bluuebunny/crossref_metadata_2025 huggingface dataset:
Microendoscopic anterior cervical foraminotomy: a preliminary series of 76 cases
Authors: Kabil Mohamed Samir , Abdel-ghany Walid
Published: May 2020

Background

Anterior cervical foraminotomy represents a relatively recent minimally invasive approach that can potentially preserve the intervertebral disc and thus the functional motion segment.

Objective

This study aims to evaluate the clinical outcome of microendoscopic anterior cervical foraminotomy (MACF) for patients with cervical unilateral radiculopathy due to single level soft disc herniation or hard disc-osteophyte complex (DOC).

Methods

In the period between August 2009 and March 2015, 76 consecutive patients with symptomatic unilateral cervical radiculopathy were included in this study. There were 40 left-sided cervical radiculopathy cases and 36 right-sided; of those, 42 had soft disc fragment herniation, 18 had DOC, 12 had a migrated disc fragment whether cranial or caudal, and four had far lateral (foraminal) disc herniation. In all cases, MACF with root decompression was performed. Cervical magnetic resonance imaging (MRI), computed tomography (CT) scan, and plain X-rays were performed for all patients and then repeated postoperatively. All patients were followed-up for at least a year. Clinical and functional outcomes were assessed using visual analogue scale (VAS) and Odom’s criteria.

Results

According to VAS score, there was an improvement in neck pain from 6.4 (range 5–10) to 1.5 (1–5) and in arm pain from 7.2 (range 6–10) to 1.2 (0–4) at final follow-up (P< 0.05). Functional outcomes according to Odom’s criteria were excellent in 59 (78%) cases, good in ten (13%), fair in six (8%), and poor in one (1%) case. Success of surgery was considered to be achieved in 91% (excellent + good) of cases. Mean operating time was 81 min, and mean intraoperative blood loss was 21 ml. Most significant complications included a dural tear in one case, transient postoperative dysesthesia in six cases, excess bony work resulting in unintended uncinectomy in three cases, fracture of transverse process in one case, unintended near total discectomy in two cases, infective discitis in one case, and persistent radicular pain due to incomplete osteophyte removal in one case.

Conclusions

This preliminary report suggests that MACF yields overall excellent results in selected patients with unilateral cervical radiculopathy. The technique potentially can preserve the functional motion segment, thus patients typically experience immediate postoperative neck mobility and do not need to wear a cervical collar.
A pharmacological characterization of Cannabis sativa chemovar extracts
Authors: Devsi Alykhan , Kiyota Brett , Ouellette Theophile , Hegle Andrew P. , Rivera-Acevedo Ricardo E. , Wong Jasper , Dong Ying , Pugsley Michael K. , Fung Timothy
Published: May 2020

Background

Cannabis contains Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) as the primary constituents responsible for pharmacological activity. However, there are numerous additional chemically-related structures to Δ9–THC and CBD that are pharmacologically active and may influence the pharmacological properties of Δ9-THC and CBD. This study chemically characterized the cannabinoid constituents in a series of cannabis chemovar extracts and investigated the potential cannabinoid entourage effect in two behavioral assays.

Methods

Six chemovar extracts were compared to pure Δ9-THC, CBD and morphine for effects on the following behavioral assays in mice: hot plate and tail suspension. The battery of behavioral tests was conducted post intravenous administration of cannabis chemovar extract. Cannabinoid profiles of extracts were analyzed using high performance liquid chromatography. Cannabis extracts were administered at equal doses of Δ9-THC to investigate the role of their cannabinoid profiles in modulating the effects of Δ9-THC. Dose response curves were fit using a log[inhibitor] vs response three parameter model and differences between group means were determined using a one-way ANOVA followed by a post hoc test.

Results

Cannabis chemovars tested in this study exhibited substantially different cannabinoid profiles. All chemovars produced dose-dependent immobility in the tail suspension assay and dose-dependent antinociception in the hot plate assay. The maximum antinociceptive effect and ED50 was comparable between cannabis chemovars and Δ9-THC. Two cannabis chemovars produced significantly greater immobility in the tail suspension test, with no significant differences in ED50.

Conclusions

Commercially available cannabis chemovars vary widely in cannabinoid content, but when equalized for Δ9-THC content, they produce similar behavioral effects with two exceptions. These findings provide only limited support for the entourage hypothesis. Further studies are necessary to characterize the nature of these pharmacological differences between cannabis chemovars and pure Δ9-THC.
Impact of intermittent dietary restriction on the health-related outcomes of faith-based fasting
Authors: Halawa Abdelhadi
Published: May 2020

Background and purpose

For much of the history of studying the effects of intermittent fasting on the health of people who engage in fasting for religious reasons, there has been no conclusive evidence-based consensus on the health outcomes of this form of intervallic fasting. The purpose of the present study is to examine the health-related outcomes of intermittent faith-based fasting. Whereas there are several forms of faith-based and non-faith based fasting, the present study will be primarily dedicated to examining the health effects associated with one of the most ubiquitous forms of religious fasting practiced globally by the preponderance of the eligible adults among 1.8 billion Muslims, which is fasting during the annual Islamic month of Ramadan. Therefore, Ramadan fasting provides a significant research paradigm to investigate the health effects of intervallic fasting in humans.

Methods

A systematic review and meta-analysis methodology was employed to search major databases, printed books, and official web-based electronic publications to identify and select a multitude of relevant peer-reviewed studies on the health effects of faith-based intermittent fasting. The data garnered from the selected studies were systematically reviewed, analyzed, and combined. The findings were compared and examined to evaluate whether there were patterns of significant or no significant results of specific health-related effects associated with intermittent faith-based fasting.

Results

The systematic review and data analysis suggest that Ramadan intermittent fasting is associated with both health risks and health benefits. The most vulnerable group of people who are most at risk for exposure to adverse health effects of fasting are those individuals who fast Ramadan with underlying pre-existing health conditions such as diabetes, asthma, kidney, and cardiovascular diseases, which can be exacerbated by the daily fasting for long hours.

Conclusions

The health outcomes of intermittent fasting and voluntary caloric restriction are prefatory and inconclusive The findings of the present study suggest that there is scientific evidence to support the hypothesis that intermittent fasting and forms of meal timing schedules may be associated with both favorable and unfavorable health outcomes. Fasting individuals with adverse pre-exciting health conditions would benefit significantly from seeking a pre-Ramadan medical evaluation, personalized dietary counseling, and Ramadan fasting-tailored health and wellness education as imperative interventions to avert potential medical crises and reduce any further health complications.
Characteristics of different ethnic and traditional bread from the perspective of Islamic traditional medicine
Authors: Emami Seyed Ahmad , Sobhani Zahra
Published: May 2020

Background

Bread is one of the staple foods throughout the world due to its great nutritional attributes. There are numerous types of bread in different countries that some of them are specific to a particular region or ethnic group. Bread is one of the main sources of the daily dietary pattern of Iranian society and Muslims and it satisfies a large part of daily energy needs. Therefore, it has long been considered by Islamic traditional practitioners. In Islamic traditional medicine (ITM), the first step in treatment is the modification of the diet based on a person’s temperament and humors. For this reason, special attention has been paid to bread as a staple food.

Scope and approach

This review described the ethnic bread of Iran and the views of some prominent ITM scientists such as Ibn Beytâr, Ibn Sinâ, Râzi, and Aqili on bread. They described the characteristics of the different types of bread based on the flour used, the amount of bran, and the method of baking with details. Furthermore, they prescribe a specific bread according to the nutritional value of each bread, the speed of digestion, and the temperament of the individual.

Key findings and conclusions

Following the recommendations of traditional medicine can improve the bakery industry as well as reduce the side effects of some bread and their related diseases.
Incidence and Outcomes of CNS Tumors in Chinese Children: Comparative Analysis With the Surveillance, Epidemiology, and End Results Program
Authors: Liu Anthony P. Y. , Liu Qi , Shing Matthew M. K. , Ku Dennis T. L. , Fu Eric , Luk Chung-Wing , Ling Siu-Cheung , Cheng Kevin K. F. , Kwong Dora L. W. , Ho Wilson W. S. , Ng Ho-Keung , Gajjar Amar , Yasui Yutaka , Chan Godfrey C. F. , Armstrong Gregory T.
Published: May 2020

PURPOSE

Despite being the most common pediatric solid tumors, incidence and outcome of CNS tumors in Chinese children have not been systematically reported. We addressed this knowledge gap by comparing the epidemiology of pediatric CNS tumors in Hong Kong and the United States.

PATIENTS AND METHODS

Data between 1999 and 2016 from a population-based cancer registry in Hong Kong, China, on patients < 18 years old with CNS tumors (Hong Kong cohort) and from the US SEER Program (Asian/Pacific Islander and all ethnicities) were compared. Incidence and overall survival (OS) by histology were evaluated.

RESULTS

During the study period, 526 children were newly diagnosed with CNS tumors in Hong Kong (crude incidence rate, 2.47 per 100,000; 95% CI, 2.26 to 2.69). Adjusted incidences were significantly lower in the Hong Kong (2.51; 95% CI, 2.30 to 2.74) than in the SEER (Asian/Pacific Islander: 3.26; 95% CI, 2.97 to 3.57; P < .001; all ethnicities: 4.10 per 100,000; 95% CI, 3.99 to 4.22; P < .001) cohorts. Incidences of germ cell tumors (0.57 v 0.24; P < .001) were significantly higher, but those of glial and neuronal tumors (0.94 v 2.61; P < .001), ependymomas (0.18 v 0.31; P = .005), and choroid plexus tumors (0.08 v 0.16; P = .045) were significantly lower in Hong Kong compared with SEER (all ethnicities) cohorts. Compared with the SEER (Asian/Pacific Islander) cohort, histology-specific incidences were similar except for a lower incidence of glial and neuronal tumors in Hong Kong (0.94 v 1.74; P < .001). Among cohorts, OS differed only for patients with glial and neuronal tumors (5-year OS: Hong Kong, 52.5%; SEER [Asian/Pacific Islander], 73.6%; SEER [all ethnicities], 79.9%; P < .001).

CONCLUSION

We identified important ethnic differences in the epidemiology of CNS tumors in Chinese children. These results will inform the development of pediatric neuro-oncology services in China and aid further etiologic studies.
Drug Absorption Parameters Obtained Using the Isolated Perfused Rat Lung Model Are Predictive of Rat In Vivo Lung Absorption
Authors: Eriksson Johanna , Sjögren Erik , Lennernäs Hans , Thörn Helena
Published: May 2020

The ex vivo isolated perfused rat lung (IPL) model has been demonstrated to be a useful tool during drug development for studying pulmonary drug absorption. This study aims to investigate the potential use of IPL data to predict rat in vivo lung absorption. Absorption parameters determined from IPL data (ex vivo input parameters) in combination with intravenously determined pharmacokinetic data were used in a biopharmaceutics model to predict experimental rat in vivo plasma concentration-time profiles and lung amount after inhalation of five different inhalation compounds. The performance of simulations using ex vivo input parameters was compared with simulations using in vitro input parameters, to determine whether and to what extent predictability could be improved by using input parameters determined from the more complex ex vivo model. Simulations using ex vivo input parameters were within twofold average difference (AAFE < 2) from experimental in vivo data for all compounds except one. Furthermore, simulations using ex vivo input parameters performed significantly better than simulations using in vitro input parameters in predicting in vivo lung absorption. It could therefore be advantageous to base predictions of drug performance on IPL data rather than on in vitro data during drug development to increase mechanistic understanding of pulmonary drug absorption and to better understand how different substance properties and formulations might affect in vivo behavior of inhalation compounds.
An interview with Matthias Lutolf
Authors: Grewal Seema
Published: May 2020

Matthias Lutolf is Head of the Laboratory of Stem Cell Bioengineering at the EFP Lausanne, Switzerland. While Matthias initially trained as a Materials Engineer, his current research sits at the interface between bioengineering and stem cell biology. Matthias recently joined Development as an Associate Editor so we caught up with him at a recent conference to ask him more about his work, why he agreed to take on the role and the types of papers he hopes to see in Development.
Abl-mediated PI3K activation regulates macrophage podosome formation
Authors: Zhou Yuhuan , Feng Zhen , Cao Fakun , Liu Xiaoting , Xia Xiaojie , Yu Cheng-han
Published: May 2020

Podosomes play crucial roles in macrophage adhesion and migration. Wiskott–Aldrich syndrome protein (WASP; also known as WAS)-mediated actin polymerization is one of the key events initiating podosome formation. Nevertheless, membrane signals to trigger WASP activation at macrophage podosomes remain unclear. Here, we show that phosphatidylinositol (3,4,5)-trisphosphate [PI(3,4,5)P3] lipids are enriched at the podosome and stably recruit WASP rather than the WASP-5KE mutant. Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit β (PIK3CB) is spatially located at the podosome core. Inhibition of PIK3CB and overexpression of phosphatase and tensin homolog (PTEN) impede F-actin polymerization of the podosome. PIK3CB activation is regulated by Abl1 and Src family kinases. At the podosome core, Src and Hck promote the phosphorylation of Tyr488 in the consensus Y-x-x-M motif of Abl1, which enables the association of phosphoinositide 3-kinase (PI3K) regulatory subunits. Knockdown of Abl1 rather than Abl2 suppresses the PI3K/Akt pathway, regardless of Src and Hck activities. Reintroduction of wild-type Abl1 rather than the Abl1-Y488F mutant rescues PI3KR1 recruitment and PI3K activation. When PIK3CB, Abl1 or Src/Hck is suppressed, macrophage podosome formation, matrix degradation and chemotactic migration are inhibited. Thus, Src/Hck-mediated phosphorylation of Abl1 Tyr488 triggers PIK3CB-dependent PI(3,4,5)P3 production and orchestrates the assembly and function of macrophage podosomes.
AURKA destruction is decoupled from its activity at mitotic exit but is essential to suppress interphase activity
Authors: Abdelbaki Ahmed , Akman H. Begum , Poteau Marion , Grant Rhys , Gavet Olivier , Guarguaglini Giulia , Lindon Catherine
Published: May 2020

Activity of AURKA is controlled through multiple mechanisms including phosphorylation, ubiquitin-mediated degradation and allosteric interaction with TPX2. Activity peaks at mitosis, before AURKA is degraded during and after mitotic exit in a process strictly dependent on the APC/C coactivator FZR1. We used FZR1 knockout cells (FZR1KO) and a novel FRET-based AURKA biosensor to investigate how AURKA activity is regulated in the absence of destruction. We found that AURKA activity in FZR1KO cells dropped at mitotic exit as rapidly as in parental cells, despite absence of AURKA destruction. Unexpectedly, TPX2 was degraded normally in FZR1KO cells. Overexpression of an N-terminal TPX2 fragment sufficient for AURKA binding, but that is not degraded at mitotic exit, caused delay in AURKA inactivation. We conclude that inactivation of AURKA at mitotic exit is determined not by AURKA degradation but by degradation of TPX2 and therefore is dependent on CDC20 rather than FZR1. The biosensor revealed that FZR1 instead suppresses AURKA activity in interphase and is critically required for assembly of the interphase mitochondrial network after mitosis.

This article has an associated First Person interview with the first authors of the paper.
Analyzing oropharyngeal cancer survival outcomes: a decision tree approach
Authors: De Felice Francesca , Humbert-Vidan Laia , Lei Mary , King Andrew , Guerrero Urbano Teresa
Published: May 2020

Objectives:

To analyze survival outcomes in patients with oropharygeal cancer treated with primary intensity modulated radiotherapy (IMRT) using decision tree algorithms.

Methods:

A total of 273 patients with newly diagnosed oropharyngeal cancer were identified between March 2010 and December 2016. The data set contained nine predictor variables and a dependent variable (overall survival (OS) status). The open-source R software was used. Survival outcomes were estimated by Kaplan–Meier method. Important explanatory variables were selected using the random forest approach. A classification tree that optimally partitioned patients with different OS rates was then built.

Results:

The 5 year OS for the entire population was 78.1%. The top three important variables identified were HPV status, N stage and early complete response to treatment. Patients were partitioned in five groups on the basis of these explanatory variables.

Conclusion:

The proposed classification tree could help to guide future research in oropharyngeal cancer field.

Advances in knowledge:

Decision tree method seems to be an appropriate tool to partition oropharyngeal cancer patients.
COVID-19 Pandemic: Impact of Quarantine on Medical Students’ Mental Wellbeing and Learning Behaviors
Authors: Meo Sultan Ayoub , Abukhalaf Dr Abdulelah Adnan , Alomar Ali Abdullah , Sattar Kamran , Klonoff David C
Published: May 2020

Background and Objectives: The novel coronavirus COVID-19 pandemic causes great public health and socioeconomic harms. Worldwide many countries implemented quarantine policies to minimize the spread of this highly contagious disease. The present study aim was to investigate the impact of quarantine on the medical students’ mental wellbeing and learning behaviors.

Methods: In this descriptive study, we used a questionnaire with a Five-Point Likert Scale to collect the information. The questionnaire was distributed among 625 medical students through their emails with a response rate of 530 (84.8%), majority 294 (55.47%) being female. The survey questionnaire consisted of total 20 items; 12 items were related to psychological wellbeing and stress-allied queries and 08 items were about learning behaviors.

Results: The findings encompass two important characteristics related to quarantine, psychological wellbeing, and learning behaviors. A combined cohort of 234 medical students, either female or male, (which was 44.1% of the total responders) showed a sense of being emotionally detached from family, friends and fellow students, 125/ 530 (23.5%) medical students felt disheartened. Both female and male medical students showed a marked decrease in their overall work performance. Moreover, 56.2% of the total students (61.5% of the females and 49.5% of the males) felt a decrease in the time they spent studying.

Conclusions: Both female and male medical students have identified that quarantine has caused them to feel emotionally detached from family, fellows, and friends and decrease their overall work performance and study period. The findings also show that one-fourth of the medical students who participated in this study felt disheartened during the quarantine period. The long-term quarantine due to COVID-19 pandemic may causes further worsening in the psychological and learning behaviors of these medical students.

doi: https://doi.org/10.12669/pjms.36.COVID19-S4.2809

How to cite this:Meo SA, Abukhalaf AA, Alomar AA, Sattar K, Klonoff DC. COVID-19 Pandemic: Impact of Quarantine on Medical Students’ Mental Wellbeing and Learning Behaviors. Pak J Med Sci. 2020;36(COVID19-S4):COVID19-S43-S48. doi: https://doi.org/10.12669/pjms.36.COVID19-S4.2809

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Workplace violence against security personnel at a university hospital in Egypt: a cross-sectional study
Authors: Albadry Ahmed A. , El-Gilany Abdel-Hady , Abou-ElWafa Hala Samir
Published: May 2020

Background: Violence is common among security personnel. To the best of the authors' knowledge no recent studies have investigated this problem. This study aimed to estimate the prevalence and associated factors of violence against hospital security personnel and describe circumstances of violence, type of perpetrators, and victims’ response.

Methods: In total, 170 security personnel from a university hospital in Egypt were recruited in this cross-sectional study. Data were collected using the Arabic version of a questionnaire developed by the International Labour Office.

Results: The majority (87.3%) of security personnel reported violence exposure in the past year. Being a woman and working more than 5 years were independent predictors of violence exposure. The commonest forms of physical violence were pushing and beating. Verbal abuse and threats were the commonest emotional violence. Patients and their relatives/friends were the commonest perpetrators of violence.

Conclusions: Violence is common among hospital security personnel in this setting. Adequate training and recruitment of more security personnel may contribute to decreasing violence.
Recruiting the innate immune system with GM-CSF to fight viral diseases, including West Nile Virus encephalitis and COVID-19
Authors: Potter Huntington , Boyd Timothy D. , Clarke Penny , Pelak Victoria S. , Tyler Kenneth L.
Published: May 2020

As the coronavirus disease 2019 (COVID-19) pandemic grows throughout the world, it is imperative that all approaches to ameliorating its effects be investigated, including repurposing drugs that show promise in other diseases. We have been investigating an approach to multiple disorders that involves recruiting the innate immune system to aid the body’s healing and regenerative mechanism(s). In the case of West Nile Virus encephalitis and potentially COVID-19, the proposed intervention to stimulate the innate immune system may give the adaptive immune response the necessary time to develop, finish clearing the virus, and provide future immunity. Furthermore, we have found that GM-CSF-induced recruitment of the innate immune system is also able to reverse brain pathology, neuroinflammation and cognitive deficits in mouse models of Alzheimer’s disease and Down syndrome, as well as improving cognition in normal aging and in human patients with cognitive deficits due to chemotherapy, both of which exhibit neuroinflammation. Others have shown that GM-CSF is an effective treatment for both bacterial and viral pneumonias, and their associated inflammation, in animals and that it has successfully treated pneumonia-associated Acute Respiratory Distress Syndrome in humans. These and other data strongly suggest that GM-CSF may be an effective treatment for many viral infections, including COVID-19.
Transmission dynamics, serial interval and epidemiology of COVID-19 diseases in Hong Kong under different control measures
Authors: Chan Yung-Wai Desmond , Flasche Stefan , Lam Tin-Long Terence , Leung Mei-Hung Joanna , Wong Miu-Ling , Lam Ho-Yeung , Chuang Shuk-Kwan
Published: May 2020

Background: The outbreak of coronavirus disease 2019 (COVID-19) started in Wuhan, China in late December 2019, and subsequently became a pandemic. Hong Kong had implemented a series of control measures since January 2020, including enhanced surveillance, isolation and quarantine, border control and social distancing. Hong Kong recorded its first case on 23 January 2020, who was a visitor from Wuahn. We analysed the surveillance data of COVID-19 to understand the transmission dynamics and epidemiology in Hong Kong.

Methods: Based on cases recorded from 23 January to 6 April 2020, we constructed the epidemic curve of daily COVID-19 incidence and used this data to estimate the time-varying reproduction number (Rt) with the R package EpiEstim, with serial interval computed from local data. We described the demographic and epidemiological characteristics of reported cases. We computed weekly incidence by age and residential district to understand the spatial and temporal transmission of the disease.

Results: COVID-19 disease in Hong Kong was characterised with local cases and clusters detected after two waves of importations, first in late January and the second one in early March. The Rt increased to approximately 2 and approximately 1, respectively, following these importations; it decreased to below 1 afterwards, which coincided with the implementation, modification and intensification of different control measures. Compared to local cases, imported cases were younger (mean age: 52 years among local cases vs 35 years among imported cases), had a lower proportion of underlying disease (9% vs 5%) and severe outcome (13% vs 5%). Cases were recorded in all districts but the incidence was highest in those in the Hong Kong Island region.

Conclusions: Stringent and sustained public health measures at population level could contain the COVID-19 disease at a relatively low level.
Renewable Energy Source Enactment for Speed Control of BLDC Motor with Proportional Integral (PI) Controller
Authors: Soedibyo Soedibyo
Published: May 2020

This paper present about speed control of Brushless Direct Current (BLDC) Motor 1 kW in which supplied using Photovoltaic (PV) Array 1.5 kW that simulated using MATLAB 2016a.  Speed control of BLDC exactly depend on voltage condition, so speed control mean voltage control. Furthermore, Proportional Integral (PI) controller will be implemented to get best performance of the system during irradiance change or some load implemented. For detail analysis purpose, the simulation will do in some case such by vary irradiation of PV, Vary the speed reference then vary of load. From simulation result we get the information that dynamic irradiance, load and speed reference will influence the response stability of speed so do Power Consumption, Voltage and Current response.
FLC-DTC METHOD FOR TORQUE RIPPLES MINIMIZATION OF 8/6 SWITCHED RELUCTANCE MOTORS DRIVE
Authors: Haq Hafeezul , Okumus Halil Ibrahim
Published: May 2020

The switched reluctance motor gains a significant response in industries in the past decade because of its ruggedness, high torque to inertia ratio, simple structure, high reliability and inexpensive manufacturing capability. These features make it a suitable candidate for various applications and electric drives. However, In the field of electric drives a switched reluctance motor drive is having doubly salient structure thus it inherently produces high torque ripples and acoustic noise problems and its controlling difficulties that is an undesirable effect for vehicle applications, especially at low speed. The main objective of this paper is to minimize the torque ripples and to control its speed. In this paper a fuzzy logic controller based direct torque control method is used for speed controlling and for controlling of torque ripples of the 8/6 SRM drive. It’s modelling and application of fuzzy logic controller based direct torque control method is done in MATLAB/SIMULINK environment.
Use of Hybrid Phase Shifter for Congestion Management in A Grid with RESs and EVs: Transmission Efficiency Benefit in Comparison with Phase Shifting Transformer
Authors: Gasim Mohamed Salah Eldeen
Published: May 2020

Integration of renewable energy sources (RESs) and electric vehicles (EVs) to electric power grids is increasing. These RESs and EVs may introduce major problems to grid such as transmission lines congestion. Owing to the causative factors nature, congestion may regularly happen and continue forlong commulative time. Thus, transmission efficiency (TE) is a major factorwhen relieving congestion. Congestion can be relieved by using phase shifting transformers (PSTs), hybrid phase shifters (HPSs), or flexible AC transmission system (FACTS) devices. However, PSTs have technical drawbacks such as their large steps, which may result in increased losses, and FACTS devices cost is high. This paper investigates benefits of using an HPS rather than a PST in terms of TE. As HPS operates continuously, it provides more precise control of active power flow than PST. A modified IEEE-14 bus test system is used and a security margin is kept in each simulated case with HPS/PST. Results revealed higher TE when an HPS is used. Thus, RESs and EVs can be more optimally hosted with HPSs.
The recumbent ewe
Authors: Macrae Alastair
Published: May 2020

The recumbent ewe around lambing time is a common presentation. There are a number of nutritionally-related conditions often seen in sheep at this critical time during the production cycle which may cause recumbency including hypocalcaemia, pregnancy toxaemia, listeriosis and hypomagnesaemia. Differentiation of these various conditions can be achieved on the basis of detailed clinical examination and history, backed up by appropriate laboratory biochemical analyses using parameters such as β-OH butyrate and calcium. However there will often have been prior treatment by the farmer which may complicate a clinical diagnosis, and there is often overlap between the various conditions in terms of clinical presentation and disease incidence. The focus is therefore on achieving a correct diagnosis, giving the farmer a simple treatment plan for recumbent ewes, and implementing preventative measures.
Design of a high-efficiency LED low-beam headlamp using Oliker’s compound ellipsoidal reflector
Authors: Chu Shu-Chun , Chen Po-Yo , Huang Cing-Yi , Chang Kuo-Chih
Published: May 2020

This paper presents a design for a high-efficiency, low-beam headlamp with Oliker’s ellipses technology [Computing Lett. 2, 29 (2006)1574-040410.1163/157404006777491981]. In addition to the one-time intrinsic light absorption of reflection, the designed low-beam lampshade can reflect all the light from the LED in the on-demand illumination range. This study proposes and adopts a matrix calculation method to accelerate the calculation speed of constructing an Oliker’s composite ellipsoidal reflector, which in turn increases the ellipsoidal facet number of the compound ellipsoidal reflector. In the design of the low-beam headlamp, the illumination weight on the target plane is defined by the method of curve fitting, which ensures that the light-field pattern of the low-beam headlamp changes smoothly rather than in a patchy distribution. The content of this study itself also provides a design method and example for applying Oliker’s ellipses technology to on-demand spatial lighting.
Aerial infrared target tracking method based on KCF for frequency-domain scale estimation
Authors: Zhang Kai , Wei Gaole , Yang Xi , Li Shaoyi , Yan Jie
Published: May 2020

The kernel correlation filter (KCF) tracking algorithm encounters the issue of tracking accuracy degradation due to large changes in scale and rotation of aerial infrared targets. Therefore, this paper proposes a new scale estimation KCF-based aerial infrared target tracking method, which can extract scale feature information of images in the frequency domain based on the distribution characteristics and change laws of frequency-domain energy. In addition, the proposed method can improve the accuracy of target scale information estimation. First, the KCF tracking algorithm is used to obtain the target position. Then, spectral eigenvalues are calculated as eigenvectors, and frequency-domain rotation scale invariance is adopted to extract the eigenvector between two frames as the target rotation change information. Reverse rotation is performed on the current frame spectrum map for isolating the effects of target rotation on scale information estimation. Then, the current target scale is estimated on the basis of the eigenvectors between the adjacent frames. Finally, the length-to-width ratio and the scale of the tracking box are updated on the basis of the target rotation information, which improves the adaptability of the tracking box to changes in the target scale and rotation. The results indicate that the proposed algorithm is suitable for stable tracking of target scales and rapid changes in attitudes. The average tracking accuracy and the average success rate of the algorithm are 0.954 and 0.782, which represent improvements of 5.3% and 18.9%, respectively, compared with the KCF algorithm. The average tracking success rate is improved by 4.1% compared with the discriminative scale space tracker algorithm, and the average tracking performance is better than that of related filter tracking algorithms based on other scale estimation methods.
Improved multi-resolution foveated laparoscope with real-time digital transverse chromatic correction
Authors: Katz Jeremy I. , Lee Sang-yoon , Hua Hong
Published: May 2020

A multi-resolution foveated laparoscope (MRFL) with autofocus and zooming capabilities was previously designed to address the limiting trade-off between spatial resolution and field of view during laparoscopic minimally invasive surgery. The MRFL splits incoming light into two paths enabling simultaneous capture of the full surgical field and a zoomed-in view of the local surgical site. A fully functional prototype was constructed to demonstrate and test the autofocus, zooming capabilities, and clinical utility of this new laparoscope. The test of the prototype in both dry lab and animal models was successful, but it also revealed several major limitations of the prototype. In this paper, we present a brief overview of the aforementioned MRFL prototype design and results, and the shortcomings associated with its optical and mechanical designs. We then present several methods to address the shortcomings of the existing prototype with a modified optical layout and redesigned mechanics. The performances of the new and old system prototypes are comparatively analyzed in accordance with the design goals of the new MRFL. Finally, we present and demonstrate a real-time digital method for correcting transverse chromatic aberration to further improve the overall image quality, which can be adapted to future MRFL systems.
In vivo photoacoustic potassium imaging of the tumor microenvironment
Authors: Tan Joel W. Y. , Folz Jeff , Kopelman Raoul , Wang Xueding
Published: May 2020

The accumulation of potassium (K+) in the tumor microenvironment (TME) has been recently shown to inhibit immune cell efficacy, and thus immunotherapy. Despite the abundance of K+ in the body, few ways exist to measure it in vivo. To address this technology gap, we combine an optical K+ nanosensor with photoacoustic (PA) imaging. Using multi-wavelength deconvolution, we are able to quantitatively evaluate the TME K+ concentration in vivo, and its distribution. Significantly elevated K+ levels were found in the TME, with an average concentration of approximately 29 mM, compared to 19 mM found in muscle. These PA measurements were confirmed by extraction of the tumor interstitial fluid and subsequent measurement via inductively coupled plasma mass spectrometry.
Graphene-based ultrasensitive optical microfluidic sensor for the real-time and label-free monitoring of simulated arterial blood flow
Authors: Wu Tiange , Shen Junfeng , Li Zongwen , Zou Tingting , Xin Wei , Xing Fei , Zhang Fang , Man Zhongsheng , Fu Shenggui
Published: May 2020

Highly sensitive, real-time and label-free sensing of liquid flow in microfluidic environments remains challenging. Here, by growing high-quality graphene directly on a glass substrate, we designed a microfluidic-integrated graphene-based flow sensor (GFS) capable of detecting complex, weak, and transient flow velocity and pressure signals in a microfluidic environment. This device was used to study weak and transient liquid flows, especially blood flow, which is closely related to heart and artery functions. By simulating cardiac peristalsis and arterial flow using peristaltic pumps and microfluidic systems, we monitored simulated arterial blood flow. This ultrasensitive graphene-based flow sensor accurately detected a flow velocity limit as low as 0.7 mm/s, a pumping frequency range of 0.04 Hz to 2.5 Hz, and a pressure range from 0.6 kPa to 14 kPa. By measuring the blood flow velocities and pressures, pathological blood flow signals were distinguished and captured by the corresponding flow velocities or pressures, which can reflect vascular occlusion and heart functions. This sensor may be used for the real-time and label-free monitoring of patients’ basic vital signs using their blood flow and provide a possible new method for the care of critically ill patients.
Application analysis of clipping and digital resolution enhancer in high-speed direct-detection PAM4 transmission
Authors: Shu Liang , Yu Zhenming , Wan Zhiquan , Xu Kun
Published: May 2020

In this paper, the application of a clipping and digital resolution enhancer (DRE) is numerically investigated in 56-GBaud direct-detection four-ary pulse amplitude modulation (PAM4) transmission systems. The influence of the tap length and the digital-to-analog converter (DAC) samples per symbol on DRE gain is first studied. After optimizing clipping probability, sampling jitter is introduced. The combination of clipping and DRE can increase jitter tolerance by ∼1.7% sampling time for 4-bit DAC. Then, the required optical signal-to-noise ratio (OSNR) at the hard-decision forward error correction (HD-FEC) threshold of 3.8×10−3 is investigated in back-to-back case and 80-km fiber transmission. It is shown that the combination of clipping and DRE can reduce the required OSNR significantly for 3-bit and 4-bit DAC. Finally, the performance gain introduced by clipping and DRE is analyzed from a perspective of the transmitted average signal power and the received mean-squared quantization error.
Grüneisen-relaxation photoacoustic microscopy at 1.7  µm and its application in lipid imaging
Authors: Shi Jiawei , Li Can , Mao Huade , Ren Yuxuan , Luo Zhi-Chao , Rosenthal Amir , Wong Kenneth K. Y.
Published: May 2020

We report the first, to the best of our knowledge, demonstration of
Grüneisen relaxation photoacoustic microscopy (GR-PAM) of lipid-rich
tissue imaging at the 1.7 µm band, implemented with a high-energy
thulium-doped fiber laser and a fiber-based delay line. GR-PAM
enhances the image contrast by intensifying the region of strong
absorbers and suppressing out-of-focus signals. Using GR-PAM to image
swine-adipose tissue at 1725 nm, an 8.26-fold contrast enhancement is
achieved in comparison to conventional PAM. GR-PAM at the 1.7 µm band
is expected to be a useful tool for label-free high-resolution imaging
of lipid-rich tissue, such as atherosclerotic plaque and nerves.
Temperature-dependent thermal and spectroscopic properties of Yb:YALO3 perovskite crystal for a cryogenically cooled near IR laser
Authors: Song Yanjie , Zong Nan , Liu Ke , Wang Zhimin , Wang Xiaojun , Bo Yong , Peng Qinjun , Xu Zuyan
Published: May 2020

Temperature dependent thermal and spectroscopic properties of Yb:YAlO3 (Yb:YAP) perovskite crystal at temperatures ranging from 77 to 298 K are presented. Thermal properties including specific heat, thermal expansion coefficient and thermal conductivity were investigated. Thermal shock resistance parameters were evaluated and the thermal shock resistance parameters were significantly increased from 0.68 × 106 W m-1 to 12.32 × 106 W m-1 in Yb:YAP as temperature varies from 298 to 77 K. The spectroscopic parameters, such as absorption, fluorescence, lifetime were also studied. The results of our study indicate that Yb:YAP crystal is a promising laser medium for high-power solid-state laser. The calculated cross-sections together with relevant thermal properties provide important information for the design in a new generation of cryogenically cooled near infrared laser.
Zur Messung des Einflusses von „Augmented Reality“ auf die individuelle Produktivität bei Montagearbeiten
Authors: Rosenberger Manfred , Fellmann Michael , Lambusch Fabienne , Poppe Michael , Spitzer Michael
Published: May 2020

Durch die Verfügbarkeit und Leistungsfähigkeit neuartiger Hardware sind zunehmend die Voraussetzungen gegeben, Technologien der erweiterten Realität (Augmented Reality) in der Montage, bzw. dem Zusammenbau von Produkten einzusetzen. Dabei handelt es sich beispielsweise um in das Sichtfeld eingeblendete 3D-Explosionszeichnungen oder unterstützende Zusatzinformationen. Auch wenn ein zentrales Versprechen solcher Ansätze die Erleichterung und Beschleunigung komplexer Montageaufgaben ist, bleibt bisher jedoch weitgehend unklar, welchen Effekt der Einsatz der erweiterten Realität auf die Mitarbeitenden und deren Produktivität tatsächlich hat und wie diese Auswirkungen messbar sind. Für Unternehmen (nicht nur) in Ländern mit hohen Lohnkosten ist eine Beurteilung neuer Technologien hinsichtlich des Einflusses auf die Produktivität allerdings unerlässlich, wobei zudem die Perspektive der Mitarbeitenden bzw. Anwendenden oft vernachlässigt wird. Daher steht in diesem Beitrag die Betrachtung der individuellen Produktivität aus der Perspektive prospektiver Technologieanwendender im Vordergrund. In einem Experten-Workshop wurde dazu ein konkretes Szenario zur Montage eines Getriebes unter Einsatz einer Microsoft HoloLens einer kritischen Analyse unterzogen. Der Beitrag reflektiert anhand dieses Beispiels die Auswirkungen des Technologieeinsatzes und beleuchtet zudem die Akzeptanz von Messverfahren bezüglich der Produktivität. Dazu werden die im Workshop erarbeiteten Wirkfaktoren und Rahmenbedingungen der Messung auch Erkenntnissen aus der Literatur zur Messung von Produktivität gegenübergestellt und die Möglichkeiten und Grenzen der Produktivitätsmessung aufgezeigt.
What Drives Illegal Hunting with Dogs? Traditional Practice in Contemporary South Africa
Authors: Chambers Jaime
Published: May 2020

Illegal hunting with dogs in rural South Africa converges around issues of conservation, resource use, and livelihood. Hunting with dogs has a long cultural history, tethered to tradition and subsistence. Today, it is tightly regulated but practiced outside the law. Academic literature and mainstream media alike paint a multidimensional picture of the phenomenon. Some sources portray disenfranchised people practicing a culturally significant livelihood strategy; others emphasize illegal hunting’s destructive nature, severed from traditional context. The drivers of illegal hunting in rural South Africa sit at the nexus of multiple gaps of scholarly insight, linked to a history of widespread stratification of land use, prohibition of traditional hunting, and systematic control of African possession of dogs. There is a need for ethnographic work rooted in environmental history to grapple with the complex connections underlying this issue.
Eastern Shoshone and Northern Arapaho Traditional Ecological Knowledge (TEK) and Ethnobotany for Wind River Reservation Rangelands
Authors: Friday Colleen , Scasta John Derek
Published: May 2020

The need to affirm and revitalize cultural knowledge of native plant communities is impera-tive for Indigenous people. This ethnobotanical study documents Traditional Ecological Knowledge (TEK) structured from an Indigenous paradigm by exploring the connection be-tween plants collected in two high-elevation basins and tribal members on the Wind River Indian Reservation (WRIR). We sought to qualitatively understand the plant resources by looking through the lens of Indigenous language and perspectives. Existing names of the ba-sin plants in both the Eastern Shoshone and Northern Arapaho languages were compiled through an ethnobotanical literature review, seven in-person interviews with Eastern Sho-shone and Northern Arapaho tribal members, and attendance at language workshops. We documented 53 Eastern Shoshone and 44 Northern Arapaho plant names, respectively. His-torical impacts of past Federal Indian policy eras have shaped TEK as it currently exists within tribal communities. Both tribes used and had Indigenous names for Northern sweetgrass (Hierochloe hirta ssp. hirta), bitterroot (Lewisia rediviva), junipers (Juniperus ssp.), and bear-berry or Kinnikinnick (Arctostaphylos uva-ursi). The resiliency of TEK is attributed to the perse-verance of Indigenous people continuing to practice and teach traditions. The historical con-text specific to both the Eastern Shoshone and Northern Arapaho tribes and their languages are important for enhancing our current understanding of the ethnobotanical TEK of plants on the WRIR. Recognizing the value of ethnobotanical TEK and incorporating it into natural resource management plans and decisions can bridge diverse perspectives on land use for meaningful collaboration with tribal communities.
Information and Communication Technologies Adoption in Small Firms
Authors: Malaquias Rodrigo Fernandes , Malaquias Fernanda Francielle de Oliveira
Published: May 2020

Information and Communication Technologies (ICTs) can provide a set of benefits to companies, such as efficiency gains in managerial activities, cost reduction and faster communication with consumers. The ICT literature has studies showing the positive impact that the IT adoption can generate on the company’s performance. ICT benefits are also extensive to small business, but their particular characteristics do not always support their adoption by these enterprises, especially when they are enterprises situated in developing countries. In this context, the aim of this paper was to identify how the ICT adoption and the ICT intention of use are in Brazilian small firms. We have used a case study and we have collected data from four enterprises. In order to collect the data, we used qualitative interviews, direct observation and documental analysis. The main results have shown that the owner’s characteristics, the understanding of the ICT benefits, the ICT complexity and the costs/time related to training people are factors associated with the ICT adoption and intention of use. Based on the literature review and on the empirical evidence, we have found that there is an opportunity cost related to postponing the decision of the ICT investments. We also discuss the role of geographical localization of the enterprises, which can contribute to the ICT literature.