A qualitative exploration of fear of cancer recurrence in caregivers.

OBJECTIVE: Fear of cancer recurrence (FCR) is one of the most common unmet needs for cancer patients and caregivers. Yet little is known about the potentially unique nature of caregiver FCR. Our research aimed to address this gap by qualitatively exploring the features and impact of caregiver FCR. METHODS: Eighteen semi-structured telephone interviews with cancer caregivers were conducted to explore the content and impact of caregiver fears and worries about cancer recurrence or progression. Data analysis used a Framework Approach. RESULTS: Qualitative analysis identified three themes (1) fear of the patient suffering, (2) the need to protect the patient from a recurrence and/or cancer-related distress, and (3) caregiver's sense of unpreparedness and uncertainty. Underpinning these themes was an overarching sense of personal responsibility for the life of the patient. This overarching theme was identified as a key driver of caregivers' personal and patient-centred fears. CONCLUSIONS: Our findings confirm the conceptual differences between patient and caregiver FCR. Future research must therefore acknowledge the unique experiences of caregivers and prioritise the development of empirically driven theoretical models, instruments, and interventions for caregiver FCR.

Disorder in convergent floral nanostructures enhances signalling to bees.

Diverse forms of nanoscale architecture generate structural colour and perform signalling functions within and between species. Structural colour is the result of the interference of light from approximately regular periodic structures; some structural disorder is, however, inevitable in biological organisms. Is this disorder functional and subject to evolutionary selection, or is it simply an unavoidable outcome of biological developmental processes? Here we show that disordered nanostructures enable flowers to produce visual signals that are salient to bees. These disordered nanostructures (identified in most major lineages of angiosperms) have distinct anatomies but convergent optical properties; they all produce angle-dependent scattered light, predominantly at short wavelengths (ultraviolet and blue). We manufactured artificial flowers with nanoscale structures that possessed tailored levels of disorder in order to investigate how foraging bumblebees respond to this optical effect. We conclude that floral nanostructures have evolved, on multiple independent occasions, an effective degree of relative spatial disorder that generates a photonic signature that is highly salient to insect pollinators.

Discovering Karima (Euphorbiaceae), a New Crotonoid Genus from West Tropical Africa Long Hidden within Croton.

Croton scarciesii (Euphorbiaceae-Crotonoideae), a rheophytic shrub from West Africa, is shown to have been misplaced in Croton for 120 years, having none of the diagnostic characters of that genus, but rather a set of characters present in no known genus of the family. Pollen analysis shows that the new genus Karima belongs to the inaperturate crotonoid group. Analysis of a concatenated molecular dataset combining trnL-F and rbcL sequences positioned Karima as sister to Neoholstia from south eastern tropical Africa in a well-supported clade comprised of genera of subtribes Grosserineae and Neoboutonieae of the inaperturate crotonoid genera. Several morphological characters support the relationship of Karima with Neoholstia, yet separation is merited by numerous characters usually associated with generic rank in Euphorbiaceae. Quantitative ecological data and a conservation assessment supplement illustrations and descriptions of the taxon.

Pollen structure and function in caesalpinioid legumes.

PREMISE OF THE STUDY: A diverse range of pollen morphologies occurs within the large, paraphyletic legume subfamily Caesalpinioideae, especially among early-branching lineages. Previous studies have hypothesized an association between surface ornamentation and pollination syndrome or other aspects of pollen function such as desiccation tolerance and adaptations to accommodate volume changes. METHODS: We reviewed caesalpinioid pollen morphology using light microscopy, scanning and transmission electron microscopy, in combination with a literature survey of pollination vectors. KEY RESULTS: Pollen structural diversity is greatest in the early-branching tribes Cercideae and Detarieae, whereas Cassieae and Caesalpinieae are relatively low in pollen diversity. Functional structures to counter desiccation include opercula (lids) covering apertures and reduced aperture size. Structures preventing wall rupture during dehydration and rehydration include different forms of colpi (syncolpi, parasyncolpi, pseudocolpi), striate supratectal ornamentation, and columellate or granular wall structures that resist tensile or compressive forces respectively. Specialized aperture structures (Zwischenkörper) may be advantageous for efficient germination of the pollen tube. CONCLUSIONS: In Detarieae and Cercideae in particular, there is potential to utilize pollen characters to estimate pollination systems where these are unknown. Supratectal verrucae and gemmae have apparently evolved iteratively in Cercideae and Detarieae. At the species level, there is a potential correlation between striate/verrucate patterns and vertebrate pollination.

The flower of Hibiscus trionum is both visibly and measurably iridescent.

Living organisms can use minute structures to manipulate the reflection of light and display colours based on interference. There has been debate in recent literature over whether the diffractive optical effects produced by epoxy replicas of petals with folded cuticles persist and induce iridescence in the original flowers when the effects of petal pigment and illumination are taken into account. We explored the optical properties of the petal of Hibiscus trionum by macro-imaging, scanning and transmission electron microscopy, and visible and ultraviolet (UV) angle-resolved spectroscopy of the petal. The flower of Hibiscus trionum is visibly iridescent, and the iridescence can be captured photographically. The iridescence derives from a diffraction grating generated by folds of the cuticle. The iridescence of the petal can be quantitatively characterized by spectrometric measurements with several square-millimetres of sample area illuminated. The flower of Hibiscus trionum has the potential to interact with its pollinators (honeybees, other bees, butterflies and flies) through iridescent signals produced by its cuticular diffraction grating.

The unique pollen morphology of Duparquetia (Leguminosae: Caesalpinioideae): developmental evidence of aperture orientation using confocal microscopy.

BACKGROUND AND AIMS: The phylogenetic affinities of the aberrant monotypic genus Duparquetia (subfamily Caesalpinioideae) are at present unresolved. Preliminary results from molecular analyses suggest a basal, isolated position among legumes. A study of Duparquetia pollen was carried out to provide further morphological characters to contribute to multi-data set analyses. Understanding the development of Duparquetia pollen was necessary to clarify the orientation of the apertures. METHODS: Pollen grains and developing microspores were examined using light microscopy, confocal microscopy and scanning electron microscopy. Evidence for the orientation of the apertures was provided by the examination of microspores within developing tetrads, using (a) confocal microscopy to locate the position of the ectoapertures, and (b) light microscopy and Alcian blue stain to locate the position of the endoapertures. KEY RESULTS: Confocal microscopy has been used for the first time to examine developing microspores in order to obtain information on ectoapertures that was unavailable using other techniques. Pollen in Duparquetia develops in tetrahedral tetrads as in other eudicots, with the apertures arranged in a modified pattern following Fischer's rule. Pollen grains are asymmetrical and have one equatorial-encircling ectoaperture with two equatorial endoapertures, a unique feature in Leguminosae, and in eudicots. CONCLUSIONS: The pollen morphology of Duparquetia is so unusual that it provides little information to help determine its closest relatives. However, it does fit with a pattern of greater pollen morphological diversity in the first-branching caesalpinioid legume groups than in the more derived clades. The latitudinal ectoaperture of Duparquetia is unique within the Fabales and eudicot clades, resembling more closely the monosulcate pollen found in monocots and basal angiosperms; however, developmental patterns are recognizably similar to those of all other legume pollen types.

Structure of pollen apertures in the Detarieae sensu stricto (Leguminosae: Caesalpinioideae), with particular reference to underlying structures (Zwischenkörper).

This study presents the pollen aperture morphology of 148 out of approx. 200 species in 16 genera of the Detarieae s.s. and 13 related genera, investigated with light microscopy, scanning electron microscopy and transmission electron microscopy, using various staining techniques. Features of detarioid legume pollen apertures are described, illustrated and discussed in relation to function and phylogeny. Protruding apertures in the mature pollen grains of taxa in the Detarieae s.s are associated with underlying structures composed of pectic substances called 'Zwischenkörper'. This is the first report of Zwischenkörper in legume pollen. A review of previous literature on Zwischenkörper, evidence of how they differ from onci, and a discussion of developmental origins, terminology and function, is given. Zwischenkörper occur in pollen of Daniellia, Eurypetalum, Eperua, Augouardia, Stemonocoleus, Baikiaea, Copaifera, Pseudosindora, Detarium, Sindora, Sindoropsis, Tessmannia, Gilletiodendron, Hylodendron, Hymenaea, Peltogyne and Guibourtia of the Detarieae s.s. clade of recent molecular analyses. Exinous projections and/or bridges are present over the centre of apertures in the pollen of Sindora, Copaifera, Detarium, Pseudosindora, Hylodendron and Sindoropsis, and may cover the Zwischenkörper of live pollen. Zwischenkörper also occur in the closely related genus Barnebydendron, the sister genus to the Detarieae s.l. clade Goniorrhachis, and also Cercis of the sister clade to the Detarieae s.l. plus Goniorrhachis. A modified form of Zwischenkörper occurs in the pollen of Schotia. Zwischenkörper were not detected in the genera Colophospermum, Prioria, Gossweilerodendron, Oxystigma, Kingiodendron and Hardwickia of the Prioria clade, or in Endertia, Lysidice and Saraca of the Amherstieae clade. None of these taxa have protruding apertures.