bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of sample size on the stability of risk scores from clinical prediction models: a case study in cardiovascular disease
Authors: Pate Alexander , Emsley Richard , Sperrin Matthew , Martin Glen P. , van Staa Tjeerd
Published: September 2020

Background

Stability of risk estimates from prediction models may be highly dependent on the sample size of the dataset available for model derivation. In this paper, we evaluate the stability of cardiovascular disease risk scores for individual patients when using different sample sizes for model derivation; such sample sizes include those similar to models recommended in the national guidelines, and those based on recently published sample size formula for prediction models.

Methods

We mimicked the process of samplingNpatients from a population to develop a risk prediction model by sampling patients from the Clinical Practice Research Datalink. A cardiovascular disease risk prediction model was developed on this sample and used to generate risk scores for an independent cohort of patients. This process was repeated 1000 times, giving a distribution of risks for each patient.N= 100,000, 50,000, 10,000,Nmin(derived from sample size formula) andNepv10(meets 10 events per predictor rule) were considered. The 5–95th percentile range of risks across these models was used to evaluate instability. Patients were grouped by a risk derived from a model developed on the entire population (population-derived risk) to summarise results.

Results

For a sample size of 100,000, the median 5–95th percentile range of risks for patients across the 1000 models was 0.77%, 1.60%, 2.42% and 3.22% for patients with population-derived risks of 4–5%, 9–10%, 14–15% and 19–20% respectively; forN= 10,000, it was 2.49%, 5.23%, 7.92% and 10.59%, and forNusing the formula-derived sample size, it was 6.79%, 14.41%, 21.89% and 29.21%. Restricting this analysis to models with high discrimination, good calibration or small mean absolute prediction error reduced the percentile range, but high levels of instability remained.

Conclusions

Widely used cardiovascular disease risk prediction models suffer from high levels of instability induced by sampling variation. Many models will also suffer from overfitting (a closely linked concept), but at acceptable levels of overfitting, there may still be high levels of instability in individual risk. Stability of risk estimates should be a criterion when determining the minimum sample size to develop models.
Performance of the parasitoid species Aphelinus asychis Walker (Hymenoptera: Aphelinidae), Aphidius ervi (Haliday) (Hymenoptera: Braconidae) and Diaeretiella rapae (McIntosh) (Hymenoptera: Braconidae), using Myzus persicae (Sulzer) (Hemiptera: Aphididae) as host
Authors: Kumar Surjeet , Kashyap Shruti , Soni Saurbh
Published: September 2020

Three parasitoid species viz. Aphelinus asychis Walker (Hymenoptera: Aphelinidae), Aphidius ervi (Haliday) (Hymenoptera: Braconidae) and Diaeretiella rapae (McIntosh) (Hymenoptera: Braconidae) parasitizing the aphid species Myzus persicae (Sulzer) (Hemiptera: Aphididae) in mid-hills of north India were studied. At different locations and times of the year, the parasitization by A. asychis, A. ervi, and D. rapae ranged from 7.53 to 37.58, 4.26 to 80.45, and 74.25 to 80.48%, respectively. All the 3 parasitoids successfully completed their development on different nymphal instars of the aphid host and the total developmental duration of A. asychis, A. ervi, and D. rapae ranged 10.4–14.6, 24.2–29.6, and 10.2–15.2 days, respectively. It was significantly longer on the 1st nymphal instar of the host. The longevity of the female parasitoids was significantly longer than their counterparts. Differences in host age significantly influenced the longevity of female parasitoids and it was more on 1 to 2-day-old nymphs than that on 4 to 5-day-old nymphs. Fecundity and ovipositional periods of the parasitoids on younger (1–2 days old) host age group were considerably prolonged than on the older ages of the aphid. Average total fecundity of A. asychis and D. rapae was significantly higher when parasitizing 1–2-day-old nymphs. In A. asychis, host feeding behavior was also observed by a total host feeding of 89.2 aphids (1–2 days old) and 43.4 aphids (4–5 days old) during its life span. It is concluded that A. asychis, A. ervi, and D. rapae can be mass reared using M. persicae as host and can be utilized successfully in augmentative biological control program.
Sublethal effects of emamectin benzoate on life table parameters of the cotton leafworm, Spodoptera littoralis (Boisd.)
Authors: Mokbel El-Sayed , Huesien Amal
Published: September 2020

Background

The cotton leafworm, Spodoptera littoralis (Boisd.), is a serious economic pest in Egypt. Pest control depends mainly on chemical control with several pesticides include conventional and modern insecticides. Comprehensive analysis of pesticides impacts needs to investigate sublethal effects in addition to lethal effect.

Results

In the current study, the leaf-dip bioassay method was used to evaluate emamectin benzoate (EMB) sublethal concentrations. Results showed that EMB proved high toxicity against S. littorals with LC50 value of 0.019 mg liter−1. Life table analysis showed that treatments with LC5 and LC15 prolonged larval period, mean longevity of males and females, mean generation time (T), doubling time (DT), adult preovipositional period (APOP), and total preovipositional period (TPOP) compared with control. On the contrary, net reproduction rates (R0), intrinsic rates of increase (r), finite rate (λ), fecundity, gross reproductive rate (GRR), and relative fitness were decreased compared to control.

Conclusions

The current study clarified that sublethal concentrations of EMB induce adverse effects and suppress the population growth of S. littorals. Our results would be useful to assess the overall effects of EMB on S. littorals and can contribute effectively in pest management.
The performance of Cu2+ as dissolved cathodic electron-shuttle mediator for Cr6+ reduction in the microbial fuel cell
Authors: Gangadharan Praveena , Nambi Indumathi M.
Published: September 2020

The study investigates the performance of Cu2+ as dissolved cathodic electron-shuttle mediator (dcESM) for simultaneous Cr6+ reduction and electricity generation in a microbial fuel cell (MFC) at pH 2 and 4 conditions. The dcESM behavior of Cu2+ on carbon cloth (CC) catalyzes the reduction of Cr6+ into Cr3+ at pH 2 by undergoing redox reactions. However, at pH 4, a simultaneous reduction of Cu2+ and Cr6+ was observed. Cyclic voltammetry studies were performed at pH 2 and 4 to probe the dcESM behavior of Cu2+ for Cr6+ reduction on CC electrode. Also, at pH 2, increasing the concentration of Cu2+ from 50 to 500 mg L− 1 favors the Cr6+ reduction by reducing the reaction time from 108 to 48 h and improving the current production from 3.9 to 6.2 mA m− 2, respectively. Nevertheless, at pH 4, the efficacy of Cr6+ reduction and electricity generation from MFC is decreased from 63 to 18% and 4.4 to 1.1 mA m− 2, respectively, by increasing the Cu2+ concentration from 50 to 500 mg L− 1. Furthermore, the performance of dcESM behavior of Cu2+ was explored on carbon felt (CF) and platinum (Pt) electrodes, and compare the results with CC. In MFC, at pH 2, with an initial concentration of 100 mg L− 1, the reduction of Cr6+ in 60 h is 9.6 mg L− 1 for CC, 0.2 mg L− 1 for CF, and 51.3 mg L− 1 for Pt cathodes. The reduction of Cr6+ (initial concentration of 100 mg L− 1) at pH 4 in 120 h is 44.7 mg L− 1 for CC, 32.1 mg L− 1 for CF, and 70.9 mg L− 1 for Pt cathodes. Maximum power densities of 1659, 1509, and 1284 mW m− 2 were achieved when CF, CC, and Pt, respectively were employed as cathodes in the MFC.
Internal biliary diversion to avoid liver transplantation in an adult with intractable pruritus due to idiopathic intrahepatic cholestasis
Authors: Siriwardana R. C. , Jayatunge D. S. P. , Ekanayake C. S. , Tilakaratne S. , Niriella M. A. , Gunathilake B. , Dassanayake A. S.
Published: September 2020

Background

Cholestasis is due to the obstruction at any level of the excretory pathway of bile. One particularly troublesome symptom of cholestasis is pruritus which leads to a profound effect on a patient’s quality of life. In children with progressive familial intrahepatic cholestasis (PFIC), medical treatment often fails. An alternative surgical procedure using biliary diversion offers significant relief for intractable pruritus in non-responders.

Case presentation

A 43-year-old male presented with a history of persistent jaundice and intractable pruritus for a 2-month duration. His liver enzymes were markedly elevated. However, his liver synthetic function was preserved. After extensive evaluation, a cause for cholestasis was not identified. A multi-disciplinary decision was to consider liver transplantation, but as his liver synthetic functions were remarkably preserved and the intractable pruritus was the sole indication for a transplantation, it was finally decided that internal biliary diversion should be done for symptomatic relief. His pruritus dramatically improved at 6 weeks post-operative. His liver enzymes and bilirubin levels also decreased compared to his pre-operative status. Currently, his liver functions are being closely monitored.

Conclusion

Though it is not used in adults, the experience of biliary diversion in children with PFIC shows that there is a considerable improvement of symptoms and postpone the need for a transplant. In our patient, liver function and bilirubin as expected did not show a major improvement. But the dramatic improvement of the symptoms gave us the time to postpone the liver transplantation. A biliary diversion is a reasonable option that needs to be considered even in adults with refectory pruritus due to cholestasis.
An investigation on the behavior and morphology of sulphanilamide crystallization in different nucleation conditions
Authors: Dasari Smita Shivraj , Tallapaka Ajit Kumar , Thati Jyothi
Published: September 2020

Background

Crystallization is used as a purification process in majority of the industries such as pharmaceuticals, food products, chemicals, catalysts, and cosmetics. Crystallization of active pharmaceutical ingredients is carried out to increase the dissolution rate and attain sufficient bioavailability in pharmaceutical industries. It can also enhance the flow properties and drug dosage control of the active pharmaceutical ingredients.

Single crystals give us a lucid understanding of the intrinsic properties of a material. A material made up of many crystals will have grain boundaries which do not allow us to measure properties such as thermal and electrical resistance effectively. Single crystals will not have defects or impurities in them. Thus, help us in making comparisons with other materials and contribute to a better understanding of particular behaviors. Therefore, it is important to investigate the growth of single crystals.

Sulphanilamide is a sulpha class drug used as an intermediate and starting material for the production of various drugs. It is an antibacterial agent and is often used in pharmaceutics and cosmetics. In this study, we wanted to obtain sulphanilamide crystals by two different crystallization methods and compare the results gathered. Sulphanilamide usually crystallizes in the form of needles, thus is ideal for the purpose of this study. In this work, crystallization of sulphanilamide was carried out by cooling method and solvent evaporation method. In Cooling method as temperature was brought down the crystals separated out. On the other hand, in solvent evaporation method, the solvent evaporated leaving behind the crystals. The process parameters that varied included stirring rate of the solution at a constant temperature, concentration of the solute in a constant volume of solvent, solvent systems chosen-acetone, methanol and ethanol, and time allowed for crystallization.

Results

Crystals were obtained under the varying conditions. Characterization of the crystals formed was carried out using X-ray diffraction method, scanning electron microscopy, and differential scanning calorimetry. The size and morphology of the crystals formed was observed and the results were compared. It was found that the crystals obtained from using methanol as solvent, with high concentration of solute, gave the most uniform and large-sized cubic crystals under solvent evaporation method. The surface of the crystal was also seen to be smooth with well-defined edges as shown in the SEM images. Stirring reduced the size of crystals formed, and longer time of crystal formation resulted in larger crystals. Solvent evaporation method gave more uniform crystals compared to cooling method.

Conclusion

This study gives us an understanding of how each parameter affects crystal growth. Thus, optimum conditions for crystal growth can be determined.
Development of a novel TLR8 agonist for cancer immunotherapy
Authors: Wang Yuxun , Yang Heping , Li Huanping , Zhao Shuda , Zeng Yikun , Zhang Panpan , Lin Xiaoqin , Sun Xiaoxiang , Wang Longsheng , Fu Guangliang , Gao Yaqiao , Wang Pei , Gao Daxin
Published: September 2020

Toll-like receptors (TLRs) are a family of proteins that recognize pathogen associated molecular patterns (PAMPs). Their primary function is to activate innate immune responses while also involved in facilitating adaptive immune responses. Different TLRs exert distinct functions by activating varied immune cascades. Several TLRs are being pursued as cancer drug targets. We discovered a novel, highly potent and selective small molecule TLR8 agonist DN052. DN052 exhibited strong in vitro cellular activity with EC50 at 6.7 nM and was highly selective for TLR8 over other TLRs including TLR4, 7 and 9. DN052 displayed excellent in vitro ADMET and in vivo PK profiles. DN052 potently inhibited tumor growth as a single agent. Moreover, combination of DN052 with the immune checkpoint inhibitor, selected targeted therapeutics or chemotherapeutic drugs further enhanced efficacy of single agents. Mechanistically, treatment with DN052 resulted in strong induction of pro-inflammatory cytokines in ex vivo human PBMC assay and in vivo monkey study. GLP toxicity studies in rats and monkeys demonstrated favorable safety profile. This led to the advancement of DN052 into phase 1 clinical trials.
Between-Batch Bioequivalence (BBE): a Statistical Test to Evaluate In Vitro Bioequivalence Considering the Between-Batch Variability
Authors: Bodin Jonathan , Liandrat Stéphanie , Kocevar Gabriel , Petitcolas Céline
Published: September 2020

Bioequivalence testing is an essential step during the development of generic drugs. Regulatory agencies have drafted recommendations and guidelines to frame this step but without finding any consensus. Different methodologies are applied depending on the geographical region. For instance, in the EU, EMA recommends using average bioequivalence test (ABE), while in the USA, FDA recommends using population bioequivalence (PBE) test. Both methods present some limitations (e.g., when batch variability is non-negligible) making it difficult to conclude to equivalence without subsequently increasing the sample size. This article proposes an alternative method to evaluate bioequivalence: between-batch bioequivalence (BBE). It is based on the comparison between the mean difference (Reference − Test) and the Reference between-batch variability. After presenting the theoretical concepts, BBE relevance is evaluated through simulation and real case (nasal spray) studies. Simulation results showed high performance of the method based on false positive and false negative rate estimations (type I and type II errors respectively). Especially, BBE has shown significantly greater true positive rates than ABE and PBE when the Reference residual standard deviation is higher than 15%, depending on the between-batch variability and the number of batches. Finally, real case applications revealed that BBE is more efficient than ABE and PBE to demonstrate equivalence, in some well-known situations where the between-batch variability is not negligible. These results suggest that BBE could be considered as an alternative to the state-of-the-art methods allowing costless development.
Plasma Epinephrine Contributes to the Development of Experimental Hypoglycemia-Associated Autonomic Failure
Authors: Lontchi-Yimagou Eric , Aleksic Sandra , Hulkower Raphael , Gospin Rebekah , Goyal Akankasha , Kuo Bryan , Mitchell William G , You Jee Young , Upadhyay Laxmi , Carey Michelle , Sandu Oana A , Gabriely Ilan , Shamoon Harry , Hawkins Meredith
Published: September 2020

Background

Recurrent hypoglycemia blunts counter-regulatory responses to subsequent hypoglycemic episodes, a syndrome known as hypoglycemia-associated autonomic failure (HAAF). Since adrenergic receptor blockade has been reported to prevent HAAF, we investigated whether the hypoglycemia-associated rise in plasma epinephrine contributes to pathophysiology and reported interindividual differences in susceptibility to HAAF.

Methods

To assess the role of hypoglycemia-associated epinephrine responses in the susceptibility to HAAF, 24 adult nondiabetic subjects underwent two 2-hour hyperinsulinemic hypoglycemic clamp studies (nadir 54 mg/dL; 0-2 hours and 4-6 hours) on Day 1, followed by a third identical clamp on Day 2. We challenged an additional 7 subjects with two 2-hour infusions of epinephrine (0.03 μg/kg/min; 0-2 hours and 4-6 hours) vs saline on Day 1 followed by a 200-minute stepped hypoglycemic clamp (90, 80, 70, and 60 mg/dL) on Day 2.

Results

Thirteen out of 24 subjects developed HAAF, defined by ≥20% reduction in average epinephrine levels during the final 30 minutes of the third compared with the first hypoglycemic episode (P < 0.001). Average epinephrine levels during the final 30 minutes of the first hypoglycemic episode were 2.3 times higher in subjects who developed HAAF compared with those who did not (P = 0.006).

Compared to saline, epinephrine infusion on Day 1 reduced the epinephrine responses by 27% at the 70 and 60 mg/dL glucose steps combined (P = 0.04), with a parallel reduction in hypoglycemic symptoms (P = 0.03) on Day 2.

Conclusions

Increases in plasma epinephrine reproduce key features of HAAF in nondiabetic subjects. Marked interindividual variability in epinephrine responses to hypoglycemia may explain an individual’s susceptibility to developing HAAF.
Brain Aromatase and the Regulation of Sexual Activity in Male Mice
Authors: Brooks David C , Coon V John S , Ercan Cihangir M , Xu Xia , Dong Hongxin , Levine Jon E , Bulun Serdar E , Zhao Hong
Published: September 2020

The biologically active estrogen estradiol has important roles in adult brain physiology and sexual behavior. A single gene, Cyp19a1, encodes aromatase, the enzyme that catalyzes the conversion of testosterone to estradiol in the testis and brain of male mice. Estradiol formation was shown to regulate sexual activity in various species, but the relative contributions to sexual behavior of estrogen that arises in the brain versus from the gonads remained unclear. To determine the role of brain aromatase in regulating male sexual activity, we generated a brain-specific aromatase knockout (bArKO) mouse. A newly generated whole-body total aromatase knockout mouse of the same genetic background served as a positive control. Here we demonstrate that local aromatase expression and estrogen production in the brain is partially required for male sexual behavior and sex hormone homeostasis. Male bArKO mice exhibited decreased sexual activity in the presence of strikingly elevated circulating testosterone. In castrated adult bArKO mice, administration of testosterone only partially restored sexual behavior; full sexual behavior, however, was achieved only when both estradiol and testosterone were administered together. Thus, aromatase in the brain is, in part, necessary for testosterone-dependent male sexual activity. We also found that brain aromatase is required for negative feedback regulation of circulating testosterone of testicular origin. Our findings suggest testosterone activates male sexual behavior in part via conversion to estradiol in the brain. These studies provide foundational evidence that sexual behavior may be modified through inhibition or enhancement of brain aromatase enzyme activity and/or utilization of selective estrogen receptor modulators.
Novel Mutations and Genes That Impact on Growth in Short Stature of Undefined Aetiology: The EPIGROW Study
Authors: Perchard Reena , Murray Philip George , Payton Antony , Highton Georgina Lee , Whatmore Andrew , Clayton Peter Ellis
Published: September 2020

Background

Children with short stature of undefined aetiology (SS-UA) may have undiagnosed genetic conditions.

Purpose

To identify mutations causing short stature (SS) and genes related to SS, using candidate gene sequence data from the European EPIGROW study.

Methods

First, we selected exonic single nucleotide polymorphisms (SNPs), in cases and not controls, with minor allele frequency (MAF) < 2%, whose carriage fitted the mode of inheritance. Known mutations were identified using Ensembl and gene-specific databases. Variants were classified as pathogenic, likely pathogenic, or variant of uncertain significance using criteria from the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. If predicted by ≥ 5/10 algorithms (eg, Polyphen2) to be deleterious, this was considered supporting evidence of pathogenicity. Second, gene-based burden testing determined the difference in SNP frequencies between cases and controls across all and then rare SNPs. For genotype/phenotype relationships, we used PLINK, based on haplotype, MAF > 2%, genotype present in > 75%, and Hardy Weinberg equilibrium P > 10–4.

Results

First, a diagnostic yield of 10% (27/263) was generated by 2 pathogenic (nonsense in ACAN) and a further 25 likely pathogenic mutations, including previously known missense mutations in FANCB, IGFIR, MMP13, NPR2, OBSL1, and PTPN11. Second, genes related to SS: all methods identified PEX2. Another 7 genes (BUB1B, FANCM, CUL7, FANCA, PTCH1, TEAD3, BCAS3) were identified by both gene-based approaches and 6 (A2M, EFEMP1, PRKCH, SOS2, RNF135, ZBTB38) were identified by gene-based testing for all SNPs and PLINK.

Conclusions

Such panels improve diagnosis in SS-UA, extending known disease phenotypes. Fourteen genes related to SS included some known to cause growth disorders as well as novel targets.
Eligibility for Liver Transplantation in Patients with Perihilar Cholangiocarcinoma
Authors: Vugts Jaynee J. A. , Gaspersz Marcia P. , Roos Eva , Franken Lotte C. , Olthof Pim B. , Coelen Robert J. S. , van Vugt Jeroen L. A. , Labeur Tim A. , Brouwer Lieke , Besselink Marc G. H. , IJzermans Jan N. M. , Darwish Murad Sarwa , van Gulik Thomas M. , de Jonge Jeroen , Polak Wojciech G. , Busch Olivier R. C. , Erdmann Joris L. , Groot Koerkamp Bas , Buettner Stefan
Published: September 2020

Background

Liver transplantation (LT) has been performed in a select group of patients presenting with unresectable or primary sclerosing cholangitis (PSC)-associated perihilar cholangiocarcinoma (pCCA) in the Mayo Clinic with a reported 5-year overall survival (OS) of 53% on intention-to-treat analysis. The objective of this study was to estimate eligibility for LT in a cohort of pCCA patients in two tertiary referral centers.

Methods

Patients diagnosed with pCCA between 2002 and 2014 were included from two tertiary referral centers in the Netherlands. The selection criteria used by the Mayo Clinic were retrospectively applied to determine the proportion of patients that would have been eligible for LT.

Results

A total of 732 consecutive patients with pCCA were identified, of whom 24 (4%) had PSC-associated pCCA. Overall, 154 patients had resectable disease on imaging and 335 patients were ineligible for LT because of lymph node or distant metastases. An age limit of 70 years led to the exclusion of 50 patients who would otherwise be eligible for LT. After applying the Mayo Clinic criteria, only 34 patients (5%) were potentially eligible for LT. Median survival from diagnosis for these 34 patients was 13 months (95% CI 3–23).

Conclusion

Only 5% of all patients presenting with pCCA were potentially eligible for LT under the Mayo criteria. Without transplantation, a median OS of about 1 year was observed.
Using contact data to model the impact of contact tracing and physical distancing to control the SARS-CoV-2 outbreak in Kenya
Authors: Wagner Moritz , Kombe Ivy K. , Kiti Moses Chapa , Aziza Rabia , Barasa Edwine , Nokes D. James
Published: September 2020

Background: Across the African continent, other than South Africa, COVID-19 cases have remained relatively low. Nevertheless, in Kenya, despite early implementation of containment measures and restrictions, cases have consistently been increasing. Contact tracing forms one of the key strategies in Kenya, but may become infeasible as the caseload grows. Here we explore different contact tracing strategies by distinguishing between household and non-household contacts and how these may be combined with other non-pharmaceutical interventions.

Methods: We extend a previously developed branching process model for contact tracing to include realistic contact data from Kenya. Using the contact data, we generate a synthetic population of individuals and their contacts categorised by age and household membership. We simulate the initial spread of SARS-CoV-2 through this population and look at the effectiveness of a number of non-pharmaceutical interventions with a particular focus on different contact tracing strategies and the potential effort involved in these.

Results: General physical distancing and avoiding large group gatherings combined with contact tracing, where all contacts are isolated immediately, can be effective in slowing down the outbreak, but were, under our base assumptions, not enough to control it without implementing extreme stay at home policies. Under optimistic assumptions with a highly overdispersed R0 and a short delay from symptom onset to isolation, control was possible with less stringent physical distancing and by isolating household contacts only.

Conclusions: Without strong physical distancing measures, controlling the spread of SARS-CoV-2 is difficult. With limited resources, physical distancing combined with the isolation of households of detected cases can form a moderately effective strategy, and control is possible under optimistic assumptions. More data are needed to understand transmission in Kenya, in particular by studying the settings that lead to larger transmission events, which may allow for more targeted responses, and collection of representative age-related contact data.
ECG of the month
Authors: Regan Martin
Published: September 2020

In this issue's ECG of the month, Martin Regan presents a case of a 29-year-old woman with no prior health problems who was admitted to the emergency department with breathlessness and chest pain.
End-of-life care part 1: implications for paramedic practice
Authors: Taylor Helen , Brogan James
Published: September 2020

Caring for patients who are approaching the end of life is an important part of the paramedic's role. Patients' circumstances are individual; for some, death is expected and may even a welcome (albeit sad) relief from a long period of pain and distress, while for others it is a tragic, unexpected outcome after every effort to prevent it has been exhausted. Regardless of circumstances, paramedics have to make wide-ranging clinical decisions, underpinned by a complex legal and regulatory framework. Paramedics generally have to obtain a patient's informed consent before proceeding with any intervention. They may be challenged if a dying patient refuses life-sustaining treatment or no longer has the mental capacity to consent and need to know the law on decision-making in these cases. This article discusses issues around capacity and consent at the end of life. The next article in this series considers issues such as advance decisions to refuse treatment and do not attempt CPR decisions.
Anterior distal femoral hemiepiphysiodesis with and without patellar tendon shortening for fixed knee flexion contractures in children with cerebral palsy
Authors: Rethlefsen Susan A. , Hanson Alison M. , Wren Tishya A. L. , Abousamra Oussama , Kay Robert M.
Published: September 2020

Purpose

Surgery is often required for fixed knee flexion contractures in patients with neuromuscular conditions. Anterior distal femoral hemiepiphysiodesis (ADFH) is an alternative to distal femoral extension osteotomy (DFEO) in skeletally immature patients. ADFH is typically not accompanied by patellar tendon shortening surgery (PTS). Our purpose was to compare ADFH alone versus ADFH with PTS for treatment of fixed knee flexion contractures and crouched gait in children with cerebral palsy (CP).

Methods

Retrospective review of pre- and postoperative gait analysis data for children with CP who underwent ADFH alone, or ADFH with PTS. Data were analysed using linear mixed models to control for covariates.

Results

In total, 25 participants (42 limbs) were included, 17 male and eight female, mean age at surgery 12.9 (sd 1.9) years. Both groups experienced significant improvement in popliteal angle, knee extension range of motion (ROM) and knee extension in stance phase. Greater improvement was seen for all variables in the ADFH/PTS group, mainly due to greater popliteal angle and knee flexion during gait preoperatively in that group (p ≤ 0.02) rather than the procedure performed (p ≥ 0.19). There was no difference between groups postoperatively. Rate of contracture resolution was 0.5° to 1.0° per month, faster in larger contractures (p = 0.02).

Conclusions

ADFH with and without PTS is effective in improving knee extension in skeletally immature patients with CP, correcting contractures at a rate of 0.5° to 1.0° per month. Combined ADFH and PTS surgery may be preferable in patients with larger contractures of up to 30° to 35°.

Level of evidence

III
Concave aspheric test combining Dall with Offner null compensation using a plane wave
Authors: Wang Xin , Liu Qiang , Zhou Hao , He Zhiping , Shu Rong
Published: September 2020

A plane wave aspheric surfaces test is simpler and easier to assemble than a spherical wave test. An optical system combining Dall with Offner null compensation using a plane wave is proposed for measuring large-aperture and large-relative-aperture aspheric concave surfaces. One back compensation lens and one front compensation lens are used in the system, which can realize a high-precision null test. Based on the third-order aberration theory, the normalized theoretical parameters are calculated by formula derivation, and then are optimized after analysis. The design characteristic is compared with the classical plane wave Offner null test. A prototype experiment of the proposed method is carried out with a parabolic mirror of 500 mm diameter, at relative aperture 1/1, showing that RMS surface error of

λ

/

40

can be obtained.
Digital holography for spatially resolved analysis of the semiconductor optical response
Authors: Besaga Vira R. , Gerhardt Nils C. , Hofmann Martin R.
Published: September 2020

We present spatially resolved measurements of the below-band-gap carrier-induced absorption and concurrent phase change in a semiconductor with the help of transmission digital holography. The application is demonstrated for a bulk GaAs sample, while the holograms are recorded with a conventional CMOS sensor. We show that the phase information enables spatially resolved monitoring of excess carrier distributions. Based on that, we discuss a phase-based approach for separation of carrier and heat related effects in the semiconductor optical response.
Structure-preserving spectral reflectance estimation using guided filtering
Authors: Sippel Frank , Seiler Jürgen , Genser Nils , Kaup André
Published: September 2020

Light spectra are a very important source of information for diverse classification problems, e.g., for discrimination of materials. To lower the cost of acquiring this information, multispectral cameras are used. Several techniques exist for estimating light spectra out of multispectral images by exploiting properties about the spectrum. Unfortunately, especially when capturing multispectral videos, the images are heavily affected by noise due to the nature of limited exposure times in videos. Therefore, models that explicitly try to lower the influence of noise on the reconstructed spectrum are highly desirable. Hence, a novel reconstruction algorithm is presented. This novel estimation method is based on the guided filtering technique that preserves basic structures, while using spatial information to reduce the influence of noise. The evaluation based on spectra of natural images reveals that this new technique yields better quantitative and subjective results in noisy scenarios than other state-of-the-art spatial reconstruction methods. Specifically, the proposed algorithm lowers the mean squared error and the spectral angle up to 46% and 35% in noisy scenarios, respectively. Furthermore, it is shown that the proposed reconstruction technique works out of the box and does not need any calibration or training by reconstructing spectra from a real-world multispectral camera with nine channels.
Oscillations of charge carrier domains in photorefractive bipolar semiconductors
Authors: Ziółkowski Andrzej , Weinert-Raczka Ewa
Published: September 2020

The article presents analysis of the formation of charge carrier domains generated by a localized optical beam and the phenomenon of their oscillations. The research was carried out for bipolar photorefractive semiconductors characterized by nonlinear transport of electrons. The analysis allowed us to determine a set of basic quantitative parameters that have an impact on the appearance of carrier oscillations and their character.
Tunable multiresonance using complementary circular metamaterial: publisher’s note
Authors: Zhan Fengwei , Lin Yu-Sheng
Published: September 2020

This publisher’s note contains corrections to Opt. Lett.
45, 3633 (2020)OPLEDP0146-959210.1364/OL.394137.
PEMIKIRAN TASAWUF FALSAFI AWAL: RABI’AH AL-‘ADAWIYYAH, AL-BUSTAMĪ, DAN AL-HALLAJ
Authors: Sulaeman Mubaidi
Published: September 2020

Many researchers believe that the philosophical Sufism tradition in Islam only emerged in the sixth century Hijriah. Is that right? If it is explored in more depth, it will soon be found that this is not quite right because long before that, in the Islamic tradition there were already some thoughts of Sufism that tended to lead to philosophical Sufism. Among the philosophical ideas of Sufism that were born in this early period were mahabbah, Ilahiyyah, fana', ittihad, and Hulul. Therefore, in this paper the author tries to describe the initial philosophical Sufism thought  contained in the thoughts of three Sufi figures, namely Rabi'ah al-'Adawiyyah, alBustami, and al-Hallaj. By presenting the philosophical Sufism thought that exists in their works, this article shows that the philosophical Sufism tradition in Islam has emerged long before the sixth century Hijriah, as is often believed by many circles.
ILUSI KEBENARAN DALAM PERSPEKTIF SHANKARA
Authors: Maulana Ilham
Published: September 2020

Recent times, news spreads fast without knowing whether the news is true or not. The truth was fought over. Each person/group claims that he or she is the truth while the others are wrong. Seeing this phenomenon, it seems to be interesting to see the illusionary concept of truth initiated by Shankara. For this reason, this article then discusses the illusionary concept (maya) of Adi Shankara (788-820), a mystic known as the Advaita Vedanta philosophy. It was Shankara who challenged what we had thought to be the truth. In the Advaita Vedanta it is taught that the only truth is Brahman. Apart from Brahman, everything is an illusion. The illusion of truth here—which is always conditioned—does not want to say that truth is relative, that is, there is no absolute truth because each person/group has their own version of truth. But that truth is transcendent, it is unreachable.
Karakteristik Modal Sosial pada Kelompok Pengrajin Batik Kota Semarang
Authors: Putri Yoshe Rezky Adhitama Mywa , Nugroho Prihadi
Published: September 2020

Batik is one of many small and medium enterprises (SMEs) which is being developed in Semarang City. However, location becomes the weakness of the batik industry in Semarang City. The scattered location of batik craftpersons makes public did not concern to the existence of batik Semarang. Therefore, FEDEP (Forum Economic Development and Employement Promotion) of Semarang City has formed a Semarang’s Batik Craftperson Group since 2006. The existence of this group has triggered the social capital among the craftperson, so they can interact and cooperate to improve their business productivity. This study aims to explain how the characteristics of social capital on Batik Craftperson Group in Semarang City. The method used sequential mix method with data unit is 31 members of Semarang’s Batik Craftperson Group. Trust, norms, and networks have their own characteristics to improve the business through interactions and communications. These three components also play a role in group management to make strategies, allocations, cooperations, and group activities. The characteristics of social capital on Batik Craftperson Group is expected to prove that so many factors that can develop SMEs, not only location but also the social capital of its business actors.
Motivated Helplessness in the Context of the Covid-19 Pandemic: Evidence for a Curvilinear Relationship Between Perceived Ability to Avoid the Virus and Anxiety
Authors: Lifshin Uri , Mikulincer Mario , Kretchner Mabelle
Published: September 2020

Introduction: We tested the hypothesis that feelings of helplessness — i.e., the perception that one is unable to control and prevent negative events — may serve a protective psychological function against fear and anxiety arousal in the context of the COVID-19 pandemic.

Methods: We conducted a large scale study with participants from different countries (N = 3,632) to examine if perceived helplessness to avoid being infected with COVID-19 relates to lower levels of fear of COVID-19, and state anxiety.

Results: We found a curvilinear relationship between feeling helpless to avoid being infected with COVID-19 and self-reported anxiety. Individuals who reported either low or high degrees of helplessness reported less anxiety and fear of being infected with COVID-19 compared to those who reported moderate levels of helplessness. Additional analyses within countries with adequate power (N > 160) indicated that this curvilinear effect was found among participants from the USA, UK, Poland, Estonia, and the Netherlands, but not in Argentina and Germany.

Discussion: We discuss the implications for research on the psychological function of helplessness and for understanding peoples' responses to the COVID-19 pandemic.
Modeling RNA Translation with Craft Supplies
Authors: Bierema Andrea M.-K.
Published: September 2020

Students often struggle with the concept of protein synthesis, which incorporates two main processes: transcription and translation. This article describes an activity in which students use craft supplies to physically model the process of translation. The teacher creates the modeling kits, and then students use a worksheet to prepare the kit for a specific amino acid sequence. They practice the process of translation, including the start, tRNAs movement through the ribosome, the amino acid chain building, and the stop. This article describes how to create the model kits and implement the activity in the classroom. We have performed this hands-on activity in college classrooms as large as 170 students. Students appreciate the hands-on approach and find the activity extremely useful in understanding translation. While students model translation, the teaching team identifies and helps students overcome any misconceptions and gaps in their knowledge.
Resistir la Covid-19. Intersecciones en la Educación de Ciudad Juárez, México
Authors: Cervantes Holguín Evangelina , Gutiérrez Sandoval Pavel Roel
Published: September 2020

En el 2020, México se enfrentó a la nueva enfermedad por coronavirus declarada como emergencia de salud pública de importancia internacional. En respuesta, durante el mes de marzo la Secretaría de Educación Pública y la Secretaría de Salud implementaron un conjunto de medidas para prevenir y contener la propagación del virus. Los objetivos son: identificar las acciones implementadas por el gobierno y analizar sus implicaciones pedagógicas, sociales y económicas. Se desarrolló un ejercicio cualitativo de tipo documental que permitió la localización, clasificación, selección, análisis y comparación de diversos documentos. Como resultado se identificaron tres acciones prioritarias y 20 medidas de atención primaria para su implementación en todo el territorio nacional. Se encontró que el cierre de las escuelas reveló un conjunto de desafíos para las autoridades educativas, el profesorado y las familias, en tanto la ejecución de estas medidas se configura en un entramado de circunstancias educativas, sociales y económicas que, en suma, profundizan la desigualdad educativa. Se concluye que escuelas y profesorado son agentes clave en la contención sanitaria, sin embargo, las condiciones de las escuelas y las características socioeconómicas de las comunidades definen la experiencia de prevención y confinamiento.
Incidencia del Estado de Alarma en la Desigualdad Escolar de la Adolescencia Acogida por el Sistema de Protección en Galicia
Authors: Fernández-Simo Deibe , Cid Fernández Xosé Manuel , Carrera-Fernández María Victoria
Published: September 2020

Los itinerarios académicos de exclusión escolar son mayoritarios entre el alumnado con expediente administrativo de protección. La declaración del estado de alarma, motivado por la alerta sanitaria del Covid-19, se traduce en un cambio en las dinámicas escolares. Esta investigación se propone analizar qué aspectos de la planificación docente, así como de la colaboración entre profesorado y profesionales de los recursos específicos de protección de Galicia, durante el estado de alarma, tienen incidencia en la inclusión o exclusión escolar del alumnado en dificultad social. Se realizan 11 seguimientos longitudinales con 11 adolescentes, cinco chicos y seis chicas. Asimismo, el estudio se diseña según la teoría fundamentada con la intención de triangular los discursos derivados de las entrevistas con el alumnado con estudios de casos instrumentales en los que participan 14 figuras profesionales. La muestra de equipos educativos está compuesta por 11 educadoras y tres educadores. Los resultados ponen de relieve que las dinámicas de desigualdad escolar se ven incrementadas durante el periodo del estado de alarma, observándose que el contacto entre alumnado y profesorado se reduce derivando en déficits en el trabajo de las tareas escolares; y que la colaboración entre figuras profesionales del sistema de protección y la escuela se limita a intercambios puntuales de información. Estos resultados destacan que, durante el estado de alarma motivado por la crisis sanitaria actual, la escuela y las políticas educativas en Galicia desatienden la situación de mayor dificultad social en la que se encuentra el alumnado en protección.
Sulfate Mineral Lakes of Western Transbaikalia: Formation Conditions and Chemical Composition of Waters and Bottom Sediments
Authors: Plyusnin A.M. , Khazheeva Z.I. , Sanzhanova S.S. , Peryazeva E.G. , Angakhaeva N.A.
Published: September 2020

—The paper presents the formation of the chemical composition of water in the sulfate mineral lakes of western Transbaikalia. It is shown that sodium sulfate water in the regional lakes forms in two zones of continental salinization, the Barguzin and Gusinoe Ozero–Orongoi depressions. The average mineralization of the lakes reaches 30.8 g/L, pH = 7.90–8.84, the fractional content of sulfate ion is 55.2–81.8% eq, and the fractional content of sodium ion is 59.1–82.1% eq. The paper presents the major-ion and trace-element composition of lake waters and the chemical and mineral composition of bottom sediments. It is shown that groundwater enriched in sodium sulfate plays a major role in the lake formation.
Analysis of Water–Gas System Equilibria in Jurassic–Cretaceous Reservoirs (by the Example of the Yamal-Kara Depression)
Authors: Novikov D.А.
Published: September 2020

—The paper presents results of the pioneering study of equilibria in the water–gas system by the example of Jurassic–Cretaceous deposits of the Yamal–Kara depression located within northern West Siberia and its Arctic regions. Numerical modeling of physicochemical equilibria and evasion–invasion processes in the water–gas system allowed determination of the degree of groundwater saturation with gases and the nature of diffusive redistribution of gases in the media that form at the hydrocarbon deposit–groundwater contact. According to the degree of water saturation with gases (Kg), aquifers with poorly (<0.2) to ultimately (0.8–1.0) gas-saturated waters have been established. The revealed increase in the degree of groundwater saturation with gases in sinking producing reservoirs reflects its dependence on their total gas saturation. All waters with a total gas saturation of more than 1.8 L/L become ultimately saturated with gases (Kg = 1.0), thus theoretically predetermining the formation of hydrocarbon accumulations. Major gas condensate deposits are confined to the zone of gas-saturated waters with Kg from 0.8 to 1.0, while oil accumulations, to waters with lower gas saturation. Based on the established nature of water–gas, we can argue that oil and gas accumulations in Jurassic–Cretaceous reservoirs act as a conservative element of the lithosphere, i.e., its geologic and geochemical “relics”. The surrounding subsurface waters, as a more active constituent of the system, have largely anticipated its geochemical development, which is manifested in the differentiation of the fugacity ratios of individual gases in groundwater and hydrocarbon accumulations. The composition of the latter is therefore subjected to slow directional changes while the equilibrium is established, to usher in the qualitatively new state of the geochemical water–gas system.