Comparing Response Times Research Articles

Facial Emotion Perception in Families Affected With Borderline Personality Disorder.

Emotion perception biases may precipitate problematic interpersonal interactions in families affected with borderline personality disorder (BPD) and lead to conflictual relationships. In the present study, the authors investigated the familial aggregation of facial emotion recognition biases for neutral, happy, sad, fearful, and angry expressions in probands with BPD (n = 89), first-degree biological relatives (n = 67), and healthy controls (n = 87). Relatives showed comparable accuracy and response times to controls in recognizing negative emotions in aggregate and most discrete emotions. For sad expressions, both probands and relatives displayed slower response latencies, and they were more likely than controls to perceive sad expressions as fearful. Nonpsychiatrically affected relatives were slower than controls in responding to negative emotional expressions in aggregate, and fearful and sad facial expressions more specifically. These findings uncover potential biases in perceiving sad and fearful facial expressions that may be transmitted in families affected with BPD.

Assessing the efficacy of tablet-based simulations for learning pseudo-surgical instrumentation.

Nurses and surgeons must identify and handle specialized instruments with high temporal and spatial precision. It is crucial that they are trained effectively. Traditional training methods include supervised practices and text-based study, which may expose patients to undue risk during practice procedures and lack motor/haptic training respectively. Tablet-based simulations have been proposed to mediate some of these limitations. We implemented a learning task that simulates surgical instrumentation nomenclature encountered by novice perioperative nurses. Learning was assessed following training in three distinct conditions: tablet-based simulations, text-based study, and real-world practice. Immediately following a 30-minute training period, instrument identification was performed with comparable accuracy and response times following tablet-based versus text-based training, with both being inferior to real-world practice. Following a week without practice, response times were equivalent between real-world and tablet-based practice. While tablet-based training does not achieve equivalent results in instrument identification accuracy as real-world practice, more practice repetitions in simulated environments may help reduce performance decline. This project has established a technological framework to assess how we can implement simulated educational environments in a maximally beneficial manner.

A parameter identification method of power grid load model based on edge computing in IoT environment

Load parameter identification is one of the keys and difficult points in power system analysis and research. With the rapid development of the grid scale, the load structure is becoming more and more complex, and the adaptability of the load model structure and typical parameters to the actual power grid has become increasingly prominent. In response to this problem, a parameter identification method for power grid load models in the internet of things (IoT) environment is proposed. Firstly, a load model is established under the power IoT “cloud-network-edge-terminal” architecture. Secondly, the genetic algorithm (GA) is used to identify the parameters of the dynamic load model in the edge layer. At the same time, without changing the structure of the load model, a load parameter security protection method based on edge computing is proposed to ensure the safety and effectiveness of the load parameter identification results. Finally, the effectiveness of the proposed load parameter identification method is tested by comparing response time, load parameter identification accuracy, and edge computing loss.

Incentives and voluntary stopping: The intentional hand task

Intentional inhibition, the endogenous decision to stop or cancel an action, is arguably a more ecologically valid process than automatized, reactive, inhibition which occurs in response to an external stop signal without active decision making at the moment of inhibition. Choosing to stop an act of opening the fridge door, or of reaching for a bottle of alcohol may therefore extend beyond a reactive inhibitory process, e.g. stopping at a red traffic light. Existing paradigms of intentional inhibition focus on the proportions of intentional stops. Here we developed the Intentional Hand Task, which provides stop response times for intentional and instructed trials. Participants move a cursor by initiating an arm movement, after which a Go, Stop or Choice trial occurs. In Go trials, participants are instructed to make a speeded continuation of their arm movement towards a target whereas in the Stop trials participants are instructed to rapidly stop the already initiated movement. In Choice trials, participants chose whether to continue or stop the movement. By comparing response times when movement was stopped, we found that intentionally stopping took significantly longer than externally instructed stopping. We further investigated the influence of reward incentives, by cueing trials with either the prospect of No, Low or High reward for correctly continuing in Go trials, stopping in Stop trials or achieving a random balance of intentional Go and Stops in Choice trials. Reward incentives led to greater approach behaviours, indicated by significantly higher Go accuracy in instructed Go trials and faster response times across both Go trial types. The presence of reward incentives led to significantly fewer intentional stop choices. Our findings suggest intentional inhibition of an ongoing action may require a further decisional process. Furthermore, monetary incentives may implicitly trigger an appetitive system thus facilitating approach rather than intentional inhibitory behaviour. These findings are particularly relevant to cue-related relapse in disorders of addiction where cues may facilitate approach behaviours to the detriment of intentional inhibitory control.

196 Comparing Response Times, Intensity of Care and Outcomes between Private versus Municipal Emergency Medical Services Systems

The financial and oversight complexities associated with providing emergency medical services (EMS) in the United States ultimately led to the creation of both private and municipal-based EMS systems providing out-of-hospital medical care to our communities. For over four decades an emotional debate has spurned regarding which system can provide better coverage and quality of care to patients. Although there are many heated editorials and commentary papers on this topic, there is very little scientific research to support one method of delivery over the other. The primary objective of this study was to identify any quantitative differences in care between private and municipal EMS systems related to response times, intensity of services and patient outcomes. This IRB approved retrospective chart review included all patients presenting to a 60 bed community Emergency Department (ED) via advanced life support (ALS) ambulance between Jan 1, 2017 and March 31, 2017. Our ED receives ambulance traffic from 9 EMS agencies (7 municipal, 2 private) who provide 911 coverage for approximately 20 square miles of suburban communities. Data were collected using the hospital’s electronic records and included patient age, emergency severity index score (ESI), out-of-hospital response and transport times, IVs started, fluids and medications given, airway interventions (oxygen delivery, CPAP, Intubation), cardiac monitoring, 12 lead EKGs, ED intubations, ED mortality, hospital mortality and ICU admission. Categorical data were summarized as counts and percentages, and continuous data as means with corresponding standard deviations. Between-group mean differences were compared by calculating t-tests for independent measures. Categorical data were compared using the chi-square test for association or Fisher’s exact test. A total of 769 patients were included into the study sample with 483 in the private EMS cohort and 286 in the municipal EMS cohort. A detailed breakdown of cohort demographics, out-of-hospital response times, intensity of services, outcomes and comparisons between these groups are displayed in Table 1. A p-value ≤0.05 (two-tail) was considered statistically significant. The current operating structure of providing EMS to our communities is based around the premise that there are no significant quality and safety differences between municipal and private EMS systems. It is therefore surprising to see so many statistically and potentially clinically significant differences between these two modes of EMS delivery. Municipal EMS agencies in our community were identified to provider faster care with more intense services in nearly every out-of-hospital time and intensity of care metric. Despite these differences, no outcome disparities were identified in regards to ED and hospital mortality, ICU admissions or ED intubations. Recognizing strengths and potential weakness related to these two systems is essential as we continue to minimize any disparities in care to our communities and maximize the benefits of mutual aid within our national EMS system.

Changing in a GIF (Graphics Interchange Format): Innovations in Before and After Photography.

Before and after images are an important part of aesthetic counseling, but no studies have examined ways to optimize change detection through the layout of displayed images. This study compares 3 different image layouts to determine which presentation style improves perception of postprocedure changes. In this prospective, randomized study, participants viewed sequential images of patients who either had or had not undergone upper eyelid blepharoptosis repair or blepharoplasty ("change" and "no-change," respectively). These paired images were randomly presented in 1 of 3 formats: side-by-side, up-and-down, or alternation flicker (in which 2 images are superimposed and alternated in a graphics interchange format). Participants were asked if a procedure had been performed based on the 2 photographs. Paired t tests were used to compare response times and change detection rates between individual-level pairs of presentation modes. Of 299 recruited patients, 286 completed the study. Rate of change detection trended toward increased sensitivity for alternation flicker over static images. This became statistically significant for patients less than 45 years old. Detection rates did not differ significantly between the 2 static layouts (side-by-side and up-and down). Enhancing and customizing aesthetics counseling for different ages can improve patient understanding, expectations, and advertising. When using static photography, the layout, whether side-by-side or up-and-down, can be chosen to fit the mode of presentation with no statistically significant difference. To optimize detection of changes in before and after photography in a demographic less than 45 years old, the animated, alternation flicker format was statistically significantly more effective.

Global positioning system alerted volunteer first responders arrive before emergency medical services in more than four out of five emergency calls

AimTo evaluate response rates for volunteer first responders (VFRs) activated by use of a smartphone GPS-tracking system and to compare response times of VFRs with those of emergency medical services (EMS). Furthermore, to evaluate 30-day-survival after out-of-hospital cardiac arrest (OHCA) on a rural island. MethodsSince 2012 a GPS-tracking system has been used on a rural island to activate VFRs during all emergency calls requesting an EMS. When activated, three VFRs were recruited and given distinct roles, including collection of the nearest automatic external defibrillator (AED). We retrospectively investigated EMS response data from April 2012 to December 2017. These were matched with VFR response times from the GPS-tracking system. The 30-day survival in OHCA patients was also assessed. ResultsIn 2266 of 2662 emergency calls (85%) at least one VFR arrived to the site before EMS. Median response times for VFRs (n = 2662) was 4:46 min:sec (IQR 3:16–6:52) compared with 10:13 min:sec (6:14–13:41) for EMS (p < 0.0001). A total of 17 OHCAs took place in public locations and 65 in residential areas. Thirty-day survival in these were 24% and 15%, respectively. ConclusionUse of a smartphone GPS-tracking system to dispatch VFRs ensures that in more than four of five cases, a VFR arrives to the site before EMS. Response times for VFRs were also found to be lower than EMS response times. Finally, the 30-day survival of OHCA patients in a rural area, based on these results, surpass our expectations.

Adaptive partitioning and indexing for in situ query processing

The constant flux of data and queries alike has been pushing the boundaries of data analysis systems. The increasing size of raw data files has made data loading an expensive operation that delays the data-to-insight time. To alleviate the loading cost, in situ query processing systems operate directly over raw data and offer instant access to data. At the same time, analytical workloads have increasing number of queries. Typically, each query focuses on a constantly shifting—yet small—range. As a result, minimizing the workload latency requires the benefits of indexing in in situ query processing. In this paper, we present an online partitioning and indexing scheme, along with a partitioning and indexing tuner tailored for in situ querying engines. The proposed system design improves query execution time by taking into account user query patterns, to (i) partition raw data files logically and (ii) build lightweight partition-specific indexes for each partition. We build an in situ query engine called Slalom to showcase the impact of our design. Slalom employs adaptive partitioning and builds non-obtrusive indexes in different partitions on-the-fly based on lightweight query access pattern monitoring. As a result of its lightweight nature, Slalom achieves efficient query processing over raw data with minimal memory consumption. Our experimentation with both microbenchmarks and real-life workloads shows that Slalom outperforms state-of-the-art in situ engines and achieves comparable query response times with fully indexed DBMS, offering lower cumulative query execution times for query workloads with increasing size and unpredictable access patterns.

Design and Analysis of High-Resolution Electrostatic Adhesive Brakes Towards Static Refreshable 2.5D Tactile Shape Display.

Tactile displays are haptic devices capable of rendering shape and texture information. Unsolved challenges in building tactile shape displays include their traditionally large form factors, low spatial resolution, and high costs. Using electrostatic adhesion to individually brake each pin and a single platform for global actuation, we developed a prototype static refreshable tactile shape display with high spatial resolution (1.7 mm pitch, 0.8 mm pin width; 4 mm pitch, 1.6 mm pin width), high resistance force (76.3 gf static-loading force per pin for 1.6 mm width) and low cost ($0.11 USD per pin for raw material). We present an analytical model of our electroadhesive brake mechanism and evaluate its maximum contact force and robustness in various conditions. To demonstrate the mechanism's potential, we built a static tactile shape display prototype with a 4×2 array of pins controlled using electroadhesive brakes. To further increase maximsum contact force allowed by our device, we develop and evaluate a global mechanical clutch which can be engaged during user interaction. A user study is carried out to compare our static tactile shape display's performance with printed 2.5D tactile graphics in a shape recognition task, and comparable shape recognition rates and response times are observed.

MXene Ti3C2Tx: A Promising Photothermal Conversion Material and Application in All‐Optical Modulation and All‐Optical Information Loading

AbstractAll‐optical modulators, where one light modulates the parameters of another light (intensity, phase, frequency, etc.) without external electronic control, have drawn extraordinary attention in all‐optical information processing. In this contribution, by taking advantage of the two‐pass structure of Michelson interferometer and the strong photothermal conversion efficiency of MXene nanomaterials, an all‐optical modulator is demonstrated with a modulation depth of &gt;27 dB, a free spectrum range of 16.8 nm and a pump‐induced phase shift slope of 0.043 π mW−1. Moreover, the all‐optical modulator is successfully employed to switch on/off the intensity of the signal light and load information from one channel to another with comparable response time and baudrate. It is believed that the MXene‐based all‐optical modulator will open a door to practical applications of 2D materials‐based all‐optical devices in all‐optical signal processing.

Estimating and Comparing Response Times in Traditional and Connected Environments

Response time (RT) is a critical human factor that influences traffic flow characteristics and traffic safety, and is governed by drivers’ decision-making behavior. Unlike the traditional environment (TE), the connected environment (CE) provides information assistance to drivers. This in-vehicle informed environment can influence drivers’ decision-making and thereby their RTs. Therefore, to ascertain the impact of CE on RT, this study develops RT estimation methodologies for TE (RTEM-TE) and CE (RTEM-CE), using vehicle trajectory data. Because of the intra-lingual inconsistency among traffic engineers, modelers, and psychologists in the usage of the term RT, this study also provides a ubiquitous definition of RT that can be used in a wide range of applications. Both RTEM-TE and RTEM-CE are built on the fundamental stimulus–response relationship, and they utilize the wavelet-based energy distribution of time series of speeds to detect the stimulus–response points. These methodologies are rigorously examined for their efficiency and accuracy using noise-free and noisy synthetic data, and driving simulator data. Analysis results demonstrate the excellent performance of both the methodologies. Moreover, the analysis shows that the mean RT in CE is longer than the mean RT in TE.

A US National Study of the Association Between Income and Ambulance Response Time in Cardiac Arrest

Emergency medical services (EMS) provide critical prehospital care, and disparities in response times to time-sensitive conditions, such as cardiac arrest, may contribute to disparities in patient outcomes. To investigate whether ambulance 9-1-1 times were longer in low-income vs high-income areas and to compare response times with national benchmarks of 4, 8, or 15 minutes across income quartiles. A retrospective cross-sectional study was performed of the 2014 National Emergency Medical Services Information System data in June 2017 using negative binomial and logistic regressions to examine the association between zip code-level income and EMS response times. The study used ambulance 9-1-1 response data for out-of-hospital cardiac arrest from 46 of 50 state repositories (92.0%) in the United States. The sample included 63 600 cardiac arrest encounters of patients who did not die on scene and were transported to the hospital. Four time measures were examined, including response time, on-scene time, transport time, and total EMS time. The study compared response times with EMS response time benchmarks for responding to cardiac arrest calls within 4, 8, and 15 minutes. The study sample included 63 600 cardiac arrest encounters of patients (mean [SD] age, 60.6 [19.0] years; 57.9% male), with 37 550 patients (59.0%) from high-income areas and 8192 patients (12.9%) from low-income areas. High-income areas had greater proportions of white patients (70.1% vs 62.2%), male patients (58.8% vs 54.1%), privately insured patients (29.4% vs 15.9%), and uninsured patients (15.3% vs 7.9%), while low-income areas had a greater proportion of Medicaid-insured patients (38.3% vs 15.8%). The mean (SD) total EMS time was 37.5 (13.6) minutes in the highest zip code income quartile and 43.0 (18.8) minutes in the lowest. After controlling for urban zip code, weekday, and time of day in regression analyses, total EMS time remained 10% longer (95% CI, 9%-11%; P < .001), translating to 3.8 minutes longer in the poorest zip codes. The EMS response time to patients in high-income zip codes was more likely to meet 8-minute and 15-minute cutoffs compared with low-income zip codes. Patients with cardiac arrest from the poorest neighborhoods had longer EMS times compared with those from the wealthiest, and response times were less likely to meet national benchmarks in low-income areas, which may lead to increased disparities in prehospital delivery of care over time.

On the Power-of-d-choices with Least Loaded Server Selection

Motivated by distributed schedulers that combine the power-of-d-choices with late binding and systems that use replication with cancellation-on-start, we study the performance of the LL(d) policy which assigns a job to a server that currently has the least workload among d randomly selected servers in large-scale homogeneous clusters. We consider general job size distributions and propose a partial integro-differential equation to describe the evolution of the system. This equation relies on the earlier proven ansatz for LL(d) which asserts that the workload distribution of any finite set of queues becomes independent of one another as the number of servers tends to infinity. Based on this equation we propose a fixed point iteration for the limiting workload distribution and study its convergence. For exponential job sizes we present a simple closed form expression for the limiting workload distribution that is valid for any work-conserving service discipline as well as for the limiting response time distribution in case of first-come-first-served scheduling. We further show that for phase-type distributed job sizes the limiting workload and response time distribution can be expressed via the unique solution of a simple set of ordinary differential equations. Numerical and analytical results that compare response time of the classic power-of-d-choices algorithm and the LL(d) policy are also presented and the accuracy of the limiting response time distribution for finite systems is illustrated using simulations.

Probabilistic motor sequence learning in a virtual reality serial reaction time task

The serial reaction time task is widely used to study learning and memory. The task is traditionally administered by showing target positions on a computer screen and collecting responses using a button box or keyboard. By comparing response times to random or sequenced items or by using different transition probabilities, various forms of learning can be studied. However, this traditional laboratory setting limits the number of possible experimental manipulations. Here, we present a virtual reality version of the serial reaction time task and show that learning effects emerge as expected despite the novel way in which responses are collected. We also show that response times are distributed as expected. The current experiment was conducted in a blank virtual reality room to verify these basic principles. For future applications, the technology can be used to modify the virtual reality environment in any conceivable way, permitting a wide range of previously impossible experimental manipulations.

Critical Test Result Notification via Mobile Phone-Based Automated Text Message System in the Radiologic Field: Single Institutional Experience

PurposeTo investigate the feasibility of sharing critical test result (CTR) notifications (CTRNs) via automated text messaging. Materials and methodsCTRNs via automated text messaging was used to notify physicians of CTRs in a tertiary hospital with 1,786 beds. From June 2016 to September 2016, notifications for 545 CTRs were given via a CTRN system. Among them, 490 CTRs (292 male and 198 female patients; mean age, 53.6 years old [range, 1-88]) were included in analysis. CTR levels (CTRLs) were assigned to four categories (CTRL1 to CTRL3 and unclassified) when reported, and reclassified into three CTRLs according to their clinical relevance and urgency. Response time was defined as time lapse between CTR reporting and documentation by physicians. Analysis of variance was performed to compare response times according to CTRLs and patients’ location. ResultsCorresponding actions were taken in 404 of 490 cases (82.4%) without any delayed CTRN-related morbidity. There were 15 CTRL1 (3.1%), 50 CTRL2 (10.2%), 112 CTRL3 (22.9%) cases, and the remaining 313 CTRL cases were unclassified. After reclassification, CTRL1, CTRL2, and CTRL3 were 81 (16.5%), 177 (36.1%), and 232 cases (47.3%), respectively. Response time of reclassified CTRL3 was significantly longer than that of reclassified CTRL1 (median 23.0, [interquartile range 2.0-133.5] hours versus 4.0 [0.0-22.0] hours; P < .001). Response time of outpatient cases (80.0 [6.0 to 157.0] hours) was significantly longer (P < .001) than those of inpatient (3.0 [0.0-16.0]) and emergency department cases (5.0 [1.0-21.0]). ConclusionAutomated text messaging could be a feasible option for CTRNs in the radiologic field. Further large-scale investigations regarding efficiency of this system are warranted.

"To Name or Not to Name: That is the Question": The Role of Response Inhibition in Reading.

Reading is a complex process that includes the integration of information about letters (graphemes) and sounds (phonemes). In many circumstances, such as noisy environments, response inhibition is an additional factor that plays a marked role in successful oral reading. Response inhibition can take the form of task relevant inhibition (i.e., foils in a go/no-go task) and task irrelevant inhibition (i.e., distractor information). Here we investigated task relevant inhibition by having participants (N = 30) take part in two tasks: go/no-go naming with nonwords foils (GNG-NW) and go/no-go naming with pseudohomophones foils (GNG-PH). Also, we investigated the addition of task irrelevant inhibition by having participants (N = 28) take part in two tasks: GNG-NW + information masking and GNG-PH + information masking. We provide evidence that during a task relevant inhibition task, sub-word sound level information can be successfully inhibited, as evidenced by comparable response times for regular words and exception words, provided the foils do not contain familiar sound-based information (GNG-NW). In contrast, regular words were read aloud faster than exception words in a GNG-PH task, indicating that sub-word level interference occurs when the foils contain familiar sound-based information. The addition of task irrelevant inhibition (i.e., information masking at the phoneme level), served to increase response time overall, but did not impact the pattern of response times between regular words and exception words. Together these findings provide useful information regarding the role of response inhibition in word recognition and may be useful in computational models of word recognition and future work may benefit from accounting for the effects outlined in this paper.

Will Rogers Is Jenksing Police Response Times

Because police jurisdictions typically rely on different call classification schemes and handle a different mix of calls, it is difficult to compare multi-priority police response time distributions between two or more jurisdictions. For the same reasons, it can be challenging to compare response time trends over time, even within a given police jurisdiction. Hypothetical examples illustrate the main analytical challenges. Then, a simple clustering approach, the Jenks natural breaks method, is demonstrated. This approach can be used to objectively compare police response time distributions. The resulting comparisons remain unaffected by differences or changes in call classification rules and cannot be easily manipulated or skewed, either intentionally or inadvertently. Although the discussion is framed within a police context, the proposed analytical approach has the potential to be useful for other emergency services and benchmarking settings.

An investigation of spatial representation of pitch in individuals with congenital amusia.

Spatial representation of pitch plays a central role in auditory processing. However, it is unknown whether impaired auditory processing is associated with impaired pitch-space mapping. Experiment 1 examined spatial representation of pitch in individuals with congenital amusia using a stimulus-response compatibility (SRC) task. For amusic and non-amusic participants, pitch classification was faster and more accurate when correct responses involved a physical action that was spatially congruent with the pitch height of the stimulus than when it was incongruent. However, this spatial representation of pitch was not as stable in amusic individuals, revealed by slower response times when compared with control individuals. One explanation is that the SRC effect in amusics reflects a linguistic association, requiring additional time to link pitch height and spatial location. To test this possibility, Experiment 2 employed a colour-classification task. Participants judged colour while ignoring a concurrent pitch by pressing one of two response keys positioned vertically to be congruent or incongruent with the pitch. The association between pitch and space was found in both groups, with comparable response times in the two groups, suggesting that amusic individuals are only slower to respond to tasks involving explicit judgments of pitch.

Assessing inhibitory control in early-stage Alzheimer's and Parkinson's disease using the Hayling Sentence Completion Test.

The ability to inhibit irrelevant information is essential for coping with the demands of everyday life. Inhibitory deficits are present in all stages of dementia and commonly observed in people with Parkinson's disease (PwPD). Inhibition is frequently tested with the Stroop test, but this may lack ecological validity. This study investigates inhibitory control in people with Alzheimer's disease dementia (PwD) and PwPD using the Hayling Sentence Completion Test (HSCT), which aspires to be a more ecologically valid task. A total of 117 people completed the HSCT, a test where participants have to complete a sentence with an unrelated word. The sample comprised 30 PwD, 33 PwPD, and 54 healthy older controls. We compared response times and the number and type of errors across the three groups. Completion time in Part B (Inhibition) did not distinguish between PwD, PwPD, and controls when controlling for the initiation speed, but a higher proportion of Category A errors (producing a word that fits the sentence when instructed otherwise) was a unique characteristic of inferior performance in PwD and PwPD. While not part of the standard test scoring protocol, controlling for the initiation speed and distinguishing between speed and accuracy in test performance appear to be essential for accurate evaluation of the inhibitory control in HSCT in older people. The findings suggest that the HSCT may be sensitive to verbal suppression deficits and may provide insight into inhibitory control in PwD and PwPD.

Slalom

The constant flux of data and queries alike has been pushing the boundaries of data analysis systems. The increasing size of raw data files has made data loading an expensive operation that delays the data-to-insight time. Hence, recent in-situ query processing systems operate directly over raw data, alleviating the loading cost. At the same time, analytical workloads have increasing number of queries. Typically, each query focuses on a constantly shifting -- yet small -- range. Minimizing the workload latency, now, requires the benefits of indexing in in-situ query processing. In this paper, we present Slalom, an in-situ query engine that accommodates workload shifts by monitoring user access patterns. Slalom makes on-the-fly partitioning and indexing decisions, based on information collected by lightweight monitoring. Slalom has two key components: (i) an online partitioning and indexing scheme, and (ii) a partitioning and indexing tuner tailored for in-situ query engines. When compared to the state of the art, Slalom offers performance benefits by taking into account user query patterns to (a) logically partition raw data files and (b) build for each partition lightweight partition-specific indexes. Due to its lightweight and adaptive nature, Slalom achieves efficient accesses to raw data with minimal memory consumption. Our experimentation with both micro-benchmarks and real-life workloads shows that Slalom outperforms state-of-the-art in-situ engines (3 -- 10×), and achieves comparable query response times with fully indexed DBMS, offering much lower (∼ 3×) cumulative query execution times for query workloads with increasing size and unpredictable access patterns.