bluuebunny/crossref_metadata_2025 huggingface dataset:
Effective indexing for dynamic structural graph clustering
Authors: Zhang Fangyuan , Wang Sibo
Published: September 2022

Graph clustering is a fundamental data mining task that clusters vertices into different groups. The structural graph clustering algorithm (
SCAN
) is a widely used graph clustering algorithm that derives not only clustering results, but also special roles of vertices like hubs and outliers. In this paper, we consider structural graph clustering on dynamic graphs under Jaccard similarity. The state-of-the-art index-based solution focuses on static graphs and incurs prohibitive update costs to maintain indices. Lately, an efficient approximate dynamic structural graph clustering algorithm Dyn-StrClu under Jaccard similarity is proposed. However, their solution needs to fix input parameters while parameter settings of SCAN usually need to be fine-tuned to achieve good clustering results.

Motivated by these limitations, we present a study on devising effective index structures for SCAN algorithm on dynamic graphs. Similar to the state-of-the-art dynamic scheme, our main idea to reduce the time complexity is still by bringing approximation to clustering results. However, our solution does not need to fix the input parameters. To achieve this, our solution includes two key components. The first is to maintain a bottom-
k
sketch for each vertex so that the similarities of affected vertices can be easily updated. The second key is a bucketing strategy that allows us to update clustering results and roles of vertices efficiently. Our theoretical analysis shows that our proposed algorithm achieves
O
(log
n
· log
M
+
m
/
pf
) expected update cost and guarantees to return approximate clustering results with probability 1 -
pf
after up to
M
updates. Extensive experiments show that our solution is up to two orders of magnitude faster than the state-of-the-art index-based solution while still achieving high-quality clustering results.
Are updatable learned indexes ready?
Authors: Wongkham Chaichon , Lu Baotong , Liu Chris , Zhong Zhicong , Lo Eric , Wang Tianzheng
Published: September 2022

Recently, numerous promising results have shown that updatable learned indexes can perform better than traditional indexes with much lower memory space consumption. But it is unknown how these learned indexes compare against each other and against the traditional ones under realistic workloads with changing data distributions and concurrency levels. This makes practitioners still wary about how these new indexes would actually behave in practice. To fill this gap, this paper conducts the first comprehensive evaluation on updatable learned indexes. Our evaluation uses ten real datasets and various workloads to challenge learned indexes in three aspects: performance, memory space efficiency and robustness. Based on the results, we give a series of takeaways that can guide the future development and deployment of learned indexes.
FHL-cube
Authors: Liu Ziyi , Li Lei , Zhang Mengxuan , Hua Wen , Zhou Xiaofang
Published: September 2022

Multi-Constraint Shortest Path (
MCSP
) generalizes the classic shortest path from single to multiple criteria such that more personalized needs can be satisfied. However,
MCSP
query is essentially a high-dimensional skyline problem and thus time-consuming to answer. Although the current
Forest Hop Labeling (FHL)
index can answer
MCSP
efficiently, it takes a long time to construct and lacks the flexibility to handle arbitrary criteria combinations. In this paper, we propose a skyline-cube-based
FHL
index that can handle the flexible
MCSP
efficiently. Firstly, we analyze the relation between low and high-dimensional skyline paths theoretically and use a cube to organize them hierarchically. After that, we propose methods to derive the high-dimensional path from the lower ones, which can adapt to the flexible scenario naturally and reduce the expensive high dimensional path concatenation. Then we introduce efficient methods for both single and multi-hop cube concatenations and propose pruning methods to further alleviate the computation. Finally, we improve the
FHL
structure with lower height for faster construction and query. Experiments on real-life road networks demonstrate the superiority of our method over the state-of-the-art.
Optimizing differentially-maintained recursive queries on dynamic graphs
Authors: Ammar Khaled , Sahu Siddhartha , Salihoglu Semih , Özsu M. Tamer
Published: September 2022

Differential computation (DC) is a highly general incremental computation/view maintenance technique that can maintain the output of an arbitrary and possibly recursive dataflow computation upon changes to its base inputs. As such, it is a promising technique for graph database management systems (GDBMS) that support continuous recursive queries over dynamic graphs. Although differential computation can be highly efficient for maintaining these queries, it can require prohibitively large amount of memory. This paper studies how to reduce the memory overhead of DC with the goal of increasing the scalability of systems that adopt it. We propose a suite of optimizations that are based on dropping the differences of operators, both completely or partially, and recomputing these differences when necessary. We propose deterministic and probabilistic data structures to keep track of the dropped differences. Extensive experiments demonstrate that the optimizations can improve the scalability of a DC-based continuous query processor.
Tair-PMem
Authors: Gong Caixin , Tian Chengjin , Wang Zhengheng , Wang Sheng , Wang Xiyu , Fu Qiulei , Qin Wu , Qian Long , Chen Rui , Qi Jiang , Wang Ruo , Zhu Guoyun , Yang Chenghu , Zhang Wei , Li Feifei
Published: September 2022

In-memory databases (IMDBs) have been the backbone of modern systems that demand high throughput and low latency. Because of the cost and volatility of DRAM, IMDBs become incompetent when dealing with workloads that require large data volume and strict durability. The emergence of non-volatile memory (NVM) brings new opportunities for IMDBs to tackle this situation. However, it is non-trivial to build an NVM-based IMDB, due to performance degradation, NVM programming complexity, and other challenges. In this paper, we present
Tair-PMem
, an NVM-based enterprise-strength database atop Redis, the most popular IMDB.
Tair-PMem
adopts a well-controlled data layout and a
log-as-user-data
design to mitigate NVM overheads. It eases the NVM programming complexity by providing a hybrid memory programming toolkit. To better leverage the enterprise-strength features and implementations from Redis,
Tair-PMem
retrofits it in a less intrusive way to achieve full compatibility and stability, while retaining its advanced features. With all of the above techniques elaborately implemented,
Tair-PMem
satisfies full durability, high throughput, and low latency at the same time.
Tair-PMem
has now been publicly available as a cloud service on Alibaba Cloud. To the best of our knowledge,
Tair-PMem
is the first cloud service that makes good use of the persistence capability of NVM.
TencentCLS
Authors: Yu Muzhi , Lin Zhaoxiang , Sun Jinan , Zhou Runyun , Jiang Guoqiang , Huang Hua , Zhang Shikun
Published: September 2022

With the trend of cloud computing, the cloud log service is becoming increasingly important, as it plays a critical role in tasks such as root cause analysis, service monitoring and security audition. To meet these needs, we provide Tencent Cloud Log Service (TencentCLS), a one-stop solution for log collection, storage, analysis and dumping. It currently hosts more than a million tenants, of which the largest ones can generate up to PB-level logs per day.

The most important challenge that TencentCLS faces is to support both low-latency and resource-efficient queries on such large quantities of log data. To address that challenge, we propose a novel search engine based upon Lucene. The system features a novel procedure for querying logs within a time range, an indexing technique for the time field, as well as optimized query algorithms dedicated to multiple critical and common query types.

As a result, the search engine at TencentCLS gains significant performance improvements against Lucene. It achieves 20x performance increase with standard queries, and 10x performance increase with histogram queries in massive log query scenarios. In addition, TencentCLS also supports storing and querying with microsecond-level time precision, as well as the microsecond-level time order preservation capability.
Meta's next-generation realtime monitoring and analytics platform
Authors: Harizopoulos Stavros , Hopper Taylor , Mo Morton , Chandrasekaran Shyam Sundar , Chen Tongguang , Cui Yan , Ganesh Nandini , Helmling Gary , Pham Hieu , Wong Sebastian
Published: September 2022

Unlike traditional database systems where data and system availability are tied together, there is a wide class of systems targeting realtime monitoring and analytics over structured logs where these properties can be decoupled. In these systems, responsiveness and freshness of data are often more important than perfectly complete answers. One such system is Meta's Scuba [2].

Historically, Scuba has favored system availability along with speed and freshness of results over data completeness and durability. While these choices allowed Scuba to grow from terabyte scale to petabyte scale and continue onboarding a variety of use cases, they also came at an operational cost of dealing with incomplete data and managing data loss.

In this paper, we present the next generation of Scuba's architecture, codenamed
Kraken
, which decouples storage management from the query serving system and introduces a single, durable source of truth. This enables tangible improvements to system fault tolerance and query performance while still respecting tolerable bounds of client observed data freshness. We also describe the journey of how we deployed Kraken into full production as we gradually turned off the older system with no user-visible down time.
CaJaDE
Authors: Li Chenjie , Lee Juseung , Miao Zhengjie , Glavic Boris , Roy Sudeepa
Published: September 2022

In this work, we demonstrate CaJaDE (Context-Aware Join-Augmented Deep Explanations), a system that explains query results by augmenting provenance with contextual information from other related tables in the database. Given two query results whose difference the user wants to understand, we enumerate possible ways of joining the
provenance
(i.e., contributing input tuples) of these two query results with tuples from other relevant tables in the database that were
not
used in the query. We use patterns to concisely explain the difference between the
augmented provenance
of the two query results. CaJaDE, through a comprehensive UI, enables the user to formulate questions and explore explanations interactively.
MOCHA
Authors: Tan Jess , Yeo Desmond , Neoh Rachael , Chua Huey-Eng , Bhowmick Sourav S
Published: September 2022

The database systems course is offered in many major universities. A key learning goal of learners taking such a course is to understand how sql queries are processed in an RDBMS in
practice.
To this end, comprehension of the impact of various physical operators on the selected query execution plan (QEP) of a query is paramount. Unfortunately, off-the-shelf RDBMS typically only expose the QEP to users without revealing information about the impact of alternative choices of various physical operators on it in a
user-friendly
manner to aid learning. In this demonstration, we present a novel system called MOCHA that facilitates exploration and visualization of the impact of alternative physical operator choices on the QEP of a given SQL query. MOCHA accepts an SQL query as input, and
compares
and
visualizes
the QEP and
alternative plans
which are selected based on learner-specified
operator preferences.
Furthermore, it intuitively
explains
why the key operators in a QEP are chosen by connecting them to established knowledge in the literature.
DPDS
Authors: Chapman Adriane , Lauro Luca , Missier Paolo , Torlone Riccardo
Published: September 2022

Successful data-driven science requires a complex combination of data engineering pipelines and data modelling techniques. Robust and defensible results can only be achieved when each step in the pipeline that is designed to clean, transform and alter data in preparation for data modelling can be justified, and its effect on the data explained. The
DPDS
toolkit presented in this paper is designed to make such justification and explanation process an integral part of data science practice, adding value while remaining as un-intrusive as possible to the analyst. Catering to the broad community of python/pandas data engineers,
DPDS
implements an observer pattern that is able to capture the fine-grained provenance associated with each individual element of a dataframe, across multiple transformation steps. The resulting provenance graph is stored in Neo4j and queried through a UI, with the goal of helping engineers and analysts to justify and explain their choice of data operations, from raw data to model training, by highlighting the details of the changes through each transformation.
DBMS annihilator
Authors: Lerner Alberto , Jasny Matthias , Jepsen Theo , Binnig Carsten , Cudré-Mauroux Philippe
Published: September 2022

Modern DBMS engines can achieve unprecedented transaction processing speeds thanks to the invention of clever data structures, concurrency schemes, and improvements in CPU and memory subsystems. However, developing realistic and efficient networked clients to benchmark these systems remains daunting. Simply put, traditional client-side networking stacks present high overheads and thus cannot exercise the high performance that modern DBMSs can, in principle, provide. In this demo, we propose a different approach to benchmarking; we showcase a new framework that leverages hardware-software co-design. With our system, which we call the DBMS Annihilator, workloads are specified using a high-level language that is then converted into hardware (FPGA) for execution. The hardware we use is a commodity Smart NIC, allowing workloads to be fully reproducible to anyone using such hardware. A software console and dashboard provide real-time visibility and interactivity, which we explore in this demo.
Theseus
Authors: Boniol Paul , Paparrizos John , Kang Yuhao , Palpanas Themis , Tsay Ruey S. , Elmore Aaron J. , Franklin Michael J.
Published: September 2022

The detection of anomalies in time series has gained ample academic and industrial attention, yet, no comprehensive benchmark exists to evaluate time-series anomaly detection methods. Therefore, there is no final verdict on which method performs the best (and under what conditions). Consequently, we often observe methods performing exceptionally well on one dataset but surprisingly poorly on another, creating an illusion of progress. To address these issues, we thoroughly studied over one hundred papers, and summarized our effort in TSB-UAD, a new benchmark to evaluate univariate time series anomaly detection methods. In this paper, we describe Theseus, a modular and extensible web application that helps users navigate through the benchmark, and reason about the merits and drawbacks of both anomaly detection methods and accuracy measures, under different conditions. Overall, our system enables users to compare 12 anomaly detection methods on 1980 time series, using 13 accuracy measures, and decide on the most suitable method and measure for some application.
DORIAN in action
Authors: Redyuk Sergey , Kaoudi Zoi , Schelter Sebastian , Markl Volker
Published: September 2022

Existing automated machine learning solutions and intelligent discovery assistants are popular tools that facilitate the end-user with the design of data science (DS) pipelines. However, they yield limited applicability for a wide range of real-world use cases and application domains due to (a) the limited support of DS tasks; (b) a small, static set of available operators; and (c) restriction to evaluation processes with quantifiable loss functions. We demonstrate DORIAN, a human-in-the-loop approach for the
assisted design of data science pipelines
that supports a large and growing set of DS tasks, operators, and arbitrary user-defined evaluation processes. Based on the user query, i.e., a dataset and a DS task, DORIAN computes a ranked list of candidate pipelines that the end-user can choose from, alter, execute and evaluate. It stores executed pipelines in an experiment database and utilizes similarity-based search to identify relevant previously-run pipelines from the experiment database. DORIAN also takes user interaction into account to improve suggestions over time. We show how users can interact with DORIAN to create and compare DS pipelines on various real-world DS tasks without the need for writing any code.
Towards AI-powered data-driven education
Authors: Amer-Yahia Sihem
Published: September 2022

Educational platforms are increasingly becoming AI-driven. Besides providing a wide range of course filtering options, personalized recommendations of learning material and teachers are driving today's research. While accuracy plays a major role in evaluating those recommendations, many factors must be considered including learner retention, throughput, upskilling ability, equity of learning opportunities, and satisfaction. This creates a tension between learner-centered and platform-centered approaches. I will describe research at the intersection of data-driven recommendations and education theory. This includes multi-objective algorithms that leverage collaboration and affinity in peer learning, studying the impact of learning strategies on platforms and people, and automating the generation of sequences of courses. The paper ends with a discussion of the central role data management systems could play in enabling modern online education.
The costs and benefits of certification for community forests managed by traditional peoples in south-eastern Tanzania
Authors: Frey G.E. , Charnley S. , Makala J.
Published: September 2022

Community forests managed by indigenous, traditional, and local communities must be environmentally, socially, and economically sustainable for their benefits to persist. Certification of community forests communicates that products harvested there meet these standards. However, certification
of community forests has been limited, particularly in Africa. Financial analysis, review of audit reports, and a survey of forest managers were used to explore monetary and non-monetary social costs and benefits of Forest Stewardship Council certification for 14 timberproducing community
forests managed by traditional peoples in south-eastern Tanzania. Direct monetary costs of certification outweighed monetary benefits, threatening economic sustainability. Nevertheless, forest managers believed that community forests should retain certification because they valued its non-monetary
benefits, which were consistent with the Forest Stewardship Council's social principles. This study demonstrates that certification of community forests can help indigenous and traditional peoples ensure safe working conditions, strengthen forest tenure rights, sustain multiple community benefits,
and protect culturally-important sites, however, financial barriers persist.
Samråd: an institutional arrangement in the context of forestry and reindeer husbandry in northern Sweden
Authors: Roos U. , Lidestav G. , Sandström S. , Sandström P.
Published: September 2022

In northern Sweden, forestry and reindeer husbandry overlap spatially and judicially. To mitigate conflicting objectives regarding land use, the concept of " samråd" has been introduced as a form of institutional arrangement of environmental politics. This study
explores how stakeholders have interpreted this concept and corresponding processes from its first introduction in 1923 to 2019. Language, including the cartographic language, is regarded as a mean for argumentation. Results show that the understandings and expectations of samråd
differ among actors in terms of procedure, issues, efficiency and outcomes. As compared to the lexical definition and understanding, the samråd practice has merely become an instrument for information exchange before decisions are made, rather than a functional arrangement for
conflict mitigation. This ambiguity is in parallel to a deregulated forest policy and a watered-down meaning of samråd in public administration. However, the transformative potential of participatory mapping suggests a new way of thinking about power relations in land use matters
within the framework of samråd.
Bounds for eigenfunctions of the Neumann p-Laplacian on noncompact Riemannian manifolds
Authors: Barletta Giuseppina , Cianchi Andrea , Maz’ya Vladimir
Published: September 2022

Eigenvalue problems for the p-Laplace operator in domains with finite volume, on noncompact Riemannian manifolds,
are considered. If the domain does not coincide with the whole manifold, Neumann boundary conditions are imposed.
Sharp assumptions ensuring

L
q

{L^{q}}

- or

L
∞

{L^{\infty}}

-bounds for eigenfunctions are
offered either in terms of the isoperimetric function or of the isocapacitary function of the domain.
On the new bicomplex generalization of Hurwitz–Lerch zeta function with properties and applications
Authors: Chandola Ankita , Pandey Rupakshi Mishra , Nisar Kottakkaran Sooppy
Published: September 2022

In the recent years, various authors introduced different generalizations of the Hurwitz–Lerch zeta function and discussed its various properties. The main aim of our study is to introduce a new bicomplex generalization of
the Hurwitz–Lerch zeta function using the new generalized form of the beta function that involves the Appell series and Lauricella functions. The new bicomplex generalization of the Hurwitz–Lerch zeta function reduces to some already known functions like the Hurwitz–Lerch zeta function, Hurwitz zeta function, Riemann zeta function and polylogarithmic function. Its different properties such as recurrence relation, summation formula, differentiation formula, generating relations and integral representations are investigated. All results induced are general in nature and reducible to already known results. As an application of the new bicomplex generalization of the Hurwitz–Lerch zeta function, we have developed a new generalized form of fractional kinetic equation and obtained its solution using the natural transform.
Molecular characterization of weak Hardy spaces associated with ball quasi-Banach function spaces on spaces
of homogeneous type with its applications to Littlewood–Paley function characterizations
Authors: Sun Jingsong , Yang Dachun , Yuan Wen
Published: September 2022

Let

(
𝕏
,
d
,
μ
)

{(\mathbb{X},d,\mu)}

be a space of homogeneous type
in the sense of R. R. Coifman and G. Weiss, and let

X
⁢

(
𝕏
)

{X(\mathbb{X})}

be a ball quasi-Banach
function space on

𝕏

{\mathbb{X}}

. In this article, the authors introduce the weak Hardy space

W
⁢
H

~

X

⁢

(
𝕏
)

{\widetilde{WH}_{X}(\mathbb{X})}

associated with

X
⁢

(
𝕏
)

{X(\mathbb{X})}

via the Lusin area function.
Then the authors characterize

W
⁢
H

~

X

⁢

(
𝕏
)

{\widetilde{WH}_{X}(\mathbb{X})}

by the
molecule, the grand maximal function, and the Littlewood–Paley g-function
and

g
λ
*

{g^{*}_{\lambda}}

-function. Moreover, all these results have a wide generality. Particularly, the
results of this article are also new even when they are applied, respectively, to weighted Lebesgue spaces, Orlicz
spaces, and variable Lebesgue spaces, which actually are new even on RD-spaces
(that is, spaces of homogeneous type with additional reverse doubling condition).
The main novelties of this article exist in that the authors take full advantage of
the geometrical properties of

𝕏

{\mathbb{X}}

expressed by both the dyadic
cubes and the exponential decay of the approximations of the identity to
overcome the difficulties caused by the deficiencies of both the explicit expression of the quasi-norm
of

X
⁢

(
𝕏
)

{X(\mathbb{X})}

and the reverse doubling condition of μ, and that
the authors use the tent space on

𝕏
×
ℤ

{\mathbb{X}\times\mathbb{Z}}

to characterize

W
⁢
H

~

X

⁢

(
𝕏
)

{\widetilde{WH}_{X}(\mathbb{X})}

by the Littlewood–Paley

g
λ
*

{g^{*}_{\lambda}}

-function,
where the range of λ might be best possible in some cases.
Geometric characterizations of Gromov hyperbolic Hölder domains
Authors: Zhou Qingshan , Rasila Antti
Published: September 2022

In this paper, we investigate Hölder continuity of quasiconformal mappings in

ℝ
n

{\mathbb{R}^{n}}

from the points of view of quasihyperbolic geometry and the theory of Gromov hyperbolic spaces. We establish several characterizations of Gromov hyperbolic domains satisfying the Gehring–Martio-type quasihyperbolic boundary conditions. As applications, we generalize certain results concerning Hölder continuity of conformal mappings, establishing counterparts of results of Becker and Pommerenke, Smith and Stegenga, and Näkki and Palka in higher-dimensional Euclidean spaces.
Design and parametric optimization of a fan-notched baffle structure mixer for enhancement of liquid-liquid two-phase chemical process
Authors: Zhao Shuangfei , Nie Yingying , Wei Yimin , Yu Pengjie , He Wei , Zhu Ning , Li Yuguang , Ji Dong , Guo Kai
Published: September 2022

The mixing uniformity plays a crucial role in a liquid-liquid two-phase chemical process. To quantify the uniformity of the liquid–liquid process, the specific surface area ratio is proposed and studied through computational fluid dynamics simulation. There is a scale effect in the liquid–liquid two phase chemical processing that the specific surface area ratio decreases to 7.01% when the diameter of the Y-like mixer increases from 1 mm to 10 mm. A millimeter-scale mixer with a fan-notched baffle structure was designed, and the baffle unit length, baffle tilt angle, baffle notch size and baffle thickness of the mixer were optimized. Compared with the 1 mm Y-like mixer, the specific surface area ratio of the 10 mm mixer with notched baffle structures increases to 2.5 times and the treatment capacity increases to 100 times. Additionally, experiment and simulation results prove that FNBS is considered to be a suitable structure for enhancing liquid-liquid two-phase. This study will provide a useful reference for the design of large-scale mixers applicable to liquid-liquid heterogeneous chemical processes.
Resistance Training–Induced Acute Hypoalgesia in Women With Persistent Pain After Breast Cancer Treatment
Authors: Rasmussen G.H.F. , Madeleine P. , Arroyo-Morales M. , Voigt M. , Kristiansen M.
Published: September 2022

Fogh Rasmussen, GH, Madeleine, P, Arroyo-Morales, M, Voigt, M, and Kristiansen, M. Resistance training–induced acute hypoalgesia in women with persistent pain after breast cancer treatment. J Strength Cond Res 37(3): e16–e24, 2023—The aim of this study was to determine whether a single bout of resistance training (RT) produces acute exercise-induced hypoalgesia (EIH) in breast cancer survivors (BCS) suffering from persistent pain ≥1.5 years after treatment. Twenty individuals with self-reported pain ≥3 on a 0–10 Numerical Rating Scale after treatment for breast cancer completed 3 experimental sessions, (a) familiarization; (b) 1 repetition maximum (1RM) normalization, and (c) training, consisting of 3 sets of 10 repetitions at 60% of 1 repetition maximum. Pressure pain thresholds (PPTs) were measured before and after training for the dorsal and ventral shoulder regions of the affected side. Movement-evoked pain (MEP) and rating of perceived exertion (RPE) were collected immediately after each set. A p-value less than 0.05 was considered statistically significant. The results demonstrated a significant increase in PPTs of the ventral shoulder region after a single bout of RT (p ≤ 0.05), indicating a localized analgesic response for this area. By contrast, no change was detected in PPTs on the dorsal shoulder region. No significant differences were found in MEP between sessions despite a significant increase in load and RPE during 1RM assessment (p ≤ 0.05), indicating that MEP was not affected by increase in absolute and relative intensity. In conclusion, a single bout of submaximal RT reduced PPTs for the ventral shoulder region of BCS with persistent pain after treatment and was well tolerated. Hence, RT may be a useful therapeutic tool for managing persistent pain after breast cancer treatment in clinical practice.
The relationship between ignimbrite lithofacies and topography in a foothill setting formed on Miocene pyroclastics – a case study from the Bükkalja, Northern Hungary
Authors: Biró Tamás , Hencz Mátyás , Telbisz Tamás , Cseri Zoltán , Karátson Dávid
Published: September 2022

Units with extremely variable erodibility are typical in the succession of pyroclastic-dominated volcanic fields. Welded ignimbrites are usually resistant to erosion, thus, they often appear as positive landforms, i.e., mesas or tilted plateaus after millions of years of denudation. The Bükkalja Volcanic Area being part of the most extended foothill area of the North Hungarian Mountains, is composed predominantly of Miocene ignimbrites, where the frequency distributions of elevation a.s.l., slope, aspect, as well as topographic openness, were investigated using a 30 m resolution SRTM-based digital surface model at four sample areas located at different relative distances from the assumed source localities of the ignimbrites, showing both non-welded and welded facies. The degree of dissection was also examined along swath profiles. The topography of the sample area closest to the source localities is dominated by slabs of moderately dissected welded ignimbrites, gently dipping towards SE. Farther away from the source the topography is dominated by erosional valleys and ridges, resulting in a narrower typical elevation range, a higher proportion of pixels with greater than 5° slope, higher frequencies of NE and SW exposures, and more significant incision resulted in more frequent pixels with positive topographic openness less than 1.5 radians here. Higher thicknesses and emplacement temperatures of ignimbrites, often showing welded facies are more common closer to the source vent. Thus, the erosional pattern around calderas can be used to draw conclusions on the spatial extent of the most intense ignimbrite accumulation, i.e., the location of eruption centres even in highly eroded ignimbrite fields.
Interview: Andreas Wimmer and Helmut K. Anheier
Authors: Wimmer Andreas , Anheier Helmut K.
Published: September 2022

In this interview, Helmut K Anheier and Andreas Wimmer discuss his work on methodological nationalism, nation building, democracy, war, and longer-term economic, socio-political developments. They also explore the post-colonial debate and the decolonization movement in the academy. They touch upon foresight methods and review the state of the social sciences, in particular anthropology and sociology.
Numerical investigation to analyse the effect of fin shape on performance of finned tube heat exchanger
Authors: Shah Dr. Rupesh , Shah Mayank
Published: September 2022

Numerical investigations are carried out to determine the effect of change in geometrical parameter of annular fin on thermal and hydraulic characteristics. Fin shape is changed by varying horizontal diameter of fin. Three different cases of annular fin are investigated corresponding to fin diameter ratio (X) of 0.65, 0.85 and 1. Turbulence is modelled using k-ω shear stress transport model. Relative assessment of tube with annular fin of different horizontal diameter (D01) is done for 2500 < Re < 13000. The comparison of Nusselt number reveals that circular tube with annular fin enhances heat transfer rate. Nusselt number augments by 35% and 10% in case of annular fin with diameter ratio of 0.65 and 0.85 as compared to that of annular fin with diameter ratio of 1.00 for 2500 < Re< 13000. Pressure drop augments with increase in horizontal diameter of fin and Reynolds number. Annular fin with diameter ratio of 0.65 performs better in terms of heat transfer and pressure penalty as compared to other cases for range of reported Reynolds number.
Effect of gable roof with various roof pitches and obstacle heights on natural ventilation performance for an isolated building
Authors: ZOBAIED AKKIK , Tai Vin Cent , Go Tze Fong , Chong Perk Lin , Moey Lip Kean
Published: September 2022

Numerical analysis based on CFD steady RANS equations was used to study the  airflow characteristics around and within an isolated gable roof building. Parameters that are the main study focus of this research include: streamlines of normalized velocity, pressure coefficient and ventilation rate. The effect of gable roof with four different roof pitches namely 15º, 25º, 35º & 45 were investigated against varying obstacle heights of 40, 50, 60 & 70 mm. From the simulation results, the streamlines show that larger roof pitch leads to increased velocity at the window and roof openings due to the external and internal pressure difference in the building. The corresponding increment in internal obstacle height on the other hand leads to gradual alteration of airflow direction in front of the obstacle, and also an increase of the pressure coefficient inside the building because of wind blocking effect. This pressure coefficient also sees a reduction in value at the windward and inside of the building with an increase in steepness of the roof pitch due to increasing internal velocity. Hence, airflow behavior and characteristics are clearly dependent on roof pitch and internal obstacle height which indicates a good agreement with the findings from the previous studies. Gable roof with a steeper roof pitch building coupled with lower internal obstacle height will therefore yield better ventilation rates.
Investigation on the jet penetrated metal-diesel closed structures in condition of single-layer and multi-layer
Authors: Changfang Zhao  , Zhang Kebin , Zhao Changxing
Published: September 2022

For improving the protective performance of Armor, a multi-layer metal-diesel closed structure (MLMDCS) was proposed. The concept of equivalent layer number n and specific residual head velocity (SRHV) for describing the anti-jet penetration performance of single-layer metal-diesel closed structure (SLMDCS) and MLMDCS was put forward. The finite element simulation method by experimental verification was used to simulate the shaped charge jet (SCJ) penetrates the MLMDCS and SLMDCS. The simulation results show that when the equivalent layer number n (n>1) is the same, the residual head velocity of the jet through the MLMDCS is lower than that of the SLMDCS, and the time is longer than that of the SLMDCS. The energy consumption of jet in MLMDCS is more than that of in SLMDCS. The jet head becomes blunt after penetrating out the MLMDCS, but the head shape remains basically unchanged after the jet penetrates out the SLMDCS. The velocity streamline of diesel at the intersection of each layer in the MLMDCS is disordered, which forms local turbulence and disjoint phenomenon. The distribution positions of the diesel velocity streamline and pressure in the SLMDCS are basically the same. Compared with the SLMDCS, the MLMDCS has better anti-jet penetration properties, and the anti-jet penetration properties of the MLMDCS are better with the increase in the equivalent layer number. The research results provide a design reference for the new generation protective armor.
Mechanical characterisation of water-jet shot peened H13 tool steel surface
Authors: Anati N. , S.N. Aqida  , I. Ismail  , M.S. Kasim
Published: September 2022

A wear-resistant surface is achievable via the surface treatment of various sources such as laser, water-jet, ion beam, and plasma. This paper investigates the parameters of water-jet shot-peened H13 tool steel for minimum surface roughness and maximum hardness properties. Water jet processing parameters are significant in determining the surface roughness as well as hardness properties. Water-jet shot-peened (WJSP) was used in this experiment to improve the surface properties of H13 tool steel. The parameters are pressure and feed rate of 172 MPa to 310 MPa and 2600 mm/min to 10000 mm/min. The shot-peened samples were characterised for surface topography, surface roughness, and hardness properties. A laser confocal microscope was used to determine the dimension of the modified surface from shot peening and average surface roughness. Hardness properties were measured using the Vickers scale. From topography analysis, the surface roughness reading on the shot-peened surface was measured as much as 6.88 µm to 14.06 µm. Minimum surface roughness measured was 6.88 µm on sample processed at pressure and feed rate 172 MPa and 2600 mm/min. The hardness properties of the shot-peened subsurface were between 196 HV and 227 HV. The resulted hardness properties were due to plastic deformation from abrasive particle bombardment during shot peening. The findings are important to designing enhanced surface properties for mould and die applications.
Fat, adipokines, bone structure and bone regulatory factors associations in obesity
Authors: Vilaca T , Evans A , Gossiel F , Paggiosi M , Eastell R , Walsh J S
Published: September 2022

Context

Obese (OB) adults (BMI ≥ 30) have a higher bone mineral density (BMD) and more favourable bone microarchitecture than normal-weight (NW) adults (BMI 18.5–24.9).

Objective

The objective of this study was to identify which fat compartments have the strongest association with bone density and bone turnover and whether biochemical factors (adipokines, hormones and bone regulators) are likely to be important mediators of the effect of obesity on bone.

Design

This was a cross-sectional, observational, matched case-control study.

Setting

Participants were recruited from the local community.

Participants

Two hundred healthy men and women aged 25–40 or 55–75 were recruited in individually matched OB and NW pairs. Body composition, BMD and bone microarchitecture were determined by dual-energy X-ray absorptiometry (DXA), computed tomography (CT) and high-resolution peripheral CT (HR-pQCT). Bone turnover and potential regulators such as C-terminal cross-linking telopeptide (CTX), type 1 procollagen N-terminal peptide (PINP), sclerostin, periostin, parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHD), insulin-like growth factor 1 (IGF1), adiponectin, leptin and insulin were assessed.

Main outcome

Planned exploratory analysis of the relationships between fat compartments, areal and volumetric BMD, bone microarchitecture, bone turnover markers and bone regulators.

Results

Compared with NW, OB had lower CTX, PINP, adiponectin, IGF1, and 25OHD and higher leptin, PTH and insulin (all P < 0.05). CTX and subcutaneous adipose tissue (SAT) were the bone marker and fat compartment most consistently associated with areal and volumetric BMD. In regression models, SAT was negatively associated with CTX (P < 0.001). When leptin was added to the model, SAT was no longer associated with CTX, but leptin (P < 0.05) was negatively associated with CTX.

Conclusions

SAT is associated with lower bone resorption and properties favourable for bone strength in obesity. Leptin may be an important mediator of the effects of SAT on the skeleton.
Early Clinical Outcomes of Thoracoscopic Mitral Valvuloplasty: The First 90 Cases
Authors: Lin Xin-fan , Xu Zheng , Zheng Zi-he , Wang Tao , Dai Xiao-fu
Published: September 2022

Background: We reported 90 cases of thoracoscopic mitral valvuloplasty in its early stages and sought to analyze early clinical outcomes.
Methods: Ninety consecutive patients, who underwent thoracoscopic mitral valvuloplasty at our institute between April 2020 and December 2021, were assessed for outcomes. Clinical data, including baseline characteristics, operative data, postoperative data, and early follow-up results, were collected. The early clinical outcomes were used to assess the reliability and efficiency of this technique.
Results: No in-hospital death occurred. One patient underwent a median sternotomy for bleeding. Intraoperative transesophageal echocardiography revealed no mitral regurgitation in 82 patients and mitral regurgitation of 0–2 cm2 in six. The remaining two patients with mitral regurgitation >2 cm2 experienced serious systolic anterior motion but underwent successful re-valvuloplasty during a second pump-up. the mean cardiopulmonary bypass time was 177.1±54.8 min and aortic clamping time, 114.0±44.9 min. Each patient received a prosthetic ring (CG Future™), and 64 patients received artificial chordae with an average of 2.7±1.5 (ranging from 1 to 6) pairs. The mean follow up was 8.8±7.0 (range, 1–22 months), while two patients were lost to follow up. Recurrent severe mitral regurgitation was observed in one patient three months after the operation, and mitral valve replacement was performed via median sternotomy. During follow up, one patient died of upper respiratory tract infection, and one suffered from low cardiac output.
Conclusions: Thoracoscopic mitral valvuloplasty is safe and effective and, once surgeons overcome the learning curve, can achieve excellent early clinical outcomes.
Systemic Immune-Inflammation Index: A Novel Predictor for Risk of Postoperative Atrial Fibrillation in Patients Undergoing Isolated Coronary Artery Bypass Grafting
Authors: Uğuz Berat , Topal Dursun , Badem Serdar , KAHRAMAN NAİL , Uğuz İlken
Published: September 2022

Objective: To investigate the utility of systemic immune-inflammation index (SII) and inflammatory panel in predicting the risk of postoperative atrial fibrillation (PoAF) among patients undergoing elective isolated coronary artery bypass grafting (CABG).
Methods: A total of 116 patients (mean age: 61.9 ± 9.8 years, 78.4% were males) undergoing   isolated CABG were included in this retrospective study. Patients were divided into two groups, including those who developed PoAF (N = 26) and those without PoAF (N = 90). Inflammatory panel was evaluated in both groups.
Results: Patients with PoAF had significantly higher values for P-wave dispersion (PWD; 53.9 ± 5.9 versus 40.2 ± 5.1, P < .001), HATCH score (2.4 ± 1.3 versus 1 ± 1.1, P < .001), and left atrial dimension (4.0 ± 0.3 versus 3.8 ± 0.2 cm, P = .003). In the multivariate analysis with inclusion of PWD, HATCH score and SII, only SII (OR 1.007, 95% CI 1.002 to 1.012, P = .003) and PWD (OR 1.86, 95% CI 1.225 to 2.757, P = .002) were shown to be independent predictors of increased risk for PoAF.
Conclusion: Preoperative SII seems to be a non-invasive readily available marker that significantly predicts the risk of PoAF in patients undergoing isolated CABG.
Transapical Transcatheter Aortic Valve Implantation for Aortic Regurgitation in Takayasu Arteritis
Authors: Ning Xiaoping , Wang Wei , Lu Fanglin , Li Mengxing , Wang He , Li Ning , Zhou Guangwei , Qiao Fan , Xu Zhiyun , Tang Hao
Published: September 2022

Transcatheter aortic valve implantation (TAVI) has become a popular treatment for surgical high-risk patients with severe aortic stenosis (AS). Recently, we have applied TAVI to the treatment of aortic regurgitation (AR). Compared with conventional surgical procedures, TAVI is less invasive and considered a useful option for these high-risk patients. In this study, we reported a patient who underwent transapical TAVI. The patient was a 52-year-old female with Takayasu arteritis (TA) for 25 years, as well as with severe aortic regurgitation, porcelain aortas, and heart failure. Transapical TAVI successfully was accomplished without neurological complications, and heart failure immediately improved postoperatively.
M2 Macrophage-Derived Exosomes Regulate Myocardial Ischemia-Reperfusion And Pyroptosis Via ROS/NLRP3 Pathway
Authors: Hu Hui , Qi Lei , Ren Changjie , Yan Suhua
Published: September 2022

Objective: To evaluate whether M2 macrophage-derived exosomes protect against MI/R injury and reveal the protective mechanism of exosomes [Kourembanas 2015].
Methods: I/R model injury was induced by temporary left anterior descending coronary artery occlusion in Sprague-Dawley (SD) rats, macrophages isolated from bone marrow-derived macrophages (BMDMs) were induced to M2 polarization, and H9C2 cells subjected to hypoxia/reperfusion (H/R) were used to establish an in vitro model. I/R-induced rats and H/R-induced H9C2 cells were treated with M2-exos in vivo and in vitro, respectively. Masson staining was performed to observe myocardial fibrosis in rats. Immunohistochemical (IHC) staining of myocardial tissues showed the expression of NLRP3 inflammasome activation and pyrolysis. Exosomes derived from IL-4-treated macrophages (M2-exos) were detected by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and western bolt. Western bolt was performed to determine the protein level, including NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1β, cleaved IL-1β, gasdermin D (GSDMD), and N-terminus of gasdermin D (GSDMD-N).
Results: Activity of NLRP3 inflammasome and existence of pyroptosis in the rats subjected to MI/R were significantly higher than those in the control (P < 0.05). Moreover, we confirmed the accumulation of ROS during I/R injury in cardiomyocytes. M2-exos protected against I/R injury and reduced activity of NLRP3 inflammasome and existence of pyroptosis, accompanied with attenuating oxidative stress. In vitro studies showed similar effects, H9c2 cells co-cultured with M2-exos could attenuated H/R-induced cell injury, while M2-exos suppressed the expression of NLRP3 inflammasome and pyroptosis (P < 0.05).
A Case of Thoracic Aortic Endovascular Repair of a Ruptured Mycotic Aortic Aneurysm Due to Pasteurella Multocida
Authors: Kitashima Fumihiro , Itagaki Ryo , Sezai Akira , Taoka Makoto , Osaka Shunji , Machii Yojiro , Hanamura Taisuke , Tanaka Masashi
Published: September 2022

An 81-year-old man was admitted for general fatigue of one month’s duration. Two sets of blood cultures revealed bacteremia, due to Pasteurella multocida, while computed tomography (CT) revealed a 47-mm descending aortic saccular aneurysm. After transfer to our hospital, the saccular aneurysm rapidly grew to 54 mm. An emergency thoracic endovascular aortic repair was performed, due to the aneurysm immediately rupturing after the CT scan. The patient was discharged on postoperative day 28.
Designing and Conducting Scholarly Quality Improvement: A Practical Guide for Improvers Everywhere
Authors: Carroll Alison R. , Smith Christine M. , Frazier S. Barron , Weiner Jeffrey G. , Johnson David P.
Published: September 2022

Successful publication of quality improvement (QI) work is predicated on the use of established QI frameworks and rigorous analytical methods that allow teams to understand the impact of interventions over time. This article is meant to help QI teams disseminate their work more broadly through publication by providing tangible methods that many journals desire in QI articles with specific examples of published works referenced throughout the article. We introduce improvement frameworks that teams should identify early and use as a foundation throughout their projects. We review vital aspects of QI projects, such as team formation, creation of a succinct and clear aim statement, defining primary, process, and balancing measures, as well as QI tools like key driver diagrams, Ishikawa (fishbone) diagrams, and Pareto charts. Finally, we highlight the importance of analyzing data over time to understand the impacts of plan-do-study-act cycles on data. Annotated run charts or, more preferably, annotated statistical process control (or Shewhart) charts are both statistically sound methods to identify significant changes over time. Deliberate planning and execution of QI projects using these concepts will lead to improved chances of QI teams finding success in their project and eventual article acceptance.