bluuebunny/crossref_metadata_2025 huggingface dataset:
Variation of some Water Quality Parameters with Fluctuation of Groundwater Table in Wana Sub-District Northern Iraq
Authors: Al-Aarajy Ghazwan Ghanem , Al-Azzo Omar Nabhan , Mahmood Hazim Jumaa
Published: August 2023

This study aims to investigate the effect of groundwater fluctuation on some water quality characteristics in the Wana region of Northern Iraq. The fluctuations in water table levels in 18 tube wells were monitored to find out if there is a relationship between water table levels with some water quality factors. Groundwater samples were collected monthly from September 2020 to April 2021. Electric conductivity (EC), temperature, pH, water table level, total hardness (TH), sulfate and nitrate concentrations were all measured monthly for eight months. The results showed a wide range of water salinity variation ranging from 715 to 4420 µmohs/cm, with more than half of the examined samples exceeding 3000 µmohs/cm. Even in the same wells, water salinity varied during the monthly monitoring. The depth to the water table ranged from 3.39 to 37.56 m, depending on the topography, recharge rate, and aquifer conditions in the area. All of the wells produced very hard water as a result of the dissolution of gypsum and anhydrite bedrock, with about 84% having high sulphate concentrations of over 250 mg/l. More than a quarter of the samples tested showed pollution with nitrate at concentrations extremely close to or over 50 mg/l. It was found that there is no obvious correlation between groundwater quality properties and the fluctuation of the water table.
Effect of Levels of Organic Matter on Adsorption and Liberation of Gypsum Soil
Authors: Algnaby Yasir Hamod , Aldawri Hawazin Dyaa
Published: August 2023

In an experiment for iron adsorption for nine levels of iron (0,1,2,5,10,25,50,100,200)mg/L. This experiment was carried out to find the behaviour of iron in soils of varying gypsum and organic content to know the conditions for adsorption and liberation of iron in them, using three gypsums (10,20,30)% with percentages of organic matter from sheep feces (0,1,2)%. The Langmeyer equation, the Feinrendlach equation, and the Timken equation were used, through which the most excellent adsorption and binding energy were calculated. The most outstanding adsorption values were In medium gypsum soil with sheep feces (2%) with a ratio in the Langmeyer equation (46.948) mg/kg. The highest binding energy value was (7.497) L.mg-1 in soils with low gypsum content as a control. Lanckmeyer equation was chosen as the best It is fair to describe the adsorption process with a capacity determination coefficient of (85)%. In comparison, the highest value for the maximum adsorption of the Freindlch equation was recorded (0.788) litre.mg-1 in soils with high gypsum content with sheep feces by (2%). The highest percentage of binding energy in medium soils, gypsum control, was (16.195) mg.kg-1. The highest binding energy value in the Tamken equation was (12.436) mg.kg-1 in medium gypsum control soil. The highest binding energy value was (2.844) L.kg-1 in medium gypsum soil control. As for the liberation experiment, the highest values for liberated iron were in the high levels of addition (18.513) mg.kg-1 in soils with low gypsum content (2)% of sheep feces, noting the low values Released iron with low values of adsorbed iron.
Study and Evaluation of Soil Contamination with some Heavy Metals According to International Standards for Pollution
Authors: Al-Mashhadi Mortada Jabr Hussein , Alabadi Luma Abdalalah Sagban
Published: August 2023

This study was conducted to assess soil pollution with some selected elements according to the use of international pollution standards. Three areas were selected (Baghdad, Hilla, Diwaniyah) along both sides of the outer highway extending from Diwaniyah to Baghdad at specific distances ranging from (10, 20, 50, and 100 m) and surface depths of (30 cm). The results showed, through international pollution standards, all soils were contaminated with heavy elements (Cd, Pb, Ni, Zn), which were contaminated between medium to heavy elements but did not exceed internationally allowed limits except for Cd. The results also showed that the increase in concentrations of these heavy elements has led to an increase in the values of the pollution load index (PLI). Hence, these soils are contaminated with heavy elements. Other than that, they fall within the level (PLI>1), which indicates a confirmed pollution state and the deterioration of the soil of those areas on both sides of the extended highway between Baghdad and Diwaniyah. Thus, this soil has a high accumulation of long-term concentrations and toxic effects, which poses a great risk to public health after entering the food chain.
Assessment the Impact of Climate Changes on Snow Cover Area Using Landsat Data in Sulaymaniyah City, Iraq
Authors: Altemimi Doaa G. , Al-Lami Alaa M. , Hashim Bassim M.
Published: August 2023

Snow due to its unique reflective nature and wide surface exposure is an important component of the Earth’s radiation balance. Data from Landsat5 TM and Landsat8 OLI images were used to detect the change in snow cover, values of water bodies, and land surface temperature during the study period years 1987, 1999, 2009, and 2022. ArcGIS 10.8 is used to determine the variations and calculate NDSI, NDSInw, NDWI, and LST index indices. This study aimed to monitor the snow cover area in Sulaymaniyah city, northeastern Iraq, and evaluate the impact of climate changes on snow cover. The results showed significant changes in the snow cover, and the area and percentage of snow cover decreased continuously during the study periods. Some regions have preserved the snow cover and these regions are concentrated in the northeastern part of the province. The finding also revealed that NDSI overestimated the amount of snow and ice cover, because it employs the near-infrared and visible bands, and NDSInw can extract ice cover in areas with water cover more effectively due to its usage of the NIR band.
The competitive advantage of sustainable construction site practices among contractors in Malaysia
Authors: Xhi Zhuan T , Abidin N I , Darus N , Mohd S
Published: August 2023

The sustainability of construction projects is an important issue to address since the sector will grow rapidly, especially in developing countries. Excessive resource consumption and climate change due to construction activities have become critical for countries such as Malaysia which have limited natural resources water, electricity and other natural resources. It has increased pressure among construction stakeholders to adopt sustainable practices, especially during the construction phase. As builders of any construction project, contractors play an important role in promoting sustainable development to minimize negative impacts on the environment and society while maximizing their economic contribution. As a result, this research is to investigate the influence of contractors’ sustainable practices during a project’s construction phase and the project’s competitiveness. Forty-five (45) contractors from G1 – G7 are involved in collecting their standpoints on sustainable practices through an online questionnaire survey. Statistical Package for the Social Science (SPSS) was used to analyse the collected data by conducting the Frequency Analysis and Mean Analysis. This study found that the most potential sustainable practice to be implemented is the ‘reduce method’ due to it is the most effective and efficient method to achieve the low production of construction wastes that meets the purpose of sustainability. While the improved image is found as the top potential competitive advantage for contractors when implementing sustainable practices to have a good corporate image to expand their businesses further. As sustainable practices are becoming more crucial, this study provides insight for contractors to foresee the benefits of adopting sustainable practices to increase their project competitiveness further.
The Awareness Of CIPAA in Remedying Payment Issue Among Contractors In Malaysia
Authors: Kamil AbdulˋIzz Mohd , Amir Siti Sarah Fatihah , Ejau Ruth Lua , Hassan Ahmad Arzlee , Nasir Nasyairi Mat , Muhammad Wan Mohd Nurdden Wan
Published: August 2023

Payment in the Malaysian construction industry has generally been an issue of concern. The government has embarked on severe afford to reduce payment default issues by enacting the Construction Industry Payment and Adjudication Act (CIPAA) in 2014. Since CIPAA was relatively new, the possibility of the industry’s key players needing more information and awareness about CIPAA is greater. Thus, this research aims to investigate the current level of awareness of CIPAA and identify the strategies to increase the awareness level of CIPAA among contractors in Malaysia. The research methods used for this study are quantitative. The data are collected from previous studies, journals, articles, questionnaire surveys, and interviews. The result shows that many contractors in Malaysia still need to be made aware of CIPAA. The level of awareness of the contractors in Malaysia towards CIPAA is still low. For future recommendations, the contractor in Malaysia must be provided with more guidelines and awareness regarding the CIPAA.
Comparative Learning Environment of Architectural Design Studio Layout in Malaysia
Authors: Arshard Wan Nur Rukiah Mohd , Kadir Tengku Anis Qarihah Raja Abdul , Aziz Tengku Intan Suraya Tengku , Mokhtar Zuhairah Mohd
Published: August 2023

Architecture is a collective art with many design projects of group-based were held. The design culture of the school is influenced by each particular project, which makes the students participate in this critical group discussion and highly urged to work in the studio. This study tends to compare the spatial layout of architectural design studios by highlighting the advantages and disadvantages affecting the student’s productivity. They were differences in the learning cultures among architecture students in universities A, B and C as the local university in Malaysia. The current generation of students demands a smart studio with an interactive spatial design layout, which may foster students’ development, especially in their learning-based studio sessions. This study aims to identify the characteristic of a good spatial design layout suitable for the architectural design course with better anthropometric measurements. The qualitative methodologies involved observation of the studio’s environment based on the three selected universities in Perak, Selangor and Johor Bahru. The comparative analysis involved a few attributes, such as the space layout, walkway distance, lecture space and furniture arrangement in the studio, which affect the student’s learning and the lecturer’s teaching method. In summary, characteristics of a good and conducive learning environment will be highlighted, and recommendations for interactive space for students were proposed for them to learn and work in good conditions by improving the studio’s spatial design.
The Transformation Revealed Concept of Smart City Application in Urban Planning
Authors: Bakhtiar Ida Shaheera , Samsudin Noor Aimran , Orlowski Aleksander
Published: August 2023

The purpose of this paper is to present the findings of research conducted to reveal a smart city application concept in urban planning. The method is discussed in the context of case studies of smart city concepts in Malaysian states namely Johor, Penang and Selangor, with the efficient and effective state for implementation and application in urban planning being selected. The case study method was utilised to demonstrate the conceptual framework of smart city application in urban planning, as well as seven smart city criteria. The basic requirement for the proposed framework is that individuals must have urban planning expertise in the field of smart city applications. The authors, who are well-versed in urban planning and smart city concepts from the point of view of urban planning, propose a solution relevant to any urban planning circumstance.
Utilizing of 500 MHz Ground Penetrating Radar Antenna Coupling at Different Interval Heights Clearance
Authors: Junoh Mohd Soleh Amin Bin Mat , Sulaiman Saiful Aman Hj , Razali Mohamad Hezri , Rashid Nur Emileen Abd , Mahmood Mohd Khairil Adzhar Bin , Satirapod Chalermchon
Published: August 2023

Understanding the characteristics of the GPR antenna for underground utility detection purposes is critical to ensuring that buried pipes and cables can be accurately located. Considering the ground coupling antenna is the most effective way to carry out the GPR scan, most of the operators applied this setup to ensure the maximum amount of the electromagnetic wave could be penetrated into the ground. However, the contact between the GPR and the ground surface causes the bottom of the antenna enclosure to become scratched and worn out. Due to the cost and time involved in transportation to replace the antenna protector, a few GPR operators changed the protector to the cheapest one, which affects the characteristics of the antenna and could alter the depth of the underground utilities. A 500 MHz GPR antenna are tested to identify the optimum antenna coupling based on the accuracy assessment at various interval clearance heights in order to reduce damage and preserve the antenna. An experiment was carried out at Department of Survey and Mapping Malaysia (JUPEM) Kuala Lumpur’s Underground Utility Test Base. Based on the result of the signal strength, the higher the antenna is lifted, the higher the rate of the signal becomes weak or lost. For the depth accuracy test, the high differences in depth when the antenna is lifted up at 4cm to 6cm based on the result of comparison with the standard values provided by the JUPEM. On the other hand, the accuracy of each antenna height is compared and validated based on the Residual Mean Square Error (RMSE). Overall, this study could lead to the conclusion that the result of the assessment is within the acceptable RMSE tolerance, which is below 0.1m. The objective of the research is successfully achieved when the antenna at a 3cm to 6cm interval height setup provides the best clearance based on the criteria of signal strength, depth comparison, and accuracy assessment. Finally, the issue of contact between the antenna and the ground surface, which causes the antenna to become scratched and worn out, could be reduced and preserved as a result of the findings.
Growth of branched nanowires via solution-based Au seed particle deposition
Authors: Adham Kristi , Zhao Yue , Hrachowina Lukas , Alcer David , Wallenberg Reine , Borgström Magnus T
Published: August 2023

Nanowires offer unprecedented flexibility as nanoscale building blocks for future optoelectronic devices, especially with respect to nanowire solar cells and light-emitting diodes. A relatively new concept is that of charge carrier diffusion-induced light-emitting diodes, for which nanowires offer an interesting architecture by use of particle-assisted core-branch growth. The branches should be homogenously distributed along the cores. However, most deposition techniques, such as aerosol particle deposition, mainly yield particles at the nanowire tips for dense nanowire arrays. In this study, we demonstrate a liquid-based approach for homogeneously distributed formation of catalytic Au particles on the core nanowire sidewalls which is cost and time-efficient. Subsequently, we demonstrate the synthesis of dispersed nanowire branches. We show that by changing the deposition parameters, we can tune the number of branches, their dimensions, and their growth direction.
On Medium-Rank Lie Primitive and Maximal Subgroups of Exceptional Groups of Lie Type
Authors: Craven David
Published: August 2023

We study embeddings of groups of Lie type

H
H

in characteristic

p
p

into exceptional algebraic groups

G

\mathbf {G}

of the same characteristic. We exclude the case where

H
H

is of type

P
S
L

2

\mathrm {PSL}_2

. A subgroup of

G

\mathbf {G}

is Lie primitive if it is not contained in any proper, positive-dimensional subgroup of

G

\mathbf {G}

.

With a few possible exceptions, we prove that there are no Lie primitive subgroups

H
H

in

G

\mathbf {G}

, with the conditions on

H
H

and

G

\mathbf {G}

given above. The exceptions are for

H
H

one of

P
S
L

3

(
3
)

\mathrm {PSL}_3(3)

,

P
S
U

3

(
3
)

\mathrm {PSU}_3(3)

,

P
S
L

3

(
4
)

\mathrm {PSL}_3(4)

,

P
S
U

3

(
4
)

\mathrm {PSU}_3(4)

,

P
S
U

3

(
8
)

\mathrm {PSU}_3(8)

,

P
S
U

4

(
2
)

\mathrm {PSU}_4(2)

,

P
S
p

4

(
2

)
′

\mathrm {PSp}_4(2)’

and

2

B
2

(
8
)

{}^2\!B_2(8)

, and

G

\mathbf {G}

of type

E
8

E_8

. No examples are known of such Lie primitive embeddings.

We prove a slightly stronger result, including stability under automorphisms of

G

\mathbf {G}

. This has the consequence that, with the same exceptions, any almost simple group with socle

H
H

, that is maximal inside an almost simple exceptional group of Lie type

F
4

F_4

,

E
6

E_6

,

2

E
6

{}^2\!E_6

,

E
7

E_7

and

E
8

E_8

, is the fixed points under the Frobenius map of a corresponding maximal closed subgroup inside the algebraic group.

The proof uses a combination of representation-theoretic, algebraic group-theoretic, and computational means.
The strong Stark conjecture for totally odd characters
Authors: Nickel Andreas
Published: August 2023

We prove the

p
p

-part of the strong Stark conjecture for every totally odd character and every odd prime

p
p

.

Let

L

/

K

L/K

be a finite Galois CM-extension with Galois group

G
G

, which has an abelian Sylow

p
p

-subgroup for an odd prime

p
p

. We give an unconditional proof of the minus

p
p

-part of the equivariant Tamagawa number conjecture for the pair

(

h
0

(
Spec
⁡
(
L
)
)
,

Z

[
G
]
)

(h^0(\operatorname {Spec}(L)), \mathbb {Z}[G])

under certain restrictions on the ramification behavior in

L

/

K

L/K

.
An extension of Bohr’s theorem
Authors: Brevig Ole , Kouroupis Athanasios
Published: August 2023

The following extension of Bohr’s theorem is established: If a somewhere convergent Dirichlet series

f
f

has an analytic continuation to the half-plane

C

θ

=
{
s
=
σ
+
i
t

:

σ
>
θ
}

\mathbb {C}_\theta = \{s = \sigma +it\,:\, \sigma >\theta \}

that maps

C

θ

\mathbb {C}_\theta

to

C

∖
{
α
,
β
}

\mathbb {C} \setminus \{\alpha ,\beta \}

for complex numbers

α
≠
β

\alpha \neq \beta

, then

f
f

converges uniformly in

C

θ
+
ε

\mathbb {C}_{\theta +\varepsilon }

for any

ε
>
0

\varepsilon >0

. The extension is optimal in the sense that the assertion no longer holds should

C

∖
{
α
,
β
}

\mathbb {C}\setminus \{\alpha ,\beta \}

be replaced with

C

∖
{
α
}

\mathbb {C}\setminus \{\alpha \}

.
The nonlocal dispersal equation with seasonal succession
Authors: Zhang Qianying , Wang Mingxin
Published: August 2023

In this paper, we focus on the nonlocal dispersal monostable equation with seasonal succession, which can be used to describe the dynamics of species in an environment alternating between bad and good seasons. We first prove the existence and uniqueness of global positive solution, and then discuss the long time behaviors of solution. It is shown that its dynamics is completely determined by the sign of the principal eigenvalue, i.e., the time periodic problem has no positive solution and the solution of the initial value problem tends to zero when principal eigenvalue is non-negative, while the time periodic positive solution exists uniquely and is globally asymptotically stable when principal eigenvalue is negative.
Linear dynamics of an operator associated to the Collatz map
Authors: Béhani Vincent
Published: August 2023

In this paper, we study the dynamics of an operator

T

\mathcal T

naturally associated to the so-called Collatz map, which maps an integer

n
≥
0

n \geq 0

to

n

/

2

n / 2

if

n
n

is even and

3
n
+
1

3n + 1

if

n
n

is odd. This operator

T

\mathcal T

is defined on certain weighted Bergman spaces

B

ω
2

\mathcal B ^2 _\omega

of analytic functions on the unit disk. Building on previous work of Neklyudov, we show that

T

\mathcal T

is hypercyclic on

B

ω
2

\mathcal B ^2 _\omega

, independently of whether the Collatz Conjecture holds true or not. Under some assumptions on the weight

ω
\omega

, we show that

T

\mathcal T

is actually ergodic with respect to a Gaussian measure with full support, and thus frequently hypercyclic and chaotic.
A note on polynomial equations over algebras
Authors: Illmer Maximilian , Netzer Tim
Published: August 2023

We provide sufficient conditions for systems of polynomial equations over general (real or complex) algebras to have a solution. This generalizes known results on quaternions, octonions and matrix algebras. We also generalize the fundamental theorem of algebra for quaternions to polynomials with two monomials in the leading form, while showing that it fails for three.
Small 𝐴_{∞} results for Dahlberg-Kenig-Pipher operators in sets with uniformly rectifiable boundaries
Authors: David Guy , Li Linhan , Mayboroda Svitlana
Published: August 2023

In the present paper we consider elliptic operators

L
=
−
d
i
v
(
A
∇
)

L=-div(A\nabla )

in a domain bounded by a chord-arc surface

Γ
\Gamma

with small enough constant, and whose coefficients

A
A

satisfy a weak form of the Dahlberg-Kenig-Pipher condition of approximation by constant coefficient matrices, with a small enough Carleson norm, and show that the elliptic measure with pole at infinity associated to

L
L

is

A
∞

A_\infty

-absolutely continuous with respect to the surface measure on

Γ
\Gamma

, with a small

A
∞

A_\infty

constant. In other words, we show that for relatively flat uniformly rectifiable sets and for operators with slowly oscillating coefficients the elliptic measure satisfies the

A
∞

A_\infty

condition with a small constant and the logarithm of the Poisson kernel has small oscillations.
A Donaldson-Thomas crepant resolution conjecture on Calabi-Yau 4-folds
Authors: Cao Yalong , Kool Martijn , Monavari Sergej
Published: August 2023

Let

G
G

be a finite subgroup of

S
U

(
4
)

\mathrm {SU}(4)

such that its elements have age at most one. In the first part of this paper, we define

K
K

-theoretic stable pair invariants on a crepant resolution of the affine quotient

C

4

/

G

{\mathbb {C}}^4/G

, and conjecture a closed formula for their generating series in terms of the root system of

G
G

. In the second part, we define degree zero Donaldson-Thomas invariants of Calabi-Yau 4-orbifolds, develop a vertex formalism that computes the invariants in the toric case, and conjecture closed formulae for their generating series for the quotient stacks

[

C

4

/

Z

r

]

[{\mathbb {C}}^4/{\mathbb {Z}}_r]

,

[

C

4

/

Z

2

×

Z

2

]

[{\mathbb {C}}^4/{\mathbb {Z}}_2\times {\mathbb {Z}}_2]

. Combining these two parts, we formulate a crepant resolution correspondence which relates the above two theories.
ReProMSig: an integrative platform for development and application of reproducible multivariable models for cancer prognosis supporting guideline-based transparent reporting
Authors: Zhao Tingting , Cao Lihua , Ji Jiafu , Chang David K , Wu Jianmin
Published: August 2023

Adequate reporting is essential for evaluating the performance and clinical utility of a prognostic prediction model. Previous studies indicated a prevalence of incomplete or suboptimal reporting in translational and clinical studies involving development of multivariable prediction models for prognosis, which limited the potential applications of these models. While reporting templates introduced by the established guidelines provide an invaluable framework for reporting prognostic studies uniformly, there is a widespread lack of qualified adherence, which may be due to miscellaneous challenges in manual reporting of extensive model details, especially in the era of precision medicine. Here, we present ReProMSig (Reproducible Prognosis Molecular Signature), a web-based integrative platform providing the analysis framework for development, validation and application of a multivariable prediction model for cancer prognosis, using clinicopathological features and/or molecular profiles. ReProMSig platform supports transparent reporting by presenting both methodology details and analysis results in a strictly structured reporting file, following the guideline checklist with minimal manual input needed. The generated reporting file can be published together with a developed prediction model, to allow thorough interrogation and external validation, as well as online application for prospective cases. We demonstrated the utilities of ReProMSig by development of prognostic molecular signatures for stage II and III colorectal cancer respectively, in comparison with a published signature reproduced by ReProMSig. Together, ReProMSig provides an integrated framework for development, evaluation and application of prognostic/predictive biomarkers for cancer in a more transparent and reproducible way, which would be a useful resource for health care professionals and biomedical researchers.
KOunt: a reproducible KEGG orthologue abundance workflow
Authors: Mattock Jennifer , Martínez-Álvaro Marina , Cleveland Matthew A , Roehe Rainer , Watson Mick
Published: August 2023

Accurate gene prediction is essential for successful metagenome analysis. We present KOunt, a Snakemake pipeline, that precisely quantifies KEGG orthologue abundance.

Availability and implementation

KOunt is available on GitHub: https://github.com/WatsonLab/KOunt. The KOunt reference database is available on figshare: https://doi.org/10.6084/m9.figshare.21269715. Test data are available at https://doi.org/10.6084/m9.figshare.22250152 and version 1.2.0 of KOunt at https://doi.org/10.6084/m9.figshare.23607834.
A novel reconfiguration of the solar array to enhance peak power and efficiency under partial shading conditions: experimental validation
Authors: Mishra Vijay Laxmi , Chauhan Yogesh K , Verma K S
Published: August 2023

Non-homogeneous irradiation patterns and temperature levels immensely affect the performance of solar photovoltaic arrays. Partial shading conditions on solar arrays reduce the peak power and efficiency. This paper provides a new remedy called a novel Ramanujan reconfiguration (NRR) to eliminate this physical shading problem in solar photovoltaic systems. NRR is a static-based reconfigured technique that is built using a three-diode model with the help of the MATLAB®/Simulink® tool. The special feature of the proposed NRR technique is that when shade occurs on the solar modules, it gets realigned in a particular row, column, diagonal, corner, centre and middle peripheral cages. This helps over a wide range of shade dispersion on the solar array. The novel topology is tested against the conventional total cross-tied (TCT) model and recently introduced advanced reconfigured models, namely odd–even topology (OET) and Kendoku topology (KDT). The results are tested under certain shading conditions. The proposed NRR technique increases the peak power by 4.45, 2.15 and 2.17 W under the first shading condition regarding TCT, OET and KDT. Its efficiency is improved by 0.51–2.18% under the third shading condition compared with other considered models in this study. In addition, NRR leads to smooth output curves under the second, third and fourth shading conditions, effectively mitigating the local power peaks. The experimental results show the proposed enhanced performance of the novel model against the other models.
Power quality assessment in different wind power plant models considering wind turbine wake effects
Authors: Khatamiaghda Mohsen , Bahraminejad Saeed , Fadaeinedjad Roohollah
Published: August 2023

The intense increase in the installed capacity of wind farms has required a computationally efficient dynamic equivalent model of wind farms. Various types of wind-farm modelling aim to identify the accuracy and simulation time in the presence of the power system. In this study, dynamic simulation of equivalent models of a sample wind farm, including single-turbine representation, multiple-turbine representation, quasi-multiple-turbine representation and full-turbine representation models, are performed using a doubly-fed induction generator wind turbine model developed in DIgSILENT software. The developed doubly-fed induction generator model in DIgSILENT is intended to simulate inflow wind turbulence for more accurate performance. The wake effects between wind turbines for the full-turbine representation and multiple-turbine representation models have been considered using the Jensen method. The developed model improves the extraction power of the turbine according to the layout of the wind farm. The accuracy of the mentioned methods is evaluated by calculating the output parameters of the wind farm, including active and reactive powers, voltage and instantaneous flicker intensity. The study was carried out on a sample wind farm, which included 39 wind turbines. The simulation results confirm that the computational loads of the single-turbine representation (STR), the multiple-turbine representation and the quasi-multiple-turbine representation are 1/39, 1/8 and 1/8 times the full-turbine representation model, respectively. On the other hand, the error of active power (voltage) with respect to the full-turbine representation model is 74.59% (1.31%), 43.29% (0.31%) and 7.19% (0.11%) for the STR, the multiple-turbine representation and the quasi-multiple representation, respectively.
Safety Profile and Clinical and Virological Outcomes of Nirmatrelvir-Ritonavir Treatment in Patients With Advanced Chronic Kidney Disease and Coronavirus Disease 2019
Authors: Chan Gordon Chun Kau , Lui Grace Chung Yan , Wong Candy Ngai Sze , Yip Sindy Sin Ting , Li Timothy Chun Man , Cheung Catherine Siu King , Sze Ryan Kin Ho , Szeto Cheuk Chun , Chow Kai Ming
Published: August 2023

Background

Nirmatrelvir-ritonavir is currently not recommended in patients with an estimated glomerular filtration rate (eGFR) <30 mL/minute/1.73 m2.

Methods

To determine the safety profile and clinical and virological outcomes of nirmatrelvir-ritonavir use at a modified dosage in adults with chronic kidney disease (CKD), a prospective, single-arm, interventional trial recruited patients with eGFR <30 mL/minute/1.73 m2 and on dialysis. Primary outcomes included safety profile, adverse/serious adverse events, and events leading to drug discontinuation. Disease symptoms, virological outcomes by serial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral polymerase chain reaction (PCR) tests, rapid antigen tests, and virological and symptomatic rebound were also recorded.

Results

Fifty-nine (69.4%) of the 85 participants had stage 5 CKD and were on dialysis. Eighty (94.1%) completed the full treatment course; 9.4% and 5.9% had adverse and serious adverse events, and these were comparable between those with eGFR < or >30 mL/minute/1.73 m2. The viral load significantly decreased on days 5, 15, and 30 (P < .001 for all), and the reduction was consistent in the subgroup with eGFR <30 mL/minute/1.73 m2. Ten patients had virological rebound, which was transient and asymptomatic.

Conclusions

Among patients with CKD, a modified dose of nirmatrelvir-ritonavir is a well-tolerated therapy in mild COVID-19 as it can effectively suppress the SARS-CoV-2 viral load with a favorable safety profile. Virological and symptomatic rebound, although transient with low infectivity, may occur after treatment. Nirmatrelvir-ritonavir should be considered for use in patients with CKD, including stage 5 CKD on dialysis.

Clinical Trials Registration. Clinical Trials.gov; identifier: NCT05624840.
Risk of Misleading Conclusions in Observational Studies of Time-to-Antibiotics and Mortality in Suspected Sepsis
Authors: Pak Theodore R , Young Jessica , McKenna Caroline S , Agan Anna , DelloStritto Laura , Filbin Michael R , Dutta Sayon , Kadri Sameer S , Septimus Edward J , Rhee Chanu , Klompas Michael
Published: August 2023

Background

Influential studies conclude that each hour until antibiotics increases mortality in sepsis. However, these analyses often (1) adjusted for limited covariates, (2) included patients with long delays until antibiotics, (3) combined sepsis and septic shock, and (4) used linear models presuming each hour delay has equal impact. We evaluated the effect of these analytic choices on associations between time-to-antibiotics and mortality.

Methods

We retrospectively identified 104 248 adults admitted to 5 hospitals from 2015–2022 with suspected infection (blood culture collection and intravenous antibiotics ≤24 h of arrival), including 25 990 with suspected septic shock and 23 619 with sepsis without shock. We used multivariable regression to calculate associations between time-to-antibiotics and in-hospital mortality under successively broader confounding-adjustment, shorter maximum time-to-antibiotic intervals, stratification by illness severity, and removing assumptions of linear hourly associations.

Results

Changing covariates, maximum time-to-antibiotics, and severity stratification altered the magnitude, direction, and significance of observed associations between time-to-antibiotics and mortality. In a fully adjusted model of patients treated ≤6 hours, each hour was associated with higher mortality for septic shock (adjusted odds ratio [aOR]: 1.07; 95% CI: 1.04–1.11) but not sepsis without shock (aOR: 1.03; .98–1.09) or suspected infection alone (aOR: .99; .94–1.05). Modeling each hour separately confirmed that every hour of delay was associated with increased mortality for septic shock, but only delays >6 hours were associated with higher mortality for sepsis without shock.

Conclusions

Associations between time-to-antibiotics and mortality in sepsis are highly sensitive to analytic choices. Failure to adequately address these issues can generate misleading conclusions.
Effect of serum creatinine difference between the Jaffe and the enzymatic method on kidney disease detection and staging
Authors: Boss Kristina , Stolpe Susanne , Müller André , Wagner Bernd , Wichert Marc , Assert Roland , Volbracht Lothar , Stang Andreas , Kowall Bernd , Kribben Andreas
Published: August 2023

Background

Serum creatinine (SCr), mainly determined by the Jaffe or an enzymatic method, is the central marker to assess kidney function. Deviations between these two methods may affect the diagnosis and staging of acute kidney injury (AKI) and chronic kidney disease (CKD).

Methods

The results of the first parallel SCr measurement (Jaffe and enzymatic method) of adult in- and outpatients in the same serum sample at the University Hospital Essen (Essen, Germany) between 2020–2022 were retrospectively evaluated. A Bland–Altman plot with 95% limits of agreement (LoAs) was used to assess the difference between the Jaffe and the enzymatic SCr (eSCr) method. We used the 2009 Chronic Kidney Disease Epidemiology Collaboration equation for determination of estimated glomerular filtration rate (eGFR) according to the Kidney Disease: Improving Global Outcomes guidelines.

Results

A total of 41 144 parallel SCr measurements were evaluated. On average, Jaffe SCr was 0.07 mg/dl higher than eSCr (LoA −0.12; 0.25 mg/dl). In 19% of all cases there was a different CKD stage when comparing eGFR between both SCr methods, of which 98% resulted in a more severe CKD stage determined with Jaffe SCr. In 1.6% of all cases Jaffe SCr was ≥0.3 mg/dl higher than eSCr.

Conclusion

The present study showed that methods of SCr measurement may affect both the diagnosis and staging of AKI and CKD. This must be taken into account when interpreting measurements of renal function in everyday clinical practice, but also when planning and comparing studies on renal diseases. One should therefore stay with one method for SCr measurement, preferably with the enzymatic method.
Apical post-infarction ventricular septal defect blockage using the direct externalization and enmeshment to the right ventricular moderator band concept: case series
Authors: Toledano Bryan Rene F , Rivera Ramon Miguel M , Prado Jose Paolo A , Sabas Michelangelo L , Cheng Dexter Eugene D
Published: August 2023

Background

Transcatheter treatment in post-infarction ventricular septal defects can be unique and complex; hence, the development of a new technique is needed to improve outcomes.

We describe two cases in which large and complex apical post-infarction ventricular septal defects were treated with a novel transcatheter approach as salvage and the other due to refusal for open surgical repair. By direct externalization and enmeshment of a device to the right ventricular moderator band, the defect was blocked and immediate improvement of haemodynamics was achieved.

Conclusion

In large, complex, apical post-infarction ventricular septal defects with no apical rims, the DEXTER technique allows for exclusion of the defect and vestigialization of the right ventricular apex. An immediate and dramatic haemodynamic improvement can therefore be achieved.
How to: a practical guide to cardiac conduction devices on chest radiograph
Authors: Tun Kyaw Soe , Reidy Donnchadh , Buckley Una
Published: August 2023

With the increasing number of cardiac conduction devices (CCDs) insertions with various complexities in recent decades, it is crucial for clinicians (especially internal medicine residents and cardiologists) to have an up-to-date review of the current devices on chest radiograph. Chest X-ray remains the most cost-effective and accessible imaging modality to assess the device position and its associated complications, not only immediately after insertion but also during the follow-up visit as outpatient. Various types of CCDs such as permanent pacemaker, implantable cardioverter defibrillator, and cardiac resynchronization therapy (CRT, CRT with defibrillation or pacing) with their appearances on chest radiograph and possible complications with a step-by-step guide to how to assess are discussed in this article.
O01 Why is urinary tract infection so hard to diagnose and treat? Hints from a unique human microtissue model of bladder infection
Authors: Flores Carlos , Jafari Nazila , Ling Jefferson , Loh Amanda , Maset Ramón Garcia , Hoedek Marloes , Leung Richard , Aw Angeline , White Ian J , Fernando Raymond , Rohn Jennifer L
Published: August 2023

Although urinary tract infection (UTI) appears, on the face of it, to be a simple bacterial infection, upwards of one in four UTI cases recur despite antibiotic therapy. While antimicrobial resistance after empirical treatment undoubtedly accounts for some of these failures, recurrent UTI despite the administration of an appropriate antibiotic, or in the face of prophylactic therapy, remains poorly understood and is likely due to complex and multifactorial aspects of the interaction between the pathogen and its host. In parallel, the role of the healthy uromicrobiome in this process is also far from clear. The vast majority of what little we know about UTI host/pathogen interactions at the urothelial surface has been extrapolated from forced infection experiments in mice, a species that does not naturally experience UTI and whose bladder environment differs significantly from that of humans. For this reason, our lab has been developing alternative, human-cell-based lab models to study the behaviour of both uropathogens and healthy commensals using fully stratified and differentiated urothelial platforms, including lab-on-chip models with flow and stretch parameters. In this talk, I will present recent data putting the most common uropathogens through their paces in our most advanced static model, 3D-UHU. All uropathogens tested, including Escherichia coli, Klebsiella, Enterococcus, Pseudomonas, Group B Streptococcus and Proteus, were able to invade the urothelium to take up residence inside cells, where they would be expected to avoid detection by diagnostic urine tests as well as host neutrophils. Intracellular residence would also foil most oral antibiotics, which are poorly permeant to the urothelial barrier. Some bacteria species, especially Pseudomonas and Proteus, formed biofilms on the surface of the urothelium, a behaviour that would also help the bacteria to withstand antibiotic treatment. What's more, we observed that some bacteria susceptible to antibiotics in diagnostic media were effectively resistant in the human organoid environment, suggesting that there could be a disconnect between predicted drug and clinical outcome. This phenomenon may be partly explained by our experiments showing that, in some species of uropathogen, the urine environment encourages biofilm formation over the free planktonic state. These experiments highlight diverse infection strategies, shed light on how diagnosis and treatment can fail, and reveal strategies for improving both in the future.
P04 Urinary tract infections in HSCT: how big is the problem?
Authors: Baltas Ioannis , Kavallieros Konstantinos , Konstantinou Ioannis , Gibani Malick M , Davies Frances , Pavlu Jiri
Published: August 2023

Objectives

Urinary tract infections (UTIs) in HSCT recipients are understudied. We aimed to describe the incidence, clinical and laboratory findings of patients with UTIs during HSCT.

Methods

This was a retrospective analysis of all patients admitted for HSCT between 1 January 2020 and 31 December 2022 in a large London tertiary centre. Patient-level data were collected from the electronic medical record.

Results

There was a total of 400 admissions for HSCT during the study period, 56.25% (227/400) for autografts and 43.25% (173/400) for allografts. Median age was 55 years (IQR 43–62) and 59% of patients were male. A total of 588 infection episodes were recorded (mean 1.43 episodes per patient, 95% CI 1.39–1.56). Almost all patients (96.75%, 387/400) developed at least one infection episode during their inpatient stay for HSCT. The most common sources of infection were neutropenic fever (56.1%, 330/588) and non-neutropenic fever (17%, 100/588), followed by central line-associated bloodstream infections (10.2%, 60/588) and hospital- or ventilator-associated pneumonias (7%, 41/588). UTIs accounted for only 2% (12/588) of the total infection episodes. Only two UTIs (16.7%, 2/12) were associated with bacteraemia. A total of 1307 urine cultures were sent for all patients (3.23 per patient) and 93.5% of all patients had at least one urine culture. Growth of a specific pathogen was observed in 50/1307 cultures (3.8% positivity rate). The most common isolates included Escherichia coli (50%, 25/50) and Enterococcus spp. (22%, 11/50). The most common clinical syndrome for patients with positive cultures was neutropenic fever 40%, 20/50), followed by UTI (22%, 11/50) and non-neutropenic fever (6%, 3/50). 32% of positive samples (16/50) were considered to represent colonization. Pyuria was uncommon (8%, 4/50), including in patients with UTIs (18.2%, 2/11), as was haematuria (10%, 5/50 for all patients, 9.1%, 1/11 for patients with UTI).

Conclusions

UTIs account for a small proportion of infections in HSCT recipients during their inpatient stay. Urine culture results are challenging to interpret, as they are often associated with undifferentiated fever syndromes or represent colonization. Urine microscopy results are unreliable in HSCT patients and should not be used to rule in or rule out UTI.
P15 Women’s satisfaction with the management of urinary tract infections during the COVID-19 pandemic: a qualitative analysis of free-text comments from a national survey in England
Authors: Dababneh A’mar , Sanyaolu Leigh , Ahmed Haroon , Alagiyawanna Dushyanthi , Lecky Donna , Cooper Emily
Published: August 2023

Background

Urinary tract infections (UTIs) are one of the most common bacterial infections affecting women. The COVID-19 pandemic altered how healthcare was accessed and delivered with rapid adoption of remote technologies. This study explored women’s satisfaction with the care they received for UTI in general practice during the pandemic.

Methods

We analysed 799 responses to an open-ended question regarding women’s satisfaction with the management of their most recent UTIs. A thematic analysis was inductively conducted and supported by NVivo V.12.

Results

Most women (72.7%) were satisfied with their UTI management. Main study themes related to consultation, management, patient’s feelings, and safety during the pandemic. Themes on positive aspects of care were related to thorough assessment and treatment by a doctor and having a positive experience with the healthcare provider (HCP). Themes on the negative aspects of care were related to long waiting times, use of virtual consultations, and patients feeling uninformed and invalidated about their UTIs.

Conclusions

Patient satisfaction was closely linked to a positive face-to-face HCP interaction, prompt assessment and treatment, and discussion about prevention and self-care. To improve satisfaction, systems and consultations should account for patient choice in the HCP they consult with, allow for additional information about when and why a urine test should be provided, and ensure there is a platform for discussing patient preferences for antibiotic prescription or alternative therapy. Using resources to discuss these topics with patients may help address these issues, including risks and benefits of antibiotics, alternative treatments, prevention and self-care.
Regimes in astrophysical lensing: refractive optics, diffractive optics, and the Fresnel scale
Authors: Jow Dylan L , Pen Ue-Li , Feldbrugge Job
Published: August 2023

Astrophysical lensing has typically been studied in two regimes: diffractive optics and refractive optics. Previously, it has been assumed that the Fresnel scale, RF, is the relevant physical scale that separates these two regimes. With the recent introduction of Picard–Lefschetz theory to the field of lensing, it has become possible to generalize the refractive description of discrete images to all wave parameters, and, in particular, exactly evaluate the diffraction integral at all frequencies. In this work, we assess the regimes of validity of refractive and diffractive approximations for a simple one-dimensional lens model through comparison with this exact evaluation. We find that, contrary to previous assumptions, the true separation scale between these regimes is given by $R_F/\sqrt{\kappa }$, where κ is the convergence of the lens. Thus, when the lens is strong, refractive optics can hold for arbitrarily small scales. We also argue that intensity variations in diffractive optics are generically small, which has implications for the study of strong diffractive interstellar scintillation.
Achromatic rapid flares in hard X-rays in the γ-ray binary LS I + 61 303
Authors: Saavedra Enzo A , Romero Gustavo E , Bosch-Ramon Valenti , Kefala Elina
Published: August 2023

We report on the presence of very rapid hard X-ray variability in the γ-ray binary LS I + 61 303. The results were obtained by analysing Nuclear Spectroscopic Telescope Array (NuSTAR) data, which show two achromatic strong flares on ks time-scales before apastron. The Swift/Burst Alert Telescope orbital X-ray light curve is also presented, and the NuSTAR data are put in the context of the system orbit. The spectrum and estimated physical conditions of the emitting region indicate that the radiation is synchrotron emission from relativistic electrons, likely produced in a shocked pulsar wind. The achromaticity suggests that losses are dominated by escape or adiabatic cooling in a relativistic flow, and the overall behaviour in hard X-rays can be explained by abrupt changes in the size of the emitting region and/or its motion relative to the line of sight, with Doppler boosting potentially being a prominent effect. The rapid changes of the emitter could be the result of different situations such as quick changes in the intra-binary shock, variations in the re-accelerated shocked pulsar wind outside the binary, or strong fluctuations in the location and size of the Coriolis shock region. Although future multiwavelength observations are needed to further constrain the physical properties of the high-energy emitter, this work already provides important insight into the complex dynamics and radiation processes in LS I + 61 303.