the coadministration of 1 mg of the 5α-reductase inhibitor finasteride daily throughout the treatment period. Serum testosterone was increased with all formulations of oral testosterone. The modified slow-release formulation significantly delayed the postdose peaks of serum testosterone and reduced peak concentrations of serum DHT compared with the immediate-release formulation. The addition of finasteride further increased serum testosterone and decreased serum DHT. We conclude that the oral modified slow-release testosterone formulation exhibits superior pharmacokinetics compared with immediate-release oral testosterone both alone and in combination with finasteride. This formulation might have efficacy for the treatment of testosterone deficiency. PMID:20378927

Androgens are bronchoactive drugs that act by relaxing airway smooth muscle and preventing bronchospasm.

PubMed

Montaño, Luis M; Espinoza, Julia; Flores-Soto, Edgar; Chávez, Jaime; Perusquía, Mercedes

2014-07-01

Changes in the androgen levels in asthmatic men may be associated with the severity of asthma. Androgens induce a nongenomic relaxation in airway smooth muscle, but the underlying mechanisms remain unclear. The aim of this study was to investigate the potential bronchorelaxing action of testosterone (TES) and its metabolites (5α- and 5β-dihydrotestosterone (DHT). A preventive effect on ovalbumin (OVA)-induced bronchospasm was observed in sensitized guinea pigs for each androgen. Androgens were studied in response to bronchoconstrictors: carbachol (CCh) and KCl in isolated trachea rings with and without epithelium from non-sensitized and sensitized animals as well as on OVA-induced contraction. Androgens concentration-dependently abolished the contraction in response to CCh, KCl, and OVA. There were significant differences in the sensitivity to the relaxation induced by each androgen. 5β-DHT was more potent for relaxing KCl-induced contraction, while TES and 5α-DHT were more potent for CCh- and OVA-induced contraction. No differences were found in preparations with and without epithelium or in the presence of a nitric oxide (NO) synthase inhibitor or an inhibitor of K(+) channels. These data indicate the absence of involvement of the epithelium-, NO- and K(+) channels-dependent pathway in androgen-induced relaxation. However, in dissociated tracheal myocytes loaded with the calcium-binding fluorescent dye Fura -2, physiological concentrations of androgens decreased the KCl-induced [Ca(2+)]i increment. 5β-DHT was the most potent at decreasing KCl-induced [Ca(2+)]i increment and preventing bronchospasm. We suggest that androgen-induced brochorelaxation was mediated via decreased Ca(2+) influx through L-type Ca(2+)channels but additional Ca(2+) entry blockade may be involved. Molecular changes in androgen structure may determine its preferential site of action. © 2014 Society for Endocrinology.

Effects of sex steroids on expression of genes regulating growth-related mechanisms in rainbow trout (Oncorhynchus mykiss).

PubMed

Cleveland, Beth M; Weber, Gregory M

2015-05-15

Effects of a single injection of 17β-estradiol (E2), testosterone (T), or 5β-dihydrotestosterone (DHT) on expression of genes central to the growth hormone (GH)/insulin-like growth factor (IGF) axis, muscle-regulatory factors, transforming growth factor-beta (TGFβ) superfamily signaling cascade, and estrogen receptors were determined in rainbow trout (Oncorhynchus mykiss) liver and white muscle tissue. In liver in addition to regulating GH sensitivity and IGF production, sex steroids also affected expression of IGF binding proteins, as E2, T, and DHT increased expression of igfbp2b and E2 also increased expression of igfbp2 and igfbp4. Regulation of this system also occurred in white muscle in which E2 increased expression of igf1, igf2, and igfbp5b1, suggesting anabolic capacity may be maintained in white muscle in the presence of E2. In contrast, DHT decreased expression of igfbp5b1. DHT and T decreased expression of myogenin, while other muscle regulatory factors were either not affected or responded similarly for all steroid treatments. Genes within the TGFβ superfamily signaling cascade responded to steroid treatment in both liver and muscle, suggesting a regulatory role for sex steroids in the ability to transmit signals initiated by TGFβ superfamily ligands, with a greater number of genes responding in liver than in muscle. Estrogen receptors were also regulated by sex steroids, with era1 expression increasing for all treatments in muscle, but only E2- and T-treatment in liver. E2 reduced expression of erb2 in liver. Collectively, these data identify how physiological mechanisms are regulated by sex steroids in a manner that promotes the disparate effects of androgens and estrogens on growth in salmonids. Published by Elsevier Inc.

The cellular and molecular effects of the androgen receptor agonist, Cl-4AS-1, on breast cancer cells.

PubMed

Ahram, Mamoun; Mustafa, Ebtihal; Abu Hammad, Shatha; Alhudhud, Mariam; Bawadi, Randa; Tahtamouni, Lubna; Khatib, Faisal; Zihlif, Malek

2018-03-26

The androgen receptor (AR) has attracted attention in the treatment of breast cancer. Due to the undesirable side effects of AR agonists, attempts have been undertaken to develop selective AR modulators. One of these compounds is Cl-4AS-1. This study examined this compound more closely at the cellular and molecular levels. Three different breast cancer cell lines were utilized, namely the luminal MCF-7 cells, the molecular apocrine MDA-MB-453 cells, and the triple negative, basal MDA-MB-231 cells. High and significant concordance between dihydrotestosterone (DHT) and Cl-4AS-1 in regulation of gene expression in MDA-MB-453 cells was found. However, some differences were noted including the expression of AR, which was upregulated by DHT, but not Cl-4AS-1. In addition, both DHT and Cl-4AS-1 caused a similar morphological change and reorganization of the actin structure of MDA-MB-453 cells into a mesenchymal phenotype. Treatment of cells with DHT resulted in induction of proliferation of MCF-7 and MDA-MB-453 cells, but no effect was observed on the growth of MDA-MB-231 cells. On the other hand, increasing doses of Cl-4AS-1 resulted in a dose-dependent inhibition on the growth of the three cell lines. This inhibition was a result of induction of apoptosis whereby Cl-4AS-1 caused a block in entry of cells into the S-phase followed by DNA degradation. These results indicate that although Cl-4AS-1 has characteristics of classical AR agonist, it has dissimilar properties that may make it useful in treating breast cancer.

Effects of Steroidal Antiandrogen or 5-alpha-reductase Inhibitor on Prostate Tissue Hormone Content.

PubMed

Shibata, Yasuhiro; Arai, Seiji; Miyazawa, Yoshiyuki; Shuto, Takahiro; Nomura, Masashi; Sekine, Yoshitaka; Koike, Hidekazu; Matsui, Hiroshi; Ito, Kazuto; Suzuki, Kazuhiro

2017-05-01

The effects of a steroidal antiandrogen (AA) and 5-alpha-reductase inhibitor (5ARI) on prostate tissue hormone content and metabolism are not fully elucidated. The objective of this study is to investigate the hormone content and metabolism of the prostate tissues of patients treated with AA or 5ARI using the ultra-sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Thirty-nine patients with benign prostatic hyperplasia (BPH) undergoing transurethral surgery were included. Serum and prostate tissue hormone and prostate tissue hormone metabolism analyses were performed using LC-MS/MS after 1 month of treatment with chlormadinone acetate (CMA; steroidal AA, 50 mg/day) or dutasteride (DUTA; dual 5ARI, 0.5 mg/day). Serum testosterone (T), dihydrotestosterone (DHT), and adrenal androgen levels were lower in the CMA group than the control group. Prostate tissue T and DHT levels were also lower in the CMA group than the control group. In the DUTA group, only serum and prostate DHT concentrations were reduced compared to the control group; in contrast, those of other hormones, especially T and 4-androstene-3,17-dione in the prostate tissue, showed marked elevations up to 70.4- and 11.4-fold normal levels, respectively. Moreover, the hormone metabolism assay confirmed that the conversion of T to DHT was significantly suppressed while that of T to 4-androstene-3,17-dione was significantly accelerated in the prostate tissue of DUTA-treated patients. Although treatment with AA and 5ARI show similar clinical outcomes, their effect on tissue hormone content and metabolism varied greatly. Prostate 77: 672-680, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Generating region proposals for histopathological whole slide image retrieval.

PubMed

Ma, Yibing; Jiang, Zhiguo; Zhang, Haopeng; Xie, Fengying; Zheng, Yushan; Shi, Huaqiang; Zhao, Yu; Shi, Jun

2018-06-01

Content-based image retrieval is an effective method for histopathological image analysis. However, given a database of huge whole slide images (WSIs), acquiring appropriate region-of-interests (ROIs) for training is significant and difficult. Moreover, histopathological images can only be annotated by pathologists, resulting in the lack of labeling information. Therefore, it is an important and challenging task to generate ROIs from WSI and retrieve image with few labels. This paper presents a novel unsupervised region proposing method for histopathological WSI based on Selective Search. Specifically, the WSI is over-segmented into regions which are hierarchically merged until the WSI becomes a single region. Nucleus-oriented similarity measures for region mergence and Nucleus-Cytoplasm color space for histopathological image are specially defined to generate accurate region proposals. Additionally, we propose a new semi-supervised hashing method for image retrieval. The semantic features of images are extracted with Latent Dirichlet Allocation and transformed into binary hashing codes with Supervised Hashing. The methods are tested on a large-scale multi-class database of breast histopathological WSIs. The results demonstrate that for one WSI, our region proposing method can generate 7.3 thousand contoured regions which fit well with 95.8% of the ROIs annotated by pathologists. The proposed hashing method can retrieve a query image among 136 thousand images in 0.29 s and reach precision of 91% with only 10% of images labeled. The unsupervised region proposing method can generate regions as predictions of lesions in histopathological WSI. The region proposals can also serve as the training samples to train machine-learning models for image retrieval. The proposed hashing method can achieve fast and precise image retrieval with small amount of labels. Furthermore, the proposed methods can be potentially applied in online computer-aided-diagnosis systems. Copyright © 2018 Elsevier B.V. All rights reserved.

Improving Sector Hash Carving with Rule-Based and Entropy-Based Non-Probative Block Filters

DTIC Science & Technology

2015-03-01

0x20 exceeds the histogram rule’s threshold of 256 instances of a single 4-byte value. The 0x20 bytes are part of an Extensible Metadata Platform (XMP...block consists of data separated by NULL bytes of padding. The histogram rule is triggered for the block because the block contains more than 256 4...sdash can reduce the rate of false positive matches. After characteristic features have been selected, the features are hashed using SHA -1, which creates

Fast parallel approach for 2-D DHT-based real-valued discrete Gabor transform.

PubMed

Tao, Liang; Kwan, Hon Keung

2009-12-01

Two-dimensional fast Gabor transform algorithms are useful for real-time applications due to the high computational complexity of the traditional 2-D complex-valued discrete Gabor transform (CDGT). This paper presents two block time-recursive algorithms for 2-D DHT-based real-valued discrete Gabor transform (RDGT) and its inverse transform and develops a fast parallel approach for the implementation of the two algorithms. The computational complexity of the proposed parallel approach is analyzed and compared with that of the existing 2-D CDGT algorithms. The results indicate that the proposed parallel approach is attractive for real time image processing.

Metabolic, Behavioral and Reproductive Effects of Vertical Sleeve Gastrectomy in an Obese Rat Model of Polycystic Ovary Syndrome

PubMed Central

Ressler, Ilana B.; Grayson, Bernadette E.; Seeley, Randy J.

2014-01-01

Introduction Polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting women of reproductive age. Its clinical expression is diverse, including metabolic, behavioral and reproductive effects, with many affected by obesity and decreased quality of life. Women with PCOS who have undergone surgically-induced weight loss have reported tremendous benefit, not only with weight loss, but also improvement of hyperandrogenism and menstrual cyclicity. Methods In a rat model of PCOS achieved via chronic administration of dihydrotestosterone (DHT) exposure, we investigated the ability of bariatric surgery, specifically vertical sleeve gastrectomy (VSG), to ameliorate the metabolic, behavioral and reproductive abnormalities invoked by this PCOS model. Results We found that DHT-treatment combined with exposure to a high-fat diet resulted in increased body weight and body fat, impaired fasting glucose, hirsutism, anxiety and irregular cycles. VSG resulted in reduced food intake, body weight and adiposity with improved fasting glucose and triglycerides. VSG induced lower basal corticosterone levels and attenuated stress responsivity. Once the DHT levels decreased to normal, regular estrous cyclicity was also restored. Conclusion VSG, therefore, improved PCOS manifestations in a comprehensive manner and may represent a potential therapeutic approach for specific aspects of PCOS. PMID:24408363

Metabolic, behavioral, and reproductive effects of vertical sleeve gastrectomy in an obese rat model of polycystic ovary syndrome.

PubMed

Ressler, Ilana B; Grayson, Bernadette E; Seeley, Randy J

2014-06-01

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting women of reproductive age. Its clinical expression is diverse, including metabolic, behavioral, and reproductive effects, with many affected by obesity and decreased quality of life. Women with PCOS who have undergone surgically induced weight loss have reported tremendous benefit, not only with weight loss, but also improvement of hyperandrogenism and menstrual cyclicity. In a rat model of PCOS achieved via chronic administration of dihydrotestosterone (DHT) exposure, we investigated the ability of bariatric surgery, specifically vertical sleeve gastrectomy (VSG), to ameliorate the metabolic, behavioral, and reproductive abnormalities invoked by this PCOS model. We found that DHT treatment combined with exposure to a high-fat diet resulted in increased body weight and body fat, impaired fasting glucose, hirsutism, anxiety, and irregular cycles. VSG resulted in reduced food intake, body weight, and adiposity with improved fasting glucose and triglycerides. VSG induced lower basal corticosterone levels and attenuated stress responsivity. Once the DHT levels decreased to normal, regular estrous cyclicity was also restored. VSG, therefore, improved PCOS manifestations in a comprehensive manner and may represent a potential therapeutic approach for specific aspects of PCOS.

Regulation of aromatase expression in the anterior amygdala of the developing mouse brain depends on ERβ and sex chromosome complement.

PubMed

Cisternas, Carla Daniela; Cabrera Zapata, Lucas Ezequiel; Arevalo, María Angeles; Garcia-Segura, Luis Miguel; Cambiasso, María Julia

2017-07-13

During development sex differences in aromatase expression in limbic regions of mouse brain depend on sex chromosome factors. Genes on the sex chromosomes may affect the hormonal regulation of aromatase expression and this study was undertaken to explore that possibility. Male E15 anterior amygdala neuronal cultures expressed higher levels of aromatase (mRNA and protein) than female cultures. Furthermore, treatment with oestradiol (E2) or dihydrotestosterone (DHT) increased Cyp19a1 expression and aromatase protein levels only in female neuronal cultures. The effect of E2 on aromatase expression was not imitated by oestrogen receptor (ER) α agonist PPT or the GPER agonist G1, but it was fully reproduced by DPN, a specific ligand of ERβ. By contrast, the effect of DHT on aromatase expression was not blocked by the anti-androgen flutamide, but completely abrogated by the ERβ antagonist PHTPP. Experiments using the four core genotype model showed a sex chromosome effect in ERβ expression (XY > XX) and regulation by E2 or DHT (only XX respond) in amygdala neurons. In conclusion, sex chromosome complement governs the hormonal regulation of aromatase expression through activation of ERβ in developing mouse brain.

Steroidal androgens and nonsteroidal, tissue-selective androgen receptor modulator, S-22, regulate androgen receptor function through distinct genomic and nongenomic signaling pathways.

PubMed

Narayanan, Ramesh; Coss, Christopher C; Yepuru, Muralimohan; Kearbey, Jeffrey D; Miller, Duane D; Dalton, James T

2008-11-01

Androgen receptor (AR) ligands are important for the development and function of several tissues and organs. However, the poor oral bioavailability, pharmacokinetic properties, and receptor cross-reactivity of testosterone, coupled with side effects, place limits on its clinical use. Selective AR modulators (SARMs) elicit anabolic effects in muscle and bone, sparing reproductive organs like the prostate. However, molecular mechanisms underlying the tissue selectivity remain ambiguous. We performed a variety of in vitro studies to compare and define the molecular mechanisms of an aryl propionamide SARM, S-22, as compared with dihydrotestosterone (DHT). Studies indicated that S-22 increased levator ani muscle weight but decreased the size of prostate in rats. Analysis of the upstream intracellular signaling events indicated that S-22 and DHT mediated their actions through distinct pathways. Modulation of these pathways altered the recruitment of AR and its cofactors to the PSA enhancer in a ligand-dependent fashion. In addition, S-22 induced Xenopus laevis oocyte maturation and rapid phosphorylation of several kinases, through pathways distinct from steroids. These studies reveal novel differences in the molecular mechanisms by which S-22, a nonsteroidal SARM, and DHT mediate their pharmacological effects.

Antihypertensive effects of androgens in conscious, spontaneously hypertensive rats.

PubMed

Perusquía, Mercedes; Herrera, Nieves; Ferrer, Mercedes; Stallone, John N

2017-03-01

Androgens are vasoactive steroids that induce acute vasodilation in a number of isolated vascular beds from different species, but the effects of these hormones on systemic blood pressure (BP) have been studied little. Although it has been reported that androgens exert systemic hypotensive effects through peripheral vasodilation in normotensive rats, there have not been any reports of systemic hypotensive effects of androgens in animals with hypertension. This study was designed to evaluate the acute effects of testosterone (TES) and its 5-reduced metabolites on systemic BP in hypertensive rats and to test the hypothesis that hypotestosteronemia may be involved in the pathogenesis of hypertension. Chronic, indwelling catheters were implanted in carotid artery and jugular vein of 18-21-week-old male spontaneously hypertensive rats (SHR) and normotensive-control Wistar-Kyoto (WKY) rats, for BP recording and drug administration, respectively. Bolus injections of TES, 5α- or 5β-dihydrotestosterone (5α- and 5β-DHT), were administrated cumulatively to conscious rats at doses of 0.1-100μmolkg -1 min -1 . 5β-DHT was also administrated during the pressor effect of Bay K 8644, an L-type voltage-operated Ca 2+ channel (L-VOCC) agonist. In separate experiments, BP of orchidectomized normotensive male WKY and Wistar rats, with or without androgen-replacement therapy, was evaluated weekly for 10 weeks by tail-cuff plethysmography. TES and its metabolites reduced BP in a dose-dependent manner, while heart rate was reduced with some androgens at the highest doses. The hypotensive effects of androgens were markedly greater in SHR, with a rank order potency of: 5β-DHT>TES>5α-DHT. 5β-DHT, the most potent antihypertensive androgen, abolished the pressor response to Bay K 8644 in SHR. TES deprivation by orchidectomy increased BP in normotensive WKY and Wistar rats, but this hypertension was prevented by TES replacement therapy. BP responses to androgens are androgen structure-dependent. These data indicate that: 1) androgens play a significant role in the control of BP and may contribute to the pathogenesis of hypertension; 2) blockade of L-VOCC is involved in the antihypertensive effects of androgens, which are non-genomically mediated; and 3) hypotestosteronemia may be a risk factor for hypertension. Copyright © 2016 Elsevier Ltd. All rights reserved.

Androgen receptor-mediated non-genomic effects of vinclozolin on porcine ovarian follicles and isolated granulosa cells: Vinclozolin and non-genomic effects in porcine ovarian follicles.

PubMed

Wartalski, Kamil; Knet-Seweryn, Malgorzata; Hoja-Lukowicz, Dorota; Tabarowski, Zbigniew; Duda, Malgorzata

2016-05-01

The present study investigated the influence of the androgen receptor (AR) agonists testosterone (T) and dihydrotestosterone (DHT), and vinclozolin (Vnz), a fungicide with antiandrogenic activity, on non-genomic signal transduction within ovarian follicles. Porcine granulosa cells (GCs) isolated from mature follicles were cultured for 48h. For the last 24h of culture, they were exposed to T (10(-7)M), DHT (10(-7)M), Vnz (1.4×10(-5)M), T and Vnz (T+Vnz), or DHT and Vnz (DHT+Vnz) at the same concentrations. To better imitate in vivo conditions, whole follicles (4-6mm in diameter) were incubated (24h) in an organ culture system with the same factors. Expression of AR mRNA and protein was determined by real-time PCR and western blot analyses. To demonstrate AR localization in cultured GCs and whole follicles, immunocytochemistry and immunohistochemistry were performed, respectively. To elucidate the possible non-genomic action of Vnz in GCs, protein expression and the activity of ERK1/2 and Akt kinases were determined by western blot and ELISA analyses. The immunocytochemistry and immunohistochemistry results showed that exposure of GCs and follicles to Vnz resulted in cytoplasmic and perinuclear AR localization. Real-time PCR and western blot analysis showed that AR mRNA and protein expression increased (P≤0.001) in GC cultures after combined treatment with an androgen and Vnz. In whole follicles, such treatment also increased AR mRNA with a decrease in the respective protein expression (P≤0.001). Moreover, addition of T or DHT with Vnz increased the activity of ERK1/2 and Akt kinases in cultured GCs (P≤0.001). The results suggest a novel mechanism for Vnz action in porcine ovarian follicles on both AR mRNA and protein levels. Thus, this environmental antiandrogen activates non-genomic signaling pathways, as indicated by the increased activity of both investigated kinases observed within minutes of Vnz addition. Given the widespread presence of Vnz in the environment, elucidation of its non-genomic action should be the subject of studies on female fertility. Copyright © 2016 Elsevier GmbH. All rights reserved.

Dental skill mix: a cross-sectional analysis of delegation practices between dental and dental hygiene-therapy students involved in team training in the South of England.

PubMed

Wanyonyi, Kristina L; Radford, David R; Gallagher, Jennifer E

2014-11-18

Research suggests that health professionals who have trained together have a better understanding of one another's scope of practice and are thus equipped for teamwork during their professional careers. Dental hygiene-therapists (DHTs) are mid-level providers that can deliver routine care working alongside dentists. This study examines patterns of delegation (selected tasks and patients) by dental students to DHT students training together in an integrated team. A retrospective sample of patient data (n = 2,063) was extracted from a patient management system showing the treatment activities of two student cohorts (dental and DHT) involved in team training in a primary care setting in the South of England over two academic years. The data extracted included key procedures delegated by dental students to DHT students coded by skill-mix of operator (e.g., fissure sealants, restorations, paediatric extractions) and patient demography. χ2 tests were conducted to investigate the relationship between delegation and patient age group, gender, smoking status, payment-exemption status, and social deprivation. A total of 2,063 patients managed during this period received treatments that could be undertaken by either student type; in total, they received 14,996 treatment procedures. The treatments most commonly delegated were fissure sealants (90%) and restorations (51%); whilst the least delegated were paediatric extractions (2%). Over half of these patients (55%) had at least one instance of delegation from a dental to a DHT student. Associations were found between delegation and patient age group and smoking status (P <0.001). Children under 18 years old had a higher level of delegation (86%) compared with adults of working age (50%) and patients aged 65 years and over (56%). A higher proportion of smokers had been delegated compared with non-smokers (45% cf. 26%; P <0.001). The findings suggest that delegation of care to DHT students training as a team with dental students, involved significantly greater experience in treating children and adult smokers, and providing preventive rather than invasive care in this integrated educational and primary care setting. The implications for their contribution to dentistry and the dental team are discussed, along with recommendations for primary care data recording.

Comparison of Spatiotemporal Mapping Techniques for Enormous Etl and Exploitation Patterns

NASA Astrophysics Data System (ADS)

Deiotte, R.; La Valley, R.

2017-10-01

The need to extract, transform, and exploit enormous volumes of spatiotemporal data has exploded with the rise of social media, advanced military sensors, wearables, automotive tracking, etc. However, current methods of spatiotemporal encoding and exploitation simultaneously limit the use of that information and increase computing complexity. Current spatiotemporal encoding methods from Niemeyer and Usher rely on a Z-order space filling curve, a relative of Peano's 1890 space filling curve, for spatial hashing and interleaving temporal hashes to generate a spatiotemporal encoding. However, there exist other space-filling curves, and that provide different manifold coverings that could promote better hashing techniques for spatial data and have the potential to map spatiotemporal data without interleaving. The concatenation of Niemeyer's and Usher's techniques provide a highly efficient space-time index. However, other methods have advantages and disadvantages regarding computational cost, efficiency, and utility. This paper explores the several methods using a range of sizes of data sets from 1K to 10M observations and provides a comparison of the methods.

A Study on the Secure User Profiling Structure and Procedure for Home Healthcare Systems.

PubMed

Ko, Hoon; Song, MoonBae

2016-01-01

Despite of various benefits such as a convenience and efficiency, home healthcare systems have some inherent security risks that may cause a serious leak on personal health information. This work presents a Secure User Profiling Structure which has the patient information including their health information. A patient and a hospital keep it at that same time, they share the updated data. While they share the data and communicate, the data can be leaked. To solve the security problems, a secure communication channel with a hash function and an One-Time Password between a client and a hospital should be established and to generate an input value to an OTP, it uses a dual hash-function. This work presents a dual hash function-based approach to generate the One-Time Password ensuring a secure communication channel with the secured key. In result, attackers are unable to decrypt the leaked information because of the secured key; in addition, the proposed method outperforms the existing methods in terms of computation cost.

Cryptographic framework for document-objects resulting from multiparty collaborative transactions.

PubMed

Goh, A

2000-01-01

Multiparty transactional frameworks--i.e. Electronic Data Interchange (EDI) or Health Level (HL) 7--often result in composite documents which can be accurately modelled using hyperlinked document-objects. The structural complexity arising from multiauthor involvement and transaction-specific sequencing would be poorly handled by conventional digital signature schemes based on a single evaluation of a one-way hash function and asymmetric cryptography. In this paper we outline the generation of structure-specific authentication hash-trees for the the authentication of transactional document-objects, followed by asymmetric signature generation on the hash-tree value. Server-side multi-client signature verification would probably constitute the single most compute-intensive task, hence the motivation for our usage of the Rabin signature protocol which results in significantly reduced verification workloads compared to the more commonly applied Rivest-Shamir-Adleman (RSA) protocol. Data privacy is handled via symmetric encryption of message traffic using session-specific keys obtained through key-negotiation mechanisms based on discrete-logarithm cryptography. Individual client-to-server channels can be secured using a double key-pair variation of Diffie-Hellman (DH) key negotiation, usage of which also enables bidirectional node authentication. The reciprocal server-to-client multicast channel is secured through Burmester-Desmedt (BD) key-negotiation which enjoys significant advantages over the usual multiparty extensions to the DH protocol. The implementation of hash-tree signatures and bi/multidirectional key negotiation results in a comprehensive cryptographic framework for multiparty document-objects satisfying both authentication and data privacy requirements.

An image retrieval framework for real-time endoscopic image retargeting.

PubMed

Ye, Menglong; Johns, Edward; Walter, Benjamin; Meining, Alexander; Yang, Guang-Zhong

2017-08-01

Serial endoscopic examinations of a patient are important for early diagnosis of malignancies in the gastrointestinal tract. However, retargeting for optical biopsy is challenging due to extensive tissue variations between examinations, requiring the method to be tolerant to these changes whilst enabling real-time retargeting. This work presents an image retrieval framework for inter-examination retargeting. We propose both a novel image descriptor tolerant of long-term tissue changes and a novel descriptor matching method in real time. The descriptor is based on histograms generated from regional intensity comparisons over multiple scales, offering stability over long-term appearance changes at the higher levels, whilst remaining discriminative at the lower levels. The matching method then learns a hashing function using random forests, to compress the string and allow for fast image comparison by a simple Hamming distance metric. A dataset that contains 13 in vivo gastrointestinal videos was collected from six patients, representing serial examinations of each patient, which includes videos captured with significant time intervals. Precision-recall for retargeting shows that our new descriptor outperforms a number of alternative descriptors, whilst our hashing method outperforms a number of alternative hashing approaches. We have proposed a novel framework for optical biopsy in serial endoscopic examinations. A new descriptor, combined with a novel hashing method, achieves state-of-the-art retargeting, with validation on in vivo videos from six patients. Real-time performance also allows for practical integration without disturbing the existing clinical workflow.

Applications of a hologram watermarking protocol: aging-aware biometric signature verification and time validity check with personal documents

NASA Astrophysics Data System (ADS)

Vielhauer, Claus; Croce Ferri, Lucilla

2003-06-01

Our paper addresses two issues of a biometric authentication algorithm for ID cardholders previously presented namely the security of the embedded reference data and the aging process of the biometric data. We describe a protocol that allows two levels of verification, combining a biometric hash technique based on handwritten signature and hologram watermarks with cryptographic signatures in a verification infrastructure. This infrastructure consists of a Trusted Central Public Authority (TCPA), which serves numerous Enrollment Stations (ES) in a secure environment. Each individual performs an enrollment at an ES, which provides the TCPA with the full biometric reference data and a document hash. The TCPA then calculates the authentication record (AR) with the biometric hash, a validity timestamp, and a document hash provided by the ES. The AR is then signed with a cryptographic signature function, initialized with the TCPA's private key and embedded in the ID card as a watermark. Authentication is performed at Verification Stations (VS), where the ID card will be scanned and the signed AR is retrieved from the watermark. Due to the timestamp mechanism and a two level biometric verification technique based on offline and online features, the AR can deal with the aging process of the biometric feature by forcing a re-enrollment of the user after expiry, making use of the ES infrastructure. We describe some attack scenarios and we illustrate the watermarking embedding, retrieval and dispute protocols, analyzing their requisites, advantages and disadvantages in relation to security requirements.

Recent Advances in Drug Design and Drug Discovery for Androgen- Dependent Diseases.

PubMed

Cabeza, Marisa; Sánchez-Márquez, Araceli; Garrido, Mariana; Silva, Aylín; Bratoeff, Eugene

2016-01-01

This article summarizes the importance of different targets such as 5α-reductase, 17β-HSD, CYP17A, androgen receptor and protein kinase A for the treatment of prostate cancer and benign prostatic hyperplasia. It is a well known fact that dihydrotestosterone (DHT) is associated with the development of androgen-dependent afflictions. At the present time, several research groups are attempting to develop new steroidal and non-steroidal molecules with the purpose of inhibiting the synthesis and biological response of DHT. This review also discusses the most recent studies reported in the literature that describe the therapeutic potential of novel compounds, as well as the new drugs, principally inhibitors of 5α-reductase.

Isolation and Applications of Prostate Side Population Cells Based on Dye Cycle Violet Efflux

PubMed Central

Gangavarapu, Kalyan J.; Huss, Wendy J.

2011-01-01

This unit describes methods for the digestion of human prostate clinical specimens, dye cycle violet (DCV) staining procedure for the identification, isolation, and quantitation of radiolabeled dihydrotestosterone (DHT) retention of side population cells. The principle of the side population assay is based on differential efflux of DCV, a cell membrane permeable fluorescent dye, by cells with high ATP binding cassette (ABC) transporter activity. Cells with high ABC transporter activity efflux DCV and fall in the lower left quadrant of a flow cytograph are designated as “side population” cells. This unit emphasizes tissue digestion, DCV staining, flow settings for sorting side population cells and quantitation of radiolabeled DHT retention. PMID:21400686

[Dihydrotestosterone improves the osseointegration of cobalt-chromium implants].

PubMed

Maus, U M; Lühmann, M; Ohnsorge, J A K; Andereya, S; Schmidt, H; Zombory, G; Siebert, C; Niedhart, C

2013-02-01

The osseointegration of actually rarely implanted cobalt-chromium implants can be critical in an elderly population. The aim of our study was to evaluate the effect of preoperative testosterone treatment on the osseointegration of cobalt-chromium implants. Press-fit implantation of 1.6 mm-diameter cobalt-chromium-molybdenum (CoCrMo) implants was performed in rats without pre-treatment in one group (n = 10) and after pre-treatment with 1 mg dihydrotestosterone (DHT) 2 days before surgery in the other group (n = 10). After 14 days, the specimens were examined by a pull-out test, histology and histomorphometry. The biomechanical testing delivered inconsistent data leading to no significant difference (6.45 ± 6.94 N vs. 4.66 ± 3.77 N). Histology showed closed contact between surrounding tissue and the implants in both groups. The bone/implant contact area was significantly enhanced after treatment with DHT (42.23 % ± 9.25 vs. 57.57 % ± 16.71, p < 0.05), while the ratio of osteoid was reduced (38.68 % ± 16.7 vs. 27.38 % ± 13.02, not significant). Pre-treatment with DHT enhances osseointegration of cobalt-chromium implants through enhanced mineralisation of peri-implant tissue. The treatment might additionally shorten postoperative rehabilitation due to its positive effects on musculature. Georg Thieme Verlag KG Stuttgart · New York.

Changes in serum sex steroid levels throughout the reproductive cycle of Bufo arenarum females.

PubMed

Medina, Marcela F; Ramos, Inés; Crespo, Claudia A; González-Calvar, Silvia; Fernández, Silvia N

2004-04-01

The changes in the serum levels of the sexual steroids estradiol-17beta (E(2)), testosterone (T), dihydrotestosterone (DHT), and progesterone (P) in Bufo arenarum females were determined by radioimmunoassay (RIA) during 3 consecutive cycles (1999-2001). The serum concentrations of T and DHT, which showed a close parallelism during the annual reproductive cycle, exhibited the highest levels during the preovulatory period, when oogenesis is advanced, while lowest serum levels of these hormones were found during the ovulatory period. The data obtained for E(2) showed a pattern contrary to that determined for androgens. The maximum E(2) concentrations detected in the early postovulatory period might be associated with vitellogenesis and follicular growth. Lowest E(2) concentrations were reached during the period in which B. arenarum undergoes its final hibernation stage. Serum P showed a peak during the preovulatoy period, related to the induction of nuclear maturation in full grown oocytes. A strong decrease in the levels of the circulating hormones was observed after ovariectomy. Our results showed that, out of the four hormones examined, T and DHT were the best indicators of ovarian and oviductal stage, as shown by the strong positive correlation found between androgen levels and organ weight, while E(2) showed a weak negative correlation with ovarian and oviductal weight.

Culture of prostate epithelial cells of the rhesus monkey on extracellular matrix substrate: influence of steroids and insulin-like growth factors.

PubMed

Udayakumar, T S; Jeyaraj, D A; Rajalakshmi, M; Sharma, R S

1999-09-01

Rhesus monkey prostate epithelial cells from the cranial lobe were isolated and cultured in flasks coated either with collagen IV or laminin. The effects of stromal cell medium, androgens and growth factors on cell number, thymidine incorporation and secretory activity were assessed. The results indicate that dihydrotestosterone (DHT) and androstenedione have stimulatory influences on cell proliferation and secretion in coated flasks. DHT was more effective in increasing cell number but the induction of secretory activity was similar with both steroids. The combination of IGF-I and -II resulted in inducing better cell proliferation and secretory activity than the individual IGFs but, of the two IGFs, IGF-I was more effective than IGF-II. DHT with IGFs was more potent in inducing proliferation, differentiation and secretion than androstenedione. Even in the absence of steroids or growth factors, colony formation and confluence occurred in coated flasks but cell differentiation and secretion only to a limited extent. In conclusion, we were able to establish an in vitro primary culture of prostate epithelial cells from rhesus monkey using extracellular matrix proteins, steroids and growth factors as additional supplements. This culture system may be useful to study prostate cell physiology and to identify drugs that can inhibit cell proliferation.

Finasteride for Chronic Central Serous Chorioretinopathy

PubMed Central

Forooghian, Farzin; Meleth, Annal D.; Cukras, Catherine; Chew, Emily Y.; Wong, Wai T.; Meyerle, Catherine B.

2010-01-01

Purpose To evaluate the safety and efficacy of finasteride, an inhibitor of dihyroxytestosterone (DHT) synthesis, in the treatment of chronic central serous chorioretinopathy (CSC). Methods Five patients with chronic CSC were prospectively enrolled in this pilot study. Patients were administered finasteride (5mg) daily for 3 months, following which study medication was withheld and patients were observed for 3 months. Main outcome measures included best-corrected visual acuity (BCVA), center-subfield macular thickness and subretinal fluid volume as assessed by optical coherence tomography (OCT). Serum DHT, serum testosterone, and urinary cortisol were also measured. Results There was no change in mean BCVA. Mean center-subfield macular thickness and subretinal fluid volume reached a nadir at 3 months, and rose to levels that were below baseline by 6 months. The changes in both OCT parameters paralleled changes in serum DHT level. In four patients, center-subfield macular thickness and/or subretinal fluid volume increased following discontinuation of finasteride. In the remaining patient, both OCT parameters normalized with finasteride and remained stable when the study medication was discontinued. Conclusion Finasteride may represent a novel medical treatment for chronic CSC. Larger controlled clinical trials are needed to further assess the efficacy of finasteride for the treatment of CSC. Summary Pilot study to evaluate finasteride for treatment of chronic central serous chorioretinopathy suggests efficacy and tolerability. PMID:21273946

Differential effects of testosterone, dihydrotestosterone and estradiol on carotenoid deposition in an avian sexually selected signal

PubMed Central

Dijkstra, Cor; Tagliavini, James; Goerlich, Vivian C.; Groothuis, Ton G. G.

2010-01-01

Recent studies have demonstrated that carotenoid-based traits are under the control of testosterone (T) by up-regulation of carotenoid carriers (lipoproteins) and/or tissue-specific uptake of carotenoids. T can be converted to dihydrotestosterone (DHT) and estradiol (E2), and variation in conversion rate may partly explain some contradictory findings in the literature. Moreover, most studies on the effect of T on sexual signals have focused on the male sex only, while in many species females show the same signal, albeit to a lesser extent. We studied the effects of T, DHT, and E2 treatment in male and female diamond doves Geopelia cuneata in which both sexes have an enlarged red eye ring, which is more pronounced in males. We first showed that this periorbital ring contains very high concentration of carotenoids, of which most are lutein esters. Both T and DHT were effective in enhancing hue, UV-chroma and size in both sexes, while E2 was ineffective. However, E2 dramatically increased the concentration of circulating lipoproteins. We conclude that in both sexes both color and size of the secondary sexual trait are androgen dependent. The action of androgens is independent of lipoproteins regulation. Potential mechanisms and their consequences for trade-off are discussed. PMID:20824278

Using global unique identifiers to link autism collections.

PubMed

Johnson, Stephen B; Whitney, Glen; McAuliffe, Matthew; Wang, Hailong; McCreedy, Evan; Rozenblit, Leon; Evans, Clark C

2010-01-01

To propose a centralized method for generating global unique identifiers to link collections of research data and specimens. The work is a collaboration between the Simons Foundation Autism Research Initiative and the National Database for Autism Research. The system is implemented as a web service: an investigator inputs identifying information about a participant into a client application and sends encrypted information to a server application, which returns a generated global unique identifier. The authors evaluated the system using a volume test of one million simulated individuals and a field test on 2000 families (over 8000 individual participants) in an autism study. Inverse probability of hash codes; rate of false identity of two individuals; rate of false split of single individual; percentage of subjects for which identifying information could be collected; percentage of hash codes generated successfully. Large-volume simulation generated no false splits or false identity. Field testing in the Simons Foundation Autism Research Initiative Simplex Collection produced identifiers for 96% of children in the study and 77% of parents. On average, four out of five hash codes per subject were generated perfectly (only one perfect hash is required for subsequent matching). The system must achieve balance among the competing goals of distinguishing individuals, collecting accurate information for matching, and protecting confidentiality. Considerable effort is required to obtain approval from institutional review boards, obtain consent from participants, and to achieve compliance from sites during a multicenter study. Generic unique identifiers have the potential to link collections of research data, augment the amount and types of data available for individuals, support detection of overlap between collections, and facilitate replication of research findings.

Dihydrotestosterone treatment rescues the decline in protein synthesis as a result of sarcopenia in isolated mouse skeletal muscle fibres.

PubMed

Wendowski, Oskar; Redshaw, Zoe; Mutungi, Gabriel

2017-02-01

Sarcopenia, the progressive decline in skeletal muscle mass and function with age, is a debilitating condition. It leads to inactivity, falls, and loss of independence. Despite this, its cause(s) and the underlying mechanism(s) are still poorly understood. In this study, small skeletal muscle fibre bundles isolated from the extensor digitorum longus (a fast-twitch muscle) and the soleus (a slow-twitch muscle) of adult mice of different ages (range 100-900 days old) were used to investigate the effects of ageing and dihydrotestosterone (DHT) treatment on protein synthesis as well as the expression and function of two amino acid transporters; the sodium-coupled neutral amino acid transporter (SNAT) 2, and the sodium-independent L-type amino-acid transporter (LAT) 2. At all ages investigated, protein synthesis was always higher in the slow-twitch than in the fast-twitch muscle fibres and decreased with age in both fibre types. However, the decline was greater in the fast-twitch than in the slow-twitch fibres and was accompanied by a reduction in the expression of SNAT2 and LAT2 at the protein level. Again, the decrease in the expression of the amino acid transporters was greater in the fast-twitch than in the slow-twitch fibres. In contrast, ageing had no effect on SNAT2 and LAT2 expressions at the mRNA level. Treating the muscle fibre bundles with physiological concentrations (~2 nM) of DHT for 1 h completely reversed the effects of ageing on protein synthesis and the expression of SNAT2 and LAT2 protein in both fibre types. From the observations that ageing is accompanied by a reduction in protein synthesis and transporter expression and that these effects are reversed by DHT treatment, we conclude that sarcopenia arises from an age-dependent reduction in protein synthesis caused, in part, by the lack of or by the low bioavailability of the male sex steroid, DHT.

Androgens have antiresorptive effects on trabecular disuse osteopenia independent from muscle atrophy.

PubMed

Laurent, Michaël R; Jardí, Ferran; Dubois, Vanessa; Schollaert, Dieter; Khalil, Rougin; Gielen, Evelien; Carmeliet, Geert; Claessens, Frank; Vanderschueren, Dirk

2016-12-01

Aging hypogonadal men are at increased risk of osteoporosis and sarcopenia. Testosterone is a potentially appealing strategy to prevent simultaneous bone and muscle loss. The androgen receptor (AR) mediates antiresorptive effects on trabecular bone via osteoblast-lineage cells, as well as muscle-anabolic actions. Sex steroids also modify the skeletal response to mechanical loading. However, it is unclear whether the effects of androgens on bone remain effective independent of mechanical stimulation or rather require indirect androgen effects via muscle. This study aims to characterize the effects and underlying mechanisms of androgens on disuse osteosarcopenia. Adult male mice received a unilateral botulinum toxin (BTx) injection, and underwent sham surgery or orchidectomy (ORX) without or with testosterone (ORX+T) or dihydrotestosterone (ORX+DHT) replacement. Compared to the contralateral internal control hindlimb, acute trabecular number and bone volume loss was increased by ORX and partially prevented DHT. T was more efficient and increased BV/TV in both hindlimbs over sham values, although it did not reduce the detrimental effect of BTx. Both androgens and BTx regulated trabecular osteoclast surface as well as tartrate-resistant acid phosphatase expression. Androgens also prevented BTx-induced body weight loss but did not significantly influence paralysis or muscle atrophy. BTx and ORX both reduced cortical thickness via endosteal expansion, which was prevented by T but not DHT. In long-term follow-up, the residual trabecular bone volume deficit in sham-BTx hindlimbs was prevented by DHT but T restored it more efficiently to pre-treatment levels. Conditional AR deletion in late osteoblasts and osteocytes or in the satellite cell lineage increased age-related trabecular bone loss in both hindlimbs without influencing the effect of BTx on trabecular osteopenia. We conclude that androgens have antiresorptive effects on trabecular disuse osteopenia which do not require AR actions on bone via muscle or via osteocytes. Copyright © 2016 Elsevier Inc. All rights reserved.

Aromatase inhibition by letrozole attenuates kainic acid-induced seizures but not neurotoxicity in mice.

PubMed

Iqbal, Ramsha; Jain, Gaurav K; Siraj, Fouzia; Vohora, Divya

2018-07-01

Evidence shows neurosteroids play a key role in regulating epileptogenesis. Neurosteroids such as testosterone modulate seizure susceptibility through its transformation to metabolites which show proconvulsant and anticonvulsant effects, respectively. Reduction of testosterone by aromatase generates proconvulsant 17-β estradiol. Alternatively, testosterone is metabolized into 5α-dihydrotestosterone (5α-DHT) by 5α-reductase, which is then reduced by 3α-hydroxysteroid oxidoreductase enzyme (3α-HSOR) to form anticonvulsant metabolite 3α-androstanediol (3α-Diol), a potent GABA A receptor modulating neurosteroid. The present study evaluated whether inhibition of aromatase inhibitor letrozole protects against seizures and neuronal degeneration induced by kainic acid (KA) (10 mg/kg, i.p.) in Swiss albino mice. Letrozole (1 mg/kg, i.p.) administered one hour prior to KA significantly increased the onset time of seizures and reduced the% incidence of seizures. Pretreatment with finasteride, a selective inhibitor of 5α-reductase and indomethacin, a selective inhibitor of 3α-hydroxysteroid oxidoreductase enzyme (3α-HSOR), reversed the protective effects of letrozole in KA-induced seizures in mice. Microscopic examination using cresyl violet staining revealed that letrozole did not modify KA-induced neurotoxicity in the CA1, CA3 and DG region of the hippocampus. Letrozole treatment resulted in the reduced levels of 17-β estradiol and elevated the levels of 5α-dihydrotestosterone (DHT) and 3α-Diol in the hippocampus. Finasteride and indomethacin attenuated letrozole-induced elevations of 5α-DHT and 3α-Diol. Our results indicate the potential anticonvulsant effects of letrozole against KA-induced seizures in mice that might be mediated by inhibiting aromatization of testosterone to 17β-estradiol, a proconvulsant hormone and by redirecting the synthesis to anticonvulsant metabolites, 5α-DHT and 3α-Diol. Acute aromatase inhibition, thus, might be used as an adjuvant in the treatment of status epilepticus and can be pursued further. Copyright © 2018 Elsevier B.V. All rights reserved.

Androgens inhibit adipogenesis during human adipose stem cell commitment to predipocyte formation

PubMed Central

Chazenbalk, Gregorio; Singh, Prapti; Irge, Dana; Shah, Amy; Abbott, David H; Dumesic, Daniel A

2013-01-01

Androgens play a pivotal role in the regulation of body fat distribution. Adipogenesis is a process whereby multipotent adipose stem cells (ASCs) initially become preadipocytes (ASC commitment to preadipocytes) before differentiating into adipocytes. Androgens inhibit human (h) subcutaneous (SC) abdominal preadipocyte differentiation in both sexes, but their effects on hASC commitment to preadipocyte formation is unknown. We therefore examined whether androgen exposure to human (h) ASCs, isolated from SC abdominal adipose of nonobese women, impairs their commitment to preadipocyte formation and/or subsequent differentiation into adipocytes. For this, isolated hASCs from SC abdominal lipoaspirate were cultured in adipogenesis-inducing medium for 0.5–14 days in the presence of testosterone (T, 0–100 nM) or dihydrotestosterone (DHT, 0–50 nM). Adipogenesis was determined by immunofluorescence microscopy and by quantification of adipogenically relevant transcriptional factors, PPARγ, C/EBPα and C/EBPβ. We found that a 3-day exposure of hASCs to T (50 nM) or DHT (5 nM) in adipogenesis-inducing medium impaired lipid acquisition and decreased PPARγ, C/EBPα and C/EBPβ gene expression. The inhibitory effects of T and DHT at this early-stage of adipocyte differentiation, were partially and completely reversed by flutamide (F, 100 nM), respectively. The effect of androgens on hASC commitment to a preadipocyte phenotype was examined via activation of BMP4 signaling. T (50 nM) and DHT (5nM) significantly inhibited the stimulatory effect of BMP4-induced ASC commitment to the preadipocyte phenotype, as regards PPARγ and C/EBPα gene expression. Our findings indicate that androgens, in part through androgen receptor action, impair BMP4-induced commitment of SC hASCs to preadipocytes and also reduce early-stage adipocyte differentiation, perhaps limiting adipocyte numbers and fat storage in SC abdominal adipose. PMID:23707571

Synaptic long-term potentiation and depression in the rat medial vestibular nuclei depend on neural activation of estrogenic and androgenic signals.

PubMed

Scarduzio, Mariangela; Panichi, Roberto; Pettorossi, Vito Enrico; Grassi, Silvarosa

2013-01-01

Estrogenic and androgenic steroids can be synthesised in the brain and rapidly modulate synaptic transmission and plasticity through direct interaction with membrane receptors for estrogens (ERs) and androgens (ARs). We used whole cell patch clamp recordings in brainstem slices of male rats to explore the influence of ER and AR activation and local synthesis of 17β-estradiol (E2) and 5α-dihydrotestosterone (DHT) on the long-term synaptic changes induced in the neurons of the medial vestibular nucleus (MVN). Long-term depression (LTD) and long-term potentiation (LTP) caused by different patterns of high frequency stimulation (HFS) of the primary vestibular afferents were assayed under the blockade of ARs and ERs or in the presence of inhibitors for enzymes synthesizing DHT (5α-reductase) and E2 (P450-aromatase) from testosterone (T). We found that LTD is mediated by interaction of locally produced androgens with ARs and LTP by interaction of locally synthesized E2 with ERs. In fact, the AR block with flutamide prevented LTD while did not affect LTP, and the blockade of ERs with ICI 182,780 abolished LTP without influencing LTD. Moreover, the block of P450-aromatase with letrozole not only prevented the LTP induction, but inverted LTP into LTD. This LTD is likely due to the local activation of androgens, since it was abolished under blockade of ARs. Conversely, LTD was still induced in the presence of finasteride the inhibitor of 5α-reductase demonstrating that T is able to activate ARs and induce LTD even when DHT is not synthesized. This study demonstrates a key and opposite role of sex neurosteroids in the long-term synaptic changes of the MVN with a specific role of T-DHT for LTD and of E2 for LTP. Moreover, it suggests that different stimulation patterns can lead to LTD or LTP by specifically activating the enzymes involved in the synthesis of androgenic or estrogenic neurosteroids.

Effect of Exercise on Serum Sex Hormones in Men: A 12-Month Randomized Clinical Trial

PubMed Central

HAWKINS, VIVIAN N.; FOSTER-SCHUBERT, KAREN; CHUBAK, JESSICA; SORENSEN, BESS; ULRICH, CORNELIA M.; STANCYZK, FRANK Z.; PLYMATE, STEPHEN; STANFORD, JANET; WHITE, EMILY; POTTER, JOHN D.; MCTIERNAN, ANNE

2011-01-01

Purpose The effect of exercise on androgens in middle-aged to older men is poorly understood, and it could have implications for several aspects of health. This analysis was conducted to examine the effects of long-term aerobic exercise on serum sex hormones in middle-aged to older men. Methods One hundred two sedentary men, ages 40–75 yr, were randomly assigned to a 12-month exercise intervention or a control group (no change in activity). The combined facility- and home-based exercise program consisted of moderate/vigorous-intensity aerobic activity for 60 min·d−1, 6 d·wk−1. Serum concentrations of testosterone, free testosterone, dihydrotestosterone (DHT), 3α-androstanediol glucuronide (3α-Diol-G), estradiol, free estradiol, and sex hormone–binding globulin (SHBG) were measured at baseline, 3, and 12 months. Results Exercisers trained a mean of 370 min·wk−1 (102% of goal), with only two dropouts. Cardiopulmonary fitness (V̇O2max) increased 10.8% in exercisers and decreased by 1.8% in controls (P < 0.001). DHT increased 14.5% in exercisers versus 1.7% in controls at 3 months (P = 0.04); at 12 months, it remained 8.6% above baseline in exercisers versus a 3.1% decrease in controls (P = 0.03). SHBG increased 14.3% in exercisers versus 5.7% in controls at 3 months (P = 0.04); at 12 months, it remained 8.9% above baseline in exercisers versus 4.0% in controls (P = 0.13). There were significant trends toward increasing DHT and SHBG, with greater increases in V̇O2max at 3 and 12 months in exercisers. No statistically significant differences were observed for testosterone, free testosterone, 3α-Diol-G, estradiol, or free estradiol in exercisers versus controls. Conclusions A yearlong, moderate-intensity aerobic exercise program increased DHT and SHBG, but it had no effect on other androgens in middle-aged to older men. PMID:18202581

Responses of Withdrawal Interneurons to Serotonin Applications in Naïve and Learned Snails Are Different

PubMed Central

Bogodvid, Tatiana K.; Andrianov, Vyatcheslav V.; Deryabina, Irina B.; Muranova, Lyudmila N.; Silantyeva, Dinara I.; Vinarskaya, Aliya; Balaban, Pavel M.; Gainutdinov, Khalil L.

2017-01-01

Long-term changes in membrane potential after associative training were described previously in identified premotor interneurons for withdrawal of the terrestrial snail Helix. Serotonin was shown to be a major transmitter involved in triggering the long-term changes in mollusks. In the present study we compared the changes in electrophysiological characteristics of identifiable premotor interneurons for withdrawal in response to bath applications of serotonin (5-HT) or serotonin precursor 5-hydroxytryptophan (5-HTP) in preparations from naïve, neurotoxin-injected or associatively trained snails. It was found that 5-HT or 5-HTP applications caused a significant decrease of membrane potential in premotor interneurons of naïve snails, associatively trained snails and snails with impaired serotonergic system by injection of a selective neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) 1 week before the experiments. Applications of 5-HT or 5-HTP did not cause significant changes in the action potential (AP) threshold potential of these neurons in naïve snails. Conversely, applications of 5-HT or 5-HTP to the premotor interneurons of previously trained or 5,7-DHT-injected snails caused a significant increase in the firing threshold potential in spite of a depolarizing shift of the resting membrane potential. Results demonstrate that responsiveness of premotor interneurons to extracellularly applied 5-HT or 5-HTP changes for days after the associative training or serotonin depletion. Similarity of the effects in trained and 5,7-DHT-injected animals may be due to massive release of serotonin elicited by 5,7-DHT injection. Our results suggest that serotonin release due to aversive conditionining or elicited by the neurotoxin administration triggers similar changes in resting membrane potential and AP threshold in response to bath applications of 5-HT or its precursor 5-HTP. PMID:29311833

Association Between Circulating Levels of Sex Steroid Hormones and Barrett's Esophagus in Men: a Case–Control Analysis

PubMed Central

Cook, Michael B.; Wood, Shannon N.; Cash, Brooks D.; Young, Patrick; Acosta, Ruben D.; Falk, Roni T.; Pfeiffer, Ruth M.; Hu, Nan; Su, Hua; Wang, Lemin; Wang, Chaoyu; Gherman, Barbara; Giffen, Carol; Dykes, Cathy; Turcotte, Veronique; Caron, Patrick; Guillemette, Chantal; Dawsey, Sanford M.; Abnet, Christian C.; Hyland, Paula L.; Taylor, Philip R.

2014-01-01

Background & Aims Esophageal adenocarcinoma is believed to result from the progression of gastroesophageal reflux disease to erosive esophagitis and re-epithelialization of the esophagus with a columnar cell population termed Barrett's esophagus (BE). Men develop BE and esophageal adenocarcinoma more frequently than women, and the ratio is increasing; approximately 7 men are diagnosed with malignancy for every woman, yet little is known about the mechanisms of this difference. We assessed whether sex steroid hormones were associated with BE in a male population. Methods We analyzed data from the Barrett's Esophagus Early Detection Case Control Study, based at the Walter Reed National Military Medical Center. Blood samples were collected from 173 men with BE and 213 men without BE (controls, based on endoscopic analysis); 13 sex steroid hormones were measured by mass spectrometry and sex hormone binding globulin was measured by ELISA. We also calculated free estradiol, free testosterone and free dihydrotestosterone (DHT). We used multivariable logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for age, race, smoking status, alcohol consumption, body mass index (BMI; kg/m2), heartburn, regurgitation, and gastroesophageal symptom score (excluding heartburn and regurgitation). Results Levels of free testosterone and free DHT were positively associated with BE risk; patients in the highest quartile for these hormones were most likely to have BE (for free testosterone, OR=5.36; 95% CI, 2.21–13.03; P=0.0002 and for free DHT, OR=4.25, 95% CI, 1.87–9.66; P=.001). Level of estrone sulfate was inversely associated with BE risk (P for trend=.02). No other hormone was associated with BE risk. Relationships were not modified by age or BMI. Conclusions In an analysis of men, levels of free testosterone and free DHT were significantly associated with risk of BE. PMID:25158929

A Multiscale, Mechanism-Driven, Dynamic Model for the Effects of 5α-Reductase Inhibition on Prostate Maintenance

PubMed Central

Zager, Michael G.; Barton, Hugh A.

2012-01-01

A systems-level mathematical model is presented that describes the effects of inhibiting the enzyme 5α-reductase (5aR) on the ventral prostate of the adult male rat under chronic administration of the 5aR inhibitor, finasteride. 5aR is essential for androgen regulation in males, both in normal conditions and disease states. The hormone kinetics and downstream effects on reproductive organs associated with perturbing androgen regulation are complex and not necessarily intuitive. Inhibition of 5aR decreases the metabolism of testosterone (T) to the potent androgen 5α-dihydrotestosterone (DHT). This results in decreased cell proliferation, fluid production and 5aR expression as well as increased apoptosis in the ventral prostate. These regulatory changes collectively result in decreased prostate size and function, which can be beneficial to men suffering from benign prostatic hyperplasia (BPH) and could play a role in prostate cancer. There are two distinct isoforms of 5aR in male humans and rats, and thus developing a 5aR inhibitor is a challenging pursuit. Several inhibitors are on the market for treatment of BPH, including finasteride and dutasteride. In this effort, comparisons of simulated vs. experimental T and DHT levels and prostate size are depicted, demonstrating the model accurately described an approximate 77% decrease in prostate size and nearly complete depletion of prostatic DHT following 21 days of daily finasteride dosing in rats. This implies T alone is not capable of maintaining a normal prostate size. Further model analysis suggests the possibility of alternative dosing strategies resulting in similar or greater effects on prostate size, due to complex kinetics between T, DHT and gene occupancy. With appropriate scaling and parameterization for humans, this model provides a multiscale modeling platform for drug discovery teams to test and generate hypotheses about drugging strategies for indications like BPH and prostate cancer, such as compound binding properties, dosing regimens, and target validation. PMID:22970204

Musculoskeletal and prostate effects of combined testosterone and finasteride administration in older hypogonadal men: a randomized, controlled trial

PubMed Central

Yarrow, Joshua F.; Conover, Christine F.; Nseyo, Unyime; Meuleman, John R.; Lipinska, Judyta A.; Braith, Randy W.; Beck, Darren T.; Martin, Jeffrey S.; Morrow, Matthew; Roessner, Shirley; Beggs, Luke A.; McCoy, Sean C.; Cannady, Darryl F.; Shuster, Jonathan J.

2013-01-01

Testosterone acts directly at androgen receptors and also exerts potent actions following 5α-reduction to dihydrotestosterone (DHT). Finasteride (type II 5α-reductase inhibitor) lowers DHT and is used to treat benign prostatic hyperplasia. However, it is unknown whether elevated DHT mediates either beneficial musculoskeletal effects or prostate enlargement resulting from higher-than-replacement doses of testosterone. Our purpose was to determine whether administration of testosterone plus finasteride to older hypogonadal men could produce musculoskeletal benefits without prostate enlargement. Sixty men aged ≥60 yr with a serum testosterone concentration of ≤300 ng/dl or bioavailable testosterone ≤70 ng/dl received 52 wk of treatment with testosterone enanthate (TE; 125 mg/wk) vs. vehicle, paired with finasteride (5 mg/day) vs. placebo using a 2 × 2 factorial design. Over the course of 12 mo, TE increased upper and lower body muscle strength by 8–14% (P = 0.015 to <0.001), fat-free mass 4.04 kg (P = 0.032), lumbar spine bone mineral density (BMD) 4.19% (P < 0.001), and total hip BMD 1.96% (P = 0.024) while reducing total body fat −3.87 kg (P < 0.001) and trunk fat −1.88 kg (P = 0.0051). In the first 3 mo, testosterone increased hematocrit 4.13% (P < 0.001). Coadministration of finasteride did not alter any of these effects. Over 12 mo, testosterone also increased prostate volume 11.4 cm3 (P = 0.0051), an effect that was completely prevented by finasteride (P = 0.0027). We conclude that a higher-than-replacement TE combined with finasteride significantly increases muscle strength and BMD and reduces body fat without causing prostate enlargement. These results demonstrate that elevated DHT mediates testosterone-induced prostate enlargement but is not required for benefits in musculoskeletal or adipose tissue. PMID:24326421

The relationship between plasma steroid hormone concentrations and the reproductive cycle in the Northern Pacific rattlesnake, Crotalus oreganus.

PubMed

Lind, Craig M; Husak, Jerry F; Eikenaar, Cas; Moore, Ignacio T; Taylor, Emily N

2010-05-01

We describe the reproductive cycle of Northern Pacific rattlesnakes (Crotalus oreganus) by quantifying steroid hormone concentrations and observing reproductive behaviors in free-ranging individuals. Additionally, we examined reproductive tissues from museum specimens. Plasma steroid hormone concentrations were quantified for both male and female snakes throughout the active season (March-October). We measured testosterone (T), 5alpha-dihydrotestosterone (DHT), and corticosterone (B) concentrations in both sexes and 17beta-estradiol (E2) and progesterone (P) in females only. We observed reproductive behaviors (e.g., consortship, courtship, and copulation) in the field and measured testis and follicle size in male and female snakes from museum collections to relate steroid hormone concentrations to the timing of reproductive events. Our study revealed that C. oreganus in central California exhibits a bimodal pattern of breeding, with most mating behavior occurring in the spring and some incidences of mating behavior observed in late summer/fall. Each breeding period corresponded with elevated androgen (T or DHT) levels in males. Testes were regressed in the spring when the majority of reproductive behavior was observed in this population, and they reached peak volume in August and September during spermatogenesis. Although we did not detect seasonal variation in female hormone concentrations, some females had high E2 in the spring and fall, coincident with mating and with increased follicle size (indicating vitellogenesis) in museum specimens. Females with high E2 concentrations also had high T and DHT concentrations. Corticosterone concentrations in males and females were not related either to time of year or to concentrations of any other hormones quantified. Progesterone concentrations in females also did not vary seasonally, but this likely reflected sampling bias as females tended to be underground, and thus unobtainable, in summer months when P would be expected to be elevated during gestation. In females, P was positively correlated with T and DHT, and E2 was positively correlated with T. Published by Elsevier Inc.

Accumulation of Palmitoylcarnitine and Its Effect on Pro-Inflammatory Pathways and Calcium Influx in Prostate Cancer.

PubMed

Al-Bakheit, Ala'a; Traka, Maria; Saha, Shikha; Mithen, Richard; Melchini, Antonietta

2016-10-01

Acylcarnitines are intermediates of fatty acid oxidation and accumulate as a consequence of the metabolic dysfunction resulting from the insufficient integration between β-oxidation and the tricarboxylic acid (TCA) cycle. The aim of this study was to investigate whether acylcarnitines accumulate in prostate cancer tissue, and whether their biological actions could be similar to those of dihydrotestosterone (DHT), a structurally related compound associated with cancer development. Levels of palmitoylcarnitine (palcar), a C16:00 acylcarnitine, were measured in prostate tissue using LC-MS/MS. The effect of palcar on inflammatory cytokines and calcium (Ca(2+) ) influx was investigated in in vitro models of prostate cancer. We observed a significantly higher level of palcar in prostate cancerous tissue compared to benign tissue. High levels of palcar have been associated with increased gene expression and secretion of the pro-inflammatory cytokine IL-6 in cancerous PC3 cells, compared to normal PNT1A cells. Furthermore, we found that high levels of palcar induced a rapid Ca(2+) influx in PC3 cells, but not in DU145, BPH-1, or PNT1A cells. This pattern of Ca(2+) influx was also observed in response to DHT. Through the use of whole genome arrays we demonstrated that PNT1A cells exposed to palcar or DHT have a similar biological response. This study suggests that palcar might act as a potential mediator for prostate cancer progression through its effect on (i) pro-inflammatory pathways, (ii) Ca(2+) influx, and (iii) DHT-like effects. Further studies need to be undertaken to explore whether this class of compounds has different biological functions at physiological and pathological levels. Prostate 76:1326-1337, 2016. © 2016 The Authors. The Prostate published by Wiley Periodicals, Inc. © 2016 The Authors. The Prostate published by Wiley Periodicals, Inc.

Twitter K-H networks in action: Advancing biomedical literature for drug search.

PubMed

Hamed, Ahmed Abdeen; Wu, Xindong; Erickson, Robert; Fandy, Tamer

2015-08-01

The importance of searching biomedical literature for drug interaction and side-effects is apparent. Current digital libraries (e.g., PubMed) suffer infrequent tagging and metadata annotation updates. Such limitations cause absence of linking literature to new scientific evidence. This demonstrates a great deal of challenges that stand in the way of scientists when searching biomedical repositories. In this paper, we present a network mining approach that provides a bridge for linking and searching drug-related literature. Our contributions here are two fold: (1) an efficient algorithm called HashPairMiner to address the run-time complexity issues demonstrated in its predecessor algorithm: HashnetMiner, and (2) a database of discoveries hosted on the web to facilitate literature search using the results produced by HashPairMiner. Though the K-H network model and the HashPairMiner algorithm are fairly young, their outcome is evidence of the considerable promise they offer to the biomedical science community in general and the drug research community in particular. Copyright © 2015 Elsevier Inc. All rights reserved.

Controllable band structure and topological phase transition in two-dimensional hydrogenated arsenene

PubMed Central

Wang, Ya-ping; Ji, Wei-xiao; Zhang, Chang-wen; Li, Ping; Li, Feng; Ren, Miao-juan; Chen, Xin-Lian; Yuan, Min; Wang, Pei-ji

2016-01-01

Discovery of two-dimensional (2D) topological insulator such as group-V films initiates challenges in exploring exotic quantum states in low dimensions. Here, we perform first-principles calculations to study the geometric and electronic properties in 2D arsenene monolayer with hydrogenation (HAsH). We predict a new σ-type Dirac cone related to the px,y orbitals of As atoms in HAsH, dependent on in-plane tensile strain. Noticeably, the spin-orbit coupling (SOC) opens a quantum spin Hall (QSH) gap of 193 meV at the Dirac cone. A single pair of topologically protected helical edge states is established for the edges, and its QSH phase is confirmed with topological invariant Z2 = 1. We also propose a 2D quantum well (QW) encapsulating HAsH with the h-BN sheet on each side, which harbors a nontrivial QSH state with the Dirac cone lying within the band gap of cladding BN substrate. These findings provide a promising innovative platform for QSH device design and fabrication operating at room temperature. PMID:26839209

Supervised graph hashing for histopathology image retrieval and classification.

PubMed

Shi, Xiaoshuang; Xing, Fuyong; Xu, KaiDi; Xie, Yuanpu; Su, Hai; Yang, Lin

2017-12-01

In pathology image analysis, morphological characteristics of cells are critical to grade many diseases. With the development of cell detection and segmentation techniques, it is possible to extract cell-level information for further analysis in pathology images. However, it is challenging to conduct efficient analysis of cell-level information on a large-scale image dataset because each image usually contains hundreds or thousands of cells. In this paper, we propose a novel image retrieval based framework for large-scale pathology image analysis. For each image, we encode each cell into binary codes to generate image representation using a novel graph based hashing model and then conduct image retrieval by applying a group-to-group matching method to similarity measurement. In order to improve both computational efficiency and memory requirement, we further introduce matrix factorization into the hashing model for scalable image retrieval. The proposed framework is extensively validated with thousands of lung cancer images, and it achieves 97.98% classification accuracy and 97.50% retrieval precision with all cells of each query image used. Copyright © 2017 Elsevier B.V. All rights reserved.

Modeling and Simulation of the Economics of Mining in the Bitcoin Market.

PubMed

Cocco, Luisanna; Marchesi, Michele

2016-01-01

In January 3, 2009, Satoshi Nakamoto gave rise to the "Bitcoin Blockchain", creating the first block of the chain hashing on his computer's central processing unit (CPU). Since then, the hash calculations to mine Bitcoin have been getting more and more complex, and consequently the mining hardware evolved to adapt to this increasing difficulty. Three generations of mining hardware have followed the CPU's generation. They are GPU's, FPGA's and ASIC's generations. This work presents an agent-based artificial market model of the Bitcoin mining process and of the Bitcoin transactions. The goal of this work is to model the economy of the mining process, starting from GPU's generation, the first with economic significance. The model reproduces some "stylized facts" found in real-time price series and some core aspects of the mining business. In particular, the computational experiments performed can reproduce the unit root property, the fat tail phenomenon and the volatility clustering of Bitcoin price series. In addition, under proper assumptions, they can reproduce the generation of Bitcoins, the hashing capability, the power consumption, and the mining hardware and electrical energy expenditures of the Bitcoin network.

Controllable band structure and topological phase transition in two-dimensional hydrogenated arsenene

NASA Astrophysics Data System (ADS)

Wang, Ya-Ping; Ji, Wei-Xiao; Zhang, Chang-Wen; Li, Ping; Li, Feng; Ren, Miao-Juan; Chen, Xin-Lian; Yuan, Min; Wang, Pei-Ji

2016-02-01

Discovery of two-dimensional (2D) topological insulator such as group-V films initiates challenges in exploring exotic quantum states in low dimensions. Here, we perform first-principles calculations to study the geometric and electronic properties in 2D arsenene monolayer with hydrogenation (HAsH). We predict a new σ-type Dirac cone related to the px,y orbitals of As atoms in HAsH, dependent on in-plane tensile strain. Noticeably, the spin-orbit coupling (SOC) opens a quantum spin Hall (QSH) gap of 193 meV at the Dirac cone. A single pair of topologically protected helical edge states is established for the edges, and its QSH phase is confirmed with topological invariant Z2 = 1. We also propose a 2D quantum well (QW) encapsulating HAsH with the h-BN sheet on each side, which harbors a nontrivial QSH state with the Dirac cone lying within the band gap of cladding BN substrate. These findings provide a promising innovative platform for QSH device design and fabrication operating at room temperature.

Endothelin‐1 mediates natriuresis but not polyuria during vitamin D‐induced acute hypercalcaemia

PubMed Central

Tokonami, Natsuko; Cheval, Lydie; Monnay, Isabelle; Meurice, Guillaume; Loffing, Johannes; Feraille, Eric

2017-01-01

Key points Hypercalcaemia can occur under various pathological conditions, such as primary hyperparathyroidism, malignancy or granulomatosis, and it induces natriuresis and polyuria in various species via an unknown mechanism.A previous study demonstrated that hypercalcaemia induced by vitamin D in rats increased endothelin (ET)‐1 expression in the distal nephron, which suggests the involvement of the ET system in hypercalcaemia‐induced effects.In the present study, we demonstrate that, during vitamin D‐induced hypercalcaemia, the activation of ET system by increased ET‐1 is responsible for natriuresis but not for polyuria.Vitamin D‐treated hypercalcaemic mice showed a blunted response to amiloride, suggesting that epithelial sodium channel function is inhibited.We have identified an original pathway that specifically mediates the effects of vitamin D‐induced hypercalcaemia on sodium handling in the distal nephron without affecting water handling. Abstract Acute hypercalcaemia increases urinary sodium and water excretion; however, the underlying molecular mechanism remains unclear. Because vitamin D‐induced hypercalcaemia increases the renal expression of endothelin (ET)‐1, we hypothesized that ET‐1 mediates the effects of hypercalcaemia on renal sodium and water handling. Hypercalcaemia was induced in 8‐week‐old, parathyroid hormone‐supplemented, male mice by oral administration of dihydrotachysterol (DHT) for 3 days. DHT‐treated mice became hypercalcaemic and displayed increased urinary water and sodium excretion compared to controls. mRNA levels of ET‐1 and the transcription factors CCAAT‐enhancer binding protein β and δ were specifically increased in the distal convoluted tubule and downstream segments in DHT‐treated mice. To examine the role of the ET system in hypercalcaemia‐induced natriuresis and polyuria, mice were treated with the ET‐1 receptor antagonist macitentan, with or without DHT. Mice treated with both macitentan and DHT displayed hypercalcaemia and polyuria similar to that in mice treated with DHT alone; however, no increase in urinary sodium excretion was observed. To identify the affected sodium transport mechanism, we assessed the response to various diuretics in control and DHT‐treated hypercalcaemic mice. Amiloride, an inhibitor of the epithelial sodium channel (ENaC), increased sodium excretion to a lesser extent in DHT‐treated mice compared to control mice. Mice treated with either macitentan+DHT or macitentan alone had a similar response to amiloride. In summary, vitamin D‐induced hypercalcaemia increases the renal production of ET‐1 and decreases ENaC activity, which is probably responsible for the rise in urinary sodium excretion but not for polyuria. PMID:28120456

Three-dimensional model-based object recognition and segmentation in cluttered scenes.

PubMed

Mian, Ajmal S; Bennamoun, Mohammed; Owens, Robyn

2006-10-01

Viewpoint independent recognition of free-form objects and their segmentation in the presence of clutter and occlusions is a challenging task. We present a novel 3D model-based algorithm which performs this task automatically and efficiently. A 3D model of an object is automatically constructed offline from its multiple unordered range images (views). These views are converted into multidimensional table representations (which we refer to as tensors). Correspondences are automatically established between these views by simultaneously matching the tensors of a view with those of the remaining views using a hash table-based voting scheme. This results in a graph of relative transformations used to register the views before they are integrated into a seamless 3D model. These models and their tensor representations constitute the model library. During online recognition, a tensor from the scene is simultaneously matched with those in the library by casting votes. Similarity measures are calculated for the model tensors which receive the most votes. The model with the highest similarity is transformed to the scene and, if it aligns accurately with an object in the scene, that object is declared as recognized and is segmented. This process is repeated until the scene is completely segmented. Experiments were performed on real and synthetic data comprised of 55 models and 610 scenes and an overall recognition rate of 95 percent was achieved. Comparison with the spin images revealed that our algorithm is superior in terms of recognition rate and efficiency.

Creating an Assured Joint DOD and Interagency Interoperable Net-Centric Enterprise. Report of the Defense Science Board Task Force on Achieving Interoperability in a Net-Centric Environment

DTIC Science & Technology

2009-03-01

policy, elliptic curve public key cryptography using the 256 -bit prime modulus elliptic curve as specified in FIPS-186-2 and SHA - 256 are appropriate for...publications/fips/fips186-2/fips186-2-change1.pdf 76 I P ART I . CH A PT E R 5 Hashing via the Secure Hash Algorithm (using SHA - 256 and...lithography and processing techniques. Field programmable gate arrays ( FPGAs ) are a chip design of interest. These devices are extensively used in

Recent Advances in Drug Design and Drug Discovery for Androgen-Dependent Diseases

PubMed Central

Cabeza, Marisa; Sánchez-Márquez, Araceli; Garrido, Mariana; Silva, Aylín; Bratoeff, Eugene

2016-01-01

This article summarizes the importance of different targets such as 5α-reductase, 17β-HSD, CYP17A, androgen receptor and protein kinase A for the treatment of prostate cancer and benign prostatic hyperplasia. It is a well known fact that dihydrotestosterone (DHT) is associated with the development of androgen-dependent afflictions. At the present time, several research groups are attempting to develop new steroidal and non-steroidal molecules with the purpose of inhibiting the synthesis and biological response of DHT. This review also discusses the most recent studies reported in the literature that describe the therapeutic potential of novel compounds, as well as the new drugs, principally inhibitors of 5α-reductase. PMID:26861003

Nano-Al Reaction with Nitrogen in the Burn Front of Oxygen-Free Energetic Materials

NASA Astrophysics Data System (ADS)

Tappan, Bryce

2005-07-01

Nano-particulate aluminum metal was added to the high nitrogen energetic materials dihydrazinotetrazine (DHT) and triaminoguanidium azotetrazolate (TAGzT) in order to determine the effects on decomposition behavior. Standard safety testing (sensitivity to impact, spark and friction) are reported, show that the addition of nano-Al actually decreases the sensitivity of the pure DHT and TAGzT. Thermo-equilibrium calculations (Cheetah) indicate that the all of the Al reacts to form AlN in both materials at the levels of interest, and the calculated specific impulses are reported. Emission spectra were collected to determine AlN formation in combustion. Burning rates were also collected, and the effects of nano-Al on rates are discussed.

A comparison study of different physical treatments on cartilage matrix derived porous scaffolds for tissue engineering applications

PubMed Central

Moradi, Ali; Pramanik, Sumit; Ataollahi, Forough; Abdul Khalil, Alizan; Kamarul, Tunku; Pingguan-Murphy, Belinda

2014-01-01

Native cartilage matrix derived (CMD) scaffolds from various animal and human sources have drawn attention in cartilage tissue engineering due to the demonstrable presence of bioactive components. Different chemical and physical treatments have been employed to enhance the micro-architecture of CMD scaffolds. In this study we have assessed the typical effects of physical cross-linking methods, namely ultraviolet (UV) light, dehydrothermal (DHT) treatment, and combinations of them on bovine articular CMD porous scaffolds with three different matrix concentrations (5%, 15% and 30%) to assess the relative strengths of each treatment. Our findings suggest that UV and UV–DHT treatments on 15% CMD scaffolds can yield architecturally optimal scaffolds for cartilage tissue engineering. PMID:27877731

Sparse Unorganized Point Cloud Based Relative Pose Estimation for Uncooperative Space Target.

PubMed

Yin, Fang; Chou, Wusheng; Wu, Yun; Yang, Guang; Xu, Song

2018-03-28

This paper proposes an autonomous algorithm to determine the relative pose between the chaser spacecraft and the uncooperative space target, which is essential in advanced space applications, e.g., on-orbit serving missions. The proposed method, named Congruent Tetrahedron Align (CTA) algorithm, uses the very sparse unorganized 3D point cloud acquired by a LIDAR sensor, and does not require any prior pose information. The core of the method is to determine the relative pose by looking for the congruent tetrahedron in scanning point cloud and model point cloud on the basis of its known model. The two-level index hash table is built for speeding up the search speed. In addition, the Iterative Closest Point (ICP) algorithm is used for pose tracking after CTA. In order to evaluate the method in arbitrary initial attitude, a simulated system is presented. Specifically, the performance of the proposed method to provide the initial pose needed for the tracking algorithm is demonstrated, as well as their robustness against noise. Finally, a field experiment is conducted and the results demonstrated the effectiveness of the proposed method.

Sparse Unorganized Point Cloud Based Relative Pose Estimation for Uncooperative Space Target

PubMed Central

Chou, Wusheng; Wu, Yun; Yang, Guang; Xu, Song

2018-01-01

This paper proposes an autonomous algorithm to determine the relative pose between the chaser spacecraft and the uncooperative space target, which is essential in advanced space applications, e.g., on-orbit serving missions. The proposed method, named Congruent Tetrahedron Align (CTA) algorithm, uses the very sparse unorganized 3D point cloud acquired by a LIDAR sensor, and does not require any prior pose information. The core of the method is to determine the relative pose by looking for the congruent tetrahedron in scanning point cloud and model point cloud on the basis of its known model. The two-level index hash table is built for speeding up the search speed. In addition, the Iterative Closest Point (ICP) algorithm is used for pose tracking after CTA. In order to evaluate the method in arbitrary initial attitude, a simulated system is presented. Specifically, the performance of the proposed method to provide the initial pose needed for the tracking algorithm is demonstrated, as well as their robustness against noise. Finally, a field experiment is conducted and the results demonstrated the effectiveness of the proposed method. PMID:29597323

Design and implementation of a privacy preserving electronic health record linkage tool in Chicago

PubMed Central

Cashy, John P; Jackson, Kathryn L; Pah, Adam R; Goel, Satyender; Boehnke, Jörn; Humphries, John Eric; Kominers, Scott Duke; Hota, Bala N; Sims, Shannon A; Malin, Bradley A; French, Dustin D; Walunas, Theresa L; Meltzer, David O; Kaleba, Erin O; Jones, Roderick C; Galanter, William L

2015-01-01

Objective To design and implement a tool that creates a secure, privacy preserving linkage of electronic health record (EHR) data across multiple sites in a large metropolitan area in the United States (Chicago, IL), for use in clinical research. Methods The authors developed and distributed a software application that performs standardized data cleaning, preprocessing, and hashing of patient identifiers to remove all protected health information. The application creates seeded hash code combinations of patient identifiers using a Health Insurance Portability and Accountability Act compliant SHA-512 algorithm that minimizes re-identification risk. The authors subsequently linked individual records using a central honest broker with an algorithm that assigns weights to hash combinations in order to generate high specificity matches. Results The software application successfully linked and de-duplicated 7 million records across 6 institutions, resulting in a cohort of 5 million unique records. Using a manually reconciled set of 11 292 patients as a gold standard, the software achieved a sensitivity of 96% and a specificity of 100%, with a majority of the missed matches accounted for by patients with both a missing social security number and last name change. Using 3 disease examples, it is demonstrated that the software can reduce duplication of patient records across sites by as much as 28%. Conclusions Software that standardizes the assignment of a unique seeded hash identifier merged through an agreed upon third-party honest broker can enable large-scale secure linkage of EHR data for epidemiologic and public health research. The software algorithm can improve future epidemiologic research by providing more comprehensive data given that patients may make use of multiple healthcare systems. PMID:26104741

Design and implementation of a privacy preserving electronic health record linkage tool in Chicago.

PubMed

Kho, Abel N; Cashy, John P; Jackson, Kathryn L; Pah, Adam R; Goel, Satyender; Boehnke, Jörn; Humphries, John Eric; Kominers, Scott Duke; Hota, Bala N; Sims, Shannon A; Malin, Bradley A; French, Dustin D; Walunas, Theresa L; Meltzer, David O; Kaleba, Erin O; Jones, Roderick C; Galanter, William L

2015-09-01

To design and implement a tool that creates a secure, privacy preserving linkage of electronic health record (EHR) data across multiple sites in a large metropolitan area in the United States (Chicago, IL), for use in clinical research. The authors developed and distributed a software application that performs standardized data cleaning, preprocessing, and hashing of patient identifiers to remove all protected health information. The application creates seeded hash code combinations of patient identifiers using a Health Insurance Portability and Accountability Act compliant SHA-512 algorithm that minimizes re-identification risk. The authors subsequently linked individual records using a central honest broker with an algorithm that assigns weights to hash combinations in order to generate high specificity matches. The software application successfully linked and de-duplicated 7 million records across 6 institutions, resulting in a cohort of 5 million unique records. Using a manually reconciled set of 11 292 patients as a gold standard, the software achieved a sensitivity of 96% and a specificity of 100%, with a majority of the missed matches accounted for by patients with both a missing social security number and last name change. Using 3 disease examples, it is demonstrated that the software can reduce duplication of patient records across sites by as much as 28%. Software that standardizes the assignment of a unique seeded hash identifier merged through an agreed upon third-party honest broker can enable large-scale secure linkage of EHR data for epidemiologic and public health research. The software algorithm can improve future epidemiologic research by providing more comprehensive data given that patients may make use of multiple healthcare systems. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Modulation of paracrine signaling by CD9 positive small extracellular vesicles mediates cellular growth of androgen deprived prostate cancer

PubMed Central

Soekmadji, Carolina; Riches, James D.; Russell, Pamela J.; Ruelcke, Jayde E.; McPherson, Stephen; Wang, Chenwei; Hovens, Chris M.; Corcoran, Niall M.; Hill, Michelle M.; Nelson, Colleen C.

2017-01-01

Proliferation and maintenance of both normal and prostate cancer (PCa) cells is highly regulated by steroid hormones, particularly androgens, and the extracellular environment. Herein, we identify the secretion of CD9 positive extracellular vesicles (EV) by LNCaP and DUCaP PCa cells in response to dihydrotestosterone (DHT) and use nano-LC–MS/MS to identify the proteins present in these EV. Subsequent bioinformatic and pathway analyses of the mass spectrometry data identified pathologically relevant pathways that may be altered by EV contents. Western blot and CD9 EV TR-FIA assay confirmed a specific increase in the amount of CD9 positive EV in DHT-treated LNCaP and DUCaP cells and treatment of cells with EV enriched with CD9 after DHT exposure can induce proliferation in androgen-deprived conditions. siRNA knockdown of endogenous CD9 in LNCaPs reduced cellular proliferation and expression of AR and prostate specific antigen (PSA) however knockdown of AR did not alter CD9 expression, also implicating CD9 as an upstream regulator of AR. Moreover CD9 positive EV were also found to be significantly higher in plasma from prostate cancer patients in comparison with benign prostatic hyperplasia patients. We conclude that CD9 positive EV are involved in mediating paracrine signalling and contributing toward prostate cancer progression. PMID:28881726

Optimal dehydrothermal processing conditions to improve biocompatibility and durability of a weakly denatured collagen scaffold.

PubMed

Nakada, Akira; Shigeno, Keiji; Sato, Toshihiko; Hatayama, Takahide; Wakatsuki, Mariko; Nakamura, Tatsuo

2017-11-01

Collagen scaffolds are essential for tissue regeneration; however, preprocessing of these scaffolds is necessary because of their poor mechanical properties. The aim of this study was to determine the optimal condition for preparing a collagen scaffold with biocompatibility and durability. An atelocollagen fiber suspension was made and stored at -10°C in a container that could be cooled from the bottom to provide an orientation perpendicular to the collagen fiber and facilitate cell infiltration into the scaffold. After freeze-drying the frozen suspension, various collagen scaffolds were made by dehydrothermal (DHT) treatment under different conditions (processing temperature: 120-160°C for 0-28 h). Sections of the obtained materials were embedded under the back skin of rats, and the thickness and biocompatibility of the residual scaffold were evaluated after 2 weeks. The number of foreign body giant cells was counted to evaluate biocompatibility. Although the residual scaffold was thick, excessive DHT treatment caused a strong foreign body reaction. Weak DHT treatment resulted in a collagen scaffold with good biocompatibility but with reduced thickness. Overall, these results showed the restricted optimal conditions to make a collagen scaffold with good biocompatibility and ability to maintain sufficient space for tissue regeneration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2301-2307, 2017. © 2016 Wiley Periodicals, Inc.

Neuroendocrine androgen action is a key extraovarian mediator in the development of polycystic ovary syndrome.

PubMed

Caldwell, Aimee S L; Edwards, Melissa C; Desai, Reena; Jimenez, Mark; Gilchrist, Robert B; Handelsman, David J; Walters, Kirsty A

2017-04-18

Polycystic ovary syndrome (PCOS) is a complex hormonal disorder characterized by reproductive, endocrine, and metabolic abnormalities. As the origins of PCOS remain unknown, mechanism-based treatments are not feasible and current management relies on treatment of symptoms. Hyperandrogenism is the most consistent PCOS characteristic; however, it is unclear whether androgen excess, which is treatable, is a cause or a consequence of PCOS. As androgens mediate their actions via the androgen receptor (AR), we combined a mouse model of dihydrotestosterone (DHT)-induced PCOS with global and cell-specific AR-resistant (ARKO) mice to investigate the locus of androgen actions that mediate the development of the PCOS phenotype. Global loss of the AR reveals that AR signaling is required for all DHT-induced features of PCOS. Neuron-specific AR signaling was required for the development of dysfunctional ovulation, classic polycystic ovaries, reduced large antral follicle health, and several metabolic traits including obesity and dyslipidemia. In addition, ovariectomized ARKO hosts with wild-type ovary transplants displayed normal estrous cycles and corpora lutea, despite DHT treatment, implying extraovarian and not intraovarian AR actions are key loci of androgen action in generating the PCOS phenotype. These findings provide strong evidence that neuroendocrine genomic AR signaling is an important extraovarian mediator in the development of PCOS traits. Thus, targeting AR-driven mechanisms that initiate PCOS is a promising strategy for the development of novel treatments for PCOS.

Hydrodynamic and thermal modeling of two-dimensional microdroplet arrays for digitized heat transfer

NASA Astrophysics Data System (ADS)

Baird, Eric S.

This document describes hydrodynamic and thermal modeling of two-dimensional microdroplet arrays for use in digitized heat transfer (DHT), a novel active thermal management technique for high power density electronics and integrated microsystems. In DHT, thermal energy is transported by a discrete array of electrostatically activated microdroplets of liquid metals, alloys or aqueous solutions with the potential of supporting significantly higher heat transfer rates than classical air-cooled heat sinks. Actuation methods for dispensing and transporting individual fluid slugs with a high degree of precision and programmability are described, with simple approximate formulae for net forces for steady state and transient velocities in terms of known parameters. A modified cavity flow solver is developed to provide details on the internal flow properties of a translating microdroplet and used to detail the effects of droplet curvature, internal mixing, Peclet number and other parameters on the heat transfer capabilities of a discretized liquid flow. The concept of Nusselt number is generalized to an individual fluid slug and shown to oscillate with a period equal to the droplet's mixing rate. In whole, DHT is demonstrated to be a viable new alternative for achieving the most important objectives of electronic cooling (i.e., minimization of the maximum substrate temperature, reduction of the substrate temperature gradient and removal of substrate hot spots) and a sound fundamental description of the method's electro-, hydro- and thermodynamics is provided.

Action Mechanism of Ginkgo biloba Leaf Extract Intervened by Exercise Therapy in Treatment of Benign Prostate Hyperplasia

PubMed Central

Peng, Chiung-Chi; Liu, Jia-Hong; Chang, Chi-Huang; Chung, Jin-Yuan; Chen, Kuan-Chou

2013-01-01

Benign prostatic hyperplasia (BPH), an imbalance between androgen/estrogen, overexpression of stromal, and epithelial growth factors associated with chronic inflammation, has become an atypical direct cause of mortality of aged male diseases. Ginkgo possesses anti-inflammatory, blood flow-enhancing, and free radical scavenging effects. Considering strenuous exercise can reduce BPH risks, we hypothesize Ginkgo + exercise (Ginkgo + Ex) could be beneficial to BPH. To verify this, rat BPH model was induced by s.c. 3.5 mg testosterone (T) and 0.1 mg estradiol (E2) per head per day successively for 8 weeks, using mineral oil as placebo. Cerenin® 8.33 μL/100 g was applied s.c. from the 10th to the 13th week, and simultaneously, Ex was applied (30 m/min, 3 times/week). In BPH, Ginkgo alone had no effect on T, 5α-reductase, and dihydrotestosterone (DHT), but suppressed androgen receptor (AR), aromatase, E2 and estrogen receptor (ER), and the proliferating cell nuclear antigen (PCNA); Ex alone significantly reduced T, aromatase, E2, ER, AR, and PCNA, but highly raised DHT. While Ginkgo + Ex androgenically downregulated T, aromatase, E2, and ER, but upregulated DHT, AR, and PCNA, implying Ginkgo + Ex tended to worsen BPH. Conclusively, Ginkgo or Ex alone may be more beneficial than Ginkgo + Ex for treatment of BPH. PMID:23690843

Androgen-primed castrate males are sufficient for methamphetamine-facilitated increases in proceptive behavior in female rats

PubMed Central

Rudzinskas, Sarah A.; Mong, Jessica A.

2015-01-01

Methamphetamine (MA) is a psychomotor stimulant associated with increases in sex drive in both men and women. Women, however, are far more likely to face social disadvantages as a consequence of MA use, and their increased sexual motivation poses additional health concerns such as unplanned pregnancies. To better understand the mechanisms underlying MA-facilitated sexual motivation in females, we previously established a rodent model where a ‘binge”-type administration paradigm of MA to sexually receptive female rats significantly increases proceptive behavior in the presence of a sexually active, gonadally-intact male. Our previous work with this model has led us to consider whether the increases in proceptive behavior are truly indicative of increased sexual motivation, or instead a consequence of heightened motor responsivity. Here, we test whether MA-induced increases in proceptive behaviors are specific to a sexually relevant stimulus. Females’ sexual, social, exploratory behaviors, and interaction times were scored during the exposure to stimulus males, including castrates, and dihydrotestosterone (DHT)-treated castrates. MA-treated females demonstrated significant increases in proceptive behaviors toward DHT-treated castrate males but not toward castrate males. While the non-MA-treated females did display proceptive behavior, there was no significant difference between behaviors elicited by DHT-CX males compared to CX males. Our results support the hypothesis that MA facilitates proceptive behavior only in response to specific, androgen mediated sexually-relevant cues. PMID:26497407

Androgenic regulation of chemoinvestigatory behaviors in male and female hamsters.

PubMed

Powers, J B; Bergondy, M L

1983-03-01

In male hamsters, chemosensory responsiveness to sexually relevant female odors is facilitated by testosterone (T). Some evidence suggests that this is not a sexually dimorphic response in that adult females can respond similarly to males following administration of T. This was evaluated and additionally, the hypothesis that facilitation of chemosensory responsiveness by T might be mediated by the conversion of T to aromatized or 5 alpha-reduced metabolites was tested. In 2-min tests, we measured the time adult males or females investigated female hamster vaginal secretion (FHVS). These animals were gonadectomized and administered T, 5 alpha-dihydrotestosterone (DHT), estradiol (E2), or a combination of DHT and E2, by subcutaneous implantation of Silastic capsules. FHVS tests were conducted either 2 and 4 weeks, or 4 and 6 weeks subsequent to gonadectomy and hormone treatment. Comparisons among groups receiving different hormone doses indicated that (1) males and females are not equally responsive to the attractant properties of FHVS, and that (2) neither DHT, E2, nor their combination, can duplicate the effects of T in facilitating responsiveness to FHVS in either sex. The copulatory behavior of males under the hormone conditions described was also tested and it was found that variations in the rate at which the test males sniffed or licked the receptive female's anogenital region correlated with variations in measures of the males' sexual performance.

Maintenance of human hyperplastic prostate implants at different sites in athymic mice.

PubMed

Soós, G; Debiec-Rychter, M; Jones, R F; Zukowski, K; Haas, G P; Wang, C Y

1995-01-01

The present study determined the influence of implantation sites, androgens, and the graft's fibrovascular elements on the maintenance of epithelial elements of human benign hyperplastic prostate tissue (BPH) in the nude mouse. BPH fragments prepared from fresh surgical specimens were implanted subcutaneously (s.c.), intraperitoneally (i.p.), or under the renal capsules (r.c.) into male Beige nude mice, which had been implanted s.c. with a Silastic tube filled with 4-dihydrotestosterone (DHT) or cholesterol. Two weeks later the BPH tissues were removed from the mouse and examined microscopically. The implants from all three sites maintained a comparable morphology, with epithelial and/or angio-leiomyomatous stromal hyperplastic appearance, without striking signs of atrophy, irrespective of supplementation with DHT. Expression of proliferating cell nuclear antigen in the implants was comparable, indicating that there was no significant influence of implantation site on the proliferative ability of either epithelia or the stromal fibroblasts. The PCNA-positive cells in the implants, including the vascular and myofibrous elements, hybridized in situ to a human-specific repeated-sequence DNA probe, indicating that these proliferating cells were of human origin. Our data suggest that during the early phases of the adaptation and maintenance of BPH implants, survival of epithelial cells is actively supported by fibro-vascular mesenchymal elements of the prostate grafts in a manner apparently unaffected by DHT supplements.

An AKT activity threshold regulates androgen-dependent and androgen-independent PSA expression in prostate cancer cell lines.

PubMed

Paliouras, Miltiadis; Diamandis, Eleftherios P

2008-06-01

The androgen receptor (AR) plays an important role in early prostate cancer by activating transcription of a number of genes participating in cell proliferation and growth and cancer progression. However, as the cancer progresses, prostate cancer cells transform from an androgen-dependent to an androgen-independent state. Androgen-independent prostate cancer can manifest itself in several forms, including a percentage of cancers that show reduced levels of prostate-specific antigen (PSA) and can progress without the need for the ligand or active receptor. Therefore, our goal was to examine the role of intracellular signaling pathways in an androgen-independent prostate cancer in vitro model. Using the cell line PC3(AR)(2), we stimulated cells with 5-alpha-dihydrotestosterone (DHT) and epidermal growth factor (EGF) and then analyzed PSA expression. We observed lower PSA expression when cells were jointly stimulated with DHT and EGF, and this was associated with an increase in AKT activity. We examined the role of AKT in AR activity and PSA expression by creating stable PC3(AR)(2) cell lines transfected with a PI3K-Ras-effector loop mutant. These cell lines showed lower DHT-stimulated PSA expression that correlated to changes in the phosphorylated state of AR. Therefore, we propose an in vitro androgen-independent model in which a PI3K/AKT activity threshold and subsequent AR transactivation regulate PSA expression.

A hash based mutual RFID tag authentication protocol in telecare medicine information system.

PubMed

Srivastava, Keerti; Awasthi, Amit K; Kaul, Sonam D; Mittal, R C

2015-01-01

Radio Frequency Identification (RFID) is a technology which has multidimensional applications to reduce the complexity of today life. Everywhere, like access control, transportation, real-time inventory, asset management and automated payment systems etc., RFID has its enormous use. Recently, this technology is opening its wings in healthcare environments, where potential applications include patient monitoring, object traceability and drug administration systems etc. In this paper, we propose a secure RFID-based protocol for the medical sector. This protocol is based on hash operation with synchronized secret. The protocol is safe against active and passive attacks such as forgery, traceability, replay and de-synchronization attack.

Graph Coarsening for Path Finding in Cybersecurity Graphs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hogan, Emilie A.; Johnson, John R.; Halappanavar, Mahantesh

2013-01-01

n the pass-the-hash attack, hackers repeatedly steal password hashes and move through a computer network with the goal of reaching a computer with high level administrative privileges. In this paper we apply graph coarsening in network graphs for the purpose of detecting hackers using this attack or assessing the risk level of the network's current state. We repeatedly take graph minors, which preserve the existence of paths in the graph, and take powers of the adjacency matrix to count the paths. This allows us to detect the existence of paths as well as find paths that have high risk ofmore » being used by adversaries.« less

Deeply learnt hashing forests for content based image retrieval in prostate MR images

NASA Astrophysics Data System (ADS)

Shah, Amit; Conjeti, Sailesh; Navab, Nassir; Katouzian, Amin

2016-03-01

Deluge in the size and heterogeneity of medical image databases necessitates the need for content based retrieval systems for their efficient organization. In this paper, we propose such a system to retrieve prostate MR images which share similarities in appearance and content with a query image. We introduce deeply learnt hashing forests (DL-HF) for this image retrieval task. DL-HF effectively leverages the semantic descriptiveness of deep learnt Convolutional Neural Networks. This is used in conjunction with hashing forests which are unsupervised random forests. DL-HF hierarchically parses the deep-learnt feature space to encode subspaces with compact binary code words. We propose a similarity preserving feature descriptor called Parts Histogram which is derived from DL-HF. Correlation defined on this descriptor is used as a similarity metric for retrieval from the database. Validations on publicly available multi-center prostate MR image database established the validity of the proposed approach. The proposed method is fully-automated without any user-interaction and is not dependent on any external image standardization like image normalization and registration. This image retrieval method is generalizable and is well-suited for retrieval in heterogeneous databases other imaging modalities and anatomies.

Modeling and Simulation of the Economics of Mining in the Bitcoin Market

PubMed Central

Marchesi, Michele

2016-01-01

In January 3, 2009, Satoshi Nakamoto gave rise to the “Bitcoin Blockchain”, creating the first block of the chain hashing on his computer’s central processing unit (CPU). Since then, the hash calculations to mine Bitcoin have been getting more and more complex, and consequently the mining hardware evolved to adapt to this increasing difficulty. Three generations of mining hardware have followed the CPU’s generation. They are GPU’s, FPGA’s and ASIC’s generations. This work presents an agent-based artificial market model of the Bitcoin mining process and of the Bitcoin transactions. The goal of this work is to model the economy of the mining process, starting from GPU’s generation, the first with economic significance. The model reproduces some “stylized facts” found in real-time price series and some core aspects of the mining business. In particular, the computational experiments performed can reproduce the unit root property, the fat tail phenomenon and the volatility clustering of Bitcoin price series. In addition, under proper assumptions, they can reproduce the generation of Bitcoins, the hashing capability, the power consumption, and the mining hardware and electrical energy expenditures of the Bitcoin network. PMID:27768691

A Novel Approach for Constructing One-Way Hash Function Based on a Message Block Controlled 8D Hyperchaotic Map

NASA Astrophysics Data System (ADS)

Lin, Zhuosheng; Yu, Simin; Lü, Jinhu

2017-06-01

In this paper, a novel approach for constructing one-way hash function based on 8D hyperchaotic map is presented. First, two nominal matrices both with constant and variable parameters are adopted for designing 8D discrete-time hyperchaotic systems, respectively. Then each input plaintext message block is transformed into 8 × 8 matrix following the order of left to right and top to bottom, which is used as a control matrix for the switch of the nominal matrix elements both with the constant parameters and with the variable parameters. Through this switching control, a new nominal matrix mixed with the constant and variable parameters is obtained for the 8D hyperchaotic map. Finally, the hash function is constructed with the multiple low 8-bit hyperchaotic system iterative outputs after being rounded down, and its secure analysis results are also given, validating the feasibility and reliability of the proposed approach. Compared with the existing schemes, the main feature of the proposed method is that it has a large number of key parameters with avalanche effect, resulting in the difficulty for estimating or predicting key parameters via various attacks.

SEXUAL BEHAVIOR IN MALE RODENTS

PubMed Central

Hull, Elaine M.; Dominguez, Juan M.

2007-01-01

The hormonal factors and neural circuitry that control copulation are similar across rodent species, although there are differences in specific behavior patterns. Both estradiol (E) and dihydrotestosterone (DHT) contribute to the activation of mating, although E is more important for copulation and DHT, for genital reflexes. Hormonal activation of the medial preoptic area (MPOA) is most effective, although implants in the medial amygdala (MeA) can also stimulate mounting in castrates. Chemosensory inputs from the main and accessory olfactory systems are the most important stimuli for mating in rodents, especially in hamsters, although genitosensory input also contributes. Dopamine agonists facilitate sexual behavior, and serotonin (5-HT) is generally inhibitory, though certain 5-HT receptor subtypes facilitate erection or ejaculation. Norepinephrine agonists and opiates have dose-dependent effects, with low doses facilitating and high doses inhibiting behavior. PMID:17499249

Design and synthesis of tricyclic tetrahydroquinolines as a new series of nonsteroidal selective androgen receptor modulators (SARMs).

PubMed

Nagata, Naoya; Miyakawa, Motonori; Amano, Seiji; Furuya, Kazuyuki; Yamamoto, Noriko; Inoguchi, Kiyoshi

2011-03-15

Some tricyclic tetrahydroquinolines (THQs) were found to have the potential of a new series of nonsteroidal selective androgen receptor modulators (SARMs). Compound 5b was first designed and synthesized under our hypothesis based on a four-point pharmacophoric requirement of the 3-carbonyl, 18-methyl, 17-hydroxyl, and 13-quaternary carbon groups of dihydrotestosterone (DHT). It was revealed that this compound exhibits not only a strong androgen receptor (AR) agonistic activity (EC(50)=9.2 nM) but also the highest selectivity in binding affinity to AR among the steroid hormone receptors. Furthermore, this compound showed a weak virilizing effect with retention of the desired anabolic effect as compared with DHT in vivo. Copyright © 2011 Elsevier Ltd. All rights reserved.

Metabolism of sex steroids is influenced by acquired adiposity-A study of young adult male monozygotic twin pairs.

PubMed

Vihma, Veera; Naukkarinen, Jussi; Turpeinen, Ursula; Hämäläinen, Esa; Kaprio, Jaakko; Rissanen, Aila; Heinonen, Sini; Hakkarainen, Antti; Lundbom, Jesper; Lundbom, Nina; Mikkola, Tomi S; Tikkanen, Matti J; Pietiläinen, Kirsi H

2017-09-01

Obesity and ageing are associated with lower serum testosterone levels in men. How fat distribution or adipose tissue metabolism, independent of genetic factors and age, are related to sex steroid metabolism is less clear. We studied the associations between adiposity and serum sex hormone concentrations, and mRNA expression of genes regulating sex hormone metabolism in adipose tissue in young adult male monozygotic (MZ) twin pairs. The subjects [n=18 pairs; mean age, 32 years; individual body mass indexes (BMIs) 22-36kg/m 2 ] included 9 male MZ twin pairs discordant for BMI [intra-pair difference (Δ) in BMI ≥3kg/m 2 ]. Sex steroid concentrations were determined by liquid chromatography-tandem mass spectrometry, body composition by dual-energy X-ray absorptiometry and magnetic resonance imaging, and mRNA expressions from subcutaneous adipose tissue by Affymetrix. In BMI-discordant pairs (mean ΔBMI=5.9kg/m 2 ), serum dihydrotestosterone (DHT) was lower [mean 1.9 (SD 0.7) vs. 2.4 (1.0) nmol/l, P=0.040] and mRNA expressions of DHT-inactivating AKR1C2 (P=0.021) and cortisol-producing HSD11B1 (P=0.008) higher in the heavier compared to the leaner co-twins. Serum free 17β-estradiol (E2) was higher [2.3 (0.5) vs. 1.9 (0.5) pmol/l, P=0.028], and in all twin pairs, serum E2 and estrone concentrations were higher in the heavier than in the leaner co-twins [107 (28) vs. 90 (22) pmol/l, P=0.006; and 123 (43) vs. 105 (27) pmol/l, P=0.025]. Within all twin pairs, i.e. independent of genetic effects and age, 1) the amount of subcutaneous fat inversely correlated with serum total and free testosterone, DHT, and sex hormone-binding globulin (SHBG) concentrations (P<0.01 for all), 2) intra-abdominal fat with total testosterone and SHBG (P<0.05), and 3) liver fat with SHBG (P=0.006). Also, 4) general and intra-abdominal adiposity correlated positively with mRNA expressions of AKR1C2, HSD11B1, and aromatase in adipose tissue (P<0.05). In conclusion, acquired adiposity was associated with decreased serum DHT and increased estrogen concentrations, independent of genetic factors and age. The reduction of DHT could be linked to its increased degradation (by AKR1C2 and HSD11B1) and increased estrogen levels to increased adiposity-related expression of aromatase in adipose tissue. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dihydrotestosterone treatment rescues the decline in protein synthesis as a result of sarcopenia in isolated mouse skeletal muscle fibres

PubMed Central

Wendowski, Oskar; Redshaw, Zoe

2016-01-01

Abstract Background Sarcopenia, the progressive decline in skeletal muscle mass and function with age, is a debilitating condition. It leads to inactivity, falls, and loss of independence. Despite this, its cause(s) and the underlying mechanism(s) are still poorly understood. Methods In this study, small skeletal muscle fibre bundles isolated from the extensor digitorum longus (a fast‐twitch muscle) and the soleus (a slow‐twitch muscle) of adult mice of different ages (range 100–900 days old) were used to investigate the effects of ageing and dihydrotestosterone (DHT) treatment on protein synthesis as well as the expression and function of two amino acid transporters; the sodium‐coupled neutral amino acid transporter (SNAT) 2, and the sodium‐independent L‐type amino‐acid transporter (LAT) 2. Results At all ages investigated, protein synthesis was always higher in the slow‐twitch than in the fast‐twitch muscle fibres and decreased with age in both fibre types. However, the decline was greater in the fast‐twitch than in the slow‐twitch fibres and was accompanied by a reduction in the expression of SNAT2 and LAT2 at the protein level. Again, the decrease in the expression of the amino acid transporters was greater in the fast‐twitch than in the slow‐twitch fibres. In contrast, ageing had no effect on SNAT2 and LAT2 expressions at the mRNA level. Treating the muscle fibre bundles with physiological concentrations (~2 nM) of DHT for 1 h completely reversed the effects of ageing on protein synthesis and the expression of SNAT2 and LAT2 protein in both fibre types. Conclusion From the observations that ageing is accompanied by a reduction in protein synthesis and transporter expression and that these effects are reversed by DHT treatment, we conclude that sarcopenia arises from an age‐dependent reduction in protein synthesis caused, in part, by the lack of or by the low bioavailability of the male sex steroid, DHT. PMID:27239418

Trace analysis of 28 steroids in surface water, wastewater and sludge samples by rapid resolution liquid chromatography-electrospray ionization tandem mass spectrometry.

PubMed

Liu, Shan; Ying, Guang-Guo; Zhao, Jian-Liang; Chen, Feng; Yang, Bin; Zhou, Li-Jun; Lai, Hua-Jie

2011-03-11

A sensitive rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) method, combined with solid-phase extraction, ultrasonic extraction and silica gel cartridge cleanup, was developed for 28 steroids including 4 estrogens (estrone (E1), 17β-estradiol (E2), 17α-ethynyl estradiol (EE2), diethylstilbestrol (DES)), 14 androgens (androsta-1,4-diene-3,17-dione (ADD), 17α-trenbolone, 17β-trenbolone, 4-androstene-3,17-dione, 19-nortestoserone, 17β-boldenone, 17α-boldenone, testosterone (T), epi-androsterone (EADR), methyltestosterone (MT), 4-hydroxy-androst-4-ene-17-dione (4-OHA), 5α-dihydrotestosterone (5α-DHT), androsterone (ADR), stanozolol (S)), 5 progestagens (progesterone (P), ethynyl testosterone (ET), 19-norethindrone, norgestrel, medroxyprogesterone (MP)), and 5 glucocorticoids (cortisol, cortisone, prednisone, prednisolone, dexamethasone) in surface water, wastewater and sludge samples. The recoveries of surface water, influents, effluents and sludge samples were 90.6-119.0% (except 5α-DHT was 143%), 44.0-200%, 60.7-123% and 62.6-138%, respectively. The method detection limits for the 28 analytes in surface water, influents, effluents and freeze-dried sludge samples were 0.01-0.24 ng/L, 0.02-1.44 ng/L, 0.01-0.49 ng/L and 0.08-2.06 ng/g, respectively. This method was applied in the determination of the residual steroidal hormones in two surface water of Danshui River, 12 wastewater and 8 sludge samples from two wastewater treatment plants (Meihu and Huiyang WWTPs) in Guangdong (China). Ten analytes were detected in surface water samples with concentrations ranging between 0.4 ng/L (17β-boldenone) and 55.3 ng/L (5α-DHT); twenty analytes in the wastewater samples with concentrations ranging between 0.3 ng/L (P) and 621 ng/L (5α-DHT); and 12 analytes in the sludge samples with concentrations ranging between 1.6 ng/g (E1) and 372 ng/g (EADR). Copyright © 2011 Elsevier B.V. All rights reserved.

The Nrf2-inducers tanshinone I and dihydrotanshinone protect human skin cells and reconstructed human skin against solar simulated UV☆

PubMed Central

Tao, Shasha; Justiniano, Rebecca; Zhang, Donna D.; Wondrak, Georg T.

2013-01-01

Exposure to solar ultraviolet (UV) radiation is a causative factor in skin photocarcinogenesis and photoaging, and an urgent need exists for improved strategies for skin photoprotection. The redox-sensitive transcription factor Nrf2 (nuclear factor-E2-related factor 2), a master regulator of the cellular antioxidant defense against environmental electrophilic insult, has recently emerged as an important determinant of cutaneous damage from solar UV, and the concept of pharmacological activation of Nrf2 has attracted considerable attention as a novel approach to skin photoprotection. In this study, we examined feasibility of using tanshinones, a novel class of phenanthrenequinone-based cytoprotective Nrf2 inducers derived from the medicinal plant Salvia miltiorrhiza, for protection of cultured human skin cells and reconstructed human skin against solar simulated UV. Using a dual luciferase reporter assay in human Hs27 dermal fibroblasts pronounced transcriptional activation of Nrf2 by four major tanshinones [tanshinone I (T-I), dihydrotanshinone (DHT), tanshinone IIA (T-II-A) and cryptotanshinone (CT)] was detected. In fibroblasts, the more potent tanshinones T-I and DHT caused a significant increase in Nrf2 protein half-life via blockage of ubiquitination, ultimately resulting in upregulated expression of cytoprotective Nrf2 target genes (GCLC, NQO1) with the elevation of cellular glutathione levels. Similar tanshinone-induced changes were also observed in HaCaT keratinocytes. T-I and DHT pretreatment caused significant suppression of skin cell death induced by solar simulated UV and riboflavin-sensitized UVA. Moreover, feasibility of tanshinone-based cutaneous photoprotection was tested employing a human skin reconstruct exposed to solar simulated UV (80 mJ/cm2 UVB; 1.53 J/cm2 UVA). The occurrence of markers of epidermal solar insult (cleaved procaspase 3, pycnotic nuclei, eosinophilic cytoplasm, acellular cavities) was significantly attenuated in DHT-treated reconstructs that displayed increased immunohistochemical staining for Nrf2 and γ-GCS together with the elevation of total glutathione levels. Taken together, our data suggest the feasibility of achieving tanshinone-based cutaneous Nrf2-activation and photoprotection. PMID:24273736

Ovarian and adrenal vein steroids in healthy women with ovulatory cycles--selective catheterization findings.

PubMed

Moltz, L; Sörensen, R; Schwartz, U; Hammerstein, J

1984-04-01

Bilateral ovarian-adrenal vein catheterization and androgen measurements in the efferent samples were utilized to directly assess glandular steroid release in 8 healthy volunteers with proven ovulatory cycles during the early follicular phase. Side effects did not occur in any of the women. Hormone levels were as follows (mean +/- SD; ng/ml) T: peripheral vein (PV) 0.36 +/- 0.16, ovarian veins (OV) 0.39 +/- 0.13, adrenal veins (AV) 0.85 +/- 0.63; dihydro-T (DHT): PV 0.25 +/- 0.09, OV 0.29 +/- 0.10, AV 0.93 +/- 0.65; delta 4-androstendione (A): PV 0.88 +/- 0.34, OV 1.82 +/- 1.04, AV 9.22 +/- 8.04; DHEA; PV 5.13 +/- 1.96, OV 6.73 +/- 2.69, AV 146.79 +/- 217.24; DS PV 1860 +/- 850, OV 1937 +/- 1039, AV 2567 +/- 1201; 17 alpha-hydroxyprogesterone (17P): PV 0.60 +/- 0.19, OV 1.46 +/- 1.64, AV 6.94 +/- 6.20; F: PV 170 +/- 50, OV 130 +/- 21, AV 788 +/- 1320; the bilateral differences of effluent levels were not significant. Glandular-peripheral vein steroid gradients served as semiquantitative estimates of momentary secretory activity; they were as follows (mean +/- SD; ng/ml) T: ovarian-peripheral vein gradient (OPG) 0.03 +/- 0.09, adrenal-peripheral vein gradient (APG) 0.48 +/- 0.57; DHT: OPG 0.05 +/- 0.05, APG 0.69 +/- 0.60; A: OPG 0.97 +/- 1.13, APG 8.33 +/- 7.86; DHEA: OPG 1.70 +/- 1.80, APG 141.80 +/- 216.60; DS: OPG 191 +/- 72, APG 706 +/- 824; 17P: OPG 0.87 +/- 1.67, APG 6.30 +/- 6.10; F: OPG 38 +/- 11, APG 610 +/- 1329. Gradient, analysis revealed that the ovaries produced significant quantities of A, DHEA and 17P, but no T, DHT or F between day 3-7 of the cycle; direct gonadal DS output was detected in 2 individuals. A significant OPG for DS was detected in two individuals possibly indicating its partially gonadal origin. The adrenals released larger amounts of A, DHEA and 17P than the ovaries at this stage (P less than 0.05); also, they consistently secreted T, DHT, DS and F.

Synaptic Long-Term Potentiation and Depression in the Rat Medial Vestibular Nuclei Depend on Neural Activation of Estrogenic and Androgenic Signals

PubMed Central

Scarduzio, Mariangela; Panichi, Roberto; Pettorossi, Vito Enrico; Grassi, Silvarosa

2013-01-01

Estrogenic and androgenic steroids can be synthesised in the brain and rapidly modulate synaptic transmission and plasticity through direct interaction with membrane receptors for estrogens (ERs) and androgens (ARs). We used whole cell patch clamp recordings in brainstem slices of male rats to explore the influence of ER and AR activation and local synthesis of 17β-estradiol (E2) and 5α-dihydrotestosterone (DHT) on the long-term synaptic changes induced in the neurons of the medial vestibular nucleus (MVN). Long-term depression (LTD) and long-term potentiation (LTP) caused by different patterns of high frequency stimulation (HFS) of the primary vestibular afferents were assayed under the blockade of ARs and ERs or in the presence of inhibitors for enzymes synthesizing DHT (5α-reductase) and E2 (P450-aromatase) from testosterone (T). We found that LTD is mediated by interaction of locally produced androgens with ARs and LTP by interaction of locally synthesized E2 with ERs. In fact, the AR block with flutamide prevented LTD while did not affect LTP, and the blockade of ERs with ICI 182,780 abolished LTP without influencing LTD. Moreover, the block of P450-aromatase with letrozole not only prevented the LTP induction, but inverted LTP into LTD. This LTD is likely due to the local activation of androgens, since it was abolished under blockade of ARs. Conversely, LTD was still induced in the presence of finasteride the inhibitor of 5α-reductase demonstrating that T is able to activate ARs and induce LTD even when DHT is not synthesized. This study demonstrates a key and opposite role of sex neurosteroids in the long-term synaptic changes of the MVN with a specific role of T-DHT for LTD and of E2 for LTP. Moreover, it suggests that different stimulation patterns can lead to LTD or LTP by specifically activating the enzymes involved in the synthesis of androgenic or estrogenic neurosteroids. PMID:24265837

Postnatal loss of brainstem serotonin neurones compromises the ability of neonatal rats to survive episodic severe hypoxia

PubMed Central

Cummings, Kevin J; Hewitt, Julie C; Li, Aihua; Daubenspeck, John A; Nattie, Eugene E

2011-01-01

Abstract Pet-1−/− mice with a prenatal, genetically induced loss of 5-hydroxytryptamine (5-HT, serotonin) neurones are compromised in their ability to withstand episodic environmental anoxia via autoresuscitation. Given the prenatal role of 5-HT neurones in the development of neural networks, here we ask if a postnatal loss of 5-HT neurones also compromises autoresuscitation. We treated neonatal rat pups at postnatal day (P)2–3 with an intra-cisternal injection of 5,7-dihydroxytryptamine (5,7-DHT; ∼40 μg; n = 8) to pharmacologically lesion the 5-HT system, or vehicle (control; n = 14). At P7–10 we exposed unanaesthetized treated and control pups to 15 episodes of environmental anoxia (97% N2, 3% CO2). Medullary 5-HT content was reduced 80% by 5,7-DHT treatment (P < 0.001). Baseline ventilation (), metabolic rate (), ventilatory equivalent (/), heart rate (HR), heart rate variability (HRV) and arterial haemoglobin saturation () were no different in 5-HT-deficient pups compared to controls. However, only 25% of 5-HT-deficient pups survived all 15 episodes of environmental anoxia, compared to 79% of control littermates (P = 0.007). High mortality of 5,7-DHT-treated pups was associated with delayed onset of gasping (P < 0.001), delayed recovery of HR from hypoxic-induced bradycardia (P < 0.001), and delayed recovery of eupnoea from hypoxic-induced apnoea (P < 0.001). Treatment with 5,7-DHT affected neither the gasping pattern once initiated, nor HR, / or during the intervening episodes of room air. A significant increase in HRV occurred in all animals with repeated exposure, and in 5-HT-deficient pups this increase occurred immediately prior to death. We conclude that a postnatal loss of brainstem 5-HT content compromises autoresuscitation in response to environmental anoxia. This report provides new evidence in rat pups that 5-HT neurones serve a physiological role in autoresuscitation. Our data may be relevant to understanding the aetiology of the sudden infant death syndrome (SIDS), in which there is medullary 5-HT deficiency and in some cases evidence of severe hypoxia and failed autoresuscitation. PMID:21911619

Effect of deslorelin on testicular function, serum dihydrotestosterone and oestradiol concentrations during and after suppression of sexual activity in tom cats.

PubMed

Gültiken, Nilgün; Aslan, Selim; Ay, Serhan Serhat; Gülbahar, Mustafa Yavuz; Thuróczy, Julianna; Koldaş, Ece; Kaya, Duygu; Fındık, Murat; Schäfer-Somi, Sabine

2017-02-01

Objectives The aim of the study was to evaluate the efficacy of a 4.7 mg deslorelin implant in tom cats. Methods Nine mature male cats were included in the deslorelin group and five cats in the control group. Before the study started, all cats were confirmed to have distinct sexually dimorphic behaviour. Blood samples were taken on the implantation day, at day 7 and at day 15, then monthly, in order to measure serum dihydrotestosterone (DHT) and 17beta(β)-oestradiol concentrations. The deslorelin group (n = 9) was divided into two subgroups: five cats (cats 1-5) were neutered in the postimplantation period during suppression of sexually dimorphic behaviour, and four cats (cats 6-9) were neutered after re-expression of sexually dimorphic behaviour. The control group cats (n = 5) were castrated without administration of the implant. Results Sexually dimorphic behaviours ceased within a mean ± SD of 13-58 days (23.30 ± 14.17) after implantation. DHT concentration decreased within 30 days. The mean duration of suppression was 26.5 ± 7.42 months and reactivation coincided with increased DHT values reaching preimplantation concentrations within 1 month. 17β-oestradiol concentrations significantly correlated with DHT concentrations ( P <0.01). For cats castrated during suppression of sexual behaviour, the length of the long axes of the nuclei of Leydig cells, the diameter of seminiferous tubules and the height of the epithelium of the seminiferous tubules did not change until 3-6 months after implantation, whereas at 12 and 32 months the measured values were even lower than in the control group. For cats castrasted after reactivation, the length of long axes of the nuclei of Leydig cells and the diameter of seminiferous tubules approached the values of the control group between 4 and 6 months after reactivation. Conclusions and relevance A deslorelin implant (4.7 mg) suppresses sexually dimorphic behaviour in tom cats without any side effects and with full reversibility; however, duration of suppression is highly individual.

Rotation invariant deep binary hashing for fast image retrieval

NASA Astrophysics Data System (ADS)

Dai, Lai; Liu, Jianming; Jiang, Aiwen

2017-07-01

In this paper, we study how to compactly represent image's characteristics for fast image retrieval. We propose supervised rotation invariant compact discriminative binary descriptors through combining convolutional neural network with hashing. In the proposed network, binary codes are learned by employing a hidden layer for representing latent concepts that dominate on class labels. A loss function is proposed to minimize the difference between binary descriptors that describe reference image and the rotated one. Compared with some other supervised methods, the proposed network doesn't have to require pair-wised inputs for binary code learning. Experimental results show that our method is effective and achieves state-of-the-art results on the CIFAR-10 and MNIST datasets.

The Hong Kong/AAO/Strasbourg Hα (HASH) Planetary Nebula Database

NASA Astrophysics Data System (ADS)

Bojičić, Ivan S.; Parker, Quentin A.; Frew, David J.

2017-10-01

The Hong Kong/AAO/Strasbourg Hα (HASH) planetary nebula database is an online research platform providing free and easy access to the largest and most comprehensive catalogue of known Galactic PNe and a repository of observational data (imaging and spectroscopy) for these and related astronomical objects. The main motivation for creating this system is resolving some of long standing problems in the field e.g. problems with mimics and dubious and/or misidentifications, errors in observational data and consolidation of the widely scattered data-sets. This facility allows researchers quick and easy access to the archived and new observational data and creating and sharing of non-redundant PN samples and catalogues.

Comparison of Various Similarity Measures for Average Image Hash in Mobile Phone Application

NASA Astrophysics Data System (ADS)

Farisa Chaerul Haviana, Sam; Taufik, Muhammad

2017-04-01

One of the main issue in Content Based Image Retrieval (CIBR) is similarity measures for resulting image hashes. The main key challenge is to find the most benefits distance or similarity measures for calculating the similarity in term of speed and computing costs, specially under limited computing capabilities device like mobile phone. This study we utilize twelve most common and popular distance or similarity measures technique implemented in mobile phone application, to be compared and studied. The results show that all similarity measures implemented in this study was perform equally under mobile phone application. This gives more possibilities for method combinations to be implemented for image retrieval.

Planetary Nebula Candidates Uncovered with the HASH Research Platform

NASA Astrophysics Data System (ADS)

Fragkou, Vasiliki; Bojičić, Ivan; Frew, David; Parker, Quentin

2017-10-01

A detailed examination of new high quality radio catalogues (e.g. Cornish) in combination with available mid-infrared (MIR) satellite imagery (e.g. Glimpse) has allowed us to find 70 new planetary nebula (PN) candidates based on existing knowledge of their typical colors and fluxes. To further examine the nature of these sources, multiple diagnostic tools have been applied to these candidates based on published data and on available imagery in the HASH (Hong Kong/ AAO/ Strasbourg Hα planetary nebula) research platform. Some candidates have previously-missed optical counterparts allowing for spectroscopic follow-up. Indeed, the single object spectroscopically observed so far has turned out to be a bona fide PN.

Role of olfactory bulb serotonin in olfactory learning in the greater short-nosed fruit bat, Cynopterus sphinx (Chiroptera: Pteropodidae).

PubMed

Ganesh, Ambigapathy; Bogdanowicz, Wieslaw; Haupt, Moritz; Marimuthu, Ganapathy; Rajan, Koilmani Emmanuvel

2010-09-17

The role of olfactory bulb (OB) serotonin [5-hydroxytryptamine (5-HT)] in olfactory learning and memory was tested in the greater short-nosed fruit bat, Cynopterus sphinx (family Pteropodidae). Graded concentrations (25, 40, and 60microg) of 5,7-dihydroxytryptamine (5,7-DHT) or saline were injected into the OB of bats one day before training to the novel odor. In a behavioral test, 5,7-DHT (60microg) injected bats made significantly fewer feeding attempts and bouts when compared to saline-injected bats during learning and in the memory test. Subsequent biochemical analysis showed that 5-HT level was effectively depleted in the OB of 5,7-DHT injected bats. To test odor-induced 5-HT mediated changes in 5-HT receptors and second messenger cascade in the OB, we examined the expression of 5-HT receptors and mitogen-activated protein kinase (MAPK)/Erk cascade after training to the novel odor. We found that odor stimulation up-regulated the expression of 5-HT(1A) receptor, Erk1 and Creb1 mRNA, and phosphorylation of ERK1 and CREB1. Odor stimulation failed to induce expression in 5-HT-depleted bats, which is similar to control bats and significantly low compared to saline-treated bats. Together these data revealed that the level of 5-HT in the OB may regulate olfactory learning and memory in C. sphinx through Erk and CREB.

Neuroendocrine androgen action is a key extraovarian mediator in the development of polycystic ovary syndrome

PubMed Central

Caldwell, Aimee S. L.; Edwards, Melissa C.; Desai, Reena; Jimenez, Mark; Gilchrist, Robert B.; Walters, Kirsty A.

2017-01-01

Polycystic ovary syndrome (PCOS) is a complex hormonal disorder characterized by reproductive, endocrine, and metabolic abnormalities. As the origins of PCOS remain unknown, mechanism-based treatments are not feasible and current management relies on treatment of symptoms. Hyperandrogenism is the most consistent PCOS characteristic; however, it is unclear whether androgen excess, which is treatable, is a cause or a consequence of PCOS. As androgens mediate their actions via the androgen receptor (AR), we combined a mouse model of dihydrotestosterone (DHT)-induced PCOS with global and cell-specific AR-resistant (ARKO) mice to investigate the locus of androgen actions that mediate the development of the PCOS phenotype. Global loss of the AR reveals that AR signaling is required for all DHT-induced features of PCOS. Neuron-specific AR signaling was required for the development of dysfunctional ovulation, classic polycystic ovaries, reduced large antral follicle health, and several metabolic traits including obesity and dyslipidemia. In addition, ovariectomized ARKO hosts with wild-type ovary transplants displayed normal estrous cycles and corpora lutea, despite DHT treatment, implying extraovarian and not intraovarian AR actions are key loci of androgen action in generating the PCOS phenotype. These findings provide strong evidence that neuroendocrine genomic AR signaling is an important extraovarian mediator in the development of PCOS traits. Thus, targeting AR-driven mechanisms that initiate PCOS is a promising strategy for the development of novel treatments for PCOS. PMID:28320971

Programming of Dopaminergic Neurons by Neonatal Sex Hormone Exposure: Effects on Dopamine Content and Tyrosine Hydroxylase Expression in Adult Male Rats

PubMed Central

Espinosa, Pedro; Silva, Roxana A.; Sanguinetti, Nicole K.; Venegas, Francisca C.; Riquelme, Raul; González, Luis F.; Cruz, Gonzalo; Renard, Georgina M.; Moya, Pablo R.; Sotomayor-Zárate, Ramón

2016-01-01

We sought to determine the long-term changes produced by neonatal sex hormone administration on the functioning of midbrain dopaminergic neurons in adult male rats. Sprague-Dawley rats were injected subcutaneously at postnatal day 1 and were assigned to the following experimental groups: TP (testosterone propionate of 1.0 mg/50 μL); DHT (dihydrotestosterone of 1.0 mg/50 μL); EV (estradiol valerate of 0.1 mg/50 μL); and control (sesame oil of 50 μL). At postnatal day 60, neurochemical studies were performed to determine dopamine content in substantia nigra-ventral tegmental area and dopamine release in nucleus accumbens. Molecular (mRNA expression of tyrosine hydroxylase) and cellular (tyrosine hydroxylase immunoreactivity) studies were also performed. We found increased dopamine content in substantia nigra-ventral tegmental area of TP and EV rats, in addition to increased dopamine release in nucleus accumbens. However, neonatal exposure to DHT, a nonaromatizable androgen, did not affect midbrain dopaminergic neurons. Correspondingly, compared to control rats, levels of tyrosine hydroxylase mRNA and protein were significantly increased in TP and EV rats but not in DHT rats, as determined by qPCR and immunohistochemistry, respectively. Our results suggest an estrogenic mechanism involving increased tyrosine hydroxylase expression, either by direct estrogenic action or by aromatization of testosterone to estradiol in substantia nigra-ventral tegmental area. PMID:26904299

Programming of Dopaminergic Neurons by Neonatal Sex Hormone Exposure: Effects on Dopamine Content and Tyrosine Hydroxylase Expression in Adult Male Rats.

PubMed

Espinosa, Pedro; Silva, Roxana A; Sanguinetti, Nicole K; Venegas, Francisca C; Riquelme, Raul; González, Luis F; Cruz, Gonzalo; Renard, Georgina M; Moya, Pablo R; Sotomayor-Zárate, Ramón

2016-01-01

We sought to determine the long-term changes produced by neonatal sex hormone administration on the functioning of midbrain dopaminergic neurons in adult male rats. Sprague-Dawley rats were injected subcutaneously at postnatal day 1 and were assigned to the following experimental groups: TP (testosterone propionate of 1.0 mg/50 μL); DHT (dihydrotestosterone of 1.0 mg/50 μL); EV (estradiol valerate of 0.1 mg/50 μL); and control (sesame oil of 50 μL). At postnatal day 60, neurochemical studies were performed to determine dopamine content in substantia nigra-ventral tegmental area and dopamine release in nucleus accumbens. Molecular (mRNA expression of tyrosine hydroxylase) and cellular (tyrosine hydroxylase immunoreactivity) studies were also performed. We found increased dopamine content in substantia nigra-ventral tegmental area of TP and EV rats, in addition to increased dopamine release in nucleus accumbens. However, neonatal exposure to DHT, a nonaromatizable androgen, did not affect midbrain dopaminergic neurons. Correspondingly, compared to control rats, levels of tyrosine hydroxylase mRNA and protein were significantly increased in TP and EV rats but not in DHT rats, as determined by qPCR and immunohistochemistry, respectively. Our results suggest an estrogenic mechanism involving increased tyrosine hydroxylase expression, either by direct estrogenic action or by aromatization of testosterone to estradiol in substantia nigra-ventral tegmental area.

Effect of Male House Mouse Pheromone Components on Behavioral Responses of Mice in Laboratory and Field Experiments.

PubMed

Musso, Antonia E; Gries, Regine; Zhai, Huimin; Takács, Stephen; Gries, Gerhard

2017-03-01

Urine of male house mice, Mus musculus, is known to have primer pheromone effects on the reproductive physiology of female mice. Urine-mediated releaser pheromone effects that trigger certain behavioral responses are much less understood, and no field studies have investigated whether urine deposits by male or female mice, or synthetic mouse pheromone, increase trap captures of mice. In field experiments, we baited traps with bedding soiled with urine and feces of caged female or male mice, and recorded captures of mice in these and in control traps containing clean bedding. Traps baited with female bedding preferentially captured adult males, whereas traps baited with male bedding preferentially captured juvenile and adult females, indicating the presence of male- and female-specific sex pheromones in soiled bedding. Analyses of headspace volatiles emanating from soiled bedding by gas chromatography/mass spectrometry revealed that 3,4-dehydro-exo-brevicomin (DEB) was seven times more prevalent in male bedding and that 2-sec-butyl-4,5-dihydrothiazole (DHT) was male-specific. In a follow-up field experiment, traps baited with DEB and DHT captured 4 times more female mice than corresponding control traps, thus indicating that DEB and DHT are sex attractant pheromone components of house mouse males. Our study provides impetus to identify the sex attractant pheromone of female mice, and to develop synthetic mouse pheromone as a lure to enhance the efficacy of trapping programs for mouse control.

Chronic Alterations in Serotonin Function: Dynamic Neurochemical Properties in Agonistic Behavior of the Crayfish, Orconectes rusticus

PubMed Central

Panksepp, Jules B.; Huber, Robert

2016-01-01

The biogenic amine serotonin [5-hydroxytryptamine (5-HT)] has received considerable attention for its role in behavioral phenomena throughout a broad range of invertebrate and vertebrate taxa. Acute 5-HT infusion decreases the likelihood of crayfish to retreat from dominant opponents. The present study reports the biochemical and behavioral effects resulting from chronic treatment with 5-HT-modifying compounds delivered for up to 5 weeks via silastic tube implants. High performance liquid chromatography with electrochemical detection (HPLC-ED) confirmed that 5,7-dihydroxytryptamine (5,7-DHT) effectively reduced 5-HT in all central nervous system (CNS) areas, except brain, while a concurrent accumulation of the compound was observed in all tissues analyzed. Unexpectedly, two different rates of chronic 5-HT treatment did not increase levels of the amine in the CNS. Behaviorally, 5,7-DHT treated crayfish exhibited no significant differences in measures of aggression. Although treatment with 5-HT did not elevate 5-HT content in the CNS, infusion at a slow rate caused animals to escalate more quickly while 5-HT treatment at a faster rate resulted in slower escalation. 5,7-DHT is commonly used in behavioral pharmacology and the present findings suggest its biochemical properties should be more thoroughly examined. Moreover, the apparent presence of powerful compensatory mechanisms indicates our need to adopt an increasingly dynamic view of the serotonergic bases of behavior like crayfish aggression. PMID:11891663

Secure Hashing of Dynamic Hand Signatures Using Wavelet-Fourier Compression with BioPhasor Mixing and [InlineEquation not available: see fulltext.] Discretization

NASA Astrophysics Data System (ADS)

Wai Kuan, Yip; Teoh, Andrew B. J.; Ngo, David C. L.

2006-12-01

We introduce a novel method for secure computation of biometric hash on dynamic hand signatures using BioPhasor mixing and[InlineEquation not available: see fulltext.] discretization. The use of BioPhasor as the mixing process provides a one-way transformation that precludes exact recovery of the biometric vector from compromised hashes and stolen tokens. In addition, our user-specific[InlineEquation not available: see fulltext.] discretization acts both as an error correction step as well as a real-to-binary space converter. We also propose a new method of extracting compressed representation of dynamic hand signatures using discrete wavelet transform (DWT) and discrete fourier transform (DFT). Without the conventional use of dynamic time warping, the proposed method avoids storage of user's hand signature template. This is an important consideration for protecting the privacy of the biometric owner. Our results show that the proposed method could produce stable and distinguishable bit strings with equal error rates (EERs) of[InlineEquation not available: see fulltext.] and[InlineEquation not available: see fulltext.] for random and skilled forgeries for stolen token (worst case) scenario, and[InlineEquation not available: see fulltext.] for both forgeries in the genuine token (optimal) scenario.

Limitations and requirements of content-based multimedia authentication systems

NASA Astrophysics Data System (ADS)

Wu, Chai W.

2001-08-01

Recently, a number of authentication schemes have been proposed for multimedia data such as images and sound data. They include both label based systems and semifragile watermarks. The main requirement for such authentication systems is that minor modifications such as lossy compression which do not alter the content of the data preserve the authenticity of the data, whereas modifications which do modify the content render the data not authentic. These schemes can be classified into two main classes depending on the model of image authentication they are based on. One of the purposes of this paper is to look at some of the advantages and disadvantages of these image authentication schemes and their relationship with fundamental limitations of the underlying model of image authentication. In particular, we study feature-based algorithms which generate an authentication tag based on some inherent features in the image such as the location of edges. The main disadvantage of most proposed feature-based algorithms is that similar images generate similar features, and therefore it is possible for a forger to generate dissimilar images that have the same features. On the other hand, the class of hash-based algorithms utilizes a cryptographic hash function or a digital signature scheme to reduce the data and generate an authentication tag. It inherits the security of digital signatures to thwart forgery attacks. The main disadvantage of hash-based algorithms is that the image needs to be modified in order to be made authenticatable. The amount of modification is on the order of the noise the image can tolerate before it is rendered inauthentic. The other purpose of this paper is to propose a multimedia authentication scheme which combines some of the best features of both classes of algorithms. The proposed scheme utilizes cryptographic hash functions and digital signature schemes and the data does not need to be modified in order to be made authenticatable. Several applications including the authentication of images on CD-ROM and handwritten documents will be discussed.

EFFECTS OF ENVIRONMENTAL ANTIANDROGENS IN EXPERIMENTAL ANIMALS

EPA Science Inventory

In mammals, the androgens testosterone (T) and dihydrotestosterone (DHT) are critical for normal male reproductive development and function. In humans, drugs that act as androgen receptor (AR) agonists and antagonists or inhibit fetal steroidogenesis can cause pseudohermaphrodi...

Validation of a temperature prediction model for heat deaths in undocumented border crossers.

PubMed

Ruttan, Tim; Stolz, Uwe; Jackson-Vance, Sara; Parks, Bruce; Keim, Samuel M

2013-04-01

Heat exposure is a leading cause of death in undocumented border crossers along the Arizona-Mexico border. We performed a validation study of a weather prediction model that predicts the probability of heat related deaths among undocumented border crossers. We analyzed a medical examiner registry cohort of undocumented border crosser heat- related deaths from January 1, 2002 to August 31, 2009 and used logistic regression to model the probability of one or more heat deaths on a given day using daily high temperature (DHT) as the predictor. At a critical threshold DHT of 40 °C, the probability of at least one heat death was 50 %. The probability of a heat death along the Arizona-Mexico border for suspected undocumented border crossers is strongly associated with ambient temperature. These results can be used in prevention and response efforts to assess the daily risk of deaths among undocumented border crossers in the region.

A short note on the use of the red-black tree in Cartesian adaptive mesh refinement algorithms

NASA Astrophysics Data System (ADS)

Hasbestan, Jaber J.; Senocak, Inanc

2017-12-01

Mesh adaptivity is an indispensable capability to tackle multiphysics problems with large disparity in time and length scales. With the availability of powerful supercomputers, there is a pressing need to extend time-proven computational techniques to extreme-scale problems. Cartesian adaptive mesh refinement (AMR) is one such method that enables simulation of multiscale, multiphysics problems. AMR is based on construction of octrees. Originally, an explicit tree data structure was used to generate and manipulate an adaptive Cartesian mesh. At least eight pointers are required in an explicit approach to construct an octree. Parent-child relationships are then used to traverse the tree. An explicit octree, however, is expensive in terms of memory usage and the time it takes to traverse the tree to access a specific node. For these reasons, implicit pointerless methods have been pioneered within the computer graphics community, motivated by applications requiring interactivity and realistic three dimensional visualization. Lewiner et al. [1] provides a concise review of pointerless approaches to generate an octree. Use of a hash table and Z-order curve are two key concepts in pointerless methods that we briefly discuss next.

Reduced estradiol synthesis by letrozole, an aromatase inhibitor, is protective against development of pentylenetetrazole-induced kindling in mice.

PubMed

Rashid, Davood; Panda, B P; Vohora, Divya

2015-11-01

Neurosteroids, such as testosterone and their metabolites, are known to modulate neuronal excitability. The enzymes regulating the metabolism of these neurosteroids, thus, may be targeted as a noval strategy for the development of new antiepileptic drugs. The present work targeted two such enzymes i,e aromatase and 5α-reductase in order to explore the potential of letrozole (an aromatase inhibitor) on pentylenetetrazole (PTZ)-induced kindling in mice and the ability of finasteride (a 5α-reductase inhibitor) to modulate any such effects. PTZ (30 mg/kg, i.p.), when administered once every two days (for a total of 24 doses) induced kindling in Swiss albino mice. Letrozole (1 mg/kg, p.o.), administered prior to PTZ, significantly reduced the % incidence of kindling, delayed mean onset time of seizures and reduced seizure severity score. Letrozole reduced the levels of plasma 17β-estradiol after induction of kindling. The concurrent administration of finasteride and letrozole produced effects similar to letrozole on PTZ-kindling and on estradiol levels. This implies that the ability of letrozole to redirect the synthesis of dihydrotestosterone (DHT) and 5α-androstanediol from testosterone doesn't appear to play a significant role in the protective effects of letrozole against PTZ kindling. Letrozole, however, increased the levels of 5α-DHT in mice plasma. The aromatase inhibitors, thus, may be exploited for inhibiting the synthesis of proconvulsant (17β-estradiol) and/or redirecting the synthesis of anticonvulsant (DHT and 5α-androstanediol) neurosteroids. Copyright © 2015 Elsevier Ltd. All rights reserved.

Increased androgen levels in rats impair glucose-stimulated insulin secretion through disruption of pancreatic beta cell mitochondrial function.

PubMed

Wang, Hongdong; Wang, Xiaping; Zhu, Yunxia; Chen, Fang; Sun, Yujie; Han, Xiao

2015-11-01

Although insulin resistance is recognized to contribute to the reproductive and metabolic phenotypes of polycystic ovary syndrome (PCOS), pancreatic beta cell dysfunction plays an essential role in the progression from PCOS to the development of type 2 diabetes. However, the role of insulin secretory abnormalities in PCOS has received little attention. In addition, the precise changes in beta cells and the underlying mechanisms remain unclear. In this study, we therefore attempted to elucidate potential mechanisms involved in beta cell alterations in a rat model of PCOS. Glucose-induced insulin secretion was measured in islets isolated from DHT-treated and control rats. Oxygen consumption rate (OCR), ATP production, and mitochondrial copy number were assayed to evaluate mitochondrial function. Glucose-stimulated insulin secretion is significantly decreased in islets from DHT-treated rats. On the other hand, significant reductions are observed in the expression levels of several key genes involved in mitochondrial biogenesis and in mitochondrial OCR and ATP production in DHT-treated rat islets. Meanwhile, we found that androgens can directly impair beta cell function by inducing mitochondrial dysfunction in vitro in an androgen receptor dependent manner. For the first time, our study demonstrates that increased androgens in female rats can impair glucose-stimulated insulin secretion partly through disruption of pancreatic beta cell mitochondrial function. This work has significance for hyperandrogenic women with PCOS: excess activation of the androgen receptor by androgens may provoke beta cell dysfunction via mitochondrial dysfunction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Excess androgen during puberty disrupts circadian organization in female rats.

PubMed

Sellix, Michael T; Murphy, Zachary C; Menaker, Michael

2013-04-01

Circadian clocks have been described in each tissue of the hypothalamo-pituitary-ovarian axis. Although a role for the clock in the timing of ovulation is indicated, the impact of diseases that disrupt fertility on clock function or the clocks' role in the etiology of these pathologies has yet to be fully appreciated. Polycystic ovary syndrome (PCOS) is a particularly devastating endocrinopathy, affecting approximately 10% of women at childbearing age. Common features of PCOS are a polycystic ovary, amenorrhea, and excess serum androgen. Approximately 40% of these women have metabolic syndrome, including hyperinsulinemia, dyslipidemia, and hyperleptinemia. It has been suggested that excess androgen is a critical factor in the etiology of PCOS. We have examined the effects of androgen excess during puberty on the phase of circadian clocks in tissues of the metabolic and hypothalamo-pituitary-ovarian axes. Female period1-luciferase (per1-luc) rats were exposed to androgen (5α-dihydrotestosterone [DHT]) or placebo for 4-6 weeks (short term) or 9-15 weeks (long term). As expected, DHT-treated animals gained more weight than controls and had disrupted estrous cycles. At the end of treatment, tissues, including the liver, lung, kidney, white adipose, cornea, pituitary, oviduct, and ovarian follicles, were cultured, and per1-luc expression in each was recorded. Analysis of per1-luc expression revealed that DHT exposure increased phase distribution of multiple oscillators, including ovarian follicles, liver, and adipose, and altered phase synchrony between animals. These data suggest that excess androgen during puberty, a common feature of PCOS, negatively affects internal circadian organization in both the reproductive and metabolic axes.

Excess Androgen During Puberty Disrupts Circadian Organization in Female Rats

PubMed Central

Murphy, Zachary C.; Menaker, Michael

2013-01-01

Circadian clocks have been described in each tissue of the hypothalamo-pituitary-ovarian axis. Although a role for the clock in the timing of ovulation is indicated, the impact of diseases that disrupt fertility on clock function or the clocks' role in the etiology of these pathologies has yet to be fully appreciated. Polycystic ovary syndrome (PCOS) is a particularly devastating endocrinopathy, affecting approximately 10% of women at childbearing age. Common features of PCOS are a polycystic ovary, amenorrhea, and excess serum androgen. Approximately 40% of these women have metabolic syndrome, including hyperinsulinemia, dyslipidemia, and hyperleptinemia. It has been suggested that excess androgen is a critical factor in the etiology of PCOS. We have examined the effects of androgen excess during puberty on the phase of circadian clocks in tissues of the metabolic and hypothalamo-pituitary-ovarian axes. Female period1-luciferase (per1-luc) rats were exposed to androgen (5α-dihydrotestosterone [DHT]) or placebo for 4-6 weeks (short term) or 9-15 weeks (long term). As expected, DHT-treated animals gained more weight than controls and had disrupted estrous cycles. At the end of treatment, tissues, including the liver, lung, kidney, white adipose, cornea, pituitary, oviduct, and ovarian follicles, were cultured, and per1-luc expression in each was recorded. Analysis of per1-luc expression revealed that DHT exposure increased phase distribution of multiple oscillators, including ovarian follicles, liver, and adipose, and altered phase synchrony between animals. These data suggest that excess androgen during puberty, a common feature of PCOS, negatively affects internal circadian organization in both the reproductive and metabolic axes. PMID:23417420

Effect of steroid hormones on Bufo arenarum oviduct. Ultrastructural study.

PubMed

Medina, Marcela Fátima; Crespo, Claudia Alejandra; Ramos, Inés; Cisint, Susana Beatriz; Fernández, Silvia Nélida

2007-06-01

The endocrine regulation of the mucosa of the oviductal pars convoluta was analyzed by ultrastructural studies demonstrating that ovariectomy, together with a decrease in ovarian steroids circulating levels, caused a marked regression in this portion of Bufo arenarum oviduct. Twenty-five days after ovariectomy, a decrease in the depth of the epithelial and glandular layers was observed due to the notable loss of secretory cells, whose number was clearly smaller than in nonovariectomized females. The remaining secretory cells showed involution signs, with few secretory granules in their cytoplasm, little endoplasmic reticulum near poorly developed Golgi complexes and a large amount of lipid droplets. Cells in an advanced autolysis state were found in the lumen. These characteristics evidence a nonfunctional state of the pars convoluta. Treatment with 5alpha-dihydrotestosterone (DHT) completely reversed the ovariectomy effect, inducing pars convoluta growths and restoring the characteristics of epithelial and glandular secretory cells in the whole pars convoluta, with micrographs similar to the control. These same effects were observed after treatment with estradiol-17beta (E2), progesterone (P) o E(2)+P in the glandular layer of the whole pars convoluta, but only in the epithelial layer of the most anterior region of this duct. In the secretory cells of other segments these treatments induced the formation of granules of high electron density and homogeneous aspect. Each steroid had a particular effect on the pars convoluta. Although E2 and DHT induced the development of the organoids involved in the proteins biosynthesis, P and DHT acted as secretagogues. (c) 2007 Wiley-Liss, Inc.

Cardiac fatty acid uptake and metabolism in the rat model of polycystic ovary syndrome.

PubMed

Tepavčević, Snežana; Milutinović, Danijela Vojnović; Macut, Djuro; Stojiljković, Mojca; Nikolić, Marina; Božić-Antić, Ivana; Ćulafić, Tijana; Bjekić-Macut, Jelica; Matić, Gordana; Korićanac, Goran

2015-09-01

Polycystic ovary syndrome (PCOS) is associated with an altered plasma lipid profile and increased risk for cardiovascular diseases. We hypothesized that molecular mechanisms underlying cardiac pathology in PCOS involve changes in expression and subcellular localization of several key proteins involved in cardiac lipid transport and metabolism, such as fatty acid transporter CD36, lipin 1, peroxisome proliferator-activated receptor α (PPARα), peroxisome proliferator-activated receptor γ coactivator-1 (PGC1), and carnitine palmitoyltransferase 1 (CPT1). We used the animal model of PCOS obtained by treating female rats with dihydrotestosterone (DHT). Protein levels of CD36, lipin 1, PPARα, PGC1, and antioxidative enzymes were assessed by Western blot in different cardiac cell compartments. Cardiac triglycerides (TG) and lipid peroxidation were also measured. The content of CD36 was decreased in both the cardiac plasma membranes and intracellular pool. On the other hand, total content of cardiac lipin 1 in DHT-treated rats was elevated, in contrast to decreased microsomal lipin 1 content. An increase in nuclear content of lipin 1 was observed together with elevation of nuclear PPARα and PGC1, and an increase in CPT1 expression. However, lipid peroxidation was reduced in the heart, without alterations in antioxidative enzymes expression and cardiac TG content. The results indicate that treatment of female rats with DHT is accompanied by a decrease of fatty acid uptake and a reduction of lipid peroxidation in the heart. The observed elevation of lipin 1, PPARα, PGC1, and CPT1 expression suggests that cardiac fatty acid metabolism is shifted toward mitochondrial beta oxidation.

The effects of nitric oxide-cGMP pathway stimulation on dopamine in the medial preoptic area and copulation in DHT-treated castrated male rats

PubMed Central

Sato, Satoru M.; Wersinger, Scott R.; Hull, Elaine M.

2007-01-01

Dopamine (DA) in the medial preoptic area (MPOA) provides important facilitative influence on male rat copulation. We have shown that the nitric oxide-cGMP (NO-cGMP) pathway modulates MPOA DA levels and copulation. We have also shown that systemic estradiol (E2) maintains neuronal NO synthase (nNOS) immunoreactivity in the MPOA of castrates, as well as relatively normal DA levels. This effect of E2 on nNOS probably accounts for at least some of the previously demonstrated behavioral facilitation by intra-MPOA E2 administration in castrates. Therefore, we hypothesized that stimulation of the MPOA NO-cGMP pathway in dihydrotestosterone (DHT)-treated castrates should restore DA levels and copulatory behaviors. Reverse-dialysis of a NO donor, sodium nitroprusside (SNP), increased extracellular DA in the MPOA of DHT-treated castrates and restored the ability to copulate to ejaculation in half of the animals. A cGMP analog, 8-Br-cGMP, also increased extracellular DA, though not as robustly, but did not restore copulatory ability. The effectiveness of the NO donor in restoring copulation and MPOA DA levels is consistent with our hypothesis. However, the lack of behavioral effects of 8-Br-cGMP, despite its increase in MPOA DA, suggests that NO may have additional mediators in the MPOA in the regulation of copulation. Furthermore, the suboptimal copulation seen in the NO donor-treated animals suggests the importance of extra-MPOA systems in the regulation of copulation. PMID:17467707

Gonadal steroids regulate the expression of aggrecanases in human endometrial stromal cells in vitro

PubMed Central

Wen, Jiadi; Zhu, Hua; Leung, Peter CK

2013-01-01

The human endometrium undergoes cyclic change during each menstrual cycle in response to gonadal steroids. Proteolysis of endometrial extracellular matrix (ECM) is necessary to prepare this dynamic tissue for pregnancy. Proteolytic enzymes such as matrix metalloproteinase (MMP) and closely related a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) have been assigned key roles in the highly regulated cyclic remodelling of the endometrial ECM. We have previously shown that ADAMTS-1 undergoes spatiotemporal changes in human endometrial stromal cells under the regulation of gonadal steroids. This suggests that other ADAMTS subtypes, known as aggrecanases, may contribute to the ECM remodelling events that occur in female physiological cycles and in preparation for pregnancy. To determine whether progesterone (P4), 17β-estradiol (E2), or dihydrotestosterone (DHT), alone or in combination, are capable of regulating ADAMTS-4, -5, -8 or -9 expression in human endometrial stromal cells in vitro. Real-time quantitative PCR and Western blot analysis were used to measure ADAMTSs mRNA and protein levels in primary cultures of human endometrial stromal cells (n = 12). P4, DHT but not E2 have regulatory effects on ADAMTS-8, -9 and -5 expression. Combined treatment with gonadal steroids did not show any synergistic or antagonistic effects. However, the synthetic steroid antagonists RU486 and hydroxyflutamide specifically inhibited the P4- or DHT-mediated regulatory effects on ADAMTS expression. These studies provide evidence that the regulation of aggrecanases by gonadal steroids in human endometrial stromal cells may play an important role during decidualization. PMID:23947778

To fight or mate? Hormonal control of sex recognition, male sexual behavior and aggression in the gecko lizard.

PubMed

Schořálková, Tereza; Kratochvíl, Lukáš; Kubička, Lukáš

2018-01-01

Squamate reptiles are a highly diversified vertebrate group with extensive variability in social behavior and sexual dimorphism. However, hormonal control of these traits has not previously been investigated in sufficient depth in many squamate lineages. Here, we studied the hormonal control of male sexual behavior, aggressiveness, copulatory organ (hemipenis) size and sex recognition in the gecko Paroedura picta, comparing ovariectomized females, ovariectomized females treated with exogenous dihydrotestosterone (DHT), ovariectomized females treated with exogenous testosterone (T), control females and males. The administration of both T and DHT led to the expression of male-typical sexual behavior in females. However, in contrast to T, increased circulating levels of DHT alone were not enough to initiate the full expression of male-typical offensive aggressive behavior and development of hemipenes in females. Ovariectomized females were as sexually attractive as control females, which does not support the need for the demasculinization of the cues used for sex recognition by ovarian hormones as suggested in other sauropsids. On the other hand, our results point to the masculinization of the sex recognition cues by male gonadal androgens. Previously, we also demonstrated that sexually dimorphic growth is controlled by ovarian hormones in P. picta. Overall, it appears that individual behavioral and morphological sexually-dimorphic traits are controlled by multiple endogenous pathways in this species. Variability in the endogenous control of particular traits could have permitted their disentangling during evolution and the occurrence of (semi)independent changes across squamate phylogeny. Copyright © 2017 Elsevier Inc. All rights reserved.

Uptake and metabolism of (/sup 3/H)testosterone in the brain, pituitary gland and genital tract of the male cynomolgus monkey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonsall, R.W.; Rees, H.D.; Micheal, R.P.

1986-03-01

To study the mechanism by which testosterone restores the sexual potency of castrated cynomolgus monkeys, two males (body weights 5.2 and 5.3 kg) were castrated and, 3 days later, injected with 3 mCi (/sup 3/H)testosterone ((/sup 3/H)T) as an intravenous bolus. After 30 min, males were killed and brains and samples of other tissues were rapidly removed and placed on ice. Samples were dissected from the right halves of the brain and homogenized. Purified cell nuclei were prepared and ether extracts were analyzed by reverse-phase HPCL. Generally, unchanged (/sup 3/H)T was the major form of radioactivity in brain and pituitarymore » gland, but in cell nuclei from hypothalamus, preoptic area and amygdala, a large proportion (34 - 61%) was in the form of (/sup 3/H)estradiol ((/sup 4/H)E/sub 2/). Little or no (/sup 3/H)dihydrotestosterone ((/sup 3/H)DHT) was detected in cell nuclei from any brain region or from pituitary gland. However, (/sup 3/H)DHT was the major form (61 - 95%) of radioactivity in cell nuclei from glans penis, prostrate and seminal vesicles. In autoradiograms of the left halves of the same brains, the percentage of cells that accumulated radioactivity in their nuclei was high in specific regions of the hypothalamus, preoptic areas and amygdala. The authors conclude that the peripheral actions of T are mediated via DHT, but its central actions are dependent on unchanged T or on E/sub 2/ formed locally by aromatization.« less

EFFECTS OF ENVIRONMENTAL ANTIANDROGENS ON REPRODUCTIVE DEVELOPMENT IN EXPERIMENTAL ANIMALS

EPA Science Inventory

In mammals, the androgens testosterone (T) and dihydrotestosterone (DHT) are critical for normal male reproductive development and function. In humans, drugs that act as androgen receptor (AR) agonists and antagonists or inhibit fetal steroidogenesis can cause pseudohermaphrodi...

DOE Office of Scientific and Technical Information (OSTI.GOV)

AISL-CRYPTO is a library of cryptography functions supporting other AISL software. It provides various crypto functions for Common Lisp, including Digital Signature Algorithm, Data Encryption Standard, Secure Hash Algorithm, and public-key cryptography.

Implementation of 3D spatial indexing and compression in a large-scale molecular dynamics simulation database for rapid atomic contact detection.

PubMed

Toofanny, Rudesh D; Simms, Andrew M; Beck, David A C; Daggett, Valerie

2011-08-10

Molecular dynamics (MD) simulations offer the ability to observe the dynamics and interactions of both whole macromolecules and individual atoms as a function of time. Taken in context with experimental data, atomic interactions from simulation provide insight into the mechanics of protein folding, dynamics, and function. The calculation of atomic interactions or contacts from an MD trajectory is computationally demanding and the work required grows exponentially with the size of the simulation system. We describe the implementation of a spatial indexing algorithm in our multi-terabyte MD simulation database that significantly reduces the run-time required for discovery of contacts. The approach is applied to the Dynameomics project data. Spatial indexing, also known as spatial hashing, is a method that divides the simulation space into regular sized bins and attributes an index to each bin. Since, the calculation of contacts is widely employed in the simulation field, we also use this as the basis for testing compression of data tables. We investigate the effects of compression of the trajectory coordinate tables with different options of data and index compression within MS SQL SERVER 2008. Our implementation of spatial indexing speeds up the calculation of contacts over a 1 nanosecond (ns) simulation window by between 14% and 90% (i.e., 1.2 and 10.3 times faster). For a 'full' simulation trajectory (51 ns) spatial indexing reduces the calculation run-time between 31 and 81% (between 1.4 and 5.3 times faster). Compression resulted in reduced table sizes but resulted in no significant difference in the total execution time for neighbour discovery. The greatest compression (~36%) was achieved using page level compression on both the data and indexes. The spatial indexing scheme significantly decreases the time taken to calculate atomic contacts and could be applied to other multidimensional neighbor discovery problems. The speed up enables on-the-fly calculation and visualization of contacts and rapid cross simulation analysis for knowledge discovery. Using page compression for the atomic coordinate tables and indexes saves ~36% of disk space without any significant decrease in calculation time and should be considered for other non-transactional databases in MS SQL SERVER 2008.

Implementation of 3D spatial indexing and compression in a large-scale molecular dynamics simulation database for rapid atomic contact detection

PubMed Central

2011-01-01

Background Molecular dynamics (MD) simulations offer the ability to observe the dynamics and interactions of both whole macromolecules and individual atoms as a function of time. Taken in context with experimental data, atomic interactions from simulation provide insight into the mechanics of protein folding, dynamics, and function. The calculation of atomic interactions or contacts from an MD trajectory is computationally demanding and the work required grows exponentially with the size of the simulation system. We describe the implementation of a spatial indexing algorithm in our multi-terabyte MD simulation database that significantly reduces the run-time required for discovery of contacts. The approach is applied to the Dynameomics project data. Spatial indexing, also known as spatial hashing, is a method that divides the simulation space into regular sized bins and attributes an index to each bin. Since, the calculation of contacts is widely employed in the simulation field, we also use this as the basis for testing compression of data tables. We investigate the effects of compression of the trajectory coordinate tables with different options of data and index compression within MS SQL SERVER 2008. Results Our implementation of spatial indexing speeds up the calculation of contacts over a 1 nanosecond (ns) simulation window by between 14% and 90% (i.e., 1.2 and 10.3 times faster). For a 'full' simulation trajectory (51 ns) spatial indexing reduces the calculation run-time between 31 and 81% (between 1.4 and 5.3 times faster). Compression resulted in reduced table sizes but resulted in no significant difference in the total execution time for neighbour discovery. The greatest compression (~36%) was achieved using page level compression on both the data and indexes. Conclusions The spatial indexing scheme significantly decreases the time taken to calculate atomic contacts and could be applied to other multidimensional neighbor discovery problems. The speed up enables on-the-fly calculation and visualization of contacts and rapid cross simulation analysis for knowledge discovery. Using page compression for the atomic coordinate tables and indexes saves ~36% of disk space without any significant decrease in calculation time and should be considered for other non-transactional databases in MS SQL SERVER 2008. PMID:21831299

Adaptive Bloom Filter: A Space-Efficient Counting Algorithm for Unpredictable Network Traffic

NASA Astrophysics Data System (ADS)

Matsumoto, Yoshihide; Hazeyama, Hiroaki; Kadobayashi, Youki

The Bloom Filter (BF), a space-and-time-efficient hashcoding method, is used as one of the fundamental modules in several network processing algorithms and applications such as route lookups, cache hits, packet classification, per-flow state management or network monitoring. BF is a simple space-efficient randomized data structure used to represent a data set in order to support membership queries. However, BF generates false positives, and cannot count the number of distinct elements. A counting Bloom Filter (CBF) can count the number of distinct elements, but CBF needs more space than BF. We propose an alternative data structure of CBF, and we called this structure an Adaptive Bloom Filter (ABF). Although ABF uses the same-sized bit-vector used in BF, the number of hash functions employed by ABF is dynamically changed to record the number of appearances of a each key element. Considering the hash collisions, the multiplicity of a each key element on ABF can be estimated from the number of hash functions used to decode the membership of the each key element. Although ABF can realize the same functionality as CBF, ABF requires the same memory size as BF. We describe the construction of ABF and IABF (Improved ABF), and provide a mathematical analysis and simulation using Zipf's distribution. Finally, we show that ABF can be used for an unpredictable data set such as real network traffic.

Semi-Supervised Geographical Feature Detection

NASA Astrophysics Data System (ADS)

Yu, H.; Yu, L.; Kuo, K. S.

2016-12-01

Extraction and tracking geographical features is a fundamental requirement in many geoscience fields. However, this operation has become an increasingly challenging task for domain scientists when tackling a large amount of geoscience data. Although domain scientists may have a relatively clear definition of features, it is difficult to capture the presence of features in an accurate and efficient fashion. We propose a semi-supervised approach to address large geographical feature detection. Our approach has two main components. First, we represent a heterogeneous geoscience data in a unified high-dimensional space, which can facilitate us to evaluate the similarity of data points with respect to geolocation, time, and variable values. We characterize the data from these measures, and use a set of hash functions to parameterize the initial knowledge of the data. Second, for any user query, our approach can automatically extract the initial results based on the hash functions. To improve the accuracy of querying, our approach provides a visualization interface to display the querying results and allow users to interactively explore and refine them. The user feedback will be used to enhance our knowledge base in an iterative manner. In our implementation, we use high-performance computing techniques to accelerate the construction of hash functions. Our design facilitates a parallelization scheme for feature detection and extraction, which is a traditionally challenging problem for large-scale data. We evaluate our approach and demonstrate the effectiveness using both synthetic and real world datasets.

Gencrypt: one-way cryptographic hashes to detect overlapping individuals across samples

PubMed Central

Turchin, Michael C.; Hirschhorn, Joel N.

2012-01-01

Summary: Meta-analysis across genome-wide association studies is a common approach for discovering genetic associations. However, in some meta-analysis efforts, individual-level data cannot be broadly shared by study investigators due to privacy and Institutional Review Board concerns. In such cases, researchers cannot confirm that each study represents a unique group of people, leading to potentially inflated test statistics and false positives. To resolve this problem, we created a software tool, Gencrypt, which utilizes a security protocol known as one-way cryptographic hashes to allow overlapping participants to be identified without sharing individual-level data. Availability: Gencrypt is freely available under the GNU general public license v3 at http://www.broadinstitute.org/software/gencrypt/ Contact: joelh@broadinstitute.org Supplementary information: Supplementary data are available at Bioinformatics online. PMID:22302573

Meet-in-the-Middle Preimage Attacks on Hash Modes of Generalized Feistel and Misty Schemes with SP Round Function

NASA Astrophysics Data System (ADS)

Moon, Dukjae; Hong, Deukjo; Kwon, Daesung; Hong, Seokhie

We assume that the domain extender is the Merkle-Damgård (MD) scheme and he message is padded by a ‘1’, and minimum number of ‘0’s, followed by a fixed size length information so that the length of padded message is multiple of block length. Under this assumption, we analyze securities of the hash mode when the compression function follows the Davies-Meyer (DM) scheme and the underlying block cipher is one of the plain Feistel or Misty scheme or the generalized Feistel or Misty schemes with Substitution-Permutation (SP) round function. We do this work based on Meet-in-the-Middle (MitM) preimage attack techniques, and develop several useful initial structures.

Implementation analysis of RC5 algorithm on Preneel-Govaerts-Vandewalle (PGV) hashing schemes using length extension attack

NASA Astrophysics Data System (ADS)

Siswantyo, Sepha; Susanti, Bety Hayat

2016-02-01

Preneel-Govaerts-Vandewalle (PGV) schemes consist of 64 possible single-block-length schemes that can be used to build a hash function based on block ciphers. For those 64 schemes, Preneel claimed that 4 schemes are secure. In this paper, we apply length extension attack on those 4 secure PGV schemes which use RC5 algorithm in its basic construction to test their collision resistance property. The attack result shows that the collision occurred on those 4 secure PGV schemes. Based on the analysis, we indicate that Feistel structure and data dependent rotation operation in RC5 algorithm, XOR operations on the scheme, along with selection of additional message block value also give impact on the collision to occur.

NHash: Randomized N-Gram Hashing for Distributed Generation of Validatable Unique Study Identifiers in Multicenter Research.

PubMed

Zhang, Guo-Qiang; Tao, Shiqiang; Xing, Guangming; Mozes, Jeno; Zonjy, Bilal; Lhatoo, Samden D; Cui, Licong

2015-11-10

A unique study identifier serves as a key for linking research data about a study subject without revealing protected health information in the identifier. While sufficient for single-site and limited-scale studies, the use of common unique study identifiers has several drawbacks for large multicenter studies, where thousands of research participants may be recruited from multiple sites. An important property of study identifiers is error tolerance (or validatable), in that inadvertent editing mistakes during their transmission and use will most likely result in invalid study identifiers. This paper introduces a novel method called "Randomized N-gram Hashing (NHash)," for generating unique study identifiers in a distributed and validatable fashion, in multicenter research. NHash has a unique set of properties: (1) it is a pseudonym serving the purpose of linking research data about a study participant for research purposes; (2) it can be generated automatically in a completely distributed fashion with virtually no risk for identifier collision; (3) it incorporates a set of cryptographic hash functions based on N-grams, with a combination of additional encryption techniques such as a shift cipher; (d) it is validatable (error tolerant) in the sense that inadvertent edit errors will mostly result in invalid identifiers. NHash consists of 2 phases. First, an intermediate string using randomized N-gram hashing is generated. This string consists of a collection of N-gram hashes f1, f2, ..., fk. The input for each function fi has 3 components: a random number r, an integer n, and input data m. The result, fi(r, n, m), is an n-gram of m with a starting position s, which is computed as (r mod |m|), where |m| represents the length of m. The output for Step 1 is the concatenation of the sequence f1(r1, n1, m1), f2(r2, n2, m2), ..., fk(rk, nk, mk). In the second phase, the intermediate string generated in Phase 1 is encrypted using techniques such as shift cipher. The result of the encryption, concatenated with the random number r, is the final NHash study identifier. We performed experiments using a large synthesized dataset comparing NHash with random strings, and demonstrated neglegible probability for collision. We implemented NHash for the Center for SUDEP Research (CSR), a National Institute for Neurological Disorders and Stroke-funded Center Without Walls for Collaborative Research in the Epilepsies. This multicenter collaboration involves 14 institutions across the United States and Europe, bringing together extensive and diverse expertise to understand sudden unexpected death in epilepsy patients (SUDEP). The CSR Data Repository has successfully used NHash to link deidentified multimodal clinical data collected in participating CSR institutions, meeting all desired objectives of NHash.

A proposed new test for aptitude screening of air traffic controller applicants.

DOT National Transportation Integrated Search

1972-05-01

The study concerns the development and experimental validation of a novel aptitude test, referred to as 'Directional Headings' (or DHT), for the selection of Air Traffic Control Specialist (ATCS) trainees. The test requires the subject to rapidly int...

Androgen Stimulates Growth of Mouse Preantral Follicles In Vitro: Interaction With Follicle-Stimulating Hormone and With Growth Factors of the TGFβ Superfamily

PubMed Central

Laird, Mhairi; Thomson, Kacie; Fenwick, Mark; Mora, Jocelyn; Hardy, Kate

2017-01-01

Androgens are essential for the normal function of mature antral follicles but also have a role in the early stages of follicle development. Polycystic ovary syndrome (PCOS), the most common cause of anovulatory infertility, is characterized by androgen excess and aberrant follicle development that includes accelerated early follicle growth. We have examined the effects of testosterone and dihydrotestosterone (DHT) on development of isolated mouse preantral follicles in culture with the specific aim of investigating interaction with follicle-stimulating hormone (FSH), the steroidogenic pathway, and growth factors of the TGFβ superfamily that are known to have a role in early follicle development. Both testosterone and DHT stimulated follicle growth and augmented FSH-induced growth and increased the incidence of antrum formation among the granulosa cell layers of these preantral follicles after 72 hours in culture. Effects of both androgens were reversed by the androgen receptor antagonist flutamide. FSH receptor expression was increased in response to both testosterone and DHT, as was that of Star, whereas Cyp11a1 was down-regulated. The key androgen-induced changes in the TGFβ signaling pathway were down-regulation of Amh, Bmp15, and their receptors. Inhibition of Alk6 (Bmpr1b), a putative partner for Amhr2 and Bmpr2, by dorsomorphin resulted in augmentation of androgen-stimulated growth and modification of androgen-induced gene expression. Our findings point to varied effects of androgen on preantral follicle growth and function, including interaction with FSH-activated growth and steroidogenesis, and, importantly, implicate the intrafollicular TGFβ system as a key mediator of androgen action. These findings provide insight into abnormal early follicle development in PCOS. PMID:28324051

Androgen Stimulates Growth of Mouse Preantral Follicles In Vitro: Interaction With Follicle-Stimulating Hormone and With Growth Factors of the TGFβ Superfamily.

PubMed

Laird, Mhairi; Thomson, Kacie; Fenwick, Mark; Mora, Jocelyn; Franks, Stephen; Hardy, Kate

2017-04-01

Androgens are essential for the normal function of mature antral follicles but also have a role in the early stages of follicle development. Polycystic ovary syndrome (PCOS), the most common cause of anovulatory infertility, is characterized by androgen excess and aberrant follicle development that includes accelerated early follicle growth. We have examined the effects of testosterone and dihydrotestosterone (DHT) on development of isolated mouse preantral follicles in culture with the specific aim of investigating interaction with follicle-stimulating hormone (FSH), the steroidogenic pathway, and growth factors of the TGFβ superfamily that are known to have a role in early follicle development. Both testosterone and DHT stimulated follicle growth and augmented FSH-induced growth and increased the incidence of antrum formation among the granulosa cell layers of these preantral follicles after 72 hours in culture. Effects of both androgens were reversed by the androgen receptor antagonist flutamide. FSH receptor expression was increased in response to both testosterone and DHT, as was that of Star, whereas Cyp11a1 was down-regulated. The key androgen-induced changes in the TGFβ signaling pathway were down-regulation of Amh, Bmp15, and their receptors. Inhibition of Alk6 (Bmpr1b), a putative partner for Amhr2 and Bmpr2, by dorsomorphin resulted in augmentation of androgen-stimulated growth and modification of androgen-induced gene expression. Our findings point to varied effects of androgen on preantral follicle growth and function, including interaction with FSH-activated growth and steroidogenesis, and, importantly, implicate the intrafollicular TGFβ system as a key mediator of androgen action. These findings provide insight into abnormal early follicle development in PCOS.

Postnatal expression and androgen regulation of HOXBES2 homeoprotein in rat epididymis.

PubMed

Prabagaran, Esakki; Hegde, Uma C; Moodbidri, Sudhir B; Bandivdekar, Atmaram H; Raghavan, Vijaya P

2007-01-01

The multifunctional and androgen-regulated epididymis is known to provide a conducive microenvironment for the maturation and storage of mature spermatozoa. HOXB2 homeodomain-containing epididymis-specific sperm protein (HOXBES2), a molecule first reported by our group, exhibits cell- and region-specific expression. It was found in the cytoplasm of the principal epithelial cells with maximum in the distal segments of the rat epididymis. The present study was undertaken to determine whether HOXBES2 expression is regulated by androgens and postnatal epididymal development. Toward this, the epididymis was disallowed access to circulating androgens either by chemical or biologic castration. In bilaterally orchidectomized animals, the levels of immunoreactive HOXBES2 declined to <5 % of those seen in sham-operated animals. Exogenous dihydrotestosterone (DHT) supplementation (250 microg/kg body weight) for 7 days restored the expression levels to >or= 90 % of that observed in intact animals. Ethylene dimethane sulfonate (EDS) administration completely abolished HOXBES2 expression in the epididymis, and supplementation with DHT or DHT + estradiol for 10 days re-established HOXBES2 expression to near normalcy. However, in the estradiol alone-supplemented EDS-treated group, HOXBES2 remained undetected. The unaltered HOXBES2 expression following efferent duct ligation suggested that HOXBES2 is not critically dependent on testicular factors. During postnatal development, protein expression in the epididymis begins to appear from day 40 and 50 and increased from day 60 onward, coinciding with the mature levels of circulating androgens and the well-differentiated epididymis. Thus, the data obtained from this study suggests that HOXBES2 expression could be regulated by androgens, and its expression level is closely associated with the postnatal development of the epididymis.

Arteriolar insulin resistance in a rat model of polycystic ovary syndrome.

PubMed

Sara, Levente; Antal, Peter; Masszi, Gabriella; Buday, Anna; Horvath, Eszter M; Hamar, Peter; Monos, Emil; Nadasy, Gyorgy L; Varbiro, Szabolcs

2012-02-01

To investigate the vascular dysfunction caused by insulin resistance in polycystic ovary syndrome (PCOS) and the effectiveness of vitamin D in an animal model. Controlled experimental animal study. Animal laboratory at a university research institute. Thirty female Wistar rats. Rats were divided into groups at age 21-28 weeks. Twenty of them were subjected to dihydrotestosterone (DHT) treatment (83 μg/d); ten of them also received parallel vitamin D treatment (120 ng/100 g/wk). Oral glucose tolerance tests with insulin level measurements were performed. Gracilis arterioles were tested for their contractility as well as their nitric oxide (NO)-dependent and insulin-induced dilation using pressure arteriography. Several physiologic parameters, glucose metabolism, and pressure arteriography. DHT treatment increased the passive diameter of resistance arterioles, lowered norepinephrine-induced contraction (30.1 ± 4.7% vs. 8.7 ± 3.6%) and reduced acetylcholine-induced (122.0 ± 2.9% vs. 48.0 ± 1.4%) and insulin-induced (at 30 mU/mL: 21.7 ± 5.3 vs. 9.8 ± 5.6%) dilation. Vitamin D treatment restored insulin relaxation and norepinephrine-induced contractility; in contrast, it failed to alter NO-dependent relaxation. In DHT-treated rats, in addition to metabolically proven insulin resistance, decreased insulin-induced vasorelaxation was observed and was improved by vitamin D treatment without affecting NO-dependent relaxation. The reduction in insulin-induced dilation of arterioles is an important as yet undescribed pathway of vascular damage in PCOS and might explain the clinical effectiveness of vitamin D treatment. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Long-Term Recordings of Arcuate Nucleus Kisspeptin Neurons Reveal Patterned Activity That Is Modulated by Gonadal Steroids in Male Mice.

PubMed

Vanacker, Charlotte; Moya, Manuel Ricu; DeFazio, R Anthony; Johnson, Michael L; Moenter, Suzanne M

2017-10-01

Pulsatile release of gonadotropin-releasing hormone (GnRH) is key to fertility. Pulse frequency is modulated by gonadal steroids and likely arises subsequent to coordination of GnRH neuron firing activity. The source of rhythm generation and the site of steroid feedback remain critical unanswered questions. Arcuate neurons that synthesize kisspeptin, neurokinin B, and dynorphin (KNDy) may be involved in both of these processes. We tested the hypotheses that action potential firing in KNDy neurons is episodic and that gonadal steroids regulate this pattern. Targeted extracellular recordings were made of green fluorescent protein-identified KNDy neurons in brain slices from adult male mice that were intact, castrated, or castrated and treated with estradiol or dihydrotestosterone (DHT). KNDy neurons exhibited marked peaks and nadirs in action potential firing activity during recordings lasting 1 to 3.5 hours. Peaks, identified by Cluster analysis, occurred more frequently in castrated than intact mice, and either estradiol or DHT in vivo or blocking neurokinin type 3 receptor in vitro restored peak frequency to intact levels. The frequency of peaks in firing rate and estradiol regulation of this frequency is similar to that observed for GnRH neurons, whereas DHT suppressed firing in KNDy but not GnRH neurons. We further examined the patterning of action potentials to identify bursts that may be associated with increased neuromodulator release. Burst frequency and duration are increased in castrated compared with intact and steroid-treated mice. The observation that KNDy neurons fire in an episodic manner that is regulated by steroid feedback is consistent with a role for these neurons in GnRH pulse generation and regulation. Copyright © 2017 Endocrine Society.

Androgenic and Estrogenic Response of Green Mussel Extracts from Singapore’s Coastal Environment Using a Human Cell-Based Bioassay

PubMed Central

Bayen, Stéphane; Gong, Yinhan; Chin, Hong Soon; Lee, Hian Kee; Leong, Yong Eu; Obbard, Jeffrey Philip

2004-01-01

In the last decade, evidence of endocrine disruption in biota exposed to environmental pollutants has raised serious concern. Human cell-based bioassays have been developed to evaluate induced androgenic and estrogenic activities of chemical compounds. However, bioassays have been sparsely applied to environmental samples. In this study we present data on sex hormone activities in the green mussel, Perna viridis, in Singapore’s coastal waters. P. viridis is a common bioindicator of marine contamination, and this study is a follow-up to an earlier investigation that reported the presence of sex hormone activities in seawater samples from Singapore’s coastal environment. Specimens were collected from eight locations around the Singapore coastline and analyzed for persistent organic pollutants (POPs) and heavy metals. Tissue extracts were then screened for activities on androgen receptors (ARs) and estrogen receptors (ER-α and ER-β) using a reporter gene bio-assay based on a HeLa human cell line. Mussel extracts alone did not exhibit AR activity, but in the presence of the reference androgenic hormone dihydrotestosterone (DHT), activities were up to 340% higher than those observed for DHT alone. Peak activities were observed in locations adjacent to industrial and shipping activities. Estrogenic activities of the mussel extract both alone and in the presence of reference hormone were positive. Correlations were statistically investigated between sex hormone activities, levels of pollutants in the mussel tissues, and various biological parameters (specimen size, sex ratio, lipid and moisture content). Significant correlations exist between AR activities, in the presence of DHT, and total concentration of POPs (r = 0.725, p < 0.05). PMID:15531429

Sex steroids during bone growth: a comparative study between mouse models for hypogonadal and senile osteoporosis.

PubMed

Ophoff, J; Venken, K; Callewaert, F; Boonen, S; Bouillon, R; Vanderschueren, D

2009-10-01

In this study, the role of disturbed bone mineral acquisition during puberty in the pathogenesis of osteoporosis was studied. To this end, a mouse model for senile and hypogonadal osteoporosis was used. Longitudinal follow-up showed that bone fragility in both models results from deficient bone build-up during early puberty. Male osteoporosis may result from impaired bone growth. This study characterizes the mechanisms of deficient peak bone mass acquisition in models for senile (SAMP6) and hypogonadal (orchidectomized SAMR1) osteoporosis. Bone mineral acquisition was investigated longitudinally in SAMP6 and orchidectomized SAMR1 mice (eight to ten animals per group) using peripheral quantitative computed tomography and histomorphometry. Additionally, the effects of long-term 5alpha-dihydrotestosterone (DHT) and 17beta-estradiol (E2) replacement were studied. Statistical analysis was performed using ANOVA and Student's t test. SAMP6 mice showed an early (4 weeks) medullary expansion of the cortex due to impaired endocortical bone formation (-43%). Despite compensatory periosteal bone formation (+47%), cortical thickness was severely reduced in 20-week-old SAMP6 versus SAMR1. Orchidectomy reduced periosteal apposition between 4 and 8 weeks of age and resulted in high bone turnover and less trabecular bone gain in SAMP6 and SAMR1. DHT and E2 stimulated periosteal expansion and trabecular bone in orchidectomized SAMP6 and SAMR1. E2 stimulated endocortical apposition in SAMP6. Moreover, sex steroid action occurred between 4 and 8 weeks of age. Bone fragility in both models resulted from deficient bone build-up during early puberty. DHT and E2 improved bone mass acquisition in orchidectomized animals, suggesting a role for AR and ER in male skeletal development.

Polycystic ovary syndrome: possible involvement of androgen-induced, chemerin-mediated ovarian recruitment of monocytes/macrophages.

PubMed

Lima, Patricia D A; Nivet, Anne-Laure; Wang, Qi; Chen, Yi-An; Leader, Arthur; Cheung, Annie; Tzeng, Chii-Ruey; Tsang, Benjamin K

2018-04-24

Polycystic ovary syndrome (PCOS) is a continuum of endocrine and reproductive disorders characterized by hyperandrogenism, antral follicle growth arrest and chronic inflammation. Macrophages play key role in inflammation and the balance between M1 (inflammatory) and M2 (anti-inflammatory) macrophages determines physiological/pathological outcomes. Here, we investigated if hyperandrogenism increases ovarian chemerin altering the balance of M1 and M2 macrophages and the granulosa cell death. Ovarian chemerin was up-regulated by 5α-dihydrotestosterone (DHT) in lean and overweight rats; while increased serum chemerin levels were only evident in overweight rats, suggesting that the serum chemerin may be reflective of a systemic response and associated with obesity, whereas increased ovarian chemerin expression is a localized response independent of the metabolic status. DHT altered follicle dynamics while increased the M1: M2 macrophages ratio in antral and pre-ovulatory follicles. While ovarian M1 macrophages expressing chemokine-like receptor 1 (CMKLR1) were increased, CMKLR1 + monocytes, which migrated towards chemerin-rich environment, were markedly decreased after 15 days of DHT. Androgen-induced granulosa cell apoptosis was dependent on the presence of macrophages. In humans, chemerin levels in follicular fluid, but not in serum, was higher in lean PCOS patients compared to BMI-matched controls and was associated with increased M1: M2 ratio. Our results support the concept that in PCOS, hyperandrogenemia increases chemerin expression while promotes CMKLR1 + monocytes recruitment and deregulates the immunological niche of ovaries. This study established a new immunological perspective in PCOS at the ovarian level. Hyperandrogenism is associated with up-regulation of chemerin and macrophage unbalance in the ovaries.

Gonadal steroids regulate the expression of aggrecanases in human endometrial stromal cells in vitro.

PubMed

Wen, Jiadi; Zhu, Hua; Leung, Peter C K

2013-10-01

The human endometrium undergoes cyclic change during each menstrual cycle in response to gonadal steroids. Proteolysis of endometrial extracellular matrix (ECM) is necessary to prepare this dynamic tissue for pregnancy. Proteolytic enzymes such as matrix metalloproteinase (MMP) and closely related a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) have been assigned key roles in the highly regulated cyclic remodelling of the endometrial ECM. We have previously shown that ADAMTS-1 undergoes spatiotemporal changes in human endometrial stromal cells under the regulation of gonadal steroids. This suggests that other ADAMTS subtypes, known as aggrecanases, may contribute to the ECM remodelling events that occur in female physiological cycles and in preparation for pregnancy. To determine whether progesterone (P4), 17β-estradiol (E2), or dihydrotestosterone (DHT), alone or in combination, are capable of regulating ADAMTS-4, -5, -8 or -9 expression in human endometrial stromal cells in vitro. Real-time quantitative PCR and Western blot analysis were used to measure ADAMTSs mRNA and protein levels in primary cultures of human endometrial stromal cells (n = 12). P4, DHT but not E2 have regulatory effects on ADAMTS-8, -9 and -5 expression. Combined treatment with gonadal steroids did not show any synergistic or antagonistic effects. However, the synthetic steroid antagonists RU486 and hydroxyflutamide specifically inhibited the P4- or DHT-mediated regulatory effects on ADAMTS expression. These studies provide evidence that the regulation of aggrecanases by gonadal steroids in human endometrial stromal cells may play an important role during decidualization. © 2013 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Androgen receptor signals regulate UDP-glucuronosyltransferases in the urinary bladder: a potential mechanism of androgen-induced bladder carcinogenesis.

PubMed

Izumi, Koji; Zheng, Yichun; Hsu, Jong-Wei; Chang, Chawnshang; Miyamoto, Hiroshi

2013-02-01

UDP-glucuronosyltransferases (UGTs), major phase II drug metabolism enzymes, play an important role in urinary bladder cancer initiation by detoxifying carcinogens. We aimed to determine if androgens regulate UGT expression via the androgen receptor (AR) pathway in the bladder. Real-time reverse transcription-polymerase chain reaction and Western blot analyses were used to assess UGT1A levels in the normal urothelium SVHUC cell line stably expressed with AR and in bladder tissues from AR knockout (ARKO) and castrated male mice. Immunohistochemistry was also performed in radical cystectomy specimens. Dihydrotestosterone (DHT) treatment in SVHUC-AR reduced mRNA expression of all the UGT1A subtypes (19-75% decrease), and hydroxyflutamide antagonized the DHT effects. In contrast, DHT showed only marginal effects on UGT1A expression in SVHUC-Vector. Of note were higher expression levels of UGT1As in SVHUC-Vector than in SVHUC-AR. In ARKO mice, all the Ugt1a subtypes were up-regulated, compared to wild-type littermates. In wild-type male mice, castration increased the expression of Ugt1a8, Ugt1a9, and Ugt1a10. Additionally, wild-type female mice had higher levels of Ugt1a than wild-type males. Immunohistochemical studies showed strong (3+) UGT1A staining in 11/24 (46%) cancer tissues, which was significantly lower than in corresponding benign tissues [17/18 (94%) cases (P = 0.0009)]. These results suggest that androgen-mediated AR signals promote bladder carcinogenesis by down-regulating the expression of UGTs in the bladder. Copyright © 2011 Wiley Periodicals, Inc.

Developmental programming by androgen affects the circadian timing system in female mice.

PubMed

Mereness, Amanda L; Murphy, Zachary C; Sellix, Michael T

2015-04-01

Circadian clocks play essential roles in the timing of events in the mammalian hypothalamo-pituitary-ovarian (HPO) axis. The molecular oscillator driving these rhythms has been localized to tissues of the HPO axis. It has been suggested that synchrony among these oscillators is a feature of normal reproductive function. The impact of fertility disorders on clock function and the role of the clock in the etiology of endocrine pathology remain unknown. Polycystic ovarian syndrome (PCOS) is a particularly devastating fertility disorder, affecting 5%-10% of women at childbearing age with features including a polycystic ovary, anovulation, and elevated serum androgen. Approximately 40% of these women have metabolic syndrome, marked by hyperinsulinemia, dyslipidemia, and insulin resistance. It has been suggested that developmental exposure to excess androgen contributes to the etiology of fertility disorders, including PCOS. To better define the role of the timing system in these disorders, we determined the effects of androgen-dependent developmental programming on clock gene expression in tissues of the metabolic and HPO axes. Female PERIOD2::luciferase (PER2::LUC) mice were exposed to androgen (dihydrotestosterone [DHT]) in utero (Days 16-18 of gestation) or for 9-10 wk (DHT pellet) beginning at weaning (pubertal androgen excess [PAE]). As expected, both groups of androgen-treated mice had disrupted estrous cycles. Analysis of PER2::LUC expression in tissue explants revealed that excess androgen produced circadian misalignment via tissue-dependent effects on phase distribution. In vitro treatment with DHT differentially affected the period of PER2::LUC expression in tissue explants and granulosa cells, indicating that androgen has direct and tissue-specific effects on clock gene expression that may account for the effects of developmental programming on the timing system. © 2015 by the Society for the Study of Reproduction, Inc.

Hormonal correlates of male life history stages in wild white-faced capuchin monkeys (Cebus capucinus)

PubMed Central

Jack, Katharine M.; Schoof, Valérie A.M.; Sheller, Claire R.; Rich, Catherine I.; Klingelhofer, Peter P.; Ziegler, Toni E.; Fedigan, Linda

2014-01-01

Much attention has been paid to hormonal variation in relation to male dominance status and reproductive seasonality, but we know relatively little about how hormones vary across life history stages. Here we examine fecal testosterone (fT), dihydrotestosterone (fDHT), and glucocorticoid (fGC) profiles across male life history stages in wild white-faced capuchins (Cebus capucinus). Study subjects included 37 males residing in three habituated social groups in the Área de Conservacíon Guanacaste, Costa Rica. Male life history stages included infant (0 to <12 months; N = 3), early juvenile (1 to <3 years; N = 10), late juvenile (3 to <6 years; N = 9), subadult (6 to <10 years; N = 8), subordinate adult (≥10 years; N = 3), and alpha adult (≥ 10 years; N = 4, including one recently deposed alpha). Life history stage was a significant predictor of fT; levels were low throughout the infant and juvenile phases, doubled in subadult and subordinate adults, and were highest for alpha males. Life history stage was not a significant predictor of fDHT, fDHT:fT, or fGC levels. Puberty in white-faced capuchins appears to begin in earnest during the subadult male phase, indicated by the first significant rise in fT. Given their high fT levels and exaggerated secondary sexual characteristics, we argue that alpha adult males represent a distinctive life history stage not experienced by all male capuchins. This study is the first to physiologically validate observable male life history stages using patterns of hormone excretion in wild Neotropical primates, with evidence for a strong association between fT levels and life history stage. PMID:24184868

Bone anabolic effects of S-40503, a novel nonsteroidal selective androgen receptor modulator (SARM), in rat models of osteoporosis.

PubMed

Hanada, Keigo; Furuya, Kazuyuki; Yamamoto, Noriko; Nejishima, Hiroaki; Ichikawa, Kiyonoshin; Nakamura, Tsutomu; Miyakawa, Motonori; Amano, Seiji; Sumita, Yuji; Oguro, Nao

2003-11-01

A novel nonsteroidal androgen receptor (AR) binder, S-40503, was successfully generated in order to develop selective androgen receptor modulators (SARMs). We evaluated the binding specificity for nuclear receptors (NRs) and osteoanabolic activities of S-40503 in comparison with a natural nonaromatizable steroid, 5alpha-dihydrotestosterone (DHT). The compound preferentially bound to AR with nanomolar affinity among NRs. When S-40503 was administrated into orchiectomized (ORX) rats for 4 weeks, bone mineral density (BMD) of femur and muscle weight of levator ani were increased as markedly as DHT, but prostate weight was not elevated over the normal at any doses tested. In contrast, DHT administration caused about 1.5-fold increase in prostate weight. The reduced virilizing activity was clearly evident from the result that 4-week treatment of normal rats with S-40503 showed no enlargement of prostate. To confirm the bone anabolic effect, S-40503 was given to ovariectomized (OVX) rats for 2 months. The compound significantly increased the BMD and biomechanical strength of femoral cortical bone, whereas estrogen, anti-bone resorptive hormone, did not. The increase in periosteal mineral apposition rate (MAR) of the femur revealed direct bone formation activity of S-40503. It was unlikely that the osteoanabolic effect of the compound was attribute to the enhancement of muscle mass, because immobilized ORX rats treated with S-40503 showed a marked increase in BMD of tibial cortical bone without any actions on the surrounding muscle tissue. Collectively, our novel compound served as a prototype for SARMs, which had unique tissue selectivity with high potency for bone formation and lower impact upon sex accessory tissues.

The antidepressant-like effect of ethynyl estradiol is mediated by both serotonergic and noradrenergic systems in the forced swimming test.

PubMed

Vega-Rivera, N M; López-Rubalcava, C; Estrada-Camarena, E

2013-10-10

17α-Ethynyl-estradiol (EE2, a synthetic steroidal estrogen) induces antidepressant-like effects in the forced swimming test (FST) similar to those induced by 5-HT and noradrenaline reuptake inhibitors (dual antidepressants). However, the precise mechanism of action of EE2 has not been studied. In the present study, the participation of estrogen receptors (ERs) and the serotonergic and the noradrenergic presynaptic sites in the antidepressant-like action of EE2 was evaluated in the FST. The effects of the ER antagonist ICI 182,780 (10 μg/rat; i.c.v.), the serotonergic and noradrenergic terminal destruction with 5,7-dihydroxytryptamine (5,7-DHT; 200 μg/rat, i.c.v.), and N-(2-chloro-ethyl)-N-ethyl-2-bromobenzylamine (DSP4; 10mg/kg, i.p.) were studied in ovariectomized rats treated with EE2 and subjected to the FST. In addition, the participation of α2-adrenergic receptors in the antidepressant-like action of EE2 was explored using the selective α2-receptor antagonist idazoxan (0.25, 0.5 and 1.0mg/kg, i.p.). EE2 induced an antidepressant-like action characterized by a decrease in immobility behavior with a concomitant increase in swimming and climbing behaviors. The ER antagonist, 5,7-DHT, DSP4, and idazoxan blocked the effects of EE2 on the immobility behavior, whereas ICI 182,780 and 5,7-DHT affected swimming behavior. The noradrenergic compound DSP4 altered climbing behavior, while Idazoxan inhibited the increase of swimming and climbing behaviors induced by EE2. Our results suggest that the antidepressant-like action of EE2 implies a complex mechanism of action on monoaminergic systems and estrogen receptors. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

The relationships between sex hormones and sexual function in middle-aged and older European men.

PubMed

O'Connor, Daryl B; Lee, David M; Corona, Giovanni; Forti, Gianni; Tajar, Abdelouahid; O'Neill, Terence W; Pendleton, Neil; Bartfai, Gyorgy; Boonen, Steven; Casanueva, Felipe F; Finn, Joseph D; Giwercman, Aleksander; Han, Thang S; Huhtaniemi, Ilpo T; Kula, Krzysztof; Labrie, Fernand; Lean, Michael E J; Punab, Margus; Silman, Alan J; Vanderschueren, Dirk; Wu, Frederick C W

2011-10-01

Limited data are available exploring the associations between sex hormones, multiple domains of sexual functioning, and sexual function-related distress in nonpatient samples in Europe. The aim of the study was to investigate the relationships between serum testosterone (T), estradiol (E2), and dihydrotestosterone (DHT) and sexual function in a multicenter population-based study of aging in men. Using stratified random sampling, 2838 men aged 40-79 yr completed the European Male Ageing Study-Sexual Function Questionnaire and provided a blood sample for hormone measurements. T, E2, and DHT were measured using gas chromatography-mass spectrometry. We conducted a community-based population survey in eight European centers. Self-reported sexual function (overall sexual function, sexual function-related distress, erectile dysfunction, masturbation) was measured. Total and free T, but not E2 or DHT, was associated with overall sexual function in middle-aged and older men. E2 was the only hormone associated with sexual function-related distress such that higher levels were related to greater distress. Free T levels were associated with masturbation frequency and erectile dysfunction in the fully adjusted models, such that higher T was associated with less dysfunction and greater frequency. Moreover, there was a T threshold for the relationship between total T, sexual function, and erectile dysfunction. At T concentrations of 8 nmol/liter or less, T was associated with worse sexual functioning, whereas at T levels over 8 nmol/liter, the relationship came to a plateau. These findings suggest that different hormonal mechanisms may regulate sexual functioning (T) vs. the psychological aspects (E2) of male sexual behavior. Moreover, there was a T threshold for overall sexual function such that at levels greater than 8 nmol/liter the relationship between T and sexual function did not become stronger.

A role for 5alpha-reductase activity in the development of male homosexuality?

PubMed

Alias, A G

2004-12-01

Higher body hair with lower mesmorphism ratings were observed in Caucasian homosexual men compared with the general male population, reflecting elevated 5alpha-reductase (5alphaR) activity, and higher dihydrotestosterone-to-testosterone (DHT-to-T) ratio, in sharp contrast to 46,XY 5alphaR 2 deficiency subjects, who are often born with ambiguous, or female genitalia, but tend to grow up to be muscular, heterosexual men with very little body hair, or beard. One study also showed them scoring around dull normal IQs. A greater prevalence of liberal body hair growth in men with higher IQs and/or educational levels was also observed in several samples. The exceptions to this statistical trend are too unsettling, however. Nevertheless, the results of a number of published studies, including one showing higher DHT-to-T ratio in homosexual men, done with different objectives over a span of 80 years, together strongly support these findings. Furthermore, in an animal model, "cognitive-enhancing effects" of "5alpha-reduced androgen [metabolites]" were recently demonstrated.

Tag Content Access Control with Identity-based Key Exchange

NASA Astrophysics Data System (ADS)

Yan, Liang; Rong, Chunming

2010-09-01

Radio Frequency Identification (RFID) technology that used to identify objects and users has been applied to many applications such retail and supply chain recently. How to prevent tag content from unauthorized readout is a core problem of RFID privacy issues. Hash-lock access control protocol can make tag to release its content only to reader who knows the secret key shared between them. However, in order to get this shared secret key required by this protocol, reader needs to communicate with a back end database. In this paper, we propose to use identity-based secret key exchange approach to generate the secret key required for hash-lock access control protocol. With this approach, not only back end database connection is not needed anymore, but also tag cloning problem can be eliminated at the same time.

Improving the efficiency of quantum hash function by dense coding of coin operators in discrete-time quantum walk

NASA Astrophysics Data System (ADS)

Yang, YuGuang; Zhang, YuChen; Xu, Gang; Chen, XiuBo; Zhou, Yi-Hua; Shi, WeiMin

2018-03-01

Li et al. first proposed a quantum hash function (QHF) in a quantum-walk architecture. In their scheme, two two-particle interactions, i.e., I interaction and π-phase interaction are introduced and the choice of I or π-phase interactions at each iteration depends on a message bit. In this paper, we propose an efficient QHF by dense coding of coin operators in discrete-time quantum walk. Compared with existing QHFs, our protocol has the following advantages: the efficiency of the QHF can be doubled and even more; only one particle is enough and two-particle interactions are unnecessary so that quantum resources are saved. It is a clue to apply the dense coding technique to quantum cryptographic protocols, especially to the applications with restricted quantum resources.

An evaluation of multi-probe locality sensitive hashing for computing similarities over web-scale query logs.

PubMed

Cormode, Graham; Dasgupta, Anirban; Goyal, Amit; Lee, Chi Hoon

2018-01-01

Many modern applications of AI such as web search, mobile browsing, image processing, and natural language processing rely on finding similar items from a large database of complex objects. Due to the very large scale of data involved (e.g., users' queries from commercial search engines), computing such near or nearest neighbors is a non-trivial task, as the computational cost grows significantly with the number of items. To address this challenge, we adopt Locality Sensitive Hashing (a.k.a, LSH) methods and evaluate four variants in a distributed computing environment (specifically, Hadoop). We identify several optimizations which improve performance, suitable for deployment in very large scale settings. The experimental results demonstrate our variants of LSH achieve the robust performance with better recall compared with "vanilla" LSH, even when using the same amount of space.

Tangible interactive system for document browsing and visualisation of multimedia data

NASA Astrophysics Data System (ADS)

Rytsar, Yuriy; Voloshynovskiy, Sviatoslav; Koval, Oleksiy; Deguillaume, Frederic; Topak, Emre; Startchik, Sergei; Pun, Thierry

2006-01-01

In this paper we introduce and develop a framework for document interactive navigation in multimodal databases. First, we analyze the main open issues of existing multimodal interfaces and then discuss two applications that include interaction with documents in several human environments, i.e., the so-called smart rooms. Second, we propose a system set-up dedicated to the efficient navigation in the printed documents. This set-up is based on the fusion of data from several modalities that include images and text. Both modalities can be used as cover data for hidden indexes using data-hiding technologies as well as source data for robust visual hashing. The particularities of the proposed robust visual hashing are described in the paper. Finally, we address two practical applications of smart rooms for tourism and education and demonstrate the advantages of the proposed solution.

A Fast Optimization Method for General Binary Code Learning.

PubMed

Shen, Fumin; Zhou, Xiang; Yang, Yang; Song, Jingkuan; Shen, Heng; Tao, Dacheng

2016-09-22

Hashing or binary code learning has been recognized to accomplish efficient near neighbor search, and has thus attracted broad interests in recent retrieval, vision and learning studies. One main challenge of learning to hash arises from the involvement of discrete variables in binary code optimization. While the widely-used continuous relaxation may achieve high learning efficiency, the pursued codes are typically less effective due to accumulated quantization error. In this work, we propose a novel binary code optimization method, dubbed Discrete Proximal Linearized Minimization (DPLM), which directly handles the discrete constraints during the learning process. Specifically, the discrete (thus nonsmooth nonconvex) problem is reformulated as minimizing the sum of a smooth loss term with a nonsmooth indicator function. The obtained problem is then efficiently solved by an iterative procedure with each iteration admitting an analytical discrete solution, which is thus shown to converge very fast. In addition, the proposed method supports a large family of empirical loss functions, which is particularly instantiated in this work by both a supervised and an unsupervised hashing losses, together with the bits uncorrelation and balance constraints. In particular, the proposed DPLM with a supervised `2 loss encodes the whole NUS-WIDE database into 64-bit binary codes within 10 seconds on a standard desktop computer. The proposed approach is extensively evaluated on several large-scale datasets and the generated binary codes are shown to achieve very promising results on both retrieval and classification tasks.

Fault parameter constraints using relocated earthquakes: A validation of first-motion focal-mechanism data

USGS Publications Warehouse

Kilb, Debi; Hardebeck, J.L.

2006-01-01

We estimate the strike and dip of three California fault segments (Calaveras, Sargent, and a portion of the San Andreas near San Jaun Bautistia) based on principle component analysis of accurately located microearthquakes. We compare these fault orientations with two different first-motion focal mechanism catalogs: the Northern California Earthquake Data Center (NCEDC) catalog, calculated using the FPFIT algorithm (Reasenberg and Oppenheimer, 1985), and a catalog created using the HASH algorithm that tests mechanism stability relative to seismic velocity model variations and earthquake location (Hardebeck and Shearer, 2002). We assume any disagreement (misfit >30° in strike, dip, or rake) indicates inaccurate focal mechanisms in the catalogs. With this assumption, we can quantify the parameters that identify the most optimally constrained focal mechanisms. For the NCEDC/FPFIT catalogs, we find that the best quantitative discriminator of quality focal mechanisms is the station distribution ratio (STDR) parameter, an indicator of how the stations are distributed about the focal sphere. Requiring STDR > 0.65 increases the acceptable mechanisms from 34%–37% to 63%–68%. This suggests stations should be uniformly distributed surrounding, rather than aligning, known fault traces. For the HASH catalogs, the fault plane uncertainty (FPU) parameter is the best discriminator, increasing the percent of acceptable mechanisms from 63%–78% to 81%–83% when FPU ≤ 35°. The overall higher percentage of acceptable mechanisms and the usefulness of the formal uncertainty in identifying quality mechanisms validate the HASH approach of testing for mechanism stability.

The role of sex hormone-binding globulin (SHBG), testosterone, and other sex steroids, on the development of type 2 diabetes in a cohort of community-dwelling middle-aged to elderly men.

PubMed

Gyawali, Prabin; Martin, Sean A; Heilbronn, Leonie K; Vincent, Andrew D; Taylor, Anne W; Adams, Robert J T; O'Loughlin, Peter D; Wittert, Gary A

2018-05-29

Contrasting findings exist regarding the association between circulating sex hormone-binding globulin (SHBG) and testosterone levels and type 2 diabetes (T2D) in men. We examined prospective associations of SHBG and sex steroids with incident T2D in a cohort of community-dwelling men. Participants were from a cohort study of community-dwelling (n = 2563), middle-aged to elderly men (35-80 years) from Adelaide, Australia (the Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) study). The current study included men who were followed for 5 years and with complete SHBG and sex steroid levels (total testosterone (TT), dihydrotestosterone (DHT) and oestradiol (E2)), but without T2D at baseline (n = 1597). T2D was identified by either self-report, fasting glucose (≥ 7.0 mmol/L), HbA1c (≥ 6.5%/48.0 mmol/mol), and/or prescriptions for diabetes medications. Logistic binomial regression was used to assess associations between SHBG, sex steroids and incident T2D, adjusting for confounders including age, smoking status, physical activity, adiposity, glucose, triglycerides, symptomatic depression, SHBG and sex steroid levels. During an average follow-up of 4.95 years, 14.5% (n = 232) of men developed new T2D. Multi-adjusted models revealed an inverse association between baseline SHBG, TT, and DHT levels, and incident T2D (odds ratio (OR) = 0.77, 95% CI [0.62, 0.95], p = 0.02; OR 0.70 [0.57, 0.85], p < 0.001 and OR 0.78 [0.63, 0.96], p = 0.02), respectively. However, SHBG was no longer associated with incident T2D after additional adjustment for TT (OR 0.92 [0.71, 1.17], p = 0.48; TT in incident T2D: OR 0.73 [0.57, 0.92], p = 0.01) and after separate adjustment for DHT (OR 0.83 [0.64, 1.08], p = 0.16; DHT in incident T2D: OR 0.83 [0.65, 1.05], p = 0.13). There was no observed effect of E2 in all models of incident T2D. In men, low TT, but not SHBG and other sex steroids, best predicts the development of T2D after adjustment for confounders.

Activation of p300 histone acetyltransferase activity and acetylation of the androgen receptor by bombesin in prostate cancer cells.

PubMed

Gong, J; Zhu, J; Goodman, O B; Pestell, R G; Schlegel, P N; Nanus, D M; Shen, R

2006-03-30

Androgen receptor signaling in prostate cancer cells is augmented by the androgen receptor (AR) coactivator p300, which transactivates and acetylates the AR in the presence of dihydrotestosterone (DHT). As prostate cancer (PC) cells progress to androgen independence, AR signaling remains intact, indicating that other factors stimulate AR activities in the absence of androgen. We previously reported that neuropeptide growth factors could transactivate the AR in the presence of very low concentrations of DHT. Here, we examine the involvement of p300 in neuropeptide activation of AR signaling. Transfection of increasing concentrations of p300 in the presence of bombesin into PC-3 cells resulted in a linear increase in AR transactivation, suggesting that p300 acts as a coactivator in neuropeptide-mediated AR transactivation. P300 is endowed with histone acetyltransferase (HAT) activity. Therefore, we examine the effect of bombesin on p300 HAT activity. At 4 h after the addition of bombesin, p300 HAT activity increased 2.0-fold (P<0.01). Incubation with neutral endopeptidase, which degrades bombesin, or bombesin receptor antagonists blocked bombesin-induced p300 HAT activity. To explore the potential signaling pathways involved in bombesin-induced p300 HAT activity, we examined Src and PKCdelta pathways that mediate bombesin signaling. Inhibitors of Src kinase activity or Src kinase siRNA blocked bombesin-induced p300 HAT activity, whereas PKCdelta inhibitors or PKCdelta siRNA significantly increased bombesin-induced p300 HAT activity suggesting that Src kinase and PKCdelta kinase are involved in the regulation of p300 HAT activity. As AR is acetylated in the presence of 100 nM DHT, we next examined whether bombesin-induced p300 HAT activity would result in enhanced AR acetylation. Bombesin-induced AR acetylation at the same motif KLKK observed in DHT-induced acetylation. Elimination of p300 using p300 siRNA reduced AR acetylation, demonstrating that AR acetylation was mediated by p300. AR acetylation results in AR transactivation and the expression of the AR-regulated gene prostate-specific antigen (PSA). Therefore, we examined bombesin-induced AR transactivation and PSA expression in the presence and absence of p300 siRNA and found inhibition of p300 expression reduced bombesin-induced AR transactivation and PSA expression. Together these results demonstrate that bombesin, via Src and PKCdelta signaling pathways, activates p300 HAT activity which leads to enhanced acetylation of AR resulting in increased expression of AR-regulated genes.

Optimizing the inner loop of the gravitational force interaction on modern processors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warren, Michael S

2010-12-08

We have achieved superior performance on multiple generations of the fastest supercomputers in the world with our hashed oct-tree N-body code (HOT), spanning almost two decades and garnering multiple Gordon Bell Prizes for significant achievement in parallel processing. Execution time for our N-body code is largely influenced by the force calculation in the inner loop. Improvements to the inner loop using SSE3 instructions has enabled the calculation of over 200 million gravitational interactions per second per processor on a 2.6 GHz Opteron, for a computational rate of over 7 Gflops in single precision (700/0 of peak). We obtain optimal performancemore » some processors (including the Cell) by decomposing the reciprocal square root function required for a gravitational interaction into a table lookup, Chebychev polynomial interpolation, and Newton-Raphson iteration, using the algorithm of Karp. By unrolling the loop by a factor of six, and using SPU intrinsics to compute on vectors, we obtain performance of over 16 Gflops on a single Cell SPE. Aggregated over the 8 SPEs on a Cell processor, the overall performance is roughly 130 Gflops. In comparison, the ordinary C version of our inner loop only obtains 1.6 Gflops per SPE with the spuxlc compiler.« less

NHash: Randomized N-Gram Hashing for Distributed Generation of Validatable Unique Study Identifiers in Multicenter Research

PubMed Central

Zhang, Guo-Qiang; Tao, Shiqiang; Xing, Guangming; Mozes, Jeno; Zonjy, Bilal; Lhatoo, Samden D

2015-01-01

Background A unique study identifier serves as a key for linking research data about a study subject without revealing protected health information in the identifier. While sufficient for single-site and limited-scale studies, the use of common unique study identifiers has several drawbacks for large multicenter studies, where thousands of research participants may be recruited from multiple sites. An important property of study identifiers is error tolerance (or validatable), in that inadvertent editing mistakes during their transmission and use will most likely result in invalid study identifiers. Objective This paper introduces a novel method called "Randomized N-gram Hashing (NHash)," for generating unique study identifiers in a distributed and validatable fashion, in multicenter research. NHash has a unique set of properties: (1) it is a pseudonym serving the purpose of linking research data about a study participant for research purposes; (2) it can be generated automatically in a completely distributed fashion with virtually no risk for identifier collision; (3) it incorporates a set of cryptographic hash functions based on N-grams, with a combination of additional encryption techniques such as a shift cipher; (d) it is validatable (error tolerant) in the sense that inadvertent edit errors will mostly result in invalid identifiers. Methods NHash consists of 2 phases. First, an intermediate string using randomized N-gram hashing is generated. This string consists of a collection of N-gram hashes f 1, f 2, ..., f k. The input for each function f i has 3 components: a random number r, an integer n, and input data m. The result, f i(r, n, m), is an n-gram of m with a starting position s, which is computed as (r mod |m|), where |m| represents the length of m. The output for Step 1 is the concatenation of the sequence f 1(r 1, n 1, m 1), f 2(r 2, n 2, m 2), ..., f k(r k, n k, m k). In the second phase, the intermediate string generated in Phase 1 is encrypted using techniques such as shift cipher. The result of the encryption, concatenated with the random number r, is the final NHash study identifier. Results We performed experiments using a large synthesized dataset comparing NHash with random strings, and demonstrated neglegible probability for collision. We implemented NHash for the Center for SUDEP Research (CSR), a National Institute for Neurological Disorders and Stroke-funded Center Without Walls for Collaborative Research in the Epilepsies. This multicenter collaboration involves 14 institutions across the United States and Europe, bringing together extensive and diverse expertise to understand sudden unexpected death in epilepsy patients (SUDEP). Conclusions The CSR Data Repository has successfully used NHash to link deidentified multimodal clinical data collected in participating CSR institutions, meeting all desired objectives of NHash. PMID:26554419

DEVELOPMENT OF TWO ANDROGEN RECEPTOR ASSAYS USING ADENOVIRAL TRANSDUCTION OF MMTV-LUC REPORTER AND/OR HAR FOR ENDOCRINE SCREENING

EPA Science Inventory

Abstract
The discovery of xenobiotics which interfere with androgen activity has highlighted the need to assess chemicals for their ability to modulate dihydrotestosterone (DHT)-receptor binding. Previous test systems have used cells transfected with plasmid containing a rep...

Asymmetric distances for binary embeddings.

PubMed

Gordo, Albert; Perronnin, Florent; Gong, Yunchao; Lazebnik, Svetlana

2014-01-01

In large-scale query-by-example retrieval, embedding image signatures in a binary space offers two benefits: data compression and search efficiency. While most embedding algorithms binarize both query and database signatures, it has been noted that this is not strictly a requirement. Indeed, asymmetric schemes that binarize the database signatures but not the query still enjoy the same two benefits but may provide superior accuracy. In this work, we propose two general asymmetric distances that are applicable to a wide variety of embedding techniques including locality sensitive hashing (LSH), locality sensitive binary codes (LSBC), spectral hashing (SH), PCA embedding (PCAE), PCAE with random rotations (PCAE-RR), and PCAE with iterative quantization (PCAE-ITQ). We experiment on four public benchmarks containing up to 1M images and show that the proposed asymmetric distances consistently lead to large improvements over the symmetric Hamming distance for all binary embedding techniques.

Paradeisos: A perfect hashing algorithm for many-body eigenvalue problems

NASA Astrophysics Data System (ADS)

Jia, C. J.; Wang, Y.; Mendl, C. B.; Moritz, B.; Devereaux, T. P.

2018-03-01

We describe an essentially perfect hashing algorithm for calculating the position of an element in an ordered list, appropriate for the construction and manipulation of many-body Hamiltonian, sparse matrices. Each element of the list corresponds to an integer value whose binary representation reflects the occupation of single-particle basis states for each element in the many-body Hilbert space. The algorithm replaces conventional methods, such as binary search, for locating the elements of the ordered list, eliminating the need to store the integer representation for each element, without increasing the computational complexity. Combined with the "checkerboard" decomposition of the Hamiltonian matrix for distribution over parallel computing environments, this leads to a substantial savings in aggregate memory. While the algorithm can be applied broadly to many-body, correlated problems, we demonstrate its utility in reducing total memory consumption for a series of fermionic single-band Hubbard model calculations on small clusters with progressively larger Hilbert space dimension.

Handwriting: Feature Correlation Analysis for Biometric Hashes

NASA Astrophysics Data System (ADS)

Vielhauer, Claus; Steinmetz, Ralf

2004-12-01

In the application domain of electronic commerce, biometric authentication can provide one possible solution for the key management problem. Besides server-based approaches, methods of deriving digital keys directly from biometric measures appear to be advantageous. In this paper, we analyze one of our recently published specific algorithms of this category based on behavioral biometrics of handwriting, the biometric hash. Our interest is to investigate to which degree each of the underlying feature parameters contributes to the overall intrapersonal stability and interpersonal value space. We will briefly discuss related work in feature evaluation and introduce a new methodology based on three components: the intrapersonal scatter (deviation), the interpersonal entropy, and the correlation between both measures. Evaluation of the technique is presented based on two data sets of different size. The method presented will allow determination of effects of parameterization of the biometric system, estimation of value space boundaries, and comparison with other feature selection approaches.

Genomics-Based Security Protocols: From Plaintext to Cipherprotein

NASA Technical Reports Server (NTRS)

Shaw, Harry; Hussein, Sayed; Helgert, Hermann

2011-01-01

The evolving nature of the internet will require continual advances in authentication and confidentiality protocols. Nature provides some clues as to how this can be accomplished in a distributed manner through molecular biology. Cryptography and molecular biology share certain aspects and operations that allow for a set of unified principles to be applied to problems in either venue. A concept for developing security protocols that can be instantiated at the genomics level is presented. A DNA (Deoxyribonucleic acid) inspired hash code system is presented that utilizes concepts from molecular biology. It is a keyed-Hash Message Authentication Code (HMAC) capable of being used in secure mobile Ad hoc networks. It is targeted for applications without an available public key infrastructure. Mechanics of creating the HMAC are presented as well as a prototype HMAC protocol architecture. Security concepts related to the implementation differences between electronic domain security and genomics domain security are discussed.

A one-time pad color image cryptosystem based on SHA-3 and multiple chaotic systems

NASA Astrophysics Data System (ADS)

Wang, Xingyuan; Wang, Siwei; Zhang, Yingqian; Luo, Chao

2018-04-01

A novel image encryption algorithm is proposed that combines the SHA-3 hash function and two chaotic systems: the hyper-chaotic Lorenz and Chen systems. First, 384 bit keystream hash values are obtained by applying SHA-3 to plaintext. The sensitivity of the SHA-3 algorithm and chaotic systems ensures the effect of a one-time pad. Second, the color image is expanded into three-dimensional space. During permutation, it undergoes plane-plane displacements in the x, y and z dimensions. During diffusion, we use the adjacent pixel dataset and corresponding chaotic value to encrypt each pixel. Finally, the structure of alternating between permutation and diffusion is applied to enhance the level of security. Furthermore, we design techniques to improve the algorithm's encryption speed. Our experimental simulations show that the proposed cryptosystem achieves excellent encryption performance and can resist brute-force, statistical, and chosen-plaintext attacks.

A hybrid cloud read aligner based on MinHash and kmer voting that preserves privacy

NASA Astrophysics Data System (ADS)

Popic, Victoria; Batzoglou, Serafim

2017-05-01

Low-cost clouds can alleviate the compute and storage burden of the genome sequencing data explosion. However, moving personal genome data analysis to the cloud can raise serious privacy concerns. Here, we devise a method named Balaur, a privacy preserving read mapper for hybrid clouds based on locality sensitive hashing and kmer voting. Balaur can securely outsource a substantial fraction of the computation to the public cloud, while being highly competitive in accuracy and speed with non-private state-of-the-art read aligners on short read data. We also show that the method is significantly faster than the state of the art in long read mapping. Therefore, Balaur can enable institutions handling massive genomic data sets to shift part of their analysis to the cloud without sacrificing accuracy or exposing sensitive information to an untrusted third party.

A hybrid cloud read aligner based on MinHash and kmer voting that preserves privacy

PubMed Central

Popic, Victoria; Batzoglou, Serafim

2017-01-01

Low-cost clouds can alleviate the compute and storage burden of the genome sequencing data explosion. However, moving personal genome data analysis to the cloud can raise serious privacy concerns. Here, we devise a method named Balaur, a privacy preserving read mapper for hybrid clouds based on locality sensitive hashing and kmer voting. Balaur can securely outsource a substantial fraction of the computation to the public cloud, while being highly competitive in accuracy and speed with non-private state-of-the-art read aligners on short read data. We also show that the method is significantly faster than the state of the art in long read mapping. Therefore, Balaur can enable institutions handling massive genomic data sets to shift part of their analysis to the cloud without sacrificing accuracy or exposing sensitive information to an untrusted third party. PMID:28508884

A dynamic re-partitioning strategy based on the distribution of key in Spark

NASA Astrophysics Data System (ADS)

Zhang, Tianyu; Lian, Xin

2018-05-01

Spark is a memory-based distributed data processing framework, has the ability of processing massive data and becomes a focus in Big Data. But the performance of Spark Shuffle depends on the distribution of data. The naive Hash partition function of Spark can not guarantee load balancing when data is skewed. The time of job is affected by the node which has more data to process. In order to handle this problem, dynamic sampling is used. In the process of task execution, histogram is used to count the key frequency distribution of each node, and then generate the global key frequency distribution. After analyzing the distribution of key, load balance of data partition is achieved. Results show that the Dynamic Re-Partitioning function is better than the default Hash partition, Fine Partition and the Balanced-Schedule strategy, it can reduce the execution time of the task and improve the efficiency of the whole cluster.

Quantum key management

DOEpatents

Hughes, Richard John; Thrasher, James Thomas; Nordholt, Jane Elizabeth

2016-11-29

Innovations for quantum key management harness quantum communications to form a cryptography system within a public key infrastructure framework. In example implementations, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a Merkle signature scheme (using Winternitz one-time digital signatures or other one-time digital signatures, and Merkle hash trees) to constitute a cryptography system. More generally, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a hash-based signature scheme. This provides a secure way to identify, authenticate, verify, and exchange secret cryptographic keys. Features of the quantum key management innovations further include secure enrollment of users with a registration authority, as well as credential checking and revocation with a certificate authority, where the registration authority and/or certificate authority can be part of the same system as a trusted authority for quantum key distribution.

An evaluation of multi-probe locality sensitive hashing for computing similarities over web-scale query logs

PubMed Central

2018-01-01

Many modern applications of AI such as web search, mobile browsing, image processing, and natural language processing rely on finding similar items from a large database of complex objects. Due to the very large scale of data involved (e.g., users’ queries from commercial search engines), computing such near or nearest neighbors is a non-trivial task, as the computational cost grows significantly with the number of items. To address this challenge, we adopt Locality Sensitive Hashing (a.k.a, LSH) methods and evaluate four variants in a distributed computing environment (specifically, Hadoop). We identify several optimizations which improve performance, suitable for deployment in very large scale settings. The experimental results demonstrate our variants of LSH achieve the robust performance with better recall compared with “vanilla” LSH, even when using the same amount of space. PMID:29346410

ARC-2007-ACD07-0184-003

NASA Image and Video Library

2007-09-26

From left: Data Parallel Line Relaxation (DPLR) software team members Kerry Trumble, Deepak Bose and David Hash analyze and predict the extreme environments NASA's space shuttle experiences during its super high-speed reentry into Earth’s atmosphere.

Effects of sex steroids on indices of protein turnover in rainbow trout (Oncorhynchus mykiss) white muscle

USDA-ARS?s Scientific Manuscript database

Effects of 17-estradiol (E2), testosterone, and 5a-dihydrotestosterone (DHT) on protein turnover and proteolytic gene expression were determined in rainbow trout (Oncorhynchus mykiss) primary myocytes and white muscle tissue. E2 reduced rates of protein synthesis and increased rates of protein degr...

Effects of sex steroids on expression of genes regulating growth-related mechanisms in rainbow trout (Oncorhynchus mykiss)

USDA-ARS?s Scientific Manuscript database

Effects of a single injection of 17-estradiol (E2), testosterone (T), or 5a-dihydrotestosterone (DHT) on expression of genes central to the growth hormone (GH)/insulin-like growth factor (IGF) axis, muscle-regulatory factors, TGF-beta superfamily signaling cascade, and estrogen receptors were determ...

A FEEDBACK MODEL FOR TESTICULAR-PITUITARY AXIS HORMONE KINETICS AND THEIR EFFECTS ON THE REGULATION OF THE PROSTATE IN ADULT MALE RATS

EPA Science Inventory

The testicular-hypothalamic-pituitary axis regulates male reproductive system functions. A model describing the kinetics and dynamics of testosterone (T), dihydrotestosterone (DHT) and luteinizing hormone (LH) was developed based on a model by Barton and Anderson (1997). The mode...

Androgen and AR contribute to breast cancer development and metastasis: an insight of mechanisms.

PubMed

Feng, J; Li, L; Zhang, N; Liu, J; Zhang, L; Gao, H; Wang, G; Li, Y; Zhang, Y; Li, X; Liu, D; Lu, J; Huang, B

2017-05-18

The role of androgen and androgen receptor (AR) in breast carcinogenesis has long been a disputed issue. This report provides a mechanistic insight into how androgen and AR contributes to invasion and metastasis of breast cancer. We find that dihydrotestosterone (DHT) is able to induce the epithelial-to-mesenchymal transition in breast cancer cells in an AR-dependent/estrogen receptor-independent manner. This process is dependent on the demethylation activity of lysine-specific demethylase 1A (LSD1) by epigenetically regulating the target genes E-cadherin and vimentin. In vivo, DHT promotes metastasis in a nude mouse model, and AR and LSD1 are indispensable in this process. We establish that higher expression of nucleus AR to cytoplasm AR associated with worse prognostic outcomes in breast cancer patient samples. This study maps an 'androgen-AR/LSD1-target genes' pathway in breast carcinogenesis, implicating the importance of hormonal balance in women, and the potential clinical significance of serum androgen and AR in prediction of breast cancer and selection of breast cancer therapy.

Androgen Receptor-Mediated Growth Suppression of HPr-1AR and PC3-Lenti-AR Prostate Epithelial Cells

PubMed Central

Bolton, Eric C.

2015-01-01

The androgen receptor (AR) mediates the developmental, physiologic, and pathologic effects of androgens including 5α-dihydrotestosterone (DHT). However, the mechanisms whereby AR regulates growth suppression and differentiation of luminal epithelial cells in the prostate gland and proliferation of malignant versions of these cells are not well understood, though they are central to prostate development, homeostasis, and neoplasia. Here, we identify androgen-responsive genes that restrain cell cycle progression and proliferation of human prostate epithelial cell lines (HPr-1AR and PC3-Lenti-AR), and we investigate the mechanisms through which AR regulates their expression. DHT inhibited proliferation of HPr-1AR and PC3-Lenti-AR, and cell cycle analysis revealed a prolonged G1 interval. In the cell cycle, the G1/S-phase transition is initiated by the activity of cyclin D and cyclin-dependent kinase (CDK) complexes, which relieve growth suppression. In HPr-1AR, cyclin D1/2 and CDK4/6 mRNAs were androgen-repressed, whereas CDK inhibitor, CDKN1A, mRNA was androgen-induced. The regulation of these transcripts was AR-dependent, and involved multiple mechanisms. Similar AR-mediated down-regulation of CDK4/6 mRNAs and up-regulation of CDKN1A mRNA occurred in PC3-Lenti-AR. Further, CDK4/6 overexpression suppressed DHT-inhibited cell cycle progression and proliferation of HPr-1AR and PC3-Lenti-AR, whereas CDKN1A overexpression induced cell cycle arrest. We therefore propose that AR-mediated growth suppression of HPr-1AR involves cyclin D1 mRNA decay, transcriptional repression of cyclin D2 and CDK4/6, and transcriptional activation of CDKN1A, which serve to decrease CDK4/6 activity. AR-mediated inhibition of PC3-Lenti-AR proliferation occurs through a similar mechanism, albeit without down-regulation of cyclin D. Our findings provide insight into AR-mediated regulation of prostate epithelial cell proliferation. PMID:26372468

Estrogen-Induced Maldevelopment of the Penis Involves Down-Regulation of Myosin Heavy Chain 11 (MYH11) Expression, a Biomarker for Smooth Muscle Cell Differentiation1

PubMed Central

Okumu, L.A.; Bruinton, Sequoia; Braden, Tim D.; Simon, Liz; Goyal, Hari O.

2012-01-01

ABSTRACT Cavernous smooth muscle cells are essential components in penile erection. In this study, we investigated effects of estrogen exposure on biomarkers for smooth muscle cell differentiation in the penis. Neonatal rats received diethylstilbestrol (DES), with or without the estrogen receptor (ESR) antagonist ICI 182,780 (ICI) or the androgen receptor (AR) agonist dihydrotestosterone (DHT), from Postnatal Days 1 to 6. Tissues were collected at 7, 10, or 21 days of age. The smooth muscle cell biomarker MYH11 was studied in depth because microarray data showed it was significantly down-regulated, along with other biomarkers, in DES treatment. Quantitative real time-PCR and Western blot analyses showed 50%–80% reduction (P ≤ 0.05) in Myh11 expression in DES-treated rats compared to that in controls; and ICI and DHT coadministration mitigated the decrease. Temporally, from 7 to 21 days of age, Myh11 expression was onefold increased (P ≥ 0.05) in DES-treated rats versus threefold increased (P ≤ 0.001) in controls, implying the long-lasting inhibitory effect of DES on smooth muscle cell differentiation. Immunohistochemical localization of smooth muscle alpha actin, another biomarker for smooth muscle cell differentiation, showed fewer cavernous smooth muscle cells in DES-treated animals than in controls. Additionally, DES treatment significantly up-regulated Esr1 mRNA expression and suppressed the neonatal testosterone surge by 90%, which was mitigated by ICI coadministration but not by DHT coadministration. Collectively, results provided evidence that DES treatment in neonatal rats inhibited cavernous smooth muscle cell differentiation, as shown by down-regulation of MYH11 expression at the mRNA and protein levels and by reduced immunohistochemical staining of smooth muscle alpha actin. Both the ESR and the AR pathways probably mediate this effect. PMID:22976277

Neonatal and Pubertal Development in Males of a Cooperatively Breeding Primate, the Cotton-Top Tamarin (Saguinus oedipus oedipus)1

PubMed Central

Ginther, Anita J.; Carlson, Anne A.; Ziegler, Toni E.; Snowdon, Charles T.

2006-01-01

In cooperatively breeding groups of mammals, reproduction is usually restricted to a small number of individuals within the social group. Sexual development of mammals can be affected by social environment, but we know little regarding effects of the cooperative-breeding system on males. Cotton-top tamarin (Saguinus oedipus oedipus) offspring typically do not reproduce in their natal group, even though they may be physically mature. We examined neonatal and pubertal development in captive male cotton-top tamarins as an example of reproductive development within a cooperative-breeding system and to compare cotton-top tamarins with the general primate model. Puberty was characterized using both hormonal and physical measures. Data were collected on urinary levels of LH, testosterone (T), dihydrotestosterone (DHT), cortisol, and the ratio of DHT to T; testicular development; body weight; and breeding age. We determined that 1) pubertal LH secretion began at Week 37, 2) a surge of T secretion followed at Weeks 41–44, and 3) an increase in the metabolism of T to DHT may have occurred at an average age of 48.6 wk. Most of the rapid weight gain was completed by Week 24, before hormonal increases and rapid scrotal growth. We concluded that rapid pubertal testicular growth in captive cotton-top males was completed by an average 76 wk, but that completion of the individual pubertal spurt can occur between 56 and 122 wk. In a cooperative-breeding system, the opportunity for successful reproduction is dictated by the social environment, but we found no evidence that male offspring were developmentally suppressed in their natal social groups. Our findings suggest that puberty in male New World callitrichid primates occurs more quickly than puberty in Old World primates, even though both have similar patterns of development. PMID:11804940

Serum sex steroids and steroidogenesis-related enzyme expression in skeletal muscle during experimental weight gain in men.

PubMed

Sato, K; Samocha-Bonet, D; Handelsman, D J; Fujita, S; Wittert, G A; Heilbronn, L K

2014-12-01

Low-circulating testosterone is associated with development of type 2 diabetes in obese men. In this study, we examined the effects of experimental overfeeding and weight gain on serum levels of sex hormones and skeletal muscle expression of steroidogenic enzymes in healthy men with (FH+) and without (FH-) a family history of type 2 diabetes. Following a 3-day lead in energy balanced diet, FH+ (n = 9) and FH- men (n = 11) were overfed by 5200 kJ/day (45% fat) for 28 days. Body weight, fasting glucose, insulin, sex steroid, sex hormone binding globulin (SHBG) levels, insulin sensitivity (hyperinsulinaemic-euglycaemic clamp) and body fat (DXA) were assessed in all individuals at baseline and day 28, and sex steroidogenesis-related enzyme expression in vastus lateralis biopsies was examined in a subset (n = 11). Body weight, fat mass and fasting insulin levels were increased by overfeeding (P < 0.01) and insulin was increased significantly more in FH+ men (P<0.01). Serum sex hormone binding globulin (SHBG) and 5α-dihydrotestosterone (DHT) were reduced with overfeeding (P < 0.05), and serum testosterone and DHT were reduced to a greater extent in FH+ men (P < 0.05). Overfeeding reduced mRNA expression of 3β-hydroxysteroid dehydrogenase (HSD) and 17βHSD (P ≤ 0.007), independently of group. 5α-Reductase (SRD5A1) mRNA expression was not changed overall, but a time by group interaction was observed (P = 0.04). Overfeeding reduced SHBG and muscle expression of enzymes involved in the formation of testosterone in skeletal muscle. Men with a family history of T2DM were more susceptible to deleterious outcomes of overfeeding with greater reductions in serum testosterone and DHT and greater increases in markers of insulin resistance, which may contribute to increased risk of developing type 2 diabetes. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Artificial masculinization in tilapia involves androgen receptor activation.

PubMed

Golan, Matan; Levavi-Sivan, Berta

2014-10-01

Estrogens have a pivotal role in natural female sexual differentiation of tilapia while lack of steroids results in testicular development. Despite the fact that androgens do not participate in natural sex differentiation, synthetic androgens, mainly 17-α-methyltestosterone (MT) are effective in the production of all-male fish in aquaculture. The sex inversion potency of synthetic androgens may arise from their androgenic activity or else as inhibitors of aromatase activity. The current study is an attempt to differentiate between the two alleged activities in order to evaluate their contribution to the sex inversion process and aid the search for novel sex inversion agents. In the present study, MT inhibited aromatase activity, when applied in vitro as did the non-aromatizable androgen dihydrotestosterone (DHT). In comparison, exposure to fadrozole, a specific aromatase inhibitor, was considerably more effective. Androgenic activity of MT was evaluated by exposure of Sciaenochromis fryeri fry to the substance and testing for the appearance of blue color. Flutamide, an androgen antagonist, administered concomitantly with MT, reduced the appearance of the blue color and the sex inversion potency of MT in a dose-dependent manner. In tilapia, administration of MT, fadrozole or DHT resulted in efficient sex inversion while flutamide reduced the sex inversion potency of all three compounds. In the case of MT and DHT the decrease in sex inversion efficiency caused by flutamide is most likely due to the direct blocking of the androgen binding to its cognate receptor. The negative effect of flutamide on the efficiency of the fadrozole treatment may indicate that the masculinizing activity of fadrozole may be attributed to excess, un-aromatized, androgens accumulated in the differentiating gonad. The present study shows that when androgen receptors are blocked, there is a reduction in the efficiency of sex inversion treatments. Our results suggest that in contrast to natural sex differentiation, during sex inversion treatments, androgens, either endogenous or exogenous, participate in inducing testicular differentiation. Copyright © 2014 Elsevier Inc. All rights reserved.

The longitudinal relationship of sexual function and androgen status in older men: the Concord Health and Ageing in Men Project.

PubMed

Hsu, Benjumin; Cumming, Robert G; Blyth, Fiona M; Naganathan, Vasi; Le Couteur, David G; Seibel, Markus J; Waite, Louise M; Handelsman, David J

2015-04-01

It is unclear whether declining sexual function in older men is a cause or consequence of reduced androgen status. Longitudinal associations were examined between reproductive hormones and sexual function in older men. Men aged 70 years and older from the Concord Health and Ageing in Men Project study were assessed at baseline (n = 1705) and 2-year follow-up (n = 1367), with a total of 1226 men included in the final analyses. At both visits, serum testosterone (T), dihydrotestosterone (DHT), estradiol (E2), and estrone (E1) were measured by liquid chromatography-tandem mass spectrometry, and SHBG, LH, and FSH were measured by immunoassay. Sexual functions (erectile function, sexual activity, and sexual desire) were self-reported via standardized questions. In longitudinal analyses, although baseline hormones (T, DHT, E2, and E1) did not predict decline in sexual function, the decline in serum T (but not DHT, E2, or E1) over 2 years was strongly related to the change in sexual activity and desire (but not erectile function). For each 1-SD decrease in T from baseline to 2-year follow-up, there was a multivariate-adjusted odds ratio of 1.23 (95% confidence interval, 1.12-1.36) for an additional risk of further decline in sexual activity. However, the magnitude of the decrease in serum T was strikingly small (<10%). Similar associations were found for changes over 2 years in serum T and decline in sexual desire, but not for erectile function. We found a consistent association among older men followed over 2 years between the decline in sexual activity and desire, but not in erectile function, with a decrease in serum T. Although these observational findings cannot determine causality, the small magnitude of the decrease in serum T raises the hypothesis that reduced sexual function may reduce serum T rather than the reverse.

ERG/AKR1C3/AR Constitutes a Feed-Forward Loop for AR Signaling in Prostate Cancer Cells.

PubMed

Powell, Katelyn; Semaan, Louie; Conley-LaComb, M Katie; Asangani, Irfan; Wu, Yi-Mi; Ginsburg, Kevin B; Williams, Julia; Squire, Jeremy A; Maddipati, Krishna R; Cher, Michael L; Chinni, Sreenivasa R

2015-06-01

Intratumoral androgen synthesis in prostate cancer contributes to the development of castration-resistant prostate cancer (CRPC). Several enzymes responsible for androgen biosynthesis have been shown to be overexpressed in CRPC, thus contributing to CRPC in a castrated environment. The TMPRSS2-ERG transcription factor has been shown to be present in primary prostate cancer tumors as well as CRPC tumors. We hypothesize that TMPRSS2-ERG fusions regulate androgen biosynthetic enzyme (ABE) gene expression and the production of androgens, which contributes to the development of CRPC. We used a panel of assays, including lentivirus transduction, gene expression, chromatin immunoprecipitation and sequencing, liquid chromatography-mass spectrometric quantitation, immunocytochemistry, immunohistochemistry, and bioinformatics analysis of gene microarray databases, to determine ERG regulation of androgen synthesis. We found that ERG regulated the expression of the ABE AKR1C3 in prostate cancer cells via direct binding to the AKR1C3 gene. Knockdown of ERG resulted in reduced AKR1C3 expression, which caused a reduction in both DHT synthesis and PSA expression in VCaP prostate cancer cells treated with 5α-androstanedione (5α-Adione), a DHT precursor metabolite. Immunohistochemical staining revealed that ERG was coexpressed with AKR1C3 in prostate cancer tissue samples. These data suggest that AKR1C3 catalyzes the biochemical reduction of 5α-Adione to DHT in prostate cancer cells, and that ERG regulates this step through upregulation of AKR1C3 expression. Elucidation of ERG regulation of ABEs in CRPC may help to stratify TMPRSS2-ERG fusion-positive prostate cancer patients in the clinic for anti-androgen receptor-driven therapies; and AKR1C3 may serve as a valuable therapeutic target in the treatment of CRPC. ©2015 American Association for Cancer Research.

Fattening ability and carcass value of Dhamari and Tehami ram lambs, F₁ crossbreds of Dhamari × Tehami in Yemen.

PubMed

Al Khewani, Talal; Momani Shaker, Mohamed; Al-Olofi, Samer

2014-12-01

A fattening experiment was carried out to analyze and evaluate the effect of ram lamb genotype on the growth, feed conversion (FC), and carcass value of Dhamari ram lambs, F1 crossbreds of Dhamari × Tehami (F1 DhT), and Tehami ram lambs. Genotype of the ram lambs including the experiment (n = 30) had high significant effect on total weight gain (TWG), average daily gain (ADG), and FC (P < 0.01-0.001). Genotype of the lamb had significant effect on hot and cold dressing percentage (P < 0.001). Also, genotype of the lamb had significant effect on the highest leg percentage (P < 0.001). Furthermore, genotype of the ram lambs had significant effect on musculus longissimus dorsi (MLD) area (P < 0.001). Genotype of the ram lamb had significant effect on TWG, ADG, and FC (P < 0.001). The results of moisture percentage, crude protein percentage, and ash percentage of muscle samples were significantly influenced by ram lamb's genotype (P < 0.001). Fasting live weight and other carcass measurements (hot carcass weight, leg weight, loin weight, shoulder weight, first quality cuts weight) have a positive and highest correlations (P < 0.001). The positive and the highest correlations were found between fasting live weight and hot carcass weight, first quality parts weight. In addition, the positive and the highest correlations were found between hot carcass weight and first quality cuts weight. In general, the results of this study documented that F1 DhT was better than Tehami ram lambs in ADG, TWG, and FC. Additionally, the results show that the feed conversion was in F1 DhT crossbreds ram lambs better than pure Dhamari and Tehami ram lambs, mainly in the carcass indicators.

Running Clubs--A Combinatorial Investigation.

ERIC Educational Resources Information Center

Nissen, Phillip; Taylor, John

1991-01-01

Presented is a combinatorial problem based on the Hash House Harriers rule which states that the route of the run should not have previously been traversed by the club. Discovered is how many weeks the club can meet before the rule has to be broken. (KR)

InChIKey collision resistance: an experimental testing

PubMed Central

2012-01-01

InChIKey is a 27-character compacted (hashed) version of InChI which is intended for Internet and database searching/indexing and is based on an SHA-256 hash of the InChI character string. The first block of InChIKey encodes molecular skeleton while the second block represents various kinds of isomerism (stereo, tautomeric, etc.). InChIKey is designed to be a nearly unique substitute for the parent InChI. However, a single InChIKey may occasionally map to two or more InChI strings (collision). The appearance of collision itself does not compromise the signature as collision-free hashing is impossible; the only viable approach is to set and keep a reasonable level of collision resistance which is sufficient for typical applications. We tested, in computational experiments, how well the real-life InChIKey collision resistance corresponds to the theoretical estimates expected by design. For this purpose, we analyzed the statistical characteristics of InChIKey for datasets of variable size in comparison to the theoretical statistical frequencies. For the relatively short second block, an exhaustive direct testing was performed. We computed and compared to theory the numbers of collisions for the stereoisomers of Spongistatin I (using the whole set of 67,108,864 isomers and its subsets). For the longer first block, we generated, using custom-made software, InChIKeys for more than 3 × 1010 chemical structures. The statistical behavior of this block was tested by comparison of experimental and theoretical frequencies for the various four-letter sequences which may appear in the first block body. From the results of our computational experiments we conclude that the observed characteristics of InChIKey collision resistance are in good agreement with theoretical expectations. PMID:23256896

InChIKey collision resistance: an experimental testing.

PubMed

Pletnev, Igor; Erin, Andrey; McNaught, Alan; Blinov, Kirill; Tchekhovskoi, Dmitrii; Heller, Steve

2012-12-20

InChIKey is a 27-character compacted (hashed) version of InChI which is intended for Internet and database searching/indexing and is based on an SHA-256 hash of the InChI character string. The first block of InChIKey encodes molecular skeleton while the second block represents various kinds of isomerism (stereo, tautomeric, etc.). InChIKey is designed to be a nearly unique substitute for the parent InChI. However, a single InChIKey may occasionally map to two or more InChI strings (collision). The appearance of collision itself does not compromise the signature as collision-free hashing is impossible; the only viable approach is to set and keep a reasonable level of collision resistance which is sufficient for typical applications.We tested, in computational experiments, how well the real-life InChIKey collision resistance corresponds to the theoretical estimates expected by design. For this purpose, we analyzed the statistical characteristics of InChIKey for datasets of variable size in comparison to the theoretical statistical frequencies. For the relatively short second block, an exhaustive direct testing was performed. We computed and compared to theory the numbers of collisions for the stereoisomers of Spongistatin I (using the whole set of 67,108,864 isomers and its subsets). For the longer first block, we generated, using custom-made software, InChIKeys for more than 3 × 1010 chemical structures. The statistical behavior of this block was tested by comparison of experimental and theoretical frequencies for the various four-letter sequences which may appear in the first block body.From the results of our computational experiments we conclude that the observed characteristics of InChIKey collision resistance are in good agreement with theoretical expectations.

Privacy-Preserving Patient Similarity Learning in a Federated Environment: Development and Analysis.

PubMed

Lee, Junghye; Sun, Jimeng; Wang, Fei; Wang, Shuang; Jun, Chi-Hyuck; Jiang, Xiaoqian

2018-04-13

There is an urgent need for the development of global analytic frameworks that can perform analyses in a privacy-preserving federated environment across multiple institutions without privacy leakage. A few studies on the topic of federated medical analysis have been conducted recently with the focus on several algorithms. However, none of them have solved similar patient matching, which is useful for applications such as cohort construction for cross-institution observational studies, disease surveillance, and clinical trials recruitment. The aim of this study was to present a privacy-preserving platform in a federated setting for patient similarity learning across institutions. Without sharing patient-level information, our model can find similar patients from one hospital to another. We proposed a federated patient hashing framework and developed a novel algorithm to learn context-specific hash codes to represent patients across institutions. The similarities between patients can be efficiently computed using the resulting hash codes of corresponding patients. To avoid security attack from reverse engineering on the model, we applied homomorphic encryption to patient similarity search in a federated setting. We used sequential medical events extracted from the Multiparameter Intelligent Monitoring in Intensive Care-III database to evaluate the proposed algorithm in predicting the incidence of five diseases independently. Our algorithm achieved averaged area under the curves of 0.9154 and 0.8012 with balanced and imbalanced data, respectively, in κ-nearest neighbor with κ=3. We also confirmed privacy preservation in similarity search by using homomorphic encryption. The proposed algorithm can help search similar patients across institutions effectively to support federated data analysis in a privacy-preserving manner. ©Junghye Lee, Jimeng Sun, Fei Wang, Shuang Wang, Chi-Hyuck Jun, Xiaoqian Jiang. Originally published in JMIR Medical Informatics (http://medinform.jmir.org), 13.04.2018.

UQlust: combining profile hashing with linear-time ranking for efficient clustering and analysis of big macromolecular data.

PubMed

Adamczak, Rafal; Meller, Jarek

2016-12-28

Advances in computing have enabled current protein and RNA structure prediction and molecular simulation methods to dramatically increase their sampling of conformational spaces. The quickly growing number of experimentally resolved structures, and databases such as the Protein Data Bank, also implies large scale structural similarity analyses to retrieve and classify macromolecular data. Consequently, the computational cost of structure comparison and clustering for large sets of macromolecular structures has become a bottleneck that necessitates further algorithmic improvements and development of efficient software solutions. uQlust is a versatile and easy-to-use tool for ultrafast ranking and clustering of macromolecular structures. uQlust makes use of structural profiles of proteins and nucleic acids, while combining a linear-time algorithm for implicit comparison of all pairs of models with profile hashing to enable efficient clustering of large data sets with a low memory footprint. In addition to ranking and clustering of large sets of models of the same protein or RNA molecule, uQlust can also be used in conjunction with fragment-based profiles in order to cluster structures of arbitrary length. For example, hierarchical clustering of the entire PDB using profile hashing can be performed on a typical laptop, thus opening an avenue for structural explorations previously limited to dedicated resources. The uQlust package is freely available under the GNU General Public License at https://github.com/uQlust . uQlust represents a drastic reduction in the computational complexity and memory requirements with respect to existing clustering and model quality assessment methods for macromolecular structure analysis, while yielding results on par with traditional approaches for both proteins and RNAs.

Privacy-Preserving Patient Similarity Learning in a Federated Environment: Development and Analysis

PubMed Central

Sun, Jimeng; Wang, Fei; Wang, Shuang; Jun, Chi-Hyuck; Jiang, Xiaoqian

2018-01-01

Background There is an urgent need for the development of global analytic frameworks that can perform analyses in a privacy-preserving federated environment across multiple institutions without privacy leakage. A few studies on the topic of federated medical analysis have been conducted recently with the focus on several algorithms. However, none of them have solved similar patient matching, which is useful for applications such as cohort construction for cross-institution observational studies, disease surveillance, and clinical trials recruitment. Objective The aim of this study was to present a privacy-preserving platform in a federated setting for patient similarity learning across institutions. Without sharing patient-level information, our model can find similar patients from one hospital to another. Methods We proposed a federated patient hashing framework and developed a novel algorithm to learn context-specific hash codes to represent patients across institutions. The similarities between patients can be efficiently computed using the resulting hash codes of corresponding patients. To avoid security attack from reverse engineering on the model, we applied homomorphic encryption to patient similarity search in a federated setting. Results We used sequential medical events extracted from the Multiparameter Intelligent Monitoring in Intensive Care-III database to evaluate the proposed algorithm in predicting the incidence of five diseases independently. Our algorithm achieved averaged area under the curves of 0.9154 and 0.8012 with balanced and imbalanced data, respectively, in κ-nearest neighbor with κ=3. We also confirmed privacy preservation in similarity search by using homomorphic encryption. Conclusions The proposed algorithm can help search similar patients across institutions effectively to support federated data analysis in a privacy-preserving manner. PMID:29653917

Matching Aerial Images to 3D Building Models Using Context-Based Geometric Hashing

PubMed Central

Jung, Jaewook; Sohn, Gunho; Bang, Kiin; Wichmann, Andreas; Armenakis, Costas; Kada, Martin

2016-01-01

A city is a dynamic entity, which environment is continuously changing over time. Accordingly, its virtual city models also need to be regularly updated to support accurate model-based decisions for various applications, including urban planning, emergency response and autonomous navigation. A concept of continuous city modeling is to progressively reconstruct city models by accommodating their changes recognized in spatio-temporal domain, while preserving unchanged structures. A first critical step for continuous city modeling is to coherently register remotely sensed data taken at different epochs with existing building models. This paper presents a new model-to-image registration method using a context-based geometric hashing (CGH) method to align a single image with existing 3D building models. This model-to-image registration process consists of three steps: (1) feature extraction; (2) similarity measure; and matching, and (3) estimating exterior orientation parameters (EOPs) of a single image. For feature extraction, we propose two types of matching cues: edged corner features representing the saliency of building corner points with associated edges, and contextual relations among the edged corner features within an individual roof. A set of matched corners are found with given proximity measure through geometric hashing, and optimal matches are then finally determined by maximizing the matching cost encoding contextual similarity between matching candidates. Final matched corners are used for adjusting EOPs of the single airborne image by the least square method based on collinearity equations. The result shows that acceptable accuracy of EOPs of a single image can be achievable using the proposed registration approach as an alternative to a labor-intensive manual registration process. PMID:27338410

40 CFR 86.145-82 - Calculations; particulate emissions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... final reported test results for the mass particulate (Mp) in grams/mile shall be computed as follows. Mp = 0.43(Mp1 + Mp2)/(Dct + Ds) + 0.57(Mp3 + Mp2)/(Dht = Ds) where: (1) Mp1 = Mass of particulate...) for determination.) (2) Mp2 = Mass of particulate determined from the “stabilized” phase of the cold...