Spectral effects of LEDs on chlorophyll fluorescence and pigmentation in Phalaenopsis ‘Vivien’ and ‘Purple Star’

We examined the effect of light emitting diode (LED) lighting in greenhouse facilities on growth, chlorophyll fluorescence and pigmentation in Phalaenopsis ‘Vivien’ and ‘Purple Star’ under purpose‐built LED arrays yielding c. 200 µmol m^?2 s^?1 at plant height for 14 h per day and 24/18°C day/night temperature, respectively, from January to April 2013. The light treatments were (1) 40% blue in 60% red (40% B/R), (2) 0% blue in 100% red (0% B/R) and (3) white LEDs with 32% blue in white (32% B/W, control), with background daylight under shade screens. The plants were harvested twice for leaf growth and pigmentation. There was no clear pattern in the spectral effect on growth since the order of leaf size differed between harvests in March and April. F_v/F_m was in the range of 0.52–0.72, but overall slightly higher in the control, which indicated a permanent downregulation of PSII in the colored treatments. The fluorescence quenching showed no acclimation to color in ‘Purple Star’, while ‘Vivien’ had lower ETR and higher NPQ in the 40% B/R, resembling low light acclimation. The pigmentation showed corresponding spectral response with increasing concentration of lutein while increasing the fraction of blue light, which increased the light absorption in the green/yellow part of the spectrum. The permanent downregulation of PSII moved a substantial part of the thermal dissipation from the light regulated NPQ to non‐regulated energy losses estimated by Φ_NPQ and Φ_NO and the difference found in the balance between Φ_PSII and Φ_NPQ in ‘Vivien’ disappeared when Φ_NO was included in the thermal dissipation.     

Molecular identification of diverse ‘Candidatus Phytoplasma’ species associated with grapevine decline in Iran

Grapevine (Vitis vinifera) is one of the most important fruits in Iran where the provinces of Qazvin, Lorestan and Markazi are main producers. During 2013–2015, vineyards located in these provinces were surveyed to verify the presence of phytoplasma. The sample collection was based on symptomatology including decline, leaf yellowing and shortening of internodes. Total DNA was extracted from symptomatic and symptomless grapevine samples and used in nested‐polymerase chain reaction (PCR) assays with phytoplasma ribosomal primers (P1/Tint followed by R16F2n/R2, R16mF1/mR1, R16(I)F1/R1 or 6R758f/16R1232r). Nested‐PCR products were obtained only for symptomatic samples while samples from symptomless plants yielded no PCR products. Restriction fragment length polymorphism (RFLP) analyses with Tru1I, TaqI and Tsp509I and direct sequencing of amplicons followed by phylogenetic analyses indicated the presence of ‘Candidatus Phytoplasma fraxini’, ‘Ca. P. aurantifolia’, ‘Ca. P. solani’ and ‘Ca. P. phoenicium’‐related strains. In Marzaki province, there ‘Ca. P. aurantifolia’ strains were mainly detected, while in the other two provinces, all the four ‘Candidatus species’ were identified with the prevalence of ‘Ca. P. solani’‐related strains. In both provinces in one case, mixed phytoplasma infection was also detected by RFLP analyses. The presence of different phytoplasmas in positive samples indicates great phytosanitary significance due to grapevine economic importance for country. Grapevine phytoplasma infection represents a threat for other crops suggesting grapevine as alternative host species for the phytoplasmas already reported in Iran, while the ‘Ca. P. fraxini’ is for the first time identified in Iran.     

A SNP in the promoter region of the<Emphasis Type="Italic">VvmybA1</Emphasis> gene is responsible for differences in grape berry color between two related bud sports of grape

The VvmybA1 gene in grape (Vitis vinifera) plays a key role in the biosynthesis of anthocyanin. The grape cultivars, ‘Benitaka’ (red color) and ‘Brazil’ (black color) were the result of a bud mutation. ‘Benetika’ was derived from ‘Italia’ (green color) and ‘Brazil’ was developed from ‘Benetika’. Single sequence repeat (SSR) molecular marker analysis was performed in order to demonstrate that the three cultivars have a common pedigree. A sequence analysis of the promoter region and coding sequence of VvmybA1 revealed a base substitution between ‘Benitaka’ and ‘Brazil’ in the promoter region and a deletion of a large DNA fragment in the promoter region of ‘Italia’. Anthocyanin content and expression of the VvmybA1 and UFGT genes in ‘Brazil’ were higher than in ‘Benitaka’ and barely detectable in ‘Italia’. A transient expression system was used to introduce VvmybA1 driven by the three different promoters present in ‘Italia’, ‘Brazil’, and ‘Benitaka’ into somatic embryos of ‘Centennial Seedless’ (Vitis vinifera L.) by Agrobacterium-mediated transformation. This resulted in the production of red cells in the embryos transformed with the constructs of VvmybA1 from ‘Brazil’ and ‘Benitaka’ and no color production in embryos transformed with the VvmybA1 construct from ‘Italia’. In addition, the embryos transformed with the ‘Brazil’ construct had more red color than the embryos transformed with the ‘Benitaka’ construct. These results suggested that a SNP mutation in the promoter region of VvmybA1 in ‘Benitaka’ (red color) was responsible for the color change displayed by ‘Brazil’ (black color).     

A new colorimetric and far‐red fluorescent probe for hydrazine with a large red‐shifted absorption spectrum

Recently, growing attention has been paid to the detection of hydrazine (NH₂NH₂) because of its important roles in industrial chemical and high toxicity to human beings. Herein, we have constructed a new colorimetric and far‐red fluorescent probe containing a receptor of 4‐bromobutanoate to selectively detect hydrazine. The probe could detect hydrazine quantitatively in the range of 40–500 μM with the detection limit of 2.9 μM. In addition, the probe could monitor hydrazine by the ratiometric method with a large (185 nm) red‐shifted absorption spectrum, and the color changes from yellow to blue make it as a ‘naked‐eye’ indicator for hydrazine. Consequently, our proposed probe would be of great benefit for monitoring hydrazine in aqueous solution.     

A single‐stranded conformational polymorphism (SSCP)‐derived quantitative variable to monitor the virulence of a Barley yellow dwarf virus‐PAV (BYDV‐PAV) isolate during adaptation to the TC14 resistant wheat line

A standardized single‐stranded conformational polymorphism (SSCP) procedure is proposed as an alternative to the time‐consuming biological characterization of Barley yellow dwarf virus‐PAV (BYDV‐PAV) isolates. Using this procedure, six of 21 overlapping regions used to scan the viral genome gave patterns specific to ‘4E’ (avirulent) or ‘4T’ (‘4E’‐derived virulent) isolates. The calibration of samples and integration of SSCP patterns corresponding to the nucleotide region 1482–2023 allowed the estimation of P_T values that reflect the proportions of a ‘4T’‐specific band. Analysis of the biological (area under the pathogen progress curve) and molecular (P_T) data suggested a positive linear relation between these variables. Moreover, sequence analysis of the nucleotide region 1482–2023 highlighted the presence of a nucleotide polymorphism (C/A₁₈₃₅) which can be considered as a candidate for virus–host interactions linked to the monitored virulence. According to these parameters, P_T values associated with ‘4E’‐ and ‘4T’‐derived populations show that: (i) long‐term infection of a BYDV‐PAV isolate on the ‘TC14’ resistant host leads to the fixation of virulent individuals in viral populations; and (ii) the introduction of susceptible hosts in successive ‘TC14’ infections results in the maintenance of low virulence of the populations. Thus, the presented study demonstrates that SSCP is a useful tool for monitoring viral populations during the host adaptation process. The described impact of host alternation provides new opportunities for the use of the ‘TC14’ resistance source in BYDV‐resistant breeding programmes. This study is part of the global effort made by the scientific community to propose sustainable alternatives to the chemical control of this viral disease.     

A lack of functional NK1 receptors explains most,but not all,abnormal behaviours of NK1R‐/‐ mice1

Mice lacking functional neurokinin‐1 receptors (NK1R‐/‐) display abnormal behaviours seen in Attention Deficit Hyperactivity Disorder (hyperactivity, impulsivity and inattentiveness). These abnormalities were evident when comparing the behaviour of separate (inbred: ‘Hom’) wildtype and NK1R‐/‐ mouse strains. Here, we investigated whether the inbreeding protocol could influence their phenotype by comparing the behaviour of these mice with that of wildtype (NK1R+/+) and NK1R‐/‐ progeny of heterozygous parents (‘Het’, derived from the same inbred strains). First, we recorded the spontaneous motor activity of the two colonies/genotypes, over 7 days. This continuous monitoring also enabled us to investigate whether the diurnal rhythm in motor activity differs in the two colonies/genotypes. NK1R‐/‐ mice from both colonies were hyperactive compared with their wildtypes and their diurnal rhythm was also disrupted. Next, we evaluated the performance of the four groups of mice in the 5‐Choice Serial Reaction‐Time Task (5‐CSRTT). During training, NK1R‐/‐ mice from both colonies expressed more impulsive and perseverative behaviour than their wildtypes. During testing, only NK1R‐/‐ mice from the Hom colony were more impulsive than their wildtypes, but NK1R‐/‐ mice from both colonies were more perseverative. There were no colony differences in inattentiveness. Moreover, a genotype difference in this measure depended on time of day. We conclude that the hyperactivity, perseveration and, possibly, inattentiveness of NK1R‐/‐ mice is a direct consequence of a lack of functional NK1R. However, the greater impulsivity of NK1R‐/‐ mice depended on an interaction between a functional deficit of NK1R and other (possibly environmental and/or epigenetic) factors.     

Bright solid‐state luminescence of green‐red tunable CdTe@BaCO3 composite: Synthesis and properties

Realizing efficient solid‐state luminescence is of great important to expand quantum dots (QDs) application fields. This work reports the preparation of CdTe@BaCO₃ composite by a one‐pot precipitation method. Both steady‐state PL and PL decay characteristics in either solid‐state or colloid solution show no obvious difference, mainly benefited from the effective protection of BaCO₃ on QDs from the external environment. By utilizing green and red CdTe QDs as dual‐color emission centers, precise emitting‐color control from green (0.312, 0.667) to red (0.691, 0.292) could be achieved in CdTe@BaCO₃ composite by adjusting volume ratio of CdTe solution precursor. Our results demonstrate that this composite material shows bright solid‐state luminescence and facile adjustment of the emitting color in QDs‐based composite is feasible, which could offer new path to design color‐tunable luminescent materials for future optoelectronic applications.     

SENSORY AND INSTRUMENTAL EVALUATION OF STRAWBERRY YOGURT COLOR

Eleven samples of strawberry yogurt prepared with different red color concentrations using Ponceau 4R (E-124) were evaluated by instrumental and sensory methods. Color intensity evaluation was carried out by a panel of eight assessors specifically trained to measure strawberry color in yogurt. Color acceptability was measured with 120 regular and frequent consumers of yogurt. Color was measured with a Minolta Chroma Meter CR-200b, obtaining parameters L*, a* and b*. Principal component analysis was performed on the instrumental variables. Regression models between the instrumental first principal component, red color concentration, sensory intensity, and acceptability allowed determining quality control limits for red color attribute. These limits may be controlled by selecting either instrumental or sensory methods, being the latter easy to implement and providing dependable results.     

Publication bias in ecology and evolution: an empirical assessment using the 'trim and fill' method

Recent reviews of specific topics, such as the relationship between male attractiveness to females and fluctuating asymmetry or attractiveness and the expression of secondary sexual characters, suggest that publication bias might be a problem in ecology and evolution. In these cases, there is a significant negative correlation between the sample size of published studies and the magnitude or strength of the research findings (formally the ‘effect size’). If all studies that are conducted are equally likely to be published, irrespective of their findings, there should not be a directional relationship between effect size and sample size; only a decrease in the variance in effect size as sample size increases due to a reduction in sampling error. One interpretation of these reports of negative correlations is that studies with small sample sizes and weaker findings (smaller effect sizes) are less likely to be published. If the biological literature is systematically biased this could undermine the attempts of reviewers to summarise actual biology relationships by inflating estimates of average effect sizes. But how common is this problem? And does it really effect the general conclusions of literature reviews? Here, we examine data sets of effect sizes extracted from 40 peer‐reviewed, published meta‐analyses. We estimate how many studies are missing using the newly developed ‘trim and fill’ method. This method uses asymmetry in plots of effect size against sample size (‘funnel plots’) to detect ‘missing’ studies. For random‐effect models of meta‐analysis 38% (15/40) of data sets had a significant number of ‘missing’ studies. After correcting for potential publication bias, 21% (8/38) of weighted mean effects were no longer significantly greater than zero, and 15% (5/34) were no longer statistically robust when we used random‐effects models in a weighted meta‐analysis. The mean correlation between sample size and the magnitude of standardised effect size was also significantly negative (r_s=‐0.20, P < 0‐0001). Individual correlations were significantly negative (P < 0.10) in 35% (14/40) of cases. Publication bias may therefore effect the main conclusions of at least 15–21% of meta‐analyses. We suggest that future literature reviews assess the robustness of their main conclusions by correcting for potential publication bias using the ‘trim and fill’ method.     

The Role of Melanocortin‐1 Receptor Polymorphism in Skin Cancer Risk Phenotypes

We have examined melanocortin‐1 receptor (MC1R) variant allele frequencies in the general population and in a collection of adolescent dizygotic and monozygotic twins to determine statistical associations of pigmentation phenotypes with increased skin cancer risk. This included hair and skin color, freckling, mole count and sun exposed skin reflectance. Nine variants were studied and designated as either strong R (OR = 63; 95% CI 32–140) or weak r (OR = 5; 95% CI 3–11) red hair alleles. Penetrance of each MC1R variant allele was consistent with an allelic model where effects were multiplicative for red hair but additive for skin reflectance. To assess the interaction of the brown eye color gene BEY2/OCA2 on the phenotypic effects of variant MC1R alleles we imputed OCA2 genotype in the twin collection. A modifying effect of OCA2 on MC1R variant alleles was seen on constitutive skin color, freckling and mole count. In order to study the individual effects of these variants on pigmentation phenotype we have established a series of human primary melanocyte strains genotyped for the MC1R receptor. These include strains which are MC1R wild‐type consensus, variant heterozygotes, and homozygotes for strong R alleles Arg151Cys and Arg160Trp. Ultrastructural analysis demonstrated that only consensus strains contained stage III and IV melanosomes in their terminal dendrites whereas Arg151Cys and Arg160Trp homozygous strains contained only immature stage I and II melanosomes. Such genetic association studies combined with the functional analysis of MC1R variant alleles in melanocytic cells should provide a link in understanding the association between pigmentary phototypes and skin cancer risk.     

Equivocal locations: being ‘red’ in ‘Red Bologna’

This article addresses a classic ethnographic problem in the study of Italy: how is it that people can subscribe simultaneously to seemingly contradictory ideologies, such as Catholicism and Communism? It does so by describing examples from Italy's ‘showcase city’ of the left, ‘Red Bologna’, in which to be ‘red’ is ubiquitous but each person's ‘red’ is a different thing: being ‘red’ (differently) is the idiom in which real political distinctions are expressed over issues like religion or immigration. In parallel, I discuss the relationship between the ‘field’ as a location and the ‘field’ as a conceptual topic. My account replicates internal ethnographic differences at the analytical level by highlighting the differences between being left‐wing in Bologna and its meaning as a concept in anthropology. Hence the ‘equivocal location’: a field‐site that is productively different, from what an inexperienced ethnographer expected from it, from conceptual discussions in anthropology, and from itself.     

The histological analysis,colorimetric evaluation,and chemical quantification of melanin content in ‘suntanned’ fish

Human melanocytes respond to UV irradiation by increasing the synthesis of melanin. While much is now understood of the pathways governing this process and the nature of the melanin synthesized, little is known of melanins produced by lower vertebrates and their capacity to respond to UV. Here we report that a fish, red seabream, can undergo ‘suntanning’. Histological, colorimetric and chemical assays were performed for suntanned red seabream fish bred in net cages to analyse the melanins and compared with shaded or wild red seabream fish. For color evaluation, the L* values of suntanned fish were dramatically lower than those in the other two groups. Pyrrole‐2,3,5‐tricarboxylic acid (PTCA), an indicator of eumelanin, was detected in suntanned fish at five times higher levels than in shaded or wild fish while 4‐amino‐3‐hydroxyphenyl‐alanine (4‐AHP), a marker for pheomelanin, could not be detected in any of the samples. Histological analysis showed that melanocytes in the suntanned skin enlarged and increased in number to form a monolayer at the surface of the skin. Analysis of L* values and PTCA levels showed quite a high correlation coefficient (r = ?0.843). When comparing shaded and wild red seabream fish, the scores were closer but some significant differences were still found in some body areas. These results indicate that eumelanin accumulates in suntanned fish during the increase in skin color, which is induced by sunlight, presumably by ultraviolet radiation.     

Evaluation of Hydrangea macrophylla for Resistance to Leaf‐Spot Diseases

Garden hydrangea (Hydrangea macrophylla) is a popular ornamental plant that can be devastated by leaf‐spot diseases. Information is needed to determine susceptibility of commercial cultivars to leaf‐spot diseases. To address this need, 88 cultivars of H. macrophylla were evaluated for their resistance to leaf‐spot diseases in full‐shade (2007–2008), full‐sun (2007–2008) and partial‐shade (2009–2010) environments in McMinnville, TN, USA. Ten cultivars [‘Ami Pasquier’, ‘Ayesha’, ‘Blue Bird’, ‘Forever Pink’, ‘Fuji Waterfall’ (‘Fujinotaki’), ‘Miyama‐yae‐Murasaki’, ‘Seafoam’, ‘Taube’, ‘Tricolor’ and ‘Veitchii’] were rated resistant (R) or moderately resistant to leaf spot under each of the three environments. In 2007–2008, approximately 51% of the cultivars were rated R in full shade, but only 5% were R in full sun. In 2009–2010, only 1% of the cultivars were rated R in partial shade. Although environmental parameters including temperature and rainfall influence disease severity and host reaction, a shaded environment was least favourable for leaf‐spot disease development, which demonstrates that establishing hydrangea in shaded environment can be an effective tool along with cultivar selection for managing leaf‐spot diseases on hydrangea. Six pathogens, Corynespora cassiicola, Cercospora spp., Myrothecium roridum, Glomerella cingulata (Anamorph: Colletotrichum gloeosporioides), Phoma exigua and Botrytis cinerea, were associated with leaf‐spot diseases of garden hydrangea. Of the leaf‐spot pathogens, C. cassiicola was most frequently isolated (55% of all isolates), followed by Cercospora spp. (20%) and other pathogens (25%). Because symptoms attributed to each leaf‐spot pathogen were similar, cultivars were selected for resistance to multiple leaf‐spot pathogens.     

A new practical tool for deriving a functional signature for herbaceous vegetation

Hypothesis: For any one time and place a ‘functional signature’ can be derived for a sample of herbaceous vegetation in a way that concisely represents the balance between the different clusters of functional attributes that are present among component species. Methods: We developed a spreadsheet‐based tool for calculating functional signatures within the context of the C‐S‐R system of plant functional types. We used the tool to calculate and compare signatures for specimen British vegetation samples which differed in management regime and location in time. Conclusion: The integrative power of the ‘C‐S‐R signature’ is useful in comparative studies involving widely differing samples. Movements in the signature can be used to indicate degree of resistance, resilience, eutrophication and dereliction. Systems of plant functional types other than C‐S‐R might also be approached in this way. Availability: The tool can be downloaded free of charge from the first author's web pages or from the journal's electronic archive.     

Assessing group differences in biodiversity by simultaneously testing a user‐defined selection of diversity indices

Comparing diversities between groups is a task biologists are frequently faced with, for example in ecological field trials or when dealing with metagenomics data. However, researchers often waver about which measure of diversity to choose as there is a multitude of approaches available. As Jost (2008, Molecular Ecology, 17 , 4015) has pointed out, widely used measures such as the Shannon or Simpson index have undesirable properties which make them hard to compare and interpret. Many of the problems associated with the use of these ‘raw’ indices can be corrected by transforming them into ‘true’ diversity measures. We introduce a technique that allows the comparison of two or more groups of observations and simultaneously tests a user‐defined selection of a number of ‘true’ diversity measures. This procedure yields multiplicity‐adjusted P‐values according to the method of Westfall and Young (1993, Resampling‐Based Multiple Testing: Examples and Methods for p‐Value Adjustment, 49, 941), which ensures that the rate of false positives (type I error) does not rise when the number of groups and/or diversity indices is extended. Software is available in the R package ‘simboot’.     

The ‘standardized search’: An improved way to conduct bird surveys

Abstract Bird surveys are among the most widely used biodiversity inventories and serve as the basis for an increasing proportion of pure and applied ecological research. It is rarely possible to conduct exhaustive censuses of all individuals present at a particular site, so stopping rules are routinely used to determine when sampling should finish. Most bird survey methods use (implicit) effort‐based stopping rules, either fixed times, fixed sampling areas (quadrats) or both, to standardize samples of different sites. If between‐site variation is high, however, a fixed sampling effort will generate samples of variable completeness with samples from smaller, less complex sites being more representative and complete than samples from larger, more complex sites. More importantly, quadrat‐based methods shift the scope of the overall study from bird occurrence in sites to bird occurrence in quadrats within sites, diminishing the impact of the research given that results cannot be extrapolated to relevant biological and management scales. Here I advocate an alternative means of conducting bird surveys, whereby the entire site is sampled and a results‐based stopping rule is used to ensure sample completeness is uniform across all sites. For example, a researcher may decide to continue sampling each site until two or fewer previously unencountered species are recorded in a 40‐min period. Samples of different sites will vary in both area and duration but will all be equivalently accurate estimates of species richness. This approach allows the avifauna of entire sites (whether territories, woodland remnants or catchments) to be sampled and compared directly, generating results and implications at the appropriate scale. In addition to yielding reliable measures of species richness, data collected this way can be used to calculate estimates of sample completeness and species incidence, two valuable metrics for ecological studies. This paper includes detailed worked examples of how to conduct a ‘standardized search’ and calculate sample completeness and species incidence estimates. I encourage further research on bird survey methods, and suggest that most current methods are insufficient, inconsistent and unreliable.     

E‐Selectin Genotypes and Risk of Type 2 Diabetes in Women

Endothelial dysfunction increases risk for type 2 diabetes. We examined whether variation in the gene for E‐selectin (SELE), a biomarker of endothelial dysfunction, was associated with levels of E‐selectin or diabetes quantitative traits (including fasting levels of insulin and hemoglobin A_1c) in 719 nondiabetic participants of the Nurses’ Health Study or with risk of diabetes in 602 incident (over 10 years of follow‐up) cases and 655 control women matched for age, race, and fasting status. Variation in three single nucleotide polymorphisms previously associated with cardiovascular disease risk and having effects on E‐selectin function, S128R, G98T, and L554F, was not significantly (p > 0.05) associated with levels of E‐selectin or diabetes quantitative traits, or with risk of incident diabetes in the primary analysis. Among women with low levels of subclinical inflammation (C‐reactive protein levels below the population median), S128R R allele carriers had a diabetes risk factor‐adjusted relative risk of incident diabetes of 1.71 (95% confidence interval, 1.04 to 2.81) relative to those with the SS genotype. Apart from an association in this subgroup, we conclude that the E‐selectin variants we examined are not important genetic risk factors for type 2 diabetes in women.     

Litter quality and environmental controls of home‐field advantage effects on litter decomposition

The ‘home‐field advantage (HFA) hypothesis’ predicts that plant litter is decomposed faster than expected in the vicinity of the plant where it originates from (i.e. its ‘home’) relative to some other location (i.e. ‘away’) because of the presence of specialized decomposers. Despite growing evidence for the widespread occurrence HFA effects, what drives HFA is not understood as its strength appears highly variable and context‐dependent. Our work advances current knowledge about HFA effects by testing under what conditions HFA is most important. Using published data on mass loss from 125 reciprocal litter transplants from 35 studies, we evaluated if HFA effects were modulated by macroclimate, litter quality traits, and the dissimilarity between ‘home’ and ‘away’ of both the quality of reciprocally exchanged litters and plant community type. Our results confirmed the occurrence of an overall, worldwide, HFA effect on decomposition with on average 7.5% faster decomposition at home. However, there was considerable variation in the strength and direction (sometimes opposite to expectations) of these effects. While macroclimate and average litter quality had weak or no impact on HFA effects, home‐field effects became stronger (regardless of the direction) when the quality of ‘home’ and ‘away’ litters became more dissimilar (e.g. had a greater dissimilarity in N:P ratio; F_1,42 = 6.39, p = 0.015). Further, home‐field effects were determined by the degree of difference between the types of dominant plant species in the ‘home’ versus ‘away’ communities (F_2,105 = 4.03, p = 0.021). We conclude that home‐field advantage is not restricted to particular litter types or climate zones, and that the dissimilarity in plant communities and litter quality between the ‘home’ and ‘away’ locations, are the most significant drivers of home‐field effects.