Implications of non-volatile memory as primary storage for database management systems

Traditional Database Management System (DBMS) software relies on hard disks for storing relational data. Hard disks are cheap, persistent, and offer huge storage capacities. However, data retrieval latency for hard disks is extremely high. To hide this latency, DRAM is used as an intermediate storage. DRAM is significantly faster than disk, but deployed in smaller capacities due to cost and power constraints, and without the necessary persistency feature that disks have. Non-Volatile Memory (NVM) is an emerging storage class technology which promises the best of both worlds. It can offer large storage capacities, due to better scaling and cost metrics than DRAM, and is non-volatile (persistent) like hard disks. At the same time, its data retrieval time is much lower than that of hard disks and it is also byte-addressable like DRAM. In this paper, we explore the implications of employing NVM as primary storage for DBMS. In other words, we investigate the modifications necessary to be applied on a traditional relational DBMS to take advantage of NVM features. As a case study, we have modified the storage engine (SE) of PostgreSQL enabling efficient use of NVM hardware. We detail the necessary changes and challenges such modifications entail and evaluate them using a comprehensive emulation platform. Results indicate that our modified SE reduces query execution time by up to 40% and 14.4% when compared to disk and NVM storage, with average reductions of 20.5% and 4.5%, respectively.The research leading to these results has received funding from the European Union’s 7th Framework Programme under grant agreement number 318633, the Ministry of Science and Technology of Spain under contract TIN2015-65316-P, and a HiPEAC collaboration grant awarded to Naveed Ul Mustafa.Peer ReviewedPostprint (author's final draft

PANC Study (Pancreatitis: A National Cohort Study): national cohort study examining the first 30 days from presentation of acute pancreatitis in the UK

Abstract Background Acute pancreatitis is a common, yet complex, emergency surgical presentation. Multiple guidelines exist and management can vary significantly. The aim of this first UK, multicentre, prospective cohort study was to assess the variation in management of acute pancreatitis to guide resource planning and optimize treatment. Methods All patients aged greater than or equal to 18 years presenting with acute pancreatitis, as per the Atlanta criteria, from March to April 2021 were eligible for inclusion and followed up for 30 days. Anonymized data were uploaded to a secure electronic database in line with local governance approvals. Results A total of 113 hospitals contributed data on 2580 patients, with an equal sex distribution and a mean age of 57 years. The aetiology was gallstones in 50.6 per cent, with idiopathic the next most common (22.4 per cent). In addition to the 7.6 per cent with a diagnosis of chronic pancreatitis, 20.1 per cent of patients had a previous episode of acute pancreatitis. One in 20 patients were classed as having severe pancreatitis, as per the Atlanta criteria. The overall mortality rate was 2.3 per cent at 30 days, but rose to one in three in the severe group. Predictors of death included male sex, increased age, and frailty; previous acute pancreatitis and gallstones as aetiologies were protective. Smoking status and body mass index did not affect death. Conclusion Most patients presenting with acute pancreatitis have a mild, self-limiting disease. Rates of patients with idiopathic pancreatitis are high. Recurrent attacks of pancreatitis are common, but are likely to have reduced risk of death on subsequent admissions. </jats:sec

Enriching Enea OSE for Better Predictability Support

A real-time application is designed as a set of tasks with specific timing attributes and constraints. These tasks can be categorized as periodic, sporadic or aperiodic, based on the timing attributes that are specified for them which in turn define their runtime behaviors. To ensure correct execution and behavior of the task set at runtime, the scheduler of the underlying operating system should take into account the type of each task (i.e.,  periodic, sporadic, aperiodic). This is important so that the scheduler can schedule the task set in a predictable way and be able to allocate CPU time to each task appropriately in order for them to achieve their timing constraints. ENEA OSE is a real-time operating system with fixed priority preemptive scheduling policy which is used heavily in embedded systems, such as telecommunication systems developed by Ericsson. While OSE allows for specification of priority levels for tasks and schedules them accordingly, it can not distinguish between different types of tasks. This thesis work investigates mechanisms to build a scheduler on top of OSE, which can identify three types of real-time tasks and schedule them in a more predictable way. The scheduler can also monitor behavior of task set at run-time and invoke violation handlers if time constraints of a task are violated. The scheduler is implemented on OSE5.5 soft kernel. It identifies periodic, aperiodic and sporadic tasks. Sporadic and aperiodic tasks can be interrupt driven or program driven. The scheduler implements EDF and RMS as scheduling policy of periodic tasks. Sporadic and aperiodic tasks can be scheduled using polling server or background scheme. Schedules generated by the scheduler  deviate from expected timing behavior due to scheduling overhead. Approaches to reduce deviation are suggested as future extension of thesis work. Usability of the scheduler can be increased by extending the scheduler to support other scheduling algorithm in addition to RMS and EDF.CHES

Deciphering the Potential of Bioactivated Rock Phosphate and Di-Ammonium Phosphate on Agronomic Performance, Nutritional Quality and Productivity of Wheat (Triticum aestivum L.)

Wheat is one of the leading staple crops in many countries. Phosphorus (P) plays an important role for wheat growth and yield as it takes part in many metabolic pathways. Even for soluble phosphatic fertilizers, most of the Pakistani soils, being alkaline and calcareous in nature, show phosphorus use efficiency (PUE) not more than 10–25%. The major issue is the unavailability of P due to fixation and precipitation reactions with soil particles. Composting of rock-phosphate with animal and poultry manures supplied with bio-stimulated phosphate solubilizing bacteria (PSB) not only enhances the RP solubilization but also serves as a potent source of P for plants. Composted/bio-activated rock-phosphate (B-RP), prepared by group of three bacterial strains i.e., Pseudomonas sp. (E11), Bacillus sp. (MN54) and Enterobacter sp. (MN17) aided with molasses (5%) and urea (10%), was tested alone and in various combinations with di-ammonium phosphate (DAP). In this pot trial, the combined application of B-RP and DAP was found superior to the sole application of B-RP. Even the combination of B-RP and DAP sharing equal amount of recommended P showed better results as compared to the sole application of DAP, giving improved shoot biomass (25%), total P-uptake (67%), recovery efficiency of P (75%), dry matter (29%), crude protein (29%), and other yield, physiological and nutritional quality parameters of wheat. So, it could be concluded that integrated use of B-RP and DAP with equal proportion of recommended P could serve as a better management practice for not only improving quantity but also the quality of the wheat grain

Mental Health and Coping Strategies among University Staff during the COVID-19 Pandemic : A Cross-Sectional Analysis from Saudi Arabia

This study examined psychological health and coping strategies among faculty and staff at a Saudi Arabian university. A web-based self-administered survey was used to assess probable anxiety, depression, post-traumatic stress disorder (PTSD), and coping strategies by using the Generalized Anxiety Disorder-7 (GAD-7), Patient Health Questionnaire-9 (PHQ-9), Impact of Event Scale-Revised (IES-R), and Brief-COPE scale, respectively. Of 502 participants (mean age 36.04 +/- 10.32 years, male: 66.3%), 24.1% (GAD-7 &gt;= 10) had probable anxiety. Anxiety score was significantly higher in females (p &lt; 0.001), those with a history of COVID-19 infection (p = 0.036), and participants with less work experience (p = 0.019). Approximately 40% of participants met the criteria of probable depression, with females (p &lt; 0.001) and participants with less experience having more depressive symptoms. Around one-fourth (27.7%) of study participants indicated probable PTSD (score +/- 33), with higher symptoms in females (p &lt;0.001), less experienced staff (p &lt; 0.00 1), and academic staff (p = 0.006). Correlation analysis indicated a significant positive correlation between anxiety and depression (r = 0.844, p &lt; 0.001), anxiety and PTSD (r = 0.650, p &lt; 0.001), and depression and PTSD (r = 0.676, p &lt; 0.001). Active coping, religious/spiritual coping, and acceptance were common coping strategies, while substance use was the least adopted coping method among the study participants. This study indicated a high prevalence of probable psychological ailments among university staff

Thigh-length compression stockings and DVT after stroke

Controversy exists as to whether neoadjuvant chemotherapy improves survival in patients with invasive bladder cancer, despite randomised controlled trials of more than 3000 patients. We undertook a systematic review and meta-analysis to assess the effect of such treatment on survival in patients with this disease

Azithromycin in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Background Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatory actions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19. Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospital with COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients were randomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once per day by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatment groups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment and were twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants and local study staff were not masked to the allocated treatment, but all others involved in the trial were masked to the outcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936. Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) were eligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was 65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomly allocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall, 561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days (rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median 10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days (rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, no significant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilation or death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24). Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or other prespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restricted to patients in whom there is a clear antimicrobial indication. Funding UK Research and Innovation (Medical Research Council) and National Institute of Health Research