bluuebunny/crossref_metadata_2025 huggingface dataset:
Medical students' perception of live lectures compared to video lectures in basic sciences medical education: a cross-sectional survey of medical colleges in Pakistan
Authors: Khan Maria , Abdul Jabbar Ali Bin , Khan Daniyal Ali , Javed Muhammad Abdullah , Raja Mohummad Hassan Raza , Muzaffar Kanza
Published: January 2021

Background:
Live lectures are commonly used in medical education, yet many students prefer video lectures instead. As different learning modalities may affect knowledge, it was necessary to explore medical students' perspectives about the two learning modalities in Pakistan.

Objectives:
This study aimed to explore and compare the medical students' perspectives regarding live lectures and video lectures.

Methods:
This cross-sectional study used an online questionnaire. This was distributed to medical students via internet platforms after institutional approval. Data were analyzed with SPSS version 23 using descriptive statistics.

Results:
585 students, from 11 medical colleges across six cities of Pakistan, were enrolled. 64.4% (n=377) of the students were females, while 34.0% (n=199) were males. The first years comprised 32.7% (n=191), second years, 29.2% (n=171), and third years, 38.1% (n=223) of the total. The commonest reason for attending live lectures was 'they are compulsory'. The commonest reason for not attending was 'poor teaching quality'. 5.0% (n=29) of 585 students reported live lectures and 51.8% (n=290 of 560) found video lectures to be 'very helpful' in concept clarification. 85.1% (n=258) of 303 students found video lectures more effective for learning. For 45.4% (n=254) of students, video lectures improved their grades a lot; more students used video lectures for exam preparation over the years. 50.6% (n=296) of students wanted video lectures to be compulsory, compared with 28.5% (n=167) for live lectures. The main improvement in live lectures was not using slides.

Conclusion:
Medical students in Pakistan prefer video lectures over live lectures for learning and exam preparation. More students wanted video lectures to be compulsory in medical education. Several improvements have been suggested for live lectures.
Neural Network-derived perfusion maps: a Model-free approach to computed tomography perfusion in patients with acute ischemic stroke
Authors: Gava Umberto A. , D’Agata Federico , Tartaglione Enzo , Grangetto Marco , Bertolino Francesca , Santonocito Ambra , Bennink Edwin , Bergui Mauro
Published: January 2021

Purpose

In this study we investigate whether a Convolutional Neural Network (CNN) can generate clinically relevant parametric maps from CT perfusion data in a clinical setting of patients with acute ischemic stroke.

Methods

Training of the CNN was done on a subset of 100 perfusion data, while 15 samples were used as validation. All the data used for the training/validation of the network and to generate ground truth (GT) maps, using a state-of-the-art deconvolution-algorithm, were previously pre-processed using a standard pipeline. Validation was carried out through manual segmentation of infarct core and penumbra on both CNN-derived maps and GT maps. Concordance among segmented lesions was assessed using the Dice and the Pearson correlation coefficients across lesion volumes.

Results

Mean Dice scores from two different raters and the GT maps were > 0.70 (good-matching). Inter-rater concordance was also high and strong correlation was found between lesion volumes of CNN maps and GT maps (0.99, 0.98).

Conclusion

Our CNN-based approach generated clinically relevant perfusion maps that are comparable to state-of-the-art perfusion analysis methods based on deconvolution of the data. Moreover, the proposed technique requires less information to estimate the ischemic core and thus might allow the development of novel perfusion protocols with lower radiation dose.
Tau assemblies do not behave like independently acting prion-like particles in mouse neural tissue
Authors: Mukadam Aamir S. , Miller Lauren V. C. , Durrant Claire S. , Vaysburd Marina J. , Katsinelos Taxiarchis , Tuck Benjamin J. , Sanford Sophie , Sheppard Olivia , Knox Claire , Cheng Shi , James Leo C. , Coleman Michael P. , McEwan William A.
Published: January 2021

A fundamental property of infectious agents is their particulate nature: infectivity arises from independently-acting particles rather than as a result of collective action. Assemblies of the protein tau can exhibit seeding behaviour, potentially underlying the apparent spread of tau aggregation in many neurodegenerative diseases. Here we ask whether tau assemblies share with classical pathogens the characteristic of particulate behaviour. We used organotypic hippocampal slice cultures from P301S tau transgenic mice in order to precisely control the concentration of extracellular tau assemblies. Whilst untreated slices displayed no overt signs of pathology, exposure to tau assemblies could result in the formation of intraneuronal, hyperphosphorylated tau structures. However, seeding ability of tau assemblies did not titrate in a one-hit manner in neural tissue. The results suggest that seeding behaviour of tau only arises at supra-physiological concentrations, with implications for the interpretation of high-dose intracranial challenge experiments and the possible contribution of seeded aggregation to human disease.
Persistently increased systemic ACE2 activity and Furin levels are associated with increased inflammatory response in smokers with SARS-CoV-2 COVID-19
Authors: Kaur Gagandeep , Yogeswaran Shaiesh , Muthumalage Thivanka , Rahman Irfan
Published: January 2021

Background

Tobacco smoking is known to be involved in the pathogenesis of several cardiopulmonary diseases, and smokers are susceptible to infectious agents. However, the progression of lung injury based on COVID-19 susceptibility and severity amongst smokers and those with pre-existing pulmonary diseases is not known. We determined the systemic expression and activity of COVID-19 related proteins, cytokine/chemokines, and lipid mediators (lipidomics) amongst COVID-19 patients with and without a history of smoking with a view to define biomarkers.

Methods

We obtained serum from COVID-19 positive and COVID-19 recovered patients with and without a history of smoking. We conducted a Luminex multiplex assay (cytokine levels), LC/MS (eicosanoids or oxylipin panel) and enzymatic activity assays on the serum samples to study the systemic changes in COVID-19 patients.

Results

On comparing the cytokine profiles among COVID-19 positive and COVID-19 negative patients, we found a significant upregulation in the production of pro-inflammatory cytokines like IL-1α, IL-8, IL-2, VEGF and IL-10 in COVID-19 positive patients as compared to the respective controls. Interestingly, smoking history resulted in further augmentation of the release of some hyper-inflammatory cytokines, like IFN-γ, Eotaxin, MCP-1 and IL-9 amongst COVID-19 positive patients. The enzymatic activity for ACE2, the binding partner for SARS-CoV2 virus in the host cell, was found to be significantly increased in the serum of patients with a smoking history compared to the serum collected from the non-smoking controls. Similarly to our cytokine analysis, our measurement of serum Furin levels was also affected by the patient’s smoking history, in which we reported a substantial rise in serum Furin levels of COVID-19 patients. The analysis of lipid mediators revealed a distinct signature amongst the COVID-19 positive versus recovered subjects in PGF2α, HETEs, LXA4 and LTB4 levels. However, we did not find any changes in the levels of any lipid mediators based on the smoking history of the patients. Overall, our results point towards distinct systemic signatures amongst COVID-19 positive patients. We also show that smoking adversely affects the systemic levels of inflammatory markers and COVID-19 related proteins, thus suggesting that COVID-19 infection may have severe outcomes amongst smokers which is reflected systemically.
How to best test suspected cases of COVID-19: an analysis of the diagnostic performance of RT-PCR and alternative molecular methods for the detection of SARS-CoV-2
Authors: Mironas Adrian , Jarrom David , Campbell Evan , Washington Jennifer , Ettinger Sabine , Wilbacher Ingrid , Endel Gottfried , Vrazic Hrvoje , Myles Susan , Prettyjohns Matthew
Published: January 2021

As COVID-19 testing is rolled out increasingly widely, the use of a range of alternative testing methods will be beneficial in ensuring testing systems are resilient and adaptable to different clinical and public health scenarios. Here, we compare and discuss the diagnostic performance of a range of different molecular assays designed to detect the presence of SARS-CoV-2 infection in people with suspected COVID-19. Using findings from a systematic review of 103 studies, we categorised COVID-19 molecular assays into 12 different test classes, covering point-of-care tests, various alternative RT-PCR protocols, and alternative methods such as isothermal amplification. We carried out meta-analyses to estimate the diagnostic accuracy and clinical utility of each test class. We also estimated the positive and negative predictive values of all diagnostic test classes across a range of prevalence rates. Using previously validated RT-PCR assays as a reference standard, 11 out of 12 classes showed a summary sensitivity estimate of at least 92% and a specificity estimate of at least 99%. Several diagnostic test classes were estimated to have positive predictive values of 100% throughout the investigated prevalence spectrum, whilst estimated negative predictive values were more variable and sensitive to disease prevalence. We also report the results of clinical utility models that can be used to determine the information gained from a positive and negative test result in each class, and whether each test is more suitable for confirmation or exclusion of disease. Our analysis suggests that several tests exist that are suitable alternatives to standard RT-PCR and we discuss scenarios in which these could be most beneficial, such as where time to test result is critical or, where resources are constrained. However, we also highlight methodological concerns with the design and conduct of many included studies, and also the existence of likely publication bias for some test classes. Our results should be interpreted with these shortcomings in mind. Furthermore, our conclusions on test performance are limited to their use in symptomatic populations: we did not identify sufficient suitable data to allow analysis of testing in asymptomatic populations.
From “don, doff, and discard” to “don, doff, and decontaminate” – determination of filtering facepiece respirator and surgical mask integrity and inactivation of a SARS-CoV-2 surrogate and a small non-enveloped virus following multiple-cycles of vaporised hydrogen peroxide, ultraviolet germicidal irradiation, and dry heat decontamination
Authors: Ludwig-Begall Louisa F. , Wielick Constance , Jolois Olivier , Dams Lorène , Razafimahefa Ravo M. , Nauwynck Hans , Demeuldre Pierre-Francois , Napp Aurore , Laperre Jan , Farnir Frédéric , Thiry Etienne , Haubruge Eric
Published: January 2021

Background

As the SARS-CoV-2 pandemic accelerates, the supply of personal protective equipment remains under strain. To combat shortages, re-use of surgical masks and filtering facepiece respirators has been recommended. Prior decontamination is paramount to the re-use of these typically single-use only items and, without compromising their integrity, must guarantee inactivation of SARS-CoV-2 and other contaminating pathogens.

Aim

We provide information on the effect of time-dependent passive decontamination at room temperature and evaluate inactivation of a SARS-CoV-2 surrogate and a non-enveloped model virus as well as mask and respirator integrity following active multiple-cycle vaporised hydrogen peroxide (VHP), ultraviolet germicidal irradiation (UVGI), and dry heat (DH) decontamination.

Methods

Masks and respirators, inoculated with infectious porcine respiratory coronavirus or murine norovirus, were submitted to passive decontamination or single or multiple active decontamination cycles; viruses were recovered from sample materials and viral titres were measured via TCID50 assay. In parallel, filtration efficiency tests and breathability tests were performed according to EN standard 14683 and NIOSH regulations.

Results and Discussion

Infectious porcine respiratory coronavirus and murine norovirus remained detectable on masks and respirators up to five and seven days of passive decontamination. Single and multiple cycles of VHP-, UVGI-, and DH were shown to not adversely affect bacterial filtration efficiency of masks. Single- and multiple UVGI did not adversely affect respirator filtration efficiency, while VHP and DH induced a decrease in filtration efficiency after one or three decontamination cycles. Multiple cycles of VHP-, UVGI-, and DH slightly decreased airflow resistance of masks but did not adversely affect respirator breathability. VHP and UVGI efficiently inactivated both viruses after five, DH after three, decontamination cycles, permitting demonstration of a loss of infectivity by more than three orders of magnitude. This multi-disciplinal approach provides important information on how often a given PPE item may be safely reused.
Anticipating the curve: can online symptom-based data reflect COVID-19 case activity in Ontario, Canada?
Authors: Maharaj Arjuna S. , Parker Jennifer , Hopkins Jessica P. , Gournis Effie , Bogoch Isaac I. , Rader Benjamin , Astley Christina M. , Ivers Noah , Hawkins Jared B. , Lee Liza , Tuite Ashleigh R. , Fisman David N. , Brownstein John S. , Lapointe-Shaw Lauren
Published: January 2021

Background

Limitations in laboratory diagnostic capacity and reporting delays have hampered efforts to mitigate and control the ongoing COVID-19 pandemic globally. Syndromic surveillance of COVID-19 is an important public health tool that can help detect outbreaks, mobilize a rapid response, and thereby reduce morbidity and mortality. The primary objective of this study was to determine whether syndromic surveillance through self-reported COVID-19 symptoms could be a timely proxy for laboratory-confirmed case trends in the Canadian province of Ontario.

Methods

We retrospectively analyzed self-reported symptoms data collected using an online tool – Outbreaks Near Me (ONM) – from April 20th to Oct 11th, 2020 in Ontario, Canada. We estimated the correlation coefficient between the weekly proportion of respondents reporting a COVID-like illness (CLI) to both the weekly number of PCR-confirmed COVID-19 cases and the percent positivity in the same period for the same week and with a one-week lag.

Results

There were 314,686 responses from 188,783 unique respondents to the ONM symptom survey. Respondents were more likely to be female and be in the 40-59 age demographic compared to the Ontario general population. There was a strong positive correlation between the weekly number of reported cases in Ontario and the percent of respondents reporting CLI each week (r = 0.89, p <0.01) and with a one-week lag (r = 0.89, p <0.01).

Interpretation

We demonstrate a strong positive and significant correlation (r = 0.89, p <0.01) between percent of self-reported COVID-like illness and the subsequent week’s COVID-19 cases reported, highlighting that a rise in CLI may precede official statistics by at least 1 week. This demonstrates the utility of syndromic surveillance in predicting near-future disease activity. Digital surveillance systems are low-cost tools that may help measure the burden of COVID-19 in a community if there is under-detection of cases through conventional laboratory diagnostic testing. This additional information can be used to guide a healthcare response and policy decisions.
A study on episodic memory reconsolidation that tells us more about consolidation
Authors: Craig Michael , Knowles Christopher , Hill Stephanie , Dewar Michaela
Published: January 2021

Awake quiescence immediately after encoding is conducive to episodic memory consolidation. Retrieval can render episodic memories labile again, but reconsolidation can modify and restrengthen them. It remained unknown whether awake quiescence after retrieval supports episodic memory reconsolidation. We sought to examine this question via an object-location memory paradigm. We failed to probe the effect of quiescence on reconsolidation, but we did observe an unforeseen “delayed” effect of quiescence on consolidation. Our findings reveal that the beneficial effect of quiescence on episodic memory consolidation is not restricted to immediately following encoding but can be achieved at a delayed stage and even following a period of task engagement.
Identification and characterization of novel ACD variants: modulation of TPP1 protein level offsets the impact of germline loss-of-function variants on telomere length
Authors: Henslee Gabrielle , Williams Christopher L. , Liu Pengfei , Bertuch Alison A.
Published: January 2021

Telomere biology disorders, largely characterized by telomere lengths below the first centile for age, are caused by variants in genes associated with telomere replication, structure, or function. One of these genes, ACD, which encodes the shelterin protein TPP1, is associated with both autosomal dominantly and autosomal recessively inherited telomere biology disorders. TPP1 recruits telomerase to telomeres and stimulates telomerase processivity. Several studies probing the effect of various synthetic or patient-derived variants have mapped specific residues and regions of TPP1 that are important for interaction with TERT, the catalytic component of telomerase. However, these studies have come to differing conclusions regarding ACD haploinsufficiency. Here, we report a proband with compound heterozygous novel variants in ACD (NM_001082486.1)—c.505_507delGAG, p.(Glu169del); and c.619delG, p.(Asp207Thrfs*22)—and a second proband with a heterozygous chromosomal deletion encompassing ACD: arr[hg19] 16q22.1(67,628,846-67,813,408)x1. Clinical data, including symptoms and telomere length within the pedigrees, suggested that loss of one ACD allele was insufficient to induce telomere shortening or confer clinical features. Further analyses of lymphoblastoid cell lines showed decreased nascent ACD RNA and steady-state mRNA, but normal TPP1 protein levels, in cells containing heterozygous ACD c.619delG, p.(Asp207Thrfs*22), or the ACD-encompassing chromosomal deletion compared to controls. Based on our results, we conclude that cells are able to compensate for loss of one ACD allele by activating a mechanism to maintain TPP1 protein levels, thus maintaining normal telomere length.
Crystal structure and spectroscopic properties of (E)-1,3-dimethyl-2-[3-(4-nitrophenyl)triaz-2-enylidene]-2,3-dihydro-1H-imidazole
Authors: Heras Martinez Hector Mario , Chavez Flores David , Hillesheim Patrick C. , Patil Siddappa , Bugarin Alejandro
Published: January 2021

The title compound (E)-1,3-dimethyl-2-[3-(4-nitrophenyl)triaz-2-enylidene]-2,3-dihydro-1H-imidazole, C11H12N6O2, has monoclinic (C2/c) symmetry at 100 K. This triazene derivative was synthesized by the coupling reaction of 1,3-dimethylimidazolium iodide with 1-azido-4-nitro benzene in the presence of sodium hydride (60% in mineral oil) and characterized by 1H NMR, 13C NMR, IR, mass spectrometry, and single-crystal X-ray diffraction. The molecule consists of six-membered and five-membered rings, which are connected by a triazene moiety (–N=N—N–). In the solid-state, the molecule is found to be planar due to conjugation throughout the molecule. The extended structure shows two layers of molecules, which present weak intermolecular interactions that facilitate the stacked arrangement of the molecules forming the extended structure. Furthermore, there are several weak pseudo-cyclical interactions between the nitro oxygen atoms and symmetry-adjacent H atoms, which help to arrange the molecules.
Financial liberalization and the behavior of reversals in emerging market economies
Authors: Munir Ali Fayyaz , Shaharuddin Shahrin Saaid , Sukor Mohd Edil Abd , Albaity Mohamed , Ismail Izlin
Published: January 2021

Purpose

This paper investigates the behavior of contrarian strategy payoffs under varying degrees of financial liberalization in the context of Asia-Pacific emerging market namely China, India, Indonesia, Korea, Malaysia, Pakistan, Philippines and Thailand for the period 1997–2017. These markets represent economies that display a gradual change in the degree of financial liberalization instead of fully opening their markets to foreign investors at once.

Design/methodology/approach

Using a daily dataset of 2,468 firms and four different measures of the degree of financial liberalization, the paper employs portfolio formation, panel regressions and binary modeling methods to reveal the impact of partial and complete financial liberalization on contrarian returns.

Findings

This paper documents a negative relationship between the degree of financial liberalization and contrarian strategy payoffs. The results further indicate that small-sized emerging markets reveal more significant and higher contrarian returns as compared to their larger counterparts. Moreover, the returns are significantly higher during negative market states, higher volatility and crises periods. The study findings are consistent with the investor-base broadening hypothesis.

Practical implications

The findings may serve as a useful input for investors and fund managers to devise contrarian investment strategies in emerging market economies. Together, the study provides additional insights for policymakers in managing financial liberalization and integration policies within their respective countries.

Originality/value

This study provides a novel viewpoint by examining the relationship between the degree of financial liberalization and contrarian strategy payoffs. The authors contribute to the existing debate by shifting the discussion to the investor-based broadening argument in which small and less liberalized emerging markets offer opportunities for investors and fund managers to produce abnormal contrarian returns that cannot be earned by other conventional investment strategies.
Architecture for an efficient MBIST using modified March-y algorithms to achieve optimized communication delay and computational speed
Authors: O.S. Nisha , K. Sivasankar
Published: January 2021

Purpose

In this work, an efficient architecture for memory built in self-test (MBIST) that incorporates a modified March Y algorithm using concurrent technique and a modified linear feedback shift register (LFSR)–based address generator is proposed.

Design/methodology/approach

Built in self-test (BIST) is emerging as the essential ingredient of the system on chip. In the ongoing high speed, high tech sophistication technology of the very large-scale integrated circuits, testing of these memories is a very tedious and challenging job, since the area overhead, the testing time and the cost of the test play an important role.

Findings

With the efficient service of the adapted architecture, switching activity is considerably cut down. As the switching activity is in direct proportion to the power consumed scaling down, the switching process of the address generator inevitably leads to the reduction in power consumption of the MBIST.

Originality/value

To improve the yield and fault tolerance of on-chip memories without degradation on its performance self-repair mechanisms can be implemented on chip.
Antecedents of smartphone multitasking: roles of demographics, personalities and motivations
Authors: Chen Xingyu , Wang Yitong , Tao Da , Jiang Ling , Li Shaobo
Published: January 2021

Purpose

Smartphone multitasking behavior has become prevalent in our daily lives, yet factors influencing smartphone multitasking behavior have not been fully investigated. This study aimed to examine the roles of a set of demographic, personality and motivational factors on smartphone multitasking behavior, and how these factors were related to general and application-specific types of smartphone multitasking behavior.

Design/methodology/approach

A cross-sectional study was conducted in which 2,659 smartphone users were invited to complete an online survey on smartphone multitasking behavior. Hierarchical multiple regression analyses were used to examine the roles of demographic, personality and motivational factors on smartphone multitasking behavior.

Findings

The results showed that, in general, demographic factors, such as gender, age, occupation status, education and smartphone usage time significantly predicted smartphone multitasking behavior. People characterized by agreeableness, extraversion, neuroticism and openness to experience were more likely to multitask with smartphones. Information seeking, efficiency and habit motivations were identified as major motivational factors for smartphone multitasking behavior. The roles of demographic, personality and motivational factors differed much across varied types of application-specific smartphone multitasking behavior.

Originality/value

This study extends and advances the literature on media multitasking, smartphone multitasking in particular, by identifying a set of demographic, personality and motivational factors as antecedents of smartphone multitasking behavior. In addition, this study revealed the differentiated roles of the above-mentioned factors across varied types of smartphone application usages. The findings provide important implications for practitioners to tailor smartphone applications and services to different target smartphone users and use situations.
Proxy problems: Why a calibration is essential for interpreting quantified changes in energy expenditure from biologging data
Authors: Halsey Lewis G. , Bryce Caleb M.
Published: January 2021

We do not yet have the means to directly measure the energy expenditure of wild animals, particularly at a high temporal resolution. However, we can instead measure factors that correlate with energy expenditure, such as heart rate or accelerometry, that is, energy expenditure proxies.

To estimate the magnitude of differences in energy expenditure between contexts (such as day and night, or travelling singly vs. in a group), our energy expenditure proxy must be calibrated. However, perhaps because of the logistical challenges of conducting such calibrations and the observation that most calibrations are linear, researchers sometimes interpret the degree of change in energy expenditure between contexts based on uncalibrated proxy data. When doing so, they implicitly assume that the ratio of the proxy values between contexts represents the ratio of energy expenditure values between those contexts.

This approach, however, is usually spurious because unless the relationship between energy expenditure and proxy passes through the origin (i.e. y‐intercept = 0), the ratio of change in the proxy between contexts does not represent the ratio of change in energy expenditure.

We model the error induced when data from an uncalibrated proxy are used to interpret changes in energy expenditure. We also estimate the errors made in published articles that employ this approach, by comparing the claimed change in energy expenditure between two contexts with the change in energy expenditure estimated by applying the best available calibrations now available. As predicted by the models we developed, the apparent size of the error in published articles is related to the relative size of the calibration y‐intercept.

Species‐ and activity‐specific empirical calibrations are the best option for interpreting proxies of energy expenditure. However, for mammals and birds, enough data have been amassed such that energy expenditure can be predicted from measures of heart rate by knowing animal heart mass or even body mass; perhaps a somewhat analogous predictive tool will be available in the future for accelerometry.

A free Plain Language Summary can be found within the Supporting Information of this article.
Cascading effects of algal warming in a freshwater community
Authors: Tseng Michelle , Di Filippo Carla M. , Fung Madeline , Kim Jihyun O. , Forster Ian P. , Zhou Yilin
Published: January 2021

Research on the effects of climate warming on ecological communities has focused on how temperature affects resource quantity. However, resource quality is also affected by warming, and changes in resource quality can have meaningful effects on the productivity of higher trophic levels.

Aquatic communities in particular experience temperature‐mediated shifts in resource quality because the nutritional value of algae is highly sensitive to temperature. For example, the production of healthful omega‐3 polyunsaturated fatty acids (n‐3 PUFA) by algae often decreases with warming.

Decreased levels of some algal PUFAs with warming have led to the hypothesis that global warming should lead to an overall decrease in productivity in aquatic communities. However, this hypothesis: (a) potentially oversimplifies the relationship between algal PUFAs and temperature, and (b) assumes that the nutritional requirements of consumers are not affected by temperature. Here, we test these assumptions using a freshwater community (Scenedesmus algae, Daphnia zooplankton, Chaoborus insects).

Warming temperatures increased total algal PUFAs, but decreased algal cell size, resulting in no net effect of temperature on PUFA per algal cell. In contrast, quantities of algal neutral lipids decreased with warming. At the consumer level, Daphnia fed 12°C‐reared algae maintained higher population sizes than those fed 20°C or 28°C‐reared algae. However, the effect of algal food type diminished as Daphnia rearing temperature increased. The indirect effects of cold‐reared algae on the growth rate of Chaoborus predators were minor.

These data highlight the importance of investigating the effects of temperature on both resource quality and on the nutritional needs of consumers. Our results suggest that at warmer temperatures, consumer nutritional requirements may be reduced. We caution against broad claims that the negative relationship between some algal PUFAs and temperature should result in overall declines in aquatic productivity with ongoing climate warming.

A free Plain Language Summary can be found within the Supporting Information of this article.
Diversity begets diversity: Phorophyte and microsite relations of foliicolous lichens in the lowland rain forest at Los Tuxtlas Biosphere Reserve (Veracruz, Mexico)
Authors: Martínez Colín Paola , Lücking Robert , Herrera‐Campos María de los Ángeles
Published: January 2021

We analyzed the structure of foliicolous lichen communities in the northernmost lowland forest of the Neotropics, Los Tuxtlas Tropical Biology Station in Veracruz, Mexico, and its dependence on phorophyte and microclimate. Along a 420‐m long transect with 15 equidistant sampling points, within a 10 m radius of each point, we sampled a total 137 phorophytes and 411 leaves. The phorophytes represented 13 species, with diverse leaf traits regarding size, texture, presence of hairs and/or glands, and longevity, including: Astrocaryum mexicanum (Arecaceae), Chamaedorea ernesti‐augustii (Arecaceae), Costus scaber (Costaceae), Guarea glabra (Meliaceae), Heliconia latispatha (Heliconiaceae), Monstera acuminata (Araceae), Myriocarpa longipes (Urticaceae), Piper hispidum (Piperaceae), Poulsenia armata (Moraceae), Pseudolmedia oxyphyllaria (Moraceae), Salacia megistophylla (Celastraceae), Siparuna thecaphora (Siparunaceae) and Syngonium podophyllum (Araceae). NDMS ordination and cluster analysis grouped the phorophytes into hierarchically structured clusters variously correlated with microsite, phorophyte species and foliicolous lichen species richness. Indicator species analysis revealed statistically significant foliicolous lichen species characteristic for terminal clusters and for phorophyte species. We conclude that the principle of “diversity begets diversity” may apply, in that phorophyte diversity influences the diversity of foliicolous lichen communities through the manifestation of subtle phorophyte preferences, best seen in well‐developed communities on leaves with higher longevity. Thus, well‐preserved forest ecosystems, with a higher diversity of suitable phorophytes, will support a higher diversity of foliicolous lichens, a phenomenon that extents to epiphytes in general.
Genetic diversity in natural populations of the endangered Neotropical orchidTelipogon peruvianus
Authors: Martel Carlos , Scopece Giovanni , Cozzolino Salvatore , Ayasse Manfred , Pinheiro Fabio , Cafasso Donata
Published: January 2021

Telipogon peruvianusis a highly restricted, sexually deceptive, Neotropical orchid species, endemic to the southern Peruvian Andes. It is only known from two localities, which are affected by anthropogenic disturbance. Here, we investigated whether the restricted distribution ofT. peruvianushas led to low genetic diversity and inbreeding, thus threatening its survival. We isolated 10 novel microsatellite loci specific forT. peruvianus(and that also cross‐amplified in related species) from two adjacent populations. We found that genetic diversity within populations was only moderately reduced, along with some evidence of inbreeding. We found low levels of genetic differentiation, suggesting connectivity by pollen/seed flow between the two populations. Effective population size was comparable to the real number of flowering individuals in the populations and we did not detect the signature of recent bottlenecks. Taken together, these results show that, despite increasing anthropogenic pressure, the two investigated populations ofT. peruvianusstill host valuable genetic diversity that should be preserved through appropriate conservation strategies.
Fungal volatiles emitted by members of the microbiome of desert plants are diverse and capable of promoting plant growth
Authors: Camarena‐Pozos D. A. , Flores‐Núñez V. M. , López M. G. , Partida‐Martínez L. P.
Published: January 2021

Fungi represent a group of eukaryotic microorganisms that are an important part of the plant microbiome. They produce a vast array of metabolites, including fungal volatile organic compounds (fVOCs). However, the diversity and biological activities of fVOCs emitted by the mycobiota of plants native to arid and semi‐arid environments remain under‐explored. We characterized the chemical diversity of fVOCs produced by 22 representative members of the microbiome of agaves and cacti using SPME‐GC–MS. We further tested the effects of pure compounds on the growth and development of Arabidopsis thaliana and host plants. Members of the Sordariomycetes (nine strains), Eurotiomycetes (three), Dothideomycetes (eight), Saccharomycetes (one) and Mucoromycetes (one) were included in our study. We identified 94 fungal organic volatiles classified into nine chemical classes. Terpenes showed the greatest chemical diversity, followed by alcohols and aliphatic compounds. We discovered that camphene and benzyl benzoate, together with the widely distributed and already tested benzyl alcohol, 2‐phenylethyl alcohol and 3‐methyl‐1‐butanol, improved plant growth and development of A. thaliana, Agave tequilana and Agave salmiana. Our studies on the fungal VOCs from desert plants underscore an untapped chemical diversity with promising biotechnological applications.
Narrowversusbroad: sexual dimorphism in the wing form of western European species of the subgenusAvaritia(Culicoides, Ceratopogonidae)
Authors: MUÑOZ‐MUÑOZ Francesc , PAGÈS Nonito , DURAO Ana. F. , ENGLAND Marion , WERNER Doreen , TALAVERA Sandra
Published: January 2021

While wing form is known to differ between males and females of the genusCulicoides, detailed studies of sexual dimorphism are lacking. In this study, we analyze sex‐specific differences in the wing form of 5 species of the subgenusAvaritia, using geometric morphometrics and comparative phylogenetic methods. Our results confirm the existence of marked sexual dimorphism in the wing form of the studied species and reveal for the first time that while there is a shared general pattern of sexual shape dimorphism within the subgenus, sexual size dimorphism, and particular features of sexual shape dimorphism differ among species. Sexual shape dimorphism was found to be poorly associated to size and the evolutionary history of the species. The tight association of sexual shape dimorphism with aspect ratio suggests that the shape of the wing is optimized for the type of flight of each sex, that is, dispersal flight in females versus aerobatic flight in males. Moreover, the fact that interspecific shape differences are greater and more strongly associated to aspect ratio in males than in females might be indicating that in males the selective pressures affecting flight performance characteristics are more heterogeneous and/or stronger than in females among the studied species.
Survey of Salmonella in raw tree nuts at retail in the United States
Authors: Zhang Guodong , Hu Lijun , Luo Yan , Santillana Farakos Sofia M , Johnson Rhoma , Scott Virginia N. , Curry Phillip , Melka David , Brown Eric W. , Strain Errol , Bunning Vincent K. , Musser Steven M. , Hammack Thomas S.
Published: January 2021

The objective of this survey was to estimate the prevalence, contamination level, and genetic diversity of Salmonella in selected raw, shelled tree nuts (Brazil nuts, cashews, hazelnuts, macadamia nuts, pecans, pine nuts, pistachios, and walnuts) at retail markets in the United States. A total of 3,374 samples of eight tree nuts were collected from different types of retail stores and markets nationwide between September 2015 and March 2017. These samples (375 g) were analyzed using a modified FDA's BAM Salmonella culture method. Of the 3,374 samples, 15 (0.44%) (95% confidence interval [CI] [0.25, 0.73]) were culturally confirmed as containing Salmonella; 17 isolates were obtained. Among these isolates, there were 11 serotypes. Salmonella was not detected in Brazil nuts (296), hazelnuts (487), pecans (510), pine nuts (500), and walnuts (498). Salmonella prevalence estimates in cashews (510), macadamia (278), and pistachios (295) were 0.20% (95% CI [<0.01, 1.09]), 2.52% (95% CI [1.02, 5.12]), and 2.37% (95% CI [0.96, 4.83]), respectively. The rates of Salmonella isolation from major/big‐chain supermarkets (1381), small‐chain supermarkets (328), discount/variety/drug stores (1329), and online (336) were 0.29% (95% CI [0.08, 0.74]), 0.30% (95% CI [0.01, 1.69]), 0.45% (95% CI [0.17, 0.98]), and 1.19% (95% CI [0.33, 3.02]), respectively. Salmonella prevalence in organic (530) and conventional (2,844) nuts was not different statistically (P = 0.0601). Of the enumerated samples (15), 80% had Salmonella levels ≤0.0092 most probable number (MPN)/g. The highest contamination level observed was 0.75 MPN/g. The prevalence and contamination levels of Salmonella in the tree nuts analyzed were generally comparable to previous reports. Pulsed‐field gel electrophoresis, serotype, and sequencing data all demonstrated that Salmonella population in nuts is very diverse genetically.

Practical Application

The prevalence, contamination level, and genetic diversity of Salmonella in eight types of tree nuts (3,374 samples collected nationwide) revealed in this survey could help the development of mitigation strategies to reduce public health risks associated with consumption of these nuts.
Formulation of a mixed fruit beverage using fuzzy logic optimization of sensory data and designing its batch thermal pasteurization process
Authors: Dhar Rishab , Bhalerao Prasanna P. , Chakraborty Snehasis
Published: January 2021

The study aims to formulate a mixed fruit beverage through sensory analysis, and the composition was optimized using a fuzzy logic algorithm. The fuzzy optimization algorithm was developed using a modified Takagi and Sugeno's approach, polynomial mixture modeling, and nonlinear solver engine. The optimized blend consisted of amla juice, pineapple juice, and coconut water in 14.3, 63.0, and 22.7%, respectively. Further, the batch thermal treatment was carried out within 50 to 95 °C for an isothermal holding time of 1 s to 10 min, and pasteurization condition for the beverage was estimated from kinetic modeling. The concept of thermal pulse inactivation due to non‐isothermal heat‐up‐time and cool‐down‐time has been introduced within the process time calculation. From the kinetic study, polyphenoloxidase enzyme appeared to be the most resistant entity towards inactivation among all the natural microbiota and quality deteriorating enzymes. Pasteurization in terms of achieving a 5D reduction of both aerobic mesophilic and yeast‐mold counts was attained over a range of 80 to 95 °C for 10.2 + 1.4 to 3.1 + 2.0 min (1.4 and 2.0 min = heat‐up‐time + cool‐down‐time), respectively. The 90% inactivation of both polyphenoloxidase and peroxidase enzymes was obtained over a range of 90 to 95 °C for 12.8 + 1.7 to 8.4 + 2.0 min, respectively. While obtaining both the microbial and enzyme stability at the isothermal condition of 95 °C for 8.4 min, the corresponding retention in ascorbic acid, total phenolics, and antioxidant capacity were observed as 49.7, 63.0, and 61.4%, respectively.

Practical Application

In this work, the formulation of a fruit blend was optimized through an intelligent optimization technique (fuzzy algorithm) applied to the sensory data set. The approach for calculating thermal processing time or pasteurization condition provides a new dimension with better precision. The thermal treatment condition of 95 °C for 10 min can be used for this mixed beverage to achieve both microbial stability (5‐log reduction) and enzyme stability (90% reduction). The presented study can be used as a reference for other similar beverages to achieve a complete process design from basic formulation optimization to thermal (batch‐type) processing conditions.
Dietary and plasma carotenoids are positively associated with alpha diversity in the fecal microbiota of pregnant women
Authors: Schmidt Kristen M. , Haddad Eliot N. , Sugino Kameron Y. , Vevang Karin R. , Peterson Lisa A. , Koratkar Revati , Gross Myron D. , Kerver Jean M. , Comstock Sarah S.
Published: January 2021

Because microbes use carotenoids as an antioxidant for protection, dietary carotenoids could be associated with gut microbiota composition. We aimed to determine associations among reported carotenoid intake, plasma carotenoid concentrations, and fecal bacterial communities in pregnant women. Pregnant women (n = 27) were enrolled in a two‐arm study designed to assess feasibility of biospecimen collection and delivery of a practical nutrition intervention. Plasma and fecal samples were collected and women were surveyed with a 24‐hr dietary checklist and recalls. Plasma carotenoids were analyzed by HPLC using photodiode array detection. Fecal bacteria were analyzed by 16S rRNA DNA sequencing. Results presented are cross‐sectional from the 36‐week gestational study visit combined across both study arms due to lack of significant differences between intervention and usual care groups (n = 23 women with complete data). Recent intake of carotenoid‐containing foods included carrots, sweet potatoes, mangos, apricots, and/or bell peppers for 48% of women; oranges/orange juice (17%); egg (39%); tomato/tomato‐based sauces (52%); fruits (83%); and vegetables (65%). Average plasma carotenoid concentrations were 6.4 µg/dL α‐carotene (AC), 17.7 µg/dL β‐carotene (BC), 11.4 µg/dL cryptoxanthin, 39.0 µg/dL trans‐lycopene, and 29.8 µg/dL zeaxanthin and lutein. AC and BC concentrations were higher in women who recently consumed foods high in carotenoids. CR concentrations were higher in women who consumed oranges/orange juice. Microbiota α‐diversity positively correlated with AC and BC. Microbiota β‐diversity differed significantly across reported intake of carotenoid containing foods and plasma concentrations of AC. This may reflect an effect of high fiber or improved overall dietary quality, rather than a specific effect of carotenoids.

Practical Application

Little is known about the association between the gut microbiome and specific dietary microconstituents, such as carotenoids, especially during pregnancy. This research demonstrates that a carotenoid‐rich diet during pregnancy supports a diverse microbiota, which could be one mechanism by which carotenoids promote health.
Aspergillus fumigatus AR04 obeys Arrhenius' rule in cultivation temperature shifts from 30 to 40°C
Authors: Nieland Susanne , Barig Susann , Salzmann Julian , Gehrau Frauke , Zamani Arief Izzairy , Richter Annabell , Ibrahim Julia , Gräser Yvonne , Ng Chyan Leong , Stahmann Klaus‐Peter
Published: January 2021

To set a benchmark in fungal growth rate, a differential analysis of prototrophic Aspergillus fumigatus AR04 with three ascomycetes applied in > 103 t year‐1 scale was performed, i.e. Ashbya gosspyii (riboflavin), Aspergillus niger (citric acid) and Aspergillus oryzae (food‐processing). While radial colony growth decreased 0.5‐fold when A. gossypii was cultivated at 40°C instead of 28°C, A. fumigatus AR04 responded with 1.7‐fold faster hyphal growth. A. niger and A. oryzae formed colonies at 40°C, but not at 43°C. Moreover, all A. fumigatus strains tested grew even at 49°C. In chemostat experiments, A. fumigatus AR04 reached steady state at a dilution rate of 0.7 h‐1 at 40°C, 120% more than reported for A. gossypii at 28°C. To study mycelial growth rates under unlimited conditions, carbon dioxide increase rates were calculated from concentrations detected online in the exhaust of batch fermentations for 3 h only. All rates calculated suggest that A. fumigatus AR04 approximates Arrhenius’ rule when comparing short cultivations at 30°C with those at 40°C. Linearization of the exponential phase and comparison of the slopes revealed an increase to 192% by the 10°C up‐shift.
Iatrogenic acid‐induced gingival recession during crown cementation: A case report
Authors: Kofina V , An H , Rawal SY
Published: January 2021

Accidental contact of various chemicals in dentistry may cause damage to the gingiva. A male patient presented for a full mouth rehabilitation with ceramic crowns. The patient underwent the steps of ceramic crown preparation uneventfully. At the time of crown delivery, cotton rolls were placed in several vestibular areas for isolation. They were regularly changed during different steps of etching and cementation process, which included the use of Multilink Primer B (Ivoclar Vivadent™). On removal of the cotton roll in the area of upper right canine, the gingival tissues appeared blanched and grayish white. The cotton roll was found to have absorbed some etching material in it. As the patient was asymptomatic, he was dismissed. Two weeks later, the patient presented with inflammation and gingival recession in the same area. Initially, he was treated palliatively, and subsequently, he received a connective tissue graft on the upper right canine. This case report showed that acid etching material used during the prosthodontic cementation may have caused a gingival recession, which was successfully treated with tunnel flap and connective tissue graft. Optimal isolation of the operative field should be performed to avoid this problem.