15 research outputs found
RAMPART: RowHammer Mitigation and Repair for Server Memory Systems
RowHammer attacks are a growing security and reliability concern for DRAMs
and computer systems as they can induce many bit errors that overwhelm error
detection and correction capabilities. System-level solutions are needed as
process technology and circuit improvements alone are unlikely to provide
complete protection against RowHammer attacks in the future. This paper
introduces RAMPART, a novel approach to mitigating RowHammer attacks and
improving server memory system reliability by remapping addresses in each DRAM
in a way that confines RowHammer bit flips to a single device for any victim
row address. When RAMPART is paired with Single Device Data Correction (SDDC)
and patrol scrub, error detection and correction methods in use today, the
system can detect and correct bit flips from a successful attack, allowing the
memory system to heal itself. RAMPART is compatible with DDR5 RowHammer
mitigation features, as well as a wide variety of algorithmic and probabilistic
tracking methods. We also introduce BRC-VL, a variation of DDR5 Bounded Refresh
Configuration (BRC) that improves system performance by reducing mitigation
overhead and show that it works well with probabilistic sampling methods to
combat traditional and victim-focused mitigation attacks like Half-Double. The
combination of RAMPART, SDDC, and scrubbing enables stronger RowHammer
resistance by correcting bit flips from one successful attack. Uncorrectable
errors are much less likely, requiring two successful attacks before the memory
system is scrubbed.Comment: 16 pages, 13 figures. A version of this paper will appear in the
Proceedings of MEMSYS2
The rise and fall of the ancient northern pike master sex-determining gene
The understanding of the evolution of variable sex determination mechanisms across taxa requires comparative studies among closely related species. Following the fate of a known master sex-determining gene, we traced the evolution of sex determination in an entire teleost order (Esociformes). We discovered that the northern pike (Esox lucius) master sex-determining gene originated from a 65 to 90 million-year-old gene duplication event and that it remained sex linked on undifferentiated sex chromosomes for at least 56 million years in multiple species. We identified several independent species- or population-specific sex determination transitions, including a recent loss of a Y chromosome. These findings highlight the diversity of evolutionary fates of master sex-determining genes and the importance of population demographic history in sex determination studies. We hypothesize that occasional sex reversals and genetic bottlenecks provide a non-adaptive explanation for sex determination transitions
The rise and fall of the ancient northern pike master sex determining gene
The understanding of the evolution of variable sex determination mechanisms across taxa requires comparative studies among closely related species. Following the fate of a known master sex-determining gene, we traced the evolution of sex determination in an entire teleost order (Esociformes). We discovered that the northern pike (Esox lucius) master sex-determining gene originated from a 65 to 90 million-year-old gene duplication event and that it remained sex-linked on undifferentiated sex chromosomes for at least 56 million years in multiple species. We identified several independent species- or population-specific sex determination transitions, including a recent loss of a Y-chromosome. These findings highlight the diversity of evolutionary fates of master sex-determining genes and the importance of population demographic history in sex determination studies. We hypothesize that occasional sex reversals and genetic bottlenecks provide a non-adaptive explanation for sex determination transitions
Pediatric Gastrointestinal Endoscopy: European Society of Pediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) and European Society of Gastrointestinal Endoscopy (ESGE) Guidelines
ABSTRACT: This Guideline refers to infants, children and adolescents aged 0–18 years. The areas covered include: indications for diagnostic and therapeutic esophagogastroduodenoscopy and ileo-colonoscopy; endoscopy for foreign body ingestion; corrosive ingestion and stricture/stenosis endoscopic management; upper and lower gastrointestinal bleeding; endoscopic retrograde cholangio-pancreatography and endoscopic ultrasonography. Percutaneous endoscopic gastrostomy and endoscopy specific to inflammatory bowel disease (IBD) has been dealt with in other Guidelines [1–3] and are therefore not mentioned in this Guideline. Training and ongoing skill maintenance are to be dealt with in an imminent sister publication to this
Pediatric gastrointestinal endoscopy: European Society of Gastrointestinal Endoscopy (ESGE) and European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) Guideline Executive summary
This Executive summary of the Guideline on pediatric gastrointestinal endoscopy from the European Society of Gastrointestinal Endoscopy (ESGE) and the European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) refers to infants, children, and adolescents aged 0 - 18 years. The areas covered include: indications for diagnostic and therapeutic esophagogastroduodenoscopy and ileocolonoscopy; endoscopy for foreign body ingestion; endoscopic management of corrosive ingestion and stricture/stenosis; upper and lower gastrointestinal bleeding; endoscopic retrograde cholangiopancreatography, and endoscopic ultrasonography. Percutaneous endoscopic gastrostomy and endoscopy specific to inflammatory bowel disease (IBD) have been dealt with in other Guidelines and are therefore not mentioned in this Guideline. Training and ongoing skill maintenance will be addressed in an imminent sister publicatio
Paediatric gastrointestinal endoscopy: European society for paediatric gastroenterology hepatology and nutrition and European society of gastrointestinal endoscopy guidelines
This guideline refers to infants, children, and adolescents ages 0 to 18 years. The areas covered include indications for diagnostic and therapeutic esophagogastroduodenoscopy and ileocolonoscopy; endoscopy for foreign body ingestion; corrosive ingestion and stricture/stenosis endoscopic management; upper and lower gastrointestinal bleeding; endoscopic retrograde cholangiopancreatography; and endoscopic ultrasonography. Percutaneous endoscopic gastrostomy and endoscopy specific to inflammatory bowel disease has been dealt with in other guidelines and are therefore not mentioned in this guideline. Training and ongoing skill maintenance are to be dealt with in an imminent sister publication to this
Pediatric gastrointestinal endoscopy: European Society of Gastrointestinal Endoscopy (ESGE) and European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) Guideline Executive summary
This Executive summary of the Guideline on pediatric
gastrointestinal endoscopy from the European
Society of Gastrointestinal Endoscopy
(ESGE) and the European Society for Paediatric
Gastroenterology Hepatology and Nutrition (ESPGHAN)
refers to infants, children, and adolescents
aged 0–18 years. The areas covered include: indications
for diagnostic and therapeutic esophagogastroduodenoscopy
and ileocolonoscopy;
endoscopy for foreign body ingestion; endoscopic
management of corrosive ingestion and stricture/
stenosis; upper and lower gastrointestinal bleeding;
endoscopic retrograde cholangiopancreatography,
and endoscopic ultrasonography. Percutaneous
endoscopic gastrostomy and endoscopy
specific to inflammatory bowel disease (IBD)
have been dealt with in other Guidelines and are
therefore not mentioned in this Guideline. Training
and ongoing skill maintenance will be addressed
in an imminent sister publication
Search for intermediate mass black hole binaries in the first observing run of Advanced LIGO
International audienceDuring their first observational run, the two Advanced LIGO detectors attained an unprecedented sensitivity, resulting in the first direct detections of gravitational-wave signals produced by stellar-mass binary black hole systems. This paper reports on an all-sky search for gravitational waves (GWs) from merging intermediate mass black hole binaries (IMBHBs). The combined results from two independent search techniques were used in this study: the first employs a matched-filter algorithm that uses a bank of filters covering the GW signal parameter space, while the second is a generic search for GW transients (bursts). No GWs from IMBHBs were detected; therefore, we constrain the rate of several classes of IMBHB mergers. The most stringent limit is obtained for black holes of individual mass 100 M⊙, with spins aligned with the binary orbital angular momentum. For such systems, the merger rate is constrained to be less than 0.93 Gpc−3 yr−1 in comoving units at the 90% confidence level, an improvement of nearly 2 orders of magnitude over previous upper limits