bluuebunny/crossref_metadata_2025_split huggingface dataset:
Population biology and ecology of the endangered Euphorbia susannae Marloth, an endemic to the Little Karoo, South Africa
Authors: Jabar Laaiqah , Siebert Stefan John , Pfab Michele , Cilliers Dirk 
Published: October 2021

Abstract. Jabar L, Siebert SJ, Pfab MF, Cilliers DP. 2021. Population biology and ecology of the endangered Euphorbia susannae Marloth, an endemic to the Little Karoo, South Africa. Biodiversitas 22: 4583-4596. Many euphorbias in the semi-arid parts of South Africa are restricted edaphic specialists with small populations at risk of extinction. Euphorbia susannae is one such species, which grows on the edges of quartz patches along a section of the northern foot slopes of the Langeberg Mountains. This study set out to acquire data on the biology and ecology of the species during a first-ever comprehensive field survey. The resultant dataset allowed for the determination of the geographic distribution of the species, as well as the size and number of populations. Biotic and abiotic environmental variables were employed to generate a habitat profile and a species distribution model. The population structure, regeneration potential, and stability of each subpopulation and the population were also assessed. Euphorbia susannae is a range-restricted species (EOO 170 km2 and AOO 36 km2) confined to eight subpopulations that vary considerably in size. According to this study, 1845 individuals remain in the wild. Habitat preferences of the species were considered in detail and linked to a species distribution model for conservation purposes. It was shown that the species preferred nurse plants. The smallest adults size class was the largest cohort in all the sub-populations and was ascribed to pulse recruitments after an unknown favorable event. Although individuals were not evenly distributed among the size classes, annual recruitments levels were healthy, suggesting good pollination, seed set, and germination conditions.
Passively mode-locked thulium-doped fiber laser based on saturable absorption of carbon nanofibers
Authors: Wang Fang , Lan Dongfang , Zhang Xuenan , Cheng Tonglei 
Published: October 2021

As a new type of carbon-based material, carbon nanofibers (CNFs) have
attracted much attention due to their unique physical structure and
optical properties. In this paper, we propose the application of CNFs
as the saturable absorber (SA) and established a passively mode-locked
thulium-doped fiber laser (TDFL) for verification. By mixing sodium
carboxymethyl cellulose solution with CNFs, CNF SA was prepared, the
nonlinearity of which was tested as follows: the modulation depth was

∼

1.3

%

, and the saturation intensity was

18

M
W

/

c

m

2

. By inserting the CNF SA into the
TDFL ring cavity, mode-locked laser pulses of a central wavelength of
1954.47 nm and a 3 dB bandwidth of 5.93 nm were obtained. The spectral
pulse width was 1.31 ps; the repetition frequency was 32.68 MHz; and
the signal-to-noise ratio (SNR) was calculated to be

∼

57

d
B

. To our knowledge, this is the first
time that CNFs have been reported as SAs for mode-locked lasers in the
2 µm wavelength region. Our work provides a new reference for using
carbon-based materials in the realization of ultrafast lasers, and the
proposed CNFs are highly advantageous in the development of
ultrahigh-speed optical modulators and next-generation
high-performance nonlinear photonic devices.
HMG-CoA reductase inhibitors and COVID-19 mortality in Stockholm, Sweden: A registry-based cohort study
Authors: Bergqvist Rita , Ahlqvist Viktor H. , Lundberg Michael , Hergens Maria-Pia , Sundström Johan , Bell Max , Magnusson Cecilia 
Published: October 2021

Background
The relationship between statin treatment and Coronavirus Disease 2019 (COVID-19) mortality has been discussed due to the pleiotropic effects of statins on coagulation and immune mechanisms. However, available observational studies are hampered by study design flaws, resulting in substantial heterogeneity and ambiguities. Here, we aim to determine the relationship between statin treatment and COVID-19 mortality.

Methods and findings
This cohort study included all Stockholm residents aged 45 or older (N = 963,876), followed up from 1 March 2020 until 11 November 2020. The exposure was statin treatment initiated before the COVID-19-pandemic, defined as recorded statin dispensation in the Swedish Prescribed Drug Register between 1 March 2019 and 29 February 2020. COVID-19-specific mortality was ascertained from the Swedish Cause of Death Registry. Hazard ratios (HRs) were calculated using multivariable Cox regression models. We further performed a target trial emulation restricted to initiators of statins.
In the cohort (51.6% female), 169,642 individuals (17.6%) were statin users. Statin users were older (71.0 versus 58.0 years), more likely to be male (53.3% versus 46.7%), more often diagnosed with comorbidities (for example, ischemic heart disease 23.3% versus 1.6%), more frequently on anticoagulant and antihypertensive treatments, less likely to have a university-level education (34.5% versus 45.4%), and more likely to have a low disposable income (20.6% versus 25.2%), but less likely to reside in crowded housing (6.1% versus 10.3%).
A total of 2,545 individuals died from COVID-19 during follow-up, including 765 (0.5%) of the statin users and 1,780 (0.2%) of the nonusers. Statin treatment was associated with a lowered COVID-19 mortality (adjusted HR, 0.88; 95% CI, 0.79 to 0.97, P = 0.01), and this association did not vary appreciably across age groups, sexes, or COVID-19 risk groups. The confounder adjusted HR for statin treatment initiators was 0.78 (95% CI, 0.59 to 1.05, P = 0.10) in the emulated target trial. Limitations of this study include the observational design, reliance on dispensation data, and the inability to study specific drug regimens.

Conclusions
Statin treatment had a modest negative association with COVID-19 mortality. While this finding needs confirmation from randomized clinical trials, it supports the continued use of statin treatment for medical prevention according to current recommendations also during the COVID-19 pandemic.
J-waves in acute COVID-19: A novel disease characteristic and predictor of mortality?
Authors: Zagidullin Naufal Shamilevich , Motloch Lukas J. , Musin Timur Ilgamovich , Bagmanova Zilya Adibovna , Lakman Irina Alexandrovna , Tyurin Anton Viktorovich , Gumerov Ruslan Mansurovich , Enikeev Dinar , Cai Benzhi , Gareeva Diana Firdavisovna , Davtyan Paruir Artakovich , Gareev Damir Aidarovich , Talipova Halima Malikovna , Badykov Marat Rifkatovich , Jirak Peter , Kopp Kristen , Hoppe Uta C. , Pistulli Rudin , Pavlov Valentin Nikolaevich 
Published: October 2021

Background
J-waves represent a common finding in routine ECGs (5–6%) and are closely linked to ventricular tachycardias. While arrhythmias and non-specific ECG alterations are a frequent finding in COVID-19, an analysis of J-wave incidence in acute COVID-19 is lacking.

Methods
A total of 386 patients consecutively, hospitalized due to acute COVID-19 pneumonia were included in this retrospective analysis. Admission ECGs were analyzed, screened for J-waves and correlated to clinical characteristics and 28-day mortality.

Results
J-waves were present in 12.2% of patients. Factors associated with the presence of J-waves were old age, female sex, a history of stroke and/or heart failure, high CRP levels as well as a high BMI. Mortality rates were significantly higher in patients with J-waves in the admission ECG compared to the non-J-wave cohort (J-wave: 14.9% vs. non-J-wave 3.8%, p = 0.001). After adjusting for confounders using a multivariable cox regression model, the incidence of J-waves was an independent predictor of mortality at 28-days (OR 2.76 95% CI: 1.15–6.63; p = 0.023). J-waves disappeared or declined in 36.4% of COVID-19 survivors with available ECGs for 6–8 months follow-up.

Conclusion
J-waves are frequently and often transiently found in the admission ECG of patients hospitalized with acute COVID-19. Furthermore, they seem to be an independent predictor of 28-day mortality.
Factors associated with nutritional status, knowledge and attitudes among tuberculosis patients receiving treatment in Ghana: A cross-sectional study in the Tema Metropolis
Authors: Appiah Prince Kubi , Osei Bright , Amu Hubert 
Published: October 2021

Background
Nutritional deficiencies are generally associated with increased risk and severity of tuberculosis. This study investigated the nutritional status, knowledge, and attitudes of tuberculosis (TB) patients receiving treatment in the Tema Metropolis.

Method
A cross-sectional design was used to collect data on the nutritional knowledge, attitude, and status of TB patients. Nutritional status was analysed using World Health Organization’s formula for body mass index. Pearson’s chi-square and logistic regression models were used to assess associations between predictor and outcome variables. All statistical analyses were considered significant at p-values < 0.05.

Result
The prevalence of malnutrition among TB patients was 39.7%, 14.4%, and 4.8% for underweight, overweight, and obesity respectively. There was a high (61.0%) knowledge of nutrition among the patients. Also, 65.8% had good attitude towards nutrition. There were significant associations between normal nutritional status and age of the TB patients (p = 0.041), highest educational level attained (p = 0.036), employment status (p = 0.019), status of alcohol intake (p = 0.031), number of months on TB treatment (p = 0.021), and attitude towards nutrition (p = 0.028).

Conclusion
There was a reasonable nutrition-related knowledge and attitude towards nutrition among the TB patients. However, that did not reflect on their nutritional status. We recommend continuing education on smoking cessation, avoidance of harmful use of alcohol, and the establishment of food aid and other livelihood intervention programs for TB patients.
Health care providers’ perceptions and experiences related to Midwife-led continuity of care–A qualitative study
Authors: Hailemeskel Solomon , Alemu Kassahun , Christensson Kyllike , Tesfahun Esubalew , Lindgren Helena 
Published: October 2021

BackgroundThough Midwife-led care remains a key to improving the health status of pregnant mothers, in Ethiopia, maternity care has traditionally been based on a model in which responsibility for care is shared by hospital-based midwives, nurses, general practitioners, and obstetricians. This type of care has been seen as representing a fragmented approach.ObjectiveThe aim of this study was to explore health care providers’ perceptions and experiences related to Midwife-led continuity of care at primary hospitals in the north Shoa zone EthiopiaMethodsA qualitative approach was selected as the methodology for this study. Data were collected from 25 midwives and 8 integrated emergency surgical officers (IESO) and medical doctors working in maternal health care units in four primary hospitals in the north Shoa zone, Amhara Regional State. Four focus group discussions and eight individual interviews were conducted. The facilitator utilized a set of open-ended questions for the focus group discussion. Semi-structured interview questions were used for the interviews and thematic data analysis was done.FindingThe main theme extracted was “Midwives welcome consideration of a Midwife-led model that would provide greater continuity of care, but they expressed concerns about organisation and workload”. The midwives said that they would welcome working with the midwife-led care model, as they believed using it could lead to improving the quality of maternal health care, provide greater continuity, and improve coverage, birth outcomes, and maternal satisfaction. The midwives could become more autonomous and be able to take more responsibility for maternity care. The group of 25 midwives and the group of 8 IESO and medical doctors perceived that working procedures and changes in the organization of care in the health facility would have to be studied carefully before any changes can be considered.ConclusionIn this study, we found that replacing the existing system of maternal care with a Midwife-led model would require careful analysis of how this model of care might be implemented in Ethiopia. Further investigation will be of great importance in providing insights that will help in developing a final model.
Exploring the factors associated with the mental health of frontline healthcare workers during the COVID-19 pandemic in Cyprus
Authors: Kapetanos Konstantinos , Mazeri Stella , Constantinou Despo , Vavlitou Anna , Karaiskakis Marios , Kourouzidou Demetra , Nikolaides Christoforos , Savvidou Niki , Katsouris Savvas , Koliou Maria 
Published: October 2021

Introduction
The spread of COVID-19 into a global pandemic has negatively affected the mental health of frontline healthcare-workers. This study is a multi-centre, cross-sectional epidemiological study that uses nationwide data to assess the prevalence of stress, anxiety, depression and burnout among health care workers managing COVID-19 patients in Cyprus. The study also investigates the mechanism behind the manifestation of these pathologies, as to allow for the design of more effective protective measures.

Methods
Data on the mental health status of the healthcare workers were collected from healthcare professionals from all over the nation, who worked directly with Covid patients. This was done via the use of 64-item, self-administered questionnaire, which was comprised of the DASS21 questionnaire, the Maslach Burnout Inventory and a number of original questions. Multivariable logistic regression models were used to investigate factors associated with each of the mental health measures.

Results
The sample population was comprised of 381 healthcare professionals, out of which 72.7% were nursing staff, 12.9% were medical doctors and 14.4% belonged to other occupations. The prevalence of anxiety, stress and depression among the sample population were 28.6%, 18.11% and 15% respectively. The prevalence of burnout was 12.3%. This was in parallel with several changes in the lives of the healthcare professionals, including; working longer hours, spending time in isolation and being separated from family.

Discussion
This study indicates that the mental health of a significant portion of the nation’s workforce is compromised and, therefore, highlights the need for an urgent intervention particularly since many countries, including Cyprus, are suffering a second wave of the pandemic. The identified risk factors should offer guidance for employers aiming to protect their frontline healthcare workers from the negative effects of the COVID-19 pandemic.
Effect of axial length on peripapillary microvasculature: An optical coherence tomography angiography study
Authors: Park Kee Sup , Lim Hyung Bin , Shin Yong Il , Park Gi Seok , Lee Woo Hyuk , Kim Jung-Yeul 
Published: October 2021

Objective
To investigate the effects of axial length (AL) on the peripapillary microvascular density acquired from optical coherence tomography angiography (OCTA).

Methods
Retrospective observational study. A total of 111 eyes from 111 normal healthy subjects were examined. The subjects were divided into three groups according to the AL: Group 1 (AL: < 24.0 mm; 35 eyes), Group 2 (AL: 24.0–25.99 mm; 37 eyes), and Group 3 (AL: ≥ 26 mm; 39 eyes). Peripapillary OCTA images were acquired using 6× 6 mm angiography scans, and vessel density (VD) and perfusion density (PD) of the superficial capillary plexus were calculated automatically. VD and PD were compared among the three groups according to the distance from the optic disc (inner and outer rings). Linear regression analyses were also performed to identify clinical factors associated with average VD.

Results
The average ALs of Groups 1–3 were 23.33± 0.57, 25.05± 0.60, and 27.42± 0.82, respectively. Average VD (P = 0.009) and PD (P = 0.029) in the inner ring increased with increasing AL. However, average VD (P < 0.001) and PD (P < 0.001) in the outer ring decreased with AL increased; the same trends were found for the full areas (VD, p<0.001; PD, p = 0.001). Average VDs in the inner and outer rings were not associated (P = 0.938).

Conclusions
Peripapillary VD and PD were significantly associated with AL. Depending on the distance from the disc, peripapillary VDs and PDs of the inner and outer rings were differentially affected by AL. Physicians should therefore consider the effects of AL in the analyses of peripapillary microvasculature.
Instability of corticotropin during long-term storage – myth or reality?
Authors: Hillebrand Jacquelien J. , Zhou Li , Marcinkus Marilee A. , Datwyler Maria , Gawel Susan H. , Martens Frans , Davis Gerard J. , Heijboer Annemieke C. 
Published: October 2021

Abstract

Objectives
Corticotropin is notorious for its instability. Whereas several studies have investigated its short-term stability in plasma following venous blood sampling, studies on long-term stability are lacking. Here we investigated the long-term storage stability of corticotropin in ethylenediaminetetraacetic acid containing plasma.

Methods
Specimens from healthy volunteers (neat, spiked) were stored in polypropylene microcentrifuge tubes with socket screw-caps at −20 °C and −70 °C for up to one and a half years. Corticotropin in plasma was measured using an Abbott research only immunoassay. Separately, specimens from patients were collected during diagnostic routine testing and stored in polystyrene tubes with push-caps at −20 °C for up to 6 years. In these samples corticotropin hormone was measured using the Diasorin corticotropin immunoassay.

Results
Storage of specimens at −20 °C or −70 °C for up to one and a half years showed minimal changes (<11%) in corticotropin levels, while storage of patient samples at −20 °C for up to 6 years showed a significant (54%) reduction in corticotropin levels.

Conclusions
Corticotropin levels are stable in plasma when stored at −20 °C for one and a half years using the Abbott research only assay, but with longer storage time a significant reduction in corticotropin levels can be expected. Once specimens are stored for future corticotropin measurements, one should consider storage time, storage temperature and assay differences.
The lateralization of labio-dorsals in Hmongic
Authors: Jacques Guillaume 
Published: October 2021

Abstract
This paper provides support for Ratliff’s hypothesis of a highly unusual shift from labio-dorsal to lateral affricates in some Hmongic languages. It proposes that this shift, which results from a series of sound changes, constitutes evidence for positing a ‘Tlowic’ subgroup within Hmongic. In addition, it disproves attempts to use correspondences between Chinese labiovelars and Hmongic lateral affricates in borrowings as evidence to revise Chinese historical phonology.
The passive voice in ancient Indo-European languages: inflection, derivation, periphrastic verb forms
Authors: Luraghi Silvia , Inglese Guglielmo , Kölligan Daniel 
Published: October 2021

AbstractThe IE languages developed different strategies for the encoding of the passive function. In some language branches, the middle voice extended to the passive function to varying extents. In addition, dedicated derivational formations arose in a number of languages, such as the Greek -ē-/-thē-aorist and the Indo-Aryan -ya-presents. Periphrastic formations involving a verbal adjective or a participle are also widely attested, and played an important role in the building of the passive paradigm in e.g. Romance and Germanic languages. As the periphrastic passive is also attested in Hittite alongside passive use of the middle, both strategies seem to be equally ancient. Some minor strategies include lexical passives and the extensive lability of verbs. A survey of possible strategies provides evidence for the rise of a disparate number of morphemes and constructions, and for their ongoing incorporation into the inflectional paradigms (paradigmaticization) of given languages, thus adding to our knowledge about cross-linguistic sources of passive morphology and grammaticalization processes involved.
Apriori association rule and K-means clustering algorithms for interpretation of pre-event landslide areas and landslide inventory mapping
Authors: Kusak Lutfiye , Unel Fatma Bunyan , Alptekin Aydın , Celik Mehmet Ozgur , Yakar Murat 
Published: October 2021

Abstract
In this paper, an inventory of the landslide that occurred in Karahacılı at the end of 2019 was created and the pre-landslide conditions of the region were evaluated with traditional statistical and spatial data mining methods. The current orthophoto of the region was created by unmanned aerial vehicle (UAV). In this way, the landslide areas in the region were easily determined. According to this, it was determined that the areas affected by the landslides had an average slide of 26.56 m horizontally. The relationships among the topographic, hydrographic, and vegetative factors of the region were revealed using the Apriori algorithm. It was determined that the areas with low vegetation in the study area with 55% confidence were of a Strong Slope feature from the Apriori algorithm. In addition, the cluster distributions formed by these factors were determined by K-means. Among the five clusters created with K-means, it was determined that the study area was 38% in the southeast, had a Strong Slope, Low Vegetation, Non-Stream Line, and a slope less than 140 m. K-means results of the study were made with performance metrics. Average accuracy, recall, specificity, precision, and F-1 score were found as 0.77, 0.69, 0.84, and 0.73 respectively.
Tribological characterization of graphene oxide by laser ablation as a grease additive
Authors: Ziakhodadadian Siamak , Ren Tianhui 
Published: October 2021

Abstract
In this work, the structural and tribological behavior of graphene oxide samples as a grease addi-tive was studied. By Nd:YAG laser ablation system and using graphite target at two laser energy of 0.3 W and 0.6 W, graphene oxide (GO) samples were successfully prepared. GO samples were characterized using Raman spectroscopy, field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR) and energy dispersive X-ray spectroscopy (EDAX). Also, tribological behaviors of the lubricating grease, with and without the graphene oxide in grease, by the pin-on disc tribometer were determined. The Raman spectroscopy measurements showed D and G bound, which confirmed the successful synthesis of the graphene oxide sample and also the I
D/I
G, decreased by increasing laser power due to decreasing disorder in graphene oxide structure. FESEM images show that by ablating carbon atoms from graphite target in water, particles assemble to form a GO micro-cluster due to thermodynamically agglomeration with average size of about 3–4 µm, which the size of them depends on the laser pulse energy. Based on FTIR and EDAX analysis, GO sample which prepared at lower laser energy possessed the highest content of oxygen and oxygen functional groups. In addition, the results of tribological behavior showed that the friction-reducing ability and antiwear property of the grease can be improved effectively with the addition of GO. However, it is revealed that the small size GO has a better lubricating performance and therefore cluster size appears to play a role in the degree of wear protection due to its impact on the physical and chemical properties. The results of this study indicate that the GO sample prepared at lower laser energy (0.3 W) has a smaller size and the higher the oxygen content therefore provide better friction-reducing and anti-wear effect. Also, additive of graphene oxide in lubricating grease decreases coefficient of friction as well as wear. Based on our results, the application of GO as an additive in grease leads to increased performance of the lubricated kinematic machine.