bluuebunny/crossref_metadata_2025 huggingface dataset:
Rehabilitation and clinical-evolutive aspects in a case of paraparesis after multilevel lumbar disc herniation, spinal canal stenosis and spondylolisthesis iteratively operated, in a pluripathological context
Authors: OPREA (MANDU) Mihaela , CONSTANTIN Elena , BADIU Cristinel Dumitru , BAJENARU Alina , STAVRICA Alexandru , CIMPEANU Cristina , POPESCU Cristina , ONOSE Gelu
Published: January 2021

Introduction. Disc herniation occurs most commonly in the lumbar region (95% of the cases). The current trend is to have surgery on patients with disc herniation if the kinetic treatment was not beneficial. The data from the literature suggest that early active recovery after lumbar disc herniation is more beneficial than a traditional, less active training program.
Material and method. Having the patient's consent and the approval of the Ethics Committee of “Bagdasar-Arseni” Clinical Emergency Hospital, N.O. 17464 / 14.06.2019, the paper presents the case of a 75-year-old patient with paraparesis after multilevel lumbar disc herniation, spinal canal stenosis and spondylolisthesis iteratively operated, in pluripathological context (hyperplastic type II obesity, hypertension, prostate adenocarcinoma operated in 2015, Clostridium enterocolitis). The patient was clinically and functionally evaluated, according to the standardized protocols implemented in our clinic, through the assessment scales (ASIA, FIM, FAC, QoL, Ashworth and Penn) and also paraclinically, in order to evaluate his biological reserve and his bearing availability of the recovery program.
Results and discussions. The patient presented a slowly favorable evolution (slowed down not only by his multiple above-mentioned comorbidities) from a dysfunctional point of view.
Conclusions. Early active recovery after lumbar disc herniation surgery is more beneficial than a traditional, less active training program for operated herniated discs.

Keywords: Schizophrenia, spinal cord injury, multidisciplinary, suicide attempt, rehabilitation,
Case presentation: The interdisciplinary and rehabilitation treatment of lumbar disc hernia on a patient with corticoterapy dependency and history of lymph node TB
Authors: TOMA Andrei-Alexandru , GHINGULEAC Ioan Bogdan , GHINGULEAC Lucetta Alexandra , CALOTĂ Nicoleta , OPREA Doinița  , IONESCU Elena Valentina , ILIESCU Mădălina Gabriela , STANCIU Liliana Elena
Published: January 2021

Introduction. Disc herniation means the movement of an intervertebral disc. Lumbar disc herniation is an evolutionary phase of lumbar vertebral discopathy , by de Seze classification: phase I (low back pain), phase II (lumbar pain and paravertebral contracture), phase III (discal hernia, with three stages , radicular pain, paresthesias and motor deficiency). Materials and Methods. We are presenting the situation of a female patient, aged 62, from the urban area, with confirmed vices of smoking and sedentary lifestyle, which presented in Emergency Room in Constanta for lumbosciatalgias and paresthesias, impaired walking and presence of antalgic positions that required hospitalization in Neurosurgery section. The patient has a 15 points Glasgow score, with medical history of Hypertension, Rheumatoid Arthritis with corticotherapy, minor stroke and lymph node Tuberculosis. The muscular and osteoarticular system: apparently integral, with difficulty for active movements. The magnetic rezonance examination reveals 2 lumbar disc hernias at level L4. The neurosurgical treatment was applied: discectomy in the L4 disc herniation bilaterally with the removal of the disc fragments. Subsequently, the patient was transferred to the medical rehabilitation department from Techirghiol Sanatorium. The patient was evaluated clinically, functionally in dynamics to track the effectiveness of the neuromotor rehabilitation program. Results. Through the program of early rehabilitation established, the therapeutic yield was significant with the improvement of the clinical symptomatology as well as the marked increase of the functional parameters, assuring the patient a high degree of mobility, of autonomy, but also of reintegration in the social and family life. Conclusions. The peculiarity of this case was the critical condition of the patient at the hospitalization, corticodependence, which makes the surgery but also the medical rehabilitation much complicated by functional osteoporosis and low bone consistency. Neurosurgery together with medical rehabilitation have sounded excellent together with in many cases, with ability to restore strength, functionality as well as better health of patients, which creates an indispensability between the two specializations.
Keywords: corticodependency, lumbar disc herniation, rehabilitation, neurosurgery,
Uveitis – Possible adverse reaction to secukinumab in a patient with rehabilitation treatment for ankylosing spondylitis (case report)
Authors: OPREA Doinița , JIMBU Diana , IONESCU Elena Valentina , ILIESCU Mădălina Gabriela , STANCIU Liliana Elena , OPREA Carmen
Published: January 2021

Introduction. Ankylosing spondylitis (AS) is a chronic inflammatory disease that predominantly affects the spine, but also peripheral joints, the major characteristic of the disease being the early involvement of the sacroiliac joint. The most common extra skeletal manifestations are ocular disorders and appear to 25-30% of the patients, being more frequent to HLA B27 positive patients. Episodes of previous acute uveitis, known as iridocyclitis, may precede or may occur during or after inflammatory joint manifestations. Materials and Methods. We present a 41-year-old patient diagnosed 11 years ago with Ankylosing spondylitis, on its axial form, without extra-articular manifestations, periodically treated with anti-inflammatory drugs and balneary treatment, but with inefficient clinic and biological response. Since November 2019, his treatment with Secukinumab, started to improve the clinic and paraclinical symptoms. Secukinumab is a fully human monoclonal antibody, the first care that selectively targets IL-17A, an essential cytokine treatment that produces inflammation, and bone remodeling, characteristic of AS. Results. In January 2020, the patient presents increased pain and redness in the right eye area, subsequently diagnosed as anterior acute uveitis. Conclusions. This anterior acute uveitis, may be an extra-articular manifestation in the context of the natural evolution of the disease insufficiently controlled by the recently introduced therapy, or it may be an adverse reaction to Secukinumab, being known that the optic malfunction is a less common side effect.
Keywords: Ankylosing Spondylitis, Uveitis, Secukinumab, extra-articular manifestations, rehabilitation, treatment,
Managing Opportunistic Consumer Returns in Retail Operations
Authors: Altug Mehmet Sekip , Aydinliyim Tolga , Jain Aditya
Published: January 2021

Retailers use lenient return policies to stimulate demand and increase revenues, as such policies help customers assess uncertain product valuations at low (or no) return cost and yield higher equilibrium prices. However, generous refunds also yield unintended consequences such as opportunistic returns, which take place when customers intentionally rent a product for short-term use. Accounting for 11% of all product returns in the United States in 2017, opportunistic returns prompt retailers to seek tactics to address adverse revenue and cost implications. We consider two alternative proposals using a price- and refund-setting newsvendor framework with two customer types: honest returners and renters. The first proposal, targeted-refunds, uses retail analytics firms to distinguish renters from honest returners and implements return policies tailored for each segment. The second proposal, menu-of-refunds, presents customers multiple price-refund pairs and lets them self-select. We compare and contrast the optimal decisions and the profit implications of both proposals with respect to two benchmark settings: one without any renters and another proposal, uniform-refunds, wherein the retailer merely reoptimizes its decisions while acknowledging that renters exist. We characterize the conditions under which the menu-of-refunds proposal separates customer types and thus matching or exceeding the performance of the targeted-refunds proposal. Furthermore, we study several alternative model specifications to confirm that our main finding concerning the effectiveness of the menu-of-refunds proposal is robust.

This paper was accepted by Vishal Gaur, operations management.
Analyze the Usage of Social Media and Its Effects on Tertiary Level Students Social Life
Authors: Hossain Sajjat , Islam Nazrul , Prodhan Tabiur Rahman
Published: January 2021

Social media (SM) are the fundamental component of the tertiary-level students’ daily life, but it’s a major concern that the usage of social media has various effects on the students’ social life. The goal of the research was to examine the usage of SM and its effects on the students’ social life at the tertiary level. The hypothesis of this study was to identify the association between the daily checking frequencies of SM and the effects of SM on tertiary level students’ social, academic and personal life. To meet the study purpose, researchers employed quantitative survey methods and conducted a questionnaire-based face to face survey among 126 (67 male and 59 female) respondents, selected by the techniques of simple random sampling, the ages of the respondents were between 18 to 26 and studied at two tertiary level institutes in Rangpur city, the northern part of Bangladesh, which was selected purposively. From the participants, 94.44% had an account on SM. The popular SM was Facebook (90.48%). Most of the respondents’ were (80.95%) used SM for entertainment. 62.7% of the students spent 1 to 4 hours in a day for SM usage. The using time is continuously increased among 77.78% of respondents while they start using SM. For measuring the SM Usage Effects (SMUE), researchers use 5 points Likert scale and use 10 statements where they found that seven (SMUE2, SMUE4, SMUE6, SMUE7, SMUE8, SMUE9, and SMUE10) have high effect, two (SMUE3 and SMUE5) have moderate effect, and only one (SMUE1) item has a low effect among the students. Researchers investigate the association with the participants’ daily check SM and SMUE items, and 5 Pattern of SM Using (PSMU) items, all of the items were positive correlation and significant at p<0.001 level. Future studies should consider both quantitative and qualitative approaches to measure the impact of tertiary level students’ social life and also to investigate the extent of addiction of SM users.
Comaximal factorization in a commutative Bezout ring
Authors: Zabavsky B. V. , Romaniv O. ,   Ivan Franko National University, Kuznitska B. ,   Lviv National Agrarian University, Hlova T. ,   Hetman Petro Sahaidachnyi National Army Academy
Published: January 2021

We study an analogue of unique factorization rings in the case of an elementary divisor domain.
Witt equivalence of function fields of conics
Authors:   Institute of Mathematics University of Silesia, Gladki P. , Marshall M.
Published: January 2021

Two fields are Witt equivalent if, roughly speaking, they have the same quadratic form theory. Formally, that is to say that their Witt rings of symmetric bilinear forms are isomorphic. This equivalence is well understood only in a few rather specific classes of fields. Two such classes, namely function fields over global fields and function fields of curves over local fields, were investigated by the authors in their earlier works [5] and [6]. In the present work, which can be viewed as a sequel to the earlier papers, we discuss the previously obtained results in the specific case of function fields of conic sections, and apply them to provide a few theorems of a somewhat quantitive flavour shedding some light on the question of numbers of Witt non-equivalent classes of such fields.
Gentle m-Calabi-Yau tilted algebras
Authors:   Universisty of Graz Institute of Mathematicsand Scientific Computing - NAWI Graz, Garcia Elsener A.
Published: January 2021

We prove that all gentle 2-Calabi-Yau tilted algebras are Jacobian, moreover their bound quiver can be obtained via block decomposition. For two related families, the m-cluster-tilted algebras of type A and A~, we prove that a module M is stable Cohen-Macaulay if and only if Ωm+1τM≃M.
On the lattice of weak topologies on the bicyclic monoid with adjoined zero
Authors:   Institute of Mathematics Kurt Gödel Research Center, Bardyla S. , Gutik O. ,   National University of Lviv
Published: January 2021

A Hausdorff topology τ on the bicyclic monoid with adjoined zero C0 is called weak if it is contained in the coarsest inverse semigroup topology on C0. We show that the lattice W of all weak shift-continuous topologies on C0 is isomorphic to the lattice SIF1×SIF1 where SIF1 is the set of all shift-invariant filters on ω with an attached element 1 endowed with the following partial order: F≤G if and only if G=1 or F⊂G. Also, we investigate cardinal characteristics of the lattice W. In particular, we prove that W contains an antichain of cardinality 2c and a well-ordered chain of cardinality c. Moreover, there exists a well-ordered chain of first-countable weak topologies of order type t.
An elementary description of K1(R) without elementary matrices
Authors:   Queen’s University Belfast School of Mathematics and Physics, Hüttemann T. , Zhang Z. ,   School of Mathematics Beijing Institute of Technology
Published: January 2021

Let R be a ring with unit. Passing to the colimit with respect to the standard inclusions GL(n,R)→GL(n+1,R) (which add a unit vector as new last row and column) yields, by definition, the stable linear group GL(R); the same result is obtained, up to isomorphism, when using the `opposite' inclusions (which add a unit vector as new first row and column). In this note it is shown that passing to the colimit along both these families of inclusions simultaneously recovers the algebraic K-group K1(R)=GL(R)/E(R) of R, giving an elementary description that does not involve elementary matrices explicitly.
Teachers as Ethnographers: Narrative Study of Inquiry of Indonesian Teachers Assigned to Teach in Remote Areas
Authors: Ahmadi Anas
Published: January 2021

The research explores the narrative inquiry of Indonesian teachers who are assigned to teach in remote areas. The research was conducted from 2019 until 2020. The teachers, in this case, are considered ethnographers because they try to recognize and enter remote island areas that have not been recognized. During this time, in the education context, narrative inquiry is more focused on teacher identity, teaching, curriculum, assessment, and counseling. In terms of narrative inquiry, the teacher as an ethnographer is very interesting to be studied, because it can provide ethnographic insight into the teacher’s perspective. The research used qualitative methods supported by ethnographic studies and involved 21 participants. Data analysis techniques used were the stages of identification, classification, reduction, and verification. The interview used was unstructured. The results show that the teacher as an ethnographer learned the local language in the early stage. The second stage is understanding the cultural situation of the local community. The third stage is the contribution of the teacher to the local community in the education context.
The Effective Diffusion of Educational Robotics in Rural Areas: A Case Study in the Sakha Republic of Russia
Authors: Maximova Maria , Kim Young Hwan
Published: January 2021

The purpose of this study was to find the determinants of effective diffusion of educational robotics in rural areas. The study analysed the key components, difficulties, and major lessons of the successful case of the remote northern region of Russia – Sakha Republic. The study used a mixed-method approach consisting of interviews, survey, literature analysis, and participants’ observation.  In the survey participated 57 robotics teachers and 113 elementary, middle, and high school students of the Sakha Republic. From survey participants were randomly chosen 30 robotics teachers and 18 middle and high school students for the interview. The literature analysis explored reports and articles on the educational robotics activities in the Sakha Republic for the period of 2011-2018. Based on the findings, the study developed a process model with five principles and ten components that influenced educational robotics diffusion in the Sakha Republic. One of the main determinants of the model was a support system of public-private partnerships and a local community of educators. Another was the need to consider the local area’s constraints, possibilities, and culture when implementing any technology in the rural region's education. In the researched case two major determinants would not be possible and sustainable without strong leadership. The findings showed that strong local leadership could use knowledge of the local area to provide more appropriate solutions and could build the active support of the local community and public-private partnerships that would accelerate the diffusion of technology in the rural region's education.
Socio-Scientific Issues as a Vehicle to Promote Soft Skills and Environmental Awareness
Authors: Susilawati Susilawati , Aznam Nurfina , Paidi Paidi , Irwanto Irwanto
Published: January 2021

This research aims to investigate the effect of socio-scientific issues (SSI) based instruction on preservice science teachers’ soft skills and environmental awareness. By applying cluster random sampling, 83 preservice science teachers (PSTs) were selected from the Department of Science Education at a university in Indonesia. The participants were divided into two groups which comprised the experimental group who were taught using SSI-based instruction, while the control group received direct instruction. The quasi-experimental study was carried out through a pre- and posttest control group design. Data was gathered quantitatively using soft skills and environmental awareness questionnaires. The soft skills questionnaire comprised six sub-skills questions: communication, collaboration, problem-solving, creativity, teamwork, and social interaction. The environmental awareness questionnaire contained questions about the PSTs’ attitudes, behavior, and willingness to act. These sub-skills were developed based on literature studies and reviews of previous studies. Face validity was conducted by the experts, and Cronbach’s alpha coefficients of 0.84 (for soft skills) and 0.86 (for environmental awareness) were obtained. The data were analyzed using the Wilcoxon signed-rank test. The result showed that SSI-based instruction had a significant effect on improving preservice science teachers’ soft skills and environmental awareness. After being taught using SSI-based instruction, all the sub-skills of the soft skills of the experimental group had increased compared to before. A similar trend was also found in their scores for environmental awareness. All the components of environmental awareness, after lecturing using SSI-based instruction, showed a significant increase compared to before. These results support the claim that SSI-based instruction fosters soft skills and promotes environmental awareness.
Adaptation of the Epistemological Belief Scale to Kosovo
Authors: Kervan Serdan , Tezci Erdoğan , Morina Shemsi
Published: January 2021

The investigation of epistemological beliefs has become important in both pre-service and in-service education of teachers. Different scales have been developed to determine teachers’ epistemological beliefs. The same scale yields different results in different cultures especially due to the cultural aspects of education. Therefore, testing the scales in different cultures contributes to their use. Within this framework, the scale developed by Schommer and adapted to Turkish culture by Deryakulu and Büyüköztürk was adapted to Kosovo culture. In the study, whether the Albanian, Bosnian and Turkish versions of the scale support the same factor structure was tested by employing the quantitative research method. First, the Epistemological Belief Scale was translated into Albanian and Bosnian and expert opinion was received. The scale was applied to 200 teachers who serve in schools where education languages are Albanian, Bosnian and Turkish. The scale comprised 35 items and 3 factors. Linguistic equivalence was prioritized, as the study was carried out in Kosovo. The Confirmatory Factor Analysis was employed to confirm the suitability of the three-factor structure of the scale. The analyses were carried out separately for each language and revealed acceptable fit indices. Reliability analysis produced satisfactory results.
Primary Science Teachers’ Perspectives about Metacognition in Science Teaching
Authors: Sulaiman Tajularipin , Abdul-Rahim Suzieleez Syrene , Yan Wong Kai , Subramaniam Punnithann
Published: January 2021

Metacognition in science teaching involves processes that include self-awareness and self-regulation. Metacognition enables the teachers to facilitate student learning and to reflect on their teaching in order to enable themselves to improve or to make any changes to their teaching. In particular, teaching activities, especially in the 21st century, do not merely involve the transfer of knowledge and then applying that knowledge into daily life, but teachers need to reflect, plan and evaluate learning outcomes to enhance further in teaching. This study attempts to gain the perspective and implementation of metacognition skills in teaching science in the primary school classroom. The data was collected through a qualitative research method based on interviews with six science teachers in primary school using semi-structured interview protocol. The interview data were analysed for emerging themes, guided by the research questions. Teachers have a similar perspective of the understanding of metacognition in science teaching. Further discussion focuses on the implementation of metacognition in science teaching. This discussion is divided into three aspects, which are constraints faced, overcoming the constraints, and efforts made to implement metacognition in science teaching. Hence, the understanding of science teachers in regards to metacognition in science teaching is important and gives a positive impact towards teaching and learning in primary science teaching.
Static and Dynamic Space Usage of Late-Gestation Sows
Authors: Leonard Suzanne M. , Xin Hongwei , Ramirez Brett C. , Stinn John P. , Dutta Somak , Liu Kai , Brown-Brandl Tami M
Published: January 2021

Highlights

A calibration procedure was conducted using a Kinect V2 to convert image pixels to physical measurements.

A total of 61 sows were observed, and their static and dynamic space usage was measured from depth images.

Equations were developed to predict the length, width, and height of sow space usage.

Abstract. The amount of space provided to individually housed sows has both financial and animal welfare implications. Many U.S. swine producers use stall dimensions based on recommendations published in the 1980s (length × width × height: 2.13 m × 0.61 m × 1.00 m). Limited empirical data are available concerning the space allocation needed to accommodate modern sows housed in stalls during breeding, gestation, or farrowing. This study used a time-of-flight depth sensor to quantify static and dynamic space usage of 61 modern sows in late gestation. A calibration equation was developed to convert image pixels to physical dimensions. Statistical models were developed to relate the length, width, and height of sow space usage to body weight. The dimensions of sow space usage were then predicted. Results showed that free choice space usage of average (228 kg) sows was 1.96 m × 1.15 m × 0.93 m (length × width × height). For 95th percentile (267 kg) sows, space usage was 2.04 m × 1.12 m × 0.95 m. The width of space usage was primarily attributed to sow body depth when lying recumbent and the dynamic space used for transitioning between postures. These results help to inform future gestating and farrowing sow housing designs. Further work is needed to understand how restrictions on sow space usage may impact sow welfare and production performance, as well as the space needed to perform behaviors such as defecating, feeding, and turning around. Keywords: Animal welfare, Computer vision, Farrowing stall, Gestation stall, Kinect V2, Space allowance.
Freeform optical surface design in an off-axis reflective imaging system by a double seed curve extension algorithm
Authors: Zhang YangLiu , Wang Xu , Su ZhouPing , Pan HongXiang , Chen XingTao , Zhang WenYu
Published: January 2021

A double seed curve extension (DSCE) method is proposed to design a freeform surface directly in an off-axis reflective imaging system. Compared with the basic seed curve extension (SCE) method, the DSCE can effectively reduce the error of freeform surface construction and improve the imaging quality of the off-axis reflective imaging system. In addition, the method can be employed to design an off-axis reflective imaging system consisting of multiple freeform surfaces with several virtual image points set in advance. In order to verify the DSCE method, three examples are given. One is the off-axis freeform one-mirror system, one is a compact off-axis three-mirror imaging system with two freeform surfaces, and the other is an off-axis reflective system with three freeform surfaces. The modulation transfer function (MTF) of the one-mirror system is greater than 0.9 at 20 lp/mm, which is close to the diffraction limit. The average of the sagittal and tangential MTFs of the second system designed by the SCE and DSCE methods are 0.26 and 0.74 at spatial frequency of 20 lp/mm, respectively. And the MTF of the last system designed by the DSCE method is greater than 0.9 at 20 lp/mm, which is better than that of the SCE method.
Cost analysis of rural roll-out using a long-reach passive optical network: trading off the upfront cost under uncertainty of the user take-up rate
Authors: Żukowski Cezary , Mukhopadhyay Atri , Payne David B. , Ruffini Marco
Published: January 2021

High deployment cost with respect to expected revenue is the main barrier to fiber-to-the-home (FTTH) roll-out in rural areas. This problem, as shown in this paper, is exacerbated by the uncertainty associated with the end-user take-up rate. The randomness associated with subscribers’ service take-up yields considerable fluctuation and escalation in the total cost of deployment. This adverse and varying environment makes it difficult to produce firm business cases and can increase the reluctance of potential investors and incumbent operators to deploy FTTH access networks. In this paper, we develop a holistic framework for examining real-world FTTH deployment scenarios, taking as a case study one of the most rural counties in Ireland. Further, we carry out an in-depth techno-economic analysis identifying the methods more applicable in the rural scenario. We analyze the cost effectiveness of FTTH deployment, also proposing solutions that provide different levels of upfront investment risk, relating it to uncertainty in customers’ take-up rates. For example, we show how a lower take-up rate can be made profitable by adopting a strategy that favors lower upfront costs at the expense of higher connectivity costs.
Surface beams resistant to diffraction and attenuation and structured at the millimeter scale
Authors: de Sarro Jhonas O. , Ambrosio Leonardo A.
Published: January 2021

The construction of millimeter-structured surface beams by superimposing scalar Bessel beams has proven to be a powerful technique for creating visual two-dimensional (2D) images in lossless media. In the present paper, we show that surface frozen waves can indeed be designed even in media having non-zero extinction ratios. Examples are provided for specific surface intensity patterns, revealing that our proposed solutions are promising candidates for a wide range of applications encompassing optical trapping displays, 2D and three-dimensional (3D) imaging and printing, nanochannel ablation in glass, optical trapping and manipulation of micro-sized particles and atoms, and so on.
Coherence of a dynamically decoupled single neutral atom
Authors: Chow Chang Hoong , Ng Boon Long , Kurtsiefer Christian
Published: January 2021

Long qubit coherence and efficient atom–photon coupling are essential for advanced applications in quantum communication. One technique to maintain coherence is dynamical decoupling (DD), where a periodic sequence of refocusing pulses is employed to reduce the interaction of the system with the environment. We experimentally study the implementation of DD on an optically trapped, spin-polarized

87

R
b

atom. We use the two magnetic-sensitive

5

S

1

/

2

Zeeman levels

|

F
=
2
,

m
F

=
−
2
⟩

and

|

F
=
1
,

m
F

=
−
1
⟩

as qubit states, motivated by the possibility of coupling

|

F
=
2
,

m
F

=
−
2
⟩

to

5

P

3

/

2

the excited state

|

F
′

=
3
,

m
F
′

=
−
3
⟩

via a closed optical transition. With more refocusing pulses in the DD technique, we manage to extend the coherence time from 38(3) µs to around 7 ms. We also observe a strong correlation between the motional states of the atom and the qubit coherence after the refocusing, which can be used as a measurement basis to resolve trapping parameters.
Plasmon-enhanced graphene photodetector with CMOS-compatible titanium
nitride
Authors: AlAloul Mohammed , Rasras Mahmoud
Published: January 2021

Graphene has emerged as an ultrafast optoelectronic material for
on-chip photodetector applications. The 2D nature of graphene enables
its facile integration with complementary metal–oxide semiconductor
(CMOS) microelectronics and silicon photonics, yet graphene absorbs
only

∼

2.3
%

of light. Plasmonic metals can
enhance the responsivity of graphene photodetectors, but may result in
CMOS-incompatible devices, depending on the choice of metal. Here we
propose a plasmon-enhanced photothermoelectric graphene detector using
CMOS-compatible titanium nitride on the silicon-on-insulator platform.
The device performance is quantified by its responsivity, operation
speed, and noise equivalent power. Its bandwidth exceeds 100 GHz, and
it exhibits a nearly flat photoresponse across the telecom C-band. The
photodetector responsivity is as high as 1.4 A/W (1.1 A/W external) at
an ultra-compact length of 3.5 µm, which is the most compact footprint
reported for a graphene-based waveguide photodetector. Furthermore, it
operates at zero-bias, consumes zero energy, and has an ultra-low
intrinsic noise equivalent power (

N
E
P

<
20

p
W

/

H
z

).
Entropy rate of chaos in an optically injected semiconductor laser for physical random number generation
Authors: Kawaguchi Yu , Okuma Tomohiko , Kanno Kazutaka , Uchida Atsushi
Published: January 2021

We evaluate the (ɛ, τ) entropy of chaotic laser outputs generated by an optically injected semiconductor laser for physical random number generation. The vertical resolution ɛ and sampling time τ are numerically optimized by comparing the (ɛ, τ) entropy with the Kolmogorov–Sinai entropy, which is estimated from the Lyapunov exponents using linearized model equations. We then investigate the dependence of the (ɛ, τ) entropy on the optical injection strength of the laser system. In addition, we evaluate the (ɛ, τ) entropy from the experimentally obtained chaotic temporal waveforms in an optically injected semiconductor laser. Random bits with an entropy close to one bit per sampling point are extracted to satisfy the conditions of physical random number generation. We find that the extraction of the third-most significant bit from eight-bit experimental chaotic data results in an entropy of one bit per sample for certified physical random number generation.
Comparison of the impact of nonlinearity in a p-i-n and an MUTC photodetector on electro-optic frequency combs
Authors: Jamali Mahabadi Seyed Ehsan , Carruthers Thomas F. , Menyuk Curtis R. , McKinney Jason D. , Williams Keith J.
Published: January 2021

We calculate the impact of nonlinearity in both a

p
-
i
-
n

photodetector (PD) and a modified uni-traveling carrier (MUTC) PD on an RF-modulated frequency comb generated using 100-fs optical pulses with a 50-MHz repetition rate. We take into account bleaching (nonlinear saturation) that is due to the high peak-to-average-power ratio and contributes to the device nonlinearity. Nonlinear impairment of an RF-modulated continuous wave is typically characterized by the second- and third-order intermodulation distortion products (IMD2 and IMD3). In contrast, an RF-modulated frequency comb must be characterized by a distinct

I
M
D
2

n

and

I
M
D
3

n

for each comb line

n

. We calculate

I
M
D
2

n

and

I
M
D
3

n

in both

p
-
i
-
n

and MUTC PDs and compare the results. We also calculate the ratio of the

I
M
D
2

n

power and the

I
M
D
3

n

power to the fundamental power

S

in

in both

p
-
i
-
n

and MUTC PDs. We find that nonlinear distortion has a greater impact at high frequencies in the MUTC PD than in the

p
-
i
-
n

PD.
Birefringent transmissive metalens with an ultradeep depth of focus and high resolution
Authors: Qi Jiaran , Mu Yongheng , Wang Shaozhi , Yin Zhiying , Qiu Jinghui
Published: January 2021

Depth of focus (DOF) and transverse resolution define the longitudinal range and definition of the focusing lens. Although metasurface axilenses and light-sword metalenses with radial and angular modulations can elongate the DOF, these approaches have inherent limitations in being reliable only for small numerical aperture (NA) cases, which in turn compromises the transverse resolution for the given aperture dimension. To conquer this limitation, we propose and experimentally demonstrate a birefringent metalens, achieving an ultradeep DOF of

41
λ

in terms of the total scattered field, corresponding to a record-breaking wide NA range from 0.14 to 0.7. Meanwhile, the diffraction limited focal spot size in this NA range can guarantee acquisition of images with high resolution. A hybrid methodology is proposed that utilizes both the accuracy of holography in electromagnetic field reconstruction and the polarization multiplexing to double the DOF. A stratified transmissive meta-atom is utilized to encode a pair of independent phase profiles in two orthogonal polarization channels. Furthermore, we combine the generalized scattering matrix with the multipole expansion theory for the first time to elucidate the mechanism of maintaining high transmittance and widening the transmission phase coverage by using the multilayered structure. The proposed metalens provides a competitive platform for devising high-resolution deep DOF systems for imaging and detection applications.
Highly efficient ultraviolet high-harmonic generation from epsilon-near-zero indium tin oxide films
Authors: Tian Wendong , Liang Fei , Lu Dazhi , Yu Haohai , Zhang Huaijin
Published: January 2021

High-harmonic generation in the ultraviolet region is promising for wireless technology used for communications and sensing. However, small high-order nonlinear coefficients prevent us from obtaining high conversion efficiency and functional photonic devices. Here, we show highly efficient ultraviolet harmonic generation extending to the fifth order directly from an epsilon-near-zero indium tin oxide (ITO) film. The real part of the annealed ITO films was designed to reach zero around 1050 nm, matching with the central wavelength of an Yb-based fiber laser, and the internal driving electric field was extremely enhanced. A high energy conversion efficiency of

10

−
4

and

10

−
6

for 257.5 nm (fourth-order) and 206 nm (fifth-order) ultraviolet harmonic generation was obtained, which is at least 2 orders of magnitude higher than early reports. Our results demonstrate a new route for overcoming the inefficiency problem and open up the possibilities of compact solid-state high-harmonic generation sources at nanoscale.
Memory impairment in chronic experimental Chagas disease: Benznidazole therapy reversed cognitive deficit in association with reduction of parasite load and oxidative stress in the nervous tissue
Authors: Vilar-Pereira Glaucia , Castaño Barrios Leda , Silva Andrea Alice da , Martins Batista Angelica , Resende Pereira Isabela , Cruz Moreira Otacílio , Britto Constança , Mata dos Santos Hílton Antônio , Lannes-Vieira Joseli
Published: January 2021

Memory impairment has been associated with chronic Chagas disease (CD), a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi. In degenerative diseases, memory loss has been associated with increased oxidative stress, revealed as enhanced lipid peroxidation, in the cerebral cortex. Benznidazole (Bz), a trypanocidal drug efficient to reduce blood parasite load in the acute and chronic phases of infection, showed controversial effects on heart disease progression, the main clinical manifestation of CD. Here, we evaluated whether C57BL/6 mice infected with the Colombian type I T. cruzi strain present memory deficit assessed by (i) the novel object recognition task, (ii) the open field test and (iii) the aversive shock evoked test, at 120 days post infection (dpi). Next, we tested the effects of Bz therapy (25mg/Kg/day, for 30 consecutive days) on memory evocation, and tried to establish a relation between memory loss, parasite load and oxidative stress in the central nervous system (CNS). At 120 dpi, T. cruzi-infected mice showed memory impairment, compared with age-matched non-infected controls. Bz therapy (from 120 to 150 dpi) hampered the progression of habituation and aversive memory loss and, moreover, reversed memory impairment in object recognition. In vehicle-administered infected mice, neuroinflammation was absent albeit rare perivascular mononuclear cells were found in meninges and choroid plexus. Bz therapy abrogated the infiltration of the CNS by inflammatory cells, and reduced parasite load in hippocampus and cerebral cortex. At 120 and 150 dpi, lipid peroxidation was increased in the hippocampus and cortex tissue extracts. Notably, Bz therapy reduced levels of lipid peroxidation in the cerebral cortex. Therefore, in experimental chronic T. cruzi infection Bz therapy improved memory loss, in association with reduction of parasite load and oxidative stress in the CNS, providing a new perspective to improve the quality of life of Chagas disease patients.
The chronic kidney disease and acute kidney injury involvement in COVID-19 pandemic: A systematic review and meta-analysis
Authors: Liu Ya-Fei , Zhang Zhe , Pan Xiao-Li , Xing Guo-Lan , Zhang Ying , Liu Zhang-Suo , Tu Sheng-Hao
Published: January 2021

Background

Currently, the SARS-CoV-2 promptly spread across China and around the world. However, there are controversies about whether preexisting chronic kidney disease (CKD) and acute kidney injury complication (AKI) are involved in the COVID-19 pandemic.

Measurements

Studies reported the kidney outcomes in different severity of COVID-19 were included in this study. Standardized mean differences or odds ratios were calculated by employing Review Manager meta-analysis software.

Results

Thirty-six trials were included in this systematic review with a total of 6395 COVID-19 patients. The overall effects indicated that preexisting CKD (OR = 3.28), complication of AKI (OR = 11.02), serum creatinine (SMD = 0.68), abnormal serum creatinine (OR = 4.86), blood urea nitrogen (SMD = 1.95), abnormal blood urea nitrogen (OR = 6.53), received continuous renal replacement therapy (CRRT) (OR = 23.63) were significantly increased in severe group than that in nonsevere group. Additionally, the complication of AKI (OR = 13.92) and blood urea nitrogen (SMD = 1.18) were remarkably elevated in the critical group than that in the severe group.

Conclusions

CKD and AKI are susceptible to occur in patients with severe COVID-19. CRRT is applied frequently in severe COVID-19 patients than that in nonsevere COVID-19 patients. The risk of AKI is higher in the critical group than that in the severe group.
Empirical evaluation of the association between daily living skills of adults with autism and parental caregiver burden
Authors: Marsack-Topolewski Christina N. , Samuel Preethy Sarah , Tarraf Wassim
Published: January 2021

Background

Despite the joy of parenting, the burden of daily caregiving for children with autism spectrum disorders (ASD) can be overwhelming and constant. Parents can expect to provide enduring care for their children with ASD. Given that the majority of individuals with autism spectrum disorders (ASD) remain in their family homes well into adulthood, often the need for assistance with activities of daily living (ADLs) is placed on parents. Providing ongoing support to adult children who have difficulty with completing ADLs can increase parental caregiving demands. Therefore, the purpose of this study was to examine the relationship between the ability of adults with ASD to perform ADLs with parental perceptions of caregiver burden.

Methods

Quantitative analysis of cross-sectional multi-state data gathered electronically using Qualtrics from 320 aging parents of adults with ASD was conducted. Regression models were fit to examine the association of ADL challenges with total caregiver burden and its four domains (emotional, financial, time dependence, and developmental).

Results

Parental perceptions of caregiver burden decreased, particularly time dependence and developmental burden, when adult children were less dependent in ADLs, even after adjusting for parental health and behavioral challenges.

Conclusions

Findings support the need for family-centered interventions to improve the capacity of adults with ASD to perform ADLs independently.
Does the longevity of the Sardinian population date back to Roman times? A comprehensive review of the available evidence
Authors: Floris Piergiorgio , Dore Maria Pina , Pes Giovanni Mario
Published: January 2021

The discovery early in this century of the exceptional longevity of the Sardinian population has given new impetus to demographic studies of this phenomenon during the classical period. In the 1970s, it was hypothesised that the average mortality rate in Roman Sardinia was lower than in metropolitan Rome itself, postulating an ancient precedent for the remarkable longevity observable nowadays in the island’s population. In the present study, the available evidence was examined in order to test this hypothesis. Literary, juridical, epigraphic, papyrological, anthropological and archaeological sources regarding the population of the Roman Empire, including Sardinia, were retrieved by accessing Science Direct, PubMed, Scopus and Google Scholar databases, as well as regional libraries, regardless of time limitation, and were independently reviewed by the authors. For Roman Sardinia, only funerary epitaphs were retrieved, in contrast with the numerous sources available for the whole Roman Empire. Inscriptions revealing the existence of three alleged nonagenarians, two centenarians, two ultracentenarians and one supercentenarian were found, corresponding to 2% in a total of 381 inscriptions. The majority were located in a highly Romanised rural area of central-western Sardinia. However, the ages reported in the epitaphs may be inaccurate because of the influence of confounders such as age rounding, approximations and/or amplifications, and are unrelated to the total number of inhabitants. In conclusion, the funerary evidence, the only available data from Roman Sardinia, is too weak to estimate the life expectancy of the local ancient population and cannot offer valuable arguments to support the hypothesis that exceptional longevity has been a Sardinian trait since Roman times.
Colonialism, water and the Black body
Authors: Gooden Mario
Published: January 2021

For the Black body, water is a topological condition that has been a medium for European colonialism and the construction of race illustrated in the earliest fifteenth century Portuguese nautical master charts depicting the latest knowledge of African coastlines by the transport of enslaved Africans to the shores of the ‘new world’ in North America, South America and the Caribbean, as a means of delineating spatial separation through segregated water fountains, swimming pools and beaches in the United States and South Africa; by the forced migration of people of colour due to sea-level rise and disastrous typhoons and hurricanes such as Irma, Maria, Harvey and most recently Dorian – all the result of global climate change induced by centuries-old pollution in the industrialized nations of Europe and North America; by the lack of access to clean drinking water not only in former European colonies in Africa but also in cities such as Flint, Michigan and Newark, NJ, and to the paucity of water and severe drought in places like the former Portuguese colony of Cape Verde as well as Cape Town, South Africa, formerly colonized by the Dutch and the British. Water as a line from coloniality to climate change represents the spectacle of vulnerability within the quotidian condition of Black life and its indigeneity and diasporic formation linked by a vicious history of imperialism and colonization. The topology of water refers to not only geometric properties of water in terms of its liquidity, flows, movement and capacity for infinite temporal and morphological containments but also the cultural landscape of water defined by relationships of power that do not so much change but take up new guises of privilege and subjugation.
Colonizing islands
Authors: Smith Chris L.
Published: January 2021

When Edward Said spoke of an ‘imaginative geography’, it was both to question the geographic positions adopted as part of colonial accounts and to posit the role of imagination itself in the construction of geographies. For Said, the ‘dramatic boundaries’ of imaginative geography are at once abstract and mobile, and yet might constitute ‘a form of radical realism’. The discourse is thus at once about perspective, position and the empirical (and imperial) imposition of that which is speculative, literary and fluid. But it is also about the unmediated engagements of radical realism and a form of geography we can only imagine. This article turns to the imaginative geography of islands and takes three islands as its departure point. The first is the island of Gilles Deleuze’s article ‘Desert islands’ (), an island ‘toward which one drifts’. The second is the island of absent subjectivity that is explored in Jean Baudrillard’s extended essay Why Hasn’t Everything Already Disappeared? (). The third island upon which this article fixates is perhaps more archipelago than island. It is the spomeniki that are dotted over the landscape of the former Yugoslavia. These monuments were largely commissioned by Josip Broz Tito and built across the 1960s and 1970s and into the early 1980s to mark the places where the battles of the National Liberation War (Second World War) had occurred and where concentration camps had once stood. These monuments sit as odd and haunting gestures. Many sculptors and architects were involved. Some spomeniki are anchored and sit heavy on the landscape, as one might expect of memorials, and others appear to launch themselves towards elsewhere. Some are small and unimposing, and others at a scale well beyond the human body. Some are well tended, and others have faded into oblivion. This article turns specifically to the spomenik at the Valley of Heroes, Tjentište, designed by the sculptor Miodrag Živović and completed in 1971. Like all the spomeniki, this monument has endured further war since its erection. This magnificent fractal concrete form marks the Battle of Sutjeska, but rather than fixate upon a singular geo-historical moment, it appears more likely to take flight. I will argue that this magnificent sculpture is perhaps engaged in what Baudrillard calls ‘the art of disappearance’.