| 1. |
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| 2. |
- Abelev, Betty, et al.
(författare)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
-
Ingår i: Journal of High Energy Physics. - 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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| 3. |
- Akgun, OmerCan, et al.
(författare)
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Energy-minimum sub-threshold self-timed circuits using current sensing completion detection
- 2011
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Ingår i: IET Computers and Digital Techniques. - : Institution of Engineering and Technology (IET). - 1751-8601. ; 5:4, s. 342-353
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Tidskriftsartikel (refereegranskat)abstract
- This study addresses the design of self-timed energy-minimum circuits, operating in the sub-VT domain and a generic implementation template using bundled-data circuitry and current sensing completion detection (CSCD). Furthermore, a fully decoupled latch controller was developed, which integrates with the current-sensing circuitry. Different configurations that utilise the proposed latch controller are highlighted. A contemporary synchronous electronic design automation tools-based design flow, which transforms a synchronous design into a corresponding self-timed circuit, is outlined. Different use cases of the CSCD system are examined. The design flow and the current-sensing technique are validated by the implementation of a self-timed version of a wavelet-based event detector for cardiac pacemaker applications in a standard 65 nm CMOS process. The chip was fabricated and verified to operate down to 250 mV. Spice simulations indicate a gain of 52.58% in throughput because of asynchronous operation. By trading the throughput improvement, energy dissipation is reduced by 16.8% at the energy-minimum supply voltage.
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| 4. |
- Akgun, OmerCan, et al.
(författare)
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High-level energy estimation in the sub-VT domain: simulation and measurement of a cardiac event detector
- 2012
-
Ingår i: IEEE Transactions on Biomedical Circuits and Systems. - 1932-4545. ; 6:1, s. 15-27
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a flow that is suitable to estimate energy dissipation of digital standard-cell based designs which are determined to be operated in the sub-threshold regime. The flow is applicable on gate-level netlists, where back-annotated toggle information is used to find the minimum energy operation point, corresponding maximum clock frequency, as well as the dissipated energy per clock cycle. The application of the model is demonstrated by exploring the energy efficiency of pipelining, retiming and register balancing. Simulation results, which are obtained during a fraction of SPICE simulation time, are validated by measurements on a wavelet based cardiac event detector that was fabricated in 65 nm low-leakage high-threshold technology. The mean of the absolute modeling error is calculated as 5.2 %, with a standard deviation of 6.6% over the measurement points. The cardiac event detector dissipates 0.88 pJ/sample at a supply voltage of 320mV.
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| 5. |
- Akgun, OmerCan, et al.
(författare)
-
Minimum-energy sub-threshold self-timed circuits: design methodology and a case study
- 2010
-
Ingår i: 2010 IEEE Symposium on Asynchronous Circuits and Systems. - 9781424468591 - 9781424468607
-
Konferensbidrag (refereegranskat)abstract
- This paper addresses the design of self-timed energy minimum circuits, operating in the sub-VT domain. The paper presents a generic implementation template using bundled-data circuitry and current sensing completion detection. To support this, a fully-decoupled latch controller has been developed, which integrates the current sensing circuitry. The paper outlines a corresponding design flow, which is based on contemporary synchronous EDA tools, and which transforms a synchronous design, into a corresponding self-timed circuit. The design flow and the current-sensing technique is validated by the implementation of an asynchronous version of a wavelet based event detector for cardiac pacemaker applications in a standard 65nm CMOS process. The chip has been fabricated and the area overhead due to power domain separation and completion detection circuitry is 13.6 %. The improvement in throughput due to asynchronous operation is 52.58 %. By trading the throughput improvement, energy dissipation is reduced by 16.8% at the energy-minimum supply voltage.
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| 6. |
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| 7. |
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| 8. |
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| 9. |
- Andersson, Oskar, et al.
(författare)
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Dual-VT 4kb Sub-VT Memories with <1 pW/bit Leakage in 65 nm CMOS
- 2013
-
Ingår i: Proceedings of the ESSCIRC (ESSCIRC), 2013. - 1930-8833. - 9781479906437 ; , s. 192-200
-
Konferensbidrag (refereegranskat)abstract
- Two standard-cell based memories (SCMs) for op- eration in the subthreshold (sub-VT) region are presented. The SCMs accomplish the task of robust sub-VT storage and fill the gap of missing sub-VT memory compilers. The storage elements (latches) of these SCMs are custom-designed cells using a dual- VT approach to balance timing. Additionally, two read-logic styles are presented: 1) a segmented 3-state implementation that increases performance compared to a pure 3-state implemen- tation; and 2) a purely MUX-based implementation with the 1st stage (NAND gate) integrated into the storage cell. Silicon measurements of two 4kb SCMs manufactured in a low-power 65 nm CMOS technology show that read access speed increases by 4X and 8X compared to a pure 3-state implementation for the segmented 3-state and integrated NAND, respectively, while bit-access energy only increases by 2.7X and 2X to 39 and 29 fJ, respectively.
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| 10. |
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| 11. |
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| 12. |
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| 13. |
- Andersson, Oskar, et al.
(författare)
-
Two Flavors of 4kb Standard-Cell Based Subvt Memory in 65 nm CMOS
- 2013
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Ultra-low power (ULP) biomedical implants and sensor nodes typically require small memories of a few kb, while previous work on reliable subthreshold (sub-VT) memories targets several hundreds of kb. Standard-cell based memories (SCMs) are a straightforward approach to realize robust sub- VT storage arrays and fill the gap of missing sub-VT memory compilers. This paper presents an ultra-low-leakage 4kb SCM manufactured in 65nm CMOS technology. To minimize leakage power during standby, a single custom-designed standard-cell (D- latch with 3-state output buffer) addressing all major leakage contributors of SCMs is seamlessly integrated into the fully automated SCM compilation flow. Silicon measurements of a 4kb SCM indicate a leakage power of 500fW per stored bit (at a data-retention voltage of 220mV) and a total energy of 14fJ per accessed bit (at energy-minimum voltage of 500mV), corresponding to the lowest values in 65 nm CMOS reported to date.
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| 14. |
- Andersson, Oskar, et al.
(författare)
-
Ultra Low Voltage Synthesizable Memories: A Trade-Off Discussion in 65nm CMOS
- 2016
-
Ingår i: IEEE Transactions on Circuits and Systems Part 1: Regular Papers. - 1549-8328. ; 63:6, s. 806-817
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, design considerations for ultra low voltage (ULV) standard-cell based memories (SCM) are presented. Trade-offs for area cost, leakage power, access time, and access energy are discussed and realized using different read logic styles, latch architecture designs, and process options. Furthermore, deployment of multiple threshold voltages (Vth) options in a single standard-cell/bitcell enables additional architectural choices. Silicon measurements from five memory designs, optimized at the transistor level in conjunction with gate-level optimizations, are considered to demonstrate the different trade-off corners. Measurements show that substituting the storage element in an SCM with a D-latch using transistor stacking and channel length stretching results in lowest leakage power. Alternatively, a pass- transistor based latch as storage element reduces the area footprint at a cost of reduced access speed, which can be compensated by using a lower-Vth pass-transistor. However, relatively high speed (tens of MHz) in the near- to subthreshold (sub-Vth) region is achievable if general purpose transistors are used instead of low power transistors. A discussion is included to illustrate when to implement ULV memories using SCMs and when to choose sub-Vth SRAMs. The discussion shows that the border is between 4-6 kb, depending on the number of words and the wordlength configuration.
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| 15. |
- Bardizbanyan, Alen, 1986, et al.
(författare)
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Logic Filter Cache for Wide-VDD-Range Processors
- 2016
-
Ingår i: Proceedings of 23rd IEEE Int. Conf. on Electronics, Circuits and Systems. - 9781509061136 ; , s. 376-379
-
Konferensbidrag (refereegranskat)abstract
- Wide-VDD-range processors offer high energy efficiency for varying embedded workloads. But reducing the VDD of the cache as aggressively as the VDD of the CPU logic is not straightforward, since standard 6T SRAMs cease to operate at lower VDDs. We implement a data and instruction filter cache, using logic cells located in the CPU VDD domain, to permit the level-1 (L1) cache to be reliably powered at a higher SRAM VDD. On top of eliminating many energy-wasting L1 cache accesses, the filter cache reduces the total number of executed cycles. Furthermore, the filter cache can be reconfigured as CPU VDD is reduced, to filter out an increasing proportion of cache accesses. We evaluate our approach using a 65-nm 1.2-V low-leakage CMOS process, with a minimal CPU and SRAM VDD of 0.4 and 0.95V, respectively. Assuming 16kB+16kB L1 caches and 256B+256B filter caches, introducing the filter cache reduces the total cache access energy by 71% at 1.2V and 87% at 0.4V at an area overhead which is 13% of the L1 cache area.
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| 16. |
- Behmanesh, Baktash, et al.
(författare)
-
An 88% fractional bandwidth reconfigurable power amplifier for NB-IoT and LTE-M in 22 nm CMOS FDSOI
- 2022
-
Ingår i: 2022 IEEE Nordic Circuits and Systems Conference (NorCAS). - 9798350345513 - 9798350345506
-
Konferensbidrag (refereegranskat)abstract
- A wideband power amplifier (PA), with 88% fractional bandwidth operating in the 700 MHz to 1.8 GHz range, which covers most of the standardized narrowband internet-of-things (NB-IoT) and LTE-M bands, is fully integrated in 22 nm CMOS FDSOI. A single-stage differential amplifier core, combined with an on-chip balun, realizes a single-ended output. A stacked circuit architecture, with 3.3 V LDMOS transistors as output devices and thin-oxide flipped-well transistors as the input common-source (CS) stage, enable a wide bandwidth and reliable operation at a supply voltage of 2.55 V. Capacitor banks with stacked thin-oxide transistor switches tune the PA frequency characteristics over the wide frequency range. The PA delivers a saturated output power (P sat ) of up to +24.4 dBm with up to 45% power-added efficiency, which is compliant with the current 3GPP standard for NB-IoT and LTE-M. The maximum power-gain varies between 30.7 dB and 29.2 dB over the whole frequency range. The PA core circuit occupies 0.32 mm 2 of silicon area, of which 0.2 mm 2 is occupied by the low loss balun.
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| 17. |
- Bottero, Irene, et al.
(författare)
-
Impact of landscape configuration and composition on pollinator communities across different European biogeographic regions
- 2023
-
Ingår i: Frontiers in Ecology and Evolution. - 2296-701X. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Heterogeneity in composition and spatial configuration of landscape elements support diversity and abundance of flower-visiting insects, but this is likely dependent on taxonomic group, spatial scale, weather and climatic conditions, and is particularly impacted by agricultural intensification. Here, we analyzed the impacts of both aspects of landscape heterogeneity and the role of climatic and weather conditions on pollinating insect communities in two economically important mass-flowering crops across Europe. Methods: Using a standardized approach, we collected data on the abundance of five insect groups (honey bees, bumble bees, other bees, hover flies and butterflies) in eight oilseed rape and eight apple orchard sites (in crops and adjacent crop margins), across eight European countries (128 sites in total) encompassing four biogeographic regions, and quantified habitat heterogeneity by calculating relevant landscape metrics for composition (proportion and diversity of land-use types) and configuration (the aggregation and isolation of land-use patches). Results: We found that flower-visiting insects responded to landscape and climate parameters in taxon- and crop-specific ways. For example, landscape diversity was positively correlated with honey bee and solitary bee abundance in oilseed rape fields, and hover fly abundance in apple orchards. In apple sites, the total abundance of all pollinators, and particularly bumble bees and solitary bees, decreased with an increasing proportion of orchards in the surrounding landscape. In oilseed rape sites, less-intensively managed habitats (i.e., woodland, grassland, meadows, and hedgerows) positively influenced all pollinators, particularly bumble bees and butterflies. Additionally, our data showed that daily and annual temperature, as well as annual precipitation and precipitation seasonality, affects the abundance of flower-visiting insects, although, again, these impacts appeared to be taxon- or crop-specific. Discussion: Thus, in the context of global change, our findings emphasize the importance of understanding the role of taxon-specific responses to both changes in land use and climate, to ensure continued delivery of pollination services to pollinator-dependent crops.
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| 18. |
- Constantin, Jeremy, et al.
(författare)
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An Ultra-Low-Power Application-Specific Processor for Compressed Sensing
- 2013
-
Ingår i: IFIP Advances in Information and Communication Technology. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783642450723 - 9783642450730 ; 418, s. 88-106
-
Bokkapitel (refereegranskat)abstract
- Compressed sensing (CS) is a universal low-complexity data compression technique for signals that have a sparse representation in some domain. While CS data compression can be done both in the analog- and digital domain, digital implementations are often used on low-power sensor nodes, where an ultra-low-power (ULP) processor carries out the algorithm on Nyquist-rate sampled data. In such systems an energy-efficient implementation of the CS compression kernel is a vital ingredient to maximize battery lifetime. In this paper, we propose an application-specific instruction-set processor (ASIP) processor that has been optimized for CS data compression and for operation in the subthreshold (sub-VT) regime. The design is equipped with specific sub-VT capable standard-cell based memories, to enable low-voltage operation with low leakage. Our results show that the proposed ASIP accomplishes 62× speed-up and 11.6× power savings with respect to a straightforward CS implementation running on the baseline low-power processor without instruction set extensions.
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| 19. |
- Constantin, Jeremy, et al.
(författare)
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TamaRISC-CS: An Ultra-Low-Power Application-Specific Processor for Compressed Sensing
- 2012
-
Ingår i: IEEE/IFIP 20th International Conference on VLSI and System-on-Chip (VLSI-SoC), 2012. - 9781467326575 ; , s. 159-164
-
Konferensbidrag (refereegranskat)abstract
- Compressed sensing (CS) is a universal technique for the compression of sparse signals. CS has been widely used in sensing platforms where portable, autonomous devices have to operate for long periods of time with limited energy resources. Therefore, an ultra-low-power (ULP) CS implementation is vital for these kind of energy-limited systems. Sub-threshold (sub-VT) operation is commonly used for ULP computing, and can also be combined with CS. However, most established CS implementations can achieve either no or very limited benefit from sub-VT operation. Therefore, we propose a sub-VT application-specific instruction-set processor (ASIP), exploiting the specific operations of CS. Our results show that the proposed ASIP accomplishes 62x speed-up and 11.6x power savings with respect to an established CS implementation running on the baseline low-power processor.
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| 20. |
- Diaz, Isael, et al.
(författare)
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A New Digital Front-End for Flexible Reception in Software Defined Radio
- 2015
-
Ingår i: Microprocessors and Microsystems. - : Elsevier BV. - 0141-9331. ; 39:8, s. 889-900
-
Tidskriftsartikel (refereegranskat)abstract
- Future mobile terminals are expected to support an ever increasing number of Radio Access Technologies (RAT) concurrently. This imposes a challenge to terminal designers already today. Software Defined Radio (SDR) solutions are a compelling alternative to address this issue in the digital baseband, given its high flexibility and low Non-Recurring Engineering (NRE) cost. However, the challenge still remains in the Digital Front-End (DFE), where many operations are too complex or energy hungry to be implemented as software instructions. Thus, new architectures are needed to feed the SDR digital baseband while keeping complexity and energy consumption at bay. In this article the architecture of a Digital Front-End Receiver (DFE-Rx) for the next-generation mobile terminals is presented. The flexibility needed for multi-standard support is demonstrated by detecting, synchronizing and reporting carrier-frequency offset, of multiple concurrent radio standards. Moreover, the proposed architecture has been fabricated in a 65 nm CMOS low power high-VT cell technology in a die size of 5 mm2. The core module of the DFE-Rx, the synchronization engine, has been measured at 1.2 V and reports an average power consumption of 1.9 mW during Wireless Local Area Network (WLAN) reception and 1.6 mW during configuration, while running at 10 MHz.
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| 21. |
- Diaz, Isael, et al.
(författare)
-
A sign-bit auto-correlation architecture for fractional frequency offset estimation in OFDM
- 2010
-
Ingår i: ; , s. 3765-3768
-
Konferensbidrag (refereegranskat)abstract
- This paper presents an architecture of an auto-correlator for Orthogonal Frequency Division Multiplexing systems. The received signal is quantized to only the sign-bit, which dramatically simplifies the frequency offset estimation. Hardware cost is reduced under the assumption that synchronization during acquisition does not have to be very accurate, but sufficient for coarse estimation. The architecture is synthesized towards a 65nm low-leakage high threshold standard cell CMOS library. The proposed architecture results in area reduction of 93% if compared to typical 8-bit implementation. The area occupied by the architecture is 0.063mm^2. The architecture is evaluated for WLAN, LTE and DVB-H. Power simulations for DVB-H transmission shows a power consumption of 4.8uW per symbol.
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| 22. |
- Diaz, Isael, et al.
(författare)
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Highly Scalable Implementation of a Robust MMSE Channel Estimator for OFDM Multi-Standard Environment
- 2011
-
Ingår i: IEEE Workshop on Signal Processing Systems. - 1520-6130. ; , s. 311-315
-
Konferensbidrag (refereegranskat)abstract
- Abstract in UndeterminedIn this paper a VLSI implementation of a highly scalable MMSE (Minimum Mean Square Estimator) is presented with the ultimate goal of demonstrating the potential of MMSE as enabler for multi-standard channel estimation. By selecting an appropriate implementation, a complexity reduction of 98% is achieved when compared to Time-Domain Maximum Likelihood Estimation (TDMLE), whereas low power consumption is accomplished by implementing a low-power-mode. The architecture is capable of performing Least Square (LS) estimation and MMSE compliant with 3GPP LTE (Long Term Evolution), IEEE 802.11n (WLAN), and DVB-H (Digital Video Broadcast for Handheld Devices), The estimator is synthesized using a 65 nm low-leakage high-threshold standard-cell CMOS library. The design occupies an area of 0.169 mm(2), is capable of running upto 250 MHz, providing a throughput of 78 M estimates/second. Simulations under a typical LTE reception show that the implementation dissipates 4.9 mu W per sample.
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| 23. |
- Diaz, Isael, et al.
(författare)
-
Next Generation Digital Front-End for Multi-Standard Concurrent Reception
- 2013
-
Ingår i: [Host publication title missing].
-
Konferensbidrag (refereegranskat)abstract
- This article presents an architecture of a Digital Front-End Receiver (DFE-Rx) for the next-generation mobile terminals. A main focus is placed in flexibility, scalability and concurrency. The architecture is capable of detecting, synchronizing and reporting carrier-frequency offset, of multiple concurrent radio standards. The proposed receiver is fabricated in a 65nm CMOS low power high-VT cell technology in a die size of 5mm2. The synchronization engine has been measured at 1.2V and reports an average power consumption of 1.9mW during IEEE 802.11 reception and 1.6mW during configuration, while running at 10MHz.
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| 24. |
- Diaz, Isael, et al.
(författare)
-
Sign-Bit based architecture for OFDM acquisition for multiple-standards
- 2009
-
Ingår i: [Host publication title missing]. - 9781424443109
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a hardware mapping of an auto-correlator for Orthogonal Frequency Division Multiplexing stage for three radio standards: LTE, DVB-H, and IEEE 802.11n. Hardware cost is minimized by using only the sign bit in the autocorrelation function. The frequency offset estimation procedure is dramatically simplified by reducing the phase of the envelope to pi/2 resolution, which in turn reduces the need of specialized components. The architecture is synthesized towards a 65 nm low-leakage high threshold standard cell CMOS library. The 1-bit architecture reports an area reduction of 90% for memories, 56% for the logic and a power dissipation reduction of 35%, when compared to an identical 8-bit implementation. The approximate area occupied by the architecture is 0.03mm^2. Power simulations for IEEE 802.11n packet reports a power dissipation of 42uW.
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| 25. |
- Engel, Philipp, et al.
(författare)
-
The Bee Microbiome: Impact on Bee Health and Model for Evolution and Ecology of Host-Microbe Interactions
- 2016
-
Ingår i: mBio. - : American Society for Microbiology. - 2161-2129 .- 2150-7511. ; 7:2
-
Forskningsöversikt (refereegranskat)abstract
- As pollinators, bees are cornerstones for terrestrial ecosystem stability and key components in agricultural productivity. All animals, including bees, are associated with a diverse community of microbes, commonly referred to as the micro biome. The bee micro biome is likely to be a crucial factor affecting host health. However, with the exception of a few pathogens, the impacts of most members of the bee microbiome on host health are poorly understood. Further, the evolutionary and ecological forces that shape and change the microbiome are unclear. Here, we discuss recent progress in our understanding of the bee microbiome, and we present challenges associated with its investigation. We conclude that global coordination of research efforts is needed to fully understand the complex and highly dynamic nature of the interplay between the bee micro biome, its host, and the environment. High-throughput sequencing technologies are ideal for exploring complex biological systems, including host-microbe interactions. To maximize their value and to improve assessment of the factors affecting bee health, sequence data should be archived, curated, and analyzed in ways that promote the synthesis of different studies. To this end, the BeeBiome consortium aims to develop an online database which would provide reference sequences, archive metadata, and host analytical resources. The goal would be to support applied and fundamental research on bees and their associated microbes and to provide a collaborative framework for sharing primary data from different research programs, thus furthering our understanding of the bee microbiome and its impact on pollinator health.
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| 26. |
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| 27. |
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| 28. |
- Forsgren, Eva, et al.
(författare)
-
Sample preservation, transport and processing strategies for honeybee RNA extraction: Influence on RNA yield, quality, target quantification and data normalization
- 2017
-
Ingår i: Journal of Virological Methods. - : Elsevier BV. - 0166-0934 .- 1879-0984. ; 246, s. 81-89
-
Tidskriftsartikel (refereegranskat)abstract
- Viral infections in managed honey bees are numerous, and most of them are caused by viruses with an RNA genome. Since RNA degrades rapidly, appropriate sample management and RNA extraction methods are imperative to get high quality RNA for downstream assays. This study evaluated the effect of various sampling transport scenarios (combinations of temperature, RNA stabilizers, and duration) of transport on six RNA quality parameters; yield, purity, integrity, cDNA synthesis efficiency, target detection and quantification. The use of water and extraction buffer were also compared for a primary bee tissue homogenate prior to RNA extraction. The strategy least affected by time was preservation of samples at -80 degrees C. All other regimens turned out to be poor alternatives unless the samples were frozen or processed within 24 h. Chemical stabilizers have the greatest impact on RNA quality and adding an extra homogenization step (a QIAshredder (TM) homogenizer) to the extraction protocol significantly improves the RNA yield and chemical purity. This study confirms that RIN values (RNA Integrity Number), should be used cautiously with bee RNA. Using water for the primary homogenate has no negative effect on RNA quality as long as this step is no longer than 15 min.
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| 29. |
- Forsgren, Eva, et al.
(författare)
-
SLU:s verksamhet med bin
- 2016
-
Ingår i: Bitidningen. - 0006-3886. ; , s. 11-15
-
Tidskriftsartikel (populärvet., debatt m.m.)
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| 30. |
- Fries, Ingemar, et al.
(författare)
-
The principal parasites and pathogens of honeybees
- 2011
-
Ingår i: Bees in Europe and sustainable honey production (BEE SHOP) : results of a pan-european research network. - 9781612093369 ; , s. 49-105
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 31. |
- Fries, Ingemar, et al.
(författare)
-
Verksamhet med bin 2010 vid SLU
- 2011
-
Ingår i: Bitidningen. - 0006-3886. ; 109, s. 10-14
-
Tidskriftsartikel (populärvet., debatt m.m.)
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| 32. |
- Fries, Ingemar, et al.
(författare)
-
Verksamhet med bin vid SLU 2011.
- 2012
-
Ingår i: Bitidningen. - 0006-3886. ; 111, s. 12-16
-
Tidskriftsartikel (populärvet., debatt m.m.)
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| 33. |
- Fries, Ingemar, et al.
(författare)
-
Verksamhet med bin vid SLU 2013
- 2014
-
Ingår i: Bitidningen. - 0006-3886. ; 113, s. 16-19
-
Tidskriftsartikel (populärvet., debatt m.m.)
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| 34. |
- Fries, Ingemar, et al.
(författare)
-
Är GMO-grödor farliga för bin?
- 2014
-
Ingår i: Bitidningen. - 0006-3886. ; , s. 32-33
-
Tidskriftsartikel (populärvet., debatt m.m.)
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| 35. |
- Hedberg, Hugo, et al.
(författare)
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Teaching digital ASIC design to students with heterogeneoms previous knowledge
- 2005
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Ingår i: Proceedings. 2005 IEEE International Conference on Microelectronic Systems Education. - 0769523749 ; , s. 15-16
-
Konferensbidrag (refereegranskat)abstract
- This paper describes a MSc level digital ASIC project course. The majority of the course participants are international students, having a wide spread in previous knowledge in the field of digital HW-design. A course outline adapting to this fact has been developed, changing from one joint VLSI project towards smaller individual projects. The diversity in previous knowledge is evened out by adding lectures regarding design methodology and used EDA-tools, and making the first part of the course purely, laboratory. To enhance and highlight different aspects of HDL-design, mandatory assignments allow the students to gradually take command over the complete design flow. As a result, comprehension of digital ASIC design is increased among the students and course administration is reduced.
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| 36. |
- Hodge, Simon, et al.
(författare)
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Design and Planning of a Transdisciplinary Investigation into Farmland Pollinators : Rationale, Co-Design, and Lessons Learned
- 2022
-
Ingår i: Sustainability (Switzerland). - : MDPI AG. - 2071-1050. ; 14:17
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Tidskriftsartikel (refereegranskat)abstract
- To provide a complete portrayal of the multiple factors negatively impacting insects in agricultural landscapes it is necessary to assess the concurrent incidence, magnitude, and interactions among multiple stressors over substantial biogeographical scales. Trans-national ecological field investigations with wide-ranging stakeholders typically encounter numerous challenges during the design planning stages, not least that the scientific soundness of a spatially replicated study design must account for the substantial geographic and climatic variation among distant sites. ‘PoshBee’ (Pan-European assessment, monitoring, and mitigation of Stressors on the Health of Bees) is a multi-partner transdisciplinary agroecological project established to investigate the suite of stressors typically encountered by pollinating insects in European agricultural landscapes. To do this, PoshBee established a network of 128 study sites across eight European countries and collected over 50 measurements and samples relating to the nutritional, toxicological, pathogenic, and landscape components of the bees’ environment. This paper describes the development process, rationale, and end-result of each aspect of the of the PoshBee field investigation. We describe the main issues and challenges encountered during the design stages and highlight a number of actions or processes that may benefit other multi-partner research consortia planning similar large-scale studies. It was soon identified that in a multi-component study design process, the development of interaction and communication networks involving all collaborators and stakeholders requires considerable time and resources. It was also necessary at each planning stage to be mindful of the needs and objectives of all stakeholders and partners, and further challenges inevitably arose when practical limitations, such as time restrictions and labour constraints, were superimposed upon prototype study designs. To promote clarity for all stakeholders, for each sub-component of the study, there should be a clear record of the rationale and reasoning that outlines how the final design transpired, what compromises were made, and how the requirements of different stakeholders were accomplished. Ultimately, multi-national agroecological field studies such as PoshBee benefit greatly from the involvement of diverse stakeholders and partners, ranging from field ecologists, project managers, policy legislators, mathematical modelers, and farmer organisations. While the execution of the study highlighted the advantages and benefits of large-scale transdisciplinary projects, the long planning period emphasized the need to formally describe a design framework that could facilitate the design process of future multi-partner collaborations.
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| 37. |
- Hosseini-Nejad, Hossein, et al.
(författare)
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A 128-channel discrete cosine transform-based neural signal processor for implantable neural recording microsystems
- 2015
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Ingår i: International Journal of Circuit Theory and Applications. - : Wiley. - 1097-007X .- 0098-9886. ; 43:4, s. 489-501
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Tidskriftsartikel (refereegranskat)abstract
- A 128-channel neural signal processor for implantable neural recording microsystems is presented. The processor compresses the neural information of 128 simultaneous recording channels using discrete cosine transform, achieving a compression factor of 69 at the expense of a 5.6% root mean square error. The proposed processor is implemented on register transfer level and synthesized in a 65-nm complementary metal-oxide semiconductor process. The post-layout simulated power consumption at 1.2 V is 33.06 μW (258 nW per channel) at an area cost of 0.46 mm2
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| 38. |
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| 39. |
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| 40. |
- Jagadish, Anupama, et al.
(författare)
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Development and optimization of a TaqMan assay for Nosema bombycis, causative agent of pebrine disease in Bombyx mori silkworm, based on the β-tubulin gene
- 2021
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Ingår i: Journal of Microbiological Methods. - : Elsevier BV. - 0167-7012 .- 1872-8359. ; 186
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Tidskriftsartikel (refereegranskat)abstract
- “Pébrine” is a devastating disease of Bombyx mori silkworms that is highly contagious and can completely destroy an entire crop of silkworms and is thus a serious threat for the viability and profitability of sericulture. The disease is most commonly attributed to microsporidians of the genus Nosema, which are obligate intracellular parasites that are transmitted through spores. Nosema infections in silkworms are diagnosed primarily through light microscopy, which is labour intensive and less reliable, sensitive, and specific than PCR-based techniques. Here, we present the development and optimization of a new TaqMan based assay targeting the β-tubulin gene in the pébrine disease causing agent Nosema bombycis in silkworms. The assay displayed excellent quantification linearity over multiple orders of magnitude of target amounts and a limit of detection (LOD) of 6.9 × 102 copies of target per reaction. The method is highly specific to N. bombycis with no cross-reactivity to other Nosema species commonly infecting wild silkworms. This specificity was due to three nucleotides in the probe-binding region unique to N. bombycis. The assay demonstrated a high reliability with a Coefficient of variation (CV) <5% for both intra-assay and inter-assay variability. The assay was used to trace experimental N. bombycis infection of silkworm larvae, in the fat body, midgut and ovary tissues, through pupation and metamorphosis to the emerging female moth, and her larval off-spring, confirming the vertical transmission of N. bombycis in silkworms. The TaqMan assay revealed a gradual increase in infection levels in the post-infection samples. The assay is reliable and simple to implement and can be a suitable complement to microscopy for routine diagnostics and surveillance in silkworm egg production centres with appropriate infrastructure.
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| 41. |
- Kamuf, Matthias, et al.
(författare)
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A variable-rate Viterbi decoder in 130-nm CMOS: design, measurements, and cost of flexibility
- 2008
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Ingår i: Proceedings, Norchip Conference. ; , s. 137-141
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Konferensbidrag (refereegranskat)abstract
- This paper discusses design and measurements of a flexible Viterbi decoder fabricated in 130-nm digital CMOS. Flexibility was incorporated by providing various code rates and modulation schemes to adjust to varying channel conditions. Based on previous trade-off studies, flexible building blocks were carefully designed to cause as little area penalty as possible. The chip runs down to a minimal core supply of 0.8V. It turns out that striving for more modulation schemes is beneficial in terms of power consumption once the price is paid for accepting different code rates viz. radices in the trellis and survivor path units.
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| 42. |
- Kamuf, Matthias, et al.
(författare)
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Design and Measurement of a Variable-Rate Viterbi Decoder in 130-nm Digital CMOS
- 2010
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Ingår i: Microprocessors and Microsystems. - : Elsevier BV. - 0141-9331. ; 34:2010, s. 129-137
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Tidskriftsartikel (refereegranskat)abstract
- This paper discusses design and measurements of a flexible Viterbi decoder fabricated in 130-nm digital CMOS. Flexibility was incorporated by providing various code rates and modulation schemes to adjust to varying channel conditions. Based on previous trade-off studies, flexible building blocks were carefully designed to cause as little area penalty as possible. The chip runs down to a minimal core supply of 0.8V. It turns out that striving for more modulation schemes is beneficial in terms of power consumption once the price is paid for accepting different code rates viz. radices in the trellis and survivor path units.
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| 43. |
- Kardum Hjort, Cecilia, et al.
(författare)
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Genomic divergence and a lack of recent introgression between commercial and wild bumblebees (Bombus terrestris)
- 2022
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Ingår i: Evolutionary Applications. - : Wiley. - 1752-4571. ; 15:3, s. 365-382
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Tidskriftsartikel (refereegranskat)abstract
- The global movement of bees for agricultural pollination services can affect local pollinator populations via hybridization. When commercial bumblebees are of the same species but of different geographic origin, intraspecific hybridization may result in beneficial integration of new genetic variation, or alternatively may disrupt locally adapted gene complexes. However, neither the existence nor the extent of genomic introgression and evolutionary divergence between wild and commercial bumblebees is fully understood. We obtained whole-genome sequencing data from wild and commercial Bombus terrestris collected from sites in Southern Sweden with and without long-term use of commercially imported B. terrestris. We search for evidence of introgression, dispersal and genome-wide differentiation in a comparative genomic analysis of wild and commercial bumblebees. Commercial B. terrestris were found in natural environments near sites where commercial bumblebees were used, as well as drifting wild B. terrestris in commercial bumblebee colonies. However, we found no evidence for widespread, recent genomic introgression of commercial B. terrestris into local wild conspecific populations. We found that wild B. terrestris had significantly higher nucleotide diversity (Nei's pi, π), while the number of segregating sites (Watterson's theta, θw) was higher in commercial B. terrestris. A highly divergent region on chromosome 11 was identified in commercial B. terrestris and found to be enriched with structural variants. The genes present in this region are involved in flight muscle contraction and structure and pathogen immune response, providing evidence for differing evolutionary processes operating in wild and commercial B. terrestris. We did not find evidence for recent introgression, suggesting that co-occurring commercial B. terrestris have not disrupted evolutionary processes in wild B. terrestris populations.
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| 44. |
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| 45. |
- Kawakami, Takeshi, et al.
(författare)
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Substantial Heritable Variation in Recombination Rate on Multiple Scales in Honeybees and Bumblebees
- 2019
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Ingår i: Genetics. - : GENETICS SOCIETY AMERICA. - 0016-6731 .- 1943-2631. ; 212:4, s. 1101-1119
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Tidskriftsartikel (refereegranskat)abstract
- Meiotic recombination shuffles genetic variation and promotes correct segregation of chromosomes. Rates of recombination vary on several scales, both within genomes and between individuals, and this variation is affected by both genetic and environmental factors. Social insects have extremely high rates of recombination, although the evolutionary causes of this are not known. Here, we estimate rates of crossovers and gene conversions in 22 colonies of the honeybee, Apis mellifera, and 9 colonies of the bumblebee, Bombus terrestris, using direct sequencing of 299 haploid drone offspring. We confirm that both species have extremely elevated crossover rates, with higher rates measured in the highly eusocial honeybee than the primitively social bumblebee. There are also significant differences in recombination rate between subspecies of honeybee. There is substantial variation in genome-wide recombination rate between individuals of both A. mellifera and B. terrestris and the distribution of these rates overlap between species. A large proportion of interindividual variation in recombination rate is heritable, which indicates the presence of variation in trans-acting factors that influence recombination genome-wide. We infer that levels of crossover interference are significantly lower in honeybees compared to bumblebees, which may be one mechanism that contributes to higher recombination rates in honeybees. We also find a significant increase in recombination rate with distance from the centromere, mirrored by methylation differences. We detect a strong transmission bias due to GC-biased gene conversion associated with noncrossover gene conversions. Our results shed light on the mechanistic causes of extreme rates of recombination in social insects and the genetic architecture of recombination rate variation.
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| 46. |
- Knapp, Jessica L, et al.
(författare)
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Ecological traits interact with landscape context to determine bees' pesticide risk
- 2023
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Ingår i: Nature Ecology and Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 7, s. 547-556
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Tidskriftsartikel (refereegranskat)abstract
- Widespread contamination of ecosystems with pesticides threatens non-target organisms. However, the extent to which life-history traits affect pesticide exposure and resulting risk in different landscape contexts remains poorly understood. We address this for bees across an agricultural land-use gradient based on pesticide assays of pollen and nectar collected by Apis mellifera, Bombus terrestris and Osmia bicornis, representing extensive, intermediate and limited foraging traits. We found that extensive foragers (A. mellifera) experienced the highest pesticide risk-additive toxicity-weighted concentrations. However, only intermediate (B. terrestris) and limited foragers (O. bicornis) responded to landscape context-experiencing lower pesticide risk with less agricultural land. Pesticide risk correlated among bee species and between food sources and was greatest in A. mellifera-collected pollen-useful information for future postapproval pesticide monitoring. We provide foraging trait- and landscape-dependent information on the occurrence, concentration and identity of pesticides that bees encounter to estimate pesticide risk, which is necessary for more realistic risk assessment and essential information for tracking policy goals to reduce pesticide risk.
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| 47. |
- Kosek, S., et al.
(författare)
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Antibody-Positive Autoimmune Encephalitis and Paraneoplastic Neurological Syndrome: Epidemiology and Outcome of Neuronal Antibody Testing in Sweden
- 2023
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Ingår i: ACTA NEUROLOGICA SCANDINAVICA. - : WILEY. - 0001-6314 .- 1600-0404. ; 2023
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To estimate the 5-year incidence rate of autoimmune encephalitis (AE) and paraneoplastic neurological syndrome (PNS) in Sweden. Methods. All patients who were tested for a neuronal antibody in Sweden between 2015 and 2019 were included. Patients in Healthcare region Mid Sweden (population 2.1 million) were invited to participate in a case ascertainment substudy. AE and PNS cases were defined using established diagnostic criteria. Crude and age-adjusted incidence rates of AE and PNS in Healthcare region Mid Sweden were estimated. Results. The number of tests for neuronal antibodies in Sweden increased between 2015 and 2019 from 1867 to 2505 (serum) and 863 to 1376 (CSF) per annum. The frequencies of positive results were stable over the entire study period, and the mean value was 6.1% for serum (CI95% 5.5-6.7) and 4.8% for CSF (CI95% 4.0-5.6). In total, 125 patients tested positive for neuronal antibodies in Healthcare region Mid Sweden between 2015 and 2019. Of these, 94 were included, and after case ascertainment, thirty-one cases of definite AE or PNS could be identified. The 5-year incidence rate of AE and PNS was 3.0 per million person-years (95% CI 1.9-4.1). The yearly incidence rates increased in the study period, from 1.5 per million person-years in 2015 (95% CI 0.0-3.2) to 4.3 per million person-years in 2019 (95% CI 1.5-7.1). Conclusions. In this first epidemiological study of AE and PNS in Sweden, the number of cases doubled from 2015 to 2019. This likely reflects increased availability of testing and awareness of these conditions.
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| 48. |
- Lamei, Sepideh, et al.
(författare)
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Feeding Honeybee Colonies with Honeybee-Specific Lactic Acid Bacteria (Hbs-LAB) Does Not Affect Colony-Level Hbs-LAB Composition or Paenibacillus larvae Spore Levels, Although American Foulbrood Affected Colonies Harbor a More Diverse Hbs-LAB Community
- 2020
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Ingår i: Microbial Ecology. - : Springer Science and Business Media LLC. - 0095-3628 .- 1432-184X. ; 79:3, s. 743-755
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Tidskriftsartikel (refereegranskat)abstract
- The main current methods for controlling American Foulbrood (AFB) in honeybees, caused by the bacterial pathogen Paenibacillus larvae, are enforced incineration or prophylactic antibiotic treatment, neither of which is fully satisfactory. This has led to an increased interest in the natural relationships between the pathogenic and mutualistic microorganisms of the honeybee microbiome, in particular, the antagonistic effects of Honeybee-Specific Lactic Acid Bacteria (hbs-LAB) against P. larvae. We investigated whether supplemental administration of these bacteria affected P. larvae infection at colony level over an entire flowering season. Over the season, the supplements affected neither colony-level hbs-LAB composition nor naturally subclinical or clinical P. larvae spore levels. The composition of hbs-LAB in colonies was, however, more diverse in apiaries with a history of clinical AFB, although this was also unrelated to P. larvae spore levels. During the experiments, we also showed that qPCR could detect a wider range of hbs-LAB, with higher specificity and sensitivity than mass spectrometry. Honeybee colonies are complex super-organisms where social immune defenses, natural homeostatic mechanisms, and microbiome diversity and function play a major role in disease resistance. This means that observations made at the individual bee level cannot be simply extrapolated to infer similar effects at colony level. Although individual laboratory larval assays have clearly demonstrated the antagonistic effects of hbs-LAB on P. larvae infection, the results from the experiments presented here indicate that direct conversion of such practice to colony-level administration of live hbs-LAB is not effective.
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| 49. |
- Lamei, Sepideh, et al.
(författare)
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The secretome of honey bee-specific lactic acid bacteria inhibits Paenibacillus larvae growth
- 2019
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Ingår i: Journal of Apicultural Research. - : Informa UK Limited. - 0021-8839 .- 2078-6913. ; 58:3, s. 405-412
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Tidskriftsartikel (refereegranskat)abstract
- American Foulbrood (AFB) is a particularly pernicious bacterial disease of honey bees due to the extreme persistence of endospores of the causative agent Paenibacillus larvae. These spores are resistant to harsh environmental conditions, unaffected by antimicrobial agents and can remain viable for decades. The germination of the endospore in the larval midgut is the crucial first step leading to infection, followed by vegetative growth, tissue invasion and disease, culminating in spore formation when the host´s nutrients have been exhausted. Therefore, inhibiting spore germination or impeding early vegetative growth would be a highly effective strategy for limiting the impact of AFB. We previously showed that honey bee-specific lactic acid bacteria (hbs–LAB) had a major inhibitory effect on P. larvae both in culture and in larval bioassays. The present study documents the progress towards characterization of compounds, processes and interactions between P. larvae and the hbs–LAB responsible for this inhibitory effect. Firstly, we used an agar diffusion assay and larval infection bioassay to show that most, if not all, of the inhibitory effect was associated with the extracellular fraction (secretome). Secondly, we employed a turbidimetric growth assay to demonstrate that the hbs–LAB secretome strongly inhibited P. larvae vegetative growth, however, probably not by reducing spore germination. The inhibition was similarly effective against both major P. larvae genotypes (ERIC-I and II) in all experiments. The implications of our results for characterization of the secretome and for the management and treatment of AFB and P. larvae are further discussed.
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| 50. |
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