bluuebunny/crossref_metadata_2025 huggingface dataset:
RELACIONES ENTRE PENSAMIENTO PROPORCIONAL Y PENSAMIENTO PROBABILÍSTICO EN SITUACIONES DE TOMA DE DECISIONES
Authors: Vergara Gómez Andrea , Estrella Soledad , Vidal-Szabó Pedro
Published: March 2020

Tomar decisiones es un acto cotidiano en el ser humano, a mayor incertidumbre más difícil es decidir. A partir de una situación de aprendizaje, consistente en decidir entre dos juegos aleatorios con dados, se estudia la relación entre el pensamiento proporcional y el pensamiento probabilístico, considerando tres estados para el pensamiento proporcional y tres tipos de pensamiento probabilístico. bajo el enfoque de un estudio de casos instrumental, se analizan las decisiones y argumentos de estudiantes de secundaria chilenos. los resultados indican que existen relaciones tanto beneficiosas como perjudiciales entre el pensamiento proporcional y el probabilístico, y que las dificultades en la determinación de probabilidades no necesariamente obedecen a la ausencia del uso de proporciones. Se recomienda una enseñanza que considere la argumentación y el aprendizaje del espacio muestral para encauzar el uso de recursos intuitivos.
HIPÓTESIS Y CONJETURAS EN EL DESARROLLO DEL PENSAMIENTO ESTOCÁSTICO: RETOS PARA SU ENSEÑANZA Y EN LA FORMACIÓN DE PROFESORES
Authors: Huerta M. Pedro
Published: March 2020

En este artículo se reflexiona alrededor de la importancia que puede tener la dialéctica hipótesis-conjeturas no solo para el desarrollo del razonamiento demostrativo, sino que también para el desarrollo del pensamiento estocástico en los estudiantes. Se argumenta para ello razones de tipo curricular, de un enfoque de la enseñanza basado en la resolución de problemas, de una manera de resolver los problemas que considera la simulación como método de resolución con contenido heurístico y, finalmente, en nuevas propuestas sobre las matemáticas que requerirá el ciudadano del siglo XXI y que incluye el análisis de datos en contextos de incertidumbre. En consecuencia, se presenta una propuesta de formación inicial del profesorado que les permita abordar tales retos.
Optimal Commissions and Subscriptions in Networked Markets
Authors: Birge John , Candogan Ozan , Chen Hongfan , Saban Daniela
Published: March 2020

Problem definition: We consider a platform that charges commission rates and subscription fees to sellers and buyers for facilitating transactions but does not directly control the transaction prices, which are endogenously determined. Buyers and sellers are divided into types, and we represent the compatibility between different types using a bipartite network. Traders are heterogeneous in terms of their valuations, and different types have possibly different value distributions. Buyers may have additional value for trading with some seller types. The platform chooses commissions/subscriptions to maximize its revenues. Academic/practical relevance: Two salient features of most online platforms are that they do not dictate the transaction prices, and they use commissions/subscriptions for extracting revenues. We shed light on how these commissions/subscriptions should be set in networked markets. Methodology: Using tools from convex optimization and combinatorial optimization, we obtain tractable methods for computing the optimal commissions/subscriptions and provide insights into the platform’s revenues, buyer/seller surplus, and welfare. Results: We provide a tractable convex optimization formulation to obtain the revenue-maximizing commissions/subscriptions, and establish that, typically, different types should be charged different commissions/subscriptions depending on their network positions. We establish that the latter result holds even when the traders on each side have identical value distributions, and in this setting we provide lower and upper bounds on the platform’s revenues in terms of the supply-demand imbalance across the network. Motivated by simpler schemes used in practice, we show that the revenue loss can be unbounded when all traders on the same side are charged the same commissions/subscriptions, and bound the revenue loss in terms of the supply-demand imbalance across the network. Charging only buyers or only sellers leads to at least half of the optimal revenues, when different types on the same side can be charged differently. Managerial implications: Our results highlight the suboptimality of commonly used payment schemes and showcase the importance of accounting for the compatibility between different user types.
the paradox of philosophy for children and how to resolve it
Authors: Kasmirli Maria
Published: March 2020

There is a paradox in the idea of philosophy for children (P4C). Good teaching starts from the concrete and particular, and it engages with each student’s individual interests, beliefs, and experiences. Preadolescents (and to some extent everyone) find this approach more natural than a more impersonal one and respond better to it. But doing philosophy involves focusing on the abstract and general and disengaging oneself from one’s personal interests and beliefs. It involves critiquing one’s attitudes, seeing abstract relations, and applying general principles. So, if good teaching focuses on the concrete and personal, and good philosophy on the abstract and impersonal, how can there be good teaching of philosophy to children? I call this the paradox of philosophy for children, and in this paper I explore how teachers should respond to it. Should they sacrifice good teaching practice, adopting a heavily teacher-centred approach in order to correct their students’ natural biases? Should they lower their expectations of what philosophical skills children can acquire? Should they even attempt to teach philosophy to children? The paper will argue that there is a better option, which exploits children’s imaginative abilities. The core idea is that by encouraging children to imaginatively identify with other perspectives, we can use their natural focus on the concrete and particular to lever them into more abstract, critical ways of thinking. In this way, their focus on the concrete and personal can be the very means to get them to think abstractly and critically. The paper will go on to outline a general strategy for implementing this approach, the Scenario-Identification-Reflection (SIR) method, which will be illustrated with examples drawn from the author’s own classroom practice. The paper will also respond to some objections to the proposed strategy and offer some general reflections on the SIR method.
improvising inquiry in the community: the teacher profile
Authors: Zorzi Eleonora , Santi Marina
Published: March 2020

Improvising involves participants adopting attitudes and dispositions that make them welcoming towards what happens, even when it is unforeseen. How is the discourse on improvisation and a disposition to improvise in the community connected to the concept of inquiry? What type of reasoning can be developed? This paper aims to reflect on two different perspectives. On the one hand, we consider the feasibility of improvising inquiry in the community, promoting inquiry as an activity that can be developed extemporaneously when teacher and students form a community with an “improvising” habitus. On the other hand, we underscore the intrinsic improvisational dimension of inquiry that takes shape in philosophical dialogue in the community. To develop these two educational and formative perspectives, participants students and particularly teachers must first acquire a “readiness” for improvisation which is a sort of complex attitude. Some results of previous research on improvisation are presented to explain and emphasize the features of this complex disposition. Teachers who improvise suddenly open a window on events happening in the community, serving as an example for the class which is invited to do the same. Teachers thus become improviser-facilitators within the community, embracing the feature of a new jazz-pedagogy at the same time.
mapping identity prejudice: locations of epistemic injustice in philosophy for/with children
Authors: Elicor Peter paul Ejera
Published: March 2020

This article aims to map the locations of identity prejudice that occurs in the context of a Community of Inquiry. My claim is that epistemic injustice, which usually originates from seemingly ‘minor’ cases of identity prejudice, can potentially leak into the actual practice of P4wC. Drawing from Fricker, the various forms of epistemic injustice are made explicit when epistemic practices are framed within concrete social circumstances where power, privilege and authority intersect, which is observable in school settings. In connection, despite the pedagogical improvements P4wC offers, some forms of identity prejudice prevalent in traditional classrooms may persist, affecting children who are identified with negatively stereotyped social groups. It is, therefore, important to pay attention to the reality of epistemic injustice and the possible locations where it may potentially surface in the COI. Drawing from my P4wC experience, I show that identity prejudice stems from the intersections of the roles and positionalities of the participants in a philosophical dialogue. These intersections point towards the epistemic relationships of the P4wC teacher, the students, and the P4wC program itself. I conclude that identity prejudice arises circumstantially and/or substantively in P4wC scholarship and practice.
PRÁTICAS DE ENSINO COM O USO DE TECNOLOGIAS DIGITAIS: o papel da formação docente
Authors: Oliveira Ariane Xavier de , Mello Diene Eire de , Franco Sandra Aparecida Pires
Published: March 2020

O objetivo do presente estudo foi promover uma discussão acerca do papel da formação de professores enquanto mobilizadoras de boas práticas com tecnologias digitais. Trata-se de um estudo qualitativo de caráter exploratório que utilizou como fonte de dados, entrevistas e consulta a documentos oficiais. Participaram das entrevistas cinco professores e uma assessora pedagógica. O estudo tem como base principal os fundamentos da Teoria Histórico-Cultural. Para a análise dos dados utilizou-se da análise de conteúdo. De posse dos dados analisados foi possível apreender a relevância da formação em serviço como mobilizadora de boas práticas com esses artefatos.
Limited sequence MRI to improve standards of care for suspected cauda equina syndrome
Authors: Gnanasekaran Ramal , Beresford-Cleary Nicholas , Aboelmagd Tariq , Aboelmagd Karim , Rolton Daniel , Hughes Richard , Seel Edward , Blagg Stuart
Published: March 2020

Aims

Early cases of cauda equina syndrome (CES) often present with nonspecific symptoms and signs, and it is recommended that patients undergo emergency MRI regardless of the time since presentation. This creates substantial pressure on resources, with many scans performed to rule out cauda equina rather than confirm it. We propose that compression of the cauda equina should be apparent with a limited sequence (LS) scan that takes significantly less time to perform.

Methods

In all, 188 patients with suspected CES underwent a LS lumbosacral MRI between the beginning of September 2017 and the end of July 2018. These images were read by a consultant musculoskeletal radiologist. All images took place on a 3T or 1.5T MRI scanner at Stoke Mandeville Hospital, Aylesbury, UK, and Royal Berkshire Hospital, Reading, UK.

Results

The 188 patients, all under the age of 55 years, underwent 196 LS lumbosacral MRI scans for suspected CES. Of these patients, 14 had cauda equina compression and underwent emergency decompression. No cases of CES were missed. Patients spent a mean 9.9 minutes (8 to 10) in the MRI scanner.

Conclusion

Our results suggest that a LS lumbosacral MRI could be used to diagnose CES safely in patients under the age of 55 years, but that further research is needed to assess safety and efficacy of this technique before changes to existing protocols can be recommended. In addition, work is needed to assess if LS MRIs can be used throughout the spine and if alternative pathology is being considered. Cite this article: Bone Joint J 2020;102-B(4):501–505.
Cemented or uncemented acetabular fixation in combination with the Exeter Universal cemented stem
Authors: Gwynne-Jones David P. , Gray Andrew R.
Published: March 2020

Aims

To compare long-term survival of all-cemented and hybrid total hip arthroplasty (THA) using the Exeter Universal stem.

Methods

Details of 1,086 THAs performed between 1999 and 2005 using the Exeter stem and either a cemented (632) or uncemented acetabular component (454) were collected from local records and the New Zealand Joint Registry. A competing risks regression survival analysis was performed with death as the competing risk with adjustments made for age, sex, approach, and bearing.

Results

There were 61 revisions (9.7%; 0.82 revisions/100 observed component years, (OCYs)) in the all-cemented group and 18 (4.0%; 0.30/100 OCYs) in the hybrid group. The cumulative incidence of revision at 18 years was 12.1% for cemented and 5.2% for hybrids. There was a significantly greater risk of revision for all-cemented compared with hybrids (unadjusted sub-hazard ratio (SHR) 2.44; p = 0.001), and of revision for loosening, wear, or osteolysis (unadjusted SHR 3.77; p < 0.001). After adjustment, the increased risk of all-cause revision did not reach significance at age 70 years and above. The advantage for revision for loosening, wear, and osteolysis remained at all ages.

Conclusion

This study supports the use of uncemented acetabular fixation when used in combination with the Exeter stem with improved survivorship for revision for aseptic loosening, wear, and osteolysis at all ages and for all-cause revision in patients less than 70 years. Cite this article: Bone Joint J 2020;102-B(4):414–422
Reduction in patient outcomes but implant-derived preservation of function following total knee arthroplasty: longitudinal follow-up of a randomized controlled trial
Authors: Hamilton David F. , Burnett Richard , Patton James T. , MacPherson Gavin J. , Simpson A. H. R. W. , Howie Colin R. , Gaston Paul
Published: March 2020

Aims

There are comparatively few randomized studies evaluating knee arthroplasty prostheses, and fewer still that report longer-term functional outcomes. The aim of this study was to evaluate mid-term outcomes of an existing implant trial cohort to document changing patient function over time following total knee arthroplasty using longitudinal analytical techniques and to determine whether implant design chosen at time of surgery influenced these outcomes.

Methods

A mid-term follow-up of the remaining 125 patients from a randomized cohort of total knee arthroplasty patients (initially comprising 212 recruited patients), comparing modern (Triathlon) and traditional (Kinemax) prostheses was undertaken. Functional outcomes were assessed with the Oxford Knee Score (OKS), knee range of movement, pain numerical rating scales, lower limb power output, timed functional assessment battery, and satisfaction survey. Data were linked to earlier assessment timepoints, and analyzed by repeated measures analysis of variance (ANOVA) mixed models, incorporating longitudinal change over all assessment timepoints.

Results

The mean follow-up of the 125 patients was 8.12 years (7.3 to 9.4). There was a reduction in all assessment parameters relative to earlier assessments. Longitudinal models highlight changes over time in all parameters and demonstrate large effect sizes. Significant between-group differences were seen in measures of knee flexion (medium-effect size), lower limb power output (large-effect size), and report of worst daily pain experienced (large-effect size) favouring the Triathlon group. No longitudinal between-group differences were observed in mean OKS, average daily pain report, or timed performance test. Satisfaction with outcome in surviving patients at eight years was 90.5% (57/63) in the Triathlon group and 82.8% (48/58) in the Kinemax group, with no statistical difference between groups (p = 0.321).

Conclusion

At a mean 8.12 years, this mid-term follow-up of a randomized controlled trial cohort highlights a general reduction in measures of patient function with patient age and follow-up duration, and a comparative preservation of function based on implant received at time of surgery. Cite this article: Bone Joint J 2020;102-B(4):434–441.
Bipolar hemiarthroplasty versus total hip arthroplasty in allograft-prosthesis composite reconstruction of the proximal femur following primary bone tumour resection
Authors: Jamshidi Khodamorad , Mirkazemi Masoud , Gharedaghi Mohammad , Izanloo Azra , Mohammadpour Mehdi , Pisoudeh Karim , Bagherifard Abolfazl , Mirzaei Alireza
Published: March 2020

Aims

The consensus is that bipolar hemiarthroplasty (BHA) in allograft-prosthesis composite (APC) reconstruction of the proximal femur following primary tumour resection provides more stability than total hip arthroplasty (THA). However, no comparative study has been performed. In this study, we have compared the outcome and complication rates of these two methods.

Methods

In a retrospective study, 57 patients who underwent APC reconstruction of proximal femur following the primary tumour resection, either using BHA (29) or THA (28), were included. Functional outcome was assessed using the Musculoskeletal Tumour Society (MSTS) scoring system and Harris Hip Score (HHS). Postoperative complications of the two techniques were also compared.

Results

The mean follow-up of the patients was 8.3 years (standard deviation (SD) 5.5) in the BHA and 6.9 years (SD 4.7) in the THA group. The mean HHS was 65 (SD 16.6) in the BHA group and 88 (SD 11.9) in the THA group (p = 0.036). The mean MSTS score of the patients was 73.3% (SD 16.1%) in the BHA and 86.7% (SD 12.2%) in the THA group (p = 0.041). Limping was recorded in 19 patients (65.5%) of the BHA group and five patients (17.8%) of the THA group (p < 0.001). Dislocation occurred in three patients (10.3%) of the BHA group and two patients (7.1%) of the THA group.

Conclusion

While the dislocation rate was not higher in THA than with BHA, the functional outcome was significantly superior. Based on our results, we recommend THA in APC reconstruction of the proximal femur. Cite this article: Bone Joint J 2020;102-B(4):524–529.
Risk factors for heterotopic ossification in operatively treated proximal humeral fractures
Authors: Cirino Carl M. , Chan Jimmy J. , Patterson Diana C. , Jia Rachel , Poeran Jashvant , Parsons Bradford O. , Cagle Paul J.
Published: March 2020

Aims

Heterotopic ossification (HO) is a potentially devastating complication of the surgical treatment of a proximal humeral fracture. The literature on the rate and risk factors for the development of HO under these circumstances is lacking. The aim of this study was to determine the incidence and risk factors for the development of HO in these patients.

Methods

A retrospective analysis of 170 patients who underwent operative treatment for a proximal humeral fracture between 2005 and 2016, in a single institution, was undertaken. The mean follow-up was 18.2 months (1.5 to 140). The presence of HO was identified on follow-up radiographs.

Results

The incidence of HO was 15% (n = 26). Our multivariate model revealed that male sex (odds ratio (OR) 3.57, 95% confidence interval (CI) 1.30 to 9.80 compared to female) and dislocation as the initial injury (OR 5.01, 95% CI 1.31 to 19.22) were significantly associated with the formation of HO (p < 0.05) while no significant associations were seen for the age of the patient, the characteristics of the injury, or the type of operative treatment.

Conclusion

This retrospective radiological study is the first to investigate the association between the method of surgical treatment for a proximal humeral fracture and the formation of HO postoperatively. We found that male sex and dislocation as the initial injury were risk factors for HO formation, whereas the method of surgical treatment, the age of the patient, and the pattern of the fracture were not predictive of HO formation. While additional studies are needed, these findings can help to identify those at an increased risk for HO formation under these circumstances. Cite this article: Bone Joint J 2020;102-B(4):539–544.
The effects of dual plating on the vascularity of the distal femur
Authors: Rollick Natalie C. , Gadinsky Naomi E. , Klinger Craig E. , Kubik Jeremy F. , Dyke Jonathan P. , Helfet David L. , Wellman David S.
Published: March 2020

Aims

Dual plating of distal femoral fractures with medial and lateral implants has been performed to improve construct mechanics and alignment, in cases where isolated lateral plating would be insufficient. This may potentially compromise vascularity, paradoxically impairing healing. This study investigates effects of single versus dual plating on distal femoral vascularity.

Methods

A total of eight cadaveric lower limb pairs were arbitrarily assigned to either 1) isolated lateral plating, or 2) lateral and medial plating of the distal femur, with four specimens per group. Contralateral limbs served as matched controls. Pre- and post-contrast MRI was performed to quantify signal intensity enhancement in the distal femur. Further evaluation of intraosseous vascularity was done with barium sulphate infusion with CT scan imaging. Specimens were then injected with latex medium and dissection was completed to assess extraosseous vasculature.

Results

Quantitative MRI revealed a mean reduction of 21.2% (SD 1.3%) of arterial contribution in the lateral plating group and 25.4% (SD 3.2%) in the dual plating group (p = 0.051); representing a mean decrease in arterial contribution of 4.2%. The only significant difference found between both experimental groups was regionally, at the lateral aspect of the distal femur with a mean drop in arterial contribution in the lateral plating group of 18.9% (SD 2.6%) versus 24.0% (SD 3.2%) in the dual plating group (p = 0.048), representing a mean decrease in arterial contribution of 5.1%. Gross dissection revealed complete destruction of periosteal vessels underneath either medial or lateral plates in both groups. The network of genicular branches contributing to the posterior and distal femoral condyles was preserved in all specimens. A medial vascular pedicle was found dividing from the superficial femoral artery at a mean 12.7 cm (SD 1.7) proximal to the medial epicondyle and was undisrupted in the dual plating group.

Conclusion

Lateral locking-plate application resulted in mean 21.2% reduction in distal femur vascularity. Addition of medial plates did not further markedly decrease vascularity. As such, the majority of the vascular insult occurred with lateral plating alone. Supplemental medially based fixation did not lead to marked devascularization of the distal femur, and should therefore be considered in the setting of comminution and poor bone stock in distal femoral fractures. Further clinical research is required to confirm the results of this study. Cite this article: Bone Joint J 2020;102-B(4):530–538.
Short communication: The genotype of growth hormone gene that affects the birth weight and average daily gain in crossbred beef cattle
Authors: Hartatik Tety , AHMAD FATHONI  , SIGIT BINTARA  , ISMAYA  , PANJONO  , B.P. WIDYOBROTO  , ALI AGUS  , IGS. BUDISATRIA  , PASCAL LEROY
Published: March 2020

Abstract. Hartatik T., Fathoni A, Bintara S., Ismaya, Panjono, Widyobroto B.P, Agus A, Budisatria I.G.S, Leroy P. 2020. Short communication: The genotype of growth hormone gene that affects the birth weight and average daily gain in crossbred beef cattle. Biodiversitas 21: 941-945. Growth Hormone gene has been proposed to direct search for quantitative trait loci, and polymorphisms at these loci have been associated with several production traits in bovine. This research aimed to investigate the association of the genotype of partial growth hormone gene with birth weight and average daily gain in crossbred beef cattle. The materials of this research consist of 47 samples from four different breeds. Birth weight was measured just after calving delivery from the mother. The average daily gain was calculated from the period since birth weight to the second weight (90 days). Genotyping of the growth hormone gene was determined by the sequencing and PCR-RFLP method with the AluI restriction enzyme. The association between genotype and growth traits data was analyzed using analysis of variance (ANOVA) by RStudio version 1.1.383. The results showed the significantly different (P<0.001) in birth weight and average daily gain according to the different breed. Friesian Holstein breed showed the highest birth weight, followed by Belgian Blue Bull cross and others. The genotype valine/valine only occurs in Belgian blue bull cross and Wagyu bull cross cattle and showed moderate birth weight. Genotype affects birth weight significantly (P<0.001). The birth weight for genotype leucine/leucine, leucine/valine, and valine/valine was 34.82±18.13, 25.31±13.10, and 29.35±13.65, respectively. There was no significant difference in average daily genes according to the different genotypes. In conclusion, the growth hormone gene was probably one of the molecular genetics markers for excellent growth traits in different crossbred beef cattle.
The The diversity and abundance of Hymenoptera insects on tidal swamp rice field in Indragiri Hilir District, Indonesia
Authors: IKHSAN ZAHLUL , HIDRAYANI  , YAHERWANDI  , HASMIANDY HAMID
Published: March 2020

Abstract. Ikhsan Z, Hidrayani, Yaherwandi, Hamid H. 2020. The diversity and abundance of Hymenoptera insects on tidal swamp rice field in Indragiri Hilir District, Indonesia. Biodiversitas 21: 1020-1026. Hymenoptera is one of the four largest insect orders and it plays a vital role in human life as pollinators, parasitoids, and predators. Hymenoptera parasitoids are particularly important as agents of biological control of pest. The objective of this research was to study the diversity and abundance of Hymenoptera on tidal swamp rice field in Indragiri Hilir District, Riau Province, Indonesia. Samplings were conducted in 3 sub-districts of rice production centers, namely Batang Tuaka, Keritang and Reteh, using four trapping techniques (i.e. insect net, malaise trap, pitfall trap, and yellow pan trap). Shannon diversity index (H '), Krebs evenness index (E), and Jaccard similarity index (Is) were calculated. We found 4,701 individuals consisting of 39 families and 319 species of Hymenoptera at the three studied areas. Tidal swamp rice in Indragiri Hilir District had a high species diversity of Hymenoptera parasitoids and Hymenoptera predators, but a moderate species diversity of Hymenoptera pollinators. Species diversity and evenness of Hymenoptera parasitoids and predators were higher in Keritang than in Batang Tuaka and Reteh. The families of Formicidae, Braconidae, Ichneumonidae, and Scelionidae had the highest number of species, while Formicidae, Scelionidae, Diapriidae, and Braconidae had the highest number of individuals. Based on these findings, the abundance and diversity of Hymenoptera insects in Indragiri Hilir District have the potentials to be developed as biological agents to control pests on tidal swamp rice in this area.
Short Communication: Optimization of extraction of sulfhydryl compounds from several legumes seeds in Indonesia with various ethanol concentrations
Authors: Wardatun Sri , Harahap Yahdiana , Mun'im Abdul , NOORWATI SUTANDYO
Published: March 2020

Abstract. Wardatun S, Harahap Y, Mun’im A. 2020. Short Communication: Optimization of extraction of sulfhydryl compounds from several legumes seeds in Indonesia with various ethanol concentrations. Biodiversitas 21: 1060-1064. Leucaena leucocephala (Lam.) de Wit (petai Cina), Parkia speciosa Hassk. (petai), and Archidendron jiringa (Jack) I.C. Nielsen (jengkol) seeds extracts contain sulfhydryl compounds and have various therapeutic properties. The main objective of this research was to compare the effect of various ethanol concentration on the yield of extract and levels of sulfhydryl compounds from leguminous seeds. Dried seeds were macerated at room temperature (25°C) with a ratio of solids and solvents was 1:10. The solvent concentrations used were 30%, 50%, 70% and 96% ethanol. The yield of extract was expressed as the ratio of the weight of extract to the weight of dried seeds, the level of sulfhydryl compound was expressed as reduced L-glutathione (GSH) equivalent. The level of sulfhydryl compounds was determined by Ellman reagent and further analyzed using a spectrophotometer at 411 nm wavelength. Stink bean produced the highest yield of extract, while the highest level of sulfhydryl compounds was obtained from petai cina seed extract. The concentration of ethanol gave a significant difference to the yield of extract and the level of sulfhydryl compounds. The results showed that ethanol concentration affected the efficiency of the extraction of total sulfhydryl compounds and the yield of the extract on leguminous seeds.
Vegetation analysis, physico-chemical properties and economic potential of damar (Agathis dammara) in Mount Halimun Salak National Park,West Java, Indonesia
Authors: Adalina Yelin , RENY SAWITRI
Published: March 2020

Abstract. Adalina Y, Sawitri R. 2020. Vegetation analysis, physico-chemical properties and economic potential of damar (Agathis dammara) in Mount Halimun Salak National Park,West Java, Indonesia. Biodiversitas 21: 1122-1129. Analysing the potential of non-timber forest product (NTFP) plants in Mount Halimun Salak National Park (MHSNP) is one of the important aspects in supporting conservation and improving the economic status of communities around the forest. This study aims to determine the economic potential and benefits of damar plants (Agathis dammara) in MHSNP area of Kawah Ratu Resort, Sukabumi District, West Java, Indonesia along with analysis of damar plant forest and physico-chemical analysis of the copal/resin. The selection of research village was by purposive sampling and the selection of respondents was by random sampling. Forest vegetation in the Kawah Ratu Resort is entirely dominated by damar plants. The Important Value Index (IVI) of damar plant trees is 300% and the density is 582 trees/ha. The quality of copal from Kawah Ratu Resort meets SNI standards in parameters like ash content, soft point and melting point, while the saponification number is above SNI standard. Level of dung in copal chunks meet SNI standards and has better quality than copal in the form of powder. The present average income of farmers from resin tapping is Rp 624,000/person /month, which makes an average contribution of 63.08% to the total household income of farmers. But the actual economic potential of gum resin in Kawah Ratu Resort was estimated to be around Rp 596,920,000/month.
Diversity, consumption dynamics and ethnomedical claims of traditional leafy vegetables consumed by a rural community in the KwaMbonambi area, northern KwaZulu-Natal, South Africa
Authors: Mncwango Ngcebo , Mavengahama Sydney , Ntuli Nontuthuko , Van Jaarsveld Corlina
Published: March 2020

Abstract. Mncwango NC, Mavengahama S, Ntuli NR, van Jaarsveld CM. 2020. Diversity, consumption dynamics and ethnomedical claims of traditional leafy vegetables consumed by a rural community in the KwaMbonambi area, northern KwaZulu-Natal, South Africa. Biodiversitas 21: 1196-1202. Traditional leafy vegetables  (TLVs) are mostly wild and informally-domesticated edible plant species. Their nutritious leaves, shoot tips, flowers and fruits are consumed as vegetables, particularly by rural communities in Africa. However, their consumption and cultivation are still marginal. This study aimed to identify the most preferred TLVs, as well as factors that affect the consumption and cultivation of these species. A questionnaire was administered among 100 respondents to record the preferred TLVs; the reason (s) for preference; consumption frequency; and constraints towards consumption of these vegetable species. This study recorded a total of 18 TLVs that belong to 14 genera and 11 families. Among these, Amaranthus hybridus, A. spinosus, A. thunbergii, Bidens biternata and Corchorus olitorius were the most preferred species. Vegetables were preferred primarily based on the taste; where most people ate them once a week when they are available. The major TLV consumption constraints were seasonal availability and low shelf life. A decline in the availability of TLVs was primarily caused by drought. Regardless of the observed decline, only 23% of respondents practiced informal cultivation of Amaranthus species. Bidens pilosa, Momordica balsamina, and Corchorus olitorius vegetable species were also known to possess some medicinal values. Future research on improving taste, increasing edible plant parts and elongating shelf life for preferred TLVs, is a necessity.
Local indigenous strategy to rehabilitate and conserve mangrove ecosystem in the southeastern Gulf of Kupang, East Nusa Tenggara, Indonesia
Authors: RONGGO SADONO  , DJOKO SOEPRIJADI  , ARI SUSANTI  , Matatula Jeriels , EKO PUJIONO  , FAHMI IDRIS  , PANDU YUDHA ADI PUTRA WIRABUANA
Published: March 2020

Abstract. Sadono R, Soeprijadi D, Susanti A, Matatula J, Pujiono E, Idris F, Wirabuana PYAP. 2020. Local indigenous strategy to rehabilitate and conserve mangrove ecosystem in the southeastern Gulf of Kupang, East Nusa Tenggara, Indonesia. Biodiversitas 21: 1250-1257.  The existence of local communities around mangrove ecosystems plays essential role to support the effort of conservation programs in this area. This study is aimed to investigate a set of situation faced by local communities in the southeastern Gulf of Kupang (SGK), East Nusa Tenggara Province which led to the rehabilitation of once degraded mangrove forests in SGK and the strategies to conserve the recovered mangrove forests. A case study approach was developed using purposive sampling to collect information regarding the historical situation of mangrove forests in SGK. Further, remote sensing method using multi-temporal observation data was used to investigate the changes in mangrove cover from 1994 to 2019. This study revealed that a series of situations became the fundamental of the success in retaining the existence of mangrove ecosystems in SGK. First, the negative impacts of mangrove degradation affected the communities badly in relation to their livelihoods in fisheries and marine sector as well as other environmental services. Then, this situation led to the emergent of a local champion to initiate mangrove rehabilitation efforts which firstly did not get attention from most of the communities. After some initial successes, the efforts of the local champion was then followed by other members of communities, triggering a bigger scale of mangrove rehabilitation. Having the mangrove recovered, the communities set of highly strict local indigenous rules in which every indigenous people who conducting illegal logging in the mangroves would be expelled from the village, while a large fine was given for outside people who did the similar action. Currently, more than 90% of respondents have understood the benefits of mangroves and derived advantages from it, particularly in improving their prosperity and security. The results of the success of mangrove rehabilitation and conservation in SGK was confirmed by the increasing extent of mangrove vegetation using remote sensing data. The case study of rehabilitation and conservation in SGK provided valuable learning for communities in other areas.
How social enterprises called benefit organisations fulfil the triple bottom line
Authors: Dhakal Hem Raj
Published: March 2020

The purpose of this qualitative multi-case study was to explore how the leaders of benefit organisations fulfil the triple bottom line (social, economic, and environmental missions) of social enterprises that were formed as benefit corporations, benefit LLCs (limited liability companies),
and certified benefit corporations between 2010 and 2015 in Maryland and Virginia. The theoretical foundation used for this study was the triple bottom line (TBL) model. This research contributed to the existing body of knowledge by investigating the interdependence between the three components
of the TBL. Thirteen top leaders of benefit organisations participated in this study. The data were collected from documentation, interviews, and questionnaires. The key findings of this study indicated that leaders of social enterprises used holistic thinking instead of paradoxical thinking
to fulfil the TBL. These leaders developed internal and external collaboration and coordination to accomplish the triple missions. Finally, the data of this study revealed the synergistic interrelationships between these missions.
Tunable compression of THz chirped pulses using a helical graphene ribbon-loaded hollow-core waveguide
Authors: Razavizadeh Seyed Mohammadreza , Kashani Zahra Ghattan , Sadeghzadeh Ramezanali , Navarro-Cía Miguel
Published: March 2020

Pulse shaping is important for communications, spectroscopy, and other applications that require high peak power and pulsed operation, such as radar systems. Unfortunately, pulse shaping remains largely elusive for terahertz (THz) frequencies. To address this void, a comprehensive study on the dispersion tunability properties of THz chirped pulses traveling through a dielectric-lined hollow-core waveguide loaded with a helical graphene ribbon is presented. It is demonstrated that there is an optimal compression waveguide length over which THz chirped pulses reach the maximum compression. The optimal length is dependent on the chirp pulse duration. It is shown that by applying an electrostatic controlling gate voltage (

V
g

) of 0 and 30 V on the helical graphene ribbon, the temporal input pulses of width 8 and 12 ps, propagating through two different lengths, can be tuned by 5.9% and 8%, respectively, in the frequency range of 2.15–2.28 THz.
High-temperature stereo-digital image correlation using a single polarization camera
Authors: Chen Bin , Ji Lei , Pan Bing
Published: March 2020

We propose a new, to the best of our knowledge, full-frame, single-camera stereo-digital image correlation (stereo-DIC) technique that is capable of measuring surface profile and deformation over a wide temperature range. This technique uses a single polarization camera and a polarizing beam splitter to synchronously capture two full-frame sub-images with orthogonal polarization directions. By further adopting the idea of active imaging that combines monochromatic blue-light active lighting and narrow bandpass filter imaging, this system can capture stable and high-contrast speckle images of specimens at extremely high temperatures. From the captured sub-image pairs, profile and deformation fields can be retrieved using a regular stereo-DIC algorithm. Compared with the existing full-frame single-camera stereo-DIC systems implemented on a color camera, the established system offers wider applicability, since it is insensitive to serious variations in ambient light in non-laboratory environments and to the thermal radiation of hot objects in extreme high-temperature environments. The effectiveness and accuracy of the proposed technique are validated by room-temperature tests and high-temperature tests at up to 1000°C. The advantages of a simple configuration, free synchronization, and full-frame high-temperature deformation measurement ability offer the proposed technique potential in both high-speed and high-temperature 3D measurement applications.
When does “bright” mean “prototypical”? Color-term modifiers in eight European languages, examined with color-survey data
Authors: Uusküla Mari , Bimler David L.
Published: March 2020

Certain modified color terms encountered in a multi-language corpus of unconstrained color-naming data, elicited with 65 Color-aid Corporation tiles, can be glossed into English as “bright (or vivid) X” (e.g., Estonian “ere-X”), while other modifiers are glossed “light” or “dark.” However, translation between languages or into the terms of colorimetry is never assured. We address the problem empirically by examining the denotata of each modified term and treating its uses as a distribution across a metric color space in which tiles are located as points. We compared each distribution with that of theunmodifiedterm X, identifying the latter with the focus of X (the within-language consensus about the most prototypical exemplar of X). In some cases the modifiers operate as “bright” in the sense of “intense” or “saturated,” so “bright-X” and “X” share a centroid, but this is not universal.
Coherence time characterization method for hard X-ray free-electron lasers
Authors: Zhou Guanqun , Jiao Yi , Raubenheimer Tor O. , Wang Jiuqing , Holman Aaron J. , Tsai Cheng-Ying , Wu Jerome Y. , Wu Weiwei , Yang Chuan , Yoon Moohyun , Wu Juhao
Published: March 2020

Coherence time is one of the fundamental characteristics of light sources. Methods based on autocorrelation have been widely applied from optical domain to soft X-rays to characterize the radiation coherence time. However, for the hard X-ray regime, due to the lack of proper mirrors, it is extremely difficult to implement such autocorrelation scheme. In this paper, a novel approach for characterizing the coherence time of a hard X-ray free-electron laser (FEL) is proposed and validated numerically. A phase shifter is adopted to control the correlation between X-ray and microbunched electrons. The coherence time of the FEL pulse can be extracted from the cross-correlation. Semi-analytical analysis and three-dimensional time-dependent numerical simulations are presented to elaborate the details. A coherence time of 218.2 attoseconds for 6.92 keV X-ray FEL pulses is obtained in our simulation based on the configuration of Linac Coherent Light Source. This approach provides critical temporal coherence diagnostics for X-ray FELs, and is decoupled from machine parameters, applicable for any photon energy, radiation brightness, repetition rate and FEL pulse duration.
Improvement of the depth resolution of swept-source THz-OCT for non-destructive inspection
Authors: Momiyama Homare , Sasaki Yoshiaki , Yoshimine Isao , Nagano Shigenori , Yuasa Tetsuya , Otani Chiko
Published: March 2020

We construct a terahertz swept source optical coherence tomography system using a continuous-wave diode multiplier source in the 600-GHz band for defect inspection in multilayer objects and evaluate its performance. Using this system, we image a multilayer plastic sample to demonstrate the effectiveness of nondestructive three-dimensional imaging. To enhance the depth resolution, we apply an annihilating filter to the analysis and confirm that two surfaces of a 1-mm-thick plastic plate can be resolved. In addition, the repeatability of measured thicknesses is 0.22 mm. These values are approximately one-half and one-tenth of the resolution achievable by conventional Fourier analysis, respectively.
Power scaling of Raman fiber amplifier based on the optimization of temporal and spectral characteristics
Authors: Chen Yizhu , Song Jiaxin , Ye Jun , Yao Tianfu , Xu Jiangming , Xiao Hu , Leng Jinyong , Zhou Pu
Published: March 2020

We comprehensively study the effects of temporal and spectral optimization on single-mode Raman fiber amplifiers. Amplified spontaneous emission sources and ytterbium-doped fiber lasers are employed as seed or pump lasers for comparison, and passive fibers are utilized as gain media. The influences of various parameters of the laser on 2nd order Raman threshold and maximum output power are investigated experimentally, including bandwidth, seed power, wavelength separation between pump and seed laser, and temporal stability. With the 190 m passive fiber, the output power increases from 99.5 W to 142.4 W, corresponding to 43.1% improvement through the optimization of seed laser power, pump wavelength and temporal performance of pump source in this amplifier, which has guidance on the establishment of high-power single-mode Raman fiber amplifiers.
Lateral bipolar junction transistor on a silicon photonics platform
Authors: Jha Aashu , de Lima Thomas Ferreira , Saeidi Hooman , Bilodeau Simon , Tait Alexander N. , Huang Chaoran , Abbaslou Siamak , Shastri Bhavin , Prucnal Paul R.
Published: March 2020

Integration of active electronics into photonic systems is necessary for large-scale photonic integration. While heterogeneous integration leverages high-performance electronics, a monolithic scheme can coexist by aiding the electronic processing, improving overall efficiency. We report a lateral bipolar junction transistor on a commercial silicon photonics foundry process. We achieved a DC current gain of 10 with a Darlington configuration, and using measured S-parameters for a single BJT, the available AC gain was at least 3dB for signal frequencies up to 1.1 GHz. Our single BJT demonstrated a transimpedance of 3.2mS/μm, which is about 70 times better than existing literature.
Non-reciprocal polarization rotation using dynamic refractive index modulation
Authors: Wang Jiahui , Shi Yu , Fan Shanhui
Published: March 2020

One of the most prominent classes of non-reciprocal devices relies upon the effect of non-reciprocal polarization conversion, such as those observed in Faraday isolators. This effect is usually achieved with the use of magneto-optical materials. Here, we introduce a waveguide type optical isolator based on non-reciprocal polarization conversion, without the use of magneto-optical materials. Our isolator is based on spatial-temporal dynamic refractive index modulation, which is more readily amenable for on-chip integration. We numerically demonstrate our design with both first-principle multi-frequency electromagnetic simulations and the vectorial coupled mode theory formalism.
Double-arrow metasurface for dual-band and dual-mode polarization conversion
Authors: Yu Yizhuo , Xiao Fajun , He Chong , Jin Ronghong , Zhu Weiren
Published: March 2020

We present experimentally a double-arrow metasurface for high-efficiently manipulating the polarization states of electromagnetic waves in the dual-band. The metasurface is capable of converting a linearly polarized (LP) incident wave into a circularly polarized (CP) wave or its cross-polarized LP wave at different frequencies. It is numerically shown that in the two bands from 14.08 to 15.71 GHz and from 17.63 to 19.55 GHz the metasurface can convert the LP wave into CP wave, of which the axis ratio is lower than 3 dB. Meanwhile, the proposed metasurface also can convert the LP wave into its cross-polarized LP wave at 13.39 GHz and 20.29 GHz. To validate the theoretical analysis and simulated results, a prototype is fabricated and measured. The experimental results are reasonably consistent with the theoretical and simulated results, which demonstrates that such a metasurface can successfully achieve dual-band and dual-mode polarization conversion.
Wide-range wavelength and angle resolved light scattering measurement setup
Authors: Fouchier Marin , Zerrad Myriam , Lequime Michel , Amra Claude
Published: March 2020

We present a new version of a light scattering measurement setup, using a high-power supercontinuum laser source, two volume hologram filters, and two low-noise scientific grade cameras. This configuration enables spectral and angle resolved characterization of the light scattered by complex thin-film filters from 400 to 1650 nm. Measurements carried out on specific filters illustrate the performances of the setup.